全文获取类型
收费全文 | 1984篇 |
免费 | 86篇 |
国内免费 | 2篇 |
出版年
2023年 | 5篇 |
2022年 | 15篇 |
2021年 | 17篇 |
2020年 | 13篇 |
2019年 | 25篇 |
2018年 | 18篇 |
2017年 | 34篇 |
2016年 | 32篇 |
2015年 | 57篇 |
2014年 | 75篇 |
2013年 | 126篇 |
2012年 | 109篇 |
2011年 | 116篇 |
2010年 | 83篇 |
2009年 | 99篇 |
2008年 | 134篇 |
2007年 | 116篇 |
2006年 | 125篇 |
2005年 | 130篇 |
2004年 | 126篇 |
2003年 | 109篇 |
2002年 | 111篇 |
2001年 | 17篇 |
2000年 | 17篇 |
1999年 | 19篇 |
1998年 | 23篇 |
1997年 | 21篇 |
1996年 | 17篇 |
1995年 | 9篇 |
1994年 | 19篇 |
1993年 | 26篇 |
1992年 | 20篇 |
1991年 | 20篇 |
1990年 | 19篇 |
1989年 | 24篇 |
1988年 | 8篇 |
1987年 | 11篇 |
1986年 | 12篇 |
1985年 | 16篇 |
1984年 | 13篇 |
1983年 | 7篇 |
1982年 | 16篇 |
1981年 | 13篇 |
1980年 | 6篇 |
1978年 | 4篇 |
1975年 | 4篇 |
1974年 | 6篇 |
1971年 | 3篇 |
1970年 | 4篇 |
1967年 | 4篇 |
排序方式: 共有2072条查询结果,搜索用时 15 毫秒
1.
Keiichi Tsuji 《Bioscience, biotechnology, and biochemistry》2013,77(6):1501-1503
The peptic hydrolysis of bovine β-lactoglobulin (β-Lg) was performed to establish the basis for producing a low-phenylalanine peptide rather than a free amino acid mixture for use in the dietetics of phenylketonuria. A 1% β-Lg solution (pH 1.5) was incubated with 0.01% pepsin at 37°C for 24 hr. The peptides produced were fractionated by high-performance liquid chromatograhy to analyze their constituent amino acids. Most of the major peptides were identified in the light of the primary structure of α-Lg to assign 31 cutting points in their protein molecule. These included cutting points at the carboxyl side of Phe-82, Phe-105 and Phe-136. This result suggests that further hydrolysis of the peptic hydrolysate of β-Lg with an exopeptidase, particularly with a carboxypeptidase, would be effective in liberating phenylalanine to produce a low-phenylalanine peptide mixture. 相似文献
2.
3.
Andreas M. Stadler Tobias Unruh Keiichi Namba Fadel Samatey Giuseppe Zaccai 《Biophysical journal》2013
The bacterial flagellar filament is a very large macromolecular assembly of a single protein, flagellin. Various supercoiled states of the filament exist, which are formed by two structurally different conformations of flagellin in different ratios. We investigated the correlation between supercoiling of the protofilaments and molecular dynamics in the flagellar filament using quasielastic and elastic incoherent neutron scattering on the picosecond and nanosecond timescales. Thermal fluctuations in the straight L- and R-type filaments were measured and compared to the resting state of the wild-type filament. Amplitudes of motion on the picosecond timescale were found to be similar in the different conformational states. Mean-square displacements and protein resilience on the 0.1 ns timescale demonstrate that the L-type state is more flexible and less resilient than the R-type, whereas the wild-type state lies in between. Our results provide strong support that supercoiling of the protofilaments in the flagellar filament is determined by the strength of molecular forces in and between the flagellin subunits. 相似文献
4.
5.
Seasonal and ontogenetic changes in natural development timewere studied for Eodiaptomus japonicus in Lake Biwa in 1986and 1987. Wild individuals in a certain developmental stagewere collected, fed on natural food and examined until theyhad moulted twice. Natural development times fluctuated irrespectiveof temperature from May to October. Food deficiency delayeddevelopment in all feeding stages, and food availability probablydetermined natural development time. Serious food limitationraised mortality in copepodid stage I. In November developmentwas delayed even with enough food. The development of E.japonicuswas almost isochronal except for a short prefeeding naupliarstage I and a long copepodid stage V. 相似文献
6.
Midori Hiramatsu Rei Edamatsu Shigeo Suzuki Masakazu Shimada Akitane Mori 《Neurochemical research》1990,15(8):821-825
Inbred mutant El mice are highly susceptible to convulsive seizures upon tossing stimulation. The levels of excitatory (e.g. glutamate and aspartate) and inhibitory amino acids [e.g. -aminobutyrate (GABA)] were examined in discrete regions of stimulated El mice [El(+)] non-stimulated El mice [El(-)] and ddY mice, which do not have convulsive disposition. In comparison with ddY, a general increased levels of aspartate, glutamate, glutamine, and taurine were detected in brain regions of El(-). The levels of GABA and glycine were almost the same in ddY and El(-). Compared to El(+), the levels of aspartate, glutamate, glutamine, and GABA in El(-) were either the same or higher. In the case of taurine and glycine, the levels in El(-) were either the same or lower than El(+). Alanine is special in that El(-) have a higher level than El(+) in hippocampus but lower in cerebellum. Furthermore, while marked changes were registered in several brain regions, none of the amino acids investigated showed any significant differences in the hypothalamus of three different groups of mice. 相似文献
7.
M Hiramatsu M Kashimata N Minami A Sato M Murayama N Minami 《Biochemistry international》1988,17(2):311-317
Castration of adult male mice caused a marked reduction in the amount of immunoreactive epidermal growth factor (EGF) in the ventral prostate, and the treatment of such castrated mice with testosterone increased the EGF level significantly. Gel filtration of prostate extract showed that the immunoreactive EGF in the prostate had the same molecular weight (6,045) as the submandibular gland EGF. Moreover, its isoelectric point (pH 4.5) was almost similar to that (pH 4.55) of the submandibular gland peptide. These results suggest that under the control of androgens, mouse ventral prostate synthesizes EGF structurally and functionally identical to the submandibular gland EGF. 相似文献
8.
Isogai Akira; Takayama Seiji; Shiozawa Hideyuki; Tsukamoto Chise; Kanbara Takeshi; Hinata Kokichi; Okazaki Keiichi; Suzuki Akinori 《Plant & cell physiology》1988,29(8):1331-1336
S-Glycoproteins (S-locus-specific glycoproteins) in Brassicaspecies are present only in stigmas and thought to play an importantrole in self-incompatibility system. The stigma extract containsalso several other glycoproteins reacting with the antiserumto S-glycoproteins, among which some glycoproteins from S8S8-and S9S9-homozygotes have the same pI value. Both of the glycoproteinswhich were tentatively termed NS8- and NS8S9-glycoproteins,respectively, were isolated and analyzed. Those were revealedto be identical. Its amino acid sequence was homologous withthe S-glycoproteins in Brassica species. The NS-glycoproteinswere expressed at the same time and only in stigma as S-glycoproteins. (Received July 19, 1988; Accepted September 7, 1988) 相似文献
9.
Indu S. Ambudkar Timothy Lockwich Yukiharu Hiramatsu Bruce J. Baum 《Molecular and cellular biochemistry》1992,114(1-2):73-77
Conclusions While it is generally accepted that Ca2+ plays an important regulatory role in the physiology of a number of non-excitable cells, the mechanisms which regulate intracellular [Ca2+ are far from well established. Ca2+ transporting mechanisms which distribute Ca2+ intracellularly as well as those which allow influx of extracellular Ca2+ are involved in mediating intracellular Ca2+ homestasis. In this paper we have described recent studies on the regulation of the Ca2+ influx system in the data, it appears that the process of Ca2+ entry is extremely complex and may involve several levels of regulation. Understanding the molecular basis of these regulatory mechanisms presents a challeging problem for future studies. 相似文献
10.
Keiichi Matsuura 《Ichthyological Research》1986,33(3):223-224
A new sharpnose pufferfish,Canthigaster flavoreticulata, is described on the basis of two specimens collected from the Tonga Submarine Ridge in the South Pacific. This species is distinguished from other congeners by having many wavy yellow lines on the dorsal half of the body. 相似文献