NUMERICAL MODELLING OF HEAT TRANSFER FROM AN ISOTHERMAL CYLINDER BURIED IN HETEROGENEOUS POROUS MEDIA

Heat transfer from an isothermal pipe buried in porous media and superimposed by a fluid layer has been investigated numerically using the commercial software FLUENT (6.3.26). Due to natural and induced heterogeneity, soils have variations in their hydraulic and volumetric properties; these must be considered for accurate design purposes. Two types of porous media have been investigated, sand and clay. For sand media, the study investigates the effects of different flow and geometric conditions on the heat transfer process. The flow parameters are represented by the Rayleigh number, the permeability ratio of the backfill to the seabed and the permeability anisotropy of the backfill, while the geometric parameters are represented by the trench size and shape and the position of the pipe in the trench. For clay media, two states of the backfill were investigated; these are slurried and lumpy clays. The study also shows the impact of the different trenching conditions on insulation of the pipe as opposed to expensive coating. Lowest heat losses were achieved for a sand backfill of a permeability 100 times the permeability of the seabed and permeability anisotropy of (Kth/Ktv=50). Clay slurry backfill gave the lowest heat transfer results as the main mode of heat transfer in this case was conduction. In contrast, the high permeability and intergranular porosity of clay lumps, allowed for pure convection heat transfer. It was also noticed that clay lumps of sizes 5 and 10 cm allowed for more heat losses than for a pipe with no backfill at all

The sisters of the Muslim Brotherhood: Islamic activism for better or for worse

This study is meant to tell the story of the Muslim Brotherhood Sisters (Al-Akhawat Al-Muslimat) in urban Cairo, Egypt. It mainly attempts to answer two questions: (1) what motivates the Sisters’ Islamic activism within the Brotherhood and within the Egyptian society at large despite its huge risks? (2) how do they (re)construct, contest and relate to the gender ideology of the Muslim Brotherhood? Relying on ethnographic fieldwork, this study explores the ways through which the Sisters of the Muslim Brotherhood conceptualize their engagement in Islamist politics amid the crackdown of 2013. Through examining the Muslim Brotherhood’s contexts, contention repertoires and cultural framing, this project discusses how the movement seeks to recruit and engage young university educated and career accomplished women who set out to change the political and the societal scene. It also argues that the gender ideology of the Muslim Brotherhood is not static, nor is it a discourse in vacuum, but rather a reflection of wider societal views on gender roles and gender dynamics

Rad5, HLTF, and SHPRH: A fresh view of an old story

Not only have helicase-like transcription factor (HLTF) and SNF2 histone-linker PHD-finger RING-finger helicase (SHPRH) proved to be important players in post-replication repair like their yeast counterpart, Rad5, but they are also involved in multiple biological functions and are associated with several human disorders. We provide here an updated view of their functions, associated diseases, and potential therapeutic approaches

ACE2 coding variants in different populations and their potential impact on SARS-CoV-2 binding affinity

The susceptibility of different populations to SARS-CoV-2 infection is not yet understood. Here, we combined ACE2 coding variants' analysis in different populations and computational chemistry calculations to probe the effects on SARS-CoV-2/ACE2 interaction. ACE2-K26R; which is most frequent in Ashkenazi Jewish population decreased the SARS-CoV-2/ACE2 electrostatic attraction. On the contrary, ACE2-I468V, R219C, K341R, D206G, G211R increased the electrostatic attraction; ordered by binding strength from weakest to strongest. The aforementioned variants are most frequent in East Asian, South Asian, African and African American, European, European and South Asian populations, respectively

Contrast-Induced Nephropathy

With the worldwide increase in the incidence of atherosclerotic coronary artery disease, the rate of coronary interventions has increased. One of the serious complications of this procedure is contrast-induced nephropathy (CIN). This complication can lead to poor outcomes, with an increase in morbidity and mortality of patients. The pathophysiology and risk factors for the occurrence of contrast-induced nephropathy are several and interconnected. The most proposed management of this entity is prophylaxis and thus avoidance of its occurrence. We will take a deeper look on the pathophysiology, the mechanisms by which this complication is aggravated, and how to expect and manage such a problem

Recent advances in stem cells therapy: A focus on cancer, Parkinson’s and Alzheimer’s

Stem cells serve as potential therapeutics due to their high proliferative capacity, low immunogenic reactivity and their differentiating capabilities. Several pre-clinical and early-stage clinical studies are carried out to treat genetic diseases, cancers and neurodegenerative disorders with promising preliminary results. However, there are still many challenges that scientists are trying to overcome such as the unclear expression profile of stem cells in vivo, the homing of stem cells to the site of injury and their potential immune-reactivity. Prospective research lies in gene editing of autologous stem cells in vitro and safe injection of these modified cells back into patients. Here, we review the clinical trials executed using stem cell therapy in an attempt to cure challenging diseases like cancer, Parkinson’s and Alzheimer’s diseases

Short‐acting erythropoiesis‐stimulating agents for anaemia in predialysis patients

Background The benefits of erythropoiesis‐stimulating agents (ESA) for chronic kidney disease (CKD) patients have been previously demonstrated. However, the efficacy and safety of short‐acting epoetins administered at larger doses and reduced frequency as well as of new epoetins and biosimilars remains uncertain. Objectives This review aimed to evaluate the benefits and harms of different routes, frequencies and doses of epoetins (epoetin alpha, epoetin beta and other short‐acting epoetins) for anaemia in adults and children with CKD not receiving dialysis. Search methods We searched the Cochrane Kidney and Transplant Specialised Register to 12 September 2016 through contact with the Information Specialist using search terms relevant to this review. Studies contained in the Specialised Register are identified through search strategies specifically designed for CENTRAL, MEDLINE, and EMBASE; handsearching conference proceedings; and searching the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov. Selection criteria We included randomised control trials (RCTs) comparing different frequencies, routes, doses and types of short‐acting ESAs in CKD patients. Data collection and analysis Two authors independently assessed study eligibility and four authors assessed risk of bias and extracted data. Results were expressed as risk ratio (RR) or risk differences (RD) with 95% confidence intervals (CI) for dichotomous outcomes. For continuous outcomes the mean difference (MD) with 95% confidence intervals (CI) was used. Statistical analyses were performed using the random‐effects model. Main results We identified 14 RCTs (2616 participants); nine studies were multi‐centre and two studies involved children. The risk of bias was high in most studies; only three studies demonstrated adequate random sequence generation and only two studies were at low risk of bias for allocation concealment. Blinding of participants and personnel was at low risk of bias in one study. Blinding of outcome assessment was judged at low risk in 13 studies as the outcome measures were reported as laboratory results and therefore unlikely to be influenced by blinding. Attrition bias was at low risk of bias in eight studies while selective reporting was at low risk in six included studies. Four interventions were compared: epoetin alpha or beta at different frequencies using the same total dose (six studies); epoetin alpha at the same frequency and different total doses (two studies); epoetin alpha administered intravenously versus subcutaneous administration (one study); epoetin alpha or beta versus other epoetins or biosimilars (five studies). One study compared both different frequencies of epoetin alpha at the same total dose and at the same frequency using different total doses. Data from only 7/14 studies could be included in our meta‐analyses. There were no significant differences in final haemoglobin (Hb) levels when dosing every two weeks was compared with weekly dosing (4 studies, 785 participants: MD ‐0.20 g/dL, 95% CI ‐0.33 to ‐0.07), when four weekly dosing was compared with two weekly dosing (three studies, 671 participants: MD ‐0.16 g/dL, 95% CI ‐0.43 to 0.10) or when different total doses were administered at the same frequency (four weekly administration: one study, 144 participants: MD 0.17 g/dL 95% CI ‐0.19 to 0.53). Five studies evaluated different interventions. One study compared epoetin theta with epoetin alpha and found no significant differences in Hb levels (288 participants: MD ‐0.02 g/dL, 95% CI ‐0.25 to 0.21). One study found significantly higher pain scores with subcutaneous epoetin alpha compared with epoetin beta. Two studies (165 participants) compared epoetin delta with epoetin alpha, with no results available since the pharmaceutical company withdrew epoetin delta for commercial reasons. The fifth study comparing the biosimilar HX575 with epoetin alpha was stopped after patients receiving HX575 subcutaneously developed anti‐epoetin antibodies and no results were available. Adverse events were poorly reported in all studies and did not differ significantly within comparisons. Mortality was only detailed adequately in four studies and only one study included quality of life data. Authors' conclusions Epoetin alpha given at higher doses for extended intervals (two or four weekly) is non‐inferior to more frequent dosing intervals in maintaining final Hb levels with no significant differences in adverse effects in non‐dialysed CKD patients. However the data are of low methodological quality so that differences in efficacy and safety cannot be excluded. Further large, well designed, RCTs with patient‐centred outcomes are required to assess the safety and efficacy of large doses of the shorter acting ESAs, including biosimilars of epoetin alpha, administered less frequently compared with more frequent administration of smaller doses in children and adults with CKD not on dialysis

High-throughput sequencing reveals genetic determinants associated with antibiotic resistance in Campylobacter spp. from farm-to-fork

[EN]Campylobacter species are one of the most common causative agents of gastroenteritis worldwide. Resistance against quinolone and macrolide antimicrobials, the most commonly used therapeutic options, poses a serious risk for campylobacteriosis treatment. Owing to whole genome sequencing advancements for rapid detection of antimicrobial resistance mechanisms, phenotypic and genotypic resistance trends along the “farm-to-fork” continuum can be determined. Here, we examined the resistance trends in 111 Campylobacter isolates (90 C. jejuni and 21 C. coli) recovered from clinical samples, commercial broiler carcasses and dairy products in Cairo, Egypt. Multidrug resistance (MDR) was observed in 10% of the isolates, mostly from C. coli. The prevalence of MDR was the highest in isolates collected from broiler carcasses (13.3%), followed by clinical isolates (10.5%), and finally isolates from dairy products (4%). The highest proportion of antimicrobial resistance in both species was against quinolones (ciprofloxacin and/or nalidixic acid) (68.4%), followed by tetracycline (51.3%), then erythromycin (12.6%) and aminoglycosides (streptomycin and/or gentamicin) (5.4%). Similar resistance rates were observed for quinolones, tetracycline, and erythromycin among isolates recovered from broiler carcasses and clinical samples highlighting the contribution of food of animal sources to human illness. Significant associations between phenotypic resistance and putative gene mutations was observed, with a high prevalence of the gyrA T86I substitution among quinolone resistant isolates, tet(O), tet (W), and tet(32) among tetracycline resistant isolates, and 23S rRNA A2075G and A2074T mutations among erythromycin resistant isolates. Emergence of resistance was attributed to the dissemination of resistance genes among various lineages, with the dominance of distinctive clones. For example, sub-lineages of CC828 in C. coli and CC21 in C. jejuni and the genetically related clonal complexes ‘CC206 and CC48’ and ‘CC464, CC353, CC354, CC574’, respectively, propagated across different niches sharing semi-homogenous resistance patterns.SIThis work was partially funded by the Zewail City internal research fund (agreement number ZC 004-2019) and joint ASRT-BA research grant (project number 1110) awarded to Dr. Mohamed Elhadidy. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

A role for Rad5 in ribonucleoside monophosphate (rNMP) tolerance

YesRibonucleoside monophosphate (rNMP) incorporation in genomic DNA poses a significant threat to genomic integrity. In addition to repair, DNA damage tolerance mechanisms ensure replication progression upon encountering unrepaired lesions. One player in the tolerance mechanism is Rad5, which is an E3 ubiquitin ligase and helicase. Here, we report a new role for yeast Rad5 in tolerating rNMP incorporation, in the absence of the bona fide ribonucleotide excision repair pathway via RNase H2. This role of Rad5 is further highlighted after replication stress induced by hydroxyurea or by increasing rNMP genomic burden using a mutant DNA polymerase (Pol ε - Pol2-M644G). We further demonstrate the importance of the ATPase and ubiquitin ligase domains of Rad5 in rNMP tolerance. These findings suggest a similar role for the human Rad5 homologues helicase-like transcription factor (HLTF) and SNF2 Histone Linker PHD RING Helicase (SHPRH) in rNMP tolerance, which may impact the response of cancer cells to replication stress-inducing therapeutics