The Concentration of Surfactant and organic co - solvent in the micellar mobile phase have significant effects on retention and selectivity in micellar Liquid chromatography (MLC). As a result the effects of concentration of sodium dodecyl sulfate (SDS) and isopropanol on retention and selectivity were evaluated simultaneously. The tridimensional curve of variation of selectivity with the concentrations of isopropanol and SDS for separation of phenylthiohydantion amino acids indicate that optimum concentration of isopropanol and SDS are 3% (V/V) and 0.015 M respectively. The effect of pH in mobile phase at the range of 3.14 - 6.26 showed an increase in selectivity at higher pH for separation of PTH - amino acids.

Introduction: Some factors such as peritonitis can cause decrease ultrafiltration and adequacy of peritoneal dialysis. Serum PTH and calciumphosphor (Ca-P) product can result in extraosseous calcification such as calcification of peritoneal membrane. The aim of this study is to evaluate of effect of serum PTH and Ca-P product on membrane function in CAPD patients.Methods: A multicenter, retrospective cohort study was carried out on 1284 patients receiving CAPD at least three months. According to first six months measurement of serum PTH and Ca-P product, patients were calcified into three groups (PTH<150, PTH between 150 to 300, and PTH ³ 300) and two groups (Ca-P product<55, Ca-P product ³ 55), respectively. According to classified PTH and Ca-P product, the baseline GFR, total Cr clearance, Kt/v and UF were compared with the last these variables.Results: The mean age was 51 ± 16 (18 to 92 years).Patients had PTH<150, 52%, PTH between 150 to 300, 33%, and PTH ³ 300, 14%. Ca-P product<55 and  ³ 55 were in 67% and 12% of patients, respectively. In the end of the study, patients with Ca-P product ³ 55 had more frequency of total Cr clearance<70 and Kt/v<2.1 compared with patients with Ca-P product<55 (57% versus 37%, P<.0001) and (65% versus 45%, P<.001).There was no difference between Ca-P product groups regarding GFR. There were no differences between PTH groups regarding last Kt/v, total Cr clearance, and GFR.Conclusions: High serum Ca-P product can decrease Kt/v and total Cr clearance. However, serum PTH has no effects on PD adequacy and GFR.

The computation of the inverse roots of matrices arises in evaluating unsymmetric eigenvalue problems, solving nonlinear matrix equations, computing some matrix functions, control theory and several other areas of applications. It is possible to approximate the matrix inverse PTH roots by exploiting a specialized version of Newton's method, but previous researchers have mentioned that some iterations have poor convergence and stability proper- ties. In this work, a stable recursive technique to evaluate an inverse PTH root of a given matrix is presented. The scheme is analyzed and its properties are investigated. Computational experiments are also performed to illustrate the strengths and weaknesses of the proposed method.

Background: The role of high levels of parathyroid hormone in the development ofanemia either directly or by mediating mechanisms is unclear, and there is acontroversy about the pathophysiological role of parathyroid hormone (PTH) in thedevelopment and intensification of anemia associated with renal disease. The aim ofthis study was to investigate the relationship between anemia and parathyroid hormoneand dialysis adequacy in chronic hemodialysis patients. Methods: A cross-sectional study was performed in patients undergoing dialysis inSoodeh Hemodialysis Center, Vavan city, Tehran province, Iran, in two years(September 2013 to September 2015). Patients with age>18 years who underwentdialysis for at least three months were enrolled. Anemia was calculated based on theabsolute amount of hemoglobin, hematocrit, and the percentage of patients whoachieved the hemoglobin treatment goal of more than 11 g/dL. Parathyroid hormonelevels were measured intact PTH and enzyme immunoassay (EIA) method. Results: 176 patients who had entry criteria participated in this study. Patients included102 males (58%) and 74 women (42%). The mean age of the patients was 54. 14± 13. 98years (18-85 years). The mean weight of patients was 68. 07± 14. 17 kg (36-120 kg). 23(13. 1%) of the patients had a previous history of kidney transplantation. Of the 176patients, only one had a history of parathyroidectomy (0. 6%). The mean dialysis time inthe patients was 6. 38± 5. 29 years (1-28 years). The type of dialysis access in 132patients (75%) was AV fistula and in 44 patients (25%) was Shaldon catheter. Themean erythropoietin intake of patients was 10, 000 units per week. The mean ofhemoglobin, hematocrit and PTH were 10. 73 g/dl 33. 6% and 403 pg/ml, respectively. Conclusion: The findings of the study showed that there was no significant correlationbetween hemoglobin and hematocrit levels with parathyroid hormone levels anddialysis adequacy. Increased levels of serum iron, total iron binding capacity (TIBC)and resistance to erythropoietin were associated with a decrease in hematocrit levelsdue to decreased hemoglobin levels and resistance to erythropoietin.

Multi-factor patterns used to predict stock returns are static patterns, and dynamic changes over time are influenced by hidden factors such as government economic policies, crises, and the like that lead to a breakdown in returns. Stock and changes are not like a price bubble or a sharp drop in price. Using the Fama-McButt regression in a dynamic estimation of the factors influencing factors, and in particular the distinction between the effects of hidden and overt factors affecting the company's future performance, a more accurate estimate can be made in the turbulent conditions of Iran's economy. A random sample of Tehran Stock Exchange companies during the monthly periods in a 10-year period ending on 2019, have been tested. The results showed that, based on the Gibbons test (1987), only a pattern based on the Q pattern can be able to explain anomalies in stock returns. Also, the Q-factor model is able to explain the anomaly of optional commitment items, research and development and return (PTH) costs.

Background: Control of the phosphorus, parathyroid hormone, and serum lipids in dialysis’ patients is very important and can be done in many ways. The purpose of the study was to determine the effect of niacin on the serum phosphorus, parathyroid hormone and lipid profile among hemodialysis patients.Materials and methods: This double blind controlled randomized study was done on 120 dialysis patients whom were divided into two groups: 60 patients (taking niacin) and 60 patients as control groups (taking placebo). Niacin was prescribed as increasing dose from 200 mg to 600 mg monthly in three steps. Phosphorus, PTH and lipid profile were measured in the both groups. P-value<0.05 was considered as significant.Results: 40 patients of case group (66.7%) and 37 patients (61.7%) of control group were male. Niacin significantly decreased serum levels of phosphorus (p<0.001) and parathyroid hormone (PTH) (p<0.001), also it significantly increased serum levels of HDL (p<0.01). Conclusion: Nicotinic acid can decrease serum phosphorous and PTH level, and increase HDL cholesterol level. However, it needs a well design and larger trial study for determining the most effective doses of the nicotinic acid.