VA Concentration Research Articles

Interaction and association between multiple vitamins and social adaptability and severity of autism: A large-scale retrospective study from China.

Since children with autism spectrum disorder (ASD) often exhibit selective eating behaviors, it is generally believed that they may have abnormal nutrient structure, leading to aberrant concentrations of some serum vitamins. However, previous studies on serum vitamins in individuals with ASD are mixed. Additionally, the interaction and association between multiple serum vitamin and ASD-related symptoms remain unclear. This study utilized a cross-sectional survey with a large sample size (n = 1235) from China to clarify previous mixed findings, and examine the interaction and association between multiple serum vitamins (including folic acid [FA], vitamin A [VA], vitamin E [VE], vitamin B12 [VB12], and vitamin D [VD]) and social adaptability and symptom severity in children with ASD. Findings found that symptom severity was negatively associated with concentrations of serum VA, VE, VB12, and VD; while, social adaptability was significantly associated with the natural log-transformed concentrations of FA and VB12. Finding also revealed the interaction of VA and VE on the association between both vitamins and severity of ASD symptoms, as well as the interaction of VB12 and FA on the association between both vitamins and social adaptability. In particular, the combination of low concentration of VA and high concentration of VE is associated with the lowest risk of being "severely autistic"; while, the combination of low concentration of FA and high concentration of VB12 is associated with the lowest risk of being "poor social adaptability". This study offers the evidence for the requirement of considering multiple vitamins comprehensively, as well as valuable references for revealing the association between vitamin disparities and food selectivity in children with ASD.

Repeated High-Dose Vitamin A Supplements, Standard of Care for Treating Xerophthalmia, Leads to Hypervitaminosis A in Piglets

BackgroundVitamin A (VA) deficiency and excess negatively affect development, growth, and bone health. The World Health Organization’s standard of care for xerophthalmia due to VA deficiency, is 3 high-dose VA supplements of 50,000–200,000 IU, based on age, which may cause hypervitaminosis A in some individuals. ObjectivesThis study measured VA status following 3 VA doses in 2 piglet studies. MethodsIn Study 1, 5 groups of piglets (n = 10/group) were weaned 10 d postbirth to VA-free feed and orally administered 0; 25,000; 50,000; 100,000; or 200,000 IU VA ester on days 0, 1, and 7. On days 14 and 15, the piglets underwent the modified relative dose–response (MRDR) test for VA deficiency, and were killed. Tissues were collected for high-pressure liquid chromatography analysis. Study 2 used the same design in 3 groups (n = 13/group) weaned at 16 d and administered 0; 25,000; and 200,000 IU doses. ResultsIn Study 1 (final weight: 3.6 ± 0.7 kg), liver VA concentration was hypervitaminotic in 40%, 90%, and 100% of 50,000; 100,000; and 200,000 IU groups, respectively. The 25,000 IU group was 100% adequate, and the placebo group was 40% deficient. In Study 2 (final weight: 8.7 ± 0.8 kg), where 200,000 IU could be prescribed to infants with a similar body weight, 31% of the piglets were hypervitaminotic, the 25,000 IU group was 100% VA adequate, and the placebo group was 100% deficient. The MRDR test measured deficiency in 50% and 70% of the placebo group in each study but had 3 false positives among hypervitaminotic piglets in Study 1. ConclusionsRepeated high-dose VA may cause hypervitaminosis, indicating dose sizes may need reduction. The MRDR resulted in false positives in a hypervitaminotic state during malnutrition and should be paired with serum retinyl ester evaluation to enhance VA status assessment in populations with overlapping interventions.

Effects of dietary supplementation of vitamin A on the tibia quality of goslings.

This study was conducted to evaluate the effect of dietary supplementation of vitamin A (VA) on the tibial growth, calcium (Ca) and phosphorus (P) metabolism, VA, and vitamin D (VD) deposition, and associated gene expression in goslings. A total of 180 healthy, 1-day-old male goslings were randomly divided into 3 treatment groups (0, 9,000, and 15,000 IU VA/kg), with 6 replicates containing 10 goslings each. They were weighed and sampled on days 14, 28, 42, 56, and 70. No addition of VA reduced VA content in the serum and liver of goslings, and supplementation of 15,000 IU/kg VA increased VA content from day 14 (p<0.05). The trend of VA concentration in the serum and liver was in line with the relative mRNA expression of retinoic acid receptor β in the jejunal mucosa. In both no addition of VA and supplementation of 15,000 IU/kg VA reduced 25-hydroxycholecalciferol (25-OH-VD3) content in the serum and VD content in the liver (p<0.05). From day 28, no addition of VA or supplementation of 15,000 IU/kg VA had a negative effect on tibia length, strength, and Ca, P, and ash content in goslings (p<0.05). Tibia P content was lower in the supplementation of 15,000 IU/kg VA group than in the no addition of VA group (p<0.05). No addition of VA or supplementation of 15,000 IU/kg VA had the most effect on early serum parathyroid hormone (PTH) levels in goslings (p<0.05). The effect of no addition of VA on the bone Gla protein (BGP) content of goslings started from day 14 (p<0.05). The relative mRNA expression of bone Gla-protein (BGLAP) and bone morphogenetic protein 4 (BMP4) in the liver and jejunal mucosa was decreased by either no addition of VA or supplementation of 15,000 IU/kg VA (p<0.05). Both no addition of VA and supplementation of 15,000 IU/kg VA affected the mineralization process of the bone, and ultimately reduced tibial quality.

Analysis of the vestibular aqueduct development on the risk for suffering from idiopathic sudden sensorineural hearing loss

ObjectiveLarge vestibular aqueduct syndrome (LVAS) is one of the etiology of hearing loss. Clinically, we observed that the VA size of patients with idiopathic sudden sensorineural hearing loss (ISSNHL) did not meet the diagnostic criteria of VA enlargement, but there were individual variations. Through this study, we want to understand the VA development and explore its risk for suffering from ISSNHL. Methods74 patients with ISSNHL were retrospectively reviewed in our department from June 2018 to September 2021. Meanwhile, 57 people with no ear diseases were randomly selected as the control group. All their clinical information were systematically collected. The axial thin-slice CT images of temporal bone were used to observe and measure the VA in ISSNHL and controls. ISSNHL were classified as different types and grades according to pure tone audiometry and the degree of hearing loss, respectively. Logistic regression analysis was adopted to evaluate the risk factors of different types and grades of ISSNHL. ResultsThe operculum morphology could be funnel-shaped, tubular and invisible, but they had no statistical difference in the morbidity of ISSNHL. The operculum width of the affected sides in the case group was significantly wider than that of the matched sides in the control group (0.84±0.35mm vs 0.68±0.34mm, p=0.009), but the midpoint width had no statistical difference (p=0.447). The operculum width was an independent risk factor for the total hearing loss type (p=0.036, OR=4.49, 95% CI=1.10-18.29), moderate (p=0.013, OR=17.62, 95% CI=1.82-170.95) and profound (p=0.031, OR=4.50, 95% CI=1.14-17.67) grade of ISSNHL. Hypertension was an independent risk factor for the severe grade (p=0.004, OR=12.44, 95% CI=2.19-70.64) of ISSNHL. Both the operculum width (p=0.048, OR=7.14, 95% CI=1.02-50.26) and hypertension (p=0.014, OR=6.73, 95% CI=1.46-30.97) were the risk factors for the flat type of ISSNHL. The midpoint width of the VA, gender, age, diabetes mellitus, hyperlipidemia, and plasma fibrinogen concentration had no significant effect on the risk for suffering from ISSNHL. ConclusionThe development of the VA operculum is a risk factor for some types and grades of ISSNHL. Hypertension remained a risk factor for ISSNHL.

An in situ inferior vena cava ligation-stenosis model to study thrombin generation rates with flow

BackgroundBlood flow-induced shear stress affects platelet participation in coagulation and thrombin generation. We aimed to develop an in vivo model to characterize thrombin generation rates under flow.MethodsAn in situ inferior vena cava (IVC) ligation-stenosis model was established using C57BL/6 mice. Wild type C57BL/6 mice were fed normal chow diet for two weeks before experiments. On the day of experiments, mice were anesthetized, followed by an incision through the abdominal skin to expose the IVC, which was then ligated (followed by reperfusion through a stenosis for up to 2 h). IVC blood flow rate was monitored using a Transonic ultrasound flow meter. In sham animals, the IVC was exposed following the same procedure, but no ligation was applied. Thrombin generation following IVC ligation was estimated by measuring mouse plasma prothrombin fragment 1–2 concentration. Mouse plasma factor Va concentration was measured using phospholipids and a modified prothrombinase assay. Blood vessel histomorphology, vascular wall ICAM-1, von Willebrand Factor, tissue factor, and PECAM-1 expression were measured using immunofluorescence microscopy.ResultsIVC blood flow rate increased immediately following ligation and stenosis formation. Sizable clots formed in mouse IVC following ligation and stenosis formation. Both plasma factor Va and prothrombin fragment 1–2 concentration reduced significantly following IVC ligation/stenosis, while no changes were observed with ICAM-1, von Willebrand Factor, tissue factor and PECAM-1 expression.ConclusionClot formation was successful. However, the prothrombin-thrombin conversion rate constant in vivo cannot be determined as local thrombin and FVa concentration (at the injury site) cannot be accurately measured. Modification to the animal model is needed to further the investigation.

Modulation of p-glycoprotein-mediated efflux pirarubicin in living multidrug-resistant K562/Dox cell lines by 4-hydroxybenzoic acid and 4-hydroxy-3-methoxybenzoic acid via impairment of the cellular energetic state

The objective was to investigate the effect of 4-hydroxybenzoic acid (4-HBA) and 4-hydroxy-3-methoxybenzoic acid (Vanillic acid, VA) on p-glycoprotein (P-gp) activity in multidrug-resistant K562/Dox cancer cells. The cytotoxic and co-treatment with pirarubicin (Pira) were analyzed using a resazurin assay. A noninvasive functional spectrofluorometric technique was used to determine the kinetics of Pira uptake in living multidrug-resistant K562/Dox cancer cells. The three biological endpoints for determination of cellular energetic state included the activity of mitochondria, mitochondrial membrane potential (ΔΨm), and ATP levels. The results revealed that 4-HBA (10 mM) and VA (5 and 10 mM) statistically decreased cell viability in K562 and multidrug-resistant K562/Dox cancer cells. In ways consistent with that result, 4-HBA and VA (0.01, 0.1, 1, and 10 mM) could statistically decrease the IC50 of Pira in K562 and multidrug-resistant K562/Dox cancer cells at 48 and 72 h. The overall intracellular Pira concentration increased in 4-HBA- and VA-treated multidrug-resistant K562/Dox cancer cells when compared to control. The ratio of kai/ka0 in 4-HBA- and VA-treated multidrug-resistant K562/Dox cancer cells was significantly decreased when 4-HBA and VA concentration increased. The activity of mitochondria, ΔΨm, and ATP levels significantly reduced in multidrug-resistant K562/Dox cancer cells incubated with 0.01, 0.1, 1, and 10 mM 4-HBA and VA at all harvest time points. In conclusion, 4-HBA and VA were able to bring about cell death in multidrug-resistant K562/Dox cancer cell at high concentrations. The 4-HBA and VA could modify P-gp function via an impaired cellular energetic state, resulting in increased in intracellular drug concentration in multidrug-resistant K562/Dox cancer cells.

Vitamin A Status and Deposition in Neonatal and Weanling Rats Reared by Mothers Consuming Normal and High-Fat Diets with Adequate or Supplemented Vitamin A.

The circulating level of vitamin A (VA; retinol) was reported to be lower in obese adults. It is unknown if maternal obesity influences the VA status of offspring. The objective of the study was to determine the VA status and deposition of neonatal and weanling rats reared by mothers consuming a normal or high-fat diet (NFD or HFD) with or without supplemented VA. Pregnant Sprague-Dawley rats were randomized to an NFD or HFD with 2.6 mg/kg VA. Upon delivery, half of the rat mothers in the NFD or HFD cohort were switched to an NFD or HFD with supplemented VA at 129 mg/kg (NFD+VA and HFD+VA group). The other half remained on their original diet (NFD and HFD group). At postnatal day 14 (P14), P25, and P35, pups (n = 4 or 3/group/time) were euthanized. The total retinol concentration in the serum, liver, visceral white adipose tissue (WAT), and brown adipose tissue (BAT) was measured. At P14, the HFD+VA group showed a significantly lower serum VA than the NFD+VA group. At P25, both the VA concentration and total mass in the liver, WAT, and BAT were significantly higher in the HFD+VA than the NFD+VA group. At P35, the HFD group exhibited a significantly higher VA concentration and mass in the liver and BAT compared with the NFD group. In conclusion, maternal HFD consumption resulted in more VA accumulation in storage organs in neonatal and/or weanling rats, which potentially compromised the availability of VA in circulation, especially under the VA-supplemented condition.

Catalytic Degradation of Poly(Vinyl Alcohol) by FexMnyCuzOw/γ-Al2O3 Nano-particles Catalyst Using Box-Behnken Design

FexMnyCuzOw/γ-Al2O3 nanoparticles were prepared by a wet impregnation -calcination method and characterized by means of XRD, BET, SEM-EDS. Box-Behnken design was used to investigate the degradation of PVA in aqueous solution. Besides, the effect of different calcination temperature, FexMnyCuzOw/γ-Al2O3 dosage, H2O2 dosage, initial P VA concentration and initial solution pH on the removal of P VA were also studied. Results showed that P VA can be efficiently removed and oxidized by the heterogeneous Fenton-like process with appropriate amount of FexMnyCuzOw/γ-Al2O3 and H2O2. In this paper, the efficiency of P VA was above 90 % by FexMnyCuzOw/γ-Al2O3 nanoparticles at an initial P VA concentration below 25 g/l, temperature at 60 oC, initial pH from 1.0 to 6.0, H2O2 and catalyst dose of 60 ml/l and 0.5 g/l, respectively. In addition, chromatography (GPC) was applied to further analyze the degradation of P VA under different experimental conditions, which revealed that the backbone chain of P VA could be effectively broken and oxidized. Several unsaturated degradation products, including butanones, benzaldehydes, hexanals and acetic acids were also detected and identified by gas chromatography-mass spectrometry (GC-MS). Besides, the nano catalyst maintained favorable catalytic ability during the five-times utilization, which means it could be recycled by filtration and calcination.

In vitro rumen biohydrogenation kinetics of mixed linoleic and alfa-linolenic acids

Background: Dietary linoleic (LA) and alpha-linolenic (LN) acids are extensively isomerized and hydrogenated by rumen microbes, and this activity can further contribute to the fatty acid profile of ruminant-derived food products. Objective: To evaluate the effects of LA:LN ratio in lipid supplements on the rumen biohydrogenation kinetics of LA and LN, as well as on the trans-vaccenic acid (VA) production, using an in vitro system. Methods: Rumen fluid was collected from a fistulated steer, diluted with incubation buffer, and then incubated with 500 mg of kikuyu grass (Cenchrus clandestinus) supplemented with 16.3 mg of different LA:LN mixtures (100:0, 75:25, 50:50, 25:75 or 0:100). Incubations were performed in triplicate for a period of 0, 2, 4, 6, 8 or 16 hours. Differences between treatments were evaluated in a completely randomized design. Alternatively, computational chemistry was used to determine the changes in the Gibbs free energy (ΔGrxn) at 39 °C for the principal steps of LA and LN ruminal biohydrogenation. Results: Partial replacement of LA by LN decreased the VA concentration and its accumulation rate; it also increased the stearic acid concentration and the rates of transfer from LA to conjugated linoleic acid (CLA), and from CLA to VA. The conversion from CLAto VA(ΔGrxn = -2.65 kJ/mol) was more spontaneousthan that from trans-11, cis-15 octadecadienoic acid (TA) to VA (ΔGrxn = -0.29 kJ/mol). Conclusion: The LA:LN ratio in lipids can modulate LA and LN biohydrogenation (BH) kinetics, as well as the VA production in the rumen.

Vitamin A Supplementation Only Transiently Increases Retinol Concentrations in Extrahepatic Organs of Neonatal Rats Raised under Vitamin A‐Marginal Conditions

Vitamin A (VA, retinol) supplementation is recommended for children &gt; 6 mo old in countries with high rates of malnutrition, based on the positive results of clinical trials conducted in the 1990s. However, the results of studies on the benefits of supplementing neonates &lt; 5 mo old are inconsistent. The objective of this study was to determine the distribution of VA in bodies of neonatal rats raised under VA‐marginal conditions (control group) and the effect of VA supplementation on the concentration and mass of retinol in the body, including plasma, liver, and lungs, as well as several understudied extrahepatic organs, such as the brain, brown adipose tissue, and skin.MethodsNeonatal rats (n = 103), nursed by mothers fed a VA‐marginal diet, were randomized and treated on postnatal day 4 (P4) with an oral dose of either VA (6 μg retinyl palmitate/g body weight) or canola oil as control. Subsequently, pups (n = 4/group/time) were euthanized at 13 time points from 30 min to 24 d after dosing and the following organs were collected: plasma, liver, lungs, kidneys, stomach, intestine, brain, white and brown adipose tissue, skin, and the remaining carcass. The total retinol concentration and mass in each organ was measured with ultra‐performance liquid chromatography.ResultsControl pups maintained a marginal plasma VA concentration, while the VA concentration in the liver was deficient. Despite its deficient status, the liver contained most (~77%) of the whole‐body VA mass, similarly as in previous studies of adult rats with an adequate liver VA concentration. White adipose tissue, which was nearly absent prior to P12, contained only ~1% of the whole‐body VA mass, compared to 10–20% reported in adult rats. The remaining extrahepatic, non‐digestive organs together stored &lt; 10% of the whole‐body retinol mass. VA supplementation significantly increased total retinol concentrations in all organs. However, this increase lasted for only 1 d in most extrahepatic organs, with the exception of white adipose tissue, where it lasted for 18 d.ConclusionsOur findings suggest that extrahepatic organs in neonatal rats may not be sufficiently developed to store VA at the adult capacity and that the scarcity of adipose tissue may predispose neonates to a low VA status. Moreover, given the transient effect of VA supplementation on extrahepatic organs, a more frequent supplementation schedule, along with other nutrition interventions, may be necessary to maintain a steady supply of retinol to the rapidly developing extrahepatic organs.Support or Funding InformationSupported by NIH grant HD‐066982

The effect of cumin (Cuminum cyminum) seed extract on the inhibition of PUFA biohydrogenation in the rumen of lactating goats via changes in the activity of rumen bacteria and linoleate isomerase enzyme

In this study, two experiments were conducted to evaluate the effect of cumin (Cuminum cyminum) seed extract (CSE) on PUFA biohydrogenation. The first experiment was arranged in a completely randomized design in which eighteen crossbred goats were assigned to three dietary treatments: one group received basal diet (control; C0) consisting of forage and concentrate at equal ratio while the other two groups received the same diet with supplemented CSE (at 1.27% and 2.53% of dry matter intake as C1 and C2, respectively). The rumen content was sampled on day 27 and 29 of the experiment and then subjected to volatile fatty acids (VFA) and long chain fatty acids analyses. The CSE had no effect on molar proportion of VFA (P>0.05). However, the addition of the CSE to the diet of goats increased the ruminal concentration of rumenic acid (RA; C18:2(c9,t11)) by 34.8% (P=0.041) and vaccenic acid (VA; C18:1(11)) by 11.4% (P=0.01) in lower supplemented group in comparison to the CSE-free diet. In the CSE-fed goats, the concentration of linoleic acid (LA; C18:2(9,12)) and linolenic acid (LNA; 18:3(9,12,15)) was higher (P<0.05) and stearic acid (SA; C18:0) was lower (P=0.036) than that of the control group, suggesting the inhibition of biohydrogenation. There was no dose dependent effect of the CSE on PUFA content. In the second experiment, linoleate isomerase activity and the growth of five strains of Butyrivibrio sp. and ten predominant species of rumen bacteria was tested at presence of the CSE. The results revealed that CSE did not inhibit the growth of Butyrivibrio sp. but it decreased the growth of some main species of the rumen bacteria such as Prevotella brevis, Streptococcus bovis, Peptostreptococcus anaerobius and Lachnospira multiparus (P<0.05), which are involved in ruminal biohydrogenation. Moreover, the linoleate isomerase activity of the only stearate forming bacterium, Butyrivibrio proteoclasticus, decreased by 53% in the presence of the CSE (4.25μg CSE/ml; P=0.002). Initially, the inhibition of LA metabolism by this species decreases the rate of RA and VA formation, but it gradually results in the accumulation of RA and VA. It was found that CSE altered the bacterial biohydrogenation activity, thus increasing RA and VA concentration in the rumen.

Effects of Spent Engine Oil Polluted Soil and Organic Amendment on Soil Chemical Properties, Micro-Flora on Growth and Herbage of &lt;i&gt;Telfairia Occidentalis&lt;/i&gt; (hook f).

A trial was conducted at the Screen House of the Department of Crop Science, University of Benin, Benin City, Nigeria to evaluate the efficacy of using organic fertilizer as bioremediant for spent engine oil polluted soils. Three concentrations of spent engine oil (0, 5 and 10 % w/w, spent engine oil in soil) and three application rates of organic fertilize (0, 5 and 10 t ha-1) were utilized in a 3 x 3 factorial arrangement and laid out as a completely randomized design with three replication. Soil pH, available P and exchangeable cations were significantly reduced by spent engine oil except organic C compared to control. Heavy metals (Va and Pb) concentration increased with increasing concentration of spent engine oil. Amendment of spent engine oil polluted soil with organic fertilizer significantly remediated the degraded soil and decreases the heavy metal concentration. In addition, 10 t ha-1 organic fertilizer showed superiority over 5tha-1 organic fertilizer in amending spent engine oil degraded soil for pH, total N, available P, exchangeable Ca2+ and reduced heavy metal concentration. Soil pollution adversely affected number of leaves, dry vine weight, dry leaf weight and herbage yield. Growth and herbage yield were much higher in organic fertilizer amended spent engine oil polluted soil. the highest herbage yield (9.23 t ha-1) was obtained from unpolluted soil treated with 10 t ha-1 organic fertilizer which was statistically comparable with soil polluted with 5 % spent engine oil and amended with 10 t ha-1 organic fertilizer (7.10 t ha-1). Soils polluted with 5 % spent engine oil had higher bacteria population compared to control, while organic fertilizer had depressing effect on soil without spent oil pollution. However, unpolluted soiltreated with 10 t ha-1 organic fertilizer had the fungi (0.77 x 106cfu g-1) population which was statistically compared to 5 t ha-1 organically treated soil without spent engine oil pollution (0.76 x 106cfu g-1). Soil polluted with spent engine oil has been bioremediated with organic fertilizer and hence put into productive use.Keyword: Growth, herbage yield, micro-flora, organic fertilizer, spent engine oil, Telfairia occidentalis.

Mathematical modeling of poly[(R)-3-hydroxyalkanoate] synthesis by Cupriavidus necator DSM 545 on substrates stemming from biodiesel production

Two low structured mathematical models for fed-batch production of polyhydroxybutyrate and poly[hydroxybutyrate-co-hydroxyvalerate] by Cupriavidus necator DSM 545 on renewable substrates (glycerol and fatty acid methyl esters-FAME) combined with glucose and valeric acid, were established. The models were used for development/optimization of feeding strategies of carbon and nitrogen sources concerning PHA content and polymer/copolymer composition. Glycerol/glucose fermentation featured a max. specific growth rate of 0.171h−1, a max. specific production rate of 0.038h−1 and a PHB content of 64.5%, whereas the FAME/valeric acid fermentation resulted in a max. specific growth rate of 0.046h−1, a max. specific production rate of 0.07h−1 and 63.6% PHBV content with 4.3% of 3-hydroxyvalerate (3HV) in PHBV. A strong inhibition of glycerol consumption by glucose was confirmed (inhibition constant ki,G=4.28×10−4gL−1). Applied concentration of FAME (10–12gL−1) positively influenced on PHBV synthesis. HV/PHBV ratio depends on applied VA concentration.

Titanium nanotubes grown by titanium anodization

In this work we investigated the structural and electrical properties of titanium dioxide (TiO2) nanotubes (NTs) grown by electrochemical anodization of Ti metal sheets in NH4F+H2O+glycerol electrolyte at different anodization voltages (Va) and electrolyte composition. Our results revealed that TiO2 NTs can be grown in a wide range of anodization voltages from 10 to 240 V. The maximum NH4F acid concentration, at which NTs can be formed, decreases with the anodization voltage, which is 0.7% for Va&amp;lt;60 V, and decreases to 0.1% at Va=240 V. Addition of water to the electrolyte results in an increase in NT growth rate and modification of NT film morphology. Glancing angle x-ray diffraction experiments show that as-grown amorphous TiO2 transforms to anatase phase after annealing at 400 °C and further transforms to rutile phase at annealing temperatures above 500 °C. Samples grown in 30–120 V voltage range have higher crystal quality as seen from anatase (101) peak intensity and reduced linewidth. The electrical resistivity of the NTs varies with Va concentration and increases by eight orders of magnitude when Va increases from 10 to 240 V. The resistivity is also greatly dependent on H2O concentration increasing with its concentration up to nine orders of magnitude. Temperature dependent I-V and photoinduced current transient spectroscopy were employed to analyze electrical properties and defect structure on NT samples.

Effects of a potato pulp silage supplement on the composition of milk fatty acids when fed to grazing dairy cows

This study was completed to determine the effects of potato pulp silage (PPS) as a diet supplement on the composition of milk fatty acids in grazing dairy cows in comparison to a barley grain supplement. Eight late lactation Holstein dairy cows were fed grazing based diets supplemented with 150 g/kg of PPS (‘PPS’) as a substitute for barley (‘barley’), and grazed on 4.3 ha swards, mainly containing orchard grass, for 56 days. Total dry matter (DM) and pasture DM intake and milk yields, as well as milk composition, did not differ between treatments. The linolenic acid intake did not differ (329 g/day vs. 323 g/day DM). The trans11C18:1vaccenic acid (VA) concentration in blood was higher in cows fed PPS (2.4 g/100 g FA) compared to those fed barley (1.9 g/100 g FA). There were no differences between treatments in the cis9 trans11conjugated linoleic acid (CLA) concentration in blood. The short-chain and medium-chain fatty acids in milk also did not differ between treatments. The VA concentration in milk was increased in cows fed PPS (2.32 g/100 g FA) compared to those fed barley (1.84 g/100 g FA), and CLA was higher in cows fed PPS (1.25 g/100 g FA) than those fed barley (0.95 g/100 g FA). Milk CLA concentration was positively correlated to blood VA concentration. Results suggest that an increase in milk CLA concentration is related to an increase of the VA concentration in blood by Δ 9-desaturase in mammary glands in the PPS fed compared to barley fed groups.

Optical and Electrical Properties of TiO2 Nanotubes Grown by Titanium Anodization

AbstractIn this work we investigated the structural, electrical, and optical properties of titanium dioxide (TiO2) nanotubes (NTs) formed by electrochemical anodization of Ti metal sheets in NH4F+glycerol electrolyte at different anodization voltages (Va) and acid concentrations. Our results revealed that TiO2 NTs can be grown in a wide range of anodization voltages from 10 V to 240 V. The maximum NH4F acid concentration, at which NTs can be formed, decreases with the anodization voltage, which is 0.7% for Va&lt;60V, and decreases to 0.1% at Va =240 V. Glancing angle X-ray diffraction (GAXRD) experiments show that as-grown amorphous TiO2 transforms to anatase phase after annealing at 400 oC, and further transforms to rutile phase at annealing temperatures above 500 oC. Samples grown in 30-120 voltage range have higher crystal quality as seen from anatase (101) peak intensity and reduced linewidth. The electrical resistivity of the NTs varies with Va concentration and increases by eight orders of magnitude when Va increases from 10 V to 240 V. This is consistent with cathodoluminescense studies which showed improved optical properties for samples grown in this voltage range. Optical properties of samples were also studied by low temperature photoluminescence. Temperature dependent I-V and photo-induced current transient spectroscopy were employed to analyze electrical properties and defect structure on NT samples.

Identification of Surface Epitopes of Human Coagulation Factor Va That Are Important for Interaction with Activated Protein C and Heparin

Inactivation of factor Va (FVa) by activated protein C (APC) is a key reaction in the down-regulation of thrombin formation. FVa inactivation by APC is correlated with a loss of FXa cofactor activity as a result of three proteolytic cleavages in the FVa heavy chain at Arg306, Arg506, and Arg679. Recently, we have shown that heparin specifically inhibits the APC-mediated cleavage at Arg506 and stimulates cleavage at Arg306. Three-dimensional molecular models of APC docked at the Arg306 and Arg506 cleavage sites in FVa have identified several FVa amino acids that may be important for FVa inactivation by APC in the absence and presence of heparin. Mutagenesis of Lys320, Arg321, and Arg400 to Ala resulted in an increased inactivation rate by APC at Arg306, which indicates the importance of these residues in the FVa-APC interaction. No heparin-mediated stimulation of Arg306 cleavage was observed for these mutants, and stimulation by protein S was similar to that of wild type FVa. With this, we have now demonstrated that a cluster of basic residues in FVa comprising Lys320, Arg321, and Arg400 is required for the heparin-mediated stimulation of cleavage at Arg306 by APC. Furthermore, mutations that were introduced near the Arg506 cleavage site had a significant but modest effect on the rate of APC-catalyzed FVa inactivation, suggesting an extended interaction surface between the FVa Arg506 site and APC.

Ultrasound-assisted hydrolysis and acidogenesis of solid organic wastes in a rotational drum fermentation system

The hydrolysis and acidogenesis of solid organic wastes in a rotational drum fermentation system (RDFS) were improved by direct ultrasonic irradiation (DUSI) and a modified ultrasonic treatment (MUST) composed of dilution, ultrasonic irradiation, and filtration. The effect of DUSI on VA desorption from particle surfaces was estimated. DUSI delivered few distinctions from the broth characteristics, but elevated pH and VS degradation rate (53% higher than the control) in the subsequent acidogenesis. The results demonstrated that DUSI could dislodge VA from particle surfaces and disrupt large-size particles by hydro-mechanical shear force. To improve VA desorption and removal, a MUST process was constructed. The influences of MUST on the characteristics of the fermentation broth and the subsequent acidogenic performance were investigated. MUST raise the broth pH level from 5.1 to 5.5 and remarkably decreased VA concentration from 11.0 to 3.5 g/L. At the end of the subsequent acidogenesis, VA increasing ratios, VS degradation ratios, and surface based hydrolysis constants of the fermentors with the control broth (CF) and the treated broth (MUSTF) were 166.7% and 732.0%, 17.0% and 26.7%, and 16.9% and 26.8 × 10 −6 kg m −2 d −1, respectively. With the assistance of MUST, a considerably improved acidogenic performance of solid organic wastes was accomplished in terms of VA production, VS degradation, and particle hydrolysis.

Cholesterol and Phosphatidylethanolamine Enhance the Binding of Factor Va and Factor Xa to Phospholipid Vesicles and Promote Assembly of the Prothrombinase Complex on Membranes Containing Low Concentrations of Phosphatidylserine.

Platelet membranes are composed of cholesterol (CH) and phospholipids including phosphatidylethanolamine (PE), sphingomeylin (SM), phosphatidylcholine (PC) and phosphatidylserine (PS). Phospholipid vesicles containing 20–25% PS have been used extensively to characterize assembly and regulation of the prothrombinase complex. However, the concentration of PS on the surface of activated platelets has been determined to be only 4–13%. Smeets et al (Thromb. Res. 81:419, 1996) demonstrated that CH and PE in the presence of 0–10% PS have stimulating effects on prothrombinase activity, while SM has an inhibitory one. To further investigate the roles of CH, PE and SM in the binding of factor Va and Xa to phospholipid vesicles and assembly of the prothrombinase complex, vesicles consisting of 1–25% DOPS plus 30% CH, 30% DOPE and/or 20% SM, were prepared for prothrombinase assays as a function of DOPS concentration. Compared to individual effect of DOPS alone or DOPS plus CH, PE or SM on prothrombinase activity, a synergistic effect was observed on vesicles containing CH, DOPE and SM, which was significant in the range of 1–15% DOPS. The PS concentration required for half-maximal rates of thrombin generation was 5.3% for vesicles containing CH, DOPE and SM, compared to 10.6, 11.2, 8.3 and 12.6% for vesicles containing DOPS alone, plus CH, plus DOPE or plus SM, respectively. This demonstrates that the requirement for PS is substantially decreased in the presence of CH, PE and SM. In order to further define the mechanisms for this effect, direct binding of factor Va to vesicles containing 30% CH, 30% PE and 20% SM was investigated using a fluorescence resonance energy transfer assay. These binding experiments demonstrated that factor Va bound to vesicles containing 1, 5, 10, and 20% DOPS with Kd values of 2.88±0.43 nM, 1.15±0.17 nM, 1.16±0.13 nM, and 1.18±0.19 nM, respectively. At low concentrations of PS (≤ 5%), CH, DOPE and SM increased the binding affinity of factor Va 2 to 6-fold compared to vesicles containing only DOPS. When prothrombinase activity was measured as a function of factor Va concentration on vesicles containing 5, 10, and 20% DOPS, K1/2Va values of 0.63±0.08nM, 0.38±0.05nM, and 0.37±0.07nM were observed which were comparable to the Kd's determined in direct factor Va binding experiments. These results indicate that factor Va binds tightly to phospholipid vesicles mimicking the phospholipid composition of activated platelets even at very low concentrations of PS. When direct binding of factor Xa to vesicles containing 5, 10, and 20% DOPS plus CH, DOPE and SM was examined, the Kd values were 70.5±6.8 nM, 62.6±6.6 nM, and 49.6±4.0 nM, respectively. When the interaction of factor Xa with membranes was investigated using prothrombinase assays, K1/2Xa values of 0.12±0.03nM, 0.04±0.01nM, and 0.01±0.01nM were observed. In conclusion, the presence of CH and PE increases the affinity of factor Va and factor Xa binding to phospholipid vesicles containing physiologic concentrations of PS. The binding of factor Va to vesicles containing 1% PS is not sufficient for assembly and function of the prothrombinase complex, suggesting that higher concentrations of PS are needed to support the binding of factor Xa and prothrombin.

Thermally stimulated and photoinduced depolarization processes in PbI2 crystals

The thermally stimulated depolarization (TSD) of photo-, thermo-, and electroelectret states in undoped lead iodide crystals was studied in the temperature range 85–330 K. The results demonstrate that the centers responsible for the electret charge localization in PbI2 crystals are related to structural defects. The peak observed in the PbI2 thermoelectret TSD current at 170 K arises from the dipole relaxation of donor-acceptor pairs formed by Pb+ ions and anion vacancies Va, and the peak at 295–305 K is due to the formation of a space charge during poling owing to the displacement of anion vacancies. The electroelectret formation during poling of PbI2 near 85 K in the dark is probably associated with the electric-field ionization of Pb+ and Pb0 centers and the formation of electronic F-centers, responsible for the IR sensitivity of PbI2. The main peak (130–135 K), present in both the thermo-and electroelectret TSD current curves, arises from the thermal dissociation of those centers. IR irradiation of crystals photopolarized at 85 K leads to electron release from trapping centers, accompanied by electret field decay and an increase in Va concentration.