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In STEMNET's report, 76% of 500 teachers interviewed stated that joining the STEM Club increased students' ability to solve real-world problems. This study aims to develop a valid and reliable measurement tool for evaluating STEM clubs. The research sample consisting of 149 teachers who carry out STEM club activities in schools in Turkey was determined using the purposive sampling method. Content and construct validity and reliability analyses have been performed for this purpose. To ensure content validity, (1) a pool of questions based on the literature was created, (2) draft scale items were determined, (3) an expert was allowed to check them, and (4)item difficulty and discrimination index were calculated. To ensure construct validity, (1) exploratory factor analyses (EFA) and (2) confirmatory factor analyses (CFA) were performed on both the same and different samples. As a result of the analyses, having the same data set be analyzed with different software was sufficient for verifying the factor structure. A three-factor structure consisting of 29 items was obtained, which explains 52% of the variance. Cronbach's alpha of reliability for the overall scale was calculated as 0.92. As a result, a valid and reliable scale was determined to have been developed for researchers and program practitioners to evaluate STEM clubs. Suggestions have been made that the scale can be used on STEM clubs at the provincial, district, and school levels to determine their efficiency and productivity.

In the present study, the potential of barium zirconate (BaZrO₃; 1-5 wt%) on the sinterability, and properties of bovine hydroxyapatite (BHA) was evaluated. BHA decomposed into beta and alpha-tricalcium phosphate (β and α-TCP) at a 4.7% rate. Tetracalcium phosphate (TTCP) was detected as the decomposition phase in the BaZrO₃ added BHAs, and it increased up to 10.7% with an increasing BaZrO₃ ratio. In addition to TTCP, the phases of BaZrO₃, Ba₂ZrO₄, σ-Ba₂P₂O₇, Ba₃P₂O₈ and CaZrO₃ were detected in the composites. The addition of BaZrO₃ at an amount of 3 wt% has a higher potential than the others to improve the sinterability and properties of BHA. It contributed to the increase in the fracture toughness from 0.99 ± 0.13 to 1.80 ± 0.12 MPam1/2 and the compressive strength from 115.75 ± 4.27 to 173.66 ± 13.61 MPa, and the decrease in the brittleness index from 4.24 ± 0.31 to 2.45 ± 0.15 μ-1/2. The in-vitro bioactivity of BHA also increases with the additional BaZrO₃. However; it is recommended to be used in applications that do not require load bearing in the human body due to its insufficient fracture toughness.

In the present paper, the effect of La2O3 (0.25, 0.5 and 1 wt.%) addition on the phase stability, porosity, density, hardness, fracture toughness, compressive strength and brittleness index of hydroxyapatite modified with 1 wt.% of MgO was investigated. Hydroxyapatite (HA) without additives sintered at 1300°C has mixture of dominant hydroxyapatite phase with beta-tricalcium phosphate (α-TCP), alpha-tricalcium phosphate (β-TCP) and calcium oxide (CaO) phases. The microstructure is characterized with transgranular microcracks and oversized grains. Although the density and hardness of the pure HA increased with increasing temperature, a steady decrease in fracture toughness (from 0.96 to 0.71MPa•m1/2) and compressive strength (from 130.2 to 65.6MPa) was observed. For the HA modified with 1 wt.% of MgO the highest compressive strength (183.2MPa) and fracture toughness (1.47MPa•m1/2) were obtained at 1200°C and at this temperature the brittleness index was 3.24 μm-1/2. Increase in the sintering temperature led to the increase of the brittleness index of the pure HA,MgO modified HA and La2O3-MgO modified HA samples. The addition of 1 wt.%La2O3 to 1 wt.% MgO-HA contributed to the increase in the compressive strength of about 10%(from 183.2 to 202.0MPa), fracture toughness of about 69% (from 1.37 to 2.32MPa•m1/2) and also decrease of the brittleness index from 3.24 to 2.18 μm-1/2. The best performance after sintering at 1300°C was obtained for the MgO-HA sample with 0.25wt.% La2O3. As a result of this study, a new candidate material for biomedical application with superior mechanical properties and the phases that do not cause adverse reactions in the human body could be 1 wt.% MgO-HA modified with 1 wt.% La2O3 and sintered at 1200°C.

Objective(s): We aimed to investigate the levels of transient receptor potential melastatin (TRPM) gene expression, and the antioxidant and histopathologic effect of thymoquinone (Tmq) in the hepatic I/R rat model. Materials and Methods: Fifty Wistar rats were divided into 5 groups. Group 1: Control; Group 2: Sham; Group 3: Hepatic I/R (45 min/45 min); Group 4: Tmq (50 mg/kg); Group 5: Tmq+I/R (ten days before I/R at the dose of 50 mg/kg of Tmq). The hepatic I/R (45min/45min) model was performed at the portal vein and the hepatic artery with atraumatic vascular clamp in the ischemia groups. The liver tissues and blood samples that were taken at the end of the study were evaluated for histopathologic and biochemical analysis. Besides TRPM gene expression levels were determined in liver tissues. It was seen that cellular swelling, congestion, PNL, and apoptosis parameters statistically decreased in Tmq and Tmq+I/R groups in comparison with the I/R group in histopathological evaluation. Results: It was observed that biochemical parameters, AST, ALT, GGT, LDH, creatinine, and urea levels significantly increased in the I/R group as compared with, sham, Tmq, and Tmq+I/R groups. It was found that TRPM2,6,7,8 gene expression decreased significantly in Tmq+I/R groups as compared to the I/R group. Conclusion: We showed that thymoquinone can inhibit the entry of Ca+2 into the cell by decreasing TRPM2,6,7,8 gene expression. Based on our findings, we think that Tmq application in the treatment of liver diseases due to I/R damage may be important in terms of both ischemia and apoptosis and can also be used in the treatment of liver-related diseases. [ABSTRACT FROM AUTHOR]

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Aim: Total parenteral nutrition (TPN) is a technique which is use to give vitally mandatory substances in to the venous compartments whenever the gastrointestinal system cannot be used by the patients. Telomerase catalyzes DNA synthesis, which is necessary to maintain telomere length and stabilize the genome to allow continued cell proliferation. In this study, we explored the effects of TPN administration on telomerase reverse transcriptase (TERT) expression in various tissue and serum telomerase level. Material and Methods: In this study a number of 42 same-aged albino, equal number of male and female, new zealand rabbits were use, divided in to three groups. Group 1 rabbits received TPN for 10 days via a central venous catheter. Group 2 received 50 mL/ kg/day physiological saline via a central venous catheter. Group 3 served as the control group. The rabbits were sacrificed after 10 days, and serum telomerase levels were measured by enzyme-linked immunosorbent assay. TERT expression in gonadal, liver, jejunum, and skin tissues were determined immunohistochemically. Blood samples were obtained before and after TPN and saline administration in the TPN and serum saline groups, respectively, and at the end of the experiment in the control group. Results: Telomerase expression in liver, gonads and serum level of TPN group was significantly higher than control and serum saline groups. Conclusion: TPN may be a positive effect in liver and gonadal telomer kinetic. However, we think that TPN increases DNA damage throughout the body. [ABSTRACT FROM AUTHOR]

Mean platelet volume (MPV) has been reported to be related to inflammation. Prostate-specific antigen (PSA) is a protein produced by the prostate, and this protein may be elevated for several reasons, including prostatitis, benign prostatic hyperplasia, and/or cancer. The aim of the current study was to investigate the predictive effect of MPV values on nonsymptomatic prostatitis diagnosis and the relation between MPV and PSA. A total of 275 patients, 89 affected by benign prostate hyperplasia, 94 by prostate adenocancer, and 92 by prostatitis were included in the current study. PSA, total blood count parameters, and urine analysis were investigated. Findings were compared with the groups. The correlation between MPV and the other parameters were analyzed. Univariate and multivariate logistic regression analysis was performed to determine independent predictors of nonsymptomatic prostatitis diagnosis. MPV was significantly higher in patients with nonsymptomatic prostatitis than the other groups. There were negative correlations between MPV and age, total PSA or free PSA (r = −.123; p = .042, r = −.235; p < .001, r = −.184; p = .006, respectively). According to multivariate regression model, only MPV was identified as the predictive factor for nonsymptomatic prostatitis (odds ratio: 1.451, 95% confidence interval [1.116, 1.887], p = .005). MPV, in the absence of other reasons that increased the MPV level, was significantly increased in cases with nonsymptomatic prostatitis; this increase is significantly higher than elevated PSA level in nonsymptomatic prostatitis patients. MPV could have a predictive value for the diagnosis of nonsymptomatic prostatitis. [ABSTRACT FROM AUTHOR]