全文获取类型
收费全文 | 2384篇 |
免费 | 136篇 |
出版年
2022年 | 9篇 |
2021年 | 15篇 |
2020年 | 8篇 |
2019年 | 16篇 |
2018年 | 24篇 |
2017年 | 17篇 |
2016年 | 34篇 |
2015年 | 49篇 |
2014年 | 55篇 |
2013年 | 147篇 |
2012年 | 123篇 |
2011年 | 116篇 |
2010年 | 68篇 |
2009年 | 75篇 |
2008年 | 111篇 |
2007年 | 108篇 |
2006年 | 120篇 |
2005年 | 102篇 |
2004年 | 101篇 |
2003年 | 130篇 |
2002年 | 113篇 |
2001年 | 74篇 |
2000年 | 82篇 |
1999年 | 63篇 |
1998年 | 37篇 |
1997年 | 41篇 |
1996年 | 32篇 |
1995年 | 31篇 |
1994年 | 29篇 |
1993年 | 35篇 |
1992年 | 51篇 |
1991年 | 47篇 |
1990年 | 48篇 |
1989年 | 34篇 |
1988年 | 45篇 |
1987年 | 24篇 |
1986年 | 19篇 |
1985年 | 40篇 |
1984年 | 20篇 |
1983年 | 19篇 |
1982年 | 18篇 |
1981年 | 23篇 |
1980年 | 13篇 |
1979年 | 19篇 |
1978年 | 30篇 |
1977年 | 16篇 |
1976年 | 18篇 |
1975年 | 9篇 |
1969年 | 9篇 |
1966年 | 9篇 |
排序方式: 共有2520条查询结果,搜索用时 46 毫秒
991.
Isolation and Characterization of a Boron-Polysaccharide Complex from Radish Roots 总被引:12,自引:0,他引:12
Matoh Toru; Ishigaki Ken-ichi; Ohno Kaori; Azuma Jun-ichi 《Plant & cell physiology》1993,34(4):639-642
A boron-polysaccharide complex was purified from a Driselasedigest of cell walls of radish roots. The complex had a molecularweight of 7.5 KDa and contained boron (0.232%, w/w), uronicacid (52.3%, w/w) and neutral sugars (32.4%). 11B-NMR spectroscopicanalysis suggested that the boron was present as a tetravalent1 : 2 borate-diol complex.
1This work was supported by a Grant-in-Aid (no. 04660069) fromthe Ministry of Education, Science and Culture.
4Present address: Kasai Experimental Farm, Sumitomo ChemicalCo., Ltd. Kasai, Hyogo, 675-23 Japan. 相似文献
992.
Jun Nishikawa Mikio Naganobu Taro Ichii Haruto Ishii Makoto Terazaki Kouichi Kawaguchi 《Polar Biology》1995,15(1):31-39
Distribution and biomass of salps and Antarctic krill (Euphausia superba) were investigated near the South Shetland Islands during austral summer 1990–1991. Salp biomass ranged between 0 and 556 mgC·m–3 and was greatest at a station in the Bransfield Strait in late December 1990. Salp biomass was lower than that of E. superba. Two species of salps; Salpa thompsoni and Ihlea racovitzai were found, and the former was dominant numerically. Spatial distribution and generation composition of these two species was different. Spatial distributions of salps and E. superba did not overlap particularly so the January–February period. While E. superba was found mainly in the coastal area which showed high-chlorophyll a values, salps exhibited high biomass in the oceanic area with low chlorophyll a concentrations. Predation by salps on small krill and the competitive removal of food by them, are discussed as potential reasons for the relatively low abundance of E. superba at the stations where salps were present in great numbers. 相似文献
993.
Danilo B. Largo Kimio Fukami Toshitaka Nishijima Masao Ohno 《Journal of applied phycology》1995,7(6):539-543
The most common perception of unfavorable environmental factors causing the ice-ice disease in the farmed seaweeds, Kappaphycus and Eucheuma, was demonstrated in this study for the first time using stressful conditions of abiotic factors in a continuous culture system. Light intensity of less than 50 mol photon m–2 s–1 and salinity of 20% or less induced ice-ice whitening characterized by short segments at midbranches which were similar to those observed in the Philippine seaweed farms, while temperatures of up to 33–35 °C resulted in wide-scale whitening leading to complete damage of the branches. These effects were preceded by slow growth rates from an optimum of 3.7% d–1 to almost –2.0% d–1. Mechanical stress by wound injury did not result to ice-ice whitening similar to the above. Environmental factors observed to trigger ice-ice in the laboratory, although may not necessarily parallel those in the field, may act synergestically to produce similar effects. 相似文献
994.
Identification of the factors that interact with NCBP, an 80 kDa nuclear cap binding protein. 总被引:9,自引:1,他引:8
下载免费PDF全文
![点击此处可从《Nucleic acids research》网站下载免费的PDF全文](/ch/ext_images/free.gif)
It has been shown that the monomethylated cap structure plays important roles in pre-mRNA splicing and nuclear export of RNA. As a candidate for the factor involved in these nuclear events we have previously purified an 80 kDa nuclear cap binding protein (NCBP) from a HeLa cell nuclear extract and isolated its full-length cDNA. In this report, in order to obtain a clue to the cellular functions of NCBP, we attempted to identify a factor(s) that interacts with NCBP. Using the yeast two-hybrid system we isolated three clones from a HeLa cell cDNA library. We designated the proteins encoded by these clones NIPs (NCBP interacting proteins). NIP1 and NIP2 have an RNP consensus-type RNA binding domain, whereas NIP3 contains a unique domain of Arg-Glu or Lys-Glu dipeptide repeats. We also show that NCBP requires NIP1 for binding to the cap structure. Possible roles of NIPs in cap-dependent nuclear processes are discussed. 相似文献
995.
S. Kayashima H. Ohno T. Fujioka N. Taniguchi N. Nagata 《European journal of applied physiology and occupational physiology》1995,70(5):413-420
The effects of strenuous physical exercise on the serial changes in the haematological, biochemical and hormonal markers were investigated. A group of 14 soldiers, aged 24–36 years, took part in a military training course for about 13 weeks. After severe exercise stress, an increase (90%) in the number of peripheral blood leucocytes was observed. The degree of leucocytosis showed a close correlation with the values of some serum parameters, such as concentrations of aspartate aminotransferase (AST;r = 0.747), lactate dehydrogenase (LD;r = 0.748), blood urea nitrogen (r = 0.756), creatine kinase (CK;r = 0.637), manganese-superoxide dismutase (Mn-SOD;r = 0.508), alanine aminotransferase (ALT;r = 0.542) and uric acid (r = 0.538), and concentrations of urinary parameters, such as vanilmandelic acid (r = 0.429) and free cortisol (r = 0.437). The subjects showing prominent leucocytosis over 9500 cells · l–1 exhibited a lower concentration of serum cholinesterase than those who showed milder leucocytosis. The serum Mn-SOD concentration was closely correlated with the serial changes in serum concentrations of AST, ALT, LD and CK, indicating exercise-induced muscle and liver damage. The change in peripheral leucocyte number was assumed to be diagnostically informative and may be a prognostic marker, reflecting organ damage and restoration after strenuous physical exercise. 相似文献
996.
Michio Kato Kunitaka Hirose Michinori Hakozaki Masakazu Ohno Yoichi Saito Ryo Izutani Jun Noguchi Yuichi Hori Satoru Okumoto Daisuke Kuroda Hideaki Nomura Shinichi Nishimatsu Harumasa Ohoyanagi 《Cancer immunology, immunotherapy : CII》1995,40(3):152-156
The protein-bound polysaccharide extracted from a fungus, PSK, has been used as a biological response modifier in the treatment of cancer patients in Japan for over 16 years. The administration of PSK to tumor-bearing rodents inhibited tumor growth and modulated immune responses. Recently, an in vitro study has revealed that PSK is a strong inducer of cytokine gene expression and production in human peripheral blood mononuclear cells (PBMC). To establish whether PSK has cytokine-inducing activities in vivo, we have orally administered PSK (1 g, the clinical dose) to 12 healthy volunteers and 9 gastric cancer patients who had undergone gastrectomy, and assessed the gene expression for cytokines in PBMC of each subject. As determined by the reverse-transcribed polymerase chain reaction method, the induction of gene expression for both tumor necrosis factor and interleukin-8 (IL-8) was detected in PBMC from 5 of the 12 healthy volunteers (42%) and 4 of the 9 patients (44%). Furthermore, the concentration of serum IL-8 was elevated in 5 healthy volunteers given PSK orally, who had shown induction of IL-8 gene expression, as detected by enzyme-linked immunosorbent assay. These findings indicate that responsiveness of PBMC to PSK, in terms of gene expression and production of cytokines, varies among individuals. Thus, when using PSK to treat cancer patients, it seems advisable to select patients on the basis of their responsiveness to PSK. We speculate that the cytokines induced by PSK might mediate the immunoenhancing action of this agent in vivo. 相似文献
997.
Horiuchi K Tsurushima H Soo Kim B Qin Liu S Saijo K Saijo Y Nukiwa T Nomura N Matsumura M Ohno T 《Cytotechnology》1998,26(2):119-124
Human tumor specific cytotoxic T lymphocytes (CTL) were expanded on formalin-fixed autologous target tumor cells derived from
glioblastoma multiforme. Growth response of the CTL restimulated with the fixed target cells was larger than those with live
target cells. The results suggest that formalin-fixed tumor cells will be stable sources of tumor antigen for efficient autologous
CTL expansion and be useful for adoptive immunotherapy of tumors.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
998.
999.
Morphological aspects of feeding and improvement in feeding ability in early stage larvae of the milkfish,Chanos chanos 总被引:1,自引:0,他引:1
Hiroshi Kohno Riza Ordonio-Aguilar Atsushi Ohno Yasuhiko Taki 《Ichthyological Research》1996,43(2):133-140
The osteological development of elements comprising the oral cavity and fins was examined in early stage larvae of laboratory-reared
milkfish,Chanos chanos, from hatching to 200 hours after hatching. Fundamental elements of the oral cavity had developed by the time of initial
mouth opening, 54 hours after hatching. The oral cavity was long and cylindrical, with a short, robust Meckel's cartilage,
and robust quadrate and symplectic-hyomandibular cartilages. The initial ossification of existing elements and addition of
new elements occurred between 120–146 hours after initial mouth opening (HAMO), whereas the cartilaginous basihyal and caudal
fin-supports appeared at 37.5 and 61.5 HAMO, respectively. Based on the morphology and developmental patterns of characters
examined in this study, the feeding mode of early stage larval milkfish was considered to be “straining,” with an improvement
in feeding ability occurring between 120–146 HAMO. 相似文献
1000.
Structure and expression of a cloned cDNA for mouse interferon-beta 总被引:20,自引:0,他引:20
Y Higashi Y Sokawa Y Watanabe Y Kawade S Ohno C Takaoka T Taniguchi 《The Journal of biological chemistry》1983,258(15):9522-9529
A unique sequence in the mouse genome which cross-hybridized to a cloned human interferon-beta 1 gene was detected by DNA blot analysis. Taking advantage of this, a cDNA library prepared from partially purified mRNA for mouse interferon-beta was screened using human interferon-beta 1 DNA as a probe. One of the positive clones, pM beta-3, contained a 680-base pair cDNA insert, whose base sequence contained a single large open reading frame for 182 amino acids. The coding sequences of the cDNA showed homologies of 63% at the nucleotide and 48% at the amino acid level with respect to human interferon-beta 1 cDNA (Taniguchi, T., Ohno, S., Fujii-Kuriyama, Y., and Muramatsu, M. (1980) Gene 10, 11-15). The first 21 amino acids, considered to be the signal peptide, were followed by 24 amino acids, whose sequence was identical with the NH2-terminal sequence that had been reported for mouse interferon-beta from Ehrlich ascites tumor cells (Taira, H., Broeze, R. J., Jayaram, B. M., Lengyel, P., Hunkapiller, M. W., and Hood, L. E. (1980) Science (Wash. D.C.) 207, 528-530). The complete primary sequence of mature interferon-beta polypeptide consisting of 161 amino acids (Mr = 19,700) was deduced. There are three N-glycosylation sites, and this offers an explanation for the larger molecular size (Mr = 26,000-40,000) of natural mouse interferon-beta in comparison to the deduced interferon polypeptide. The cDNA, when fused to a SV40 promoter sequence and then introduced into COS-7 cells, directed the synthesis and secretion of a protein product indistinguishable from the authentic mouse interferon-beta. 相似文献