Pub Date : 2022-01-27DOI: 10.3329/jbas.v45i2.57208
Z. I. Seraj, Sabrina Hque
The CRISPR system consists of a guide RNA (gRNA) complementary to a target editable DNA sequence and a CRISPR-associated endonuclease (Cas). The gRNA and Cas together form a ribonucleoprotein (RNP) complex. The gRNA guides the Cas enzyme to the precise site for cutting the target DNA. In bacteria, the gRNA leads the endonuclease to the viral DNA for destruction. This ingenious bacterial immune principle has been used to design gRNA to target an organism’s genome at precise locations for gene editing purposes. Gene edits may include deletion or insertion, repression or activation, base, and epigenome editing, or nucleotide replacement. Therefore the CRISPR-Cas system has created the potential for altering genomes of microbes, plants, and animals. The CRISPR-Cas system has now been developed for use in many applications like finding functions of genes, searching for drug targets, diagnostics, crop improvement, and gene therapy. J. Bangladesh Acad. Sci. 45(2); 131-145: December 2021
{"title":"Remodelling of a bacterial immune system as the simple gene editing tool, Crispr-Cas, for food security and human health","authors":"Z. I. Seraj, Sabrina Hque","doi":"10.3329/jbas.v45i2.57208","DOIUrl":"https://doi.org/10.3329/jbas.v45i2.57208","url":null,"abstract":"The CRISPR system consists of a guide RNA (gRNA) complementary to a target editable DNA sequence and a CRISPR-associated endonuclease (Cas). The gRNA and Cas together form a ribonucleoprotein (RNP) complex. The gRNA guides the Cas enzyme to the precise site for cutting the target DNA. In bacteria, the gRNA leads the endonuclease to the viral DNA for destruction. This ingenious bacterial immune principle has been used to design gRNA to target an organism’s genome at precise locations for gene editing purposes. Gene edits may include deletion or insertion, repression or activation, base, and epigenome editing, or nucleotide replacement. Therefore the CRISPR-Cas system has created the potential for altering genomes of microbes, plants, and animals. The CRISPR-Cas system has now been developed for use in many applications like finding functions of genes, searching for drug targets, diagnostics, crop improvement, and gene therapy.\u0000J. Bangladesh Acad. Sci. 45(2); 131-145: December 2021","PeriodicalId":15109,"journal":{"name":"Journal of Bangladesh Academy of Sciences","volume":"43 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81035977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-27DOI: 10.3329/jbas.v45i2.57205
Mesbahuddin Ahmed
Abstract not available J. Bangladesh Acad. Sci. 45(2): December 2021
[j] .科学学报，45(2):2021年12月
{"title":"Late Professor Dr.Harun or Rashid (1933-2021)","authors":"Mesbahuddin Ahmed","doi":"10.3329/jbas.v45i2.57205","DOIUrl":"https://doi.org/10.3329/jbas.v45i2.57205","url":null,"abstract":"Abstract not available \u0000J. Bangladesh Acad. Sci. 45(2): December 2021","PeriodicalId":15109,"journal":{"name":"Journal of Bangladesh Academy of Sciences","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75430156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-26DOI: 10.3329/jbas.v45i2.57321
Abdullah Al Kafi Majumdar
This paper derives the conditions under which the sum of squares of (2N+1) natural numbers in the arithmetic progression is a perfect square. It is shown that the problem leads to a Diophantine equation, which in turn indicates that there is, in fact, an infinite number of such numbers. Some particular cases are investigated. J. Bangladesh Acad. Sci. 45(2); 241-250: December 2021
{"title":"On a sum of squares of integers in arithmetic progression","authors":"Abdullah Al Kafi Majumdar","doi":"10.3329/jbas.v45i2.57321","DOIUrl":"https://doi.org/10.3329/jbas.v45i2.57321","url":null,"abstract":"This paper derives the conditions under which the sum of squares of (2N+1) natural numbers in the arithmetic progression is a perfect square. It is shown that the problem leads to a Diophantine equation, which in turn indicates that there is, in fact, an infinite number of such numbers. Some particular cases are investigated.\u0000J. Bangladesh Acad. Sci. 45(2); 241-250: December 2021","PeriodicalId":15109,"journal":{"name":"Journal of Bangladesh Academy of Sciences","volume":"39 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73255937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-26DOI: 10.3329/jbas.v45i2.57212
M. Alauddin
Effects of solvents and temperature on the structural, thermodynamic, and electronic properties of L-configuration of N-acetyl-phenylalaninyl amide (NAPA) were studied using density functional theory (DFT) and time-dependent density functional theory (TD-DFT) approach. Enthalpy (H), entropy (S) and specific heat capacity (Cv) were found to increase with the increase of temperature (100 K-1600 K) because of the increasing intensities of molecular vibration. On the contrary, Gibb’s free energy (G) was found to decrease with the increase of temperature. The UV-light absorption maximum, λmax, is red-shifted in the presence of polar protic, aprotic and non-polar solvents. On the other hand, calculation shows that dipole moment in polar solvents (protic and aprotic), non-polar solvents, and the gas phase are ~3.35, ~3.0, and 2.5 D, respectively. However, no significant change was found in the HOMO-LUMO energy gap in the presence of different types of solvents. J. Bangladesh Acad. Sci. 45(2); 205-215: December 2021
采用密度泛函理论(DFT)和时间相关密度泛函理论(TD-DFT)方法研究了溶剂和温度对n -乙酰基苯丙酰胺(NAPA) l-构型结构、热力学和电子性质的影响。热焓(H)、熵(S)和比热容(Cv)随着温度(100 K ~ 1600 K)的升高而增大，这是由于分子振动强度的增大。相反，吉布自由能(G)随着温度的升高而减小。紫外吸收最大值λmax在极性质子溶剂、非质子溶剂和非极性溶剂存在下发生红移。另一方面，计算表明极性溶剂(质子溶剂和非质子溶剂)、非极性溶剂和气相中的偶极矩分别为~3.35、~3.0和2.5 D。而在不同类型溶剂的存在下，HOMO-LUMO能隙没有明显变化。科学通报，2011 (2);205-215: 2021年12月
{"title":"Effect of solvents and temperature on the structural, thermodynamic and electronic properties of capped phenylalanine: A computational study","authors":"M. Alauddin","doi":"10.3329/jbas.v45i2.57212","DOIUrl":"https://doi.org/10.3329/jbas.v45i2.57212","url":null,"abstract":"Effects of solvents and temperature on the structural, thermodynamic, and electronic properties of L-configuration of N-acetyl-phenylalaninyl amide (NAPA) were studied using density functional theory (DFT) and time-dependent density functional theory (TD-DFT) approach. Enthalpy (H), entropy (S) and specific heat capacity (Cv) were found to increase with the increase of temperature (100 K-1600 K) because of the increasing intensities of molecular vibration. On the contrary, Gibb’s free energy (G) was found to decrease with the increase of temperature. The UV-light absorption maximum, λmax, is red-shifted in the presence of polar protic, aprotic and non-polar solvents. On the other hand, calculation shows that dipole moment in polar solvents (protic and aprotic), non-polar solvents, and the gas phase are ~3.35, ~3.0, and 2.5 D, respectively. However, no significant change was found in the HOMO-LUMO energy gap in the presence of different types of solvents.\u0000J. Bangladesh Acad. Sci. 45(2); 205-215: December 2021","PeriodicalId":15109,"journal":{"name":"Journal of Bangladesh Academy of Sciences","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80980083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-26DOI: 10.3329/jbas.v45i2.56023
M. Shahjahan, Sagar Chandra Roy, Md Jafrul Sadique
The Heusler type compounds (A2-x-yZy)MnZ (A = Ni, Pd, Pt; Z = Sb, Sn; x = 1, 0; and y = 0, antisite defects of Z atoms) are investigated to understand the induced magnetic properties. The structural phases C1b type half Heusler (x = 1, y = 0) compounds AMnZ and the corresponding L21 type full Heusler (x = y = 0) compounds A2MnZ and some disordered compounds (A1-yZy)MnZ and (A2-yZy)MnZ (y = 0.01, 0.05) were calculated using the Korringa-Kohn-Rostoker Green’s function method. The antisite doping of 1% (5%) Sb retained (suppressed) the half metallicity at (Ni1-ySby)MnSb, whereas the other compounds were found to be gapless in both spin directions. The density of states at the Fermi level exhibits the explicit spin polarization in the compounds. The net magnetic moments of the compounds are closer in their values, wherein the manganese atom is responsible for the major contribution to the magnetic moments, which is much larger than the partial moment of the other constituents. The Curie temperature (TC) of the ordered ferromagnetic compounds was estimated using the mean-field approximation. The TC higher than the room temperature was found for the ordered compounds, except for the cases of Pt2MnSb and Pt2MnSn. No literature value of TC has been reported yet for these two compounds. Calculated spin moments and TC agree well with the experimental results, where available. J. Bangladesh Acad. Sci. 45(2); 217-229: December 2021
Heusler型化合物(A2-x-yZy)MnZ (A = Ni, Pd, Pt;Z = Sb, Sn;X = 1,0;和y = 0 (Z原子的对位缺陷)，以了解感应磁性能。采用Korringa-Kohn-Rostoker Green 's function法计算结构相C1b型半Heusler (x = 1, y = 0)化合物AMnZ和相应的L21型全Heusler (x = y = 0)化合物A2MnZ和部分无序化合物(A1-yZy)MnZ和(A2-yZy)MnZ (y = 0.01, 0.05)。1% (5%) Sb的反位掺杂保留(抑制)了(Ni1-ySby)MnSb的半金属丰度，而其他化合物在两个自旋方向上都是无间隙的。化合物在费米能级上的态密度表现出明显的自旋极化。化合物的净磁矩值更接近，其中锰原子对磁矩的主要贡献，比其他成分的部分力矩大得多。用平均场近似法估计了有序铁磁化合物的居里温度。除Pt2MnSb和Pt2MnSn外，其余有序化合物的TC均高于室温。目前尚无文献报道这两种化合物的TC值。计算得到的自旋矩和TC与实验结果吻合较好。科学通报，2011 (2);217-229: 2021年12月
{"title":"A Comparative Study of Spin Magnetic Moment, Spin Polarization and Curie Temperature of Heusler type Compounds (A2-X-YZy)Mnz (A = Ni, Pd, Pt And Z = Sb, Sn)","authors":"M. Shahjahan, Sagar Chandra Roy, Md Jafrul Sadique","doi":"10.3329/jbas.v45i2.56023","DOIUrl":"https://doi.org/10.3329/jbas.v45i2.56023","url":null,"abstract":"The Heusler type compounds (A2-x-yZy)MnZ (A = Ni, Pd, Pt; Z = Sb, Sn; x = 1, 0; and y = 0, antisite defects of Z atoms) are investigated to understand the induced magnetic properties. The structural phases C1b type half Heusler (x = 1, y = 0) compounds AMnZ and the corresponding L21 type full Heusler (x = y = 0) compounds A2MnZ and some disordered compounds (A1-yZy)MnZ and (A2-yZy)MnZ (y = 0.01, 0.05) were calculated using the Korringa-Kohn-Rostoker Green’s function method. The antisite doping of 1% (5%) Sb retained (suppressed) the half metallicity at (Ni1-ySby)MnSb, whereas the other compounds were found to be gapless in both spin directions. The density of states at the Fermi level exhibits the explicit spin polarization in the compounds. The net magnetic moments of the compounds are closer in their values, wherein the manganese atom is responsible for the major contribution to the magnetic moments, which is much larger than the partial moment of the other constituents. The Curie temperature (TC) of the ordered ferromagnetic compounds was estimated using the mean-field approximation. The TC higher than the room temperature was found for the ordered compounds, except for the cases of Pt2MnSb and Pt2MnSn. No literature value of TC has been reported yet for these two compounds. Calculated spin moments and TC agree well with the experimental results, where available.\u0000J. Bangladesh Acad. Sci. 45(2); 217-229: December 2021","PeriodicalId":15109,"journal":{"name":"Journal of Bangladesh Academy of Sciences","volume":"328 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76640757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-26DOI: 10.3329/jbas.v45i2.57209
M. Hossain, S. Nahar, Mesbahuddin Ahmad, K. Saha
Five long-chain hydrocarbons and a new brominated nitrogenous terpenoid were isolated from the acidic and basic fraction respectively of an ethanol extract of the male flowers of Carica Papaya for the first time. It was collected from Bangladesh Agriculture Development Corporation, Gazipur. J. Bangladesh Acad. Sci. 45(2); 181-186: December 2021
{"title":"Chemical investigation on the male flowers of Carica Papaya using acid-base separation process","authors":"M. Hossain, S. Nahar, Mesbahuddin Ahmad, K. Saha","doi":"10.3329/jbas.v45i2.57209","DOIUrl":"https://doi.org/10.3329/jbas.v45i2.57209","url":null,"abstract":"Five long-chain hydrocarbons and a new brominated nitrogenous terpenoid were isolated from the acidic and basic fraction respectively of an ethanol extract of the male flowers of Carica Papaya for the first time. It was collected from Bangladesh Agriculture Development Corporation, Gazipur.\u0000J. Bangladesh Acad. Sci. 45(2); 181-186: December 2021","PeriodicalId":15109,"journal":{"name":"Journal of Bangladesh Academy of Sciences","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73781243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-26DOI: 10.3329/jbas.v45i2.57213
Najira Akter, M. A. Haque, Md Fazlul Hoque
An experiment was conducted with three levels of salinity (0, 60, and 120 mM NaCl) and four levels of silicon (0, 5, 10, and 20 mM) in petridish. All the growth parameters were decreased gradually with increasing salt concentration, whereas increasing silicon concentration progressively increased the parameters up to 10 mM Si across all the salt concentrations. The beneficial role of Si was noticed both in saline and non-saline conditions. Silicon application in the growth medium dramatically reduced shoot Na content, making plants tolerant to salt stress. J. Bangladesh Acad. Sci. 45(2); 251-253: December 2021
实验采用3种盐度水平(0、60和120 mM NaCl)和4种硅含量水平(0、5、10和20 mM)的培养皿进行。随着盐浓度的增加，所有生长参数都逐渐降低，而随着硅浓度的增加，所有盐浓度下的生长参数都逐渐增加，直至10 mM Si。在盐水和非盐水条件下，Si的有益作用都得到了注意。在生长培养基中添加硅可显著降低植株茎部钠含量，使植株对盐胁迫具有耐性。科学通报，2011 (2);251-253: 2021年12月
{"title":"Improvement of growth of maize by application of silicon through its suppressing effect on sodium uptake under salt stress condition","authors":"Najira Akter, M. A. Haque, Md Fazlul Hoque","doi":"10.3329/jbas.v45i2.57213","DOIUrl":"https://doi.org/10.3329/jbas.v45i2.57213","url":null,"abstract":"An experiment was conducted with three levels of salinity (0, 60, and 120 mM NaCl) and four levels of silicon (0, 5, 10, and 20 mM) in petridish. All the growth parameters were decreased gradually with increasing salt concentration, whereas increasing silicon concentration progressively increased the parameters up to 10 mM Si across all the salt concentrations. The beneficial role of Si was noticed both in saline and non-saline conditions. Silicon application in the growth medium dramatically reduced shoot Na content, making plants tolerant to salt stress.\u0000J. Bangladesh Acad. Sci. 45(2); 251-253: December 2021","PeriodicalId":15109,"journal":{"name":"Journal of Bangladesh Academy of Sciences","volume":"1217 43","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91457216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-26DOI: 10.3329/jbas.v45i2.57211
S. A. Sultana, M. A. Rahman
The 209Bi(p,d) 208Bi reaction has been studied with 42 MeV protons. The laboratory angles are 25°, 30°, and 35°. Energy spectra have been calculated theoretically as an incoherent sum of many shell-orbits constituents based on the Distorted-Wave Born Approximation (DWBA). An asymmetric Lorentzian form strength response function having energy-dependent spreading width is adopted in this analysis. The calculated deuteron energy spectrum is reasonably well reproduced in the direct reaction region. The agreement between the experiment and the calculated double differentials cross-sections up to all experimental points is reasonable and satisfactory, thereby yielding confidence in the theoretical models used. J. Bangladesh Acad. Sci. 45(2); 197-203: December 2021
{"title":"Study of (P, D) Reaction on 209Bi at 42 Mev","authors":"S. A. Sultana, M. A. Rahman","doi":"10.3329/jbas.v45i2.57211","DOIUrl":"https://doi.org/10.3329/jbas.v45i2.57211","url":null,"abstract":"The 209Bi(p,d) 208Bi reaction has been studied with 42 MeV protons. The laboratory angles are 25°, 30°, and 35°. Energy spectra have been calculated theoretically as an incoherent sum of many shell-orbits constituents based on the Distorted-Wave Born Approximation (DWBA). An asymmetric Lorentzian form strength response function having energy-dependent spreading width is adopted in this analysis. The calculated deuteron energy spectrum is reasonably well reproduced in the direct reaction region. The agreement between the experiment and the calculated double differentials cross-sections up to all experimental points is reasonable and satisfactory, thereby yielding confidence in the theoretical models used.\u0000J. Bangladesh Acad. Sci. 45(2); 197-203: December 2021","PeriodicalId":15109,"journal":{"name":"Journal of Bangladesh Academy of Sciences","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75079072","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-26DOI: 10.3329/jbas.v45i2.57210
A. Sultana, M. Shoeb, M. I. R. Mamun, Nilufar Nahar
Identification and quantification of aflatoxins; B1, B2, G1, and G2 in twenty different rice samples were done by high-performance liquid chromatography coupled with a fluorescence detector. The rice samples were extracted with aqueous methanol and the extract was purified by immunoaffinity column by following the officially recognized ISO 16050 method. A post column derivatization device (Kobra cell) was used to make Bromo-derivative of the aflatoxins. The method for analysis of aflatoxins in the rice sample was validated in terms of selectivity, linearity, sensitivity, and recovery. Calibration curves were linear with a coefficient of variation r2 ≥ 0.9998, 09997, 0.9956, and 0.9969 for B1, B2, G1, and G2, respectively. The limit of detection (LOD) was 0.009, 0.006, 0.039, and 0.025 μg kg-1 and the limit of quantification (LOQ) was 0.025, 0.018, 0.116 and 0.075 μg kg-1 for B1, B2, G1, and G2, respectively. Recoveries (n=4) were carried out at two different spiking concentrations (1.39 and 2.77 μg kg-1 for B1, 0.49 and 0.98 μg kg-1 for B2, 1.56 and 3.12 μg kg-1 for G1 and 0.51 and 1.01 μg kg-1 for G2) and were ranged from 56.71±1.60-70.37±5.59%, 57.71±0.58-75.36±6.77%, 65.53±0.73-72.85±5.93% and 65.83±2.92-99.20±3.16% for B1, B2, G1, and G2, respectively. Aflatoxin B1, B2, G1, and G2 in rice samples were found to be present at 70, 60, 40, and 10%, respectively. The total aflatoxins (B1, B2, G1, and G2) in the rice samples were found to be in the range of trace- 3.54 μg kg-1. The results revealed that 18 out of 20 samples contained the detectable number of aflatoxins. The total aflatoxins content was found to be below the tolerance level (4 μg kg-1) according to the European Union (EU). So, the rice samples were safe for consumption, but the major concern is that a large population, especially in rural areas, consumes rice three times a day. If the rice sample contained aflatoxins even, below the present tolerance limit, there is a possibility of bad health implications from the consumption. J. Bangladesh Acad. Sci. 45(2); 187-196: December 2021
{"title":"Analysis of aflatoxins; B1, B2, G1, and G2 in some rice samples of Bangladesh","authors":"A. Sultana, M. Shoeb, M. I. R. Mamun, Nilufar Nahar","doi":"10.3329/jbas.v45i2.57210","DOIUrl":"https://doi.org/10.3329/jbas.v45i2.57210","url":null,"abstract":"Identification and quantification of aflatoxins; B1, B2, G1, and G2 in twenty different rice samples were done by high-performance liquid chromatography coupled with a fluorescence detector. The rice samples were extracted with aqueous methanol and the extract was purified by immunoaffinity column by following the officially recognized ISO 16050 method. A post column derivatization device (Kobra cell) was used to make Bromo-derivative of the aflatoxins. The method for analysis of aflatoxins in the rice sample was validated in terms of selectivity, linearity, sensitivity, and recovery. Calibration curves were linear with a coefficient of variation r2 ≥ 0.9998, 09997, 0.9956, and 0.9969 for B1, B2, G1, and G2, respectively. The limit of detection (LOD) was 0.009, 0.006, 0.039, and 0.025 μg kg-1 and the limit of quantification (LOQ) was 0.025, 0.018, 0.116 and 0.075 μg kg-1 for B1, B2, G1, and G2, respectively. Recoveries (n=4) were carried out at two different spiking concentrations (1.39 and 2.77 μg kg-1 for B1, 0.49 and 0.98 μg kg-1 for B2, 1.56 and 3.12 μg kg-1 for G1 and 0.51 and 1.01 μg kg-1 for G2) and were ranged from 56.71±1.60-70.37±5.59%, 57.71±0.58-75.36±6.77%, 65.53±0.73-72.85±5.93% and 65.83±2.92-99.20±3.16% for B1, B2, G1, and G2, respectively. Aflatoxin B1, B2, G1, and G2 in rice samples were found to be present at 70, 60, 40, and 10%, respectively. The total aflatoxins (B1, B2, G1, and G2) in the rice samples were found to be in the range of trace- 3.54 μg kg-1. The results revealed that 18 out of 20 samples contained the detectable number of aflatoxins. The total aflatoxins content was found to be below the tolerance level (4 μg kg-1) according to the European Union (EU). So, the rice samples were safe for consumption, but the major concern is that a large population, especially in rural areas, consumes rice three times a day. If the rice sample contained aflatoxins even, below the present tolerance limit, there is a possibility of bad health implications from the consumption.\u0000J. Bangladesh Acad. Sci. 45(2); 187-196: December 2021","PeriodicalId":15109,"journal":{"name":"Journal of Bangladesh Academy of Sciences","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88674536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-26DOI: 10.3329/jbas.v45i2.57320
Abdullah Al Kafi Majumdar, Abul Kalam Ziauddin Ahmed
The Sandor-Smarandache function, denoted by SS(n), is a recently posed Smarandache-type arithmetic function. This paper concentrates on the function SS(210m), where m ( ≥1) is an integer. At the end of the paper, a table giving values of SS(210m) for m = 1(1)100, calculated on a computer, is appended. J. Bangladesh Acad. Sci. 45(2); 255-258: December 2021
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