Background Due to the unique working environment and numerous occupational disease hazards, workers in mining industry are particularly susceptible to psychological problems such as occupational stress. Objective To understand the current status of occupational stress, depressive symptoms, anxiety symptoms and sleep quality of workers in ferrous and non-ferrous metal mining industry in Gansu Province, and to explore the effects of occupational stress on depressive symptoms, anxiety symptoms, and sleep. Methods From April to December 2022, the workers of 25 large, medium, and small and micro enterprises were selected by stratified cluster random sampling and surveyed in ferrous and non-ferrous metal mining industry in Gansu Province. The Occupational Health Literacy Questionnaire of National Key Population, Core Occupational Stress Scale, Patient Health Questionnaire-q, Generalized Anxiety Disorder, and Self-administer Sleep Questionnaire were used to collect basic information, occupational stress, depressive symptoms, anxiety symptoms, and sleep quality of the workers. Chi-square test was used to compare occupational stress, depressive symptoms, anxiety symptoms and sleep disorders among different categories. Logistic regression model was used to study the effects of occupational stress on depressive symptoms, anxiety symptoms, and sleep quality. Results In this study, 2192 workers in mining industry were surveyed, of which 2087 returned valid questionnaires, and the recovery rate of valid questionnaires was 95.2%. Among them, 728 (38.4%) reported occupational stress. There were statistically significant differences in the positive rate of occupational stress among workers by gender, age, marital status, education level, average monthly income, length of service, enterprise size, and night shifts (P<0.001). The positive rates of depressive symptoms, anxiety symptoms, and sleep disorders in the mining industry workers were 85.6%, 49.8%, and 47.3%, respectively. The positive rates of depressive symptoms, anxiety symptoms, and sleep disorders among workers with higher occupational stress were higher than those among workers without occupational stress (P<0.001). The logistic regression analysis showed that occupational stress was a common risk factor for depressive symptoms (OR=3.29, 95%CI: 2.26, 4.79), anxiety symptoms (OR=2.87, 95%CI: 2.33, 3.53), and sleep disorder (OR=1.78, 95%CI: 1.46, 2.16). In addition, length of service and enterprise-scale were also risk factors for depressive symptoms, anxiety symptoms, and sleep disorders. In the 5−<10 and 10−<20 years of service groups, the risks of reporting depressive symptoms were 1.80 (95%CI: 1.18, 2.74) and 1.73 (95%CI: 1.10, 2.71) times higher than that of workers with less than 1 year of service, respectively; the risks of reporting anxiety symptoms were 1.98 (95%CI: 1.42, 2.76) and 2.11 (95%CI: 1.48, 3.01) times higher than that with less than 1 year of service, respectively; the risks of reporting sleep disorders were 1.58 (95%CI: 1.15, 2.16) and 1.78 (95%CI: 1.29, 2.45) times higher than that with less than 1 year of service, respectively. Workers in large enterprises were inclined to report more depressive symptoms, anxiety symptoms, and sleep disturbances than those in micro and small enterprises (OR=3.53, 95%CI: 2.41, 5.16; OR=2.49, 95%CI: 1.98, 3.13; OR=2.10, 95%CI: 1.67, 2.62). Conclusion The occupational stress level of mining industry workers in Gansu Province is high, and reporting occupational stress, 5−<10 and 10−<20 working age groups, and large enterprises are important risk factors affecting workers' mental health and sleep. It is necessary to increase the attention and develop intervention programs for mental health of miners in the working age group of 5−20 years old and in large enterprises.

Objective To observe the severity of cerebral edema after mechanical thrombectomy in the patients with acute ischemic stroke caused by large vessel occlusion,and to statistically analyze the related fac-tors affecting the prognosis quality of the patients,so as to guide the patients to conduct scientific interven-tion.Methods Ninety-one patients with acute ischemic stroke due to anterior circulation large vessel occlusion treated with mechanical thrombectomy in this hospital from October 2021 to October 2022 served as the ana-lytic subjects.According to the severity of brain edema,they were divided into the group Ⅰ(mild),group Ⅱ(moderate),and group Ⅲ(severe);after 12-week treatment,the improved Rankin scale was used to evaluate the prognosis.The patients with good prognosis were included in the excellent group,and the patients with poor prognosis were included in the poor group.Single factor and multifactor logistic analysis was used to ana-lyze the influencing factors and prognostic related factors of different degrees of brain edema.Results The univariate analysis showed that the percentage of patients with NIHSS score at admission ≥15,time from on-set to thrombolysis ≥6 h,history of hypertension,successful vascular recanalization and good collateral circu-lation were significantly different among the groups Ⅰ,Ⅱ and Ⅲ(P＜0.05);the multivariate logistic regres-sion analysis results showed that the NIHSS score at admission ≥15,time from onset to thrombolysis ≥6 h,and hypertension history were the risk factors leading to severe cerebral edema,while successful recanalization of blood vessels was a protective factor for cerebral edema(P＜0.05).The univariate analysis showed that in the good prognosis group the percentage of patients had good circulation of lateral branches,successful reca-nalization of blood vessels,severe cerebral edema,hypertension,time from onset to thrombolysis ≥6 h,and NIHSS score ≥15 at admission were significantly different from those in the poor prognosis group(P＜0.05).The multivariate logistic regression analysis results showed that severe cerebral edema,time from onset to thrombolysis ≥6 h and NIHSS score ≥15 at admission were the risk factors for poor prognosis,while good collateral circulation and successful recanalization of blood vessels were the positive factors for good prognosis(P＜0.05).Conclusion Mechanical thrombectomy patients with hypertension and time from onset to throm-bolysis ≥6 h and NIHSS score at admission ≥15 have more severe brain edema after treatment;severe brain edema,time from onset to thrombolysis ≥6 h,NIHSS score at admission ≥15 were the adverse factors affect-ing the prognosis of the patients with mechanical thrombectomy.

Objective:To identify the differentially expressed proteins that caused hippocampal damage after liver ischemia-reperfusion (I/R) in rats.Methods:Eighteen clean-grade healthy juvenile male Sprague-Dawley rats, aged 2 weeks, weighing 20-30 g, were divided into 2 groups ( n=9 each) using a random number table method: sham operation group (S group) and liver I/R group (IR group). A rat model of liver I/R injury was prepared by restoring perfusion after 1 h of liver ischemia. The rats were sacrificed after being anesthetized at day 3 of reperfusion, and the hippocampal tissue was isolated and analyzed to obtain gene expression profiles. Differentially expressed genes were identified using the R software, and further protein interaction networks were constructed through Cytoscape and Kyoto Encyclopedia Genes and Genomes pathway analysis to determine the differentially expressed proteins. Quantitative real-time polymerase chain reaction and Western blot were used for validation. Results:A total of 45 differentially expressed proteins were identified by the proteomic analysis of hippocampal tissues, including 36 significantly up-regulated proteins and 9 significantly down-regulated proteins. The proteins with significant expression related to injury were identified from the PPI network complex using the CytoHubBA plug-in cystscape: Ras-related C3 botulinum toxin substrate (RAC2), HRAS, phosphatidylinositol-3-kinase inhibitor phosphatase and tensin homologue (PTEN), and N-methyl-D-aspartate ionotropic glutamate receptor 2b (GRIN2b). The results of quantitative real-time polymerase chain reaction and Western blot showed that the expression of RAC2, HRAS, PTEN, and GRIN2b in the hippocampal tissue was significantly up-regulated in IR group compared with S group ( P<0.05). The results of Kyoto Encyclopedia of Genes and Genomes pathway analysis showed that differentially expressed proteins were significantly enriched in the expression of PD-L1 and its checkpoint pathway, long-term potentiation, and regulation of the Wnt signaling pathway in cancer. Conclusions:The mechanism by which liver I/R induces hippocampal injury may be related to the up-regulation of the expression of RAC2, HRAS, PTEN and GRIN2b in rats.

Objective:To investigate the effect and mechanism of vitamin D supplementation on Hashimoto′s thyroiditis(HT).Methods:Female SD rats were randomly divided into four groups by random number table method: control group, experimental autoimmune thyroiditis(EAT) control model group(model group), low-dose(VD1 group) and high-dose(VD2 group) active vitamin D intervention groups. The morphology of thyroid cells, thyroid function, thyroid antibodies, various CD4 + T cells, and related cytokine levels among different groups were compared. Results:The levels of thyroid peroxidase antibody(TPOAb) and thyroid globulin antibody(TgAb) in model group were significantly higher than those in control group, while the levels of VD1 and VD2 groups were significantly lower than those in model group( P<0.05). Compared with control group, HE staining in model group showed severe damage of follicular epithelial cells; Compared with model group, the degree of atrophy and destruction of follicular epithelial cells in VD1 and VD2 groups were reduced. The proportion of helper T cell(Th)1 and Th17 cells and related cytokine levels in model group were significantly higher than those in control group, while those in VD1 and VD2 groups were lower than those in model group( P<0.05); The proportion of regulatory T cell(Treg) cells and related cytokine levels in model group were significantly lower than those in control group, while those in VD1 and VD2 groups were higher than those in model group( P<0.05). Conclusions:After supplementing with vitamin D, the levels of TPOAb and TgAb in EAT rats decreased, and the number of various CD4 + T cells and related cytokine levels tended towards normalization. This suggests that vitamin D may improve HT by regulating CD4 + T cell differentiation, providing a theoretical basis for the role of vitamin D supplementation in HT treatment.

Objective To explore the changes in macrophage infiltration behavior during the dynamic evolution of thrombi following the formation of acute carotid artery thrombosis occlusion(ACTO).Methods 15 healthy male New Zealand rabbits were selected to establish an ACTO model by causing injury to the rabbit carotid artery using surgical sutures treated with ferric chloride.All rabbits were randomly divided into 5 groups according to the end-point time using the random number table method,namely 24-hour group,1 week group,4week group,8 week group,and 12week group postoperatively,with 3 rabbits in each group.At 24 hours post-operation,the ACTO model was examined by DS A.At 24 hours,1 week,4 weeks,8 weeks,and 12 weeks post-operation,samples were taken from the thrombotic arterial segment of the 3 rabbits in each group and embedded in paraffin.The thrombus samples were stained with hematoxylin-eosin(HE)and Martius scarlet blue(MSB)to analyze changes in thrombus morphology and composition(including red blood cells,fibrin and collagen fibers).Orbit Imaging Analysis software was used for semi-quantitative analysis of the thrombus composition components.Using immunohistochemistry to detect the distribution of MO and M2 macrophages in thrombi,aimed to summarize the dynamic evolution of thrombus morphology,composition,and macrophage infiltration behavior at different stages following ACTO occurrence.Results The 24-hour DSA results indicated that all experimental rabbits successfully established the ACTO model.(1)HE staining showed a continuous increase in thrombus size from 24 hours to 1 week.By 4 weeks,signs of thrombus dissolution appeared,and at 8 weeks,neovascularization was observed within the thrombus.By 12 weeks,signs of fibrosis were evident in the thrombus.(2)MSB staining revealed that during the acute phase of thrombus formation(within 24 hours after surgery),red blood cells were the predominant component initially,but after this period,fibrin and collagen fibers became the main components.(3)The detection results of MO macrophages showed that 24 hours after surgery,MO macrophages in the thrombus were not evenly distributed throughout the thrombus,but mainly gathered at the thrombus edge;at 1 week after surgery,the positive area percentage of MO macrophage in the thrombus increased compared with 24 hours after surgery(thrombus edge:[41.7±27.0]％vs.[24.6±16.7]％,thrombus core:[35.7±19.6]％vs.[11.1±10.4]％,all P＜0.001),and evenly distributed within the thrombus;at 4 weeks after surgery,MO macrophages in the thrombus decreased compared with 1 week after surgery(thrombosis edge:[10.7±6.1]％vs.[41.7±27.0]％,thrombus core:[12.1±8.5]％vs.[35.7±19.6]％,all P＜0.001),the differences were statistically significant.At 4,8,and 12 weeks after surgery,MO macrophages within the thrombus did not change significantly with time(thrombus edge:[10.7±6.1]％,[8.0±7.7]％,and[8.9±5.3]％;thrombus core:[12.1±8.5]％,[9.5±4.2]％,and[15.7±11.0]％),and the differences were not statistically significant(all P＞0.05).In addition,at 12 weeks after surgery,MO macrophages at the thrombus edge was less than the thrombus core([8.9+5.3]％vs.[15.7±11.0]％,P＜0.01).The detection results of M2 macrophages showed that 24 hours after surgery,M2 macrophages in the thrombus were widely distributed throughout the thrombus;at 1 week after surgery,the positive area percentage of M2 macrophages in the thrombus increased compared with 24 hours after surgery(thrombus edge:[22.1±11.3]％vs.[11.4±8.7]％,P＜0.001;thrombus core:[24.5±9.8]％vs.[7.6±6.0]％,P＜0.001);at 4 weeks after surgery,M2 macrophage in the thrombus decreased compared with 1 week after surgery(thrombosis edge:[10.6±3.7]％vs.[22.1±11.3]％,P＜0.001;thrombus core:[9.2±4.3]％vs.[24.5±9.8]％,P＜0.001);at 8 weeks after surgery,M2 macrophages in the thrombus increased compared with 4 weeks after surgery([17.9±8.8]％vs.[9.2±4.3]％,P＜0.001),and the differences were statistically significant.However,M2 macrophages in the thrombus did not change significantly from 8 weeks to 12 weeks after surgery(thrombus edge:[9.4±6.3]％vs.[8.5±5.3]％,P＞0.05;thrombus core:[17.9±8.8]％vs.[14.4±10.0]％,P＞0.05).In addition,at 8 and 12 weeks after surgery,M2 macrophages in the thrombus core was greater than the thrombus edge(8 weeks after surgery:[17.9±8.8]％vs.[9.4±6.3]％,P＜0.001;12weeks after surgery:[14.4±10.0]％vs.[8.5±5.3]％,P＜0.001).Conclusions This study successfully established an ACTO animal model and demonstrated for the first time the dynamic evolution of macrophages within 12 weeks post-thrombus formation.Macrophages may played a significant role in both thrombus formation and fibrinolysis,as well as in the promotion of thrombus dissolution and the formation of new blood vessels within the thrombus which may potentially promote the spontaneous reperfusion of the occluded vessels.The results of this study need further verification.

Objective:To explore the safety key points of total pancreaticoduodenectomy in the era of vascular resection technology and the important factors affecting rapid postoperative recovery.Methods:The clinical data of 52 patients with pancreatic cancer who underwent total pancreaticoduodenectomy in Beijing Chaoyang Hospital Affiliated to Capital Medical University from November 2014 to September 2022 were retrospectively analyzed, including 34 males and 18 females, aged (62±9). The intraoperative situation, incidence of postoperative complication, postoperative blood glucose control and postoperative survival rate were analyzed.Results:All operations of the 52 patients were successfully completed, including 48 patients underwent total pancreaticoduodenectomy combined with portal vein resection and allograft vascular grafts via artery approach. The portal vein occlusion time was (20±5) min. The incidence of postoperative complications was 28.8% (15/52), including 2 cases of abnormal gastric empty, 2 cases of diarrhea, 2 cases of chylous fistula, 4 cases of abdominal infection, 1 case of gastrointestinal fistula, 3 cases of gastrointestinal bleeding, and 1 case of pulmonary infection. Subcutaneous short-acting insulin injection was used to control blood glucose in the early stage after surgery, short-acting insulin combined with long-acting insulin was used for subcutaneous injection before sleep for diet recovery. All patients did not experience uncontrolled hyperglycemia. The median survival time of 52 patients was 13 months, and the longest follow-up time was 38 months. There were 37 patients died of tumor recurrence, 4 patients died of cardiovascular and cerebrovascular accidents, and 1 patient died of pulmonary infection in the 42 died patients.Conclusions:Total pancreaticoduodenectomy via artery approach can improve the R 0 resection rate in pancreatic cancer patients with vascular invasion, the rate of postoperative complication and mortality has no significant increase. The postoperative blood sugar control is satisfactory and the quality of life is guaranteed.

Objective:To explore the effect of esketamine on inflammatory cytokines and myocardial injury markers in children undergoing living-donor liver transplantation (LT).Methods:Considering the inclusion criteria, 50 children with biliary atresia were selected for living donor LT. They were equally randomized into two groups of control (C) and esketamine (E) (25 cases each). Esketamine 0.5 mg/kg was administered to group E during induction and continued at a dose of 0.5 mg·kg –1·h -1 after an induction of anesthesia. Group C provided the same dose of 0.9% sodium chloride injection during induction and then continued to pumping until the end of the procedure. Basic profiles of two groups were recorded. Hemodynamic parameters, such as heart rate (HR), mean arterial pressure (MAP) and central venous pressure (CVP), were monitored at 5 min of anesthesia induction (T 0), 30 min of anhepatic phase (T 1), immediately after repercussion (T 2), 30 min of neohepatic phase (T 3) and end of surgery (T 4) in both groups. Central venous blood samples were collected at T 0, T 1, T 3 and T 4. Serum levels of cardiac troponin I (cTnI), creatine kinase isoenzyme-MB (CK-MB) ,tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) were measured. The incidence of adverse cardiac events, postoperative mechanical ventilation time, ICU stay and hospitalization length were compared. Results:As compared with T 0, mean arterial pressure (MAP) at T 2 declined markedly in group E [(48.6±12.7) mmHg (1 mmHg=0.133 kPa) vs (55.6±10.7) mmHg, P<0.001] and C [(39.3±8.0) mmHg vs (53.2±9.4) mmHg, P<0.001 ] ;As compared with T 0, the TNF-α and IL-6 spiked at T 3 in group C [169.0 (207.1) ng/L vs 43.8 (26.4) ng/L, (132.63±51.75) ng/L vs (51.79±17.83) ng/L, P<0.001] and E [78.5 (138.8) ng/L vs 43.8 (26.4) ng/L, (87.44±32.17) ng/L vs (51.79±17.83) ng/L, P<0.001 ] ; In group C, the concentration of myocardial injury markers CK-MB and cTnI rose at T 3/T 4 compared with T 0[T 3 vs T 0: 5.7 (5.4) μg/L vs 4.0 (3.5) μg/L, 0.09 (0.08) μg/L vs 0.02 (0.02) μg/L; T 4 vs T 0: 5.3 (5.0) μg/L vs 4.0 (3.5) μg/L, 0.07 (0.08) μg/L vs 0.02 (0.02) μg/L, P<0.001 ]. In group E, the levels of CK-MB and cTnI were higher at T 3/T 4 than those at T 0[T 3 vs T 0: 7.0 (5.0) μg/L vs 4.6 (2.1) μg/L, 0.06 (0.09) μg/L vs 0.03 (0.04) μg/L; T 4 vs T 0: 5.4 (4.9) μg/L vs 4.6 (2.1) μg/L, 0.03 (0.06) μg/L vs 0.03 (0.04) μg/L; P<0.001]. Compared with group C, the MAP of E rose at T 1/T 2/T 3 [(58.8±10.3) mmHg vs (53.3±8.6) mmHg, P=0.048; (48.6±12.7) mmHg vs (39.3± 8.0) mmHg, P=0.003; (55.8±7.4) mmHg vs (51.5±7.3) mmHg, P=0.044]. Compared with group C, TNF-α and IL-6 decreased in E at T 3/T 4[T 3: 78.5 (138.8) ng/L vs 169.0 (207.1) ng/L, P=0.010; (87.44±32.17) ng/L vs (132.63±51.75) ng/L, P=0.017. T 4: 62.3 (118.3) ng/L vs 141.3 (129.2) ng/L, P=0.001; (74.34±26.38) ng/L vs (100.59±30.40) ng/L, P=0.002]. Compared with group C, cTnI decreased in E at T 3/T 4[0.06 (0.09) μg/L vs 0.09 (0.08) μg/L, P=0.014; 0.03 (0.06) μg/L vs 0.07 (0.08) μg/L, P=0.003]. Compared with group C, the mechanical ventilation time in group E decreased [195 (120) min vs 315 (239) min, P<0.001]. Compared with group C, the incidence of severe hypotension [16%(4/25) vs 48% (12/25), P=0.015 ], bradycardia [12% (3/25) vs 36 % (9/25), P=0.047 ], myocardial ischemia [4 % (1 /25) vs 24 % (6/25), P=0.042 ] and premature ventricular contractions [0 vs 4 %(1/25), P=0.312 ] decreased in group E. Conclusion:Intraoperative dosing of esketamine may suppress inflammatory reactions and alleviate perioperative myocardial injury in children undergoing living-donor LT.

Objective:To compare the myocardial protection in pediatric patients undergoing living-donor liver transplantation (LDLT) performed under propofol- versus desflurane-based anesthesia. Methods:Sixty American Society of Anesthesiologists Physical Status classification Ⅲ or Ⅳ pediatric patients of both sexes, aged 5-24 months, weighing 5-15 kg, scheduled for elective LDLT under general anesthesia, were divided into 2 groups ( n=30 each) using a random number table method: propofol group (group P) and desflurane anesthesia group (group D). During anesthesia maintenance, propofol 5-10 mg·kg -1·min -1 was intravenously infused in group P, desflurane 0.65 MAC-1.30 MAC was inhaled in group D. At 5 min after induction of anesthesia, at 1 h of reperfusion, at the end of surgery, at 1, 2, 3, 7 and 14 days after surgery, and on the day of discharge, the concentrations of serum high-sensitivity cardiac troponin I, creatine kinase isoenzyme, N-terminal pro-B-type natriuretic peptide were determined by enzyme-linked immunosorbent assay, the occurrence of nausea and vomiting, agitation, and shivering, postoperative tracheal extubation time, intensive care unit stay time, and postoperative length of hospital stay were recorded within 24 h after surgery. Results:Compared with group P, the concentrations of serum high-sensitivity cardiac troponin I and creatine kinase isoenzyme were significantly decreased after surgery, the extubation time and intensive care unit stay time were shortened ( P<0.05), and no significant change was found in serum N-terminal pro-B-type natriuretic peptide concentrations, postoperative length of hospital stay and incidence of postoperative adverse effects at each time point in group D ( P>0.05). Conclusions:Desflurane has better myocardial protection than propofol in pediatric patients undergoing LDLT, which is helpful for early prognosis.

Objective:To evaluate the value of preoperative serum miRNA-146a-5p expression in predicting postoperative delirium (POD) in the pediatric patients undergoing living donor liver transplantation.Methods:Eighty pediatric patients with congenital biliary atresia, aged 5-12 months, with body mass index of 4-10 kg, of American Society of Anesthesiologists Physical Status classification Ⅱ or Ⅲ, undergoing elective living donor liver transplantation in our hospital, were selected. Venous blood samples were collected at 1 day before surgery, and serum miRNA-146a-5p expression was detected by quantitative real-time polymerase chain reaction. The children′s cognitive function was evaluated using the Mini-Mental State Examination and the Modified Montreal Cognitive Assessment at 1 day before operation and at 1, 3 and 7 days after operation. The pediatric patients were divided into POD group and non-POD group according to whether POD occurred within 7 days after surgery. Multiple logistic regression analysis was used to evaluate the relationship between serum miRNA-146a-5p expression and POD, Pearson′s correlation analysis was used to analyze the correlation between miRNA-146a-5p and POD, and the receiver operating characteristic curves were used to evaluate the accuracy of serum miRNA-146a-5p concentrations in predicting the occurrence of POD.Results:There were 30 cases in POD group and 50 cases in non-POD group, and the incidence of POD was 38%. The results of multiple logistic regression analysis showed that down-regulated serum miR-146a-5p expression was an independent risk factor for POD in pediatric patients undergoing living donor liver transplantation ( P<0.05). The incidence of POD was negatively correlated with serum miRNA-146a-5p expression ( r=-0.658, P<0.001). The area under the receiver operating characteristic curve of serum miRNA-146a-5p expression in predicting POD was 0.870 in pediatric patients undergoing living donor liver transplantation, with a sensitivity of 0.825 and a specificity of 0.875. Conclusions:Preoperative serum miRNA-146a-5p expression has a certain predictive value for POD in the pediatric patients undergoing living donor liver transplantation.

Objective:To evaluate the effect of patent foramen ovale (PFO) on the perioperative complications and survival rate in pediatric patients undergoing living donor liver transplantation.Methods:The medical records from pediatric patients of either sex with biliary atresia, aged<18 yr, who underwent living donor liver transplantation from January 2020 to January 2022, were retrospectively collected. The pediatric patients were divided into PFO group and non-PFO group according to the results of echocardiography before operation. The postreperfusion syndrome, acute lung injury, acute kidney injury, postoperative delirium and 1-year survival rate were recorded.Results:There was no significant difference in the incidence of postreperfusion syndrome, acute lung injury, acute kidney injury, postoperative delirium and one-year survival rate between PFO group and non-PFO group ( P>0.05). Conclusions:PFO has no obvious effect on the incidece of intraoperative and early postoperative complications and 1-year survival rate in pediatric patients undergoing living donor liver transplantation.