Objective:To evaluate the effects of several kinds of surface treatment methods on the bond strength of zirconia prosthesis,and to provide references for improving the bond strength of zirconia prosthesis.Methods:Sixty zirconia blocks(10 mm×10 mm×2 mm) were divided into 6 groups according to the surface treatment methods:sandblasting,silica coating,Z-PRIME Plus,sandblasting+Z-PRIME Plus,sandblasting+silica coating,and silica coating+Z-PRIME Plus groups.The zirconia-resin specimens were fabricated using ScotchbondTM Universal;shear bond test was performed to detect the shear bond strength after treated with water storage(37℃) for 24 h by universal mechanical testing mechine;the fracture types were observed by stereoscopic microscope.One fracture specimen was randomly chosen from each group,and the morphology of the specimen was examined under scanning electron microscope.Results:The shear bond strength of the specimen in Z-PRIME Plus group was higher than those in the other groups(P<0.05).The adhesive failure was predominantly observed in sandblasting,silica coating,sandblasting+silica coating and silica coating+Z-PRIME Plus groups.There were 4 cases of mixed failure in Z-PRIME Plus group and there were 8 cases of mixed failure in sandblasting+Z-PRIME group.No cohesive failure was observed in all the groups.The scanning electron microscope results showed that the fracture surface occurred on the resin-zirconia interface of the specimens in sandblasting group,Z-PRIME Plus group,and sandblasting+Z-PRIME Plus group.The silica-zirconia fracture of specimens occurred in silica coating group and silica coating+Z-PRIME Plus group.The silica-resin interface fracture of specimens partially occurred in sandblasting+silica coating group.Conclusion:The application of Z-PRIME Plus can significantly improve the bond strength between zirconia and resin.

BACKGROUND:Although several prosthetic methods, such as artificial denture and dental implants, are clinical therapies to tooth loss, they are thought to have safety and usage time issues. With the development of biological and biomaterial sciences, recently, tooth tissue engineering has attracted more and more attention.
OBJECTIVE:To reflect advances and problems of tissue engineering technologies for promotion of tooth regeneration.
METHODS:Using the keywords of“tissue engineering, tooth regeneration”in English and Chinese, PubMed and CNKI databases from 2007 to 2013 were retrieved. A total of 65 literatures addressing tooth regeneration and tissue engineering were col ected, including 25 Chinese articles and 40 English articles. Published early, repetitive, and similar researches were excluded. Final y, 48 articles were included.
RESULTS AND CONCLUSION:The combination of stem cells and suitable scaffolds is widely used in tooth regeneration today, and growth factors or bone marrow which can produce promote tooth regeneration are added as wel , which has achieved partial or whole tooth regeneration. But there are apparent deficiencies in studies which focus on mechanisms behind tooth regeneration.

ObjectiveTo investigate the risk factors for failure in emergency endoscopic injection sclerotherapy (EIS) combined with sequential histoacryl injection (HI) for esophagogastric variceal bleeding (EGVB) with portal vein embolus (PVE). MethodsA total of 109 EGVB patients with PVE who underwent emergency gastroscopy in Beijing Shijitan Hospital, Capital Medical University, and The Fifth Medical Center of Chinese PLA General Hospital from January 2018 to December 2019 were enrolled, and according to the outcome of hemostatic treatment under emergency gastroscopy, the patients were divided into hemostatic failure group with 28 patients and hemostatic success group with 81 patients. The two groups were compared in terms of general information, varices and bleeding manifestations under gastroscopy, blood biochemical parameters, Child-Pugh class, and Model for End-Stage Liver Disease (MELD) score, and the risk factors for hemostatic failure were analyzed. The t-test or the Mann-Whitney U test was used for comparison of continuous data between groups, and the chi-square test was used for comparison of categorical data between groups; a logistic regression analysis was used for multivariate analysis. ResultsCompared with the hemostatic success group, the hemostatic failure group had significantly higher peripheral white blood cell count (WBC), total bilirubin (TBil), Child-Pugh class, and MELD score (Z=3.794, Z=4.751, χ2=40.104, Z=6.412, all P＜0001) and significantly lower prothrombin time activity (PTA), albumin (Alb), and cholinesterase (CHE) (t=9.653, Z=3.093, Z=4.092, P＜0.001, P=0.002, and P＜0.001). WBC (odds ratio ［OR］=28.543, 95% confidence interval ［CI］: 1.285-634.113, P＜0.05), PTA(OR=0.194, 95%CI: 0.045-0.835, P＜0.05), TBil (OR=2.197, 95%CI: 1.004-4.810, P＜0.05), Alb (OR=0448, 95%CI: 0.209-0.961, P＜0.05), and Child-Pugh class (OR=5.164, 95%CI: 1.307-20.406, P＜0.05) were independent risk factors for hemostatic failure. ConclusionWBC, PTA, TBil, Alb, and Child-Pugh class are independent risk factors for failure in emergency EIS combined with sequential HI in the treatment of EGVB with PVE, and adequate preoperative evaluation and correction may help to improve the success rate of hemostasis.

Objective:To investigate the bacterial composition and antimicrobial resistance profile of clinical isolates from bloodstream infections in China.Methods:The clinical bacterial strains isolated from blood culture were collected during January 2020 to December 2020 in member hospitals of Blood Bacterial Resistant Investigation Collaborative System (BRICS). Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical Laboratory Standards Institute(CLSI, USA). WHONET 5.6 was used to analyze data.Results:During the study period, 10 043 bacterial strains were collected from 54 hospitals, of which 2 664 (26.5%) were Gram-positive bacteria and 7 379 (73.5%) were Gram-negative bacteria. The top 10 bacterial species were Escherichia coli (38.6%), Klebsiella pneumoniae (18.4%), Staphylococcus aureus (9.9%), coagulase-negative Staphylococci (7.5%), Pseudomonas aeruginosa (3.9%), Enterococcus faecium (3.3%), Enterobacter cloacae (2.8%), Enterococcus faecalis (2.6%), Acinetobacter baumannii (2.4%) and Klebsiella spp (1.8%). The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative Staphylococcus aureus were 27.6% and 74.4%, respectively. No glycopeptide- and daptomycin-resistant Staphylococci were detected. More than 95% of Staphylococcus aureus were sensitive to rifampicin and SMZco. No vancomycin-resistant Enterococci strains were detected. Extended spectrum β-lactamase (ESBL) producing Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis were 48.4%, 23.6% and 36.1%, respectively. The prevalence rates of carbapenem-resistance in Escherichia coli and Klebsiella pneumoniae were 2.3% and 16.1%, respectively; 9.6% of carbapenem-resistant Klebsiella pneumoniae strains were resistant to ceftazidime/avibactam combination. The prevalence rate of carbapenem-resistance in Acinetobacter baumannii was 60.0%, while polymyxin and tigecycline showed good activity against Acinetobacter baumannii. The prevalence rate of carbapenem-resistance of Pseudomonas aeruginosa was 23.2%. Conclusions:The surveillance results in 2020 showed that the main pathogens of bloodstream infection in China were gram-negative bacteria, while Escherichia coli was the most common pathogen, and ESBL-producing strains declined while carbapenem-resistant Klebsiella pneumoniae kept on high level. The proportion and the prevalence of carbapenem-resistant Pseudomonas aeruginosa were on the rise slowly. On the other side, the MRSA incidence got lower in China, while the overall prevalence of vancomycin-resistant Enterococci was low.

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.

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.