全文获取类型
收费全文 | 4661篇 |
免费 | 221篇 |
国内免费 | 1篇 |
出版年
2021年 | 29篇 |
2019年 | 21篇 |
2018年 | 37篇 |
2017年 | 37篇 |
2016年 | 61篇 |
2015年 | 104篇 |
2014年 | 111篇 |
2013年 | 489篇 |
2012年 | 223篇 |
2011年 | 239篇 |
2010年 | 163篇 |
2009年 | 154篇 |
2008年 | 228篇 |
2007年 | 267篇 |
2006年 | 235篇 |
2005年 | 273篇 |
2004年 | 308篇 |
2003年 | 243篇 |
2002年 | 252篇 |
2001年 | 47篇 |
2000年 | 40篇 |
1999年 | 58篇 |
1998年 | 64篇 |
1997年 | 62篇 |
1996年 | 38篇 |
1995年 | 49篇 |
1994年 | 52篇 |
1993年 | 60篇 |
1992年 | 64篇 |
1991年 | 38篇 |
1990年 | 38篇 |
1989年 | 46篇 |
1988年 | 46篇 |
1987年 | 47篇 |
1986年 | 54篇 |
1985年 | 46篇 |
1984年 | 44篇 |
1983年 | 39篇 |
1982年 | 43篇 |
1981年 | 51篇 |
1980年 | 48篇 |
1979年 | 33篇 |
1978年 | 35篇 |
1977年 | 26篇 |
1976年 | 35篇 |
1975年 | 25篇 |
1974年 | 26篇 |
1973年 | 21篇 |
1972年 | 17篇 |
1970年 | 18篇 |
排序方式: 共有4883条查询结果,搜索用时 15 毫秒
91.
Noriko Takahashi Katsuyoshi Masuda Kenji Hiraki Kazuo Yoshihara Hung-Hsiang Huang Kay-Hooi Khoo Koichi Kato 《European journal of biochemistry》2003,270(12):2627-2632
To determine the glycoforms of squid rhodopsin, N-glycans were released by glycoamidase A digestion, reductively aminated with 2-aminopyridine, and then subjected to 2D HPLC analysis [Takahashi, N., Nakagawa, H., Fujikawa, K., Kawamura, Y. & Tomiya, N. (1995) Anal. Biochem.226, 139-146]. The major glycans of squid rhodopsin were shown to possess the alpha1-3 and alpha1-6 difucosylated innermost GlcNAc residue found in glycoproteins produced by insects and helminths. By combined use of 2D HPLC, electrospray ionization-mass spectrometry and permethylation and gas chromatography-electron ionization mass spectrometry analyses, it was revealed that most (85%) of the N-glycans exhibit the novel structure Manalpha1-6(Manalpha1-3)Manbeta1-4GlcNAcbeta1-4(Galbeta1-4Fucalpha1-6)(Fucalpha1-3)GlcNAc. 相似文献
92.
Joji Sekine Kazuo Sano Masataka Uehara Tsugio Inokuchi 《Biotechnic & histochemistry》1996,71(3):152-156
A technique Is described for rapid detection of S-pha?e cells of tumor tissues in smear specimens using bromodeoxyuridine (BrdU) immunostaining. Mouse NR-S1 tumors and human tumor specimens were prepared for smear cytology after incubation in RPMI 1640 culture medium containing 200 μM BrdU at 37 °C under 3 atm for 1 hr. Samples were fixed in 70% ethanol for 30 min and used immediately or air dried for 30 min. Samples were then denatured in either 4 N HC1 or 0.07 N NaOH to prepare partially single-stranded DMA. Fixation with air drying for 30 min followed by 30 min in 70% ethanol and 1 min denaturation with 0.07 N NaOH resulted in satisfactory staining quality. Cultured tumor specimens were processed for routine paraffin sections after smears were made for cytology. The labeling indices of the smear specimens and of the paraffin sections gave similar results. This technique should be useful in evaluating the cell proliferative potential of tumor tissue in smear cytology without processing paraffin sections. 相似文献
93.
94.
Fumi Katoh Kazuo Kitamura Hiromi Niina Ryuichi Yamamoto Hisanori Washimine †Kenji Kangawa Yoshitaka Yamamoto Hideyuki Kobayashi Tanenao Eto Akihiko Wada 《Journal of neurochemistry》1995,64(1):459-461
Abstract: In cultured bovine adrenal medullary cells, stimulation of nicotinic receptors by carbachol evoked the Ca2+ -dependent exocytotic cosecretion of proadrenomedullin N-terminal 20 peptide (PAMP) (EC50 = 50.1 µ M ) and catecholamines (EC50 = 63.0 µ M ), with the molar ratio of PAMP/catecholamines secreted being equal to the ratio in the cells. Addition of PAMP[1–20]NH2 inhibited carbachol-induced 22 Na+ influx via nicotinic receptors (IC50 = 2.5 µ M ) in a noncompetitive manner and thereby reduced carbachol-induced 45 Ca2+ influx via voltage-dependent Ca2+ channels (IC50 = 1.0 µ M ) and catecholamine secretion (IC50 = 1.6 µ M ). It did not alter high K+ -induced 45 Ca2+ influx via voltage-dependent Ca2+ channels or veratridine-induced 22 Na+ influx via voltage-dependent Na+ channels. PAMP seems to be a novel antinicotinic peptide cosecreted with catecholamines by a Ca2+ -dependent exocytosis in response to nicotinic receptor stimulation. 相似文献
95.
Takashi Hirayarna Tatsuya Maeda Haruo Saito Kazuo Shinozaki 《Molecular & general genetics : MGG》1995,249(2):127-138
Yeast cells can respond and adapt to osmotic stress. In our attempt to clarify the molecular mechanisms of cellular responses to osmotic stress, we cloned seven cDNAs for hyperosmolarity-responsive (HOR) genes from Saccharomyces cerevisiae by a differential screening method. Structural analysis of the clones revealed that those designated HOR1, HORS, HOR4, HOR5 and HOR6 encoded glycerol-3-phosphate dehydrogenase (Gpd1p), glucokinase (Glklp), hexose transporter (Hxtlp), heat-shock protein 12 (Hsp12p) and Na+, K+, Li+-ATPase (Enalp), respectively. HOR2 and HOR7 corresponded to novel genes. Gpdlp is a key enzyme in the synthesis of glycerol, which is a major osmoprotectant in S. cerevisiae. Cloning of HOR1/GPD1 as a HOR gene indicates that the accumulation of glycerol in yeast cells under hyperosmotic stress is, at least in part, caused by an increase in the level of GPDH protein. We performed a series of Northern blot analyses using HOR cDNAs as probes and RNAs prepared from cells grown under various conditions and from various mutant cells. The results suggested that all the HOR genes are regulated by common signal transduction pathways. However, the fact that they exhibited certain distinct responses indicated that they might also be regulated by specific pathways in addition to the common pathways. Ca2+ seemed to be involved in the signaling systems. In addition, Hog1p, one of the MAP kinases in yeast, appeared to be involved in the regulation of expression of HOR genes, although its function seemed to be insufficient for the overall regulation of expression of these genes. 相似文献
96.
Expression of gicerin in development, oncogenesis and regeneration of the chick kidney 总被引:1,自引:0,他引:1
97.
98.
The karyomorphology of 16 species in 13 genera representing Moraceae and Cecropiaceae was investigated in an effort to contribute
to a better understanding of chromosome features and evolution in the families. All genera investigated have similar karyomorphology,
but differences are found in (1) chromosome features of Interphase nucleus (simple, simple-complex, or complex chromocenter
type), (2) basic chromosome number (x=13 or 14), (3) size variation (mono-or bimodial), and (4) frequencies of chromosomes with median centromeres (m-chromosome) (25–85%) and those with subterminal (or terminal) centromeres (st-chromosome) (14–69%). Comparisons with Ulmaceae as an outgroup of the remainder of Urticales suggest that the simple chromocenter
type,x=14 comprising bothm- andst-chromosomes, and the monomodial karyotype are plesiomorphies in Moraceae and Cecropiaceae. Most of Moraceae and Cecropiaceae
retain generalized chromosome features of the order, but have involved a few evolutionary changes in karyomorphology. Based
on some detailed karyomorphological data, inter- and infrafamilial relationships are also briefly discussed. 相似文献
99.
Takahiro Morio Hiroyuki Adachi Kazuo Sutoh Kaichiro Yanagisawa Yoshimasa Tanaka 《Journal of plant research》1995,108(1):111-114
Using a plasmid pBsr2 which carries a blasticidin S-resistant gene, we have improved the method of REMI (restriction enzyme-mediated
integration) provided for insertional mutagenesis inDictyostelium discoideum (bsr-REMI). To confirm usefulness of thebsr-REMI, transformation efficiency, copy number of integrated DNA, and randomness of integration into genome were examined. 相似文献
100.
Peter J. Robinson Michael Steinmetz Kazuo Moriwaki Kirsten Fischer Lindahl 《Immunogenetics》1984,20(6):655-665
To determine the distribution of beta-2 microglobulin (B2m) alleles in wild mice we have typed mice derived from natural populations in Europe, North Africa, South America, and East Asia. Mus musculus domesticus mice from Germany, France, Italy, and Peru were all B2m
a
as were most from the United Kingdom. M.m. musculus mice from Denmark and Czechoslovakia, several stocks of M.m. molossinus from Japan, and M.m. castaneus from China, Thailand, and the Philippines were of B2m
b
type. This is consistent with the notion that C57BL/6 may have obtained some of its genes, including B2m, from Eastern mice. A BgII restriction site characteristic of B2m
b
was also found in mice from Czechoslovakia and Japan, confirming that B2m
b
is a naturally occurring allele of B2m. A new type of
2m (
2mw1) was found in four stocks of M. spretus from Portugal, Spain, and Morocco. This molecule differs in apparent size and charge from the a and b types.
2mw2 was found together with
2 ma in one stock of M.m. domesticus (brevirostris) from Morocco.
2mw3 and
2mw4 were found in a few M. m. bactrianus from Pakistan. In all cases tested, these new
2m molecules associate with class I histocompatibility antigens.Abbreviations used in this paper
2m
beta-2 microglobulin
-
B2m
gene for beta-2 microglobulin
- IEF
isoelectric focusing
- SDS-PAGE
polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate
- MHC
major histocompatibility complex
- T. E.
Tris-EDTA buffer 相似文献