Emergency Medical Service (EMS) of Beijing Olympic Games needs to cover not only all the venues of the Olympic and Paralympic Games, but also emergency medical service for citizens at large and other emergency events. To this end, Beijing Emergency Medical Center made efficient preparations for the Olympic Games, namely upgraded dispatch system, first-aid stations, ambulances and equipment, and volunteer recruitment among others. Thanks to such efforts made, the EMS successfully served the Beijing Olympic Games and citizens at large. Furthermore, the Beijing Olympic Games promoted the development of the Beijing EMS system.

Objective To explore the clinical and MRI features of spontaneous osteonecrosis of the knee(SONK).Methods 15 patients with SONK diagnosed by clinic and imaging were collected.All of cases were examined by MRI,of them 5 cases underwent CT scan and 3 cases underwent radiographic examinations.Results The subchondral lesions were seen in all cases on MRI and the lesions located in the femoral condyle weight-bearing zone in 14 cases.The subchondral "fracture cleft"sign was found in 2 cases;the subchondral long T1 and short T2 linear abnormal signal intensity surrounding with bone marrow edema were shown by MRI in 3 cases of them.The subchondral focal lesions were slight long T1 and long T2 signal intensity in 10 cases.The subchondral lesion were showed clearly only in 2 cases of 5 cases with CT scan,and only 1 case of 3 cases with plain X-ray examinations.Conclusion MRI is more sensitive than CT and radiography in showing the lesions of SONK.The SONK can be diagnosed based on the clinical and MRI features.

Objective To evaluate the value of diffusion weighted imaging (DWI)in distinguishing the solid solitary pulmonary nodule (SPN).Methods 42 patients with SPN (malignant in 25 and benign in 1 7)who were confirmed by operation,biopsy or follow up after treatment underwent routine chest T1 WI,T2 WI and DWI.The b values were chosen as 300,500,800 and 1 000 s/mm2 ,and the corresponding apparent diffusion coefficient (ADC)values and the signal intensity (SI)were respectively measured.Results The ADC values and SI of benign and malignant SPNs were gradually reduced with increasing b value.The ADC value between benign and malignant SPNs was statistically significant with b value of 500 s/mm2 (P 500 =0.03 <0.05 ),meanwhile the SI was statistically significant with b values from 300 to 1000 s/mm2 (P 300 <0.001,P 500 =0.03 <0.05,P 800 =0.01 <0.05, P 1 000 =0.02<0.05).Conclusion Both SI and ADC value of DWI play important role in distinguishing benign and malignant SPNs, and the diagnostic efficiency of SI is superior to ADC value.

Objective: To investigate the effect of biology and mTOR pathway activity of down-regulated TSC2 gene expression on U937 leukemia cells. Methods: Gene expression was down-regulated by lentivirus induced RNA interference on TSC2 high expressed U937 cell line; the proliferation, apoptosis and differentiation were detected by CCK-8 assay, colony formation assay and flow cytometry; the gene expression level and protein kinase activity were detected by qRT-PCR and Western blot. Results: Down-regulated expression of TSC2 gene promoted U937 cell proliferation and colony formation ability (P<0.05) . The proportion in G₀/G₁ phase of TSC2 down-regulated U937 cell was much lower than that of the control cells [ (52.53±3.75) % vs (75.10±4.33) %, t=6.829, P=0.002], the S phase [ (22.43±1.00) % vs (15.47±1.20) %, t=-5.581, P=0.019] and G₂/M phase [ (25.03±4.34) % vs (14.33±0.91) %, t=-5.413, P=0.013] was remarkably higher than that of the control cells (P<0.05) . There were no statistically significant differences in cell apoptosis and differentiation (P>0.05) . Down-regulation of TSC2 led to the increased activity of mTOR, 4EBP1 and S6K1, but did not influence the activity of AKT. The expressions of proliferation related cyclinD1, c-myc and PTEN were also up-regulated after TSC2 silenced, but the expressions of P27KIP and BCL-XL were not changed. Conclusion Downregulation of TSC2 could promote the proliferation of U937 cells through up-regulation of mTOR activity.

Objective:To investigate factors associated with acute kidney injury(AKI) in postoperative colorectal cancer patients.Methods:The clinical data of 376 colorectal carcinoma (CRC) patients at Department of General Surgery, Affiliated Cancer Hospital of Zhengzhou University from Jan 2018 to Jun 2021 were retrospectively analyzed. Patients were divided into acute kidney injury (AKI) ( n=29) and non-AKI groups ( n=347). The demographic information, perioperative status, laboratory results and other relevant data of the two groups were compared . Binary logistic regression was used to analyze the independent risk factors for postoperative AKI. Results:Twenty-nine CRC patients (7.7%) had postoperative AKI. Binary Logistic regression analysis showed that preoperative hypertension ( OR=3.487, 95% CI: 1.081-11.251, P=0.037), anemia ( OR=3.158, 95% CI: 1.114-8.953, P=0.031), inadequate intraoperative crystalloid infusion ( OR=0.998, 95% CI: 0.997-0.999, P=0.007), low intraoperative mean arterial pressure ( OR=0.915, 95% CI: 0.863-0.970, P=0.003) and moderate to severe postoperative decline in hemoglobin levels ( OR=4.105, 95% CI: 1.487-11.335, P=0.006) were independent risk factors. Conclusion:Preoperative hypertension, anemia, inadequate intraoperative crystalloid infusion, low intraoperative mean arterial pressure, and moderate to severe postoperative decline in hemoglobin levels were independent risk factors for AKI development in colorectal cancer patients.