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991.
Goujon D Zellweger M Radu A Grosjean P Weber BC van den Bergh H Monnier P Wagnières G 《Journal of biomedical optics》2003,8(1):17-25
The changes in the autofluorescence characteristics of the bronchial tissue is of crucial interest as a cancer diagnostic tool. Evidence exists that this native fluorescence or autofluorescence of bronchial tissues changes when they turn dysplastic and to carcinoma in situ. There is good agreement that the lesions display a decrease of autofluorescence in the green region of the spectrum under illumination with violet-light, and a relative increase in the red region of the spectrum is often reported. Imaging devices rely on this principle to detect early cancerous lesions in the bronchi. Based on a spectroscopic study, an industrial imaging prototype is developed to detect early cancerous lesions in collaboration with the firm Richard Wolf Endoskope GmbH, Germany. A preliminary clinical trial involving 20 patients with this spectrally optimized system shows that the autofluorescence can help to detect most lesions that would otherwise have remained invisible to an experienced endoscopist under white light illumination. A systematic off line analysis of the autofluorescence images pointed out that real-time decisional functions can be defined to reduce the number of false positive results. Using this method, a positive predictive value (PPV) of 75% is reached using autofluorescence only. Moreover, a PPV of 100% is obtained, when combining the white light (WL) mode and the autofluorescence (AF) mode, at the applied conditions. Furthermore, the sensitivity is estimated to be twice higher in the AF mode than in WL mode. 相似文献
992.
Synthesis and Dielectric Study of New Liquid‐crystalline Polysiloxanes Presenting a Thioether Spacer
Paul‐Philippe Gilles Jean‐Claude Milano Jean‐Louis Vernet 《Macromolecular chemistry and physics.》2003,204(18):2222-2232
Three new cyanobiphenyl polysiloxanes presenting long thioether spacers have been carried out. This type of spacer leads to very stable liquid‐crystalline polymers at room temperature and remove the crystallinity phenomenon. Dielectric analysis results show that the thioether spacer brings much more molecular flexibility to the system.
993.
Gueguen Y Garnier J Robert L Lefranc MP Mougenot I de Lorgeril J Janech M Gross PS Warr GW Cuthbertson B Barracco MA Bulet P Aumelas A Yang Y Bo D Xiang J Tassanakajon A Piquemal D Bachère E 《Developmental and comparative immunology》2006,30(3):283-288
Antimicrobial peptides play a major role in innate immunity. The penaeidins, initially characterized from the shrimp Litopenaeus vannamei, are a family of antimicrobial peptides that appear to be expressed in all penaeid shrimps. As of recent, a large number of penaeid nucleotide sequences have been identified from a variety of penaeid shrimp species and these sequences currently reside in several databases under unique identifiers with no nomenclatural continuity. To facilitate research in this field and avoid potential confusion due to a diverse number of nomenclatural designations, we have made a systematic effort to collect, analyse, and classify all the penaeidin sequences available in every database. We have identified a common penaeidin signature and subsequently established a classification based on amino acid sequences. In order to clarify the naming process, we have introduced a 'penaeidin nomenclature' that can be applied to all extant and future penaeidins. A specialized database, PenBase, which is freely available at , has been developed for the penaeidin family of antimicrobial peptides, to provide comprehensive information about their properties, diversity and nomenclature. 相似文献
994.
Staelens S Desmet J Ngo TH Vauterin S Pareyn I Barbeaux P Van Rompaey I Stassen JM Deckmyn H Vanhoorelbeke K 《Molecular immunology》2006,43(8):1243-1257
Many antithrombotic agents have only a small therapeutic window, frequently leading to bleeding problems. However, interfering with platelet adhesion through the collagen-VWF-GPIbalpha axis is expected to cause less bleeding problems. Our group developed a monoclonal antibody, 82D6A3, directed against the von Willebrand factor (VWF) A3-domain, which inhibits the VWF-interaction to fibrillar collagen. 82D6A3 has antithrombotic effects in vivo without bleeding time prolongation. To further investigate the promising features of 82D6A3, we have humanized it by variable domain resurfacing and grafting on the constant regions of a human IgG4. First, the sequence of the variable domains was determined and the murine scFv was constructed. The expressed scFv had a comparable activity as the IgG of 82D6A3, and its DNA was thus used in subsequent humanization procedures. For this, a new approach was introduced to identify non-human like framework surface residues, since the general distribution of accessible residues described for human and murine heavy and light chain variable domains showed several discrepancies with the homology modelled Fv of 82D6A3. Identification of non-human like framework residues and evaluation of their surface accessibility within the context of the homology modelled Fv of 82D6A3, revealed 10 residues that need to be humanized without influencing the conformation of the CDR loops. Indeed, the humanized scFv of 82D6A3, obtained by mutating all 10 residues to their human counterpart, was still binding with high affinity to VWF and retained the inhibitory properties of the murine scFv. Next, in order to increase its half life and to decrease its immunogenicity, the humanized variable domains were grafted on the constant regions of a human IgG4, resulting in h82D6A3 with an in vitro activity comparable to that of the murine IgG. 相似文献
995.
Haouzi P 《Respiratory physiology & neurobiology》2006,151(2-3):267-279
For over a century of creative research, many theories on the possible mechanisms controlling respiration during exercise have been developed and discussed. One of the most enduring questions is certainly related to the mechanisms that can prevent P(a)(CO(2)) rising when CO(2) production increases. As multiple systems and structures are capable of increasing ventilation (V (E)), not all the mechanisms controlling respiration can provide a proper answer to this question. Indeed, exercise is a complex physiological condition combining motor activity with a change in metabolic rate. The most intriguing aspect of exercise is that when the changes in metabolism are dissociated from the motor and locomotor activity, the strategy 'chosen' by the respiratory control system is to follow the metabolic rate (or more precisely factors temporally associated with the pulmonary gas exchange rate) regardless of the motor act. The strategy used by the respiratory system during exercise therefore appears to select from among various sources of information the most relevant to follow the rate at which CO(2) is ultimately exchanged by the lungs. Yet, the nature of the signal(s) which prevents CO(2)/H(+) disturbance during exercise is the fundamental question addressed by this simple observation and remains to be clarified. This review illustrates the attempts of many physiologists to collect experimental evidence for theories which could provide satisfactory mechanisms accounting for the matching between ventilation and the rate at which CO(2) leaves the tissues and is exchanged at the lungs. More recent models based on somatic information of circulatory origin are presented and discussed. 相似文献
996.
Characterization and clinical application of human CD34+ stem/progenitor cell populations mobilized into the blood by granulocyte colony-stimulating factor 总被引:13,自引:0,他引:13
Gordon MY Levicar N Pai M Bachellier P Dimarakis I Al-Allaf F M'Hamdi H Thalji T Welsh JP Marley SB Davies J Dazzi F Marelli-Berg F Tait P Playford R Jiao L Jensen S Nicholls JP Ayav A Nohandani M Farzaneh F Gaken J Dodge R Alison M Apperley JF Lechler R Habib NA 《Stem cells (Dayton, Ohio)》2006,24(7):1822-1830
997.
Testing of a whole genome PCR scanning approach to identify genomic variability in four different species of lactic acid bacteria 总被引:2,自引:0,他引:2
Ben Zakour N Grimaldi C Gautier M Langella P Azevedo V Maguin E Le Loir Y 《Research in microbiology》2006,157(4):386-394
Genomes can be markedly heterogeneous in conspecific bacterial strains. Genome sequences can be used to analyze genome plasticity via a PCR(2) (plasticity of chromosome revealed by PCR) approach. Small-sized chromosomes can indeed be fully amplified by long-range PCR with a set of primers designed using a reference strain and then applied to several other strains. Analysis of the resulting patterns can reveal genome plasticity. GenoFrag, a software package for the design of primers optimized for PCR(2) [N. Ben Zakour, M. Gautier, R. Andonov, D. Lavenier, M.F. Cochet, P. Veber, A. Sorokin, Y. Le Loir, GenoFrag: Software to design primers optimized for whole genome scanning by long-range PCR amplification, Nucleic Acids Res. 32 (2004) 17-24] was developed for the analysis of bacterial genome plasticity by whole genome amplification in approximately 10-kb-long fragments. By applying GenoFrag, we provide herewith evidence that genome plasticity can be analyzed in lactic acid bacteria using a PCR(2) approach. The genome sequences of Lactococcus lactis IL1403, Lactobacillus plantarum WCFS1, Lactobacillus bulgaricus ATCC11842 and Bifidobacterium longum NCC2705 were used to design four sets of primers. Each set was evaluated in silico to check that it ensured optimum coverage of the bacterial chromosome. To validate the primers generated by GenoFrag, a subset of primers was successfully used in LR-PCR experiments on genomic DNA from four L. bulgaricus strains. 相似文献
998.
The HIV evolutionary processes continuously unfold, leaving a measurable footprint in viral gene sequences. A variety of statistical models and inference techniques have been developed to reconstruct the HIV evolutionary history and to investigate the population genetic processes that shape viral diversity. Remarkably different population genetic forces are at work within and among hosts. Population-level HIV phylogenies are mainly shaped by selectively neutral epidemiologic processes, implying that genealogy-based population genetic inference can be useful to study the HIV epidemic history. Such evolutionary analyses have shed light on the origins of HIV, and on the epidemic spread of viral variants in different geographic locations and in different populations. The HIV genealogies reconstructed from within-host sequences indicate the action of selection pressure. In addition, recombination has a significant impact on HIV genetic diversity. Accurately quantifying both the adaptation rate and the population recombination rate of HIV will contribute to a better understanding of immune escape and drug resistance. Characterizing the impact of HIV transmission on viral genetic diversity will be a key factor in reconciling the different population genetic processes within and among hosts. 相似文献
999.
Jacquemont ML Sanlaville D Redon R Raoul O Cormier-Daire V Lyonnet S Amiel J Le Merrer M Heron D de Blois MC Prieur M Vekemans M Carter NP Munnich A Colleaux L Philippe A 《Journal of medical genetics》2006,43(11):843-849
Background
Autism spectrum disorders (ASD) refer to a broader group of neurobiological conditions, pervasive developmental disorders. They are characterised by a symptomatic triad associated with qualitative changes in social interactions, defect in communication abilities, and repetitive and stereotyped interests and activities. ASD is prevalent in 1 to 3 per 1000 people. Despite several arguments for a strong genetic contribution, the molecular basis of a most cases remains unexplained. About 5% of patients with autism have a chromosome abnormality visible with cytogenetic methods. The most frequent are 15q11–q13 duplication, 2q37 and 22q13.3 deletions. Many other chromosomal imbalances have been described. However, most of them remain undetectable using routine karyotype analysis, thus impeding diagnosis and genetic counselling.Methods and results
29 patients presenting with syndromic ASD were investigated using a DNA microarray constructed from large insert clones spaced at approximately 1 Mb intervals across the genome. Eight clinically relevant rearrangements were identified in 8 (27.5%) patients: six deletions and two duplications. Altered segments ranged in size from 1.4 to 16 Mb (2–19 clones). No recurrent abnormality was identified.Conclusion
These results clearly show that array comparative genomic hybridisation should be considered to be an essential aspect of the genetic analysis of patients with syndromic ASD. Moreover, besides their importance for diagnosis and genetic counselling, they may allow the delineation of new contiguous gene syndromes associated with ASD. Finally, the detailed molecular analysis of the rearranged regions may pave the way for the identification of new ASD genes.Autism spectrum disorders (ASD) belong to the group of pervasive developmental disorders (PDD). According to the Diagnostic statistical manual for mental disorders—fourth edition (DSM IV) classification,1 ASD are characterised by impairments in communication, social skills and restricted or stereotyped pattern of behaviours and interests. A diagnosis within the autism spectrum requires one or more symptoms in each of the three areas of impairment. The prevalence of ASD is estimated at about 1/1000 to 3/1000.2,3 ASD are heterogeneous conditions which can be either isolated or syndromic—that is, associated with other clinical features such as facial dysmorphism, limb or visceral malformations, and growth abnormalities.A total of 10–20% of ASD cases are due to known medical conditions involving chromosomal imbalances, genetic disorders (X fragile syndrome and tuberous sclerosis)4 or environmental factors (valproate5 and rubella). The other cases remain unexplained. Twin and familial studies have documented a higher concordance rate in monozygotic twins (90%) than in dizygotic twins (4.5%),6,7,8 and a 75‐fold greater risk to siblings in idiopathic patients than in the general population.9,10 Collectively, these studies support the involvement of numerous genes in autistic disorders.About 1.7–4.8% of people with ASD have chromosome abnormalities. Almost all chromosomes have been involved, including unbalanced translocations, inversions, rings, and interstitial or terminal deletions and duplications.11,12,13,14 The rare chromosome abnormalities that have been reported on more than one occasion are duplication of 15q,15 deletions of 18q,16,17 Xp,18,19 2q37,20 22q1321,22 and the sex chromosome aneuploidies 47,XYY23,24 and 45,X/46,XY.25,26 This diversity of loci suggests that studying chromosomal aberrations in relationship to autism will require efficient and highly sensitive tools. In addition to the importance for diagnosis, identification of chromosomal imbalances in patients with ASD may also be instrumental for cloning disease‐causing genes. Analysis of Xp22.3 deletion has indeed allowed the identification of the NLGN4 gene.27Recent technological developments, such as array‐based comparative genomic hybridisation (array‐CGH),28,29,30 allow the investigation of the human genome at a resolution that is 5–10 times higher than that of routine chromosome analysis by karyotyping.29,31,32,33 Array‐CGH has been used successfully for analysis of tumour samples and cell lines, and for high‐resolution analysis of patients with mental retardation and congenital anomalies.34,35,36,37,38Here, we report the application of genomewide array‐CGH, at 1 Mb resolution, to the study of 29 patients with syndromic ASD. In addition to their clinical relevance, our results emphasise the importance of chromosomal imbalance in the aetiology of syndromic ASD and may help the identification of new genes involved in autistic disorders. 相似文献1000.
Temple Gary; Lamesch Philippe; Milstein Stuart; Hill David E.; Wagner Lukas; Moore Troy; Vidal Marc 《Human molecular genetics》2006,15(13):2184
Human Molecular Genetics (2006) 15, 相似文献