501 research outputs found
Electron transport components of the parasitic protozoon Giardia lamblia
AbstractThe energy metabolism of the intestinal parasite, Giardia lamblia, involves the iron-sulphur protein, pyruvate:ferredoxin oxidoreductase. Cell fractionation studies showed that this enzyme is associated with the membranes. NADH and NADPH dehydrogenases were found in both the membrane and cytosolic fractions. EPR spectroscopic studies showed the presence of iron-sulphur clusters in the membrane fraction and in the cytosolic fraction, non-sedimentable at 6 × 106g · min. An acidic, soluble protein fraction was separated from the cytosol. It had an EPR spectrum in the reduced state, characteristic of the 2[4Fe-4S] type of ferredoxin, with g-factors at 2.04, 1.93 and l .89. and the midpoint redox potential was estimated to be −360 mV. This species is probably a ferredoxin, like those of anaerobic bacteria such as Closlridium and Desiilfovihrio spp. and also that of Entamoeba histolytica. The protein was readily and irreversibly oxidized to give [3Fe 4S] clusters
Secondary Flow in Semi-Circular Ducts
Turbulent secondary flows are motions in the transverse plane, perpendicular to a main, axial flow. They are encountered in non-circular ducts and can, although the velocity is only of the order of 1-3% of the streamwise bulk velocity, affect the characteristics of the mean flow and the turbulent structure. In this work, the focus is on secondary flow in semi-circular ducts which has previously not been reported. Both numerical and experimental analyses are carried out with high accuracy. It is found that the secondary flow in semi-circular ducts consists of two pairs of counter rotating corner vortices, with a velocity in the range reported previously for related configurations. Agreement between simulation and experimental results are excellent when using a second moment closure turbulence model, and when taking the experimental and numerical uncertainty into account. New and unique results of the secondary flow in semi-circular ducts have been derived from verified simulations and validating laser-based experiments
Модернізація стоматологічної установки УС- 30
Background: The novel chemokine CXCL17 acts as chemoattractant for monocytes, macrophages and dendritic cells. CXCL17 also has a role in angiogenesis of importance for tumour development. Methods: Expression of CXCL17, CXCL10, CXCL9 and CCL2 was assessed in primary colon cancer tumours, colon carcinoma cell lines and normal colon tissue at mRNA and protein levels by real-time qRT-PCR, immunohistochemistry, two-colour immunofluorescence and immunomorphometry. Results: CXCL17 mRNA was expressed at 8000 times higher levels in primary tumours than in normal colon (P<0.0001). CXCL17 protein was seen in 17.2% of cells in tumours as compared with 0.07% in normal colon (P = 0.0002). CXCL10, CXCL9 and CCL2 mRNAs were elevated in tumours but did not reach the levels of CXCL17. CXCL17 and CCL2 mRNA levels were significantly correlated in tumours. Concordant with the mRNA results, CXCL10-and CXCL9-positive cells were detected in tumour tissue, but at significantly lower numbers than CXCL17. Two-colour immunofluorescence and single-colour staining of consecutive sections for CXCL17 and the epithelial cell markers carcinoembryonic antigen and BerEP4 demonstrated that colon carcinoma tumour cells indeed expressed CXCL17. Conclusions: CXCL17 is ectopically expressed in primary colon cancer tumours. As CXCL17 enhances angiogenesis and attracts immune cells, its expression could be informative for prognosis in colon cancer patients
Interleukin-1 receptor antagonist haplotype associated with prostate cancer risk
IL1-RN is an important anti-inflammatory cytokine that modulate the inflammation response by binding to IL1 receptors, and as a consequence inhibits the action of proinflammatory cytokines IL1α and IL1β. In this study, we hypothesise that sequence variants in the IL1-RN gene are associated with prostate cancer risk. The study population, a population-based case–control study in Sweden, consisted of 1383 prostate cancer case patients and 779 control subjects. We first selected 18 sequence variants covering the IL1-RN gene and genotyped these single-nucleotide polymorphisms (SNPs) in 96 control subjects. Gene-specific haplotypes of IL1-RN were constructed and four haplotype-tagging single-nucleotide polymorphisms (htSNPs) were identified (rs878972, rs315934, rs3087263 and rs315951) that could uniquely describe >95% of the haplotypes. All study subjects were genotyped for the four htSNPs. No significant difference in genotype frequencies between cases and controls were observed for any of the four SNPs based on a multiplicative genetic model. Overall there was no significant difference in haplotype frequencies between cases and controls; however, the prevalence of the most common haplotype (ATGC) was significantly higher among cases (38.7%) compared to controls (33.5%) (haplotype-specific P=0.009). Evaluation of the prostate cancer risk associated with carrying the ‘ATGC' haplotype revealed that homozygous carriers were at significantly increased risk (odds ratio (OR)=1.6, 95% confidence interval (CI)=1.2–2.2), compared to noncarriers, while no significant association was found among subjects heterozygous for the haplotype (OR=1.0, 95% CI=0.8–1.2). Restricting analyses to advanced prostate cancer strengthened the association between the ‘ATGC' haplotype and disease risk (OR for homozygous carriers vs noncarriers 1.8, 95% CI=1.3–2.5). In conclusion, the results from this study support the hypothesis that inflammation has a role of in the development of prostate cancer, but further studies are needed to identify the causal variants in this region and to elucidate the biological mechanism for this association
Mobile gaming: Industry challenges and policy implications
Mobile games are a prime example of a successful mobile application and demonstrate the increasing range of platforms for the media and entertainment industries. Against this convergent background, this paper introduces the basic features of the mobile gaming market and its industrial ecosystem together with its main actors and activities. The focus of the paper lies in the challenges ahead for the evolution of mobile applications into a potentially dominant game platform and the possible disruptions along this road. The deep personal relationships between users and their mobile devices are considered to further explore the link between mobile games, players’ strategies and pending techno-economic developments. The paper concludes with a brief discussion of some policy options to assist with the development of this domain
Overexpression of the rhamnose catabolism regulatory protein, RhaR: a novel mechanism for metronidazole resistance in Bacteroides thetaiotaomicron
Antioxidant defence of colostrum and milk in consecutive lactations in sows
<p>Abstract</p> <p>Background</p> <p>Parturition is supposed to be related to oxidative stress, not only for the mother, but also for the newborn. Moreover, it is not clear whether consecutive pregnancies, parturitions, and lactations are similar to each other in regards to intensity of metabolic processes or differ from each other. The aim of the study was to compare dynamic changes of antioxidative parameters in colostrum and milk of sows taken during 72 h postpartum from animals in consecutive lactations. Activities of glutathione peroxidase (GSH-Px), glutathione transferase (GSH-Tr), and superoxide dismutase (SOD), and amount of vitamin A and C were measured. Healthy pregnant animals were divided into 4 groups according to the assessed lactation: A -1<sup>st </sup>lactation (n = 10), B - 2<sup>nd </sup>and 3<sup>rd </sup>lactation (n = 7), C - 4<sup>th </sup>and 5<sup>th </sup>lactation (n = 11), D - 6<sup>th </sup>- 8<sup>th </sup>lactation (n = 8). The colostrum was sampled immediately after parturition and after 6, 12, 18 and 36 h while the milk was assessed at 72 h after parturition. Spectrophotometric methods were used for measurements.</p> <p>Results</p> <p>The activity of antioxidative enzymes and the concentration of vitamin A increased with time postpartum. The concentration of vitamin C was the highest between the 18th and 36th h postpartum.</p> <p>Conclusions</p> <p>Dynamic changes in the values of antioxidant parameters measured during the study showed that sows milk provides the highest concentration of antioxidants in the 2<sup>nd </sup>and 3<sup>rd </sup>and 4<sup>th </sup>and 5<sup>th </sup>lactation giving the best defence against reactive oxygen species to newborns and mammary glands.</p
Dolphin morbillivirus infection in different parts of the Mediterranean Sea
Morbillivirus were isolated from Mediterranean striped dolphins (Stenella coeruleoalba) dying along the coasts of Italy and Greece in 1991. They were antigenically identical to the morbilliviruses isolated from striped dolphins in Spain in 1990
Effect of short-term versus long-term grassland management and seasonal variation in organic and conventional dairy farming on the composition of bulk tank milk
Bulk tank milk from 28 dairy farms was sampled every second month for 2 yr to assess the effects of grassland management, production system and season on milk fatty acid (FA) composition, concentrations of fat-soluble vitamins, Se, and milk sensory quality. Grassland management varied in terms of time since establishment. Short-term grassland management (SG) was defined as establishment or reseeding every fourth year or more often, and long-term grassland management (LG) was defined as less frequent establishment or reseeding. Fourteen organic (ORG) dairy farms with either short-term or long-term grassland management were paired with 14 conventional (CON) farms with respect to grassland management. Within ORG farms, SG farms differed from LG farms in herbage botanical composition, but not in concentrate FA concentrations, dry matter intake, or milk yield. Within CON farms, herbage composition, concentrate FA concentrations, dry matter intake, and milk yield showed no or insignificant variations. The ORG farms differed from CON farms in herbage botanical composition, concentrate FA concentrations, concentrate intake, and milk yield. Compared with ORG-LG farms, ORG-SG farms produced milk fat with higher proportions of C10:0 and C12:0 associated with higher herbage proportions of legumes (Fabaceae) and lower proportions of other dicotyledon families. Compared with milk from CON farms, milk fat from ORG farms had higher proportions of most saturated FA and all n-3 FA, but lower proportions of C18:0 and C18:1 cis-9 associated with higher forage proportion and differences in concentrations of FA in concentrates. Compared with the outdoor-feeding periods, the indoor feeding periods yielded milk fat with higher proportions of most short-chain and medium-chain FA and lower proportions of most C18-FA associated with grazing and higher forage proportions. Milk concentrations of α-tocopherol and β-carotene were lower during the grazing periods. Inclusion of fishmeal in organic concentrates may explain higher Se concentrations in organically produced milk. Milk sensory quality was not affected in this study. In conclusion, grassland management had minor effects on milk composition, and differences between ORG farms and CON farms may be explained by differences in concentrate intake and concentrate FA concentrations. Milk produced on ORG farms versus CON farms and milk produced during the outdoor versus indoor feeding periods had potential health benefits due to FA composition. In contrast, the higher milk-fat proportions of saturated FA in milk from ORG farms may be perceived as negative for human health
The cross-sectional associations between sense of coherence and diabetic microvascular complications, glycaemic control, and patients' conceptions of type 1 diabetes
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