Objective To select a matrix modifier,which can effectively eliminate the matrix interference in the determination of chromium in cosmetics by graphite furnace atomic absorption spectrometry(GFAAS).Methods The orthogonal experiment design was used to define the best operation parameter of graphite furnace.Vitamin C,(NH4)H2PO4,(NH4)2HPO4,NH4Cl and Mg(NO3)2 were added respectively as the matrix modifiers.The effect of five matrix modifiers was compared by precision test.Results When(NH4)H2PO4 was taken as the chemical modifier,the determination result was satisfied.The characteristic mass was 5.68?10-12 g,relative standard deviation were from 2.11% to 4.46%.The rate of recovery of two cosmetics samples were 95.2% and 102.01%.Conclusion(NH4)H2PO4 can increase the ashing temperature,decrease the atomization temperature,eliminate the matrix interference and the result has good precision and accuracy.

Objective To develop a field psychological emergency rescue chest to improve mental health service during disaster relief.Methods The instruments and medicine involved in for mental health were determined based on service orientation,function design and expert survey,and the psychological emergency rescue chest was developed based on optimization of the external and internal structures of field Ⅳ-type chest.Results The chest developed was composed of office instruments,psychological devices,logistics instruments and first-aid medicine for mental health.conclusion The chest gains advantages in design,structure,size,transport,utilization,equipped devices and function integration,and thus is worthy promoting for field mental health service during disaster relief.

Objective:To investigate the pathogenic bacteria distribution and risk factors of pulmonary infection after tracheotomy in patients with stroke coma,and to put forward preventive measures.Methods:96 patients with stroke coma from January 2016 to February 2017 in our hospital were retrospectively analyzed.The incidence of pulmonary infection and distribution of pathogenic bacteria of patients with stroke coma were analyzed.At the same time,the risk factors of pulmonary infection were analyzed by single factor and multiple factors logistic regression analysis,and corresponding preventive measures were put forward.Results:The incidence of pulmonary infection after tracheotomy in 96 patients with stroke coma was 48.96％ (47/96).A total of 104 pathogens were isolated and cultured,including gram negative bacteria 69 strains (66.35％),gram positive bacteria 20 strains (19.23％) and fungus 15 strains (14.42％).Single factor regression analysis results showed that pulmonary infection after tracheotomy in patients with stroke coma was closely related with age,basic diseases,time of tracheotomy,and bed time,use of broad-spectrum antibiotics,smoking history,artificial airway,times of sputum suction and inhalation(P＜0.05),and it was not related to the patient's gender,weight,stroke type (P＞0.05).Multivariate logistic regression analysis showed that age 45 years old,complicated with basic disease,time oftracheotomy 5 d,use of broad-spectrum antibiotics,smoking history and the establishment of artificial airway were risk factors of pulmonary infection after tmcheotomy in patients with stroke coma (P＜0.05).ROC analysis results showed that the critical point (threshold C) oftmcheotomy time was 4.3 days,and the sensitivity and specificity were 0.851 and 0.918 respectively.Conclusion:The main pathogenic bacteria of pulmonary infection after tracheotomy in patients with stroke coma is gram-negative bacteria,age 45 years old,complicated with basic disease,time of tmcheotomy 5d,use of broad-spectrum antibiotics,smoking history and the establishment of artificial airway can lead to pulmonary infection after tracheotomy in patients with stroke coma,and the risk of pulmonary infection in patients with stroke coma will increase considerably after the time of tracheotomy for more than 4.3 days.Targeted measures should be taken to reduce the risk of pulmonary infection according to pathogenic features and risk factors.

To perform modal analysis of CT shelter by applying computer simulation technology so as to pro-vide theoretical guidance for CT shelter structure optimization. Based on CAD model, the finite element model of a CT shelter was established with ANSYS simulation platform. Through modal analysis, different-order modal frequency and modal shape of the shelter were computed and the kinetic characteristics were evaluated. Low order modal frequency was kept away from the natural frequency range of chassis system resonance to avoid the overall structure reso-nance; the 3rd and the 4th modal frequency and engine idle speed frequency were very close so that local resonance might occur; road roughness excitation frequency covered the first 6 order modal frequencies and the further vibration-re-ducing measures of CT equipment were suggested. Based on the theories of finite element method and current software platform, modal analysis of shelter structure can be simulated and the results can provide valuable data for the improvement of kinetic characteristics and structure design.

Objective To observe the expression changes of 12 ischemia-related microRNAs (miRNA) in cerebral ischemia-reperfusion injury after deep hypothermic low flow (DHLF) in mice.Methods A total of 80 3-w eek-old healthy and clean grade C57BL/6 male mice w ere randomly divided into either a DHLF model group or a sham operation group. Each group w as redivided into 4 subgroups according to the time points of 2, 6, 12, and 24 h (10 in each group). The bilateral carotid arteries of the DHLF model group w ere clipped and a DHLF model w as established, w hile the carotid arteries of the sham operation group w ere not clipped. The mice w ere sacrified at each time point and the brain tissue w as removed. The total RNA w as extracted. Quantitative reverse transcriptase polymerase chain reaction w as used to detect miRNA expression. Results Compared w ith the sham operation group, the expression levels of 9 miRNAs w ere upregulated, 2 w ere dow n-regulated, and 1 did not have any significant change in the DHLF model group. Conclusions The expression levels of 11 miRNAs changed significantly after DHLF. It might have a regulatory role in cerebral ischemia-reperfusion injury after DHLF.

Objective To evaluate the effect of TGF-β3 on rabbit nucleus pulposus( NP) cells cultured in three-dimensional polylactic-co-glycolic acid (PLGA)scaffold in vitro.Methods PLGA scaffolds were fabricated by particulate leaching method and soaked in rabbit NP cells suspension(1 × 106/scaffold).PLGA-seeded NP cells were devided into 4 groups: 100 ng/mL TGF-β3/PLGA,500 ng/mL TGF-β3/PLGA,1 μg/mL TGF-β3/PLGA, PLGA control group.Cell proliferation activity was measured using MTT assay.The glycosaminoglycan ( GAG ) analysis were performed by 1, 9-dimethylmethylene blue(DMMB) assay.mRNA expression was measured by quantitive PCR at each time point.Histological observation was performed to elucidate the morphological changes of NP cells in PLGA effected by TGF-β3.Results Higher cellular proliferation activity, GAG production,Collagen type II, Aggrean expression were observed in TGF-β3 /PLGA-seeded NP cells compared with PLGA control group on day-7,day-14,day-21(P<0.05). Higher dose of TGF-β3 exhibited intense cellular proliferation activity and peri-cellular matrix by increasing trend(P<0.05).Histological observation showed TGF-β3/PLGA developed more significant disc cells cluster than PLGA groups on day-21.Conclusion The 3D porous PLGA scaffold-seeded cells using TGF-β3 can promotes cell proliferation, and prompt extracellular matrix(ECM) production.It is a potential biotherapy for the treatment of disc degeneration.

BACKGROUND: Imatinib has a significant pro-apoptosis effect on chronic myelogenous leukemia (CML), but there are still some patients being resistant to it. Human umbilical cord mesenchymal stem cells (hUC-MSCs) affect the apoptosis of a variety of hematologic malignancies. However, the impacts of hUC-MSCs on the apoptosis of CML cells induced by imatinib remain unclear.OBJECTIVE: To investigate whether hUC-MSCs have an influence on the apoptosis of K562 cells induced by imatinib and to reveal the possible underlying mechanism.METHODS: K562 cells were cultured with hUC-MSCs or/and imatinib. Cellular apoptosis was measured with Annexin-V and PI staining by flow cytometry analysis. The protein expressions of Bax, Bcl-2, caspase-3, caspase-9 and cleaved-PARP in K562 cells were detected by western blot assay. Pan-caspase inhibitor Z-VAD-FMK was used to block apoptosis in each group, and during this process the effect of caspase apoptosis signaling pathway was detected.RESULTS AND CONCLUSION: The apoptosis of K562 cells was enhanced, when imatinib was combined with hUC-MSCs. Western blot analysis showed that the expression of pro-apoptotic protein Bax was enhenced and the expression of anti-apoptotic protein Bcl-2 was suppressed. Furthermore, the cleaved forms of caspase-9, caspase-3 and PARP in K562 cell were higher in the hUC-MSCs+imatinib group than in the imatinib group. The apoptosis of K562 cells induced by the hUC-MSCs combined with imatinib was significantly inhibited by Z-VAD-FMK. In conclusion, these findings indicate that hUC-MSCs can enhance imatinib-induced apoptosis of K562 cells by activating caspase apoptosis signaling pathway.

OBJECTIVE To explore expression of IL-13 in eosinophilic chronic rhinosinusitis with nasal polyps(EOS-CRSwNP) and further investigate the correlation between IL-13 and MUC5AC in EOS-CRSwNP. METHODS MUC5AC was detected in tissues from normal nasal mucosa and EOS-CRSwNP by immunohistochemistry and ELISA. We also used ELISA to detect the expression of IL-13 in normal nasal mucosa and EOS-CRSwNP. Correlation between IL-13 and MUC5AC in EOS-CRSwNP was investigated by correlation analysis. Secretion of MUC5AC in IL-13 incubated primary air-liquid interface(ALI)-cultured nasal polyp epithelial cells was examined by ELISA. RESULTS MUC5AC is mainly expressed in the epithelium of nasal mucosa by immunohistochemistry. By ELISA, expressions of MUC5AC and IL-13 are higher in EOS-CRSwNP than those in normal nasal mucosa. Correlation analysis shows that there exists a high correlation between MUC5AC and IL-13 in EOS-CRSwNP. IL-13 upregulates expression of MUC5AC in IL-13 incubated primary ALI-cultured nasal polyp epithelial cells for 7 or 14 days. CONCLUSION Expressions of MUC5AC and IL-13 are higher in EOS-CRSwNP than those in normal nasal mucosa respectively, and MUC5AC correlates with IL-13 highly in EOS-CRSwNP.

Objectives To detect the cord blood vitamin D level in neonates and to determine the association between the cord blood vitamin D level and neonatal outcomes. Methods A total of 223 eligible mother-and-singleton-offspring pairs were recruited. The information of mothers' pregnancy was collected by questionnaires. The weight, length, and head circumference of neonates were measured. The levels of 25(OH)D in cord blood of neonates and in blood of late pregnancy mothers were determined by chemiluminescence immunoassay. Results The median concentration of 25(OH)D in cord blood was 20.7 nmol/L, and 82.1% of neonate had vitamin D deficiency, and 12.1% had severe vitamin D deficiency (<10 nmol/L). The concentration of 25(OH)D in cord blood was consistent with that in blood of late pregnancy mother. The distribution of concentration of 25(OH)D in cord blood was significantly different in neonates in different seasons of birth (P<0.05). There were more cases <10 nmol/L in winter and spring. The concentration of 25(OH)D in cord blood had no significant associations with the incidences of low birth weight (LBW) and small for gestational age (SGA) (P>0.05). After the variables of sex, gestational age and birth season are controlled, the birth weight and head circumference were significantly different in neonates with different concentrations of 25(OH)D in cord blood (P<0.05). Conclusions The concentration of 25(OH)D in cord blood in term neonates was generally lower. The vitamin D status in neonates was consistet with that in their late pregnancy mothers. Cord blood 25(OH) D levels were associated with neonates' birth weight and head circumference, but it should be confirmed by larger sample size in the future.

Objective To evaluate the selectively killing effect of adenovirus (Ad) mediated double suicide gene driven by KDR promoter on vein endothelial ECV304 cells.Methods KDR producing cells ECV304 and the KDR nonproducing cells LS174T were infected by Ad respectively, followed by treatment with 5-FC and GCV.Killing effects were evaluated and bystander effects were analyzed.Distribution of cell cycle was detected by flow cytometric assay and pathological character of cells was observed by electron microscopy.Results The infection rate of the resultant recombinant Ad to all the cells was not apparently different, and it increased gradually with the addition of multiple of infection (MOI) of Ads.ECV304 cells infected with Ad-KDR-CDglyTK were sensitive highly to the prodrugs, but the LS174T cells infected with Ad-KDR-CDglyTK appeared to be unsensitive to the two prodrugs ( P