BACKGROUND:Studies have shown that there are significant differences in the geometric morphology of the distal femur of different races and genders,and there are more short female patients in southern China,so the phenomenon of overhanging or insufficient coverage of imported knee prostheses often occurs during surgery. OBJECTIVE:To investigate the characteristics of distal femur bones in southern Chinese women and compare them with imported joint prostheses by simulating the three-dimensional reconstruction of the distal femur bone and matching the femoral side after osteotomy with common imported joint prostheses. METHODS:From January to December 2021,120 female volunteers underwent a CT scan of knee joints.The images were imported into Mimics 20.0 software in Dicom format for three-dimensional reconstruction and then imported into Magic 22.0 software to simulate osteotomy by posterior cruciate ligament preserved total knee arthroplasty and to conduct a matching study with a normal imported joint prosthesis. RESULTS AND CONCLUSION:(1)The functional anteroposterior dimension(fAP)of the distal femur and Persona matched prosthesis had a total overhang rate of 25%(30/120).The fAP≤47 mm group had an overhang than the other groups(P<0.05).The poor coverage rate of Triathlon prosthesis was 12.5%(15/120),and poor coverage was more likely in fAP>53 mm group than in fAP≤53 mm group(P<0.05).(2)The total poor coverage rate of femoral intercondylar width matching with Triathlon prosthesis was 27.5%(33/120).Therefore,the poor coverage rate of bone surface in the central region of the distal femur was more likely in the fAP≤47 mm group than in other groups(P<0.05).The overhang rate of Journey II was 21.6%(26/120),and the overhang rate was higher in the fAP>53 mm group than in the fAP≤53 mm group(P<0.05).(3)Journey II CR prosthesis had the largest difference with the length of the anterior mediolateral diameter of the femur,which was easy to hang out on the anterolateral side of the femoral prosthesis.The Persona CR prosthesis has the largest difference with the length of the posterior mediolateral diameter of the femur,which is easy to be poorly covered in the posterior medial part of the prosthesis.It is recommended to increase the femoral prosthesis with reduced mediolateral diameter in the fAP≤47 mm group and add wider and narrower sizes than the conventional size of intercondylar width,and optimize the anterolateral angular arc design of the femoral prosthesis to improve the matching of posterior cruciate ligament reserved knee prosthesis.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of national bloodstream infection Bacterial Resistant Investigation Collaborative System（BRICS）were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:During the study period，9 035 strains of Gram-negative bacteria were collected from 51 hospitals，of which 7 895（87.4%）were Enterobacteriaceae and 1 140（12.6%）were non-fermenting bacteria. The top 5 bacterial species were Escherichia coli（ n=4 510，49.9%）， Klebsiella pneumoniae（ n=2 340，25.9%）， Pseudomonas aeruginosa（ n=534，5.9%）， Acinetobacter baumannii complex（ n=405，4.5%）and Enterobacter cloacae（ n=327，3.6%）. The ESBLs-producing rates in Escherichia coli， Klebsiella pneumoniae and Proteus spp. were 47.1%（2 095/4 452），21.0%（427/2 033）and 41.1%（58/141），respectively. The prevalence of carbapenem-resistant Escherichia coli（CREC）and carbapenem-resistant Klebsiella pneumoniae（CRKP）were 1.3%（58/4 510）and 13.1%（307/2 340）；62.1%（36/58）and 9.8%（30/307）of CREC and CRKP were resistant to ceftazidime/avibactam combination，respectively. The prevalence of carbapenem-resistant Acinetobacter baumannii（CRAB）complex was 59.5%（241/405），while less than 5% of Acinetobacter baumannii complex was resistant to tigecycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa（CRPA）was 18.4%（98/534）. There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of main Gram-negative bacteria resistance among different regions，with statistically significant differences in the prevalence of CRKP and CRPA（ χ2=20.489 and 20.252， P<0.001）. The prevalence of CREC，CRKP，CRPA，CRAB，ESBLs-producing Escherichia coli and Klebsiella pneumoniae were higher in provinicial hospitals than those in municipal hospitals（ χ2=11.953，81.183，10.404，5.915，12.415 and 6.459， P<0.01 or <0.05），while the prevalence of CRPA was higher in economically developed regions（per capita GDP ≥ 92 059 Yuan）than that in economically less-developed regions（per capita GDP <92 059 Yuan）（ χ2=6.240， P=0.012）. Conclusions:The proportion of Gram-negative bacteria in bloodstream infections shows an increasing trend，and Escherichia coli is ranked in the top，while the trend of CRKP decreases continuously with time. Decreasing trends are noted in ESBLs-producing Escherichia coli and Klebsiella pneumoniae. Low prevalence of carbapenem resistance in Escherichia coli and high prevalence in CRAB complex have been observed. The composition ratio and antibacterial spectrum of bloodstream infections in different regions of China are slightly different，and the proportion of main drug resistant bacteria in provincial hospitals is higher than those in municipal hospitals.

BACKGROUND:Prosthesis restricted selection,soft tissue release,patellar trajectory recovery,and bone defect reconstruction were need to be optimized in total knee arthroplasty for moderate and severe valgus knee.The medial parapatellar approach has disadvantages in the treatment of valgus knee,such as aggravating the medial soft tissue relaxation.In recent years,it has been found that the lateral parapatellar approach has advantages in the treatment of valgus knee,such as exposure and release. OBJECTIVE:To observe the efficacy of the lateral and medial parapatellar approach in total knee arthroplasty for moderate and severe valgus knee,and to explore a more suitable surgical approach for moderate and severe valgus knee. METHODS:Totally 56 patients with moderate and severe valgus knee underwent total knee arthroplasty and would take turns performing surgery through the medial and lateral parapatellar approach according to the order of admission.The lateral group(n=28)underwent total knee arthroplasty through lateral parapatellar approach,and the medial group(n=28)through medial parapatellar approach.Posterior stablized knee prosthesis was used in all patients.The restricted types of prosthesis,thickness of polyethylene,operation time,amount of blood loss,femoro-tibia angle,patellar tilt angle,range of motion,Hospital for Special Surgery score,Western Ontario and McMaster Universities Arthritis Index(WOMAC)score,and complications were collected as observation indexes for statistical analysis. RESULTS AND CONCLUSION:(1)The utilization rate of condyle-restricted prosthesis in the lateral group was significantly lower than that in the medial group.The average thickness of polyethylene liner was lower,and the operation time was shorter in the lateral group compared with the medial group.There were significant differences between the two groups(P<0.05),and there was no significant difference in the amount of surgical bleeding.(2)56 patients were followed up for an average of 2-5 years.There were no signs of prosthesis loosening or bone resorption in all patients.The average patellar tilt angle and femoral tibial angle of the lateral group were lower than those of the medial group,and the average Hospital for Special Surgery score and WOMAC score of the lateral group were higher than those of the medial group,with significant differences(P<0.05).There was no significant difference in the range of motion of the knees between the two groups.(3)Incision fat liquefaction and calf intermuscular venous thrombosis occurred in one case in each group.No infection,poor incision healing,incisional hematoma,prosthesis dislocation,iatrogenic nerve injury,ectopic ossification,or periprosthesis fracture occurred during follow-up.(4)In conclusion,the treatment of moderate and severe valgus knee by lateral parapatellar approach can better protect the tension of the medial soft tissue of the knee,use less condylar restrictive prostheses,and have a more friendly patellar trajectory and higher postoperative function score.

177Lu-prostate specific membrane antigen(PSMA)radio-ligand therapy has been approved abroad for advanced prostate cancer and has been in several clinical trials in China.Based on domestic clinical practice and experimental data and referred to international experience and viewpoints,the expert group forms a consensus on the clinical application of 177Lu-PSMA radio-ligand therapy in prostate cancer to guide clinical practice.

Objective To explore the application value of test bolus combined with a high-flow rate injection scheme in improving the quality of thyroid CT enhancement images.Methods A total of 126 patients who underwent thyroid plain scan and enhanced CT were selected.Among them,63 underwent conventional examination methods(control group),while the remaining 63 patients received test bolus and high-flow rate injection scheme(experimental group).Objective evaluation included the signal-to-noise ratio(SNR),contrast-to-noise ratio(CNR),thyroid enhancement rate,thyroid parenchyma-cancer difference,artifact index(AI)of the two groups of arterial phase images,thyroid enhancement rate of the two groups of venous phase images,and contrast agent dose of the two groups were all compared.Statistical analysis was performed via independent sample t-test or Mann-Whitney U test.Subjective evaluation included the evaluation of thyroid display in two groups of arterial phase images was conducted via the 4-point method,followed by the implementation of the Mann-Whitney U test.Results The SNR,CNR,thyroid enhancement rate,thyroid parenchyma-cancer difference,and AI in the arterial phase images of the experimental group were all significantly superior to those of the control group(P＜0.05).There was no statistically significant difference in the thyroid enhancement rate in the venous phase between control group and experimental group(P＞0.05);The contrast agent dose of the experimental group was significantly lower than that of the control group(P＜0.01).The thyroid display score observed in the arterial phase images of the experimental group was significantly higher than that of the control group(P＜0.01).Conclusion Using a test bolus combined with a high-flow rate injection scheme can significantly improve the image quality of thyroid CT enhancement.

Objective:To investigate the biological effects of acute high-dose radon exposure on mice.Methods:BALB/c male mice aged 6 to 8 weeks were exposed once in an HD-3 ecological radon chamber with an average radon concentration of 7 × 10 5 Bq/m 3 for 10 h. Mice were weighed, their lung tissues and blood samples were collected at 1, 2 and 3 months after exposure. Control groups were set up at the three time points with four mice in each group. For these mice, the lung tissue pathology was observed using hematoxylin-eosin (HE) staining method, routine blood tests were conducted using a hematology analyzer and the levels of superoxide dismutase (SOD) and malondialdehyde (MDA) in the serum and lung tissues were measured using corresponding assay kits. Results:The HE staining result revealed that compared to the control groups, the experimental groups exhibited thickening of alveolar walls and increased infiltration of granulocyte, whose degrees, however, reduced over time and displayed no significant difference at 3 months after exposure. There was no significant difference in body weight or blood routine between the experimental and control groups. The detection result revealed decreased SOD levels in the lung tissues at 2 months after exposure, which were (11.34 ± 1.03) U/mgprot and (9.75 ± 0.71) U/mgprot, respectively for the control and experimental groups ( t = 2.54, P < 0.05). The MDA levels in lung tissue increased at 1 month after exposure, which were(2.30 ± 0.24) and (2.77 ± 0.29) nmol/mgprot, respectively for the control and experimental groups ( t = 2.49, P < 0.05). At 3 months after exposure, the SOD and MDA levels differed insignificantly between the control and experimental groups ( P > 0.05). Conclusions:After acute high-dose radon exposure, the mice suffered damage to the lung tissue, with changes in their oxidative stress indicators being detected. However, these effects gradually diminished at 3 months after exposure. Additionally, acute high-dose radon exposure did not give rise to significant changes in the body weight or routine blood result of the mice.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-positive bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-positive bacteria from blood cultures in member hospitals of National Bloodstream Infection Bacterial Resistant Investigation Collaborative System（BRICS）were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:A total of 3 163 strains of Gram-positive pathogens were collected from 51 member units，and the top five bacteria were Staphylococcus aureus（ n=1 147，36.3%），coagulase-negative Staphylococci（ n=928，29.3%）， Enterococcus faecalis（ n=369，11.7%）， Enterococcus faecium（ n=296，9.4%）and alpha-hemolyticus Streptococci（ n=192，6.1%）. The detection rates of methicillin-resistant Staphylococcus aureus（MRSA）and methicillin-resistant coagulase-negative Staphylococci（MRCNS）were 26.4%（303/1 147）and 66.7%（619/928），respectively. No glycopeptide and daptomycin-resistant Staphylococci were detected. The sensitivity rates of Staphylococcus aureus to cefpirome，rifampin，compound sulfamethoxazole，linezolid，minocycline and tigecycline were all >95.0%. Enterococcus faecium was more prevalent than Enterococcus faecalis. The resistance rates of Enterococcus faecium to vancomycin and teicoplanin were both 0.5%（2/369），and no vancomycin-resistant Enterococcus faecium was detected. The detection rate of MRSA in southern China was significantly lower than that in other regions（ χ2=14.578， P=0.002），while the detection rate of MRCNS in northern China was significantly higher than that in other regions（ χ2=15.195， P=0.002）. The detection rates of MRSA and MRCNS in provincial hospitals were higher than those in municipal hospitals（ χ2=13.519 and 12.136， P<0.001）. The detection rates of MRSA and MRCNS in economically more advanced regions（per capita GDP≥92 059 Yuan in 2022）were higher than those in economically less advanced regions（per capita GDP<92 059 Yuan）（ χ2=9.969 and 7.606， P=0.002和0.006）. Conclusions:Among the Gram-positive pathogens causing bloodstream infections in China， Staphylococci is the most common while the MRSA incidence decreases continuously with time；the detection rate of Enterococcus faecium exceeds that of Enterococcus faecalis. The overall prevalence of vancomycin-resistant Enterococci is still at a low level. The composition ratio of Gram-positive pathogens and resistant profiles varies slightly across regions of China，with the prevalence of MRSA and MRCNS being more pronounced in provincial hospitals and areas with a per capita GDP≥92 059 yuan.

Objective:To investigate the effects of transepithelial photorefractive keratectomy (TransPRK) and femtosecond small incision lenticule extraction (SMILE) on corneal biomechanics measured by the Ocular Response Analyzer in the early postoperative period.Methods:A cohort study was conducted.The right eyes of 56 patients who underwent TransPRK and 52 patients who underwent SMILE in Dalian Medical University Affiliated Dalian Third People's Hospital from November 2020 to June 2021 were continuously included.The postoperative follow-up was 3 months.The central corneal thickness (CCT) and keratometry (Km) were measured 1 month and 3 months after surgery.The corneal-compensated intraocular pressure (IOPcc), corneal resistance factor (CRF), corneal hysteresis (CH), and 19 repeatable mechanical infrared signal waveform parameters measured by the Ocular Response Analyzer were recorded before the surgery, 1 month and 3 months after the surgery, respectively.The measurement indexs at different time points between two groups were compared.This study adhered to the Declaration of Helsinki and the study protocol was approved by the Ethics Committee of Dalian Medical University Affiliated Dalian Third People's Hospital (No.2019-KT-010). Written informed consent was obtained from each patient before surgery.Results:There was no significant difference in CCT, Km, and IOPcc between the two groups at 1 month and 3 months after the surgery (all at P>0.05). In both groups, CRF, CH, p1area, p2area, p1area1, p2area1, w1, w2, w11, w21, h1, h2, h11, h21, dive1, dive2 and mslew1 were decreased, while path1, path2, path11, and aplhf were increased at 1 month after the surgery compared with before surgery, showing statistically significant differences (all at P<0.05). In both groups, CRF, CH, p1area, p2area, p1area1, p2area1, w1, w2, w11, w21, h1, h2, h11, h21, dive1 decreased, while path1, path2, path11, and aplhf were increased at 3 months after the surgery in comparison with before surgery, showing statistically significant differences (all at P<0.05). In SMILE group, the dive2 were decreased at 3 months after the surgery compared with before surgery, and the difference was statistically significant ( P<0.01). At 1 month after the surgery, p1area, p2area, p1area1, p2area1, w1, w2, w11, w21, dive1 and dive2 were higher, while CH, path1, path2, and path11 were smaller in TransPRK group than in SMILE group, showing statistically significant differences between them (all at P<0.05). At 3 months after the surgery, p1area, p2area, p1area1, p2area1, w1, w2, w11, w21, h2, h21, dive1 and dive2 were higher, while path1, path2, and path11 were smaller in TransPRK group than in SMILE group, showing statistically significant differences between them (all at P<0.05). Conclusions:Corneal biomechanics are weakened after both TransPRK and SMILE.In the early postoperative period, the mechanical infrared waveform parameters measured by the Ocular Response Analyzer are better after TransPRK than after SMILE.

Objective:To investigate the differences and changes in early postoperative visual quality after small incision lenticule extraction (SMILE) and smart pulse technology-assisted transepithelial photorefractive keratectomy (SPT-TransPRK).Methods:A cohort study was performed.A total of 92 patients (92 eyes) who underwent corneal laser refractive surgery were enrolled in Dalian Third People's Hospital Affiliated to Dalian Medical University from February 2021 to May 2021.The data from the right eye were collected for analysis.The patients were divided into SMILE group (40 patients, 40 eyes) and SPT-TransPRK group (52 patients, 52 eyes). Preoperative, 1- and 3-month postoperative visual acuity were measured to calculate the effectiveness, which was defined as the ratio of postoperative uncorrected visual acuity (UCVA) to preoperative best corrected visual acuity.Refraction was measured by an AR-1 autorefractor.Corneal higher-order aberration (HOA) including total HOA, spherical aberration and coma was measured by Sirius corneal topographer.Objective scatter index (OSI), modulation transfer function cut-off frequency (MTF cut-off), Strehl ratio (SR), simulated contrast visual acuity VA100 (day), VA20 (dusk) and VA9 (night) were measured via OQAS II visual quality analysis system.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of the Dalian Third People's Hospital Affiliated to Dalian Medical University (No.2019-KT-010). Written informed consent was obtained from each subject.Results:There was no significant difference in 3-month postoperative UCVA and effectiveness between the two groups ( Z=0.880, P=0.380; t=0.920, P=0.058). Patients in SPT-TransPRK group showed mild hyperopia 3 months after surgery.Preoperative, 1- and 3-month postoperative total corneal HOA was (0.47±0.18), (0.70±0.22) and (0.74±0.19)μm in SMILE group, and (0.40±0.14), (0.98±0.35) and (0.94±0.22)μm in SPT-TransPRK group respectively, showing statistically significant differences ( Fgroup=13.851, P=0.001; Ftime=29.960, P<0.001). Preoperative, 1- and 3-month postoperative spherical aberration was (-0.20±0.09), (-0.44±0.14) and (-0.44±0.15)μm in SMILE group, and (-0.20±0.10), (-0.71±0.23) and (-0.75±0.20)μm in SPT-TransPRK group respectively, showing statistically significant differences ( Fgroup=31.037, P<0.001; Ftime=48.005, P<0.001). The postoperative total corneal HOA and spherical aberration were increased in both groups compared with before surgery, with statistically significant differences (all at P<0.05). The 1- and 3-month postoperative total corneal HOA and spherical aberrations were smaller in SMILE group than in SPT-TransPRK group, and the differences were statistically significant (all at P<0.05). The 1- and 3-month postoperative coma were increased in both groups compared with before surgery, showing statistically significant differences (all at P<0.05). In SMILE group, 1-month postoperative OSI was higher and 1-month postoperative MTF cut-off, SR, and VA9 were lower than those before surgery, and 3-month postoperative OSI was higher and 3-month postoperative SR and VA9 were lower than those before surgery, showing statistically significant differences (all at P<0.05). In SPT-TransPRK group, 1-month postoperative OSI was higher and 1-month postoperative MTF cut-off, SR, VA100, VA20, and VA9 were lower than those before surgery, showing statistically significant differences (all at P<0.05). There was no significant difference in OSI, MTF cut-off, SR, VA100, VA20, and VA9 between 3 months postoperatively and before surgery in the SPT-TransPRK group (all at P>0.05). There was no significant difference in coma, OSI, MTF cut-off, SR, VA100, VA20, and VA9 between two groups (all at P>0.05). Conclusions:Both SMILE and SPT-TransPRK are effective methods for correcting myopia and they have comparable visual quality.Compared with SPT-TransPRK, corneal total HOA and spherical aberration are smaller after SMILE.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical bacterial isolates from bloodstream infections in China in 2021.Methods:The clinical bacterial strains isolated from blood culture from member hospitals of Blood Bacterial Resistant Investigation Collaborative System (BRICS) were collected during January 2021 to December 2021. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical Laboratory Standards Institute (CLSI). WHONET 5.6 was used to analyze data.Results:During the study period, 11 013 bacterial strains were collected from 51 hospitals, of which 2 782 (25.3%) were Gram-positive bacteria and 8 231 (74.7%) were Gram-negative bacteria. The top 10 bacterial species were Escherichia coli (37.6%), Klebsiella pneumoniae (18.9%), Staphylococcus aureus (9.8%), coagulase-negative Staphylococci (6.3%), Pseudomonas aeruginosa (3.6%), Enterococcus faecium (3.6%), Acinetobacter baumannii (2.8%), Enterococcus faecalis (2.7%), Enterobacter cloacae (2.5%) and Klebsiella spp (2.1%). The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative Staphylococcus aureus were 25.3% and 76.8%, respectively. No glycopeptide- and daptomycin-resistant Staphylococci was detected; more than 95.0% of Staphylococcus aureus were sensitive to ceftobiprole. No vancomycin-resistant Enterococci strains were detected. The rates of extended spectrum B-lactamase (ESBL)-producing isolated in Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis were 49.6%, 25.5% and 39.0%, respectively. The prevalence rates of carbapenem-resistance in Escherichia coli and Klebsiella pneumoniae were 2.2% and 15.8%, respectively; 7.9% of carbapenem-resistant Klebsiella pneumoniae was resistant to ceftazidime/avibactam combination. Ceftobiprole demonstrated excellent activity against non-ESBL-producing Escherichia coli and Klebsiella pneumoniae. Aztreonam/avibactam was highly active against carbapenem-resistant Escherichia coli and Klebsiella pneumoniae. The prevalence rate of carbapenem-resistance in Acinetobacter baumannii was 60.0%, while polymyxin and tigecycline showed good activity against Acinetobacter baumannii (5.5% and 4.5%). The prevalence of carbapenem-resistance in Pseudomonas aeruginosa was 18.9%. Conclusions:The BRICS surveillance results in 2021 shows that the main pathogens of blood stream infection in China are gram-negative bacteria, in which Escherichia coli is the most common. The MRSA incidence shows a further decreasing trend in China and the overall prevalence of vancomycin-resistant Enterococci is low. The prevalence of Carbapenem-resistant Klebsiella pneumoniae is still on a high level, but the trend is downwards.