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921.
922.
Rodolpho Santos Telles Menezes Seán Gary Brady Ant?nio Freire Carvalho Marco Antonio Del Lama Marco Ant?nio Costa 《PloS one》2015,10(3)
The Neotropical Region harbors high biodiversity and many studies on mammals, reptiles, amphibians and avifauna have investigated the causes for this pattern. However, there is a paucity of such studies that focus on Neotropical insect groups. Synoeca de Saussure, 1852 is a Neotropical swarm-founding social wasp genus with five described species that is broadly and conspicuously distributed throughout the Neotropics. Here, we infer the phylogenetic relationships, diversification times, and historical biogeography of Synoeca species. We also investigate samples of the disjoint populations of S. septentrionalis that occur in both northwestern parts of South America through Central American and the Brazilian Atlantic rainforests. Our results showed that the interspecific relationships for Synoeca could be described as follows: (S. chalibea + S. virginea) + (S. cyanea + (S. septentrionalis/S. surinama)). Notably, samples of S. septentrionalis and S. surinama collected in the Atlantic Forest were interrelated and may be the result of incomplete lineage sorting and/or mitochondrial introgression among them. Our Bayesian divergence dating analysis revealed recent Plio-Pleistocene diversification in Synoeca. Moreover, our biogeographical analysis suggested an Amazonian origin of Synoeca, with three main dispersal events subsequently occurring during the Plio-Pleistocene. 相似文献
923.
Fernando Oliveira Costa Luís Otávio Miranda Cota José Roberto Cortelli Sheila Cavalca Cortelli Renata Magalh?es Cyrino Eugênio José Pereira Lages Ana Paula Lima Oliveira 《PloS one》2015,10(10)
Background and Objective
Prospective studies that investigated the influence of surgical and nonsurgical procedures in the recurrence of periodontitis and tooth loss in periodontal maintenance therapy (PMT) programs have not been previously reported. The objective of this study was to evaluate longitudinally the recurrence of periodontitis in regular compliers (RC) and irregular compliers (IC) individuals undergoing surgical and non-surgical procedures over 5 years in a program of PMT.Materials and Methods
A total of 212 individuals participated in this study. Full-mouth periodontal examination including bleeding on probing, probing depth, and clinical attachment level were determined at all PMT visits over 5 years. The recurrence of periodontitis was evaluated in RC and IC individuals undergoing surgical and non-surgical procedures in PMT. The influences of risk variables of interest were tested through univariate analysis and multivariate logistic regression.Results
Recurrence of periodontitis was significantly lower among RC when compared to IC. Individuals with recurrence of periodontitis and undergoing surgical procedures showed higher probing depth and clinical attachment loss than those who received non-surgical procedures. Recurrence of periodontitis was higher in individual undergoing surgical procedures and irregular compliance during PMT.Conclusions
Irregular compliance and surgical procedures in individuals undergoing PMT presented higher rates of recurrence of periodontitis when compared to regular compliant patients undergoing non-surgical procedures. 相似文献924.
Ant?nio J. S. Gon?alves Edson R. A. Oliveira Simone M. Costa Marciano V. Paes Juliana F. A. Silva Adriana S. Azevedo Marcio Mantuano-Barradas Ana Cristina M. A. Nogueira Cecília J. Almeida Ada M. B. Alves 《PLoS neglected tropical diseases》2015,9(12)
Dengue virus (DENV) is spread through most tropical and subtropical areas of the world and represents a serious public health problem. At present, the control of dengue disease is mainly hampered by the absence of antivirals or a vaccine, which results in an estimated half worldwide population at risk of infection. The immune response against DENV is not yet fully understood and a better knowledge of it is now recognized as one of the main challenge for vaccine development. In previous studies, we reported that a DNA vaccine containing the signal peptide sequence from the human tissue plasminogen activator (t-PA) fused to the DENV2 NS1 gene (pcTPANS1) induced protection against dengue in mice. In the present work, we aimed to elucidate the contribution of cellular and humoral responses elicited by this vaccine candidate for protective immunity. We observed that pcTPANS1 exerts a robust protection against dengue, inducing considerable levels of anti-NS1 antibodies and T cell responses. Passive immunization with anti-NS1 antibodies conferred partial protection in mice infected with low virus load (4 LD50), which was abrogated with the increase of viral dose (40 LD50). The pcTPANS1 also induced activation of CD4+ and CD8+ T cells. We detected production of IFN-γ and a cytotoxic activity by CD8+ T lymphocytes induced by this vaccine, although its contribution in the protection was not so evident when compared to CD4+ cells. Depletion of CD4+ cells in immunized mice completely abolished protection. Furthermore, transfer experiments revealed that animals receiving CD4+ T cells combined with anti-NS1 antiserum, both obtained from vaccinated mice, survived virus infection with survival rates not significantly different from pcTPANS1-immunized animals. Taken together, results showed that the protective immune response induced by the expression of NS1 antigen mediated by the pcTPANS1 requires a cooperation between CD4+ T cells and the humoral immunity. 相似文献
925.
Simone Lanini Alessandro Nanni Costa Vincenzo Puro Francesco Procaccio Paolo Antonio Grossi Francesca Vespasiano Andrea Ricci Sergio Vesconi Michael G. Ison Yehuda Carmeli Giuseppe Ippolito Donor-Recipient Infection Collaborative Study Group 《PloS one》2015,10(4)
Background
Bacterial infections remain a challenge to solid organ transplantation. Due to the alarming spread of carbapenem-resistant gram negative bacteria, these organisms have been frequently recognized as cause of severe infections in solid organ transplant recipients.Methods and Findings
Between 15 May and 30 September 2012 we enrolled 887 solid organ transplant recipients in Italy with the aim to describe the epidemiology of gram negative bacteria spreading, to explore potential risk factors and to assess the effect of early isolation of gram negative bacteria on recipients’ mortality during the first 90 days after transplantation. During the study period 185 clinical isolates of gram negative bacteria were reported, for an incidence of 2.39 per 1000 recipient-days. Positive cultures for gram negative bacteria occurred early after transplantation (median time 26 days; incidence rate 4.33, 1.67 and 1.14 per 1,000 recipient-days in the first, second and third month after SOT, respectively). Forty-nine of these clinical isolates were due to carbapenem-resistant gram negative bacteria (26.5%; incidence 0.63 per 1000 recipient-days). Carbapenems resistance was particularly frequent among Klebsiella spp. isolates (49.1%). Recipients with longer hospital stay and those who received either heart or lung graft were at the highest risk of testing positive for any gram negative bacteria. Moreover recipients with longer hospital stay, lung recipients and those admitted to hospital for more than 48h before transplantation had the highest probability to have culture(s) positive for carbapenem-resistant gram negative bacteria. Forty-four organ recipients died (0.57 per 1000 recipient-days) during the study period. Recipients with at least one positive culture for carbapenem-resistant gram negative bacteria had a 10.23-fold higher mortality rate than those who did not.Conclusion
The isolation of gram-negative bacteria is most frequent among recipient with hospital stays >48 hours prior to transplant and in those receiving either heart or lung transplants. Carbapenem-resistant gram negative isolates are associated with significant mortality. 相似文献926.
Marcela Parra Xia Liu Steven C. Derrick Amy Yang Alvaro Molina-Cruz Carolina Barillas-Mury Hong Zheng Phuong Thao Pham Martha Sedegah Arnel Belmonte Dianne D. Litilit Thomas A. Waldmann Sanjai Kumar Sheldon L. Morris Liyanage P. Perera 《PloS one》2015,10(10)
Malaria remains a major global public health problem with an estimated 200 million cases detected in 2012. Although the most advanced candidate malaria vaccine (RTS,S) has shown promise in clinical trials, its modest efficacy and durability have created uncertainty about the impact of RTS,S immunization (when used alone) on global malaria transmission. Here we describe the development and characterization of a novel modified vaccinia virus Ankara (MVA)–based malaria vaccine which co-expresses the Plasmodium yoelii circumsporozoite protein (CSP) and IL-15. Vaccination/challenge studies showed that C57BL/6 mice immunized with the MVA-CSP/IL15 vaccine were protected significantly better against a P. yoelii 17XNL sporozoite challenge than either mice immunized with an MVA vaccine expressing only CSP or naïve controls. Importantly, the levels of total anti-CSP IgG were elevated about 100-fold for the MVA-CSP/IL15 immunized group compared to mice immunized with the MVA-CSP construct that does not express IL-15. Among the IgG subtypes, the IL-15 expressing MVA-CSP vaccine induced levels of IgG1 (8 fold) and IgG2b (80 fold) higher than the MVA-CSP construct. The significantly enhanced humoral responses and protection detected after immunization with the MVA-CSP/IL15 vaccine suggest that this IL-15 expressing MVA construct could be considered in the development of future malaria immunization strategies. 相似文献
927.
Lucas Martins França Larissa Nara Costa Freitas Vinicyus Teles Chagas Caio Fernando Ferreira Coêlho Wermerson Assunção Barroso Graciomar Conceição Costa Lucilene Amorim Silva Victor Debbas Francisco Rafael Martins Laurindo Antonio Marcus de Andrade Paes 《Biochemical and biophysical research communications》2014
Non-alcoholic fatty liver disease (NAFLD) is intimately associated with insulin resistance and hypertriglyceridemia, whereas many of the mechanisms underlying this association are still poorly understood. In the present study, we investigated the relationship between microsomal triglyceride transfer protein (MTP) and markers of endoplasmic reticulum (ER) stress in the liver of rats subjected to neonatal monosodium l-glutamate (MSG)-induced obesity. At age 120 days old, the MSG-obese animals exhibited hyperglycemia, hypertriglyceridemia, insulin resistance, and liver steatosis, while the control (CTR) group did not. Analysis using fast protein liquid chromatography of the serum lipoproteins revealed that the triacylglycerol content of the very low-density lipoprotein (VLDL) particles was twice as high in the MSG animals compared with the CTR animals. The expression of ER stress markers, GRP76 and GRP94, was increased in the MSG rats, promoting a higher expression of X-box binding protein 1 (XBP-1), protein disulfide isomerase (PDI), and MTP. As the XBP-1/PDI/MTP axis has been suggested to represent a significant lipogenic mechanism in the liver response to ER stress, our data indicate that hypertriglyceridemia and liver steatosis occurring in the MSG rats are associated with increased MTP expression. 相似文献
928.
Anna C. A. Yendo Fernanda de Costa Grace Gosmann Arthur G. Fett-Neto 《Molecular biotechnology》2010,46(1):94-104
Triterpenoid saponins are a class of plant secondary metabolites with structure derived from the precursor oxidosqualene in
which one or more sugar residues are added. They have a wide range of pharmacological applications, such as antiplatelet,
hypocholesterolemic, antitumoral, anti-HIV, immunoadjuvant, anti-inflammatory, antibacterial, insecticide, fungicide and anti-leishmanial
agents. Their accumulation in plant cells is stimulated in response to changes mediated by biotic and abiotic elicitors. The
enhancement of saponin yields by methyl jasmonate in plants and cell cultures in several species indicates the involvement
of these metabolites in plant defence mechanisms. The elucidation of their biosynthesis at the molecular level has advanced
recently. Most studies to date have focused on the participation of early enzymes in the pathway, including oxidosqualene
cyclase, squalene synthase and dammarenediol synthase, as well as in isolating and characterizing genes that encode β-amyrin
synthase. Yields of bioactive saponins in various plant species and experimental systems have been successfully increased
by treating cells and tissues with jasmonate or by exposing these to oxidative stress. These elicitation and molecular studies
are consolidating a robust knowledge platform from which to launch the development of improved sources for commercial supply
of bioactive saponins. 相似文献
929.
Arnaud Costa Ingrid Ricard Anthony C. Davison Ted C. J. Turlings 《Journal of Insect Behavior》2010,23(4):303-318
Associative learning is known to modify foraging behavior in numerous parasitic wasps. This is in agreement with optimal foraging
theory, which predicts that the wasps will adapt their responses to specific cues in accordance with the rewards they receive
while perceiving these cues. Indeed, the generalist parasitoid Cotesia marginiventris shows increased attraction to a specific plant odor after perceiving this odor during contact with hosts. This positive associative
learning is common among many parasitoids, but little is known about the effects of unrewarding host searching events on the
attractiveness of odors. To study this, preferences of female C. marginiventris for herbivore-induced odors of three plant species were tested in a six-arm olfactometer after the wasps perceived one of
these odors either i) without contacting any caterpillars, ii) while contacting the host caterpillar Spodoptera littoralis, or iii) while contacting the non-host caterpillar Pieris rapae. The results confirm the effects of positive associative learning, but showed no changes in innate responses to the host-induced
odors after “negative” experiences. Hence, a positive association is made during an encounter with hosts, but unsuccessful
host-foraging experiences do not necessarily lead to avoidance learning in this generalist parasitoid. 相似文献
930.
The food habits and seed dispersal promoted by five didelphid marsupials, were investigated through fecal analysis in a cerrado reserve located in the central part of the Espinhaço mountain range in Minas Gerais state, southeastern Brazil. The studied species presented a remarkable constancy in their diets and just for C. philander a seasonal change in diet seems to be present with a high consumption of fruits during the wetter season. Arthropods such as hymenopterans, coleopterans and homopterans were the main food resource detected but seeds belonging to pioneer plants were found with high frequencies in samples of all didelphids. Fruits of pioneer plants belonging to the families Melastomataceae (Clidemia urceolata and Miconia holocericea) and Rubiaceae (Psychotria barbiflora and P. capitata) present high germination rates and were among the mostly consumed. In spite of the differences observed in food preferences, all of the didelphids studied must be considered effective seed dispersers of pioneer plants. 相似文献