233 research outputs found

    A two-stage traveling-wave thermoacoustic electric generator with loudspeakers as alternators

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    This paper presents the design, construction and tests of a traveling-wave thermoacoustic electric generator. A two-stage travelling-wave thermoacoustic engine converts thermal energy to acoustic power. Two low-impedance linear alternators (i.e., audio loudspeakers) were installed to extract and convert the engine’s acoustic power to electricity. The coupling mechanism between the thermoacoustic engine and alternators has been systematically studied numerically and experimentally, hence the optimal locations for installing the linear alternators were identified to maximize the electric power output and/or the thermal-to-electric conversion efficiency. A ball valve was used in the loop to partly correct the acoustic field that was altered by manufacturing errors. A prototype was built based on this new concept, which used pressurized helium at 1.8 MPa as the working gas and operated at a frequency of about 171 Hz. In the experiment, a maximum electric power of 204 W when the hot end temperature of the two regenerators reaches 512℃ and 452℃, respectively. A maximum thermal-to-electric efficiency of 3.43% was achieved when the hot end temperature of the two regenerators reaches 597℃ and 511℃, respectively. The research results presented in this paper demonstrate that multi-stage travelling-wave thermoacoustic electricity generator has a great potential for developing inexpensive electric generators

    The Experiences of Staff Nurses Who Remained in Their Permanent Positions During the COVID-19 Pandemic

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    Amidst the persistent shortage of practicing nurses in the nursing profession, exacerbated by the unprecedented challenges of the COVID-19 pandemic, this study investigates the experiences of permanent staff nurses during the pandemic, with a specific focus on the factors influencing their decision to remain in their roles despite the adversities. Employing a phenomenological approach, in-depth interviews were conducted with thirteen permanent staff nurses to explore the intricacies of their experiences. Throughout the pandemic, the participants encountered profound ethical dilemmas. However, their determination to persist was fueled by a sense of professional duty, solidarity within their professional community, and deep camaraderie with colleagues. Nevertheless, the post-pandemic landscape brought a palpable decrease in significance and support, leading to an observable exodus of bedside nurses. Among the participants who remained steadfast in their positions, two overarching themes emerged: a genuine enjoyment of their role and a strong sense of camaraderie with peers. Strategic recommendations from the participants included prioritizing nurses\u27 autonomy, fostering supportive management, and enhancing educational support. The findings of this study underscore the necessity for healthcare institutions to prioritize the well-being and professional development of bedside nurses. Implementing these proactive measures can foster resilience among nursing staff, facilitate effective nurse retention, mitigate staffing shortages, and ultimately ensure the delivery of high-quality patient care

    Do Chinese Stock Markets React To The Newspaper Recommendations?

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    This paper studies how the stock prices in Chinese stock markets react to the stock recommendations from a Chinese business newspaper Zhong Guo Zheng Quan Bao (China Security). Using event study methodology and market model as a benchmark, we calculate abnormal returns to ascertain the impact of published recommendations. We find that there are no statistically significant long-term abnormal returns associated with the published recommendations. However, there are profitable opportunities if investors act prior to the published recommendations. We also find that the recommendations from the newspaper causes a significant short term movement two days after the publication day, suggesting a delayed response from the investors who act on the recommendation. The delayed response shows the gradual dissemination of the information in Chinese stock markets. In summary, these results indicate that press recommendations of Chinese stocks contain no useful economic information for investors who act on the published recommendations. The possible abnormal returns for investors who buy the stocks before the recommendations are made public are evidence of a market that is strong-form inefficient and the delayed response from investors to the newspaper recommendations is most likely the evidence of a market that is semi-strong-form inefficient

    Economic Growth And FDI In China

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    This paper studies the importance of foreign direct investment (FDI) in economic development in China. By analyzing the data from China and comparing China with other developed and developing countries, the paper finds that FDI becomes a force in economic growth, especially in the later stage of industrialization; Specifically, the paper finds that a country’s foreign trade is the engine in the initial stage of the economic development, while FDI is the main force in the post-industrialization stage

    Aberrant resting-state brain activity in Huntington's disease: A voxel-based meta-analysis

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    IntroductionFunctional neuroimaging could provide abundant information of underling pathophysiological mechanisms of the clinical triad including motor, cognitive and psychiatric impairment in Huntington's Disease (HD).MethodsWe performed a voxel-based meta-analysis using anisotropic effect size-signed differential mapping (AES-SDM) method.Results6 studies (78 symptomatic HD, 102 premanifest HD and 131 healthy controls) were included in total. Altered resting-state brain activity was primarily detected in the bilateral medial part of superior frontal gyrus, bilateral anterior cingulate/paracingulate gyrus, left insula, left striatum, right cortico-spinal projections area, right inferior temporal gyrus area, right thalamus, right cerebellum and right gyrus rectus area. Premanifest and symptomatic HD patients showed different alterative pattern in the subgroup analyses.DiscussionThe robust and consistent abnormalities in the specific brain regions identified in the current study could help to understand the pathophysiology of HD and explore reliable neuroimaging biomarkers for monitoring disease progression, or even predicting the onset of premanifest HD patients

    Characterization of Bovidae sex-determining gene SRY

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    In mammals, testis determination is under the control of the sex-determining gene SRY. This Y-linked gene encodes a protein with a DNA binding domain similar to those found in high-mobility-group proteins. Here we report the cloning and sequences of the SRY genes of yak and Chinese native cattle. Our data show that SRY genes in Bovidae are less divergent, especially in the coding and 3' regions

    Data from a comparative proteomic analysis of tumor-derived lung-cancer CD105+ endothelial cells

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    AbstractIncreasing evidence indicates that tumor-derived endothelial cells (TECs) are more relevant for the study of tumor angiogenesis and for screening antiangiogenic drugs than normal ECs (NECs). In this data article, high-purity (>98%) primary CD105+ NECs and TECs purified from a mouse Lewis lung carcinoma model bearing 0.5cm tumors were identified using 2D-PAGE and Matrix-assisted laser desorption/ionization tandem mass spectrometry (MALDI-MS/MS). All the identified proteins were categorized functionally by Gene Ontology (GO) analysis, and gene-pathway annotated by Kyoto Encyclopedia of Genes and Genomes (KEGG). Finally, protein–protein interaction networks were also built. The proteomics and bioinformatics data presented here provide novel insights into the molecular characteristics and the early modulation of the TEC proteome in the tumor microenvironment

    Can HIV service data be used for surveillance purposes?: a case study in Guangzhou, China.

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    BACKGROUND: Timely monitoring HIV epidemic among key populations is a formidable challenge. This study aimed to evaluate the agreement between data collected from an enhanced HIV sentinel surveillance (HSS+) and an HIV service, and to discuss whether testing service data can be used for surveillance purposes. METHODS: The HSS+ data were collected from HIV sentinel surveillance conducted annually among men who have sex with men (MSM) between 2009 and 2013 in Guangzhou, China. The HIV service data were obtained from the China-Bill & Melinda Gates Foundation Cooperation Program on HIV Prevention and Care (China-Gates HIV Program) in Guangzhou during the same period. The China-Gates HIV Program aimed to increase HIV counseling and testing among MSM. We compared demographic characteristics, condom use, HIV testing history, and the HIV status among individuals in these two datasets. The Armitage-trend test was used to evaluate the HIV epidemic and behaviors of the participants in the two datasets over the study period. RESULTS: Overall, a total of 2224 and 5311 MSM were included in the surveillance and service datasets, respectively. The majority of participants in the two datasets were between 20 and 29 years old, at least attended college, and had never been married. However, socio-demographic characteristics varied slightly between the two datasets. Similar trends were observed for the HIV epidemic in these two datasets. The surveillance dataset indicated that HIV prevalence increased from 3.9% in 2009 to 11.4% in 2013 (P-value for trend < 0.001), while data from the HIV service dataset indicated that MSM HIV prevalence during this same period increased from 6.2 to 8.9% (P-value for trend = 0.025). The rates of condom use were similar between the two datasets and remained consistent throughout the study period. CONCLUSION: HIV service data can complement existing HIV surveillance systems for MSM in China, though it may underestimate the HIV prevalence (HSS+ data contains people whose status is already know, while service data contains people who were initially negative or people of unknown status). HIV service data can be used for surveillance purposes, when prerequisite variables are collected from a large number people, if the quality assessment is conducted
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