Two coupled-mode methods, namely DGMCM （Direct-Global-Matrix Coupled- Mode Method） and CCMM （Consistent Coupled-Mode Method）, are analyzed and compared. First, both of these two methods provide two-way solutions, ...Two coupled-mode methods, namely DGMCM （Direct-Global-Matrix Coupled- Mode Method） and CCMM （Consistent Coupled-Mode Method）, are analyzed and compared. First, both of these two methods provide two-way solutions, and hence they are accurate models. Second, the series of local vertical modes in DGMCM converges as fast as that in CCMM, whereas DGMCM has a more tolerable requirement of the number of segments than CCMM. Third, these two models obtain the field solution by solving the coupled-mode system with different coefficient matrices, in which the computational effort for the required parameters is almost the same. Finally, DGMCM can handle some problems which are difficult for CCMM, such as in a waveguide with a rough bottom, a line source located right on top of a sloping bot- tom, or in the presence of multiple sources. In DGMCM, closed-form expressions for coupling matrices in a two-layer waveguide are given. In addition, the formulation for the line-source problem in plane geometry is derived to update CCMM.展开更多
The emergence and prevalence of multidrug-resistant Acinetobacter baumannii(MRAB)poses a huge challenge to clinical treatment.To investigate the genetic and epidemiologic characteristics of MRAB in Liaocheng,China,and...The emergence and prevalence of multidrug-resistant Acinetobacter baumannii(MRAB)poses a huge challenge to clinical treatment.To investigate the genetic and epidemiologic characteristics of MRAB in Liaocheng,China,and to explore potential resistance mechanisms,56 MRAB strains were collected from the clinical departments of seven hospitals in Liaocheng between 2020 and 2022.Molecular typing,antimicrobial resistance patterns,and epidemiological characteristics were determined by genome sequencing and comparative genome analysis.Sequence type(ST)540 was the most prevalent ST of the 56 MRAB in Liaocheng,and most strains(92.86%)were grouped into CC92.Core genome multilocus sequence typing subdivided the strains according to the number of allelic differences and could distinguish different outbreaks caused by ST540 isolates in the hospitals.All the isolates harbored blaOXA-23 and blaADC-25,and at least 92.86%of the isolates were resistant to 10 antibiotics.The major MRAB epidemic clone detected in Liaocheng was ST540,which was different from the results reported in other regions in China.Furthermore,several inter-hospital transmissions of ST540 isolates were observed.The findings highlight the urgent need for effective nosocomial infection control measures and the continuous surveillance of ST540 MRAB in Liaocheng.展开更多
基金supported by the National Natural Sciencc Foundation of China(11125420,11104312)
文摘Two coupled-mode methods, namely DGMCM （Direct-Global-Matrix Coupled- Mode Method） and CCMM （Consistent Coupled-Mode Method）, are analyzed and compared. First, both of these two methods provide two-way solutions, and hence they are accurate models. Second, the series of local vertical modes in DGMCM converges as fast as that in CCMM, whereas DGMCM has a more tolerable requirement of the number of segments than CCMM. Third, these two models obtain the field solution by solving the coupled-mode system with different coefficient matrices, in which the computational effort for the required parameters is almost the same. Finally, DGMCM can handle some problems which are difficult for CCMM, such as in a waveguide with a rough bottom, a line source located right on top of a sloping bot- tom, or in the presence of multiple sources. In DGMCM, closed-form expressions for coupling matrices in a two-layer waveguide are given. In addition, the formulation for the line-source problem in plane geometry is derived to update CCMM.
基金funded by the Shandong Medical and Health Science and Technology Development Program,grant number 202212061076.
文摘The emergence and prevalence of multidrug-resistant Acinetobacter baumannii(MRAB)poses a huge challenge to clinical treatment.To investigate the genetic and epidemiologic characteristics of MRAB in Liaocheng,China,and to explore potential resistance mechanisms,56 MRAB strains were collected from the clinical departments of seven hospitals in Liaocheng between 2020 and 2022.Molecular typing,antimicrobial resistance patterns,and epidemiological characteristics were determined by genome sequencing and comparative genome analysis.Sequence type(ST)540 was the most prevalent ST of the 56 MRAB in Liaocheng,and most strains(92.86%)were grouped into CC92.Core genome multilocus sequence typing subdivided the strains according to the number of allelic differences and could distinguish different outbreaks caused by ST540 isolates in the hospitals.All the isolates harbored blaOXA-23 and blaADC-25,and at least 92.86%of the isolates were resistant to 10 antibiotics.The major MRAB epidemic clone detected in Liaocheng was ST540,which was different from the results reported in other regions in China.Furthermore,several inter-hospital transmissions of ST540 isolates were observed.The findings highlight the urgent need for effective nosocomial infection control measures and the continuous surveillance of ST540 MRAB in Liaocheng.
