0.999). The characteristic masses and detection limits achieved were as follows,as for As,21 pg and 0.13 ?g/L,as for Se,32 pg and 0.33 ?g/L. The recoveries were 96.0%-103.6% for As,98.3%-104.7% for Se and the RSDs were 0.6%-1.7% for As,0.6%-2.8% for Se. Conclusion This method was accurate, simple and sensitive,it is applicable to the determination of trace As and Se in water.

Hepatic myelopathy is one of special category changes of nervous system,which was secondary to the end-stage hepatic diseases and is a syndrome of myeleterosis.It usually occurred after portosystemic shunt surgery or collateral circulation of portosystemic vein.The prognosis of hepatic myelopathy is poor,and the progression of this disease is slow.Surgical approaches such as dissociation of colon and anastomosis of ileum and rectum aimed at reducing the absorption of toxic substance and thus to breakdown the blood ammonia and improve the symptoms of nervous system,but the effects are not satisfactory.The clinical data of 1 patient with hepatic myelopathy who received liver transplantation at the Second Affiliated Hospital of Dalian Medical University in April 2012 were retrospectively analyzed.The clinical symptoms and physical signs were improved,and muscle strength was effectively recovered in the patient.Liver transplantation might be an effective method for the treatment of hepatic myelopathy.

AIM: To determine the relationship between the mutation of the RII gene and RER status in the tumorigenesis of sporadic colorectal cancer. METHODS: We screened RER status and mutation of the RII gene from 50 sporadic colorectal cancers (19 in the proximal colon, 31 in the distal colorectum). RESULTS: RER was found in 13 cases (8 in the proximal colon, 5 in the distal colorectum), and 5 of them showed mutations of the RII gene. All 5 cancers carrying a TGF-? RII gene mutation showed RER+, but there wasn't any mutation of RII gene in RER(-) cases. Four of 5 RII mutation were located at the cecum. CONCLUSION: These data indicate that the TGF-? RII gene is a major target of microsatellite instability and mutation of the RII gene play an important role in carcinogenesis of sporadic colorectal cancer with microsatellite instability, especially at the cecum. [

The idea of establishing Shanghai Academy of Medical Sciences was brought forward　in the background of great external changes.It was to meet the demand for resolving all kinds of　conflicts about researches arised from the long time operation of Medical Institutes in Shanghai.This　article mainly discusses about the necessity and plans for establishing Shanghai Academy of Medical　Sciences.

OBJECTIVETo establish a method for simultaneous determination of 54 elements in whole blood by inductively coupled plasma mass spectrometry (ICP-MS).

METHODSThe whole blood sample was digested with nitric acid and hydrogen peroxide in a water bath at 90°C, and then analyzed by ICP-MS with 0.1% ethanol as an matrix-matching agent.

RESULTSA good linear relationship was achieved when the concentrations of the 54 elements in whole blood were in the standard range (all r >0.999). The recovery rate of the sample plus the standard was between 80% and 106%, and the relative standard deviation was less than 5%. The standard material of whole blood was determined and the results met the certification requirements.

CONCLUSIONThe method is simple, rapid, sensitive, and accurate. It is applicable for simultaneous determination of multi-elements in a large number of whole blood samples.

This study surveyed medical research institutions in Shanghai for the structure set, input and output, development orientation, bottleneck and other aspects. Problems were found with their relationship management, discipline arrangement, research efficacy and else.

Objective Colloidal palladium was used as chemical modifier in the determination of blood thallium by graphite furnace atomic absorption spectrometry.Methods Blood samples were precipitated with 5％ (V/V) nitric acid,and then determined by GFAAS with colloidal palladium used as a chemical modifier.0.2％ (W/V) sodium chloride was added in the standard series to improve the matrix matching between standard solution and sample.Results The detection limit was 0.2 μg/L.The correlation coefficient was 0.9991.The recoveries were between 93.9％ to 101.5％.The relative standard deviations were between 1.8％ to 2.7％.The certified reference material of whole blood thallium was determined and the result was within the reference range Conclusion The method is accurate,simple and sensitive,and it can meet the needs of detection thallium in blood entirely.

Objective Colloidal palladium was used as chemical modifier in the determination of blood thallium by graphite furnace atomic absorption spectrometry.Methods Blood samples were precipitated with 5％ (V/V) nitric acid,and then determined by GFAAS with colloidal palladium used as a chemical modifier.0.2％ (W/V) sodium chloride was added in the standard series to improve the matrix matching between standard solution and sample.Results The detection limit was 0.2 μg/L.The correlation coefficient was 0.9991.The recoveries were between 93.9％ to 101.5％.The relative standard deviations were between 1.8％ to 2.7％.The certified reference material of whole blood thallium was determined and the result was within the reference range Conclusion The method is accurate,simple and sensitive,and it can meet the needs of detection thallium in blood entirely.

Objective:To analyze the epidemiological characteristics of novel coronavirus positive cases including confirmed cases with clinical symptoms and asymptomatic infected cases in Guangzhou.Methods:Epidemiological data were collected on the nucleic acid positive cases of COVID-19 in Guangzhou from January to September 2020. The epidemiological characteristics, the distribution of time intervals between the confirmed/isolation date and the date of the first positive detection were analyzed, at last the influencing factors for the confirmed cases and asymptomatic infected persons were discussed.Results:From January 7 to September 4 in 2020, a total of 1 097 nucleic acid positive cases were identified, including 658 confirmed cases (59.98%) and 439 asymptomatic infected cases (40.02%). Among the 658 confirmed cases, the median age was 42 years old, the cases indicated two significant peaks. one of the peaks was related to the imported and associated cases from Hubei province, and the other peak was connected with individuals from overseas. In terms of 439 asymptomatic infected cases, the median age was 32 years old. There were two stages in these cases. The first stage followed the second peak of confirmed cases, and the second stage overlapped with the confirmed cases in Guangzhou when the epidemic was in a period of normal prevention and control, mainly related to imported cases from abroad. The asymptomatic infected persons accounted for 57.32% in all the imported infected cases. In both of asymptomatic and symptomatic cases, the positive rate of pharyngeal swabs was higher than that of nasopharyngeal swabs and anal swabs. There were statistically significant differences in age, source of infection and gender composition between confirmed cases and asymptomatic infected persons ( P<0.05). Older age groups were more likely to have clinical symptoms, with ≥40 years being the risk factor for confirmed cases (OR=2.334, P=0.001), and 20-39 years less likely to have clinical symptoms (OR=0.620, P=0.047), compared with the 0-19 years old group. Compared with those infected in China, those infected abroad were less likely to develop clinical symptoms and became confirmed cases (OR=0.723, P=0.013). Women were more likely to have clinical symptoms than men (OR=1.574, P=0.001). Conclusions:At present, asymptomatic infected persons and confirmed patients with clinical symptoms co-existed, and the number of asymptomatic infected patients was higher than that of confirmed cases in Guangzhou. High age, domestic infection and female may be risk factors for confirmed cases. It was of great value to further explore these underlying mechanisms for the prevention and treatment of the COVID-19.

Objective: To explore the cumulative effects of unintentional injury among children in rural area, in order to provide information for early intervention of unintentional injury. Methods: Through multistage clustering sampling method, 2 109 primary caregivers of students from 8 rural primary and elementary schools of Heilongjiang Province were recruited. Strengths and Difficulties Questionnaire (SDQ), Injury Behavior Checklist (IBC), Perceptions of Risks and Hazards were used to collect as the risk factors, while Perceptions of Risks and Hazards (PSAPQ), Home Observation for Measurement of the Environment (HOME) and Knowledge, Attitude and Practice for Children Unintentional Injury (KAP) were also used as the protective factors. Risk factors index (RFI) and protective factors index (PFI) were computed in the study. Results: The severity of unintentional injury were positively correlated with SDQ, IBC and perceptions of risks and hazards(r=0.15, 0.23, 0.12, P<0.01), and were negatively correlated with HOME, PSAPQ and KAP(r=-0.25, -0.14, -0.09, P<0.01). Hierarchical linear regression showed that the total scores of SDQ, IBC and environmental of HOME predicted the severity of unintentional injury which could explain 34% variant of unintentional injury. It also indicated that the severity of unintentional injury were positively correlated with RFI (β=0.21) and negatively correlated with PFI(β=-0.18), the interaction was significant(β=-0.11,R2=0.31)(P<0.01). Conclusion Both risk and protective factors of unintentional injury have cumulative effects on the severity of injury among rural children. The relationship between risk factors and injury could be mediated by protective factors.