聚乳酸(PLA)的脆性与易燃性限制了其更为广泛的应用。文中以9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物(DOPO)为阻燃剂、聚丁二酸丁二醇酯(PBS)为增韧剂、环氧大豆油(ESO)为反应型增容剂,研究了ESO的加入对PLA/PBS/DOPO复合材料性能的影响...聚乳酸(PLA)的脆性与易燃性限制了其更为广泛的应用。文中以9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物(DOPO)为阻燃剂、聚丁二酸丁二醇酯(PBS)为增韧剂、环氧大豆油(ESO)为反应型增容剂,研究了ESO的加入对PLA/PBS/DOPO复合材料性能的影响。力学性能测试、差示扫描量热分析、热重分析、动态力学热分析、扫描电子显微镜、极限氧指数(LOI)及垂直燃烧(UL-94)等测试结果表明,ESO明显提高了PLA与PBS间的相容性。PLA/PBS/ESO/DOPO(79/10/6/5)复合材料的综合性能最为优异,断裂伸长率达到了153.12%,较纯PLA提升了30倍,拉伸强度为34.44 MPa,冲击强度为18.13 k J/m^(2),增韧效果显著;LOI达到了26%,UL-94测试达到了V-0级别,获得了同时具有优异力学性能和阻燃性能的复合材料。展开更多
Background:This study aimed to evaluate the diagnostic accuracy of magnetocardiograph,a relatively new noninvasive device,in patients with myocardial infarction(MI).Methods:To identify studies assessing the diagnostic...Background:This study aimed to evaluate the diagnostic accuracy of magnetocardiograph,a relatively new noninvasive device,in patients with myocardial infarction(MI).Methods:To identify studies assessing the diagnostic accuracy of magnetocardiography for MI,we searched four databases on November 7,2022,the Cochrane Central Register of Controlled Trials,MEDLINE,EMBASE,and Web of Science,plus ClinicalTrials.gov.Three reviewers screened the studies independently and emailed the authors for more precise data when necessary.The Quality Assessment of Diagnostic Accuracy Studies 2 tool was used to evaluate the quality of the included studies.STATA(version 17;Stata Corporation,College Station,TX,USA)was used for meta-analysis of 22 contingency table data.Results:A total of 6 articles were included in this study.The diagnostic parameters of all included studies were summarized as follows:the pooled sensitivity was 0.91(95%confidence intervals[95%CIs]:0.81–0.96;I 2=88.54);specificity was 0.83(95%CI:0.75–0.89;I 2=83);positive likelihood ratio was 5.3(95%CI:3.5–8.2);negative likelihood ratio was 0.1(95%CI:0.04–0.24);and diagnostic odds ratio was 51(95%CI:16–161).The area under the curve for the receiver operating characteristic curve was 0.92(95%CI:0.89–0.94).After metaregression analysis,we found that the number of channels and the way of environmental magnetic noise elimination were heterogeneous sources.Conclusion:In summary,our meta-analysis shows that magnetocardiography holds a high accuracy in diagnosing MI and takes the advantages of noninvasive,radiation-free,and noncontact.However,further high-quality studies to confirm its usefulness in diagnosing MI are warranted.展开更多
In the present work,we report the growth of all-inorganic perovskite nanorings with dual compositional phases of CsPbBr_(3)and CsPb_(2)Br5 via a facile hot injection process.The self-coiling of CsPbBr_(3)-CsPb_(2)Br5 ...In the present work,we report the growth of all-inorganic perovskite nanorings with dual compositional phases of CsPbBr_(3)and CsPb_(2)Br5 via a facile hot injection process.The self-coiling of CsPbBr_(3)-CsPb_(2)Br5 nanorings is driven by the axial stress generated on the outside surface of the as-synthesized nanobelts,which results from the lattice mismatch during the transformation of CsPbBr_(3)to CsPb_(2)Br5.The tailored growth of nanorings could be achieved by adjusting the key experimental parameters such as reaction temperature,reaction time and stirring speed during the cooling process.The photoluminescence intensity and quantum yield of nanorings are higher than those of CsPbBr_(3)nanobelts,accompanied by a narrower full width at half maximum(FWHM),suggesting their high potential for constructing self-assembled optoelectronic nanodevices.展开更多
文摘聚乳酸(PLA)的脆性与易燃性限制了其更为广泛的应用。文中以9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物(DOPO)为阻燃剂、聚丁二酸丁二醇酯(PBS)为增韧剂、环氧大豆油(ESO)为反应型增容剂,研究了ESO的加入对PLA/PBS/DOPO复合材料性能的影响。力学性能测试、差示扫描量热分析、热重分析、动态力学热分析、扫描电子显微镜、极限氧指数(LOI)及垂直燃烧(UL-94)等测试结果表明,ESO明显提高了PLA与PBS间的相容性。PLA/PBS/ESO/DOPO(79/10/6/5)复合材料的综合性能最为优异,断裂伸长率达到了153.12%,较纯PLA提升了30倍,拉伸强度为34.44 MPa,冲击强度为18.13 k J/m^(2),增韧效果显著;LOI达到了26%,UL-94测试达到了V-0级别,获得了同时具有优异力学性能和阻燃性能的复合材料。
基金supported by the National Key R&D Program of China(2020YFC1512700,2020YFC1512705,and 2020YFC1512703)National Science and Technology Fundamental Resources Investigation Project(2018FY100600 and 2018FY100602)+4 种基金Key R&D Program of Shandong Province(2021ZLGX02,2021SFGC0503,and 2022ZLGX03)Taishan Pandeng Scholar Program of Shandong Province(tspd20181220)Taishan Young Scholar Program of Shandong Province(tsqn202211312)the Interdisciplinary Young Researcher Groups Program of Shandong University(2020QNQT004)Youth Top-Talent Project of National Ten Thousand Talents Plan,and Qilu Young Scholar Program.
文摘Background:This study aimed to evaluate the diagnostic accuracy of magnetocardiograph,a relatively new noninvasive device,in patients with myocardial infarction(MI).Methods:To identify studies assessing the diagnostic accuracy of magnetocardiography for MI,we searched four databases on November 7,2022,the Cochrane Central Register of Controlled Trials,MEDLINE,EMBASE,and Web of Science,plus ClinicalTrials.gov.Three reviewers screened the studies independently and emailed the authors for more precise data when necessary.The Quality Assessment of Diagnostic Accuracy Studies 2 tool was used to evaluate the quality of the included studies.STATA(version 17;Stata Corporation,College Station,TX,USA)was used for meta-analysis of 22 contingency table data.Results:A total of 6 articles were included in this study.The diagnostic parameters of all included studies were summarized as follows:the pooled sensitivity was 0.91(95%confidence intervals[95%CIs]:0.81–0.96;I 2=88.54);specificity was 0.83(95%CI:0.75–0.89;I 2=83);positive likelihood ratio was 5.3(95%CI:3.5–8.2);negative likelihood ratio was 0.1(95%CI:0.04–0.24);and diagnostic odds ratio was 51(95%CI:16–161).The area under the curve for the receiver operating characteristic curve was 0.92(95%CI:0.89–0.94).After metaregression analysis,we found that the number of channels and the way of environmental magnetic noise elimination were heterogeneous sources.Conclusion:In summary,our meta-analysis shows that magnetocardiography holds a high accuracy in diagnosing MI and takes the advantages of noninvasive,radiation-free,and noncontact.However,further high-quality studies to confirm its usefulness in diagnosing MI are warranted.
基金supported by the National Natural Science Foundation for Excellent Young Scholars of China(No.51522402)the National Natural Science Foundation of China(No.51972178),the Zhejiang Provincial Nature Science Foundation(No.LQ17E020002)The authors thank Engineer Dongsheng He for the help on double Cs-corrected transmission electron microscopy.
文摘In the present work,we report the growth of all-inorganic perovskite nanorings with dual compositional phases of CsPbBr_(3)and CsPb_(2)Br5 via a facile hot injection process.The self-coiling of CsPbBr_(3)-CsPb_(2)Br5 nanorings is driven by the axial stress generated on the outside surface of the as-synthesized nanobelts,which results from the lattice mismatch during the transformation of CsPbBr_(3)to CsPb_(2)Br5.The tailored growth of nanorings could be achieved by adjusting the key experimental parameters such as reaction temperature,reaction time and stirring speed during the cooling process.The photoluminescence intensity and quantum yield of nanorings are higher than those of CsPbBr_(3)nanobelts,accompanied by a narrower full width at half maximum(FWHM),suggesting their high potential for constructing self-assembled optoelectronic nanodevices.
