667 research outputs found
Correlation between Mean Arterial Pressure and Regional Cerebral Oxygen Saturation on Cardiopulmonary Bypass in Pediatric Cardiac Surgery
Some pediatric cardiac patients might experience low regional cerebral oxygen saturation (rSO2) during surgery. We investigated whether a pediatric patient’s mean arterial pressure (MAP) can affect the rSO2 value during cardiopulmonary bypass (CPB). We retrospectively analyzed the cases of the pediatric patients who underwentcardiac surgery at our hospital (Jan. –Dec. 2019; n=141). At each MAP stage, we constructed line charts through the mean of the rSO2 values corresponding to each MAP and then calculated the correlation coefficients. We next divided the patients into age subgroups (neonates, infants, children) and into cyanotic congenital heart disease (CHD) and acyanotic CHD groups and analyzed these groups in the same way. The analyses of all 141 patients revealed that during CPB the rSO2 value increased with an increase in MAP (r=0.1626). There was a correlation between rSO2 and MAP in the children (r=0.2720) but not in the neonates (r=0.06626) or infants (r=0.05260). Cyanotic CHD or acyanotic CHD did not have a significant effect on the rSO2/MAP correlation. Our analysis demonstrated different patterns of a correlation between MAP and rSO2 in pediatric cardiac surgery patients, depending on age. MAP was positively correlated with rSO2 typically in children but not in neonate or infant patients
Relationship of Intraoperative SpO2 and ETCO2 Values with Postoperative Hypoxemia in Elderly Patients after Non-Cardiac Surgery
Elderly patients are at higher risk of postoperative hypoxemia due to their decreased respiratory function. The aim of this study was to investigate the relationship of intraoperative oxygen saturation (SpO2) and end-expiratory carbon dioxide (ETCO2) values with postoperative hypoxemia in elderly patients. The inclusion criteria were: 1) patients aged≥75 years; 2) underwent general anesthesia in non-cardiac surgery; 3) operative time longer than two hours; and 4) admission to the intensive care unit (ICU) following surgery performed between January and December 2019. Intraoperative SpO2 and ETCO2 values were collected every minute for the first two hours during surgery. The 253 patients were divided into two groups: SpO2≥92% and SpO2 20%) in elderly patients who underwent major non-cardiac surgery. Postoperative hypoxemia was associated with low intraoperative SpO2 and relatively higher ETCO2
A novel sampling method for time domain acoustic inverse source problems
This paper is concerned with the inverse acoustic scattering problems of
reconstructing time-dependent multiple point sources and sources on a curve
of the form . A direct sampling method with a
novel indicator function is proposed to reconstruct the sources. The sampling
method is easy to implement and low in calculation cost. Based on the sampling
method, numerical algorithms are provided to get the positions and intensities
of the sources. Both theoretical analysis of the indicator function and
numerical experiments are provided to show the effectiveness of the proposed
method.Comment: 22 pages, 43 figure
The Interactive Effects of Type of Audit Firm, Managing Director Changes and Financial Distress on Auditor Independence in UK
Audit places an essential role in providing additional assurance on the credibility of company’s financial statements. It is important for policy makers to identify the factors which influence companies’ decisions to switch their auditor. This study is intended to examine the interactive effects of type of audit firm, managing director changes and financial distress together with audit qualification and other four control variables (auditee size; audit fees, growth rate of auditee and gearing) on auditor switching. Based on the data collected from 53 UK listed companies between 2007 and 2009, it finds that type of audit firm is perceived to be the first order important factor on propensity to switch, indicating that clients prefer reputable audit firms. Change in managing director is more important to explain auditor switching than financial condition. Other findings revealed that qualified audit opinion is not statistically associated with subsequent audit switching, implying the general enhancement in audit independent in UK as opinion shopping tend to be less frequent. However, it finds in addition that financial distressed companies are less likely to change auditor. This finding does not support the preceding analytical studies
Intelligent-Reflecting-Surface-Assisted UAV Communications for 6G Networks
In 6th-Generation (6G) mobile networks, Intelligent Reflective Surfaces
(IRSs) and Unmanned Aerial Vehicles (UAVs) have emerged as promising
technologies to address the coverage difficulties and resource constraints
faced by terrestrial networks. UAVs, with their mobility and low costs, offer
diverse connectivity options for mobile users and a novel deployment paradigm
for 6G networks. However, the limited battery capacity of UAVs, dynamic and
unpredictable channel environments, and communication resource constraints
result in poor performance of traditional UAV-based networks. IRSs can not only
reconstruct the wireless environment in a unique way, but also achieve wireless
network relay in a cost-effective manner. Hence, it receives significant
attention as a promising solution to solve the above challenges. In this
article, we conduct a comprehensive survey on IRS-assisted UAV communications
for 6G networks. First, primary issues, key technologies, and application
scenarios of IRS-assisted UAV communications for 6G networks are introduced.
Then, we put forward specific solutions to the issues of IRS-assisted UAV
communications. Finally, we discuss some open issues and future research
directions to guide researchers in related fields
Epstein-Barr Virus-Positive Natural Killer/T-Cell Lymphoma
Extranodal natural killer/T-cell lymphoma, nasal type (ENKL), is a rare malignancy of Non-Hodgkin lymphoma characterized by an aggressive clinical course and poor prognosis. It shows strong association with Epstein-Barr virus infection and occurs more commonly in Asia and Latin America. Various genetic alterations have been identified in ENKL by gene expression profiling and sequencing techniques. The frequent deletion of chromosome 6q21 was reported to lead to the silence of several tumor suppressor genes. Also, there have been novel genetic mutations that were recently uncovered and were found to frequently activate several oncogenic pathways, including the JAK/STAT, NF-ÎşB, and MAPK pathways. Besides, we believe that deregulated single genes and epigenetic dysregulation might be relevant to the mechanism of this disease and thus, may have the potential to shed lights on the development of new therapeutic strategies. The consensus on the standard treatment for ENKL has not yet been currently established. For localized ENKL patients, radiotherapy with concurrent chemotherapy and sequential patterns of chemotherapy and radiotherapy are recommended as first-line therapy. As for advanced or relapsed/refractory ENKL patients, the application of non-anthracycline-containing regimens have significantly improved the clinical outcome, contributing to higher response rate, longer overall survival and progression-free survival. Hematopoietic stem cell transplantation is widely recommended for consolidation after a complete remission or partial remission has been achieved. The anti-programmed death 1 antibody, an immune checkpoint inhibitor, has demonstrated favorable results in treating relapsed or refractory ENKL. Of the current ENKL treatment, researchers are still striving to validate how radiotherapy and chemotherapy should be optimally combined and which of the non-anthracycline-containing regimens is superior. In this review, we summarize the main genetic alterations frequently found in ENKL and their role in providing new insights into the therapeutic targets of this disease, and highlight the recent findings regarding new biologic markers, novel therapeutic strategies applied to this intriguing neoplasm
Query with Assumptions for Probabilistic Relational Databases
Users may have prior knowledge about a probabilistic database. They prefer to query over a probabilistic database on their prior knowledge which cannot be written as component clauses of conventional SQL queries. A naive approach is to query over a new database version, which is generated by transforming the original probabilistic database to satisfy users\u27 prior knowledge; however, it is impractical to generate a different probabilistic database version for each prior knowledge. In this paper, we propose the concept of the query with assumptions which allow users to describe their prior knowledge with a newly introduced ASSUMPTION clause of SQL. We also propose an approach to obtain the result of a query based on assumption clauses. The experimental studies show our approach has better performance compared to the naive approach
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