Organic solvent removal by pervaporation membrane technology: experimental and simulation

Abstract

This work presents purification of cyclohexane using polydimethylsiloxane (PDMS) membranes in pervaporation (PV) process. The PDMS is a rubbery polymer and appropriate as membrane material for purification of cyclohexane. PV which is a low-energy separation process was chosen for purification of cyclohexane due to its superior advantages compared to other processes. Effect of feed concentration on separation factor was investigated in order to optimize the process. It was indicated that dehydration of 80 wt% cyclohexane mixture at a temperature of 300 K and a vacuum pressure of 10 mmHg could be effectively achieved and high separation factor of 2500 was obtained. Furthermore, a two-dimensional mechanistic model was proposed for predicting mass transfer of cyclohexane in the process. The mechanistic model accounts for mass transfer of cyclohexane across the membrane, and concentration distribution of cyclohexane was determined. It was revealed that the most mass transfer flux of cyclohexane occur at the region near the inlet of feed channel, while the flux at the upper side of the module reaches zero value due to the effect of velocity distribution on the convective mass transfer of cyclohexane.

https://ift.tt/2K2rBvM

Leachate phytotoxicity of flue gas desulfurization residues from coal-fired power plant

Abstract

Flue gas desulfurization residues (FGDR) are the main solid wastes produced in coal-fired power plants that can be reused as alternative materials for civil and agricultural applications. However, the pollutants contained in the FGDR might contaminate the local environment, hindering their material reuse. In this study, the physical-chemical characteristics, leaching, and phytotoxicity (Triticum aestivum) of the material were investigated. The FGDR samples were obtained from three pulverized coal-fired power plants in China. Multivariate statistical analyses were used to consider the contributions of the leaching components to the germination index of wheat seeds in the FGDR leachates. The FGDR contained a high percentage of amorphous mass. The ranges of selected metals and micronutrients in the FGDR are As (31.5–63.0 mg/kg), B (574–3090 mg/kg), Ba (2799–3073 mg/kg), Cr (up to 4.73 mg/kg), Cu (0.29–1.38 mg/kg), Mn (136–370 mg/kg), Ni (9.93–22.9 mg/kg), Pb (1.29–7.29 mg/kg), Sr (886–1706 mg/kg), and Zn (335–458 mg/kg). The leaching toxicity of the FGDR leachates was lower than the regulatory limit of the identification standards for hazardous waste, indicating that the FGDR are non-hazardous materials. Metals, especially Ba, Cu, Fe, and Pb, as well as As and B, in the leachate had inhibitory effects on seed germination than the other constituents. The results in this study showed that the leachate phytotoxicity resulting from FGDR could be evaluated before the utilization of FGDR, giving crucial information for the adaptation of these alternative materials.

https://ift.tt/2rpy25w

Association between oral mucosal lesions and crack and cocaine addiction in men: a cross-sectional study

Abstract

The aim of this cross-sectional study was to evaluate the prevalence of oral mucosal lesions (OMLs) and their association with crack/cocaine addiction in men. Clinical oral examination was performed in 161 adult male patients at the School of Dentistry of the Federal University of Bahia, Brazil. Crack/cocaine addiction was determined from the medical records, and all drug-addicted individuals used both crack and cocaine. All participants (40 crack/cocaine-addicted men and 121 non-addicted men) underwent a systematic evaluation of the lips, labial mucosa, commissures, buccal mucosa and sulcus, gingiva and alveolar ridge, tongue, floor of the mouth, and soft and hard palate by a single examiner. Bivariate and regression analyses were conducted to assess for the presence of OMLs and the association of OMLs with crack/cocaine addiction. OMLs were found in 22 participants with a significantly greater prevalence in the crack/cocaine-addicted group (25 vs. 9.9%; p = 0.01). The most prevalent types of lesions in the addicted group were traumatic ulcer and actinic cheilitis (7.5% for each) followed by fistulae associated with a retained dental root (5%). After adjusting for covariates, crack/cocaine addiction was significantly associated with OMLs (OR = 2.87; 95% CI = 1.08–7.67; p = 0.03). The prevalence of OMLs was higher in crack/cocaine-addicted individuals, and crack/cocaine addiction was significantly associated with OMLs. A public health program aimed at the early diagnosis and treatment of OMLs is vital to improving the oral health status of individuals addicted to crack/cocaine.

https://ift.tt/2K1vLEc

A mechanism of interleukin-25 production from airway epithelial cells induced by Japanese cedar pollen

Publication date: Available online 7 May 2018
Source:Clinical Immunology
Author(s): Hideaki Kouzaki, Hirotaka Kikuoka, Koji Matsumoto, Tomohisa Kato, Ichiro Tojima, Shino Shimizu, Takeshi Shimizu
IL-25 likely has vital roles in initiating and activating type-2 immune responses in AR. We hypothesized that the molecules produced IL-25 by allergen-producing organisms such as JC is involved in the pathogenesis of AR. Participants included 13 patients with Japanese cedar pollinosis and 10 HCs. We measured the IL-25 protein concentration in nasal secretions and in culture supernatants of PNECs. NHBE cells were stimulated with pharmacological and immunological agents and JC. The IL-25 concentration in nasal secretions was significantly higher in patients with Japanese cedar pollinosis than in HCs. JC stimulated IL-25 production from PNECs. TNF-α, IL-4, and IL-13 significantly enhanced JC-induced IL-25 production; their activation by serine proteases was sufficient to enhance IL-25 production. Furthermore, the NADPH oxidase activity, including JC enhanced IL-25 production. A better understanding of JC-induced IL-25 production by epithelial cells may allow the development of novel therapeutic and preventive strategies for Japanese cedar pollinosis.



https://ift.tt/2jIfhG2

Maternal T-cell engraftment impedes with diagnosis of a SCID-ADA patient

Publication date: Available online 7 May 2018
Source:Clinical Immunology
Author(s): Arnalda Lanfranchi, Vassilios Lougaris, Lucia Dora Notarangelo, Elena Soncini, Marta Comini, Alessandra Beghin, Federica Bolda, Alessandro Montanelli, Luisa Imberti, Fulvio Porta
We describe the case of a child affected by severe combined immunodeficiency (SCID) with adenosine deaminase (ADA) deficiency showing a maternal T-cell engraftment, a finding that has never been reported before. The presence of engrafted maternal T cells was misleading. Although ADA enzymatic levels were suggestive of ADA-SCID, the child did not present the classical signs of ADA deficiency; therefore, the initial diagnosis was of a conventional SCID. However, ADA toxic metabolites and molecular characterization confirmed this diagnosis. Polyethylene glycol-modified bovine (PEG) ADA therapy progressively decreased the number of maternal engrafted T cells. The child was grafted with full bone marrow from a matched unrelated donor, after a reduced conditioning regimen, and the result was the complete immunological reconstitution.



https://ift.tt/2I575KG

Oleanolic acid protects against cognitive decline and neuroinflammation-mediated neurotoxicity by blocking secretory phospholipase A2 IIA-activated calcium signals

Publication date: July 2018
Source:Molecular Immunology, Volume 99
Author(s): Leguo Zhang, Ruixue Xia, Jianpu Jia, Lixuan Wang, Kuo Li, Yanhua Li, Junling Zhang
Neuroinflammation causes neurotoxic injury and underlies the pathogenesis of neurodegenerative disorders including Alzheimer's disease (AD). Astrocytes are the predominant immunoregulatory cells in AD. Oleanolic acid (OA) is a promising anti-inflammatory therapeutic agent that can ameliorate cerebral damage in ischemic environments, but its role in AD remains poorly elucidated. Here, preconditioning with OA inhibited the transcription and secretion of inflammatory cytokines IL-6, TNF-α, and IL-1β in amyloid-beta peptide (Aβ)-activated astrocytes. Moreover, OA ameliorated primary neuron death triggered by incubation in conditioned medium from Aβ-treated astrocytes. Furthermore, OA also suppressed Aβ-induced expression and production of group IIA secretory phospholipase A2 (sPLA2-IIA) in astrocytes. Supernatants supplemented with exogenous sPLA2-IIA reversed the protective role of OA against astrocyte activation-mediated neurotoxicity by suppressing cell viability and increasing LDH release, apoptosis, the contents of neurotoxic mediator arachidonic acid, and prostaglandin D2. Simultaneously, treatment with sPLA2 inhibitor aristolochic acid also counteracted neurotoxicity induced by Aβ-activated astrocytes through increasing cell viability, inhibiting cell apoptosis, and reducing the releases of arachidonic acid and prostaglandin D2. Additionally, OA restrained Ca²⁺ influx in neurons after incubation with supernatants from Aβ-activated astrocytes, which was abrogated by adding sPLA2-IIA. Activating Ca²⁺ signaling with BayK, an L-type Ca2 + channel agonist, reversed the beneficial role of OA against neurotoxicity induced by astrocyte activation-mediated inflammatory response. OA also ameliorated cognitive deficits in an adolescent rat model of Aβ-evoked AD. These findings confirm that OA abrogates neuroinflammation and subsequent neurotoxicity induced by conditioned media from Aβ-activated astrocytes in sPLA2-IIA mediated-calcium signals. Therefore, OA may protect neurons from injury caused by neighboring astrocyte activation in AD, indicating a promising therapeutic strategy against AD.



https://ift.tt/2ws7llE

Immune-modulation of two BATF3 paralogues in rainbow trout Oncorhynchus mykiss

Publication date: July 2018
Source:Molecular Immunology, Volume 99
Author(s): Jun Wang, Min Liu, Yang Wu, Sohye Yoon, Abdo Alnabulsi, Fuguo Liu, Clara Fernández-Álvarez, Tiehui Wang, Jason W. Holland, Chris J. Secombes, Jun Zou
Basic leucine zipper transcription factor ATF-like (BATF) -3 is a member of the activator protein 1 (AP‑1) family of transcription factors and is known to play a vital role in regulating differentiation of antigen-presenting cells in mammals. In this study, two BATF3 homologues (termed BATF3a and BATF3b) have been identified in rainbow trout (Oncorhynchus mykiss). Both genes were constitutively expressed in tissues, with particularly high levels of BATF3a in spleen, liver, pyloric caecae and head kidney. BATF3a was also more highly induced by PAMPs and cytokines in cultured cells, with type II IFN a particularly potent inducer. In rIL-4/13 pre-stimulated cells, the viral PAMPS polyI:C and R848 had the most pronounced effect on BATF3 expression. BATF3 expression could also be modulated in vivo, following infection with Yersinia ruckeri, a bacterial pathogen causing redmouth disease in salmonids, or with the rhabdovirus IHNV. The results suggest that BATF3 may be functionally conserved in regulating the differentiation and activation of immune cells in lower vertebrates and could be explored as a potential marker for comparative investigation of leucocyte lineage commitment across the vertebrate phyla.



https://ift.tt/2IlJTv4

In-depth molecular characterization and biodegradability of water-extractable organic nitrogen in Erhai Lake sediment

Abstract

Dissolved organic nitrogen (DON) constitutes a significant fraction of the total dissolved nitrogen content of most aquatic systems and is thus a major nitrogen source for bacteria and phytoplankton. The present work applied Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) to a compound-level analysis of the depth-dependent molecular composition of water-extractable organic nitrogen (WEON) in lake sediment. The study focused on Erhai Lake, China. It was found that a large portion (from 16.33 ± 7.87 to 39.54 ± 5.77%) of the WEON in the lake sediment was reactive under cultivation by algal or bacteria. The WEON in the mid-region of Erhai sediment particularly exhibited a lower bioavailability, having been less affected by the basin environment. The FT-ICR MS results revealed the presence of thousands of compounds in the Erhai Lake sediment samples collected at different depths, with the N-containing compounds accounting for 28.3–34.4% of all the compounds. The WEON molecular weight was also observed to increase with increasing sediment depth. A van Krevelen diagram showed that the lignin-type components were dominant (~ 56.2%) in the sediment WEON, contributing to its stabilization and reducing the risk of sediment nutrient release. The FT-ICR MS results further revealed 204 overlapping formulas of WEON for each core sediment sample, attributable to the presence of refractory components. It was observed that 78.4% of the formulas were within the lignin-like region, suggesting unique allochthonous DON sources. The aliphatic component proportion of all the unique formulas was also found to increase with increasing sediment depth. This indicates that, with the development and evolution of the Erhai Basin, the more labile WEON components were transformed into more stable lignin-like substrates, with a positive effect on the Lake Erhai ecosystem.

Graphical abstract

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https://ift.tt/2KGvKGS

Advanced oxidation processes on doxycycline degradation: monitoring of antimicrobial activity and toxicity

Abstract

Advanced oxidation processes (AOPs) have been highly efficient in degrading contaminants of emerging concern (CEC). This study investigated the efficiency of photolysis, peroxidation, photoperoxidation, and ozonation at different pH values to degrade doxycycline (DC) in three aqueous matrices: fountain, tap, and ultrapure water. More than 99.6% of DC degradation resulted from the UV/H₂O₂ and ozonation processes. Also, to evaluate the toxicity of the original solution and throughout the degradation time, antimicrobial activity tests were conducted using Gram-positive (Bacillus subtilis) and Gram-negative (Escherichia coli) bacteria, and acute toxicity test using the bioluminescent marine bacterium (Vibrio fischeri). Antimicrobial activity reduced as the drug degradation increased in UV/H₂O₂ and ozonation processes, wherein the first process only 6 min was required to reduce 100% of both bacteria activity. In ozonation, 27.7 mg L⁻¹ of ozone was responsible for reducing 100% of the antimicrobial activity. When applied the photoperoxidation process, an increase in the toxicity occurred as the high levels of degradation were achieved; it means that toxic intermediates were formed. The ozonated solutions did not present toxicity.

https://ift.tt/2FSdTtd

Efficiency analysis of the electrocoagulation and electroflotation treatment of poultry slaughterhouse wastewater using aluminum and graphite anodes

Abstract

The application of electrocoagulation (EC) and electroflotation (EF) was investigated for the treatment of poultry slaughterhouse wastewater in a bench scale unit cell electrolyzer with different EC-to-EF ratios at current densities of 3, 9, and 15 mA cm⁻². The EC-to-EF ratio was controlled by current reversal using aluminum and graphite electrodes. The electrochemical treatment showed satisfactory removal efficiencies for Al coagulant loads greater than 51.8 mg L⁻¹. The 4/5 EC to EF ratio (69.1 mg L⁻¹ Al and 32.2 NmL L⁻¹ additional EF gas) and 3/5 (51.8 mg L⁻¹ Al/64 NmL L⁻¹ additional EF gas) presented the best results for the removal of COD (76–85%), color (93–99%), and turbidity (95–99%), with the additional benefit of reducing the electrode consumption and sludge disposal costs proportionally to the EC-to-EF ratio. The effects of the EC-to-EF ratio and the current density on efficiency of the electrochemical treatment for the removal of COD, apparent color, turbidity, TSS, TSD, and NH₃-N were discussed in the light of the physicochemical and electrochemical processes underlying the removal mechanism for each parameter. In particular, the blow-off mechanism seems to play an important role in the NH₃-N removal, whereas indirect electrooxidation mechanism accounts for a fraction of the soluble COD removal for the electrodes configuration used in the treatment.

https://ift.tt/2KKqL83

Patent Foramen Ovale Closure: The Pendulum Swings.

Author: Hankey, Graeme J. MD, FRACP, FRCP; McQuillan, Brendan M. MBBS, PhD, FRACP

Page: 1991-1993

https://ift.tt/2rsjVMG

The Dyspnea Clinic.

Author: Ryan, John J. MD; Waxman, Aaron B. MD, PhD

Page: 1994-1996

https://ift.tt/2wl5wqu

High-Dose Versus Low-Dose Pitavastatin in Japanese Patients With Stable Coronary Artery Disease (REAL-CAD): A Randomized Superiority Trial.

Author: Taguchi, Isao MD, PhD *,; Iimuro, Satoshi MD, PhD *,; Iwata, Hiroshi MD, PhD *,; Takashima, Hiroaki MD, PhD; Abe, Mitsuru MD, PhD; Amiya, Eisuke MD, PhD; Ogawa, Takanori MD, PhD; Ozaki, Yukio MD, PhD; Sakuma, Ichiro MD, PhD; Nakagawa, Yoshihisa MD, PhD; Hibi, Kiyoshi MD, PhD; Hiro, Takafumi MD, PhD; Fukumoto, Yoshihiro MD, PhD; Hokimoto, Seiji MD, PhD; Miyauchi, Katsumi MD, PhD; Yamazaki, Tsutomu MD, PhD; Ito, Hiroshi MD, PhD; Otsuji, Yutaka MD, PhD; Kimura, Kazuo MD, PhD; Takahashi, Jun MD, PhD; Hirayama, Atsushi MD, PhD; Yokoi, Hiroyoshi MD; Kitagawa, Kazuo MD, PhD; Urabe, Takao MD, PhD; Okada, Yasushi MD, PhD; Terayama, Yasuo MD, PhD; Toyoda, Kazunori MD, PhD; Nagao, Takehiko MD, PhD; Matsumoto, Masayasu MD, PhD; Ohashi, Yasuo PhD; Kaneko, Tetsuji MS; Fujita, Retsu MS; Ohtsu, Hiroshi MSc; Ogawa, Hisao MD, PhD; Daida, Hiroyuki MD, PhD; Shimokawa, Hiroaki MD, PhD; Saito, Yasushi MD, PhD; Kimura, Takeshi MD, PhD; Inoue, Teruo MD, PhD; Matsuzaki, Masunori MD, PhD; Nagai, Ryozo MD, PhD

Page: 1997-2009

https://ift.tt/2jDEGR5

Extending the "Lower is Better" Principle to Japanese and Possibly Other Asian Populations.

Author: Teramoto, Tamio MD, PhD

Page: 2010-2012

https://ift.tt/2I50MXw

High- Versus Low-Dose Statin: Effects on Cardiovascular Events and All-Cause Death.

Author: Barter, Philip J. MBBS, PhD, FRACP

Page: 2013-2015

https://ift.tt/2rrOCBJ

Worsening Renal Function in Patients With Acute Heart Failure Undergoing Aggressive Diuresis Is Not Associated With Tubular Injury.

Author: Ahmad, Tariq MD, MPH *,; Jackson, Keyanna BA *,; Rao, Veena S. PhD; Tang, W.H. Wilson MD; Brisco-Bacik, Meredith A. MD, MSCE; Chen, Horng H. MBBCh; Felker, G. Michael MD, MHS; Hernandez, Adrian F. MD, MHS; O'Connor, Christopher M. MD; Sabbisetti, Venkata S. PhD; Bonventre, Joseph V. MD, PhD; Wilson, F. Perry MD, MHS; Coca, Steven G. DO, MS; Testani, Jeffrey M. MD, MTR

Page: 2016-2028

https://ift.tt/2wkyiay

Creatinine and Cystatin C: Not the Troponin of the Kidney.

Author: Costanzo, Maria Rosa MD; Barasch, Jonathan MD, PhD

Page: 2029-2031

https://ift.tt/2rsbJvL

Time to Epinephrine Administration and Survival From Nonshockable Out-of-Hospital Cardiac Arrest Among Children and Adults.

Author: Hansen, Matthew MD, MCR; Schmicker, Robert H. MS; Newgard, Craig D. MD, MPH; Grunau, Brian MD, MHSc; Scheuermeyer, Frank MD, MHSc; Cheskes, Sheldon MD; Vithalani, Veer MD; Alnaji, Fuad MD; Rea, Thomas MD, MPH; Idris, Ahamed H. MD; Herren, Heather RN, MPH; Hutchison, Jamie MD; Austin, Mike MD; Egan, Debra MPH; Daya, Mohamud MD, MS; for the Resuscitation Outcomes Consortium Investigators

Page: 2032-2040

https://ift.tt/2I1PVxn

Association Between Prompt Defibrillation and Epinephrine Treatment With Long-Term Survival After In-Hospital Cardiac Arrest.

Author: Patel, Krishna K. MD; Spertus, John A. MD, MPH; Khariton, Yevgeniy MD; Tang, Yuanyuan PhD; Curtis, Lesley H. PhD; Chan, Paul S. MD, MSc; for the American Heart Association's Get With the Guidelines-Resuscitation Investigators; Chan, Paul S. MD, MSc; Grossestreuer, Anne PhD; Moskowitz, Ari MD; Edelson, Dana P. MD, MS; Ornato, Joseph P. MD; Peberdy, Mary Ann MD, DACC; Churpek, Matthew M. MD, MPH, PhD; Kurz, Michael C. MD, MS-HES; Starks, Monique Anderson MD; Howard, Patricia Kunz PhD, RN; Girotra, Saket MBBS, SM; Perman, Sarah M. MD, MSCE; Goldberger, Zachary D. MD, MS

Page: 2041-2051

https://ift.tt/2jEFHbF

MicroRNA-195 Regulates Metabolism in Failing Myocardium Via Alterations in Sirtuin 3 Expression and Mitochondrial Protein Acetylation.

Author: Zhang, Xiaokan PhD; Ji, Ruiping MD, PhD; Liao, Xianghai PhD; Castillero, Estibaliz PhD; Kennel, Peter J. MD; Brunjes, Danielle L. PhD; Franz, Marcus MD, PhD; Mobius-Winkler, Sven MD; Drosatos, Konstantinos PhD; George, Isaac MD; Chen, Emily I. PhD; Colombo, Paolo. C. MD; Schulze, P. Christian MD, PhD

Page: 2052-2067

https://ift.tt/2wnPxYN