Study of microvoids in high-rate a-Si:H using positron annihilation

Theme: Amorphous and microcrystalline silicon technologyIn this paper, we have carried out the positron annihilation measurement on high-rate and low-rate a-Si;H thin films deposited by PECVD. By means of the slow positron beam Doppler-broadening technique, the depth profiles of microvoids in a-Si:H have been determined. We have also studied the vacancy-type defect in the surface region in high-rate grown a-Si:H, making comparison between high-rate and low-rate a-Si:H. By plotting S and W parameters in the (S, W) plane, we have shown that the vacancies in all of the high-rate and low-rate deposited intrinsic samples, and in differently doped low-rate samples are of the same nature.published_or_final_versio

Interface characterisation and internal electric field evaluation of a-Si:H pin solar cell by variable energy positron annhilation spectroscopy

Symposium Theme: Amorphous and microcrystalline silicon technologyBy means of the slow positron beam Doppler-broadening technique, the depth profile of microvoids across a p-i-n double junction solar cell has been resolved. VEPFIT fitting results indicate an approximately uniform density of the defects throughout the solar cell, but with an enhanced concentration at all of the interfaces possibly due to network mismatch. In order to evaluate the internal electric field, Variable Energy Positron Annihilation Spectroscopy (VEPAS) measurements have been performed on a single junction pin solar cell at different biases. The internal electric field effect on positrons has also been examined in terms of the bias dependence of positron drift in a-Si:H single junction pin solar cell.published_or_final_versio

Identification of vacancy-like defects in high-rate grown a-Si before and after ligh soaking by vepas

Symposium Theme: Amorphous and microcrystalline silicon technologyWe show how positron annihilation can distinguish vacancies in undoped hydrogenated amorphous silicon by performing Variable Energy Positron Annihilation Spectroscopy experiments before and after light soaking. We find that vacancy clusters, di-vacancies and a new type of single vacancies are created in undoped as-grown a-Si:H thin film by light illumination. The fact that the vacancy clusters are eliminated by the thermal annealing suggests that the Staebler-Wronski effect is closely related to vacancy clusters in a-Si:H material. The creation of vacancy clusters and redistribution of di-vacancies and even single vacancies probably result in photo-induced structural changes in this material.published_or_final_versio

Natural gaits of the non-pathological flat foot and high-arched foot

There has been a controversy as to whether or not the non-pathological flat foot and high-arched foot have an effect on human walking activities. The 3D foot scanning system was employed to obtain static footprints from subjects adopting a half-weight-bearing stance. Based upon their footprints, the subjects were divided into two groups: the flat-footed and the high-arched. The plantar pressure measurement system was used to measure and record the subjects' successive natural gaits. Two indices were proposed: distribution of vertical ground reaction force (VGRF) of plantar and the rate of the footprint areas. Using these two indices to compare the natural gaits of the two subject groups, we found that (1) in stance phase, there is a significant difference (p<0.01) in the distributions of VGRF of plantar; (2) in a stride cycle, there is also a significant difference (p<0.01) in the rates of the footprint areas. Our analysis suggests that when walking, the VGRF of the plantar brings greater muscle tension to the flat-footed while a smaller rate of the footprint areas brings greater stability to the high-arched.Comment: 8 pages, 4 figure

Structure of hadron resonances with a nearby zero of the amplitude

We discuss the relation between the analytic structure of the scattering amplitude and the origin of an eigenstate represented by a pole of the amplitude.If the eigenstate is not dynamically generated by the interaction in the channel of interest, the residue of the pole vanishes in the zero coupling limit. Based on the topological nature of the phase of the scattering amplitude, we show that the pole must encounter with the Castillejo-Dalitz-Dyson (CDD) zero in this limit. It is concluded that the dynamical component of the eigenstate is small if a CDD zero exists near the eigenstate pole. We show that the line shape of the resonance is distorted from the Breit-Wigner form as an observable consequence of the nearby CDD zero. Finally, studying the positions of poles and CDD zeros of the KbarN-piSigma amplitude, we discuss the origin of the eigenstates in the Lambda(1405) region.Comment: 7 pages, 3 figures, v2: published versio

The Characteristics of Blood Glucose and WBC Counts in Peripheral Blood of Cases of Hand Foot and Mouth Disease in China: A Systematic Review

Background: Outbreaks of Hand Foot and Mouth Disease (HFMD) have occurred in many parts of the world especially in China. We aimed to summarize the characteristics of the levels of blood glucose and white blood cell (WBC) counts in cases of HFMD in Mainland China and Taiwan, using meta-analysis based on systematic review of published articles. Methods: We systematically reviewed published studies, from the MEDLINE and WANFANG Data, about the levels of blood glucose and WBC counts in cases of HFMD until 15 th June 2011, and quantitatively summarized the characteristics of them using meta-analysis. Results: In total, 37 studies were included in this review. In Mainland China and Taiwan, generally, the average level of blood glucose, the prevalence of hyperglycemia, WBC counts and the prevalence of leukocytosis increased with the severity of the illness. There was no significant difference in the prevalence of leukocytosis between ANS (autonomic nervous system dysregulation)/PE (pulmonary edema) group and CNS (central nervous system) group, and in the average level of blood glucose between healthy controls and mild cases of HFMD. WBC counts in cases infected by EV71 were less than those in cases infected by CA16. Conclusions: our analyses indicated that blood glucose and WBC counts increased with the severity of HFMD disease, which would help doctors to manage patients efficiently

Betel nut chewing and incidence of newly diagnosed type 2 diabetes mellitus in Taiwan.

<p>Abstract</p> <p>Background</p> <p>Betel nut chewing is associated with type 2 diabetes mellitus (T2DM) in a recent prevalence study in Taiwan. The present study further investigated its link with the incidence of newly diagnosed T2DM during the years 1992-1996.</p> <p>Methods</p> <p>Population-based datasets of a sample of 93,484 out of 256,036 diabetic patients from 66 medical settings using the National Health Insurance scheme covering > 96% of the population, published population prevalence of betel nut chewing and the governmental census of national population were used for calculation of odds ratios, incidence rates and incidence rate ratios between chewers and never-chewers in the male population for the year 1992 to 1996.</p> <p>Results</p> <p>Ever chewers among the diabetic patients were younger, more obese and had higher prevalence of parental diabetes than never-chewers (all <it>p </it>values < 0.001). Odds ratios for T2DM for ever chewers vs. never-chewers in the age of < 40, 40-49, 50-59, 60-69 and ≥70 years were 1.06 (0.92-1.23), 1.60 (1.45-1.76), 2.12 (1.88-2.39), 3.58 (3.10-4.13) and 7.14 (5.47-9.31), respectively. In 1996, incidence rates (per 100,000 population) in the respective age groups were 19.1, 251.5, 567.3, 721.7 and 971.4 for never-chewers; and were 30.2, 520.9, 2566.9, 11672.8 and 630.3 for ever chewers. The respective incidence rate ratios were 1.58, 2.07, 4.52, 16.17 and 0.65. The age-specific incidence rates and rate ratios were relatively consistent from 1992 to 1996. The differences in obesity and parental diabetes between ever chewers and never-chewers were mostly not statistically significant after age stratification, suggesting the link could not be attributed to these two factors.</p> <p>Conclusions</p> <p>Chewing betel nut is associated with newly diagnosed T2DM, supporting the suggestion that the habit is diabetogenic.</p

Developmental changes in the role of different metalinguistic awareness skills in Chinese reading acquisition from preschool to third grade

Copyright @ 2014 Wei et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.The present study investigated the relationship between Chinese reading skills and metalinguistic awareness skills such as phonological, morphological, and orthographic awareness for 101 Preschool, 94 Grade-1, 98 Grade-2, and 98 Grade-3 children from two primary schools in Mainland China. The aim of the study was to examine how each of these metalinguistic awareness skills would exert their influence on the success of reading in Chinese with age. The results showed that all three metalinguistic awareness skills significantly predicted reading success. It further revealed that orthographic awareness played a dominant role in the early stages of reading acquisition, and its influence decreased with age, while the opposite was true for the contribution of morphological awareness. The results were in stark contrast with studies in English, where phonological awareness is typically shown as the single most potent metalinguistic awareness factor in literacy acquisition. In order to account for the current data, a three-stage model of reading acquisition in Chinese is discussed.National Natural Science Foundation of China and Knowledge Innovation Program of the Chinese Academy of Sciences

Community health needs assessment with precede-proceed model: a mixed methods study

<p>Abstract</p> <p>Background</p> <p>Community health services in China have developed over the last few decades. In order to use limited health resources more effectively, we conducted a community health needs assessment. This aimed to provide an understanding of the community's health problems and the range of potential factors affecting risk behaviours for the priority health problems.</p> <p>Methods</p> <p>We used the precede-proceed model for the needs assessment. Triangulation of data, methods and researchers were employed in data collection.</p> <p>Results</p> <p>Main findings include: cardiovascular diseases (CVDs) were identified as the priority health problems in the study communities; risk factors associated with CVDs included smoking, physical inactivity and unhealthy eating behaviours, particularly amongst male residents with low education level; factors negatively affecting behaviours were classified into predisposing factors (limited knowledge, beliefs and lack of perceived needs), enabling factors (limited access to health promotion activities, unawareness of health promotion, lack of work-site and school health promotion, absence of health promotion related policy) and reinforcing factors (culture). Policies and organization were not perfect; there were limited staff skilled in providing health promotion in the community.</p> <p>Conclusion</p> <p>CVDs were identified by the communities as priority health problems. Future health programs should focus on smoking, physical inactivity and unhealthy eating behaviours. Behaviour change strategies should take predisposing factors, enabling factors and reinforcing factors into consideration. Policies, organization and human resource need strengthening.</p