Experience in establishing a high-risk biocontainment facility in response to COVID-19 pandemic under resource constrain settings

The health care systems in resource limited countries are facing major challenges in dealing with Coronavirus disease (COVID-19). In Bangladesh, a steady increase in the number of COVID-19 cases since its first report on March 8, 2020, has led to an increased demand for COVID-19 detection facilities throughout the country. The detection of severe acute respiratory syndrome (SARS-CoV-2), the causative organism of COVID-19 and a highly infectious group 3(three) organism, requires a high biocontainment laboratory with a certain standard prerequisite infrastructure. This study describes the necessary steps for establishing and running a COVID-19 laboratory under resource constraint settings. Our experience indicates that, with collaborative efforts, funding, and technical support from locally available expertise, it is feasible to set up an optimally functional biocontainment facility with an acceptable quality performance despite several short comings. BSMMU J 2021; 14 (COVID -19 Supplement): 45-5

Activation of GPR35 protects against cerebral ischemia by recruiting monocyte-derived macrophages.

Pamoic acid is a potent ligand for G protein Coupled Receptor 35 (GPR35) and exhibits antinociceptive property. GPR35 activation leads to increased energy utilization and the expression of anti-inflammatory genes. However, its role in brain disorders, especially in stroke, remains unexplored. Here we show in a mouse model of stroke that GPR35 activation by pamoic acid is neuroprotective. Pharmacological inhibition of GPR35 reveals that pamoic acid reduces infarcts size in a GPR35 dependent manner. The flowcytometric analysis shows the expression of GPR35 on the infiltrating monocytes/macrophages and neutrophils in the ischemic brain. Pamoic acid treatment results in a preferential increment of noninflammatory Ly-6CLo monocytes/macrophages in the ischemic brain along with the reduced neutrophil counts. The neuroprotective effect of GPR35 activation depends on protein kinase B (Akt) and p38 MAPK. Together we conclude that GPR35 activation by pamoic acid reprograms Ly-6CLo monocytes/macrophages to relay a neuroprotective signal into the ischemic brain

Potential anticancer agents identification of Hystrix Brachyura Bezoar through gas chromatography-mass spectrometry-based metabolomics and protein-ligand interaction with molecular docking analyses

Background: Bezoar (PB) is a rare, solidified form of undigested food commonly found in the gastrointestinal tract of porcupine (Hystrix brachyura). It is believed to be traditionally used to treat various diseases including different kinds of cancers in Malaysia. However, its active principles have not been found out yet. The purpose of this study was to investigate the anticancer property of PB extract as well as to identify the metabolites responsible for its anticancer effect through a widely acclaimed metabolomics approach. Methods: Initially, 25 PB extracts using various solvent ratios of methanol–water (100, 75, 50, 25, 0% v/v) were prepared in regard to metabolomics approach and subsequently the cytotoxicity of each extract was determined against (melanoma) A375 cell line. The metabolites profiling of the most potent extract was conducted using gas chromatography mass spectrometry (GC-MS) and in silico investigation was performed on Bcl-2 and cyclin/CDK1 complex protein. Results: The correlation of the bioactivity with GC-MS data produced an orthogonal partial least square (OPLS) model which pinpointed four putative active compounds namely (1) cholest-7-en-3-beta-ol,4,4-dimethyl-,acetate; (2) 4-androsten-4-ol-3,17-dione; (3) isolongifolol and (4) gallic acid. The in silico data suggested the binding score and binding mode of active metabolites with the amino acid residues of protein via hydrophobic interactions. Conclusion: This study is the first to report the identified anticancer compounds from PB extract and evaluate them using molecular docking. This further confirms and justifies its traditional usage as an alternative medicine for the treatment of cancer in Malaysia

Potential anticancer agents identification of Hystrix brachyura bezoar through gas chromatography-mass spectrometry-based metabolomics and protein-ligand interaction with molecular docking analyses

Background: Bezoar (PB) is a rare, solidified form of undigested food commonly found in the gastrointestinal tract of porcupine (Hystrix brachyura). It is believed to be traditionally used to treat various diseases including different kinds of cancers in Malaysia. However, its active principles have not been found out yet. The purpose of this study was to investigate the anticancer property of PB extract as well as to identify the metabolites responsible for its anticancer effect through a widely acclaimed metabolomics approach. Methods: Initially, 25 PB extracts using various solvent ratios of methanol–water (100, 75, 50, 25, 0% v/v) were prepared in regard to metabolomics approach and subsequently the cytotoxicity of each extract was determined against (melanoma) A375 cell line. The metabolites profiling of the most potent extract was conducted using gas chromatography mass spectrometry (GC–MS) and in silico investigation was performed on Bcl-2 and cyclin/CDK1 complex protein. Results: The correlation of the bioactivity with GC–MS data produced an orthogonal partial least square (OPLS) model which pinpointed four putative active compounds namely (1) cholest-7-en-3-beta-ol,4,4- dimethyl-,acetate; (2) 4-androsten-4-ol-3,17-dione; (3) isolongifolol and (4) gallic acid. The in silico data suggested the binding score and binding mode of active metabolites with the amino acid residues of protein via hydrophobic interactions. Conclusion: This study is the first to report the identified anticancer compounds from PB extract and evaluate them using molecular docking. This further confirms and justifies its traditional usage as an alternative medicine for the treatment of cancer in Malaysia

Microstructure Evolution of Chalcogenide Materials via Molecular Dynamics

The properties of a material are defined by its granular microstructure which is determined by its grain evolution and the types of grain boundaries present in the structure. For example, the performance of Cadmium Sulfide/Cadmium Telluride (CdS/CdTe) solar cells can be affected by the presence of grain boundaries which makes the study of grain structure evolution a very important part of solar cell performance optimization. Grain boundary mobilities are important properties in material science and engineering as they determine grain structures under given processing and operating conditions. In this thesis, several computational tools were used to analyze the formation and behavior of grains and grain boundaries in polycrystalline CdTe/CdS and bi-crystalline CdTe structures. Recently, the simulated growth of a polycrystalline CdTe/CdS structure via molecular dynamics was reported which very closely mimics the experimental structure of these materials. However, a detailed analysis of the grain boundaries in the simulated CdTe/CdS is lacking. The goal of this thesis is to develop a general methodology to quantitatively analyze the behavior of the grain boundaries in the CdTe/CdS structure. Orientation of the grains within the polycrystalline CdTe/CdS was successfully computed using a combination of computational tools. The determination of the orientation of neighboring grains in a polycrystalline sample is important for computing the type of grain boundaries within the structure. Moreover, the migration of Σ3(111), Σ7(111) and Σ11(311) grain boundaries in CdTe bi-crystals at various temperatures and one driving forces was also computed. The grain boundary migration study is important to calculate the mobility of the grain boundary. Future work will focus on computing the grain boundary types in the polycrystalline sample and studying their dynamic behavior

Computational Study of Grain Structure Evolution in Cdte/CdS via Molecular Dynamics

Grain structure analysis plays an important role in the identification of grain boundary characteristics, which can affect the efficiency of Cadmium Telluride/Cadmium Sulfide (CdTe/CdS) solar cells since they can act as recombination centers for carriers. Computer simulations such as molecular dynamics (MD) can be a very convenient and cost- effective method of investigating the growth evolution and grain structure of materials. The recently reported and experimentally validated MD simulated growth of polycrystalline CdTe/CdS films shows that these materials mostly consist of zinc blende (ZB) and wurtzite (WZ) structures, along with highly disordered atoms. However, little information about the semiconductor compound grain structure quantification and evolution has been reported in the literature. In this dissertation, several computational tools were used to analyze the formation and behavior of grains and grain boundaries in polycrystalline CdTe/CdS structures. A computational approach was applied to analyze the CdTe/CdS films obtained from our molecular dynamics simulations. It was demonstrated that by focusing on ZB and WZ structures, or even cation and anion sublattices of the tetragonal crystal structure of the compound, the parameters obtained from the centrosymmetric, polyhedral template matching and common neighbor analyses can be used to calculate the orientation of each atom in the grain tracking algorithm. This provides a variety of useful information, such as grain domains, grain orientations, and sample texture. Furthermore, microstructure evolution was performed to understand grain growth mechanisms and kinetics. There are other useful features that are not included in the current tool, such as identification and tracking of point defects — especially vacancies at grain boundaries. Nonetheless, the current approach is useful and our CdTe/CdS results provide inputs for further computational studies to relate grain structures to physical, chemical, mechanical, and electronic properties. Moreover, dynamic machine learning models of structure evolution could be developed using these identified features through an automated procedure

Computational Study Of Grain Structure Evolution In Cdte/cds Via Molecular Dynamics

Grain structure analysis plays an important role in the identification of grain boundary characteristics, which can affect the efficiency of Cadmium Telluride/Cadmium Sulfide (CdTe/CdS) solar cells since they can act as recombination centers for carriers. Computer simulations such as molecular dynamics (MD) can be a very convenient and cost- effective method of investigating the growth evolution and grain structure of materials. The recently reported and experimentally validated MD simulated growth of polycrystalline CdTe/CdS films shows that these materials mostly consist of zinc blende (ZB) and wurtzite (WZ) structures, along with highly disordered atoms. However, little information about the semiconductor compound grain structure quantification and evolution has been reported in the literature. In this dissertation, several computational tools were used to analyze the formation and behavior of grains and grain boundaries in polycrystalline CdTe/CdS structures. A computational approach was applied to analyze the CdTe/CdS films obtained from our molecular dynamics simulations. It was demonstrated that by focusing on ZB and WZ structures, or even cation and anion sublattices of the tetragonal crystal structure of the compound, the parameters obtained from the centrosymmetric, polyhedral template matching and common neighbor analyses can be used to calculate the orientation of each atom in the grain tracking algorithm. This provides a variety of useful information, such as grain domains, grain orientations, and sample texture. Furthermore, microstructure evolution was performed to understand grain growth mechanisms and kinetics. There are other useful features that are not included in the current tool, such as identification and tracking of point defects â?? especially vacancies at grain boundaries. Nonetheless, the current approach is useful and our CdTe/CdS results provide inputs for further computational studies to relate grain structures to physical, chemical, mechanical, and electronic properties. Moreover, dynamic machine learning models of structure evolution could be developed using these identified features through an automated procedure

Molecular Dynamics Calculations of Grain Boundary Mobility in CdTe

Molecular dynamics (MD) simulations have been applied to study mobilities of Σ3, Σ7 and Σ11 grain boundaries in CdTe. First, an existing MD approach to drive the motion of grain boundaries in face-centered-cubic and body-centered-cubic crystals was generalized for arbitrary crystals. MD simulations were next performed to calculate grain boundary velocities in CdTe crystals at different temperatures, driving forces, and grain boundary terminations. Here a grain boundary is said to be Te-terminated if its migration encounters sequentially C d · T e − C d · T e … planes, where “·” and “−” represent short and long spacing respectively. Likewise, a grain boundary is said to be Cd-terminated if its migration encounters sequentially T e · C d − T e · C d … planes. Grain boundary mobility laws, suitable for engineering time and length scales, were then obtained by fitting the MD results to Arrhenius equation. These studies indicated that the Σ3 grain boundary has significantly lower mobility than the Σ7 and Σ11 grain boundaries. The Σ7 Te-terminated grain boundary has lower mobility than the Σ7 Cd-terminated grain boundary, and that the Σ11 Cd-terminated grain boundary has lower mobility than the Σ11 Te-terminated grain boundary

Mixed convection boundary layer flow of viscoelastic fluids past a sphere with constant wall temperature

The mixed convection boundary layer of a viscoelastic fluid past a sphere with constant temperature is discussed. The governing non-similar partial differential equations are first transformed into dimensionless forms and then solved numerically using the Keller-box method by augmenting an extra boundary condition at infinity. Numerical results are presented for different values of the viscoelastic and mixed convection parameters K and λ, respectively. It is found that for cases of cooling sphere (λ 0), the boundary layer separates from the sphere

A Vivacious Delineation of Public Universities at Dhaka: An Emphatic Gaze on Quality Education

ABSTRACT Education is considered as a basic right of human being and perhaps it is the most important elementary need that human deserves. As society is flourishing its paragon of beauty for developing it towards a newer mould day by day human is in a nee