首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   44篇
  免费   4篇
  2020年   1篇
  2017年   2篇
  2014年   1篇
  2013年   4篇
  2012年   1篇
  2011年   1篇
  2009年   1篇
  2008年   2篇
  2007年   1篇
  2006年   2篇
  2004年   1篇
  2003年   1篇
  2002年   2篇
  2001年   1篇
  1999年   1篇
  1997年   1篇
  1994年   2篇
  1993年   1篇
  1990年   1篇
  1988年   1篇
  1987年   1篇
  1986年   2篇
  1985年   1篇
  1984年   1篇
  1983年   3篇
  1982年   1篇
  1980年   1篇
  1979年   3篇
  1978年   2篇
  1972年   2篇
  1971年   1篇
  1970年   1篇
  1969年   1篇
排序方式: 共有48条查询结果,搜索用时 15 毫秒
1.
Summary The antitumor activities and capacity for tumor necrosis factor (TNF) production of traditional Chinese herbal preparations (Zhu-ling-tang, Xiao-chai-hu-tang), crude drugs (Polyporus, Hoelen, Bupleuri radix, Angelica radix, Cnidii rhizoma, Cinnamomum cortex), and Krestin (PSK) were investigated. These drugs were given to DDY mice in the drinking water before and after transplantation of Ehrlich tumors, and the development of the intradermally transplanted Ehrlich tumors and survival rate were observed. A good survival rate and sometimes a complete cure were found in the groups administered Bupleuri radix, Xiao-chai-hu-tang, Angelica radix, or Cinnamomum cortex, while the group given Hoelen showed poor results. To examine the capacity for TNF production these drugs were given to DDY mice PO as initial stimulating agents, to stimulate the reticuloendothelial system (RES) prior to lipopolysaccharide injection. The TNF activity was tested from the cytotoxicity against L cells. Significant differences in capacity for TNF production were observed among the drugs. Relatively high levels of TNF activity were noted in the groups given Angelica radix, Bupleuri radix, Cnidii rhizoma, or Cinnamomum cortex, very low activities in the groups given Xiao-chai-hu-tang, Zhu-ling-tang, or Krestin, and no TNF activities in the groups given Polyporus or Hoelen. The TNF capacity for production broadly paralleled the survival rate of the mice transplanted to Ehrlich tumors. Our findings suggest that one mechanism underlying the antitumor activities of these drugs is based on stimulation of the RES and is closely related of TNF production.This work was supported in part by a grant-in-aid from the Ministry of Education, Japan  相似文献   
2.
3.
The influence of equilibration time before vitrification on the viability of vitrified morula- to blastocyst-stage bovine embryos and in vivo viability of vitrified embryos following transfer to recipients were investigated. In experiment 1, the embryos were exposed to an equilibration solution (50% VSED) containing 12.5% v/v ethylene glycol and 12.5% v/v dimethyl sulfoxide in modified Dulbecco's phosphate buffered saline with 4 mg/ml BSA (m-PBS) for 1, 2 and 5 minutes at room temperature (22 to 24 degrees C). The embryos were then placed in 15mul vitrification solution (VSED) consisting of 25% v/v ethylene glycol and 25% v/v dimethyl sulfoxide in m-PBS and were loaded into 0.25 ml plastic straws at room temperature. After 30 seconds, the straws were placed in liquid nitrogen (LN(2)) vapor for 2 minutes, plunged and stored in LN(2). To thaw, the straws were warmed in water at 20 degrees C for 15 seconds and the contents of the straws were expelled into a plastic dish. The embryos were diluted in 0.5 M sucrose + m-PBS for 5 minutes and were cultured in TCM-199 supplemented with bovine oviductal epithelial tissue. Viability of the embryos was assessed by the forming or reforming of the blastocoele after 24 hours of culture. High in vitro survival rates (73 approximately 90%) of vitrified embryos were obtained after 1 and 2 minute equilibrations, but was reduced (P<0.05) after 5 minute equilibration. In Experiment 2, morula- to blastocyst-stage embryos were vitrified after 1 minute equilibration in 50% VSED and 30 seconds of exposure to VSED. The vitrified-warmed embryos were transferred to recipient heifers at 7 days after estrus (1 embryo per recipient). Five (38%) of 13 (40%) of 10 recipients that had received blastocysts were diagnosed as pregnant using ultrasonography 60 days following transfer.  相似文献   
4.
5.
The ADP-glucose- or UDP-glucose-specific starch synthetase bound to sweet-potato (Ipomoea batatas) starch granules is localized in the granules, and the UDP-glucose-specific enzyme was solubulized by urea/pullulanase treatment of the starch granules.  相似文献   
6.
Eukaryotic translation initiation factor 3 (eIF3) in the yeast Saccharomyces cerevisiae comprises about eight polypeptides and plays a central role in the binding of methionyl-tRNAi and mRNA to the 40S ribosomal subunit. The fourth largest subunit, eIF3-p39, was gel purified, and a 12-amino-acid tryptic peptide was sequenced, enabling the cloning of the TIF34 gene. TIF34 encodes a 38,753-Da protein that corresponds to eIF3-p39 in size and antigenicity. Disruption of TIF34 is lethal, and depletion of eIF3-p39 by glucose repression of TIF34 expressed from a GAL promoter results in cessation of cell growth. As eIF3-p39 levels fall, polysomes become smaller, indicating a role for eIF3-p39 in the initiation phase of protein synthesis. Unexpectedly, depletion results in degradation of all of the subunit proteins of eIF3 at a rate much faster than the normal turnover rates of these proteins. eIF3-p39 has 46% sequence identity with the p36 subunit of human eIF3. Both proteins are members of the WD-repeat family of proteins, possessing five to seven repeat elements. Taken together, the results indicate that eIF3-p39 plays an important, although not necessarily direct, role in the initiation phase of protein synthesis and suggest that it may be required for the assembly and maintenance of the eIF3 complex in eukaryotic cells.  相似文献   
7.
Patients with chronic hepatitis C, with a high serum viral load (> or = 1 Meq/ml) and genotype 1b seem to be resistant to interferon (IFN) therapy. To evaluate the efficacy of a herbal medicine (Mao-to) in combination with natural IFN-beta for the treatment of these patients, eighteen Japanese patients were enrolled in this study. Every patient received 6 million units (MU) of IFN-beta intravenously daily for 8 weeks. Mao-to was given orally 3-4 times a day during the IFN-beta administration, Sixteen of the 18 patients (89%) became negative for serum HCV RNA at the end of treatment, but only 2 of them (11%) remained negative for the virus RNA at 6 months of follow-up. Serum ALT levels normalized in 17 patients (94%) at 2 weeks of follow-up after the cessation of therapy, and 11 patients (61%) retained normal ALT levels for more than 6 months of follow-up. This rate of biochemical response was high as compared with that of therapy with IFN-beta alone (19%) in the largest IFN-beta trial in Japan. Serum hyaluronic acid levels were decreased significantly from 147.0 +/- 110.5 ng/ml to 77.4 +/- 67.4 ng/ml in the sustained biochemical response group (P = 0.003). None of the patients needed to interrupt therapy because of side effects of IFN-beta. Thus, Mao-to administration together with IFN-beta treatment could increase the sustained biochemical response rate, and reduce liver fibrosis.  相似文献   
8.
We have studied in vivo neo-galactosylation in Saccharomyces cerevisiae and analyzed the critical factors involved in this system. Two heterologous genes, gma12(+) encoding alpha1, 2-galactosyltransferase (alpha1,2 GalT) from Schizosaccharomyces pombe and UGT2 encoding UDP- galactose (UDP-Gal) transporter from human, were functionally expressed to examine the intracellular conditions required for galactosylation. Detection by fluorescence labeled alpha-galactose specific lectin revealed that 50% of the cells incorporated galactose to cell surface mannoproteins only when the gma12(+) and hUGT2 genes were coexpressed in galactose media. Integration of both genes in the Delta mnn1 background cells increased galactosylation to 80% of the cells. Correlation between cell surface galactosylation and UDP-galactose transport activity indicated that an exogenous supply of UDP-Gal transporter rather than alpha1,2 GalT played a key role for efficient galactosylation in S.cerevisiae. In addition, this heterologous system enabled us to study the in vivo function of S. pombe alpha1,2 GalT to prove that it transfers galactose to both N - and O -linked oligosaccharides. Structural analysis indicated that this enzyme transfers galactose to O -mannosyl residue attached to polypeptides and produces Galalpha1,2-Man1-O-Ser/Thr structure. Thus, we have successfully generated a system for efficient galactose incorporation which is originally absent in S. cerevisiae, suggesting further possibilities for in vivo glycan remodeling toward therapeutically useful galactose containing heterologous proteins in S. cerevisiae.   相似文献   
9.
Vaccination against the type III secretion system of P. aeruginosa is a potential prophylactic strategy for reducing the incidence and improving the poor prognosis of P. aeruginosa pneumonia. In this study, the efficacies of three different adjuvants, Freund's adjuvant (FA), aluminum hydroxide (alum) and CpG oligodeoxynucleotide (ODN), were examined from the viewpoint of inducing PcrV‐specific immunity against virulent P. aeruginosa. Mice that had been immunized intraperitoneally with recombinant PcrV formulated with one of the above adjuvants were challenged intratracheally with a lethal dose of P. aeruginosa. The PcrV–FA immunized group attained a survival rate of 91%, whereas the survival rates of the PcrV–alum and PcrV–CpG groups were 73% and 64%, respectively. In terms of hypothermia recovery after bacterial instillation, PcrV–alum was the most protective, followed by PcrV–FA and PcrV–CpG. The lung edema index was lower in the PcrV–CpG vaccination group than in the other groups. PcrV–alum immunization was associated with the greatest decrease in myeloperoxidase in infected lungs, and also decreased the number of lung bacteria to a similar number as in the PcrV–FA group. There was less neutrophil recruitment in the lungs of mice vaccinated with PcrV–alum or PcrV–CpG than in those of mice vaccinated with PcrV–FA or PcrV alone. Overall, in terms of mouse survival the PcrV–CpG vaccine, which could be a relatively safe next‐generation vaccine, showed a comparable effect to the PcrV–alum vaccine.  相似文献   
10.
Gambierol is a polycyclic ether toxin, isolated as a toxic constituent from the marine dinoflagellate Gambierdiscus toxicus. We describe here the synthesis and biological evaluation of structural analogues of gambierol. The present preliminary structure-activity relationship studies clearly indicate that the H ring functionality and the unsaturated side chain of gambierol are crucial for its potent toxicity.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号