全文获取类型
收费全文 | 3734篇 |
免费 | 244篇 |
国内免费 | 23篇 |
专业分类
耳鼻咽喉 | 36篇 |
儿科学 | 107篇 |
妇产科学 | 105篇 |
基础医学 | 517篇 |
口腔科学 | 115篇 |
临床医学 | 264篇 |
内科学 | 957篇 |
皮肤病学 | 82篇 |
神经病学 | 327篇 |
特种医学 | 44篇 |
外科学 | 604篇 |
综合类 | 22篇 |
预防医学 | 272篇 |
眼科学 | 72篇 |
药学 | 251篇 |
中国医学 | 34篇 |
肿瘤学 | 192篇 |
出版年
2023年 | 20篇 |
2022年 | 61篇 |
2021年 | 87篇 |
2020年 | 55篇 |
2019年 | 77篇 |
2018年 | 114篇 |
2017年 | 58篇 |
2016年 | 74篇 |
2015年 | 100篇 |
2014年 | 121篇 |
2013年 | 143篇 |
2012年 | 215篇 |
2011年 | 239篇 |
2010年 | 153篇 |
2009年 | 135篇 |
2008年 | 202篇 |
2007年 | 252篇 |
2006年 | 204篇 |
2005年 | 182篇 |
2004年 | 200篇 |
2003年 | 172篇 |
2002年 | 167篇 |
2001年 | 66篇 |
2000年 | 94篇 |
1999年 | 85篇 |
1998年 | 52篇 |
1997年 | 36篇 |
1996年 | 22篇 |
1995年 | 31篇 |
1994年 | 25篇 |
1993年 | 15篇 |
1992年 | 28篇 |
1991年 | 46篇 |
1990年 | 32篇 |
1989年 | 34篇 |
1988年 | 40篇 |
1987年 | 34篇 |
1986年 | 37篇 |
1985年 | 26篇 |
1984年 | 20篇 |
1983年 | 17篇 |
1982年 | 14篇 |
1981年 | 13篇 |
1979年 | 22篇 |
1978年 | 19篇 |
1973年 | 12篇 |
1972年 | 15篇 |
1971年 | 14篇 |
1969年 | 12篇 |
1968年 | 12篇 |
排序方式: 共有4001条查询结果,搜索用时 15 毫秒
1.
2.
Luis Gajate Ascensión Martín Elena Elías Maria T Tenorio Angélica de Pablo Cristina Carrasco Adolfo Martínez Angel Candela Javier Zamora Fernando Lia?o 《Liver transplantation》2006,12(9):1371-1380
Although renal dysfunction is common after liver transplantation, postoperative renal function after split liver transplantation (SLT) has not been well studied. Renal function immediately after surgery was analyzed retrospectively in 16 patients that received a SLT (SLT group). The results were compared with corresponding data from 31 matched patients that received a full-size liver transplant (FSLT group) during the same period. Serum creatinine (SCr) was measured before surgery, and, after transplantation, daily during the first week and at days 14, 21, and 28. Renal dysfunction (RD) was defined as the requirement for renal replacement therapy (RRT) or a 100% increase in SCr if the basal value had been <1.0 mg/dL or a 50% increase in SCr if the basal value had been >1.0 mg/dL. SCr had to be at least 1.5 mg/dL for a diagnosis of RD to be considered. The classification of RD was: mild, SCr 1.5-2.4 mg/dL; moderate, SCr 2.5-4.0 mg/dL; or severe, SCr >4.0 mg/dL (the requirement for RRT). Both donor and recipient age and cold ischemia time were lower in the SLT group than in the FSLT group (P < 0.05). Length of surgery was longer in the SLT group (P < 0.05). There were no significant differences between groups with respect to Model for End-Stage Liver Disease scores, the need for transfusions, the length of admission to the intensive care unit (ICU), survival rate, individual severity index, or sepsis-related organ failure assessment scores at the time of diagnosing RD. Immunosuppression regimens were similar in both groups. RD developed in 82% of SLT patients, but in only 58% of FSLT patients (P = not significant [NS]). Among SLT patients, RD (23.0% mild, 15.5% moderate, and 61.5% severe) was more severe (P = 0.007) than in FSLT patients (63.1% mild, 15.8% moderate, and 24.1% severe). The requirement for RRT in the SLT group (43.7%) was significantly greater (P < 0.05) than that in the FSLT group (12.9%). This finding may be due to the different incidence of sepsis in the 2 groups (SLT 37.5% vs. FSLT 9.7%; P < 0.05). In conclusion, although the number of patients studied was small, our data suggest a higher incidence of RD and a greater requirement for RRT in patients that receive a split liver graft than in those that receive a full size liver graft. 相似文献
3.
Transplacental IgG Subclass Concentrations in Pregnancies at Risk of Haemolytic Disease of the Newborn 总被引:5,自引:0,他引:5
A. Lubenko Marcela Contreras C.H. Rodeck U. Nicolini Julia Savage and H. Chana 《Vox sanguinis》1994,67(3):291-298
The relationship of haemolytic disease of the newborn (HDN) to the transplacental passage of the four IgG subclasses was assessed at varous gestational ages by comparing the maternal and fetal IgG subclass concentrations in 34 pregnancies at risk of HDN with those in 30 pregnancies not at risk. Higher maternal and fetal IgG1 levels were attained in pregnancies at risk of HDN than in pregnancies not at risk. In contrast, a slight decrease in maternal IgG2 and IgG4 levels occurred in pregnancies at risk of HDN, as compared with a slight rise in maternal IgG2 and IgG4 levels in pregnancies not at risk of HDN. Changes in fetal IgG2 and 4 concentrations in either type of pregnancy were very similar, showing only slight increases between the 19th and 34th week of gestation. A slight decrease in maternal IgG3 occurred in both types of pregnancy. In contrast, higher and fairly steady levels of fetal IgG3 were observed in fetuses not at risk of HDN throughout gestation, when compared with those in 'at risk' pregnancies. However, the statistical reliability of these results is not clear since only small numbers of samples were tested and because wide variations in IgG concentrations were observed. The IgG subclass concentrations in 50 paired maternal and cord blood samples were also measured and revealed that IgG1 levels were substantially higher in cord rather than maternal blood; cord and maternal IgG2, 3 and 4 levels, on the other hand, were fairly similar. 相似文献
4.
Lucy Yardley David Papo Adolfo Bronstein Michael Gresty Mark Gardner Nilli Lavie Linda Luxon 《Neuropsychologia》2002,40(4):373-383
The aim of this series of experiments was to determine whether attention is normally required for continuously processing vestibular information concerning orientation, or is required only when orientation is disrupted (eg by vestibular dysfunction or by conflicting visual and vestibular orientation cues). In the first two studies, healthy subjects were passively oscillated, and indicated when they perceived they were passing through their starting position. There was only weak evidence for interference between performance on this 'continuous orientation monitoring task' and on concurrent mental tasks. However, a third study showed that when patients with vestibular imbalance carried out the continuous orientation monitoring task their performance on a concurrent mental arithmetic task was substantially impaired. This dual task interference was correlated with inaccuracy in judging orientation on the continuous orientation monitoring task, which in turn correlated with severity of recent vestibular symptomatology (assessed by questionnaire). In a fourth experiment, disorientation was induced in healthy subjects by rotating the visual field about the line of sight. Bidirectional interference was observed between monitoring orientation (assessed by accuracy in setting a rod to the perceived vertical) and performance of an arithmetic task. Dual task interference was correlated with baseline levels of disorientation induced by the visual field, as indicated by inaccuracy in judging the visual vertical. These findings suggest that monitoring orientation makes significant demands upon cortical processing resources when disorientation is induced, whether the disorientation results from deficient sensory functioning or from ambiguous perceptual information. 相似文献
5.
An extensive field survey allowed us to expand the geographical distribution of the scorpion Tityus perijanensis in the Perijá range, western Zulia State, Venezuela, including areas where adult cases of severe scorpionism have been reported. 16S ribosomal RNA (rRNA) gene sequencing, DL(50) determination, and native PAGE suggest low genetic and venom proteomic divergence across the distribution range. The results also indicate phylogenetic divergence between T. perijanensis and T. discrepans, the species prevalent in northcentral Venezuela. T. perijanensis venom lethality (0.91-0.94 mg/kg) is comparable to that of the Brazilian T. serrulatus and ranks highest among toxic Venezuelan Tityus studied so far. The data indicate that the Perijá range should be included amongst the endemic areas of scorpionism of Venezuela and Colombia. 相似文献
6.
7.
Paolo Ammendola Adolfo Zambelli Leone Oliva Teodorico Tancredi 《Macromolecular chemistry and physics.》1986,187(5):1175-1188
The chain propagation rate constants for the polymerization of ethylene and propene in the presence of δ-TiCl3/Al(CH3)3 at 22 °C are determined by means of a 13C NMR analysis of suitable block copolymers. The numerical values of the rate constants are compared with those previously reported. 相似文献
8.
F Monroy-Guzmán L V Díaz-Archundia A Contreras Ramírez 《Applied radiation and isotopes》2003,59(1):27-34
Zirconium molybdate gels have shown to be viable alternatives for preparation of 99mTc generators using 99Mo produced by neutron activation. The aim of this work was to investigate the effect of the Zr:Mo molar ratio on the gel chemical structure and correlate it with the elution efficiency. A series of gels were prepared at Zr:Mo molar ratios from 0.5:1 to 2.3:1 and characterized by TGA, IR, XRD and UV. It was found that the variation of Zr:Mo ratio produces different polymolybdate arrangements on the octahedral units around to the zirconia which is mainly influenced by the water content. When the matrix molybdenum concentration was increased a lesser amount of water was found and the elution efficiencies were increased. However high elution efficiencies produce higher 99Mo breakthrough values. The gel formulation appears thus to be a compromise between the elution efficiency and the molybdenum breakthrough. The chemical-physical properties of these gels are presented and discussed. 相似文献
9.
F. Contreras J. L. Rodriguez-Peralto J. Palacios M. Patron R. Martin-Molinero 《Journal of cutaneous pathology》1987,14(4):238-241
We report the case of a 67-year-old man with a granular, cauliflower-pink lesion on the skin of the thigh. Histopathological study showed a typical verrucous carcinoma associated with a syringadenoma papilliferum. To our knowledge this association has not been previously reported. 相似文献
10.
Neurophysiological studies have shown that glycine potentiates the NMDA response in cultured neurons by a strychnine-insensitive mechanism. Autoradiographic data have demonstrated a correspondence between strychnine-insensitive [3H]glycine binding sites and NMDA-sensitive [3H]glutamate binding sites. Here we report that in synaptic plasma membranes from rat brain, the binding of a PCP analog, [3H]TCP, was enhanced more than 5-fold by 1 microM glycine. This glycine stimulation of binding of [3H]TCP was blocked by the competitive NMDA-receptor antagonist, D-AP7. These data provide support for the hypothesis that a unique amino acid recognition site is associated with the proposed NMDA/PCP receptor complex in brain. 相似文献