全文获取类型
收费全文 | 90篇 |
免费 | 13篇 |
出版年
2022年 | 1篇 |
2021年 | 4篇 |
2020年 | 1篇 |
2018年 | 1篇 |
2017年 | 3篇 |
2015年 | 3篇 |
2014年 | 1篇 |
2013年 | 3篇 |
2012年 | 6篇 |
2011年 | 2篇 |
2010年 | 4篇 |
2009年 | 7篇 |
2008年 | 5篇 |
2007年 | 6篇 |
2006年 | 4篇 |
2005年 | 2篇 |
2003年 | 2篇 |
2002年 | 2篇 |
2001年 | 1篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1998年 | 6篇 |
1997年 | 2篇 |
1995年 | 4篇 |
1993年 | 1篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1984年 | 2篇 |
1982年 | 1篇 |
1981年 | 4篇 |
1979年 | 1篇 |
1978年 | 3篇 |
1972年 | 1篇 |
1971年 | 2篇 |
1970年 | 2篇 |
1968年 | 2篇 |
1966年 | 1篇 |
1965年 | 1篇 |
1963年 | 1篇 |
排序方式: 共有103条查询结果,搜索用时 296 毫秒
91.
We report here the structural determination of N-linked oligosaccharides
found on extracellular hemoglobins of the hydrothermal vent tube worm
Riftia pachyptila. Structures were elucidated by a combination of
electrospray ionization tandem mass spectrometry, matrix- assisted laser
desorption/ionization mass spectrometry, normal-phase high performance
liquid chromatography, and exoglycosidase digestion. The sugar chains were
found to consist mainly of high-mannose-type glycans with some structures
partially capped by one or two terminal glucose residues. The present study
represents the first report of the occurrence of glucose capping of
N-linked carbohydrates in a secreted glycoprotein of a metazoan.
Previously, glucose capping has only been described for a membrane-bound
surface glycoprotein from the unicellular parasite Leishmania mexicana
amazonensis.
相似文献
92.
MOTIVATION: Searching a protein sequence database for homologs is a
powerful tool for discovering the structure and function of a sequence. Two
new methods for searching sequence databases have recently been described:
Probabilistic Smith-Waterman (PSW), which is based on Hidden Markov models
for a single sequence using a standard scoring matrix, and a new version of
BLAST (WU-BLAST2), which uses Sum statistics for gapped alignments.
RESULTS: This paper compares and contrasts the effectiveness of these
methods with three older methods (Smith- Waterman: SSEARCH, FASTA and
BLASTP). The analysis indicates that the new methods are useful, and often
offer improved accuracy. These tools are compared using a curated (by Bill
Pearson) version of the annotated portion of PIR 39. Three different
statistical criteria are utilized: equivalence number, minimum errors and
the receiver operating characteristic. For complete-length protein query
sequences from large families, PSW's accuracy is superior to that of the
other methods, but its accuracy is poor when used with partial-length query
sequences. False negatives are twice as common as false positives
irrespective of the search methods if a family-specific threshold score
that minimizes the total number of errors (i.e. the most favorable
threshold score possible) is used. Thus, sensitivity, not selectivity, is
the major problem. Among the analyzed methods using default parameters, the
best accuracy was obtained from SSEARCH and PSW for complete-length
proteins, and the two BLAST programs, plus SSEARCH, for partial-length
proteins.
相似文献
93.
Although intermediates have long been recognised as fascinating species that form during the folding of large proteins, the role that intermediates play in the folding of small, single-domain proteins has been widely debated. Recent discoveries using new, sensitive methods of detection and studies combining simulation and experiment have now converged on a common vision for folding, involving intermediates as ubiquitous stepping stones en route to the native state. The results suggest that the folding energy landscapes of even the smallest proteins possess significant ruggedness in which intermediates stabilized by both native and non-native interactions are common features. 相似文献
94.
Motomi Ito Kuniaki Watanabe Yoko Kita Takayuki Kawahara DJ Crawford Tetsukazu Yahara 《Journal of plant research》2000,113(1):79-89
Eupatorium were examined by sequencing the internal transcribed spacers (ITS) of nuclear ribosomal DNA and restriction site analysis
of chloroplast DNA. Molecular data provided strong evidence that (1) this genus originated in North America, (2) the genus
diverged into three morphological species groups, Eutrochium, Traganthes and Uncasia in North America, and (3) one of the North American Uncasia lineages migrated into temperate Europe and eastern Asia over the Bering land bridge. The estimated divergence times support
a late Miocene to early Pliocene migration from North America to Eurasia via the Bering land bridge. A European species was
sister to all of the eastern Asian species examined. The disjunct distribution pattern of the genus Eupatorium is incongruent with the classical Arcto-Tertiary geoflora concept.
Received 13 September 1999/ Accepted in revised form 4 January 2000 相似文献
95.
Several studies have indicated that olfactory responses are impeded by
amiloride. Therefore, it was of interest to see whether, and if so which,
olfactory epithelial cellular compartments have amiloride- sensitive
structures. Using ultrastructural methods that involved rapid freezing,
freeze-substitution and low temperature embedding of olfactory epithelia,
this study shows that, in the rat, this tissue is immunoreactive to
antibodies against amiloride sensitive Na(+)- channels. However, microvilli
of olfactory supporting cells, as opposed to receptor cilia, contained most
of the immunoreactive sites. Apices from which the microvilli sprout and
receptor cell dendritic knobs had much less if any of the
amiloride-antibody binding sites. Using a direct ligand-binding
cytochemical method, this study also confirms earlier ones that showed that
olfactory receptor cell cilia have Na+, K(+)-ATPase. It is proposed that
supporting cell microvilli and the receptor cilia themselves have
mechanisms, different but likely complementary, that participate in
regulating the salt concentration around the receptor cell cilia. In this
way, both structures help to provide the ambient mucous environment for
receptor cells to function properly. This regulation of the salt
concentration of an ambient fluid environment is a function that the
olfactory epithelium shares with cells of transporting epithelia, such as
those of kidney.
相似文献
96.
A method is described for estimating cell-cycle parameters from experimental fraction-of-labeled-mitoses measurements. The
method is closely related to that of J. C. Barrett (1970) but is based on the analysis of Brockwell and Trucco (1970) which
takes into account population growth in the calculation of theoreticalFLM-functions. Several sets of experimental data are analyzed, among them the data for the Marshall tumor considered by Barrett.
It is found that population growth has a small but nevertheless detectable effect on the estimates of the cell parameters.
Work performed under the auspices of the United States Atomic Energy Commission.
this paper was completed after the untimely death of Dr. Trucco. 相似文献
97.
J. Brockwell 《Plant and Soil》1971,35(1):265-272
Summary Two field experiments on symbiotic nitrogen fixation by nodulated legumes are described, one relatively complex in design
and the other very simple. An appraisal has been made of the feasibility of each experiment as a model for world-wide trials
intended to provide data about the contribution to nitrogen fixation by useful legumes that can be made by indigenous strains
of Rhizobium. It is concluded that more extensive use will be made of the trial and the necessary information secured if the
model is of simple design. 相似文献
98.
Transgenic Research - 相似文献
99.
100.