Robust ferromagnetism in two-dimensional GeC/CrN heterobilayers

We have investigated the electronic and finite temperature magnetic properties of germanium carbide (GeC) and ferromagnetic chromium nitride (CrN) heterobilayers by using first-principles calculations based on density functional theory with Hubbard U correction and an effective anisotropic Heisenberg spin model. The dynamical stability of different stacking formations of heterobilayers is ensured by considering the phonon spectra. All the stacking patterns show half-metallicity with an out-of-plane easy-axis ferromagnetic ground state. We find a high Curie temperature for GeC/CrN heterobilayers within the random phase approximation (RPA). In addition to the symmetric stackings, i.e., AA and AB, the electronic properties of non-symmetric stackings at three different twist angles are also analyzed. The electronic structure analysis of twisted structures demonstrates that the half-metallicity of the GeC/CrN heterobilayer is stack independent. Furthermore, we have investigated the electronic properties, magnetic anisotropy energy, Curie temperature, and spin wave spectrum in the presence of biaxial strain. It is shown that the compressive strain dramatically reduces the magnetic anisotropy energy of the GeC/CrN heterobilayer and Curie temperature, but the Curie temperature still remains well above room temperature for all strain values. The increasing values of tensile strain reduce the magnetic exchange while it increases the magnetic anisotropy energy of the heterobilayer system which enhances the Curie temperature of the structures. The monolayer CrN on the GeC with a wide band gap and commensurate lattice together with a high Tc value can be a feasible candidate for future spintronic applications.

Easy-axis rotation in ferromagnetic monolayer CrN induced by fluorine and chlorine functionalization

The schematic energy diagram with crystal-field splitting of the d states before and after functionalization of CrN is reported.

Electronic structure and optical properties of novel monolayer gallium nitride and boron phosphide heterobilayers

An external electric field modifies the electronic structure, charge distribution and energy band gap in the heterobilayer of gallium nitride/boron phosphide.

Acute and subchronic toxicological evaluation of Stachys lavandulifolia aqueous extract in Wistar rats

Stachys lavandulifolia (S. lavandulifolia) is a plant that has been widely used as an herbal medicine in Iran. Unfortunately, despite the prevalent medicinal uses of the plant, there are no reports on the possible toxic effects of S. lavandulifolia. In the present study the potential toxicity of S. lavandulifolia after acute and subchronic administration in rats was evaluated. Rats were orally treated with single doses of S. lavandulifolia aqueous extract and screened for signs of toxicity two weeks after administration. In the sub-chronic toxicity study, S. lavandulifolia was administered for 45 days. Mortality, clinical signs, body weight changes were assayed during the study. After 45 days animals were sacrificed and hematological and biochemical parameters, as well as weight of some organs were measured. All of the rats treated with different concentrations of water extracts of S. lavandulifolia were alive for all 14 days of observation. No hematological changes were observed a part from significant increase in WBC and neutrophils counts. Moreover, serum aspartate aminotransferase (AST) and creatinine significantly increased. Histopathological examinations showed fatty change, degeneration of hepatocytes and renal glomerular atrophy in the male rats. In the female rats, atrophy of hepatocytes and dilatation of sinusoids in liver, hyperemia and degeneration of renal epithelium mostly in cortical region were observed. Based on the results of this study no observed adverse effect level (NOAEL) of the total aqueous extract of S. lavandulifolia considered to be 250 and 100 mg/kg/day for the male and female rats, respectively.

Identification and cloning of the Cu/Zn superoxide dismutase gene from halophyte plant Aeluropus littoralis

Reactive oxygen species (ROS) derived from molecular oxygen under biotic and abiotic stress such as salinity which have deleterious effects on cell metabolism. The toxic effect of ROS counteract by enzymatic as well as non-enzymatic antioxidant system. Superoxide dismutase (SOD) has a potential role for elimination of ROS. Halophytes respond to salt stress at different levels and can be a model for increasing salt tolerance in crop plants. Thus salt tolerance gene isolation and cloning of gene as well as subsequent transformation are first step for sensitive crop improvement. Aeluropus littoralis is a halophyte plant from poaceae family can be as a beneficial plant with high potential for creal breeding. There was no report on isolation of SOD gene from A. littoralis and little genomic study of this plant carried out. In this study a novel gene from A. littoralis isolated. This gene amplified by reverse transcription-PCR and cloned in E. coli pTZ57R/T cloning vector. The AlSOD gene sequence contained 456 bp and the deduced transcripts encoding 152 amino acids shared a high homology with those putative CuZnSOD of higher plants like Zea mays and Oryza sativa.

Prevalence of microalbuminuria and its risk factors in type 2 diabetic patients

A cross-sectional study was performed from November 2005 to July 2007 to determine the prevalence of microalbuminuria and its risk factors among type 2 diabetic patients.. Two hundred and eighty-eight type 2 diabetic patients (141 males and 147 females) referred to Yazd diabetes research center were randomly recruited for the study. Microalbuminuria was detected by measuring the albumin to creatinine ratio in the early morning urine. Microalbuminuria was diagnosed if this ratio was between 30 and 300 mg/g on two occasions during three months. Prevalence of microalbuminuria was 14.2%. Chi-square analysis revealed that microalbuminuria was correlated with the diastolic blood pressure (P = 0.003) and the duration of diabetes (P = 0.000). No statistically significant correlation was found between microalbuminuria and age, sex, body mass index, levels of fasting blood sugar, glycosylated hemoglobin (HbA1c), serum triglyceride, and serum cholesterol, or systolic blood pressure. For 240 patients for whom the duration of diabetes was known from the answers in their questionnaires, logistic regression was used for analysis. Results showed that two variables including the duration of diabetes and Diastolic Blood Pressure (DBP) play a role in this model and the following Logic association was obtained: g; (x) = -9.233 +/- 0.079 DBP +/- 0.114 duration according to this model, both DBP and duration of diabetes were directly correlated with microalbuminuria. Determination of the urine albumin to creatinine ratio is an easy method for screening of microalbuminuria that is suggested for all diabetic patients, especially diabetic patients with hypertension and long-term diabetes.

Chemical composition, in vitro anti-microbial, antifungal and antioxidant activities of the essential oil and methanolic extract of Hymenocrater longiflorus Benth., of Iran

In this study we identified the chemical composition, anti-microbial and antioxidant effects of essential oil and methanolic extract of Hymenocrater longiflorus Benth. Totally 87 volatile compounds from the essential oil in H. longiflorus, were identified by gas chromatography-mass spectrometry (GC-MS). These compounds are mainly monoterpene hydrocarbons, sesquiterpene hydrocarbons, oxygenated monoterpenes and oxygenated sesquiterpenoids compounds. The anti-microbial and antifungal activity of plants extracts against several pathogenic microorganisms was studied by disc diffusion and minimum inhibitory concentration procedures. The results revealed that the essential oil and polar sub-fraction are effective mostly against Staphylococcus aureus, Aspergillus niger and Candida albicans. The antioxidant activity was also determined by 1,1'-diphenyl-2-picryl-hydrazyl (DPPH) free radical scavenging, beta-carotene linoleic acid assay and reducing power. In addition the total phenol of essential oil (54.6+/-1.2), polar sub-fraction (50.0+/-1.4) and non-polar sub-fraction (64.7+/-2.0) were determined.