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*

Humans ; Aortic Valve/surgery* ; Retrospective Studies ; Transcatheter Aortic Valve Replacement ; Sex Factors ; Heart Valve Prosthesis Implantation ; Treatment Outcome ; China ; Aortic Valve Stenosis/surgery* ; Risk Factors ; Risk Assessment

Humans ; Retrospective Studies ; Transcatheter Aortic Valve Replacement/adverse effects* ; Risk Assessment ; China ; Prognosis ; Aortic Valve Stenosis/surgery* ; Treatment Outcome ; Risk Factors ; Aortic Valve

OBJECTIVE Human beings possess the ability to indirectly acquire the emotions of others.This also known as emotional contagion or empathy,enables us to rapidly perceive the emotions of others.However,an excessive empathy may result in heightened fear and sensitivity to pain.Therefore,the establishment of appropri-ate animal models for analyzing neural mechanisms underlying empathy would contribute to pharmacological research on pain sensitivity caused by psychological sus-ceptibility.METHODS We used the observed fear para-digm for assessing contagion of negative emotions in mice.To minimize the impact of emotional contagion dif-ferences caused by the subject change,we established a bilateral observation area and the two mice were trained to observe fear simultaneously.First,two observer(OB)mice were placed on either side of the observational area.Next,a demonstrator(DM)mouse was introduced into the cylindrical shock cage located at the center of the apparatus.The shock cage is made of transparent organic plastic with air holes and has provided ample space for free movement by the DM mouse.During the shock stage,DM mice were subjected to electric stimulation while the behaviors of OB mice on both sides was observed,including freezing,the side and corner time,social interaction behavior.Additionally,c-Fos staining was utilized to confirm distinct local brain activities.RESULTS In the habituation stage,OB mice on both sides showed more social preference for DM mouse,as evidenced by an increase in duration time in the designat-ed interaction zone.During the shock phase,OB mice observed the DM mouse receiving electric shocks and displayed significantly higher levels of fear contagion;however,their fear behavior was not entirely consistent.Some mice exhibited a significant increase in freezing time,while others demonstrated a significant increase in corner and side exploration time.We utilized Z-normal-ization to evaluate changes in emotionality across vari-ous behaviors and identified mice with distinct susceptibil-ities.Fos-positive neurons exhibited higher expression levels in susceptible OB mice,primarily concentrated within brain regions associated with the ascending path-ways of pain perception,such as thalamus,the anterior insular cortex,and anterior cingulate cortex.CONCLU-SION In this study,we have developed an innovative experimental facility that integrates various behavioral tests to evaluate empathic behavior in mice.Our findings highlight the robustness of emotionality measures obtained from individual mice by combining this experi-mental model with the Z-scoring method,facilitating screening for empathic fear or pain-susceptible mice and will helpful for pharmacological evaluation.

OBJECTIVE Fear can be learned indi-rectly,but excessive transmission of fear is essential for the development of mental illness.Previous research has indicated that the anterior insular cortex(AIC)may play a crucial role in the process of fear transmission,and abnormal AIC activity is a possible mechanism under-lying various affective disorders.Inhibitory neurons are crucial for maintaining local microcircuit homeostasis.With the support of novel specific neuroregulatory tech-niques,it is now possible to monitor and regulate differ-ent types of neurons in real-time.Therefore,investigating distinct subtypes of inhibitory neurons in the AIC that are involved in fear contagion may provide valuable insights into potential mechanisms underlying mental disorders.METHODS We established a modified observational fear(OF)model.A demonstrator(DM)mouse was placed in an acrylic cup at the center of the apparatus,and two observer(OB)mice were allowed to explore the DM mouse simultaneously from separate areas on either side.During the OF training,electric foot shocks were administered to the DM mouse and freezing,the side and corner time,and social interaction behavior were scored.Next,we characterized the activity patterns of distinct neuronal subtypes in the AIC using GCaMP-based calcium recording.Finally,we employed a Cre-dependent optogenetic approach to selectively modulate excitatory or inhibitory neurons in the AIC,and investigat-ed empathic fear behavior across different Cre transgenic mouse lines(CK2-Cre,PV-Cre,SOM-Cre,VIP-Cre).RESULTS During the training phase,the OB mice exhib-ited significantly higher levels of fear compared to the control group(which did not observe a traumatic event),as evidenced by increased freezing time,decreased interaction time,and increased corner zone time.Calcium fiber recording results suggested that CK2 neurons are involved in risk prediction,while PV and VIP neurons exert inhibitory control on this behavior.Optogenetic silencing of CK2-positive neurons in the AIC through injection of AAV-DIO-NpHR-mCherry in mice demon-strated a significant reduction in empathic fear.Similarly,activation of PV or VIP inhibitory neurons expressing ChR2-eYFP also resulted in a similar effect.However,activation of SOM neurons led to a significant increase in empathic fear.CONCLUSION Our study demonstrated that VIP and PV neuron activity in the AIC attenuates empathetic fear,while SOM and CK2 neuron activity enhances fear expression.These findings shed light on the distinct contributions of various inhibitory interneu-rons in the AIC to fear contagion,indicating their mutual interaction for maintaining local microcircuit homeostasis that regulates empathetic fear behaviors.

Objective To establish the method of predicting the vertical ground reaction force (vGRF) during treadmill running based on principal component analysis and wavelet neural network (PCA-WNN). Methods Nine rearfoot strikers were selected and participated in running experiment on an instrumented treadmill at the speed of 12, 14 and 16 km/h. The kinematics data and vGRF were collected using infrared motion capture system and dynamometer treadmill. A three-layer neural network framework was constructed, in which the activation function of the hidden layers was the Morlet function. Velocities of mass center of the thigh, shank and foot as well as joint angles of the hip, knee and ankle were input into the WNN model. The prediction accuracy of the model was evaluated by the coefficient of multiple correlation (CMC) and error. The consistencies between predicted and measured peak GRF were analyzed by Bland-Altman method. Results The CMC between the predicted and measured GRF at different speeds were all greater than 0.99; the root mean square error (RMSE) between the predicted and measured vGRF was 0.18-0.28 BW; and the normalized root mean square error (NRMSE) was 6.20%-8.42%; the NRMSE between the predicted and measured impact forces and propulsive forces were all smaller than 15%. Bland-Altman results showed that the predicted peak errors of propulsive force at 12 km/h and that of impact force and propulsive force at 14 km/h were within the 95% agreement interval. Conclusions The PCA-WNN model constructed in this study can accurately predict the vGRF during treadmill running. The results provide a new method to obtain kinetic data and perform real-time monitoring on a treadmill, which is of great significance for studying running injuries and rehabilitation treatment.

Objective:To explore the feasibility and conditions of in vitro and in vivo imaging of triple-negative breast cancer using visible light emitted quantum dots(QDs) as the carrier to target epidermal growth factor receptor (EGFR). Methods:The water-soluble QDs reacted with Cetuximab to synthesize the probe QD-Cetuximab. The morphology, particle size, stability and luminescence properties of the probe were examined. Human breast cancer cells MDA-MB-468 (EGFR+ ) and MDA-MB-453 (EGFR-) were cultured. Cytotoxicity assays, in vitro imaging and fluorescence intensity quantification were performed after cells incubation with QD-Cetuximab and QDs. Eight MDA-MB-468 tumor-bearing mice models were constructed, 100 μl QD-Cetuximab and QDs were injected through the tail vein. In vivo imaging and probe distribution were obtained at different time points. Independent-sample t test was used to analyze the data. Results:QD-Cetuximab had a particle size of (40.34±2.44) nm detected by transmission electron microscope (TEM), a hydrated particle size of (57.85±4.69) nm detected by dynamic light scattering (DLS), and a stable structure. When the concentration of QD-Cetuximab was ≤50 nmol/L, the relative survival rate of cells was more than 90%, and when the concentration exceeded 100 nmol/L, the relative survival rate of cells was reduced to (72.52±4.91)% ( P<0.05). The red fluorescence of MDA-MB-468 incubated with QD-Cetuximab was stronger than that of MDA-MB-468 incubated with QDs and MDA-MB-453 incubated with QD-Cetuximab or QDs. The confocal fluorescent intensity quantitative determination showed that the ratio of QD-Cetuximab group/QDs group was 5.1 (863.36/169.97). Flow cytometry showed that the uptake of QD-Cetuximab and QDs by MDA-MB-468 increased with incremental incubating concentration, and the former was more significantly( t values: 12.25-38.11, all P<0.05). When the incubating concentration was 25, 50, 100, and 200 nmol/L, the quantitative average fluorescent intensity ratio of QD-Cetuximab group/QDs group was 5.4, 6.9, 7.4 and 6.2, respectively. The QD-Cetuximab and QDs probes mainly accumulated in the liver in vivo. The fluorescence emitted by tumor was not obvious under the high fluorescence of liver as a background. However, the fluorescence was visible in the isolated tumor tissue, and the quantitative fluorescence intensity of experimental group and control group were (2.46±0.60)×10 4 and (1.29±0.05)×10 4, respectively ( t=3.392, P=0.015). Conclusions:Cetuximab can increase the targeting ability of QDs and promote cell uptake. Although the isolated tumor imaging results are acceptable, further modification of QDs should be considered to reduce the liver uptake and improving in vivo fluorescence imaging efficiency.

Objective:To investigate and understand the general situation and quality of life of migrant workers with pneumoconiosis, and analyze the influencing factors, so as to provide scientific basis for effective countermeasures to improve the quality of life of migrant workers with pneumoconiosis.Methods:In June 2019, 79 cases of migrant workers' pneumoconiosis diagnosed by Shandong Occupational Disease Hospital from March 2017 to August 2018 were selected as the study object by cluster random sampling method. Questionnaires and on-site visits were used to investigate the quality of life and its influencing factors. The questionnaire was administered by self-designed questionnaire and WHO quality of life questionnaire.Results:The farmer's pneumoconiosis patients are generally lower in culture. High school or above is only 6.33% (5/79) . Their economic income is low. The monthly income of less than 1000 RMB is 49.37% (39/79) . The disease was heavy and pneumoconiosis was 58.23% (46/79) . Pneumoconiosis patients without systematic treatment accounted for 69.62% (55/79) . Only 11.39% of rural workers with pneumoconiosis can timely increase or decrease clothing and wear masks to avoid respiratory irritation. Pneumoconiosis patients who smoked accounted for 77.22% (61/79) . The quality of life of the pneumoconiosis patients in the physiological, psychological, social and environmental fields were (10.40±2.31) , (11.40±2.82) , (11.46±3.03) and (8.38±3.37) respectively. The influencing factors of quality of life were pneumoconiosis stage, education level, economic income and smoking ( P< 0.05) . Conclusion:The quality of life of migrant workers with pneumoconiosis is generally low. The main factors that affect the quality of life of patients are disease severity (pneumoconiosis stage) , education level, economic income and smoking.

Objective:To investigate and understand the general situation and quality of life of migrant workers with pneumoconiosis, and analyze the influencing factors, so as to provide scientific basis for effective countermeasures to improve the quality of life of migrant workers with pneumoconiosis.Methods:In June 2019, 79 cases of migrant workers' pneumoconiosis diagnosed by Shandong Occupational Disease Hospital from March 2017 to August 2018 were selected as the study object by cluster random sampling method. Questionnaires and on-site visits were used to investigate the quality of life and its influencing factors. The questionnaire was administered by self-designed questionnaire and WHO quality of life questionnaire.Results:The farmer's pneumoconiosis patients are generally lower in culture. High school or above is only 6.33% (5/79) . Their economic income is low. The monthly income of less than 1000 RMB is 49.37% (39/79) . The disease was heavy and pneumoconiosis was 58.23% (46/79) . Pneumoconiosis patients without systematic treatment accounted for 69.62% (55/79) . Only 11.39% of rural workers with pneumoconiosis can timely increase or decrease clothing and wear masks to avoid respiratory irritation. Pneumoconiosis patients who smoked accounted for 77.22% (61/79) . The quality of life of the pneumoconiosis patients in the physiological, psychological, social and environmental fields were (10.40±2.31) , (11.40±2.82) , (11.46±3.03) and (8.38±3.37) respectively. The influencing factors of quality of life were pneumoconiosis stage, education level, economic income and smoking ( P< 0.05) . Conclusion:The quality of life of migrant workers with pneumoconiosis is generally low. The main factors that affect the quality of life of patients are disease severity (pneumoconiosis stage) , education level, economic income and smoking.

Objective To investigate the reliability and validity of a novel hand-held dynamometer, OE-210, for muscles strength of low-er extremities. Methods From March 1st to August 30th, 2016, 38 young adults were tested the muscle strength of quadriceps and ham-strings with OE-210 dynamometer by 2 rators, and were retested by one of the raters three days later. The isokinetic test was also conducted on all the subjects one day afterwards. The intraclass correlation coefficient (ICC) of OE-210 test results and the Pearson's correlation coeffi-cient between results of OE-210 and isokinetic test were calculated. Results The ICC of test-retest were 0.718 to 0.924, and the ICC of in-ter-rater were 0.784 to 0.870. The correlation between muscle performance measured with 2 tools were significant (P<0.001), that was light to medium on quadriceps (r=0.270-0.413), and strong on hamstrings (r=0.582-0.668). Conclusion OE-210 dynamometer was reliable for muscle strength measurement on quadriceps and hamstrings, and the conditions for valid application need further research.