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951.
The new species Paxillus orientalis is reported from Yunnan Province (south-western China). Based on morphological and molecular characters the novel taxon belongs to the sibling, holarctic alder-associated P. rubicundulus complex. Colour pictures of fresh basidiomes and line drawings are provided, accompanied by notes concerning its taxonomic and phylogenetic relationships within the genus. The new subgenus Alnopaxillus is established to accommodate P. rubicundulus and allied undescribed taxa characterized by basidiomes usually associated with Alnus and with a distinctly areolate–squamulose pileal surface.  相似文献   
952.
953.
The production of recombinant proteins usually reduces cell fitness and the growth rate of producing cells. The growth disadvantage favors faster-growing non-producer mutants. Therefore, continuous bioprocessing is hardly feasible in Escherichia coli due to the high escape rate. The stability of E. coli expression systems under long-term production conditions and how metabolic load triggered by recombinant gene expression influences the characteristics of mutations are investigated. Iterated fed-batch-like microbioreactor cultivations are conducted under production conditions. The easy-to-produce green fluorescent protein (GFP) and a challenging antigen-binding fragment (Fab) are used as model proteins, and BL21(DE3) and BL21Q strains as expression hosts. In comparative whole-genome sequencing analyses, mutations that allowed cells to grow unhindered despite recombinant protein production are identified. A T7 RNA polymerase expression system is only conditionally suitable for long-term cultivation under production conditions. Mutations leading to non-producers occur in either the T7 RNA polymerase gene or the T7 promoter. The host RNA polymerase-based BL21Q expression system remains stable in the production of GFP in long-term cultivations. For the production of Fab, mutations in lacI of the BL21Q derivatives have positive effects on long-term stability. The results indicate that adaptive evolution carried out with genome-integrated E. coli expression systems in microtiter cultivations under industrial-relevant production conditions is an efficient strain development tool for production hosts.  相似文献   
954.
Human child survival depends on adult investment, typically from parents. However, in spite of recent research advances on kin influence and birth order effects on human infant and child mortality, studies that directly examine the interaction of kin context and birth order on sibling differences in child mortality are still rare. Our study supplements this literature with new findings from large-scale individual-level panel data for three East Asian historical populations from northeast China (1789–1909), northeast Japan (1716–1870), and north Taiwan (1906–1945), where preference for sons and first-borns is common. We examine and compare male child mortality risks by presence/absence of co-resident parents, grandparents, and other kin, as well as their interaction effects with birth order. We apply discrete-time event-history analysis on over 172,000 observations of 69,125 boys aged 1–9 years old. We find that in all three populations, while the presence of parents is important for child survival, it is more beneficial to first/early-borns than to later-borns. Effects of other co-resident kin are however null or inconsistent between populations. Our findings underscore the importance of birth order in understanding how differential parental investment may produce child survival differentials between siblings.  相似文献   
955.
The aim of the present study was to evaluate the expression of the Mytilus galloprovincialis lysozyme gene in different in vivo stress situations, including injection of bacteria Vibrio splendidus LGP32, Vibrio anguillarum or Micrococcus lysodeikticus, as well as heat shock at 30 degrees C and cold stress at 5 degrees C. Injection of V. splendidus LGP32 resulted in: (i) a general down-regulation of lysozyme gene expression, as quantified by Q-PCR; (ii) reduction in the number of circulating hemocytes; (iii) decrease in the percentage of circulating hemocytes expressing lysozyme mRNA which was now restricted to only small cells, as observed by ISH; and (iv) accumulation of hemocytes expressing lysozyme in the muscle sinus where injection took place. Injection of V. anguillarum or M. lysodeikticus induced significant up-regulation of lysozyme gene expression, but only 2-3days post-injection, with no change in the total hemocyte counts but an increased percentage of hemocytes expressing lysozyme mRNA. Neither the control injection of PBS-NaCl nor temperature stress modified the lysozyme expression pattern. Consequently, the hemocyte population appears to be capable of discriminating between stress factors, and even between 2 Vibrio species.  相似文献   
956.
In recent years, depopulation and abandonment of traditional practices in the mountainous areas have affected the land use and land cover inducing the modification of the landscape mosaic. These processes have consequently facilitated the forest expansion, sometimes altering the floristic composition of the original vegetation in forests and other wooded lands. Forest expansion processes modified the structure, the stand density and the regeneration capacity of forests, thus altering the ecosystems’ functionality and resilience. These processes can be considered as a form of landscape degradation, which represents an emerging and common issue in the Mediterranean mountainous ecosystems. This study presents an overview of the main landscape dynamics occurring in the last two decades in the “Collemeluccio-Montedimezzo Alto Molise” Man and Biosphere Reserve, located in Central Italy. The results here obtained deeply describe the main effects induced by forest cover changes, such as those related to the crown coverage dynamics-biodiversity linkages, offering a valuable contribution to improve the management and planning in these situations widely replicable to similar contexts.  相似文献   
957.
Aim We examine the genetic structure of a fungal polypore, Datronia caperata (Berk.) Ryvarden (Polyporaceae), colonizing white mangrove, Laguncularia racemosa (L.) Gaertn. f. (Combretaceae), of Central America. Location Mangrove forests of Costa Rica and Panama. Methods Sequences of elongation factor alpha (EFA), beta tubulin (BTUB) and nuclear ribosomal internal transcribed spacer (ITS) regions were obtained from 54 collections of D. caperata collected from Caribbean and Pacific L. racemosa forests in Central America. Measures of haplotype and nucleotide diversity, nested clade analyses and coalescent analyses were used to estimate the direction and extent of migration of the fungus, and the factors promoting population divergence. We also conducted phylogenetic analyses using Bayesian estimation to test whether putative D. caperata collected from L. racemosa was conspecific with D. caperata colonizing other hosts from diverse Neotropical forests. Results Our results demonstrate that there is genetic isolation between D. caperata populations from Caribbean mangroves and those from Pacific mangroves. Our data suggest that the best explanation for the observed haplotype distribution is a recent range expansion from the Caribbean to the Pacific coasts, with subsequent isolation. This is supported by the infrequent overlap of haplotypes, unidirectional migration estimates from the Caribbean to the Pacific and the older estimated age of mutations in the Caribbean low‐copy BTUB and EFA loci. In addition, our data suggest that D. caperata from mangroves are not conspecific with collections from other hosts found in diverse Neotropical forests. Main conclusions The low frequency of shared haplotypes between coasts, coupled with the incomplete lineage sorting after cessation of gene flow, is consistent with isolation during the last Pleistocene glaciation. We hypothesize that the greater haplotype and nucleotide diversity in the Pacific occurs either because larger effective population sizes of D. caperata are maintained in Pacific mangroves or because D. caperata populations underwent a significant bottleneck as a result of local extinction followed by recolonization. In addition, we found that D. caperata found on L. racemosa was not conspecific with D. caperata from non‐mangrove hosts and suggest that D. caperata found on L. racemosa may be a host specialist.  相似文献   
958.
In today''s technology-assisted society, social interactions may be expressed through a variety of techno-communication channels, including online social networks, email and mobile phones (calls, text messages). Consequently, a clear grasp of human behavior through the diverse communication media is considered a key factor in understanding the formation of the today''s information society. So far, all previous research on user communication behavior has focused on a sole communication activity. In this paper we move forward another step on this research path by performing a multidimensional study of human sociality as an expression of the use of mobile phones. The paper focuses on user temporal communication behavior in the interplay between the two complementary communication media, text messages and phone calls, that represent the bi-dimensional scenario of analysis. Our study provides a theoretical framework for analyzing multidimensional bursts as the most general burst category, that includes one-dimensional bursts as the simplest case, and offers empirical evidence of their nature by following the combined phone call/text message communication patterns of approximately one million people over three-month period. This quantitative approach enables the design of a generative model rooted in the three most significant features of the multidimensional burst - the number of dimensions, prevalence and interleaving degree - able to reproduce the main media usage attitude. The other findings of the paper include a novel multidimensional burst detection algorithm and an insight analysis of the human media selection process.  相似文献   
959.
960.
Many human diseases owe their pathology, to some degree, to the erroneous conversion of proteins from their soluble state into fibrillar, β-structured aggregates, often referred to as amyloid fibrils. Neurodegenerative diseases, such as Alzheimer and spongiform encephalopathies, as well as type 2 diabetes and both localized and systemic amyloidosis, are among the conditions that are associated with the formation of amyloid fibrils. Several mathematical tools can rationalize and even predict important parameters of amyloid fibril formation. It is not clear, however, whether such algorithms have predictive powers for in vivo systems, in which protein aggregation is affected by the presence of other biological factors. In this review, we briefly describe the existing algorithms and use them to predict the effects of mutations on the aggregation of specific proteins, for which in vivo experimental data are available. The comparison between the theoretical predictions and the experimental data obtained in vivo is shown for each algorithm and experimental data set, and statistically significant correlations are found in most cases.  相似文献   
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