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Spectrophotometric estimation

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https://www.readbyqxmd.com/read/28443587/role-of-trace-elements-for-oxidative-status-and-quality-of-human-sperm
#1
Galina Nenkova, Lubomir Petrov, Albena Alexandrova
BACKGROUND: Oxidative stress affects negatively the sperm quality. For maintaining the pro/antioxidative balance, some metal ions (e.g. copper, zinc, iron, selenium), which are co-factors of the antioxidant enzymes, are essential. However, iron and copper could act as prooxidants inducing oxidative damage of spermatozoa. AIMS: This study aims to reveal a possible correlation between the concentrations of some metal ions (iron, copper, zinc, and selenium) in human seminal plasma, oxidative stress, assessed by malondialdehyde (MDA) and total glutathione (tGSH) levels, and semen quality, assessed by the parameters count, motility, and morphology...
April 6, 2017: Balkan Medical Journal
https://www.readbyqxmd.com/read/28423063/vitamin-d-status-and-its-association-with-insulin-resistance-among-type-2-diabetics-a-case-control-study-in-ghana
#2
Linda Ahenkorah Fondjo, William K B A Owiredu, Samuel Asamoah Sakyi, Edwin Ferguson Laing, Michael Acquaye Adotey-Kwofie, Enoch Odame Antoh, Eric Detoh
BACKGROUND: Vitamin D plays a major role in physiological processes that modulate mineral metabolism and immune function with probable link to several chronic and infectious conditions. Emerging data suggests a possible influence of vitamin D on glucose homeostasis. This study sought to provide preliminary information on vitamin D status among Ghanaian type 2 diabetics and assessed its association with glucose homeostasis. METHODS: In a case control study, 118 clinically diagnosed Type 2 Diabetes Mellitus (T2DM) patients attending Diabetic Clinic at the Nkawie Government Hospital were enrolled between October and December 2015...
2017: PloS One
https://www.readbyqxmd.com/read/28414560/aloe-arborescens-polysaccharides-in-vitro-immunomodulation-and-potential-cytotoxic-activity
#3
Jilan A Nazeam, Haidy A Gad, Ahmed Esmat, Hala M El-Hefnawy, Abdel-Naser B Singab
Different polysaccharides were isolated from the leaves of Aloe arborescens using the gradient power of hydrogen followed by antitumor and immunomodulatory assay. The total polysaccharide content of different fractions, water-soluble polysaccharide (WAP), acid-soluble polysaccharide (ACP), and alkaline-soluble polysaccharide (ALP), was estimated using a phenol-sulfuric acid spectrophotometric method. WAP possessed a higher content of mannose and glucose than either ACP or ALP. In vitro antitumor activity was investigated in three different cancer cell lines, and in vitro immunomodulatory potential was assessed through phagocytosis and lymphocyte transformation assay...
April 17, 2017: Journal of Medicinal Food
https://www.readbyqxmd.com/read/28407934/organophosphorus-pesticides-determination-by-novel-hplc-and-spectrophotometric-method
#4
Dave Harshit, Kothari Charmy, Patel Nrupesh
The present work describes a novel HPLC and UV-spectrophotometric method for the simultaneous estimation of chlorpyrifos and prophenofos in vegetables and fruits. In UV method, the absorbance of chlorpyrifos and prophenofos was measured at wavelength 277nm and 289nm respectively and quantitation was carried out by first order derivative method. The calibration curve for chlorpyriphos and prophenofos was found to be linear in the range of 6-16μg/mL with correlation coefficient 0.9979 and 0.9993 respectively...
September 1, 2017: Food Chemistry
https://www.readbyqxmd.com/read/28377238/characterization-of-the-interaction-of-glycyrrhizin-and-glycyrrhetinic-acid-with-bovine-serum-albumin-by-spectrophotometric-gradient-flow-injection-titration-technique-and-molecular-modeling-simulations
#5
Firouzeh Manouchehri, Yahya Izadmanesh, Jahan B Ghasemi
In this research, the interactions of glycyrrhizin (GL) and glycyrrhetinic acid (GA) with bovine serum albumin (BSA) have been investigated by the novel method of spectrophotometric- gradient flow injection titration technique. The hard-modeling multivariate approach to binding was used for calculation of binding constants and estimation of concentration-spectral profiles of equilibrium species. The stoichiometric ratio of binding was estimated using eigenvalue analysis. Results showed that GL and GA bind BSA with overall binding constants of KGL-BSA=3...
April 1, 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/28376720/dynamic-changes-of-paraoxonase-1-activity-towards-paroxon-and-phenyl-acetate-during-coronary-artery-surgery
#6
Anna Wysocka, Marek Cybulski, Henryk Berbeć, Andrzej Wysokiński, Janusz Stążka, Jadwiga Daniluk, Tomasz Zapolski
BACKGROUND: Serum paraoxonase 1 (PON1), an enzyme associated with high - density lipoproteins (HDL) particles, inhibits the oxidation of serum lipoproteins and cell membranes. PON1 activity is lower in patients with atherosclerosis and in inflammatory diseases. The systemic inflammatory response provoked during cardiopulmonary bypass grafting may contribute to the development of postoperative complications. The aim of the present study was to estimate the dynamic changes in paraoxonase 1 (PON1) activity towards paraoxon and phenyl acetate during and after coronary artery surgery...
April 4, 2017: BMC Cardiovascular Disorders
https://www.readbyqxmd.com/read/28363541/estimation-of-uronic-acids-using-diverse-approaches-and-monosaccharide-composition-of-alkali-soluble-polysaccharide-from-vitex-negundo-linn
#7
Pradeep Kumar, Vineet Kumar
Vitex negundo L. is one of the most important species in traditional system of medicine to cure various ailments. Alkali soluble polysaccharide (ASP) from V. negundo stems was isolated and purified in 0.61% yield. Complete hydrolysis of ASP followed by paper chromatography and GLC analysis indicated the presence of l-rhamnose, l-arabinose, d-xylose, d-galactose and d-glucose in mole percent of 1.28, 2.25, 73.49, 8.08, 8.11 along with 2.48 d-galacturonic acid and 4.27 d-glucuronic acid. Uronic acids were also estimated by spectrophotometric methods using carbazole, m-hydroxydiphenyl and 3, 5-dimethyl phenol (DMP) as colorimetric reagents...
June 1, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28341986/enhancing-effectiveness-of-capillary-electrophoresis-as-an-analytical-tool-in-the-supramolecular-acidity-modification
#8
Paweł Mateusz Nowak, Michał Woźniakiewicz, Magdalena Janus, Paweł Kościelniak
A strategic modification of acidity (pK a values) by the non-covalent host-guest interactions is one of the most promising concepts in current supramolecular chemistry. This work is aimed at enhancing the effectiveness of capillary electrophoresis (CE) in determination of pK a shifts caused by such interactions and their thermal dependencies crucial in a deep thermodynamic description. We show how to (i) minimize the systematic errors related to Joule heating, (ii) minimize the influence of a voltage ramp time, (iii) speed up pK a shift identification and estimation, (iv) interpret thermal effects related to two overlapped dynamic equilibria, and (v) determine pK a shifts by an alternative spectrophotometric method (CE-DAD)...
March 24, 2017: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/28317713/a-validated-fast-difference-spectrophotometric-method-for-5-hydroxymethyl-2-furfural-hmf-determination-in-corn-syrups
#9
Jucimara Kulek de Andrade, Camila Kulek de Andrade, Emy Komatsu, Hélène Perreault, Yohandra Reyes Torres, Marcos Roberto da Rosa, Maria Lurdes Felsner
Corn syrups, important ingredients used in food and beverage industries, often contain high levels of 5-hydroxymethyl-2-furfural (HMF), a toxic contaminant. In this work, an in house validation of a difference spectrophotometric method for HMF analysis in corn syrups was developed using sophisticated statistical tools by the first time. The methodology showed excellent analytical performance with good selectivity, linearity (R(2)=99.9%, r>0.99), accuracy and low limits (LOD=0.10mgL(-1) and LOQ=0.34mgL(-1))...
August 1, 2017: Food Chemistry
https://www.readbyqxmd.com/read/28315620/3-e-acridin-9-ylmethylidene-amino-1-substituted-thioureas-and-their-biological-activity
#10
Michal Bečka, Mária Vilková, Othman Salem, Jana Kašpárková, Viktor Brabec, Mária Kožurková
This paper describes the synthesis of a novel series of acridine thiosemicarbazones through a two-step reaction between various isothiocyanates and hydrazine followed by treatment with acridin-9-carbaldehyde. The properties of this series of seven new derivatives are studied using NMR and biochemical techniques, and the DNA-binding properties of the compounds are determined using spectrophotometric studies (UV-vis absorption, fluorescence, and circular/linear dichroism) and viscometry. The binding constants K are estimated as being in the range of 2...
March 8, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28303123/trichoderma-asperellum-t42-and-pseudomonas-fluorescens-okc-enhances-resistance-of-pea-against-erysiphe-pisi-through-enhanced-ros-generation-and-lignifications
#11
Jai S Patel, Ravindra N Kharwar, Harikesh B Singh, Ram S Upadhyay, Birinchi K Sarma
Plant signaling mechanisms are not completely understood in plant-fungal biotrophic pathogen interactions. Further how such interactions are influenced by compatible rhizosphere microbes are also not well-studied. Therefore, we explored the pea-Erysiphe pisi (obligate biotroph) system to understand the interaction and applied compatible rhizospheric bio-agents Trichoderma asperellum (T42) and Pseudomonas fluorescens (OKC) singly or in combination to assess their influence on the host while under the pathogen challenge...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28290364/estimation-of-kinetic-parameters-of-anthocyanins-and-color-degradation-in-vitamin-c-fortified-cranberry-juice-during-storage
#12
Sunisa Roidoung, Kirk D Dolan, Muhammad Siddiq
Color degradation in cranberry juice during storage is the most common consumer complaint. To enhance nutritional quality, juice is typically fortified with vitamin C. This study determined effect of gallic acid, a natural antioxidant, for the preservation of anthocyanins (ACYs) and color, and estimated kinetics of ACYs and color degradation. Juice, fortified with 40-80mg/100mL vitamin C and 0-320mg/100mL gallic acid, was pasteurized at 85°C for 1min and stored at 23°C for 16days. Total monomeric anthocyanins and red color intensity were evaluated spectrophotometrically and data were used to determine degradation rate constants (k values) and order of reaction (n) of ACYs and color...
April 2017: Food Research International
https://www.readbyqxmd.com/read/28282223/analytical-methods-for-metformin-estimation
#13
Durgawati Patel, Puspendra Kumar, Swapnil Sharma, Jaya Dwivedi
Metformin is a widely prescribed oral anti-hyperglycemic agent used in the management of non-insulin dependent diabetes mellitus (NIDDM) or type II diabetes. This article accentuates various analytical methods viz. HPLC, HPTLC, spectrophotometric, electrochemical, capillary electrophoresis and LC-MS for the estimation of metformin in pharmaceutical formulations and in biological matrices.
March 10, 2017: Critical Reviews in Analytical Chemistry
https://www.readbyqxmd.com/read/28275214/investigation-of-drug-polymer-compatibility-using-chemometric-assisted-uv-spectrophotometry
#14
Amir Ibrahim Mohamed, Amr Mohamed Elsayed Abd-Motagaly, Osama A A Ahmed, Suzan Amin, Alaa Ibrahim Mohamed Ali
A simple chemometric-assisted UV-spectrophotometric method was used to study the compatibility of clindamycin hydrochloride (HC1) with two commonly used natural controlled-release polymers, alginate (Ag) and chitosan (Ch). Standard mixtures containing 1:1, 1:2, and 1:0.5 w/w drug-polymer ratios were prepared and UV scanned. A calibration model was developed with partial least square (PLS) regression analysis for each polymer separately. Then, test mixtures containing 1:1 w/w drug-polymer ratios with different sets of drug concentrations were prepared...
January 16, 2017: Pharmaceutics
https://www.readbyqxmd.com/read/28272800/correlation-between-antimicrobial-antioxidant-activity-and-polyphenols-of-alkalized-nonalkalized-cocoa-powders
#15
Vanja Todorovic, Marina Milenkovic, Bojana Vidovic, Zoran Todorovic, Sladjana Sobajic
Many factors can influence antioxidative and antimicrobial characteristics of plant materials. The quality of cocoa as functional food ingredient is influenced through its processing. The main aim of this study was to test if there is difference in polyphenol content, antioxidant capacity, and antimicrobial activity between nonalkalized and alkalized cocoa powders. To estimate polyphenol and flavonoid content in cocoa samples the spectrophotometric microassays were used. Flavan-3ols were determined with reversed-phase high-performance liquid chromatography (RP-HPLC)...
April 2017: Journal of Food Science
https://www.readbyqxmd.com/read/28243615/dataset-on-absorption-spectra-and-bulb-concentration-of-phenolic-compounds-that-may-interfere-with-onion-pyruvate-determinations
#16
Vanesa H Beretta, Florencia Bannoud, Marina Insani, Claudio R Galmarini, Pablo F Cavagnaro
We present data on absorption spectra (400-540 nm) and concentration of phenolic compounds quercetin, myricetin, kaempferol, rutin, catechin, epicatechin gallate (ECG) and epigallocatechin gallate (EGCG), in yellow, red and white onions. These data are related to the article entitled "Variability in spectrophotometric pyruvate analyses for predicting onion pungency and nutraceutical value" (Beretta et al., 2017) [1]. Given the relevance of pyruvate determinations for estimating onion pungency and functional value, it is important to identify compounds that can interfere with pyruvate determinations when using two previously published analytical procedures, namely Schwimmer and Weston (1961) (SW) [2] and Anthon and Barret (2002) (AB) [3], which are based on spectrophotometry and light-absorbance at 420 nm and 515 nm, respectively...
April 2017: Data in Brief
https://www.readbyqxmd.com/read/28229626/the-role-of-hydrogen-sulfide-in-homocysteine-induced-cardiodynamic-effects-and-oxidative-stress-markers-in-the-isolated-rat-heart
#17
M Stojanovic, V Zivkovic, I Srejovic, V Jakovljevic, N Jeremic, D Djuric
This study aimed to assess the role of H2S in homocysteine-induced cardiodynamic effects in the isolated rat heart. The hearts were retrogradely perfused according to the Langendorff technique. The maximum and minimum rates of pressure in the left ventricle (dp/dt max, dp/dt min), systolic and diastolic left ventricular pressures (SLVP, DLVP), heart rate (HR), and coronary flow (CF) were measured. A spectrophotometrical method was used to measure the following oxidative stress markers: index of lipid peroxidation (thiobarbituric acid reactive substances, TBARS), nitrite level (NO2(-)), superoxide anion radicals (O2(•-)), and hydrogen peroxide (H2O2) concentrations...
December 2016: Physiology International
https://www.readbyqxmd.com/read/28217539/analysis-of-plasma-lipid-peroxidation-and-antioxidant-enzymes-status-in-patients-of-oral-leukoplakia-a-case-control-study
#18
Kumar Chandan Srivastava, Deepti Shrivastava
AIMS AND OBJECTIVES: Imbalances between the oxidant-antioxidant status have been implicated in the pathogenesis of several diseases, including oral cancer. Mostly, all oral cancer lesions are preceded by a stage of premalignancy. The present study aims to evaluate lipid peroxidation and antioxidant status in the venous blood of patients with different clinicopathologic stages of leukoplakia. MATERIALS AND METHODS: A case control study was designed with the inclusion of 20 new cases of histopathologically proven leukoplakia of various clinical stages along with an equal number of positive and negative control individuals...
December 2016: Journal of International Society of Preventive & Community Dentistry
https://www.readbyqxmd.com/read/28215962/two-colour-fluorescence-fluorimetric-analysis-for-direct-quantification-of-bacteria-and-its-application-in-monitoring-bacterial-growth-in-cellulose-degradation-systems
#19
Kwabena O Duedu, Christopher E French
Monitoring bacterial growth is an important technique required for many applications such as testing bacteria against compounds (e.g. drugs), evaluating bacterial composition in the environment (e.g. sewage and wastewater or food suspensions) and testing engineered bacteria for various functions (e.g. cellulose degradation). T?=1,^FigItem(1) ^ReloadFigure=Yesraditionally, rapid estimation of bacterial growth is performed using spectrophotometric measurement at 600nm (OD600) but this estimation does not differentiate live and dead cells or other debris...
February 17, 2017: Journal of Microbiological Methods
https://www.readbyqxmd.com/read/28159256/variability-in-spectrophotometric-pyruvate-analyses-for-predicting-onion-pungency-and-nutraceutical-value
#20
Vanesa H Beretta, Florencia Bannoud, Marina Insani, Claudio R Galmarini, Pablo F Cavagnaro
Onion pyruvate concentration is used as a predictor of flavor intensity and nutraceutical value. The protocol of Schwimmer and Weston (SW) (1961) is the most widespread methodology for estimating onion pyruvate. Anthon and Barret (AB) (2003) proposed modifications to this procedure. Here, we compared these spectrophotometry-based procedures for pyruvate analysis using a diverse collection of onion cultivars. The SW method always led to over-estimation of pyruvate levels in colored, but not in white onions, by up to 65%...
June 1, 2017: Food Chemistry
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