Experiment teaching is a most important item of college teaching, and plays a vital and unexchangeable role to train students for their ability to practice and to innovate. To construct a feasible and scientific examination system of experiment teaching, will significantly help deepen the reformation of experiment teaching and improve the teaching quality. So according to the request for cultivating qualified ap- plication person, we preliminarily constitute the valuation system throughout the whole course and in the final, of theoretic examination and practice examination, and combined with students’ self-valuation and valuation from teachers. In fact, the system works well with a perfect effect.

A new, simple and sensitive method was developed for the determination of silicon tetrahydride in the air of workplace in this study. The alkaline resin-based spherical activated carbon was used to collect sample of silicon tetrahydride at workplace. Silicon tetrahydride was then desorbed from active carbon in 100°C hot water. After reacting with ammonium molybdate, oxalic acid and 1,2,4-trichlorobenzene alpha-naphthol amino sulfonic acid under acid condition, silicon tetrahydride was transformed into silicon molybdenum blue. The absorbance of silicon molybdenum blue was quantitatively measured at the wavelength of 680 nm. The results showed that the average sampling efficiency and desorption efficiency were 97.53% and 94.94%, respectively by this method. Detection limits were 0.054 μg/mL for the spectrophotometric method and 0.14 mg/m(3) for the determination of silicon tetrahydride in the air of workplace (sampling volume was 7.5 L). The conversion rate of silicon tetrahydride gradually decreased when storage time of samples was extended. The descent rate of sample was less than 10% when the sample was sealed for 7 days in the room temperature. It was concluded that this spectrophotometric method can be successfully used to determine silicon tetrahydride in the worksites.
Air Pollutants, Occupational ; analysis ; Humans ; Limit of Detection ; Reproducibility of Results ; Silanes ; analysis ; Spectrophotometry ; methods ; Workplace

Adolescent ; Adult ; Age Factors ; China ; epidemiology ; Death ; Female ; Humans ; Male ; Middle Aged ; Sex Factors ; Suicide ; statistics & numerical data

In order to compare the differences of 35 Menthae Herba samples collected on the market and at producing areas, the contents of six total terpenoids, the essential oil and chromatographic fingerprints were analyzed, which provided evidences for drawing up the commodity specifications and grading criteria of Menthae Herba. GC-MS method was used to analyze the chemical constituents of 35 different samples. The chromatographic fingerprints obtained by using GC were then evaluated by similarity analysis, hierarchical clustering analysis and principal component analysis. The relativity between the content of six terpenoids and the essential oil were studied. In this study, the chemical profiles of 35 samples from different producing areas had significant disparity. All samples collected in the report could be categorized into four chemical types, L-menthol, pulegone, carvone and L-menthone, but the chemical profiles had no relationship with the areas. The chromatographic fingerprints of the samples from different types were dissimilar, while the different producing areas were difficult to be separated. It was indicated that the content of volatile oil was positively correlated with the content of L-menthol and the sum of six total terpenoids. The content of the essential oil, L-menthol and the sum of six total terpenoids of Menthae Herba were considered as one of the commercial specifications and grading criteria. These results in the research could be helpful to draw up the commercial specification and grading criteria of Menthae Herba from a view of chemical information.
Cluster Analysis ; Gas Chromatography-Mass Spectrometry ; Mentha ; chemistry ; Oils, Volatile ; analysis ; Principal Component Analysis ; Terpenes ; analysis

HEV is classified into H (human) group and Z (zoonosis) group according to its compatible host. H group contains genotype 1 and genotype 2 HEV isolates which infect human only; Z group contains genotype 3 and genotype 4 HEV isolates which infect both human and animals. After analysis of amino acid sequences between ORF2 aa368 and aa606, four group-conserved sites that were all located in the neutralization region of ORF2 were identified. They are aa483, aa492, aa497 and aa599. Mutation analysis and capture PCR were then performed on these sites with a group of monoclonal antibodies. Results showed that the difference of the aa497 between H and Z groups was responsible for the maintenance of their group-specific immunodominant epitopes, probably through confirmation-dependent epitope changes. Thus, aa497 and its related change on the surface structure of HEV may play important roles in host selection by H and Z groups of HEV.
Antibodies, Monoclonal ; immunology ; Base Sequence ; Genotype ; Hepatitis E virus ; classification ; genetics ; immunology ; Humans ; Immunodominant Epitopes ; Molecular Sequence Data ; Mutation ; Neutralization Tests ; Open Reading Frames

A fragment of hepatitis E virus open reading frame-2(ORF2), located from amino acid residues 394 to 604, was expressed in E. coli. The recombinant protein NE2 was found to form homodimer mostly in SDS-PAGE, which can be dissociated to monomers when treated with urea, and it was recognized more strongly in its dimeric form than the monomer by HEV reactive human serum in Western blotting. Besides, many aggregated form of NE2 from dimer to at least hexamer can be seen in MALDI-TOF-MS. And when the hydrated dynamic semidiameter of NE2 moleculars in PBS was measured as about 4 nm by Dynamic Light Scattering (DLS), being equal to tetramer, but with high polydispersity, which suggested that the NE2 moleculars were existed in PBS in many different sizes. These results suggested that the recombinant NE2 can aggregate into several oligomer forms, the association in the dimer is most strong, and dimers can assemble further to form some super-structure.
Dimerization ; Electrophoresis, Polyacrylamide Gel ; Escherichia coli ; genetics ; Gene Expression ; Protein Conformation ; Recombinant Proteins ; chemistry ; genetics ; metabolism ; Viral Proteins ; chemistry ; genetics ; metabolism

OBJECTIVETo study allergens and their relationship to the occurrence of childhood bronchial asthma in the Jiading District of Shanghai.

METHODSThree hundred and eighty-two 4 to 12-year-old children with asthma in the remission stage from Nanxiang Hospital in the Jiading District of Shanghai were used as a case group (asthma group), and 402 children from two primary schools and two kindergartens in Jiading were enrolled by cluster sampling and served as control group. Parents of the children completed a questionnaire on living conditions and allergy-related disease history. Skin prick test (SPT) for 18 common allergens was carried out in both groups. In order to examine the effect of environment and living conditions on SPT results, children in the control group were further divided into two sub-groups according to birth place: migrant (219 cases) and resident (183 cases).

RESULTSSPT results revealed that the main allergens identified in the Jiading region were dermatophagoides farinae, house dust mites, shrimps, cockroaches, and dog hair. The SPT positive rate was 67.9% in the asthma group, and this was significantly higher than in the control group (31.8%) (P<0.01). The environment and living conditions in the migrant group were significantly different from the resident group (P<0.01), whereas the SPT positive rate for this group was significantly lower than in the resident group (P<0.01).

CONCLUSIONSAllergens in the Jiading region mainly originate from dermatophagoides farinae, household dust mites, shrimps, cockroaches and dog hair. Children with asthma are more susceptible to allergens. Environment and living conditions may be relevant, to a certain extent, to an SPT positive rate.

Allergens ; immunology ; Asthma ; etiology ; Child ; Child, Preschool ; China ; Environment ; Female ; Humans ; Male ; Skin Tests ; Transients and Migrants

OBJECTIVESTo study the quantitative relationship between the levels of serum liver fibrosis markers and fibrosis stages of liver tissues in patients with chronic hepatic diseases.

METHODSIn 118 patients with chronic hepatitis, fatty liver or cirrhosis, their Serum levels of LN, HA, PCIII and CIV were investigated by EIA and their liver histological changes were studied. The relationship between the levels of serum LN, HA, PCIII and CIV and the degrees of liver tissue fibrosis was analyzed quantitatively by using the SPSS11.0.

RESULTSA correlation between the levels of serum LN, HA, PCIII and CIV and the histologically assessed grades of inflammatory activity was found (r = 0.394, 0.449, 0.443, 0.351, respectively, P <0.01). The correlation between the levels of serum LN, HA, PCIII and CIV and the histological assessed stages of liver fibrosis was strong (r = 0.456, 0.564, 0.476, 0.421 respectively, P <0.01). The levels of serum LN, HA, PCIII and CIV of the patients with a stage 2 liver fibrosis were 110 ng/ml, 110 ng/ml, 100 ng/ml and 70 ng/ml respectively, with sensibilities of diagnosing stage 2 liver fibrosis at 70%, 79%, 79% and 74% respectively. Their specificities in diagnosing stage 2 liver fibrosis were 68%, 72%, 64% and 73% respectively. The levels of LN, HA, PCIII and CIV in serum of these patients diagnosing cut-off value in stage 4 liver fibrosis (early cirrhosis) were 130 ng/ml, 140 ng/ml, 120 ng/ml and 70 ng/ml respectively. Their sensibility of diagnosing liver cirrhosis was 79%, 93%, 79% and 86% respectively. Their specificity of diagnosing liver cirrhosis was 66%, 82%, 72% and 61% respectively. As shown by the ROC curves in these patients, differentiating patients with cirrhosis or without cirrhosis, serum HA level was more valuable than LN, PCIII, CIV (the areas under the curves = 0.938 vs 0.775, 0.787, 0.791 ) When serum HA was higher than 190 ng/ml, the veracity of diagnosing liver cirrhosis was 93%.

CONCLUSIONSThere is a certain quantitative relationship between the levels of LN, HA, PCIII and CIV in serum and the degrees of liver tissue fibrosis. The level of HA in serum is an important reference datum for early diagnosing liver cirrhosis.

Adolescent ; Adult ; Aged ; Child ; Fatty Liver ; blood ; complications ; Female ; Hepatitis, Chronic ; blood ; complications ; Humans ; Hyaluronic Acid ; blood ; Laminin ; blood ; Liver ; pathology ; Liver Cirrhosis ; blood ; etiology ; pathology ; Male ; Middle Aged ; Procollagen ; blood

OBJECTIVETo investigate the relationship between the genotypes of hepatitis B virus and the clinical and liver pathological features of patients with chronic hepatitis in the Zhoushan Islands.

METHODSOne hundred eighty HBV DNA positive chronic hepatitis patients with HBV markers were enrolled in this study. They were at least second generation Zhoushan Island residents. One hundred forty-seven of them were males and 33 were females with an average age of 39.0+/-11.3. Among the 180 patients, 17 had ASC, 57 had mild CHB, 48 moderate CHB, 9 severe CHB, 6 SHB, 39 LC, and 4 had HCC. The genotypes of their serum HBV were detected by using PCR integrated with Tagman MGB probe technology, and their serum HBV markers, HBV DNA and liver functions were also examined. Out of 180 patients, 129 accepted a liver biopsy. A pathological evaluation was then performed.

RESULTSHBVs of genotype C, 135 cases (75.0%), of B, 40 cases (22.2%), and of B+C, 5 cases (2.8%) were found among these 180 patients. No genotype A or D HBV were found. The proportions of genotype C virus were 7/17, 86/114, 34/39, 6/6 in ASC, CHB, LC and SHB patients. In the hepatocellular carcinoma patients, there were 2 each of genotype B and C. Among the 99 patients with genotype C HBV, 84 cases (84.8%) showed moderate and severe inflammation histologically in their livers and among the 30 patients with B, 7 cases (23.3%) showed moderate to severe inflammation in their livers (z = 6.47, P less than 0.01). The proportion of genotype C HBV was significantly different from that of genotype B HBV in those that showed moderate and severe (S3-4) liver fibrosis. In patients infected with genotype C HBV who had moderate and severe liver pathological changes, their clinical manifestations reflected better the histological alterations of their livers.

CONCLUSIONGenotypes C, B and B+C HBV were found in CHB patients in the Zhoushan Islands of China, and type C was the predominant one. The liver pathological damage level of genotype C HBV infected patients is more serious than that of genotype B.

Adult ; China ; epidemiology ; DNA, Viral ; genetics ; Female ; Genome, Viral ; Genotype ; Hepatitis B virus ; classification ; genetics ; Hepatitis B, Chronic ; epidemiology ; pathology ; Humans ; Liver ; pathology ; Male ; Middle Aged

Objective:To analyze the influencing factors of death in patients with acute respiratory distress syndrome (ARDS) combined with acute kidney injury (AKI) in intensive care unit (ICU) after continuous renal replacement therapy (CRRT).Methods:The demographic and clinical data of ICU patients with ARDS combined with AKI after CRRT at Henan Provincial People's Hospital from January 1, 2018 to December 31, 2018 were collected. According to the final treatment results of this hospitalization, the patients were divided into death group and survival group. Survival was defined as the improved patient's condition and hospital discharge. Death was defined as the patient's death during the ICU hospitalization or confirmed death after abandoning treatment and automatically being discharged from the hospital in the follow-up. The basic clinical characteristics and CRRT status between the two groups were compared. Multivariate logistic regression method was used to analyze the influencing factors of death in patients.Results:A total of 132 patients were enrolled, of which 90 patients (68.2%) died, with 84 males (63.6%) and median age of 59(45, 73) years. Compared with the survival group, the death group had higher age, proportion of malignant tumors, sequential organ failure assessment (SOFA) score, number of organ dysfunction and proportion of positive balance of fluid accumulation at 72 hours, longer time from entering ICU to CRRT, and lower mean arterial pressure (minimum value) and oxygenation index (all P<0.05). Multivariate logistic regression analysis results showed that the age≥60 years old ( OR=4.382, 95% CI 1.543-12.440, P=0.006), large number of organ dysfunction ( OR=1.863, 95% CI 1.109-3.130, P=0.019), high SOFA score ( OR=1.231, 95% CI 1.067-1.420, P=0.004) and long time from ICU admission to CRRT ( OR=1.224, 95% CI 1.033~1.451, P=0.020) were independent influencing factors of death in patients with ARDS combined with AKI after CRRT, and high oxygenation index ( OR=0.992, 95% CI 0.986-0.998, P=0.010) was an independent protective factor for patients' prognosis. Conclusions:The mortality of patients with ARDS combined with AKI after CRRT is still high. The age≥60 years old, large number of organ dysfunction, high SOFA score and long time from ICU admission to CRRT are independent influencing factors for death, and high oxygenation index is an independent protective factor for prognosis in patients with ARDS combined with AKI after CRRT.