全文获取类型
收费全文 | 423篇 |
免费 | 29篇 |
出版年
2018年 | 5篇 |
2017年 | 2篇 |
2016年 | 10篇 |
2015年 | 8篇 |
2014年 | 7篇 |
2013年 | 11篇 |
2012年 | 14篇 |
2011年 | 16篇 |
2010年 | 9篇 |
2009年 | 7篇 |
2008年 | 21篇 |
2007年 | 15篇 |
2006年 | 29篇 |
2005年 | 14篇 |
2004年 | 11篇 |
2003年 | 19篇 |
2002年 | 22篇 |
2001年 | 20篇 |
2000年 | 15篇 |
1999年 | 13篇 |
1998年 | 4篇 |
1997年 | 3篇 |
1996年 | 6篇 |
1995年 | 8篇 |
1994年 | 6篇 |
1993年 | 8篇 |
1992年 | 25篇 |
1991年 | 18篇 |
1990年 | 10篇 |
1989年 | 9篇 |
1988年 | 8篇 |
1987年 | 11篇 |
1986年 | 3篇 |
1985年 | 6篇 |
1984年 | 11篇 |
1983年 | 5篇 |
1982年 | 2篇 |
1981年 | 9篇 |
1980年 | 4篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1975年 | 5篇 |
1974年 | 3篇 |
1972年 | 3篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1967年 | 1篇 |
1964年 | 1篇 |
1963年 | 3篇 |
1961年 | 2篇 |
排序方式: 共有452条查询结果,搜索用时 15 毫秒
1.
T Tobe S Minoshima S Yamase N H Choi M Tomita N Shimizu 《Cytogenetics and cell genetics》1991,57(4):193-195
SP-40,40 is a serum glycoprotein consisting of two different subunits (alpha and beta) assembled into a dimer by disulfide bonds. Northern blot hybridization, using total RNA from several cell lines, showed that SP-40,40 is expressed in glioblastoma and testicular tumor cells, as well as hepatoma cells. Spot blot hybridization of flow-sorted human chromosomes, using a SP-40,40 cDNA fragment as a probe, localized the gene for SP-40,40 to human chromosome 8. This gene has been given the designation CLI, for complement lysis inhibitor, by the Human Gene Nomenclature Committee. 相似文献
2.
The seed coat surface morphology of Celtidaceae and Ulmaceae (Urticales) indicates a significant evolutionary diversity.Celtis, Chaetachme andPteroceltis (Celtidaceae) have a unique sculpturing with many crateriform holes; such holes occasionally sparsely occur in seeds ofAphananthe, Gironniera (Celtidaceae) andPlanera (Ulmaceae), but not in those of the nine remaining genera of the two families. The perforated seed coat further occurs in
at least some genera of all other urticalean families. A pattern of its occurrence in families and genera suggest that the
perforation represents a common archaic feature of all Urticales, rather than a feature derived many times independently within
the order. The seed coat of Celtidaceae and Ulmaceae seems to have lately lost the holes probably by a neotenic evolution:
one or more times within Celtidaceae, and one time in an ancestral line leading to all Ulmaceae. The derived reticulate seed
coat surface sculpturing, which is shared byGironniera (Celtidaceae) and some Ulmaceae, is probably the result of parallel evolution. On the basis of evidence from seed coat morphology
and other sources, close relationships ofLozanella, Parasponia andTrema within Celtidaceae, as well as variously distinct positions ofAmpelocera, Aphananthe andGironniera, are also discussed. 相似文献
3.
Yoshinori Nio MD Takahiro Shiraishi Michihiko Tsubono Hideki Morimoto Chen-Chiu Tseng Kazuya Kawabata Yoshikazu Masai Manabu Fukumoto Takayoshi Tobe 《Biotherapy》1992,4(2):81-86
The present study was designed to evaluate the effects of a recombinant human G-CSF (rhG-CSF) and a mutein G-CSF(KW-2228) on leucopenia and tumor growth in mice treated with 5-fluorouracil (5-FU). In normal mice, the number of leucocytes (white blood cell, WBC) reached the peak 12 hours after a single injection of either type of G-CSF and decreased to the normal level after 24 hours. Daily administration induced a continuous increase in the WBC count, however, administrations at intervals did not. Meth-A fibrosarcoma was subcutaneously inoculated into the backs of syngeneic BALB/c mice. The mice were treated with 5-FU alone or with G-CSFs. Chemotherapy with 5-FU alone resulted in leucopenia and an insignificant inhibition of tumor growth. The conjunctive administration of G-CSFs with 5-FU resulted in a significantly augmented inhibition of tumor growth, and leukopenia was not seen. This augmenting effect was more prominent with KW-2228.These results suggest that in 5-FU chemotherapy G-CSFs may be beneficial in restoring the number of leucocytes from leucopenic state and in augmenting the tumor inhibitory effect. Furthermore, KW-2228 may be more beneficial than the natural type rhG-CSF. 相似文献
4.
A comparative study on immunosuppressive effects of cyclosporin A and FK 506 on peripheral blood lymphocytes in dogs 总被引:1,自引:0,他引:1
Kyoichi Takaori Yoshinori Nio Kazutomo Inoue Thein Tun Manaba Fukumoto Tohru Hashida Masato Yasuhara Ryohei Hori Takayoshi Tobe 《Biotherapy》1992,4(2):129-137
Immunosuppressive effects of cyclosporin A (CsA) and FK 506 (FK) on peripheral blood lymphocytes were studied in dogs in respect to mixed lymphocyte reaction, proliferative responses to recombinant interleukin-2 (rIL-2), phytohemagglutinin (PHA) and concanavalin-A (Con-A); phenotypes of OKIa1, CD3, CD8 and surface IgM; cytotoxic activity against xenogeneic tumor cells. CsA (2.0 or 5.0 mg/kg, intravenously) or FK (0.16 mg/kg, intramuscularly) was given to mongrel dogs every morning for serial 21 days. The blood concentrations of CsA, measured as trough levels by fluorescence polarization method, ranged from 37 to 350 ng/ml in dogs administered at 2.0 mg/kg and from 170 to 894 ng/ml in dogs administered at 5.0 mg/kg during treatment, respectively. In dogs treated with FK at a dose of 0.16 mg/kg, the drug concentrations in the plasma during treatment ranged from 0.16 to 1.8 ng/ml. Mixed lymphocyte reaction and proliferative responses to rIL-2, PHA and Con-A, which were declined by CsA, were not affected by FK. In contrast, the proportion of OKIa1+ cells was not affected by CsA, whereas FK decreased the proportion of OKIa1+ cells progressively during the course of treatment. Cytotoxic activity was suppressed by both CsA and FK. These results possibly indicate that CsA and FK exert their immunosuppressive effects via different mechanisms. 相似文献
5.
Evidence from morphology and anatomy (including embryology), as well as from palynology, chemistry and cytology, indicates
thatHydrastis is quite divergent from Ranunculaceae (in which the genus has been most often included) as well as from both Glaucidiaceae
and Berberidaceae. Distinctive features ofHydrastis, which demarcate it from Ranunculaceae but which are sometimes shared by Berberidaceae, are: the unique mode of origin of
the vascular supply to stamens and carpels; the micropyle being formed by both integuments; the xylem not V-shaped in cross
section; scalariform vessel perforations present; haploid chromosome number 13; pollen tectum consisting of a compound layer
of striae; leaf mesophyll not differentiated; the unique course of stem medullary bundles; D-galactose present. Its distinctive
higher haploid chromosome number, as well as its many less-specialized character states (in floral structure, leaf anatomy,
and xylem and vessel morphology), suggest thatHydrastis is a relictual primitive group which diverged early from a common ancestral stock of Ranunculaceae, Berberidaceae and probably
of Circaeasteraceae; at least some of the features shared byHydrastis and one or another of the families concerned seem to be a heritage from their common ancestor. We propose a reestablishment
of a monotypic family, Hydrastidaceae. 相似文献
6.
Rabbit factor H, a control protein of the alternative complement pathway, was isolated from rabbit serum by polyethylene glycol precipitation, DEAE-Sephacel chromatography, and gel chromatography on Sephadex G200. The protein migrated as a single-chain polypeptide with a molecular weight of 160,000 on sodium dodecyl sulfate-gel electrophoresis with Laemmli's buffer system, but hardly migrated into the gel with Fairbanks' buffer system. Physical and chemical properties of rabbit H were similar to those of human H, except that fragments produced by limited tryptic digestion from rabbit H had different molecular sizes from those produced from human H. Significant species-specificity was observed in the functional activity of factor H; activation of the alternative complement pathway was inhibited more efficiently with homologous H than with heterologous H. In contrast, factor H inhibited the hemolysis of homologous erythrocytes less than that of heterologous erythrocytes. 相似文献
7.
Isolation and physical mapping of temperature-sensitive mutants defective in heat-shock induction of proteins in Escherichia coli 总被引:25,自引:0,他引:25
Summary Mutants of Escherichia coli K12 that are partially or totally defective in induction of major heat-shock proteins and cannot grow at high temperature (42° C) were isolated by localized mutagenesis. These mutants carry a single mutation in the gene htpR (formerly hin) located at min 76 on the E. coli genetic map. Some mutants exhibit delayed (partial) induction of heat-shock proteins or require a higher temperature for induction than the wild type, whereas others are not induced under any of these conditions. The maximum temperature that allows growth varies among different mutants and is correlated with the residual induction capacity. Temperature-resistant revertants obtained from each mutant are fully or partially recovered in heat-shock induction. These results indicate that the inability of htpR mutants to grow at high temperature is due to the defect in heat-shock induction. In addition, a couple of mutants was found that produce significantly higher amounts of heat-shock proteins even at 30° C.The htpR gene has been cloned into plasmid pBR322 using the above mutants, and was localized to a DNA segment of 1.6 kilobase pairs. The mutants harboring certain palsmids that carry a part of htpR produce temperature-resistant recombinants at high frequency. This permits further localization of mutations within the htpR gene. Analysis of proteins encoded by each of the recombinant plasmids including the one carrying a previously isolated amber mutation (htpR165) led to the identification of a protein with an apparent molecular weight of about 36,000 daltons as the htpR gene product. 相似文献
8.
Barbara Stay Lynda S. Ostedgaard Stephen S. Tobe Alain Strambi Eugene Spaziani 《Journal of insect physiology》1984,30(8):643-651
The free (non-conjugated) ecdysteroid in the ovaries during the first gonadotrophic cycle of Diploptera punctata was identified as 20-hydroxyecdysone. The hormone, quantified by radioimmunoassay and by ultraviolet absorbance, was detectable in the ovary toward the end of vitellogenesis; the quantity increased rapidly during chorion formation. Ovaries with chorionated eggs contained 67 μg of 20-hydroxyecdysone per g fresh weight. The haemolymph free-ecdysteroid, not identified physicochemically, was quantified by radioimmunoassays. The highest concentration was observed at adult emergence; the titre declined between days 1–3 and then remained at a relatively constant level through oviposition (which occurs between day 7 and 8); titres in pregnant females were higher. Ovariectomized females exhibited the same pattern of ecdysteroid titres in the haemolymph as the sham operated controls throughout the period corresponding to the first gonadotrophic cycle. Thus the ovary may not be the only source of haemolymph ecdysteroid related to reproduction in adult females. 相似文献
9.
10.
Norimichi Kan Takashi Okino Masaki Nakanishi Kohei Satoh Kazuhisa Ohgaki Takayoshi Tobe 《Cancer immunology, immunotherapy : CII》1989,28(4):260-266
Summary The synergistic antitumor effect of interleukin-2(IL-2)-cultured tumor-bearer spleen cells (cultured lymphocytes) and immune fresh spleen cells was examined. Tumor-bearer cultured lymphocytes were obtained by culturing BALB/c spleen cells from syngeneic MOPC104E-tumor-bearing mice for 11 days with crude IL-2 and a soluble tumor extract. These cultured lymphocytes had weak antitumor activity when transferred i.p. into tumor-bearing mice that had been inoculated i.p. with 105 tumor cells 5 days previously. Immune fresh spleen cells, obtained from mice in complete remission after the treatment with cyclophosphamide, also had weak antitumor activity when transferred at the same schedule. The cultured cells and the fresh cells, mixed together before transfer, significantly augmented the therapeutic effect. At least 1×107 tumor-bearer cultured lymphocytes and 4×107 immune cells were needed for the synergistic effect. A tumor-specific combination was needed for both cultured and fresh cells. The effective subpopulation of tumor-bearer cultured lymphocytes was a cytotoxic one from an Lyt2+ precursor, and that of the immune fresh spleen cells was noncytotoxic, Lytl+ and Lyt2+ T-cells.A similar synergistic effect was also observed during in vitro coculture of tumor-bearer and immune cells. Cytotoxicity, as assessed by the 51Cr-release test, of tumor-bearer IL-2-cultured lymphocytes was maintained most effectively after 3 or 4 days of culture without IL-2 when the lymphocytes were cocultured with immune fresh spleen cells and tumor cells. 相似文献