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 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.

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.

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.

Calcinosis ; complications ; Decalcification Technique ; Humans ; Meningeal Neoplasms ; complications ; Meningioma ; complications ; Specimen Handling ; methods ; Ultrasonics

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 analyze the miss rates of colorectal adenomas during colonoscopy as well as risk factors influencing the adenoma miss rates and to take corresponding measures. Methods A total of 432 patients who underwent index and follow-up colonoscopy in 18 months were randomized and investigated. The results of two colonoscopies were compared and the missed adenomas were defined as the adenomas de-tected only during the second colonoscopy. Miss rates were calculated according to patient-based methods. Chi-square test was used to analyze the relative factors influencing the adenoma miss rate of per-patient. Then the meaningful factors were chosen into the logistic regression model for multiple factors analysis. Results Of 432 patients,116(26. 9%)had missed adenomas on first colonoscopy. Single factor analysis found that the size of adenoma( χ2 = 89. 686,P = 0. 000),the shape of adenoma( χ2 = 68. 488,P = 0. 000),the location of adenoma(χ2 = 77. 055,P = 0. 000)and adenoma tissue types(χ2 = 417. 000,P = 0. 000)were the risk factors for miss rates of colorectal adenomas. Number of polyps(χ2 = 8. 450,P= 0. 038),the organi-zation type of polyp(χ2 = 10. 718,P= 0. 013)and proficiency of colonoscopists(χ2 = 56. 069,P= 0. 000), the quality of bowel preparation(χ2 = 39. 195,P = 0. 000),insertion time(χ2 = 13. 133,P = 0. 001)were also the risk factors for miss rates of colorectal adenomas. Logistic regression analysis showed that the bigger the adenoma size,the less missed adenomas(OR= 0. 341,95%CI:0. 173-0. 671). Also,the longer insertion time took,the lower the adenoma miss rate(OR = 0. 987,95% CI:0. 981-0. 994). Per-patient miss rates were lower for high-risk adenomas compared with low-risk adenomas(OR = 0. 324,95%CI:0. 154-0. 680). Adenomas happening in multiple parts of bowel easily leads to missing(OR= 3. 791,95%CI:1. 505-9. 546). Conclusion The missed diagnosis of adenomas is not only significantly associated with features of missed adenomas,but also with skills of colonoscopists,insertion time,and bowel preparation. The key is high-quality index colonoscopy to avoid adenomas missing.

Objective To compare the three kinds of methods for in vitro primary culturing of rheumatoid arthritis synovial fibroblast-like cells (RASFs), in order to get fast and effective culture methods. Methods Synovial tissue from RA synovial arthroscopic resection were treated by collagenase digestion method, modified tissue culture method, double enzyme digestion method respectively. By using an inverted phase contrast microscope, cell morphology and growth characteristics were observed and identified with vimentin staining. Trypan blue was used to count the number of living cells after culturing for 14d. Results The three primary methods could successfully isolate and culture RASFs, and RASFs met the morphological characteristics of vimentin-positive cells>95%, namely, the proportion of RASFs cell confluence was 70% after 16-20days by the collagenase digestion method,whose cell confluence proportion reached 95%after 4 weeks;and the cell confluence proportion was above 70%after 10-14days by modified tissue culture method,and the cell confluence proportion reached 85%after 4 weeks by the double enzyme digestion method. The comparison of the viable cells number cultured same number of synovial tissue by the three methods show the viable cells number cultured by the modified tissue culture method were (1.60±0.08) ×106, those by the collagenase digestion method were (1.41±0.08) ×106, those by the double enzyme digestion method were (1.19 ±0.05) ×106, which were with significant difference among them (P<0.05) .The comparison of incubation time of RASFs primary cells showed it took (267.50±16.58) mins by the collagenase digestion method, (183.75 ±11.08) mins by the double enzyme digestion method, and 149.10 ±13.71mins by the modified tissue culture method, with significant differences (P<0.05) .Conclusion Modified tissue culture for RASFs is an efficient and fast culture method, the number and purity of RASFs can meet the requirements for biology experiments.

Relapse, which puzzled several generations of hematologists, is the bottle-neck of radical treatment for leukemias. The progress of Human Microbiome Project at the beginning of 21st century suggested that human body was a super-organism constituted by the core of human cells and symbiotic microorganisms. The elucidation and characterization of endogenous retrovirus and prion protein suggested the possible effects of co-evolutional microorganisms on human health. Recently, the elucidation of the roles of tunneling nanotubes in intercellular communication and transportation suggested a novel way for cellular communication and transport of oncogenic materials. The role and significance of in vivo cell fusion have been studied in more detail. On the other hand, donor cell leukemia was reported. All of these approaches provide novel insights for studying the mechanism of leukemia relapse. Based on previous work, the authors suggest the hypothesis: there are two possible mechanisms for the relapse of leukemias: the minimal residual disease (MRD) and intercellular transportation of oncogenic materials.
Cell Fusion ; Humans ; Leukemia ; pathology ; Neoplasm, Residual ; pathology ; Recurrence

Objective To study the effects of Hydergine on expression of N-methyl-D-aspartate receptors in hippocampus and actions of mice with ischemia-reperfusion injury.Methods 36 mice were randomly divided into model group,Hydergine group and sham-operated group. The models of ischemia-reperfusion injury were made by knotting bilateral common carotid arteries. The behavioral abnormalities were investigated by step-down test and water maze test, and the expressions of N-methyl-D-aspartate receptors in neurons of hippocampus were observed by immunohistochemistry technique. Results Compared with model group, the performance records of learning and memory in Hydergine group were better (all P