Study of Numerical Schemes for the CFD Simulation of Human Airways

Computational fluid dynamics (CFD) is increasingly used nowadays to capture air and particle transport in human respiratory tract model. In the present study, computer tomography (CT) scan based respiratory tract model is used for the CFD simulation. The main objective of the present study is to compare different pressure-velocity schemes (SIMPLE, SIMPLEC, PISO and COUPLED schemes) in terms of convergence and computational time. Numerical simulation is done for three inhalation flow rates, namely 20, 40 and 60 liters per minute for predictions of flow phenomena inside the sixth generation human airways and also to predict the effects of flow parameters; pressures and velocity on the sixth generation Human Airways. Low Reynolds Number (LNR) k-ω model is used to capture the turbulence effect. The findings will be useful for medical practitioner to understand complex airflow patterns in the human airways. Also, pressure distribution and velocity distribution help to define the medical phenomena in core engineering terms

Active Flow Control over a NACA23012 Airfoil using Hybrid Jet

A time-dependent numerical simulation is performed to examine the flow separation control with the action of a hybrid jet (the combination of synthetic and continuous jets) over a NACA23012 airfoil. The unsteady Reynolds-averaged Navier–Stokes (URANS) simulation is performed with Spalart-Allmaras (SA) turbulence model to simulate the flow field around the airfoil to analyse the effect of the hybrid jet. A combined jet is placed at the point of flow separation on the upper surface of the airfoil which is located at the 12% of the chord length from the leading edge of the airfoil for a given flow configuration. Flow simulations are performed at a chord-based Reynolds number of 2.19 × 106 for the hybrid jet oscillating frequency of 0.159 at a blowing ratio of 3.0. The contribution of the continuous jet in the hybrid jet is evident by the flow control. Variation in the continuous jet velocity is studied, which improved the aerodynamic characteristics of the airfoil. The maximum improvement in lift to drag ratio is observed from 11.19 to 22.14 at an angle of attack of 22 degree. The stall angle also shows an enhancement from 18 degree to 20 degree

Extrapulmonary Tuberculosis: A retrospective Study at a tertiary care hospital in Palpa, Nepal

Background: Extra-pulmonary tuberculosis (EPTB) is a significant global health problem. Related studies to it in different places and diff erent durations are indicated by many previous research findings. Findings of this study could be beneficial for its preventive and control strategies. Methodology: Retrospective analysis of clinical specimens submitted to Central laboratory of Lumbini Medical College and Teaching Hospital (LMCTH) for extrapulmonary tuberculosis was performed. Total 261 samples submitted from April 2011 to February 2013 were included for analysis in this study. Results: Total 20.7% (54/261) prevalence of EPTB was reported. Based on sites involved; lymph node 87.03%, pleural effusion7.40%, peritoneal5.55% were found. Genderwise equal prevalence was seen among male and females. Age-wise prevalence among patients between 21-40 years was reported. Conclusion: Our finding indicates great necessity for further large scale study on prevalence of EPTB in this location for its prevention and control

Structure, localization and histone binding properties of nuclear-associated nucleosome assembly protein from Plasmodium falciparum

<p>Abstract</p> <p>Background</p> <p>Nucleosome assembly proteins (NAPs) are histone chaperones that are crucial for the shuttling and incorporation of histones into nucleosomes. NAPs participate in the assembly and disassembly of nucleosomes thus contributing to chromatin structure organization. The human malaria parasite <it>Plasmodium falciparum </it>contains two nucleosome assembly proteins termed PfNapL and PfNapS.</p> <p>Methods</p> <p>Three-dimensional crystal structure of PfNapS has been determined and analysed. Gene knockout and localization studies were also performed on PfNapS using transfection studies. Fluorescence spectroscopy was performed to identify histone-binding sites on PfNapS. Extensive sequence and structural comparisons were done with the crystal structures available for NAP/SET family of proteins.</p> <p>Results</p> <p>Crystal structure of PfNapS shares structural similarity with previous structures from NAP/SET family. Failed attempts to knock-out the gene for PfNapS from malaria parasite suggest essentiality in the parasite. GFP-fused PfNapS fusion protein targeting indicates cellular localization of PfNapS in the parasite nucleus. Fluorescence spectroscopy data suggest that PfNapS interacts with core histones (tetramer, octamer, H3, H4, H2A and H2B) at a different site from its interaction with linker histone H1. This analysis illustrates two regions on the PfNapS dimer as the possible sites for histone recognition.</p> <p>Conclusions</p> <p>This work presents a thorough analysis of the structural, functional and regulatory attributes of PfNapS from <it>P. falciparum </it>with respect to previously studied histone chaperones.</p

Neutrophil-lymphocyte ratio as a predictor of outcome following traumatic brain injury: Systematic review and meta-analysis

Objetivos: El cociente neutrófilo-linfocito (NLR) es un parámetro hematológico sencillo y de realización rutinaria; sin embargo, los estudios sobre el NLR como herramienta pronóstica en el traumatismo craneoencefálico (TCE) han arrojado resultados contradictorios. Materiales y métodos: Esta revisión sistemática y meta-análisis se llevó a cabo de acuerdo con las Preferred Reporting Items in the Systematic Review and Meta-Analysis guidelines 2020. Se realizaron búsquedas en las bases de datos electrónicas de PubMed, Cochrane Library, Web of Science y Scopus. La población consistió en pacientes con TCE en ausencia de lesión extracraneal moderada y grave. Para el análisis se tomó el RNL del día 1. Los resultados evaluados fueron la mortalidad y la escala de resultados de Glasgow (GOS). No se impusieron restricciones en cuanto al idioma, el año y el país de publicación, y la duración del seguimiento. Se excluyeron del estudio los estudios con animales. Los estudios en los que se comunicaron datos inadecuados para los resultados se incluyeron en la síntesis cualitativa, pero se excluyeron de la síntesis cuantitativa. La calidad de los estudios se evaluó mediante la escala Newcastle-Ottawa (NOS). El riesgo de sesgo se estimó mediante la herramienta de riesgo de sesgo Cochrane RoBANS. Resultados: Se recuperaron 7213 citas mediante la estrategia de búsqueda y se excluyeron 2097 citas en función del cribado del título y el resumen. Se recuperó el texto completo de 40 artículos y se sometió a los criterios de elegibilidad, de los cuales 28 fueron excluidos del estudio. Doce estudios fueron elegibles para la síntesis de la revisión sistemática, mientras que siete estudios cumplieron los requisitos para el metanálisis. La puntuación media de los artículos fue de 8/9 según NOS. El riesgo de sesgo de selección fue bajo en todos los estudios, mientras que el riesgo de sesgo de detección fue alto en todos excepto en un estudio. Diez estudios se realizaron en pacientes adultos, mientras que dos estudios informaron sobre LCT pediátrica. Un metanálisis para GOS mostró que un NLR alto predijo resultados desfavorables en ≥6 meses con una diferencia media de -5,18 (intervalo de confianza del 95%: -10,04, -0,32); P = 0,04; heterogeneidad (I2), siendo del 98%. Las estimaciones del efecto para NLR y mortalidad fueron una diferencia media de -3,22 (intervalo de confianza del 95%: -7,12, 0,68), P = 0,11, y una I2 del 85%. El metanálisis de las características operativas del receptor del área bajo la curva (AUC) de los estudios incluidos mostró un buen poder predictivo del NLR para predecir los resultados tras una LCT, con un AUC de 0,706 (IC del 95%: 0,582-0,829). Conclusiones: Un NLR al ingreso más alto predice un mayor riesgo de mortalidad y resultados desfavorables después de una LCT. Sin embargo, es probable que futuras investigaciones aborden las lagunas existentes. 2022, Scientific Scholar LLC. Todos los derechos reservados.Objectives: The neutrophil-to-lymphocyte ratio (NLR) is a simple and routinely performed hematological parameter; however, studies on NLR as a prognostic tool in traumatic brain injury (TBI) have yielded contradictory results. Materials and Methods: This systematic review and meta-analysis was conducted according to the Preferred Reporting Items in the Systematic Review and Meta-Analysis guidelines 2020. Electronic databases of PubMed, Cochrane Library, Web of Science, and Scopus were searched. The population consisted of TBI patients in the absence of moderate and severe extracranial injury. Day 1 NLR was taken for the analysis. The outcomes evaluated were mortality and the Glasgow Outcome Scale (GOS). No restrictions were placed on the language, year and country of publication, and duration of follow-up. Animal studies were excluded from the study. Studies, where inadequate data were reported for the outcomes, were included in the qualitative synthesis but excluded from the quantitative synthesis. Study quality was evaluated using the Newcastle-Ottawa scale (NOS). The risk of bias was estimated using the Cochrane RoBANS risk of bias tool. Results: We retrieved 7213 citations using the search strategy and 2097 citations were excluded based on the screening of the title and abstract. Full text was retrieved for 40 articles and subjected to the eligibility criteria, of which 28 were excluded from the study. Twelve studies were eligible for the synthesis of the systematic review while seven studies qualified for the meta-analysis. The median score of the articles was 8/9 as per NOS. The risk of selection bias was low in all the studies while the risk of detection bias was high in all except one study. Ten studies were conducted on adult patients, while two studies reported pediatric TBI. A meta-analysis for GOS showed that high NLR predicted unfavorable outcomes at ≥6 months with a mean difference of −5.18 (95% confidence interval: −10.04, −0.32); P = 0.04; heterogeneity (I2), being 98%. The effect estimates for NLR and mortality were a mean difference of −3.22 (95% confidence interval: −7.12, 0.68), P = 0.11, and an I2 of 85%. Meta-analysis for Area under the curve (AUC) receiver operating characteristic of the included studies showed good predictive power of NLR in predicting outcomes following TBI with AUC 0.706 (95% CI: 0.582–0.829). Conclusion: A higher admission NLR predicts an increased mortality risk and unfavorable outcomes following TBI. However, future research will likely address the existing gaps. © 2022, Scientific Scholar LLC. All rights reserved

AnyMAL: An Efficient and Scalable Any-Modality Augmented Language Model

We present Any-Modality Augmented Language Model (AnyMAL), a unified model that reasons over diverse input modality signals (i.e. text, image, video, audio, IMU motion sensor), and generates textual responses. AnyMAL inherits the powerful text-based reasoning abilities of the state-of-the-art LLMs including LLaMA-2 (70B), and converts modality-specific signals to the joint textual space through a pre-trained aligner module. To further strengthen the multimodal LLM's capabilities, we fine-tune the model with a multimodal instruction set manually collected to cover diverse topics and tasks beyond simple QAs. We conduct comprehensive empirical analysis comprising both human and automatic evaluations, and demonstrate state-of-the-art performance on various multimodal tasks

Molecular Basis of the Electron Bifurcation Mechanism in the [FeFe]-Hydrogenase Complex HydABC

Electron bifurcation is a fundamental energy coupling mechanism widespread in microorganisms that thrive under anoxic conditions. These organisms employ hydrogen to reduce CO2, but the molecular mechanisms have remained enigmatic. The key enzyme responsible for powering these thermodynamically challenging reactions is the electron-bifurcating [FeFe]-hydrogenase HydABC that reduces low-potential ferredoxins (Fd) by oxidizing hydrogen gas (H2). By combining single-particle cryo-electron microscopy (cryoEM) under catalytic turnover conditions with site-directed mutagenesis experiments, functional studies, infrared spectroscopy, and molecular simulations, we show that HydABC from the acetogenic bacteria Acetobacterium woodii and Thermoanaerobacter kivui employ a single flavin mononucleotide (FMN) cofactor to establish electron transfer pathways to the NAD(P)+ and Fd reduction sites by a mechanism that is fundamentally different from classical flavin-based electron bifurcation enzymes. By modulation of the NAD(P)+ binding affinity via reduction of a nearby iron–sulfur cluster, HydABC switches between the exergonic NAD(P)+ reduction and endergonic Fd reduction modes. Our combined findings suggest that the conformational dynamics establish a redox-driven kinetic gate that prevents the backflow of the electrons from the Fd reduction branch toward the FMN site, providing a basis for understanding general mechanistic principles of electron-bifurcating hydrogenases