Influence of heat shock pretreatment on growth and development of tomatoes under controlled heat stress conditions

The effect of a previous heat shock (HS) on growth and development of different tomato (Lycopersicon esculentum Mill.) cultivars under defined heat stress (HSt) conditions were investigated. Plants were grown under two day/night temperature regimes (26/20 ºC and 37/27 ºC, respectively) in growth chambers at the Department of Vegetable Crops, Institute for Horticultural Sciences, Faculty of Agriculture and Horticulture, Humboldt University of Berlin. The experiments were conducted twice and were set up in a randomized design with five replicates. The reproductive processes in tomato were more sensitive to high temperatures than the vegetative ones. The number of pollen grains, number of fruits and fruit fresh masses produced by the heat tolerant cultivars were higher than those of the heat sensitive cultivars. However, HS pretreatments had no positive effects on tomato growth and development

Diagnostic value of Autoantibodies to GAD65 and IA-2 in Patients with Latent Autoimmune Diabetes in Adult (LADA)

Background: Latent autoimmune diabetes in adults (LADA) accounts for11 % of all cases of diabetes and often misdiagnosed as type 2diabetes. LADA resembles type 1diabetes and shares common physiological characteristics of type 1 but it does not affect children and has beenclassified distinctly as being separate from juvenile diabetes.  Autoantibodies against glutamic acid decarboxylase 65 (GADA) and tyrosine phosphatase (IA-2) are found frequently in patients withLADA. The presence of these autoantibodies in LADA predicts inevitable M cell failure and poor response to oral hypoglycemic therapy i.e., patients with LADA do not respond to oral hypoglycemic therapy.Objective: To determine an immunological marker to diagnose patients not responding to oral hypoglycemic therapy.Patients and methods: A facility-based cross sectional study was  conducted in Jabbir Abu Eliz Diabetes Center, located at Khartoum 2. Venous blood samples were obtained from the study patients. They were divided into three groups, group1 included 27 diabetic patients treated withinsulin, group2 included 15 diabetic patients of type 2 diabetes as controls, and group3 included 15 newly diagnosed patients older than 35 years at onset of diabetes. A standardized pre-tested administered questionnaire was used for data collection and the collected data were analyzed.Results: Males encountered in the study were 28 (49.1%). On patient recently diagnosed to have type 2 diabetes mellitus (T2DM) was positive for autoantibodies to GDA/IA-2. These autoantibodies were also positive in 15 patients with diabetes mellitus type 1 (T1DM)Conclusions: Autoimmune diagnostics is of particular importance in adults to discriminate between type 1 and type 2 diabetes and to assess the diagnosis of latent autoimmune diabetes in adults. The current study results revealed that autoantibodies to GAD/IA-2 are good marker for diagnosis of latent onset DM type 1. On the other hand, data indicate that the vast majority of cases of type 1 diabetes may be considered as immune-mediated, that multiple autoantibody to GAD/IA-2 analysisare of prognostic value to predict complications e.g., retinopathy. The current study recommends using of anti-GAD/IA-2 antibodies as marker for diagnosis of latent autoimmune diabetes in adults (LADA) who are not responding to oral hypoglycemic and may be at risk for getting complications. On the other hand, the study recommends using of anti-GAD/IA-2 antibodies for prognosis of the clinical progression of diabetes type 1 for prediction of insulin dependence

Numerical Simulation of the Donor-Assisted Stir Material for Friction Stir Welding of Aluminum Alloys and Carbon Steel

In this research effort, we explore the use of a donor material to help heat workpieces without wearing the tool or adding more heat than necessary to the system. The donor material would typically be a small piece (or pieces) of material, presumably of lower strength than the workpiece but with a comparable melting point. The donor, a sandwich material, is positioned between the tool head and the material to be welded, where the tool initially plunges and heats up in the same manner as the parent material that is intended for welding. The donor material heats up subsequent to tool penetration due to friction and as a result heats up the material beneath it. This preheating technique softens the harder parent material, which helps to minimize tool wear and produce better weld performance. The goal is to investigate the use of the donor material as a preheating technique that minimizes wear and tear on the tool head without negatively impacting the structural properties of the weld. To demonstrate the donor material concept, a combination of Cu-Al, Cu-1045 Carbon steel (CS), and Al-1045 CS sets of donor and parent materials were used in the simulation, in addition to control samples Al-Al and CS-CS. We simulated two thicknesses of donor material 25 and 50% of the parent material thickness, respectively. The simulation suggests that the donor material concept generates phenomenal results by reducing the temperature and axial forces for the friction stir welding of aluminum AA6061 and carbon steel 1045. It also assists downstream during welding, resulting from frictional mechanical work which is converted into stored heat

Kinetic Spectrophotometric Determination of Certain Cephalosporins in Pharmaceutical Formulations

A simple, reliable, and sensitive kinetic spectrophotometric method was developed for determination of eight cephalosporin antibiotics, namely, Cefotaxime sodium, Cephapirin sodium, Cephradine dihydrate, Cephalexin monohydrate, Ceftazidime pentahydrate, Cefazoline sodium, Ceftriaxone sodium, and Cefuroxime sodium. The method depends on oxidation of each of studied drugs with alkaline potassium permanganate. The reaction is followed spectrophotometrically by measuring the rate of change of absorbance at 610 nm. The initial rate and fixed time (at 3 minutes) methods are utilized for construction of calibration graphs to determine the concentration of the studied drugs. The calibration graphs are linear in the concentration ranges 5–15 μg mL−1 and 5–25 μg mL−1 using the initial rate and fixed time methods, respectively. The results are validated statistically and checked through recovery studies. The method has been successfully applied for the determination of the studied cephalosporins in commercial dosage forms. Statistical comparisons of the results with the reference methods show the excellent agreement and indicate no significant difference in accuracy and precision

Evaluation of electropolished stainless steel electrodes for use in DC high voltage photoelectron guns

DC high voltage photoelectron guns are used to produce polarized electron beams for accelerator-based nuclear and high-energy physics research. Low-level field emission (similar to nA) from the cathode electrode degrades the vacuum within the photogun and reduces the photoelectron yield of the delicate GaAs-based photocathode used to produce the electron beams. High-level field emission (\u3e mu A) can cause significant damage the photogun. To minimize field emission, stainless steel electrodes are typically diamond-paste polished, a labor-intensive process often yielding field emission performance with a high degree of variability, sample to sample. As an alternative approach and as comparative study, the performance of electrodes electropolished by conventional commercially available methods is presented. Our observations indicate the electropolished electrodes exhibited less field emission upon the initial application of high voltage, but showed less improvement with gas conditioning compared to the diamond-paste polished electrodes. In contrast, the diamond-paste polished electrodes responded favorably to gas conditioning, and ultimately reached higher voltages and field strengths without field emission, compared to electrodes that were only electropolished. The best performing electrode was one that was both diamond-paste polished and electropolished, reaching a field strength of 18.7 MV/m while generating less than 100 pA of field emission. The authors speculate that the combined processes were the most effective at reducing both large and small scale topography. However, surface science evaluation indicates topography cannot be the only relevant parameter when it comes to predicting field emission performance. (C) 2015 American Vacuum Society

Epidemiology of cesarean delivery in Kassala, Eastern Sudan: a community-based study 2014- 2015

Background: Cesarean delivery is a main obstetrical operation and its rate should be optimized where the World Health Organization regards that a cesarean delivery rate of 5-15% is an optimal range, putting in consideration the necessity of the procedure as a lifesaving intervention for both the mother and fetus.Objectives: To investigate the epidemiology of cesarean delivery in Kassala, Eastern Sudan from December 2014 to March 2015.Materials and Methods: A stratified, multistage, household survey was carriedout. Questionnaires were applied to gather mode of delivery and its determinants.Results: Out of 303 women, 87 (28.7%), 100 (33%), 116 (38.3) were primiparous, secondiparous and multiparous, respectively, Mothers' age ranged from 13 to 48 with mean (SD) 27.79 (5.94) years. In logistic regression, elder women (OR=1.1, 95 CI= 1.01-1.34, p = 0.005), primparae (OR= 6.4, 95% CI = 1.3-31.8, p = 0.001) and women who had medical disease (OR= 2.9, 95% CI= 1.16-7.6, p= 0.023) were at higher risk to deliver by caesarean delivery.Conclusion: The rate of cesarean delivery in Kassala in the current study is17.8% and the elder women, primiapare and women with medical disorders were at a higher risk to deliver by caesarean delivery.Keywords: Cesarean, Kassala, pregnancy, Suda

Approximate Analytical Technique to Design Reflectarray Antenna

This paper presents an analysis and design for a reflectarray antenna composed of an array of rectangular patches printed on a grounded dielectric slab. A simple analytical technique based on equivalent surface impedance is used to determine the reflection of the elements in reflectarray antenna. This equivalent surface impedance is obtained analytically in a closed form. The effect of the angle of incidence on each element in the reflectarray is included in calculations. To author’s knowledge, this property has not been included in previous analysis techniques of reflectarray antenna

Approximate Analytical Technique to Design Reflectarray Antenna

This paper presents an analysis and design for a reflectarray antenna composed of an array of rectangular patches printed on a grounded dielectric slab. A simple analytical technique based on equivalent surface impedance is used to determine the reflection of the elements in reflectarray antenna. This equivalent surface impedance is obtained analytically in a closed form. The effect of the angle of incidence on each element in the reflectarray is included in calculations. To author’s knowledge, this property has not been included in previous analysis techniques of reflectarray antenna

Post-Weld Heat Treatment Effects on Microstructure, Crystal Structure, and Mechanical Properties of Donor Stir–Assisted Friction stir Welding Material of AA6061-T6 Alloy

Friction stir welding (FSW) technology combines heat input from friction and extreme plastic deformation to produce high-quality joints in aluminum and other alloy systems. This necessitates examining the final welded joint’s mechanical and structural properties. Post-weld heat-treated AA6061-T6 alloy that resulted from the application of a Cu donor stir–assisted (CDSA) friction stir welding (FSW) material was examined for crystal structure and mechanical properties. CDSA FSW samples were tested at a constant tool rotational speed of 1400 rpm and a welding translational speed of 1 mm/s. CDSA samples of 20% and 60% thickness of the AA6061-T6 base alloy were selected to assist the FSW joining at the plunge stage. The FSW AA6061-T6 samples were solid solution treated at 540 °C for 1 h, followed by quenching in water at room temperature. The samples were then artificially aged at 180 °C for 6 h, respectively, followed by air cooling. The samples were tested for microstructure, crystal structure, chemical composition, and mechanical properties using optical microscopy, scanning electron microscopy, X-ray diffraction, and nanoindentation. The microstructure shows the additional grain refinement in the stir zone (SZ) due to recovery and recrystallization with increasing aging time. Examination of the chemical contents of the FSW AA6061-T6 alloy samples using scanning electron microscopy with energy-dispersive spectroscopy (EDS) revealed Al (parent material) as the predominant element, while Cu (CDSA) was minimally present as expected. XRD results of the CDSA FSW samples depicted crystal orientations similar to the orientations of the AA6061-T6 alloy. Nanoindentation tests revealed softening effects due to the dissolution of hardening precipitates at the SZ. The hardness of the base metal (BM), left and right regions, is reported as ~ 0.65 GPa, whereas at the SZ, the hardness is ~ 0.55 GPa at a depth of indentation of 4.7 μm