全文获取类型
收费全文 | 2252篇 |
免费 | 129篇 |
出版年
2022年 | 6篇 |
2021年 | 16篇 |
2020年 | 6篇 |
2019年 | 12篇 |
2018年 | 31篇 |
2017年 | 26篇 |
2016年 | 35篇 |
2015年 | 59篇 |
2014年 | 68篇 |
2013年 | 188篇 |
2012年 | 127篇 |
2011年 | 144篇 |
2010年 | 75篇 |
2009年 | 77篇 |
2008年 | 125篇 |
2007年 | 149篇 |
2006年 | 121篇 |
2005年 | 110篇 |
2004年 | 109篇 |
2003年 | 121篇 |
2002年 | 131篇 |
2001年 | 36篇 |
2000年 | 43篇 |
1999年 | 37篇 |
1998年 | 33篇 |
1997年 | 30篇 |
1996年 | 22篇 |
1995年 | 28篇 |
1994年 | 18篇 |
1993年 | 29篇 |
1992年 | 34篇 |
1991年 | 14篇 |
1990年 | 19篇 |
1989年 | 23篇 |
1988年 | 13篇 |
1987年 | 15篇 |
1986年 | 24篇 |
1985年 | 20篇 |
1984年 | 24篇 |
1983年 | 20篇 |
1982年 | 12篇 |
1981年 | 18篇 |
1980年 | 20篇 |
1979年 | 14篇 |
1978年 | 10篇 |
1977年 | 17篇 |
1976年 | 16篇 |
1975年 | 11篇 |
1974年 | 9篇 |
1973年 | 10篇 |
排序方式: 共有2381条查询结果,搜索用时 15 毫秒
21.
Koichiro Shimada Toyoko Yoshida Tetsuo Kuroishi Masahide Ishibashi 《Biochimica et Biophysica Acta (BBA) - Gene Structure and Expression》1983,740(2):169-178
A restriction map of chicken embryo lethal orphan (CELO) virus DNA was reported with ten restriction endonucleases (XbaI, XhoI, SalI, HindIII, EcoRI, BglI, KpnI, BamHI, PstI and SstI). CELO virus DNA was estimated by comparing CELO virus DNA fragments with marker DNA fragments to have a molecular weight of 29.3·106. 相似文献
22.
23.
Establishment of five human myeloma cell lines 总被引:3,自引:0,他引:3
Masayoshi Namba Takemi Ohtsuki Masaharu Mori Atsushi Togawa Hideho Wada Takashi Sugihara Yoshihito Yawata Tetsuo Kimoto 《In vitro cellular & developmental biology. Plant》1989,25(8):723-729
Summary Five human myeloma cell lines, KMM-1, KMS-5, KMS-11, KMS-12- PE, and KMS-12-BM, have been established at Kawasaki Medical
School since 1980. As the KMS-12-PE and KMS-12-BM lines were obtained from the same patient, these five cell lines have been
derived from four patients with multiple myeloma. The five myeloma cell lines are stably growing at present in RPMI 1640 medium
supplemented with 10% fetal bovine serum. They can also grow in a defined culture medium without serum. That these cell lines
were, human myeloma cells was confirmed by the following findings. Ultranstructually, all five cell lines showed features
characteristic of plasma cells. KMM-1 and KMS-11 cells secreted lambda and kappa chains into the culture medium, respectively,
but the other cell lines produced no immunoglobulins. KMM-1 expressed cytoplasmic lambda antigen, KMS-5 showed cytoplasmic
delta, and KMS-11 expressed surface kappa, whereas KMS-12-PE and KMS-12-BM cells showed no surface or cytoplasmic immunoglobulins.
Regarding reaction with a monoclonal plasma cell antibody (PCA-1), four of the five lines were positive, the exception being
KMS-5. Another monoclonal antibody (CD38), which also recognizes plasma cells, reponded to KMM-1, KMS-12-PE, and KSM-12-BM.
KMS-5 cells expressed acute lymphoblastic leukemia antigens (CALLA). These data suggest that such lines as KMM-1, KMS-11,
KMS-12-PE, and KMS-12-BM represent later stages of B-cell differentiation, and that KMS-5 represents a relatively early stage
of B-cell differentiation. All the cell lines lacked Epstein-Barr virus nuclear antigen, showed abnormal karyotypes of human
origin, and differed from each other in the isozyme patterns examined. Only KMS-5 was tumorigenic when transplanted subcutaneously
into nude mice. 相似文献
24.
Makoto Suematsu Shigenari Houzawa Soichiro Miura Hiroshi Nagata Tetsuji Kitahora Tetsuo Morishita Chikara Oshio Masaharu Tsuchiya 《Luminescence》1989,4(1):531-534
Reaction difference of oxyradical generation and luminol-dependent photoemission of zymosan- and phorbol ester-treated neutrophils were investigated using a conventional photomultiplier and ultrasensitive photonic imaging technique. Zymosan-treated cells released a concentrated photonic burst corresponding to the cellular distribution. In contrast, phorbol ester-treated cells produced a negligible level of photoemission, and the additional application of Ca2+ ionophore enhanced the photonic burst, which was gradually spread out into extracellular space. Serine protease inhibitors did not attenuate PMA-induced chemiluminescence but did attenuate zymosan-induced chemiluminescence. This suggests the involvement of serine protease in the respiratory burst of phagocytizing neutrophils. 相似文献
25.
Pyruvate, orthophosphate dikinase (EC 2.7.9.1
[EC]
) was activatedin the light and inactivated following a dark treatment in intactmaize mesophyll chloroplasts. Addition of catalase (100250units/ml) to the assay medium was necessary to obtain good activationand to keep the enzyme in an active state during illumination.Arsenate and carbonyl cyanide m-chlorophenyl-hydrazone, uncouplersof photophosphorylation, inhibited the activation. Pyruvate,which has been proposed to have a critical role in supportingthe light activation of pyruvate, orthophosphate dikinase, actuallyinhibited the activation. The pyruvate level in the chloroplastsuspension decreased when the enzyme was light-activated. Measurementsof adenylates and pyruvate in the chloroplasts indicated thatthe energy state of the chloroplasts was more important forthe light activation than was the level of pyruvate.
1Present address: Department of Biochemistry, Faculty of Science,Saitama University, 255, Shimo-Okubo, Urawa, 338 Japan
2Present address: National Institute of Agrobiological Resources,Yatabe, Tsukuba, Ibaraki, 305 Japan (Received May 2, 1989; Accepted October 2, 1989) 相似文献
26.
Masayoshi Takahashi Hiroshi Yokota Dai Ayusawa Michio Oishi Tetsuo Kunieda 《Biochemical genetics》1992,30(9-10):537-544
A novel restriction fragment length polymorphism (RFLP) in inbred rats was revealed by Southern blot analysis with a clone arbitrarily chosen from a rat genomic library as a probe. A clone named alpha 403 showed interstrain variations in the length of the EcoRI and HindIII fragments. The EcoRI fragments were either 0.7 or 3 kb, those of HindIII were either 4.5 or 5 kb, and three types were identified as combinations of those fragments in 20 inbred rat strains. These types segregated in backcross progeny as codominant alleles. The locus for the RFLP was thus named A403. Analysis of linkage between the RFLP locus and 13 other loci reveal that the A403 locus was closely linked to the Cs-1 locus (15 +/- 5.2%), which belongs to rat linkage group XIII. 相似文献
27.
Takashi Kamaishi Tetsuo Hashimoto Yoshihiro Nakamura Fuminori Nakamura Shigenori Murata Norihiro Okada Ken-ichi Okamoto Makoto Shimizu Masami Hasegawa 《Journal of molecular evolution》1996,42(2):257-263
Partial regions of the mRNA encoding a major part of translation elongation factor 1 (EF-1) from a mitochondrion-lacking protozoan,Glugea plecoglossi, that belongs to microsporidians, were amplified by polymerase chain reaction (PCR) and their primary structures were analyzed. The deduced amino acid sequence was highly divergent from typical EF-1's of eukaryotes, although it clearly showed a eukaryotic feature when aligned with homologs of the three primary kingdoms. Maximum likelihood (ML) analyses on the basis of six different stochastic models of amino acid substitutions and a maximum parsimony (MP) analysis consistently suggest that among eukaryotic species being analyzed,G. plecoglossi is likely to represent the earliest offshoot of eukaryotes. Microsporidians might be the extremely ancient eukaryotes which have diverged before an occurrence of mitochondrial symbiosis.
Sequence availability: The nucleotide sequence data reported here appear in the GSDB, DDBJ, EMBL, and NCBI databases with the accession number D32139 相似文献
28.
Effect of temperature and growth phase on fatty acid composition of the psychrophilic Vibrio sp. strain no. 5710 总被引:2,自引:0,他引:2
Tetsuo Hamamoto Nobuhisa Takata Toshiaki Kudo Koki Horikoshi 《FEMS microbiology letters》1994,119(1-2):77-81
Abstract The cellular fatty acid composition of the psychrophilic Vibrio sp. strain No. 5710 isolated from a deep-sea sediment sample was analyzed. The presence of docosahexaenoic acid (22:6) was demonstrated as found previously in other deep-sea bacteria, and the relative amount of 22:6 decreased as the growth temperature increased. A temperature shift from 10°C to 0°C resulted in a relative increase of 22:6, and an opposite shift led to a decrease. In addition, hexadecanoic acid (16:0) was found to increase as the growth temperature increased. Therefore, it is suggested that the adaptation of 5710 to the growth temperature was carried out by the changes in the relative amounts of 22:6 and 16:0. When 5710 was grown at low temperature, it increased the relative amount of 22:6 presumably to maintain membrane fluidity at that temperature. In contrast, 5710 grown at high temperature probably maintained the membrane fluidity by increasing the amount of a saturated fatty acid, 16:0. Furthermore, observation of the fatty acid compositions at mid-exponential phase and early stationary phase revealed the proportions of several fatty acids, including a major fatty acid, 9- cis -hexadecenoic acid (16:1c, palmitoleic acid), were affected by the growth phase which may be due to the physiological difference between the growth phases. 相似文献
29.
Tetsuo Hashimoto Eiko Otaka Jun Adachi Keiko Mizuta Masami Hasegawa 《Journal of molecular evolution》1993,36(3):282-289
Summary Using - and -hemoglobin sequences, we made a maximum likelihood inference as to the phylogenetic relationship among carnivores, including the two pandas, giant and lesser. Molecular phylogenetic studies up to 1985 had consistently indicated that the giant panda is more closely related to the bear than to the lesser panda. In 1986, however, a contradictory tree was constructed, using hemoglobins and so on, in which the two pandas link together (Tagle et al. 1986). In contrast to that tree, our conclusion supports the close relationship between bear and giant panda. The surface impression of a close relationship between the two pandas drawn from pairwise amino acid differences is explained by a rapid rate of hemoglobin evolution in the bear compared to that in the two pandas.Offprint requests to: T. Hashimoto 相似文献
30.