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991.
Aleksandro S. Da Silva Patrícia WolkmerJoao T.S. Nunes Marcos R.K. DuckCamila B. Oliveira Lucas T. GresslerMarcio M. Costa Régis A. ZanetteCinthia M. Mazzanti Sonia T.A. LopesSilvia G. Monteiro 《Biomedicine & Pharmacotherapy》2011,65(3):220-223
Drugs, which are effective during the early stage of trypanosomosis, but poorly penetrate the blood-brain barrier, are ineffective when parasites reach the brain and cause encephalitis. In order to seek alternative treatments, the aim of this study was to test the susceptibility of T. evansi to cordycepin in vitro and in rats experimentally infected. In vitro, a significant decrease (P < 0.01) in live trypanosomes in the concentrations of 5.0 and 10 μg/mL was observed 1 hour after the beginning of the study, as well as at 3, 6, 9 and 12 hours in all concentrations compared to control. Although no curative effects were observed in the in vivo assay in the majority of groups, the drug was able to maintain parasitemia at low levels, therefore increasing the longevity of rats when compared to positive control group. Rats that received cordycepin alone or in combination with adenosine deaminase inhibitor (ADA: EHNA hydrochloride), did not show trypomastigote forms of the parasite in the bloodstream 24 hours after the administration. These animals remained negative in blood smears on average for 8 days, but thereafter had a recurrence of parasitemia. Among all the infected animals, only three rats in the group treated with the combination of cordycepin (2 mg/kg) and EHNA hydrochloride (2 mg/kg) remained negative during the experimental period. The curative efficacy of 42.5% was confirmed by PCR using T. evansi-specific primers. Thus, we conclude that cordycepin has biological effect against T. evansi, as previously reported in infections by T. brucei, T. cruzi and Leishmania sp. The treatment with cordycepin, when protected by an inhibitor of ADA, can prolong the survival of T. evansi-infected rats and provide curative efficacy. 相似文献
992.
Lucas L. Colombo Marí a C. L pez GuanJie Chen Ronald R. Watson 《Immunopharmacology and immunotoxicology》2001,23(4):607-616
Oncomouse is a transgenic mouse carrying an activated v-Ha-ras oncogene under the control of the mouse mammary tumor virus promoter. The objective of this paper was to learn if the in vitro secretion of IL-2 and IFN-γ and the release of sIL-2R by Oncomice spleen and thymus cells depended on the presence of the oncogene product, on the in vivo pretreatment with cocaine, or on the in vitro treatment with cocaine or morphine. Oncomice thymocytes from different experimental groups released less sIL-2R than FVB thymocytes. Oncomice thymocytes secreted more IFN-γ than FVB thymocytes. Oncomice thymocytes cultured in the presence of Con A and cocaine showed a diminished release of sIL-2R and a lower secretion of IFN-γ, a phenomenon not observed in FVB thymocytes. IFN-γ secretion was lower in Oncomice splenocytes. In general, Oncomice thymocytes and splenocytes responded in a nearly opposite fashion to their FVB counterparts. In this study, the in vitro response to mitogens, cocaine or morphine depended on genetic background and not on the in vivo pretreatment with cocaine. Our results emphasize the role of the v-Ha-ras oncogene in defining the host immune response. 相似文献
993.
Lucas G. Gamero† Ricardo L. Armentano§ Juan G. Barra Alain Simon‡ Jaime Levenson‡ 《Experimental physiology》2001,86(4):519-528
Viscoelastic properties determine the dynamic behaviour of the arterial wall under pulsatile pressure and flow, suggesting time- or frequency-dependent responses to changes in wall stress and strain. The objectives of the present study were: (i) to develop a simplified model to derive simultaneously the elastic, viscous and inertial wall moduli; (ii) to assess Young's modulus as a function of frequency, in conscious, chronically instrumented dogs. Parametric discrete time models were used to characterise the dynamics of the arterial system based on thoracic aortic pressure (microtransducer) and diameter (sonomicrometry) measurements in control steady state and during activation of smooth muscle with the alpha-adrenoceptor agonist phenylephrine (5 microg kg(-1) min(-1), I.V.), in eight conscious dogs. The linear autoregressive model and a physically motivated non-linear model were fitted to the input-output (stress-strain) relationship. The aortic buffering function (complex Young's modulus) was obtained in vivo from the identified linear model. Elastic, viscous and inertial moduli were significantly increased from control state ((44.5 +/- 7.7) x 10(4) Pa; (12.3 +/- 4.7) x 10(4) Pa s; (0.048 +/- 0.028) x 10(4) Pa s(2) ) to active state ((85.3 +/- 29.5) x 10(4) Pa, P < 0.001; (22.4 +/- 8.3) x 10(4) Pa s, P < 0.05; (0.148 +/- 0.060) x 10(4) Pa s(2), P < 0.05). These moduli, obtained using the linear model, did not present significant differences compared with those derived using the non-linear model. In control conditions, the magnitude of the normalised complex Young's modulus was found to be similar to that reported in previous animal studies ranging from 1 to 10 Hz. During vascular smooth muscle activation, this modulus was found to be increased with regard to control conditions (P < 0.01) in the frequency range used in this study. The frequency-dependent Young's modulus of the aortic wall was obtained for the first time in conscious, unsedated dogs. The parametric modelling approach allows us to verify that vascular smooth muscle activation increases the elastic, viscous and inertial moduli with the advantage of being able to track their time evolution. Furthermore, under activation, the aortic wall remains stiff in the physiological frequency range, suggesting the impairment of the arterial buffering function. Experimental Physiology (2001) 86.4, 519-528. 相似文献
994.
E M Burke J D Haman J J Weimer A B Cheney J M Rigsbee L C Lucas 《Journal of biomedical materials research》2001,57(1):41-47
The success of calcium phosphate (CaP) coatings used to accelerate initial bone growth onto dental implants can vary depending on the CaP phases present in the coating. In this study, the effect of CaP coating crystal structure and morphology on dissolution rates was investigated. RF magnetron-sputtered CaP coatings (NTC) were compared to a less strained coating (HTC) obtained from heat treatment of sputtered samples at 550 degrees C. Coating strain differences were apparent in XRD spectra where hydroxyapatite-like planes shifted by 0.5 degrees 2theta and 0.05 degrees 2theta for the NTC and HTC coatings, respectively. HTC XRD peak widths were broader than NTC peak widths, indicating smaller crystals or grain sizes. These differences in grain size were corroborated by imaging with scanning probe microscopy. NTC coatings dissolved at a 300% faster rate than HTC coatings. A major factor contributing to this kinetic effect was the level of strain in both coatings. These results suggest an alternate design for CaP coatings can be obtained through the manipulation of coating strain. Using this approach, delivery of different ionic gradients from CaP coatings to surrounding tissue environments can be obtained from surfaces having similar chemistries. 相似文献
995.
Cavailler P Lucas M Perroud V McChesney M Ampuero S Guérin PJ Legros D Nierle T Mahoudeau C Lab B Kahozi P Deen JL von Seidlein L Wang XY Puri M Ali M Clemens JD Songane F Baptista A Ismael F Barreto A Chaignat CL 《Vaccine》2006,24(22):4890-4895
We conducted a study to assess the feasibility and the potential vaccine coverage of a mass vaccination campaign using a two-dose oral cholera vaccine in an urban endemic neighbourhood of Beira, Mozambique. The campaign was conducted from December 2003 to January 2004. Overall 98,152 doses were administered, and vaccine coverage of the target population was 58.6% and 53.6% for the first and second rounds, respectively. The direct cost of the campaign, which excludes the price of the vaccine, amounted to slightly over 90,000 dollars, resulting in the cost per fully vaccinated person of 2.09 dollars, which is relatively high. However, in endemic settings where outbreaks are likely to occur, integrating cholera vaccination into the routine activities of the public health system could reduce such costs. 相似文献
996.
997.
Chopard Romain Campia Umberto Morin Lucas Jering Karola S. Almarzooq Zaid I. Snyder Julia Elizabeth Rizzo Samantha Waxman Aaron B. Goldhaber Samuel Z. Piazza Gregory 《Journal of thrombosis and thrombolysis》2022,54(3):449-460
Journal of Thrombosis and Thrombolysis - Multidisciplinary pulmonary embolism (PE) response teams have garnered widespread adoption given the complexities of managing acute PE and provide a... 相似文献
998.
Lucas F Soveral Gabriela G Korczaguin Pedro S Schmidt Isabel S Nunes Camilo Fernandes Carlos R Z rate-Blad s 《World journal of gastroenterology : WJG》2022,28(33):4762-4772
Fecal microbiota transplantation (FMT) is a successful method for treating recurrent Clostridioides difficile (C. difficile) infection (rCDI) with around 90% efficacy. Due to the relative simplicity of this approach, it is being widely used and currently, thousands of patients have been treated with FMT worldwide. Nonetheless, the mechanisms underlying its effects are just beginning to be understood. Data indicate that FMT effectiveness is due to a combination of microbiological direct mechanisms against C. difficile, but also through indirect mechanisms including the production of microbiota-derived metabolites as secondary bile acids and short chain fatty acids. Moreover, the modulation of the strong inflammatory response triggered by C. difficile after FMT seems to rely on a pivotal role of regulatory T cells, which would be responsible for the reduction of several cells and soluble inflammatory mediators, ensuing normalization of the intestinal mucosal immune system. In this minireview, we analyze recent advances in these immunological aspects associated with the efficacy of FMT. 相似文献
999.
Chalub Lucas Orbolato Nunes Gabriel Pereira Ferrisse Túlio Morandin Strazzi-Sahyon Henrico Badaoui Dos Santos Paulo Henrique Gomes-Filho João Eduardo Cintra Luciano Tavares Angelo Sivieri-Araujo Gustavo 《Clinical oral investigations》2022,26(4):3343-3356
Clinical Oral Investigations - The objective of this systematic review and meta-analysis (SRM) was to answer the question whether the use of ultrasonic irrigation (UI) results in less postoperative... 相似文献
1000.
Velasques Bibiana Dalsasso Moura Lucas Borin Martins João Roig Damian Melissa Feres Xavier Cristina Braga 《Oral and maxillofacial surgery》2021,25(2):139-148
Oral and Maxillofacial Surgery - Le Fort I osteotomy is the most common procedure for maxillary advancement in cleft patients, and a significant relapse is expected in the postoperative period.... 相似文献