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The growth process is crucial to achieve large-sized and high-quality aluminum nitride (AlN) crystals through the physical vapor transport (PVT) method. To investigate the influence of parameters on the growth of AlN crystals, a series of quasi-steady numerical simulations on the temperature distribution, growth rate, and partial pressure of Al vapor inside the growth cell were conducted based on a self-developed finite element mass transfer module in the COMSOL package, which considers the partial pressure of gas phases, for different growth temperatures and crucible positions. The simulation results show that increasing the growth temperature significantly augments the partial pressure of Al vapor and the growth rate in the growth cell. Simultaneously, variation of the crucible position substantially alters the temperature distribution and the transport direction of Al vapor inside the crucible. A novel heat sink on the top of the crucible was designed to impair the phenomenon of uneven crystal growth on the surface of the seed caused by the nonuniform radial temperature distribution. Compared to the original crucible, the radial temperature gradient of the optimized crucible was reduced by 37%, and the uniformity of seed surface growth was improved by 89%. This work guides the design of a novel crystal growth furnace and the preparation of high-quality AlN single crystals by the PVT method. [ABSTRACT FROM AUTHOR]

Transport properties and the Stokes-Einstein (SE) relation in liquid Cu8Zr3 are studied by molecular dynamics simulation with a modified embedded atom potential. The critical temperature Tc of mode coupling theory (MCT) is derived as 930 K from the self-diffusion coefficient D and viscosity η. The SE relation breaks down around TSE = 1900 K, which is far above Tc. At temperatures below TSE, the product of D and η fluctuates around a constant value, similar to the prediction of MCT near Tc. The influence of the microscopic atomic motion on macroscopic properties is investigated by analyzing the time dependent liquid structure and the self-hole filling process. The self-holes for the two components are preferentially filled by atoms of the same component. The self-hole filling dynamics explains the different breakdown behaviors of the SE relation in Zr-rich liquid CuZr2 compared to Cu-rich Cu8Zr3. At TSE, a kink is found in the temperature dependence of both partial and total coordination numbers for the three atomic pair combinations and of the typical time of self-hole filling. This indicates a strong correlation between liquid structure, atomic dynamics, and the breakdown of SE relation. The previously suggested usefulness of the parameter d(D1/D2)/dT to predict TSE is confirmed. Additionally we propose a viscosity criterion to predict TSE in the absence of diffusion data. [ABSTRACT FROM AUTHOR]

OBJECTIVE: The purpose of this study was to detect microRNA-222-5p (miR-222- 5p) levels in placental tissues of preeclampsia (PE) pregnancies, and to explore the role of miR222-5p in the proliferative and migratory potentials of trophoblast cell line HTR-8/SVneo. PATIENTS AND METHODS: Expression levels of miR-222-5p and AHNAK in placental tissues of PE pregnancies (n=24) and healthy pregnancies (n=24) were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Potential influences of miR-222-5p and AHNAK on proliferative, migratory and apoptotic potentials in HTR-8/SVneo cells were examined. At last, Luciferase assay was conducted to illustrate the interaction between miR-222-5p and AHNAK in trophoblasts. RESULTS: It was found that miR-222-5p was downregulated in placental tissues of PE pregnancies. Overexpression of miR-222-5p stimulated proliferative and migratory potentials, and inhibited apoptosis in HTR-8/SVneo cells. Moreover, AHNAK was the target gene binding to miR-222-5p, and overexpression of AHNAK inhibited proliferative and migratory potentials and promoted apoptosis in HTR-8/SVneo cells. CONCLUSIONS: MiR-222-5p stimulates proliferative and migratory potentials and inhibits apoptosis in HTR-8/SVneo cells by negatively regulating AHNAK. [ABSTRACT FROM AUTHOR]

This study compared the effects of sodium selenite and selenium yeast and their combination on laying performance, egg quality, antioxidant capacity, and selenium (Se) contents in tissues and eggs. Two-hundred-eighty-eight Jing Hong layers that were similar in laying rate (87.5 ± 0.38%) and body weight (1.70 ± 0.02 kg) were randomly distributed into 4 treatments for 11 wk (from 203 d old to 279 d old) with 9 replicates of 8 hens per replicate. The diets (cornsoybean meal diet) were supplemented with 0 [blank control (BC)], 0.3 mg/kg Se from sodium selenite (SS), 0.15 mg/kg Se from sodium selenite and 0.15 mg/kg Se from Se yeast (SS+SY), or 0.3 mg/kg Se from Se yeast (SY). Results showed that the laying rate of the SS+SY group increased significantly (P < 0.05) compared to the BC and SY groups. There were no differences (P > 0.05) in egg quality between the Se-supplemented diets and the BC diet. The serum glutathione peroxidase (GSH-Px) activity was increased (P < 0.01) in hens fed Se-supplemented diets compared to the BC diet. The liver superoxide dismutase (SOD) activity of the SY group was increased significantly (P < 0.05) compared to the BC group. Significant increase (P < 0.01) due to SY supplementation was noted in the serum vitamin E content compared to BC and SS. Layers fed Se-supplemented diets had higher (P < 0.01) contents of Se in the serum, liver, and kidney compared to the BC diet. Compared to BC, Se content in eggs was significantly increased (P < 0.05) by feeding supplementary Se. In conclusion, the effects of SS and Se yeast were approximately equal in promoting antioxidant capacity of laying hens, while Se yeast is easier to deposit into eggs and tissues. The diet with added equal amounts of the 2 sources of Se was more cost effective and affordable than a comparable amount of Se yeast to obtain the promising production performance and nearly similar Se deposition. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To investigate the relationship between lesion patterns of single small infarct (SSI) in perforating territory of the vertebral-basilar artery and early neurological deterioration (end)/short-term functional outcome. PATIENTS AND METHODS: 126 patients with acute SSI in the perforating territory of the vertebral-basilar artery, admitted within 24 h after symptom onset, were recruited between August 2010 and May 2013. The patients were divided into proximal SSI and distal SSI according to the relationship between their lesion location and their parent artery. Early neurological deterioration (END) was defined as an increase in the National Institutes of Health Stroke Scale (NIHSS) ≥ 2 within 3 days after admission. Functional outcome at 30 days after onset was assessed using the modified Rankin Score (mRS) and dichotomized as good (0-2), and poor (≥ 3). RESULTS: Out of 126 patients, proximal SSI was found in 70 (55.56%) patients and distal SSI in 56 (44.44%) patients. After standard treatment, 36 (28.57%) patients experienced END within 3 days after admission, and 19 (15.70%) patients had a poor outcome at 30 days. Univariate analysis revealed that lesion size, baseline NIHSS score, parent artery disease, diabetes mellitus, and asymptomatic cerebral arterial atherosclerosis were significantly associated with END (with either p<005 or p<0.01), while the short-term outcome was just as significantly associated with proximal SSI, the baseline NIHSS score and END (with either p<005 or p<0.01). Results from multiple logistic regression analysis revealed that proximal SSI was an independent predictor of END (odd ratio [OR] 3.222, 95% CI 1.170-8.874, p=0.024) and that the END independently predicted a poor outcome (OR 4.126, 95% CI: 1.241-13.713, p=0.021) at 30 days after onset. CONCLUSIONS: Proximal SSI in the perforating territory of the vertebral-basilar artery was closely related to the presence of END, and the END independently predicted the subsequent poor outcome at 30 days after onset. [ABSTRACT FROM AUTHOR]

OBJECTIVES: The basic HLH transcription factor Olig is a key regulator for differentiating the oligodendrocyte lineage cells during development. Oligodendrocyte transcription factor 2 (Olig2) plays a crucial role in differentiating the oligodendrocytes in the spinal cord. We aimed to construct and investigate the eukaryotic expression recombinant plasmid in the rat Olig2. DESIGN, TIME AND SETTING: The experiment was performed at the Laboratory of Neurobiology, Xuzhou Medical College from October 2011 to March 2012. MATERIALS AND METHODS: The pEGFP-N1 vector was purchased from Invitrogen. JM101 competent cells and COS-7 cells were preserved at the Laboratory of Neurobiology, Xuzhou Medical College, China. The Olig2 cDNA fragment was cloned by RT-PCR with the total RNA from the neonatal rat spinal cord, and subsequently cloned into pGEM-T vector. The confirmed Olig2 fragment was then cloned into the pEGFP-N1 vector. The right recombinant was transfected into COS-7 cells by lipofectamine 2000. The expression of the Olig2 in COS-7 cells was detected by RT-PCR and immunoblot analysis. Enzyme digestion and sequencing of the recombinant plasmid; and expression of the Olig2 were analyzed by fluorescence microscope and western blot. RESULTS: The correct pEGFP-N1-Olig2 cloning was verified by restriction endonucle-ase digestion and sequencing. The western blot analysis indicated that the Olig2-GFP fusion protein was expressed in the COS-7/pEGFP-N1-Olig2 cells at 72 h. CONCLUSIONS: The pEGFP-N1-Olig2 vector was constructed successfully. The Olig2-GFP fusion protein was expressed in the COS-7/pEGFP-N1-Olig2 cells. This study lays the foundation for further research in gene therapy for central nervous system demyelinating diseases. [ABSTRACT FROM AUTHOR]

Radar remote sensing has demonstrated its applicability to the retrieval of basin-scale soil moisture. The mechanism of radar backscattering from soils is complicated and strongly influenced by surface roughness. Furthermore, retrieval of soil moisture using AIEM-like models is a classic example of the underdetermined problem due to a lack of credible known soil roughness distributions at a regional scale. Characterization of this roughness is therefore crucial for an accurate derivation of soil moisture based on backscattering models. This study aims to directly obtain surface roughness information along with soil moisture from multi-angular ASAR images. The method first used a semi-empirical relationship that connects the roughness slope (Zs) and the difference in backscattering coefficient (Δσ) from ASAR data in different incidence angles, in combination with an optimal calibration form consisting of two roughness parameters (the standard deviation of surface height and the correlation length), to estimate the roughness parameters. The deduced surface roughness was then used in the AIEM model for the retrieval of soil moisture. An evaluation of the proposed method was performed in a grassland site in the middle stream of the Heihe River Basin, where the Watershed Allied Telemetry Experimental Research (WATER) was taken place. It has demonstrated that the method is feasible to achieve reliable estimation of soil water content. The key challenge to surface soil moisture retrieval is the presence of vegetation cover which significantly impacts the estimates of surface roughness and soil moisture. [ABSTRACT FROM AUTHOR]

Using electromagnetic levitation in combination with the oscillating drop technique and drop calorimeter method, the surface tensions and specific heats of undercooled liquid Co-10 wt% Mo, Co-26.3 wt% Mo, and Co-37.6 wt% Mo alloys were measured. The containerless state during levitation produces substantial undercoolings up to 223 K (0.13 T L ), 213 K (0.13 T L ) and 110 K (0.07 T L ) respectively for these three alloys. In their respective undercooling ranges, the surface tensions were determined to be 1895 - 0.31( T - 1744), 1932 - 0.33( T - 1682), and 1989 - 0.34( T - 1607) mN m -1 . According to the Butler equation, the surface tensions of these three Co-Mo alloys were also calculated, and the results agree well with the experimental data. The specific heats of these three alloys are determined to be 41.85, 43.75 and 44.92 J mol -1 K -1 . Based on the determined surface tensions and specific heats, the changes in thermodynamics functions such as enthalpy, entropy and Gibbs free energy are predicted. Furthermore, the crystal nucleation, dendrite growth and Marangoni convection of undercooled Co-Mo alloys are investigated in the light of these measured thermophysical properties. [ABSTRACT FROM AUTHOR]