2,909 research outputs found

    Optimal set of grid size and angular increment for practical dose calculation using the dynamic conformal arc technique: a systematic evaluation of the dosimetric effects in lung stereotactic body radiation therapy

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    Purpose To recommend the optimal plan parameter set of grid size and angular increment for dose calculations in treatment planning for lung stereotactic body radiation therapy (SBRT) using dynamic conformal arc therapy (DCAT) considering both accuracy and computational efficiency. Materials and methods Dose variations with varying grid sizes (2, 3, and 4 mm) and angular increments (2°, 4°, 6°, and 10°) were analyzed in a thorax phantom for 3 spherical target volumes and in 9 patient cases. A 2-mm grid size and 2° angular increment are assumed sufficient to serve as reference values. The dosimetric effect was evaluated using dose–volume histograms, monitor units (MUs), and dose to organs at risk (OARs) for a definite volume corresponding to the dose–volume constraint in lung SBRT. The times required for dose calculations using each parameter set were compared for clinical practicality. Results Larger grid sizes caused a dose increase to the structures and required higher MUs to achieve the target coverage. The discrete beam arrangements at each angular increment led to over- and under-estimated OARs doses due to the undulating dose distribution. When a 2° angular increment was used in both studies, a 4-mm grid size changed the dose variation by up to 3–4% (50 cGy) for the heart and the spinal cord, while a 3-mm grid size produced a dose difference of \u3c1% (12 cGy) in all tested OARs. When a 3-mm grid size was employed, angular increments of 6° and 10° caused maximum dose variations of 3% (23 cGy) and 10% (61 cGy) in the spinal cord, respectively, while a 4° increment resulted in a dose difference of \u3c1% (8 cGy) in all cases except for that of one patient. The 3-mm grid size and 4° angular increment enabled a 78% savings in computation time without making any critical sacrifices to dose accuracy. Conclusions A parameter set with a 3-mm grid size and a 4° angular increment is found to be appropriate for predicting patient dose distributions with a dose difference below 1% while reducing the computation time by more than half for lung SBRT using DCAT

    Dietary taurine intake, nutrients intake, dietary habits and life stress by depression in Korean female college students: a case-control study

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    <p>Abstract</p> <p>Background</p> <p>The purpose of this study was to investigate the dietary taurine intake, nutrients intake, dietary habits and life stress by depression in Korean female college students.</p> <p>Methods</p> <p>In this study, research data were collected in March 2009 and 65 patients with depression and 65 controls without depression participated. The CES-D (Center for Epidemiologic Studies Depression) scale was used for depression measure and controls were matched for age. A 3-day recall method was used for dietary assessment (2 weekdays and 1 weekend day).</p> <p>Results</p> <p>Average height, weight and body mass index (BMI) were 161.3±0.5cm, 55.3±1.0kg and 21.2±0.4kg/m<sup>2</sup> for depression patients and those of control group were 161.4±0.7cm, 53.1±0.8kg and 20.3±0.2kg/m<sup>2</sup>, respectively. Average dietary taurine intakes of depression patients and control group were 89.1 and 88.0 mg/day, respectively. There was no significant difference in dietary taurine intake between depression patients and control group. The average intakes of vitamin A (p<0.05), β-carotene (p<0.01), vitamin C (p<0.05), folic acid (p<0.05) and fiber (p<0.05) of depression patients were significantly lower compared to control group. The average total dietary habit score of depression patients (47.2) was significantly lower than that of control group (51.3) (p<0.01). The average dietary habit scores of “eating meals at regular times” (p<0.05), “eating adequate amount of meals” (p<0.05), “having meals with diverse foods” (p<0.05), “avoiding eating spicy foods” (p<0.01) and “eating protein foods such as meat, fish, eggs, beans more than 2 times a day” (p<0.05) were significantly lower in depression patients compare to control group. The average scores of total life stress (p<0.001) and all stress categories of depression patients were significantly higher than those of control group except faculty problem score.</p> <p>Conclusions</p> <p>These results show that depression patients have poor dietary habits and unbalanced nutrition status. Also depression patients have higher life stress score.</p> <p>Therefore, continuous nutrition education and counselling for good dietary habits and balanced nutrition status are needed to prevent depression in Korean college students.</p

    Ethyl 4-hydr­oxy-2,6-diphenyl-1-(2-thio­morpholinopropano­yl)-1,2,5,6-tetra­hydro­pyridine-3-carboxyl­ate

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    In the title compound, C27H32N2O4S, the thio­morpholine ring adopts a chair conformation and the tetra­hydro­pyridine ring is in a distorted envelope conformation. The mol­ecular structure is stabilized by an intra­molecular O—H⋯O inter­action and the crystal packing is stabilized by an inter­molecular C—H⋯O inter­action, generating an S(6) motif and a dimer of the type R 2 2(18), respectively

    Antiobesity and hypolipidemic effects of lotus leaf hot water extract with taurine supplementation in rats fed a high fat diet

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    <p>Abstract</p> <p>Background</p> <p>Lotus (<it>Nelumbo nucifera</it>) leaf has been used to treat obesity. The purpose of this study was to investigate the antiobesity and hypolipidemic effects of lotus leaf hot water extract with taurine supplementation in high fat diet-induced obese rats.</p> <p>Methods</p> <p>Four week-old male Sprague-Dawley rats were randomly divided into four groups with 8 rats in each group for a period of 6 weeks (normal diet, N group; high fat diet, HF group; high fat diet + lotus leaf hot water extract, HFL group; high fat diet + lotus leaf hot water extract + taurine, HFLT group). Lotus leaf hot water extract was orally administrated to HFL and HFLT groups and the same amount of distilled water was orally administered (400 mg/kg/day) to N and HF groups. Taurine was supplemented by dissolving in feed water (3% w/v).</p> <p>Results</p> <p>The body weight gain and relative weights of epididymal and retroperitoneal adipose tissues were significantly lower in N, HFL and HFLT groups compared to HF group. HFL and HFLT groups showed lower concentrations of total cholesterol, triglyceride and low density lipoprotein cholesterol in serum. HFLT group showed higher the ratio of high density lipoprotein cholesterol/total cholesterol compared to HFL group. HFLT group showed better blood lipid profiles compared to HFL group.</p> <p>Conclusions</p> <p>Lotus leaf hot water extract with taurine supplementation showed antiobesity and hypolipidemic effects in high fat diet-induced obese rats, which was more effective than lotus leaf hot water extract alone.</p

    Activation of spleen tyrosine kinase is required for TNF-α-induced endothelin-1 upregulation in human aortic endothelial cells

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    AbstractEndothelin-1 (ET-1) promotes atherosclerosis. We tested whether spleen tyrosine kinase (Syk) mediates tumor necrosis factor-α (TNF-α)-induced ET-1 upregulation in human aortic endothelial cells (HAECs) and sought to identify the signal pathways involved. TNF-α-induced reactive oxygen species (ROS) activated Syk and phosphatidylinositol 3-kinase (PI3K), which was required for the activation of AP-1 and subsequent ET-1 gene transcription. ROS mediated c-Jun NH2-terminal kinase (JNK) is also required for AP-1 activation, but Syk and PI3K regulated AP-1 activation independently of JNK. Through regulation of ET-1 production, Syk could be implicated in atherosclerosis
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