Porous silica nanosheets in PIM-1 membranes for CO2 separation

PIM-1-based freestanding mixed matrix membranes (MMMs) and thin film nanocomposites (TFNs) were prepared by incorporating porous silica nanosheets (SN) and exfoliated SN (E-SN) derived from natural vermiculite (Verm) in the PIM-1 polymer matrix. In addition, SN were functionalized by sulfonic acid and amine groups (S-SN and N-SN, respectively) and were also used as fillers for the preparation of MMMs. The gas separation performance was evaluated using CO2/CH4 and CO2/N2 (1:1, v:v) binary gas mixtures. Among freestanding membranes, fresh ones (i.e. tested right after preparation) containing 0.05 wt% functionalized SN and E-SN outperformed the neat PIM-1, surpassing the 2008 Robeson upper bound. At the same filler concentration, fresh MMMs with sulfonic acid-functionalized SN (S-SN) exhibited 40% higher CO2 permeability, 20% higher CO2/N2 selectivity and almost the same CO2/CH4 selectivity as neat PIM-1 membranes. Moreover, after 150 days of aging, these membranes were capable of maintaining up to 68% of their initial CO2 permeability (compared to 37% for neat PIM-1). When prepared as TFN membranes, the incorporation of 0.05 wt% of S-SN led to 35% higher initial CO2 permeance and five times higher CO2 permeance after 28 days

RIETVELD TEXTURE REFINEMENT ANALYSIS OF LINDE TYPE A ZEOLITE FROM X-RAY DIFFRACTION DATA

Rietveld method was used to conduct a texture refinement analysis for Linde type A zeolite prepared by hydrothermal conditions of 100 ºC for 4 h. Material Analysis Using Diffraction software, which is an open access/user-friendly software, was used to accomplish the analysis using the observed X-ray diffraction data. This study shows the feasibility of using Material Analysis Using Diffraction software for zeolite analysis because it has not been applied for zeolite before. Implementation of this software for the texture refinement analysis for zeolite can contributes to the field of zeolite preparation in term of adding more reliability to the experimental results. The X-ray diffraction results of the prepared zeolite concur well with the standard Linde type A zeolite. All parameters calculated by Rietveld refinement method for the prepared zeolite were close enough to those for the standard zeolite A. Also, ImageJ software was used for image analysis to obtain the average particle size for zeolite A sample

Independence from kinetoplast DNA maintenance and expression is associated with multi-drug resistance in Trypanosoma brucei in vitro

It is well known that several antitrypanosomatid drugs accumulate in the parasite's mitochondrion, where they often bind to the organellar DNA, the kinetoplast. To what extent this property relates to the mode of action of these compounds has remained largely unquantified. Here we show that single point mutations that remove the dependence of laboratory strains of the sleeping sickness parasite Trypanosoma brucei on a functional kinetoplast result in significant resistance to the diamidine and phenanthridine drug classes

Locating primary somatosensory cortex in human brain stimulation studies: experimental evidence

Transcranial magnetic stimulation (TMS) over human primary somatosensory cortex (S1) does not produce immediate outputs. Researchers must therefore rely on indirect methods for TMS coil positioning. The “gold standard” is to use individual functional and structural magnetic resonance imaging (MRI) data, but the majority of studies don’t do this. The most common method to locate the hand area of S1 (S1-hand) is to move the coil posteriorly from the hand area of primary motor cortex (M1-hand). Yet, S1-hand is not directly posterior to M1-hand. We localized the index finger area of S1-hand (S1-index) experimentally in four ways. First, we reanalyzed functional MRI data from 20 participants who received vibrotactile stimulation to their 10 digits. Second, to assist the localization of S1-hand without MRI data, we constructed a probabilistic atlas of the central sulcus from 100 healthy adult MRIs and measured the likely scalp location of S1-index. Third, we conducted two experiments mapping the effects of TMS across the scalp on tactile discrimination performance. Fourth, we examined all available neuronavigation data from our laboratory on the scalp location of S1-index. Contrary to the prevailing method, and consistent with systematic review evidence, S1-index is close to the C3/C4 electroencephalography (EEG) electrode locations on the scalp, ~7–8 cm lateral to the vertex, and ~2 cm lateral and 0.5 cm posterior to the M1-hand scalp location. These results suggest that an immediate revision to the most commonly used heuristic to locate S1-hand is required. The results of many TMS studies of S1-hand need reassessment

Epicardial vasomotor responses to acetylcholine are not predicted by coronary atherosclerosis as assessed by intracoronary ultrasound

Objectives.The purpose of this study was to use intravascular ultrasound to determine the morphologic appearance of the coronary arteries, relating the absence, presence and extent of atherosclerosis to the response of the coronary arteries to acetylcholine infusion.Background.Endothelial function plays a major role in the pathophysiology of myocardial ischemia and angina pectoris. The response of the coronary arteries to selective infusion of acetylcholine has been used to examine endothelial function, with vasoconstriction occurring in the absence of intact endothelial function. Vasoconstriction to acetylcholine infusion in humans without overt coronary artery disease has been attributed to early atherosclerosis not detected by coronary angiography.Methods.Twenty-nine patients without overt coronary artery disease underwent selective coronary angiography and selective intracoronary infusion of increasing concentrations of acetylcholine (10−6, 10−5and 10−4mol/liter), followed by intravascular ultrasound imaging.Results.The response of the coronary arteries to acetylcholine infusion was not dependent on the absence or presence of atherosclerotic plaque, as detected by intravascular ultrasound. The percent change in epicardial coronary artery diameter during acetylcholine infusion versus baseline was −14 ± 28% (mean ± SD) in the seven patients with no visible atherosclerosis on intravascular ultrasound versus −9 ± 20% in the 22 patients with visible atherosclerosis on intravascular ultrasound (p = NS, confidence interval −14% to 25%). There was a greater vasoconstrictive response to acetylcholine infusion in patients with risk factors for coronary artery disease than in those without risk factors (p = 0.003).Conclusions.The vasoreactive response to acetylcholine is not necessarily dependent on ultrasound detection of the presence or absence of atherosclerosis

Trans-Atlantic Engagement: a Novel Dental Educational Exchange

Introduction Newcastle University School of Dental Sciences (NUSDS) and Indiana University School of Dentistry in the United States of America (IUSD) are like-minded institutions committed to civic engagement. Over the last 15 years, both universities have built civic engagement into the dental curricula, however each institution operates within significantly different healthcare systems. Aim Co-development of unique collaborative dental education; the first UK/US educational exchange programme engaged with the dental student community. Design A dental educational exchange was developed enabling NUSDS and IUSD students to learn alongside each other within dental and community settings in both countries. Students participate in a unique face-to-face collaborative and interdisciplinary education programme within respective dental schools and by a series of video conferences scheduled before on-site visits. They gain mutual awareness of delivery, access to care and possible barriers facing patients relating to the oral healthcare systems in England, the state of Indiana and the USA. Logistical considerations were significant, aided by scoping visits to the respective partner school and video conferencing. Planning encompassed timetable restrictions, scheduling student video conferences, students' clinical access/observerships, occupational health clearances, overall educational content, student/staff evaluation and potential areas for education research. Conclusions Currently in its fourth year, this is a unique example of a collaborative educational exchange between the UK and USA

Denitri®cation in a nitrogen-limited stream ecosystem.

Abstract. Denitrification was measured in hyporheic, parafluvial, and bank sediments of Sycamore Creek, Arizona, a nitrogen-limited Sonoran Desert stream. We used three variations of the acetylene block technique to estimate denitrification rates, and compared these estimates to rates of nitrate production through nitrification. Subsurface sediments of Sycamore Creek are typically well-oxygenated, relatively low in nitrate, and low in organic carbon, and therefore are seemingly unlikely sites of denitrification. However, we found that denitrification potential (C & N amended, anaerobic incubations) was substantial, and even by our conservative estimates (unamended, oxic incubations and field chamber nitrous oxide accumulation), denitrification consumed 5-40% of nitrate produced by nitrification. We expected that denitrification would increase along hyporheic and parafluvial flowpaths as dissolved oxygen declined and nitrate increased. To the contrary, we found that denitrification was generally highest at the upstream ends of subsurface flowpaths where surface water had just entered the subsurface zone. This suggests that denitrifiers may be dependent on the import of surface-derived organic matter, resulting in highest denitrification rate at locations of surface-subsurface hydrologic exchange. Laboratory experiments showed that denitrification in Sycamore Creek sediments was primarily nitrogen limited and secondarily carbon limited, and was temperature dependent. Overall, the quantity of nitrate removed from the Sycamore Creek ecosystem via denitrification is significant given the nitrogen-limited status of this stream

Autotaxin, bile acid profile and effect of ileal bile acid transporter inhibition in primary biliary cholangitis patients with pruritus

Background and Aims Pruritus is a common symptom in patients with primary biliary cholangitis (PBC) for which ileal bile acid transporter (IBAT) inhibition is emerging as a potential therapy. We explored the serum metabonome and gut microbiota profile in PBC patients with pruritus and investigated the effect of GSK2330672, an IBAT inhibitor. Methods We studied fasting serum bile acids (BAs), autotaxin and faecal microbiota in 22 PBC patients with pruritus at baseline and after 2 weeks of GSK2330672 treatment. Control group included 31 asymptomatic PBC patients and 18 healthy volunteers. BA profiling was done by ultra performance liquid chromatography coupled to a mass spectrometry (UPLC‐MS). Faecal microbiomes were analysed by 16S ribosomal RNA gene sequencing. Results \ud In PBC patients with pruritus, serum levels of total and glyco‐conjugated primary BAs and autotaxin were significantly elevated. Autotaxin activity correlated significantly with tauro‐ and glyco‐conjugated cholic acid (CA) and chenodeoxycholic acid (CDCA), both at baseline and after GSK2330672. GSK2330672 significantly reduced autotaxin and all tauro‐ and glyco‐ conjugated BAs and increased faecal levels of CA (P = 0.048) and CDCA (P = 0.027). Gut microbiota of PBC patients with pruritus was similar to control groups. GSK2330672 increased the relative abundance of Firmicutes (P = 0.033) and Clostridia (P = 0.04) and decreased Bacteroidetes (P = 0.033) and Bacteroidia (P = 0.04). Conclusions Pruritus in PBC does not show a distinct gut bacterial profile but is associated with elevated serum bile acid and autotaxin levels which decrease after IBAT inhibition. In cholestatic pruritus, a complex interplay between BAs and autotaxin is likely and may be modified by IBAT inhibition

Understanding cognition in older patients with cancer

Cancer and neurocognitive disorders, such as dementia and delirium, are common and serious diseases in the elderly that are accompanied by high degree of morbidity and mortality. Furthermore, evidence supports the under-diagnosis of both dementia and delirium in older adults. Complex questions exist regarding the interaction of dementia and delirium with cancer, beginning with guidelines on how best measure disease severity, the optimal screening test for either disorder, the appropriate level of intervention in the setting of abnormal findings, and strategies aimed at preventing the development or progression of either process. Ethical concerns emerge in the research setting, pertaining to the detection of cognitive dysfunction in participants, validity of consent, disclosure of abnormal results if screening is pursued, and recommended level of intervention by investigators. Furthermore, understanding the ways in which comorbid cognitive dysfunction and cancer impact both cancer and non-cancer-related outcomes is essential in guiding treatment decisions. In the following article, we will discuss what is presently known of the interactions of pre-existing cognitive impairment and delirium with cancer. We will also discuss identified deficits in our knowledge base, and propose ways in which innovative research may address these gaps