Objective:To explore the predictive value of different critical values of slow gait speed on adverse outcomes in elderly maintenance hemodialysis (MHD) patients.Methods:The study was a prospective cohort study. The clinical data of elderly patients (≥ 60 years old) who received MHD treatment in the Third Affiliated Hospital of Guangzhou Medical University from March 1 to June 30, 2021 were collected, including demographic characteristics, diseases-related data and laboratory examination results. The follow-up period was one year. The six-meter walking test was used to measure the gait speed (m/s), and 0.6 m/s, 0.8 m/s and 1.0 m/s were used as the different critical values of the gait speed for grouping. The differences of clinical data between different groups were compared. Logistic regression analysis method was used to assess the association of slow gait speed with adverse outcomes (falls and hospitalization) in elderly MHD patients. The receiver operating characteristic (ROC) curve was performed to evaluate the best critical value of slow gait speed to predict the risk of falls and hospitalization.Results:A total of 108 elderly patients with MHD were included, with 57 males and 51 females. There were 43 patients (39.8%) of falls and 34 patients (31.5%) of hospitalization. There were statistically significant differences in age, Charlson's comorbidity index, and the proportions of hypertension, family support needed in daily life, walking aids needed, falls and hospitalization events among the four groups of the patients grouped according to gait speed (all P < 0.05). Multivariate logistic regression analysis results showed that the risk of falls predicted by gait speed of 0.6- < 0.8 m/s was higher than that by gait speed of > 1.0 m/s ( OR=3.973, 95% CI 1.116-14.136, P=0.033). The risk of hospitalization predicted by gait speed < 0.6 m/s was higher than that by gait speed > 1.0 m/s ( OR=9.147, 95% CI 1.658-50.453, P=0.011). The logistic regression analysis was performed with the critical values of 0.6 m/s, 0.8 m/s and 1.0 m/s as the classification variables, and the results showed that the gait speed of < 0.8 m/s was an influencing factor of the falls risk in elderly MHD patients (≥ 0.8 m/s as reference, OR=3.200, 95% CI 1.099-9.318, P=0.033). The gait speed < 0.8 m/s and < 0.6 m/s were influencing factors of hospitalization (≥ 0.8 m/s as reference, OR=3.899, 95% CI 1.355-11.216, P=0.012; ≥ 0.6 m/s as reference, OR=4.226, 95% CI 1.107-16.140, P=0.035). The area under the ROC curve for gait speed of < 0.6 m/s, < 0.8 m/s and < 1.0 m/s to predict the risk of falls were 0.605(95% CI 0.493-0.717, P=0.065), 0.668(95% CI 0.562-0.774, P=0.003), and 0.634 (95% CI 0.529-0.739, P=0.019), respectively. The best critical value of slow gait speed to predict the risk of fall was 0.73 m/s, and the area under the ROC curve was 0.720(95% CI 0.623-0.817, P < 0.001), with the sensitivity and specificity of 0.846 and 0.512, respectively. The area under the ROC curve for gait speed of < 0.6 m/s, < 0.8 m/s and < 1.0 m/s to predict the risk of hospitalization were 0.629(95% CI 0.509-0.749, P=0.032),0.683(95% CI 0.573-0.793, P=0.002), and 0.608(95% CI 0.497- 0.719, P=0.073). The best critical value of slow gait speed to predict the risk of hospitalization was 0.81 m/s, and the area under the ROC curve was 0.688(95% CI 0.576-0.800, P=0.002), with the sensitivity and specificity of 0.689 and 0.676, respectively. Conclusion:The critical value of gait speed 0.8 m/s can be used to predict the risk of falls and hospitalization in elderly MHD patients.

Undergraduates in colleges and universities have great academic potential. In order to cultivate undergraduate innovative scientific research talents, the key is to improve the cultivation mode of undergraduates and stimulate students' academic potential. Taking the evidence-based medicine research group of Guangdong Medical University as an example, this paper systematically analyzes the specific measures and relevant practical experiences of the research team in the cultivation of undergraduates. The research team creatively uses the methods of "student guidance system", "PBL" mode and real-time feedback mechanism, and a complete talent training system has formed to explore a group of excellent undergraduate talents. Through innovative scientific research training, these undergraduates have made many achievements in academic research. This paper hopes these strategies and experiences can provide some reference for the cultivation of undergraduates in colleges and universities all over the country.

Objective:To investigate the effect of the average diameter of regional lymph node on tumor recurrence after operation of pancreatic head adenocarcinoma without lymph node metastasis.Methods:Clinical data of 49 patients with pancreatic head adenocarcinoma admitted to the 909th Hospital of Joint Logistic Support Force from January 2017 to June 2019 were retrospectively analyzed. The receiver operating characteristic (ROC) curve was used to analyze the average regional lymph node diameter for predicting the optimal threshold of tumor recurrence. The relationship between the average diameter of regional lymph nodes, recurrence and clinicopathological features were analyzed. The influencing factors of tumor recurrence 3 years after surgery were analyzed by logistic regression.Results:All 49 patients with pancreatic head adenocarcinoma were divided into a relapse group ( n=29) and a no-recurrence group ( n=20) based on whether the tumor recurred or not, and the recurrence rate was 59.18%. ROC curve analysis showed that the best threshold of average regional lymph node diameter for predicting tumor recurrence was 0.635 cm, the area under the curve was 0.82, the sensitivity was 0.69, and the specificity was 0.85. The average diameter of regional lymph nodes increased in patients with tumor diameter ≥2 cm ( t=-2.12, P=0.040), tumor with moderate and poorly differentiation ( t=-2.24, P=0.013), vascular invasion ( t=-3.47, P=0.001), nerve invasion ( t=-3.75, P<0.001), capsular invasion ( t=-4.25, P<0.001), and tumor recurrence ( t=-4.42, P<0.001). Univariate analysis showed that tumor diameter ( χ2=5.98, P=0.015), tumor stage ( χ2=3.88, P=0.049), tumor differentiation ( χ2=5.98, P=0.015), vascular invasion ( χ2=3.84, P=0.050), capsular invasion ( χ2=5.79, P=0.016), average lymph node diameter ( χ2=15.61, P<0.001), and postoperative chemotherapy ( χ2=3.89, P=0.049) were all related to whether the tumor recurred or not in patients with pancreatic head adenocarcinoma 3 years after surgery. Multivariate analysis results showed that tumor diameter ≥2 cm ( OR=2.72, 95% CI: 1.46-11.28, P=0.016), tumor with moderate and poorly differentiation ( OR=2.22, 95% CI: 1.23-6.53, P=0.020), capsular invasion ( OR=2.30, 95% CI: 2.19-8.91, P=0.017), and average lymph node diameter ≥0.635 cm ( OR=7.93, 95% CI: 1.25-50.31, P=0.002) were all independent influencing factors for tumor recurrence in pancreatic head adenocarcinoma patients 3 years after surgery. Conclusion:In patients with pancreatic head adenocarcinoma without lymph node metastasis, tumor diameter ≥2 cm, tumor with moderate and poorly differentiation, capsular invasion and average lymph node diameter ≥0.635 cm are independent risk factors for postoperative tumor recurrence. Patients with the average diameter of regional lymph nodes ≥0.635 cm increase the possibility of tumor recurrence after surgery, which can be used as the basis for postoperative evaluation and has certain clinical application value.