نتائج البحث

MBRLSearchResults

mbrl.module.common.modules.added.book.to.shelf
تم إضافة الكتاب إلى الرف الخاص بك!
عرض الكتب الموجودة على الرف الخاص بك .
وجه الفتاة! هناك خطأ ما.
وجه الفتاة! هناك خطأ ما.
أثناء محاولة إضافة العنوان إلى الرف ، حدث خطأ ما :( يرجى إعادة المحاولة لاحقًا!
هل أنت متأكد أنك تريد إزالة الكتاب من الرف؟
{{itemTitle}}
{{itemTitle}}
وجه الفتاة! هناك خطأ ما.
وجه الفتاة! هناك خطأ ما.
أثناء محاولة إزالة العنوان من الرف ، حدث خطأ ما :( يرجى إعادة المحاولة لاحقًا!
    منجز
    مرشحات
    إعادة تعيين
  • الضبط
      الضبط
      امسح الكل
      الضبط
  • مُحَكَّمة
      مُحَكَّمة
      امسح الكل
      مُحَكَّمة
  • نوع العنصر
      نوع العنصر
      امسح الكل
      نوع العنصر
  • الموضوع
      الموضوع
      امسح الكل
      الموضوع
  • السنة
      السنة
      امسح الكل
      من:
      -
      إلى:
  • المزيد من المرشحات
15 نتائج ل "Aryan, Mehdi"
صنف حسب:
Probabilistic Risk-Based Performance Evaluation of Seismically Base-Isolated Steel Structures Subjected to Far-Field Earthquakes
The performance of base-isolated steel structures having special moment frames is assessed. The archetypes, which are designed per ASCE/SEI 7–2016, are simulated in the Finite Element (FE) computational platform, OpenSees. Adopting nonlinear dynamic analyses using far-field ground motions, the performance of Drift-Sensitive Structural Components (DS-SC), and Drift-/Acceleration-Sensitive Non-Structural Components (DS/AS NSC) at slight, moderate, extensive, and collapse damage states are investigated. The effects of structural height, effective transformed period (Teff), response modification coefficient (RI), and isolation type on the performance of 26 archetypes mounted on Lead Rubber Bearings (LRBs) and Triple Concave Friction Pendulums (TCFPs) are evaluated. Computing 50-year probability of exceedance using the fragility curves and seismic hazard curves of the site, increasing Teff reduces the role of RI in the structural performance; variations in the height, as well as RI, do not affect the risk of damages to the AS-NSC; the risk of collapse is not sensitive to the variations of Teff. The TCFP systems represent superior performance than LRB systems in lower intensities. For longer periods and taller structures, the isolation type has less effect on the performance of NSC. Finally, the archetypes have less than 1% risk of collapse in 50 years; nevertheless, high-rise structures with RI = 2.0 have more than 10% probability of collapse given the maximum earthquake.
Validity of the models predicting 10-year risk of cardiovascular diseases in Asia: A systematic review and prediction model meta-analysis
We aimed to review the validity of existing prediction models for cardiovascular diseases (CVDs) in Asia. In this systematic review and meta-analysis, we included studies that validated prediction models for CVD risk in the general population in Asia. Various databases, including PubMed, Web of Science conference proceedings citation index, Scopus, Global Index Medicus of the World Health Organization (WHO), and Open Access Thesis and Dissertations (OATD), were searched up to November 2022. Additional studies were identified through reference lists and related reviews. The risk of bias was assessed using the PROBAST prediction model risk of bias assessment tool. Meta-analyses were performed using the random effects model, focusing on the C-statistic as a discrimination index and the observed-to-expected ratio (OE) as a calibration index. Out of 1315 initial records, 16 studies were included, with 21 external validations of six models in Asia. The validated models consisted of Framingham models, pooled cohort equations (PCEs), SCORE, Globorisk, and WHO models, combined with the results of the first four models. The pooled C-statistic for men ranged from 0.72 (95% CI 0.70 to 0.75; PCEs) to 0.76 (95% CI 0.74 to 0.78; Framingham general CVD). In women, it varied from 0.74 (95% CI 0.22 to 0.97; SCORE) to 0.79 (95% CI 0.74 to 0.83; Framingham general CVD). The pooled OE ratio for men ranged from 0.21 (95% CI 0.018 to 2.49; Framingham CHD) to 1.11 (95%CI 0.65 to 1.89; PCEs). In women, it varied from 0.28 (95%CI 0.33 to 2.33; Framingham CHD) to 1.81 (95% CI 0.90 to 3.64; PCEs). The Framingham, PCEs, and SCORE models exhibited acceptable discrimination but poor calibration in predicting the 10-year risk of CVDs in Asia. Recalibration and updates are necessary before implementing these models in the region.
COVID-19 disrupts the blood–testis barrier through the induction of inflammatory cytokines and disruption of junctional proteins
Objective Junctional proteins are the most important component of the blood-testis barrier and maintaining the integrity of this barrier is essential for spermatogenesis and male fertility. The present study elucidated the effect of SARS-CoV-2 infection on the blood–testis barrier (BTB) in patients who died from severe acute respiratory syndrome coronavirus 2 (COVID-19) complications. Methods In this study, lung and testis tissue was collected from autopsies of COVID-19 positive ( n  = 10) and negative men ( n  = 10) and was taken for stereology, immunocytochemistry, and RNA extraction. Results Evaluation of the lung tissue showed that the SARS-CoV-2 infection caused extensive damage to the lung tissue and also increases inflammation in testicular tissue and destruction of the testicular blood barrier. Autopsied testicular specimens of COVID-19 showed that COVID-19 infection significantly changes the spatial arrangement of testicular cells and notably decreased the number of Sertoli cells. Moreover, the immunohistochemistry results showed a significant reduction in the protein expression of occluding, claudin-11, and connexin-43 in the COVID-19 group. In addition, we also observed a remarkable enhancement in protein expression of CD68 in the testes of the COVID-19 group in comparison with the control group. Furthermore, the result showed that the expression of TNF-α, IL1β, and IL6 was significantly increased in COVID-19 cases as well as the expression of occludin, claudin-11, and connexin-43 was decreased in COVID-19 cases. Conclusions Overall, the present study demonstrated that SARS-CoV-2 could induce the up-regulation of the pro-inflammatory cytokine and down-regulation of junctional proteins of the BTB, which can disrupt BTB and ultimately impair spermatogenesis.
Prevalence and trends of coronary artery disease risk factors and their effect on age of diagnosis in patients with established coronary artery disease: Tehran Heart Center (2005-2015)
Coronary artery disease (CAD) is a universal public health challenge, more prominently so in the low- and middle-income countries. In this study, we aimed to determine prevalence and trends of CAD risk factors in patients with documented CAD and to determine their effects on the age of CAD diagnosis. We conducted a registry-based, serial cross-sectional study using the coronary angiography data bank of the Tehran Heart Center. Adult patients who had obstructive (> 50% stenosis) CAD were included in the study. The prevalence and 11-year trends of conventional CAD risk factors were analyzed by sex and age, and their adjusted effects on the age of CAD diagnosis were calculated. From January 2005 to December 2015, data for 90,094 patients were included in this analysis. A total of 61,684 (68.5%) were men and 28,410 (31.5%) were women. Men were younger at diagnosis than women, with a mean age of 60.1 in men and 63.2 in women (p < 0.001), and had fewer risk factors at the time of diagnosis. Mean age at diagnosis had an overall increasing trend during the study period. Increasing trend was seen in body-mass index, hypertension prevalence, diabetes mellitus. All lipid profile components (total cholesterol, low-density lipoprotein cholesterol, triglycerides, and high-density lipoprotein cholesterol) decreased over time. Of particular interest, opium consumption was associated with 2.2 year earlier age of CAD diagnosis. The major results of this study (lower age of CAD diagnosis in men, lower age of diagnosis associated with most risk factors, and lower prevalence of serum lipids over time) were expected. A prominent finding of this study is confirming opium use was associated with a much younger age of CAD onset, even after adjusting for all other risk factors. In addition to recommendations for control of the traditional risk factors, spreading information about the potential adverse effect of opium use, which has only recently been associated with higher risk of CAD, may be necessary.
The 15-year national trends of urinary cancers incidence among Iranian men and women; 2005-2020
Urinary tract cancers including bladder, kidney, ureter, and pelvis are a common malignancy worldwide with high mortality ratio. Aimed to investigate the prevalence of these cancers, we conducted this study. In this study, all the information related to ICD10 codes, gender, age and province of residence of individuals were obtained from the data of Iran's cancer registry by the Ministry of Health, Medicine and Medical Education and demographic evidence for each sub-country from the reports of Statistics Center of Iran (SCI). Also, the data of two Iranian national survey studies CASPIAN-III, IV, and V (information related to the care and prevention of non-communicable diseases (NCD) in childhood and adolescence) and STEPs (including information on NCD in adults over 18 years old) were used. The data was analyzed using Poisson regression with mixed effects to estimate the incidence of cancers. Bladder and kidney neoplasm are the most common cancers of the urinary system in Iran. The prevalence of bladder cancer has increased from 5.82 to 11.50 per 100,000 individuals. The increasing trend is growing faster in men compared with women. The incidence of kidney neoplasm has increased over the years (2.03 in 2005 vs. 7.02 in 2020 per 100,000). Having a higher incidence ratio compared with bladder cancer, kidney cancer is responsible for 35.06% of all urinary cancers in 2020 compared with 23.71% in 2005. Both neoplasms of the ureter and renal pelvis were recorded rarely and with lower incidence in both sexes during this period. Considering the increasing trend in the incidence of urinary neoplasms in Iran during these years, the advantage of focusing on the risk of urinary cancers is highlighted. Therefore, investigating the prevalence and incidence of urinary cancers to plan and manage these cancers will result in prevention and reduction of the disease burden on the Iranian society. Future studies in this field can help in the prevention and well-timed diagnosis of these cancers.
Prevalence of Anaplasma, Ehrlichia and Rickettsia infections in dogs in Iran: A meta‐analysis study
The current study aims to assess the prevalence of different genera of Rickettsiales, intracellular bacteria, in dogs across various regions of Iran. Rickettsiales, as zoonotic pathogens, can have various manifestations in different species, including immunosuppression, anaemia and neuropathy. Due to their close interactions with people and livestock, dogs can serve as reservoirs and transmit these pathogens to humans and other animals. The data from this research can be valuable for managing and controlling related diseases and complications in Iran and possibly neighbouring countries. Pertinent data for this study was gathered without time limitations until 1 March 2022, from different databases. Of all the inspected studies, 26 were eligible based on the inclusion criteria. The Egger test result and asymmetry in the funnel plot revealed significant publication bias; therefore, the meta‐analysis model was corrected with the trim‐and‐fill method. After correction, the prevalence of rickettsial infections among dogs varies by genus – 20.1% for Anaplasma spp. and 10% for Ehrlichia spp. – with an overall prevalence estimated at 18.3% by random‐effects analysis. The highest and lowest estimated pooled prevalences were associated with the southwestern (38.5%) and southern (0.3%) provinces of Iran, respectively. The pooled prevalence of rickettsial infection was higher in female dogs (OR = 1.198; p < 0.978; 95% CI, 0.842–1.705) and in dogs ≤2 years (OR = 1.014; p < 0.312; 95% CI, 0.598–1.72), but the difference was not statistically significant. Ultimately, the pooled prevalence of rickettsial infections among dogs is relatively low compared to other countries like Qatar, Iraq, Saudi Arabia and Turkey, which are nearby Iran. Given the significant clinical outcomes of this disease, necessary measures for prevention should be taken. This study assesses Rickettsiales bacteria prevalence in Iranian dogs, which can affect both animals and humans. Dogs’ interactions with people and livestock make them potential carriers of these zoonotic pathogens. Data gathered until 1 March 2022, from various sources revealed disparities among genera, with 20.1% for Anaplasma spp. and 10% for Ehrlichia spp., higher in certain regions and slightly more among female and younger dogs. Despite these variations, Iran's overall prevalence remained lower than neighbouring countries like Qatar and Iraq.
MgO Nanoparticle-Catalyzed Synthesis and Broad-Spectrum Antibacterial Activity of Imidazolidine- and Tetrahydropyrimidine-2-Thione Derivatives
The biological properties of imidazolidine- and tetrahydropyrimidine-2-thione derivatives such as antiviral, antitumor, anti-inflammatory, and analgesic activities increase the demand for mild and efficient synthetic routes. In this regard, methods such as reaction of diaminoalkanes with carbon disulfide have been developed. However, this method usually suffers from relatively long reaction times, using excess reagents, vigorous reaction conditions, and emission of pernicious hydrogen sulfide gas. In this project, MgO nanoparticle was used as an efficient, non-toxic, recyclable, and economic catalyst to synthesize cyclic five- or six-membered thioureas 3a – h via reaction of 1:1 molar ratios of 1,2- or 1,3-diaminoalkanes 1a – h and carbon disulfide in ethanol at ambient temperature. More interestingly, no hydrogen sulfide emission was detected during the reaction progress. The in vitro antimicrobial properties of synthesized compounds were investigated against 14 different Gram-positive and Gram-negative pathogenic bacteria according to CLSI (Clinical and Laboratory Standards Institute) broth microdilution and disk diffusion methods. The results were compared to those of penicillin, gentamicin, and ceftriaxone, and reported as inhibition zone diameter (IZD), the minimum inhibitory concentration (MIC), and the minimum bactericidal concentration (MBC) values. The best inhibitory effects were observed with imidazolidine-2-thiones 3c and 3d . They were effective against 14 and 11 pathogens, respectively. The structure-activity relationships of the prepared heterocyclic compounds were also studied.
Environmental Risk Factors for Pediatric Acute Leukemia: Methodology and Early Findings
BackgroundAcute leukemia is the most common type of malignancy in children, and no major environmental risk factors have been identified relating to its pathogenesis. This study has been conducted with the aim for identifying risk factors associated with this disease. MethodsThis study was conducted in 2016-2020 among children aged <15 years residing in Isfahan Province, Iran. Children with newly diagnosed Acute lymphoblastic leukemia, including Acute myeloid leukemia (ALL and AML) were considered a case group. The control group was selected among children hospitalized in orthopedic and surgery wards in the same region. Demographic data, parental occupational exposures and educational level, maternal obstetric history, type of feeding during infancy and parental smoking habits, exposure to pesticides, and hydrocarbons besides dietary habits (using a food frequency questionnaire) were evaluated. ResultsOverall, 497 children (195 cases and 302 controls) completed the survey. In the initial analysis, there was no significant difference between case and control groups about type of milk feeding (P = 0.34) or parental age (P = 0.56); however, an association between mothers' education and increased risk for ALL was observed (P = 0.02). ConclusionsThe results of this study can be helpful in better understanding the environmental risk factors involved in the incidence of acute leukemia. Future publications based on the analysis of the database created in the present study can lead to recognizing these factors. In addition, evaluating the effect of these factors on treatment outcomes is an important step in reducing the burden of the disease.
Development and Assessment of Loop-Mediated Isothermal Amplification (LAMP) Assay for the Diagnosis of Human Visceral Leishmaniasis in Iran
Parasitological methods for the diagnosis of Visceral leishmaniasis (VL) require invasive procedures, so serological and molecular approaches have been developed but are not generally applicable in the field. We evaluated a loop mediated isothermal amplification (LAMP) assay using blood from VL patients and compared it to nested PCR. Forty-seven subjects with clinical features (fever, hepatosplenomegaly and anemia) were confirmed positive for VL by the direct agglutination test (DAT) at titers >3200. Forty DAT negative individuals from non-endemic areas with no clinical signs or symptoms of VL served as controls. A LAMP assay was performed using a set of six primers targeting Leishmania infantum kinetoplast DNA (kDNA) minicircle gene under isothermal (64 °C) conditions. For nested PCR we used primers targeting the kDNA minicircle gene. The LAMP assay provided a detection limit of 1 parasite in 1 ml of peripheral blood and detected L. infantum DNA in 44 of 47 DAT-confirmed VL cases, with diagnostic sensitivity of 93.6% (95% CI). No L. infantum DNA was amplified in controls, indicating a specificity of 100%. The nested PCR yielded sensitivity of 96% (95% CI) and a specificity of 100% (95% CI). The LAMP assay gave results similar to those of nested PCR but in a shorter time. The LAMP method is simple; requires no sophisticated equipment; has a short reaction time; and results, indicated by turbidity of the reaction mixture, are observable with the naked eye.