Correlation between Crystallographic Alignment of Self-induced GaN Nanowires and Features of Si(111) Nitridation

Formation and spatial ordering of self-induced GaN nanowires grown by molecular beam epitaxy on a spatially pre-nitridazed Si(111) substrate have been studied. It was found the close correlation between Si substrate nitridation parameters and crystallographic alignment of NWs. Conditions for NWs nucleation and in- plane orientation are predefined by a structural anisotropy of silicon nitride nanolayer. Mechanism of NWs orderly emergence suggested. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3540

Increase in the Synthesis of Polyfructan in the Cultures of Chicory “Hairy Roots” with Plant Natural Growth Regulators

Experiments were conducted to study the benefit of using the new plant growth regulators (PGRs) Ivin, Emistim, Biolan and Charkor in nutrient medium ½ MS for intensification of biomass growth and the increased synthesis of polyfructan (PF) in the cultures of chicory “hairy roots” (Cichorium intybus L.), obtained by Аgrobacterium rhizogenes-mediated transformation,. The best indexes of increased specific quantities of PF are observed after using Biolan at a concentration of 5.0 μL/L (up to 130 mg/g dry mass of roots) and Emistim at a concentration 2.5 µL/L (up to 220 mg/g dry mass of roots). The greatest stimulation of root growth activity was expressed on using the growth regulators Emistim, Ivin and Charkor, in concentrations between 2.5 and 10.0 µL/L, considerably raising the total quantity of PF: compared with the control the use of regulator Emistim showed a rise of up to 35 times, regulator Ivin showed an increase of up to 28 times and regulator Charkor showed an increase up to 7.0-7.5 times. The results thus obtained definitely prove the benefit of applying these regulators to increase the biomass growth and PF synthesis in the culture of chicory «hairy roots»

Magnetic field penetration in MgB₂ single crystals: pinning and Meissner holes

The evolution of flux distribution in MgB₂ single crystals during their remagnetization was imaged with magneto-optical technique. Meissner holes, formed as the areas where the annihilation of vortices and antivortices takes place, were found at the boundary between oppositely magnetized parts of the crystal. Gradient of magnetic induction in the vicinity of Meissner holes was found to be enhanced. Finger-like structures of convex shape, formed during the penetration of magnetic flux inside the crystal, were observed and explained as an effect of inhomogeneous pinning and demagnetizing field redistribution in the sample

Peak expiratory flow rate shows a gender-specific association with vitamin D deficiency

Context: To our knowledge, no previous studies examined the longitudinal relationship between vitamin D status and pulmonary function in a population-based sample of older persons. Objective: Our objective was to examine the cross-sectional as well as the longitudinal relationship between vitamin D status and peak expiratory flow rate (PEFR) in a representative sample of the Dutch older population. Design, Setting, and Participants: Participants included men and women in the Longitudinal Aging Study Amsterdam, an ongoing cohort study in older people. Main Outcome Measure: PEFR was measured using the mini-Wright peak flow meter. Results: Men with serum 25-hydroxyvitamin D (25-OHD) levels below 10 ng/ml (25 nmol/liter) had a significantly lower PEFR in the cross-sectional analyses, and men with serum 25-OHD levels below 20 ng/ml (50 nmol/liter) had a significantly lower PEFR in the longitudinal analyses as compared with men with serum 25-OHD levels above 30 ng/ml (75 nmol/liter) (cross-sectional: β = -47.0, P = 0.01 for serum 25-OHD<10 ng/ml; longitudinal: β = -45.0, P<0.01 for serum 25-OHD<10 ng/ml; and β = -20.2, P = 0.03 for serum 25-OHD = 10-20 ng/ml in the fully adjusted models). Physical performance (β = -32.5, P = 0.08 for serum 25-OHD<10 ng/ml) and grip strength (β = -40.0, P = 0.03 for serum 25-OHD <10 ng/ml) partly mediated the cross-sectional associations but not the longitudinal associations. In women, statistically significant associations between 25-OHD and PEFR were observed in the cross-sectional analyses after adjustment for age and season of blood collection but not in the fully adjusted models or in the longitudinal analyses. Conclusions: A strong relationship between serum 25-OHD and PEFR was observed in older men, both in the cross-sectional as well as longitudinal analyses, but not in older women. The association in men could partly be explained by physical performance and muscle strength. Copyright © 2012 by The Endocrine Society

Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine 8 PACS 85

Abstract. We consider the features of formation of AuTiPd ohmic contacts to p + -Si. Metallization was made by vacuum thermal sputtering of Pd, Ti and Au films onto the Si substrate heated up to 330 С. It is shown that the contact resistivity increases with temperature; this is typical of metallic conductivity. We suggest that the ohmic contact is formed owing to appearance of shunts at Pd deposition on dislocations or other structural defects. The number of shunts per unit area is close to the measured density of structural defects at the metalSi interface

Optimal Use of Vitamin D When Treating Osteoporosis

Inadequate serum 25-hydroxyvitamin D (25[OH]D) concentrations are associated with muscle weakness, decreased physical performance, and increased propensity in falls and fractures. This paper discusses several aspects with regard to vitamin D status and supplementation when treating patients with osteoporosis in relation to risks and prevention of falls and fractures. Based on evidence from literature, adequate supplementation with at least 700 IU of vitamin D, preferably cholecalciferol, is required for improving physical function and prevention of falls and fractures. Additional calcium supplementation may be considered when dietary calcium intake is below 700 mg/day. For optimal bone mineral density response in patients treated with antiresorptive or anabolic therapy, adequate vitamin D and calcium supplementation is also necessary. Monitoring of 25(OH)D levels during follow-up and adjustment of vitamin D supplementation should be considered to reach and maintain adequate serum 25(OH)D levels of at least 50 nmol/L, preferably greater than 75 nmol/L in all patients

Serum 25-hydroxyvitamin D, parathyroid hormone, calcium intake, and bone mineral density in Spanish adults

Summary Vitamin D insufficiency is very common among Spanish community-dwelling adult subjects. A threshold of serum 25(OH)D around 30 ng/ml would be necessary for the prevention of secondary hyperparathyroidism and hip bone loss in our population, regardless of the dairy calcium ingestion. Introduction This study aims to assess 25-hydroxyvitamin D?25(OH)D?status in Spanish adult subjects and to analyze its relationships with serum PTH levels, calcium intake, and bone mineral density (BMD). Methods A total of 1811 individuals (1154 postmenopausal women and 657 men) aged 44?93 years participated in the study. Serum 25(OH)D, intact parathyroid hormone (PTH), aminoterminal propeptide of type I collagen (P1NP), and Cterminal telopeptide of type I collagen (?-CTX) levels were measured by electrochemiluminescence. BMD was determined by dual x-ray absorptiometry (DXA) at lumbar spine, femoral neck, and total hip. Results Serum 25(OH)D levels were below 10, 20, and 30 ng/ml in 5, 40, and 83%of participants, respectively. There was a significant seasonal difference in mean serum 25(OH)D, with higher levels in summer?autumn. In multivariate analysis, 25(OH)D levels were negatively correlated with age, serum PTH and creatinine, body mass index, smoking, alcohol intake, and a number of chronic diseases, but positively with dairy calcium intake. The magnitude of the difference in serum PTH according to 25(OH)D quartiles was not influenced by calcium intake. A threshold of serum 25(OH)D around 30 ng/ml was observed for serum PTH and hip BMD. Conclusions Vitamin D insufficiency is very common among Spanish community-dwelling adult subjects. A threshold of serum 25(OH)D around 30 ng/ml would be necessary for the prevention of secondary hyperparathyroidism and hip bone loss in our population, regardless of the dairy calcium ingestion. Programs to improve vitamin D status may be required in our country

Management of osteoporosis in patients hospitalized for hip fractures

Hip fracture is associated with high morbidity, mortality, and economic burden worldwide. It is also a major risk factor for a subsequent fracture. A literature search on the management of osteoporosis in patients with hip fracture was performed on the Medline database. Only one clinical drug trial was conducted in patients with a recent hip fracture. Further studies that specifically address post-fracture management of hip fracture are needed. The efficacy of anti-osteoporosis medication in older individuals and those at high risk of fall is reviewed in this paper. Adequate nutrition is vital for bone health and to prevent falls, especially in malnourished patients. Protein, calcium, and vitamin D supplementation is associated with increased hip BMD and a reduction in falls. Fall prevention, exercise, and balance training incorporated in a comprehensive rehabilitation program are essential to improve functional disability and survival. Exclusion of secondary causes of osteoporosis and treatment of coexistent medical conditions are also vital. Such a multidisciplinary team approach to the management of hip fracture patients is associated with a better clinical outcome. Although hip fracture is the most serious of all fractures, osteoporosis management should be prioritized to prevent deterioration of health and occurrence of further fracture