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31.
Mariele Porto Carneiro Le?o Patricia Vieira Tiago Fernando Dini Andreote Welington Luiz de Araújo Neiva Tinti de Oliveira 《Genetics and molecular biology》2015,38(1):86-92
The entomopathogenic fungi of the genus Metarhizium have several
subtilisin-like proteases that are involved in pathogenesis and these have been used
to investigate genes that are differentially expressed in response to different
growth conditions. The identification and characterization of these proteases can
provide insight into how the fungus is capable of infecting a wide variety of insects
and adapt to different substrates. In addition, the pr1A gene has
been used for the genetic improvement of strains used in pest control. In this study
we used quantitative RT-PCR to assess the relative expression levels of the
pr1A gene in M. anisopliae and M.
acridum during growth in different culture conditions and during
infection of the sugar cane borer, Diatraea saccharalis Fabricius.
We also carried out a pathogenicity test to assess the virulence of both species
against D. saccharalis and correlated the results with the pattern
of pr1A gene expression. This analysis revealed that, in both
species, the pr1A gene was differentially expressed under the growth
conditions studied and during the pathogenic process. M. anisopliae
showed higher expression of pr1A in all conditions examined, when
compared to M. acridum. Furthermore, M. anisopliae
showed a greater potential to control D. saccharalis. Taken
together, our results suggest that these species have developed different strategies
to adapt to different growing conditions. 相似文献
32.
Mechanical clearing of understory vegetation is increasingly used in Euro-Mediterranean forests to reduce fire hazard, yet
its long-term consequences for biodiversity remain poorly understood. This study analysed the influence of time since understory
management and management frequency, on herbaceous species richness, cover and composition, functional richness and composition,
and richness and cover within functional groups (life and growth forms, dispersal strategy, clonality, and plant height),
using a chronosequence of cork oak (Quercus suber) stands spanning about 70 years. Overall species richness was virtually constant over time, but the richness of species with
annual life form and plasticity in height was much higher in recently and recurrently treated stands; the opposite was found
for perennial (mainly hemicryptophytes and chamaephytes), tussock-forming and clonal species richness, and functional richness.
Overall herbaceous cover and that of annual, semi-basal, non-clonal and plastic species (in height) were favoured by recent
and recurrent fuel treatments; cover by perennial (hemicryptophytes and chamaephytes), short basal, tussock-forming, and clonal
species tended to increase for >10–20 years after management, and declined with management frequency. There was a marked shift
in species and functional composition associated with time since understory management and management frequency. These findings
suggest that widespread fuel management at <10 year intervals may shift understory herb communities to early-successional
stages, impairing the persistence of species and functional groups recovering slowly after disturbance. Fuel management needs
to balance the dual goals of fire hazard reduction and biodiversity conservation, retaining undisturbed patches in landscapes
otherwise managed to reduce fuel accumulation. 相似文献
33.
Scarlet Nere Ortega Marcia Nitschke Ana Maria Mouad Maria Diva Landgraf Maria Olímpia Oliveira Rezende Mirna Helena Regali Seleghim Lara Durães Sette André Luiz Meleiro Porto 《Biodegradation》2011,22(1):43-50
The fungi Aspergillus sydowii Ce15, Aspergillus sydowii Ce19, Aspergillus sydowii Gc12, Bionectria sp. Ce5, Penicillium miczynskii Gc5, Penicillium raistrickii Ce16 and Trichoderma sp. Gc1, isolated from marine sponges Geodia corticostylifera and Chelonaplysylla erecta, were evaluated for their ability to grow in the presence of DDD pesticide. Increasing concentrations of DDD pesticide, i.e.,
5.0 mg (1.56 × 10−12 mmol), 10.0 mg (3.12 × 10−2 mmol) and 15.0 mg (4.68 × 10−2 mmol) in solid and liquid culture media were tested. The fungi Trichoderma sp. Gc1 and Penicillium miczynskii Gc5 were able to grow in the presence of up to 15.0 mg of DDD, suggesting their potential for biodegradation. A 100% degradation
of DDD was attained in liquid culture medium when Trichoderma sp. Gc1 was previously cultivated for 5 days and supplemented with 5.0 mg of DDD in the presence of hydrogen peroxide. However,
the quantitative analysis showed that DDD was accumulated on mycelium and biodegradation level reached a maximum value of
58% after 14 days. 相似文献
34.
Fernanda Errero Porto Ana Luiza de Brito Portela-Castro Isabel Cristina Martins-Santos 《Ichthyological Research》2011,58(3):225-231
Cytogenetic analysis in three Rineloricaria pentamaculata populations revealed diploid number 2n = 56 chromosomes, karyotype formula 8m/sm + 48st/a and FN = 64. Owing to the presence of the heteromorphic chromosome pair
with a big submetacentric chromosome and a small acrocentric one in both males and females, 42.9% of specimens in the Tauá
Stream population had the karyotype formula 9m/sm + 47st/a and FN = 65. Analysis of the nucleolus-organizing region by Ag-NOR
and FISH techniques showed a single NOR system at pair 5 for R. pentamaculata populations of the Keller River and the Tauá Stream. However, specimens of populations of the Tatupeba Stream had multiple
NOR systems at pairs 5 and 8. A constitutive heterochromatin pattern in R. pentamaculata is mainly distributed in the pericentromeric and telomeric regions with interstitial markers in certain chromosomes. Heterochromatin
is located in the telomeric and centromeric positions of the acrocentric chromosome in the heteromorphic pair of the Tauá
Stream population. In the submetacentric chromosome the markings are located in the telomeric (short arm), pericentomeric
and interstitial (long arm) positions. The origins of polymorphisms are discussed. 相似文献
35.
Carolina A. Lima José L. Lima Filho Benício B. Neto Attilio Converti Maria G. Carneiro da Cunha Ana L. F. Porto 《Biotechnology and Bioprocess Engineering》2011,16(3):549-560
A 24 full factorial design was used to identify the main effects and interactions of the initial medium pH, soybean flour concentration,
temperature and orbital agitation speed on extracellular collagenase production by Penicillium aurantiogriseum URM4622. The most significant variables for collagenase production were soybean flour concentration and initial medium pH
that had positive main effects, and temperature that had a negative one. Protein concentration in soybean flour revealed to
be a significant factor for the production of a collagenase serine proteinase. The most favorable production conditions were
found to be 0.75% soybean flour, pH 8.0, 200 rpm, and 28°C, which led to a collagenase activity of 164 U. The enzyme showed
an optimum activity at 37°C and pH 9.0, was stable over wide ranges of pH and temperature (6.0 ∼ 10.0 and 25 ∼ 45°C, respectively)
and was strongly inhibited by 10 mM phenylmethylsulphonylfluoride. The firstorder rate constants for collagenase inactivation
in the crude extract, calculated from semi-log plots of the residual activity versus time, were used in Arrhenius and Eyring
plots to estimate the main thermodynamic parameters of thermoinactivation (E*
d
= 107.4 kJ/mol and ΔH*
d
= 104.7 kJ/mol). The enzyme is probably an extracellular neutral serine collagenase effective on azocoll, gelatin and collagen
decomposition. 相似文献
36.
We derive an analytic expression for site-specific stationary distributions of amino acids from the structurally constrained neutral (SCN) model of protein evolution with conservation of folding stability. The stationary distributions that we obtain have a Boltzmann-like shape, and their effective temperature parameter, measuring the limit of divergent evolutionary changes at a given site, can be predicted from a site-specific topological property, the principal eigenvector of the contact matrix of the native conformation of the protein. These analytic results, obtained without free parameters, are compared with simulations of the SCN model and with the site-specific amino acid distributions obtained from the Protein Data Bank. These results also provide new insights into how the topology of a protein fold influences its designability, i.e., the number of sequences compatible with that fold. The dependence of the effective temperature on the principal eigenvector decreases for longer proteins, as a possible consequence of the fact that selection for thermodynamic stability becomes weaker in this case. 相似文献
37.
38.
Udrisar DP Wanderley MI Porto RC Cardoso CL Barbosa MC Camberos MC Cresto JC 《Experimental biology and medicine (Maywood, N.J.)》2005,230(7):479-486
Innumerous data support the fact that insulin-degrading enzyme (IDE) is the primary enzymatic mechanism for initiating and controlling cellular insulin degradation. Nevertheless, insulin degradation is unlikely to be the only cellular function of IDE, because it appears that some cellular effects of insulin are mediated by IDE as a regulatory protein. Insulin-degrading enzyme shows a significant correlation with various cellular functions, such as cellular growth and differentiation, and the expression of IDE is developmentally regulated. Besides insulin, other substrates are also degraded by IDE, including various growth-promoting peptides. It has also been shown that IDE enhances the binding of androgen to DNA in the nuclear compartment. It is also known that the androgen hormones have a stimulatory effect on prostate growth, and that estradiol stimulates uterine growth. To establish whether IDE is regulated by a cellular prostate/uterine growth stimulus, the present study assessed whether IDE was modified in quantity and activity during proliferative conditions (castration + testosterone in the male rat, or castration + estradiol or the proestrus phase of the estrous cycle in the female rat) and autolysis (castration or the metestrus phase of the estrous cycle) using cytosolic and nuclear fractions of rat prostate and cytosolic fractions of rat uterus. The activity and amount of IDE decreased in the cytosolic fraction with castration and during metestrus, and increased with testosterone or estradiol treatment and during proestrus. In the nuclear fraction, the quantity of the IDE followed the same pattern observed in the cytosolic fraction, although without degradative activity. The data presented here suggest that IDE may participate in prostatic and uterine growth and that the testosterone or estradiol and/or prostate and uterus insulin-like growth factors may be important factors for the expression and regulation of IDE in the prostate and uterus. 相似文献
39.
DeLaat DM Carvalho MR Lovato MB Acedo MD da Fonseca CG 《Genetics and molecular research : GMR》2005,4(4):716-725
RAPD (random amplification of polymorphic DNA) molecular markers can be utilized for analyzing genetic variability in populations for which only a few or no molecular markers are available. They were used in a study of an endangered species, Peripatus acacioi, found in the Tripuí Ecological Station, in Ouro Preto, MG, Brazil. The ecological station was specifically created to protect this velvet worm species, the first of this group found in Brazil. For an initial evaluation of the genetic diversity of this species, DNA samples from the lobopods of four individuals, collected at random, were analyzed using RAPD. Each reaction was run with a different primer (Operon RAPD 10-mer Kits), totaling 13 primers (OPC2, OPC3, OPC4, OPC6, OPC8, OPC10, OPC11, OPL2, OPL7, OPL11, OPL13, OPL18, and OPL19). Due to the low amplification yield, RAPD fragments were separated in polyacrylamide gels and stained with silver nitrate. Numerous bands were observed. Fifty-five of the amplified bands proved to be reproducible, both in terms of presence and intensity. Among these, 27 were variable and 28 were constant. The average number of bands per gel was 4.2. Nine of the 13 primers tested allowed the identification of constant and variable bands among these four individuals. RAPD analysis of genetic variation using silver-stained polyacrylamide gel electrophoresis provided measures of band sharing among the individuals, and therefore could be used in population genetics studies of P. acacioi. 相似文献
40.