Objective To make a accurate, simple method for determination which is suitable for application in basic level units to test nitrate nitrogen in drinking water. Methods Based on the principle that catalyzed by the Cu2+, NO3- is reduced by hydrazine sulfate into NO2-, then it reacts on sulfanilamide in hydrochloric acid to produce a diazo compound, the latter reacts on NEDD to produce a rose dye. Results The maximum wave-length of the was 555 nm, the molar absorption coefficient was 6.5?106L/(mol?cm), RSD were 0.55%-2.07%, the rates of recovery were 91.3%-109.6%. Beer's law was obeyed in the range of 40-320 ?g/L(1-8 ?g /25 ml). Conclusion This method is simple, rapid, accurate and suitable for application in basic level units to determine nitrate nitrogen in drinking water.

Speeding up the training of quality personnel in clinical medicine is an important historic mission of clinicians. Practice has proven that the training, growth and maturity of quality clinical personnel are inseparable from clinical practice. Thus, firstly, clinical workers must, in accordance with the goals of training, rigorously enforce process management, including implementation of the training regulations, strict assessments, and cultivation of abilities in doing scientific research and writing up research papers. Secondly, the overall quality of postgraduates must be enhanced. Thirdly, files of postgraduates must be set up. Fourthly, experience in training academic degree postgraduates in clinical medicine should be constantly summed up, including ways of strengthening organization and control and clarifying goals and requirements

Objective To investigate the effect of construct the Notch1 (NICD) eukaryotic expression vector on the proliferation and differentiation of rat bone marrow mesenchymal stem cells (BMSCs) in vitro. Methods Rat BMSCs were experimented as the object. NICD eukaryotic expression vector was constructed. pEGFP-N1-NICD expressing plasmids were used to transfect BMSCs. The study included control group (CON group), empty vector group (VEC group) and the trans-fection group (TRA group). After 48-hour transfection, BMSCs were observed for general morphology. The protein expres-sions of NSE, GFAP and Notch1 were detected by real-time PCR and Western blotting assay respectively. The apoptosis, cy-cle distribution and cell proliferation were evaluated by flow cytometry and MTT assay. Results The DNA sequencing con-firmed that the pEGFP-N1-NICD recombinant plasmid was successfully constructed, and both VEC group and TRA group expressed green fluorescence after 48-hour transfection. The relative expression levels of Notch1 and GFAP mRNA and pro-tein were significantly higher in TRA group than those in VEC group and CON group (P<0.05), and there was no significant difference between VEC group and CON group. After 48-hour transfection, the ratio of living cells was significantly lower in TRA group than that of CON group and VEC group, and the early apoptotic rate and late apoptotic rate were significantly higher in TRA group than those of CON group and VEC group (P<0.05). The late apoptotic rate was significantly higher in VEC group than that of CON group. The proportion of G1/G0 cells was significantly higher in TRA group than that of CON group and VEC group, but S and G2/M cells were significantly lower (P<0.05). The value of growth curve was gradually de-creased in TRA group than that of CON group and VEC group (P<0.05). Conclusion The high expression of NICD gene might induce apoptosis of BMSCs, inhibit the proliferation in part, and induce into glial-like cell differentiation.

BACKGROUND:In vitro experiment has shown that the survival time of conventional chemical induction-induced neuron-like cells differentiated from bone marrow mesenchymal stem cells(BMSCs)was short,which limited its further application.With regard to the possibility of extension of iodine-induced neuron-like cells,the survival time has not yet been professionally reported.OBJECTIVE:To research the effects of the micro-element iodine on the survival time of neuron-like cells differentiated by BMSCs.METHODS:Rat mesenchymal stem cells at passage 3 were obtained under sterile condition,and divided into groups A-F.In group A,iodine ion was not added.In groups B-F,iodine ion at mass concentrations of 2,55,90,125 and 2 500 mg/L was added respectively.An additional blank control group was established,and simultaneously the cells were induced into neuron-like cells with dimethyl sulphoxide(DMSO).Cells following induction were subjected to immunohistochemistry.Survival time of neuron-like cells was observed under different mass concentrations of iodine ion.RESULTS AND CONCLUSION:When mass concentrations of iodine ion were between 55-125 mg/L,the survival time of neuron-like cells prolonged to about 5 days and structures of induced cells were intact.From then on,the number of dead cells was gradually increased till approximately one week,all neuron-like cells died.When mass concentrations of iodine ion were 2 mg/L and 2 500 mg/L,cell survival time was from 12-36 hours.No significant difference was determined compared with group A.Till 2 or 3 days,all neuron-like cells died.Above-described results indicated that an appropriated concentration of iodine iron added in the common chemical induction may be benefit for the survival time of the neuron-like cells differentiated by BMSCs,but the effect may be negligible for the survival time of neuron-like cells induced when the added concentration of iodine iron is too low or too high.

BACKGROUND:Wnt signaling pathway is the key to regulation of cell proliferation and differentiation.The evidence suggests that this pathway participates in the neural precursor cell proliferation,differentiation and determination of the regulation of cell fate.At present,the Wnt signaling pathway effects on the mesenchymal stem cells(MSCs)differentiated into neuron-like cells have not been reported.OBJECTIVE:To seek Wnt signal molecule that promotes the differentiation of MSCs into neuron-like cells.METHODS:MSCs were isolated from the femur of Sprague Dawley rats in vitro using the density gradient centrifugation,and then cultured.Following passage,cell surface markers CD29,CD44,CD34 and CD45 were measured using morphology and flow cytometry.These cells were selected and evaluated.Using neurotrophic factor and basic fibroblast growth factor combined with Wnt3a and Wnt5a induction scheme,effects of Wnt3a and Wnt5a during the differentiation of MSCs into neuron-like cells were compared utilizing immunohistochemistry and reverse transcription-polymerase chain reaction(RT-PCR).Simple culture of basic fibroblast growth factor served as controls.RESULTS AND CONCLUSION:Following culture and passage of MSCs,cells adhered to the wall,showing even spindle shape.Flow cytometry showed great expression of CD29 and CD44 and low expression of CD34 and CD45.Following Wnt3a induction,cells were positive for nestin,neuron specific enolase,but no significantly expressed glial fibrillary acidic protein.Following induction,cell viability was good.In the Wnt5a induction and control groups,weakly positive expression of nestin was found,but neuron specific enolase and glial fibrillary acidic protein were negative.RT-PCR results demonstrated that nestin expression was detected in the Wnt3a induction group before and after induction.Significant amplified bands for neuron specific enolase were detected at day 5 following induction,and became more significant at day 10.Weak bands for glial fibrillary acidic protein were visible at day 10 following induction.These indicated that Wnt3a can promote the differentiation of MSCs into neuron-like cells in vitro.

The performance of CRA directly affects the quality of clinical trials. In the appraisal of the CRA performance, satisfaction of clinical institutions plays a vital role. This article presents the outcome of a satisfaction survey on 16 clinical research centers in Shandong province, and the analysis of 503 survey samples regarding their exploratory factor and confirmatory factor respectively. The purpose is to identify the main factors for the satisfaction and to build a model to evaluate the satisfaction of hospitals for CRA.

Objective To observe the value of diffusion-weighted imaging (DWI)and ADC value in the differential diagnosis of benign and malignant lesions of the tongue.Methods 75 patients with lingual lesions,including 32 benign lesions and 43 malignant tumors,underwent conventional MRI,contrast-enhanced MRI and DWI with b values of 0 and 1 000 s/mm2 before therapy.ADC maps were reconstructed,and the ADC values of the lingual lesions were calculated.Diagnostic performance of ADC was compared using receiver operating characteristic curves (ROC).Results The mean ADC values of benign lesions and malignant tumors were (1.84±0.47)×10 -3 mm2/s and (1.12±0.21)×10 -3 mm2/s,respectively.Malignant tumors had lower ADCs than benign lesions (t=-8.038,P <0.000).The areas under the ROC curves of ADC diagnosing benign and malignant lesions of the tongue was 0.957±0.022.The optimal cutoff values of ADC for differentiating benign and malignant lesions of the tongue was 1.30 × 10 -3 mm2/s with sensitivity of 90.7%,specificity of 93.8% and accuracy of 92%.And ADC had a high consistency compared with pathological results (Kappa values were 0.813).Conclusion Different features between benign and malignant lesions of the tongue are able to be identified with DWI,which can be applied as a complementary tool in the detection of benign and malignant lesions of the tongue.

Objective: To investigate the quantitative analysis value of T2 mapping in the evaluation of pathological type, tumor grade and lymphovascular space invasion (LVSI) of cervical cancer. Methods: Totally 57 patients with pathologically proven cervical cancer underwent conventional MRI, DWI and T2 mapping before therapy. T2 and ADC values were obtained and compared between tumor and normal tissue (myometrium), squamous cell carcinomas and adenocarcinomas, well/moderately differentiated tumor and poorly differentiated tumor, LVSI-positive and LVSI-negative cervical cancer, respectively. ROC curve was constructed to evaluate diagnostic performances. Results: T2 and ADC values showed significant differences between cervical cancer and normal tissue (both P<0.001). No significant difference was observed in T2 and ADC values between squamous cell carcinomas and adenocarcinomas (both P>0.05). Compared to well/moderately differentiated tumors, poorly differentiated tumors showed decreased T2 and ADC values (both P <0.05). T2 values were significantly lower in LVSI-positive than in LVSI-negative cervical cancer (P=0.002), while ADC values were not significantly different (P=0.675). The AUC of T2 and ADC values for distinguishing tumor grade were 0.709 and 0.747, respectively. The AUC of T2 value in discriminating the presence of LVSI was 0.856. Conclusion: Quantitative T2 mapping can putatively differentiate the grade of cervical cancer. Moreover, quantitative T2 value exhibits better than ADC for discriminating the presence of LVSI.

Objective To observe the resection of the scapholunate interosseous ligament (SLIL)and its subregions on the three-dimensional(3-D)movement of the scaphoid and lunate so as to discuss the role of SLIL in the 3D flexion-extension motion of the scaphoid and lunate.Methods Twelve upper extremities(six left extremities and six right extremities)from adult cadaver were used in this study and divided into five groups:normal group,proximal subregion resection group,proximal subregion plus dorsal subregion resection group,proximal subregion plus palmar subregion resection group and whole SLIL resection group.The 3-D laser scan and reconstruction technique were used for meusure ment of the 3-D flexion-extension motion of the scaphoid and lunate.Results In the normal group,the scaphoid and lunate flexed and the radial deviated at the same direction during wrist flexion-extension motion.At the same time,there was minimal scaphoid and lunate pronation-supination during wrist flexionextension.After resection of the proximal and palmar(or dorsal)subregions of the SLIL,some different movements were found compared with the normal specimen.Whole SLIL resection resulted in increase of the flexion motion of the scaphoid but decrease of the palmar flexion of the lunate.Conclusions 3-D laser scanning and image reconstruction techniques can accurately measure the 3D motion of the scaphoid and lunate.Partial or whole resection of SLIL may exert significant effect on the flexion-extension motion of the scaphoid and lunate.However,the proximal subregion of SLIL has no prominent effect on the motion of the scaphoid and lunate.

Objective To investigate the value of ADC and T2WI in differentiating of skull base chordoma and invasive pituitary adenomas(IPA).Methods 15 patients with skull base chordoma and 19 patients with IPA which involve paranasal sinus were reviewed retrospectively.All diagnosis were demonstrated by pathology.Quantitative analysis of minimum ADC, normal ADC and rT2WI values were performed.Differences in minimum ADC, normal ADC and rT2WI values between skull base chordoma and IPA were evaluated using the independent samples t test and receiver operating curves(ROC).Results Statistical analysis revealed a significant difference among normal ADC, minimum ADC and rT2WI values (P<0.01),and the area under the ROC curves decreased in turn.Conclusion Both ADC values and rT2WI SI are effective parameter for differentiating diagnosis of skull base chordoma and IPA.