Antioxidant activity of cowpea protein isolate hydrolyzed by pepsin

Antioxidant activity was studied for hydrolysates obtained from cowpea protein isolate by enzymatic hydrolysis using pepsin. Effects of 3 hydrolysis parameters: pH, temperature, and time were analysed using response surface methodology. A second-order polynomial model was used for predicting antioxidant activity of the hydrolysates. This model was adequate to fit experimental data and explained more than 85% of the variation. Interaction between pH and temperature was the major effect affecting antioxidant activity. Optimum antioxidant activity was observed after hydrolysis for 176 min, at pH 2.15, and temperature 38.2 °C. Under these conditions, the predicted antioxidant activity (22.69%) was in agreement with the experimental one. Degree of hydrolysis of the hydrolysate under optimum conditions was 25.70%, and the electrophoretic profile revealed the cleavage of several protein bands present in the isolate

Effects of increasing acylation and enzymatic hydrolysis on functional properties of bambara bean (Vigna subterranea) protein concentrate

Bambara bean protein concentrate was acylated and partially hydrolysed with pancreatin in order to improve its functional properties. Increasing acetylation and succinylation (from 0.0 to 1.0 g anhydride/g concentrate) modified lysine at similar rate. Acylation markedly improved protein solubility and water solubility index at neutral pH, which reached to 92 and 94%, respectively. Acetylation showed greater effect on emulsifying activity, which was maximum at 0.5 g anhydride/g concentrate, and emulsifying stability was higher at 0.25 g anhydride/g concentrate. A significant increase in foam capacity was recorded at 0.5 g succinic anhydride/g concentrate, and foam stability decreased detrimentally following acylation. Fat absorption capacity was not improved by acylation. At pH 3.5, protein solubility of acylated concentrate was low (<14%). Hydrolysis of protein concentrate with pancreatin resulted in significant increase in protein solubility at neutral pH. At isoelectric pH, solubility of protein hydrolysates increased with the increasing degree of hydrolysis

Measurement of Soil Bulk Density by Using Gamma Ray Backscattering Spectroscopy

This study deals with a nuclear method of Gamma- Ray Backscattering Spectroscopy as a method that could be applied in measuring material bulk density specially soil density. The detection system consists of a 3” × 3” inch NaI(Tl) detector connected to multichannel analyzer Inspector 2000 from Canberra instruments and lap top computer. 137Cs is used as a Gamma-Ray emitter with energy of 662 KeV. Different soil types with different bulk densities are used in calibration process. Before applying this technology in the field, calibration process took place in order to find a relationship between material bulk density and the collected count rate for that material. Calibration measurements are performed using three different material with three different bulk densities filled in wooden boxes constructed specially for this purpose with dimensions of 59×42×34 cm. Gamma ray source is shielded to prevent direct gamma photons from reach the detector in direct way. The detector and shielded gamma-ray source are placed on the top of the material’s surface, and gamma ray spectrum for 137Cs is collected for measurement times of 60 seconds to prevent background radiation measurement and the elevation on instrument’s temperature which could lead to mistaken the measurement. Collected spectra are analyzed using Genie 2000 software. Count rates are calculated for each spectrum, then a calibration curve is found making it easy to find the mathematical relationship between the count rate and the bulk density. Field measurements of bulk density (BD) are performed to check the validity of the system calibration. Results of Terra Rossa soil were in very good agreement with the measurement density. iii Count Rate for the calibration process for Terra Rossa with 10 cm as a detector-source separation distance was (406 counts. s-1), in the Terra Rossa field with the same distance (430 counts.s-1 ). With using 20 cm, count rate in calibration process was (144 counts.s-1), in the field it was (141 counts.s-1), we can notice how much the measurements are closed., the count rate from energy range of (250-730 KeV). Measurement of bulk density are conducted in five different locations at Al-Quds University Main-Campus site. Results of there measurements are consistent relating to the type of soil and other materials present at the investigated locations. Field measurements also are performed to study the effect of rain on soil bulk density determination.تناقش هذه الدراسة طريقة لقياس آثافة المواد الظاهرية بواسطة استخدام تقنية نووية. و لتحقيق هذا استخدمت تقنية مطيافية أشعة جاما الحقلية . يتكون نظام القياس من مكشاف اشعاع و ميضي ( بلورة يوديد الصوديوم المطعم بعنصر الثاليوم) بحجم 3 × "3 "انش متصل مع محلل طيف من نوع 2000 Inspector من شرآة آانبيرا و بطاقة ( KeV 662 (آمصدر لأشعة جاما ، آما 137 ذالك مع جهاز آمبيوتر محمول. استخدم عنصر Cs استخدمت أنواع مختلفة من التربة بكثافات ظاهرية مختلفة لاجراء عملية المعايرة. قبل تطبيق هذه التقنية في الحقل أجريت عملية المعايرة لايجاد علاقة مناسبة بين آثافة المادة الظاهرية و طيف جاما الذي تم جمعه (قياسه). تمت عملية المعايرة باستخدام ثلاثة مواد مختلفة ذات ثلاثة آثافات مختلفة معبأة بداخل صناديق خشبية بأبعاد 34×42×59 سم صنعت مخصصة لهذا Cs ( بدرع من الرصاص لمنع مرور أشعة جاما بشكل مباشر 137 الغرض. يغطى مصدر اشعاع جاما ( نحو المكشاف . ثم يوضع آل من مصدر أشعاع جاما و المكشاف فوق سطح المادة المراد قياسها لتبدأ عملية القياس لوقت قصير(60(ثانية. حتى يتم تفادي قياس شعاع جاما الطبيعي في بيئة القياس و تفادي ارتفاع درجة حرارة الاجهزة الذي يؤدي الى احداث فروقات في القراءات. تعالج أطياف جاما التي تم جمعها و قياسها باستخدام نظام 2000 Genie . يحسب معدل اشعاع جاما (Rate Count (لكل عملية قياس على حده. ثم يوضع منحنى المعايرة الذي يوضح العلاقة بين آثافة المادة و معدل اشعاع جاما الذي تمت معالجته مما يسهل ايجاد علاقة رياضية مناسبة بين آثافة المادة و معدل اشعاع جاما. v تمت عملية القياس في الحقل حتى يتم التأآد من مدى دقة عملية المعايرة.النتائج الخاصة بتربة Rossa Terra آانت متوافقة جدا مع النتائج التي تم قياسها من قبل. تم القيام بقياسات الحقل بعد انهاء عملية المعايرة مستخدمين العلاقة الناتجة عن عملية المعايرة، حيث آان معدل العد في عملية المعايرة Rossa Terra وباستخدام مسافة 10 سم و هي المسافة الفاصلة 406 ، ( و آان القياس في الحقل و على نفس المسافة 1 -بين المكشاف و مصدر اشعاع جاما ( s.counts 144 (اما 1 ، ( -اما باستخدام مسافة 20 سم آان القياس في عملية المعايرة ( s.counts 1 ) -s.counts 430 ( 141 ،(و نلاحظ تقارب النتائج، و هذا في مجال الطاقة الذي يمثل الجزء (KeV 1 -في الحق s.conts 730 -250 (من طيف أشعة جاما. و قد أجريت قياسات ميدانية في خمسة مواقع مختلفة في الحرم الرئيسي في جامعة القدس. و تشير نتائج تقدير الكثافة الظاهرية في المناطق الخمسة المختلفة الى نتائج منطقية تتناسب و نوعية التربة و المواد المتواجدة في مواقع القياس. آما ان عملية القياس قد اجريت ايضا بهدف قياس تأثير مياه الامطار على قياس آثافةالتربة

Field-induced water electrolysis switches an oxide semiconductor from an insulator to a metal

Here we demonstrate that water-infiltrated nanoporous glass electrically switches an oxide semiconductor from an insulator to metal. We fabricated the field effect transistor structure on an oxide semiconductor, SrTiO3, using 100%-water-infiltrated nanoporous glass - amorphous 12CaO*7Al2O3 - as the gate insulator. For positive gate voltage, electron accumulation, water electrolysis and electrochemical reduction occur successively on the SrTiO3 surface at room temperature, leading to the formation of a thin (~3 nm) metal layer with an extremely high electron concentration of 10^15-10^16 cm^-2, which exhibits exotic thermoelectric behaviour.Comment: 21 pages, 12 figure

Re-think It Conference Proceedings

Essays contributed by participants in Re-think it: Libraries for a New Age, a conference on library design, services, values, and visions, which was held in the Mary Idema Pew Library Learning and Information Commons at Grand Valley State University, August 10 - 12, 2015.https://scholarworks.gvsu.edu/rethinkit_proceedings/1000/thumbnail.jp

Magnesium reduces calcification in bovine vascular smooth muscle cells in a dose-dependent manner

WOS: 000300421300010PubMed ID: 21750166Vascular calcification (VC), mainly due to elevated phosphate levels, is one major problem in patients suffering from chronic kidney disease. In clinical studies, an inverse relationship between serum magnesium and VC has been reported. However, there is only few information about the influence of magnesium on calcification on a cellular level available. Therefore, we investigated the effect of magnesium on calcification induced by beta-glycerophosphate (BGP) in bovine vascular smooth muscle cells (BVSMCs). BVSMCs were incubated with calcification media for 14 days while simultaneously increasing the magnesium concentration. Calcium deposition, transdifferentiation of cells and apoptosis were measured applying quantification of calcium, von Kossa and Alizarin red staining, real-time reverse transcription-polymerase chain reaction and annexin V staining, respectively. Calcium deposition in the cells dramatically increased with addition of BGP and could be mostly prevented by co-incubation with magnesium. Higher magnesium levels led to inhibition of BGP-induced alkaline phosphatase activity as well as to a decreased expression of genes associated with the process of transdifferentiation of BVSMCs into osteoblast-like cells. Furthermore, estimated calcium entry into the cells decreased with increasing magnesium concentrations in the media. In addition, higher magnesium concentrations prevented cell damage (apoptosis) induced by BGP as well as progression of already established calcification. Higher magnesium levels prevented BVSMC calcification, inhibited expression of osteogenic proteins, apoptosis and further progression of already established calcification. Thus, magnesium is influencing molecular processes associated with VC and may have the potential to play a role for VC also in clinical situations.Fresenius Medical Care Deutschland GmbH, GermanyThis study was supported by Fresenius Medical Care Deutschland GmbH, Germany

Down-regulation of vascular GLP-1 receptor expression in human subjects with obesity

It has been thought that incretin signaling prevents arteriosclerosis, and very recently anti-arteriosclerotic effects through GLP-1 receptor were finally demonstrated in clinical human study. The purpose of this study was to investigate how vascular GLP-1 receptor expression is influenced in human subjects. First, we evaluated GLP-1 receptor expression in human arteries in immunostaining. Next, we separated the artery into the intima and media, and evaluated gene expression levels of various factors. We divided the subjects into obesity and non-obesity group and compared their expression levels between them. Finally, we evaluated which factors determine vascular GLP-1 receptor expression. GLP-1 receptor expression in intima and media was lower in obesity group compared to non-obesity group which was correlated with the alteration of TCF7L2 expression. Multiple regression analyses showed that BMI was an independent determining factor for GLP-1 receptor expression in the intima and media. Furthermore, using small interfering RNA method and TCF7L2-EGFP adenovirus, we showed that TCF7L2 was involved in GLP-1 receptor expression in human vascular cells. Taken together, vascular GLP-1 receptor and TCF7L2 expression was significantly down-regulated in human subjects with obesity. In addition, it is likely that TCF7L2 functions as a modulator of vascular GLP-1 receptor expression

Lack of Renal 11 Beta-Hydroxysteroid Dehydrogenase Type 2 at Birth, a Targeted Temporal Window for Neonatal Glucocorticoid Action in Human and Mice

International audienceBackground Glucocorticoid hormones play a major role in fetal organ maturation. Yet, excessive glucocorticoid exposure in utero can result in a variety of detrimental effects, such as growth retardation and increased susceptibility to the development of hypertension. To protect the fetus, maternal glucocorticoids are metabolized into inactive compounds by placental 11beta-hydroxysteroid dehydrogenase type2 (11βHSD2). This enzyme is also expressed in the kidney, where it prevents illicit occupation of the mineralocorticoid receptor by glucocorticoids. We investigated the role of renal 11βHSD2 in the control of neonatal glucocorticoid metabolism in the human and mouse. Methods Cortisol (F) and cortisone (E) concentrations were measured in maternal plasma, umbilical cord blood and human newborn urine using HPLC. 11βHSD2 activity was indirectly assessed by comparing the F/E ratio between maternal and neonatal plasma (placental activity) and between plasma and urine in newborns (renal activity). Direct measurement of renal 11βHSD2 activity was subsequently evaluated in mice at various developmental stages. Renal 11βHSD2 mRNA and protein expression were analyzed by quantitative RT-PCR and immunohistochemistry during the perinatal period in both species. Results We demonstrate that, at variance with placental 11βHSD2 activity, renal 11βHSD2 activity is weak in newborn human and mouse and correlates with low renal mRNA levels and absence of detectable 11βHSD2 protein. Conclusions We provide evidence for a weak or absent expression of neonatal renal 11βHSD2 that is conserved among species. This temporal and tissue-specific 11βHSD2 expression could represent a physiological window for glucocorticoid action yet may constitute an important predictive factor for adverse outcomes of glucocorticoid excess through fetal programming

Diminished 11β-Hydroxysteroid Dehydrogenase Type 2 Activity Is Associated With Decreased Weight and Weight Gain Across the First Year of Life

Context: Low birth weight is associated with adverse metabolic outcome in adulthood. Exposure to glucocorticoid (GC) excess in utero is associated with decreased birth weight, but the prospective longitudinal relationship between GC metabolism and growth has not been examined. Objective: We have hypothesized that changes in GC metabolism leading to increased availability may impair growth. Design: This was a prospective, longitudinal study with clinical measurements and 24-hour urinary steroid metabolite analysis at 1, 4, 12, 26, and 52 weeks after delivery in mothers and their babies. Setting: The study was conducted with observations and samples collected in the volunteers' own homes. Participants: Healthy mothers and newborn babies/infants participated in the study. Interventions: There were no interventions. Main outcome measures: Urinary steroid metabolite excretion quantified by gas chromatography/mass spectroscopy across the first year of life in relation to change in weight was measured. Results: The total production of the GC metabolites quantified increased across the first year of life. Markers of 11β-hydroxysteroid dehydrogenase type 1 activity increased from the age of 3 months as did those of 5α-reductase activity. After correcting for confounding variables, low markers of 11β-hydroxysteroid dehydrogenase type 2 activity was associated with reduced absolute weight and decreased weight gain over the first year of life. In the mothers, 5α-reductase activity was low at birth and progressively increased to normal over the first 6 months postpartum. Conclusions: Increased GC exposure as a consequence of reduced 11β-hydroxysteroid dehydrogenase type 2 activity is likely to be a critical determinant of growth in early life. This not only highlights the central role of GCs and their metabolism, but also emphasizes the need for detailed longitudinal analyses