Anisotropic luminescence and third-order electric susceptibility of Mg-doped gallium oxide under the half-bandgap edge.

Strong anisotropy of photoluminescence of a (100)-cut ß-Ga2O3 and a Mg-doped ß-Ga2O3 single crystals was found in UV and visible spectral range, the bands of which were attributed to different types of transitions in the samples. Green photoluminescence in the Mg-doped sample was enhanced approximately twice. A remarkable enhancement of two-photon absorption and self-focusing in ß-Ga2O3 after doping was revealed by 340-fs laser Z-scanning at 515 nm. The absolute value of complex third order susceptibility χ(3) determined from the study increases by 19 times in [001] lattice direction. Saturable absorption and associated self-defocusing were found in the undoped crystal in the [010] direction, which was explained by the anisotropic excitation of F-centers on intrinsic oxygen defects. This effect falls out of resonance in the Mg-doped crystal. The χ(3) values which are provided by a decrease of bandgap in Mg-doped ß-Ga2O3 are χ(3) [001] = 1.85·10-12 esu and χ(3) [010]=χ(3)yyyy = 0.92·10-12 esu. Our result is only one order of magnitude lower than the best characteristic in green demonstrated by a Mg-doped GaN, which encourages subsequent development of Mg-doped ß-Ga2O3 as an effective nonlinear optical material in this region.

Effect of surfactant and surfactant blends on pseudoternary phase diagram behavior of newly synthesized palm kernel oil esters.

BACKGROUND: The purpose of this study was to select appropriate surfactants or blends of surfactants to study the ternary phase diagram behavior of newly introduced palm kernel oil esters. METHODS: Nonionic surfactant blends of Tween(®) and Tween(®)/Span(®) series were screened based on their solubilization capacity with water for palm kernel oil esters. Tween(®) 80 and five blends of Tween(®) 80/Span(®) 80 and Tween(®) 80/Span(®) 85 in the hydrophilic-lipophilic balance (HLB) value range of 10.7-14.0 were selected to study the phase diagram behavior of palm kernel oil esters using the water titration method at room temperature. RESULTS: High solubilization capacity was obtained by Tween(®) 80 compared with other surfactants of Tween(®) series. High HLB blends of Tween(®) 80/Span(®) 85 and Tween(®) 80/Span(®) 80 at HLB 13.7 and 13.9, respectively, have better solubilization capacity compared with the lower HLB values of Tween(®) 80/Span(®) 80. All the selected blends of surfactants were formed as water-in-oil microemulsions, and other dispersion systems varied in size and geometrical layout in the triangles. The high solubilization capacity and larger areas of the water-in-oil microemulsion systems were due to the structural similarity between the lipophilic tail of Tween(®) 80 and the oleyl group of the palm kernel oil esters. CONCLUSION: This study suggests that the phase diagram behavior of palm kernel oil esters, water, and nonionic surfactants is not only affected by the HLB value, but also by the structural similarity between palm kernel oil esters and the surfactant used. The information gathered in this study is useful for researchers and manufacturers interested in using palm kernel oil esters in pharmaceutical and cosmetic preparation. The use of palm kernel oil esters can improve drug delivery and reduce the cost of cosmetics.

Intracellular cytoskeletal elements and cytoskeletons in bacteria.

Within a short period of time after the discovery of bacterial cytoskletons, major progress had been made in areas such as general spatial layout of cytoskeletons, their involvement in a variety of cellfunctions (shape control, cell division, chromosome segregation, cell motility). This progress was achieved by application of advanced investigation techniques. Homologs of eukaryotic actin, tubulin, and intermediate filaments were found in bacteria; cytoskeletal proteins not closely or not at all related to any of these major cytoskeletal proteins were discovered in a number of bacteria such as Mycoplasmas, Spiroplasmas, Spirochetes, Treponema, Caulobacter. A structural role for bacterial elongation factor Tu was indicated. On the basis of this new thinking, new approaches in biotechnology and new drugs are on the way.

Investigations of positronium formation and destruction using 3gamma/2gammaannihilation-ratio measurements.

Positronium (Ps) produced by 4 to 40 eV positrons colliding with Ne, Ar, Kr, CO2, and O2 is investigated by measuring the ratio of signals of two gamma rays in coincidence resulting from (a) three gamma annihilation of ortho-Ps and (b) two annihilation gamma rays due to para-Ps decay and destruction of ortho-Ps at an aluminum scattering cell surface. These ratios provide evidence that relates to the kinetic energy dependence of ortho-Ps interactions with an aluminum surface, the Ps formation potential at this surface, and the fact that Ps is being formed with inner orbital electrons for CO2 and O2.

Quality assessment of primary health care services provided for diabetes mellitus control in Alexandria.

Diabetes is a growing health problem worldwide. It is recognized as a particular threat to public health of the third world communities, particularly those living in rapidly developing countries. Therefore, the present study was conducted aiming at: assessment of the quality of primary health care (PHC) services provided for the control of diabetes mellitus (DM) in Alexandria; and opportunistic screening of high risk individuals attending PHC facilities for DM. Accordingly, the availability of human and nonhuman resources for DM control in two rural and two urban PHC centers in Alexandria (one of them was serving a desert area) was assessed by a pre-designed checklist 920 adult PHC attendants were screened for risk factors of DM. Individuals having more than one of the following risk factors: age above 50 years, overweight (body mass index > or =27 kg/m2), family history of DM in first degree relatives, history of hypertension, hypertension (systolic blood pressure > or =140 mm Hg and /or diastolic blood pressure > or =90 mm Hg), history of hyperlipidemia and history of gestational diabetes or birth of a large sized baby in females- were subjected to random capillary blood glucose (RCBG) testing. Cases were considered likely diabetic if RCBG was >200 mg/dl The performance of all PHC physicians examining and managing 560 diabetic patients was observed over a period of two months. One fourth of the diabetic cases were checked for the level of glycaemic control by fasting capillary blood glucose testing. The results revealed that 61.7% of the studied PHC attendants were at risk of developing DM and 14% were likely diabetic, with an urban: desert ratio of 2:1 The following factors were found to be independently associated with an increasing risk of DM occurrence among males: overweight (about 14 folds), family history of DM (9 folds), age above 50 years and history of hypertension (4 folds each). Whereas, among females the following risk factors were found: family history of DM (8 folds), history of gestational diabetes (6 folds) and overweight (4 folds). The majority of diabetic patients were poorly examined, investigated and managed; and an optimal level of glycaemic control was achieved in only 12.9% of the cases, as the PHC physicians didn't follow a model treatment plan for DM and due to unavailability of some equipment, laboratory facilities and essential drugs.

The role of primary health care in patient education for diabetes control.

The major components of diabetes management are dietary therapy, exercise and drug treatment. Therefore, education of people with diabetes is the cornerstone of management. The aim of the present work was to study the role of primary health care (PHC) in patient education for diabetes control in Alexandria. Accordingly, the knowledge and perception concerning diabetes and its management of all 88 PHC physicians and 104 nurses working in the two rural health centers and two randomly chosen urban health centers of Alexandria governorate were assessed by pre-designed self-administered questionnaire. All diabetic patients over 20 years of age attending the study health facilities over a period of two months were assessed for their knowledge and attitude concerning diabetes and self-management and asked about their degree of satisfaction with the provided PHC services by a pre-designed interview questionnaire. They amounted to 560 diabetic patients. The results revealed that the PHC physicians had sufficient knowledge about causes and complications of the disease, but insufficient knowledge about diagnosis and management, as only 10.2% & 4.5% of the physicians recognized the importance of regular exercise and patient education for diabetes management. Some misconceptions and false beliefs were observed among PHC nurses, as many of them considered diabetes a contagious disease or primarily caused by stress; that liver failure, hearing impairment and splenomegaly are among the complications of diabetes and that young age and immunodeficiency disorders are among the risk factors for developing diabetes. Moreover, most of them believed that the amount of carbohydrates given to diabetic patients should be reduced or even completely restricted; that vitamins are essential for all diabetic patients and that hot-water bottles are good for providing warmth to the diabetic feet. They also disagreed on the use of artificial sweeteners as sugar substitutes. Most of the diabetic patients had poor knowledge about diabetes and its management (85.7%) and a negative attitude towards self-management (61.6%) and only 23.6% of them were satisfied with the services provided by the PHC facilities for diabetes control. They were mainly dissatisfied with the role of PHC physicians in patient education. Some misconceptions and false beliefs were also recognized among diabetic patients. Many of them considered diabetes a contagious disease or primarily caused by stress. They didn't know the importance of regular exercise in diabetes control. They also believed in the efficacy of herbal therapy in diabetes control; that vitamins are essential for all people with diabetes; that water intake should be decreased when passing large amounts of urine, that anti-diabetic drugs should be stopped during associated illnesses and that patients on insulin treatment can't be shifted to oral drugs. Moreover, they believed that the amount of carbohydrates in diet should be reduced or even restricted and that the amount of proteins should not be reduced. They also refused the use of artificial sweeteners as sugar substitutes. Thus, it may be concluded that there is a serious gap in the provision of basic educational services to the majority of diabetic patients attending PHC facilities in Alexandria.

Health status assessment of drug addicts in Alexandria.

The case-control study was conducted among addicts in Alexandria to determine the different health problems among them, as well as to study the correlation between addiction and these problems. One hundred drug addicts and eighty apparently healthy controls were included in this study. The whole sample was subjected to the following: filling a predesigned questionnaire sheet, clinical and electrocardiogram (ECG) examination, measurements of Body Mass Index (BMI), complete blood picture and antistreptolysin O titre (ASO), testing for hepatitis B surface antigen (HBsAg) and antibody to hepatitis B core antigen (anti HBc), skin scrapings from superficial fungal lesions in addition to complete urine and stool examination. The results revealed that chest rhonchi, hepatomegaly, central nervous system (CNS) abnormalities, skin lesions lymphadenopathy, underweight and anaemia were significantly higher among addicts than the controls. Hepatitis B virus (HBV) exposure and HBsAg seropositivity were found 48.0% and 21.0%, respectively among addicts compared to 26.3% and 5.0%, respectively among the controls. The intravenous injections and tattooing were the most risky routes for HBV infection among addicts. A positive correlation was revealed between HBV exposure and both the duration and the number of daily injections. Chest X-ray suggestive of pulmonary tuberculosis were found in 7.0% of the addicts. Addiction potentiated the risk of fungal infection among low social class, but it had no effect on the relationship between anaemia and social class nor on that between loss of appetite and underweight.

Mechanism of bromocriptine-induced hyperglycaemia.

Results reveal that bromocriptine at a dose of 6 mg/kg. I.P. in mice caused a significant hyperglycaemic effect which was accompanied by a marked increase in liver glycogen. After adrenalectomy, the effect of bromocriptine on serum glucose level was reduced whereas its effect on liver glycogen content was abolished. In rats, administration of bromocriptine (17.5 mg/kg I.P.) induced a significant rise in serum glucose level which was associated with marked reduction in serum insulin activity and increase in serum corticosterone level with no effect on serum triiodothyronine (T3) or thyroxine (T4) levels. It could be concluded that bromocriptine-induced hyperglycaemia might be attributed at least partially to inhibition of insulin release and stimulation of corticosterone secretion.

Synthesis and antidiabetic activity of some sulfonylurea derivatives of 3,4,5-trisubstituted pyrazoles.

Three series of 3,4,5-trisubstituted pyrazolesulfonylurea derivatives were prepared and evaluated as hypoglycemic agents. Preliminary biological testing revealed that the new compounds possess moderate hypoglycemic activity.

Synthesis and antidiabetic activity of some sulfonylurea derivatives of 3,5-disubstituted pyrazoles.

Two series of 3,5-disubstituted pyrazolesulfonylurea derivatives were prepared and evaluated as hypoglycemic agents. Preliminary biological testing revealed that the new compounds possess potent hypoglycemic activity.

Preparation and antidiabetic activity of cyclic sulfonylthiourea derivatives.

3-Substituted 5-methyl-1-(p-[(3,5-dimethyl)pyrazol-1-yl]-, 5-methyl-1-(p-[(5-methyl-3-carboxy)pyrazol-1-yl]-, 1-(p-[(3-methyl-5-phenyl)pyrazol-1-yl]-, and 1-(p-[(3-methyl-4-bromo-5-phenyl)pyrazol-1-yl]benzenesulfonyl)-2-thiohydantoin and their 5-methyl-2-thiohydantoin and 5,6-dihydro-4(3H)-oxo-2(1H)-pyrimidinethione derivatives were prepared for evaluation as hypoglycemic agents. Biological testing showed that some of these compounds possessed antidiabetic activity.

Mitochondrial metabolism of (D,L)-threo-9, 10-dibromo plamitic acid.

Bromination of palmitoleic or palmitelaidic acid proceeds by trans addition and yields dibrominated products which cannot undergo beta-oxidation when incubated with mitochondria isolated from hamster brown adipose tissue. These mitochondria were selected because they have a high capacity for oxidation of C16 fatty acids and because they are readily uncoupled by an excess of free fatty acids of this chain length. The only metabolites which could be recovered from the incubation mixtures were dibromopalmitoylcarnitine and dibromopalmitoyl CoA. Free fatty acid was also recovered. Addition of synthetic carnitine or CoA esters of brominated fatty acids did not interfere with subsequent oxidation of palmitoylcarnitine. Addition of the free brominated fatty acids did not significantly increase the rate of oxidation of subsequent additions of palmitoylcarnitine, as did other known synthetic uncouplers. These results are consistent with observations by others that feeding brominated oils leads to brominated fatty acid incorporation into tissue lipids, and indicate why this is so. They also provide a possible explanation for the hepatic damage noted in feeding experiments.