A Novel Dual-Membranes WGS Reactor with Palladium Alloy and Polyvinyl Alcohol Membranes for Enhanced Hydrogen Recovery

A novel membrane reactor concept including palladium alloy membrane (selective to H2) and polyvinyl alcohol membrane (selective to CO2) is proposed for water gas shift reaction. The mathematical model of the reactor is developed for two reactor schemes, namely plug dual-membrane reactor (PDMR) and CSTR dual-membrane reactor (CDMR) with uni-dimensional and non-isothermal conditions. A comparison between PDMR and palladium alloy membrane reactor (PAMR) showed that PDMR volume becomes 30 % less than PAMR with 20 bar increase in feed pressure. Then the effect of Damkholer number, feed composition, and feed pressure on hydrogen recovery and CO conversion for PDMR and CDMR has been studied. Under the same operating conditions, CO conversion in PDMR is 10 % more than CDMR while its temperature decreases. The new proposed reactor configuration could pave the way for simultaneous production of hydrogen, increased CO conversion, and CO2 separation on an industrial scale

Public availability of information from WFME-recognized accreditation agencies

The World Federation for Medical Education (WFME) Recognition Programme was created to ensure the comparability of medical school accrediting agencies, so that the schools accredited by those agencies would have similar educational quality. WFME explicitly values transparency and has recognition criteria that relate to agencies making information publicly available. Our study examined 20 WFME-recognized agencies’ transparency by reviewing agency websites for 27 information elements related to accreditation standards, procedures, and processes. We contacted agencies as needed for information that we could not find on their websites. We were only able to retrieve additional information from 3 of the 12 agencies that we attempted to contact. We found that while 12 agencies had over 90% of expected information elements available, 6 agencies had less than 50%. Our findings illustrate barriers for those who wish to better understand medical school accreditation in some regions and raise questions about how comparable WFME-recognized agencies are

Can concurrent lower gastrointestinal manifestations help the timely diagnosis of small intestinal bacterial overgrowth in CVID patients?

Summary Introduction and objective. Gastrointestinal complications are considered as one of the most common manifestations in patients with Common Variable Immunodeficiency (CVID). These complications can result from Small Intestinal Bacterial Overgrowth (SIBO). Hydrogen breath test is extensively used to diagnose SIBO. The objective of this study was to evaluate the prevalence of SIBO using the Hydrogen Breath Test (HBT) in patients with CVID. Materials and methods. Twenty-seven patients with CVID entered this cross-sectional study. Demographic and lower gastrointestinal symptoms were recorded in a check list. Hemoglobin level was measured in all patients. The concentration of IgA and IgG was assessed using nephelometry. Moreover, SIBO was detected by means of Glucose hydrogen breath test. Results. The mean (± SD) age of the patients was 35.25 (± 11.69) years. Twenty patients (74.1) manifested at least one lower gastrointestinal symptom. The most frequent lower gastrointestinal manifestations were bloating (66.7) and chronic diarrhea (40.7), respectively. IgA level less than 10 mg/dl and IgG level less than 600 mg/dl were determined in 77.8 and 25.9 of patients, respectively. Positive HBT was detected in 40.7 (n = 11) of the patients. In the positive HBT group, bloating, chronic diarrhea and abdominal pain were the most common lower GI manifestations. There was no significant difference in terms of age, BMI, IgA level, and duration of CVID between the positive and negative HBT groups. The significant association of co-occurrence of anemia and abdominal pain with positive HBT (positive predictive value: 100) might be considered as a clue to SIBO diagnosis. Conclusions. Regarding the high prevalence and non-specific manifestation of SIBO, it is suggested to consider concurrent symptoms in patients with CVID to manage the timely and precise diagnosis of SIBO. © 2021 Associazione Allergologi Immunologi Italiani Territoriali e Ospedalieri-AAIITO. Published by EDRA SpA. All rights reserved

Novel Approach for Electrochemical Functionalization of Graphene with Surfactant

The electrochemical exfoliation of graphite via intercalation is one of the attractive methods to obtain graphene. However, presence of course graphite particles in product is the drawback of this method. In this research, the effect of adding cetyl trimethyl ammonium chloride (CTAC), on the amount of exfoliated graphene and functional groups was studied. Transmission electron microscopy, weighing, UV-vis spectroscopy and electrical conductivity were used for characterization of the products. According to results, presence of this surfactant decreases the erosion, while it increases the exfoliation of graphene flakes. However, after critical micelle concentration (CMC) of the surfactant, exfoliated weight decreased

Comparison of Separation Performance of a Structured Packed Column with a Tray-Type Column for H

Absorption of acid gases, H2S and CO2, by methyl diethanol amine in a structured packed column equipped with Montz-Pak A3-500 was mathematically modeled. The dimensions of the channels as well as their number and liquid film flow model are similar to the Shilkin's work. Heat and mass transfer equations are derived for reacting liquid film and gas flowing counter currently into the column. Concentration distribution is calculated across the moving liquid film and no zone with equilibrium concentration conditions is considered in the reacting liquid. The results of the model for the structured column show a better performance for H2S absorption compared with a tray column operating in the same conditions. The results obtained by the model indicate appreciable distribution of concentration and temperature along the column

Evaluation of Performance of an Industrial Gas Sweetening Plant by Application of Sequential Modular and Simultaneous Modular Methods

In this study the simultaneous-modular and sequential modular methods are used to predict performance of desorption and absorption columns in the loop of an industrial sweetening plant. Mathematical model of absorption and desorption cycle for acid gases in methyldiethanolamine has been developed. This model is based on mass and energy balance and takes into account the chemical interactions between solvent and gases. Application of the simultaneous-modular method to model of the plant provides 31 equations with 31 unknowns. Simultaneous solution of these equations presents details of operating conditions on each section of the process. In the sequential modular method, the calculations have been carried out for each unit as a single module in the loop. This way, the output of each module supplies the input data to the next unit. Data of a commercial gas refinery has been used to validate the models and compare the two methods. After validating, the model effects of some parameters on the performance of the loop have been investigated

A Patient with CTLA-4 Haploinsufficiency with Multiple Autoimmune Presentations: A Case Report

Increased susceptibility to autoimmunity, malignancy, and allergy in addition to recurrent infections are the main characteristics suggesting for the primary immunodeficiency diseases (PID). CTLA-4 is predominantly expressed on activated and regulatory T-cells, which can bind to CD80/CD86 molecules on antigen-presenting cells as a negative regulator. Here, we describe a 24-year-old male born from consanguineous parents with heterozygous CTLA-4 mutation who presented with multiple autoimmune diseases. His past clinical history revealed alopecia areata at four years old and subsequently, he developed Evans syndrome, type 1 diabetes mellitus, hypothyroidism, and chronic diarrhea while chronic rhinosinusitis and cytomegalovirus (CMV) colitis were the only infectious manifestations. Immunologic investigations revealed: low B cell count, abnormal Lymphocyte transformation test (LTT) to phytohemagglutinin (PHA), and hypogammaglobulinemia. Although all available treatments such as Intravenous Immunoglobulin (IVIG) therapy, immunosuppressive drugs, and antibiotic therapy were applied, diarrhea was not controlled due to colitis, which remained challenging. Whole exome sequencing was performed and the result showed heterozygous variant CHR2.204,735,635 G>A in the CTLA-4 gene, which was confirmed by the Sanger method. CTLA4 haploinsufficiency leads to autoimmune disorders, recurrent respiratory infections, hypogammaglobulinemia, lymphoproliferation with organ infiltration, and lymphocytic interstitial lung disease

Histopathologic and Radiographic evaluation of the electroacupuncture effects on ulna fracture healing in dogs

Acupuncture can affect bone healing by stimulation of sensory nerves and releasing of local and systemic neuropeptides. The purpose of this experimental study was to evaluate the effects of electroacupuncture on ulna fracture healing in dogs. In this study, 12 healthy dogs were randomly divided in to four equal groups, where group 1 was kept as control group and evaluated for 45 days, group 2: treatment group and evaluated for 45 days, group3: control group of 90 days and group 4: treatment group of 90 days. After induction of anesthesia, the ulna was cut with Gigli wire saw in each groups, 10 days after operation, the treatment (acupuncture) group was treated with 10 minutes electroacupuncture stimulations on the acupoints Kid1, Kid3, Kid6 and Kid7, for 10 days. Histopathologic samples of all dogs were harvested from bone osteotomized site in 45 and 90 days after surgery. Indices like, count of inflammatory cells, cartilaginous tissue, fibrotic tissue and deposition of collagen were evaluated on samples and classified with 0, 1, 2, and 3 degrees. Also, radiographic evaluation of the patients was applied using radiographic scoring system on days: 7, 15, 30, 45, 60 and 90 after surgery. This study revealed that, acupuncture had no effect on bone healing (p>0.05). Cause of non-significant difference changes between the control and treatment groups, and lack of complete healing in both groups may be due to lack of ulna bone fixation. Alternatively, selection of other acupoints in acupuncture could have a better healing role.Keywords: Acupuncture, Dog, Histopathology, Radiography, Uln

Histopathologic and Radiographic evaluation of the electroacupuncture effects on ulna fracture healing in dogs

Acupuncture can affect bone healing by stimulation of sensory nerves and releasing of local and systemic neuropeptides. The purpose of this experimental study was to evaluate the effects of electroacupuncture on ulna fracture healing in dogs. In this study, 12 healthy dogs were randomly divided in to four equal groups, where group 1 was kept as control group and evaluated for 45 days, group 2: treatment group and evaluated for 45 days, group3: control group of 90 days and group 4: treatment group of 90 days. After induction of anesthesia, the ulna was cut with Gigli wire saw in each groups, 10 days after operation, the treatment (acupuncture) group was treated with 10 minutes electroacupuncture stimulations on the acupoints Kid1, Kid3, Kid6 and Kid7, for 10 days. Histopathologic samples of all dogs were harvested from bone osteotomized site in 45 and 90 days after surgery. Indices like, count of inflammatory cells, cartilaginous tissue, fibrotic tissue and deposition of collagen were evaluated on samples and classified with 0, 1, 2, and 3 degrees. Also, radiographic evaluation of the patients was applied using radiographic scoring system on days: 7, 15, 30, 45, 60 and 90 after surgery. This study revealed that, acupuncture had no effect on bone healing (p>0.05). Cause of non-significant difference changes between the control and treatment groups, and lack of complete healing in both groups may be due to lack of ulna bone fixation. Alternatively, selection of other acupoints in acupuncture could have a better healing role