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1.
Type Ⅰ,Ⅲ and Ⅴ collagens were extracted from bovine dermis and cornea by using pepsin treatment in acetic acid solution,followed by salt precipitation and dialysis,to purify and isolate each type of collagens.The preparation process was analyzed by using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE).A reducing agent,2-mercaptoethanol,was used to remove disulfide bonds and analyze the structure of the bonds involved between α chains in some types of collagens.The use of delayed reducin...  相似文献   

2.
The structural change of the oviduct of freshwater shrimp （Macrobrachium nipponense） during spawning was examined by electron microscopy. The oviduct wall structural characteristics seem to be influenced significantly by the spawning process. Before the parturition and ovulation, two types of epithelial cells （types Ⅰ and Ⅱ） are found in the epithelium. The free surfaces of type Ⅰ and type Ⅱ cells have very dense long microvilli. Under the type Ⅰ and type Ⅱ cells, are a relatively thick layer of secreting material and a layer of mostly dead cells. After ovulation, two other types of epithelial cells （types Ⅲ and Ⅳ） are found in the oviduct wall epithelium. The free surface of type Ⅲ cells only has short microvilli scattered on the surface. The thick layer with secreting material and the dead cell layer disappeared at this stage. In some type Ⅲ cells, the leaking out of cytoplasm from broken cell membrane led to the death of these type Ⅲ cells. The transformation of all four types of epithelial cells was in the order： Ⅳ→Ⅰ→Ⅱ→Ⅲ.  相似文献   

3.
Objectives： To detect the serum proteomic patterns by using SELDI-TOF-MS （surface enhanced laser desorption/ ionization-time of flight-mass spectrometry） technology and CM10 ProteinChip in colorectal cancer （CRC） patients, and to evaluate the significance of the proteomic patterns in the tumour staging of colorectal cancer. Methods： SELDI-TOF-MS and CM10 ProteinChip were used to detect the serum proteomic patterns of 76 patients with colorectal cancer, among them, 10 Stage Ⅰ, 19 Stage Ⅱ, 16 Stage Ⅲ and 31 Stage Ⅳ samples. Different stage models were developed and validated by support vector machines, disctiminant analysis and time-sequence analysis. Results： The Model Ⅰ formed by 6 protein peaks （m/z： 2759.58, 2964.66, 2048.01, 4795.90, 4139.77 and 37761.60） could be used to distinguish local CRC patients （Stage Ⅰ and Stage Ⅱ） from regional CRC patients （Stage Ⅲ） with an accuracy of 86.67% （39/45）. The Model Ⅱ formed by 3 protein peaks （m/z： 6885.30, 2058.32 and 8567,75） could be used to distinguish locoregional CRC patients （Stage Ⅰ, Stage Ⅱ and Stage Ⅲ） from systematic CRC patients （Stage IV） With an accuracy of 75.00% （57/76）. The Model Ⅲ could distinguish Stage Ⅰ from Stage Ⅱ with an accuracy of 86.21% （25/29）. The Model Ⅳ could distinguish Stage Ⅰ from Stage Ⅲ with accuracy of 84.62% （22/26）. The Model Ⅴ could distinguish Stage Ⅱ from Stage Ⅲ with accuracy of 85.71% （30/35）. The Model Ⅵ could distinguish Stage Ⅱ from Stage Ⅳ with accuracy of 80.00% （40/50）. The Model Ⅶ could distinguish Stage Ⅲ from Stage Ⅳ with accuracy of 78.72% （37/47）. Different stage groups could be distinguished by the two-dimensional scattered spots figure obviously. Conclusion： This method showed great success in preoperatively determining the colorectal cancer stage of patients.  相似文献   

4.
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5.
Objective: The age-related change is important part of degenerative disc disease. However, no appropriate animal model or objective evaluation index is available. This study aimed to investigate the features of intervertebral disc degeneration in aging process of rats. Methods: 22-month-old Sprague-Dawley (SD) rats were used as spontaneously occurring intervertebral disc degeneration models and 6-month-old rats as young controls. Expression of collagen types Ⅱ and Ⅹ was measured by immunohistochemistry. Degenerations of intervertebral discs were scored according to Miyamoto's method. Numbers and areas of afferent vascular buds were measured. The thicknesses of non-calcified and calcified layers were measured and statistically analyzed.Results: There were less collagen type Ⅱ expression and more collagen type Ⅹ expression in the calcified layer of the cartilage endplates and nucleus pulposus in the rats of the aged group than in the young control. There were fewer and smaller afferent vascular buds in the rats of the aged group than in the young control group. The ratio of the non-calcified to the calcified layers in the rats of the aged group significantly decreased, compared with that of the young control group (P＜0.01). Conclusion: Rats can spontaneously establish intervertebral disc age-related degeneration. The expression of collagen types Ⅱ and Ⅹ, numbers and areas of afferent vascular buds, the ratio of the non-calcified to the calcified layers, and water and glycosaminoglycan contents in the nucleus pulposus are sensitive indexes of intervertebral disc degeneration.  相似文献   

6.
Hydantoinase and N-carbamoylase play important roles in the production of optically pure amino acids from racemic 5-monosubstituted hydantoins. In this report, hydantoinase and the N-carbamoylase from Burkholderia cepecia, njut01 were purified to homogeneity by chromatography (Pharmacia Explorer 100 system). The substrate specificity, enantioselectivity, pH dependence of activity and temperature stability of the activity were characterized. The results show that the hydantoinase and N-carbamoylase induced from Burkholderia cepecia, njut01 are both strict D-stereo selective enzymes. They both hydrolyze substrates with side chains containing aliphatic and aromatic residues with higher activity and affinity toward aromatic than aliphatic substituted substrates. The hydantoinase is a homotetramer with subtmit molecular weight near 52,000 and is active between pH 6.5 and 10 with an optimum near pH 9.0. The enzyme is active at temperatures up to 60~C, however, it appears instable at higher temperatures. The subunit molecular weight of N-carbamoylase is about 35KD. The N-carbamoylase is active in the pH range from 6.0 to 9.5. The optira-pH is 7.2 and the optinfizing bioconversion temperature of the N-carbamyolase is 52℃.  相似文献   

7.
1 Introduction 1 The sheet type geogrids, which are characterized by grid structures with apertures of (10 to 100) mm between longitudinal and transverse ribs respectively are made from pre-extruded high density polyethylene sheets by punching and drawing process, and the drawing process forms the structures of grid and enhances the tensile strength of geogrids to a grea extent. Since the geogrids possess high tensile strength in nature, they are widely used as reinforcement in segmental retai…  相似文献   

8.
Education is the backbone for the development of society. With the advent of technology, it is becoming necessary and being used for the advancement of society. Technology is being used for education as being used in other important fields of life. Usage of technology for education can play a big part in bringing improvement in education For this purpose, this research aims to explore the usage and effects of technology for education. While using the survey method, a questionnaire was constructed for data collection. The sample of the study consists of graduate and postgraduate students from both ODL and regular universities and the sample size would be of 300 respondents （150 from each type of university） who were selected by using simple random sampling. The present study concluded that technology is widely used by both regular and ODL students. This study further concluded that ODL students are more dependent on technology as compared to regular students.  相似文献   

9.
The active metabolite in the post-harvested biomass of zinc(Zn) and cadmium(Cd) hyperaccumulator Sedum alfredii Hance from phytoextraction is of great interest in China.The current study demonstrates that a salidroside-type metabolite can be yielded from the Zn/Cd hyperaccumulator S.alfredii biomass by means of sonication/ethanol extraction and macroporous resin column(AB-8 type) isolation.The concentrations of Zn and Cd in the salidroside-type metabolite were below the limitation of the national standards.  相似文献   

10.
Objective:The present study was designed to use an in vivo rabbit ear scar model to investigate the efficacy of systemic administration of endostatin in inhibiting scar formation.Methods:Eight male New Zealand white rabbits were randomly assigned to two groups.Scar model was established by making six full skin defect wounds in each ear.For the intervention group,intraperitoneal injection of endostatin was performed each day after the wound healed(about 15 d post wounding).For the control group,equal volume of saline was injected.Thickness of scars in each group was measured by sliding caliper and the scar microcirculatory perfusion was assessed by laser Doppler flowmetry on Days 15,21,28,and 35 post wounding.Rabbits were euthanatized and their scars were harvested for histological and proteomic analyses on Day 35 post wounding.Results:Macroscopically,scars of the control group were thicker than those of the intervention group.Significant differences between the two groups were observed on Days 21 and 35(p<0.05).Scar thickness,measured by scar elevation index(SEI) at Day 35 post wounding,was significantly reduced in the intervention group(1.09±0.19) compared with the controls(1.36±0.28).Microvessel density(MVD) observed in the intervention group(1.73±0.94) was significantly lower than that of the control group(5.63±1.78) on Day 35.The distribution of collagen fibers in scars treated with endostatin was relatively regular,while collagen fibers in untreated controls were thicker and showed disordered alignment.Western blot analysis showed that the expressions of type I collagen and Bcl-2 were depressed by injection of endostatin.Conclusions:Our results from the rabbit ear hypertrophic scar model indicate that systemic application of endostatin could inhibit local hypertrophic scar formation,possibly through reducing scar vascularization and angiogenesis.Our results indicated that endostatin may promote the apoptosis of endothelial cells and block their release of platelet-derived growth factor(PDGF) and fibroblast growth factor(FGF),thereby controlling collagen production by fibroblasts.Blood vessel-targeted treatment may be a promising strategy for scar therapy.  相似文献   

11.
Astragalus mongholicus (AM) derived from the dry root of Astragalus membranaceus Bge. var. mongolicus (Bge.) Hsiao is a widely used traditional Chinese medicine. The present study investigated the potential role of AM on renal fibrosis on a rat model of unilateral ureteral obstruction (UUO). We divided 48 Sprague-Dawley rats randomly into 4 groups: sham-operated group (Sham), untreated UUO group, AM-treated (10 g/(kg·d)) UUO group, and losartan-treated (20 mg/(kg·d)) UUO group as positive control. Haematoxylin & eosin (HE) and Masson staining were used to study the dynamic histological changes of the kidneys 7 and 14 d after operation. The expressions of fibronectin (FN), type I collagen (colI), hepatocyte growth factor (HGF), transforming growth factor-β1 (TGF-β1), and α-smooth muscle actin (α-SMA) were analyzed by real-time polymerase chain reaction (PCR), immunohistochemistry staining, and Western blot. Results show that, similar to losartan, AM alleviated the renal damage and decreased the deposition of FN and colI from UUO by reducing the expressions of TGF-β1 and α-SMA (P<0.05), whereas HGF increased greatly with AM treatment (P<0.05). Our findings reveal that AM could retard the progression of renal fibrosis. The renoprotective effect of AM might be related to inhibition of myofibroblast activation, inducing of HGF and reducing of TGF-β1 expression. Project (No. 30170437) supported by the National Natural Science Foundation of China  相似文献   

12.
In this paper, we consider some polynomial (α,β)-metrics, and discuss the sufficient and necessary conditions for a Finsler metric in the form F=α a1β a2β2/α a4β4/α3 to be projectively flat, where ai (i=1,2,4) are constants with a1≠0, α is a Riemannian metric and β is a 1-form. By analyzing the geodesic coefficients and the divisibility of certain polynomials, we obtain that there are only five projectively flat cases for metrics of this type. This gives a classification for such kind of Finsler metrics.  相似文献   

13.
INTRODUCTION One century ago, Hilbert announced his famous 23 problems. The Hilbert’s Fourth Problem is to characterize the (not-necessarily-reversible) distance functions on an open subset in ún such that straight lines are shortest paths. Distance functions induced by a Finsler metric are regarded as smooth ones. Thus Hilbert’s Fourth Problem in the smooth case is to characterize Finsler metric on an open subset in ún whose geodesics are straight lines. Finsler metric on an ope…  相似文献   

14.
In this work, we study the Asanov Finsler metric F=α(β2/α2 gβ/α 1)1/2exp{(G/2)arctan[β/(hα) G/2]}, where α=(αijyiyj)1/2 is a Riemannian metric and β=biyj is a 1-form, g∈(-2,2), h=(1-g2/4)1/2, G=g/h. We give the necessary and sufficient condition for Asanov metric to be locally projectively flat, i.e., α is projectively flat and β is parallel with respect to α. Moreover, we proved that the Douglas tensor of Asanov Finsler metric vanishes if and only if β is parallel with respect to α.  相似文献   

15.
Congruences for finite triple harmonic sums   总被引：1，自引：0，他引：1  
Zhao (2003a) first established a congruence for any odd prime p>3, S(1,1,1;p)≡-2Bp-3 (mod p), which holds when p=3 evidently. In this paper, we consider finite triple harmonic sum S(α,β,γ;p) (mod p) is considered for all positive integers α,β,γ. We refer to w=α β γ as the weight of the sum, and show that if w is even, S(α,β,γ;p)≡0 (mod p) for p≥w 3; if w is odd, S(α,β,γ;p)≡rBp≥w (mod p) for p≥w, here r is an explicit rational number independent of p. A congruence of Catalan number is obtained as a special case.  相似文献   

16.
INTRODUCTION In recent years, significant progress has been made in the study of Finsler metris which have straight lines in local coordinates (Hamel, 1903). Finsler metrics with this property are called locally projectively flat metrics. An important fact about these metrics is that locally projectively flat Finsler metrics have scalar flag curvature, a natural extension of the sectional curvature in Riemannian geometry. In general, it also depends on the direction (flag pole) in the se…  相似文献   

17.
Consider the mixed-effect coefficient semiparametric regression modelZ=X'α+Y'β+g(T)+e, whereX, Y andT are random vectors onR p×R q×[0, 1], α is a p-dimensional fixed-effect parameter, β is a q-dimensional random-effect parameter (Eβ=b, Cov(β)=Σ),g(.) is an unknown function on [0, 1], e is a random error with mean zero and variance σ2, and (X, Y, T) and (β,e), β ande are mutually independent. We estimate α,b andg(.) by the nearest neighbor and the least square method. In this paper, we prove that estimations of α,b have asymptotic normality and obtain the best convergence raten −1/3 for the estimation ofg(.). Project supported by the NSFC and the Natural Science Foundation of Zhejiang Province.  相似文献   

18.
Let k,m,n be positive integers,and k≥2,α∈(0,1],0＜r＜min {m,n} an integer,d=r (m-r)/(k α),and iff∈ Ck,α(Rm,R″),A =Cr(f)= {x ∈ Rm ,rank(Df(x))≤r},thenf(A)is d-null.Thus the statement posed by Arthur Sard in 1965 can be completely solved when k≥2.  相似文献   

19.
Mulberry longicorn beetle, Apriona germari, has been reported to produce two endo-β-1,4-glucanases or AgEGases (accession Nos. Q6SS52 and Q5XQD1). AgEGase sequence contains catalytic motif (amino acid residues 37~48), which is the characteristic of family Glycohydrolase 45 and is identified as the substrate binding site. The application of bioinformatics ap-proaches includes sequence analysis, structural modeling and inhibitor docking to relate the structure and function of AgEGases. We have dissected the sequence and structure of AgEGase catalytic motif and compared it with crystal structure of Humicola insolens endoglucanases V. The results show an involvement of sulfur containing amino acid residues in the active site of the enzyme. Cys residues and position of disulfide bonds are highly conserved between the two structures of endoglucanases of A. germari. Surface calculation of AgEGase structure in the absence of Cys residues reveals greater accessibility of the catalytic site to the substrate involving Asp42, a highly conserved residue. For the inhibition study, tannin-based structure was docked into the catalytic site of AgEGase using ArgusLab 4.0 and it resulted in a stable complex formation. It is suggested that the inhibition could occur through formation of a stable transition state analog-enzyme complex with the tannin-based inhibitor, as observed with other insect cellulases in our laboratory.  相似文献   

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