Objective To establish a simplified simulation method of rocking-chair archwire(RCA),explore the biomechanical effect of RCA during anterior teeth retraction with sliding mechanics,and provide guidance for clinical treatment.Methods A standard 0.019 in×0.025 in(0.483 mm×0.635 mm)labial archwire was imported into ANSYS software and preloaded spring was used to simulate RCA at different angles to achieve parameterized modeling.A three-dimensional(3D)finite element model with labial straight wire appliance,teeth,periodontium and maxillary bone was established to analyze the displacement and force of anterior/posterior teeth under 1.5 N intra-arch traction combined with RCA at different angles.Results Preloading forces of 1.5,3,4.5,and 6 N in spring induced angles of approximately 5°,10°,15°,and 20° for RCA,demonstrating the flexibility and convenience of the parameterized modeling method.During intra-arch traction with increased angle of RCA,lingual crown displacement of the middle incisor gradually decreased,while the lateral incisor and canine showed decreased crown tipping and increased lingual root displacement;when the RCA angle was 20°,the lateral incisor and canine achieved almost bodily retraction.Meanwhile,premolars showed an extrusion tendency,while molars demonstrated distal crown tipping and intrusion tendency.As the RCA angle increased from 0° to 20°,intrusive force on the anterior teeth increased,and the moment-force ratio(M/F)at bracket level increased from 0 to near 9 mm.Conclusions RCA can effectively control the moving pattern of the maxillary anterior teeth and prevent their over-erection and extrusion during retraction with sliding mechanics.During intra-arch traction with rigid stainless steel archwire,theoretically RCA of 20° has sufficient torque control on the anterior teeth to achieve their en-masse retraction.

Objective To establish a stable and reproducible animal model of abdominal intestinal firearm penetrating injury in a cold high-altitude environment.Methods Twenty landrace pigs were randomly and equally assigned to a low-altitude normal temperature(LN)group and a high-altitude cold(HC)group.The HC group was placed in a cold environment at high altitudes,and the LN group was placed in a normal-temperature environment at low altitudes.They were raised for 48 hours respectively.After anesthesia,they were suspended on the shooting range,and the right lower abdomen of the experimental pigs was shot with a gun.After injury,they were simply bandaged and transported back to the laboratory for observation in the normal temperature environment of the low altitudes.The vital signs and injuries at 0,2,4,8,12 and 24 h and 24 h survival rates of experimental pigs were compared.Laparotomy was immediately performed on the dead pigs and the experimental pigs still alive at 24 h to explore the injuries and observe the pathology of the small intestine and colon.Results The 24 h survival rate of the HC group was 70％,with no statistically significant difference compared to the LN group's 90％(P＞0.05).After the injury,the body temperature of both groups gradually increased.The body temperature of the HC group was significantly higher than the LN group at 0,2,4 and 8 h time points(P＜0.001),and the LN group exceeded the HC group at 24 h(P＜0.05).Both groups showed an initial increase followed by a decrease in heart rate,with the HC group significantly higher than the LN group only at 0 h(P＜0.01),and no statistically significant differences were observed at other time points(P＞0.05).Both groups showed an early increase and later decrease in respiratory rate,with the HC group higher than the LN group at 0,4,8,12 and 24 h(P＜0.05 or P＜0.001).There was no statistically significant difference(P＞0.05)between the HC group and the LN group in small intestine rupture,small intestine contusion,mesenteric injury,colon rupture and wound diameter.The pathology of the small intestine and colon in the HC group showed extensive necrosis and shedding of the mucosa layer,severe congestion and edema of the submucosa,and extensive lymphocyte infiltration.The LN group also showed similar symptoms but to a lesser extent.Conclusion This study established a pig model of abdominal firearm intestinal perforation injury in a cold environment at high-altitudes.The model has strong operability and stable damage,which can provide a reference for subsequent research.

Objective To investigate the predictive value of quantitative parameters of contrast-enhanced ultrasound (CEUS) in evaluating kidneys from donation after brain death (DBD) for the occurrence of delayed graft function (DGF) in recipients. Methods The clinical data of 134 DBD donors and 202 corresponding kidneys and recipients were retrospective analyzed. The recipients were divided into DGF group (n=39) and non-DGF group (n=163) according to the renal function after kidney transplantation. Conventional ultrasound, CEUS parameters, and clinical data were compared between the two groups. Receiver operating characteristic (ROC) curves were used to determine the optimal cut-off values for predicting DGF using CEUS parameters, clinical parameters, and their combination, based on the highest Youden index. The predictive ability of different parameters for DGF was evaluated. Results There were statistically significant differences in cortical peak intensity (PIc), medullary peak intensity (PIm), donor albumin (ALB), serum creatinine (Scr) after admission, and the Na⁺ concentration of recipients between the two groups (all P<0.05). The area under the curve (AUC) for predicting DGF using the combination of CEUS parameters PIc and PIm was 0.711, with an optimal cut-off value of 0.193 and a Youden index of 0.382. The AUC for predicting DGF using the combination of CEUS parameters PIc, PIm and clinical parameters was 0.808, with an optimal cut-off value of 0.191 and a Youden index of 0.517. The sensitivity and specificity were 0.769 and 0.613 for the former, and 0.769 and 0.748 for the latter, respectively. The AUC for predicting DGF using CEUS parameters PIc and PIm combined with clinical parameters was significantly higher than that using CEUS parameters PIc and PIm (P<0.05). Conclusions The CEUS quantitative parameters PIc and PIm have good predictive value in assessing kidneys from DBD donors for DGF in recipients, and the diagnostic efficacy is better when combined with clinical parameters.

Objective To assess on-related association and causality of vitamin C supplementation and sepsis risk by using two-sample Mendelian randomization(MR)design.Methods The study was based on Genome-Wide Association Studies data to screen single nucleotide polymorphisms associated with vitamin C supplementation as instrumental variables.The association of vitamin C supplementation and risk of sepsis was assessed by MR Egger,weighted median,inverse variance weighting,simple model,and weighted model.Results Inverse variance weighting showed a significant negative association between vitamin C supplementation and the risk of sepsis(P=0.030).Sensitivity analysis was consistent with no significant evidence of significant heterogeneity or pleiotropy.Conclusion There is a potential reverse causal relationship between vitamin C supplementation and reduced sepsis risk,and appropriate vitamin C supplementation may provide a feasible intervention for sepsis prevention.

Objective To establish a simplified simulation method of rocking-chair archwire(RCA),explore the biomechanical effect of RCA during anterior teeth retraction with sliding mechanics,and provide guidance for clinical treatment.Methods A standard 0.019 in×0.025 in(0.483 mm×0.635 mm)labial archwire was imported into ANSYS software and preloaded spring was used to simulate RCA at different angles to achieve parameterized modeling.A three-dimensional(3D)finite element model with labial straight wire appliance,teeth,periodontium and maxillary bone was established to analyze the displacement and force of anterior/posterior teeth under 1.5 N intra-arch traction combined with RCA at different angles.Results Preloading forces of 1.5,3,4.5,and 6 N in spring induced angles of approximately 5°,10°,15°,and 20° for RCA,demonstrating the flexibility and convenience of the parameterized modeling method.During intra-arch traction with increased angle of RCA,lingual crown displacement of the middle incisor gradually decreased,while the lateral incisor and canine showed decreased crown tipping and increased lingual root displacement;when the RCA angle was 20°,the lateral incisor and canine achieved almost bodily retraction.Meanwhile,premolars showed an extrusion tendency,while molars demonstrated distal crown tipping and intrusion tendency.As the RCA angle increased from 0° to 20°,intrusive force on the anterior teeth increased,and the moment-force ratio(M/F)at bracket level increased from 0 to near 9 mm.Conclusions RCA can effectively control the moving pattern of the maxillary anterior teeth and prevent their over-erection and extrusion during retraction with sliding mechanics.During intra-arch traction with rigid stainless steel archwire,theoretically RCA of 20° has sufficient torque control on the anterior teeth to achieve their en-masse retraction.

Objective To assess on-related association and causality of vitamin C supplementation and sepsis risk by using two-sample Mendelian randomization(MR)design.Methods The study was based on Genome-Wide Association Studies data to screen single nucleotide polymorphisms associated with vitamin C supplementation as instrumental variables.The association of vitamin C supplementation and risk of sepsis was assessed by MR Egger,weighted median,inverse variance weighting,simple model,and weighted model.Results Inverse variance weighting showed a significant negative association between vitamin C supplementation and the risk of sepsis(P=0.030).Sensitivity analysis was consistent with no significant evidence of significant heterogeneity or pleiotropy.Conclusion There is a potential reverse causal relationship between vitamin C supplementation and reduced sepsis risk,and appropriate vitamin C supplementation may provide a feasible intervention for sepsis prevention.

BACKGROUND:Poisoned patients often suffer damage to multiple systems,and those experiencing central nervous system disorders present more severe conditions,prolonged hospital stays,and increased mortality rates.We aimed to assess the efficacy of rehabilitation interventions for patients with toxic encephalopathy. METHODS:This retrospective,observational,comparative cohort study was performed at the teaching hospital affiliated of Nanjing Medical University,from October 2020 to December 2022.Patients who met the diagnostic criteria for toxic encephalopathy and exclusion criteria were included,and patients were divided into three subgroups according to Glasgow Coma Scale(GCS).Demographic and clinical characteristics were collected.The effect of the rehabilitation intervention on patients were assessed in the improvement of consciousness status(Glasgow Coma Scale[GCS]score),muscle strength and movement and swallowing function(Fugl-Meyer Assessment[FMA]scale,Water Swallow Test[WST],and Standardized Swallowing Assessment[SSA]).Subgroup analysis was based on different toxic species. RESULTS:Out of the 464 patients with toxic encephalopathy,184 cases received rehabilitation treatments.For the severe toxic encephalopathy patients,patients without rehabilitation intervention have a 2.21 times higher risk of death compared to patients with rehabilitation intervention(Hazard ratio[HR]=2.21).Subgroup analysis revealed that rehabilitation intervention significantly increased the survival rate of patients with pesticide poisoning(P=0.02),while no significant improvement was observed in patients with drug/biological agent poisoning(P=0.44).After rehabilitation intervention,significant improvement in GCS and FMA were observed in severe patients with toxic encephalopathy(P<0.01). CONCLUSION:Active rehabilitation intervention for patients exposed to poisons that can potentially cause toxic encephalopathy may improve the prognosis and reduce the mortality rate in clinical practice.

This article reports a patient with hepatic coma who underwent artificial liver support therapy and liver transplantation successfully， and the patient recovered well in the later stage after active treatment. This article also discusses the timing of liver transplantation.

Objective:To explore the early coagulation function changes of penetrating intestinal firearm injury of pig in high-altitude environments.Methods:Twenty healthy long white piglets were selected and divided into the plain group and the high-altitude group using the random number table method, with 10 pigs in each group. Pigs in the plain group were placed in a plain environment at an altitude of 800 meters, while pigs in the high-altitude group were placed in an experimental chamber simulating an altitude of 6 000 meters for 48 hours. Both groups received pistol gunshot to have firearm penetrating wounds to the abdominal intestinal tract and then returned to the plain observation room. At 0, 2, 4, 8, 12 and 24 hours after injury, coagulation in the peripheral blood and fibrinolytic indexes [prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), fibrinogen (Fbg), D-dimer (D-D), and fibrinogen degradation product (FDP)], thromboelastogram (TEG) [reaction time (R), clotting time (K), clot formation rate (α), maximum amplitude (MA) and coagulation composite index (CI) ], platelet parameters [platelet count (PLT), mean platelet volume (MPV), platelet distribution width (PDW), and platelet-large cell ratio (P-LCR)] in the two groups were detected separately.Results:The PT values at 0 and 2 hours after injury in the high-altitude group were significantly lower than those in the plain group, while they were significantly higher at 8, 12 and 24 hours than those in the plain group ( P<0.01); there was no significant difference at 4 hours between the two groups ( P>0.05). The APTT values at 0, 2 and 4 hours after injury in the high-altitude group were significantly lower than those in the plain group, while they were significantly higher at 8, 12 and 24 hours after injury than those in the plain group ( P<0.01). The TT values at 0, 2 and 4 hours after the injury in the high-altitude group were significantly lower than those in the plain group, while they were significantly higher at 12 and 24 hours after injury than those in the plain group ( P<0.01); there was no significant difference at 8 hours after injury between the two groups ( P>0.05). The Fbg, D-D and FDP values at 0, 2, 4, 8, 12 and 24 hours after injury were higher in the high-altitude group than those in the plain group ( P<0.01). The R values at 0, 2 and 4 hours after injury in the high-altitude group were significantly lower than those in the plain group, while they were significantly higher at 8, 12 and 24 hours after injury than those in the plain group ( P<0.01). The K values at 0, 2, 4 and 8 hours after injury in the high-altitude group were significantly lower than those in the plain group, while they were significantly higher at 12 and 24 hours after injury than those in the plain group ( P<0.05 or 0.01). The α angles at 0, 2 and 4 hours after injury in the high-altitude group were significantly higher than those in the plain group, while they were significantly lower at 8, 12 and 24 hours after injury than those in the plain group ( P<0.01). The MA values at 0, 2 and 4 hours after the injury in the high-altitude group were significantly higher than those in the plain group, while they were significantly lower at 8, 12 and 24 hours after injury than those in the plain group ( P<0.01). The CI values at 0, 2 and 4 hours after injury in the high-altitude group were significantly higher than those in the plain group, while they were significantly lower at 8, 12 and 24 hours after injury than those in the plain group ( P<0.01). The PLT values at 0, 2, 4 and 8 hours after injury in the high-altitude group were significantly higher than those in the plain group, while they were significantly lower at 12 and 24 hours after injury than those in the plain group ( P<0.05 or 0.01). The MPV values at 0, 2, 4, 8, 12 and 24 hours after injury in the high-altitude group were significantly higher than those in the plain group ( P<0.01). The PDW values at 2, 4, 8, 12 and 24 hours after injury in the high-altitude group were significantly higher than those in the plain group ( P<0.05 or 0.01), while there was no significant difference in PDW at 0 hour after injury between the two groups ( P>0.05). The P-LCR values at 0, 2, 4, 8, 12 and 24 hours after injury in the high-altitude group were all significantly higher than those in the plain group ( P<0.01). Conclusion:Compared with the plain environments, pig intestinal firearm penetrating injury in the high-altitude environments is more prone to early hypercoagulable state accompanied by mild hyperfibrinolysis, and faster to reach a hypocoagulable state accompanied by obvious hyperfibrinolysis.

BACKGROUND:Poisoned patients often suffer damage to multiple systems,and those experiencing central nervous system disorders present more severe conditions,prolonged hospital stays,and increased mortality rates.We aimed to assess the efficacy of rehabilitation interventions for patients with toxic encephalopathy. METHODS:This retrospective,observational,comparative cohort study was performed at the teaching hospital affiliated of Nanjing Medical University,from October 2020 to December 2022.Patients who met the diagnostic criteria for toxic encephalopathy and exclusion criteria were included,and patients were divided into three subgroups according to Glasgow Coma Scale(GCS).Demographic and clinical characteristics were collected.The effect of the rehabilitation intervention on patients were assessed in the improvement of consciousness status(Glasgow Coma Scale[GCS]score),muscle strength and movement and swallowing function(Fugl-Meyer Assessment[FMA]scale,Water Swallow Test[WST],and Standardized Swallowing Assessment[SSA]).Subgroup analysis was based on different toxic species. RESULTS:Out of the 464 patients with toxic encephalopathy,184 cases received rehabilitation treatments.For the severe toxic encephalopathy patients,patients without rehabilitation intervention have a 2.21 times higher risk of death compared to patients with rehabilitation intervention(Hazard ratio[HR]=2.21).Subgroup analysis revealed that rehabilitation intervention significantly increased the survival rate of patients with pesticide poisoning(P=0.02),while no significant improvement was observed in patients with drug/biological agent poisoning(P=0.44).After rehabilitation intervention,significant improvement in GCS and FMA were observed in severe patients with toxic encephalopathy(P<0.01). CONCLUSION:Active rehabilitation intervention for patients exposed to poisons that can potentially cause toxic encephalopathy may improve the prognosis and reduce the mortality rate in clinical practice.