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*

Objectives:Comparative analysis of the beagles acute-phase electrocardiographic,hemodynamic,left ventricular flow field status,and energy consumption characteristics of pacing at different sites of conduction system may help to elucidate the scientific mechanism of left bundle branch pacing(LBBP)as a option of physiological pacing therapy.Methods:Eight healthy adult beagles were used in this study.Initially,an active fixation lead was implanted in the right atrial appendage,followed by implantation of another active fixation lead at the right ventricular apex,distal His bundle,and left bundle septal branch,respectively.After connecting a dual-chamber pacemaker,electrocardiographic and acute phase hemodynamic parameters under sinus rhythm,right ventricular apex pacing(RVAP),distal His bundle pacing(DHBP),and LBBP states were collected and analyzed.Three complete cardiac cycles of standard apical three-chamber color Doppler dynamic images were acquired under vector flow mapping(VFM)mode.Offline analysis was performed on obtained parameters including isovolumic contraction period,rapid ejection period,isovolumic relaxation period,rapid filling period,atrial contraction period,and left ventricular intracavitary energy consumption.These parameters were compared under pacing at different sites and the linear correlations of major parameters were analyzed.Results:The QRS duration of baseline intrinsic sinus rhythm,RVAP,DHBP and LBBP were(45.0±4.0)ms,(98.4±6.2)ms,(50.0±4.5)ms and(62.0±4.7)ms,respectively.The LBBP-QRS duration was significantly wider than intrinsic sinus rhythm and DHBP,but significantly narrower than RVAP(all P<0.01).Compared with baseline AOO mode(the pacing rate was performed at 10 beats/min above the intrinsic heart rate),the change of acute phase maximum left ventricular pressure rise rate(LVdP/dtmax)in RVAP,DHBP and LBBP was([-7.89±5.67]% ),([0.74±2.05]% )and([-0.14±3.59]% ),respectively.There was no significant difference in LVdP/dtmax changes between DHBP and LBBP(P=0.667),but both pacing modalities were significantly better than RVAP(all P<0.01).The average energy consumption of the left ventricle under RVAP was significantly higher than that of intrinsic sinus rhythm,DHBP,and LBBP in isovolumic contraction period,rapid ejection period,isovolumic relaxation period,rapid filling period,and atrial contraction period(all P<0.01).However,there was no statistically significant difference in energy consumption among intrinsic sinus rhythm,DHBP,and LBBP during the above five phases(all P>0.05).DHBP and LBBP did not show a significant increase in the number of left ventricular vortices,vortex area,and circulation intensity compared to intrinsic sinus rhythm,and LBBP did not show a significant increase in vortex area and circulation intensity compared to DHBP.Conclusions:Although LBBP canines significantly prolonged the paced QRS duration,it showed no significant differences in acute phase left ventricular hemodynamics,left ventricular flow field status,and energy consumption compared to intrinsic sinus rhythm and DHBP.Performance of LBBP was superior to RVAP.This study may contribute to revealing the theoretical basis of LBBP as a feasible physiological pacing therapy.

Objectives:Comparative analysis of the beagles acute-phase electrocardiographic,hemodynamic,left ventricular flow field status,and energy consumption characteristics of pacing at different sites of conduction system may help to elucidate the scientific mechanism of left bundle branch pacing(LBBP)as a option of physiological pacing therapy.Methods:Eight healthy adult beagles were used in this study.Initially,an active fixation lead was implanted in the right atrial appendage,followed by implantation of another active fixation lead at the right ventricular apex,distal His bundle,and left bundle septal branch,respectively.After connecting a dual-chamber pacemaker,electrocardiographic and acute phase hemodynamic parameters under sinus rhythm,right ventricular apex pacing(RVAP),distal His bundle pacing(DHBP),and LBBP states were collected and analyzed.Three complete cardiac cycles of standard apical three-chamber color Doppler dynamic images were acquired under vector flow mapping(VFM)mode.Offline analysis was performed on obtained parameters including isovolumic contraction period,rapid ejection period,isovolumic relaxation period,rapid filling period,atrial contraction period,and left ventricular intracavitary energy consumption.These parameters were compared under pacing at different sites and the linear correlations of major parameters were analyzed.Results:The QRS duration of baseline intrinsic sinus rhythm,RVAP,DHBP and LBBP were(45.0±4.0)ms,(98.4±6.2)ms,(50.0±4.5)ms and(62.0±4.7)ms,respectively.The LBBP-QRS duration was significantly wider than intrinsic sinus rhythm and DHBP,but significantly narrower than RVAP(all P<0.01).Compared with baseline AOO mode(the pacing rate was performed at 10 beats/min above the intrinsic heart rate),the change of acute phase maximum left ventricular pressure rise rate(LVdP/dtmax)in RVAP,DHBP and LBBP was([-7.89±5.67]% ),([0.74±2.05]% )and([-0.14±3.59]% ),respectively.There was no significant difference in LVdP/dtmax changes between DHBP and LBBP(P=0.667),but both pacing modalities were significantly better than RVAP(all P<0.01).The average energy consumption of the left ventricle under RVAP was significantly higher than that of intrinsic sinus rhythm,DHBP,and LBBP in isovolumic contraction period,rapid ejection period,isovolumic relaxation period,rapid filling period,and atrial contraction period(all P<0.01).However,there was no statistically significant difference in energy consumption among intrinsic sinus rhythm,DHBP,and LBBP during the above five phases(all P>0.05).DHBP and LBBP did not show a significant increase in the number of left ventricular vortices,vortex area,and circulation intensity compared to intrinsic sinus rhythm,and LBBP did not show a significant increase in vortex area and circulation intensity compared to DHBP.Conclusions:Although LBBP canines significantly prolonged the paced QRS duration,it showed no significant differences in acute phase left ventricular hemodynamics,left ventricular flow field status,and energy consumption compared to intrinsic sinus rhythm and DHBP.Performance of LBBP was superior to RVAP.This study may contribute to revealing the theoretical basis of LBBP as a feasible physiological pacing therapy.

OBJECTIVE: To review targeted muscle reinnervation (TMR) surgery for the construction of intelligent prosthetic human-machine interface, thus providing a new clinical intervention paradigm for the functional reconstruction of residual limbs in amputees. METHODS: Extensively consulted relevant literature domestically and abroad and systematically expounded the surgical requirements of intelligent prosthetics, TMR operation plan, target population, prognosis, as well as the development and future of TMR. RESULTS: TMR facilitates intuitive control of intelligent prostheses in amputees by reconstructing the "brain-spinal cord-peripheral nerve-skeletal muscle" neurotransmission pathway and increasing the surface electromyographic signals required for pattern recognition. TMR surgery for different purposes is suitable for different target populations. CONCLUSION TMR surgery has been certified abroad as a transformative technology for improving prosthetic manipulation, and is expected to become a new clinical paradigm for 2 million amputees in China.
Humans ; Artificial Limbs ; Muscle, Skeletal ; Neurosurgical Procedures ; Plastic Surgery Procedures ; Prosthesis Implantation

Objective: To investigate the association between plasma selenium exposure and the risk of impaired glucose regulation (IGR). Methods: A case-control study was conducted to select IGR patients who were admitted to the outpatient clinic of the Department of Endocrinology to perform oral glucose tolerance test(OGTT) at the Tongji Hospital affiliated to the Tongji Medical College from September 2004 to 2016 as a case group. Participants with normal glucose tolerance recruited from an unselected group of population undergoing routine health examinations in the same hospital were selected as a control group. The control group was matched according to the age (±5 years old) and sex of the case group. The inclusion criteria for subjects recruited were as follows: age ≥30 years, body mass index (BMI) <40 kg/m², no history of a diagnosis of IGR or type 2 diabetes, and no history of receiving pharmacological treatment for hyperlipidemia or hypertension. Patients with any clinically systemic disease such as neurological or endocrine disease, acute illness, chronic inflammatory disease or infectious disease were excluded from the study. A total of 1 957 subjects, 897 in the case group and 1 060 in the control group, were included. Questionnaires were used to collect information of all subjects, and peripheral venous blood was collected after fasting and OGTT, respectively. Plasma selenium, fasting blood glucose, blood lipid (total cholesterol, triglycerides, high density lipoprotein cholesterol, and low density lipoprotein cholesterol) and 2 h OGTT plasma glucose concentration were detected, respectively. The subjects were divided into low, medium and high concentration groups according to the tertiles of plasma selenium concentration in the control group. The multivariate unconditional logistic regression analysis was performed to analyze the association between plasma selenium exposure and IGR. Results: The age (mean±SD) of the case and control group was (53.71±11.38) and (53.95±12.17) years old. The plasma selenium concentration [M (P₂₅, P₇₅)] in the case group was 92.81(77.07, 107.05) μg/L, which was significantly higher than the control group [88.73 (77.13, 100.88) μg/L] (P<0.05). The results of multivariate unconditional logistic regression analysis showed that after adjusting for age, sex, BMI, family history of diabetes and hypertension, the risk of IGR was higher in the high-concentration group and the low-concentration group compared with the middle-concentration group, the values of OR (95%CI) were 1.22 (95%CI: 0.94-1.59) and 1.81 (95%CI: 1.42-2.30), respectively. Conclusion The study suggested a U-shaped association between plasma selenium and IGR.

Objective To investigate the association between plasma selenium exposure and the risk of impaired glucose regulation (IGR). Methods A case?control study was conducted to select IGR patients who were admitted to the outpatient clinic of the Department of Endocrinology to perform oral glucose tolerance test(OGTT) at the Tongji Hospital affiliated to the Tongji Medical College from September 2004 to 2016 as a case group. Participants with normal glucose tolerance recruited from an unselected group of population undergoing routine health examinations in the same hospital were selected as a control group. The control group was matched according to the age (±5 years old) and sex of the case group. The inclusion criteria for subjects recruited were as follows: age≥30 years, body mass index (BMI)<40 kg/m2, no history of a diagnosis of IGR or type 2 diabetes, and no history of receiving pharmacological treatment for hyperlipidemia or hypertension. Patients with any clinically systemic disease such as neurological or endocrine disease, acute illness, chronic inflammatory disease or infectious disease were excluded from the study. A total of 1 957 subjects, 897 in the case group and 1 060 in the control group, were included. Questionnaires were used to collect information of all subjects, and peripheral venous blood was collected after fasting and OGTT, respectively. Plasma selenium, fasting blood glucose, blood lipid (total cholesterol, triglycerides, high density lipoprotein cholesterol, and low density lipoprotein cholesterol) and 2 h OGTT plasma glucose concentration were detected, respectively. The subjects were divided into low, medium and high concentration groups according to the tertiles of plasma selenium concentration in the control group. The multivariate unconditional logistic regression analysis was performed to analyze the association between plasma selenium exposure and IGR. Results The age (mean± SD) of the case and control group was (53.71± 11.38) and (53.95±12.17) years old. The plasma selenium concentration [M (P25, P75)] in the case group was 92.81(77.07, 107.05) μg/L, which was significantly higher than the control group [ 88.73 (77.13, 100.88) μg/L] (P<0.05). The results of multivariate unconditional logistic regression analysis showed that after adjusting for age, sex, BMI, family history of diabetes and hypertension, the risk of IGR was higher in the high?concentration group and the low?concentration group compared with the middle?concentration group, the values of OR (95%CI) were 1.22 (95%CI: 0.94-1.59) and 1.81 (95%CI: 1.42-2.30), respectively. Conclusion The study suggested a U?shaped association between plasma selenium and IGR.

Objective To investigate the association between plasma selenium exposure and the risk of impaired glucose regulation (IGR). Methods A case?control study was conducted to select IGR patients who were admitted to the outpatient clinic of the Department of Endocrinology to perform oral glucose tolerance test(OGTT) at the Tongji Hospital affiliated to the Tongji Medical College from September 2004 to 2016 as a case group. Participants with normal glucose tolerance recruited from an unselected group of population undergoing routine health examinations in the same hospital were selected as a control group. The control group was matched according to the age (±5 years old) and sex of the case group. The inclusion criteria for subjects recruited were as follows: age≥30 years, body mass index (BMI)<40 kg/m2, no history of a diagnosis of IGR or type 2 diabetes, and no history of receiving pharmacological treatment for hyperlipidemia or hypertension. Patients with any clinically systemic disease such as neurological or endocrine disease, acute illness, chronic inflammatory disease or infectious disease were excluded from the study. A total of 1 957 subjects, 897 in the case group and 1 060 in the control group, were included. Questionnaires were used to collect information of all subjects, and peripheral venous blood was collected after fasting and OGTT, respectively. Plasma selenium, fasting blood glucose, blood lipid (total cholesterol, triglycerides, high density lipoprotein cholesterol, and low density lipoprotein cholesterol) and 2 h OGTT plasma glucose concentration were detected, respectively. The subjects were divided into low, medium and high concentration groups according to the tertiles of plasma selenium concentration in the control group. The multivariate unconditional logistic regression analysis was performed to analyze the association between plasma selenium exposure and IGR. Results The age (mean± SD) of the case and control group was (53.71± 11.38) and (53.95±12.17) years old. The plasma selenium concentration [M (P25, P75)] in the case group was 92.81(77.07, 107.05) μg/L, which was significantly higher than the control group [ 88.73 (77.13, 100.88) μg/L] (P<0.05). The results of multivariate unconditional logistic regression analysis showed that after adjusting for age, sex, BMI, family history of diabetes and hypertension, the risk of IGR was higher in the high?concentration group and the low?concentration group compared with the middle?concentration group, the values of OR (95%CI) were 1.22 (95%CI: 0.94-1.59) and 1.81 (95%CI: 1.42-2.30), respectively. Conclusion The study suggested a U?shaped association between plasma selenium and IGR.

Objective To investigate the effects of notoginseng and guiding medicinals mediated notoginseng for improving the renal inter stitial fibrosis in rats with chronic kidney-disease(CKD)by regulating TGF-β signaling pathway.Methods A total of 100 male SD rats were randomly divided into five groups:normal group(NOR,n =20),model group(CKD,n =20),radix notogin-seng group(RN,n =20),radix notoginseng plus platycodi group (RNP) and radix notoginseng plus cinnamon group (RNC,n =20).Except for the NOR group,the CKD rat model in other groups was established by adenine gavage.After modeling,the NOR group and CKD group were given the same volume of normal saline by gavage,while the group RN,RNP and RNC were given corresponding drugs by gavage,for 4 weeks.After 4 weeks,the rats in each group were sacrificed for collecting serum and detecting the renal function(serum Scr,BUN),the renal tissues were taken for conducting HE and Masson staining.Then the renal tissue pathological damage severity was observed.The expressions of FN and LN in kidney tissue were detected by immunohistochemistry and the expressions of TGF-[β,α-SMA were detected by Western blot method.Results Compared with the NOR group,the model group exhibited the renal dysfunction(P＜0.01),renal interstitial severe fibrosis manifestation and increased collagen deposition(P＜0.05),and the expression of kidney tissues α-SMA(P＜0.01),TGF-β(P＜0.01),FN and LN were significantly increased.Compared with the model group,the renal function in various treatment groups was improved,Scr(P＜0.01)and BUN(P＜0.01)were significantly decreased,the renal interstitial fibrosis degree was reduced,collagen desposition was decreased(P＜0.05),renal tissue α-SMA(P＜ 0.05),TGF-β(P＜0.05),FN and LN expression were reduced to some extent,in which the effect of RNC group was stronger than that of the RN group and RNP group.Conclusion Notoginseng and guiding medicinals mediated notoginseng can retard the progression of renal interstitial fibrosis caused by adenine in CKD rat in varying degrees,its mechanism maybe reduce the expression of TGF-β protein.