全文获取类型
收费全文 | 1442篇 |
免费 | 113篇 |
国内免费 | 3篇 |
出版年
2022年 | 8篇 |
2021年 | 14篇 |
2020年 | 15篇 |
2019年 | 10篇 |
2018年 | 18篇 |
2017年 | 21篇 |
2016年 | 26篇 |
2015年 | 46篇 |
2014年 | 41篇 |
2013年 | 64篇 |
2012年 | 101篇 |
2011年 | 90篇 |
2010年 | 49篇 |
2009年 | 46篇 |
2008年 | 73篇 |
2007年 | 84篇 |
2006年 | 73篇 |
2005年 | 69篇 |
2004年 | 77篇 |
2003年 | 71篇 |
2002年 | 68篇 |
2001年 | 40篇 |
2000年 | 52篇 |
1999年 | 32篇 |
1998年 | 16篇 |
1997年 | 18篇 |
1996年 | 16篇 |
1995年 | 11篇 |
1994年 | 7篇 |
1992年 | 21篇 |
1991年 | 27篇 |
1990年 | 24篇 |
1989年 | 23篇 |
1988年 | 18篇 |
1987年 | 18篇 |
1986年 | 15篇 |
1985年 | 17篇 |
1984年 | 19篇 |
1983年 | 14篇 |
1982年 | 17篇 |
1981年 | 22篇 |
1979年 | 4篇 |
1978年 | 5篇 |
1977年 | 5篇 |
1976年 | 4篇 |
1975年 | 5篇 |
1973年 | 7篇 |
1972年 | 6篇 |
1968年 | 3篇 |
1957年 | 3篇 |
排序方式: 共有1558条查询结果,搜索用时 46 毫秒
911.
Comparative antimicrobial activity, in vitro and in vivo, of soft N-chloramine systems and chlorhexidine. 总被引:1,自引:1,他引:0 下载免费PDF全文
Antimicrobial activity of the following four new N-chloramine compounds was evaluated: two chlorinated simple amino acids, a chlorinated half-ester of succinic acid, and a chlorinated half-ester of glutaric acid. For comparison, the known bactericidal agents 3-chloro-4,4-dimethyl-2-oxazolidinone and chlorhexidine were evaluated by the same procedure. The contact germicidal efficiency screen was used to examine the in vitro bactericidal activity of all six compounds in the absence and presence of 5% horse serum or 5% Triton X-100. The four new compounds were found to have greater germicidal activity than the other compounds tested and to exhibit low toxicity and skin irritation values. The in vivo bactericidal activity was evaluated in two studies. In the occlusion test, three of the four new compounds plus chlorhexidine diacetate were tested. The N-chloramines were significantly superior to chlorhexidine in preventing the expansion of the normal flora under occlusion. In the scrub test, a gloved-hand wash method was used to compare the antimicrobial effect of a 1% solution of the chlorinated half-ester of succinic acid in triacetin with that of a commercial germicidal hand wash containing 4% chlorhexidine gluconate. The two preparations exhibited essentially the same hand-degerming activity. 相似文献
912.
913.
The production of a cytotoxic factor by mouse peritoneal macrophages and macrophage hybridomas treated with various stimulating agents 总被引:1,自引:0,他引:1
Y Takeda M Higuchi M Sugimoto O Shimoda H J Woo S Shimada T Osawa 《Microbiology and immunology》1986,30(2):143-154
Murine peritoneal macrophages elicited with a streptococcal preparation, OK-432, produced as much of a cytotoxic factor after stimulation with lipopolysaccharide (LPS) as BCG-elicited macrophages did. Proteose peptone-elicited macrophages produced a very small amount, if any, of the factor, and resident peritoneal macrophages did not release it at all even after LPS-stimulation. A newly established macrophage hybridoma, D/O-3.3, produced the factor after LPS-stimulation, but another hybridoma, D/O-3.2, did not. Experiments using these peritoneal macrophages and macrophage hybridomas demonstrated that macrophages can be divided into three subpopulations with regard to stages of activation for production of the cytotoxic factor. The first is fully activated macrophages which produce the factor after stimulation with LPS or MAF-C alone, the second is partially activated macrophages which produce the factor only after stimulation with a combination of recombinant interferon-gamma (rIFN-gamma) and LPS or rIFN-gamma and macrophage activating factor for cytotoxicity (MAF-C), and the third is nonactivated macrophages which cannot produce the factor at all. 相似文献
914.
M Konishi K Wakabayashi S Kurihara H Higuchi N Onodera Y Umazume H Tanaka T Hamanaka Y Amemiya 《Biophysical chemistry》1991,39(3):287-297
Time-resolved X-ray equatorial diffraction studies on a single frog skeletal muscle fiber were performed with a 10 ms time resolution using synchrotron radiation in order to compare the time courses of the molecular changes of contractile proteins and the intracellular Ca2+ transient during an isometric twitch contraction at 2.7 degrees C. Measurements of the Ca2+ transient using aequorin as an intracellular Ca2+ indicator were conducted separately just before and after the X-ray experiments under very similar experimental conditions. The results, which showed a similar time course of tension to that observed in the X-ray experiment, were compared with the aequorin light signal, tension and the intensity changes of the 1,0 and 1,1 equatorial reflections. No appreciable change in both reflection spacings indicated that the effect of internal shortening of the muscle was minimized during contraction. The intensity change of the equatorial reflections generally occurred after the aequorin light signal. In the rising phase, the time course of increase in the 1,1 intensity paralleled that of the rise of the light signal and the intensity peak occurred 20-30 ms after the peak of the light signal. The decrease in the 1,0 intensity showed a time course similar to that of tension and the intensity minimum roughly coincided with the tension peak, coming at 80-90 ms and about 60 ms after the peaks of the light signal and the 1,1 intensity change, respectively. In the relaxation phase, the 1,1 intensity seemed to fall rapidly just before the tension peak and then returned to the original level in parallel with the decay of tension. The 1,0 intensity returned more slowly than the tension relaxation. Thus, the change of the 1,1 intensity was faster than that of the 1,0 intensity in both the rising and relaxation phases. When the measured aequorin light signal was corrected for the kinetic delay of the aequorin reaction with a first-order rate constant of either 50 or 17 s-1, the peak of the corrected light signal preceded that of the measured one by approx. 30 ms. Thus, the peak of the Ca2+ transient appeared earlier than the peaks of the 1,1 and 1,0 intensity changes by 50-60 and 110-120 ms, respectively. The time lag between the extent of structural change and the Ca2+ transient is discussed in relation to the double-headed attachment of a cross-bridge to actin. 相似文献
915.
Hidetaka Kamimura Hirokazu Sasaki Saburo Higuchi Yuichi Shiobara 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1982,229(2)
A method for the quantitative determination of the β-stimulant formoterol in urine, using a gas chromatograph—mass spectrometer, is described. Formoterol can be analyzed after the addition of a deuterium-labelled internal standard and conversion to a mixed bispentafluoropropionyl-methyl derivative for selected ion monitoring. The detection limit was 5 ng/ml.Urinalysis after the oral administration of formoterol fumarate, using a combined enzymic hydrolysis method, revealed that the drug was conjugated with glucuronic acid in rats, dogs and humans. 相似文献
916.
Takayoshi Higuchi 《Bioscience, biotechnology, and biochemistry》2013,77(7):667-673
A pronounced increase of the activity of phenylalanine deaminase and tyrase during the lignification of bamboo shoots was observed. With progressing maturation from the basal part to the upper part of immature bamboos the pattern of the activity of the enzymes moved toward the upper part of the tissues, where the most active lignification was taking place, and the amount of cinnamic acid derivatives in the tissues was found to be in good accordance with the activity of the enzymes. l-Phenylalanine-G-14C and l-tyrosine-G-14C were both well incorporated into the lignin of bamboos. These results indicate that phenylalanine deaminase and tyrase are synthesized progressively just before the lignification of the bamboos and by the enzymes l-phenylalanine and l-tyrosine are deaminated to cinnamic acid derivatives and incorporated into lignin. 相似文献
917.
Masako Higuchi Yutaka Ohtani Kazuo Iwai 《Bioscience, biotechnology, and biochemistry》2013,77(7):1847-1853
Winged bean acidic lectin was purified by DEAE-Sephadex A-50 and affinity chromatography on N-acetylgalactosamine-agarose gel. The purified lectin was a glycoprotein homogeneous on polyacrylamide gel electrophoresis, isoelectric focusing, and gel filtration. The molecular weight of the lectin was 52,000 by gel filtration, and SDS-polyacrylamide gel electrophoresis gave a single component of molecular weight of 27,000. Its isoelectric point was 5.5. The acidic lectin was rich in acidic amino acids, and contained 2mol of methionine but no cystine. It also agglutinated both trypsinized and untreated human erythrocytes (types A, B, AB and O), but not rabbit erythrocytes. The hemagglutination was inhibited by d-galactose and related sugars. Modification of the acidic lectin with N-bromosuccinimide caused a concomitant loss of the hemagglutinating activity with oxidation of tryptophan residue. The acidic lectin was immunologically different from the purified winged bean basic lectin by double immunodiffusion using antiserum raised against the basic lectin. 相似文献
918.
919.
Megu Gunji Masaki Fujita Hiroyoshi Higuchi 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》2013,199(8):703-709
Most birds show a characteristic head movement that consists of head stabilization and quick displacement. In this movement, which is analogous to saccadic eye movement in mammals, head stabilization plays an important role in stabilizing the retinal image. This head movement, called “head bobbing”, is particularly pronounced during walking. Previous studies focusing on anatomical and behavioral features have pointed out that visual information is also important for diving birds, indicating its significance in the head movements of diving birds. In the present study, the kinematic and behavioral features of head bobbing in diving little grebes were described by motion analysis to identify the head movement in diving birds. The results showed that head-bobbing stroke (HBS) consisted of a thrust phase and a hold phase as is typical for head bobbing during walking birds. This suggests that HBS is related to visual stabilization under water. In HBS, grebes tended to dive with longer stroke length and smaller stroke frequency than in non-bobbing stroke. This suggests that the behavior, which is related to vision, affects the kinematic stroke parameters. This clarification of underwater head movement will help in our understanding not only of vision, but also of the kinematic strategy of diving birds. 相似文献
920.
Daisuke Nobuoka Toshiaki Yoshikawa Mari Takahashi Tatsuaki Iwama Kazutaka Horie Manami Shimomura Shiro Suzuki Noriko Sakemura Munehide Nakatsugawa Hiroshi Sadamori Takahito Yagi Toshiyoshi Fujiwara Tetsuya Nakatsura 《Cancer immunology, immunotherapy : CII》2013,62(4):639-652
Antigen-specific cancer immunotherapy is a promising strategy for improving cancer treatment. Recently, many tumor-associated antigens and their epitopes recognized by cytotoxic T lymphocytes (CTLs) have been identified. However, the density of endogenously presented antigen-derived peptides on tumor cells is generally sparse, resulting in the inability of antigen-specific CTLs to work effectively. We hypothesize that increasing the density of an antigen-derived peptide would enhance antigen-specific cancer immunotherapy. Here, we demonstrated that intratumoral peptide injection leads to additional peptide loading onto major histocompatibility complex class I molecules of tumor cells, enhancing tumor cell recognition by antigen-specific CTLs. In in vitro studies, human leukocyte antigen (HLA)-A*02:01-restricted glypican-3144–152 (FVGEFFTDV) and cytomegalovirus495–503 (NLVPMVATV) peptide-specific CTLs showed strong activity against all peptide-pulsed cell lines, regardless of whether the tumor cells expressed the antigen. In in vivo studies using immunodeficient mice, glypican-3144–152 and cytomegalovirus495–503 peptides injected into a solid mass were loaded onto HLA class I molecules of tumor cells. In a peptide vaccine model and an adoptive cell transfer model using C57BL/6 mice, intratumoral injection of ovalbumin257–264 peptide (SIINFEKL) was effective for tumor growth inhibition and survival against ovalbumin-negative tumors without adverse reactions. Moreover, we demonstrated an antigen-spreading effect that occurred after intratumoral peptide injection. Intratumoral peptide injection enhances tumor cell antigenicity and may be a useful option for improvement in antigen-specific cancer immunotherapy against solid tumors. 相似文献