33 research outputs found
Conversion of lignocellulosic corn agro-waste into cellulose derivative and its potential application as pharmaceutical excipient
© 2020 by the authors. Lignocellulosic biomass is widely grown in many agricultural-based countries. These are typically incinerated or discarded in open spaces, which further may cause severe health and environmental problems. Hence, the proper utilization and conversion of different parts of lignocellulosic biomasses (e.g., corn wastes derived leave, cob, stalk, and husk) into value-added materials could be a promising way of protecting both health and environments. In addition, they have high-potential for myriads applications (e.g., pharmaceuticals, cosmetics, textiles, and so on). In this context, herein, we isolated holocellulose (a mixture of alpha α, beta β, and gamma γ cellulose) from corn waste, and then it was converted into carboxymethyl cellulose (CMC). Subsequently, the prepared CMC was evaluated successfully to be used as a pharmaceutical excipient. Different characterization tools were employed for structural, morphological, and thermal properties of the extracted holocellulose and synthesized CMC. Results showed that the highest yield of CMC was obtained 187.5% along with the highest degree of substitution (DS i.e., 1.83) in a single stage (i.e., size reduction technique) with the lowest particle size of holocellulose (100 μm). This happened due to the use of a single stage instead of multiple stages. Finally, extracted CMC was successfully used as a pharmaceutical excipient with promising results compared to commercially available pharmaceutical-grade CMC
Use of the analysis of the volatile faecal metabolome in screening for colorectal cancer
Diagnosis of colorectal cancer is an invasive and expensive colonoscopy, which is usually carried out after a positive screening test. Unfortunately, existing screening tests lack specificity and sensitivity, hence many unnecessary colonoscopies are performed. Here we report on a potential new screening test for colorectal cancer based on the analysis of volatile organic compounds (VOCs) in the headspace of faecal samples. Faecal samples were obtained from subjects who had a positive faecal occult blood sample (FOBT). Subjects subsequently had colonoscopies performed to classify them into low risk (non-cancer) and high risk (colorectal cancer) groups. Volatile organic compounds were analysed by selected ion flow tube mass spectrometry (SIFT-MS) and then data were analysed using both univariate and multivariate statistical methods. Ions most likely from hydrogen sulphide, dimethyl sulphide and dimethyl disulphide are statistically significantly higher in samples from high risk rather than low risk subjects. Results using multivariate methods show that the test gives a correct classification of 75% with 78% specificity and 72% sensitivity on FOBT positive samples, offering a potentially effective alternative to FOBT
The modified Lindstedt–Poincare method for solving quadratic nonlinear oscillators
Recently, an analytical solution of a quadratic nonlinear oscillator has been presented based on the harmonic balance method. By introducing a small parameter, a set of nonlinear algebraic equations have been solved which usually appear among unknown coefficients of several harmonic terms. But the method is not suitable for all quadratic oscillators. Earlier, introducing a small parameter to the frequency series, Cheung et al. modified the Lindstedt–Poincare method and used it to solve strong nonlinear oscillators including a quadratic oscillator. But due to some limitations of both parameters, a changed form of frequency-related parameter (introduced by Cheung et al.) has been presented for solving various quadratic oscillators. </jats:p
Physical and nutritional qualities of eggs and meats fed shrimp head meal to layer chicken
The experiment was conducted to investigate the effects of substitution of soybean meal of laying hens ration by shrimp head meal (SHM) on physical and nutritional quality of eggs and meats. Three hundred Hisex White laying hens were divided into five treatment groups and allocated five experimental diets included different levels of SHM. Soybean meal contents of control ration was substituted by SHM meal at the rate of 25, 50, 75 and 100%, respectively. Samples of SHM, eggs and meats were subjected to proximate analysis. Physical properties of eggs and meats were also analyzed following the standard procedures. Highest CP contents (%) of eggs were recorded to be 11.39±0.27 and 10.83±0.18 at initial and peak production periods, respectively in laying hens group fed ration substituted SBM by SHM at the rate of 25%. Significantly (p<0.001) highest value of redness (a*) of egg yolk was recorded to be 1.39 in laying hens group fed diet where SBM was completely substituted by SHM and lowest to be -3.11 in control group (no substitution) at initial production stage (18th to 20th week). Significantly (p=0.05) highest CP (%) contents of meats was found to be 19.37±0.36 in laying hens fed diets substituted SBM at the rate of 75% by SHM and lowest in complete substituted group. It can be concluded that substitution of soybean meal of laying hens ration at the rate of 25% by SHM is suitable for better egg and meat quality.
Bang. J. Anim. Sci. 2021. 50 (1):12-21</jats:p
Metal Complexes of Mixed Nucleobases. Part I: Synthesis and Characterization of Copper(II), Zinc(II), Cadmium(II) and Mercury(II) Complexes of Adenine and Uracil
The complexes of Cu(II), Zn(II), Cd(II) and Hg(II) with adenine (AdeH) and uracil (UraH) have been synthesized and characterized by a combination of metal contents estimation, IR, UV-vis spectral data, thermogravimetric analysis (QSTG, TG and DSC) and magnetic susceptibility measurement. All the complexes are micro-crystalline, slightly soluble in water and decompose at high temperature. Both adenine and uracil deprotonated under experimental condition and then ligated to the metal ions as bidentate ligands through N(3) and N(9) of adeninato (Ade), and through N(3) and C(2)=O of uracilato (Ura) anions. On the basis of the metal contents, the complexes are formulated as [M(C5H4N5O)(C5H4N5)(H2O)2] [M = Cu(II), Zn(II) and Hg(II)] and [Cd(C5H4N5)(C4H3N2O2)(H2O)2].2H2O. The redox properties of copper and cadmium complexes were examined in aqueous solution by cyclic voltammetry. The voltammograms show quasi-reversible behavior for both the complexes. The X-ray powder diffraction study of the copper complex indicates that it is poorly crystalline in nature.
Dhaka Univ. J. Sci. 64(2): 127-133, 2016 (July)</jats:p
Synthesis and Characterization of Mixed Ligand Complexes of Copper(II) with Adenine and Dicarboxylic Acids
Three mixed ligand complexes of copper(II) with adenine and dicarboxylic acids have been synthesized. The resulting complexes were characterized by their melting point, solubility, metal content analysis, FT-IR and UV-visible spectroscopy, magnetic measurement, thermal analysis, cyclic voltammetric measurement and X-ray powder diffraction study. The products are microcrystalline powder, slightly soluble in water and decompose at high temperature. Under experimental condition, the ligands adenine (Ade) behaves as a neutral ligand, whereas oxalic acid (OxH2), succinic acid (SucH2) and tartaric acid (TarH2) are doubly deprotonated to form dianionic ligands that are coordinated to the Cu(II) ion. The Cu(II) content analysis of the complexes confine to their stoichiometry [Cu(Ade)(L)(H2O)] (L = Ox, Suc, or Tar dianion). Electrochemical redox behavior of the complexes in their reaction medium was also examined. They exhibit quasi-reversible one-electron transfer processes.
Dhaka Univ. J. Sci. 69(2): 76-81, 2021 (July)</jats:p
Studies on the Physico-Chemical Properties of Siyal Kanta (<i>Argemone mexicana</i> linn) Seed Oil
The physico-chemical properties of the extracted oil were studied by the conventional methods. It was observed that Siyal Kanta grown under the soil and climatic condition of Bangladesh contains about 35% of pale yellow coloured oil. The total lipids were fractionated into three major lipid groups, neutral lipids, glycolipid and phospholipids by silicic acid column chromatography. Among the lipids, the neutral lipids were varied from 92.1-92.3%, glycolipid 5.5-5.8% and phospholipid 1.5-1.7% of the total oil of the lipid applied. The oil was also fractionated into mono-, di- and triglyceride by silicic acid column chromatography. The triglycerides were varied from 90.1-90.3%, diglycerides from 2.3-2.8% and monoglycerides from 1.5-1.8%. The saturated and unsaturated fatty acids present in the oil were separated and found to be 14.2-14.5% and 84.2-84.8% respectively depending on the areas in which the plant grows. The fatty acid compositions of the oil were analyzed by Gas Liquid Chromatography (GLC). The major fatty acids found in the oil were oleic acid (23%), linoleic acid (58%), palmetic acid (7%) and ricinoleic acid (10%). Key words: Siyal kanta seed oil; Glyceride; Lipid; Fatty acid. DOI: http://dx.doi.org/10.3329/bjsir.v46i4.9607 BJSIR 2011; 46(4): 561-564</jats:p
Optimization of alkali-thermostable and cellulase-free eylanase production from Bacillus Sp.
Context: To analyze the nutritional and physicochemical parameters for the production of alkali-thermostable and cellulase free xylanase from bacteria. Objectives: The aim of this study was to isolation and identification and of alkali-thermostable and cellulase free xylanase producing bacteria from soil as well as optimization of process parameters for xylanase production. Materials and Methods: The bacterium Bacillus sp. was isolated from soil by serial dilution technique on xylan agar medium and identified by morphological and biochemical studies. The production of xylanase was carried out on xylan broth medium and xylanase activity was assayed by dinitrosalicylic acid (DNS) method. The effect of cultural parameters on the production of xylanase was determined by measuring the activity of xylanase. The effect of temperature and pH on the activity of partially purified xylanase as well as substrate specificity of xylanase were examined. Results: The maximum xylanase production (4000 U/L) by a Bacillus sp. was attained when the medium containing 0.5% wheat bran xylan and peptone at pH 8.0 and 50-55°C within 48-60 h. The partially purified xylanase was optimally active at pH 9.0 and 55°C. The xylanase showed high substrate activity towards wheat bran xylan but no activity towards cellulose, carboxymethyl cellulose and starch. Thus the enzyme was alkali-thermostable and cellulase free xylanase. Conclusion: The results obtained in this study suggest that the Bacillus sp. used is highly potential and useful for the production of cellulase free xylanase. DOI: http://dx.doi.org/10.3329/jbs.v19i0.12994 J. bio-sci. 19: 7-14, 2011 </jats:p
Fatty acid composition of oil palm (<i>Elaeis guineensis</i> Jacq) fruits grown in Bangladesh
This study was undertaken to evaluate the fatty acid composition and other physicochemical properties of oil palm (Elaeis guineensis) fruits grown in Bangladesh and compared these values with crude palm oil (CPO) imported from Malaysia. Ripe and fresh oil palm (Elaeis guineensis) fruits were collected from different districts of Bangladesh and the crude oils were extracted by a screw press machine and was divided into three fractions: crude palm oil (CPO), degummed palm oil (DPO) and degummed bleached palm oil (DBPO). The percent yield, their physico-chemical characteristics, fatty acid composition, β-carotene, tocopherols and tocotrienols of the fractions were determined. Fatty acid composition and other physicochemical properties of Bangladeshi crude palm oil (CPO) were found to be more or less similar to the CPO imported from Malaysia.
Bangladesh J. Sci. Ind. Res.55(2), 153-158, 2020</jats:p
Effect of pH on the Electrochemical Redox Behavior of Co2+ in Acetate Buffer Solution
The electrochemical redox behavior of transition metal ion Co2+ at different pH in acetate buffer solution has been investigated using cyclic voltammetry and differential pulse voltammetry at glassy carbon electrode (GCE). In cyclic voltammograms (CVs), Co2+ shows a pair of cathodic and a pair of anodic peak. The peak potential separation and peak current ratio reveals that the redox process of the redox couples, Co2+/Co+ and Co+/Co followed a quasi-reversible behavior and are two step one-electron transfer processes. The electrochemical processes are diffusion controlled. The nature of CV of Co2+ has greatly influenced by the potential scan rate and solution pH. With increasing scan rate both cathodic peaks shifted towards negative potential and first cathodic peak was eventually diminished. In the reverse direction, unexpected behavior such as distinguishable second anodic peak, identical heights of two anodic peaks, three humps like peaks and finally domination of second anodic peak were noticed. However, in lower pH all the above mentioned behavior appeared with higher scan rate. While at higher pH of the solution the peculiar behavior was found at lower scan rate. Nevertheless, at pH 6.5, it demonstrated intense cathodic peaks and a very large anodic peak at all scan rates.
Dhaka Univ. J. Sci. 65(2): 107-112, 2017 (July)</jats:p
