Objective:To investigate the clinical distribution characteristics changes in antimicrobial resistance, and carbapenemase resistance genes of Klebsiella pneumoniae isolated from children in Chongqing region during the period of January 2019 to December 2024, providing a basis for the rational use of antibiotics and the prevention and control of nosocomial infections.Methods:An observational study was conducted to retrospectively analyze 5 020 Klebsiella pneumoniae (KP) isolates detected in four hospitals of the Southwest Pediatric Laboratory Specialty Alliance. Antimicrobial susceptibility testing was performed by the minimum inhibitory concentration method combined with the disk diffusion method. Results were interpreted according to the 2024 Clinical and Laboratory Standards Institute (CLSI) standards. Carbapenemase resistance genes were detected by polymerase chain reaction (PCR) combined with Sanger sequencing. WHONET 5.6 was used for resistance analysis and SPSS 19.0 for statistical analysis. The chi-square test was used to assess trends in resistance rates, ESBL detection rates, and resistance rates of different CRKP carbapenemase genotypes from 2019 to 2024. Statistical significance was confirmed if the two-tailed P-value was <0.05. Results:A total of 5 020 strains were isolated, with a detection rate of 5.1% (5 020/99 063). The majority were from sputum (59.2%, 2 970/5 020), followed by pus (17.1%, 857), urine (9.7%, 487), venous blood (6.5%, 326), secretions (2.6%, 130), and other specimens (5.0%, 250).The lowest resistance rate was to amikacin (3.8%), followed by levofloxacin (10.9%), imipenem (19.1%), and meropenem (19.9%). Resistance rates to cefoperazone/sulbactam ( χ2=9.982 0, P=0.001 6), piperacillin/tazobactam ( χ2=10.110 0, P=0.001 5), ceftazidime ( χ2=3.849 0, P=0.049 8), cefotaxime ( χ2=7.605 0, P=0.005 8), cefepime ( χ2=13.510 0, P=0.000 2), aztreonam ( χ2=6.457 0, P=0.011 1), imipenem ( χ2=4.672 0, P=0.030 7), and levofloxacin ( χ2=7.555 0, P=0.006 0) showed an annual increasing trend. The main carbapenemase genes were blaNDM-5 (42.2%, 127/301), blaNDM-1 (33.9%, 102/301), and blaKPC-2 (17.3%, 52/301). Patients with KPC-2-producing strains (median age, 240 days) were older than those with NDM-1/NDM-5-producing strains (median age, 40 days) ( χ2=22.620 0, P<0.000 1). In neonatal wards, the detection rate of NDM-KP was higher than that of KPC-KP (64.6%, 148/229 vs. 26.9%, 14/52, χ2=24.680 0, P<0.000 1), whereas in ICUs, it was lower (6.1%, 14/229 vs. 26.9%, 14/52, χ2=20.450 0, P<0.000 1). Conclusion:In Chongqing region, the isolation rate of K. pneumoniae from sputum was the highest with most cases from neonatal wards. Resistance to carbapenems showed an upward trend. BlaNDM-5 was the predominant genotype in pediatric CRKP. Patients with KPC-KP were older than those with NDM-KP. NDM-KP predominated in neonatal wards, while KPC-KP predominated in ICUs, with KPC-KP showing higher antimicrobial resistance.

BACKGROUND:Dental follicle cells are widely used in periodontal tissue regeneration engineering because of their excellent characteristics.With the development of biological scaffold materials,their relationship with periodontal tissue regeneration technology is increasingly close.OBJECTIVE:To review the performance of ivory follicle cells under the influence of internal and external biological factors by different experiments,and analyze their effects on the biological characteristics of dental follicle cells with scaffold materials.METHODS:Using"dental follicle cell,scaffolds,material,periodontal tissue regeneration,tissue engineering,review"as English and Chinese key words,the articles published in PubMed,Sciencedirect,and CNKI from 2013 to 2023 were searched,and finally 95 articles were included for analysis and discussion.RESULTS AND CONCLUSION:(1)Dental follicle cells originate from dental follicle tissue,which has certain stem cell differentiation potential.Because of its excellent performance,it is actively used in periodontal tissue regeneration engineering research.(2)The proliferation and osteogenic differentiation of dental follicle cells are affected by many biological factors,and both endogenous and exogenous factors can promote the proliferation and osteogenic differentiation of dental follicle cells to a certain extent.(3)3D printing technology and nanotechnology enable researchers to manufacture more suitable scaffold materials.(4)Polymer materials show us their flexibility and plasticity in periodontal tissue regeneration.We can manufacture targeted scaffold materials according to different defect sites to achieve efficient tissue regeneration.The good biocompatibility of inorganic materials makes them widely used in periodontal tissue regeneration engineering.By adjusting the content of nanoscale inorganic materials or improving the performance of scaffolds,scaffolds with better biocompatibility can be prepared.(5)There are many new synthetic(composite)materials,which show us excellent characteristics.However,because the mechanism of biological factors in scaffold materials on dental follicle cells is complicated,and the research on dental follicle cells is mostly concentrated on in vitro culture,so how to make scaffold materials more suitable for the growth and development of dental follicle cells and apply them safely and effectively in clinical treatment is the future research direction.

Objective:To investigate the clinical distribution characteristics changes in antimicrobial resistance, and carbapenemase resistance genes of Klebsiella pneumoniae isolated from children in Chongqing region during the period of January 2019 to December 2024, providing a basis for the rational use of antibiotics and the prevention and control of nosocomial infections.Methods:An observational study was conducted to retrospectively analyze 5 020 Klebsiella pneumoniae (KP) isolates detected in four hospitals of the Southwest Pediatric Laboratory Specialty Alliance. Antimicrobial susceptibility testing was performed by the minimum inhibitory concentration method combined with the disk diffusion method. Results were interpreted according to the 2024 Clinical and Laboratory Standards Institute (CLSI) standards. Carbapenemase resistance genes were detected by polymerase chain reaction (PCR) combined with Sanger sequencing. WHONET 5.6 was used for resistance analysis and SPSS 19.0 for statistical analysis. The chi-square test was used to assess trends in resistance rates, ESBL detection rates, and resistance rates of different CRKP carbapenemase genotypes from 2019 to 2024. Statistical significance was confirmed if the two-tailed P-value was <0.05. Results:A total of 5 020 strains were isolated, with a detection rate of 5.1% (5 020/99 063). The majority were from sputum (59.2%, 2 970/5 020), followed by pus (17.1%, 857), urine (9.7%, 487), venous blood (6.5%, 326), secretions (2.6%, 130), and other specimens (5.0%, 250).The lowest resistance rate was to amikacin (3.8%), followed by levofloxacin (10.9%), imipenem (19.1%), and meropenem (19.9%). Resistance rates to cefoperazone/sulbactam ( χ2=9.982 0, P=0.001 6), piperacillin/tazobactam ( χ2=10.110 0, P=0.001 5), ceftazidime ( χ2=3.849 0, P=0.049 8), cefotaxime ( χ2=7.605 0, P=0.005 8), cefepime ( χ2=13.510 0, P=0.000 2), aztreonam ( χ2=6.457 0, P=0.011 1), imipenem ( χ2=4.672 0, P=0.030 7), and levofloxacin ( χ2=7.555 0, P=0.006 0) showed an annual increasing trend. The main carbapenemase genes were blaNDM-5 (42.2%, 127/301), blaNDM-1 (33.9%, 102/301), and blaKPC-2 (17.3%, 52/301). Patients with KPC-2-producing strains (median age, 240 days) were older than those with NDM-1/NDM-5-producing strains (median age, 40 days) ( χ2=22.620 0, P<0.000 1). In neonatal wards, the detection rate of NDM-KP was higher than that of KPC-KP (64.6%, 148/229 vs. 26.9%, 14/52, χ2=24.680 0, P<0.000 1), whereas in ICUs, it was lower (6.1%, 14/229 vs. 26.9%, 14/52, χ2=20.450 0, P<0.000 1). Conclusion:In Chongqing region, the isolation rate of K. pneumoniae from sputum was the highest with most cases from neonatal wards. Resistance to carbapenems showed an upward trend. BlaNDM-5 was the predominant genotype in pediatric CRKP. Patients with KPC-KP were older than those with NDM-KP. NDM-KP predominated in neonatal wards, while KPC-KP predominated in ICUs, with KPC-KP showing higher antimicrobial resistance.

BACKGROUND:Dental follicle cells are widely used in periodontal tissue regeneration engineering because of their excellent characteristics.With the development of biological scaffold materials,their relationship with periodontal tissue regeneration technology is increasingly close.OBJECTIVE:To review the performance of ivory follicle cells under the influence of internal and external biological factors by different experiments,and analyze their effects on the biological characteristics of dental follicle cells with scaffold materials.METHODS:Using"dental follicle cell,scaffolds,material,periodontal tissue regeneration,tissue engineering,review"as English and Chinese key words,the articles published in PubMed,Sciencedirect,and CNKI from 2013 to 2023 were searched,and finally 95 articles were included for analysis and discussion.RESULTS AND CONCLUSION:(1)Dental follicle cells originate from dental follicle tissue,which has certain stem cell differentiation potential.Because of its excellent performance,it is actively used in periodontal tissue regeneration engineering research.(2)The proliferation and osteogenic differentiation of dental follicle cells are affected by many biological factors,and both endogenous and exogenous factors can promote the proliferation and osteogenic differentiation of dental follicle cells to a certain extent.(3)3D printing technology and nanotechnology enable researchers to manufacture more suitable scaffold materials.(4)Polymer materials show us their flexibility and plasticity in periodontal tissue regeneration.We can manufacture targeted scaffold materials according to different defect sites to achieve efficient tissue regeneration.The good biocompatibility of inorganic materials makes them widely used in periodontal tissue regeneration engineering.By adjusting the content of nanoscale inorganic materials or improving the performance of scaffolds,scaffolds with better biocompatibility can be prepared.(5)There are many new synthetic(composite)materials,which show us excellent characteristics.However,because the mechanism of biological factors in scaffold materials on dental follicle cells is complicated,and the research on dental follicle cells is mostly concentrated on in vitro culture,so how to make scaffold materials more suitable for the growth and development of dental follicle cells and apply them safely and effectively in clinical treatment is the future research direction.

Objective:To characterize the biomechanics of distal dynamic locking and distal static locking of proximal femur bionic nails (PFBN) in fixation of intertrochanteric fractures by a finite element analysis.Methods:The CT image data from the hip to the upper tibia from an adult male volunteer were used to establish a three-dimensional model of the femur by Mimics 20.0 and Geomagic 2013 which was processed further into a model of Evans type I intertrochanteric fracture by software NX 12.0. With reference to the internal fixation parameters commonly used, 4 models of PFBN fixation were established: distal single transverse nail dynamic locking (model A), single oblique nail dynamic locking (model B), single nail static locking (model C) and double nail dynamic locking (model D). Abaqus 6.14 software was used to load and analyze the internal fixation stresses and displacements of fracture ends.Results:Under a 2100N loading, the peak stress was located upon the main nail in the 4 models. The smallest peak stress upon the main nail was in Model D (161.9 MPa), decreased by 15.9% compared with model A (192.5 MPa), by 15.6% compared with model B (191.9 MPa), and by 0.9% compared with model C (163.3 MPa). The peak stress upon the fixation screw was the largest in model A (95.3 MPa), the smallest in model B (91.5 MPa), and 91.5 MPa and 92.2 MPa in models C and D, respectively. The overall displacements of the implants, in a descending order, were 10.14 mm in model A, 10.10 mm in model B, 10.09 mm in model C, and 10.05 mm in model D. Similarly, the displacements of fracture ends were 0.125 mm in model A, 0.121 mm in model B, 0.110 mm in model C, and 0.098 mm in model D.Conclusion:Compared with dynamic locking, distal static locking of PFBN provides a better mechanical stability and reduces stress concentration upon internal fixation.

Pain is a defensive response to body injury or potential injury, and is also the most common clinical manifestations in orthopedic trauma. Pain is critical to determine the causes of injury and therapeutic plans in the diagnosis and treatment of orthopedic trauma. Post-traumatic acute and chronic pain not only brings physical pain to patients, but also induces a variety of complications. Moreover, improper evaluation and management of pain can easily lead to missed diagnosis and misdiagnosis, thus prolonging the treatment cycle and affecting the quality of life. At present, the management of pain has no normative standard in the diagnosis and management of orthopedic trauma. Academician Zhang Yingze′s team has summarized the pain characteristics of various orthopedic trauma patients, traced back to the sources, and conduced the innovative concept of "pain" to get the melon to address issues such as insufficient pain assessment, incomplete etiology analysis and inadequate diagnostic thinking, hoping to achieve rapid and accurate diagnosis and early treatment. The authors elaborate on the connotation of the innovative concept of "pain" to get the melon and its application in clinical orthopedic trauma, aiming to explore the application value of this innovative concept, achieve rapid and accurate diagnosis of orthopedic trauma and provide a reference for formulating reasonable diagnosis and treatment programs.

The occurrence and persistent pandemic of 2019 coronavirus pneumonia (COVID-19), caused by the infection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has taken a big toll on global public health. The development of virus detection techniques and its application played an important role in health management, including screening, identification and treatment of patients, and slowing down the spread of virus. This review briefly summarizes the biological characteristics of SARS-CoV-2, and introduces in detail the SARS-CoV-2 detection techniques developed and used worldwide. Perspectives on the follow-up development of virus detection techniques were presented, with the aim to facilitate medical diagnosis, public health protection, disease prevention and control.
COVID-19/diagnosis* ; Humans ; Pandemics/prevention & control* ; SARS-CoV-2

Objective To evaluate the application value of absorbable hemostat textile as submucosal injection of endoscopic submucosal dissection(ESD). Methods Twelve New Zealand rabbits were injected with absorbable hemostat textile solution,glycerol fructose and normal saline. The uplift effect was measured after injection. Simulated ESD was performed in the rabbit stomach and bleeding amount was measured. The injection site was pathologically examined at 30 minutes after the soluble hemostat textile and normal saline were injected. Fifteen pigs were injected with absorbable hemostat textile at two locations of 20-30 cm from the anus,and injected normal saline at another two locations of 20-30 cm from the anus.One site was performed simulated ESD and the other was not. Fifteen simulated ESD were performed in the soluble hemostatic group and the normal saline group, respectively. Operation time was recorded and difference in wound healing was compared between the two groups. Results In the uplift experiment, the absorbable hemostat textile group had higher uplift height(4.3±1.4 mm,4.1±1.9 mm,3.8±0.7 mm, 3.3±0.9 mm, respectively)at 0 min,10 min,20 min,30 min than that of the glycerol fructose group(4.3±2.2 mm,4.1± 2.0 mm,3.6±1.4 mm, 3.2±0.8 mm, respectively, P<0.05), and the glycerol fructose group was higher than that of the normal saline group(3.8±1.6 mm,2.6±1.4 mm,1.9±1.9 mm,1.1±0.7 mm, P<0.05). There was no significant difference in uplift height between the absorbable hemostat textile group and the glycerol fructose group(P>0.05). In the bleeding experiment, the bleeding amount of absorbable hemostat textile group was significantly less than that of the glycerol fructose group(0.36±0.07 mL VS 0.42±0.06 mL, P<0.05);the bleeding amount of glycerol fructose group was significantly lower than that of the normal saline group(0.42±0.06 mL VS 0.55±0.07 mL,P<0.05). There was no obvious tissue necrosis and other adverse complications in the absorbable hemostat textile group and the normal saline group. In simulated ESD experiment,complete resection rate of the absorbable hemostat textile group was higher than that of the normal saline group[86.7%(13/15)VS 46.7%(7/15), P<0.05], and mean operation time of the absorbable hemostat textile group was less than that of the normal saline group(3.2± 0.3 min VS 3.8± 0.5 min, P<0.05). No hemorrhage, perforations or other related adverse events occurred in non-ESD lesions. Conclusion Absorbable hemostat textile is safe and effective as submucosal injection of ESD.

302 teeth with wedge-shaped defect in 168 patients were restored by SDR(smart dentin replacement,n =112),glass ionomer (n =98) and light-cured composite resin(n =92) respectively.12 to 15 month follow-up showed the success rate was 96.2％,84.8％ and 86.2％ respectively(P ＜ 0.01).SDR is an ideal material in restoring wedge-shaped defect.

OBJECTIVE: To investigate the epithelial-mesenchymal transition(EMT) induced by direct or indirect exposure to free silicon dioxide(SiO_2) and the expression of surface protein marker in rat typeⅡalveolar epithelial cell RLE-6TN.METHODS: i) The alveolar macrophages(AM) were isolated from specific pathogen-free SD rat by bronchoalveolar lavage.AM and RLE-6TN were treated with 0-140 mg/L(final concentration) of SiO_2 suspension and were cultured conventionally for 24,48 and 72 hours. The cell viability was detected by CCK-8 assay. The result of CCK-8 essay was used to choose the SiO_2 concentration for the following study. ii) To establish models of RLE-6TN co-cultured with AM that were seeded in Transwell. The cells were divided into 4 groups: the direct control group(RLE-6TN,no SiO_2 exposed),the direct exposure group(RLE-6TN,treated with 100 mg/L SiO_2),the indirect control group(RLE-6TN and AM were cocultured,no SiO_2 exposed) and the indirect exposure group(RLE-6TN and AM were co-cultured,AM was treated with 100 mg/L SiO_2 directly). Western blotting was used to detect the expression of E-cadherin(E-cad) and α-smooth muscle protein(α-SMA) after cells were cultured for 0,24,48 and 72 hours. RESULTS: i) According to the CCK-8 assay,the final concentration of 100 mg/L SiO_2 was chosen for the following study. ii) The difference of relative expression of E-cad andα-SMA in RLE-6TN was statistically significant in different treatment combination and time(P < 0. 01). The E-cad expression of RLE-6TN at 48 and 72 hours in the direct exposure group and the indirect exposure group was lower than that in direct control group at the same time point(P < 0. 05). The E-cad expression in RLE-6TN at 72 hours in the direct exposure group was lower than that in the 0 and 24 hours(P < 0. 05). The E-cad expression in RLE-6TN at 48 and 72 hours in the indirect exposure group was lower than that in the 0 hour(P < 0. 05). At 48 and 72 hours,the α-SMA expression in the indirect exposure group and the direct exposure group was higher than that in their control groups at the same time point(P < 0. 05). The expression of α-SMA in the indirect exposure group was higher than that in the direct exposure group(P < 0. 05). The expression of α-SMA in both exposure groups increased in a time-effect relationship(P <0. 05). CONCLUSION: Direct or indirect exposure to free SiO_2 can induce EMT in RLE-6TN,and decrease the expression of E-cad and increase the expression of α-SMA in a time-effect relationship. Indirect exposure group is more susceptible to EMT.