On gauge invariant regularization of fermion currents

We compare Schwinger and complex powers methods to construct regularized fermion currents. We show that although both of them are gauge invariant they not always yield the same result.Comment: 10 pages, 1 figur

Effects of Soil Compaction by Animal Trampling on Growth of \u3cem\u3eAgropyron Repens\u3c/em\u3e

Animal trampling is the most important factor that increases soil compaction beyond the soil elastic property in rangelands under heavy grazing intensities (Lull, 1959). The complicated ecological interactions in a rangeland ecosystem make it difficult to predict the impact of trampling under different conditions. However, soil properties and vegetation composition are sensitive to different grazing management practices. This research, which was carried out in simulated conditions, sought to establish the contribution of soil compaction resulting from animal trampling over a long period to the decline in rangeland condition

Cytotoxicity of Sambucus ebulus on cancer cell lines and protective effects of vitamins C and E against its cytotoxicity on normal cell lines

Isolation and identification of potent anti-tumor compounds from medicinal plants, has motivated researchers to screen plant species for anti-tumor effects. Regarding the traditional utilization of Sambucus ebulus, Iranian native botany and its active ingredients (e.g. ebulitin and ebulin 1), cytotoxicity of ethyl acetate extract from S. ebulus (SEE) on HepG2 and CT26 cancer cell lines was investigated. Also, protective effects of vitamins C and E against SEE-induced cytotoxicity on normal cell lines were studied. Cytotoxicity of SEE on cancer (HepG2 and CT26) and normal (CHO and rat fibroblast) cell lines was evaluated by MTT assay. IC50 of SEE on the cell lines was assessed. Furthermore, IC50 of SEE on normal cell lines with exposure to vitamins C, E and C+E was studied. SEE possessed lower IC50 in cancer cell lines compared with normal cell lines. It manifested high cytotoxicity that can act as anticancer compound. Also, cytotoxicity of SEE on normal cell lines in presence of vitamins C+E, E and C decreased. The results demonstrate that SEE is an effective cytotoxic agent on liver and colon cancer cells and suggest that vitamins C and E may protect normal cells, when SEE were used in cancer therapy in future.Keywords: Sambucus ebulus, cytotoxicity, IC50, MTT assay, cell line, vitamins C and E.African Journal of Biotechnology Vol. 12(21), pp. 3360-336

Note on the energy-momentum tensor for general mixed tensor-spinor fields

This note provides an explicit proof of the equivalence of the Belinfante's energy-momentum tensor and the metric energy-momentum tensor for general mixed tensor-spinor fields.Comment: 7 pages, title changed, typos corrected, accepted for publication in Communications in Theoretical Physic

Juxta Cortical Tibia Metastatic Deposition in Gastric Cancer: A Case Report

We report a 41 years old man with rapidly growing and tender lump on the anteromedial surface of tibia. The patient had the history of gastrectomy and gastrojejunostomy due to gastric carcinoma. On admission, the Simple X-ray of lower extremity disclosed a slight thinning of the anterior cortex of tibia without cortical destruction. The whole-body bone scan with 99mTC MDP revealed activity of lesion in all 3 phases. The histopathological evaluation showed an infiltration of bone with tumor cells. Review No the literature revealed in previous cases of skeletal metastasis from gastric cancer in the tibia like this

Relation of hemoglobin A1c to left ventricular diastolic function in patients with type 1 diabetes mellitus and without overt heart disease

Left ventricular diastolic dysfunction is a main feature of diabetic heart disease. The aim of this prospective study was to evaluate the relation of hemoglobin A1c and diastolic function in type 1 diabetes mellitus. We examined echocardiographic studies of 25 patients with type 1 diabetes without clinical evidence of heart disease and 25 healthy age-and sex-matched normal individuals. In patients with type 1 diabetes, there was a diastolic dysfunction with lower transmitral E/A (1.28±0.3 vs. 1.6±0.3; p=0.01), more prolonged isovolumic relaxation time (99±11 vs. 71±8, p=0.003) in comparison with normal subjects. Furthermore, HbA1c correlated with diastolic indices. These results demonstrate that asymptomatic diastolic dysfunction is common in patients with type 1 diabetes mellitus and that its severity correlates with glycemic control

Effects of impervious surfaces and urban development on runoff generation and flood hazard in the Hajighoshan watershed

Urbanization is a pervasive global trend. The development of residential areas and road network in Hajighoshan watershed (northern Iran) has been observed in the recent several decades. The objective of this study is the quantitative investigation of the effects of impervious surfaces development and urban development on runoff generation and flood hazard. The study of urban area development was carried out using aerial photos, topographic maps and satellite images. Also a rainfall-runoff model was presented using GIS (HEC-GeoHMS extension) and HEC-HMS model. Then, the model was optimized with initial loss and SCS-Lag parameters. The optimized model was evaluated using the other 4 events of flood .In the next stage, the development of impervious surfaces was included in the validated hydrologic model and their effects on intensifying runoff generation and flood hazard was investigated quantitatively during the recent forty years. The results showed that the runoff generation potential has increased in Hajighoshan watershed because of urban development during forty years ago

Osteopetrosis: A Case Report and Review of the Literature

Osteopetrosis or marble bone disease is a rare heritable skeletal disorder that the bones becoming denser, caused by aberrant osteoclast-mediated bone resorption. This condition reveals a spectrum of heterogeneity of genetic defects. This metabolic disorder has an unequal balance between new bone formation and old bone resorption. Thus the result is increased bone density on radiographs. Presented here is a 25 years-old Persian female presented to our clinic with the chief complaint of low back pain and limping. She explained that her problem had been present for a long time. There were no other significant findings in past medical history and her parents and three siblings did not have any disorder of note, however, the parents were first cousin. No specific laboratory abnormalities found in the initial evaluation. On physical examination, an antalgic gait is noted. A Bone biopsy from proximal medial tibia revealed increased density of the cortex and part of medullary canal with hematopoietic marrow and irregular and thickened bone trabeculae. These factors suggested osteopetrosis disease. Osteopetrosis should be kept in mind as a rare cause of low back pain and limping and should be mentioned as a differential diagnosis of fluorosis, Paget’s disease, malignancies (lymphoma, osteoblastic cancer metastases) and myelosclerosis.Keywords: Osteopetrosis, marble bone disease, bone trabeculae, Iran

Resonantly enhanced second-harmonic generation using III-V semiconductor all-dielectric metasurfaces

Nonlinear optical phenomena in nanostructured materials have been challenging our perceptions of nonlinear optical processes that have been explored since the invention of lasers. For example, the ability to control optical field confinement, enhancement, and scattering almost independently, allows nonlinear frequency conversion efficiencies to be enhanced by many orders of magnitude compared to bulk materials. Also, the subwavelength length scale renders phase matching issues irrelevant. Compared with plasmonic nanostructures, dielectric resonator metamaterials show great promise for enhanced nonlinear optical processes due to their larger mode volumes. Here, we present, for the first time, resonantly enhanced second-harmonic generation (SHG) using Gallium Arsenide (GaAs) based dielectric metasurfaces. Using arrays of cylindrical resonators we observe SHG enhancement factors as large as 104 relative to unpatterned GaAs. At the magnetic dipole resonance we measure an absolute nonlinear conversion efficiency of ~2X10^(-5) with ~3.4 GW/cm2 pump intensity. The polarization properties of the SHG reveal that both bulk and surface nonlinearities play important roles in the observed nonlinear process