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 investigate the epidemiological characteristics and risk factors of hyperhomocysteinemia(HHcy)in military aircrew.Methods A retrospective study was conducted on 506 aircrew convalescents undergoing health examination from September 2023 to April 2024.Demographic,lifestyle,and biochemical data were analyzed.The risk factors of HHcy were identified by x2 test and multivariate Logistic regression.Results The HHcy detection rate was 21.94%(111/506),with a median homocysteine(Hcy)level of 11.75(9.70-14.30)μmol/L.Multivariate analysis revealed that smoking(OR=2.093,95%CI:1.313-3.336),service in conventional fighter aircraft(OR=1.716,95%CI:1.063-2.770),elevated low-density lipoprotein cholesterol(LDL-C)(OR=2.510,95%CI:1.413-4.458),and elevated bilirubin(OR=2.360,95%CI:1.509-3.691)were independent risk factors for HHcy(all P<0.05).Conclusion There is a high prevalence of HHcy in military pilots.It is strongly associated with smoking,aircraft type,and metabolic abnormalities.It is recommended to incorporate Hcy testing into routine physical examination,implement risk factor-based stratified interventions,and establish an atherosclerotic cardiovascular diseases early warning system integrating vascular imaging and risk assessment,aiming to reduce cardiovascular risks and safeguard combat effectiveness.

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 explore the surgical treatment experience of primary giant gastrointestinal stromal tumors(GIST)(with isolated lesions with a maximum diameter＞10 cm).Methods A retrospective analysis was conducted on the clinical and pathological data of 67 patients with primary giant GIST admitted from January 2018 to December 2024.Among them,35 cases underwent surgical operations after preoperative neoadjuvant therapy(25 effective cases and 10 ineffective cases)(neoadjuvant therapy group).Due to the initial diagnosis assessment expecting radical(R0)resection(13 cases),or preoperative complications(12 cases),or difficulty in obtaining a pathological diagnosis through puncture biopsy(7 cases),32 cases underwent direct surgery without neoadjuvant therapy(direct surgery group).Compare the general information,tumor condition,surgical condition,postoperative recovery,postoperative pathology,postoperative adjuvant therapy,and recurrence between two groups.Results Comparative analysis revealed that there was no statistically significant difference(P＞0.05)between the neoadjuvant therapy group and the direct surgery group in terms of gender,age,primary tumor location,initial maximum diameter,growth type,localized or locally advanced stage,and postoperative follow-up time.The maximum diameters of the tumors before surgery in the neoadjuvant therapy group and the direct surgery group were(12.4±7.1)cm and(18.2±5.0)cm respectively,and the operation times were(125.4±30.6)minutes and(153.0±31.7)minutes respectively.The intraoperative blood loss was(228.3±76.4)ml and(300.3±67.2)ml,respectively.The postoperative hospital stay was(9.1±2.6)days and(11.1±3.2)days,respectively.There was a statistically significant difference between the two groups(P＜0.05).The proportion of laparoscopic surgery in the neoadjuvant therapy group was 17.1％,which was higher than that in the direct surgery group(0),and the difference was statistically significant(P＜0.05).There was no statistically significant difference between the two groups in terms of the proportion of tumor rupture,combined organ resection,postoperative complications and postoperative recurrence(P＞0.05).Conclusion Primary giant gastrointestinal stromal tumors can mostly be reduced in size and progression through neoadjuvant therapy,improving the chances of minimally invasive surgery.However,there is also a risk of tumor progression during neoadjuvant therapy leading to increased surgical difficulty or even loss of curative surgical opportunities.

Objective To investigate the distribution and antimicrobial resistance profiles of common pathogens isolated from cerebrospinal fluid(CSF)in CHINET program from 2015 to 2021.Methods The bacterial strains isolated from CSF were identified in accordance with clinical microbiology practice standards.Antimicrobial susceptibility test was conducted using Kirby-Bauer method and automated systems per the unified CHINET protocol.Results A total of 14 014 bacterial strains were isolated from CSF samples from 2015 to 2021,including the strains isolated from inpatients(95.3％)and from outpatient and emergency care patients(4.7％).Overall,19.6％of the isolates were from children and 80.4％were from adults.Gram-positive and Gram-negative bacteria accounted for 68.0％and 32.0％,respectively.Coagulase negative Staphylococcus accounted for 73.0％of the total Gram-positive bacterial isolates.The prevalence of MRSA was 38.2％in children and 45.6％in adults.The prevalence of MRCNS was 67.6％in adults and 69.5％in children.A small number of vancomycin-resistant Enterococcus faecium(2.2％)and linezolid-resistant Enterococcus faecalis(3.1％)were isolated from adult patients.The resistance rates of Escherichia coli and Klebsiella pneumoniae to ceftriaxone were 52.2％and 76.4％in children,70.5％and 63.5％in adults.The prevalence of carbapenem-resistant E.coli and K.pneumoniae(CRKP)was 1.3％and 47.7％in children,6.4％and 47.9％in adults.The prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)and Pseudomonas aeruginosa(CRPA)was 74.0％and 37.1％in children,81.7％and 39.9％in adults.Conclusions The data derived from antimicrobial resistance surveillance are crucial for clinicians to make evidence-based decisions regarding antibiotic therapy.Attention should be paid to the Gram-negative bacteria,especially CRKP and CRAB in central nervous system(CNS)infections.Ongoing antimicrobial resistance surveillance is helpful for optimizing antibiotic use in CNS infections.

Objective To investigate the antimicrobial resistance of clinical isolates from elderly patients(≥65 years)in major medical institutions across China.Methods Bacterial strains were isolated from elderly patients in 52 hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program during the period from 2015 to 2021.Antimicrobial susceptibility test was carried out by disk diffusion method and automated systems according to the same CHINET protocol.The data were interpreted in accordance with the breakpoints recommended by the Clinical and Laboratory Standards Institute(CLSI)in 2021.Results A total of 514 715 nonduplicate clinical isolates were collected from elderly patients in 52 hospitals from January 1,2015 to December 31,2021.The number of isolates accounted for 34.3％of the total number of clinical isolates from all patients.Overall,21.8％of the 514 715 strains were gram-positive bacteria,and 78.2％were gram-negative bacteria.Majority(90.9％)of the strains were isolated from inpatients.About 42.9％of the strains were isolated from respiratory specimens,and 22.9％were isolated from urine.More than half(60.7％)of the strains were isolated from male patients,and 39.3％isolated from females.About 51.1％of the strains were isolated from patients aged 65-＜75 years.The prevalence of methicillin-resistant strains(MRSA)was 38.8％in 32 190 strains of Staphylococcus aureus.No vancomycin-or linezolid-resistant strains were found.The resistance rate of E.faecalis to most antibiotics was significantly lower than that of Enterococcus faecium,but a few vancomycin-resistant strains(0.2％,1.5％)and linezolid-resistant strains(3.4％,0.3％)were found in E.faecalis and E.faecium.The prevalence of penicillin-susceptible S.pneumoniae(PSSP),penicillin-intermediate S.pneumoniae(PISP),and penicillin-resistant S.pneumoniae(PRSP)was 94.3％,4.0％,and 1.7％in nonmeningitis S.pneumoniae isolates.The resistance rates of Klebsiella spp.(Klebsiella pneumoniae 93.2％)to imipenem and meropenem were 20.9％and 22.3％,respectively.Other Enterobacterales species were highly sensitive to carbapenem antibiotics.Only 1.7％-7.8％of other Enterobacterales strains were resistant to carbapenems.The resistance rates of Acinetobacter spp.(Acinetobacter baumannii 90.6％)to imipenem and meropenem were 68.4％and 70.6％respectively,while 28.5％and 24.3％of P.aeruginosa strains were resistant to imipenem and meropenem,respectively.Conclusions The number of clinical isolates from elderly patients is increasing year by year,especially in the 65-＜75 age group.Respiratory tract isolates were more prevalent in male elderly patients,and urinary tract isolates were more prevalent in female elderly patients.Klebsiella isolates were increasingly resistant to multiple antimicrobial agents,especially carbapenems.Antimicrobial resistance surveillance is helpful for accurate empirical antimicrobial therapy in elderly patients.

Objective To investigate the brain voxel-mirrored homotopic connectivity(VMHC)alterations in patients with ves-tibular migraine(VM)by using resting-state functional magnetic resonance imaging(rs-fMRI).Methods The rs-fMRI data of 30 VM patients(VM group)and 30 healthy volunteers(control group)were prospectively collected.The brain VMHC values in all subjects were calculated and the differences between the two groups were compared.The correlations between VMHC values of significant brain regions and clinical scale scores were analyzed in the VM group.Results Compared with the control group,the VMHC values of the cerebellum region 6,orbital inferior frontal gyrus,insula,superior temporal gyrus and postcentral gyrus in the VM group were all decreased[cluster-level family wise error(FWE)corrected,Pvoxel-level<0.001,Pcluster-level<0.05].In the VM group,the VMHC values of the postcentral gyrus were negatively correlated with dizziness handicap inventory(DHI)score(r=-0.383,P=0.037).Additionally,the VMHC values of the insula were negatively correlated with headache impact test-6(HIT-6)score(r=-0.430,P=0.018).Conclusion VM patients have altered VMHC in certain brain regions,indicating related dysfunctions in vestibule,pain,hearing and emotion.

Objective To investigate the distribution and antimicrobial resistance profiles of clinically isolated Haemophilus influenzae and Moraxella catarrhalis in hospitals across China from 2015 to 2021,and provide evidence for rational use of antimicrobial agents.Methods Data of H.influenzae and M.catarrhalis strains isolated from 2015 to 2021 in CHINET program were collected for analysis,and antimicrobial susceptibility testing was performed by disc diffusion method or automated systems according to the uniform protocol of CHINET.The results were interpreted according to the CLSI breakpoints in 2022.Beta-lactamases was detected by using nitrocefin disk.Results From 2015 to 2021,a total of 43 642 strains of Haemophilus species were isolated,accounting for 2.91％of the total clinical isolates and 4.07％of Gram-negative bacteria in CHINET program.Among the 40 437 strains of H.influenzae,66.89％were isolated from children and 33.11％were isolated from adults.More than 90％of the H.influenzae strains were isolated from respiratory tract specimens.The prevalence of β-lactamase was 53.79％in H.influenzae strains.The H.influenzae strains isolated from children showed higher resistance rate than the strains isolated from adults.Overall,779 strains of H.influenzae did not produce β-lactamase but were resistant to ampicillin(BLNAR).Beta-lactamase-producing strains showed significantly higher resistance rates to these antimicrobial agents than the β-lactamase-nonproducing strains.Of the 16 191 M.catarrhalis strains,80.06％were isolated from children and 19.94％isolated from adults.M.catarrhalis strains were mostly susceptible to both amoxicillin-clavulanic acid and cefuroxime,evidenced by resistance rate lower than 2.0％.Conclusions The emergence of antibiotic-resistant H.influenzae due to β-lactamase production poses a challenge for clinical anti-infective treatment.Therefore,it is very important to implement antibiotic resistance surveillance for H.influenzae and guide rational antibiotic use.All local clinical microbiology laboratories should actively improve antibiotic susceptibility testing and strengthen antibiotic resistance surveillance for H.influenzae.