In order to obtain a better heat transfer, it is important to enhance fluid mixing in heat exchangers. Since there are negative effects when heat exchangers are operating in turbulent regime (like significant pressure drop, increased size of the pump) it is necessary to apply the techniques which would provide better fluid mixing when heat exchangers are operating in laminar regime. Investigations have shown that use of sinusoidal instead of flat plates results in this effect. This study is a result of two dimensional simulation of fluid flow between two parallel sinusoidal plates. Simulation was done with the use of modified Openlb code, based on lattice Boltzmann method. Reynolds number was varied from 200 to 1000, and space between the plates was varied from 3cm to 5 cm. Results showed that sinusoidal plates enhance fluid mixing, especially with greater values of Re and smaller space between the plates, which is in agreement with previous investigations.

Subject: The concentration of serum uric acid (SUA) is one of the potential markers of cardiovascular and cerebrovascular diseases, as well as some other severe diseases. In this pharmacological – clinical study we evaluated allopurinol effect on certain values of lipid profile fractions in hyperuricemic patients diagnosed with metabolic syndrome that had pronounced cardiovascular problems, also with diagnosed hypertension. Methods: Research sample comprised 40 clinically treated hyperuricemic patients of both sexes, different ages, classified into several subgroups according to the disease diagnoses. The methods used in the study included: assay analysis, statistical and comparative methods. All clinical measurements were performed with standard IFCC methods on suitable biochemical analyzers. Results: Study established that after the first three months of allopurinol use, there was statistically significant difference in the average value of uric acid compared to the patients’ initial state. During the next three months of therapy no further statistically significant difference in average values of uric acid (p = 0,936) was detected, meaning that the desirable effects of drug use were achieved. Simultaneously, the values of triglycerides, cholesterol and LDL fractions in test subjects increased significantly (p > 0,05). The values of HDL fractions increased after three month therapy with allopurinol, but later their value remained constant. Atherogenic index increased significantly after three and six months of therapy, therewith retaining at upper limit of reference value. Conclusion: The study results confirmed the primary hypothesis, which was that the allopurinol use affects the values of lipid profile fractions in hyperuricemic patients.

Introduction. Every patient with type 2 diabetes mellitus secretes less insulin than necessary for his/her level of insulin sensitivity, and many of them have some degree of insulin resistance. The mix of insulin defi ciency and insulin resistance is different for each patient and, in any patient, it may vary during the course of the disease. The aim of our study was to examine the degree of -cells function and the presence of insulin resistance in patients with a long-standing type 2 diabetes. Methods. The study included 30 patients of both sexes (12 males, 18 females), with the mean values of age 59 years (SD=7.88) and the disease duration of 10 years (SD=5.36). The mean value of BMI was 31 kg/m2 (SD=4.74). The fasting glucose and insulin concentrations and HbA1c in the blood were determined by the standard laboratory methods. The percentages of functional -cells in the pancreas (HOMA%B), insulin sensitivity (HOMA-%S) and insulin resistance (HOMA-IR) were calculated using a HOMA calculator v2.2. Then, the data were analyzed by statistical software SPSS 19. Results. The mean HbA1c was 10 % (SD=1.52) and FBG 12 mmol/L (SD=4.15). The mean insulin was 13 μmol/L (SD=6.11) and HOMA-%B 31 % (SD=18.99). The median value of HOMA-%S was 49% (32.2-82.4) and HOMA-IR 2 (1.2-3.1). 87% of patients had a HOMA-IR >1. Conclusion. The highly reduced -cells function and the consequent insulin defi ciency, usually combined with the moderate insulin resistance was determined in the patients with a long-standing type 2 diabetes mellitus.