A simple equipment and colorimetric method for determination of chloroform in water.

Chlorination is a common and successful method for disinfection of water all around the world, especially in developing countries. However, this process can produce trihalomethanes (THMs) byproducts which are carcinogen. The major THM occurring in this process is chloroform. The purpose of this study was to design a simple equipment for colorimetric determination of chloroform in various water samples. The method is based on the colorimetric reaction of chloroform with resorcinol in strong basic medium on a filter paper. Response surface methodology (RSM) was employed to optimize the determination condition. The reagents were immobilized on filter paper and the color change was followed to quantify chloroform without using any analytical instrument. Detection limit and linear range of the proposed method were 0.007 mg/L and 0.011-1.192 mg/L, respectively for analysis of samples with volume of 2.0 L. The method was successfully applied to determine chloroform in different water samples and compared with GC-MS as a standard method. Employing the designed device, purge, trap and analysis steps were performed in a single run which can reduce the uncertainties originated by excessive steps of the analysis.

Auditory memory function in expert chess players.

BACKGROUND: Chess is a game that involves many aspects of high level cognition such as memory, attention, focus and problem solving. Long term practice of chess can improve cognition performances and behavioral skills. Auditory memory, as a kind of memory, can be influenced by strengthening processes following long term chess playing like other behavioral skills because of common processing pathways in the brain. The purpose of this study was to evaluate the auditory memory function of expert chess players using the Persian version of dichotic auditory-verbal memory test. METHODS: The Persian version of dichotic auditory-verbal memory test was performed for 30 expert chess players aged 20-35 years and 30 non chess players who were matched by different conditions; the participants in both groups were randomly selected. The performance of the two groups was compared by independent samples t-test using SPSS version 21. RESULTS: The mean score of dichotic auditory-verbal memory test between the two groups, expert chess players and non-chess players, revealed a significant difference (p≤ 0.001). The difference between the ears scores for expert chess players (p= 0.023) and non-chess players (p= 0.013) was significant. Gender had no effect on the test results. CONCLUSION: Auditory memory function in expert chess players was significantly better compared to non-chess players. It seems that increased auditory memory function is related to strengthening cognitive performances due to playing chess for a long time.

Validation of the 2010 American College of Rheumatology preliminary diagnostic criteria for fibromyalgia in an Iranian population.

The aim of this study was to validate the 2010 American College of Rheumatology (ACR) preliminary criteria for fibromyalgia (FM) in an Iranian population. In this multicenter prospective study, we enrolled 168 FM patients and 110 controls. All participants underwent dolorimetry examination by study assessors and completed a questionnaire containing variables of both the ACR 2010 preliminary and ACR 1990 criteria. We compared the performance of the ACR 2010 criteria with the expert diagnosis as well as the ACR 1990 criteria. Receiver operator characteristic analyses and Youden index were used to evaluate the test characteristics of a set of different cutoff points for two subcomponents of ACR 2010 criteria including widespread pain index (WPI) and symptom severity (SS) scale. Considering expert diagnosis as the gold standard, the ACR 2010 criteria showed comparable specificity with ACR 1990 (92.8 vs. 88.3 %, P = 0.073), but lower sensitivity (58.9 vs. 71.4 %, P = 0.003) and a tendency for lower accuracy (72.4 vs. 78.4 %, P = 0.105). Applying the ACR 1990 criteria as the gold standard, we observed a trend toward an increase in overall accuracy (72.4 vs. 79.1 %, P = 0.064). Optimal test characteristics were achieved for WPI ≥6 and SS scale score ≥4 and improved sensitivity and accuracy of ACR 2010 criteria when compared to expert, 76.1 and 81.7, respectively. The preliminary ACR 2010 criteria performed less desirably in terms of sensitivity in our set of Iranian patients. Selecting lower cutoff points as WPI ≥6 and SS scale score ≥4 improved the diagnostic values of the criteria.

The role of intravitreal bevacizumab in experimental posterior penetrating eye injury.

PURPOSE: The purpose of this study was to investigate the effect of intravitreal bevacizumab on an experimental rabbit model of penetrating posterior ocular injury. METHODS: The right eyes of 40 white New Zealand rabbits were included in a penetrating posterior ocular injury model that was consisted of a 5-mm circumferential incision placed 8 mm behind the limbus at the supratemporal quadrant. They were randomly divided into two groups. The rabbits in Group 1 (n = 20) received 1.25 mg (0.05 mL) of intravitreal bevacizumab via pars plana injection and those in Group 2 (control group, n = 20) received 0.05 mL of intravitreal balanced salt solution. On Day 28, the eyes were enucleated and evaluated by gross inspection and light microscopy. Clearance time of vitreous hemorrhage, presence of fibrous proliferation or retinal detachment, greatest linear dimension of fibrosis, and grade of fibrous extension were regarded as outcome measures. Nominal variables were evaluated by the chi-square or the Fisher's exact test; continuous variables were evaluated using the Mann-Whitney U test. RESULTS: At the end of the surgery, all the eyes had moderate (n = 9 and 7 in the case and control groups, respectively) or severe vitreous hemorrhage (n = 11 and 13 in the case and control groups, respectively) (P = 0.52). Average clearance time of vitreous hemorrhage was 3.42 ± 2.71 and 6.47 ± 3.58 days in bevacizumab and control groups, respectively (P = 0.01). The incidence of ophthalmoscopically visible fibrous proliferation was 31.6% in the bevacizumab group and 63.2% in the control group (P = 0.05). The greatest linear dimension of fibrosis was 0.91 ± 1.14 mm in the bevacizumab group and 2.00 ± 1.58 mm in the control group (P = 0.02). Retinal detachment rate was 11% (n = 2, all rhegmatogenous) and 21% (n = 4, 2 rhegmatogenous and 2 tractional) in the bevacizumab and control groups, respectively (P = 0.66). Choroidal congestion, optic disk edema, and macular edema were seen in 1 eye (5.5%) of the bevacizumab group, whereas they were found in 4 (22%), 4 (22%) and 3 (16.5%) eyes of the control group, respectively. These differences, however, did not reach statistical significance. CONCLUSION: This study showed that intravitreal injection of bevacizumab may reduce the extent of fibrovascular and/or fibrocellular proliferation and may accentuate the clearance of vitreous hemorrhage after an experimental model of posterior penetrating ocular injury in rabbits. These alterations may affect the long-term anatomical and/or functional success rate of posterior segment surgeries in these eyes.