13 research outputs found

    Operant Conditioning of Human Upper-Limb Stretch Reflexes

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    Operant conditioning of short-latency reflex (SLR) and H-reflex have been investigated in animals and humans. We modified previously established protocols for conditioning lower limb H-reflexes to up-condition the SLR in brachioradialis muscle and to investigate the effect of such conditioning on the long-latency response (LLR) of synergistic muscles. Our study included 12 healthy participants. Each participant took part in 3 baseline and 27 conditioning sessions in 6 weeks, followed by two additional sessions one month and two months after the last conditioning session. We found an increase in SLR magnitude in 50% of participants (by 15%±2.50). However, there was no significant effect at the population level. We could not find any statistically significant correlation between SLR in the conditioned muscle with SLR and LLR in synergistic muscles. Although our findings in healthy adults were weak, studying patients with spinal cord injury or other motor dysfunctions might show clinically significant results

    Association between air pollution and incidence of dementia: A systematic review and meta-analysis of cohort studies

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    Objective. To estimate the risk of dementia in association with exposure to air pollutants. Methods. Six databases were searched. Cohort studies that reported the hazard ratio (HR) of dementia in association with exposure to air pollutants in adults \u3e 40y were included. For all meta-analyses, the random-effects model was used. Results. A total of 16 and 13 studies were included in the systematic review and the meta-analysis, respectively. Risk of dementia increased by 4% per 1μg/m3 increase in fine particulate matter level (HR, 1.04; 95%CI, [1.02, 1.06]), which was statistically significant. The risk of dementia increased by 3% per 10μg/m3 increase in nitrogen oxides level (HR, 1.03; 95%CI, [0.98, 1.08]), and by 3% per 10μg/m3 increase in nitrogen dioxide level (HR, 1.03; 95%CI, [1.00, 1.07]); however, the associations were not statistically significant Conclusion. This meta-analysis indicates a significant association between exposure to fine particulate matter and incidence of dementia

    Combination of Q-Switched Nd:YAG and Fractional Erbium:YAG Lasers in Treatment of Melasma: A Randomized Controlled Clinical Trial

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    Introduction: Ablative and nonablative lasers have been used to treat melasma. We aimed to assess and compare the combining Q-switched Nd:YAG laser (QSNYL) and fractional erbium:YAG laser (FEYL) with QSNYL alone in treatment of melasma.Methods: This randomized controlled clinical trial was performed in our Research Center during 2013-2014. Women with melasma and without a history of keloid formation, hypersensitivity to hydroquinone, or pigmentary changes due to laser therapy were randomly allocated to receive four sessions of either QSNYL-FEYL combination or QSNYL alone. All patients received topical treatment with Kligman’s formula. Before laser therapy and 4 weeks after the last treatment session, patients’ skin was assessed for changes in skin color, melanin content, and erythema intensity of melasma lesions quantitatively.Results: Finally, 21 patients in QSNYL-FEYL and 20 in QSNYL group (mean age, 38.57 [5.60] and 42.60 [8.44] years, respectively) completed study. The skin color had become lighter in both groups (mean [SD] percentage change of 56.95 [40.29] and 29.25 [13.20] in QSNYL-FEYL and QSNYL groups, respectively) with significantly better results in QSNYL-FEYL group (P = 0.006). Percentage of decrease of melanin content was significantly higher in QSNYL-FEYL group (22.01 [10.67] vs. 7.69 [4.75]; P < 0.001). After adjustment for baseline values, the post treatment intensity of erythema was significantly lower in QSNYL-FEYL group (P < 0.001). The patients reported no adverse events.Conclusion: QSNYL-FEYL was significantly more effective in decreasing melanin content of lesions than QSNYL and led to a lighter skin.

    Results of a Randomized, Open-Label, Clinical Trial Investigating the Effects of Supplementation with Heracleum persicum

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    The present study evaluated the potential benefit of supplementation with Heracleum persicum as an adjunctive therapy to atorvastatin in dyslipidemic subjects. In a randomized, open-label, clinical trial, 100 dyslipidemic subjects were randomly assigned to: (1) H. persicum group (n = 50, completers = 18), receiving H. persicum extract (500 mg/day) + atorvastatin (10 mg/day) for 8 weeks, or (2) atorvastatin group (n =50, completers= 34), receiving only atorvastatin (20 mg/day) for 8 weeks. Weight, body mass index (BMI), lipid profile, and biomarkers of hepatic and renal injury were determined at baseline and at the end of the trial. There were significant reductions in serum total cholesterol and LDL-C in both the H. persicum (p = 0.001) and atorvastatin (p 0.05). Serum triglyceride levels remained statistically unchanged by the end of the trial in both groups (p > 0.05). Serum alanine (p = 0.049) and aspartate aminotransferase (p = 0.013) levels rose in the atorvastatin, but not the H. persicum (p > 0.05) group. In comparison with baseline values, no significant change was observed in weight and BMI, as well as serum levels of creatinine, blood urea nitrogen, and fasting blood sugar in either of the groups (p > 0.05). Apart from HDL-C, the effects of atorvastatin (20 mg/day) on other lipid profile parameters do not appear to be significantly superior to those achieved by combination therapy with H. persicum + atorvastatin (10 mg/day)

    Evaluation of Landfill Gas Generation for Exploitation Energy (Case Study: Landfill No. 2 of Shahinshahr)

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    Background and objective: The paper aims to estimate the environmental gases of Landfill No. 2 in Shahin Shahr (total landfill gas, methane gas and carbon dioxide gas), comparison of gas emissions over a period of 30 years, and the availability of landfill for energy extraction. Methods: The field of research is Landfill No. 2 at Shahin Shahr Recycling Plant (Isfahan) located in Ja’farabad Mountains, whose capacity was completed in 1391 and landfill gas assessment was carried out. The total amount of produced gases, methane and carbon dioxide has been calculated using the first-order degradation model over a period of 30 years. Results: The amount of these gases in Landfill has been calculated from 1394 to 1424.The results show that the amount of landfill gases has declined over time. The most amounts of methane and carbon dioxide production is about 1050000 and 287000 kilograms in 1394 and the least amount of methane and carbon dioxide production is estimated about 174 and 476 thousand kilograms, respectively, in 1424. The total volume of gases produced in this landfill has been estimated to be about 15 million cubic meters in 30 years, of which 27 percent are methane and 73 percent are carbon dioxide. The amount of methane and carbon dioxide gas is estimated to be about 15 million and 42 million kilograms in 30 years, respectively. Conclusion: Generally, landfill gases have declined over time. It is recommended to use energy recovery technologies for controlling greenhouse gas emissions and generation of required energy for the ShahinShahr recycling plant in order to use this volume of gas. &nbsp

    Comorbidity of Leishmania major with cutaneous sarcoidosis

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    Background: leishmaniasis infection might manifest as sarcoidosis; on the other hand, some evidences propose an association between sarcoidosis and leishmaniasis. Most of the times, it is impossible to discriminate idiopathic sarcoidosis from leishmaniasis by conventional histopathologic exam. Aim: We performed a cross-sectional study to examine the association of sarcoidosis with leishmaniasis in histopathologically diagnosed sarcoidal granuloma biopsy samples by polymerase chain reaction (PCR). Materials and Methods: We examined paraffin-embedded skin biopsy samples obtained from patients with clinical and histopathological diagnosis as naked sarcoidal granuloma, referred to Skin Research Center of Shaheed Beheshti Medical University from January 2001 to March 2010, in order to isolate Leishmania parasite. The samples were reassessed by an independent dermatopathologist. DNA extracted from all specimens was analyzed by the commercially available PCR kits (DNPTM Kit, CinnaGen, Tehran, Iran) to detect endemic Leishmania species, namely leishmania major (L. major). Results: L. major was positive in PCR of Eight out of twenty-five examined samples. Conclusion: Cutaneous leishmaniasis may be misinterpreted as sarcoidosis; in endemic areas, when conventional methods fail to detect Leishmania parasite, PCR should be utilized in any granulomatous skin disease compatible with sarcoidosis, regardless of the clinical presentation or histopathological interpretation

    Cutaneous Leishmaniasis with Unusual Clinical and Histological Presentation: Report of Four Cases

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    Old world cutaneous leishmaniasis (OWCL) usually causes a single, self-healing and uncomplicated lesion mainly on the exposed area of body. This report presents four cases of OWCL from Iran that misdiagnosed with sarcoidosis, lymphoma, and acne agminata. Two out of four patients showed a history of purplish red plaques for at least 5 years who misdiagnosed as sarcoidosis because of histological and clinical characteristics. The other one presented with flesh-colored nodules disseminated all over his skin that was misdiagnosed as lymphoma for ten years. The last patient was misdiagnosed as acne agminata due to tuberculoid reactions in examination of the lesion biopsy. All the patients responded to the treatment with meglumine antimonate

    Development of Porous Polyacrylonitrile Composite Fibers: New Precursor Fibers with High Thermal Stability

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    Polyacrylonitrile (PAN) fibers with unique properties are becoming increasingly important as precursors for the fabrication of carbon fibers. Here, we suggest the preparation of porous PAN composite fibers to increase the homogeneity and thermal stability of the fibers. Based on the thermodynamics of polymer solutions, the ternary phase diagram of the PAN/H2O/Dimethylformamide (DMF) system has been modeled to introduce porosity in the fibers. Adding a conscious amount of water (4.1 wt.%) as a non-solvent to the PAN solution containing 1 wt.% of graphene oxide (GO), followed by wet spinning, has led to the preparation of porous composite fibers with high thermal stability and unique physicochemical properties. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) results elucidate that PAN/GO/H2O porous composite fibers have a higher thermal decomposition temperature, increased residual weight, reduced heat release rate, and higher crystallinity in comparison with the pristine PAN fibers, being a promising precursor for the development of high-performance carbon fibers. The results show a promising application window of the synthesized PAN fibers in electronic and electrochemical devices

    Development of Porous Polyacrylonitrile Composite Fibers: New Precursor Fibers with High Thermal Stability

    Get PDF
    Polyacrylonitrile (PAN) fibers with unique properties are becoming increasingly important as precursors for the fabrication of carbon fibers. Here, we suggest the preparation of porous PAN composite fibers to increase the homogeneity and thermal stability of the fibers. Based on the thermodynamics of polymer solutions, the ternary phase diagram of the PAN/H2O/Dimethylformamide (DMF) system has been modeled to introduce porosity in the fibers. Adding a conscious amount of water (4.1 wt.%) as a non-solvent to the PAN solution containing 1 wt.% of graphene oxide (GO), followed by wet spinning, has led to the preparation of porous composite fibers with high thermal stability and unique physicochemical properties. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) results elucidate that PAN/GO/H2O porous composite fibers have a higher thermal decomposition temperature, increased residual weight, reduced heat release rate, and higher crystallinity in comparison with the pristine PAN fibers, being a promising precursor for the development of high-performance carbon fibers. The results show a promising application window of the synthesized PAN fibers in electronic and electrochemical devices
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