26 research outputs found

    Extended Functionalities of Photovoltaic Systems with Flexible Power Point Tracking:Recent Advances

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    The power system is experiencing an ever-increasing integration of photovoltaic power plants (PVPPs), which leads demand on the power system operators to force new requirements to sustain with quality and reliability of the grid. Subsequently, a significant quantity of flexible power point tracking (FPPT) algorithms have been proposed in the literature to enhance functionalities PVPPs. The intention of FPPT algorithms is to regulate the PV power to a specific value imposed by the grid codes and operational conditions. This will inevitably interfere the maximum power point tracking (MPPT) operation of PV systems. Nevertheless, the FPPT control makes PVPPs much more grid-friendly. The main contribution of this paper is to comprehensively compare available FPPT algorithms in the literature from different aspects and provide a benchmark for researchers and engineers to select suitable FPPT algorithms for specific applications. A classification and short description of them are provided. The dynamic performances of the investigated algorithms are compared with experimental tests on a scaled-down prototype. Directions for future studies in this area are also presented.MOE (Min. of Education, S’pore)Accepted versio

    Structural and functional analysis of the nucleotide and DNA binding activities of the human PIF1 helicase

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    Pif1 is a multifunctional helicase and DNA processing enzyme that has roles in genome stability. The enzyme is conserved in eukaryotes and also found in some prokaryotes. The functions of human PIF1 (hPIF1) are also critical for survival of certain tumour cell lines during replication stress, making it an important target for cancer therapy. Crystal structures of hPIF1 presented here explore structural events along the chemical reaction coordinate of ATP hydrolysis at an unprecedented level of detail. The structures for the apo as well as the ground and transition states reveal conformational adjustments in defined protein segments that can trigger larger domain movements required for helicase action. Comparisons with the structures of yeast and bacterial Pif1 reveal a conserved ssDNA binding channel in hPIF1 that we show is critical for single-stranded DNA binding during unwinding, but not the binding of G quadruplex DNA. Mutational analysis suggests that while the ssDNA-binding channel is important for helicase activity, it is not used in DNA annealing. Structural differences, in particular in the DNA strand separation wedge region, highlight significant evolutionary divergence of the human PIF1 protein from bacterial and yeast orthologues

    Prevalence and genotyping identification of Cryptosporidium in adult ruminants in central Iran

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    Background Apicomplexan parasites of the genus Cryptosporidium infect a wide range of animal species as well as humans. Cryptosporidium spp. can cause life threatening diarrhea especially in young animals, children, immunocompromised patients and malnourished individuals. Asymptomatic cryptosporidial infections in animals can also occur, making these animals potential reservoirs of infection. Methods In the present study, a molecular survey of Cryptosporidium spp. in ruminants that were slaughtered for human consumption in Yazd Province, located in central Iran was conducted. Faeces were collected per-rectum from 484 animals including 192 cattle, 192 sheep and 100 goats. DNA was extracted from all samples and screened for Cryptosporidium by PCR amplification of the 18S rRNA gene. Positives were Sanger sequenced and further subtyped by sequence analysis of the 60 kDa glycoprotein (gp60) locus. Results In total, Cryptosporidium spp. were detected in 22 animals: C. andersoni and C. bovis in seven and two cattle faecal samples, respectively, C. ubiquitum in five sheep, and C. xiaoi in six sheep and two goat samples, respectively. To our knowledge, this study provides for the first time, molecular information concerning Cryptosporidium species infecting goats in Iran, and is also the first report of C. ubiquitum and C. xiaoi from ruminants in Iran. Conclusion The presence of potentially zoonotic species of Cryptosporidium in ruminants in this region may suggest that livestock could potentially contribute to human cryptosporidiosis, in particular among farmers and slaughterhouse workers, in the area. Further molecular studies on local human populations are required to more accurately understand the epidemiology and transmission dynamics of Cryptosporidium spp. in this region

    COMPARE CPM-RMI Trial: Intramyocardial transplantation of autologous bone marrow-derived CD133+ Cells and MNCs during CABG in patients with recent MI: A Phase II/III, multicenter, placebo-controlled, randomized, double-blind clinical trial

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    Objective: The regenerative potential of bone marrow-derived mononuclear cells (MNCs) and CD133+ stem cells in the heart varies in terms of their pro-angiogenic effects. This phase II/III, multicenter and double-blind trial is designed to compare the functional effects of intramyocardial autologous transplantation of both cell types and placebo in patients with recent myocardial infarction (RMI) post-coronary artery bypass graft. Materials and Methods: This was a phase II/III, randomized, double-blind, placebo-controlled trial COMPARE CPM-RMI (CD133, Placebo, MNCs - recent myocardial infarction) conducted in accordance with the Declaration of Helsinki that assessed the safety and efficacy of CD133 and MNCs compared to placebo in patients with RMI. We randomly assigned 77 eligible RMI patients selected from 5 hospitals to receive CD133+ cells, MNC, or a placebo. Patients underwent gated single photon emission computed tomography assessments at 6 and 18 months post-intramyocardial transplantation. We tested the normally distributed efficacy outcomes with a mixed analysis of variance model that used the entire data set of baseline and between-group comparisons as well as within subject (time) and group�time interaction terms. Results: There were no related serious adverse events reported. The intramyocardial transplantation of both cell types increased left ventricular ejection fraction by 9 95% confidence intervals (CI): 2.14% to 15.78%, P=0.01 and improved decreased systolic wall thickening by -3.7 (95% CI: -7.07 to -0.42, P=0.03). The CD133 group showed significantly decreased non-viable segments by 75% (P=0.001) compared to the placebo and 60% (P=0.01) compared to the MNC group. We observed this improvement at both the 6- and 18-month time points. Conclusion: Intramyocardial injections of CD133+ cells or MNCs appeared to be safe and efficient with superiority of CD133+ cells for patients with RMI. Although the sample size precluded a definitive statement about clinical outcomes, these results have provided the basis for larger studies to confirm definitive evidence about the efficacy of these cell types (Registration Number: NCT01167751). © 2018 Royan Institute (ACECR). All Rights Reserved

    Factors Affecting Quality of Life after Menopause in Women,

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    Introduction: Most women experience significant changes in quality of life(QOL) during and after menopausal and few researchers have quantified these changes. The aim of the present research was to assess quality of life(QOL) and determine factors related to its impairment among postmenopausal Iranian women. Methods: This cross-sectional study was conducted by cluster sampling method among 300 post-menopausal women in Yazd, Islamic Republic of Iran in 2008. Data was collected using the menopause quality of life questionnaire(MENQOL) by interview. Content validity and Cronbach's alpha were used respectively to ensure the validity and reliability of the questionnaires. Inferential and descriptive statistics via SPSS.15 software were used for data analysis. Results: The mean scores for quality of life in various dimensions were as follows: vasomotor dimension 12.34±4.71, psychological dimension 18.15±8.89, physical dimension 41.09±16.37 and in sexual dimension it was 10.97±6.52. There were significant relationships between psychological , physical and sexual dimensions and education level, economic level ,health level (p < 0.05) regardless of Spearman’s correlation, There were significant relationships between ,physical and sexual dimensions and number of pregnancies and age(p < 0.05). Conclusion: Menopause causes a decrease in quality of life that is dependent on work and other sociodemographic variables. It is therefore necessary to develop effective interventional programs to improve quality of life after menopause

    A survey on knowledge, attitude and practice of high consumption households towards proper use of water in Yazd

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    Background: Population growth, urban development due to the migration to the cities and the increasing demand are of the component that influences on volume of water available. therefore water conservation in cities, espically in yazd is very important. Methods: This research as a cross-sectional study was conducted on high consumption households. Sampling was carried out to cluster method and in two stages, finally 188 questionnaires by SPSS statistical software (T-test, Mann-Whitney) were analyzed. Results: Average and SD of knowledge scores 60.04 &plusmn; 15.5, the attitude 22.28 &plusmn; 3.97 and the practice was 11.6 &plusmn; 3.63. This study showed that there is a statistically significant association between total knowledge with job and sex. The results of factor analysis indicated that the category of &quot;other parts of the house(cooler, washing automobiles,devices of reducer water consumption, etc),&quot; the highest and category of &quot;causes of water loss at house (washing yard, water leak from pipes, non-closure water faucet when brushing your teeth, etc.)&quot; had the lowest contribution in the states of total knowledge. There isn&rsquo;t any statistically significant association between the attitudes and practice of households in all the variables. Conclusion: The results showed that studied households have relatively good level of practice than the water conservation behaviors. However, intervention efforts to promote these behaviors to a higher level, is important and necessary

    The Knowledge, Attitude & Practice of Women Referred to Health Centers of Yazd on Moldy Food Contaminated with Aflatoxin

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    Introduction: Aflatoxins are toxic metabolites produced by certain fungi in/on foods and feeds. The damage they do to DNA can be mutagenic, and also carcinogenic with liver cancer. The aim of this study was to The effect of education on knowledge, attitude & practice of women referred to health centers of Yazd on moldy food contaminated with aflatoxin. Materials and Methods: This study was a cross sectional-descriptive study that was done in 2014. One hundred and fifty - two women were selected among women who were referred to health centers of Yazd. The Sampling was conducted in multi stages. The data was collected by a researcher-developed questionnaire. The validity and reliability of the questionnaire have been confirmed by content validity, face validity and equivalent reliability. The collected data was analyzed by SPSS20. Results: 107 (70%) of the patients studied to the poor knowledge of aflatoxins and Only 6.2% of them were relatively good knowledge. The performance levels were a 38 (25%), good performance, 108 (1/71%), moderate performance and 6 (9/3%) had poor performance. 0.25%, 74.3% and 0.7% Participant to the hazards food contaminated with aflatoxins were moldy and positive, average and negative attitude, respectively. Conclusions: Based on our findings, Poor knowledge of participants to aflatoxin, and the average of the attitudes and performance of most of the participants. Is necessary to provide strategies to increase public awareness in order to increase the level of attitude and function and reduce exposure to aflatoxin

    Evaluation of serum lipoproteins - A and its Association with Inflammatory Markers in Patients with Rheumatoid Arthritis

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    Introduction: Several studies suggest that lipoprotein (a) [Lp(a)] act as acute phase reactant and is associated with early atherosclerosis in rheumatoid arthritis (RA). Thus, the purpose of this study was to determine the concentration of serum LP (a) and its association with inflammatory markers in RA patients compared to healthy individuals. Methods: The study participants consisted of 100 patients with rheumatoid arthritis and 100 healthy controls. The concentration of LP(a), RF,CRP was measured using Immunoturbidometric method. Results: Average of lipoprotein - a in patients with rheumatoid arthritis was 32.41 ± 2.33 SDmg/dl which was significantly higher than the control group with a mean concentration of 20.50 ± 1.03 SD mg/ dl (P=.001). The results showed that patient's serum lipoproteins – a concentrations was higher significantly in women with rheumatoid arthritis (34.63 ± 25.020mg/dl) than women in the control group (20.60 ± 10.56 mg/dl) (P = 0.001). However, no significant difference was observed between the mean serum LP(a) concentrations in male patients and the control (p = 0.304). CRP mean was 4.05 ±2.04 SDmg/dl and 17.87±1.48 SD mg/dl respectively in control and patient groups. Furthermore, RF mean in control and patient groups was 9.11±2.33SDmg/dl and 15.42 ± 8.64SD mg/dl respectively. Conclusion: The female patients' serum LP(a) concentration was higher significantly than females in the control group. Therefore, it can be concluded that increased concentration of lipoprotein - a may be associated with the patient's sex

    Molecular typing of Giardia duodenalis in cattle, sheep and goats in an arid area of central Iran

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    Giardia duodenalis is one of the most common intestinal parasites in humans as well as livestock and wildlife. It is of both public and veterinary health importance in developing nations. A molecular survey of Giardia duodenalis assemblages in ruminants from Yazd Province, Iran was conducted on 484 animal faecal samples collected per rectum from slaughtered ruminants including 192 cattle, 192 sheep and 100 goats from June to November 2017. Species-specific and assemblage-specific PCRs for assemblages A, B and E at the triose phosphate isomerase (tpi) gene were performed, and samples positive for Giardia were confirmed by sequencing. In total, 25 (5.16%) of examined faecal samples including eight cattle (4.2%), twelve sheep (6.2%) and five goats (5%) were infected with G. duodenalis. Assemblage-specific PCR detected G. duodenalis assemblage E in seven faecal samples (six in sheep and one in a goat). Assemblages A and B were not detected. This study provides the first insight into Giardia infection in slaughtered livestock in Iran. Although the prevalence of infection with Giardia in this hot-arid area of Iran was low, educating people about direct contact with livestock such as farmers and abattoirs workers about this zoonotic infection is important
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