Objective To provide scientific basis for formulating National Standard Method for determination of 1,1_dichloroethene in water. Methods The method of head space gas chromatography was established in this assay. Results This method revealed good seperating efficiency and good linear relationship (r=0.9995,n=6). The detection limit was 0.2 ?g/L. The recovery rates of the blank drinking water samples to which was added standard solution containing 10, 20 and 40 ?g/L 1,1_dichloroethene respectively were 108%, 101% and 97% respectively, their related standard deviations were 4.6%, 4.2% and 2.8% respectively. Under the similar procedure as above, the recovery rates of the blank source water samples, added with standard solution containing 10, 20 and 40 ?g/L respectively, were 92%, 94% and 97%, their related standard deviations were 7.0%, 5.0% and 3.3% respectively. Conclusion This method was simple, convenient and effective. The levels of recovery rates and precision of this method all accorded with the requirements of the determination of 1,1_dichloroethene in water.

Objective To study the method for determination of pentachlorophenol(PCP) in water by headspace solid phase microextraction(SPME) gas chromatography. Methods Pentachlorophenol in water samples was extracted using optimized SPME technology, separated by SE30 chromatographic column and the content of pentachlorophenol in water was determined by electron capture detector (ECD) under the conditions: adjusting water samples to pH 2.0, to maintain an agitating equilibrium concentrations at 60 ℃ for 40 min, headspace absorption for 10 min using extraction head holding polyacrylic ester-coated microfiber (0.83 ?m in thickness), desorption at 280 ℃ for 3 min. Results The detection limit of the method was 0.13 ?g/L. The correlation coefficient r=0.999 was noticed in range of pentachlorophenol concentrations 0-12 ?g/L. When adding standard material of pentachlorophenol at concentrations of 1 ?g/L, 6 ?g/L, 10 ?g/L, the recovery rates were 88.9%-105.0%, 88.9%-102.8% and 98.0%-99.5% respectively and the RSD were 4.9%-8.4%, 3.1%-8.5% and 4.0%-5.4%(n=6)respectively. Conclusion The method was simple, sensitive, stable and without solvent pollution, which was an ideal method for determination of pentachlorophenol in water.

Objective To study the expression and clinical significance of vascular endothelial growth factor(VEGF)and soluble vascular cell adhesion molecule-1(sVCAM-1)in children with Henoch-Schonlein purpura(HSP).Methods The levels of plasma VEGF and sVCAM-1 were measured in 58 children with HSP and 23 normal children by enzyme-linked immunosorbent assay(ELISA),respectively.Results The plasma levels of VEGF and sVCAM-1 of HSP children at acute stage were significantely higher than those of HSP children at the remission stage and those of the controls(Pa

China ; Clinical Trials as Topic ; methods ; Humans ; Organizational Policy ; Publishing ; standards ; Registries

Humans ; Pancreatic Neoplasms ; diagnosis ; therapy

Preeclampsia is a leading cause of maternal and infant morbidity and mortality. It is very important to explore the biomarkers for the early prediction of preeclampsia. Some peptides released from placenta, such as soluble Flt-1 and placenta growth factor (PlGF), have been revealed for definite prospects of application. Meanwhile, the recent advances in proteomics, metabolomics and microRNA shed light on searching of new biomarkers for preeclampsia prediction.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Colles' Fracture ; therapy ; Exercise Therapy ; Female ; Humans ; Male ; Middle Aged ; Musculoskeletal Manipulations

Background Many eye diseases such as central retinal artery occlusion,glaucoma and ischemic optic neuropathy,etc.lead to retinal ischemia-reperfusion injury (RIRI) and furthmore visual functional damage.It is neeessary to study the treatment of RIRI.Objective This study was to observe and discuss the influence of aminoguanidine on the retina morphological changes and its mechanism after RIRI.Methods Eighty clean healthy male Japanese white rabbits were randomly divided into normal injury group,RIRI group and aminoguanidine (AG)treated group.The model of RIRI was established by infusing saline solution into the anterior chamber to elevate intraocular pressure (IOP) in both RIRI group and AG group.AG was intraperitoneally injected in the models of the AG group,and normal saline solution was used at the same method in tbe normal group and the RIRI group.The fundus photography and fundus fluorescein angiography(FFA) were pertormed on the rabbits at the moment of retina ischemia and 6,24 and 72 hours after reperfusion.The parts of rabbits were sacrificed 1,6,24 and 72 hours after reperfusion,followed by the enucleation of the eyeballs.Retinal section was prepared for TUNEL examination to evaluate the apoptosis of retinal cells.Nitric oxide (NO) concentration in retina was detected with nitrate reductase,and the activity of inducible nitric oxide synthase (iNOS) was measured by colorimetric detection.The use of the animals followed the Regulations for the Administration of Affairs Concerning Experimental Animals by State Science and Technology Commission.Results The fundus photography and FFA showed that the retinal edema was more mild,and the percentage of vascular occlusion was lower in the AG treatment group than that in RIRI group and the amount and area of fluorescein leakage were also smaller than the treatment group.The numbers of TUNEL positive cells in the AG treatment group were less than those in the RIRI model group at 1,6,24 and 72 hours after experiment (F分组 =2762.37,P =0.00 ; F时间 =894.24,P =0.00).Numbers of TUNEL positive cells between adjacent time points were significantly different in both RIRI model group and AG treatment group (RIRI group:q =24.475,36.591,-20.37,P＜0.05;AG group:q =20.94,16.79,-6.92,P＜0.05),with the peak value at 24 hours after experiment.NO contents were significantly higher in the RIRI model group compared to AG group at various time points(q =3.84,4.01,8.91,3.75,P＜0.05),and those between adjacent time points showed significant differences (RIRI group:q=4.77,13.403,-10.29,P＜0.05;AG group:q=4.55,9.05,-5.08,P＜0.05).iNOS activity was significantly elevated in the RIRI model group compared with AG group(q=-3.74,-4.94,-6.53,-3.98,P＜0.05),and obvious differences also were seen between the adjacent time points in both two groups(RIRI group:q =8.43,6.71,-6.39,P＜0.05 ;AG group:q =4.16,5.08,-3.93,P＜0.05).Conclusions Aminoguanidine can protect the retinal function and morpbology from oxidative stress damage after RIRI by reducing the NO level and inhibiting the iNOS activity in retina.

BACKGROUND:As the multipotent differentiation potential, bone marrow mesenchymal stem cells exert an important role in bone metabolism disorders, which is regulated by a variety of hormones and cytokines. Currently, the epigenetic regulatory mechanisms underlying osteogenic differentiation of bone marrow mesenchymal stem cells are unclear, and association between histone deacetylase (Hdac) and osteoporosis needs to be further explored. OBJECTIVE:To investigate the epigenetic mechanisms of bone formation by analyzing the expression of Hdac1, 3, 4 mRNA profile in bone marrow mesenchymal stem cells isolated from ovariectomized mice. METHODS:A total 30 female healthy Kunming mice were randomly divided into sham group and ovariectomy group. After 7 days of adaptive feeding, mice in the ovariectomized group (n=15) were subject to bilateral ovariectomy;mice in sham group (n=15) were sham-operated. RESULTS AND CONCLUSION:In the ovariectomy group, the trabecular bone of the femur was sparse or broken, the width of trabecular bone was narrowed, the trabecular separation was widened, and the trabecular bone volume was reduced. The level of Hdac3 mRNA was lower in bone marrow mesenchymal stem cells from ovariectomized mice compared with controls, but there was no significance between Hdac1, Hdac4 mRNA expression of the two groups. These findings demonstrate that Hdac might play an important role in bone remodeling in the model of estrogen deficiency-induced osteoporosis.

BACKGROUND: There are a variety of methods for establishing periprosthetic osteolysis animal model, and the models established by different methods and with different animals have their own characteristics.OBJECTIVE: To review the research profiles of the periprosthetic osteolysis and the characteristics of the various models, and to provide a reference for the related research. METHODS: The relevant articles on the periprosthetic osteolysis animal models were searched in PubMed from January 1999 to May 2017, with the key words of "animal model, osteolysis" in English by the computer. Similarly, Chinese Journal Full-text Database was retrieved for related articles published from January 1999 to May 2017, with the key words of "animal model, osteolysis" in Chinese. Articles that were unrelated to the periprosthetic osteolysis animal model were excluded. Classic and recently published articles were selected. RESULTS AND CONCLUSION: (1) The artificial induced animal models are the principal means to establish animal models of periprosthetic osteolysis and they have been widely used in the study of periprosthetic osteolysis pathogenesis, pathological process and treatment. (2) Small-animal models present many advantages: inexpensive to purchase, high physiological turnover, controlled source, homogenous and established genetic background. However, a limitation of these small-animal models is that the temporal pattern of osteolysis is different from the long-term osteolysis that occurs in patients. (3) The large animal model is more similar to the bone dissolution process around the human prosthesis, but the cost is high; the breeding is difficult; the operation requirement is hard. Thus, its widespread use is limited. (4) Furthermore, innovative models that combine the advantages of both are also constantly explored. Overall, the selection of models should be based on research conditions and needs to be considered.