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81.
Emiri Tejima Bing-Qiao Zhao Kiyoshi Tsuji Anna Rosell Klaus van Leyen R Gilberto Gonzalez Joan Montaner Xiaoying Wang Eng H Lo 《Journal of cerebral blood flow and metabolism》2007,27(3):460-468
We tested the hypothesis that astrocytic matrix metalloproteinase-9 (MMP-9) mediates hemorrhagic brain edema. In a clinical case of hemorrhagic stroke, MMP-9 co-localized with astrocytes and neurons in peri-hematoma areas. In a mouse model where blood was injected into striatum, MMP-9 was colocalized with astrocytes surrounding the hemorrhagic lesion. Because MMP-9 is present in blood as well as brain, we compared four groups of wild type (WT) and MMP-9 knockout (KO) mice: WT blood injected into WT brain, KO blood into KO brain, WT blood into KO brain, and KO blood into WT brain. Gel zymography showed that MMP-9 was elevated in WT hemorrhagic brain tissue but absent from KO hemorrhagic brain tissue. Edematous water content was elevated when WT blood was injected into WT brain. However, edema was ameliorated when MMP-9 was absent in either blood or brain or both. To further assess the mechanisms involved in astrocytic induction of MMP-9, we next examined primary mouse astrocyte cultures. Exposure to hemoglobin rapidly upregulated MMP-9 in conditioned media within 1 to 24 h. Hemoglobin-induced MMP-9 was reduced by the free radical scavenger U83836E. Taken together, these data suggest that although there are large amounts of MMP-9 in blood, hemoglobin-induced oxidative stress can trigger MMP-9 in astrocytes and these parenchymal sources of matrix degradation may also be an important factor in the pathogenesis of hemorrhagic brain edema. 相似文献
82.
Opioid tolerance and opioid-induced hyperalgesia are conditions that negatively affect pain management. Tolerance is defined as a state of adaptation in which exposure to a drug induces changes that result in a decrease of the drug's effects over time. Opioid-induced hyperalgesia occurs when prolonged administration of opioids results in a paradoxic increase in atypical pain that appears to be unrelated to the original nociceptive stimulus. Complex intracellular neural mechanisms, including opioid receptor desensitization and down-regulation, are believed to be major mechanisms underlying opioid tolerance. Pain facilitatory mechanisms in the central nervous system are known to contribute to opioid-induced hyperalgesia. Recent research indicates that there may be overlap in the two conditions. This article reviews known and hypothesized pathophysiologic mechanisms surrounding these phenomena and the clinical implications for pain management nurses. 相似文献
83.
Anna Gasinska Jan Skolyszewski Tadeusz Popiela Piotr Richter Zbigniew Darasz Krystyna Nowak Joanna Niemiec Beata Biesaga Agnieszka Adamczyk Krzysztof Bucki Krzysztof Malecki Marian Reinfuss Teresa Kowalska 《Journal of gastrointestinal surgery》2007,11(4):520-528
Purpose Assessment of tumor proliferation rate using Bromodeoxyuridine labeling index (BrdUrdLI) as a possible predictor of rectal
cancer response to preoperative radiotherapy (RT).
Methods and material Ninety-two patients were qualified either to short RT (5 Gy/fraction/5 days) and surgery about 1 week after RT (schedule I),
or to short RT and 4–5 weeks interval before surgery (schedule II). Tumor samples were taken twice from each patient: before
RT and at the time of surgery. The samples were incubated with BrdUrd for 1 h at 37°C, and the BrdUrdLI was calculated as
a percentage of BrdUrd-labeled cells.
Results Thirty-eight patients were treated according to schedule I and 54 patients according to schedule II. Mean BrdUrdLI before
RT was 8.5% and its value did not differ between the patients in the two compared groups. After RT tumors showed statistically
significant growth inhibition (reduction of BrdUrdLI). As the pretreatment BrdUrd LI was not predictive for early clinical
and pathologic tumor response, prognostic role of the ratio of BrdUrdLI after to BrdUrdLI before RT was considered. The ratios
were calculated separately for fast (BrdUrd LI > 8.5%) and slowly (BrdUrd LI ≤ 8.5%) proliferating tumors and correlated with
overall treatment time (OTT, i.e., time from the first day of RT to surgery). One month after RT, accelerated proliferation
was observed only in slowly proliferating tumors.
Conclusions Pretreatment BrdUrdLI was not predictive for early clinical and pathologic tumor response. The ratio after/before RT BrdUrdLI
was correlated to inhibition of proliferation in responsive tumors.
The paper was presented at ECCO 13, October 30 to November 03, 2005 in Paris, France 相似文献
84.
85.
The effect of single and repeated UVB radiation on rabbit cornea 总被引:1,自引:0,他引:1
Miroslav Fris May-Britt Tessem Jitka Čejková Anna Midelfart 《Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie》2006,244(12):1680-1687
Background Cumulative effect of ultraviolet radiation (UVR) is an important aspect of UV corneal damage. The purpose of this study was to apply high resolution magic angle spinning proton nuclear magnetic resonance (HR-MAS 1H NMR) spectroscopy to evaluate the effect of single and repeated UV radiation exposure of the same overall dose on the rabbit cornea.Methods Corneal surfaces of 24 normal rabbit eyes were examined for the effects of UVB exposure (312 nm). In the first group (UVB1), animals were irradiated with a single dose (3.12 J/cm2; 21 min) of UVB radiation. The animals in the second group (UVB2) were irradiated three times for 7 min every other day (dose of 1.04 J/cm2; days 1, 3, 5) to give the same overall dose (3.12 J/cm2). The third group served as an untreated control group. One day after the last irradiation, the animals were sacrificed, and the corneas were removed and frozen. HR-MAS 1H NMR spectra from intact corneas were obtained. Special grouping patterns among the tissue samples and the relative percentage changes in particular metabolite concentrations were evaluated using modern statistical methods (multivariate analysis, one-way ANOVA).Results The metabolic profile of both groups of UVB-irradiated samples was significantly different from the control corneas. Substantial decreases in taurine, hypo-taurine and choline-derivatives concentrations and substantial elevation in glucose and betaine levels were observed following the UVR exposure. There was no significant difference between the effect of a single and repeated UVB irradiation of the same overall dose.Conclusions For the first time, the effects of single and repeated UVR doses on the metabolic profile of the rabbit cornea were analysed and compared. The combination of HR-MAS 1H NMR spectroscopy and modern statistical methods (multivariate analysis, one-way ANOVA) proved suitable to assess the overall view of the metabolic alterations in the rabbit corneal tissue following UVB radiation exposure. 相似文献
86.
Evaluation of 188 consecutive homografts implanted in pulmonary position after 20 years. 总被引:1,自引:0,他引:1
Dietmar Boethig Heidi Goerler Mechthild Westhoff-Bleck Masamichi Ono Anna Daiber Axel Haverich Thomas Breymann 《European journal of cardio-thoracic surgery》2007,32(1):133-142
OBJECTIVE: Homografts are considered the gold standard for right ventricular outflow tract reconstruction. Their long-term durability is limited, and alternatives became available. We evaluate their long-term hemodynamic performance to permit comparisons with alternative devices. METHODS: Between 1985 and 2004, 188 homografts were implanted in pulmonary position at our institution. Mean patient age was 24.8 years (range 2 days-75 years); 56 were female and 132 male. Total follow-up time was 1073 years. Fifty-eight percent were Ross procedures (mean age 31.5 years) and 42% were different procedures (mean age 15.6 years); main diagnoses were tetralogy of Fallot (48%), truncus arteriosus (14%), transposition of the great arteries (11%). Twenty-six percent were redo implantations. We evaluated freedom from death, explantation, insufficiency, relevant gradient, degeneration, and the interval between diagnosis of degeneration and therapeutic procedure (therapeutic gap). Results were stratified by indication, age, history, homograft size, and origin. RESULTS: Ten-year-freedom-from explantation was 82% in homografts >19 mm and 45% in smaller ones. Ten-year freedom from degeneration was 68% after Ross procedure and 25% after other operations; it was 83% in patients older than 10 years at implantation and 51% in younger ones. 'Non-Ross-procedure' and 'implantation age below 10 years' were the only independent risk factors for degeneration. The observed trend towards therapeutical gap reduction was not statistically significant. CONCLUSIONS: Homograft implantation in the pulmonary position can be performed with good long-term freedom from explantation. However, freedom from degeneration is a matter of concern. Therefore, alternative valved conduits are required especially for pediatric patients. 相似文献
87.
88.
Anna Gliszczyńska-Swig?o Hester van der Woude Laura de Haan Bozena Tyrakowska Jac M M J G Aarts Ivonne M C M Rietjens 《Toxicology in vitro》2003,17(4):423-431
The effects of quercetin on viability and proliferation of Chinese Hamster Ovary (CHO) cells and CHO cells overexpressing human quinone reductase (CHO+NQO1) were studied to investigate the involvement of the pro-oxidant quinone chemistry of quercetin. The toxicity of menadione was significantly reduced in CHO+NQO1 cells compared to wild-type CHO cells, validating the NQO1-overexpression in the CHO+NQO1 transfectant. Quercetin inhibited the proliferation of wild-type CHO and CHO+NQO1 cells to a similar extent without affecting cell viability, indicating that NQO1 enrichment of CHO cells did not provide increased protection. On the other hand, inhibition of NQO1 in both types of cells by dicoumarol significantly potentiated the inhibitory effect of quercetin on cell proliferation, revealing the role of NQO1 in cellular protection against quercetin. Altogether, these results can be explained by the hypothesis that both wild-type CHO and CHO+NQO1 cells contain sufficient NQO1 activity for optimal protection against the pro-oxidant effect of quercetin on cell proliferation. The results also point at a cellular NQO1 threshold for optimal protection against quercetin. This NQO1 threshold seems to be in the range of NQO1 activities already present in various tissues. 相似文献
89.
Anna Di Landro Lorenzo Marchesi Luigi Naldi Teresio Motta Tullio Cainelli 《Pediatric dermatology》1997,14(6):449-452
Abstract: Hypopigmented mycosis fungoides is a variant of mycosis fungoides characterized by the presence of hypopigmented patches as the sole manifestation of the disease. It has been described aimost always in young black or dark-skinned patients. The only white patient described was a 64-year-oid woman who not oniy had hypopigmented lesions, but also nodular lesions with lymphadenopathy. We describe hypopigmented lesions arising in a white boy 12 years of age, born in northern Italy, without any foreign ancestors. The microscopic alterations, with epidermotropism, the immunoiogic markers, the negativity of T-cell receptor gene rearrangement, and the good response to PUVA therapy correspond to the main findings in black patients with this disease. Long-term follow-up of these patients is important to obtain better knowledge of the natural history of the disorder, Hypopigmented mycosis fungoides must now be included in the differential diagnosis of hypopigmented macular lesions not only in black or dark-skinned patients but also in white patients. 相似文献
90.
Anna P Basu Prashant Kumar Anita M Devlin Christopher J O'Brien 《European journal of paediatric neurology》2007,11(4):240-242
A 15-week old male infant presented with bilateral lower motor neuron facial palsy of unknown cause. Subsequently his growth deteriorated and he developed progressively worsening cough and wheeze. A diagnosis of cystic fibrosis was confirmed and hypovitaminosis A detected. Improvement of the facial palsy was noted following standard management of cystic fibrosis including vitamin A supplementation. 相似文献