Instrument separation is a critical complication during root canal therapy, impacting treatment success and long-term tooth preservation. The etiology of instrument separation is multifactorial, involving the intricate anatomy of the root canal system, instrument-related factors, and instrumentation techniques. Instrument separation can hinder thorough cleaning, shaping, and obturation of the root canal, posing challenges to successful treatment outcomes. Although retrieval of separated instrument is often feasible, it carries risks including perforation, excessive removal of tooth structure and root fractures. Effective management of separated instruments requires a comprehensive understanding of the contributing factors, meticulous preoperative assessment, and precise evaluation of the retrieval difficulty. The application of appropriate retrieval techniques is essential to minimize complications and optimize clinical outcomes. The current manuscript provides a framework for understanding the causes, risk factors, and clinical management principles of instrument separation. By integrating effective strategies, endodontists can enhance decision-making, improve endodontic treatment success and ensure the preservation of natural dentition.
Humans ; Root Canal Therapy/adverse effects* ; Consensus ; Root Canal Preparation/adverse effects*

Objective:To evaluate the disinfection effect of high-energy pulse ultraviolet disinfection equipment in medical institution settings.Methods:The disinfection effect was evaluated through field tests and laboratory tests. Among them, 135 high-frequency contact points were selected from nine departments in the field test. Samples were collected before and after disinfection, and the disinfection effects of 75% alcohol wipes wiping disinfection, high-energy pulse ultraviolet disinfection robot disinfection and high-energy pulse ultraviolet handheld disinfection instrument were compared. In the laboratory test, 30 infected areas of the simulated test table were exposed to vertical ultraviolet irradiation and the bacterial-killing rate before and after disinfection was calculated.Results:In the field test, the bacteria-killing rates of 75% alcohol wipes, high-energy pulse ultraviolet disinfection robot and high-energy pulse ultraviolet handheld disinfection instrument were 94.99%, 91.53% and 95.94%, respectively, and the difference was statistically significant. The disinfection effect of the high-energy pulse ultraviolet handheld disinfection instrument was better than that of the high-energy pulse ultraviolet disinfection robot ( P values <0.05). In the laboratory test, the killing log value of Staphylococcus aureus and Escherichia coli on the carrier were both greater than 3.00. In the simulated field test, the killing log value of Staphylococcus aureus on the surface samples were 4.99. Conclusion:Both the high-energy pulse ultraviolet handheld disinfection instrument and the high-energy pulse ultraviolet disinfection robot have good disinfection effects, which are similar to the disinfection effects of conventional 75% alcohol wipes.

Objective To explore the molecular epidemiological characteristics of carbapenem-resistant Klebsiella pneumoniae(CRKP),and reveal its mechanism of resistance to ceftazidime/avibactam(CZA).Methods CZA-re-sistant CRKP strains initially isolated from the Affiliated Hospital of Xuzhou Medical University from January 2021 to September 2023 were collected.The carriage of 5 carbapenemase genes(blaKPC,blaNDM,blaOXA,blaVIM,blaIMp)were detected with gene amplification method and colloidal gold method.The relative copy number and expression level of Klebsiella pneumoniae(KP)carbapenemase-producing KP(KPC-KP)was detected with real-time quantita-tive polymerase chain reaction(RT-qPCR),mutation sites of KPC mutation strains were analyzed with whole-ge-nome sequencing,and epidemic characteristics of CRKP and resistance mechanism to CZA were analyzed.Results A total of 73 CZA-resistant CRKP strains were isolated,with 37(50.68％)being KPC and NDM co-producing strains,33(45.21％)NDM-producing alone(23 strains producing NDM-5 and 10 strains producing NDM-1),and 3 KPC-producing alone.KP-2842 strain was identified as ST11-type KPC-33 variant,KP-2127 and KP-2189 strains produced KPC-2.Compared with KP ATCC BAA-1705,the copy number of blaKPC in these strains up-regulated by 1.04-3.86 fold,and the expression increased by 6.66-12.93 fold,respectively.Colloidal gold and PCR methods demonstrated good consistency and the ability to detect the enzyme co-producing and KPC-33 variant.Conclusion In this hospital,the resistance of CRKP to CZA is primarily mediated by the metalloenzyme NDM,with co-produc-tion of NDM and KPC being a characteristic of CRKP.High copy number and expression level of blaKPC-2 also con-tribute to CZA resistance.This study identified the KPC-33 variant for the first time in ST11-type CRKP in Jiangsu Province.

Objective:To evaluate the disinfection effect of high-energy pulse ultraviolet disinfection equipment in medical institution settings.Methods:The disinfection effect was evaluated through field tests and laboratory tests. Among them, 135 high-frequency contact points were selected from nine departments in the field test. Samples were collected before and after disinfection, and the disinfection effects of 75% alcohol wipes wiping disinfection, high-energy pulse ultraviolet disinfection robot disinfection and high-energy pulse ultraviolet handheld disinfection instrument were compared. In the laboratory test, 30 infected areas of the simulated test table were exposed to vertical ultraviolet irradiation and the bacterial-killing rate before and after disinfection was calculated.Results:In the field test, the bacteria-killing rates of 75% alcohol wipes, high-energy pulse ultraviolet disinfection robot and high-energy pulse ultraviolet handheld disinfection instrument were 94.99%, 91.53% and 95.94%, respectively, and the difference was statistically significant. The disinfection effect of the high-energy pulse ultraviolet handheld disinfection instrument was better than that of the high-energy pulse ultraviolet disinfection robot ( P values <0.05). In the laboratory test, the killing log value of Staphylococcus aureus and Escherichia coli on the carrier were both greater than 3.00. In the simulated field test, the killing log value of Staphylococcus aureus on the surface samples were 4.99. Conclusion:Both the high-energy pulse ultraviolet handheld disinfection instrument and the high-energy pulse ultraviolet disinfection robot have good disinfection effects, which are similar to the disinfection effects of conventional 75% alcohol wipes.

Mesenchymal stem cells (MSCs) have been officially approved in many countries to treat graft-versus-host disease, autoimmune disorders and those associated with tissue regeneration after hematopoietic stem cell transplantation. Studies in recent years have confirmed that MSC acts mainly through paracrine mechanism, in which extracellular vesicles secreted by MSC (MSC-EV) play a central role. MSC-EV has overwhelming advantages over MSC itself in the setting of adverse effects in clinical application, indicating that MSC-EV might take the place of its parent cells to be a potentially therapeutic tool for "cell-free therapy". The pharmaceutical properties of MSC-EV largely depend upon the practical and optimal techniques including large-scale expansion of MSC, the modification of MSC based on the indications and the in vivo dynamic features of MSC-EV, and the methods for preparing and harvesting large amounts of MSC-EV. The recent progresses on the issues above will be briefly reviewed.
Humans ; Extracellular Vesicles ; Hematopoietic Stem Cell Transplantation/adverse effects* ; Mesenchymal Stem Cell Transplantation/methods* ; Mesenchymal Stem Cells ; Pharmaceutical Preparations

Alcoholic liver disease (ALD) results from continuous and heavy alcohol consumption. The current treatment strategy for ALD is based on alcohol withdrawal coupled with antioxidant drug intervention, which is a long process with poor efficacy and low patient compliance. Alcohol-induced CYP2E1 upregulation has been demonstrated as a key regulator of ALD, but CYP2E1 knockdown in humans was impractical, and pharmacological inhibition of CYP2E1 by a clinically relevant approach for treating ALD was not shown. In this study, we developed a RNAi therapeutics delivered by lipid nanoparticle, and treated mice fed on Lieber-DeCarli ethanol liquid diet weekly for up to 12 weeks. This RNAi-based inhibition of Cyp2e1 expression reduced reactive oxygen species and oxidative stress in mouse livers, and contributed to improved ALD symptoms in mice. The liver fat accumulation, hepatocyte inflammation, and fibrosis were reduced in ALD models. Therefore, this study suggested the feasibility of RNAi targeting to CYP2E1 as a potential therapeutic tool to the development of ALD.

Inductively coupled plasma mass spectrometry (ICP-MS) was applied to determine the concentrations of lead (Pb), cadmium (Cd) and arsenic (As) in Lindera aggregata (Sims) Kosterm. The physiologically based extraction test (PBET) digestion in vitro/Caco-2 cell model was established to investigate the bioaccessible contents of Pb, Cd and As in decoction of Lindera aggregata (Sims) Kosterm. The target-organ toxicity dose modification of HI method (TTD) was used to evaluate the cumulative risk caused by the combined exposure of the total levels of Pb, Cd and As in Lindera aggregata (Sims) Kosterm. and the bioaccessible contents in the decoction. The results showed that the total contents of Pb, Cd and As in 4 batches of samples were in the range of 2.901-3.872, 1.299-1.800 and 0.062-0.216 mg·kg^-1, respectively. After transportation by Cacco-2 cells, the bioaccessible contents of Pb, Cd, and As in the decoction were in the range of 0.045-0.080, 0.070-0.112 and 0.004-0.018 mg·kg^-1. The results of risk assessment showed that calculated by the total amounts of heavy metals in the Lindera aggregata (Sims) Kosterm., for the end points of nervous system, the cumulative risks of co-exposure of heavy metals in 3 batches of samples were of concern. After decoction and transportation by Caco-2 cells, for the end points of cardiovascular system, blood, nervous system, kidney and testis, the TTD modification of HI values of all batches of samples were less than 1, and the health risks were acceptable. The study provided methodology basis for a more objective assessment of the health risks of heavy metals and harmful elements in traditional Chinese medicine and for a more scientific limit standard of heavy metals and harmful elements.

Background As one of the common tools for job burnout assessment, Maslach Burnout Inventory-General Survey (MBI-GS), its reliability and validity across different populations in China have not been examined yet. Objective To evaluate the reliability and validity of General Burnout Scale (GBS) by multiple occupational groups through the translation and preliminary test of MBI-GS. Methods Based on the Special Project of Occupational Hazards in Key Populations led by the Institute of Occupational Health and Poison Control, China CDC, key occupational groups in five typical industries were selected by multi-stage stratified cluster sampling, including teachers, firefighters, manufacturing workers, medical staff, and traffic police. Confirmatory factor analysis (CFA) was used to evaluate the construct validity of GBS by single-factor, two-factor, and three-factor structure models. The model fitness was assessed by ratio of the chi-square statistic to the respective degrees of freedom (χ²/ν), root mean square error of approximation (RMSEA), goodness-of-fit index (GFI), comparative fit index (CFI), and parsimony-adjusted non-normed fit index (PNFI). Spearman correlation analysis was used to calculate the criterion validity of GBS with occupational stress, depressive symptoms, and sleep disorders. Cronbach's α coefficient and composite reliability (CR) coefficient were used to evaluate the internal consistency reliability of GBS. Results A total of 3485 subjects were surveyed in this study, 3375 valid questionnaires were recovered with a valid response rate of 96.84%. The results of CFA showed that in the adjusted three-factor structure model of GBS (exhaustion, cynicism, and professional efficacy), the χ²/ν < 4, the RMSEA ranged from 0.032 to 0.069, the GFI > 0.90, the CFI > 0.90, and the PNFI > 0.70, which illustrated a good fitness than that of the single- or the two-factor structure models in different occupational groups. The Spearman correlation analysis results showed that occupational stress, depressive symptoms, and sleep disorders were positively correlated with exhaustion and cynicism dimensions, and negatively correlated with professional efficacy dimension of the GBS, with the \begin{document}$ \left| r \right| $\end{document} ranging from 0.139 to 0.662 (P<0.05) in overall subjects. For traffic police and firefighters, professional efficacy was not correlated with depressive symptoms or sleep disorders (P>0.05). The Cronbach's α coefficients ranged from 0.819 to 0.899, and the CR values ranged from 0.941 to 0.978 in different occupational groups. Conclusion The GBS shows high reliability and validity, as well as good application effects in different occupational groups.

Background Healthcare workers suffer from great internal and external pressure and are prone to burnout. Existing studies have shown that depressive symptoms are important influencing factors of burnout, both of which are closely related to job stress. Objective To analyze overall prevalence of burnout among healthcare workers using a new survey tool developed by our team, and to reveal potential influencing factors related to burnout. Methods A cross-sectional multi-center study was conducted in August–October 2019 and June–September 2020, using multi-stage stratified cluster sampling. A total of 8738 healthcare workers from 22 hospitals in 5 provinces (Shandong, Hubei, Hunan, Guangdong, and Chongqing) of China were selected in this study. A set of survey questionnaires, including the general information questionnaire and the Chinese versions of General Burnout Scale, Core Occupational Stress Scale, Patient Health Questionnaire-9, and Self-administered Sleep Questionnaire were distributed. Independent samples t-test or one-way ANOVA were employed for inter-group comparison of burnout. Spearman correlation was used to evaluate correlations among burnout, depressive symptoms, and occupational stress. Stepwise linear regression was conducted to identify factors independently associated with burnout. Process plug-in was used to test potential mediating effect of depressive symptoms on occupational stress and burnout. Results Of the 8738 questionnaires distributed, 8456 valid questionnaires were collected, and the recovery rate was 96.77%. Among the 8456 healthcare workers, the prevalence of burnout was 58.0%, that of occupational stress was 31.8%, and that of depressive symptoms was 31.0%. Among those with depressive symptoms and occupational stress, the proportions of burnout were 86.7% and 83.7%, respectively. According to the stepwise linear regression analysis, depressive symptoms, occupational stress, work experience, drinking, and marital status were all independent influencing factors of burnout. Especially, depressive symptoms, social support, and organization and reward had significant influences on burnout (b'=0.455, −0.183, 0.220, P<0.001). Depressive symptoms showed mediating effects on occupational stress (and its subscales) and burnout, and the contribution rates of the mediating effects were 41.00%, 47.02%, 43.44%, 56.62%, and 59.45%, respectively. Conclusion Burnout is a prominent problem among healthcare workers in the 5 provinces, with the prevalence of 58.0%. And nearly 1/3 suffering from depressive symptoms and occupational stress, which has a great impact on burnout.