Vacancy complexes in nonequilibrium germanium-tin semiconductors

Understanding the nature and behavior of vacancy-like defects in epitaxial GeSn metastable alloys is crucial to elucidate the structural and optoelectronic properties of these emerging semiconductors. The formation of vacancies and their complexes is expected to be promoted by the relatively low substrate temperature required for the epitaxial growth of GeSn layers with Sn contents significantly above the equilibrium solubility of 1 at.%. These defects can impact both the microstructure and charge carrier lifetime. Herein, to identify the vacancy-related complexes and probe their evolution as a function of Sn content, depth-profiled pulsed low-energy positron annihilation lifetime spectroscopy and Doppler broadening spectroscopy were combined to investigate GeSn epitaxial layers with Sn content in the 6.5-13.0 at.% range. The samples were grown by chemical vapor deposition method at temperatures between 300 and 330 {\deg}C. Regardless of the Sn content, all GeSn samples showed the same depth-dependent increase in the positron annihilation line broadening parameters, which confirmed the presence of open volume defects. The measured average positron lifetimes were the highest (380-395 ps) in the region near the surface and monotonically decrease across the analyzed thickness, but remain above 350 ps. All GeSn layers exhibit lifetimes that are 85 to 110 ps higher than the Ge reference layers. Surprisingly, these lifetimes were found to decrease as Sn content increases in GeSn layers. These measurements indicate that divacancies are the dominant defect in the as-grown GeSn layers. However, their corresponding lifetime was found to be shorter than in epitaxial Ge thus suggesting that the presence of Sn may alter the structure of divacancies. Additionally, GeSn layers were found to also contain a small fraction of vacancy clusters, which become less important as Sn content increases

Alpha lipoic acid and diabetes mellitus: potential effects on peripheral neuropathy and different metabolic parameters

Introduction: Alpha lipoic acid (ALA) is an antioxidant used in the treatment of neuroinflammation, diabetes and diabetic nephropathy. The current study aiming to gauge the effect of oral ALA on diabetic peripheral neuropathy, glycemic control, LDL-C, and HDL-C. Methods: This is a prospective, interventional study carried out on patients with type 2 diabetes mellitus (DM) who were following at the outpatient internal medicine & diabetes clinics at Benha University Hospital. Treatment with ALA for 3 months was given to patient with diabetic peripheral neuropathy. Data in the form of age, sex, body mass index (BMI), duration & treatment of DM, manifestations of peripheral neuropathy were collected. LDL-C, HDL-C, HbA1c, TSH, ALT, AST were measured before and after intervention. Peripheral neuropathy symptoms, nerve conduction velocities, cardiovascular (CV) tests of autonomic neuropathy, and cross-section area of the posterior tibial nerve were performed before and after treatment intervention. Results: 90 adult diabetic patients were recruited in the study, 42.2% were females and 57.8% were males with a median age of 50–60.3 years (IQR = 52). A statistically significant improvements of neuropathic symptoms, nerve conduction velocity, and cardiovascular autonomic neuropathy were noted after 3 months of administration of ALA (p ˂0.001). However, the cross-section area of the posterior tibial nerve at baseline and after treatment did not change significantly (p value of 0.84). There was a significant improvement in the BMI, HDLC, LDL-C, HbA1c (p ˂ 0.001). Conclusion: Oral treatment with ALA might cause ameliorations of peripheral neuropathy, HbA1c, and LDL-C & HDL-C levels in diabetic patients. Our result failed to proof effect of ALA on nerve cross-section area. The global data encourage further studies with this medication as an ancillary treatment of DM2.Clinical trial registration: It was registered in clinical trial website; ClinicalTrials.gov Identifier(NCT number): NCT04322240

Direct Measurements of the Transport of Nonequilibrium Electrons in Gold Films with Different Crystal Structures

The transport of femtosecond-laser-excited nonequilibrium electrons across polycrystalline and single-crystalline gold films has been investigated through time-of-flight measurements. The thicknesses of the films range from 25 to 400 nm. Ballistic electrons as well as electrons interacting with other electrons and/or with the lattice have been observed. The ballistic component dominates the transport in the thinner films, whereas the interactive transport mechanism is dominant at the upper end of the thickness range. A slower effective velocity of the interactive component is observed in the polycrystalline samples, and is assumed to arise from the presence of grain boundaries. The reflection coefficient of excited electrons at the grain boundaries is extracted from the experiment and is estimated to be r=0.12. The experiment also suggests that thermal equilibrium among the excited electrons is not fully established in the first 500 fs after excitation. © 1993 The American Physical Society

APPLIED STUDY OF MICROBIOLOGICAL HAZARDS IN RAW MILK SOFT WHITE CHEESE IN EGYPT

Raw milk Domiati cheese is the main soft white pickled cheese produced in Egypt. The objective of this study was to assess the microbiological hazards, physiochemical quality and safety of some raw Domiati cheese subtypes including Double Cream, Tallaga, Baramely and Istanbully. The cheese samples were randomly collected from different cheese retailers in Cairo. The results indicated that the protein content and fat content were high in Double cream cheese. The pH value was low in Baramely cheese. Total solid, ash, and EC were high in Istanbully cheese because it is high salt level. Also, results indicated high microbiological hazards. the cheese samples were highly contaminated, having microbial load exceeding the acceptable limits such as: Total bacterial count, Total coliform, Fecal E. coli and yeast & molds. Pathogenic bacteria (Staphylococcus aureus, E. coli O157:H7, Salmonella sp., Shigella sp., Listeria monocytogenes, Bacillus cereus and Campylobacter jejuni) were detected in three cheese samples.  Except Istanbully cheese sample were found free of most pathogenic bacteria.  A high microbial load of the cheese samples present a public health hazard to the consumers and emphasize the need for improving hygienic standard. Microbiological hazards must be limited to the stander limit of food safety. Raw milk soft white cheese must be manufactured according to hygienic standard

Medium Optimization using Response Surface Methodology for High Cell Mass Production of Lactobacillus acidophilus

608-614Lactobacillus acidophilus belongs to probiotic microflora inhabiting human gut that provide beneficially enhances human health. Besides balancing the intestinal flora and inhibiting pathogenic microorganisms, the existence of L. acidophilus inside the intestine can restore gut flora following antibiotics treatments. However, usually microorganisms from lactic acid bacteria group are known as fastidious microorganism and naturally required complex nutrients to promote their cellular growth. Therefore, twelve reported cultivation media were screened for their capability to support cell growth of L. acidophilus. The most suitable medium was further optimized using response surface methodology (RSM) and Box-Behnken design to maximize cell growth of L.acidophilus. Using this statistical approach, about 2.5-fold increase in maximal cell dry weight was achieved (5.14 g L-1) compared to the original medium (2.05 g L-1).This increase was accompanied by a significant increase in cell growth rates as well. The new medium formulation composed of (g L-1): glucose, 50; yeast extract, 20.91; ammonium citrate, 3.42; citric acid, 0.5; KH2PO4, 1.5; MgSO4.7H2O, 0.4; MnSO4.7H2O, 0.05; sodium acetate, 1; tween 80, 1

Red biotechnology: A healthy world

Biotechnology is an interdisciplinary field of engineering, physics, chemistry and biology. The present era of Biotechnology has reached to a stage of treating killer diseases like cancer, HIV; disorders like diabetes, cardiac diseases and even hereditary disease at the genetic level etc. This review emphasizes the applications of Biotechnology in the medicine field and the basic development of nanomedicine. © 2019 Author(s)

Towards a comprehensive methodology for applying enterprise gamification

Gamification as a new concept uses game elements in a novel way to engage users of a non-gaming system and can be used in many domains within an enterprise, to implement the organizational processes with lower costs, higher quality or in a more efficient way. Although there are many researches on gamification but a few studies can be found in the organizational gamification and there are few research works about framework and methodology for designing and implementing organizational gamification in the literature. The purpose of this article is to provide a comprehensive methodology for the enterprise gamification. This research is an attempt to overcome the mentioned gap via presenting a methodology by applying some important issues including organizational, humanity and gamification aspects together to design and implement customized enterprise gamification solutions through reviewing the related literature and experts’ commentaries. The evaluation of the methodology showed that it is an appropriate and perfect way to design gamification solutions in an organization, besides the enterprise needs to provide the necessary conditions for its implementation. This paper forwards an important debate on a comprehensive methodology for applying enterprise gamification, which explains how to properly use gamification in enterprises to increase productivity and better communication with employees, and thus contributes to literature on internal and enterprise gamification