23 research outputs found
A Strict Physicality-Preserving Scheme for a 2D Q-Tensor Flow with a Singular Potential
No full textNematic liquid crystals are a state of matter that exhibit properties between those of conventional liquids and solid crystals. Their unique ability to align molecules in specific directions makes them essential in various applications, including display technologies and advanced materials. To model their complex behavior, mathematical frameworks such as the Q-tensor model are used to describe the orientation and degree of molecular order. In this work, we introduce a numerical scheme for a two-dimensional (2D) dynamic Q-tensor model, which is formulated as an L2-gradient flow driven by the liquid crystal free energy and incorporates a singular potential to enforce physical constraints. The proposed scheme is designed to strictly preserve the physicality of the system, ensuring that the fundamental properties of the liquid crystals are respected throughout the simulation. We provide a rigorous convergence analysis of the scheme, establishing the well-posedness of the underlying partial differential equation (PDE) system for the 2D Q-tensor model. To validate its efficiency and accuracy, we perform extensive numerical experiments that demonstrate the scheme’s ability to capture key physical behaviors of nematic liquid crystals. This work highlights the robustness and potential of the proposed scheme for advancing the study and simulation of liquid crystal dynamics
Mapping the genomic position of xylanase genes on Bacillus safensis FB03 and optimizing the xylanase fermentation medium by Box-Behnken Design from an unconventional carbon source
No full textBackground: The ability of Bacillus safensis to synthesize xylanase and other industrially important enzymes utilizing lignocellulosic biomass makes it advantageous for a variety of biotechnology applications. Thus, the current investigation aimed to optimize conditions and medium components for maximizing xylanase production by a newly isolated Bacillus safensis strain using banana rachis (peel of banana tree) as a novel source of carbon. Result: Upon employing Box-Behnken Design (BBD) statistical approach, the highest enzyme activity was obtained 25.24 U/ml at 2 g/L banana rachis, 1 g/L yeast extract, 1 g/L K2HPO4, 5 g/L NaNO3, 35°C and 72 h of incubation time. The purified enzyme showed 10 times higher enzyme activity (143.6 U/ml) with 2.3 mg/ml protein concentration. The enzyme was found to maintain stability up to 60°C in a wide range of pH (6 to 10). Analysis of whole genome sequencing data revealed the presence of xylanase production and xylan metabolic genes (xynA, xynB, xylP, xylT) on Bacillus safensis FB03. Also, from genome annotation, different carbohydrate metabolic genes such as glycoside hydrolases (GHs), glycosyl transferases (GTs), polysaccharide lyases (PLs), carbohydrate esterases (CEs), auxiliary activities (AAs), and carbohydrate binding modules (CBMs) were identified. Conclusions: In accordance with our research, banana rachis can be considered as a major medium component to develop an economical fermentation process for the production of xylanase by Bacillus safensis FB03. Additionally, identification of the genomic location of xyl genes provides valuable insight towards genetic engineering for the development of a more potent industrial strain.How to cite: Boby F, Huda Bhuiyan MN, Parvez MM, et al. Mapping the genomic position of xylanase genes on Bacillus safensis FB03 and optimizing the xylanase fermentation medium by Box-Behnken Design from an unconventional carbon source. Electron J Biotechnol 2025;78. https://doi.org/10.1016/j.ejbt.2025.05.004
Experimental and numerical study of control of flow separation of a symmetric airfoil with trapped vortex cavity
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Diagnostic concordance of ultrasound and histopathology in pediatric neck masses
No full textBackground: Ultrasonography has become the most accessible, safe, and cost-effective imaging modality for evaluating pediatric neck masses, especially in resource-limited settings. The purpose of the study was to assess the diagnostic concordance between ultrasound findings and histopathological results in pediatric neck masses. The aim of the study was to evaluate the diagnostic concordance between ultrasound findings and histopathological results in pediatric neck masses.
Methods: This observational diagnostic study was conducted at Bangladesh Shishu hospital and institute from October 2023 to March 2025, involving 550 children (0-12 years) with palpable neck masses. All cases underwent ultrasound and confirmatory histopathological examination. Diagnoses were made independently by radiologists and blinded pathologists. Concordance was defined as an exact diagnostic match. Data were analyzed using SPSS v28 with descriptive statistics.
Results: Among 550 pediatric patients with neck masses, most were aged >2-5 years (50.9%) with a balanced gender distribution. Lymphadenitis was the most common ultrasound (40.6%) and histopathological (34.2%) finding. Congenital lesions like cystic hygromas, thyroglossal duct cysts, and haemangiomas were also frequent. Ultrasound showed high diagnostic concordance, particularly for cystic hygromas (98.0%), thyroglossal duct cysts (97.7%), and branchial cleft cysts (96.2%), with an overall concordance rate of 90.0%.
Conclusions: Ultrasound demonstrates high concordance with histopathology, reinforcing its value as a reliable, non-invasive first-line diagnostic tool for pediatric neck masses
Uncommon pancreatic tumor - a case report
No full textKeywords: uncommon pancreatic cancer; anaplastic carcinomaDOI: http://dx.doi.org/10.3329/bjpath.v26i1.9151 BJPATH 2011; 26(1): 39-40</jats:p
Draft genome sequence data on Bacillus safensis FB03 isolated from the rhizosphere soil of leguminous plant in BangladeshNational Center for Biotechnology Information
No full textWith the aim of investigating the biotechnological potential of Bacillus safensis' FB03, isolated from the rhizosphere soil of Bahrind region of Bangladesh, the current work focused on its complete genomic analysis and phenotypic description. The size of the genome of the isolate was 3.6 Mb with 41.59 % GC content. Genome annotation revealed the presence of many genes related to siderophore production, enzyme degradation, UV and stress tolerance. Six biosynthesis gene clusters for bacillibacin, bacilysin, bottromycin, Schizokinen, fengycin, and lychensin were identified through genome mining. Significantly, FB03 was found to contain only two acquired antimicrobial resistance genes and was anticipated to be non-pathogenic to humans. The openness of the Bacillus safensis pan-genome was demonstrated by the pan-genome analysis. According to this research, Bacillus safensis FB03 may be a good fit for a variety of biotechnological applications
