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Clara Prez‐Peinado Susana A. Dias Diogo A. Mendona Miguel A.R.B. Castanho Ana S. Veiga David Andreu 《Journal of peptide science》2019,25(8)
Ctn[15‐34], a downsized version of the snake venom cathelicidin‐like peptide crotalicidin (Ctn), shows an unusually high lifespan (t1/2, approximately 12 h) in human serum, which significantly adds to its promise as an antimicrobial and antitumor agent. Herein we investigate the role of Ctn[15‐34] structure on serum survival. Using a set of analogs, we show that C‐terminal amidation, as well as the specific layout of the Ctn[15‐34] sequence—a helical N‐terminal domain followed by a hydrophobic domain—is crucial for slow degradation, and any change in their arrangement results in significantly lower t1/2. Aside from the privileged primary structure, features such as self‐aggregation can be ruled out as causes for the long serum life. Instead, studies in other protease‐rich fluids suggest a key role for certain human serum components. Finally, we demonstrate that Ctn[15‐34] is able to induce bacterial death even after 12‐hour pre‐incubation in serum, in agreement with the proteolytic data. Altogether, the results shed light on the uncommon stability of Ctn[15‐34] in human serum and confirm its potential as an anti‐infective lead. 相似文献
84.
A covariotide model explains apparent phylogenetic structure of oxygenic photosynthetic lineages 总被引:17,自引:13,他引:4
Lockhart PJ; Steel MA; Barbrook AC; Huson DH; Charleston MA; Howe CJ 《Molecular biology and evolution》1998,15(9):1183-1188
The aims of the work were (1) to develop statistical tests to identify
whether substitution takes place under a covariotide model in sequences
used for phylogenetic inference and (2) to determine the influence of
covariotide substitution on phylogenetic trees inferred for photosynthetic
and other organisms. (Covariotide and covarion models are ones in which
sites that are variable in some parts of the underlying tree are invariable
in others and vice versa.) Two tests were developed. The first was a
contingency test, and the second was an inequality test comparing the
expected number of variable sites in two groups with the observed number.
Application of these tests to 16S rDNA and tufA sequences from a range of
nonphotosynthetic prokaryotes and oxygenic photosynthetic prokaryotes and
eukaryotes suggests the occurrence of a covariotide mechanism. The degree
of support for partitioning of taxa in reconstructed trees involving these
organisms was determined in the presence or absence of sites showing
particular substitution patterns. This analysis showed that the support for
splits between (1) photosynthetic eukaryotes and prokaryotes and (2)
photosynthetic and nonphotosynthetic organisms could be accounted for by
patterns arising from covariotide substitution. We show that the additional
problem of compositional bias in sequence data needs to be considered in
the context of patterns of covariotide/covarion substitution. We argue that
while covariotide or covarion substitution may give rise to
phylogenetically informative patterns in sequence data, this may not always
be so.
相似文献
85.
Summary The maltose utilization system of Candida utilis was affected by glucose through two different mechanisms: catabolite repression and inactivation. Maltose permease was under the control of both, whereas -glucosidase was only repressed.In glucose-maltose continuous culture, both sugars were consumed simultaneously at glucose steady-state concentrations in the fermentor below 100 mg/l, corresponding to dilution rates lower than 0.4 h-1. At higher dilution rates, and consequently higher glucose concentrations, repression increased steeply, being complete when glucose concentration reached 170 mg/l.Glucose induced inactivation of maltose permease, in maltose-growing and resting cells, by decreasing V
max, without changing maltose affinity for its transport system. The inactivation process apparently required the entrance of the inactivator into the cell and its subsequent phosphorylation because: 1) The specific inactivation rate showed a dependence on glucose similar to that of glucose transport and 2) only rapidly phosphorylated glucose analogues could mimic the inactivation effect. 相似文献
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Data from population- and clinic-based epidemiologic studies of rheumatoid arthritis patients suggest that individuals with
rheumatoid arthritis are at risk for developing clinically evident congestive heart failure. Many established risk factors
for congestive heart failure are over-represented in rheumatoid arthritis and likely account for some of the increased risk
observed. In particular, data from animal models of cytokine-induced congestive heart failure have implicated the same inflammatory
cytokines produced in abundance by rheumatoid synovium as the driving force behind maladaptive processes in the myocardium
leading to congestive heart failure. At present, however, the direct effects of inflammatory cytokines (and rheumatoid arthritis
therapies) on the myocardia of rheumatoid arthritis patients are incompletely understood. 相似文献
88.
Determinants of Readiness for Adopting Healthy Lifestyle Behaviors Among Indigenous Adolescents with Type 2 Diabetes in Manitoba,Canada: A Cross‐Sectional Study 下载免费PDF全文
89.
M. Peinado F. Alcaraz J. Delgadillo M. De La Cruz J. Alvarez J. L. Aguirre 《Plant Ecology》1994,110(1):55-66
A comparative study of the North American salt marshes between Magdalena Plain (Baja California, 24° N)_and the north of San Francisco (California 38° N) is made in order to establish relationships between floristic and zonal gradients. The sigmatistic-phytosociological method along with Average Linkage Clustering are used to describe the zonation of these salt marshes and to define the optimum zone of several halophilous plants and communities.Abbreviations (As)
Arthrocnemum subterminalis
- (Ds)
Distichlis spicata
- (Fg)
Frankenia salina
- (Jc)
Jaumea carnosa
- (MI)
Monanthochloe littoralis
- (S1)
Sarcocornia pacifica, prostrate biotype
- (S2)
Sarcocornia pacifica, erect biotype
- (Sp)
Spartina foliosa 相似文献
90.