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1.
To gain better understanding of telomerase’s possible role in the carcinogenesis of gestational trophoblastic tumors, the
authors conducted RT-PCR amplification-based analysis and carried out telomeric repeat amplification to determine the levels
of the human telomerase RNA (hTR) and that of telomerase enzymatic activity itself in 43 normal human placental tissues, 35
gestational trophoblastic tumor tissues and three choriocarcinoma cell lines. hTR was expressed in malignant gestational trophoblastic
tumor tissues as well as choriocarcinoma cell lines. The results showed that hTR of early placenta villi and a part of hydatidiform
mole were positive. But relatively low levels of the hTR could be found in placental tissues. Telomerase enzymatic activity
was strongly positive in 32 of the 35 (91.4%) gestational trophoblastic tumor tissues and all the three choriocarcinoma cell
lines. The enzymatic activity of telomerase itself was detectable at relatively low lelves in 14 of the 21 (66.7%) early placental
villi, only three of the 22 (13.6%) term placenta were weakly positive. These results suggest that telomerase activity may
be correlated with the development of trophoblastic tumors, and so, may be a useful diagnostic marker for detecting the existence
of malignant trophoblastic cells.
Project (39670753) supported by NSFC 相似文献
2.
INTRODUCTION Telomeres are distinctive DNA-protein struc-tures that cap the ends of linear chromosomes.It is very important to keep the chromosomes stabilization.Telomerase activity is closely linked to attainment of cellular immortality,a step in carcinogenesis,while lack of such activity contributes to cellular senes-cence.Telomerase is activated in more than85%ofmalignant tumors(Hiayma et al.,1997).Human te-lomeric repeat binding factor1(TRF1)is a telomere associated with proteins a… 相似文献
3.
XU Cheng-de 《上海大学学报(英文版)》2005,9(4):306-308
The line persistence of a graph G, Pt ( G ) is the minimum number of lines which must be removed to increase the diameter of G. In Ref. [7] (J. Shanghai Univ., 2003,7(4):352-357), we gave a characterization of graphs of diameter five with ρ1 ( G )≥2. In this paper we will show that each of the 8 special graphs Xi ( i = 1,2,3,4,5,6,7,8) listed in condition (2) of Theorem 1 in Ref. [7] can not be deleted. Therefore the results we obtained in Ref. [7] can not in general be improved. 相似文献
4.
ZHANG Xiu-yan RUAN Hui MU Lin HE Guo-qing TANG Xing-jun CHEN Qi-he 《浙江大学学报(A卷英文版)》2006,7(11):1948-1955
INTRODUCTION Enzymes are efficient and specific biocatalysts widely used in food industries, but their application in industrial process often involves special properties not found in natural source enzymes. In order to ob- tain desirable enzymes, in the past ten years, scientists have developed rational (Kurth et al., 1998; Mouratou et al., 1999; DeSantis et al., 1999) and irrational de- sign methods (Babbitt and Gerlt, 1997; O’Brien and Herschlag, 1999) to improve the enzyme propert… 相似文献
5.
Breast cancer is one of the leading causes of death in women today. Some of the patients are hereditary, with a large proportion
characterized by mutation in BRCA1 and/or BRCA2 genes. In this review, we provide an overview of these two genes, focusing on their relationship with hereditary breast cancers.
BRCA1/2 associated hereditary breast cancers have unique features that differ from the general breast cancers, including alterations
in cellular molecules, pathological bases, biological behavior, and a different prevention strategy. But the outcome of BRCA1/2 associated hereditary breast cancers still remains controversial; further studies are needed to elucidate the nature of BRCA1/2 associated hereditary breast cancers.
Project supported by the National Natural Science Foundation of China (No. 30772510) and the Joint Program of Ministry of
Health and Zhejiang Provincal Government of China (No. WKJ2006-2-008) 相似文献
6.
Insecticidal effects of different doses of the dust and methanol extracts of Garcinia kolae on Collosobruchus maculatus and Sitophilus zeamais were tested. The dust had no significant effect on the two insects; none of them died even at 3 d after treatment. The methanol
extracts, however, had rapid lethal effects on both C. maculatus and S. zeamais. The mortality of C. maculatus by the lowest concentration of methanol extracts ranged from 95%∼100% whereas in S. zeamais, the mortality ranged from 87.5%∼100% and 70%∼100% in concentrations of 1 g extract+3 ml methanol and 1 g extract+5 ml methanol,
respectively, from 24 to 48 h. The least concentration of 1 g extract+15 ml methanol had no significant lethal effect on Sitophilus zeamais.
相似文献
7.
Objective: To investigate the distribution ofH. pylori antigens in the gastric mucosa in patients withH. pylori infection, and the relationship between the distribution and gastric cancer. Methods: Of 112 patients confirmed by pathological
study to have chronic superficial gastritis, precancerous changes (chronic atrophic gastritis, intestinal metaplasia or atypical
hyperplasia) and gastric cancer, 28 wereH. pylori negative and 84 wereH. pylori positive.H. pylori antigens in the gastric mucosa were detected by immunohistochemistry. Results: TheH. pylori positive group, comprised 12 of 22 (50.0%) in the chronic superficial gastritis group, 22 of 25 (88.0%) in the precancerous
changes group and 13 of 35 (37.1%) in the gastric cancer group. The positive rates ofH. pylori antigens in the cytoplasm progressively increased, respectively at 0.0% (0/12), 63.6% (14/22) and 84.6% (11/13) for the same
groups (χ
2=19.76,P=0.000);H. pylori antigens were located in the mucus layer and above the neck of the mucosal gland in 9 of 12 (75.0%) cases with chronic superficial
gastritis, at the neck of the mucosal gland and the isthmus in 12 of 22 (54.5%) cases with precancerous changes, below the
isthmus in 9 of 13 (69.2%) cases with gastric cancer (χ
2=25.30,P=0.000). In theH. pylori negative group, noH. pylori antigen was observed. Conclusion: With the progression of chronic superficial gastritis→precancerous changes→gastric cancer,H. pylori antigens progressively migrated from the outer part to the inner part of the cell, and from the superficial to the deep gastric
mucosa. 相似文献
8.
A genetic linkage map comprised of 131 loci was constructed with an F2 population derived from an inter-subspecific cross betweenBrassica campestris L. ssp.chinensis cv. ‘aijiaohuang’ and ssp.rapifera cv. ‘qisihai’. The genetic map included 93 RAPD loci, 36 AFLP loci and 2 morphological loci organized into 10 main linkage
groups (LGs) and 2 small groups, covering 1810.9cM with average distance between adjacent markers being approximately 13.8cM.
The map is suitable for identification of molecular markers linked to important agronomic traits, QTL analysis, and even for
marker-assisted selection in breeding programs of Chinese cabbage and turnip.
Project (No. 39870509) supported by the National Natural Science Foundation of China 相似文献
9.
The construction of multirate rearrangeable network has long been an interesting problem. Of many results published, all were
achieved on 3-stage Clos network. The monotone routing algorithm proposed by Huet al. (2001) was also first applied to 3-stage Clos network. In this work, we adopt this algorithm and apply it to log
d
(N,m,p) networks. We first analyze the properties of log
d
(N,m,p) networks. Then we use monotone algorithm in log
d
(N,0,p) network. Furthermore we extend the result to construct multirate rearrangeable networks based on log
d
(N,m,p) network (1≤m≤n−1).
Project (No. 10371028) supported by the National Natural Science Foundation of China 相似文献
10.
11.
In this paper, the Tφ-convex functions were introduced as a generalizations of convex functions. Then the characteristics of the Tφ-convex functions were discussed. Furthermore, some new inequalities for the Tφ-convex functions were derived. 相似文献
12.
The optimization of cultural conditions for β-glucanase production byBacillus subtilis ZJF-1A5 was investigated in flask trials. Temperature had great effect on β-glucanase production which maximized at optimal
temperature of 37°C and decreased significantly when temperature was over 37°C. Charge quantity affected β-glucanase production
significantly. Adding oxygen vector N-dodecane or acetic ether benefited β-glucanase production, but it depended on the concentration
and charge quantity. The results of fractional factorial design showed that age and size of inoculum and shaking speed were
the key factors affecting β-glucanase production and the cultivation time span to reach the highest β-glucanase activity.
The optimal cultural conditions for β-glucanase production obtained with CCD were as follows: inoculum age and size (16 h,
3.82% (v/v)), shaking speed 210 r/min, charge quantity of 30 mL in 250 mL flask and initial pH 7.0, cultured at 37°C for 50
h. Repeated experimental results accorded with those predicted by a second-order polynomial model. The amount of β-glucanase,
α-amylase and neutral protease produced byB subtilis ZJF-1A5 was associated partially with cell growth. Those three enzymes' activities increased following the cell growth and
increased significantly when cells entered the stationary phase.
Project (No. B0608) supported by the National Natural Science Foundation of China and a grant (2001121B25) from Hangzhou Science
and Technology Development Project of Zhejiang Province, China 相似文献
13.
Aditya Mahabhai Vora 《上海大学学报(英文版)》2008,12(4):311-317
A well-known pseudopotential is used to investigate the superconducting state parameters (SSP), viz., electronphonon coupling strength, Coulomb pseudopotential, transition temperature, isotope effect exponent and effective
interaction strength for Ag
x
Zn1 − x
and Ag
x
Al1 − x
binary alloys theoretically for the first time. We have incorporated here five different types of the local field correction
functions to show the effect of exchange and correlation on the aforesaid properties. Very strong influence of various exchange
and correlation functions is concluded from the present study. Comparison with others such experimental values is encouraging,
which confirms applicability of the model potential in explaining the superconducting state parameters of binary mixture.
相似文献
14.
端粒是真核细胞染色体末端的特殊结构,主要功能是保护染色体不被核酸降解,防止染色体末端的丢失和融合,维持基因的稳定.端粒酶则是能合成端粒DNA的酶,使得端粒的长度和结构得以保持.端粒和端粒酶的发现激起了生命科学对衰老、肿瘤、干细胞等的研究热潮.从端粒和端粒酶与运动员科学选材、运动组织损伤的修复、对成体干细胞的修饰与应用、保护提高线粒体功能、调节胞浆Ca2+和细胞因子、参与细胞周期调控等诸方面进行综述,旨在为端粒和端粒酶这一最新成果引进运动科学研究提供参考依据. 相似文献
15.
LetH
n
be the set of real algebraic polynomials of degreen, whose zeros all lie in the interval [−1,1]. The well known Turán type inequalities tell us that forf(x)∈H
n
, it holds ‖f′‖≥C√n‖f‖. This note deals with the weighted Turán type inequalities with the weights having inner singularities underL
p
norm for 0<p≤∞. Our results essentially extend the result of Wang and Zhou (2002), and the method used in this paper is simpler and more
direct than that of Wang and Zhou (2002). The results and methods have their own values in approximation theory and computation. 相似文献
16.
Tong-bao Liu Guo-qing Chen Hang Min Fu-cheng Lin 《Journal of Zhejiang University. Science. B》2009,10(6):434-444
Fasciclin family proteins have been identified as cell adhesion molecules in various organisms. In this study, a novel Magnaporthe oryzae fasciclin-like protein encoding gene, named MoFLP1, was isolated from a subtractive suppressive cDNA library and functionally analyzed. Sequence analysis showed that the MoFLP1 gene contains an open reading frame (ORF) of 1050 nucleotides encoding 349 amino acids with a calculated molecular weight
of 35.85 kDa and a pI of 7.76. The deduced MoFLP1 protein contains a 17-amino acid secretion signal sequence and an 18-amino
acid sequence with the characteristics of a glycosylphosphotidylinositol (GPI) anchor additional signal at its N- and C-terminuses,
respectively. Potential N-glycosylation sites and domains involving cell adhesion were also identified in MoFLP1. Sequence analysis and subcellular
localization by the expression of MoFLP1-GFP fusion construct in M. oryzae indicated that the MoFLP1 protein is probably localized on the vacuole membrane. Two MoFLP1 null mutants generated by targeted gene disruption exhibited marked reduction of conidiation, conidial adhesion, appressorium
turgor, and pathogenicity. Our results indicate that fasciclin proteins play important roles in fungal development and pathogenicity
in M. oryzae.
Project supported by the National Natural Science Foundation of China (No. 30870101) and the Public Welfare Profession (Agriculture)
Research Project (No. 200803008), China 相似文献
17.
Wu Tian-xing Song Zeng-fu Cai Li-sheng Ding Xue-yan Yu Qing-sen 《Journal of Zhejiang University. Science. B》2005,6(8):798-802
Effects of dietary supplementation with fructooligosaccharides on the excretion of nitrogen and phosphorus inMiichthys miiuy fries were investigated. Nine hundredMiichthys miiuy fries were divided into 3 groups, each with triplicates. The basal diet and the basal diet supplemented with carnitine groups
were considered as the negative and positive controls respectively. Results showed that the nitrogen concentration in excreted
feces decreased significantly in fries fed the diet supplementation with 1000×10−6 fructooligosaccharides and 200×10−6 carnitine (P<0.05). The ammonic-nitrogen concentration decreased significantly in the carnitine group only (P<0.05), indicating the decreasing tendency caused by the supplementation with fructooligosaccharides. Supplementation with
both did not have significant effects on the concentration of phosphorus in feces ofMiichthys miiuy fries.
Project supported by Public Bidding Item in Key Research of Zhejiang Province (No. 02110281-2) and Ningbo Tackle Key Problem
for Agricultural Development (No. 2004C-100030), China 相似文献
18.
β-glucanase was purified from a solid-state culture ofTrichoderma reesei on wheat bran in three steps which comprised ammonium sulfate precipitation, Sephadex G-100 chromatography, and DEAE-Sephadex
A-50 chromatography. The molecular mass was determined to be 35.21 kilodaltons by sodium dodecyl sulfate-12.5% polyacrylamide
gel electrophoresis. The β-glucanase at low pHs was more stable than that at high pHs, and optimum pH was 5.0. The optimum
temperature was 60°C, and β-glucanase was relatively stable at below 40°C for 60 min. TheK
m of the enzyme on β-glucan was 10.86 mg/ml, and theV
max on β-glucan was 14286 μmol of glucose equivalents per mg of the pure enzyme per min. The β-glucanase activity was significantly
inhibited by Fe3+ ions, and was reduced in the presence of Cu2+ ions, Mn2+ ions and Mg2+ ions at 5 mmol/L and 10 mmol/L, respectively. The β-glucanase activity was stimulated by Co2+ ions, Ca2+ ions, Zn2+ ions, and Fe2+ ions at 1 mmol/L and 5 mmol/L, respectively.
Project supported by Foundation for University Key Teacher of the State Ministry of Education, the National Natural Science
Foundation of China (No. 30000118) and Zhejiang Provincial Natural Science Foundation of China (No. 399409). 相似文献
19.
Susan Louise Stewart 《Children‘s Literature in Education》2008,39(2):95-105
The author analyzes two texts, Gloria Whelan’s Homeless Bird and Deborah Ellis’s Parvana’s Journey, in an attempt to explain some of the problems and difficulties associated with those texts. The author examines Whelan’s
representations of India and finds troubling binaries associated with that text. In comparison, the author finds Ellis’s depictions
of Afghanistan more nuanced and complex. The author also discusses student reception of both texts and offers ways to problematize
some of their reactions.
相似文献
Susan Louise StewartEmail: |
20.
Embryogenic calli were induced from the seeds of creeping bentgrass (Agrostis palustris Huds.) cv. Regent and colonial bentgrass (Agrostis Tenuis Sibth. Fl. Oxen.) cv. Tiger. The embryogenic calli were precultured on fresh medium for 4–7 days and then co-cultivated withAgrobacterium tumefaciens, LBA4404. which contains plasmid vector-pSBGM harboring bar coding region, synthetic green fluorescent protein (sGFP) coding
region and matrix attachment region (MAR). After 3 days of co-cultivation, the calli were washed thoroughly and transferred
to MS medium containing 2 mg/L of 2, 4-D, 12–15 mg/L phosphinothricin (PPT) and 250 mg/L of cefotaxime. After 2–3 months of
selection, the actively growing calli of ‘Regent’ and ‘Tiger’ were transferred to MS medium with 12–15 mg/L PPT and 250 mg/L
cefotazime for regeneration. The putative transformants were maintained on MS medium with 3 mg/L PPT for long period but control
died within 1 month. After establishing in greenhouse, the transformants also showed strong resistance to 0.4% of herbicide
Basta but control plants died within 2 weeks. Under confocal microscope, both young leaves and roots showed significant GFP
expression. PCR analysis revealed the presence of a DNA fragment of GFP gene at the expected size (380 bp) in the transformants
and its absence in a randomly selected control plant. 相似文献