58 research outputs found

    Tight-Binding Studio: A Technical Software Package to Find the Parameters of Tight-Binding Hamiltonian

    Full text link
    We present the Tight-Binding Studio (TBStudio) software package for calculating tight-binding Hamiltonian from a set of Bloch energy bands obtained from first principle theories such as density functional theory, Hartree-Fock calculations or Semi-empirical band structure theory. This will be helpful for scientists who are interested in studying the electronic properties of structures using Green's function theory in tight-binding approximation. TBStudio is a cross-platform application written in C++ with a graphical user interface design that is user-friendly and easy to work with. This software is powered by Linear Algebra Package C interface library for solving the eigenvalue problems and the standard high-performance OpenGL graphic library for real-time plotting. TBStudio and its examples together with the tutorials are available for download from tight-binding.com

    The Prevalence and Characteristics of Performance-Enhancing Drug Use Among Bodybuilding Athletes in the South of Iran, Bushehr

    Get PDF
    Background: Several reports have implied progressive increase of performance-enhancing drug (PED) use among Iranian athletes. More importantly, most of the previous research in the Iranian population had mainly focused on the anabolic steroid abuse, and ignored other agents. Objectives: The aim of this study was to investigate the prevalence and characteristics of PED use among bodybuilding athletes in Bushehr, south of Iran. Methods: Four hundred and fifty three male bodybuilding athletes were recruited from Bushehr gyms between February and May of 2015. Men were eligible to participate in the survey if they had regularly participated in the strength-training exercise (minimum of 1 year and 4 hour/week). Data were collected via a face-to-face interview. The survey consisted of three separate parts including demographic data, exercise pattern and PED use. Results: According to this study, 234 (51.7%) of bodybuilding athletes had used PEDs. The PED users reported an average of 3.80 � 4.52 agents’ use in their programs and they had used PEDs for the average of 3.24 � 3.99 years. The most prevalent agents which had been abused by the athletes were anabolic steroids (used by 185 athletes (79.4% of athletes). Furthermore, 110 (47%) of athletes reported stimulant agents’ use during their routines. The most prevalent motivation for using PEDs was increasing muscle mass that was reported by 164 (70.1%) of PED users. In addition, sexual and dermatologic effects were the most prevalent adverse effects reported by the PED user athletes (114 (49.4%) and 103 (44.2%), respectively). Conclusions: This study showed the high rate of PED use among recreational and professional Iranian bodybuilding athletes that can expose them to the serious side effects of these agents

    Prevalence of Cannabis Lifetime Use in Iranian High School and College Students: A Systematic Review, Meta-Analyses,and Meta-Regression

    Get PDF
    Cannabis is the most widely used substance in the world. This study aimed to estimate the prevalence of cannabis lifetime use (CLU) in high school and college students of Iran and also to determine factors related to changes in prevalence. A systematic review of literature on cannabis use in Iran was conducted according to MOOSE guideline. Domestic scientific databases, PubMed/Medline, ISI Web of Knowledge, and Google Scholar, relevant reference lists, and relevant journals were searched up to April, 2014. Prevalences were calculated using the variance stabilizing double arcsine transformation and confidence intervals (CIs) estimated using the Wilson method. Heterogeneity was assessed by Cochran's Q statistic and I-2 index and causes of heterogeneity were evaluated using meta-regression model. In electronic database search, 4,000 citations were retrieved, producing a total of 33 studies. CLU was reported with a random effects pooled prevalence of 4.0 (95 CI = 3.0 to 5.0). In subgroups of high school and college students, prevalences were 5.0 (95 CI = 3.0 to -7.0) and 2.0 (95 CI = 2.0 to -3.0), respectively. Meta-regression model indicated that prevalence is higher in college students (beta = 0.089, p < .001), male gender (beta = 0.017, p < .001), and is lower in studies with sampling versus census studies (beta = -0.096, p < .001). This study reported that prevalence of CLU in Iranian students are lower than industrialized countries. In addition, gender, level of education, and methods of sampling are highly associated with changes in the prevalence of CLU across provinces

    Decreases in Community Viral Load Are Accompanied by Reductions in New HIV Infections in San Francisco

    Get PDF
    BACKGROUND: At the individual level, higher HIV viral load predicts sexual transmission risk. We evaluated San Francisco's community viral load (CVL) as a population level marker of HIV transmission risk. We hypothesized that the decrease in CVL in San Francisco from 2004-2008, corresponding with increased rates of HIV testing, antiretroviral therapy (ART) coverage and effectiveness, and population-level virologic suppression, would be associated with a reduction in new HIV infections. METHODOLOGY/PRINCIPAL FINDINGS: We used San Francisco's HIV/AIDS surveillance system to examine the trends in CVL. Mean CVL was calculated as the mean of the most recent viral load of all reported HIV-positive individuals in a particular community. Total CVL was defined as the sum of the most recent viral loads of all HIV-positive individuals in a particular community. We used Poisson models with robust standard errors to assess the relationships between the mean and total CVL and the primary outcome: annual numbers of newly diagnosed HIV cases. Both mean and total CVL decreased from 2004-2008 and were accompanied by decreases in new HIV diagnoses from 798 (2004) to 434 (2008). The mean (p = 0.003) and total CVL (p = 0.002) were significantly associated with new HIV cases from 2004-2008. CONCLUSIONS/SIGNIFICANCE: Reductions in CVL are associated with decreased HIV infections. Results suggest that wide-scale ART could reduce HIV transmission at the population level. Because CVL is temporally upstream of new HIV infections, jurisdictions should consider adding CVL to routine HIV surveillance to track the epidemic, allocate resources, and to evaluate the effectiveness of HIV prevention and treatment efforts

    Salivary lipid peroxidation in patients with oral lichen planus

    No full text
    Background: Oral Lichen Planus (OLP) is an inflammatory condition with unknown etiology. Reactive oxygen species (ROS) and free radicals may play an important role in the pathogenesis of this disease. Objective: The aim of this study was to compare salivary lipid peroxidation in patients with oral lichen planus with healthy subjects. Methods: This case-control study was conducted in Zahedan School of Dentistry during 2014-15. Unstimulated saliva samples were collected from 30 patients with OLP and 30 age and gender-matched healthy controls and were transferred to the laboratory. Salivary lipid peroxidation products were measured using TBARS (thiobarbituric acid reactive substance) method. Data were analyzed using Mann-Whitney U test. Findings: Salivary lipid peroxidation in patients with OLP was significantly higher than healthy controls (1.57±0.63 μM vs. 1.2±0.77μM). Mean Salivary lipid peroxidation in women with OLP was significantly higher than healthy women (1.67±0.67 μM vs. 1.16±0.82 μM). Conclusion: With regards to the results, it seems that lipid peroxidation in patients with OLP is higher than healthy subjects
    corecore