BACKGROUND:The preparation of curved root canals is a difficult point in root canal treatment,and the main way used in clinical preparation for curved root canals is to gradually deepen the technique,but this technique is prone to lateral penetration when preparing curved root canals,resulting in treatment failure.In view of this situation,some scholars have proposed the use of touch activation technology to prepare,but there are few studies on the influence of this technology combined with different mechanical nickel-titanium instruments on the forming effect of curved root canals at home and abroad.OBJECTIVE:To observe the shaping effect of WaveOneGold,Trunatomy and M3-Pro mechanized nitinol device preparation root canal by using resin simulated root canal step-down technology and tactile controlled activation.METHODS:60 single-bending resin simulated root canals were divided into 6 groups(r=10)according to the random number table method according to the nitinol instrument used.The A1 group was prepared with step-down+WaveOneGold;the A2 group was prepared with step-down+Trunatomy,and the A3 group was prepared with step-down+M3-Pro.Tactile controlled activation+WaveOneGold was used for preparation in group B1;tactile controlled activation+Trunatomy was used for group B2,and tactile controlled activation+M3-Pro was used for preparation in group B3.After the preparation was completed,the pre-preparation and posterior root canal images are obtained using a dental surgical microscope.The root canal offset was analyzed before and after preparation.RESULTS AND CONCLUSION:(1)When WaveOneGold was used,the root canal deviation at 1,4,and 7 mm from the apex was smaller with the tactile controlled activation technique than with the step-down technique(P＜0.05);when Trunatomy was used,the root canal deviation at 6,8,and 10 mm from the apex was smaller with the tactile controlled activation technique than with the step-down technique(P＜0.05);when M3-Pro was used,the root canal deviation at 1,2,and 3 mm from the apex was smaller with the tactile controlled activation technique than with the step-down technique(P＜0.05).(2)When the step-down technique was used,the root canal deviation at 1,4,5,and 7 mm from the apex was smaller with the Trunatomy than with the other two files(P＜0.05),and the root canal deviation at 1,2,3,and 6 mm from the apex was larger with the M3-Pro machine-made nickel-titanium instrument than with the other two files(P＜0.05);when the tactile controlled activation technique was used,the root canal deviation at 2,5,6,8,and 9 mm from the apex after preparation with the Trunatomy file was smaller than that of the other two groups(P＜0.05),and the root canal deviation at 1,4,5,6,and 7 mm from the apex after preparation with the M3-Pro file was larger than that of the other two groups(P＜0.05).(3)The results showed that the three files could cause root canal deviation when preparing root canals.The three files combined with the tactile controlled activation technique could reduce the root canal deviation at some sites of the root canal.The root canal deviation at some sites of the Trunatomy file was less than that of the other two files.

BACKGROUND:The preparation of curved root canals is a difficult point in root canal treatment,and the main way used in clinical preparation for curved root canals is to gradually deepen the technique,but this technique is prone to lateral penetration when preparing curved root canals,resulting in treatment failure.In view of this situation,some scholars have proposed the use of touch activation technology to prepare,but there are few studies on the influence of this technology combined with different mechanical nickel-titanium instruments on the forming effect of curved root canals at home and abroad.OBJECTIVE:To observe the shaping effect of WaveOneGold,Trunatomy and M3-Pro mechanized nitinol device preparation root canal by using resin simulated root canal step-down technology and tactile controlled activation.METHODS:60 single-bending resin simulated root canals were divided into 6 groups(r=10)according to the random number table method according to the nitinol instrument used.The A1 group was prepared with step-down+WaveOneGold;the A2 group was prepared with step-down+Trunatomy,and the A3 group was prepared with step-down+M3-Pro.Tactile controlled activation+WaveOneGold was used for preparation in group B1;tactile controlled activation+Trunatomy was used for group B2,and tactile controlled activation+M3-Pro was used for preparation in group B3.After the preparation was completed,the pre-preparation and posterior root canal images are obtained using a dental surgical microscope.The root canal offset was analyzed before and after preparation.RESULTS AND CONCLUSION:(1)When WaveOneGold was used,the root canal deviation at 1,4,and 7 mm from the apex was smaller with the tactile controlled activation technique than with the step-down technique(P＜0.05);when Trunatomy was used,the root canal deviation at 6,8,and 10 mm from the apex was smaller with the tactile controlled activation technique than with the step-down technique(P＜0.05);when M3-Pro was used,the root canal deviation at 1,2,and 3 mm from the apex was smaller with the tactile controlled activation technique than with the step-down technique(P＜0.05).(2)When the step-down technique was used,the root canal deviation at 1,4,5,and 7 mm from the apex was smaller with the Trunatomy than with the other two files(P＜0.05),and the root canal deviation at 1,2,3,and 6 mm from the apex was larger with the M3-Pro machine-made nickel-titanium instrument than with the other two files(P＜0.05);when the tactile controlled activation technique was used,the root canal deviation at 2,5,6,8,and 9 mm from the apex after preparation with the Trunatomy file was smaller than that of the other two groups(P＜0.05),and the root canal deviation at 1,4,5,6,and 7 mm from the apex after preparation with the M3-Pro file was larger than that of the other two groups(P＜0.05).(3)The results showed that the three files could cause root canal deviation when preparing root canals.The three files combined with the tactile controlled activation technique could reduce the root canal deviation at some sites of the root canal.The root canal deviation at some sites of the Trunatomy file was less than that of the other two files.

Objective To explore the feasibility of phase-contrast CT for three-dimensional visualization of in vitro intrahepatic vessels and necrotic foci in mouse model of acute liver injury(ALI).Methods Six clean grade male wild-type C57BL/6 mice were randomly divided into model group and control group(each n=3).The mice in model group were fed with overdose of acetaminophen to induce ALI,while those in control group were fed with the same amount of distilled water.After 24 h,the mice were all sacrificed,the livers were harvested and then fixed and dehydrated.Phase-contrast CT images of in vitro liver were acquired,sectional and three-dimensional images were reconstructed.The effect of phase-contrast CT for displaying the outline of liver and internal vessels and necrotic foci were observed,the maximum diameter and volume of necrotic foci were quantitatively analyzed,and the results of phase-contrast CT were compared with pathological findings.Results The original projection and sectional images of phase-contrast CT clearly showed the outline of in vitro liver and internal vasculatures.Necrotic foci within the liver were found in model group,but not in control group.The findings of phase-contrast CT corresponded accurately to those of pathology.Three-dimensional reconstruction images of phase-contrast CT clearly displayed intrahepatic portal vein system and hepatic vein system in both groups,and discontinuous punctate necrotic foci within the liver were found in model group,mainly distributed around hepatic vein,with a median maximum diameter of 18.50 μm and a median volume of 5 870.11 μm3,but was not observed in control group.Conclusion Phase-contrast CT could be used in three-dimensional visualization of intrahepatic vessels and necrotic foci of in vitro liver in mouse model of ALI.

Objective To examine the changing prevalence and antimicrobial resistance profiles of Burkholderia cepacia in 52 hospitals across China from 2015 to 2021.Methods A total of 9 261 strains of B.cepacia were collected from 52 hospitals between January 1,2015 and December 31,2021.Antimicrobial susceptibility of the strains was tested using Kirby-Bauer method or automated antimicrobial susceptibility testing systems according to a unified protocol.The results were interpreted according to the breakpoints released in the Clinical & Laboratory Standards Institute(CLSI)guidelines(2023 edition).Results A total of 9 261 strains of B.cepacia were isolated from all age groups,especially elderly patients.The proportion was 11.1％(1 032 strains)in children,significantly lower than the proportion in adults.About half(46.5％,4 310/9 261)of the strains were isolated from patients at least 60 years old and 42.3％(3 919/9 261)of the strains were isolated from young adults.Most isolates(71.1％)were isolated from sputum and respiratory secretions,followed by urine(10.7％)and blood samples(8.1％).B.cepacia isolates were highly susceptible to the five antimicrobial agents recommended in the CLSI M100 document(33rd edition,2023).B.cepacia isolates showed relatively higher resistance rates to meropenem and levofloxacin.However,the resistance rates to ceftazidime,trimethoprim-sulfamethoxazole,and minocycline remained below 8.1％.The percentage of B.cepacia strains resistant to levofloxacin was the highest compared to other antibiotics in any of the three age groups(from 12.4％in the patients＜18 years old to 20.6％in the patients aged 60 years or older).Conclusions B.cepacia is one of the clinically important non-fermenting gram-negative bacteria.Accurate and timely reporting of antimicrobial susceptibility test results and ongoing antimicrobial resistance surveillance are helpful for rational prescription of antimicrobial agents and proper prevention and control of nosocomial infections.

Objective To summarize the changing prevalence of carbapenem resistance in Enterobacterales based on the data of CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021 for improving antimicrobial treatment in clinical practice.Methods Antimicrobial susceptibility testing was performed using a commercial automated susceptibility testing system according to the unified CHINET protocol.The results were interpreted according to the breakpoints of the Clinical & Laboratory Standards Institute(CLSI)M100 31st ed in 2021.Results Over the seven-year period(2015-2021),the overall prevalence of carbapenem-resistant Enterobacterales(CRE)was 9.43％(62 342/661 235).The prevalence of CRE strains in Klebsiella pneumoniae,Citrobacter freundii,and Enterobacter cloacae was 22.38％,9.73％,and 8.47％,respectively.The prevalence of CRE strains in Escherichia coli was 1.99％.A few CRE strains were also identified in Salmonella and Shigella.The CRE strains were mainly isolated from respiratory specimens(44.23±2.80)％,followed by blood(20.88±3.40)％and urine(18.40±3.45)％.Intensive care units(ICUs)were the major source of the CRE strains(27.43±5.20)％.CRE strains were resistant to all the β-lactam antibiotics tested and most non-β-lactam antimicrobial agents.The CRE strains were relatively susceptible to tigecycline and polymyxins with low resistance rates.Conclusions The prevalence of CRE strains was increasing from 2015 to 2021.CRE strains were highly resistant to most of the antibacterial drugs used in clinical practice.Clinicians should prescribe antimicrobial agents rationally.Hospitals should strengthen antibiotic stewardship in key clinical settings such as ICUs,and take effective infection control measures to curb CRE outbreak and epidemic in hospitals.

Objective To characterize the changing species distribution and antibiotic resistance profiles of respiratory isolates in hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Methods Commercial automated antimicrobial susceptibility testing systems and disk diffusion method were used to test the susceptibility of respiratory bacterial isolates to antimicrobial agents following the standardized technical protocol established by the CHINET program.Results A total of 589 746 respiratory isolates were collected from 2015 to 2021.Overall,82.6％of the isolates were Gram-negative bacteria and 17.4％were Gram-positive bacteria.The bacterial isolates from outpatients and inpatients accounted for(6.0±0.9)％and(94.0±0.1)％,respectively.The top microorganisms were Klebsiella spp.,Acinetobacter spp.,Pseudomonas aeruginosa,Staphylococcus aureus,Haemophilus spp.,Stenotrophomonas maltophilia,Escherichia coli,and Streptococcus pneumoniae.Each microorganism was isolated from significantly more males than from females(P＜0.05).The overall prevalence of methicillin-resistant S.aureus(MRSA)was 39.9％.The prevalence of penicillin-resistant S.pneumoniae was 1.4％.The prevalence of extended-spectrum β-lactamase(ESBL)-producing E.coli and K.pneumoniae was 67.8％and 41.3％,respectively.The overall prevalence of carbapenem-resistant E.coli,K.pneumoniae,Enterobacter cloacae,Pseudomonas aeruginosa,and Acinetobacter baumannii was 3.7％,20.8％,9.4％,29.8％,and 73.3％,respectively.The prevalence of β-lactamase was 96.1％in Moraxella catarrhalis and 60.0％in Haemophilus influenzae.The H.influenzae isolates from children(＜18 years)showed significantly higher resistance rates to β-lactam antibiotics than the isolates from adults(P＜0.05).Conclusions Gram-negative bacteria are still predominant in respiratory isolates associated with serious antibiotic resistance.Antimicrobial resistance surveillance should be strengthened in clinical practice to support accurate etiological diagnosis and appropriate antimicrobial therapy based on antimicrobial susceptibility testing results.

Objective To explore the covariant network features of iron deposition in Parkinson's disease with mild cognitive impairment(PD-MCI)based on quantitative susceptibility mapping(QSM).Methods Seventy-one patients with Parkinson's disease(PD)were divided into PD-MCI group(n=37)and PD with normal cognition(PD-NC)group(n=34).The differences of edge-connection and topological property parameters of the iron deposition covariant network between the two groups were compared,respectively.Results The iron deposition covariant network edge-connection analysis showed that there were significant difference in r values of the right globus pallidus-right cerebellar dentate nucleus,right globus pallidus-left putamen,and left hippo-campus-left substantia nigra between the two groups(P＜0.05).The global topological property analysis showed that when the sparsity was 0.47 and 0.48,respectively,the Cp in PD-MCI group was significantly higher than that in PD-NC group(P＜0.05).The node topological property analysis showed that there were significant differences in the node network property parameters of the left substantia nigra,left entorhinal cortex,left precentral gyrus,left putamen,left dentate nucleus,and right orbital frontal cortex between the two groups(P＜0.05).Conclusion The changes of covariant network topological properties based on QSM may be the neuropathological mechanism in PD-MCI at the level of large-scale iron metabolism network.

OBJECTIVE To investigate the mechanisms of rutin in alleviating depressive symptoms associated with premenstrual dysphoric disorder(PMDD)characterized by liver qi stagnation syndrome.METHODS Network pharmacology was employed to identify the intersecting targets of action between PMDD and rutin.A protein-protein interaction network was constructed to screen core targets,followed by gene ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichment analysis.Molecular docking simulations validated rutin's binding affinity to core targets.The bilateral ovaries of female Wistar rats were removed,followed by artificial hormone induction.The rats were then randomly divided into normal group(10 rats)and modeling group(50 rats).PMDD rat model with liver qi stagnation syndrome was established via restraint stress.The successfully modeled rats were further divided into model group,fluoxetine group(positive control)and rutin group,with 12 rats in each group.The corresponding drug solutions or water were administered by gavage at 9:00 a.m.every day,continuing for two estrous cycles.The open-field test,forced swimming test and Y-maze test were utilized to evaluate the effects of rutin on the behavioral indexes of model rats.Additionally,the density of neuronal dendritic spines in the hippocampal tissues of the rats was observed.Serum brain-derived neurotrophic factor(BDNF)levels and the expressions of BDNF,tyrosine kinase receptor type B(TrkB),synuclein(Syn),and postsynaptic density protein 95(PSD95)in hippocampal tissues were quantified,respectively.RESULTS Network pharmacology and molecular docking revealed the core targets through which rutin ameliorated PMDD characterized by liver qi stagnation syndrome included BDNF,TrkB,PSD65,Syn,etc.The results of experimental validation demonstrated that rutin significantly increased the spontaneous alternation behavior scores of PMDD model rats with liver qi stagnation syndrome during the non-receptive phase,shortened their immobility time during the forced swimming test,and enhanced the density of neuronal dendritic spines in the hippocampal tissues.Additionally,rutin upregulated the levels of serum BDNF and the protein expressions of BDNF,TrkB and Syn in the hippocampal tissues(P＜0.05).However,it had no significant effect on the above indexes in model rats during the receptive phase(P＞0.05).CONCLUSIONS Rutin ameliorates depressive symptoms,enhances spatial memory capabilities,and reduces neuronal damage in PMDD model rats with liver qi stagnation syndrome.These effects may be associated with the activation of BDNF/TrkB signaling pathway and upregulation of Syn protein expression.

Objective To evaluate the value of biparametric MRI(bpMRI)radiomics for predicting postoperation Gleason score(GS)upgrade of prostate cancer(PCa).Methods Totally 344 PCa patients who underwent radical prostatectomy(RP)were retrospectively enrolled and divided into training set(n=241)and test set(n=103)at a ratio of 7∶3.T2WI,diffusion weighted imaging(DWI)and apparent diffusion coefficient(ADC)map radiomics signatures were constructed based on preoperative bpMRI,respectively,then logistic regression(LR)algorithm was used to establish bpMRI radiomics model.Univariate and multivariate logistic regression analyses were performed to screen independent risk factors for postoperation GS upgrade of PCa,and a clinical model was constructed.Then a clinical-radiomics combined model was established based on clinical model and bpMRI radiomics model.Receiver operating characteristic curves were drawn,the area under the curves(AUC)were calculated to evaluate the efficacy of each model for predicting postoperation GS upgrade of PCa.Results Elevated preoperative prostate imaging reporting and data system(PI-RADS)score and reduced biopsy Gleason grade group(GG)were both independent risk factors of postoperation GS upgrade of PCa(both P＜0.05).The AUC of bpMRI radiomics model and clinical-radiomics combined model for predicting postoperation GS upgrade of PCa were higher than that of single-sequence radiomics signatures and clinical model(all P＜0.05),while no significant difference was found between the former two(P＞0.05).The clinical-radiomics combined model demonstrated good efficacy for predicting postoperation GS upgrade of PCa with different biopsy GG before operation,with AUC ranging from 0.835 to 0.949 in training set and 0.803 to 0.948 in test set.Conclusion bpMRI radiomics model could effectively predict postoperation GS upgrade of PCa.

Objective To explore the feasibility of phase-contrast CT for three-dimensional visualization of in vitro intrahepatic vessels and necrotic foci in mouse model of acute liver injury(ALI).Methods Six clean grade male wild-type C57BL/6 mice were randomly divided into model group and control group(each n=3).The mice in model group were fed with overdose of acetaminophen to induce ALI,while those in control group were fed with the same amount of distilled water.After 24 h,the mice were all sacrificed,the livers were harvested and then fixed and dehydrated.Phase-contrast CT images of in vitro liver were acquired,sectional and three-dimensional images were reconstructed.The effect of phase-contrast CT for displaying the outline of liver and internal vessels and necrotic foci were observed,the maximum diameter and volume of necrotic foci were quantitatively analyzed,and the results of phase-contrast CT were compared with pathological findings.Results The original projection and sectional images of phase-contrast CT clearly showed the outline of in vitro liver and internal vasculatures.Necrotic foci within the liver were found in model group,but not in control group.The findings of phase-contrast CT corresponded accurately to those of pathology.Three-dimensional reconstruction images of phase-contrast CT clearly displayed intrahepatic portal vein system and hepatic vein system in both groups,and discontinuous punctate necrotic foci within the liver were found in model group,mainly distributed around hepatic vein,with a median maximum diameter of 18.50 μm and a median volume of 5 870.11 μm3,but was not observed in control group.Conclusion Phase-contrast CT could be used in three-dimensional visualization of intrahepatic vessels and necrotic foci of in vitro liver in mouse model of ALI.