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Geochemistry of subsurface Late Quaternary ironstones in Rajshahi and Bogra Districts, Bangladesh: implications for genetic and depositional conditions
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作者 Md.Sazzadur Rahman Ismail Hossain +3 位作者 Pradip Kumar Biswas Md.Abdur Rahim A.S.M.Mehedi Hasan Md.Ibrahim Adham 《Acta Geochimica》 EI CAS CSCD 2019年第3期404-413,共10页
The present study deals with the geochemistry of Late Quaternary ironstones in the subsurface in Rajshahi and Bogra districts, Bangladesh with the lithological study of the boreholes sediments. Major lithofacies of th... The present study deals with the geochemistry of Late Quaternary ironstones in the subsurface in Rajshahi and Bogra districts, Bangladesh with the lithological study of the boreholes sediments. Major lithofacies of the studied boreholes are clay, silty clay, sandy clay, fine to coarse grained sand, gravels and sands with(fragmentary) ironstones. The ironstones contain major oxides, Fe_2 O_3*(*total Fe)(avg. 66.6 wt%), SiO_2(avg. 15.3 wt%), Al_2 O_3(avg. 4.0 wt%), MnO(avg. 7.7 wt%), and CaO(avg. 3.4 wt%). These geochemical data imply that the higher percentage of Fe_2 O_3* along with Al_2 O_3 and MnO indicate the ironstone as goethite and siderite, which is also validated by XRD data. A comparatively higher percentage of SiO_2 indicates the presence of relative amounts of clastic quartz and manganese-rich silicate or clay in these rocks. These ironstones also have significant amounts of MnO(avg. 7.7 wt%) suggesting their depositional environments under oxygenated condition. Chemical data of these ironstones suggest that the source rock suffered deep chemical weathering and iron was mostly carried in association with the clay fraction and organic matter. Iron concretion was mostly formed by bacterial build up in swamps and marshes, and was subsequently embedded in clayey mud.Within the coastal environments, the water table fluctuates and goethite and siderite with mud and quartz became dry and compacted to form ironstone. 展开更多
关键词 IRONSTONE GEOCHEMISTRY GOETHITE SIDERITE BANGLADESH
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Effect of Nutritional Support on Treatment of Multi-Drug Resistant Tuberculosis in Rajshahi Division, Bangladesh
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作者 Md. Abu Sayem Md. Golam Hossain +2 位作者 Tahmeed Ahmed Khaled Hossain Zahangir Alam Saud 《Journal of Tuberculosis Research》 2020年第4期223-236,共14页
</span><b><span style="font-family:Verdana;">Introduction:</span></b><span style="font-family:Verdana;"></b></span><b> </b><span style... </span><b><span style="font-family:Verdana;">Introduction:</span></b><span style="font-family:Verdana;"></b></span><b> </b><span style="font-family:Verdana;">Multi</span></span><span style="font-family:Verdana;">-</span><span style="font-family:Verdana;">drug resistant tuberculosis (MDR-TB) is a public health crisis</span><span style="font-family:""><span style="font-family:Verdana;"> throughout the world including Bangladesh particularly due to its complexities in diagnosis, longer treatment regimen, and adverse drug reaction. Nutritional supplementation has significant impact on patient’s weigh gain and optimum weight gain is a biomarker of treatment response. The objective </span><span style="font-family:Verdana;">of this study was to measure body mass index (BMI) progress among</span><span style="font-family:Verdana;"> MDR-TB patients in different phases of treatment. <b></span><b><span style="font-family:Verdana;">Methodology:</span></b><span style="font-family:Verdana;"></b> A prospective observational study was conducted from March 2010 to July 2015 in Chest Disease Hospital (CDH), Rajshahi and different communities of Rajshahi Division, Bangladesh. A total of 233 confirmed MDR-TB patients were selected from CDH who received treatment and nutritional support from ongoing national TB control program (NTP). They received free diagnosis, follow up tests, treatment and nutritional support as regular diet as well as cash amount Bangladeshi taka (BDT</span></span><span style="font-family:Verdana;">.</span><span style="font-family:Verdana;">) 1000 per month in CDH. Along with treatment, they also received only cash amount BDT</span><span style="font-family:Verdana;">.</span><span style="font-family:""><span style="font-family:Verdana;"> 1500 per month as nutritional support at community level. Weight measurement was taken at regular interval from enrollment to completion of treatment. Chi-square, paired t-test and linear regression analysis were used in this study. <b></span><b><span style="font-family:Verdana;">Results:</span></b><span style="font-family:Verdana;"></b> The baseline prevalence of undernourished (BMI < 18.5 kg/m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">) was 82.4%. After two months of treatment, 14.5% underweight patients gained weight and reverted to normal BMI. Regression analysis showed the decreasing tendency of BMI progress with increasing age which was significant among male patients (p < 0.05). We observed reversely that patients gained more BMI in intensive phase than continuation phase of treatment. The cohort results demonstrated that the treatment success rate was lower (<83%) among initially underweight patients than their counterparts (>92%). </span><b><span style="font-family:Verdana;">Conclusion:</span></b><span style="font-family:Verdana;"> Nutritional support has synergistic effect on treatment response. Adequate nutritional support with proper treatment would help to get better outcomes particularly at community level. Gender issue should also be addressed at household level. 展开更多
关键词 BANGLADESH BMI Progress MDR-TB Nutritional Support
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Perception and Knowledge on Climate Change:A Case Study of University Students in Bangladesh
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作者 Bezon Kumar Arif Ibne Asad +1 位作者 Borun Chandraaroy Purnima Banik 《Journal of Atmospheric Science Research》 2019年第3期17-22,共6页
This paper mainly investigates the perception and knowledge on climate change of the university students in Bangladesh.To carry out this study,primary data collected from 370 students and several statistical methods a... This paper mainly investigates the perception and knowledge on climate change of the university students in Bangladesh.To carry out this study,primary data collected from 370 students and several statistical methods are used.Perception and knowledge on the causes,effects and mitigation ways of climate change problems,and perceived duties to combat against climate change are analyzed with descriptive statistics.This paper finds that deforestation is the main cause of global warming and climate change and,the effects of climate change is very serious on people’s health.Majority portion of the students think that it is difficult to combat against climate change problem because it has already been too late to take action.Besides this study also finds that government is crucially responsible for combating against climate change problem.The study calls for government mainly besides industry and youths to aware people about the causes,effects,mitigation ways of climate change so that they can contribute to the sustainable development by mitigating climate change problem. 展开更多
关键词 Climate Change Sustainable Development BANGLADESH
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Gas Chromatographic Method for Identification and Quantification of Commonly Used Residual Solvents in Pharmaceuticals Products
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作者 Sreekanta Nath Dalal Pranab Kumar Das 《American Journal of Analytical Chemistry》 CAS 2024年第8期241-252,共12页
Background: Impurities are not expected in the final pharmaceutical products. All impurities should be regulated in both drug substances and drug products in accordance with pharmacopeias and ICH guidelines. Three dif... Background: Impurities are not expected in the final pharmaceutical products. All impurities should be regulated in both drug substances and drug products in accordance with pharmacopeias and ICH guidelines. Three different types of impurities are generally available in the pharmaceutical’s product specification: organic impurities, inorganic impurities, and residual solvents. Residual solvents are organic volatile chemicals used or generated during the manufacturing of drug substances or drug products. Purpose: The aim of this study is to develop a cost-effective gas chromatographic method for the identification and quantification of some commonly used solvents—methanol, acetone, isopropyl alcohol (IPA), methylene chloride, ethyl acetate, tetrahydrofuran (THF), benzene, toluene, and pyridine—in pharmaceutical product manufacturing. This method will be able to identify and quantify the multiple solvents within a single gas chromatographic procedure. Method: A gas chromatography (GC) equipped with a headspace sampler and a flame ionization detector, and a column DB 624, 30-meter-long × 0.32-millimeter internal diameter, 1,8 μm-thick, Brand-Agilent was used to develop this method. The initial GC oven temperature was 40°C and held for 5 minutes. It was then increase to 80˚C at a rate of 2˚C per minute, followed by a further increase to 225˚C at a rate of 30˚C per minute, with a final hold at 225˚C for 10 minutes. Nitrogen was used as a carrier gas at a flow rate of 1.20 mL per minute. Dimethyl sulfoxide (DMSO) was selected as sample solvent. Results: The developed method is precise and specific. The percent RSD for the areas of six replicate injections of this gas chromatographic method was within 10.0 and the recovery result found within 80.0% to 120.0%. 展开更多
关键词 Method Development Gas Chromatography Compendial Method GDP SPECIFICITY RECOVERY
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Robustness Study and Superior Method Development and Validation for Analytical Assay Method of Atropine Sulfate in Pharmaceutical Ophthalmic Solution
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作者 Md. Nazmus Sakib Chowdhury Sreekanta Nath Dalal +4 位作者 Md. Ariful Islam Md. Anwar Hossain Pranab Kumar Das Shakawat Hossain Parajit Das 《American Journal of Analytical Chemistry》 CAS 2024年第5期151-164,共14页
Background: The robustness is a measurement of an analytical chemical method and its ability to contain unaffected by little with deliberate variation of analytical chemical method parameters. The analytical chemical ... Background: The robustness is a measurement of an analytical chemical method and its ability to contain unaffected by little with deliberate variation of analytical chemical method parameters. The analytical chemical method variation parameters are based on pH variability of buffer solution of mobile phase, organic ratio composition changes, stationary phase (column) manufacture, brand name and lot number variation;flow rate variation and temperature variation of chromatographic system. The analytical chemical method for assay of Atropine Sulfate conducted for robustness evaluation. The typical variation considered for mobile phase organic ratio change, change of pH, change of temperature, change of flow rate, change of column etc. Purpose: The aim of this study is to develop a cost effective, short run time and robust analytical chemical method for the assay quantification of Atropine in Pharmaceutical Ophthalmic Solution. This will help to make analytical decisions quickly for research and development scientists as well as will help with quality control product release for patient consumption. This analytical method will help to meet the market demand through quick quality control test of Atropine Ophthalmic Solution and it is very easy for maintaining (GDP) good documentation practices within the shortest period of time. Method: HPLC method has been selected for developing superior method to Compendial method. Both the compendial HPLC method and developed HPLC method was run into the same HPLC system to prove the superiority of developed method. Sensitivity, precision, reproducibility, accuracy parameters were considered for superiority of method. Mobile phase ratio change, pH of buffer solution, change of stationary phase temperature, change of flow rate and change of column were taken into consideration for robustness study of the developed method. Results: The limit of quantitation (LOQ) of developed method was much low than the compendial method. The % RSD for the six sample assay of developed method was 0.4% where the % RSD of the compendial method was 1.2%. The reproducibility between two analysts was 100.4% for developed method on the contrary the compendial method was 98.4%. 展开更多
关键词 ROBUSTNESS Method Validation HPLC Compendial Method Method Development GDP LOQ
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Divide and recombine approach for warranty database: estimating the reliability of an automobile component
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作者 Md Rezaul Karim 《Data Science and Management》 2024年第2期119-128,共10页
The continuously updated database of failures and censored data of numerous products has become large, and on some covariates, information regarding the failure times is missing in the database. As the dataset is larg... The continuously updated database of failures and censored data of numerous products has become large, and on some covariates, information regarding the failure times is missing in the database. As the dataset is large and has missing information, the analysis tasks become complicated and a long time is required to execute the programming codes. In such situations, the divide and recombine (D&R) approach, which has a practical computational performance for big data analysis, can be applied. In this study, the D&R approach was applied to analyze the real field data of an automobile component with incomplete information on covariates using the Weibull regression model. Model parameters were estimated using the expectation maximization algorithm. The results of the data analysis and simulation demonstrated that the D&R approach is applicable for analyzing such datasets. Further, the percentiles and reliability functions of the distribution under different covariate conditions were estimated to evaluate the component performance of these covariates. The findings of this study have managerial implications regarding design decisions, safety, and reliability of automobile components. 展开更多
关键词 Weibull regression model Warranty database RELIABILITY EM algorithm Divide and recombine approach Managerial implications
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Associations of PNPLA3 and LEP genetic polymorphisms with metabolic-associated fatty liver disease in Thai people living with human immunodeficiency virus
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作者 Kanuengnit Choochuay Punna Kunhapan +6 位作者 Apichaya Puangpetch Sissades Tongsima Pornpen Srisawasdi Abhasnee Sobhonslidsuk Somnuek Sungkanuparph Mohitosh Biswas Chonlaphat Sukasem 《World Journal of Hepatology》 2024年第3期366-378,共13页
BACKGROUND The prevalence of metabolic-associated fatty liver disease(MAFLD)is a growing public health issue in people living with human immunodeficiency virus(PLWH).However,the pathophysiology of MAFLD is still unkno... BACKGROUND The prevalence of metabolic-associated fatty liver disease(MAFLD)is a growing public health issue in people living with human immunodeficiency virus(PLWH).However,the pathophysiology of MAFLD is still unknown,and the role of genetic variables is only now becoming evident.AIM To evaluate the associations of gene-polymorphism-related MAFLD in PLWH.METHODS The study employed transient elastography with a controlled attenuation parameter≥248 dB/m to identify MAFLD in patients from a Super Tertiary Hospital in central Thailand.Candidate single-nucleotide polymorphisms(SNPs)were genotyped using TaqMan®MGB probe 5'nuclease assays for seven MAFLD-related genes.Statistical analyses included SNP frequency analysis,Fisher's Exact and Chi-square tests,odds ratio calculations,and multivariable logistic regression.RESULTS The G-allele carriers of PNPLA3(rs738409)exhibited a two-fold rise in MAFLD,increasing by 2.5 times in MAFLD with human immunodeficiency virus infection.The clinical features and genetic patterns imply that LEP rs7799039 A-allele carriers had a nine times(P=0.001)more significant chance of developing aberrant triglyceride among PLWH.CONCLUSION The current study shows an association between PNPLA3 rs738409 and LEP rs7799039 with MAFLD in PLWH. 展开更多
关键词 PNPLA3 LEP Metabolic-associated fatty liver disease People living with HIV THAI
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Antimicrobial activities of the rhizome extract of Zingiber zerumbet Linn 被引量:4
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作者 Golam Kader Farjana Nikkon +1 位作者 Mohammad Abdur Rashid Tanzima Yeasmin 《Asian Pacific Journal of Tropical Biomedicine》 SCIE CAS 2011年第5期409-412,共4页
Objective:To investigate antimicrobial effects of ethanolic extract of Zingiber zerumbet(Z.zerumbet)(L.)Smith and its chloroform and petroleum ether soluble fractions against pathogenic bacteria and fungi.Methods:The ... Objective:To investigate antimicrobial effects of ethanolic extract of Zingiber zerumbet(Z.zerumbet)(L.)Smith and its chloroform and petroleum ether soluble fractions against pathogenic bacteria and fungi.Methods:The fresh rhizomes of Zingiber zerumbet were extracted in cold with ethanol(4.0 L)after concentration.The crude ethanol extract was fractionated by petroleum ether and chloroform to form a suspension of ethanol extract(15.0 g),petroleum ether fraction(6.6 g)and chloroform soluble fraction(5.0 g).The crude ethanol extract and its petroleum ether and chloroform fractions were evaluated for antibacterial and antifungal activity against thirteen pathogenic bacteria and three fungi by the disc diffusion method.Commercially available kanamycin(30μg/disc)was used as standard disc and blank discs impregnated with the respective solvents were used as negative control.Results:At a concentration of 400μg/disc,all the samples showed mild to moderate antibacterial and antifungal activity and produced the zone of inhibition ranging from 6 mm to 10 mm.Among the tested samples,the crude ethanol extract showed the highest activity against Vibrio parahemolyticus(V.parahemolyticus).The minimum inhibitory concentration(MIC)of the crude ethanol extract and its fractions were within the value of 128-256μg/mL against two Gram positive and four Gram negative bacteria and all the samples showed the lowest MIC value against V.parahemolyticus(128μg/mL).Conclusions:It can be concluded that,potent antibacterial and antifungal phytochemicals are present in ethanol extract of Z.zerumbet(L.). 展开更多
关键词 Zingiberzerumbet(L.) Smith Antibacterial ANTIFUNGAL Minimum inhibitory concentration(MIC) Antimicrobial ACTIVITY RHIZOME ANTIFUNGAL ACTIVITY PHYTOCHEMICALS Disc diffusion method Soluble fraction PATHOGENIC bacteria
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Atmospheric pressure gliding arc discharge plasma treatments for improving germination, growth and yield of wheat 被引量:5
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作者 N C ROY M M HASAN +3 位作者 A H KABIR M A REZA M R TALUKDER A N CHOWDHURY 《Plasma Science and Technology》 SCIE EI CAS CSCD 2018年第11期90-100,共11页
Wheat (Triticum aestivum) seeds were treated with atmospheric pressure gliding arc discharge plasmas to investigate the effects on water absorption, seed germination rate, seedling growth and yield in wheat. The sur... Wheat (Triticum aestivum) seeds were treated with atmospheric pressure gliding arc discharge plasmas to investigate the effects on water absorption, seed germination rate, seedling growth and yield in wheat. The surface architectures and functionalities of the seeds were found to modify due to plasma treatments. 6 rain treatment was provided 95%-100% germination rate. For the treatment duration of 3 and 9 rain the growth activity, dry matter accumulation, leaves chlorophyll contents, longest spikes, number of spikes/spikelet and total soluble protein content in shoots were improved. The grain yield of wheat was increased ,--20% by 6 min treatment with H2O/O2 plasma with respect to control. 展开更多
关键词 atmospheric pressure gliding arc discharge plasmas WHEAT GERMINATION growth improvement total soluble protein
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Comparative investigation of the free radical scavenging potential and anticancer property of Diospyros blancoi(Ebenaceae) 被引量:4
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作者 Muhammad Ali Khan Mahbubur Rahman +6 位作者 Nazmul Sardar Saiful Islam Arman Badrul Islam Jahangir Alam Khandakar Mamunur Rashid Golam Sadik AHM Khurshid Alam 《Asian Pacific Journal of Tropical Biomedicine》 SCIE CAS 2016年第5期410-417,共8页
Objective: To investigate the comparative effects of Diospyros blancoi(Ebenaceae)leaves(DBL), root bark(DBRB) and stem bark(DBSB) on free radicals and cancer.Methods: The polyphenol contents, antioxidant and free radi... Objective: To investigate the comparative effects of Diospyros blancoi(Ebenaceae)leaves(DBL), root bark(DBRB) and stem bark(DBSB) on free radicals and cancer.Methods: The polyphenol contents, antioxidant and free radical scavenging properties were determined using standard spectrophotometric methods. Cytotoxicity and anticancer activities were performed on brine shrimp nauplii and Ehrlich ascite carcinoma cells, respectively.Results: Among the extracts, DBSB showed the highest total antioxidant capacity and reducing capacity on ferrous ion. Based on 1,1-diphenyl-2-picrylhydrazyl and hydroxyl radical scavenging activities, DBSB showed(95.760 ± 0.343)% and(67.460 ± 2.641)%scavenging with IC50of(3.10 ± 0.17) and(50.00 ± 3.11) mg/m L, respectively. The IC50 values of standard butylated hydroxytoluene and catechin(CA) for 1,1-diphenyl-2-picrylhydrazyl and hydroxyl radicals were(8.50 ± 0.25) and(75.00 ± 0.14) mg/m L,respectively suggesting that DBSB had a significant(P < 0.05) radical scavenging activity than standards. In lipid peroxidation inhibition assay, the inhibitory activity of the extracts and the standard was in the following order: DBSB > DBRB > CA > DBL.Also, the phenolic [(139.91 ± 3.924) mg gallic acid equivalent/g] and flavonoid contents[(412.00 ± 16.70) mg catechin equivalent/g)] of DBSB were higher than that of other extracts. In addition, the DBSB showed the moderate cytotoxic and anticancer properties.Conclusions: Our results indicate that Diospyros blancoi stem bark had the significant highest antioxidant and free radical scavenging properties as well as moderate anticancer activity.Hence, we assume that the anticancer activity of this plant can be, at least in part, attributed to its content in phenolic compounds as well as its significant free radical scavenging properties. 展开更多
关键词 DIOSPYROS blancoi Free RADICALS POLYPHENOLS Antioxidant CYTOTOXICITY ANTICANCER
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Comparative study of Mo2Ga2C with superconducting MAX phase Mo2GaC: First-principles calculations 被引量:4
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作者 M A Ali M R Khatun +1 位作者 NJahan M M Hossain 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第3期297-302,共6页
The structural, electronic, optical and thermodynamic properties of Mo2Ga2C are investigated using density func- tional theory (DFT) within the generalized gradient approximation (GGA). The optimized crystal struc... The structural, electronic, optical and thermodynamic properties of Mo2Ga2C are investigated using density func- tional theory (DFT) within the generalized gradient approximation (GGA). The optimized crystal structure is obtained and the lattice parameters are compared with available experimental data. The electronic density of states (DOS) is calculated and analyzed. The metallic behavior for the compound is confirmed and the value of DOS at Fermi level is 4.2 states per unit cell per eV. Technologically important optical parameters (e.g., dielectric function, refractive index, absorption coefficient, photo conductivity, reflectivity, and loss function) are calculated for the first time. The study of dielectric constant (ε1) indicates the Drude-like behavior. The absorption and conductivity spectra suggest that the compound is metallic. The reflectance spectrum shows that this compound has the potential to be used as a solar reflector. The thermodynamic properties such as the temperature and pressure dependent bulk modulus, Debye temperature, specific heats, and thermal expansion coefficient of Mo2Ga2C MAX phase are derived from the quasi-harmonic Debye model with phononic effect also for the first time. Analysis of Tc expression using available parameter values (DOS, Debye temperature, atomic mass, etc.) suggests that the compound is less likely to be superconductor. 展开更多
关键词 first-principles calculations density of states (DOS) optical properties thermodynamic properties
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Numerical storm surge model with higher order finite difference method of lines for the coast of Bangladesh 被引量:2
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作者 Gour Chandra Paul Md. Emran Ali 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2019年第6期100-116,共17页
In this study, the method of lines (MOLs) with higher order central difference approximation method coupled with the classical fourth order Runge-Kutta (RK(4,4)) method is used in solving shallow water equations (SWEs... In this study, the method of lines (MOLs) with higher order central difference approximation method coupled with the classical fourth order Runge-Kutta (RK(4,4)) method is used in solving shallow water equations (SWEs) in Cartesian coordinates to foresee water levels associated with a storm accurately along the coast of Bangladesh. In doing so, the partial derivatives of the SWEs with respect to the space variables were discretized with 5-point central difference, as a test case, to obtain a system of ordinary differential equations with time as an independent variable for every spatial grid point, which with initial conditions were solved by the RK(4,4) method. The complex land-sea interface and bottom topographic details were incorporated closely using nested schemes. The coastal and island boundaries were rectangularized through proper stair step representation, and the storing positions of the scalar and momentum variables were specified according to the rules of structured C-grid. A stable tidal regime was made over the model domain considering the effect of the major tidal constituent, M2 along the southern open boundary of the outermost parent scheme. The Meghna River fresh water discharge was taken into account for the inner most child scheme. To take into account the dynamic interaction of tide and surge, the generated tidal regime was introduced as the initial state of the sea, and the surge was then made to come over it through computer simulation. Numerical experiments were performed with the cyclone April 1991 to simulate water levels due to tide, surge, and their interaction at different stations along the coast of Bangladesh. Our computed results were found to compare reasonable well with the limited observed data obtained from Bangladesh Inland Water Transport Authority (BIWTA) and were found to be better in comparison with the results obtained through the regular finite difference method and the 3-point central difference MOLs coupled with the RK(4,4) method with regard to the root mean square error values. 展开更多
关键词 SHALLOW water equations METHOD of lines higher order finite difference approximation METHOD SURGE nested scheme
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Geochemical characteristics of Holocene sediments from Chuadanga district, Bangladesh: Implications for weathering, climate, redox conditions, provenance and tectonic setting 被引量:3
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作者 Ismail Hossain Krisna Kanta Roy +3 位作者 Pradip Kumar Biswas Mahbubul Alam Md. Moniruzzaman Farah Deeba 《Chinese Journal Of Geochemistry》 EI CAS CSCD 2014年第4期336-350,共15页
The present research deals with the geochemical characteristics of the Holocene sediments from Alamdanga area, Chuadanga district, Bangladesh. Main goals of the study are to delineate source rock characteristics, degr... The present research deals with the geochemical characteristics of the Holocene sediments from Alamdanga area, Chuadanga district, Bangladesh. Main goals of the study are to delineate source rock characteristics, degree of chemical weathering and sorting processes and behavior of redox conditions during deposition of the sediments. Geochemical characteristics of the sediments show comparatively a wide variation in accordance with stratigraphy in their major element contents(e.g. Si O2 69.46–82.13, Al2O3 2.28–8.88 in wt%), reflecting the distinctive provenance and in part an unstable period in terms of tectonic activity. Geochemical classification of the sediments shows mostly sub-arkose with few sub-litharenites. Some major and trace elements display comprehensible correlation with Al2O3 confirming their possible hydraulic fractionation. The chemical index of alteration(CIA*), W* index, index of compositional variability(ICV), plagioclase index of alteration(PIA*) values and the ratio of Si O2/Al2O3, suggest low degrees of chemical weathering in the source areas as well as immature to moderately mature the sediments. The sediments suggest semi-arid climatic trends within oxic deltaic depositional conditions during the Holocene, at 3–12 ka. Whole rock geochemistry and discrimination diagrams demonstrate the continental signature derivatives, which might have been derived from the felsic to intermediate igneous rocks(granitic plutonic rocks) as well as from quartzose sedimentary/metamorphic provenance. These typical sources are present in a vast region of the Himalayan belt and catchment areas of Ganges. The tectonic setting of the sediments demarcates typically passive margin with slightly continental arc system. 展开更多
关键词 地球化学特征 氧化还原条件 化学风化 沉积物 构造背景 孟加拉国 气候趋势 全新世
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Determination of volatile organic compounds in river water by solid phase extraction and gas chromatography 被引量:4
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作者 M.A.Mottaleb M.Z.Abedin M.S.Islam 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2004年第3期497-501,共5页
A simple, rapid, and reproducible method is described employing solid phase extraction(SPE) using dichloromethane followed by gas chromatography(GC) with flame ionization detection(FID) for determination of volatile ... A simple, rapid, and reproducible method is described employing solid phase extraction(SPE) using dichloromethane followed by gas chromatography(GC) with flame ionization detection(FID) for determination of volatile organic compound(VOC) from the Buriganga River water of Bangladesh. The method was applied to detect the benzene, toluene, ethylbenzene, xylene and cumene(BTEXC) in the sample collected from the surface or 15 cm depth of water. Two hundred ml of n hexane pretreated and filtered water samples were applied directly to a C 18 SPE column. BTEXC were extracted with dichloromethane and average concentrations were obtained as 0 104 to 0 372 μg/ml. The highest concentration of benzene was found as 0 372 μg/ml with a relative standard deviation(RSD) of 6 2%, and cumene was not detected. Factors influencing SPE e.g., adsorbent types, sample load volume, eluting solvent, headspace and temperatures, were investigated. A cartridge containing a C 18 adsorbent and using dichloromethane gave better performance for extraction of BTEXC from water. Average recoveries exceeding 90% could be achieved for cumene at 4℃ with a 2 7% RSD. 展开更多
关键词 solid phase extraction river water environmental analysis VOC recoveries
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In vivo anticancer activity of vanillin semicarbazone 被引量:2
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作者 Shaikh M Mohsin Ali M Abul Kalam Azad +5 位作者 Mele Jesmin Shamim Ahsan M Mijanur Rahman Jahan Ara Khanam M Nazrul Islam Sha M Shahan Shahriar 《Asian Pacific Journal of Tropical Biomedicine》 SCIE CAS 2012年第6期438-442,共5页
Objective:To evaluate the anticancer activity of vanillin semicarbazone(VSC) against Ehrlich ascites carcinoma(EAC) cells in Swiss albino mice.Methods:The compound VSC at three doses(5, 7.5 and 10 mg/kg i.p.) was admi... Objective:To evaluate the anticancer activity of vanillin semicarbazone(VSC) against Ehrlich ascites carcinoma(EAC) cells in Swiss albino mice.Methods:The compound VSC at three doses(5, 7.5 and 10 mg/kg i.p.) was administered into the intraperitoneal cavity of the EAC inoculated mice to observe its efficiency by studying the cell growth inhibition, reduction of tumour weight,enhancement of survival time as well as the changes in depleted hematological parameters. Allsuch parameters were also studied with a known standard drug bleomycin at the dose of 0.3 mg/kg(i.p.).Results:Among the doses studied, 10 mg/kg(i.p.) was found to be quite comparable in potency to that of bleomycin at the dose of 0.3 mg/kg(i.p.). The host toxic effects of VSC was found to be negligible.Conclusions:It can be concluded that VSC can therefore be considered as potent anticancer agent. 展开更多
关键词 ANTICANCER activity Ehrlich ASCITES CARCINOMA Schiffbase
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An Efficient Tide-Surge Interaction Model for the Coast of Bangladesh 被引量:2
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作者 M.Mizanur RAHMAN Gour Chandra PAUL Ashabul HOQUE 《China Ocean Engineering》 SCIE EI CSCD 2020年第1期56-68,共13页
The numerical method of lines(MOLs)in coordination with the classical fourth-order Runge Kutta(RK(4,4))method is used to solve shallow water equations(SWEs)for foreseeing water levels owing to the nonlinear interactio... The numerical method of lines(MOLs)in coordination with the classical fourth-order Runge Kutta(RK(4,4))method is used to solve shallow water equations(SWEs)for foreseeing water levels owing to the nonlinear interaction of tide and surge accompanying with a storm along the coast of Bangladesh.The SWEs are developed by extending the body forces with tide generating forces(TGFs).Spatial variables of the SWEs along with the boundary conditions are approximated by means of finite difference technique on an Arakawa C-grid to attain a system of ordinary differential equations(ODEs)of initial valued in time,which are being solved with the aid of the RK(4,4)method.Nested grid technique is adopted to solve coastal complexities closely with least computational cost.A stable tidal solution in the region of our choice is produced by applying the tidal forcing with the major tidal constituent M2(lunar semi-diurnal)along the southern open-sea boundary of the outer scheme.Numerical experimentations are carried out to simulate water levels generated by the cyclonic storm AILA along the coast of Bangladesh.The model simulated results are found to be in a reasonable agreement with the limited available reported data and observations. 展开更多
关键词 Bangladesh coast shallow water equations method of lines tide-surge interaction ISLANDS tide generating forces inverse barometer
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An Efficient Approach for Simulation of Water Levels due to the Nonlinear Interaction of Tide and Surge Along the Coast of Bangladesh 被引量:2
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作者 Gour Chandra Paul Sukumar Senthilkumar Rana Pria 《China Ocean Engineering》 SCIE EI CSCD 2020年第4期537-546,共10页
The ultimate goal and highlight of this paper are to explore water levels along the coast of Bangladesh efficiently due to the nonlinear interaction of tide and surge by employing the method of lines(MOLs)with the aid... The ultimate goal and highlight of this paper are to explore water levels along the coast of Bangladesh efficiently due to the nonlinear interaction of tide and surge by employing the method of lines(MOLs)with the aid of newly proposed RKAHeM(4,4)technique.In this regard,the spatial derivatives of shallow water equations(SWEs)were discretized by means of a finite difference method to obtain a system of ordinary differential equations(ODEs)of initial valued with time as an independent variable.The obtained system of ODEs was solved by the RKAHeM(4,4)technique.One-way nested grid technique was exercised to incorporate coastal complexities closely with minimum computational cost.A stable tidal oscillation was produced over the region of interest by applying the most influential tidal constituent M2 along the southern open boundary of the outer scheme.The newly developed model was applied to estimate water levels due to the non-linear interaction of tide and surge associated with the catastrophic cyclone April 1991 along the coast of Bangladesh.The approach employed in the study was found to perform well and ensure conformity with real-time observations. 展开更多
关键词 method of lines RKAHeM(4 4)technique error estimation storm surge nested grid
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Evaluation of Analgesic and Anti-Inflammatory Activities on Ethanolic Extract of <i>Terminalia chebula</i>Fruits in Experimental Animal Models 被引量:4
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作者 Md. Safkath Ibne Jami Zakia Sultana +2 位作者 Md. Ershad Ali Mst. Marium Begum Md. Mominul Haque 《American Journal of Plant Sciences》 2014年第1期63-69,共7页
The present study was undertaken to evaluate the analgesic and anti-inflammatory activities of ethanolic extract of Terminalia chebula (commonly known as Haritaki) fruits in experimental animal models. The study was c... The present study was undertaken to evaluate the analgesic and anti-inflammatory activities of ethanolic extract of Terminalia chebula (commonly known as Haritaki) fruits in experimental animal models. The study was carried out using Swiss Albino mice (20-25 g) and Long Evans rats (100-150 g) of either sex. The analgesic activity of Terminalia chebula was assessed by using hot plate method. For the determination of analgesic effect, doses of ethanolic extract of Terminalia chebula used in the present study were 250 mg/kg and 500 mg/kg body weight (BW). Anti-inflammatory effect was analyzed by carrageenan induced paw edema method with the administration dose of 300 mg/kg BW of animals. The analysis of experimental data was performed by statistical process of ANOVA to determine the variability of sample, while Dunnet’s test was performed for evaluation of comparative analgesic and anti-inflammatory activity of Terminalia chebula with control and standard. The animals were divided into four treatment groups of six animals each and the “Mean ± SEM” is the statistical identifiable value of the data and P values <0.05 was considered statistically significant. Hot plate test showed a significant increase in the mean reaction time to heat stimuli in hot plate method at both 250 mg/kg and 500 mg/kg BW doses throughout the observation period in 30 minutes and 60 minutes after treatment, which was comparable to the standard ketorolac and control group. In carrageenan induced paw edema method, considerable results were found after determining the percentage change in paw volume in extract. In both cases of analgesic and anti-inflammatory study, % inhibition of pain and inflammation were evaluated. Comparing with control, largest inhibition was found in inhibiting inflammation 5 hours after treatment, while the largest inhibition of pain was obtained in 30 minutes and 60 minutes after treatment of doses. The present study suggests that ethanolic extract of Terminalia chebula fruits has significant analgesic and anti-inflammatory activities. 展开更多
关键词 TERMINALIA chebula ANALGESIC Anti-Inflammatory Hot Plate CARRAGEENAN Induced PAW Edema
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Bioassay of Eucalyptus extracts for anticancer activity against Ehrlich ascites carcinoma(eac) cells in Swiss albino mice 被引量:1
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作者 Farhadul Islam Hasina Khatun +2 位作者 Soby Ghosh MM Ali JA Khanam 《Asian Pacific Journal of Tropical Biomedicine》 SCIE CAS 2012年第5期394-398,共5页
Objective:To evaluate the antineoplastic activity of Eucalyptus extract(EUE) against Ehrlich ascites carcinoma(EAC)in Swiss albino mice.Methods:Preliminary examination of four plant extracts(namely Eucalyptus,Costus,A... Objective:To evaluate the antineoplastic activity of Eucalyptus extract(EUE) against Ehrlich ascites carcinoma(EAC)in Swiss albino mice.Methods:Preliminary examination of four plant extracts(namely Eucalyptus,Costus,Azadirachla.Feroniai has been done by observing the reduction ability of number of EAC cells in previously inoculated Swiss alliino mice.Among them as EuE showed maximum capability,the whole study has been conducted with EuE only. Important parameters viz.enhancement of life span,reduction of average tumor weight etc.have been studied.In addition the effects of EuE on hematological parameters in both normal and EAC inoculated mice have been measured.Effect of EuE on normal peritoneal cells has also been studied.Results:EuE reduced tumor burden remarkably.It reduced the tumor growth rate and enhanced the life span of EAC bearing mice noticeably.It reversed back the hematological parameters towards normal,reduced the Irasplanlability of EAC cells and enhanced the immunomodulatory effects in mice.The host toxic effect of EuE in mice is minimum and mostly reversible with time.All such data have been compared with those obtained by running parallel experiments with bleomycin at dose 0.3 mg/kg(i.p.).Conclusions:The Eucalyptus extract may be considered as a potent anticancer agent for advanced researches. 展开更多
关键词 ANTINEOPLASTIC activity EUCALYPTUS extract Ehrlich ASCITES carcinoma CELLS SWISS ALBINO mice
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Hydrobiological variables as a regulatory factor on the abundance of heterotrophic flagellates in an urban pond 被引量:1
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作者 BEGUM Moni JEWEL Md.Abu Sayed +1 位作者 HAQUE Md.Ayenuddin KHATUN Mst.Samsad 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2019年第3期1030-1036,共7页
The seasonal abundance of flagellates has been monitored over a period of 1 year from December 2013 to November 2014(divided into 4 conjugative seasons namely winter,spring,summer,and autumn)in an experimental pond lo... The seasonal abundance of flagellates has been monitored over a period of 1 year from December 2013 to November 2014(divided into 4 conjugative seasons namely winter,spring,summer,and autumn)in an experimental pond located in Rajshahi City Corporation area,Bangladesh.To our knowledge,this study is the fi rst to shed light on the occurrence and possible interrelationships among heterotrophic flagellates(HF),bacteria and zooplankton in Bangladesh and the result obtained by this study will be beneficial for similar water ecosystem all over the world.Standard methods were used to determine the prescribed hydrological parameters and zooplankton cell density.Maximum HF abundance(14 346.00 cells/mL)was found in the spring and the minimum(5 215.00 cells/mL)occurred in the summer.Inverse to HF,significantly(P<0.05)higher zooplankton abundance was found during the winter(782.00±47.62 cells/mL)and the lowest value was found in the autumn(448.00±39.15 cells/mL).Whereas similar to the HF,total bacterial abundance was significantly higher during the spring((2.25±1.05)×10^5 cells/mL)and lower in the summer((0.79±0.06)×10^5 cells/mL).Multivariate analyses(ANOSIM and MDS)have shown significant seasonal differences for cell numbers where MDS ordination plot and cluster analysis based on similarity in the genera abundance of HF revealed overlapping condition between winter and spring.Canonical correspondence analysis(CCA)also showed a distinct separation among the genera based on the prevailing hydrological situation and indicated that temperature,pH,BOD5,and NO3^-were the most important environmental variables in determining the observed variation in HF community structure.Among the biological factors,zooplankton showed negative but total bacteria were positively correlated with HF abundance. 展开更多
关键词 HETEROTROPHIC FLAGELLATES ABUNDANCE hydrobiological factors URBAN POND
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