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      • KCI등재

        Effects of short-term atorvastatin use in patients with calcium stones: A randomized placebo-controlled clinical trial

        Fatemeh Taheri,Maryam Taheri,Abbas Basiri,Alireza Khoshdel,Fariba Samadian,Sanaz Tavasoli 대한비뇨의학회 2019 Investigative and Clinical Urology Vol.60 No.6

        Purpose: A few experimental and observational studies have reported that atorvastatin prevents calcium oxalate stone formation. Our study is the first to investigate the effect of atorvastatin on 24-hour urinary metabolites, urinary malondialdehyde (U-MDA) (an oxidative stress marker) and urinary neutrophil gelatinase-associated lipocalin (U-NGAL) (a renal tubular injury marker) in patients with calcium stones and hyperoxaluria. Materials and Methods: This randomized, double-blind, placebo-controlled, parallel-group clinical trial included 32 adults with recurrent calcium stone formation and hyperoxaluria. All participants received a 3-month course of either atorvastatin (20 mg/d) or placebo of an identical shape. Both groups received the usual nutritional care based on the European Association of Urology guidelines. Results: Twenty-eight participants completed the study. Serum levels of total and low-density lipoprotein cholesterol decreased in the atorvastatin group, and these changes were significantly different between groups (p<0.001). No statistically significant differences were observed between intergroup changes of the 24-hour urinary metabolite analysis, the U-MDA to creatinine ratio and the U-NGAL to creatinine ratio. Conclusions: Atorvastatin administration at a dose of 20 mg/d for 3 months did not affect 24-hour urinary metabolite, U-MDA and U-NGAL levels in recurrent calcium stone formers. However, this study could not disprove the preventive role of atorvastatin in kidney stone formation. Future studies should consider a larger sample size, longer follow-up, different drug doses, and measurements of multiple biomarkers of oxidative stress and tubular injury.

      • Optimizing the mix design of pervious concrete based on properties and unit cost

        Taheri, Bahram M.,Ramezanianpour, Amir M. Techno-Press 2021 Advances in concrete construction Vol.11 No.4

        This study focused on experimental evaluation of mechanical properties of pervious concrete mixtures with the aim of achieving higher values of strength while considering the associated costs. The effectiveness of key parameters, including cement content, water to cement ratio (W/C), aggregate to cement ratio (A/C), and sand replacement was statistically analyzed using paired-samples t-test, Taguchi method and one-way ANOVA. Taguchi analysis determined that in general, the role of W/C was more significant in increasing strength, both compressive and flexural, than cement content and A/C. It was found that increase in replacing percent of coarse aggregate with sand could undermine specimens to percolate water, though one-way ANOVA analysis determined statistically significant increases in values of strength of mixtures. Cost analysis revealed that higher strengths did not necessarily correspond to higher costs; in addition, increasing the cement content was not an appropriate scenario to optimize both strength and cost. In order to obtain the optimal values, response surface method (RSM) was carried out. RSM optimization helped to find out that W/C of 0.40, A/C of 4.0, cement content of about 330 kg/m3 and replacing about 12% of coarse aggregate with sand could result in the best values for strength and cost while maintaining adequate permeability.

      • Epidemiological Pattern of Breast Cancer in Iranian Women: Is there an Ethnic Disparity?

        Taheri, Neger Sadat,Nosrat, Sepideh Bakhshandeh,Aarabi, Mohsen,Tabiei, Mohammad Naeimi,Kashani, Elham,Rajaei, Siamak,Besharat, Sima,Semnani, Shahryar,Roshandel, Gholamreza Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.9

        Introduction: Northeastern Iran is known as a high risk area of upper gastrointestinal cancers. Recent reports have suggested a declining trend for these cancers as well as an increase in the incidence of other malignancies including breast cancer. Our present aim was to describe the epidemiological pattern of breast cancer in this region during 2004-2009. Methods: All new cancer cases from public and private diagnostic and therapeutic centers of Golestan province were registered. A structured questionnaire was prepared and used based on the standerds of the International Association of Cancer Registries. The international classification of diseases for oncology was considered for coding. Age standardized incidence rates (ASR) of breast cancer were calculated. Results: A total of 11,038 new cancer cases were registered during 2004-2009, of which, 1,101 (10%) were females with breast cancer. The median age of the breast cancer patients was 46 years. The ASR for breast cancer was 28 per 100,000 person-years. We found an unusual rapid increase in breast cancer rate at the age of 25 years. The ASR of breast cancer was significantly lower in females from Turkmen ethnicity and those from rural areas(P value <0.01). Conclusion: Our study showed high rate of breast cancer in Golestan province of Iran. We found an unusual peak of breast cancer in young women. So, the age of starting screening programs may need to be revised in this area. The rate of breast cancer was significantly lower in women from Turkmen ethnicity. Further studies are warranted to clarify the role of important determinants, especially regarding the ethnic disparity, on breast cancer in this region.

      • Factors Associated with Adherence to Colorectal Cancer Screening among Moderate Risk Individuals in Iran

        Taheri-Kharameh, Zahra,Noorizadeh, Farsad,Sangy, Samira,Zamanian, Hadi,Shouri-Bidgoli, Ali Reza,Oveisi, Helaleh Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.18

        Background: Colorectal cancer is one of the most common neoplasms in Iran. Secondary prevention (colorectal cancer screening) is important and a most valuable method of early diagnosis of this cancer. The objectives of this study were to determine the factors associated with colorectal cancer screening adherence among Iranians 50 years and older using the Health Belief Model. Materials and Methods: This cross-sectional study was conducted from June 2012 to May 2013. A convenience sample of 200 individuals aged 50 and older was recruited from the population at outpatient clinics in teaching hospitals. Data gathering tools were the Champions health belief model scale (CHBMS) with coverage of socio-demographic background and CRC screening information. Multiple logistic regression was performed to identify factors associated with colorectal cancer screening adherence. Results: The mean age of participants was $62.5{\pm}10.8$ and 75.5% were women. A high percentage of the participants had not heard or read about colorectal cancer (86.5%) and CRC screening (93.5%). Perceived susceptibility to colorectal cancer had the lowest percentage of all of the subscales. Participants who perceived more susceptibility (OR =2.99; CI 95%: 1.23-5.45) and reported higher knowledge (OR =1.29; CI 95%: 1.86-3.40) and those who reported fewer barriers (OR =.37; CI 95%:.21-.89), were more likely to have carried out colorectal cancer screening. Conclusions: Our findings indicated that CRC knowledge, perceived susceptibility and barriers were significant predictors of colorectal cancer screening adherence. Strategies to increase knowledge and overcome barriers in risk individuals appear necessary. Education programs should be promoted to overcome knowledge deficiency and negative perceptions in elderly Iranians.

      • SCIESCOPUSKCI등재

        Multiple-enzyme supplementation on digestive traits, carcass characteristics, blood lipid parameters and growth performance of broilers fed a wheat-based diet

        Taheri, Hamid Reza,Shirzadegan, Kayvan Asian Australasian Association of Animal Productio 2017 Animal Bioscience Vol.30 No.9

        Objective: A trial was conducted from 11 to 42 d post-hatch to investigate the effectiveness of the supplementation of a multiple-enzyme preparation (Natuzyme Plus) in a wheat-based diet on digesta viscosity, pH and microbial population, villus morphology, feed passage time, nutrient retention, carcass characteristics, blood lipid parameters and growth performance of broiler chickens. Methods: Three hundreds 10-d-old male Ross 308 chicks were allocated to three diets with five replicates of 20 birds per replicate. Dietary treatments were i) a wheat-based diet (W), ii) W+Natuzyme Plus (WN; 500 mg/kg of the diet), and iii) a corn-based diet (C). Results: Birds fed on the C diet had higher average daily gain (ADG, p<0.01), villus height (VH, p<0.01), total tract apparent retention (TTAR) of nitrogen (NT, p<0.01) and ether extract (EE, p<0.01), nitrogen-corrected apparent metabolizable energy ($AME_n$, p<0.05), relative weight (RW, % of body weight) of carcass (p<0.05), blood concentration of triglyceride (TG, on d 40 [p<0.01]), total cholesterol (TC, on d 22 [p<0.05]) and low density lipoprotein (LDL, on d 22 [p<0.01] and 40 [p<0.05]), and also lower feed conversion ratio (FCR, p<0.01), digesta viscosity (p<0.01), count of coliforms (p<0.01) and Escherichia coli (p<0.01) and epithelium thickness (ET, p<0.05) than those fed on the W diet. ADG, FCR, VH, ET, TTAR of NT and EE, RW of carcass, blood concentration of TG (on d 40), TC (on d 22) and LDL (on d 22 and 40) values of the WN diet did not show a significant (p>0.05) difference compared to those of the C diet. Compared to those of the W diet, the WN diet showed the higher count of Lactobacilli and lower count of coliforms (p<0.01) and digesta viscosity (p<0.01). Conclusion: In general, the results of this study showed that Natuzyme Plus supplementation in a wheat-based diet can be appropriate to achieve a comparable growth performance in broiler chickens to those given the C diet probably through improving digesta viscosity, VH, ET, TTAR of NT and EE, $AME_n$, count of Lactobacilli and coliforms.

      • SCIESCOPUSKCI등재

        Analysis, Design and Implementation of a New Chokeless Interleaved ZVS Forward-Flyback Converter

        Taheri, Meghdad,Milimonfared, Jafar,Namadmalan, Alireza,Bayat, Hasan,Bakhshizadeh, Mohammad Kazem The Korean Institute of Power Electronics 2011 JOURNAL OF POWER ELECTRONICS Vol.11 No.4

        This paper presents an interleaved active-clamping zero-voltage-switching (ZVS) forward-flyback converter without an output choke. The presented topology has two active-clamping circuits with two separated transformers. Because of the interleaved operation of the converter, the output current ripple will be reduced. The proposed converter can approximately share the total load current between the two secondaries. Therefore, the transformer copper loss and the rectifier diodes conduction loss can be decreased. The output capacitor is made of two series capacitors which reduces the peak reverse voltage of the rectifier diodes. The circuit has no output inductor and few semiconductor elements, such that the adopted circuit has a simpler structure, a lower cost and is suitable for high power density applications. A detailed analysis and the design of this new converter are described. A prototype converter has been implemented and experimental results have been recorded with an ac input voltage of 85-135Vrms, an output voltage of 12V and an output current of 16A.

      • SCIESCOPUSKCI등재

        Comparison of Efficiency for Different Switching Tables in Six-Phase Induction Motor DTC Drive

        Taheri, Asghar,Rahmati, Abdolreza,Kaboli, Shahriyar The Korean Institute of Power Electronics 2012 JOURNAL OF POWER ELECTRONICS Vol.12 No.1

        In this paper, different switching tables proposed for the Direct Torque Controlled (DTC) of a six-phase induction machine are simulated and implemented. A six-phase induction motor has 64 space voltage vectors which result in increased complexity in the selecting of inverters switching. The unsuitable selection of a switching table leads to large harmonics especially at low speed and it also reduces drive efficiency. A six-phase induction machine has large zero sequence harmonic currents of the order $6{\kappa}{\pm}1$. These harmonic currents are varied in various techniques. Decreasing this loss is essential in a six-phase induction machine. The main purpose of this paper is to improve the ST-DTC of six-phase induction machines to reduce the voltage and current harmonics and the torque pulsation. Selecting a suitable method for minimizing these harmonics is very important.

      • Epidemiology of Female Reproductive Cancers in Iran: Results of the Gholestan Population-Based Cancer Registry

        Taheri, NegarSadat,Fazel, Abdolreza,Mahmoodzadeh, Habibollah,Omranpour, Ramesh,Roshandel, Gholamreza,Gharahjeh, Saeedeh,Sedaghat, Seyed Mehdi,Poorabbasi, Mohammad,Moghaddami, Abbas,Semnani, Shahryar Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.20

        Background: Malignancies of the female reproductive tract are estimated to be the third most common group of cancers in women. Objectives: We here aimed to present their epidemiological features in Golestan province located in Northeast of Iran. Materials and Methods: Data on primary female reproductive cancers diagnosed between 2004-2010 were obtained from Golestan Population-based Cancer Registry (GPCR). CanReg-4 and SPSS software were used for data entry and analysis. Age standardized incidence rates (ASR) (per 100,000 person-years) were calculated using the world standard population. Poisson regression analysis was used to compare incidence rates. P-values of less than 0.05 were considered as significant. Results: A total of 6,064 cancer cases were registered in Golestan females in the GPCR during 2004-2010, of which 652 cases (11%) were female reproductive cancers. Cancers of the ovary (ASR=6.03) and cervix (ASR=4.97) were the most common. We found significant higher rates in females living in cities than in villages. Our results showed a rapid increase in age specific incidence rates of female reproductive cancers at the age of 30 years. Conclusions: We found significant higher rates of female reproductive cancers among residents of cities than villages. Differences in the prevalence of risk factors including reproductive behavior between the two populations may partly explain such diversity. Our results also showed a rapid increase in incidence rates of these cancers in young age females. Further studies are warranted to determine risk factors of female reproductive cancers in our population.

      • SCISCIESCOPUSKCI등재

        Efficient programmable power-of-two scaler for the three-moduli set {2<sup>n+p</sup>, 2<sup>n</sup> - 1, 2<sup>n+1</sup> - 1}

        Taheri, MohammadReza,Navi, Keivan,Molahosseini, Amir Sabbagh Electronics and Telecommunications Research Instit 2020 ETRI Journal Vol.42 No.4

        Scaling is an important operation because of the iterative nature of arithmetic processes in digital signal processors (DSPs). In residue number system (RNS)-based DSPs, scaling represents a performance bottleneck based on the complexity of intermodulo operations. To design an efficient RNS scaler for special moduli sets, a body of literature has been dedicated to the study of the well-known moduli sets {2<sup>n</sup> - 1, 2<sup>n</sup>, 2<sup>n</sup> + 1} and {2<sup>n</sup>, 2<sup>n</sup> - 1, 2<sup>n+1</sup> - 1}, and their extension in vertical or horizontal forms. In this study, we propose an efficient programmable RNS scaler for the arithmetic-friendly moduli set {2<sup>n+p</sup>, 2<sup>n</sup> - 1, 2<sup>n+1</sup> - 1}. The proposed algorithm yields high speed and energy-efficient realization of an RNS programmable scaler based on the effective exploitation of the mixed-radix representation, parallelism, and a hardware sharing technique. Experimental results obtained for a 130 nm CMOS ASIC technology demonstrate the superiority of the proposed programmable scaler compared to the only available and highly effective hybrid programmable scaler for an identical moduli set. The proposed scaler provides 43.28% less power consumption, 33.27% faster execution, and 28.55% more area saving on average compared to the hybrid programmable scaler.

      • SCIESCOPUSKCI등재

        Power Swing Detection Using rms Current Measurements

        Taheri, Behrooz,Razavi, Farzad The Korean Institute of Electrical Engineers 2018 Journal of Electrical Engineering & Technology Vol.13 No.5

        During a power swing, distance relays may mistakenly spread fault throughout the power grid, causing a great deal of damage. In some cases, such mistakes can cause global outages. For this reason, it is critical to make a distinction between power swings and faults in distance relays. In this paper, a new method is proposed based on RMS measurement to differentiate between faults and power swings. The proposed method was tested on two standard grids, demonstrating its capability in detecting a power swing and simultaneous fault with power swing. This method required no specific configurations, and was independent of grid type and zoning type of distance relays. This feature in practice allows the relay to be installed on any grid with any kind of coordination. In protective relays, the calculations applied to the microprocessor is of great importance. Distance relays are constantly calculating the current RMS values for protection purposes. This mitigates the computations in the microprocessor to detect power swings. The proposed method was able to differentiate between a fault and a power swing. Furthermore, it managed to detect faults occurring simultaneously with power swings.

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