Τρίτη 17 Οκτωβρίου 2017
Phytochemistry, pharmacology, quality control and future research of Forsythia suspensa (Thunb.) Vahl: A review
Publication date: 10 January 2018
Source:Journal of Ethnopharmacology, Volume 210
Author(s): Zhaoyi Wang, Qing Xia, Xin Liu, Wenxue Liu, Wanzhen Huang, Xue Mei, Jun Luo, Mingxu Shan, Zhiqiang Ma, Ruichao Lin
Ethnopharmacological relevanceForsythiae Fructus (called Lianqiao in Chinese), the fruit of Forsythia suspensa (Thunb.) Vahl, is utilized as a common traditional medicine in China, Japan and Korea. It is traditionally used to treat pyrexia, inflammation, gonorrhea, carbuncle and erysipelas. Depending on the different harvest time, Forsythiae Fructus can be classified into two forms, namely Qingqiao and Laoqiao. The greenish fruits that start to ripen are collected as Qingqiao, while the yellow fruits that are fully ripe are collected as Laoqiao. Both are applied to medical use. This review aims to provide a systematic summary of F. suspensa (Forsythia suspensa (Thunb.) Vahl) and to reveal the correlation between the traditional uses and pharmacological activities so as to offer inspiration for future research.Materials and methodsAll corresponding information about F. suspensa was searched by Scifinder and obtained from scientific databases including Springer, Science Direct, Wiley, Pubmed and China Knowledge Resource Integrated (CNKI). Local dissertations and books were searched as well.ResultsAccording to classical Chinese herbal texts and Chinese Pharmacopoeia, Forsythiae Fructus dominantly displays heat-clearing and detoxifying effects in TCM prescriptions. In modern research, more than 230 compounds were separated and identified from F. suspensa. 211 Of them were isolated from fruits. Lignans and phenylethanoid glycosides are considered as the characteristic and active constituents of this herb, such as forsythiaside, phillyrin, rutin and phillygenin. They exhibited anti-inflammatory, antioxidant, antibacterial, anti-virus, anti-cancer and anti-allergy effects, etc. Currently, there is no report on the toxicity of Forsythiae Fructus, despite slight toxicity of forsythiaside reported in local publications. Compared to Laoqiao, Qingqiao contains higher levels of forsythiaside, forsythoside C, cornoside, rutin, phillyrin, gallic acid and chlorogenic acid and lower levels of rengyol, β-glucose and S-suspensaside methyl ether.ConclusionHeat-clearing actions of Forsythiae Fructus are based on the anti-inflammatory and antioxidant properties of lignans and phenylethanoid glycosides. Detoxifying effects attribute to the antibacterial, antiviral and anti-cancer activities of Forsythiae Fructus. And traditional Chinese medicine (TCM) characteristics of Forsythiae Fructus (bitter flavor, slightly cold nature and lung meridian) supported its strong anti-inflammatory effects. In addition, the remarkable anti-inflammatory and antioxidant capacities of Forsythiae Fructus contribute to its anti-cancer and neuroprotective activities. The higher proportion of lignans and phenylethanoid glycosides in Qingqiao than Laoqiao might explain the better antioxidant ability of Qingqiao and more frequent uses of Qingqiao in TCM prescriptions. For future research, more in vivo experiments and clinical studies are encouraged to further clarify the relation between traditional uses and modern applications. Regarding to Qingqiao and Laoqiao, they remain to be differentiated by all-round quality control methods, and the chemical compositions and clinical effects between them should be compared.
Graphical abstract
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Curcumol induces cell cycle arrest in colon cancer cells via reactive oxygen species and Akt/ GSK3β/cyclin D1 pathway
Publication date: 10 January 2018
Source:Journal of Ethnopharmacology, Volume 210
Author(s): Juan Wang, Xu-mei Li, Zhun Bai, Bi-xia Chi, Yan Wei, Xu Chen
Ethnopharmacological relevanceCurcuma kwangsiensis S. G. Lee & C. F. Liang (Guangxi ezhu, in Chinese) belongs to the Zingiberaceae family, has been used as a traditionally Chinese medicine nearly 2000 year. Curcumol is one of the guaiane-type sesquiterpenoid hemiketal isolated from medicine plant Curcuma kwangsiensis S. G. Lee & C. F. Liang, which has been reported possesses anti-cancer effects. Our previous study found that the most contribution to inhibit nasopharyngeal carcinoma cell growth was curcumol.Aim of the studyTo assess the effect of curcumol on cell cycle arrest against human colon cancer cells (CRC) cells (LoVo and SW480) and explore its mechanism in vitro and in vivo.Materials and methodsCurcumol was dissolved in absolute ethyl alcohol. The concentration of absolute ethyl alcohol in the control group or in experimental samples was always 1/500 (v/v) of the final medium volume. LoVo and SW480 cells were treated with different concentrations of curcumol (0, 53, 106, 212 and 424μM). And then the cell cycle of each group was examined by flow cytometry. The protein levels of PI3K, p-Akt, cyclin D1, cyclin E, CDK2, CDK4 and GSK3β were determined by Western blot. The mRNA expression of PI3K, Akt, cyclin D1, CDK4, P27, p21, and P16 in the treated cells were analyzed by real-time RT-PCR. In addition, the antitumor activity of curcumol was evaluated in nude mice bearing orthotopic tumor implants.ResultsCurcumol induced cell cycle arrest in G1/S phase. RT-qPCR and Western blot data showed that curcumol enhanced the expression of GSK3β, P27, p21 and P16, and decreased the levels of PI3K, phosphorylated Akt (p-Akt), cyclin D1, CDK4, cyclin E and CDK2. Furthermore, curcumol induced reactive oxygen species (ROS) generation in LoVo cells, and ROS scavenger N-acetylcysteine (NAC) significantly reversed curcumol-induced cell growth inhibition. Besides, curcumol also prevented the growth of human colon cancer cells xenografts in nude mouse, accompanied by the reduction of PI3K, Akt, cyclin D1, CDK4, cycln E and significant increase of GSK3β.ConclusionsCurcumol caused cell cycle arrest at the G0/G1 phase by ROS production and Akt/ GSK3β/cyclin D1 pathways inactivation, indicating the potential of curcumol in the prevention of colon cancer carcinogenesis.
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Antitussive, antispasmodic, bronchodilating and cardiac inotropic effects of the essential oil from Blepharocalyx salicifolius leaves
Publication date: 10 January 2018
Source:Journal of Ethnopharmacology, Volume 210
Author(s): Jehison Jiménez Hernández, María Inés Ragone, Patricia Bonazzola, Arnaldo L. Bandoni, Alicia E. Consolini
Ethnopharmacology relevanceBlepharocalyx salicifolius (Kunth) O. Berg (Myrtaceae) is a tree native to Argentina and Uruguay that grows and is cultivated along the riverside of the Rio de la Plata. The leaves of this plant species, locally known as "anacahuita" are used in South America to prepare infusions for the empiric treatment of cough and bronchospasm, as well as diarrhoea and other intestinal disorders. Although previous phytochemical studies have been performed with the essential oil extracted from Blepharocalyx salicifolius, pharmacological evidence supporting its traditional use is still lacking.Aim of the studyTo experimentally evaluate the pharmacological properties of Blepharocalyx salicifolius based on its traditional use. The studies were performed with tincture (T-Bs) and essential oil (EO-Bs) prepared from its leaves, in isolated rat trachea, intestine and heart preparations.MethodsThe ex-vivo effects of T-Bs and EO-Bs were evaluated with the agonists carbachol (CCh) and calcium chloride (Ca2+) in the contractile concentration-response curves (CRC) of the isolated intestine. The muscle relaxant effect of EO-Bs was evaluated in the isolated trachea and compared with the effect achieved with papaverine as a positive control. The T-Bs and EO-Bs cardiac effects were analysed by perfusion of an isolated rat heart before a period of ischemia/reperfusion (stunning model). The antitussive effect of both T-Bs and EO-Bs was evaluated in mice exposed to ammonia using codeine as a positive control.ResultsBoth T-Bs and EO-Bs induced a non-competitive inhibition of the CCh-CRC in the rat intestine, with IC50 values of 170.3±48.5µg T-Bs/mL (n = 6) and 5.9±1.6µg EO-Bs/mL (n = 6), respectively. EO-Bs also inhibited non-competitively the Ca2+-CRC, with IC50 value of 1.8±0.3µg EO-Bs/mL (n = 8). A similar effect was obtained with the main active component of the EO-Bs 1,8-cineole. In isolated trachea, EO-Bs induced the relaxation of the CCh-contracted tissue (1.7±0.2µg EO-Bs/mL, n = 11) up to a maximal relaxation that was 1.9 times higher than that of papaverine. In the isolated heart, EO-Bs induced a poor negative inotropic response, and did not improve the contractile and energetic recovery after ischemia and reperfusion. In the mouse cough model, EO-Bs (90mg/Kg) was as effective as codeine (30mg/Kg) in reducing cough frequency.ConclusionsThe results indicate that the preparations from Blepharocalyx salicifolius leaves were effective as central antitussive, bronchodilating and antispasmodic agents, suggestive of a mechanism associated with the inhibition of Ca2+ influx into smooth muscle. The EO-Bs displayed only a poor ability to reduce cardiac inotropism, and was devoid of any cardioprotective properties. Thus, the present study validates the traditional use of this South American plant for asthma, cough and bronchospasm, shedding new light into its potency and putative mechanism of action.
Graphical abstract
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Alternaria alternata (Fr.) Keissl with mutation G143A in the Cyt b gene is the source of a difficult-to-control allergen
Abstract
The saprotrophic fungus Alternaria alternata is widespread in the agro-environment and produces more than ten allergenic proteins, mostly protein Alt a 1. The frequency of the Alt a 1 gene was analyzed in a group of A. alternata isolates from winter wheat kernels obtained in Poland, and the effectiveness of various fungicides targeting the pathogen was evaluated. The Alt a 1 gene was identified in four of the seven tested isolates. A. alternata colonized 35.67% kernels on average, but its frequency increased in stored grain where the presence of epiphytes was noted on 23.09 to 51.38% kernels, and endophytes—in 26.21 to 42.01% of kernels. The efficacy of field-applied fungicides did not exceed 50%, despite the fact that A. alternata is highly sensitive to propiconazole, fenpropimorph, and tebuconazole under in vitro conditions. The analyzed isolates were characterized by limited sensitivity to azoxystrobin (EC50 ranged from 0.505 to 1.350 μg cm−3) due to a mutation at codon 143 of the CYT b gene, responsible for resistance to quinone outside inhibitor fungicides, which was noted in all isolates. The spread of A. alternata can be effectively controlled with suitable fungicides and by monitoring the prevalence of pathogenic isolates in the environment.
http://ift.tt/2xQ4y5I
Multi-site lymphatic venous anastomosis using echography to detect suitable subcutaneous vein in severe lymphedema patients
The method of lymphatic venous anastomosis (LVA), including its indications or pre-operative examinations, has not been established. The purpose of this study is to reveal the possible application of pre-operative echography in surgical LVA outcome.
http://ift.tt/2yvLubJ
Three-stage folded forehead flap for nasal reconstruction: objective and subjective measurements of aesthetic and functional outcomes.
This three-stage folded forehead flap (FFF) proved to be a simple and readily available method of lining replacement. To date, no clinical trial has evaluated the outcomes of the FFF the nose shape and function.
http://ift.tt/2xMa2Ka
Investigating the pros and cons of browns gas and varying EGR on combustion, performance, and emission characteristics of diesel engine
Abstract
The significance of mileage to the fruitful operation of a trucking organization cannot be downplayed. Fuel is one of the biggest variable expenses in a trucking wander. An attempt is made in this research to improve the combustion efficiency of a diesel engine for better fuel economy by introducing hydroxy gas which is also called browns gas or HHO gas in the suction line, without compromising performance and emission. Brown's gas facilitates the air-fuel mixture to ignite faster and efficient combustion. By considering safety and handling issues in automobiles, HHO gas generation by electrolysis of water in the presence of sodium bicarbonate electrolytes (NaHCO3) and usage was explored in this research work over compressed pure hydrogen, due to generation and capacity of immaculate hydrogen as of now confines the application in diesel engine operation. Brown's gas was utilized as a supplementary fuel in a single-cylinder, four-stroke compression ignition (CI) engine. Experiments were carried out on a constant speed engine at 1500 rpm, result shows at constant HHO flow rate of 0.73 liter per minute (LPM), brake specific fuel consumption (BSFC) decreases by 7% at idle load to 16% at full load, and increases brake thermal efficiency (BTE) by 8.9% at minimum load to 19.7% at full load. In the dual fuel (diesel +HHO) operation, CO emissions decreases by 19.4, 64.3, and 34.6% at 25, 50, and 75% load, respectively, and unburned hydrocarbon (UHC) emissions decreased by 11.3% at minimum load to 33.5% at maximum load at the expense of NOx emission increases by 1.79% at 75% load and 1.76% at full load than neat diesel operation. The negative impact of an increase in NOx is reduced by adding EGR. It was evidenced in this experimental work that the use of Brown's gas with EGR in the dual fuel mode in a diesel engine improves the fuel efficiency, performance, and reduces the exhaust emissions.
http://ift.tt/2yxPCbS
Determination of element composition and extraterrestrial material occurrence in moss and lichen samples from King George Island (Antarctica) using reactor neutron activation analysis and SEM microscopy
Abstract
Seven lichens (Usnea antarctica and U. aurantiacoatra) and nine moss samples (Sanionia uncinata) collected in King George Island were analyzed using instrumental neutron activation analysis, and concentration of major and trace elements was calculated. For some elements, the concentrations observed in moss samples were higher than corresponding values reported from other sites in the Antarctica, but in the lichens, these were in the same range of concentrations. Scanning electron microscopy (SEM) and statistical analysis showed large influence of volcanic-origin particles. Also, the interplanetary cosmic particles (ICP) were observed in investigated samples, as mosses and lichens are good collectors of ICP and micrometeorites.
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Adsorption and desorption for dynamics transport of hexavalent chromium (Cr(VI)) in soil column
Abstract
Batch experiments have been carried out to study the adsorption of heavy metals in soils, and the migration and transformation of hexavalent chromium (Cr(VI)) in the soil of a vegetable base were studied by dynamic adsorption and desorption soil column experiments. The aim of this study was to investigate the effect of initial concentration and pH value on the adsorption process of Cr(VI). Breakthrough curve were used to evaluate the capacity of Cr(VI) adsorption in soil columns. The results show that the higher the initial concentration, the worse the adsorption capacity of Cr(VI). The adsorption of Cr(VI) was strongly sensitive to pH value. The capacity of Cr(VI) adsorption is maximized at very low pH value. This may be due to changes in pH that cause a series of complex reactions in Cr(VI). In a strongly acidic environment, the reaction of Cr(VI) with hydrogen ions is accompanied by the formation of Cr3+, which reacts with the soil free iron-aluminum oxide to produce hydroxide in the soil. The results of the desorption experiments indicate that Cr(VI) is more likely to leach from this soil, but if the eluent is a strong acid solution, the leaching process will be slow and persistent. During the experiment, the pH value of the effluent was in the range of 7–8.5, which tends to the original pH value of the soil. It is indicating that the soil has a strong buffer on the acid liquid. The program CXTFIT was used to fit the breakthrough curve to estimate parameters. The results of the calculation of the dispersion coefficient (D) can be obtained by this program. The two-site model fit the breakthrough curve data of Cr(VI) well, and the parameters calculated by the CXTFIT can be used to explain the behavior of Cr(VI) migration and transformation in soil columns. When pH = 2, the retardation factor (R) reach at 79.71 while the value of the R is generally around 10 in other experiments. The partitioning coefficient β shows that more than half of the adsorption sites are instantaneous in this adsorption process and non-equilibrium affects the Cr(VI) transport process in this soil.
http://ift.tt/2yxEOdy
Assessment of filtration efficiency and physiological responses of selected plant species to indoor air pollutants (toluene and 2-ethylhexanol) under chamber conditions
Abstract
Three common plant species (Dieffenbachia maculata, Spathiphyllum wallisii, and Asparagus densiflorus) were tested against their capacity to remove the air pollutants toluene (20.0 mg m−3) and 2-ethylhexanol (14.6 mg m−3) under light or under dark in chamber experiments of 48-h duration. Results revealed only limited pollutant filtration capabilities and indicate that aerial plant parts of the tested species are only of limited value for indoor air quality improvement. The removal rate constant ranged for toluene from 3.4 to 5.7 L h−1 m−2 leaf area with no significant differences between plant species or light conditions (light/dark). The values for 2-ethylhexanol were somewhat lower, fluctuating around 2 L h−1 m−2 leaf area for all plant species tested, whereas differences between light and dark were observed for two of the three species. In addition to pollutant removal, CO2 fixation/respiration and transpiration as well as quantum yield were evaluated. These physiological characteristics seem to have no major impact on the VOC removal rate constant. Exposure to toluene or 2-ethylhexanol revealed no or only minor effects on D. maculata and S. wallisii. In contrast, a decrease in quantum yield and CO2 fixation was observed for A. densiflorus when exposed to 2-ethylhexanol or toluene under light, indicating phytotoxic effects in this species.
http://ift.tt/2gqtnOc
Breast Reduction: Decreasing Complications and Improving Long-Term Aesthetic Results with Parenchymal Sutures
Background: The inverted T/keyhole pattern is commonly used for large breast reductions. This technique relies on the breast skin to retain the shape. With the passage of time "fallout" (pseudoptosis) occurs impairing the cosmetic result. A technique is described that uses parenchymal sutures and inframammary fold (IMF) reinforcement sutures to maintain the intraoperative shape. Methods: A retrospective study of 25 consecutive patients (50 breasts) where the IMF was reinforced and parenchymal sutures were inserted. The patients were followed up and the nipple to notch and nipple to IMF distance was measured and compared with that marked preoperatively and set intraoperatively. Complications, especially T junction breakdown, were also recorded. Results: The mean age was 38 years (range, 16–62 years) with a mean follow-up of 12 months. The mean body mass index was 31 (range, 22–41). The mean mass of tissue excised was 925 g (range, 340–1,800 g) per side. The distance from the suprasternal notch to the nipple remained unchanged. The distance from the nipple to the IMF remained the same as that marked preoperatively except in 3 patients who developed pseudoptosis. Only 3 patients had wound dehiscence. Conclusion: Parenchymal and superficial fascial system sutures combined with IMF reinforcement contributes to maintaining the aesthetic result and decreasing complications, in weight stable patients.http://ift.tt/2zf3Efk
Relationship between empathic processing and drinking behavior in project MATCH
Source:Addictive Behaviors, Volume 77
Author(s): Charles S.H. Robinson, Kathryn Fokas, Katie Witkiewitz
IntroductionFamily relationships, social connectedness and a greater network of supportive others each predict better drinking outcomes among individuals with alcohol use disorder (AUD). The association between social factors and drinking may be related to the ability of individuals to take the perspectives of others' mental and emotional states, defined as empathic processing (EP). As such, it may be the case that EP is associated with social support (SS) and drinking behavior among individuals with AUD, yet few prior studies have attempted to define EP in an AUD sample.MethodsThe current study was a secondary data analysis of Project MATCH (N=1726) using structural equation modeling to model EP as a latent factor. The study also sought to test the baseline associations between EP, SS, and drinking behavior, as well as sex differences in the associations between EP, SS, and drinking. It was hypothesized that EP would be positively associated with SS and negatively associated with drinking behavior.ResultsResults suggested adequate model fit of the EP construct. Structural equation models indicated significant associations between EP, SS, and both drinking consequences and percent drinking days, but only for males. Males reported significantly lower EP and SS from friends, but more SS from family, compared to females. EP was not related to drinking among females.ConclusionsThe current study validated a model of EP in a treatment-seeking sample of individuals with alcohol use disorder. Future work may consider EP as a treatment-modifiable risk factor for drinking frequency and consequences in males.
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Alcohol expectancies longitudinally predict drinking and the alcohol myopia effects of relief, self-inflation, and excess
Publication date: February 2018
Source:Addictive Behaviors, Volume 77
Author(s): Andrew Lac, Nathaniel Brack
IntroductionAlcohol myopia theory posits that alcohol consumption attenuates information processing capacity, and that expectancy beliefs together with intake level are responsible for experiences in myopic effects (relief, self-inflation, and excess).MethodsAdults (N=413) averaging 36.39 (SD=13.02) years of age completed the Comprehensive Effects of Alcohol questionnaire at baseline, followed by alcohol use measures (frequency and quantity) and the Alcohol Myopia Scale one month later. Three structural equation models based on differing construct manifestations of alcohol expectancies served to longitudinally forecast alcohol use and myopia.ResultsIn Model 1, overall expectancy predicted greater alcohol use and higher levels of all three myopic effects. In Model 2, specifying separate positive and negative expectancy factors, positive but not negative expectancy predicted greater use. Furthermore, positive expectancy and use explained higher myopic relief and higher self-inflation, whereas positive expectancy, negative expectancy, and use explained higher myopic excess. In Model 3, the seven specific expectancy subscales (sociability, tension reduction, liquid courage, sexuality, cognitive and behavioral impairment, risk and aggression, and self-perception) were simultaneously specified as predictors. Tension reduction expectancy, sexuality expectancy, and use contributed to higher myopic relief; sexuality expectancy and use explained higher myopic self-inflation; and risk and aggression expectancy and use accounted for higher myopic excess. Across all three predictive models, the total variance explained ranged from 12 to 19% for alcohol use, 50 to 51% for relief, 29 to 34% for self-inflation, and 32 to 35% for excess.ConclusionsFindings support that the type of alcohol myopia experienced is a concurrent function of self-fulfilling alcohol prophecies and drinking levels. The interpreted measurement manifestation of expectancy yielded different prevention implications.
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The influence of sleep on human hypothalamic-pituitary-adrenal (HPA) axis reactivity: a systematic review
Inadequate sleep is highly prevalent and known to decline both physical- and mental health. Literature suggests that altered functioning of the hypothalamic-pituitary-adrenal (HPA) axis might underlie this association. This assumption is mainly based on changes in basal neuroendocrine activity and it is of equal importance to elucidate whether sleep may also influence HPA stress responsiveness. The present review provides a complete outline of recent human studies that have investigated how different aspects of sleep influence cortisol reactivity to laboratory stress.
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Scholar : These new articles for International Journal of Occupational and Environmental Health are available online
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Secular trends in height, weight and body mass index of primary school children in Turkey between 1993 and 2016
Journal Name: Journal of Pediatric Endocrinology and Metabolism
Issue: Ahead of print
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Effects of 1-year growth hormone replacement therapy on thyroid volume and function of the children and adolescents with idiopathic growth hormone deficiency
Journal Name: Journal of Pediatric Endocrinology and Metabolism
Issue: Ahead of print
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Early-onset severe obesity due to complete deletion of the leptin gene in a boy
Journal Name: Journal of Pediatric Endocrinology and Metabolism
Issue: Ahead of print
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Scholar : These new articles for Pediatric Hematology and Oncology are available online
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Evaluation of mean transit time of aerosols from the area of origin to the Arctic with 210Pb/210Po daily monitoring data
Publication date: Available online 17 October 2017
Source:Journal of Environmental Radioactivity
Author(s): Weihua Zhang, Baki Sadi, Christopher Rinaldo, Jing Chen, Norman Spencer, Kurt Ungar
In this study, the activity concentrations of 210Pb and 210Po on the 22 daily air filter samples, collected at CTBT Yellowknife station from September 2015 to April 2016, were analysed. To estimate the time scale of atmospheric long-range transport aerosol bearing 210Pb in the Arctic during winter, the mean transit time of aerosol bearing 210Pb from its origin was determined based on the activity ratios of 210Po/210Pb and the parent-progeny decay/ingrowth equation. The activity ratios of 210Po/210Pb varied between 0.06 and 0.21 with a median value of 0.11. The aerosol mean transit time based the activity ratio of 210Po/210Pb suggests longer mean transit time of 210Pb aerosols in winter (12 d) than in autumn (3.7 d) and spring (2.9 d).Four years 210Pb and 212Pb monitoring results and meteorological conditions at the Yellowknife station indicate that the 212Pb activity is mostly of local origin, and that 210Pb aerosol in wintertime are mainly from outside of the Arctic regions in common with other pollutants and sources contributing to the Arctic. The activity concentration ratios of 210Pb and 212Pb have a relatively constant value in summer with a significant peak observed in winter, centered in the month of February. Comparison of the 210Pb/212Pb activity ratios and the estimated mean 210Pb transit time, the mean aerosol transit times were real reflection of the atmosphere transport characteristics, which can be used as a radio-chronometer for the transport of air masses to the Arctic region.
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Functionalized polyethylene fibers for the selective capture of palladium ions from aqueous solution
Publication date: 1 March 2018
Source:Applied Surface Science, Volume 433
Author(s): Li-juan Pang, Rong Li, Jiang-tao Hu, Lin-juan Zhang, Ming-xing Zhang, Chen-guang Yang, Guo-zhong Wu
An innovative ultrahigh molecular weight polyethylene (UHMWPE) fibrous adsorbent was successfully synthesized via radiation grafting and applied to the selective capture of palladium ions from dilute aqueous solutions. The influence of the pH, initial Pd(II) concentration, and temperature on the adsorption performance was examined in a batch adsorption experiment. Pd K-edge extended X-ray absorption fine structure (EXAFS) spectra indicated that Pd(II) was immobilized on the adsorbent surface via a ligand exchange reaction that formed a stable UHMWPE-PMDA-Pd complex. Although the concentrations of coexisting ions (Cu(II), Zn(II), Cr(VI), Fe(III), and Ni(II)) in the solution were much higher than that of Pd(II), the adsorption capacity for Pd(II) of the as-prepared absorbent was significantly greater than that for other metal ions. Kinetic studies showed good correlation with the pseudo-second-order model. The maximum capacity for Pd(II) adsorption was approximately 221.8mg·g−1 at 298K. The adsorption behavior conformed to the Langmuir isotherm model. Thermodynamic studies revealed that the adsorption of Pd(II) was a feasible, spontaneous, and endothermic process.
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Structural characterization and antimicrobial activities of transition metal complexes of a hydrazone ligand
Publication date: 15 February 2018
Source:Journal of Molecular Structure, Volume 1154
Author(s): Raghavendra P. Bakale, Ganesh N. Naik, Shrinath S. Machakanur, Chandrashekhar V. Mangannavar, Iranna S. Muchchandi, Kalagouda B. Gudasi
A hydrazone ligand has been synthesized by the condensation of 2-nitrobenzaldehyde and hydralazine, and its Co(II), Ni(II), Cu(II) and Zn(II) complexes have been reported. Structural characterization of the ligand and its metal complexes has been performed by various spectroscopic [IR, NMR, UV–Vis, Mass], thermal and other physicochemical methods. The structure of the ligand and its Ni(II) complex has been characterized by single crystal X-ray diffraction studies. All the synthesized compounds have been screened for in vitro antimicrobial activity. The antibacterial activity is tested against Gram-positive strains Enterococcus faecalis, Streptococcus mutans and Staphylococcus aureus and Gram-negative strains Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae using ciprofloxacin as the reference standard. Antifungal activity is tested against Candida albicans, Aspergillus fumigatus and Aspergillus niger using ketoconazole as the reference standard. The minimum inhibitory concentration (MIC) was determined for test compounds as well as for reference standard. Ligand, Cu(II) and Zn(II) complexes have shown excellent activity against Candida albicans.
Graphical abstract
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Coordination-organometallic hybrid materials based on the trinuclear M(II)-Ru(II) (M=Ni and Zn) complexes: Synthesis, structural characterization, luminescence and electrochemical properties
Publication date: 15 February 2018
Source:Journal of Molecular Structure, Volume 1154
Author(s): S.B. Pawal, S.R. Lolage, S.S. Chavan
A new series of trinuclear complexes of the type Ni[R-C6H4NCH(O)C6H3CCRu(dppe)2Cl]2 (1a-c) and Zn[RC6H4NCH(O)C6H3CCRu(dppe)2Cl]2 (2a-c) have been prepared from the reaction of trans-[RuCl(dppe)2CCC6H3(OH)(CHO)] (1) with aniline, 4-nitroaniline and 4-methoxyaniline (R1-3) in presence of nickel acetate and zinc acetate in CH2Cl2/MeOH (1:1) mixture. The structural properties of the complexes have been characterized by elemental analyses and spectroscopic techniques viz. FTIR, UV-Visible, 1H NMR and 31P NMR spectral studies. The crystal structure and morphology of the hybrid complexes was investigated with the help of X-ray powder diffraction (XRPD), Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). The thermal properties of 1a-c and 2a-c were studied by thermogravimetric (TG) analysis. The electrochemical behaviour of the complexes reveals that all complexes displayed a quasireversible redox behaviour corresponding to Ru(II)/Ru(III) and Ni(II)/Ni(III) couples for 1a-c and only Ru(II)/Ru(III) couple for 2a-c. All complexes are emissive in solution at room temperature revealing the influence of substituents and solvent polarity on emission properties of the complexes.
Graphical abstract
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Preremedial assessment of the municipal landfill pollution impact on soil and shallow groundwater in Subotica, Serbia
Publication date: 15 February 2018
Source:Science of The Total Environment, Volume 615
Author(s): Dejan Krčmar, Slaven Tenodi, Nenad Grba, Djurdja Kerkez, Malcolm Watson, Srdjan Rončević, Božo Dalmacija
Most regional municipal solid waste landfills in Serbia are operated without control of landfill leachate and gas or with no regard for implementation of national and European legislation. For the first time in Serbia, groundwater and soil at a landfill were subject to systematic annual monitoring according to national, European legislation and adopted methodologies. Characterisation of the groundwater and soil samples from the landfill included ten metals (Fe, Mn, As, Zn, Cd, Pb, Ni, Cr, Cu and Hg), 16 EPA PAHs, nutrients and certain physicochemical parameters, in order to assess the risks such poorly controlled landfills pose to the environment. This impact assessment was performed using specially adapted pollution indices: LWPI, the Single factor pollution index and the Nemerow index for groundwater, and geo-accumulation index, ecological risk factor and selected rations of PAHs for soil. The data analysis included multivariate statistical methods (factor analysis of principal component analysis (PCA/FA)) in order to assess the extent of the contaminants detected in the groundwater and soil samples.The pollution indices (LWPI: 3.56–8.89; Nemerow index: 2.02–3.78) indicate the quality of the groundwater at the landfill is degrading over time, with PAH16, TOC, Cr, Cu, Pb and Zn as the substances of greatest concern. Heavy metals Hg (Igeo≤3.14), Pb (Igeo≤2.22), Cr (Igeo≤3.31) and Cu (Igeo≤2.16) represent the worst soil contamination. Hg has moderate (52.9) to very high (530.0) potential ecological risk, demonstrating the long-term potential effects of bioaccumulation and biomagnification.The results of this work indicate that Cr and Cu should possibly be added to the EU Watch List of emerging substances. This proposition is substantiated by relevant state and alike environmental information from nations in the region. This study demonstrates the need to develop a model for prioritization of landfill closure and remediation based on environmental risk assessment.
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Second-harmonic generation of ZnO nanoparticles synthesized by laser ablation of solids in liquids
Publication date: 1 February 2018
Source:Optics & Laser Technology, Volume 99
Author(s): Israel Rocha-Mendoza, Santiago Camacho-López, Yryx Y. Luna-Palacios, Yasmín Esqueda-Barrón, Miguel A. Camacho-López, Marco Camacho-López, Guillermo Aguilar
We report the synthesis of small zinc oxide nanoparticles (ZnO NPs) based colloidal suspensions and the study of second-harmonic generation from aggregated ZnO NPs deposited on glass substrates. The colloidal suspensions were obtained using the laser ablation of solids in liquids technique, ablating a Zn solid target immersed in acetone as the liquid medium, with ns-laser pulses (1064nm) of a Nd-YAG laser. The per pulse laser fluence, the laser repetition rate frequency and the ablation time were kept constant. The absorption evolution of the obtained suspensions was optically characterized through absorption spectroscopy until stabilization. Raman spectroscopy, SEM and HRTEM were used to provide evidence of the ZnO NPs structure. HRTEM results showed that 5–8nm spheroids ZnO NPs were obtained. Strong second-harmonic signal is obtained from random ZnO monocrystalline NPs and from aggregated ZnO NPs, suggesting that the high efficiency of the nonlinear process may not depend on the NPs size or aggregation state.
http://ift.tt/2kWJJzJ
Altered Macular Microvasculature in Mild Cognitive Impairment and Alzheimer Disease.
Background: The goal of the present study was to analyze the macular microvacular network in mild cognitive impirment (MCI) and Alzheimer disease (AD). Methods: Twelve patients with AD and 19 patients with MCI were recruited together with 21 cognitively normal controls with a similar range of ages. Optical coherence tomography angiography was used to image the retinal microvascular network at the macular region, including retinal vascular network (RVN), superficial vascular plexus (SVP), and deep vascular plexus (DVP). Fractal analysis (box counting, Dbox) representing the microvascular density was performed in different annular zones and quadrantal sectors. The macular ganglion cell-inner plexiform layer (GC-IPL) thickness was measured using Zeiss OCT. The relationship between the retinal microvasculature and clinical manifestations was analyzed. Results: Patients with AD had lower densities of RVN, SVP, and DVP in the annulus, from 0.6 to 2.5 mm in diameter ( 0.05). There was a trend of vascular density loss from control to MCI then AD (
http://ift.tt/2zfp4Jz
http://ift.tt/2zfp4Jz
Clinical profile of silent growth hormone pituitary adenomas; higher recurrence rate compared to silent gonadotroph pituitary tumors, a large single center experience
Abstract
Purpose
Study and comparison of characteristics of silent growth hormone adenomas (SGHA), silent corticotroph adenomas (SCA), and silent gonadotroph adenomas (SGA) in a single institution cohort of surgically treated pituitary adenomas.
Methods
Retrospective analysis of SGHA surgically resected over 10 years: SGHA was defined as no clinical or biochemical evidence of acromegaly and positive GH immunostaining.
Results
Of 814 pituitary surgeries; 2.1% (n = 17) were SGHA, 4.5% (n = 37) SCA, and 18.9% (n = 70/371; 2011–2016) SGA. Mean age at SGHA diagnosis was 43 years, with a large female predominance (82%). Mean tumor size and cavernous/sphenoid sinus invasiveness for SGHA, SCA, and SGA were 1.5 ± 1.0 cm and 25%, 2.5 ± 1.2 cm and 43%, 2.9 ± 2.0 cm and 41%, respectively (tumor size p = 0.009, SGHA vs. SGA, and invasion p; not-significant). During mean follow-up of 3.9 years, two patients (11%) developed elevated insulin-like growth factor-1 and five patients (29%) required a second surgery for tumor recurrence. Rate of surgical reintervention was similar to SCA (31%), but higher than SGA (10%) (p = 0.035, SGHA vs. SGA), and 18% underwent radiation therapy, similar to SCA (19%, p; not-significant) but higher than SGA (2.9%, p = 0.018).
Conclusion
This is the largest single center study characterizing SGHA behavior with SGA and SCA control groups in a cohort of surgically resected pituitary adenomas. SGHA present mostly in young females, and should be closely followed due to their higher likelihood of recurrence and potential of progression to clinical acromegaly. We propose that a complete hormonal staining panel be routinely performed for all pituitary adenomas.
http://ift.tt/2xLSBcn
Clinical profile of silent growth hormone pituitary adenomas; higher recurrence rate compared to silent gonadotroph pituitary tumors, a large single center experience
Abstract
Purpose
Study and comparison of characteristics of silent growth hormone adenomas (SGHA), silent corticotroph adenomas (SCA), and silent gonadotroph adenomas (SGA) in a single institution cohort of surgically treated pituitary adenomas.
Methods
Retrospective analysis of SGHA surgically resected over 10 years: SGHA was defined as no clinical or biochemical evidence of acromegaly and positive GH immunostaining.
Results
Of 814 pituitary surgeries; 2.1% (n = 17) were SGHA, 4.5% (n = 37) SCA, and 18.9% (n = 70/371; 2011–2016) SGA. Mean age at SGHA diagnosis was 43 years, with a large female predominance (82%). Mean tumor size and cavernous/sphenoid sinus invasiveness for SGHA, SCA, and SGA were 1.5 ± 1.0 cm and 25%, 2.5 ± 1.2 cm and 43%, 2.9 ± 2.0 cm and 41%, respectively (tumor size p = 0.009, SGHA vs. SGA, and invasion p; not-significant). During mean follow-up of 3.9 years, two patients (11%) developed elevated insulin-like growth factor-1 and five patients (29%) required a second surgery for tumor recurrence. Rate of surgical reintervention was similar to SCA (31%), but higher than SGA (10%) (p = 0.035, SGHA vs. SGA), and 18% underwent radiation therapy, similar to SCA (19%, p; not-significant) but higher than SGA (2.9%, p = 0.018).
Conclusion
This is the largest single center study characterizing SGHA behavior with SGA and SCA control groups in a cohort of surgically resected pituitary adenomas. SGHA present mostly in young females, and should be closely followed due to their higher likelihood of recurrence and potential of progression to clinical acromegaly. We propose that a complete hormonal staining panel be routinely performed for all pituitary adenomas.
http://ift.tt/2xLSBcn
Optimal timing of dopamine agonist withdrawal in patients with hyperprolactinemia: a systematic review and meta-analysis
Abstract
Purpose
Dopamine agonists (DAs) are recommended as first-line treatment for patients with hyperprolactinemia. Generally, it is accepted that patients with hyperprolactinemia do not need lifelong medication, but the optimal timing for DA withdrawal has not been determined. The aim of this systematic review and meta-analysis is to assess the impact of DA withdrawal on the clinical outcomes of patients with hyperprolactinemia, and to explore possible factors affecting successful DA withdrawal.
Methods
The databases of PubMed, Cochrane and EMBASE were searched up to May 2016.
Results
The proportion of patients with persisting normoprolactinemia after DA withdrawal reached 36.6% in a random effects model (95% CI, 29.4–44.2%; I-squared: 82.5%). Data of stratified analysis showed that the success rate of drug withdrawal was high in patients using cabergoline (CAB) as the only treatment (41.2%; 95% CI 32.3–50.4%) and those using CAB over 24 months (48.7%; 95% CI 38.9–58.5%), especially in patients with idiopathic hyperprolactinemia (73.2%; 95% CI 55.6–87.7%). In addition, patients who received a low maintenance dose of CAB, and had a significant reduction in tumor size (over 50%) before withdrawal, were more likely to achieve success (51.5 and 49.4%, respectively).
Conclusion
The success rate of DA withdrawal has increased in recent years. Further, the success rate of CAB withdrawal was higher than that of bromocriptine, especially in patients with a duration of treatment longer than 24 months. Conclusively, the probability of success was higher in patients who received low-dose CAB maintenance treatment and those who achieved a significant reduction in tumor size before withdrawal.
http://ift.tt/2gggW3M
Optimal timing of dopamine agonist withdrawal in patients with hyperprolactinemia: a systematic review and meta-analysis
Abstract
Purpose
Dopamine agonists (DAs) are recommended as first-line treatment for patients with hyperprolactinemia. Generally, it is accepted that patients with hyperprolactinemia do not need lifelong medication, but the optimal timing for DA withdrawal has not been determined. The aim of this systematic review and meta-analysis is to assess the impact of DA withdrawal on the clinical outcomes of patients with hyperprolactinemia, and to explore possible factors affecting successful DA withdrawal.
Methods
The databases of PubMed, Cochrane and EMBASE were searched up to May 2016.
Results
The proportion of patients with persisting normoprolactinemia after DA withdrawal reached 36.6% in a random effects model (95% CI, 29.4–44.2%; I-squared: 82.5%). Data of stratified analysis showed that the success rate of drug withdrawal was high in patients using cabergoline (CAB) as the only treatment (41.2%; 95% CI 32.3–50.4%) and those using CAB over 24 months (48.7%; 95% CI 38.9–58.5%), especially in patients with idiopathic hyperprolactinemia (73.2%; 95% CI 55.6–87.7%). In addition, patients who received a low maintenance dose of CAB, and had a significant reduction in tumor size (over 50%) before withdrawal, were more likely to achieve success (51.5 and 49.4%, respectively).
Conclusion
The success rate of DA withdrawal has increased in recent years. Further, the success rate of CAB withdrawal was higher than that of bromocriptine, especially in patients with a duration of treatment longer than 24 months. Conclusively, the probability of success was higher in patients who received low-dose CAB maintenance treatment and those who achieved a significant reduction in tumor size before withdrawal.
http://ift.tt/2gggW3M
Scholar : These new articles for Archives and Manuscripts are available online
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Experimental and numerical studies on impact behaviors of recycled aggregate concrete-filled steel tube after exposure to elevated temperature
Publication date: 15 December 2017
Source:Materials & Design, Volume 136
Author(s): Wengui Li, Zhiyu Luo, Chengqing Wu, Vivian W.Y. Tam, Wen Hui Duan, Surendra P. Shah
This study investigated the impact behaviors of recycled aggregate concrete-filled steel tube (RACFST) after exposed to elevated temperatures by experimental and numerical studies. The impact test on RACFST was conducted by a split Hopkinson pressure bar (SHPB) with 100mm-diameter. After the validation of finite element method simulation by the experimental results, parametric analysis were applied to analyze the effects of RAC strength, steel strength and steel ratio on the impact behaviors and deformation properties of the RACFSTs exposed to elevated temperatures ranging from 20°C, 200°C to 500°C and to 700°C. The results show that both the increases in RAC strength, steel strength and steel ratio significantly enhance the impact resistance of RACFST. However, when RAC strength deteriorates quickly after exposure to high temperature, the increase in RAC strength just slightly improves the impact properties of RACFST, especially after exposure to elevated temperatures higher than 500°C. In conclusion, increasing steel ratio is an effective way for improving the impact behaviors of RACFST, but resulting in higher cost for practical application. For the impact design of RACFST, steel strength and steel ratio are two essential factors in terms of impact behavior enhancement and cost efficiency.
Graphical abstract
http://ift.tt/2yo1cXh
Coefficient of thermal expansion of nanostructured tungsten based coatings assessed by substrate curvature method
Publication date: 5 January 2018
Source:Materials & Design, Volume 137
Author(s): E. Besozzi, D. Dellasega, A. Pezzoli, A. Mantegazza, M. Passoni, M.G. Beghi
The in plane coefficient of thermal expansion (CTE) and the residual stress of nanostructured W based coatings are extensively investigated. The CTE and the residual stresses are derived by means of an optimized ad-hoc developed experimental setup based on the detection of the substrate curvature by a laser system. The nanostructured coatings are deposited by Pulsed Laser Deposition. Thanks to its versatility, nanocrystalline W metallic coatings, ultra-nano-crystalline pure W and W-Tantalum coatings and amorphous-like W coatings are obtained. The correlation between the nanostructure, the residual stress and the CTE of the coatings are thus elucidated. We find that all the samples show a compressive residual state of stress that decreases as the structure goes from columnar nanocrystalline to amorphous-like. The CTE of all the coatings is higher than the one of the corresponding bulk W form. In particular, as the grain size shrinks, the CTE increases from 5.1 10−6 K−1 for nanocrystalline W to 6.6 10−6 K−1 in the ultra-nano-crystalline region. When dealing with amorphous W, the further increase of the CTE is attributed to a higher porosity degree of the samples. The CTE of the coatings is also investigated as function of materials stiffness: when stiffness decreases, the CTE increases.
Graphical abstract
http://ift.tt/2ynBXnT
Micromechanics modeling of metallic alloys 3D printed by selective laser melting
Publication date: 5 January 2018
Source:Materials & Design, Volume 137
Author(s): Mohsen Taheri Andani, Mohammad Reza Karamooz-Ravari, Reza Mirzaeifar, Jun Ni
Nowadays, additive manufacturing of metallic materials plays a key role in manufacturing technology due to its unique capability of printing strong and complicated components with high precision. Currently, the approach to obtain a specific mechanical performance in 2D printed metallic parts is a challenging and expensive iterative process. Using computational models to predict the mechanical properties of selective laser melting (SLM) metallic alloys based on their microscopic features can be leveraged to reduce the iteration cost for obtaining the desired mechanical properties. An accurate computational model will also be a superior tool to investigate practical modifications in the processing parameters to improve the mechanical performance of 3D printed metals. In this paper, a novel technique is developed to study the correlation between microstructural features, including melt pools and grain structures, and the macroscopic mechanical properties of SLM products. Crystal plasticity is utilized and calibrated to represent the material properties of grains. The capability of the model in considering the role of texture, process defects, mechanical loading direction, and laser scan hatch space on the mechanical behavior of SLM parts are evaluated. The good agreement between the obtained results and the reported experimental data confirms the accuracy of the developed computational model.
Graphical abstract
http://ift.tt/2yo9xu9
Development of high-performance energy absorption component based on the structural design and nanocrystallization
Publication date: 5 January 2018
Source:Materials & Design, Volume 137
Author(s): Tao Tang, Yuan Gao, Lu Yao, Ying Li, Jian Lu
Over the past decades, to meet the ever-increasing energy-saving and environmental-friendly needs, light-weight vehicles, e.g., electric cars, have been widely advocated. Due to significant deterioration in the capability of energy dissipation, crashworthiness enhancement becomes again the most critical issue for the light-weighted vehicles. However, the design based on conventional structure has been more difficult, and the employment of high-strength materials induces much higher cost. To achieve both large safety margin and low cost, this study implemented both material enhancement and structure optimization in the energy absorber design. Since most light-weight structures involve thin-walled frames, the surface mechanical attrition treatment (SMAT), able to induce nanostructures in metals for strength enhancement without sacrificing ductility, is the perfect choice. Based on the structure of energy absorber, SMAT technology was intensively improved to take full advantage of the excellent performance of the advanced steel material and fulfill real-life application. Structure optimization was also explored through extensive experiments and numerical simulations. The final products was examined by real tests, and the results revealed that it was lighter, stronger and have high-safety impact levels compared to similar products on the present market as expected.
Graphical abstract
http://ift.tt/2yoQAHB
White Clot Syndrome
Publication date: Available online 17 October 2017
Source:European Journal of Vascular and Endovascular Surgery
Author(s): Alexandros Mallios, William Jennings
http://ift.tt/2ihU749
Scholar : These new articles for Activities, Adaptation & Aging are available online
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Scholar : These new articles for Eating Disorders are available online
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Differential physiological responses to central leptin overexpression in male and female rats
Abstract
Brains of females are more sensitive to the acute catabolic actions of leptin. However, sex differences in the long-term physiological responses to central leptin receptor modulation are unknown. To this end, we centrally delivered a viral vector to overexpress leptin (Leptin), a neutral leptin receptor antagonist (Leptin-Antagonist), or a green fluorescence protein (Control). We examined chronic changes in body weight and composition in male and female rats. Females displayed greater and sustained responses to Leptin whereas males rapidly lost physiological effects and developed leptin resistance confirmed by lower acute leptin-mediated phosphorylation of STAT3 (P-STAT3). Surprisingly, despite persistent physiological responses, Leptin-females also exhibited reduced acute leptin-mediated P-STAT3, suggesting an onset of leptin resistance near time of death. In line with this interpretation, Leptin-females and Control-females consumed the same amount of food on the last day of the experiment. Both Leptin-Antagonist groups gained similar percentages of their initial body weight and fat mass, whereas only Leptin-Antagonist-females gained lean body mass. Consequently, lean/fat mass ratio with Leptin-Antagonist was preserved in females and decreased in males, suggesting a deterioration of body composition in males. In summary, this study establishes that females are more responsive to long-term central leptin overexpression than males and that leptin antagonism has a greater physiological impact in males. The hormone environment may have played a role in these processes; however, future studies are needed to establish whether physiological responses are mediated by female or male sex hormones.
This article is protected by copyright. All rights reserved.
http://ift.tt/2kVr2fJ
Building primary care in a changing Europe [Internet].
For many citizens primary care is the first point of contact with their health care system, where most of their health needs are satisfied but also acting as the gate to the rest of the system. In that respect primary care plays a crucial role in how patients value health systems as responsive to their needs and expectations.
http://ift.tt/2iiajSI
Microbiomes of the Built Environment: A Research Agenda for Indoor Microbiology, Human Health, and Buildings.
People's desire to understand the environments in which they live is a natural one. People spend most of their time in spaces and structures designed, built, and managed by humans, and it is estimated that people in developed countries now spend 90 percent of their lives indoors. As people move from homes to workplaces, traveling in cars and on transit systems, microorganisms are continually with and around them. The human-associated microbes that are shed, along with the human behaviors that affect their transport and removal, make significant contributions to the diversity of the indoor microbiome.
http://ift.tt/2gMe1kf
Assessing Chronic Disease Management in European Health Systems: Country reports [Internet].
Many countries are exploring innovative approaches to redesign delivery systems to provide appropriate support to people with long-standing health problems. Central to these efforts to enhance chronic care are approaches that seek to better bridge the boundaries between professions, providers and institutions, but, as this study clearly demonstrates, countries have adopted differing strategies to design and implement such approaches.
http://ift.tt/2ii9xoM
Global Health Research in an Unequal World: Ethics Case Studies from Africa.
This book is a collection of fictionalised case studies of everyday ethical dilemmas and challenges, encountered in the process of conducting global health research in places where the effects of global, political and economic inequality are particularly evident. It is a training tool to fill the gap between research ethics guidelines, and their implementation 'on the ground'. The case studies, therefore, focus on 'relational' ethics: ethical actions and ideas that emerge through relations with others, rather than in regulations.
http://ift.tt/2gMdGxF
Scholar : These new articles for Norwegian Archaeological Review are available online
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Discovery of New Antimalarial Agents: Second-Generation Dual Inhibitors against FP-2 and PfDHFR via Fragments Assembely
Publication date: Available online 16 October 2017
Source:Bioorganic & Medicinal Chemistry
Author(s): Wenhua Chen, Zhenghui Huang, Wanyan Wang, Fei Mao, Longfei Guan, Yun Tang, Hualiang Jiang, Jian Li, Jin Huang, Lubin Jiang, Jin Zhu
Malaria parasites are a leading cause of worldwide mortality from infectious disease. Cysteine protease falcipain-2 (FP-2) and Plasmodium falciparum dihydrofolate reductase (PfDHFR) play vital roles, which are absolutely essential, in the parasite life cycle. In this study, based on the structures of uniform fragments of reported PfDHFR inhibitors and the first-generation dual inhibitors against FP-2 and PfDHFR, we identified a novel series of dual inhibitors through fragments assembly. Lead optimization led to the discovery of 24, which showed high potency against FP-2 (IC50=10.0 µM), PfDHFR (IC50= 84.1 nM), P. falciparum 3D7 (IC50= 53.1 nM), clinical isolated strains Fab9 (IC50= 14.2 nM) and GB4 (IC50= 23.4 nM). The in vivo inhibition assays against P. berghei in 10 days indicated 24 had a more beneficial effect on the growth inhibition of P. berghei than artemisinin and an identical effect with pyrimethamine. Additionally, 24 moderately inhibited the proliferation of chloroquine-resistant P. falciparum Dd2 strain. Collectively, these data revealed that 24 could be an excellent lead compound as FP-2 and PfDHFR dual inhibitor for the treatment of malaria.
Graphical abstract
http://ift.tt/2ysEfQc
Novel analogs of PSNCBAM-1 as allosteric modulators of cannabinoid CB1 receptor
Publication date: Available online 16 October 2017
Source:Bioorganic & Medicinal Chemistry
Author(s): Simone Bertini, Andrea Chicca, Francesca Gado, Chiara Arena, Daniela Nieri, Maria Digiacomo, Giuseppe Saccomanni, Pingwei Zhao, Mary E. Abood, Marco Macchia, Jürg Ghertsch, Clementina Manera
In this work, we explored the molecular framework of the known CB1R allosteric modulator PSNCBAM-1 with the aim to generate new bioactive analogs and to deepen the structure-activity relationships of this type of compounds. In particular, the introduction of a NH group between the pyridine ring and the phenyl nucleus generated the amino-phenyl-urea derivative SN15b that behaved as a positive allosteric modulator (PAM), increasing the CB1R binding affinity of the orthosteric ligand CP55,940. The functional activity was evaluated using serum response element (SRE) assay, which assesses the CB1R-dependent activation of the MAPK/ERK signaling pathway. SN15b and the biphenyl-urea analog SC4a significantly inhibited the response produced by CP55,940 in the low µM range, thus behaving as negative allosteric modulators (NAMs). The new derivatives presented here provide further insights about the modulation of CB1R binding and functional activity by allosteric ligands.
Graphical abstract
http://ift.tt/2yujofp
Design and synthesis of p-carborane-containing sulfamates as multitarget anti-breast cancer agents
Publication date: Available online 16 October 2017
Source:Bioorganic & Medicinal Chemistry
Author(s): Asako Kaise, Kiminori Ohta, Chinami Shirata, Yasuyuki Endo
The development of multitarget anticancer agents is of high interest to medicinal chemists in terms of overcoming drug resistance and preventing cancer-cell migration. Based on the structure of the potent carborane-containing estrogen BE120, non-steroidal multitarget anti-breast cancer agent candidates 1a–1j were designed and synthesized. Compound 1f shows potent STS-inhibitory activity (IC50 = 1.8 μM), cell-growth-inhibitory (CGI) activity against 39 human cancer cell lines (MG-MID = 2.8 μM), and tubulin-polymerization-inhibitory (TPI) activity. An analysis of the DNA content for MDA-MB-453 breast cancer cells revealed that 1f arrests the cell cycle in the G2/M phase and induces apoptosis. Accordingly, 1f should be a promising therapeutic agent for hormone-dependent breast cancer.
Graphical abstract
http://ift.tt/2ysAHxz
Selenium-containing analogues of WC-9 are extremely potent inhibitors of Trypanosoma cruzi proliferation
Publication date: Available online 16 October 2017
Source:Bioorganic & Medicinal Chemistry
Author(s): María N. Chao, Melissa Storey, Catherine Li, Maricel G. Rodríguez, Florencia Di Salvo, Sergio H. Szajnman, Silvia N.J. Moreno, Roberto Docampo, Juan B. Rodriguez
The obligate intracellular parasite, Trypanosoma cruzi is the etiologic agent of Chagas disease or American trypanosomiasis, which is the most prevalent parasitic disease in the Americas. The present chemotherapy to control this illness is still deficient particularly in the chronic stage of the disease. The ergosterol biosynthesis pathway has received much attention as a molecular target for the development of new drugs for Chagas disease. Especially, inhibitors of the enzymatic activity of squalene synthase were shown to be effective compounds on T. cruzi proliferation in in vitro assays. In the present study we designed, synthesized and evaluated the effect of a number of isosteric analogues of WC-9 (4-phenoxyphenoxyethyl thiocyanate), a known squalene synthase inhibitor, on T. cruzi growth in tissue culture cells. The selenium-containing derivatives turned out to be extremely potent inhibitors of T. cruzi growth. Certainly, 3-phenoxyphenoxyethyl, 4-phenoxyphenoxyethyl, 4-(3-fluorophenoxy)phenoxyethyl, 3-(3-fluorophenoxy)phenoxyethyl selenocyanates and (±)-5-phenoxy-2-(selenocyanatomethyl)-2,3-dihydrobenzofuran arose as relevant members of this family of compounds, which exhibited effective ED50 values of 0.084 µM, 0.11 µM, 0.083, µM, 0.085, and 0.075 µM, respectively. The results indicate that compounds bearing the selenocyanate moiety are at least two orders of magnitude more potent than the corresponding skeleton counterpart bearing the thiocyanate group. Surprisingly, these compounds exhibited excellent selectively index values ranging from 900 to 1,800 making these molecules promising candidates as antiparasitic agents.
Graphical abstract
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Benzofuran-Dihydropyridine Hybrids: A new class of potential bone anabolic agents
Publication date: Available online 17 October 2017
Source:Bioorganic & Medicinal Chemistry
Author(s): Ram K. Modukuri, Dharmendra Choudhary, Sampa Gupta, K. BhaskaraRao, SulekhaAdhikary, Tanuj Sharma, Mohammad Imran Siddiqi, Ritu Trivedi, Koneni V. Sashidhara
A series of novel benzofuran-dihydropyridine hybrids were designed by molecular hybridization approach and evaluated for bone anabolic activities. Among the screened library, ethyl 4-(7-(sec-butyl)-2-(4-methylbenzoyl)benzofuran-5-yl)-2-methyl-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate (compound 21) significantly enhanced the ALP production and mineralized nodule formation, which are primary requisites in the process of in-vitro osteogenesis. Oral administration of compound 21 at 10 mg.kg-1day-1 for two weeks led to restoration of trabecular bone microarchitecture in drill hole fracture model by significantly increasing BV/TV and Tb.N. Furthermore, histological and molecular studies showed compound 21 triggering the new bone regeneration in a drill hole defect site by increasing BMP expression. Furthermore, molecular modeling studies were performed to gain insight into the binding approach, which revealed that both benzofuran and dihydropyridine moieties are essential to show similar binding interactions to fit into the active site of BMP2 receptor, an important target of the osteogenic agents.Our results suggest that compound 21 stimulates BMP2 synthesis in osteoblast cells that promotes new bone formation (∼40%) at the fracture site which helps in shorten the healing period.
Graphical abstract
http://ift.tt/2ysEdry
Insulin modulates hippocampally-mediated spatial working memory via glucose transporter-4
Source:Behavioural Brain Research, Volume 338
Author(s): J. Pearson-Leary, V. Jahagirdar, J. Sage, E.C. McNay
The insulin-regulated glucose transporter, GluT4, is a key molecule in peripheral insulin signaling. Although GluT4 is abundantly expressed in neurons of specific brain regions such as the hippocampus, the functional role of neuronal GluT4 is unclear. Here, we used pharmacological inhibition of GluT4-mediated glucose uptake to determine whether GluT4 mediates insulin-mediated glucose uptake in the hippocampus. Consistent with previous reports, we found that glucose utilization increased in the dorsal hippocampus of male rats during spontaneous alternation (SA), a hippocampally-mediated spatial working memory task. We previously showed that insulin signaling within the hippocampus is required for processing this task, and that administration of exogenous insulin enhances performance. At baseline levels of hippocampal insulin, inhibition of GluT4-mediated glucose uptake did not affect SA performance. However, inhibition of an upstream regulator of GluT4, Akt, did impair SA performance. Conversely, when a memory-enhancing dose of insulin was delivered to the hippocampus prior to SA-testing, inhibition of GluT4-mediated glucose transport prevented cognitive enhancement. These data suggest that baseline hippocampal cognitive processing does not require functional hippocampal GluT4, but that cognitive enhancement by supra-baseline insulin does. Consistent with these findings, we found that in neuronal cell culture, insulin increases glucose utilization in a GluT4-dependent manner. Collectively, these data demonstrate a key role for GluT4 in transducing the procognitive effects of elevated hippocampal insulin.
http://ift.tt/2ysAhqZ
NMDA receptor blockade specifically impedes the acquisition of incentive salience attribution
Source:Behavioural Brain Research, Volume 338
Author(s): Jonathan J. Chow, Joshua S. Beckmann
Glutamatergic signaling plays an important role in learning and memory. Using Pavlovian conditioned approach procedures, the mechanisms that drive stimulus-reward learning and memory have been investigated. However, there are instances where reward-predictive stimuli can function beyond being solely predictive and can be attributed with "motivational value" or incentive salience. Using a Pavlovian conditioned approach procedure consisting of two different but equally predictive stimuli (lever vs. tone) we investigated the role NMDA receptor function has in the attribution of incentive salience. The results revealed that the administration of MK-801, an NMDA receptor antagonist, during acquisition of Pavlovian conditioned approach promoted goal-tracking to a lever stimulus, while control animals learned to sign-track. Moreover, within the same animals, the use of a tone stimulus elicited goal-tracking responses that were unaffected by MK-801 pretreatments. Furthermore, a lever CS that elicited sign-tracking served as a more robust conditioned reinforcer than a tone CS that elicited goal-tracking or a lever CS that elicited goal-tracking via MK-801 pretreatments. Collectively, these results demonstrate that NMDA receptor antagonism can alter the stimulus-reward relationship learned and prevent the attribution of incentive salience, rather than impede general learning.
http://ift.tt/2x2GBny
Head-turning asymmetry: A novel lateralization in rats predicts susceptibility to behavioral despair
Source:Behavioural Brain Research, Volume 338
Author(s): Efe Soyman, Guzin Duygu Yilmaz, Resit Canbeyli
Behavioral markers of laterality reflecting underlying neurobiological asymmetries between the cerebral hemispheres are related to differential susceptibility to mood disorders. In the present study, we investigated the strength and consistency of a novel behavioral lateralization, head-turning asymmetry, and its relation to behavioral despair in adult female Wistar rats. Head-turning biases were determined in a test where water-deprived rats had to turn their head to right or left to gain access to a water dispenser. This procedure was administered 4 times over 8days. Four days after the head-turning test, rats were subjected to two forced swim tests separated by 24h to examine the relationship between head-turning asymmetry and behavioral despair. Rats were administered one more head-turning test session after the second swim test to determine whether behavioral despair induction altered head-turning direction preferences. Results revealed significant correlations among head-turning test sessions indicating head-turning direction preference as measured with our method is a consistent behavioral lateralization. Although most rats were strongly lateralized, there was no bias in either direction at the population level. Importantly, we found that while rats with a left head-turning bias showed a significant increase in the duration of immobility from the first to the second swim test, right-biased rats performed similarly in the two swim tests. Behavioral despair induction did not change head-turning direction preferences. The present findings show that head-turning asymmetries are predictive of mood disorders in rats and may serve as the basis to elucidate the mechanisms relating hemispheric asymmetries to depression in humans.
http://ift.tt/2yujgfV
Impaired cognitive flexibility during sleep deprivation among carriers of the Brain Derived Neurotrophic Factor (BDNF) Val66Met allele
Source:Behavioural Brain Research, Volume 338
Author(s): Leilah K. Grant, Sean W. Cain, Anne-Marie Chang, Richa Saxena, Charles A. Czeisler, Clare Anderson
Accumulating evidence points to a genetic contribution to explain inter-individual vulnerability to sleep deprivation. A functional polymorphism in the BDNF gene, which causes a valine (Val) to methionine (Met) amino acid substitution at Codon 66, has been associated with cognitive impairment, particularly in populations with impaired frontal functioning. We hypothesised that sleep deprivation, which affects frontal function, may lead to cognitive dysfunction in Met allele carriers. To examine this, we investigated, in different BDNF genotypes, the effects of sleep deprivation on cognitive flexibility, as measured by response inhibition using the Stroop Color Naming Task. Thirty healthy, adults of European ancestry, including 12 heterozygous Met allele carriers and 18 Val/Val homozygotes, underwent 30-h of extended wakefulness under constant routine conditions. A computerised Stroop task was administered every 2h. Error rate and reaction times increased with time awake for all individuals. Participants with the Val/Met genotype made more errors on incongruent trials after 20h awake. While Val/Met participants also took significantly longer to respond when inhibiting a prepotent response irrespective of time awake, this was particularly evident during the biological night. Our study shows that carriers of the BDNF Met allele are more vulnerable to the impact of prolonged wakefulness and the biological night on a critical component of executive function, as measured by response inhibition on the Stroop task.
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