Objective To explore the feasibility of prototype of flexible ultrasound array transducer for measuring intravascular diameter and blood flow velocity.Methods A prototype of flexible ultrasonic array transducer composed of a surface mount flexible ultrasonic array transducer(referred to as the transducer)and acquisition system was designed and fabricated.Doppler body model and vascular simulation control system was used to simulate human blood.Mindray M7 color multi-functional ultrasound diagnostic instrument(abbreviated as M7)and the prototype were adopted to detect pulse wave excitation mode,spectral morphology,echo signal time interval,blood flow velocity,etc.Taken the results of M7 as standards,the effectiveness of the prototype was evaluated.Then the inner diameter and flow velocity of left common carotid artery,left brachial artery and left radial artery of 20 healthy controls(HC)were measured respectively using M7 and the prototype,and the consistency of measurement results were analyzed to evaluate the accuracy of the prototype.The safety of the prototype was evaluated according to subjectively scoring the comfort level of HC applying the transducer and whether there was skin discomfort,injury,etc.after removing the transducer.Results The collected blood flow spectrum of the above vascular simulation control system acquire with the prototype were clear,and the spectral morphology,flow velocity,as well as echo signal time interval were basically consistent with those of M7.The consistency of the inner diameter of left common carotid artery,left brachial artery and left radial artery measured by the prototype and M7 in 20 HC were all very strong(ICC=0.919-0.992),while of flow velocities were moderate or very strong(ICC=0.524-0.831).The subjective score of comfort level of application of transducer was 3(2,3),and no skin discomfort occurred.Conclusion Flexible ultrasound array transducer technology could be used to measure intravascular diameter and blood flow velocity.

Objective:In order to solve the problem that traditional theoretical examination has become more and more difficult to comprehensively and accurately evaluate the students' understanding, taking the endodontics course as the breakthrough, this study investigates the application of process evaluation method based on the "four-step" teaching method in the endodontics experimental courses. Meanwhile, the characteristics and feasibility and significance of the study are expounded.Methods:A total of 64 students were selected from two grades majoring in Stomatology in Medical School of Shenzhen University, and they were taught and assessed according to the new or old course designs. At the end of the course, comparisons of course assessment scores between the two grades were finished and the questionnaire survey was conducted to evaluate the teaching effect. SPSS 23.0 was used to perform the independent-samples t-test. Results:The analysis showed that 84.38%(27/32) of the students thought that the "four-step" teaching method helped with the learning of endodontics and significantly improved the scores of the experimental course; 90.62%(29/32) of the students thought it was helpful to stimulate self-learning skills. Compared with the students in the Class of 2018, the students in the Class of 2019 had significantly higher experimental examination scores [(87.29±4.13) vs. (84.07±1.77), P<0.01], while the scores of theoretical examination showed no significant difference between the two grades [(78.07±5.70) vs. (76.52±6.49)]. Conclusions:This teaching reform has provided the opportunities for practical operations, improved the quality of practical teaching and also stimulated the interest in independent learning of students. Moreover, it can accumulate experience for the reform of other dental experimental courses.

Objective To explore the feasibility of prototype of flexible ultrasound array transducer for measuring intravascular diameter and blood flow velocity.Methods A prototype of flexible ultrasonic array transducer composed of a surface mount flexible ultrasonic array transducer(referred to as the transducer)and acquisition system was designed and fabricated.Doppler body model and vascular simulation control system was used to simulate human blood.Mindray M7 color multi-functional ultrasound diagnostic instrument(abbreviated as M7)and the prototype were adopted to detect pulse wave excitation mode,spectral morphology,echo signal time interval,blood flow velocity,etc.Taken the results of M7 as standards,the effectiveness of the prototype was evaluated.Then the inner diameter and flow velocity of left common carotid artery,left brachial artery and left radial artery of 20 healthy controls(HC)were measured respectively using M7 and the prototype,and the consistency of measurement results were analyzed to evaluate the accuracy of the prototype.The safety of the prototype was evaluated according to subjectively scoring the comfort level of HC applying the transducer and whether there was skin discomfort,injury,etc.after removing the transducer.Results The collected blood flow spectrum of the above vascular simulation control system acquire with the prototype were clear,and the spectral morphology,flow velocity,as well as echo signal time interval were basically consistent with those of M7.The consistency of the inner diameter of left common carotid artery,left brachial artery and left radial artery measured by the prototype and M7 in 20 HC were all very strong(ICC=0.919-0.992),while of flow velocities were moderate or very strong(ICC=0.524-0.831).The subjective score of comfort level of application of transducer was 3(2,3),and no skin discomfort occurred.Conclusion Flexible ultrasound array transducer technology could be used to measure intravascular diameter and blood flow velocity.

Objective To investigate the distribution and antimicrobial resistance profiles of common pathogens isolated from cerebrospinal fluid(CSF)in CHINET program from 2015 to 2021.Methods The bacterial strains isolated from CSF were identified in accordance with clinical microbiology practice standards.Antimicrobial susceptibility test was conducted using Kirby-Bauer method and automated systems per the unified CHINET protocol.Results A total of 14 014 bacterial strains were isolated from CSF samples from 2015 to 2021,including the strains isolated from inpatients(95.3％)and from outpatient and emergency care patients(4.7％).Overall,19.6％of the isolates were from children and 80.4％were from adults.Gram-positive and Gram-negative bacteria accounted for 68.0％and 32.0％,respectively.Coagulase negative Staphylococcus accounted for 73.0％of the total Gram-positive bacterial isolates.The prevalence of MRSA was 38.2％in children and 45.6％in adults.The prevalence of MRCNS was 67.6％in adults and 69.5％in children.A small number of vancomycin-resistant Enterococcus faecium(2.2％)and linezolid-resistant Enterococcus faecalis(3.1％)were isolated from adult patients.The resistance rates of Escherichia coli and Klebsiella pneumoniae to ceftriaxone were 52.2％and 76.4％in children,70.5％and 63.5％in adults.The prevalence of carbapenem-resistant E.coli and K.pneumoniae(CRKP)was 1.3％and 47.7％in children,6.4％and 47.9％in adults.The prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)and Pseudomonas aeruginosa(CRPA)was 74.0％and 37.1％in children,81.7％and 39.9％in adults.Conclusions The data derived from antimicrobial resistance surveillance are crucial for clinicians to make evidence-based decisions regarding antibiotic therapy.Attention should be paid to the Gram-negative bacteria,especially CRKP and CRAB in central nervous system(CNS)infections.Ongoing antimicrobial resistance surveillance is helpful for optimizing antibiotic use in CNS infections.

Objective To investigate the antimicrobial resistance of clinical isolates from elderly patients(≥65 years)in major medical institutions across China.Methods Bacterial strains were isolated from elderly patients in 52 hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program during the period from 2015 to 2021.Antimicrobial susceptibility test was carried out by disk diffusion method and automated systems according to the same CHINET protocol.The data were interpreted in accordance with the breakpoints recommended by the Clinical and Laboratory Standards Institute(CLSI)in 2021.Results A total of 514 715 nonduplicate clinical isolates were collected from elderly patients in 52 hospitals from January 1,2015 to December 31,2021.The number of isolates accounted for 34.3％of the total number of clinical isolates from all patients.Overall,21.8％of the 514 715 strains were gram-positive bacteria,and 78.2％were gram-negative bacteria.Majority(90.9％)of the strains were isolated from inpatients.About 42.9％of the strains were isolated from respiratory specimens,and 22.9％were isolated from urine.More than half(60.7％)of the strains were isolated from male patients,and 39.3％isolated from females.About 51.1％of the strains were isolated from patients aged 65-＜75 years.The prevalence of methicillin-resistant strains(MRSA)was 38.8％in 32 190 strains of Staphylococcus aureus.No vancomycin-or linezolid-resistant strains were found.The resistance rate of E.faecalis to most antibiotics was significantly lower than that of Enterococcus faecium,but a few vancomycin-resistant strains(0.2％,1.5％)and linezolid-resistant strains(3.4％,0.3％)were found in E.faecalis and E.faecium.The prevalence of penicillin-susceptible S.pneumoniae(PSSP),penicillin-intermediate S.pneumoniae(PISP),and penicillin-resistant S.pneumoniae(PRSP)was 94.3％,4.0％,and 1.7％in nonmeningitis S.pneumoniae isolates.The resistance rates of Klebsiella spp.(Klebsiella pneumoniae 93.2％)to imipenem and meropenem were 20.9％and 22.3％,respectively.Other Enterobacterales species were highly sensitive to carbapenem antibiotics.Only 1.7％-7.8％of other Enterobacterales strains were resistant to carbapenems.The resistance rates of Acinetobacter spp.(Acinetobacter baumannii 90.6％)to imipenem and meropenem were 68.4％and 70.6％respectively,while 28.5％and 24.3％of P.aeruginosa strains were resistant to imipenem and meropenem,respectively.Conclusions The number of clinical isolates from elderly patients is increasing year by year,especially in the 65-＜75 age group.Respiratory tract isolates were more prevalent in male elderly patients,and urinary tract isolates were more prevalent in female elderly patients.Klebsiella isolates were increasingly resistant to multiple antimicrobial agents,especially carbapenems.Antimicrobial resistance surveillance is helpful for accurate empirical antimicrobial therapy in elderly patients.

Objective:In order to solve the problem that traditional theoretical examination has become more and more difficult to comprehensively and accurately evaluate the students' understanding, taking the endodontics course as the breakthrough, this study investigates the application of process evaluation method based on the "four-step" teaching method in the endodontics experimental courses. Meanwhile, the characteristics and feasibility and significance of the study are expounded.Methods:A total of 64 students were selected from two grades majoring in Stomatology in Medical School of Shenzhen University, and they were taught and assessed according to the new or old course designs. At the end of the course, comparisons of course assessment scores between the two grades were finished and the questionnaire survey was conducted to evaluate the teaching effect. SPSS 23.0 was used to perform the independent-samples t-test. Results:The analysis showed that 84.38%(27/32) of the students thought that the "four-step" teaching method helped with the learning of endodontics and significantly improved the scores of the experimental course; 90.62%(29/32) of the students thought it was helpful to stimulate self-learning skills. Compared with the students in the Class of 2018, the students in the Class of 2019 had significantly higher experimental examination scores [(87.29±4.13) vs. (84.07±1.77), P<0.01], while the scores of theoretical examination showed no significant difference between the two grades [(78.07±5.70) vs. (76.52±6.49)]. Conclusions:This teaching reform has provided the opportunities for practical operations, improved the quality of practical teaching and also stimulated the interest in independent learning of students. Moreover, it can accumulate experience for the reform of other dental experimental courses.

Objective To investigate the distribution and antimicrobial resistance profiles of common pathogens isolated from cerebrospinal fluid(CSF)in CHINET program from 2015 to 2021.Methods The bacterial strains isolated from CSF were identified in accordance with clinical microbiology practice standards.Antimicrobial susceptibility test was conducted using Kirby-Bauer method and automated systems per the unified CHINET protocol.Results A total of 14 014 bacterial strains were isolated from CSF samples from 2015 to 2021,including the strains isolated from inpatients(95.3％)and from outpatient and emergency care patients(4.7％).Overall,19.6％of the isolates were from children and 80.4％were from adults.Gram-positive and Gram-negative bacteria accounted for 68.0％and 32.0％,respectively.Coagulase negative Staphylococcus accounted for 73.0％of the total Gram-positive bacterial isolates.The prevalence of MRSA was 38.2％in children and 45.6％in adults.The prevalence of MRCNS was 67.6％in adults and 69.5％in children.A small number of vancomycin-resistant Enterococcus faecium(2.2％)and linezolid-resistant Enterococcus faecalis(3.1％)were isolated from adult patients.The resistance rates of Escherichia coli and Klebsiella pneumoniae to ceftriaxone were 52.2％and 76.4％in children,70.5％and 63.5％in adults.The prevalence of carbapenem-resistant E.coli and K.pneumoniae(CRKP)was 1.3％and 47.7％in children,6.4％and 47.9％in adults.The prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)and Pseudomonas aeruginosa(CRPA)was 74.0％and 37.1％in children,81.7％and 39.9％in adults.Conclusions The data derived from antimicrobial resistance surveillance are crucial for clinicians to make evidence-based decisions regarding antibiotic therapy.Attention should be paid to the Gram-negative bacteria,especially CRKP and CRAB in central nervous system(CNS)infections.Ongoing antimicrobial resistance surveillance is helpful for optimizing antibiotic use in CNS infections.

Objective To investigate the antimicrobial resistance of clinical isolates from elderly patients(≥65 years)in major medical institutions across China.Methods Bacterial strains were isolated from elderly patients in 52 hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program during the period from 2015 to 2021.Antimicrobial susceptibility test was carried out by disk diffusion method and automated systems according to the same CHINET protocol.The data were interpreted in accordance with the breakpoints recommended by the Clinical and Laboratory Standards Institute(CLSI)in 2021.Results A total of 514 715 nonduplicate clinical isolates were collected from elderly patients in 52 hospitals from January 1,2015 to December 31,2021.The number of isolates accounted for 34.3％of the total number of clinical isolates from all patients.Overall,21.8％of the 514 715 strains were gram-positive bacteria,and 78.2％were gram-negative bacteria.Majority(90.9％)of the strains were isolated from inpatients.About 42.9％of the strains were isolated from respiratory specimens,and 22.9％were isolated from urine.More than half(60.7％)of the strains were isolated from male patients,and 39.3％isolated from females.About 51.1％of the strains were isolated from patients aged 65-＜75 years.The prevalence of methicillin-resistant strains(MRSA)was 38.8％in 32 190 strains of Staphylococcus aureus.No vancomycin-or linezolid-resistant strains were found.The resistance rate of E.faecalis to most antibiotics was significantly lower than that of Enterococcus faecium,but a few vancomycin-resistant strains(0.2％,1.5％)and linezolid-resistant strains(3.4％,0.3％)were found in E.faecalis and E.faecium.The prevalence of penicillin-susceptible S.pneumoniae(PSSP),penicillin-intermediate S.pneumoniae(PISP),and penicillin-resistant S.pneumoniae(PRSP)was 94.3％,4.0％,and 1.7％in nonmeningitis S.pneumoniae isolates.The resistance rates of Klebsiella spp.(Klebsiella pneumoniae 93.2％)to imipenem and meropenem were 20.9％and 22.3％,respectively.Other Enterobacterales species were highly sensitive to carbapenem antibiotics.Only 1.7％-7.8％of other Enterobacterales strains were resistant to carbapenems.The resistance rates of Acinetobacter spp.(Acinetobacter baumannii 90.6％)to imipenem and meropenem were 68.4％and 70.6％respectively,while 28.5％and 24.3％of P.aeruginosa strains were resistant to imipenem and meropenem,respectively.Conclusions The number of clinical isolates from elderly patients is increasing year by year,especially in the 65-＜75 age group.Respiratory tract isolates were more prevalent in male elderly patients,and urinary tract isolates were more prevalent in female elderly patients.Klebsiella isolates were increasingly resistant to multiple antimicrobial agents,especially carbapenems.Antimicrobial resistance surveillance is helpful for accurate empirical antimicrobial therapy in elderly patients.

Objective:To assess the efficacy and safety of Gongxuening Capsules in reducing post-abortion bleeding following artificial abortion.Methods:A multicenter, randomized, double-blind study was conducted. From May 31, 2022 to March 31, 2023, 484 women who underwent vacuum aspiration abortion for early intrauterine pregnancy were enrolled in 11 centers and randomly assigned to control group and the study group at a 1∶1 ratio using a center-block randomization method. Control group were administered a placebo of Gongxuening Capsules for 9 d, while the study group received the actual Gongxuening Capsules for the same duration. The outcomes measured included vaginal bleeding volume, duration of vaginal bleeding, endometrial thickness, time to menstrual recovery, and complications.Results:1) A total of 484 subjects were enrolled, and 472 completed the study. Totally 450 subjects were included in the efficacy analysis set, with 224 in control group and 226 in the study group; 468 subjects were included in the safety analysis set, with 236 in control group and 232 in the study group. The baseline characteristics of the two groups were comparable (all P>0.05). 2) The vaginal bleeding volume was lower in the study group [(13.30±12.14) mL] than in control group [(19.00±17.67) mL, P<0.001]. The proportion of subjects in the study group with bleeding days less than 4 d [29.65% (67/226)] was higher than that in control group [19.20% (43/224), P=0.010]. 3) No significant differences were observed between the two groups in terms of time to menstrual recovery and endometrial thickness (all P>0.05). 4) In the study group, 3 subjects experienced non-therapeutic-related complications, while 11 subjects in control group. The incidence of complications was lower in the study group [1.29% (3/232)] than in control group [4.66% (11/236), P=0.033]. Conclusion:The administration of Gongxuening Capsules to women following artificial abortion significantly reduced vaginal bleeding volume and was associated with good safety, with the treatment being well-tolerated by the subjects.

Objective To synthesize high-quality synthetic CT (sCT) images from cone beam CT (CBCT) by learning lung CT domain image features with a deep learning algorithm. Methods A sCT generation algorithm which employs perceptual loss-based cyclic generative adversarial network model (CycleGAN) and iterative registration was presented. CycleGAN model was trained to generate high-quality sCT images by combining perceptual loss and cycle consistency loss;and Elastix was used to register the generated sCT image and the planned CT (pCT) image,and iterate CycleGAN generator model. Results Experiments were conducted on the obtained pCT and CBCT data of 70 patients with lung tumors. From a quantitative perspective,the SSIM between sCT generated by the proposed algorithm and pCT was improved by 11.9％ as compared with that between CBCT and pCT,increasing from 0.825 to 0.923;additionally,RMSE dropped from 110.97 HU to 78.62 HU,PSNR increased from 32.21 dB to 34.74 dB,and mutual information increased from 1.187 to 1.418. The visual evaluation revealed that the proposed algorithm greatly eliminated the scattering artifacts of CBCT slices,highlighted the bone structure,and repaired the soft tissue structure. The comparisons with U-CycleGAN,R-CycleGAN and CUT models confirmed the effectiveness of the proposed algorithm. Conclusion Using the proposed algorithm for sCT images generation can effectively reduce the dose error and structural error between CBCT and pCT,making it possible to apply the proposed algorithm to accurate dose calculations and assist doctors in clinical diagnosis.