5,683 research outputs found

    ADCS of THNS-1 Nanosatellite with Off-Pointing Capability

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    One of the broad objectives of the THNS-1 nanosatellite, which mass will be less 5kg, is to demonstrate the availability of micro/nano-technology. The attitude control system has a three-axis magnetometer, four two-axis sun sensors and a MIMU for providing an attitude knowledge. The extended Kalman filter will be used for determining the attitude angles and attitude velocity. Three reaction wheels will be used to perform off-nadir pointing manoeuvres with magnetorquers for momentum dumping. A gravity gradient boom with top mass, which was successfully used on many microsatellites in the world, will be used for passive nadir pointing stabilisation

    Explaining Physicians’ Acceptance and Resistance to the NHI Pharmacloud: A Theoretical Model and Empirical Test

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    The PharmaCloud allows physicians to streamline many of their healthcare processes and ensure patient safety in a more efficient and cost-effective manner. Despite its great potential, however, there are gaps in our understanding of how physicians evaluate change in relation to the PharmaCloud and why they decide to resist it. Thus, this study develops an integrated model to explain physicians’ intention to use the PharmaCloud and their intention to resist it. A field survey was conducted in Taiwan to collect data from physicians. Structural equation modeling (SEM) using the partial least squares (PLS) method was employed to test the research model. The results show that physicians’ resistance to the use of the PharmaCloud is the result of regret avoidance, inertia, perceived value, transition costs, and perceived threat. Information quality, system quality, and service quality are shown to have positive and direct effects on physicians’ intention to use the PharmaCloud. Our study illustrates the importance of incorporating user resistance in technology acceptance studies in general and health technology usage studies in particular, providing grounds for a model of resistance that can serve as the starting point for future research in this relatively unexplored yet potentially fertile area of research

    Nonalcoholic Fatty Liver Disease in Children: Role of the Gut Microbiota

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    Nonalcoholic fatty liver disease (NAFLD) has emerged as the most common cause of liver disease among children and adolescents in industrialized countries due to increasing prevalence of obesity. It is generally recognized that both genetic and environmental risk factors contribute to the pathogenesis of NAFLD. Convincing evidences have shown that gut microbiota alteration is associated with NAFLD pathogenesis both in patients and animal models. Bacterial overgrowth and increased intestinal permeability are evident in NAFLD patients and lead to increased delivery of gut-derived bacterial products, such as lipopolysaccharide and bacterial DNA, to the liver through portal vein and then activation of toll-like receptors (TLRs), mainly TLR4 and TLR9, and their downstream cytokines and chemokines, resulting in hepatic inflammation. Currently, the role of gut microbiota in the pathogenesis of NAFLD is still the focus of many active clinical/basic researches. Modulation of gut microbiota with probiotics or prebiotics has been targeted as a preventive or therapeutic strategy on this pathological condition. Their beneficial effects on the NAFLD have been demonstrated in animal models and limited human studies

    Evaluation of Influence of Acupuncture and Electro-Acupuncture for Blood Perfusion of Stomach by Laser Doppler Blood Perfusion Imaging

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    The objective of this study is to observe effects of acupuncture and electro-acupuncture (EA) on blood perfusion in the stomach, and probe into the application of laser Doppler blood perfusion imaging technique in the study of the effect of acupuncture and moxibustion on the entrails. In the acupuncture group of 20 rats, acupuncture was given at “Zusanli” (ST 36) and in EA group of 18 rats, EA was applied at “Zusanli” (ST 36), with 18 rats without acupuncture used as control group. Changes of blood perfusion and microcirculation distribution in the stomach were investigated with laser Doppler blood perfusion imager (LDPI). The laser Doppler blood perfusion image could clearly display changes of blood flow distribution in the stomach before and after acupuncture. After acupuncture or EA was given at “Zusanli” (ST 36), the blood perfusion in the stomach increased significantly, the blood perfusion in the blood vessels and microcirculation of other parts significantly increased, and the maximum increase of the blood perfusion was found at 10 min after acupuncture or EA, with increases of 0.50 _ 0.11 (PU) and 0.66 _ 0.16 (PU), respectively, and the blood perfusion still kept at a higher degree within 10 min after ceasing of the acupuncture or EA. While the blood perfusion in the stomach in the rat of the control group tended to gradual decrease. It has been concluded that both acupuncture and EA can increase blood perfusion in the stomach, the EA having stronger action, and LDPI can display the regulative action of acupuncture on the blood vessel of the stomach by using an image

    Design and clinical application of colonoscopy convenient pant

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    结肠镜检查是诊治肠道疾病的首选方法。随着肠道疾病发病率的增长,越来越多的人群需要接受结肠镜检查。为了方便检查、保护病人隐私及防止受凉等,笔者设计制作了结肠镜检查方便裤,并已经很好地将其应用于临床。Colonoscopy is the first choice for diagnosis and treatment of intestinal diseases. With the growth of the incidence of intestinal disease, more and more people need colonoscopy. In order to inspecting conveniently, protecting patients’ privacy and preventing them from catching a cold, we designed the colonoscopy convenient pant and have applied it into clinic well

    Meta-analysis of quantitative diffusion-weighted MR imaging in the differential diagnosis of breast lesions

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    BACKGROUND: To determine, in a meta-analysis, the diagnostic performance of quantitative diffusion-weighted (DW) MR imaging in patients with breast lesions. METHODS: English and Chinese studies published prior to June 2009 to assess the diagnostic performance of quantitative DWI in patients with breast lesions were reviewed and summarized with reference to the inclusion and exclusion criteria. Methodological quality was assessed by using the quality assessment of diagnostic studies (QUADAS) instrument. Publication bias analysis was performed by using Comprehensive Meta-analysis version 2. Meta-Disc version 1.4 was used to describe primary results and explore homogeneity by Chi-square test and inconsistency index; to explore threshold effect by receiver operator characteristic (ROC) space and Spearman correlation coefficient; and to pool weighted sensitivity and specificity by fixed or random effect model. A summary ROC (sROC) curve was constructed to calculate the area under the curve (AUC). RESULTS: Of 65 eligible studies, 13 with 615 malignant and 349 benign lesions were included in the original meta-analysis, among which heterogeneity arising from factors other than threshold effect and publication bias was explored. Methodological quality was moderate. The pooled weighted sensitivity and specificity with corresponding 95% confidence interval (CI) in one homogenous subgroup of studies using maximum b = 1000 s/mm(2 )were 0.84 (0.80, 0.87) and 0.84 (0.79, 0.88) respectively. AUC of sROC was 0.9085. Sensitivity analysis demonstrated that the pooled estimates were stable and reliable. CONCLUSIONS: Quantitative DWI has a higher specificity to differentiate between benign and malignant breast lesions compared to that of contrast-enhanced MRI. However, large scale randomized control trials (RCTs) are necessary to assess its clinical value because of disunified diffusion gradient factor b and diagnosis threshold
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