1,507 research outputs found
Circulating microRNA expression profile and systemic right ventricular function in adults after atrial switch operation for complete transposition of the great arteries
published_or_final_versio
Growth mode and strain evolution during InN growth on GaN(0001) by molecular-beam epitaxy
The plasma-assisted molecular-beam epitaxy technique was used to study the epitaxial growth of InN on GaN. A relationship between film growth mode and the deposition condition was established by combining reflection high-energy electron diffraction (RHEED) and scanning tunneling microscopy (STM). The sustained RHEED intensity oscillations were recorded for 2D growth while 2D nucleation islands were revealed by STM. Results showed less than three oscillation periods for 3 D growth, indicating the Strnski-Krastanov (SK) growth mode of the film.published_or_final_versio
Tests of scaling assumputions, construct validity and reliability of the Chinese child health questionnaire, partent form (CHQ-PF50) and child form (CHQ-CF87)
Poster SessionValidated instruments for assessment of quality of life in Chinese children are as yet unavailable. We determined
the construct validity and reliability of the translated Chinese versions of the Child Health Questionnaires (Landgraf,
Abetz & Ware, 1999) designed for completion by parents (CHQ-PF50) and children (CHQ-CF87). The Chinese
versions were developed through iterative forward and backward translation processes by independent parties.
The feasibility, as rated by degree of difficulty using a 4-point scale, and time for completion were evaluated for the
Chinese CHQ-PF50 and CHQ-CF87 in 15 and 11 subjects, respectively. To assess the construct validity and reliability,
1143 parents of healthy children and 823 school children were invited to complete the Chinese CHQ-PF50 and
CHQ-CF87, respectively. The results showed that both the Chinese CHQ-PF50 (mean rating 1.66) and CHQ-CF87
(mean rating 1.33) were easy to complete, with completion times of 14.23±5.23 minutes and 13.82±3.52 minutes,
respectively. Psychometric analysis on item convergent validity and discriminant validity showed perfect or near
perfect (>99%) rates of success for all ten scales in the CF87 and >94% for all but one scale in the PF50. The exception
was the general health scale (86%). Minimal floor effects were observed for both questionnaires. However, substantial
ceiling effects were observed for the five scales in both questionnaires (physical functioning, role-emotional,
behavioral, role-physical, bodily pain and family activities). The median alpha coefficient of reliability for CF87
was 0.90 (range 0.85 to 0.94). The median alpha coefficient for PF50 was 0.80 (range 0.44 to 0.88), with the mental
health scale falling just below the minimum criterion for group level analysis (0.68) and the general health scale
being the lowest (0.44). These findings suggest that the Chinese translations of CHQ-PF50 and CHQ-CF87 are
robust and sufficient. Additional work with regard to ceiling effects is required to assess the performance of the
measures in condition groups
InN Island shape and its dependence on growth condition of molecular-beam epitaxy
The three-dimensional (3D) island shapes of the InN and its dependence on growth conditions of molecular-beam epitaxy (MBE) were analyzed. The islands were dislocated and the strain in an island depended on its size. The pillar-shaped islands with low aspect ratios represented the equilibrium shape, and the pyrimidal islands with higher aspect ratios were limited by kinetics during MBE growth. The decreasing trend of island aspect ratio with respect to island size was attributed to gradual relaxation of residual strain in dislocated islands.published_or_final_versio
Step bunching of vicinal GaN(0001) surfaces during molecular beam epitaxy
Step bunching of vicinal GaN(0001) surface during epitaxial growth is observed by scanning tunneling microscopy. Large step stiffness and repulsive step-step interaction are suggested based on step morphology observations. The size of the bunch changes with time, depending on the direction in which the substrate is heated by a direct current. This observation provides evidence for the electromigration effect causing the step bunching, and from the field dependence we infer that adatoms, which are likely N, have effective positive charges. ©2000 The American Physical Society.published_or_final_versio
Scaling of three-dimensional InN islands grown on GaN(0001) by molecular-beam epitaxy
The scaling property of three-dimensional InN islands nucleated on GaN(0001) surface during molecular-beam epitaxy (MBE) is investigated. Due to the large lattice mismatch between InN and GaN (∼10%), the islands formed from the Stranski-Krastanow growth mode are dislocated. Despite the variations in (residual) strain and the shape, both the island size and pair separation distributions show the scaling behavior. Further, the size distribution resembles that for submonolayer homoepitaxy with the critical island size i = 1, suggesting that detachment of atoms is not significant. The above results also indicate strain is insignificant in determining the nucleation and growth of dislocated islands during heteroepitaxy by MBE.published_or_final_versio
NiOZnO light emitting diodes by solution-based growth
Heterojunction NiOZnO light emitting diodes have been fabricated using low temperature solution-based growth methods. While negligible light emission has been obtained for the as-grown NiO film, devices with annealed NiO film exhibit room-temperature electroluminescence (EL), which was attributed to the detrimental effects of nickel oxide hydroxide in as-grown NiO layers. The device performance can be further modified by insertion of the organic layers between NiO and ZnO and the EL spectra exhibited dependence on the bias voltage. For higher bias voltages, strong UV-violet emission peak can be obtained in spite of the dominance of defect emission in the photoluminescence spectra. © 2008 American Institute of Physics.published_or_final_versio
Reduction of threading defects in GaN grown on vicinal SiC(0001) by molecular-beam epitaxy
We observe a significant reduction of threading dislocations in GaN grown on vicinal substrates of SiC(0001). Using scanning tunneling microscopy, we find films grown on vicinal substrates maintain the surface misorientation of the substrate and display terraces with straight edges. On top of the terraces there is no spiral mound, which is the main feature found for films grown on singular substrates. Transmission electron microscopy studies confirm that threading screw dislocations are reduced by two orders of magnitude while edge dislocations are reduced by one order. © 2000 American Institute of Physics.published_or_final_versio
Effect of annealing on the performance of CrO3/ZnO light emitting diodes
Heterojunction CrO3/ZnO light emitting diodes have been fabricated. Their performance was investigated for different annealing temperature for ZnO nanorods. Annealing in oxygen atmosphere had significant influence on carrier concentration in the nanorods, as well as on the emission spectra of the nanorods. Surprisingly, annealing conditions, which yield the lowest band edge-to-defect emission ratio in the photoluminescence spectra, result in the highest band edge-to-defect emission ratio in the electroluminescence spectra. The influence of the native defects on ZnO light emitting diode performance is discussed. © 2009 American Institute of Physics.published_or_final_versio
ANXA3/JNK Signaling Promotes Self-Renewal and Tumor Growth, and Its Blockade Provides a Therapeutic Target for Hepatocellular Carcinoma
Frequent tumor relapse in hepatocellular carcinoma (HCC) has been commonly attributed to the presence of residual cancer stem cells (CSCs) after conventional treatments. We have previously identified and characterized CD133 to mark a specific CSC subset in HCC. In the present study, we found endogenous and secretory annexin A3 (ANXA3) to play pivotal roles in promoting cancer and stem cell-like features in CD133+ liver CSCs through a dysregulated JNK pathway. Blockade of ANXA3 with an anti-ANXA3 monoclonal antibody in vitro as well as in human HCC xenograft models resulted in a significant reduction in tumor growth and self-renewal. Clinically, ANXA3 expression in HCC patient sera closely associated with aggressive clinical features. Our results suggest that ANXA3 can serve as a novel diagnostic biomarker and that the inhibition of ANXA3 may be a viable therapeutic option for the treatment of CD133+ liver-CSC-driven HCC. © 2015 The Authors.published_or_final_versio
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