68 research outputs found

    Investigation of optimal design and operation of a small-scale Low Temperature District Heating (LTDH) with multiple heat sources

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    Improving energy efficiency and reducing carbon emission is among the immediate measures being taken in many countries to address the challenge of climate change. Energy consumption in buildings accounts for over 40% of total primary energy demand in the European Union (EU). Most of this energy is in the form of heat for space heating in buildings which is commonly supplied in building using onsite fossil fuelled-boiler installations in EU. The current fossil fuelled boilers are designed to supply heat at high temperature (about 80 °C) and usually oversized for the required load capacity. This process suffers from low overall thermal efficiency of the heat supply systems. In this project, it was sought to investigate an integrated approach of supplying heat to buildings by aggregating various types of heat sources and delivering heat to a common heat distribution network to form a small-scale district heating system. This is considered as an effective solution to increase efficiency through lowering the hot water temperature and encouraging the adoption of renewable energy systems. Therefore, this thesis investigates the operation and design optimisation of a Low Temperature District Heating (LTDH) network with multiple heat feed-in sources such as a heat pump, biomass boiler, gas boiler and solar thermal collector. A case study to evaluate the design of system was considered as part of the Creative Energy Homes (CEHs) at the University of Nottingham. An overall heat load demand of the site was evaluated using Energy Plus software and a computer model for low temperature heat with multiple heat sources was introduced to optimise different feed-in heat sources. To improve heat provision flexibility, maximise heat generation from renewable sources and provide heat networks flexibility, an optimisation model of the thermal store was also carried out. Furthermore, this work investigated the environmental and economic viability of the proposed low temperature heat network. The case study involves the Creative Energy Homes which consists of seven low energy homes with an aggregate heat load of 44 kW and annual energy consumption of 40258.1 kWh, including 14110.89 kWh for domestic hot water and 26417.92 kWh for space heating. It was established that a system consisting a 1.56 kW solar collector,10 kW heat pump, 15 kW biomass boiler, 20 kW gas boiler and a thermal store of 0.89

    Investigation of optimal design and operation of a small-scale Low Temperature District Heating (LTDH) with multiple heat sources

    Get PDF
    Improving energy efficiency and reducing carbon emission is among the immediate measures being taken in many countries to address the challenge of climate change. Energy consumption in buildings accounts for over 40% of total primary energy demand in the European Union (EU). Most of this energy is in the form of heat for space heating in buildings which is commonly supplied in building using onsite fossil fuelled-boiler installations in EU. The current fossil fuelled boilers are designed to supply heat at high temperature (about 80 °C) and usually oversized for the required load capacity. This process suffers from low overall thermal efficiency of the heat supply systems. In this project, it was sought to investigate an integrated approach of supplying heat to buildings by aggregating various types of heat sources and delivering heat to a common heat distribution network to form a small-scale district heating system. This is considered as an effective solution to increase efficiency through lowering the hot water temperature and encouraging the adoption of renewable energy systems. Therefore, this thesis investigates the operation and design optimisation of a Low Temperature District Heating (LTDH) network with multiple heat feed-in sources such as a heat pump, biomass boiler, gas boiler and solar thermal collector. A case study to evaluate the design of system was considered as part of the Creative Energy Homes (CEHs) at the University of Nottingham. An overall heat load demand of the site was evaluated using Energy Plus software and a computer model for low temperature heat with multiple heat sources was introduced to optimise different feed-in heat sources. To improve heat provision flexibility, maximise heat generation from renewable sources and provide heat networks flexibility, an optimisation model of the thermal store was also carried out. Furthermore, this work investigated the environmental and economic viability of the proposed low temperature heat network. The case study involves the Creative Energy Homes which consists of seven low energy homes with an aggregate heat load of 44 kW and annual energy consumption of 40258.1 kWh, including 14110.89 kWh for domestic hot water and 26417.92 kWh for space heating. It was established that a system consisting a 1.56 kW solar collector,10 kW heat pump, 15 kW biomass boiler, 20 kW gas boiler and a thermal store of 0.89

    Medical insurance payment schemes and patient medical expenses: a cross-sectional study of lung cancer patients in urban China

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    BackgroundAs the main cause of cancer death, lung cancer imposes seriously health and economic burdens on individuals, families, and the health system. In China, there is no national study analyzing the hospitalization expenditures of different payment methods by lung cancer inpatients. Based on the 2010-2016 database of insured urban resident lung cancer inpatients from the China Medical Insurance Research Association (CHIRA), this paper aims to investigate the characteristics and cost of hospitalized lung cancer patient, to examine the differences in hospital expenses and patient out-of-pocket (OOP) expenses under four medical insurance payment methods: fee-for-service (FFS), per-diem payments, capitation payments (CAP) and case-based payments, and to explore the medical insurance payment method that can be conducive to controlling the cost of lung cancer.MethodThis is a 2010-2016, 7-year cross-sectional study. CHIRA data are not available to researchers after 2016. The Medical Insurance Database of CHIRA was screened using the international disease classification system to yield 28,200 inpatients diagnosed with lung cancer (ICD-10: C34, C34.0, C34.1, C34.2, C34.3, C34.8, C34.9). The study includes descriptive analysis and regression analysis based on generalized linear models (GLM).ResultsThe average patient age was 63.4 years and the average length of hospital stay (ALOS) was 14.2 day; 60.7% of patients were from tertiary hospitals; and 45% were insured by FFS. The per-diem payment had the lowest hospital expenses (RMB7496.00/US1176.87),whileCAPhadthelowestOOPexpenses(RMB1328.18/US1176.87), while CAP had the lowest OOP expenses (RMB1328.18/US208.52). Compared with FFS hospital expenses, per-diem was 21.3% lower (95% CI = -0.265, -0.215) and case-based payment was 8.4% lower (95% CI = -0.151, -0.024). Compared with the FFS, OOP expenses, per-diem payments were 9.2% lower (95% CI = -0.130, -0.063) and CAP was 15.1% lower (95% CI = -0.151, -0.024).ConclusionFor lung cancer patients, per-diem payment generated the lowest hospital expenses, while CAP meant patients bore the lowest OOP costs. Policy makers are suggested to give priority to case-based payments to achieve a tripartite balance among medical insurers, hospitals, and insured members. We also recommend future studies comparing the disparities of various diseases for the cause of different medical insurance schemes

    Use of Traditional Chinese Medicine and Its Impact on Medical Cost among Urban Ischemic Stroke Inpatients in China: A National Cross-Sectional Study

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    Background. Traditional Chinese medicine (TCM) has long been widely adopted by the Chinese people and has been covered by China’s basic medical insurance schemes to treat ischemic stroke. Previous research has mainly highlighted the therapy effect of TCM on ischemic stroke patients. Some studies have demonstrated that employing TCM can reduce the medical burden on other diseases. But no research has explored whether using TCM could reduce inpatient medical cost for ischemic stroke in mainland China. The purpose of this study is to investigate the impact of the use of TCM on the total inpatient cost of ischemic stroke and to explore whether TCM has played the role of being complementary to, or an alternative for, conventional medicine to treat ischemic stroke. Methods. We conducted a national cross-sectional analysis based on a 5% random sample from claims data of China Urban Employee Basic Medical Insurance (UEBMI) and Urban Resident Basic Medical Insurance (URBMI) schemes in 2015. Mann–Whitney test was used to compare unadjusted total inpatient cost, conventional medication cost, and nonpharmacy cost estimates. Ordinary least square regression analysis was performed to compare demographics-adjusted total inpatient cost and to examine the association between TCM cost and conventional medication cost. Results. A total of 47321 urban inpatients diagnosed with ischemic stroke were identified in our study, with 92.6% (43843) of the patients using TCM in their inpatient treatment. Total inpatient cost for TCM users was significantly higher than TCM nonusers (USD 1217 versus USD 1036, P<0.001). Conventional medication cost was significantly lower for TCM users (USD 335 versus USD 436, P<0.001). The average cost of TCM per patient among TCM users was USD 289. Among TCM users, conventional medication costs were found to be positively associated with TCM cost after adjusting for confounding factors (Coef. = 0.144, P<0.001). Conclusion. Although the use of TCM reduced the cost of conventional medicine compared with TCM nonusers, TCM imposed an extra financial component on the total inpatient cost on TCM users. Our study suggests that TCM mainly played a complementary role to conventional medicine in ischemic stroke treatment in mainland China

    A cross-sectional study of depressive symptoms and diabetes self-care in African Americans and Hispanics/Latinos with diabetes: the role of self-efficacy

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    Purpose The purpose of this study is to examine the relationship between depressive symptoms and diabetes self-care in African American and Hispanic/Latino patients with type 2 diabetes and whether the association, if any, is mediated by diabetes-related self-efficacy. Methods The sample included self-report baseline data of African American and Hispanic/Latino patients with type 2 diabetes who were aged ≥18 years and enrolled in a diabetes self-management intervention study. Depressive symptoms were assessed with the 9-item Patient Health Questionnaire. The Summary of Diabetes Self-care Activities measured engagement in healthy eating, physical activity, blood glucose checking, foot care, and smoking. The Diabetes Empowerment Scale–Short Form assessed diabetes-related psychosocial self-efficacy. Indirect effects were examined with the Baron and Kenny regression technique and Sobel testing. Results Sample characteristics (n = 250) were as follows: mean age of 53 years, 68% women, 54% African American, and 74% with income <$20 000. Depressive symptoms showed a significant inverse association with the self-care domains of general diet, specific diet, physical activity, and glucose monitoring in the African American group. In Hispanics/Latinos, depression was inversely associated with specific diet. Self-efficacy served a significant mediational role in the relation between depression and foot care among African Americans. Conclusions Self-efficacy mediated the relationship between depression and foot care in the African American group but was not found to be a mediator of any self-care areas within the Hispanic/Latino group. In clinical practice, alleviation of depressive symptoms may improve self-care behavior adherence. Diabetes education may consider inclusion of components to build self-efficacy related to diabetes self-care, especially among African American patients

    CogVLM: Visual Expert for Pretrained Language Models

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    We introduce CogVLM, a powerful open-source visual language foundation model. Different from the popular shallow alignment method which maps image features into the input space of language model, CogVLM bridges the gap between the frozen pretrained language model and image encoder by a trainable visual expert module in the attention and FFN layers. As a result, CogVLM enables deep fusion of vision language features without sacrificing any performance on NLP tasks. CogVLM-17B achieves state-of-the-art performance on 10 classic cross-modal benchmarks, including NoCaps, Flicker30k captioning, RefCOCO, RefCOCO+, RefCOCOg, Visual7W, GQA, ScienceQA, VizWiz VQA and TDIUC, and ranks the 2nd on VQAv2, OKVQA, TextVQA, COCO captioning, etc., surpassing or matching PaLI-X 55B. Codes and checkpoints are available at https://github.com/THUDM/CogVLM

    Qingchang Wenzhong Decoction Attenuates DSS-Induced Colitis in Rats by Reducing Inflammation and Improving Intestinal Barrier Function via Upregulating the MSP/RON Signalling Pathway

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    Ulcerative colitis (UC) is a chronic, nonspecific, inflammatory disease for which an effective treatment is lacking. Our previous study found that Qingchang Wenzhong Decoction (QCWZD) can significantly improve the clinical symptoms of UC and ameliorate dextran sulphate sodium- (DSS-) induced ulcerative colitis in rats by downregulating the IP10/CXCR3 axis–mediated inflammatory response. The purpose of the present study was to further explore the mechanism of QCWZD for UC in rats models, which were established by 7-day administration of 4.5% dextran sulphate sodium solution. QCWZD was administered daily for 7 days; then we determined the serum macrophage-stimulating protein concentration (MSP) and recepteur d’origine nantais (RON) expression and its downstream proteins (protein kinase B [Akt], phosphorylated [p] Akt, occludin, zona occluden- [ZO-] 1, and claudin-2) in colon tissue using Western blotting and quantitative polymerase chain reaction. In DSS-induced UC, QCWZD significantly alleviated colitis-associated inflammation, upregulated serum MSP expression and RON expression in the colon, reduced the pAkt levels, promoted colonic occluding and ZO-1 expression, and depressed claudin-2 expression. In conclusion, the MSP/RON signalling pathway plays an important role in the pathogenesis of UC by involving the inflammatory response and improving intestinal barrier function. QCWZD appears to attenuate DSS-induced UC in rats by upregulating the MSP/RON signalling pathway

    A bibliometric and knowledge-map analysis of the glymphatic system from 2012 to 2022

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    ObjectiveTo explore the development context, research hotspots and frontiers in the glymphatic system (GS) field from 2012 to 2022 by bibliometric analysis.MethodsThe Web of Science Core Collection (WoSCC) database was searched for articles published between 2012 and 2022. Microsoft Excel was used to manage the data. VOSviewer, CiteSpace, GraphPad Prism, the Web of Science, and an online analysis platform for bibliometrics (http://bibliometric.com/) were used to analyze the countries, institutions, journals, and collaboration networks among authors and the types of articles, developmental directions, references, and top keywords of published articles.ResultsA total of 412 articles were retrieved, including 39 countries/regions, 223 research institutes and 171 academic journals. The subject classifications related to the GS were Neuroscience, Clinical Neuroscience and Radiology/Nuclear Medicine/Medical Imaging. The United States has maintained its dominant and most influential position in GS research. Among research institutions and journals, the Univ Rochester and Journal of Cerebral Blood Flow and Metabolism had the highest number of academic articles, respectively. Nedergaard M had the most published article, and Iliff JJ had the most co-citations. The top two keywords with the highest frequency were “glymphatic system” and “cerebrospinal fluid.”ConclusionThis research provides valuable information for the study of the GS. The bibliometric analysis of this area will encourage potential collaborations among researchers, defining its frontiers and directions for development

    Prevalence of Childhood Atopic Dermatitis: An Urban and Rural Community-Based Study in Shanghai, China

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    Background: Atopic dermatitis (AD) is a common inflammatory and chronically relapsing disorder with increasing prevalence. However, little is known about its prevalence in Shanghai, the top metropolitan of China. This study will estimate and compare the prevalence of AD in urban and rural areas in representative samples of 3 to 6-year-old children in Shanghai. Methodology/Principal Findings: A descriptive cross-sectional study was performed. Pre-school children were obtained by cluster sampling from 8 communities in different districts in Shanghai. The main instrument was the core questionnaire module for AD used in the U.K. Working Party’s study. All the data were statistically analyzed by EpiData 3.1 and SPSS16.0. A total of 10436 children completed the study satisfactorily, with a response rate of 95.8%. The prevalence of AD in 3 to 6-year-old children was 8.3 % (Male: 8.5%, Female: 8.2%). The prevalence in urban areas of Shanghai was gradiently and significantly higher than that in rural areas. The highest prevalence was in the core urban area (10.2 % in Xuhui Tianping) vs. the lowest far from the urban areas (4.6 % in Chongming Baozhen). Conclusions/Significance: The prevalence of AD was 8.3 % (95%CI: 7.6%–9.1%) in children aged 3 to 6 in Shanghai. Th
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