Abstract: Objective　To analyze the vaccination status of SARS-CoV-2 in children, and explore the relationship between SARS-CoV-2 vaccination and COVID-19 in children. Methods　A retrospective study was conducted to analyze the clinical data of 335 cases of SARS-CoV-2 Omicron variant infection from February 15, 2022 to March 18, 2022 in Shenzhen Third People's Hospital. Results　Among 335 children with SARS-CoV-2 infection, 174(51.9%) cases were vaccinated with the SARS-CoV-2 vaccine; 33(31.4%) cases were vaccinated in the 3-<6 years old group; 141(61.3%) cases were vaccinated in the 6-<14 years old group. There was a statistically significant difference in the proportion of SARS-CoV-2 vaccination between the 6-<14 years old group and the 3-<6 years old group (χ2=26.1, P<0.05). In the study cohort, 3-<6 years old group and 6-<14 years old group, there was no significant difference in the incidence of COVID-19 in the vaccinated group compared with the unvaccinated group (P>0.05). In the study cohort, the proportion of confirmed cases of 1 dose of SARS-CoV-2 vaccine and 2 doses or more of SARS-CoV-2 vaccine was 89.5% (68 cases) and 77.6% (76 cases), respectively; in the 6~<14 years old group, the proportion of confirmed cases of 1 dose of SARS-CoV-2 vaccine and 2 doses or more of SARS-CoV-2 vaccine was 90.0% (54 cases) and 76.5% (62 cases), respectively; the differences were statistically significant (χ2=4.264, P<0.05; χ2=4.279，P<0.05). The IgG levels of 18.28 (6.61, 55.2) AU/mL and 58.3 (25.85, 131.41) AU/mL in the study cohort who were vaccinated for 1 dose, 2 doses and more, respectively; the IgG levels of 20.13 (8.33, 44.33) AU/mL and 56.57 (25.85, 150.07) AU/mL in the 6~<14 years old group who were vaccinated for 1 dose, 2 doses and more, respectively; and the differences were statistically significant (Z=-4.37, P<0.05; Z=-3.96, P<0.05). Conclusions　Children who received 2 doses of SARS-CoV-2 vaccine have a lower incidence of COVID-19 and higher levels of SARS-CoV-2 antibodies compared with who received 1 dose . It is recommended that children are advised to be vaccinated against the COVID-19.

Over the past several years, mass spectrometry technology has become the important method of choice for the discovery of new biomarkers.Because the features of mass spectrometry-based proteomics including sensitivity, high throughput, speed, combined with advanced bioinformatics allow for the rapid analysis of a bunch of proteins simultaneously.It has become a powerful laboratory tool in clinical study.However recent studies showed that critical comments were made on the poor reproducibility,statistical analysis of the data et al.This article focused on challenges of study design, mass spectrometry technology and biological relevance associated its application of mass spectrometry based proteomics in serum or plasma.

Objective To assess the impact of pigment epithelium-derived factor(PEDF)on the proliferation and apoptosis of the glioma cells by detecting expression of apoptosis related proteins.Methods U87 cells were treated with PEDF(1000μg/ml,U87PEDF),or without PEDF(U87com0),cell proliferation assays were performed by MTT assay to test the effect of PEDF on proliferation of glioma cells;Apoptosis assays were performed by flow-cytometric analysis;Western-blot Was used for evaluating the expression of p16 protein.Results The induced inhibitony rates of glioma cells by PEDF were(54.29±0.62)% Compaxed with the control(t=2.63,P<0.05).The apoptosis assay showed that(21.84±0.36)% of PI- negative/annexin V-positive Was present in the U87 PEDF cells.The appoptosis was associated with the incteases of p16 protein(0.82±0.09)compared with tlle control(0.43±0.03,P<0.05).Conciusion PEDF may play a significant role in apoptosis regulation and proliferation of glioma cell accompanied with the increase of the p16 protein.

Objective To assess the impact of pigment epithelium-derived factor(PEDF) on the migration of the glioma cells.Methods PEDF(100 ng/ml)was added to U87 cells(U87PFDF),and VEGF of 0.25μg/ml was added to U87PEDF+VEGF while U87 cells as control(U87con).The cell migratory assav was used tbr evaluating its inhibitory migration rate of PEDF.Real time RT-PCR was used for evaluating the expression of Laminin-8 gene.Results The number of migratory cells was higher than those with added PEDF,and the inhibitory rate of migratory was 38% even in the presence of VEGF.Real time RT-PCR revealed that the mRNA expression levels of α4,β1,γl were(1.043±0.090),(0.823±0.012).(0.762±0.05) copy/μl,which were higher than those treated by PEDF(0.633±0.004),(0.442±0.005).(0.424±0.002)copy/μl,respectively (P＜0.05).Conclusion PEDF could decrease the migmtory capacity of the glioma cells even in the presence of VEGF because of the regulation of Laminin-8 in part.

Objective To express the pigment epithelium-derived factor (PEDF) in E.coli. and to assess its role in angiogenesis of gliomas.Methods The expression plasmid pET41/PEDF was constructed and the protein was purified by metal affinity tag (His Tag ) and anion-exchange chromatography. Tube formation was used for evaluating its biological activity. The changes of vascular enthothelial growth factor (VEGF) and thrombospondin-1 (TSP-1) were evaluated by the enzyme-linked immunosorbent assay.Results The high purified and inhibitory-actived PEDF proteins were acquired and PEDF had the function of decreasing the VEGF 1.8 times as well as increasing the TSP-1 5.3 times.Conclusions It is possible that PEDF expression is a potent factor for the inhibition angiogenesis in gliomas.

Objective To develop a quantitative assay method for the determination of tissue factor. Methods Lyophilized prothrombin complex was used as the source of factor Ⅶ,Ⅹ. Synthetic chromogenic substrate (S2222)was hydrolyzed into p nitroaniline. The absorbency of p nitroaniline measured spectrophotometrically at 405 nm is proportional to TF quantity in logarithm ( r =0.998). Results The linear range was from 10 U to 10 5 U. Low and high coefficients of variation were 10.3%, 6.6% within day and 18.1%, 10.2% day to day. Conclusions The method is very simple, sensitive, with good linearity, and applicable to quantitation of TF activity quickly.

Objective To evaluate the efficiency of different wash methods for removing organophosphorus pesticide residues from cucumber. Methods The cucumber samples were soaked with tap water, washed rice water, salt solution and detergent solution respectively for 2 to 15 minutes then organophosphorus pesticide residues in the soak water samples were determined with ultrasonic extraction and gas chromatography. Results Soaked in tap water for 2 to 5 minutes was the most effective and convenient way to remove methamidophos and dimethoate with the highest removing rate (about 70%). Conclusion Soaked with tap water for 2 to 5 minutes is more efficient for removing organophosphorus pesticide residues from vegetable.

Objective To assess the impact of recombinant pigment epithelium-derived factor (rPEDF) on the growth and invasion of the glioma cells.Methods The level of vascular enthothelial growth factor (VEGF) and thrombospondin-1 (TSP-1) were evaluated by enzyme-linked immunoadsorbent assay (ELISA); cell proliferation assays were performed by MTT assay; the cell migratory assay was used for evaluating its inhibitory migration rate.Results The VEGF expression (0.29?0.03) of A172_ PEDF (added the PEDF to the A_ 172 cells) decreased 4.4 times compared with the A172_ con (not added the PEDF to the A_ 172 cells, 1.31?0.02, P

According to the needs of maintenances a detection kit for ECG cable is developed to detect the onoff condition of the wire, which can form a loop, and to indicate the result on a LED. The kit proves to be simple and practical and thus can significantly increase the maintenance efficiency of ECG cable.

Objective:To explore the multi-dimensional method of medical equipment management based on comprehensive index assessment, and improve quality of medical equipment management. Methods: This essay proposed a comprehensive-index-analysis medical equipment management approach within hospital theoretic work and medical equipment management. Equipment management and project application in each clinical department were treated as evaluation criteria which conducted a multi-equality index for medical equipment operation management, using the pattern of quantitative substitute qualitative method.Results: The new method helps to quantize ability of clinical department, equipment utility and management. It refers to scientific equipment management data after procurement, which reflects differences between each department and equipments. Moreover, it helps to prevent blind procurement effectively by ranking department earning capacity.Conclusion: The new method is benefit for equipments’ evaluation and to provide reference for managers in decision-making.