Learning misclassification costs for imbalanced classification on gene expression data.

BACKGROUND: Cost-sensitive algorithm is an effective strategy to solve imbalanced classification problem. However, the misclassification costs are usually determined empirically based on user expertise, which leads to unstable performance of cost-sensitive classification. Therefore, an efficient and accurate method is needed to calculate the optimal cost weights. RESULTS: In this paper, two approaches are proposed to search for the optimal cost weights, targeting at the highest weighted classification accuracy (WCA). One is the optimal cost weights grid searching and the other is the function fitting. Comparisons are made between these between the two algorithms above. In experiments, we classify imbalanced gene expression data using extreme learning machine to test the cost weights obtained by the two approaches. CONCLUSIONS: Comprehensive experimental results show that the function fitting method is generally more efficient, which can well find the optimal cost weights with acceptable WCA.

[Application of enhanced recovery after surgery in the treatment of children with congenital choledochal cyst].

OBJECTIVE: To explore the feasibility of enhanced recovery after surgery (ERAS) in treatment of children with congenital choledochal cyst. METHODS: One hundred and thirty children with congenital choledochal cysts admitted in the Children's Hospital of Zhejiang University from June 2017 to June 2019 were divided into ERAS group (n=65) and control group (n=65) according to admission order. The intestinal tract condition during operation, time of operation, surgical results, time for eating after operation, abdominal drainage after operation, length of hospital stay after operation, total hospital expenses and complications were compared between two groups. RESULTS: Compared with the control group, the satisfaction of intestinal operation field, recovery of gastrointestinal function after operation,time required for the volume of peritoneal drainage fluid to be less than 50 mL,time of abdominal drainage tube removal, and length of hospital stay were all improved in ERAS group (P<0.05 or P<0.01).ERAS group had more peritoneal effusion after removal of abdominal drainage tube (P<0.01), but the incidence of edema after operation was lower (P<0.05). The satisfaction of parents in the two groups was similar, but the cooperation of parents in the ERAS group was improved (P<0.05) and the total cost of hospitalization was reduced (P<0.01). CONCLUSIONS: ERAS has advantages over the traditional scheme and can be used in the clinical treatment of children with congenital choledochal cyst.

Investigation on nutritional risk assessment and nutritional support status of surgical patients with colorectal cancer.

PURPOSE: To investigate the malnutrition, the incidence of nutritional risk and the application of nutritional support for patients with colorectal cancer, so as to provide a basis for the rational clinical application of nutritional support. METHODS: A total of 264 surgical patients with colorectal cancer treated/followed up from January 2016 to March 2017 in Beijing Chaoyang Hospital were selected. The nutritional risk was assessed using the Nutritional Risk Screening 2002 (NRS2002), and the nutritional risk and application of nutritional support for patients with different gender, age and clinical disease stage were analyzed; the hospitalization duration and postoperative complications were also analyzed and compared. RESULTS: According to NRS2002, malnutrition accounted for 6.06% and nutrition risk accounted for 79.55%. There was no statistically significant difference in the nutritional risk between patients with different gender (p=0.059), the nutritional risk of the elderly patients (≥60 years) was higher than that of the non-elderly patients (<60 years) (p<0.001), and the nutritional risk among patients with different clinical stages had no statistically significant difference (p=0.654). All patients received nutritional support; the parenteral nutrition (PN) support rate was 39.02%, while PN+enteral nutrition (EN) support rate was 60.98%, while there was no patient receiving complete EN support. There was no statistically significant difference in the incidence rates of postoperative complications between patients with and without nutritional risk (p=0.546), but there was a statistically significant difference in the hospitalization duration between patients with and without nutritional risk (p=0.019). CONCLUSION: The incidence rates of malnutrition and nutritional risk are high in patients with colorectal cancer and the incidence of nutritional risk is related to age. The application of NRS2002 in nutritional risk screening for patients with colorectal cancer can provide a reasonable and effective basis for the clinical nutritional support.

[Epidemiological characteristics of severe acute respiratory syndrome in Tianjin and the assessment of effectiveness on measures of control].

OBJECTIVE: To analyze the epidemiologic characteristics of severe acute respiratory syndrome (SARS) and to evaluate the effectiveness on its major control measures in Tianjn. METHODS: Adopting two case reports 1 and 2, designed by the Tianjin Centers for Disease Control and Prevention to develop a unified case-tracing table including the map of the distribution of close contacts to SARS patients. With those methods, investigation on patients and their close contacts at hospital wards, families, communities and institutions of the patients were carried out. RESULTS: From April 13 through May 8, 2003, there were 175 SARS cases including imported ones, were identified with an incidence rate of 1.9 cases per 100,000. Among them, 14 died with a fatality of 8.0%. The whole process of epidemic in Tianjin was less than one month with the following features: (1) 93.7% of the total SARS cases in Tianjin were directly or indirectly transmitted by a super-spreader. (2) 68.6% of the total SARS patients were concentrated in 3 hospitals A, B and C which was menifastated in 'clustering'. Through study on the rest of the SARS patients, results showed that 16.8% of them were transmitted through family close contact and 2.3% due to contact to colleagues. However, 12.6% of the patients were not able to show evidence that they had any contact to a diagnosed SARS patient. At the early stage of the epidemic, a number of medical practitioners were infected, taking up 38.2% of the total SARS cases. Among the total number of 1 975 medical workers who participated in the SARS medical cares and treatments, 3.4% of them got infected. During the outbreak, all index cases and chains of transmission seemed to be clear, with only 3 patients not able to be traced for the source of infection, taking up 2% of the total SARS patients in Tianjin. Among the 10 index cases, only the super spreader and another one index case transmitted the virus to their contacts but the rest of index cases did not cause any secondary infection. CONCLUSION: Though SARS is clinically severe and can be spreaded quickly, the epidemic can be under control within a short period of time if chains of SARS transmission are broken down and effective measures as isolation and quarantine against patients as well as underscoring awareness among the publics in a scientific way, being carried out.