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Investigation of the Phytochemicals, Antioxidant, and Antimicrobial Activity of the Andrographis paniculataLeaf and Stem Extracts

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Advances in Bioscience and Biotechnology 2017年第5期8卷 149-162页

作者： Shakil Ahmed Polash Tanushree Saha md. sharif hossain Satya Ranjan Sarker Department of Biotechnology and Genetic Engineering Faculty of Biological Sciences Jahangirnagar University Dhaka Bangladesh Department of Textile Engineering Dhaka University of Engineering and Technology Gazipur Bangladesh

Andrographis paniculata (Kalmegh) has been considered as a medicinal shrub and used as a medicinal plant in the remote areas of Bangladesh. A. paniculata leaf and stem extracts were prepared using the polar (i.e., water, and 70% ethanol) and nonpolar (i.e., hexane) solvents. The phytochemical contents, total phenol contents (TPC), antioxidant activity, and antibacterial activity of all the extracts of A. paniculata leaf and stem were investigated. Both the gram-positive (i.e., Bacillus subtillis) and gram-negative (i.e., E. coli, and Salmonella typhi) strains of bacteria were used for the antibacterial activity assay of the sample extracts. The ethanolic stem extracts contained the maximum amount of TPC when compared to that of the leaf extracts. However, the aqueous stem extracts had the highest free radical scavenging activity in vitro. The extracts prepared from A. paniculata stem showed better antibacterial activity against all the strains of bacteria (i.e., E. coli, S. typhi, and B. subtillis) when compared to that of the leaf extracts. More specifically, the aqueous stem extract showed superior antibacterial effect against E. coli, and B. subtillis, and the zones of inhibition were 21 mm, and 29 mm in diameter, respectively. On the other hand, the ethanolic stem extract showed the maximum antibacterial activity against S. typhi and the zone of inhibition was 8.15 mm. The minimum inhibitory concentration (MIC) value and IC50 value for all the A. paniculata extracts were ~0.05 μg/μL, and ~1 μg/μL, respectively.

关键词： Andrographis paniculata Total Phenol Content Antioxidant Antimicrobial Zone of Inhibition

Investigation of the Antimicrobial Activity and in Vivo Cytotoxicity of Diospyros malabarica (Desr.) Kostel. Fruit Extracts

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Natural Science 2021年第8期13卷 331-351页

作者： Razib Datta Shubhra Shakil Ahmed Polash md. Monir hossain Amir Hamza md. Mehedi Hasan Tushar Tanushree Saha md. Ashraful Hasan md. Maniruzzaman Sikder Nuhu Alam Zinia Islam md. sharif hossain Satya Ranjan Sarker Department of Biotechnology and Genetic Engineering Jahangirnagar University Savar Bangladesh Department of Textile Engineering Dhaka University of Engineering and Technology Gazipur Bangladesh Department of Biochemistry and Molecular Biology Jahangirnagar University Savar Bangladesh Department of Botany Jahangirnagar University Savar Bangladesh

Mankind is facing an unprecedented threat of existence due to the antibiotic resistance developed by bacteria. The unripe fruits of Diospyros malabarica (Desr.) Kostel. (family: Ebenaceae) can be considered as one of the natural sources to tackle this issue. The present study is designed to assess the antimicrobial activity of D. malabarica seed and flesh ex-tracts. Herein, D. malabarica extracts were prepared using polar solvents (i.e., water and 70% ethanol) and their antimicrobial activity as well as in vivo toxicity was investigated. Their antibacterial activity was investigated against gram positive (Bacillus subtilis) and gram negative (Escherichia coli DH5α, and Salmonella typhi) bacteria at different time points. All the extracts showed the highest antibacterial activity after 2 hours of incubation. The aqueous seed extract showed the maximum zone of inhibition (i.e., ~13 mm) against Bacillus subtilis with a minimum inhibitory concentration (MIC) value of 2 μg/μl. The an-tibacterial propensity was also confirmed through trypan blue dye exclusion assay, CellToxTM Green assay, and lipid peroxidation (LPO) assay. On the other hand, the etha-nolic seed extract demonstrated higher antifungal activity through inhibition of mycelial growth. All the extracts showed excellent hemocompatibility against both human and rat red blood cells (RBCs). They also did not show any toxicity to rat liver and kidneys. Taken together, this study demonstrates that the aqueous and ethanolic extracts of D. malabarica seed and flesh could be an effective source of natural antimicrobial agents with no cytotox-ic activity.

关键词： Diospyros malabarica (Desr.) Kostel. Antibacterial Activity Trypan Blue Assay Cell ToxTM Green Assay In Vivo Cytotoxicity

Investigation of the Phytoconstituents and Bioactivity of Various Parts of Wild Type and Cultivated Phyllanthus emblicaL.

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Advances in Bioscience and Biotechnology 2017年第7期8卷 211-227页

作者： Ratna Mondal Shakil Ahmed Polash Tanushree Saha Zinia Islam md. Maniruzzaman Sikder Nuhu Alam md. sharif hossain Satya Ranjan Sarker Department of Biotechnology and Genetic Engineering Jahangirnagar University Savar Dhaka Bangladesh Department of Textile Engineering Dhaka University of Engineering and Technology Gazipur Bangladesh Department of Botany Jahangirnagar University Savar Dhaka Bangladesh

Phyllanthus emblica L. belonging to the family Euphorbiaceae is a common medicinal plant in Bangladesh. In order to evaluate the phytoconstituents and bioactivity of various parts of P. emblica, both the wild type (i.e., small) and cultivated (i.e., big) fruits were collected from the local market of Bangladesh and six ethanolic extracts were prepared from various parts of the collected fruits for this current study. A comparative analysis of the phytochemical compositions and various bioactivities especially antibacterial, antifungal, and antioxidant activity of the six ethanolic extracts were accomplished. The qualitative phytochemical analysis of plant extracts revealed the presence of large amounts of proteins, carbohydrates, phenolic compounds, glycosides, alkaloids, coumarins, flavonoids, tannins, saponins and resins etc. The maximum antioxidant activity was observed for wild type P. emblica seed extracts and the minimum activity was observed for cultivated flesh extracts. Moreover, among the samples the wild type P. emblica extracts have excellent amount of total phenol contents and the highest free radical scavenging activity. It is also found that P. emblica samples were active against both gram-positive (i.e., B. subtilis) and gram-negative (i.e., E. coli, and S. typhi) bacteria. The highest antibacterial activity was achieved in the wild type P. emblica seed extracts against both pathogenic (S. typhi) and non-pathogenic bacterial strains (E. coli, and B. subtilis). These samples showed almost no activity against Fusarium sp. fungus.

关键词： Phyllanthus emblica Total Phenol Content Antioxidant Activity Antimicrobial Activity Zone of Inhibition and Antifungal Activity

Grid-Connected Emergency Back-Up Power Supply

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Circuits and Systems 2019年第1期10卷 1-19页

作者： Dhiman Chowdhury Mohammad sharif Miah md. F. hossain Department of Electrical Engineering University of South Carolina Columbia SC USA Department of Electrical and Electronics Engineering Daffodil International University Dhaka Bangladesh

This paper documents design and modeling of a grid-connected emergency back-up power supply for medium power applications. Back-up power supplies are very important in regard to support electrical loads in the events of grid power outage. However, grid-integration of a back-up power supply substantiates continual power transfer to the loads, especially to the critical loads, which should not suffer from power interruptions. Therefore, design and circuit modeling of switching converters based reliable grid-tied emergency back-up power supply are presented in this paper. There are a rectifier-link boost derived battery charging circuit and a 4-switch push-pull power inverter circuit which are controlled by high frequency pulse width modulation (PWM) signals. This paper presents a state averaging model and Laplace domain transfer function of the charging circuit and a switching converter model of the power inverter circuit. A changeover relay based transfer switch controls the power flow towards the utility loads. During off-grid situations, loads are fed power by the proposed inverter circuit and during on-grid situations, battery is charged by an ac-link rectifier-fed boost converter. However, there is a relay switching circuit to control the charging phenomenon of the battery. The proposed design is simulated in PLECS and the simulation results corroborate the reliability of the presented framework.

关键词： Back-Up Power Supply Laplace Domain Push-Pull Inverter State Averaging Model Switching Converter Model

Preparation and Properties of Indium Selenide （InSe） Thin Films for Selective Surface Applications

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Journal of Physical Science and Application 2011年第1期1卷 37-43页

作者： Jaker hossain md. Julkamain Kazi Shaifullah sharif Khairul Alam Khan Department of Applied Physics ＆ Electronic Engineering University of Rajshahi Rajshahi 6205 Bangladesh

Indium selenide （InSe） thin films have been prepared by e-beam technique onto glass substrate at a pressure of-8 × 10^-5 Pa. The deposition rate of the InSe thin films is -8.30 nms^-1. InSe samples grown at room temperature have been termed as virgin, whereas the films at which the transition in electrical conductivity is shown to exhibit at a temperature of 415 to 455 K have been termed as phase-transited samples. X-ray diffraction （XRD） study reveals that lnSe thin films are amorphous in nature before phase-transition while they are polycrystalline after phase-transition. Scanning electron microscopy （SEM） has been used to study the surface morphology of InSe thin films. Before phase-transition grains are absent in the films and surfaces are almost smooth and uniform. Film surfaces are seen to exhibit a number of grains after phase-transition and they are rough in surfaces. The elemental composition of the lnSe thin films has been estimated by EDAX method. The effects of temperature on the electrical properties of InSe thin films have been studied in details. Temperature dependence of electrical conductivity shows a semiconducting behavior with activation energy. Thickness dependence of conductivity is well in conformity with the Fuchs-Sondheimer theory. Thermopower study indicates that the InSe film is an n-type semiconductor. The optical study of InSe thin films is carried out in the wavelength range 360 to 1100 nm at room temperature. The study of absorption coefficient of InSe thin films shows a direct type transition with a band gap of=1.65 eV which is well agreed with the reported values. Integrated values of luminous and solar transmittance as well as of reflectance have been calculated. Appreciable order of transmittance and reflectance suggest that this material is a potential candidate for the application in selective surface devices.

关键词： InSe thin films e-beam technique XRD SEM thermopower.

Viscous and Joules Dissipation on MHD Flow past a Stretching Porous Surface Embedded in a Porous Medium

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Journal of Applied Mathematics and Physics 2015年第12期3卷 1710-1725页

作者： md. sharif Uddin Mathematics Discipline Khulna University Khulna Bangladesh

This paper investigates the influence of both viscous and joules dissipation on the problem of magneto-hydrodynamic flow past a stretching porous surface embedded in a porous medium for rotating case. Using similarity approach the system of partial differential equations is transformed into ordinary differential equations which strongly depend on the magnetic parameter, stretching parameter, rotation parameter, permeability parameter and Prandtl number. The coupled differential equations are numerically simulated using the Nactsheim-Swigert shooting technique together with Runge-Kutta six order iteration schemes. The velocity and temperature profiles are discussed and presented graphically. The comparisons for dimensionless skin friction coefficient and local Nusselt number are also taken into account and discussed and presented graphically.

关键词： Magneto-Hydrodynamic Porous Medium Joules Dissipation Viscous Dissipation Rotational Parameter

Ga(X)N/Si nanoarchitecture:An emerging semiconductor platform for sunlight-powered water splitting toward hydrogen

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Frontiers in Energy 2024年第1期18卷 56-79页

作者： Yixin LI sharif md.SADAF Baowen ZHOU Key Laboratory for Power Machinery and Engineering of the Ministry of Education Research Center for Renewable Synthetic FuelSchool of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China Centre Energie Matériaux et TélécommunicationsInstitut National de la Recherche Scientifique(INRS)-Universitédu Québec1650 Boulevard Lionel-BouletVarennesQuébec J3X1S2Canada

Sunlight-powered water splitting presents a promising strategy for converting intermittent and virtually unlimited solar energy into energy-dense and storable green *** the pioneering discovery by Honda and Fujishima,considerable efforts have been made in this research *** various materials developed,Ga(X)N/Si(X=In,Ge,Mg,etc.)nanoarchitecture has emerged as a disruptive semiconductor platform to split water toward hydrogen by *** paper introduces the characteristics,properties,and growth/synthesis/fabrication methods of Ga(X)N/Si nanoarchitecture,primarily focusing on explaining the suitability as an ideal platform for sunlight-powered water splitting toward green hydrogen *** addition,it exclusively summarizes the recent progress and development of Ga(X)N/Si nanoarchitecture for photocatalytic and photoelectrochemical water ***,it describes the challenges and prospects of artificial photosynthesis integrated device and system using Ga(X)N/Si nanoarchitectures for solar water splitting toward hydrogen.

关键词： Ga(X)N/Si nanoarchitecture artificial photosynthesis water splitting solar toward hydrogen

A Regular Study on Yarn Count, Size Box Temperature and Machine Speed to Increase Weaving Efficiency of Cotton Fabric

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Journal of Textile Science and Technology 2020年第4期6卷 168-176页

作者： Umme Magreba Takebira A. T. M. Mohibullah md. Zawadul hossain Shajidul Islam Tanim md. sharif Ahammad Redoy md. Lutfar Rahman md. Shakib Rejwan Department of Apparel Manufacturing & Technology BGMEA University of Fashion & Technology Dhaka Bangladesh

Sizing is an inherent part of weaving works, consisting in the coating of the warp yarn with a polymeric adhesive, such as starch, in order to assist efficient weaving. The study is aimed to assess the effects of squeezed roller pressure, dryer temperature, yarn count, machine speed (rpm) on cotton fabric weaving. Coarser and finer cotton yarn samples were prepared using sizing solution BENSIZE 850. Different size box temperature, yarn count, fabric construction, machine speed, squeeze roller pressure were considered to construct different weaving designs to study yarn breakages parameter. A warping plan was designed on TAROKO V5.4 (190325) software. The results established that size box lower temperature and higher machine speed provide the smallest amount yarn break during weaving for coarser cotton yarn and the highest for finer cotton yarn. Size box higher temperature and lower machine speed provide maximum yarn breakage during weaving coarser cotton yarn and minimum for fine yarn. Size penetration is uniform, which provides a higher strength of the yarn to less breakage. This aspect of the research suggested that higher yarn strength gives a lesser amount of breakage.

关键词： Sizing Material Machine Parameters Different Counts Sizing Efficiency

A Production Inventory Model of Constant Production Rate and Demand of Level Dependent Linear Trend

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American Journal of Operations Research 2016年第1期6卷 61-70页

作者： Shirajul Islam Ukil md. sharif Uddin Jahangirnagar University Savar Bangladesh

The proposed model considers the products with finite shelf-life which causes a small amount of decay. The market demand is assumed to be level dependent and in a linear form. The model has also considered the constant production rate which stops attaining a desired level of inventories and that is the highest level of inventories. Production starts with a buffer stock and without any sort of backlogs. Due to the market demand and product’s decay, the inventory reduces to the level of buffer stock where again the production cycle starts. With a numerical search procedure the proof of the proposed model has been shown. The objective of the model is to obtain the total average optimum inventory cost and optimum ordering cycle.

关键词： Production Inventory Level Dependent Linear Trend Constant Production Rate