Internet-based tendering system makes equipment purchase convenient,rapid,effective,economical and fair. This system guarantees the legal benefits of the medical organizations and suppliers to the most. At the same time this article introduces some issues that should be noticed by medical organizations and suppliers when they participate the on-line bid.

The medical equipment on-line bid is a newborn method for bid,which unites the modern computer technology,communication technology and electronic commerce technology. When the on-line bid system is applied,except for the make of comprehensive and standard tender documents,the followings also claim attention: how to correctly open the webpage of video meeting inserter,how to suitably adjust video acoustics,and how to properly adjust video images.

Cell Adhesion ; Cell Proliferation ; Cells, Cultured ; Chitosan ; chemistry ; Coated Materials, Biocompatible ; Collagen ; chemistry ; Humans ; Materials Testing ; Polyethyleneimine ; chemistry ; Static Electricity ; Surface Properties ; Titanium ; chemistry

A rapid resolution liquid chromatography coupled with quadrupole-time-of-flight mass spectrometric (RRLC-Q-TOF-MS) method was established and optimized for the analysis of pharmacokinetic behavior of ginsenoside Rb2 in rats by intravenous injection administration.The metabolism of ginsenosides Rb2 in vivo rat was also explored.In the experiment,Agilent SB C18 column was selected for the sample separation with 0.1％ aqueous formic acid solution as mobile phase (A) and acetonitrile as mobile phase (B) at a flow rate of 0.2 mL/min,and the injection volume was set to 5 μL.Q-TOF-MS was carried out in electron pray ionization (ESI) negative ion mode.The limit of quantification (LOQ,S/N =10) and limit of detection (LOD,S/N=3) were 0.10 and 0.08 μg/mL,respectively,and the linear range was 0.1-1.26 μg/mL.The experiment results showed that the concentration-time profile of ginsenoside Rb2 conformed to a two-compartment pharmacokinetic model after intravenous administration for rats.The mean plasma elimination half-lives were (23.58±1.10) min (t1/2α),(1306.55±147.23) min (t1/2β) for Rb2.By analyzing the urine of rats after intravenous administration and the fecal samples after oral administration of ginsenoside Rb2,it was found that the metabolites were M6,M2 (CY),F2,and C-K.

Objective To explore changes of metabolites in APP/ PS1 double transgenie mice of Alzbeimer disease (AD) by 1H-MR spectroscopy (1H-MRS) and the application value of in early diagnosis of AD.Methods 1H-MRS was performed in 35 APP/PS1 transgenie mice of AD ( study group) and 20 wild type mice ( control group) at age of 3, 6 and 9 months using a 7.0 T MR system.Sub-peak areas of N-acetyl aspartate (NAA), myo-inositol (mI) and creatine (Cr) in the cerebral cortex and hippocampus were measured, and the NAA/Cr and mI/Cr ratios were calculated.The changes in pathology between the two groups were compared.Using the lower limit of 95% confidence interval (CI) of the ml/Cr ratio and the upper limit of 95% CI of the NAA/Cr ratio of AD mice as the threshold, their influences on sensitivity,specificity and accuracy of various age groups of AD animals were compared.Comparison of the 1H-MRS indexes between study mice and wild type mice at each time point were conducted by a two-sample t test.Results The mean mI/Cr ratios of AD mice were 0.68± 0.03, 0.72± 0.04, and 0.77 ± 0.04 respectively at 3, 6 and 9 months of age; while they were 0.63 ± 0.04, 0.64 ± 0.03, and 0.64 ± 0.04 respoetively in control group, the difference was significant ( t = 2.814, 5.146, 14.437, P < 0.01 ).Compared with the control group, the mI/Cr ratio of the 3-month-old AD mice of the study group was significantly increased,and histological examination showed proliferation and activation of neuroglial cells in the cerebral cortex and hippoeampus.The mean NAA/Cr ratio were 1.17 ±0.08, 1.04 ±0.05, and 0.90 ±0.05 respectively at 3,6 and 9 months of age in study group, while they were 1.18 ±0.07, 1.16 ±0.07, and 1.18 ±0.08respectively in control group.There were no significant difference ( t = 0.752, P > 0.05 ) between the study group and control group at 3 months of age, and the NAA/Cr ratio decreased significantly only at 6 and 9 months of age ( t = - 8.514, - 5.646, P < 0.01 ).The immunohistochemical exam demonstrated the appearance of Aβ plaque.According to threshold of mI/Cr, the sensitivity of AD mice of 3, 6 and 9 months of age was 80% (28/35), 84% ( 26/31 ) and 85% ( 23/27 ), and the specificity was 85% ( 17/20 ),94% (17/18) and 100% ( 16/16), and the accuracy was 82% (45/55), 88% (43/49) and 91% (39/43),respectively.For NAA/Cr, the sensitivity of AD mice of 6 and 9 months of age was 84% (26/31) and 89% (24/27), and the specificity was 89% (16/18) and 100% (16/16), and the accuracy was 86% (42/49) and 93% (40/43), respectively.Conclusions NAA and mI are the most sensitive and specific markers for early assessment of AD, and change of mI is earlier than that of NAA.Quantitative analysis of mI may provide important clues for early diagnosis of AD.

Objective To study the effects of abiotic elicitors methyl jasmonate (MeJA) and salicylic acid (SA) on the alkaloids accumulation and related enzymes metabolism inPinellia ternata suspension cell cultures. Methods Using the leaf petioles-derived suspension cell cultures as the study object, the culture duration, concentrations of MeJA and SA were determined to get the optimal alkaloids accumulation, and the activities of metabolic enzymes IMP dehydrogenase and sAMP synthase were also measured.Results A 9-fold of dried biomass and a 3-fold of alkaloids accumulation were observed inP. ternata suspension cell cultures after culture for 21 d. Both MeJA and SA could significantly promote the accumulation of alkaloids inP. ternata suspension cells. 150 μmol/L MeJA enhanced alkaloids content (4.7 mg/gDW) by 3.6 folds in comparison with control group, whereas 50 μmol/L SA showed a 2.5-fold increase. Meanwhile, 100 μmol/L MeJA and 50 μmol/L SA promoted the increase in IMP dehydrogenase activity by 3.0 and 3.7 fold respectively, and 150 μmol/L MeJA and 100 μmol/L SA showed the increase by 2.6 and 4.4 fold respectively.Conclusion Proper adding exogenous MeJA and SA can promote the accumulation of alkaloids inPinellia ternata suspension cell cultures.

Objective To investigate the distribution characteristics of serum pepsinogen (PG) in healthy people and its reference interval establishment .Methods 3 753 healthy people were enrolled and divided into <45-year old ,45- <60-year old and ≥60-year old group according to their ages .Double antibody sandwich enzyme-linked immunosorbent assay was used to detect PG Ⅰ ,Ⅱ . Results Detection results of serum PG Ⅰ ,PGⅡ and PGⅠ /PGⅡ of male and female healthy people in different age group showed a skewed distribution(P<0 .05) .Serum PGⅠ and PGⅠ /PGⅡlevels of females were significantly higher than males(P<0 .01) .In the same age group ,difference of serum PGⅡ levels between males and females was not statistically significant (P>0 .05) .In the same gender ,pairwise comparison of PGⅠlevels was conducted in different age groups ,and the difference showed no statistical sig-nificance(P>0 .05) .PGⅡlevel increased with age increasing (P<0 .01) while PGⅠ /PGⅡlevel increased with age reducing (P<0 .05) .Percentile method was adopted to determine the 95% reference interval ,the bilateral reference intervals (P2 .5 - P97 .5 ) was taken for PGⅠ ,unilateral upper limit(≤ P95 ) for PGⅡ and unilateral limit (≥ P5 ) for PGⅠ /PGⅡ .Conclusion The establishment of serum PG Ⅰ ,PG Ⅱ ,PG Ⅰ /PG Ⅱ reference intervals of healthy people provides a basis for the prevention and treatment for stomach disease .

BACKGROUND: Under indirect co-culture conditions, chondrocytes can induce bone marrow mesenchymal stem cells to differentiate into chondrocytes. Osteocytes are the seed cells of chondrocytes, but co-culture of osteocytes with chondrocytes is rarely reported. OBJECTIVE: To induce the chondrogenic differentiation of periosteum-derived cells (PDCs) by indirect co-culture with chondrocytes. METHODS: Chondrocytes were isolated from the rabbits by trypsin and collagenase Ⅱ digestion. Rabbit PDCs were obtained by the explants culture method. Passage 2 chondrocytes and PDCs underwent indirect co-culture at 1:1 in Transwell system as experimental group. PDCs cultured alone were as control group. After 2 weeks of culture, the cellular morphological changes were observed by inverted contrast phase microscope. The expression levels of collagen type Ⅱ and proteoglycan were detected by collagen type Ⅱ immunohistochemistry and toluidine blue staining. The mRNA expression levels of proteoglycan, collagen type Ⅱ and SRY-related protein-9 were detected by RT-PCR. RESULTS AND CONCLUSION: After 2 weeks of culture, PDCs in the experimental group were gradually transformed to chondrocyte-like cells, while PDCs in the control group still remained long spindle-shaped. Collagen type Ⅱ immunohistochemistry staining and toluidine blue staining were positive in the experimental group, while the results were negative in the control group. Additionally, RT-PCR results indicated that the relative mRNA expression levels of proteoglycan, collagen type Ⅱ and SRY-related protein-9 in the experimental group were significantly higher than those in the control group. Therefore, chondrocytes can induce PDCs to differentiate into chondrocytes under indirect co-culture conditions.

Objective To investigate the value of MRI and~1H-MRS in diagnosis of early stage of diabetic encephalopathy by detecting regional metabolite in cynomolgus diabetes models. Methods Five pathogen-free male adolescent cynomolgus were made type 1 diabetes mellitus models (T1DM) by intravenous injection of streptozotocin (STZ) (100 mg/kg), and the reliability and stability of the modes were assessed with long term follow-up of blood glucose and intravenous glucose tolerance tests. MRI and ~1H-MRS were performed to evaluate the volume, signal intensity and metabolic ratios of NAA/Cr, mI/Cr and Cho/Cr at hippocampus, lateral temporal lobe and occipital lobe 3 years after model establishment. Cortisol in serum was detected with immunoradiometric assay. In addition, 5 normal adult cynomolgus monkeys were selected in the control group and accepted the same examination above. Results ①Intravenous administration of STZ could made stable T1DM monkey model. ②Only mI/Cr ratio increased at hippocampus of diabetic monkeys compared to the control group (P<0.05). ③There was no statistical difference of cortisol in serum between the diabetic group and the control group (P＞0.05). Conclusion ~1H-MRS may detect the metabolic changes of the hippocampus in STZ-induced diabetic adolescent cynomolgus monkeys and may contributes to the early diagnosis of diabetic encephalopathy.

BACKGROUND:Micro-arc oxidation technique is used to modify the surface properties of titanium and titanium al oy.
OBJECTIVE:To explore the surface properties of micro-arc oxidation film and its effect on the attachment, proliferation and alkaline phosphatase activity of MC3T3-E1.
METHODS:Forty-six pure titanium discs, 10 mm in diameter and 2 mm in thickness, were randomly divided into two groups. The discs of the experimental groups were treated by micro-arc oxidation technique in an electrolytic solution containing 0.02 mol/L sodiumβ-glycerophosphate and 0.2 mol/L calcium acetate;while the discs of the control group was machine-polished. The surface appearance of the discs was observed by a scanning electron microscopy, the ratio of calcium to phosphorus on the coating surface was detected by X-ray spectroscopy, and the crystal ine phase composition of the coating was detected by X-ray diffraction analysis. cellular morphology in the process of attachment was observed under the scanning electron microscope. cellproliferation was determined by cellcounting kit-8 at 2, 4, 74 days, while alkaline phosphatase activity were determined at 7 and 14 days.
RESULTS AND CONCLUSION:After micro-arc oxidation treatment, a rough and porous calcium-phosphate film was formed on the surface of titanium. The elements of micro-arc oxidation coating main mainly included Ca, P, O and Ti, and the micro-arc oxidation film was mainly composed of titanium oxide, calcium titanate, calcium phosphate and calcium metaphosphate. Under the scanning electron microscope, pseudopods appeared to grow out of the cells on the surface of micro-arc oxidation coating after 1 hour culture, and the typical morphology of the MC3T3-E1 cells could be observed at 4 hours. MC3T3-E1 proliferation (4 and 7 days of culture) and alkaline phosphatase activity (7 and 14 days of culture) were enhanced significantly in the micro-arc oxidation group compared with the control group. These findings indicate that the rough and porous calcium-phosphate coating produced by micro-arc oxidation technique on pure titanium surface could promote the early attachment, proliferation and osteogenic differentiation of MC3T3-E1.