全文获取类型
收费全文 | 1526篇 |
免费 | 148篇 |
国内免费 | 1篇 |
出版年
2023年 | 12篇 |
2022年 | 26篇 |
2021年 | 40篇 |
2020年 | 37篇 |
2019年 | 39篇 |
2018年 | 48篇 |
2017年 | 41篇 |
2016年 | 59篇 |
2015年 | 96篇 |
2014年 | 81篇 |
2013年 | 82篇 |
2012年 | 112篇 |
2011年 | 131篇 |
2010年 | 54篇 |
2009年 | 54篇 |
2008年 | 86篇 |
2007年 | 69篇 |
2006年 | 84篇 |
2005年 | 77篇 |
2004年 | 70篇 |
2003年 | 61篇 |
2002年 | 52篇 |
2001年 | 9篇 |
2000年 | 12篇 |
1999年 | 13篇 |
1998年 | 10篇 |
1997年 | 11篇 |
1995年 | 8篇 |
1994年 | 11篇 |
1993年 | 5篇 |
1992年 | 9篇 |
1991年 | 11篇 |
1990年 | 5篇 |
1989年 | 9篇 |
1988年 | 6篇 |
1987年 | 7篇 |
1986年 | 5篇 |
1985年 | 6篇 |
1984年 | 11篇 |
1983年 | 8篇 |
1982年 | 12篇 |
1981年 | 5篇 |
1980年 | 10篇 |
1979年 | 7篇 |
1978年 | 8篇 |
1976年 | 7篇 |
1975年 | 9篇 |
1973年 | 9篇 |
1972年 | 5篇 |
1969年 | 4篇 |
排序方式: 共有1675条查询结果,搜索用时 15 毫秒
1.
Nataly Mancette Rijensky Netta R. Blondheim Shraga Eilon Barnea Nir Peled Eli Rosenbaum Aron Popovtzer Solomon M. Stemmer Alejandro Livoff Mark Shlapobersky Neta Moskovits Dafna Perry Eitan Rubin Itzhak Haviv Arie Admon 《Molecular & cellular proteomics : MCP》2020,19(8):1360-1374
Highlights
- •Sufficient tumor tissues are often unavailable large HLA peptidome discovery.
- •Using patient derived xenograft (PDX) tumors can overcome this limitation.
- •The large PDX HLA peptidomes expand significantly those of the original biopsies.
- •The HLA peptidomes of the PDX tumors included many tumor antigens.
2.
Fabián Michelangeli Dalia M. Sulcas Marie-Christine Ruiz 《Cell and tissue research》1987,250(2):413-419
Summary This study is concerned with electron-microscopic observations on endocrine or paracrine cells in the fundic gastric mucosa of the bullfrog. Also, an attempt was made to identify the histamine-releasing cells involved in the secretagogue response. At least three distinct endocrine-like cell types were found. The classification is based on the appearance of secretory granules and other organelles, and the relationship of endocrine-like cells with other cells in the tissue. The amphibian endocrine-like cells resemble the ECL, D and EC cells of mammals. Type-I (ECL) cells showed degranulation after repeated stimulation with tetragastrin (TG), acetylcholine (ACh) and K+ depolarizing solution, all of which release histamine. 相似文献
3.
4.
The redistribution of surface membrane immunoglobulin molecules (sIg) was studied in two functionally distinct populations of mouse splenic B lymphocytes, namely, those bearing membrane IgM(IgG?) and those bearing IgG. Brief exposure to mitogenic doses of bacterial lipopolysaccharide (LPS) produced direct but differential effects on the subsequent ability of specific antibodies to induce this redistribution on each cell type. Studied as a function of temperature, antibody-induced redistribution of sIgM on cells previously exposed to LPS was observed to occur at temperatures lower than the temperatures required for similar sIgM redistribution on lymphocytes not exposed to LPS. In contrast, mitogen-treated sIgG+ cells demonstrated an opposite and long-lasting effect (at least 40 hr), requiring higher temperatures to allow sIgG movement comparable to that seen on untreated sIgG-bearing lymphocytes. Thus, we conclude that LPS interacts with both IgM+(IgG?) and IgG+ lymphocytes, but that such interactions produced different membrane effects on each B-cell subset. This membrane change can therefore be useful as a quasi-functional differentiation marker. Furthermore, differences in sensitivity to cellular activation by LPS seen between sIgM-bearing (sIgG?) and sIgG-bearing B cells may be a reflection of such direct, although different, membrane effects. 相似文献
5.
Flow cytometry (FCM) in conjunction with immunocytochemical-labeling was used to analyze and screen a population of Escherichia coli clones containing a genomic library from the oil-degrading microorganism Acinetobacter calcoaceticus RAG-1 for the isolation of clones which expressed specific RAG-1 surface antigens. Reconstruction experiments using mixed populations indicated that RAG-1 cells could be clearly distinguished at a ratio of one RAG-1 cell to 500 Escherichia coli cells. Using this technique two clones, WM143 and WM191, were isolated and shown by restriction endonuclease cleavage and Southern hybridization to contain plasmids carrying inserts of RAG-1 DNA of 9.4 and 9.8 kb respectively.Non-common abbreviations FCM
flow cytometry
- FITC
fluorescein-iso-thiocyanate
- LB
Luria broth
- MM
minimal salt medium
- PBS
phosphate buffered saline
- PMSF
phenylmethylsulfonyl fluoride 相似文献
6.
Zulma Gazit David W. Weiss Daniel Shouval Michal Yechezkeli Volker Schirrmacher Michael Notter Jürgen Walter Eli Kedar 《Cancer immunology, immunotherapy : CII》1992,35(2):135-144
Summary The antitumor effects of chemotherapy, recombinant human interleukin-2 (IL-2), recombinant human interferon A/D (IFN), allogeneic human lymphokine-activated killer (LAK) cells, and antitumor monoclonal antibody (mAb), administered alone and in various combinations, were tested in athymic nude mice carrying human tumor xenografts. Treatment began 6–18 days after i.v. or i.p. inoculation of colorectal carcinoma or melanoma cell lines, when macroscopic growths were evident. Chemotherapy consisted of two or three courses of 5-fluorouracil (5-FU) or dacarbazine. IL-2 and/or IFN were administered three to five times weekly for 1–3 weeks, usually starting 2–5 days after chemotherapy. Human LAK cells were infused once or twice weekly for 2 or 3 weeks concurrently with IL-2. In some experiments, murine anticolorectal carcinoma mAb (SF25) was administered. In both tumor systems, chemotherapy alone or immunotherapy alone (IL-2, IL-2 + LAK cells, IFN, IL-2 + IFN ± LAK cells) had little or no therapeutic effects. Additive effects were obtained by combining chemotherapy with IL-2 and LAK cells or with IL-2 and IFN. In the majority of the experiments, the most effective combination was chemotherapy + IL-2 + IFN + LAK cells. Treatment with mAb was beneficial in the colorectal carcinoma system when combined with 5-FU + IL-2 or 5-FU + IL-2 + IFN. Homing experiments with radiolabeled human and mouse LAK cells injected i.v. showed increased early accumulation in the liver and lungs, whereas freshly explanted mouse splenocytes localized mostly in the spleen and liver. The tissue distribution pattern of human LAK cells was similar in normal and tumor-bearing mice (with lung metastases). These findings suggest that combination of chemotherapy with cytokines and LAK cells can be partially effective for advanced solid human tumors even in the absence of the host's T-cell immune response. Preliminary experiments showed that tumor-specific, anti-melanoma T-cell clones were effective in local (s.c.) tumor growth inhibition (Winn assay) following coinjection with the autologous tumor cells. 相似文献
7.
Averell Gnatt Dalia Ginzberg Judy Lieman-Hurwitz Ronit Zamir Haim Zakut Hermona Soreq 《Cellular and molecular neurobiology》1991,11(1):91-104
1. Various hybridization approaches were employed to investigate structural and chromosomal interrelationships between the human cholinesterase genes CHE and ACHE encoding the polymorphic, closely related, and coordinately regulated enzymes having butyrylcholinesterase (BuChE) and acetylcholinesterase (AChE) activities. 2. Homologous cosmid recombination with a 190-base pair 5' fragment from BuChEcDNA resulted in the isolation of four overlapping cosmid clones, apparently derived from a single gene with several introns. The Cosmid CHEDNA included a 700-base pair fragment known to be expressed at the 3' end of BuChEcDNA from nervous system tumors and which has been mapped by in situ hybridization to the unique 3q26-ter position. In contrast, cosmid CHEDNA did not hybridize with full-length AChEcDNA, proving that the complete CHE gene does not include AChE-encoding sequences either in exons or in its introns. 3. The chromosomal origin of BuChE-encoding sequences was further examined by two unrelated gene mapping approaches. Filter hybridization with DNA from human/hamster hybrid cell lines revealed BuChEcDNA-hybridizing sequences only in cell lines including human chromosome 3. However, three BuChEcDNA-homologous sequences were observed at chromosomal positions 3q21, 3q26-ter, and 16q21 by a highly stringent in situ hybridization protocol, including washes at high temperature and low salt. 4. These findings stress the selectivity of cosmid recombination and chromosome blots, raise the possibility of individual differences in BuChEcDNA-hybridizing sequences, and present an example for a family highly similar proteins encoded by distinct, nonhomologous genes. 相似文献
8.
9.
Curves relating net photosynthetic rate to irradiance [P(I) curve relation] were estimated and analysed inMercurialis perennis L. plants stemming from three forest (spruce, beech and ash) stands with different tree leaf canopy development and different
light regime.
The saturating irradiance (Is) reached the highest values in plants of all three stands in spring (spruce forest: 438 W m−2, beech forest: 440 W m−2 and ash forest: 367 W m−2), it declined sharply in the middle of the growing season (283, 285 and 297 W m-2, respectively) and this Is level persisted until autumn. A pronounced dynamics in plants from spruce and beech forests made itself manifest also in
the adaptation (Ia) and compensating (Ic) irradiances, respectively. After a sudden decline in summer, values in autumn were close to those of the vernal season.
The most pronounced parameter, which optimally expressed the adaptation ofMercurialis perennis to various light conditions, was the photosynthetic efficiency (α) calculated as the slope of the linear part of the curve
relating net photosynthetic rate to irradiance.
At the time of the highest PN sat. value in course of the growing season (August) (spruce forest: 100, beech forest: 98.7 and ash forest: 85.8 μg CO2 m−2 s−1), RD was in its minimum; in autumn PN sat. reached the lowest values which corresponded to the most intensive RD.
It was found thatMercurialis perennis plants stemming from forest stands with different light conditions did not make use equally of the altering light conditions
in the course of the growing season. By the underlying analysis of P(I) curves this rhizomatous perennial herb (geophyte)
may be characterized as a shade tolerant species. 相似文献
10.
Summary Cytoplasmic male sterility (cms) and nuclear male sterility (nms) in Petunia were described respectively as possible autonomous and integrated states of the same genetic element by Frankel (1971). In the present study we describe genetic analysis of the interaction between the cms, the nuclear gene for male sterility (e) and the fertility restorer allele (Rf). The main findings in this study are: (1) The nuclear sterility allele can coexist in one or two dosages with the cytoplasmic male sterility elements (ste) in somatic cells or female gametes; (2) the presence of the fertility restorer allele Rf is not required for the coexistence of ste and e and (3) Rf does not interact epistatically with e, e.g., the expression of e is independent of Rf—the genotypes (S) RfRfee and (S) Rfrfee are male sterile.Contribution from the Agricultural Research Organization. The Volcani Center, Bet Dagan, Israel. 1983 series No. 846 E 相似文献