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Open access

Li-Chun Zhang

Abstract

Register data that originate from administrative or other secondary sources are increasingly being used to generate statistical outputs directly. The coverage of the input datasets is an important issue in this respect. Traditionally capture-recapture models have been used to deal with multiple list enumerations subjected to undercoverage errors. The aim of this article is to scope possible approaches to modelling capture-recapture data with additional overcoverage error. Attention is primarily given to model interpretations and conditions under which a model may provide a plausible basis for estimation and uncertainty evaluation. The setting with two list enumerations is examined in depth as it is the most common in practice. Models that can be extended to include more than two lists are identified. An additional independent coverage survey with only undercoverage error is always needed for estimation. Potential application to census coverage-error adjustment is discussed.

Open access

Li-Chun Zhang

Abstract

The problem of inference about the joint distribution of two categorical variables based on knowledge or observations of their marginal distributions, to be referred to as categorical data fusion in this paper, is relevant in statistical matching, ecological inference, market research, and several other related fields. This article organizes the use of proxy variables, to be distinguished from other auxiliary variables, both in terms of their effects on the uncertainty of fusion and the techniques of fusion. A measure of the gains of efficiency is provided, which incorporates both the identification uncertainty associated with data fusion and the sampling uncertainty that arises when the theoretical bounds of the uncertainty space are unknown and need to be estimated. Several existing techniques for generating fusion distributions (or datasets) are described and some new ones proposed. Analysis of real-life data demonstrates empirically that proxy variables can make data fusion more precise and the constructed fusion distribution more plausible.

Open access

Yong Guo, Xizheng Zhang, Chunqiu Zhang, Ruixin Li, Qiangcheng Zeng, Chun Guo and Yanjun Zhang

Abstract

Background: Mesenchymal stem cells (MSCs) known to be sensitive to mechanical stimulus. This type of stimulus plays a role in cellular differentiation, so that it might affect MSCs differentiation toward cardiomyocytes.

Objectives: Investigate the effect of mechanical stimulus on MSCs differentiation toward cardiomyocytes.

Methods: The adipose tissue-derived MSCs were induced to differentiate with 5-azacytidine, and stimulated by one Hz mechanical stretching up to 8%. After 10 days, the cell’s cardiac markers and cardiogenesis-related genes were detected by immumohistochemistrical staining and reverse transcriptase-polymerase chain reaction, and the cell’s ATPase activity was detected.

Results: The cyclic mechanical stretching enhanced the expression of cardiogenesis-related genes and cardiac markers, and stimulated the activity of Na+-K+-ATPase and Ca2+-ATPase in the MSCs treated with 5-azacytidine. Without 5-azacytidine pre-treatment, cyclic mechanical stretch alone has little effect.

Conclusion: Mechanical stretch combined with 5-azacytidine treatment could accelerate MSCs differentiation toward cardiomyocytes.

Open access

Zhang Zhi-yong, Li Ming-xu, Yu Yong-wu and Zhou Chun-hua

Abstract

Background: At present, patients with end-stage renal failure (ESRD) face the question of how to achieve adequate dialysis to maintain their survival with the best quality of life as long as possible. Therefore, the choice of suitable dialysis methods and dialysis dose is important.

Objective: To find suitable dialysis methods and an appropriate dialysis dose for patients with ESRD.

Methods: Our research compares the long-term clinical effects between the patients undergoing continuous ambulatory peritoneal dialysis (CAPD), daytime ambulatory peritoneal dialysis (DAPD), and hemodialysis (HD). Thirty-two patients subjected to peritoneal dialysis were selected and divided into group A (n = 16) and group B (n = 16), group A was treated by using the traditional CAPD pattern; group B was treated by using DAPD. Forty-six patients of renal failure at final stage were divided into group A (n = 23) and group B (n = 23), group A was treated by using a HD method, group B was treated by using a DAPD method.

Results: When the same dialysis dose was applied, the patients with long-term DAPD treatment can obtain satisfactory clinical therapeutic efficacy for the period of maintenance dialysis, thoroughness of dialysis, maintenance of nutritional status, blood pressure regulation, reduction in incidence rate of peritoneal infection, maintenance of relatively high activity in daily life and alleviation in depression, comparable to patients treated with traditional CAPD or HD methods.

Conclusion: The long-term clinical effects of DAPD are comparable to CAPD or HD.

Open access

Evangelos Ioannidis, Takis Merkouris, Li-Chun Zhang, Martin Karlberg, Michalis Petrakos, Fernando Reis and Photis Stavropoulos

Open access

Arnout van Delden, Boris Lorenc, Peter Struijs and Li-Chun Zhang

Open access

Shuiping Li, Qisheng Wu, Chun Zhang, Huajun Zhu, Changsen Zhang, Xin Wang and Cancan Kong

Abstract

LiNiO2 was prepared through two-step solid-state reaction by mechanochemical method and heat treatment, using LiOH (Li2CO3) and Ni(OH)2 as starting materials. The influence of grinding speed and time, heat treatment time, and starting materials on the structure of LiNiO2 was studied. The as-milled samples and products were characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD). The results show that uniform as-milled samples can be obtained at grinding speed of 580 rpm for 0.5 h, using LiOH and Ni(OH)2 as raw materials. Perfect crystal LiNiO2 has been prepared by calcining the as-milled samples at 700 °C for 15 h. Composite material powders consisting of Li2Ni8O10 and LiNiO2 have been obtained using Li2CO3 as lithium source.

Open access

Yue-qiu Zhang, Shao-xia Xu, Sai-nan Bian, Li-fan Zhang, Yao Zhang, Wei-hong Zhang, Ying-chun Xu and Xiao-qing Liu

Abstract

Objective To investigate the infection rate of hepatitis C virus among the ambulatory patients and in-patients of a tertiary teaching hospital, and study the demographic factors related to the prevalence of hepatitis C virus infection.

Methods All patients tested for hepatitis C virus antibody from July 2008 to July 2009 in Peking Union Medical College Hospital were enrolled in this cross-sectional analysis. The prevalence of hepatitis C virus infection was compared according to age, gender, and departments, respectively. Among patients with positive serology hepatitis C virus marker, the positivity of hepatitis C virus RNA was analysed.

Results Among 29 896 subjects included, the hepatitis C virus antibody of 494 patients were positive (1.7%). When patients were divided into 9 age groups, the age specific prevalence of hepatitis C virus antibody were 0.2%, 1.7%, 1.2%, 1.1%, 1.5%, 1.9%,2.6%, 2.4% and 2%, respectively. The prevalence of hepatitis C virus antibody in non-surgical department and surgical department was 3% and 1%, respectively. The prevalence of hepatitis C virus antibody of males was higher than that of the females. Total of 194 patients with positive hepatitis C virus antibody were tested for hepatitis C virus RNA, the RNA level of 113 patients (58.2%) were higher than the low detection limit.

Conclusions The prevalence of hepatitis C virus antibody was relatively high among patients of general tertiary hospital. Age group of 60-69, males and patients in non-surgical departments were factors associated with high rate of hepatitis C virus infection.

Open access

Xiao-Hong Zhang, Li-Na Meng, Hui-Hui Liu, Ru-Zhen Luo, Chun-Mei Zhang, Pei-Pei Zhang and Yan-Hui Liu

Abstract

Objective

Problem-solving should be a fundamental component of nursing education because it is a core ability for professional nurses. For more effective learning, nursing students must understand the relationship between self-directed learning readiness and problem-solving ability. The aim of this study was to investigate the relationships among self-directed learning readiness, problem-solving ability, and academic self-efficacy among undergraduate nursing students.

Methods

From November to December 2016, research was conducted among 500 nursing undergraduate students in Tianjin, China, using a self-directed learning readiness scale, an academic self-efficacy scale, a questionnaire related to problem-solving, and self-designed demographics. The response rate was 85.8%.

Results

For Chinese nursing students, self-directed learning readiness and academic self-efficacy reached a medium-to-high level, while problem-solving abilities were at a low level. There were significant positive correlations among the students’ self-directed learning readiness, academic self-efficacy, and problem-solving ability. Furthermore, academic self-efficacy demonstrated a mediating effect on the relationship between the students’ self-directed learning readiness and problem-solving ability.

Conclusions

To enhance students’ problem-solving ability, nursing educators should pay more attention to the positive impact of self-directed learning readiness and self-efficacy in nursing students’ education.

Open access

Pei-yan Zhang, Si-min Yao, Fan Zhang, Ming-xia Zhang, Wei Li, Jing Yuan, Xin-chun Chen and Bo-ping Zhou

Abstract

Objective Various immune cells in patients with CHB have been demonstrated to play critical roles in HBV infection. The goal of this study is to observe changes in Th17, Treg, Th1 and B lymphocytes from peripheral blood and to evaluate immune status of CHB patients undergoing antiviral treatment.

Methods Total of 49 CHB patients, 19 asymptomatic carriers and 29 healthy donors were included in our present study. The frequencies of peripheral Th17 cells (CD3+CD4+IL-17+Tcells), Treg cells (CD3+CD4+CD25+CD127- T cells), Th1 cells (CD3+CD4+IFN-γ T cells) and B lymphocytes in chronic hepatitis B (CHB) were analyzed by flow cytometry.

Results The frequency of Th17 cells increased after treatment for 6 months, but there was no statistically significant difference of IL-17 expression between baseline and 6 months after treatment. The frequencies of Treg cells, momory B cells and total CD19+ B cells decreased after antiviral treatment. The frequencies of Th1 cells and plasma cells increased after antiviral treatment.

Conclusions This study highlights that the reestablishment of immune function during antiviral treatment in CHB patients, which caused by the antiviral drugs or the patients themselves. CHB patients may exhibit varied responses to these antiviral drugs. It is essential to supplement immune therapy during the antiviral treatment, but Th17 may play a limited role in inflammation during antiviral treatment, targeting Th17 therapy may not be useful for CHB treatment. More time and more experiments are critical to explain it.