检索结果-南通市图书馆

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

引用

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

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in DNA methylation and its role in cytoplasmic male sterility in higher plants

引用

Journal of Integrative Agriculture 2024年第1期23卷 1-19页

作者： Atiqur Rahman Hasan Sofiur Rahman shakil Uddin Naima Sultana Shirin Akhter Ujjal Kumar Nath Shamsun Nahar Begum Mazadul Islam Afroz Naznin Nurul Amin Sharif ahmed Akbar Hossain Department of Genetics and Plant Breeding Bangladesh Agricultural UniversityMymensingh 2202Bangladesh Plant Breeding Division Bangladesh Institute of Nuclear AgricultureMymensingh 2202Bangladesh Tuber Crop Research Centre Bangladesh Agricultural Research Institute(BARI)Joydebpur 1701Bangladesh Horticulture Research Centre Bangladesh Agricultural Research Institute(BARI)Joydebpur 1701Bangladesh Biotechnology Division Bangladesh Agricultural Research Institute(BARI)Joydebpur 1701Bangladesh International Rice Research Institute Bangladesh OfficeDhaka 1213Bangladesh Division of Soil Science Bangladesh Wheat and Maize Research InstituteDinajpur 5200Bangladesh

The impact of epigenetic modifications like DNA methylation on plant phenotypes has expanded the possibilities for crop *** methylation plays a part in the regulation of both the chromatin structure and gene expression,and the enzyme involved,DNA methyltransferase,executes the methylation process within the plant *** regulating crucial biological pathways,epigenetic changes actively contribute to the creation of the ***,epigenome editing may assist in overcoming some of the drawbacks of genome editing,which can have minor off-target consequences and merely facilitate the loss of a gene’s *** drawbacks include gene knockout,which can have such off-target *** review provides examples of several molecular characteristics of DNA methylation,as well as some plant physiological processes that are impacted by these epigenetic changes in the *** also discuss how DNA alterations might be used to improve crops and meet the demands of sustainable and environmentally-friendly farming.

关键词： DNA methylation epigenetics CMS male sterility chromatin architecture gene expression higher plants

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Investigation of the Phytoconstituents and Antioxidant Activity of Diospyros malabaricaFruit Extracts

引用

Advances in Bioscience and Biotechnology 2019年第12期10卷 431-454页

作者： Razib Datta Shubhra shakil ahmed polash Tanushree Saha Ashraful Hasan Sharif Hossain Zinia Islam Satya Ranjan Sarker Department of Biotechnology and Genetic Engineering Jahangirnagar University Dhaka Bangladesh Department of Textile Engineering Dhaka University of Engineering and Technology Gazipur Bangladesh Department of Biochemistry and Molecular Biology Jahangirnagar University Dhaka Bangladesh

Diospyros malabarica (Deshi Gab) belonging to the family “Ebenaceae” grows well in the humid tropical climate of Bangladesh. In order to investigate the phytoconstituents both qualitatively and quantitatively, the seed and flesh extracts of D. malabarica were prepared using two polar solvents (i.e., water and 70% ethanol) and a nonpolar solvent (i.e., hexane). The maximum yield was obtained for aqueous and ethanolic seed extracts indicating that most of the phytoconstituents present in D. malabarica fruit are polar. The qualitative phytochemical analysis of the extracts revealed the presence of diverse amount of phytoconstituents in the extracts. On the other hand, the quantitative phytochemical analysis for phenols, tannins, flavonoids, alkaloids, saponin, proteins, reducing sugar and vitamin C revealed that the maximum amount of phenols, tannins, flavonoids and reducing sugar were present in aqueous seed extract. However, the maximum amount of total protein and vitamin C was found in ethanolic seed extract. D. malabarica seed powder contained more amount of alkaloids (i.e., 13.6%) than that of flesh (i.e., 3.4%). However, the content of saponin was more in flesh extract (0.74%) when compared to that of seed extract (0.42%). In vitro antioxidant properties of the extracts were also investigated by DPPH free radical scavenging assay, FRAP assay and reducing power assay. The highest antioxidant activity was observed for aqueous seed extract followed by the ethanolic seed, ethanolic flesh, and aqueous flesh extracts. The lowest antioxidant activity was obtained for hexane flesh extract. Furthermore, the lowest (i.e., 44.70 μg/ml) as well as the highest (2359.66 μg/ml) IC50 values were obtained for aqueous seed and hexane flesh extracts, respectively.

关键词： Diospyros malabarica Phytochemical Assay Total Phenol Content Total Tannin Content Total Flavonoid Content Antioxidant Activity

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

引用

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

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

引用

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

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

First-principles calculations of structural, electronic, and thermodynamic properties of ZnO_(1-x)S_x alloys

引用

Chinese Physics B 2014年第10期23卷 394-400页

作者： Muhammad Zafar Shabbir ahmed M.shakil M.A.Choudhary Simulation Laboratory Department of Physics The Islamia University of Bahawalpur

In this study the pseudo-potential method is used to investigate the structural, electronic, and thermodynamic proper- ties of ZnOl_xSx semiconductor materials. The results show that the electronic properties are found to be improved when calculated by using LDA ~ U functional as compared with local density approximation （LDA）. At various concentrations the ground-state properties are determined for bulk materials ZnO, ZnS, and their tertiary alloys in cubic zinc-blende phase. From the results, a minor difference is observed between the lattice parameters from Vegard＇s law and other calculated results, which may be due to the large mismatch between lattice parameters of binary compounds ZnO and ZnS. A small deviation in the bulk modulus from linear concentration dependence is also observed for each of these alloys. The ther- modynamic properties, including the phonon contribution to Helmholtz free energy △F, phonon contribution to internal energy △E, and specific iheat at constant-volume Cv, are calculated within quasi-harmonic approximation based on the calculated phonon dispersion relations.

关键词： first principles calculations density functional theory (DFT) semiconductor materials structural,electronic, and thermal properties

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The Effect of Injection Angle on Mixing and Flame Holding in Supersonic Combustor

引用

Journal of Thermal Science 2002年第1期11卷 80-91页

作者： shakil ahmed Mohammad Ali A. K. M. Sadrul Islam Department of Mechanical Engineering Bangladesh University of Engineering and Technology (BUET) Dhaka Bangladesh

A numerical study on mixing of hydrogen injected into a supersonic air stream has been performed by solving two-dimensional full Navier-Stokes equations. An explicit Harten-Yee Non-MUSCL Modified-flux-type TVD scheme has been used to solve the system of equations, and a zero-equation algebraic turbulence model to calculate the eddy viscosity coefficient. The main objectives of this study are to increase the mixing efficiency and flame holding capability of a supersonic combustor. The performance of combustor has been investigated by varying the hydrogen injection angle made with the direction of air stream considering anti-clockwise direction as positive. The injector position from left boundary, backward-facing step height and the inlet width of air stream are kept constant. The results show that upstream of injector the mixing is dominated by recirculation and in downstream the mixing is dominated by mass concentration of hydrogen. Upstream recirculation is dominant for injecting angle 600 and 900 . Incorporating the various effects, perpendicular injection shows the maximum mixing efficiency and its large upstream recirculation region has a good flame holding capability.

关键词： scramjet engine TVD scheme backward-facing step supersonic mixing supersonic stream flame holding.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Theoretical calculations of structural, electronic, and elastic properties of CdSe_(1-x)Te_x:A first principles study

引用

Chinese Physics B 2016年第7期25卷 324-330页

作者： M shakil Muhammad Zafar Shabbir ahmed Muhammad Raza-ur-rehman Hashmi M A Choudhary T Iqbal Department of Physics Hafiz Hayat Campus University of Gujrat Simulation Laboratory Department of Physics the Islamia University of Bahawalpur

The plane wave pseudo-potential method was used to investigate the structural, electronic, and elastic properties of Cd Se_（1-x）Te_x in the zinc blende phase. It is observed that the electronic properties are improved considerably by using LDA ＋ U as compared to the LDA approach. The calculated lattice constants and bulk moduli are also comparable to the experimental results. The cohesive energies for pure Cd Se and Cd Te binary and their mixed alloys are calculated. The second-order elastic constants are also calculated by the Lagrangian theory of elasticity. The elastic properties show that the studied material has a ductile nature.

关键词： first principles calculations density functional theory II–VI semiconductors structural electronic and elastic properties

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

First-principles calculation of the structural,electronic,and magnetic properties of cubic perovskite RbXF3(X = Mn,V,Co,Fe)

引用

Chinese Physics B 2016年第11期25卷 486-491页

作者： Muhammad Raza ur rehman Hashmi Muhammad Zafar M shakil Atif Sattar Shabbir ahmed S A Ahmad Simulation Laboratory Department of Physics The Islamia University of Bahawalpur 63100 Pakistan Department of Physics Hafiz Hayat Campus University of Gujrat Gujrat Pakistan

First-principles calculations by means of the full-potential linearized augmented plane wave method using the generalized gradient approximation with correlation effect correction（GGA＋U） within the framework of spin polarized density functional theory（DFT＋U） are used to study the structural,electronic,and magnetic properties of cubic perovskite compounds RbXF3（X = Mn,V,Co,and Fe）.It is found that the calculated structural parameters,i.e.,lattice constant,bulk modulus,and its pressure derivative are in good agreement with the previous *** results reveal that the strong spin polarization of the 3d states of the X atoms is the origin of ferromagnetism in *** energies and the magnetic moments of RbXF3 have also been *** calculated electronic properties show the half-metallic nature of RbCoF3 and RbFeF3,making these materials suitable for spintronic applications.

关键词： cubic metallic perovskite modulus correction linearized ferromagnetic augmented instance spheres

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Theoretical investigation of sulfur defects on structural, electronic,and elastic properties of ZnSe semiconductor

引用

Chinese Physics B 2015年第7期24卷 365-370页

作者： Muhammad Zafar Shabbir ahmed M.shakil M.A.Choudhary K.Mahmood Simulation Laboratory Department of PhysicsThe Islamia University of Bahawalpur 63100Pakistan Department of Physics GC UniversityFaisalabad 68000Pakistan

The structural, electronic, and elastic properties of ZnSe1-xSx for the zinc blende structures have been studied by using the density functional theory. The calculations were performed using the plane wave pseudopotential method, as implemented in Quantum ESPRESSO. The exchange-correlation potential is treated with the local density approximation pz-LDA for these properties. Moreover, LDA＋U approximation is employed to treat the ＂d＂ orbital electrons properly. A comparative study of the band gap calculated within both LDA and LDA＋U schemes is presented. The analysis of results show considerable improvement in the calculation of band gap. The inclusion of compositional disorder increases the values of all elastic constants. In this study, it is found that elastic constants C11, C12, and C44 are mainly influenced by the compositional disorder. The obtained results are in good agreement with literature.

关键词： first principles calculations density functional theory II–VI semiconductors electronic and elastic properties

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：