Phononic thermal conductivity in silicene: the role of vacancy defects and boundary scattering

We calculate the thermal conductivity of free-standing silicene using the phonon Boltzmann transport equation within the relaxation time approximation. In this calculation, we investigate the effects of sample size and different scattering mechanisms such as phonon-phonon, phonon-boundary, phonon-isotope and phonon-vacancy defect. Moreover, the role of different phonon modes is examined. We show that, in contrast to graphene, the dominant contribution to the thermal conductivity of silicene originates from the in-plane acoustic branches, which is about 70\% at room temperature and this contribution becomes larger by considering vacancy defects. Our results indicate that while the thermal conductivity of silicene is significantly suppressed by the vacancy defects, the effect of isotopes on the phononic transport is small. Our calculations demonstrate that by removing only one of every 400 silicon atoms, a substantial reduction of about 58\% in thermal conductivity is achieved. Furthermore, we find that the phonon-boundary scattering is important in defectless and small-size silicene samples, specially at low temperatures.Comment: 9 pages, 11 figure

Derivations of abelian Lie algebra extensions

Let $0 \rightarrow A\rightarrow L {\rightarrow} B \rightarrow 0$ be an abelian extension of Lie algebras. In this paper, we construct certain exact sequences which relate derivations with the Lie algebra cohomology group $H^{2}(B,A)$, and apply them to study extending derivations of $A$ and lifting derivations of $B$ to certain derivations of $L$

Effect of Aloe vera on some indicators of cell damage after a period of aerobic exercise in male athletes

Introduction: Aloe vera is a medicinal plant with antioxidant activity. The purpose of this study was to determine the effect of Aloe vera on some indicators of cell damage after a period of aerobic exercise in male athletes of 15-18 years old. Methods: In this clinical trial study, 20 male students with average weight of 64.85 &plusmn; 51 and height of 172.05 &plusmn; 6.4 were randomly assigned to 2 groups of Aloe vera supplement (n = 10) and placebo (n = 10). Then aerobic training was conducted for 4 weeks. The supplemented group took 3 capsules, each capsule contains 2 g of dried Aloe vera and placebo group took 3 capsules/day containing dextran after every meal. To determine the index of cell injury markers creatine kinase (CK), lactate dehydrogenase (LDH) and reactive protein C (CRP) were determined and blood samples were collected 24 hours before and after each test. The data were analyzed using ANOVA and independent t test. Significance level was considered as P &le; .05. Results: The use of Aloe vera during aerobic exercise significantly reduced LDH (P = .006) in the supplement group (15 reduction) compared to placebo group and CRP with 11 reduction in the supplement group compared to placebo (P = .008). There was no significant reduction in CK. Conclusion: The findings of this study showed that Aloe vera reduces cell damage and inflammation indicators. This result may reflect the role of Aloe vera as anti-inflammatory and antioxidant agent.</p

Determining the effect of aloe Vera and aerobic exercise on lactate de-hydrogenase in male athletes

Aloe Vera is a medicinal plant as antioxidants reduce cell damage and used. The purpose of this study was to determine the effect of Aloe Vera on lactate de-hydrogenase after a period of aerobic exercise in male athletes. Methods This study applied the method according to the nature of the study, based on semi-empirical research and a review of the pre-test, post-test supplements and placebo groups, respectively. In this study,20 male students weight was 64.85 ± .51 and height was 172.05 ± 6.4 were randomly assigned to two groups of Imam Ali College of Physical Education Supplement (n = 10) and placebo (10 people). Then aerobic training was conducted for 4 weeks in the supplemented group were taking 3 capsules, each capsule contains 2 grams of dried Aloe Vera and placebo group were taking 3 capsules containing Dextrin daily after every meal. To determine the index of LDH were used and blood samples were collected 24 hours before and after each test Cooper with student in the lab. To describe data, analytical data, and for the mean and standard deviation of repeated measures ANOVA and independent T-test was used for comparison between groups Significance level was P ≤ 0.05. The use of Aloe Vera during aerobic exercise significantly, cautious reduced LDH (P=0.006) in the supplement group compared to placebo was 15 reduction. Conclusion: Overall the findings of this study showed that Aloe Vera reduces lactate de-hydrogenase. This result may reflect the role of Aloe Vera has anti-inflammatory and antioxidant

Determination of prevalence of being overweight and its association with hypertension in patients referred to the healthcare center in Jandaq in 2014.

Background and aims: Obesity and overweight is a major public health problem and, alongside hypertension, is one of the risk factors of cardiovascular diseases incidence. The aim of this study was to determine the prevalence of overweight and its association with hypertension in the patients referred the healthcare center in Jandaq. Methods: This cross-sectional study was conducted on 400 patients (168 men and 232 women) referring to urban healthcare centers in Jandaq. By means of necessary instruments, the individuals’ weight and height were measured, and body mass index (BMI) was calculated. Also, the individuals’ blood pressure was measured and classified in accordance with the standard manual, and after filling out the questionnaires, the data analysis was done by SPSS. Results: The prevalence of overweight was 29.3 in men and 35.7 in women. The prevalence of hypertension was 29.1 in men and 35.3 in women. Family history of hypertension and cardiovascular disease was effective on the individuals’ acquiring hypertension. With the increase in the patients’ age, both BMI (P<0.035) and blood pressure (P<0.001) increased. Also, increase in BMI in the individuals was significantly associated with blood pressure rate (P<0.001). Conclusions: The prevalence rate of overweight and obesity in Jandaq is high. There was an association among the individuals’ BMI, blood pressure and age. Therefore, it is necessary to develop health education programs and to inform the public regarding the increase of mobility and improvement of the nutrition, and to implement effective interventions in health planning in this center

From Non-scattering to Super-scattering with the Topology of Light and Matter

Electric anapole states, arising due to the destructive interferences of primitive and toroidal electric dipole moments, have been recently introduced as the fundamental class of non-scattering sources with several potential applications ranging from nonlinear optics to thermodynamics thanks to their field confinement and minimal scattering fingerprints. Nevertheless, other non-radiating sources are also possible and can provide significant energy confinement at the nanoscale if they spectrally overlap with their electrical counterparts. On the other hand, super-scattering states represent the opposite regime of light-matter interaction wherein the scattering cross-section of a particular multipolar moment exceeds the single-channel limit, leading to a strong scattering in the direction of the pump beam. Here, we demonstrate that the interplay between the topology of incident light and the subwavelength scatterer can lead to these two opposite regimes of light-matter interactions within an isolated all-dielectric meta-atom. In particular, we show that the presented scatterer can support new non-scattering states, called hybrid anapole, leading to significant suppression of the far-field radiation and enhancement of electromagnetic energy inside the meta-atom. We also explore the role of particle orientation and its inversion symmetry on the scattering response and show how switching between non-scattering to super-scattering states can occur within the same platform. The presented study elucidates the role of light and matter topologies in the scattering response of subwavelength meta-atoms and reveals the formation of two extreme opposite regimes of light-matter interaction, opening new avenues in several applications ranging from nonlinear optics to spectroscopy.Comment: 17 pages, 6 figure

Hospital acquired diarrhea in a burn center of Tehran

Background and Objectives: Incidence of hospital-acquired diarrhea has increased rapidly and burn patients are at high risk of getting it. Infection with C. difficile is the most common cause of antibiotic associated diarrhea. The aim of this study was to determine the baseline characteristics and clinical presentation of hospital-acquired diarrhea and compare C. difficile and non-C. difficile diarrhea in burn patients treated at a burn center. Materials and Methods: During a 1-year study all patients with hospital-acquired diarrhea at Motahari Burn Hospital, Tehran, Iran enrolled in this study. We compared patients with a stool sample positive for C. difficile toxin or tracing the antigen in patients who were negative for detection of toxin in their stool sample specimens. Results: Diarrhea developed in 37 patients out of 3200 admitted patients with a mean burn size of 34.8 ±20.1. Among them, 8 patients had a positive result for C. difficile. The mean time between antibiotic therapy and occurrence of diarrhea was 9.5 ± 6.2 days. Nine (23.7) patients died in the 7.8± 4.2 days, mostly due to co-morbidities. The mean duration of diarrhea was 3.6 ± 2 days. Twenty two (57.9) patients were treated with oral metronidazol and eleven (28.9) patients were treated with combination of metronidazole and vancomycin, higher rate of combination therapy was seen in Clostridium difficile CDI. Conclusion: Overall, the prevalence of hospital-acquired diarrhea was 120/10,000 and 21 of them caused by infection with C. difficile. Presence of peripheral leukocytosis and colitis were the alarm sign for diagnosis of C. difficile infection. © 2015, Tehran University of Medical Science. All rights reserved

Effect of sticky mat usage in control of nosocomial infection in motahary burn hospital

Background and Objectives: Infection is the most common cause of death among burnt patients and infection control decrease the rate of mortality. The use of sticky mat can control contamination by preventing the entrance microorganisms into the hospital wards. This study was designed to evaluate the sticky mats effect in reduction of microorganism�s entry by personnel shoes to burn intensive care unit (BICU). Materials and Methods: This is a simple cross sectional study. We tested outer soles of personnel�s shoes with swap and cultured them before and after sticky mat contact in the entrance of BICU. Results were analyzed with IBM SPSS version 22 software. McNemar and Wilcoxon Signed Ranks tests were used. Results: We analyzed 60 outer soles of the shoes before and after contact with sticky mats. Coagulase negative Staphylococci, Gram positive bacilli, Staphylococcus aureus, Aspergillus fumigatus, Pseudomonas aeruginosa and Acinetobacter baumannii were isolated before contact from 57 (95), 32 (53), 4 (6.7) and 3 (5) cases, respectively. Coagulase negative Staphylococci, Gram positive bacilli, Staphylococcus aureus, Aspergillus fumigatus, Pseudomonas aeruginosa were isolated after contact from 36 (60), 30 (50), 16 (26.6), 2 (3.3) and 3 (5) cases, respectively. No Acinetobacter was isolated after contact with sticky mat. Total isolated colonies before and after contact with sticky mats were 2573 and 830, respectively. There were significant statistically differences between the colony counts of coagulase ngative staphylococci, Gram positive bacilli, and Staphylococci aureus before and after contact with sticky mats (P. < 0.001). Conclusion: Regarding to statistical analysis, the effect of mat in removing the microorganisms was 56. It confirms the effectiveness of sticky mat controlling the infection and reducing the amount of hospital contamination. © 2016, Tehran University of Medical Science. All rights reserved

SiC and ZrO2 Weigh Percentage Effects on Microstructure of Al Based Matrix Composite Fabricated by Spark Plasma Sintering Method

SiC and ZrO2 particle are succesfully reaction synthesized from powder of Al, ZrO2 and SiC using spark plasma sintering method. The XRD of sintered composite and microstructure of the aas-sintered products. With the ZrO2 content increasing, the grains are remarkably refined and the and the ZrO2 and nano SiC particles are dispersing more uniformly in Al matrix, forming a homogeneous structure with the least porosity