Subatmospheric boiling study of the operation of a horizontal thermosyphon reboiler loop: Instability

Distillation and chemical processing under vacuum is of immense interest to petroleum and chemical industries due to lower energy costs and improved safety. To tap into these benefits, energy efficient reboilers with lower maintenance costs are required. Here, a horizontal thermosyphon reboiler is investigated at subatmospheric pressures and low heat fluxes. This paper presents detailed experimental data obtained using Wire Mesh Sensor in a gas-liquid flow with heat transfer as well as temperatures, pressures and recirculation rates around the loop. Flow regimes which have been previously identified in other systems were detected. The nature of the instability which underpins the mechanisms involved and conditions aiding instability are reported. Churn flow pattern is persistently detected during instability. The nature of the instability and existence of oscillatory churn flow are interconnecte

A bioreactor for in-cell protein NMR

The inside of the cell is a complex environment that is difficult to simulate when studying proteins and other molecules in vitro. We have developed a device and system that provides a controlled environment for Nuclear Magnetic Resonance (NMR) experiments involving living cells. Our device comprises two main parts, an NMR detection region and a circulation system. The flow of medium from the bottom of the device pushes alginate encapsulated cells into the circulation chamber. In the chamber, the exchange of oxygen and nutrients occurs between the media and the encapsulated cells. When the media flow is stopped, the encapsulated cells fall back into the NMR detection region, and spectra can be acquired. We have utilized the bioreactor to study the expression of the natively disordered protein α-synuclein, inside Escherichia coli cells

Structures in gas–liquid churn flow in a large diameter vertical pipe

Gas–Liquid two phase co-current flow in a vertical riser with an internal diameter of 127 mm was investigated in the churn flow pattern. This paper presents detailed experimental data obtained using a Wire Mesh Sensor. It shows that the most obvious features of the flow are huge waves travelling on the liquid film. Wisps, large tendrils of liquid and the product of incomplete atomisation, which had previously detected in smaller diameter pipes, have also been found in the larger diameter pipe employed here. The output of the Wire Mesh Sensor has been used to determine the overall void fraction. When examined within a drift flux framework, it shows a distribution coefficient of ∼1, in contrast to data for lower gas flow rates. Film thickness time series extracted from the Wire Mesh Sensor output have been examined and the trends of mean film thickness, that of the base film and the wave peaks are presented and discussed. The occurrence of wisps and their frequencies have been quantified

Microbleed Prevalence and Burden in Anticoagulant-Associated Intracerebral Bleed

Prior studies suggest an association between Vitamin K antagonists (VKA) and cerebral microbleeds (CMBs); less is known about nonvitamin K oral anticoagulants (NOACs). In this observational study we describe CMB profiles in a multicenter cohort of 89 anticoagulation-related intracerebral hemorrhage (ICH) patients. CMB prevalence was 51% (52% in VKA-ICH, 48% in NOAC-ICH). NOAC-ICH patients had lower median CMB count [2(IQR:1–3) vs. 7(4–11); P \u3c 0.001]; ≥5 CMBs were less prevalent in NOAC-ICH (4% vs. 31%, P = 0.006). This inverse association between NOAC exposure and high CMB count persisted in multivariable logistic regression models adjusting for potential confounders (OR 0.10, 95%CI: 0.01–0.83; P = 0.034)

Detection of Cancer Stem Cells in Colorectal Cancer: Histopathological and Immunohistochemical Study

BACKGROUND: Growing evidence supports the notion that the onset of tumorigenesis could occur through cancer stem cells (CSCs). These tumour cells show low proliferative rates, high self-renewal capacity, propensity to differentiate into active proliferating tumour cells & resistance to chemoradiotherapy thus, possibly causing local recurrences & metastasis formation. CD44 has been used as a marker to isolate CSCs from colorectal carcinoma (CRC).AIM: To investigate the immunohistochemical expression of cancer stem cells marker (CD44) in CRC and correlate its expression with the clinicopathological aspects, TNM staging and modified Dukes’ classification.MATERIALS AND METHODS: Tumour biopsies from colectomy specimens of 60 patients with CRC were stained with hematoxylin-eosin for histological evaluation then immunostained with monoclonal antibodies against CD44 which was detected in term of negative or positive expression.RESULTS: CD44 was demonstrated in 58.3% (35/60) of cases and showed statistically significant correlation with tumour site and histological type (p-value < 0.05). However, CD44 showed statistically insignificant inverse correlation with tumour invasiveness (T), lymph node status (N), grade, TNM stage grouping and modified Dukes’ classification, while it was directly correlated with distant metastasis (M) (p-value > 0.05). Chi-square /Fisher exact test proportion independence and the p-value are set significant at 0.05 level.CONCLUSION: the CD44 rate of expression is higher in the colon than rectum and in adenocarcinoma than mucinous and undifferentiated carcinoma. CD44 showed statistically insignificant relation with T, N, M, grade, TNM stage grouping and modified Dukes’ classification

Accurate Reader Identification for the Arabic Holy Quran Recitations Based on an Enhanced VQ Algorithm

The Speaker identification process is not a new trend; however, for the Arabic Holy Quran recitation, there are still quite improvements that can make this process more accurate and reliable. This paper collected the input data from 14 native Arabic reciters, consisting of “Surah Al-Kawthar” speech signals from the Holy Quran. Moreover, this paper discusses the accuracy rates for 8 and 16 features. Indeed, a modified Vector Quantization (VQ) technique will be presented, in addition to realistically matching the centroids of the various codebooks and measuring systems’ effectiveness. Note that the VQ technique will be utilized to generate the codebooks by clustering these features into a finite number of centroids. The proposed system’s software was built and executed using MATLAB®. The proposed system’s total accuracy rate was 97.92% and 98.51% for 8 and 16 centroids codebooks, respectively. However, this study discussed two validation tactics to ensure that the outcomes are reliable and can be reproduced. Hence, the K-mean clustering algorithm has been used to validate the obtained results and discuss the outcomes of this study. Finally, it has been found that the improved VQ method gives a better result than the K-means method

Structures of Human Antibodies Bound to SARS-CoV-2 Spike Reveal Common Epitopes and Recurrent Features of Antibodies

Neutralizing antibody responses to coronaviruses mainly target the receptor-binding domain (RBD) of the trimeric spike. Here, we characterized polyclonal IgGs and Fabs from COVID-19 convalescent individuals for recognition of coronavirus spikes. Plasma IgGs differed in their focus on RBD epitopes, recognition of alpha- and beta-coronaviruses, and contributions of avidity to increased binding/neutralization of IgGs over Fabs. Using electron microscopy, we examined specificities of polyclonal plasma Fabs, revealing recognition of both S1^A and RBD epitopes on SARS-CoV-2 spike. Moreover, a 3.4Å cryo-EM structure of a neutralizing monoclonal Fab-spike complex revealed an epitope that blocks ACE2 receptor binding. Modeling based on these structures suggested different potentials for inter-spike crosslinking by IgGs on viruses and that characterized IgGs would not be affected by identified SARS-CoV-2 spike mutations. Overall, our studies structurally define a recurrent anti-SARS-CoV-2 antibody class derived from VH3-53/VH3-66 and similarity to a SARS-CoV VH3-30 antibody, providing criteria for evaluating vaccine-elicited antibodies

Bridging the gap in African biodiversity genomics and bioinformatics:Open Institute of the African BioGenome Project:

The Open Institute of the African BioGenome Project empowers African scientists and institutions with the skill sets, capacity and infrastructure to advance scientific knowledge and innovation and drive economic growth

The association between workplace smoking bans and self-perceived, work-related stress among smoking workers

<p>Abstract</p> <p>Background</p> <p>There is substantial empirical evidence on the benefits of smoking bans; however, the unintended consequences of this anti-smoking measure have received little attention. This paper examines whether workplace smoking bans (WSB's) are associated with higher self-perceived, work-related stress among smoking workers.</p> <p>Methods</p> <p>A longitudinal representative sample of 3,237 individuals from the Canadian National Population Health Survey from 2000 to 2008 is used. Work-related stress is derived from a 12-item job questionnaire. Two categories of WSB's, full and partial, are included in the analysis, with no ban being the reference category. Analysis also controls for individual socio-demographic characteristics, health status, provincial and occupational fixed-effects. We use fixed-effects linear regression to control for individual time-invariant confounders, both measured and unmeasured, which can affect the relationship between WSB's and work-related stress. To examine the heterogeneous effects of WSB's, the analysis is stratified by gender and age. We check the robustness of our results by re-estimating the baseline specification with the addition of different control variables and a separate analysis for non-smokers.</p> <p>Results</p> <p>Multivariate analysis reveals a positive and statistically significant association between full <it>(β = 0.75, CI = 0.19-1.32) </it>or partial <it>(β = 0.69, CI = 0.12-1.26) </it>WSB's, and the level of self-perceived, work-related stress among smoking workers compared to those with no WSB. We also find that this association varies by gender and age. In particular, WSB's are significantly associated with higher work stress only for males and young adults (aged 18-40). No statistically significant association is found between WSB's and the level of self-perceived work-related stress among non-smoking workers.</p> <p>Conclusion</p> <p>The results of this study do not imply that WSB's are the main determinant of self-perceived, work-related stress among smokers but provides suggestive evidence that these may be positively related.</p