全文获取类型
收费全文 | 160篇 |
免费 | 29篇 |
出版年
2018年 | 2篇 |
2016年 | 2篇 |
2015年 | 5篇 |
2014年 | 5篇 |
2013年 | 9篇 |
2012年 | 2篇 |
2011年 | 7篇 |
2010年 | 1篇 |
2009年 | 5篇 |
2008年 | 9篇 |
2007年 | 5篇 |
2006年 | 5篇 |
2005年 | 6篇 |
2004年 | 5篇 |
2003年 | 4篇 |
2002年 | 1篇 |
2001年 | 6篇 |
2000年 | 10篇 |
1999年 | 3篇 |
1998年 | 6篇 |
1997年 | 3篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1994年 | 4篇 |
1992年 | 4篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 5篇 |
1988年 | 7篇 |
1987年 | 1篇 |
1986年 | 7篇 |
1985年 | 2篇 |
1984年 | 4篇 |
1983年 | 7篇 |
1982年 | 2篇 |
1980年 | 4篇 |
1979年 | 2篇 |
1978年 | 4篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1972年 | 4篇 |
1971年 | 3篇 |
1970年 | 2篇 |
1969年 | 1篇 |
1963年 | 1篇 |
1957年 | 1篇 |
1930年 | 1篇 |
排序方式: 共有189条查询结果,搜索用时 678 毫秒
71.
K H Lue R P Lauener R J Winchester R S Geha D Vercelli 《Journal of immunology (Baltimore, Md. : 1950)》1991,147(4):1134-1138
We have recently shown that engagement of the human monocytic Ag CD14 by murine mAb induces lymphocyte function-associated antigen-1/intercellular adhesion molecule-1-dependent homotypic adhesion. To determine whether CD14 plays a role in monocyte-T cell interactions, we tested the effect of anti-CD14 mAb on the proliferation of human T cells. Our results show that anti-CD14 mAb strongly inhibited T cell proliferation induced by Ag, anti-CD3 mAb, and mitogenic lectins. Inhibition by anti-CD14 mAb was epitope-dependent and required physical contact between monocytes and T cells. CD14 engagement did not affect IL-2R expression or IL-2 synthesis but induced a state of unresponsiveness that was not IL-2 specific; proliferation of anti-CD3-activated T cell blasts in response to both IL-2 and IL-4 was abrogated by addition of monocytes preincubated with anti-CD14 mAb. Inhibition of T cell proliferation after engagement of CD14 on monocytes was likely to result from delivery of a negative signal to T cells, rather than from disruption of a costimulatory monocyte-derived signal, because incubation of monocytes with anti-CD14 mAb also inhibited monocyte-independent T cell proliferation induced by PMA and ionophore. These results, together, point to a role of CD14 in the monocyte-dependent regulation of T cell proliferation. 相似文献
72.
NZB mice which were already producing anti-erythrocyte autoantibodies were not able to respond to their own liver F antigen, thus providing evidence that their autoimmunity is not caused by a generalized breakdown in self-tolerance mechanisms. The specificity of autoantibodies produced in the spontaneous hemolytic anemia was different from that of antierythrocyte antibodies induced in normal mice and in young NZB mice by injections of rat erythrocytes. This indicates that the B-cell clones which can be triggered by heterologous antigen are different from those responsible for the NZB disease; the latter clones may not exist in normal mice. 相似文献
73.
The structural basis of the inhibition of human glycosidases by castanospermine analogues.
下载免费PDF全文
![点击此处可从《The Biochemical journal》网站下载免费的PDF全文](/ch/ext_images/free.gif)
B G Winchester I Cenci di Bello A C Richardson R J Nash L E Fellows N G Ramsden G Fleet 《The Biochemical journal》1990,269(1):227-231
A series of epimers and deoxy derivatives of castanospermine has been synthesized to investigate the contribution of the different chiral centres to the specificity and potency of inhibition of human liver glycosidases. Castanospermine inhibits all forms of alpha- and beta-D-glucosidases, but alteration to any of the five chiral centres in castanospermine markedly decreases the inhibition. 6-Epicastanospermine, which is related to D-pyranomannose in the same way as castanospermine is to D-pyranoglucose, does not inhibit lysosomal (acidic) alpha-mannosidase, but is a good inhibitor of the cytosolic or neutral alpha-mannosidase. Conversely, 1-deoxy-6-epicastanospermine inhibits acidic alpha-mannosidase strongly, but not the neutral alpha-mannosidase. An explanation of this different inhibition based on preferential recognition of different configurations of mannose by the different forms of alpha-mannosidase is postulated. All derivatives of 6-epicastanospermine also have the minimum structural feature for the inhibition of alpha-L-fucosidase, but those with a beta-anomeric substituent do not inhibit the enzyme, or do so very weakly. 1-Deoxy-6,8a-diepicastanospermine, which has four chiral centres identical with alpha-L-fucose, is, however, a potent inhibitor of alpha-L-fucosidase (Ki 1.3 microM). 相似文献
74.
A. Medina P. R. F. Bell J. D. Briggs J. J. Brown A. Fine A. F. Lever J. J. Morton A. M. Paton J. I. S. Robertson M. Tree M. A. Waite R. Weir J. Winchester 《BMJ (Clinical research ed.)》1972,4(5842):694-696
Circulating levels of renin, angiotensin I, and angiotensin II were increased in six patients with chronic renal failure and hypertension uncontrolled by dialysis and hypotensive drugs. Lower and often normal levels were found in 10 patients whose blood pressure was controlled by dialysis treatment. For a variety of reasons all patients were subjected to bilateral nephrectomy. The logarithm of the decrease in plasma concentrations of renin and angiotensin II was significantly related to the fall of blood pressure after operation. Plasma renin concentration correlated significantly with blood angiotensin I concentration and with plasma angiotensin II in samples taken before and after nephrectomy. Renin, angiotensin I, and angiotensin II were measurable in samples of blood taken 48 hours or more after the operation. 相似文献
75.
L E Ramsay M H Ramsay J Hettiarachchi D L Davies J Winchester 《BMJ (Clinical research ed.)》1978,2(6132):244-245
Forty-nine hypertensive patients who were overweight were randomly allocated to one of three strategies for attaining weight reduction and were followed for one year. Those referred to a dietitian lost more weight (mean 5.1 kg) than those given a diet sheet (mean 2.64 kg) or simply advised by the doctor to reduce weight (mean 2.15 kg). One-third of all the patients lost 6 kg or more. Successful weight loss was associated with a highly significant and substantial improvement in blood pressure control and with less frequent increases in antihypertensive treatment. 相似文献
76.
M Ferrarini T Hoffman S M Fu R Winchester H G Kunkel 《Journal of immunology (Baltimore, Md. : 1950)》1977,119(4):1525-1529
A receptor for IgM was demonstrated on the surface of human B lymphocytes by using a rosette technique with ox erythrocytes coated with rabbit IgM antibody (EAM). Lymphocytes forming rosettes with EAM did not bind sheep red cells, had membrane Ia-like antigens and, in some instances, surface immunoglobulin. The specificity of EAM rosettes was confirmed by inhibition experiments with purified human Ig. IgM but not IgG molecules inhibited the rosette reaction. In addition, inhibition of EAM rosettes with IgM fragments showed that the receptor has affinity for a part of the molecule located in the Fc portion. By analogy with the receptors previously found on certain human T cells, receptors for IgM were not detected on freshly isolated B cells, but were expressed after overnight culture in IgM-free media. Studies on different human lymphoid tissues showed that IgM receptors are expressed on a limited percentage of both circulating and noncirculating B cells. In addition to normal B cells, the malignant B cells of a majority of cases of chronic lymphocytic leukemia expressed the receptors for IgM. 相似文献
77.
Winchester JB Erickson TM Blaak JB McBride JM 《Journal of strength and conditioning research / National Strength & Conditioning Association》2005,19(1):177-183
The purpose of this study was to investigate the direction and magnitude of kinematic changes in bar path and kinetic variable changes in the power clean (PC) after 4 weeks of PC training. Eighteen healthy adult men who had a minimum of 1 year of previous experience in the PC participated as subjects in this study. The subjects were pretested for their 1 repetition maximum (1RM) and provided with visual and verbal cues during PC training sessions, which took place 3 times per week for 4 weeks. Variables measured during data collection include pre- and post-peak force, peak power, and several bar-path kinematic variables through videography at 50, 70, and 90% of the subjects' pre-1RM. Peak force was improved at 50% of 1RM from 936 +/- 338 N to 1,299 +/- 384 N, at 70% from 1,216 +/- 315 N to 1,395 +/- 331 N, and at 90% from 1,255 +/- 329 N to 1,426 +/- 321 N. Peak power was increased at 50% of 1RM from 3,430 +/- 1,280 W to 4,230 +/- 1,326 W. All variables with respect to bar-path kinematics were improved significantly. These results indicate that both kinematic and kinetic variables improve through training and feedback. It is possible that persons beginning the PC exercise or coaches who provide instruction on the PC to beginning lifters should focus on proper bar path during the movement. This may result in force and power output to develop as technique improves. However, further investigation is required to establish the link between bar-path changes and kinetic variable performance improvements. 相似文献
78.
79.
Positive selection and sequence rearrangements generate extensive polymorphism in the gamete recognition protein bindin 总被引:27,自引:12,他引:15
Bindin is a gamete recognition protein of sea urchins that mediates
species-specific attachment of sperm to an egg-surface receptor during
fertilization. Sequences of bindin from closely related urchins show fixed
species-specific differences. Within species, highly polymorphic bindin
alleles result from point substitution, insertion/deletion, and
recombination. Since speciation, positive selection favoring allelic
variants has generated diversity in bindin polypeptides. Intraspecific
bindin variation can be tolerated by the egg receptor, which suggests
functional parallels between this system and other flexible recognition
systems, including immune recognition. These results show that polymorphism
in mate recognition loci required for rapid evolution of sexual isolation
can arise within natural populations.
相似文献
80.
The molecular evolution of the alcohol dehydrogenase and alcohol dehydrogenase-related genes in the Drosophila melanogaster species subgroup 总被引:5,自引:0,他引:5
The DNA sequences of the Adh genes of three members of the Drosophila
melanogaster species subgroup have been determined. This completes the Adh
sequences of the eight species of this subgroup. Two species, D. yakuba and
D. teissieri, possess processed Adh pseudogenes. In all of the species of
the subgroup, a gene of unknown function, Adhr, is located about 300 bp 3'
to Adh. Although this gene is experiencing a higher rate of synonymous
substitution than Adh, it is more constrained at the amino acid level.
Phylogenetic relationships between all eight members of the melanogaster
subgroup have been analyzed using a variety of methods. All analyses
suggested that the D. yakuba and D. teissieri pseudogenes have a single
common ancestor, rather than evolving independently in each species, and
that D. melanogaster is the sister species to D. simulans, D. sechellia,
and D. mauritiana. The evolutionary relationships of the latter three
species remain equivocal.
相似文献