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991.
<正>臂丛神经损伤是周围神经损伤最严重的一种,常常造成病人上肢功能的部分或完全丧失,是一种致残性的疾病,对于病人本人及其家属乃至全社会的心理、经济等方面都带来了巨大的打击和损失[1]。对于臂丛神经损伤的治疗方法在国际上尚不统一,包括了神经移位、游离肌肉移植、功能重建等各种方法[1]。而当神经缺损时常采用自体神经移植法已成为治疗周围神经缺损及恢复期功能的主要措施之一。以健侧C7神经根经锥体前移位修复臂丛神经损伤为例,我院在修复 相似文献
992.
993.
Lei Yue Dan Xu Ziyu Wei Tingting Zhao Tao Lin Reshef Tenne Alla Zak Quanjun Li Bingbing Liu 《Materials》2022,15(8)
Exploring the behavior of nanocrystals with varying shapes and sizes under high pressure is crucial to understanding the relationship between the morphology and properties of nanomaterials. In this study, we investigated the compression behaviors of WS2 nanotubes (NT-WS2) and fullerene-like nanoparticles (IF-WS2) by in situ high-pressure X-ray diffraction (XRD) and Raman spectroscopy. It was found that the bulk modulus of NT-WS2 is 81.7 GPa, which is approximately twice as large as that of IF-WS2 (46.3 GPa). This might be attributed to the fact that IF-WS2 with larger d-spacing along the c-axis and higher defect density are more compressible under isotropic pressure than NT-WS2. Thus, the slender NT-WS2 possess a more stable crystal structure than the IF-WS2. Our findings reveal that the effects of morphology and size play crucial roles in determining the high-pressure properties of WS2 nanoparticles, and provide significant insight into the relationship between structure and properties. 相似文献
994.
Dan Hall Michael F. Huerta Matthew J. McAuliffe Gregory K. Farber 《Neuroinformatics》2012,10(4):331-339
The National Database for Autism Research (NDAR) is a secure research data repository designed to promote scientific data sharing and collaboration among autism spectrum disorder investigators. The goal of the project is to accelerate scientific discovery through data sharing, data harmonization, and the reporting of research results. Data from over 25,000 research participants are available to qualified investigators through the NDAR portal. Summary information about the available data is available to everyone through that portal. 相似文献
995.
Peter Kochunov L. Elliot Hong Emily L. Dennis Rajendra A. Morey David F. Tate Elisabeth A. Wilde Mark Logue Sinead Kelly Gary Donohoe Pauline Favre Josselin Houenou Christopher R. K. Ching Laurena Holleran Ole A. Andreassen Laura S. van Velzen Lianne Schmaal Julio E. Villaln-Reina Carrie E. Bearden Fabrizio Piras Gianfranco Spalletta Odile A. van den Heuvel Dick J. Veltman Dan J. Stein Meghann C. Ryan Yunlong Tan Theo G. M. van Erp Jessica A. Turner Liz Haddad Talia M. Nir David C. Glahn Paul M. Thompson Neda Jahanshad 《Human brain mapping》2022,43(1):194-206
The ENIGMA-DTI (diffusion tensor imaging) workgroup supports analyses that examine the effects of psychiatric, neurological, and developmental disorders on the white matter pathways of the human brain, as well as the effects of normal variation and its genetic associations. The seven ENIGMA disorder-oriented working groups used the ENIGMA-DTI workflow to derive patterns of deficits using coherent and coordinated analyses that model the disease effects across cohorts worldwide. This yielded the largest studies detailing patterns of white matter deficits in schizophrenia spectrum disorder (SSD), bipolar disorder (BD), major depressive disorder (MDD), obsessive–compulsive disorder (OCD), posttraumatic stress disorder (PTSD), traumatic brain injury (TBI), and 22q11 deletion syndrome. These deficit patterns are informative of the underlying neurobiology and reproducible in independent cohorts. We reviewed these findings, demonstrated their reproducibility in independent cohorts, and compared the deficit patterns across illnesses. We discussed translating ENIGMA-defined deficit patterns on the level of individual subjects using a metric called the regional vulnerability index (RVI), a correlation of an individual's brain metrics with the expected pattern for a disorder. We discussed the similarity in white matter deficit patterns among SSD, BD, MDD, and OCD and provided a rationale for using this index in cross-diagnostic neuropsychiatric research. We also discussed the difference in deficit patterns between idiopathic schizophrenia and 22q11 deletion syndrome, which is used as a developmental and genetic model of schizophrenia. Together, these findings highlight the importance of collaborative large-scale research to provide robust and reproducible effects that offer insights into individual vulnerability and cross-diagnosis features. 相似文献
996.
997.
目的探讨蛛网膜下腔出血(SAH)对皮质神经元超微结构的影响。方法将25只大耳白兔随机分为5组:A组(空白对照组)、B组、C组、D组、E组(实验组)。以脑池内血液注入法制作SAH模型。对A组动物脑枕大池内注入生理盐水,对B、C、D、E组动物注入自体鲜血。分别于术后1d(B组)、3d(C组)、5d(D组)及7d(E组)处死实验组动物及对照组动物,立即取颞叶的大脑皮质分别行光镜和电镜,观察,了解其形态学及细胞超微结构的变化。结果B组的神经元大部分保持完好,部分细胞有轻度的水肿。C组、D组、E组的神经元有明显的破坏,出现超微结构的改变,核固缩、浓染。实验组动物均有皮质细胞密度的减少,B组皮质细胞密度低于C组、D组、E组(P<0.05)。结论SAH可引起迟发性神经元死亡。 相似文献
998.
Hoare Jacqueline Heany Sarah J. Fouche Jean-Paul Phillips Nicole Joska John A. Myer Landon Zar Heather J. Stein Dan J. 《Journal of neurovirology》2019,25(2):254-262
Journal of NeuroVirology - Rapid maturation of major white matter pathways occurs in the first 2 years of life, indicating a critical neuronal developmental period. The impact of... 相似文献
999.
Bisection of the corpus callosum and hippocampal commissure, after the kindling of one dorsal hippocampus (primary site), had no effect on the rate of generalized kindled seizure development in the contralateral dorsal hippocampus (secondary site). The rate of kindling in the secondary site was very rapid in both intact and commissure-bisected rats, resulting in a positive transfer between the two sites of approximately 90%. In addition, the afterdischarge threshold response of the secondary site, after commissurotomy but before secondary site kindling, revealed mature local epileptogenesis. These observations support the suggestion that the positive transfer observed between the dorsal hippocampi is based on bilateral epileptogenesis during primary site kindling. Bisection of the anterior corpus callosum lateralized the forelimb convulsion while the hippocampal commissure independently mediated the laterality of the hippocampal afterdischarge. Commissurotomy had no significant influence on the latency to onset or offset of these motor and electrographic responses. These results are compared with those from the amygdala, and their implication for the laterality of epileptogenesis is discussed. 相似文献
1000.
Erica Bree Rosenblum Timothy Y. James Kelly R. Zamudio Thomas J. Poorten Dan Ilut David Rodriguez Jonathan M. Eastman Katy Richards-Hrdlicka Suzanne Joneson Thomas S. Jenkinson Joyce E. Longcore Gabriela Parra Olea Luís Felipe Toledo Maria Luz Arellano Edgar M. Medina Silvia Restrepo Sandra Victoria Flechas Lee Berger Cheryl J. Briggs Jason E. Stajich 《Proceedings of the National Academy of Sciences of the United States of America》2013,110(23):9385-9390
Understanding the evolutionary history of microbial pathogens is critical for mitigating the impacts of emerging infectious diseases on economically and ecologically important host species. We used a genome resequencing approach to resolve the evolutionary history of an important microbial pathogen, the chytrid Batrachochytrium dendrobatidis (Bd), which has been implicated in amphibian declines worldwide. We sequenced the genomes of 29 isolates of Bd from around the world, with an emphasis on North, Central, and South America because of the devastating effect that Bd has had on amphibian populations in the New World. We found a substantial amount of evolutionary complexity in Bd with deep phylogenetic diversity that predates observed global amphibian declines. By investigating the entire genome, we found that even the most recently evolved Bd clade (termed the global panzootic lineage) contained more genetic variation than previously reported. We also found dramatic differences among isolates and among genomic regions in chromosomal copy number and patterns of heterozygosity, suggesting complex and heterogeneous genome dynamics. Finally, we report evidence for selection acting on the Bd genome, supporting the hypothesis that protease genes are important in evolutionary transitions in this group. Bd is considered an emerging pathogen because of its recent effects on amphibians, but our data indicate that it has a complex evolutionary history that predates recent disease outbreaks. Therefore, it is important to consider the contemporary effects of Bd in a broader evolutionary context and identify specific mechanisms that may have led to shifts in virulence in this system.Emerging infectious diseases (EIDs) pose significant challenges for human health, agricultural crops, and economically and ecologically important populations in nature (1–4). The incidence of EIDs has been steadily rising over the last several decades (5, 6), and EIDs are of particular concern in an increasingly globalized world. For example, the majority of human EIDs is zoonoses that originate in wildlife (5) and subsequently, create a significant burden for global economies and public health (7, 8). Therefore, scientific efforts to understand and respond to EIDs are critical in diverse fields from biomedicine to conservation biology.Although EIDs result from a complex interplay of factors, many studies focus primarily on the emergence of novel microbial pathogens. There are, in fact, high-profile examples of EIDs caused by the rapid appearance of novel, hypervirulent, or host-switching strains (9–11), but EIDs are not always caused by rapid or recent evolution of the pathogen itself. Virulence itself is an emergent property of microbe–host–environment interactions (12). Thus, EIDs can result from shifts in any factor—or combination of factors—in the microbe–host–environment epidemiological triangle (13). Characterizing the evolutionary history of emerging pathogens is, thus, critical, allowing us to determine whether observed EIDs result from rapid, recent shifts in organisms with pathogenic potential.Chytridiomycosis is an EID responsible for declines in amphibian species around the world. The chytrid fungus Batrachochytrium dendrobatidis (Bd) was discovered and linked to amphibian declines in 1998 (14, 15). Chytridiomycosis is caused by Bd and kills amphibians by disrupting the integrity of their skin, a physiologically important organ that is involved in gas exchange, electrolyte balance, hydration, and protection from other pathogens (16, 17). Bd infects hundreds of species of amphibians, is found on all continents where amphibians occur, and is responsible for declines and extirpations in a diversity of amphibian hosts (18).Soon after Bd was discovered, researchers proposed two competing hypotheses for the emergence of chytridiomycosis. The emerging pathogen hypothesis posited that a novel disease agent caused chytridiomycosis, and the endemic pathogen hypothesis proposed that an environmental shift disrupted a previously benign microbe–host interaction (19). Over the years, spatiotemporal and genetic data have supported the emerging pathogen hypothesis (reviewed in refs. 20 and 21). Spatiotemporal data provided clear evidence that Bd arrived and spread through geographic regions where it was not present historically (22–24). Early genetic studies also found very little genetic differentiation in Bd with no geographic signal, consistent with a recent, rapid spread of a novel disease agent (25–27). Recently, genetic and genomic data have been used to describe a geographically widespread Bd lineage [termed the global panzootic lineage (GPL)] (28) and several putatively endemic Bd lineages (28–30). However, different studies have used different methods and focused sampling in different parts of the world, precluding integration across studies to determine the evolutionary history leading to the emergence of Bd as a global threat to amphibians.Here, we present whole-genome sequencing from a global panel of Bd isolates to show that Bd has a historically deeper and more complex evolutionary history than previously appreciated. We sequenced Bd genomes from around the world and also, a non-Bd chytrid outgroup that does not attack amphibians [Homolaphlyctis polyrhiza (Hp)] (31). Our focus was primarily on the evolutionary dynamics of Bd in the Americas, because many of the most devastating outbreaks have occurred in the New World. We address outstanding questions about the origins, genetic diversity, and genome structure of Bd that can be resolved using whole-genome data. We also integrate our genomic data with those data from a previous study with complementary geographic sampling (28). Our results reveal that the evolutionary history of Bd is complex, with multiple divergent lineages, heterogeneous patterns of genomic evolution, and no simple link between a single evolutionary event and observed amphibian declines. 相似文献