Publications by authors named "K Hossain"

288 Publications

Alkaline-Earth Metal Effects on Physical Properties of Ferromagnetic AVO (A = Ba, Sr, Ca, and Mg): Density Functional Theory Insights.

ACS Omega 2022 Jun 9;7(24):20914-20926. Epub 2022 Jun 9.

Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8573, Japan.

The effects of alkaline-earth metals on electronic, optical, thermodynamic, and physical properties of ferromagnetic AVO (A = Ba, Sr, Ca, and Mg) have been investigated by first-principles calculations within the GGA+ formalism based on density functional theory. The optimized structural parameters are in good agreement with the available experimental results that evaluate the reliability of our calculations. The cell and mechanical stability is discussed using the formation energy and Born stability criteria, respectively. The mechanical behaviors of AVO are discussed on the basis of the results of elastic constants, elastic moduli, Peierls stress, and Vickers hardness. The nature of the ductile-brittle transition of AVO compounds was confirmed by the values of Pugh's ratio, Poisson's ratio, and Cauchy pressure. The electronic band structures, as well as density of states, reveal the half-metallic behavior of BaVO and SrVO. However, CaVO and MgVO exhibit spin-gapless and magnetic semiconductor characteristics, respectively. The microscopic origin of the transition from the half-metallic to semiconductor nature of AVO is rationalized using electronic properties. The presence of covalent, ionic, and metallic bonds in AVO compounds is found by the analysis of bonding properties. The single-band nature of half-metallic AVO is seen by observing hole-like Fermi surfaces in this study. Furthermore, the various thermodynamic and optical properties are calculated and analyzed. The refractive index suggests that AVO could be a potential candidate for applications to high-density optical data storage devices.
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http://dx.doi.org/10.1021/acsomega.2c01630DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9219064PMC
June 2022

B Vitamins and Their Roles in Gut Health.

Microorganisms 2022 Jun 7;10(6). Epub 2022 Jun 7.

Department of Biochemistry, Memorial University of Newfoundland, St. John's, NL A1C 5S7, Canada.

B vitamins act as coenzymes in a myriad of cellular reactions. These include energy production, methyl donor generation, neurotransmitter synthesis, and immune functions. Due to the ubiquitous roles of these vitamins, their deficiencies significantly affect the host's metabolism. Recently, novel roles of B vitamins in the homeostasis of gut microbial ecology and intestinal health continue to be unravelled. This review focuses on the functional roles and biosynthesis of B vitamins and how these vitamins influence the growth and proliferation of the gut microbiota. We have identified the gut bacteria that can produce vitamins, and their biosynthetic mechanisms are presented. The effects of B vitamin deficiencies on intestinal morphology, inflammation, and its effects on intestinal disorders are also discussed.
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http://dx.doi.org/10.3390/microorganisms10061168DOI Listing
June 2022

Seroprevalence of SARS-CoV-2 antibodies in Bangladesh related to novel coronavirus infection.

IJID Reg 2022 Mar 2;2:198-203. Epub 2022 Feb 2.

International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh.

Design: A cross-sectional study was conducted amongst household members in 32 districts of Bangladesh to build knowledge about disease epidemiology and seroepidemiology of coronavirus disease 2019 (COVID-19).

Objective: Antibody responses to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) were assessed in people between April and October 2020.

Results: The national seroprevalence rates of immunoglobulin G (IgG) and IgM were estimated to be 30.4% and 39.7%, respectively. In Dhaka, the seroprevalence of IgG was 35.4% in non-slum areas and 63.5% in slum areas. In areas outside of Dhaka, the seroprevalence of IgG was 37.5% in urban areas and 28.7% in rural areas. Between April and October 2020, the highest seroprevalence rate (57% for IgG and 64% for IgM) was observed in August. IgM antibody was more prevalent in younger participants, while older participants had more frequent IgG seropositivity. Follow-up specimens from patients with COVID-19 and their household members suggested that both IgG and IgM seropositivity increased significantly at day 14 and day 28 compared with day 1 after enrolment. : SARS-CoV-2 had spread extensively in Bangladesh by October 2020. This highlights the importance of monitoring seroprevalence data, particularly with the emergence of new SARS-CoV-2 variants over time.
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http://dx.doi.org/10.1016/j.ijregi.2022.01.013DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8809641PMC
March 2022

Assessment of quality of life and its determinants in type-2 diabetes patients using the WHOQOL-BREF instrument in Bangladesh.

BMC Endocr Disord 2022 Jun 18;22(1):162. Epub 2022 Jun 18.

Pi Research Consultancy Center, Dhaka, 1211, Bangladesh.

Background: Diabetes mellitus (DM) is rising at a rapid rate worldwide. As a chronic, incurable metabolic disease, diabetes affects a person's life in all ways. Studies thus far have focused on the impact of diabetes on the physical and mental health of persons affected by the quality of life (QoL). This study aimed to explore the whole range of QoL deficits using the World Health Organization Quality of Life brief version (WHOQOL-BREF) in type-2 diabetic patients.

Methods: This cross-sectional study was carried out among individuals aged at or above 15 years with type 2 diabetes (T2DM). Patients with prior mental health illness and unwillingness to give consent were excluded. A pretested structured questionnaire including the 26-item WHOQOL-BREF questionnaire was used for face-to-face interviews. Appropriate ethical measures were ensured. All statistical analyses were carried out using the statistical software STATA (Version 16.1). Graphs were created using R (Version 4.0.0).

Results: A total of 500 T2 DM patients with a mean age of 55.8 ± 13.2 years (± SD) and a female proportion of 50.8% were included. Overall, 22.2% of participants rated their QoL as poor, and 25% were dissatisfied with their health (as assessed by questions 1 and 2 of the WHOQOL-BREF questionnaire). More than half (54% and 51.2%, respectively) had an average evaluation of their QoL and health. The QoL scores were below average, with mean scores (± SD) for the physical health, psychological, social relationship, and environmental domains of 37.2 ± 20.5, 44.2 ± 21.0, 39.6 ± 23.2, and 41.6 ± 19.5, respectively. Multiple regression analysis revealed that the patient's level of education and monthly family income were significant positive modifiers and that complications (nephropathy, retinopathy, and peripheral artery disease) were significant negative determinants of the QoL score in different domains.

Conclusion: This study found the overall quality of life among T2DM patients below average. Health authorities and clinicians should take these findings into account and incorporate necessary measures to ameliorate negative modifiers of the quality of life of sufferers.
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http://dx.doi.org/10.1186/s12902-022-01072-wDOI Listing
June 2022

Combined RIS and EBG Surfaces Inspired Meta-Wearable Textile MIMO Antenna Using Viscose-Wool Felt.

Polymers (Basel) 2022 May 13;14(10). Epub 2022 May 13.

Centre for Wireless Communications (CWC), University of Oulu, 90014 Oulu, Finland.

In this paper, we present a textile multiple-input-multiple-output (MIMO) antenna designed with a metamaterial inspired reactive impedance surface (RIS) and electromagnetic bandgap (EBG) using viscose-wool felt. Rectangular RIS was used as a reflector to improve the antenna gain and bandwidth to address well known crucial challenges-maintaining gain while reducing mutual coupling in MIMO antennas. The RIS unit cell was designed to achieve inductive impedance at the center frequency of 2.45 GHz with a reflection phase of 177.6°. The improved bandwidth of 170 MHz was achieved by using a square shaped RIS under a rectangular patch antenna, and this also helped to attain an additional gain of 1.29 dBi. When the antenna was implemented as MIMO, a split ring resonator backed by strip line type EBG was used to minimize the mutual coupling between the antenna elements. The EBG offered a sufficient band gap region from 2.37 GHz to 2.63 GHz. Prior to fabrication, bending analysis was carried out to validate the performance of the reflection coefficient () and transmission coefficient (). The results of the analysis show that bending conditions have very little impact on antenna performance in terms of S-parameters. The effect of strip line supported SRR-based EBG was further analyzed with the fabricated prototype to clearly show the advantage of the designed EBG towards the mutual coupling reduction. The designed MIMO-RIS-EBG array-based antenna revealed an reduction of -9.8 dB at 2.45 GHz frequency with overall of <-40 dB. The results also indicated that the proposed SRR-EBG minimized the mutual coupling while keeping the mean effective gain (MEG) variations of <3 dB at the desired operating band. The specific absorption rate (SAR) analysis showed that the proposed design is not harmful to human body as the values are less than the regulated SAR. Overall, the findings in this study indicate the potential of the proposed MIMO antenna for microwave applications in a wearable format.
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http://dx.doi.org/10.3390/polym14101989DOI Listing
May 2022
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