27 research outputs found

    Equivalence of Hamiltonian and Lagrangian Path Integral Quantization: Effective Gauge Theories

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    The equivalence of correct Hamiltonian and naive Lagrangian (Faddeev--Popov) path integral quantization (Matthews's theorem) is proven for gauge theories with arbitrary effective interaction terms. Effective gauge-boson self-interactions and effective interactions with scalar and fermion fields are considered. This result becomes extended to effective gauge theories with higher derivatives of the fields.Comment: 14 pages LaTeX, BI-TP 93/40, August 199

    Adsorption performance of Pb(II) ions on green synthesized GO and rGO: Isotherm and thermodynamic studies

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    Graphene oxide (GO) and reduced graphene oxide (rGO) are efficient and low-cost adsorbent carbon-based materials for removing Pb(II) ions from wastewater. In this article, the adsorption performance of environmentally friendly graphene oxide and reduced graphene oxide, which shows high adsorption capacity for Pb(II) ions, has been compared for the first time to our knowledge. Besides, the various characterization techniques are used such as X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy and scanning electron microscopy with energy dispersive X-ray spectroscopy and described in detail as well. In addition, adsorption isotherms and thermodynamic studies are discussed to comprehend the adsorption process as well. From the adsorption isotherms, the maximum adsorption capacities of Pb(II) ions on GO and rGO calculated from the Langmuir (117.6 mg/g) and Dubinin–Radushkevich isotherms (138.5 mg/g), respectively, higher than reported studies in the literature. By thermodynamic investigation, it was found that the adsorption of Pb(II) ions on GO and rGO was spontaneous and exothermic. This study will be established as a basis for future studies and will be especially valuable in understanding the potential of graphene-based materials, which are rising stars that can be considered as promising and effective adsorbents in the removal of heavy metal ions from large volumes of aqueous solutions. © 2022 The authors

    Increased plasma levels of growth hormone, insulin-like growth factor (IGF)-I and IGF-binding protein 3 in pregnant rats with exercise.

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    Growth hormone (GH) and insulin-like growth factor-I (IGF-I) are closely related molecules. Insulin-like growth factor-binding protein-3 (IGFBP-3) is a main molecule that binds IGF-I. GH, IGF-I and IGFBP-3 have important roles in growth and development. In this study, we investigated the effects of exercise during pregnancy on maternal plasma levels of GH, IGF-I and IGFBP-3 and on fetal development. We also recorded the weights of placenta, lengths of umbilical cord, fetal body weights, fetal heights, and weights of fetal tissues. Pregnant Wistar Albino rats were divided into two groups: exercise and control groups (n = 7 for each). A treadmill exercise was performed as 20 m/min for 20 min/day, once per day for 19 days in exercise group. Blood samples were collected from pregnant rats on 0, 7th, 14th and 20th days of gestation (D) under anesthesia with intracardiac puncture, and maternal plasma levels of GH, IGF-I and IGFBP-3 were determined. Fetuses were taken with cesarean section on D20, and various parameters for fetal growth were measured. Plasma GH and IGF-I levels were elevated in exercising pregnant rats on D14 and D20, respectively, when compared to controls, and IGFBP-3 levels were increased on D14 and D20. Among the growth parameters examined, only fetal body weights and weights of fetal liver were significantly decreased in the exercise group (p < 0.01 and p < 0.05, respectively). These results indicate that maternal exercise significantly increases plasma levels of GH, IGF-I and IGFBP-3 in the late period of pregnancy but causes adverse effects on fetal growth

    Hyperhomocysteinemia: a risk factor for retinal vein occlusion.

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    PURPOSE: The aim of the study was to investigate the plasma homocysteine levels in patients with retinal vein occlusion (RVO) in order to reveal whether hyperhomocysteinemia was a risk factor for RVO. METHODS: Thirty-three consecutive patients diagnosed to have RVO of any type and 25 age- and sex-matched controls without RVO were included in this prospective case-control study. Data regarding age, sex, history of hypertension, diabetes mellitus, other vascular events, glaucoma, medications and smoking habits were obtained from all subjects. Several laboratory tests relating to vascular disease including cholesterol, triglyceride and hematocrit were checked. The plasma total homocysteine (tHcy) level was measured by high-performance liquid chromatography (normal range: 5-15 micromol/l). Plasma folate, vitamin B(12) and creatinine levels were also studied since these vitamins and impairment of renal function might affect plasma tHcy values. RESULTS: Patients with RVO had a significantly higher tHcy level (median: 11.7 micromol/l, range: 7.2-25 micromol/l) compared to controls (median: 10.3 micromol/l, range: 6.7-13.4 micromol/l; p = 0.005). Nine of 33 patients with RVO (27.3%) had an elevated plasma tHcy level, whereas none of the controls had an abnormal tHcy value (p = 0.004). Plasma folate, vitamin B(12) and creatinine levels were comparable between the two groups (p > 0.05). CONCLUSIONS: The present study suggests an association between hyperhomocysteinemia and RVO. Further controlled studies with a large number of cases are needed to investigate the exact role of hyperhomocysteinemia in RVO

    Are C-reactive protein and homocysteine cardiovascular risk factors in obese children and adolescents?

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    BACKGROUND: Several prospective epidemiological studies have demonstrated that high-sensitivity C-reactive protein (hsCRP) and plasma homocysteine (hcy) are predictors of future coronary events among healthy men and women. The aim of the present study was therefore to investigate a possible relationship between hsCRP, hcy levels and body mass index (BMI), relative weight (RW), serum leptin levels, and cardiovascular risk factors in obese children and adolescents. METHODS: The study involved 28 obese children and adolescents (13 girls, 15 boys; BMI>95 per thousand for age and sex), 4.5-15 years of age (mean 10.7 +/- 0.6 years), who attended hospital for a basic obesity check-up. The association between hsCRP, hcy levels and BMI, RW, serum leptin levels, and cardiovascular risk factors such as blood pressure (BP), lipid profile, serum fasting insulin levels, and insulin resistance indexes, was investigated. RESULTS: Serum hsCRP level was positively correlated with BMI (r = 0.512, P < 0.01), RW (r = 0.438, P < 0.05), systolic and diastolic BP (r = 0.498, P < 0.01), serum leptin levels (r = 0.457, P < 0.05), but not with serum lipid, glucose, fasting insulin, plasma hcy levels or insulin resistance indexes. For hcy level, in contrast, no correlation was found with BMI, RW, systolic and diastolic BP, serum lipid levels, leptin, hsCRP, glucose, fasting insulin levels, or insulin resistance indexes. CONCLUSIONS: hsCRP is correlated with BMI, RW, BP and leptin, which are risk factors for coronary heart disease, which supports the relationship between obesity, inflammation and atherosclerosis. hsCRP in childhood obesity might be a useful index to predict possible atherosclerotic events

    Influence of acute exercise on urinary protein, creatinine, insulin-like growth factor-I (IGF-I) and IGF binding protein-3 concentrations in children.

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    Insulin-like growth factor-I (IGF-I) is a polypeptide hormone and present in human urine. Insulin-like growth factor binding protein-3 (IGFBP-3) is the major form of binding protein in human circulation and functions as a carrier for IGF-I. Our goal was to determine the effects of volleyball exercise on the concentrations of urine protein, creatinine, IGF-I, and IGFBP-3 in children and to find out whether these effects differ between boys and girls. Volunteer children (13 females and 14 males), aged 10-13 years old were included in this work. Weight and height of the subjects were measured, and urine samples of their were collected before and after 2 hours of exercise. Urinary protein, creatinine, IGF-I and IGFBP-3 levels were analysed. Urinary protein, creatinine and IGF-I concentrations were increased after two hours of exercise wheres urinary IGFBP-3 concentrations did not change. In addition, no statistically significant difference in all parameters analysed was observed between boys and girls of similar age and body mass index

    What puts women at risk of violence from their husbands? Findings from a large, nationally representative survey in Turkey.

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    A large, nationally representative, cross-sectional survey was conducted in Turkey in 2008. In this survey, which used the WHO (World Health Organization) study module on violence, information about lifetime and current violence (past 12 months) was obtained using weighted, stratified, and multistage cluster sampling. This article describes factors associated with physical or sexual violence experienced by ever-married women, aged 15 to 49, from their current or most recent husbands in the 12 months before the survey. Logistic regression analysis is used to describe the risk and protective factors from a considerable range of explanatory variables. The findings confirm that many factors are similar to the experiences of other countries. The physical or sexual violence experienced by ever-married women from their husbands was 15.1%. The violence experienced by women is significantly positively associated with early childhood abuse experiences of both women and their husbands; marriages decided by families or others; husband's behaviors such as drunkenness, adultery, controlling women's behavior, and preventing contact with women's family and friends. The age of the women, their contribution to the household income, support from women's families, women's acceptance of male authority, and nonpartner violence experience as well as regional differentials also affect the risk of violence. No significant associations were found with the employment status of women and men or education difference. This study, as one of the largest surveys ever conducted on the issue of domestic violence using face-to-face interviews, demonstrated how the patriarchal family structure still affects women's lives in Turkey. This is particularly significant, given Turkey's setting between traditional and modern values

    P-glycoprotein polymorphism in hypo- and hyper-thyroidism patients

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    P-glycoprotein (Pgp) is encoded by the multidrug resistance gene (MDR1) in humans and is the product of MDR1. It is expressed in various tissues and is related to drug distribution in intestinal erythrocytes, capillary endotel of brain, proximal tubules cells of kidneys and liver canalicular cells. Expression of Pgp is affected by Pgp polymorphism, and exon 26 C3435T polymorphism is the most common one. It has been thought that expression of Pgp is high in C-allele subjects and this situation is responsible for the resistance against some drugs and substances. Pgp may have a role in the distribution of thyroid hormones, drugs used for hypo- and hyperthyroidism and the resistance occurred. For this purpose possible relationship between T and C alleles and frequency of Pgp polymorphism as well as thyroid hormone distribution in patients with hypo- and hyperthyroidism was investigated. Thirty five hyperthyroidism patients diagnosed as Graves' disease, 78 hypothyroidism patients diagnosed as Hashimoto's thyroiditis and 100 healthy volunteers were included in the study. According to the results obtained no statistically significant difference was found in Pgp C3435T polymorphism between hypo- and hyperthyroidism patients. In addition, the serum free T3 levels of hyperthyroidism patients with C alleles was higher than those of subjects with T alleles. No statistically significant difference was seen in the CC, CT and TT genotype frequencies between the patients and control groups. In conclusion, it seems that Pgp polymorphism is not a predictor factor for the occurrence of hypo- and hyperthyroidism. There is a significant relationship between Pgp and the elevated serum free T3 levels of hyperthyroidism patients, and further research will help understand this situation. © 2007 Springer Science+Business Media B.V
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