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1.
Human acidic and basic fibroblast growth factors (aFGF and bFGF) are classic and well characterized members of the heparin-binding
growth factor family. Heparin is generally thought to play an extremely important role in regulating aFGF and bFGF bioactivities
through its strong binding with them. In order to unravel the mechanism of the interactions between heparin and FGFs, and
evaluate the importance of heparin sulfate groups' binding with FGFs, surface plasmon resonance analyses were performed using
IAsys Cuvettes System. Heparin and its regioselectively desulfated derivatives were immobilized on the cuvettes. aFGF and
bFGF solutions with different concentrations were pipetted into the cuvettes and the progress of the interaction was monitored
in real-time by Windows-based software, yielding kinetic and equilibrium constants for these interactions. In addition, in
order to reduce the delicate difference among the cuvettes, inhibition analyses of mixtures of FGFs and immobilized native
heparin by modified heparins were also done. The data from these two methods were similar, indicating that all sulfate groups
at 2-O, 6-O and N- in heparin were required for the binding to aFGF; and that their contribution to the binding was in the
order 2-O, N- and 6-O-sulfate group. In contrast, definite contribution of the 6-O-sulfate group to the binding with bFGF
was most apparent, while the other two sulfate groups appeared to be necessary in the order 2-O and N-sulfate group. These
methods established here can be used for analysing the effect of sulfate groups in heparin on the binding with other human
FGF members or other heparin-binding proteins.
The project supported by the Scientific Research Foundation for Returned Overseas Chinese Scholars, State Education Ministry
of China and Zhejiang Provincial Natural Science Foundation of China (301306) 相似文献
2.
肝素治疗胎儿生长受限临床应用探讨 总被引：1，自引：0，他引：1
目的:探讨肝素用于治疗胎儿生长受限(FGR)的临床疗效及安全性。方法:将74例胎儿生长受限患者随机分为3组,分别使用低分子右旋糖酐加复方丹参(对照组)、普通肝素(UFH)、低分子肝素(LMWH)治疗。治疗前、治疗后1周及终止妊娠前,行彩色超声检查,监测胎儿生长情况和脐血流变化,同时监测各项凝血指标,记录新生儿情况并进行随访。结果:(1)UFH组、LMWH组治疗后宫高、胎儿股骨长、头围、腹围增长值均高于对照组,差异有显著性(P<0.05),LMWH组胎儿双顶径增长显著高于对照组(P=0.031)。(2)两肝素组治疗后脐动脉收缩期最大血流速度(S)与舒张末期血流速度(D)的比值(S/D比值)、搏动指数(PI)、阻力指数(RI)与对照组比较均明显降低,差异有统计学意义(P<0.05),而两肝素组间比较无统计学差异(P>0.05)。(3)UFH组、LMWH组治疗后新生儿胎龄、出生体重、身长、胎盘重量均较对照组明显增加(P<0.05),而两肝素组间无显著差异(P>0.05);新生儿窒息、胎死宫内、新生儿死亡发生率、早产发生率和新生儿畸形发生情况各组间无统计学差异(P>0.05);对照组足月小样儿发生率明显高于两肝素组(P=0.005),而肝素组之间则无显著差异(P>0.05)。对照组与LMWH相比,新生儿转重症监护病房(NICU)几率明显升高(P=0.003)。(4)各组孕妇治疗前后各项凝血功能检测值比较,差异均无显著性(P>0.05),产后出血量及产后出血发生率相比差异亦无统计学意义。结论:肝素可改善胎盘血流,使胎儿体重增加,减少足月小样儿的发生率,且不增加产后出血发生机会,对母亲及胎儿都较安全。LWMH治疗FGR,新生儿转NICU几率明显低于对照组,效果优于普通肝素,且使用方便,产妇易于接受,更适于推广。 相似文献
3.
Heparin was grafted onto polycarbonate urethane (PCU) surface via a three-step procedure utilizing α, ωdiamino-poly(ethylene glycol) (APEG, M n =2 000) as a spacer. In the first step, isocyanate functional groups were introduced onto PCU surface by the treatment of hexamethylene diisocyanate (HDI) in the presence of di-n-butyltin dilaurate (DBTDL) as a catalyst. In the second step, APEG was linked to the PCU surface to obtain the APEG conjugated PCU surface (PCU-APEG). In the third step, heparin was covalently coupled with PCU-APEG in the presence of N-hydroxysuccinimide (NHS) and 1-ethyl-3-(3-dimethylamidopropyl) carbodiimide (EDAC). The amount of heparin (1.639 μg/cm 2 ) covalently immobilized on the PCU-APEG surface was determined by the toluidine blue method. The modified surface was characterized by water contact angle, attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). The hemocompatibility was preliminarily studied by platelet adhesion test. The results indicated that heparin was successfully grafted onto the PCU surface, and meanwhile the hydrophilicity and hemocompatibility of the modified PCU surface were improved significantly compared with the blank PCU surface. 相似文献
4.
Basic fibroblast growth factor alleviates brain injury following global ischemia reperfusion in rabbits 总被引：9，自引：0，他引：9
Zhang M Ma YF Gan JX Jiang GY Xu SX Tao XL Hong A Li JK 《Journal of Zhejiang University. Science. B》2005,6(7):637-643
The aim of this study was to explore the protective effect of basic fibroblast growth factor (bFGF) on brain injury following global ischemia reperfusion and its mechanisms. Brain injury following global ischemia was induced by four vessels occlusion and systemic hypotension. Twenty-four rabbits were randomized into three groups: group A, only dissection of vessels; group B, intravenous infusion of normal saline after reperfusion for 6 h; group C, 30 μg/kg bFGF injected intravenously at the onset of reperfusion, then infused with 10 μg/(kg·h) for 6 h. Serum neuron specific enolase (NSE), S-100B, tumor necrosis factor-α(TNF-α), interleukin-1 (IL-1), interleukin-8 (IL-8) were measured before ischemia, 30 min after ischemia, 0.5, 1, 3, 6 h after reperfusion. Brain water content was determined and cerebral histopathological damages were compared. NSE and S-100B were increased 1 h after reperfusion and reached their peaks 6 h after reperfusion, but were much higher in group B than those in group C 3, 6 h after reperfusion. In groups B and C, TNF-a was increased after ischemia and IL-1 and IL-8 were increased significantly 0.5 h after reperfusion, then reached their peaks 6 h, 3 h, 6 h after reperfusion respectively. TNF-a and IL-8 at the time points of 1 h and 3 h and IL-1 at 3 h and 6 h in group C were correspondingly lower than those in group B. These indices in group A were nearly unchanged. There were less severe cerebral histopathological damages in group C compared with group B, but no difference in brain water content. It could be concluded that bFGF alleviates brain injury following global ischemia and reperfusion by down-regulating expression of inflammatory factors and inhibiting their activities. 相似文献
5.
Marjorie Rhodes 《Child development》2012,83(6):1900-1916
Four studies examined children’s (ages 3–10, Total N = 235) naïve theories of social groups, in particular, their expectations about how group memberships constrain social interactions. After introduction to novel groups of people, preschoolers (ages 3–5) reliably expected agents from one group to harm members of the other group (rather than members of their own) but expected agents to help members of both groups equally often. Preschoolers expected between‐group harm across multiple ways of defining social groups. Older children (ages 6–10) reliably expected agents to harm members of the other group and to help members of their own. Implications for the development of social cognition are discussed. 相似文献
6.
Assessing contributions to group assignments 总被引：2，自引：1，他引：2
Lucy Johnston 《Assessment & Evaluation in Higher Education》2004,29(6):751-768
We report the use of a combination of self‐ and peer‐assessment in an undergraduate social psychology laboratory course. Students worked in small groups on a self‐directed empirical project that they each wrote up independently as a laboratory report. Marks for the written assignment were moderated by a contribution index measure based on the self‐ and peer‐assessment measures. Our analyses indicated that: (i) students took the peer‐assessment process seriously, clearly differentiating between group members on the contributions questionnaires; (ii) students show a self‐bias, rating their own contribution to the group task higher than that of other group members; (iii) for a large majority of students the contribution index resulted in very little moderation of the final assignment marks; (iv) there was a strong correlation between the contribution index and the overall assignment score. Implications for the assessment of group work are considered. 相似文献
7.
李德乐 《雁北师范学院学报》2008,24(6)
通过群的同构分类的观点,分析了16阶非交换群的生成关系,并使用霍尔德（HOlder,O．L）定理、N／C定理及元素阶的分析,重新确定了16阶非交换群的生成关系． 相似文献
8.
OBJECTIVE: It has been suggested that survivors of ongoing childhood sexual abuse (CSA) tend to have been reared in ineffective family environments that render them particularly vulnerable to maltreatment and which foster psychological difficulties beyond those accounted for solely by their abuse. If this conjecture is valid, one would expect that the family of origin environments of CSA survivors would be disturbed whether their abuser was intra-familial or extra-familial. To assess this hypothesis, two studies compared the childhood family of origin environments and supportive parenting characteristics of a clinical sample of women sexually abused by family members only (the intra-familial group), by non-family members only (the extra-familial group), and by both family and non-family members (the "both" group). METHOD: Study 1 compared the three groups (total N = 213) using the Family Environment Scale (FES). Study 2 compared groups (total N = 86) on the positive parenting scales of the Exposure to Abusive and Supportive Environments Parenting Inventory (EASE-PI). RESULTS: In Study 1, multivariate analyses indicated significant differences on the independence, cohesion, and conflict subscales of the FES. Pairwise comparisons revealed that the extra-familial group reported significantly higher levels of family independence and lower levels of conflict than the other two groups. In addition, the extra-familial group reported higher levels of cohesion than the intra-familial group. However, the effect sizes of these comparisons were extremely small. In Study 2, multivariate analyses revealed no group differences on the EASE-PI scales. CONCLUSIONS: Low effect sizes on the three significant FES scales, non-significance on the remaining seven FES scales, and non-significance on the EASE-PI scales suggest that there is considerable similarity in the family of origin environments of adult female CSA survivors seeking therapy regardless of whether their perpetrators were family members, non-family members, or both family and non-family members. 相似文献
9.
李华刚 《黔南民族师范学院学报》2008,28(3):68-72
利用滴涂于玻碳电极（GCE）表面的以Nnfion膜中负电性的磺酸基与天青I（AI）阳离子之间的静电作用,实现天青I在电极上的固定化,再通过静电吸附和自组装技术将纳米CdS吸附的辣根过氧化物酶（HRP）修饰到电极表面,制备出性能良好的H2O2生物传感器。采用循环伏安法（CV）和计时电流法考察了该传感器的电化学性质。实验表明,该传感器具有良好的生物催化活性,较高的灵敏度,良好的选择性和稳定性,且易于制作等特点。响应电流与H2O2浓度在8．0×10^-6～1．6×10^-3 moL／L范围呈现良好的线性关系,检出限为2．72×10^-6 moL／L。 相似文献
10.
The peer group as a context for the development of young adolescent motivation and achievement 总被引：14，自引：0，他引：14
Ryan AM 《Child development》2001,72(4):1135-1150
This study investigated the peer group as a context for the socialization of young adolescents' motivation and achievement in school. Social network analysis was used to identify peer groups of adolescents in middle school whose members regularly interacted with each other (N = 331). Actual reports from these peer group members were used to assess peer group characteristics. Multilevel analyses indicated that peer groups did socialize some academic characteristics, controlling for selection factors. Students' peer group context in the fall predicted changes in their liking and enjoyment of school (intrinsic value) and their achievement over the school year. Students' peer group context was unrelated to changes in their beliefs about the importance of school (utility value) or expectancies for success over the school year. 相似文献
11.
The study was designed to test several hypotheses derived from intergroup theory concerning the effects of the presence of a novel social category on the formation of intergroup attitudes. Elementary school children (N = 61; aged 6–9) were given measures of classification skill and self-esteem and assigned to 1 of 3 types of school classrooms in which teachers made: (1) functional use of "blue" and "yellow" groups assigned on the basis of a biological attribute, (2) functional use of "blue" and "yellow" groups assigned on the basis of a random drawing, or (3) no explicit groups (despite the presence of blue and yellow groups). After 4 weeks, children completed measures of intergroup attitudes and behavior. As predicted, the functional use of color groups affected children's attitudes toward group members, with children showing consistent biases favoring their own group. Children with higher levels of self-esteem showed higher levels of intergroup stereotyping. 相似文献
12.
Effect of basic fibroblast growth factor （bFGF） on the treatment of exposure of the orbital implants 总被引：5，自引：0，他引：5
Objective： To evaluate the efficacy and the indication of basic fibroblast growth factor （bFGF） in the treatment of exposure of orbital implants. Design： Retrospective and observational case series. Methods： We reviewed 41 patients （41 eyes） suffering exposure of orbital implants from Jan. 2000 to June 2006. The study group patients with mild exposure received combined treatment with bFGF and antibiotic drops, and while the control group patients with mild exposure were treated with antibiotic drops only. The study group patients with moderate and severe exposure received combined treatment with bFGF and antibiotic drops, and after 2 months they were subjected to amniotic membrane transplantation, while the control group patients with moderate and severe exposure underwent amniotic membrane transplantation after using antibiotic drops. Observation of the growth of conjunctival epithelium and comparison of the healing rate of the two groups. Results： The healing rates of the mild, moderate and severe exposure study group were 100% and 92.3%. The healing rates of the mild, moderate and severe exposure control group were 55.6% and 66.7% respectively. The difference of the healing rates of the mild exposure study group and the control group was significant （P=-0.033）. And the difference of the healing rates of the moderate and severe exposure study group and the control group was not significant （P=-0.167）. Conclusion： bFGF may promote obviously the healing of orbital implant exposure, particularly it can be the first choice for the treatment of mild degree exposure. For the moderate and severe cases, it can be administered before surgical repair to enhance neovascularization and will tend to increase the success rate of surgical repair. 相似文献
13.
Nie SP Wang X Qiao SB Zeng QT Jiang JQ Liu XQ Zhu XM Cao GX Ma CS 《Journal of Zhejiang University. Science. B》2010,11(12):895-904
Objective: Angiogenic therapy is emerging as a potential strategy for the treatment of ischemic heart disease but is limited by a relatively short half-life of growth factors.Fibrin glue (FG) provides a reservoir for controlledrelease of growth factors.The aim of this study was to evaluate the effects of basic fibroblast growth factor (bFGF) incorporating FG on angiogenesis and cardiac performance in a canine infarct model.Methods: Acute myocardial infarction was induced by ligation of the left anterior descending coronary artery (LAD).Group I (n=6) underwent ligation of LAD alone.In Group II,transmural channels were created in the infarct area (n=6).In Group III,nontransmural channels were created to locate FG cylinders containing bFGF (n=6).Eight weeks after operation,myocardial perfusion was assessed by single photon emission computed tomography,cardiac function by echocardiography,and vascular development by immunohistochemical staining.Results: Total vascular density and the number of large vessels (internal diameter ≥50 μm) were dramatically higher in Group III than in Groups I and II at eight weeks.Only the controlled-release group exhibited an improvement in regional myocardial perfusion associated with lower defect score.Animals in Group III presented improved cardiac regional systolic and diastolic functions as well as global systolic function in comparison with the other two groups.Conclusions: Enhanced and sustained angiogenic response can be achieved by controlled-release bFGF incorporating FG within transmyocardial laser channels,thus enabling improvement in myocardial perfusion and cardiac function. 相似文献
14.
Vaughn S Wexler J Leroux A Roberts G Denton C Barth A Fletcher J 《Journal of learning disabilities》2012,45(6):515-525
The authors report the effects of a yearlong, very small-group, intensive reading intervention for eighth-grade students with serious reading difficulties who had demonstrated low response to intervention (RTI) in both Grades 6 and 7. At the beginning of Grade 6, a cohort of students identified as having reading difficulties were randomized to treatment or comparison conditions. Treatment group students received researcher-provided reading intervention in Grade 6, which continued in Grade 7 for those with low response to intervention; comparison students received no researcher-provided intervention. Participants in the Grade 8 study were members of the original treatment (N = 28) and comparison (N = 13) conditions who had failed to pass a state-mandated reading comprehension test in both Grades 6 and 7. In Grade 8, treatment group students received a 50-minute, daily, individualized, intensive reading intervention in groups of two to four students per teacher. The results showed that students in the treatment condition demonstrated significantly higher scores than comparison students on standardized measures of comprehension (effect size = 1.20) and word identification (effect size = 0.49), although most continued to lack grade-level proficiency in reading despite 3 years of intervention. Findings from this study provide a rationale for intensive intervention for middle school students with severe reading difficulties. 相似文献
15.
Thi Hong Thanh Pham 《高等教育研究与发展》2013,32(6):993-1006
This study aimed to investigate the perceptions, interactions and behaviours of different-ability college students when they worked on different types of assessments. Two classes of 145 Vietnamese college students participated in this three-month study. The students were assigned to mixed-ability groups, each of which consisted of five students. The results show that assessment designed as a group project helped close the gap in communication and interactions between different-ability students within groups. When the students engaged with assessment as a group project, all levels of performers increased productive learning behaviours and provided more relevant verbal help and assistance to each other. Importantly, this type of assessment created various opportunities for the low performers to participate in, and make a contribution to, group tasks. As a result, all group members became interested in working with others. They perceived cooperative learning groups as being enjoyable and fun. 相似文献
16.
One major challenge in using group projects to assess student learning is accounting for the differences of contribution among group members so that the mark assigned to each individual actually reflects their performance. This research addresses the validity of grading group projects by evaluating different methods that derive individualized scores from group work. Both Monte Carlo simulation and real test data analyses were conducted. The four investigated methods are the within-group adjustment method, the partial adjustment method, the between-group adjustment method, and the expected contribution adjustment method. For all methods, a weighting factor is computed based on the peer and self ratings of contributions to the group project by group members. This study finds that individual differences have to be taken into account if group grades are going to be assigned and utilized for evaluating individual performance at all. Adjusting contribution differences based on peer and self ratings could be an effective way to improve the validity of group grades. Among the four studied methods, adjusting both the within-group and between-group contribution differences is the most effective, and is thus recommended for classroom use. 相似文献
17.
This article explores the effect of computerized scaffolding with different scaffolds (structuring vs. problematizing) on intra-group metacognitive interaction. In this study, we investigate 4 types of intra-group social metacognitive activities; namely ignored, accepted, shared and co-constructed metacognitive activities in 18 triads (6 control groups; no scaffolds and 12 experimental groups; 6 structuring scaffolds and 6 problematizing scaffolds). We found that groups receiving scaffolding showed significantly more intra-group interactions in which the group members co-construct social metacognitive activities. Groups receiving problematizing scaffolds showed significantly less ignored and more co-constructed social metacognitive interaction compared to groups receiving structuring scaffolds. These findings indicate that scaffolding positively influenced the group members’ intra-group social metacognitive interaction. We also found a significant relation between students’ participation in intra-group social metacognitive interaction and students’ metacognitive knowledge. Twelve percent of the variance in students’ metacognitive knowledge was explained by their participation in intra-group shared social metacognitive interaction. Therefore, future research should consider how to design scaffolds that elicit intra-group social metacognitive interaction among group members to enhance the development of students’ metacognitive knowledge. 相似文献
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Sensing Escherichia coli O157：H7 via frequency shift through a self-assembled monolayer based QCM immunosensor 总被引：1，自引：0，他引：1
Wang LJ Wu CS Hu ZY Zhang YF Li R Wang P 《Journal of Zhejiang University. Science. B》2008,9(2):121-131
By means of the specific immuno-recognition and ultra-sensitive mass detection, a quartz crystal microbalance (QCM) biosensor for Escherichia coli O157H7 detection was developed in this work. As a suitable surfactant, 16-mercaptohexadecanoic acid (MHDA) was introduced onto the Au surface of QCM, and then self-assembled with N-hydroxysuccinimide (NHS) raster as a reactive intermediate to provide an active interface for the specific antibody immobilization. The binding of target bacteria with the immobilized antibodies decreased the sensor's resonant frequency, and the frequency shift was correlated to the bacterial concentration. The stepwise assembly of the immunosensor was characterized by means of the electrochemical techniques. Using the immersion-dry-immersion procedure, this QCM biosensor could detect 2.0×102 colony forming units (CFU)/ml E. coli O157H7. In order to reduce the fabrication time, a polyelectrolyte layer-by-layer self-assembly (LBL-SA) method was adopted for fast construction. Finally, the reproducibility of this biosensor was discussed. 相似文献