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71.
Phylogenetic analysis of the outer-membrane-protein genes of Chlamydiae, and its implication for vaccine development 总被引:9,自引:0,他引:9
Examination of 18 complete and 6 partial sequences of the major outer-
membrane protein from 24 chlamydiae isolates was used to reconstruct their
evolutionary relationships. From this analysis, assuming that the clades
with 100% bootstrap support are correct, come the following conclusions:
(1) The tree of these sequences is not congruent with the phylogeny of the
hosts, and thus host switching would seem to have occurred, thereby
limiting the extent to which there has been coevolution of parasite and
host. (2) The tree is also noncongruent with clustering by type of cell
infected, thereby limiting the extent to which there has been coevolution
of parasite and the cell type that it infects. (3) The tree is also
noncongruent with clustering by the organ infected (eyes or genitalia),
thereby limiting the extent to which there has been coevolution of parasite
and the organ that it infects. (4) The tree is also noncongruent with
genital strains arising from lymphogranuloma venereum strains. (5) The tree
is also noncongruent with the geographic site at which the isolates were
obtained, thereby limiting the extent of divergence explained by geographic
separation. (6) There are estimated to be 185 amino acid positions that are
invariable (as opposed to unvaried) in the major outer-membrane protein.
There are 10 unvaried positions in the variable domains, of which 9 appear
to be invariable, giving some reason to hope that development of a vaccine
might be possible. (7) The rate of change of this protein is too small to
see increased divergence over the time span of isolation of these genes,
giving hope to any vaccine having longevity. Bootstrapping supports those
portions of the tree on which the first five conclusions above depend. The
picture that these results provide is more one of pathogen versatility than
one of coevolutionary constraints. In addition, we examined 10 60-KDa,
outer-membrane protein- 2 genes, all but one of which were from these same
strains. The tree was not, among the trachomatis strains, congruent with
the major-outer- membrane protein tree, suggesting that gene exchange could
be occurring among strains. Moreover, there is an apparent slowdown in
divergence in this gene, among the trachomatis strains.
相似文献
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73.
Alternative splicing results in two distinct forms of the platelet-derived growth factor (PDGF) A-chain that differ by a hydrophilic carboxyl terminus consisting of 18 amino acids (A194-211). The functional significance of this region is unclear. Previous results indicate that a radioiodinated tyrosinated synthetic peptide corresponding to A194-211 binds specifically, saturably, and with low affinity to a large population of sites on Balb/c 3T3 and several other cell lines (Khachigian, L. M., Owensby, D. A., and Chesterman, C. N. (1992) J. Biol. Chem. 267, 1660-1666). In this paper, we report that (Y)A194-211 and A194-211 can modulate the cellular proliferative response to normal human serum and several individual polypeptide growth factors as a consequence. When these peptides were coincubated separately with whole serum, PDGF, epidermal growth factor, or fibroblast growth factor, DNA synthesis was inhibited in a dose-dependent fashion and maximally by 200 microM peptide. In addition, both peptides could attenuate the stimulation of cell division by serum and PDGF. Peptides with similar charge or length failed to modify the level of proliferation. These observations were not due to cytotoxicity. Synthetic peptides such as (Y)A194-211 and A194-211 that influence cellular proliferation may be useful in modulating the cellular response to selected growth factors. 相似文献
74.
PÉTER BIHARI BOTOND SIPOS GEORGE MELIKA BALÁZS FEHÉR KÁLMÁN SOMOGYI GRAHAM N. STONE ZSOLT PÉNZES 《Biological journal of the Linnean Society. Linnean Society of London》2011,102(4):750-764
Insect‐induced galls on plants comprise species‐rich but self‐contained communities of herbivores and natural enemies. In the present study, we focus on galls induced by cynipid gall wasps on oaks, and on the least‐known trophic level that these galls contain: inquilines. These insects, also cynipids, feed on gall tissue and are an abundant but taxonomically poorly understood part of an otherwise well‐studied system. We used DNA sequence data to examine spatial patterns in the genetic diversity of Synergus umbraculus Olivier 1791 (Hymenoptera: Cynipidae: Synergini), a widespread species attacking many host galls across the Western Palaearctic. Analysis of 239 cytochrome b sequences revealed eight haplogroups showing significant phylogeographic pattern across the Western Palaearctic, corresponding to putative glacial refugia in Iberia, Central Europe, Turkey, and Iran. There were significant genetic discontinuities across the Pyrenees and the Anatolian diagonal but no impact of the Alps, suggesting that significant discontinuities have biotic rather than physical causes. Detailed analysis of sites in the Carpathian Basin reveal a high diversity and low spatial structure, and identify Central Europe as the source of colonists for Quaternary colonization of Germany, France, and Britain. We found no evidence for host‐associated differentiation of S. umbraculus lineages associated with the most common cynipid host galls, suggesting frequent shifts within the host gall assemblage by inquiline lineages. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 102 , 750–764. 相似文献
75.
76.
ZSOLT PÉNZES GEORGE MELIKA ZOLTÁN BOZSÓKI PÉTER BIHARI ISTVÁN MIKÓ MAJID TAVAKOLI JULI PUJADE‐VILLAR BALÁZS FEHÉR DÁVID FÜLÖP KRISZTIÁN SZABÓ MIKLÓS BOZSÓ BOTOND SIPOS KÁLMÁN SOMOGYI GRAHAM N. STONE 《Systematic Entomology》2009,34(4):688-711
Several unanswered questions remain regarding the taxonomy and phylogeny of inquiline gallwasps (Cynipidae: Synergini), obligate inhabitants of plant galls induced primarily by other gallwasps (Cynipidae: Cynipini and Diplolepidini). Here we use morphological and molecular data to revise the inquiline genus Synophrus, members of which are notable for extensively modifying the structure of galls induced by oak gallwasp hosts on oaks in the section Cerris of Quercus subgenus Quercus in the Western Palaearctic. Previous taxonomic treatments have recognized three Western Palaearctic species of Synophrus: S. pilulae, S. politus and S. olivieri. Our results support the establishment of four additional Western Palaearctic species: Synophrus hungaricus sp.n. , S. libani sp.n. , S. syriacus sp.n. and S. hispanicus sp.n. We describe and diagnose these new taxa, analyse their phylogenetic relationships, and show that Synophrus inquilines are able to impose their own gall phenotypes on those of their hosts. We provide an updated key to Synophrus. 相似文献
77.
In the previous issue of Arthritis Research & Therapy, Ducourau and colleagues report that they retrospectively detected anti-infliximab antibodies in 21% of patients with rheumatic
diseases. Patients with anti-infliximab antibodies had lower serum drug concentrations. These findings contribute to the existing
evidence of immunogenicity of biologicals and its clinical relevance. We argue for therapeutic drug monitoring to optimize
treatment response. 相似文献
78.
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80.
Alexandre C Motta Joost LM Vissers Renée Gras Betty CAM Van Esch Antoon JM Van Oosterhout Martijn C Nawijn 《Respiratory research》2009,10(1):1-8