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81.
82.
Krückert K Flachsbarth B Schulz S Hentschel U Weldon PJ 《Journal of natural products》2006,69(6):863-870
Secretions from the paracloacal glands of alligators (Alligator spp.) and caimans (Caiman spp., Melanosuchus niger, and Paleosuchus spp.) were examined by GC-MS. The secretions of the common caiman (C. crocodilus), the broad-snouted caiman (C. latirostris), the yacare caiman (C. yacare), the dwarf caiman (P. palpebrosus), and the smooth-fronted caiman (P. trigonatus) yielded a new family of 43 aliphatic carbonyl compounds that includes aldehydes, ketones, and beta-diketones with an ethyl branch adjacent to the carbonyl group. The identification of these glandular components and the syntheses and stereochemical investigations of selected compounds are described. 相似文献
83.
The aims of the present study were to explore methods used by Dutch orthodontists in daily practice to estimate and stimulate patient compliance, and to develop a theoretical model of compliance. A questionnaire, containing 38 items, was distributed among participants at the annual congress of the Dutch Society of Orthodontists in September 2002. The items concerned the need for and the level of patient adherence during orthodontic treatment, modes of estimating and stimulating compliance, and perceived reasons for non-compliance. Based on this pilot study and on an extensive literature search, a model for future research was developed in which concepts related to compliance in orthodontics were systematically organized. Of the 88 orthodontists who attended the congress, 51 responded (mean age 47 years, 22 per cent females). The respondents considered compliance to be of vital importance for a successful treatment result. Most patients were regarded as moderate compliers. The respondents believed that a lack of awareness of dental problems, a lack of motivation to co-operate, and personal problems were the main reasons for non-compliance. Only indirect methods were used to estimate compliance. It was concluded that Dutch orthodontists used subjective methods to measure compliance in daily practice, and that a theoretical model was needed to be able to examine compliance in orthodontics in a more systematic way. A multiple assessment of compliance, using a variety of research methods, seems to be the most appropriate way at present to ensure accuracy in measuring levels of patient compliance in orthodontics. 相似文献
84.
A Langkjær B Kristensen BE Hansen H Schultz L Hegedüs CH Nielsen 《Clinical immunology (Orlando, Fla.)》2012,145(1):1-10
Human B cells are able to secrete IL-10 after stimulation with mitogens, but their ability to produce IL-10 and regulate T-cell responses after stimulation with self-antigens is unclear. We co-cultured thyroglobulin-pulsed B cells from healthy donors with autologous T cells and observed production of IL-10 and TGF-β, in addition to TNF-α and IL-6. Pulsing with foreign antigen, tetanus toxoid (TT), induced a Th1-response with minimal IL-10 production. After thyroglobulin-pulsing, 1.10±0.50% of B cells and 1.00±0.20% of CD4(+) T cells produced IL-10, compared to 0.29±0.19% of B cells (P=0.01) and 0.13±0.15% of CD4(+) T cells (P=0.006) following TT-pulsing. Thyroglobulin-stimulated, IL-10-secreting B cells were enriched within CD5(+) and CD24(high) cells. While thyroglobulin-pulsed B cells induced only modest proliferation of CD4(+) T cells, B cells pulsed with TT induced vigorous proliferation. Thus, B cells mediate self-antigen-specific IL-10, TNF-α and IL-6 production in co-cultures with T cells and contribute actively to these cytokine secretions. 相似文献
85.
Greinacher A Holtfreter B Krauel K Gätke D Weber C Ittermann T Hammerschmidt S Kocher T 《Blood》2011,118(5):1395-1401
Platelet factor 4 (PF4) and heparin (H) form PF4/H complexes, the target of the immune reaction in heparin-induced thrombocytopenia (HIT). HIT seems to be a secondary immune response as anti-PF4/H-IgG antibodies occur as early as day 4 of heparin treatment. This study investigated whether prevalent infections such as periodontitis may induce the PF4/H immune response as: (1) natural anti-PF4/H Abs are present in the normal population; (2) PF4 bound to bacteria exposes the same antigen(s) as PF4/H complexes; and (3) sepsis induces PF4/H Abs in mice. We found PF4 bound to periodontal pathogens (Aggregatibacter actinomycetemcomitans; Porphyromonas gingivalis) enabling subsequent binding of human anti-PF4/H Abs. The association of natural PF4/H Abs and periodontitis was assessed in a case-control study, enrolling individuals with natural anti-PF4/H Abs (n = 40 matched pairs), and in the cross-sectional population-based Study of Health in Pomerania (SHIP; n = 3500). Both studies showed a robust association between periodontitis and presence of anti-PF4/H Abs independent of inflammation markers (case-control study: lowest vs highest tertile, odds ratio, 7.12 [95% confidence interval, 1.73-46.13; P = .005]; SHIP study, p(trend) ≤ 0.001). Thus, preimmunization to PF4/bacteria complexes by prevalent infections, for example, periodontitis, likely explains the presence of natural anti-PF4/heparin Abs and the early occurrence of anti-PF4/H-IgG in HIT. 相似文献
86.
Sander T Gottschalk S Hertel S Neppert B Helmchen C 《Journal of the neurological sciences》2011,300(1-2):176-178
Ocular muscle palsies following carotid artery disease is thought to be caused by ischemia of the cranial oculomotor nerves but it may also be due to ischemia of the extraocular muscles (EOM). We studied a patient with common carotid artery occlusion syndrome (CCAOS) to elucidate the two competing hypotheses. MRI and sonography of the orbita showed oedematous swelling of all left EOM. MRI short-tau inversion recovery (STIR) sequences showed hyperintensities and a prolonged T2-relaxation time in EOM indicating muscle oedema. It decreased within two weeks as ophthalmoplegia improved. For several reasons ischemic EOM myopathy rather than ischemic neuropathy seems to be the morphological correlate of ophthalmoplegia after ipsilateral CCAOS in this patient. 相似文献
87.
Melsen B 《Journal of orthodontics》2011,38(2):134-43; quiz 145
Three aspects have had a significant impact on orthodontics during the last few decades: the appliances being used, the anchorage being used and finally the distribution of patients being treated. Firstly, the marketing of appliances is increasingly leading the orthodontist to outsource important aspects of treatment such as wirebending and bracket positioning. Brackets and wires are being presented as the solution to all problems and metaphysical terms such as 'intelligent design,' 'working brackets' and 'intelligent wires' are dominating advertising and reducing the impact of evidence-based treatment approaches. Secondly, the introduction of skeletal anchorage has potentially widened the spectrum of orthodontics, allowing for treatments that could not be done with conventional appliances. Biomechanical knowledge is, however, mandatory if we agree that the system should not be abused. Thirdly, the orthodontic population comprises an increasing number of adult patients, many of whom are characterized by a degenerated dentition. The treatment of these patients requires a thorough knowledge not only of biomechanics but also of the reaction of the periodontal tissues to various types of loading. They can be treated only with custom-made appliances adapting the force systems and magnitude to the patient-specific treatment goal. In summary, the orthodontic world is being split between 'appliance-driven fast-food orthodontics' where the results to a large extent are dependent on both growth and function and 'orthodontist-driven' 'slow-food' treatments attempting to push the limits of the possible in relation to complicated problems and reversal of degeneration in adult patients. The latter treatments are performed with individualized appliances adapting the force system to the patient. This paper will attempt to summarize the bearing of these factors on present orthodontics. 相似文献
88.
89.
Marcus D. Hartmann Oswin Ridderbusch Kornelius Zeth Reinhard Albrecht Oli Testa Derek N. Woolfson Guido Sauer Stanislaw Dunin-Horkawicz Andrei N. Lupas Birte Hernandez Alvarez 《Proceedings of the National Academy of Sciences of the United States of America》2009,106(40):16950-16955
Most core residues of coiled coils are hydrophobic. Occasional polar residues are thought to lower stability, but impart structural specificity. The coiled coils of trimeric autotransporter adhesins (TAAs) are conspicuous for their large number of polar residues in position d of the core, which often leads to their prediction as natively unstructured regions. The most frequent residue, asparagine (N@d), can occur in runs of up to 19 consecutive heptads, frequently in the motif [I/V]xxNTxx. In the Salmonella TAA, SadA, the core asparagines form rings of interacting residues with the following threonines, grouped around a central anion. This conformation is observed generally in N@d layers from trimeric coiled coils of known structure. Attempts to impose a different register on the motif show that the asparagines orient themselves specifically into the core, even against conflicting information from flanking domains. When engineered into the GCN4 leucine zipper, N@d layers progressively destabilized the structure, but zippers with 3 N@d layers still folded at high concentration. We propose that N@d layers maintain the coiled coils of TAAs in a soluble, export-competent state during autotransport through the outer membrane. More generally, we think that polar motifs that are both periodic and conserved may often reflect special folding requirements, rather than an unstructured state of the mature proteins. 相似文献
90.