Device-to-device (D2D) communication with increased spectral efficiency and reduced communication delay has undoubtedly become a general trend in future wireless networks. However, when D2D communication is incorporated into small cell networks (SCNs) with large number of randomly overlapped small cells, the co-channel interference between small cell users (SUEs) and D2D users is an inevitable challenge, especially with the heterogeneous spectrum, i.e., licensed spectrum bands and unlicensed spectrum bands. In this paper, we study the downlink channel allocation in D2D-assisted small cell networks with heterogeneous spectrum bands. By taking the required data rate of users and the interference constraint of SUEs into account, we formulate a channel allocation problem integrating channel selection and channel sharing to maximize the network utility, which is the service satisfaction of all users. To derive the solution, we decompose the optimization problem into two games: a potential game and a coalition game. Then, a potential game-based scheme using an interference graph and a coalition scheme with D2D user transferring is proposed to solve these two games, respectively. Based on these schemes, a two-stage distributed channel allocation algorithm is proposed and can converge with low computational complexity. Moreover, the simulation results reveal that the proposed algorithm could achieve high system throughput and network utility.
In this paper, a downlink device-to-device (D2D)-assisted cellular networks with mobile edge caching, where most popular video files are independently cached in D2D users and cellular base station (BS), are studied. In the considered system model, each user may obtain the requested video from the cache of BS or/and D2D users surrounding them. According to the different collaborative schemes of BS caching and D2D caching, it can be divided into two different resource allocation schemes. In the hybrid caching transmission scheme, users could adopt the BS caching mode or alternatively the D2D caching mode. In the joint caching transmission scheme, each user may obtain the requested files from the BS server and the adjacent D2D users, simultaneously. By taking the required data rate and the interference constraint into account, we formulate two joint resource allocation problems integrating link selection, channel allocation, and power control to maximize the system energy efficiency (EE). Leveraging on the Dinkelbach method, the EE optimization problems are transformed into mixed-integer nonlinear programming problems and can be decomposed into three subproblems: link selection, channel allocation, and power control. To solve these complicated problems, we propose two optimization algorithms that consist of a modified branch and bound method as well as Lagrange dual decomposition approach. The simulation results demonstrate the superiority of these two proposed algorithms in improving system throughput and EE compared with other algorithms.
Background: The effectiveness of physical restraints (PRs) in the prevention of unplanned extubation has been increasingly questioned, and several countries have developed clinical practice guidelines for reducing the use of PRs. However, some countries, including China, have failed to establish their guidelines, and the adaptation of existing guidelines to local circumstances may be an attractive alternative.Methods: Following the guideline definition of Institute of Medicine, the guideline will be adapted following the CAN-IMPLEMENT©. Guideline scope and clinical questions will be established based on an integrative review, retrospective study, and stakeholder interviews. The guideline's quality will be assessed by the Appraisal of Guidelines for Research and Evaluation II and Appraisal of Guidelines Research and Evaluation-Recommendations Excellence. A systematic review and meta-analysis will be evaluated by A Measurement Tool to Assess Systematic Reviews. The guidelines will meet the criteria of the RIGHT-Ad@ pt Checklist.Discussion: This study describes the proposed protocol for adapting clinical practice guidelines on PRs in critically ill patients. We believe the guideline will help health professionals, especially critical care nurses, deliver safe, high-quality patient care by reducing the implementation of PRs in China.
Background Ethical conflicts are common in the critical care setting, and have compromised job satisfaction and nursing care quality. Using reliable and valid instruments to measure the ethical conflict is essential. This study aimed to translate the Ethical Conflict in Nursing Questionnaire — Critical Care Version into Chinese and determine the reliability and validity in the population of Chinese nurses. Methods Researchers obtained permission and followed the translation-backward method to develop the Chinese version of the Ethical Conflict in Nursing Questionnaire — Critical Care Version (ECNQ-CCV-C). Relevant psychometric properties were selected according to the Consensus-based standards for the selection of health status measurement instruments checklist. Critical care nurses were recruited from two tertiary public hospitals in Hangzhou, Zhejiang Province, and Kunming, Yunnan Province. Of the 264 nurses we approached, 248 gave their consent and completed the study. Results The ECNQ-CCV-C achieved Cronbach’s alphas 0.902 and McDonald’s omega coefficient 0.903. The test-retest reliability was satisfactory within a 2-week interval (intraclass correlation coefficient = 0.757). A unidimensional structure of the ECNQ-CCV-C was determined. Confirmatory factor analysis supported acceptable structure validity. Concurrent validity was confirmed by a moderate relation with a measure for hospital ethical climate (r = − 0.33, p < 0.01). The model structure was invariant across different gender groups, with no floor/ceiling effect. Conclusions The ECNQ-CCV-C demonstrated acceptable reliability and validity among Chinese nurses and had great clinical utility in critical care nursing.
This study aimed to investigate the presence and persistence of antibiotics in wastewater of four typical pharmaceutical manufactories in China and receiving water bodies and suggest the removal of antibiotics by the wastewater treatment process. It also evaluated the environmental impact of antibiotic residues through wastewater discharge into receiving water bodies. The results indicated that thirteen antibiotics were detected in wastewater samples with concentrations ranging from 57.03 to 726.79 ng/L. Fluoroquinolones and macrolides were the most abundant antibiotic classes found in wastewater samples, accounting for 42.5% and 38.7% of total antibiotic concentrations, respectively, followed by sulfonamides (16.4%) and tetracyclines (2.4%). Erythromycin-H2O, lincomycin, ofloxacin, and trimethoprim were the most frequently detected antibiotics; among these antibiotics, the concentration of ofloxacin was the highest in most wastewater samples. No significant difference was found in different treatment processes used to remove antibiotics in wastewater samples. More than 50% of antibiotics were not completely removed with a removal efficiency of less than 70%. The concentration of detected antibiotics in the receiving water bodies was an order of magnitude lower than that in the wastewater sample due to dilution. An environmental risk assessment showed that lincomycin and ofloxacin could pose a high risk at the concentrations detected in effluents and a medium risk in their receiving water bodies, highlighting a potential hazard to the health of the aquatic ecosystem. Overall, The investigation was aimed to determine and monitor the concentration of selected antibiotics in 4 typical PMFs and their receiving water bodies, and to study the removal of these substances in PMFs. This study will provide significant data and findings for future studies on antibiotics-related pollution control and management in water bodies.
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