全文获取类型
收费全文 | 49802篇 |
免费 | 2541篇 |
国内免费 | 394篇 |
专业分类
耳鼻咽喉 | 499篇 |
儿科学 | 990篇 |
妇产科学 | 1408篇 |
基础医学 | 6011篇 |
口腔科学 | 1841篇 |
临床医学 | 3805篇 |
内科学 | 13546篇 |
皮肤病学 | 1009篇 |
神经病学 | 4287篇 |
特种医学 | 1391篇 |
外科学 | 7459篇 |
综合类 | 193篇 |
一般理论 | 9篇 |
预防医学 | 3012篇 |
眼科学 | 985篇 |
药学 | 2784篇 |
中国医学 | 119篇 |
肿瘤学 | 3389篇 |
出版年
2023年 | 320篇 |
2022年 | 673篇 |
2021年 | 1568篇 |
2020年 | 843篇 |
2019年 | 1210篇 |
2018年 | 1648篇 |
2017年 | 1104篇 |
2016年 | 1184篇 |
2015年 | 1414篇 |
2014年 | 1913篇 |
2013年 | 2507篇 |
2012年 | 3879篇 |
2011年 | 3834篇 |
2010年 | 2161篇 |
2009年 | 1869篇 |
2008年 | 3288篇 |
2007年 | 3401篇 |
2006年 | 3228篇 |
2005年 | 3186篇 |
2004年 | 2918篇 |
2003年 | 2612篇 |
2002年 | 2337篇 |
2001年 | 483篇 |
2000年 | 367篇 |
1999年 | 446篇 |
1998年 | 423篇 |
1997年 | 371篇 |
1996年 | 351篇 |
1995年 | 314篇 |
1994年 | 248篇 |
1993年 | 181篇 |
1992年 | 233篇 |
1991年 | 173篇 |
1990年 | 172篇 |
1989年 | 163篇 |
1988年 | 155篇 |
1987年 | 115篇 |
1986年 | 132篇 |
1985年 | 126篇 |
1984年 | 124篇 |
1983年 | 90篇 |
1982年 | 109篇 |
1981年 | 82篇 |
1980年 | 81篇 |
1979年 | 64篇 |
1978年 | 74篇 |
1977年 | 53篇 |
1976年 | 56篇 |
1974年 | 51篇 |
1973年 | 59篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
91.
Ennio Del Giudice Maria Cristina Bianchi Michela Tosetti Andrea Varrone Alfonso Romano Angela Francesca Crisanti Luigi Titomanlio Floriana Imperati 《Epileptic Disord》2006,8(4):289-293
Patients with Taylor-type focal cortical dysplasia (TTFCD) generally present with medically intractable epilepsy and impaired neurological and/or intellectual functioning. Surgery usually proves to be the only treatment approach leading to control of seizures. We describe a 17-year-old girl with TTFCD who exhibited a very long period of seizure remission. Combined clinical and neuroimaging findings were compatible with a diagnosis of a balloon cell-subtype TTFCD. As for the clinical course, partial motor seizures began at one year of age and ceased at five: our patient has had no seizure recurrence over a 12-year-follow-up. Moreover, throughout the 15-year follow-up, neurological examinations and cognitive abilities always remained within normal limits. Neuropsychological assessment clearly showed no impairments in executive functions: planning abilities, working memory, attention and impulse control, or constructive aspects of motor coordination. The predominant deficits pertained to verbal abilities in the context of borderline intellectual performances. To our knowledge, this case report documents the longest duration of seizure remission in a patient with TTFCD, thus emphasizing the possible benign course of such dysplastic lesions which usually have a poor prognosis, leading to early surgical treatment. 相似文献
92.
G M Grasso M M D'Errico F Schioppa F Romano D Montanaro 《Epidemiology and infection》1988,101(2):315-320
A comparison was made of different culture media and procedures for detection of Serratia marcescens from faecal, pharyngeal and ocular swabs collected from 213 neonates. MacConkey agar and MacConkey agar with sorbitol (1%) and/or colistin (200 i.u./ml) were used both for primary isolation and after enrichment using Mossel Enterobacteriaceae broth with colistin (200 i.u./ml). The use of MacConkey agar supplemented with colistin for primary isolation improved considerably the isolation rate of S. marcescens from faecal swabs but not from pharyngeal swabs; the number of ocular isolations were insufficient to demonstrate differences between procedures. Moreover the enrichment procedures consistently increased the number of S. marcescens isolates especially from pharyngeal and ocular swabs. Use of sorbitol made detection of S. marcescens from clinical specimens easier and time- and cost-efficient. 相似文献
93.
Stefano Tamburin Antonio Fiaschi Domenico Idone Piergiorgio Lochner Paolo Manganotti Giampietro Zanette 《Movement disorders》2003,18(11):1316-1324
Hyperexcitability of the motor system has been reported in Parkinson's disease (PD). We evaluate how cutaneous afferents modulate motor excitability in PD patients and whether abnormal modulation is correlated to parkinsonian symptoms. Digital stimulation causes abnormal enhancement of motor responses in patients. This effect may be one of the features of motor hyperexcitability in PD. Cutaneomotor hyperexcitability correlates with clinical scores, suggesting that abnormal processing of cutaneous inputs might contribute to the pathogenesis of parkinsonian symptoms. 相似文献
94.
The stability of single nephron glomerular filtration rate (SNGFR) is assured by specific mechanisms such as the tubulo-glomerular feedback system and autoregulation. Studies on renal physiology rely heavily on the measurements of SNGFR, which are feasible only in animals. The measurement of SNGFR by collection of total tubular fluid may be influenced by the fall in intratubular hydrostatic pressure that may reflect the negative pressure applied to the sampling pipette. This effect may become more important with shortening of the distance between the sampling site and the Bowman space. We analysed this putative effect by performing collections of total tubular fluid from the late proximal (LP), and then from the early proximal (EP) segment of the same nephrons. In 128 paired collections LP-SNGFR averaged 35 (SEM 2) nl?·?min?1, and was no different from the paired mean EP-SNGFR of 37 (SEM 2) nl?·?min?1, P>0.179. Then EP- and LP- SNGFR were significantly correlated (r=0.77, P<0.001). As expected, the respective paired means of absolute and percentage reabsorptions, and those of collection rates were significantly different. The average SNGFR computed from each LP and EP paired measurement was significantly correlated with the simultaneously measured kidney glomerular filtration rate, GFR (r=0.60, P<0.0001). The ratio of GFR to SNGFR indicated the expected number of glomeruli. These data would indicate that the sampling site does not influence the measurement of SNGFR in the proximal tubule when the total fluid collection technique is correctly performed. They also exclude a time-dependent activation of the macula densa capable of upregulating SNGFR within the interval elapsing between the beginning of LP and the completion of EP collections, which in our study averaged 4.4 (SEM 0.1) min. 相似文献
95.
Eric Vivier Antonio J. da Silva Melissa Ackerly Herbert Levine Christopher E. Rudd Paul Anderson 《European journal of immunology》1993,23(8):1872-1876
The CD16: ζ: γ receptor complex allows natural killer (NK) cells to recognize and eliminate antibody-coated target cells. Whereas the ectodomain of CD16 is the receptor for Fcγ domains of immunoglobulins, disulfide-linked homo- and heterodimers composed of ζ and γ are required for the cell surface expression, and signal transduction properties of the complex. Engagement of CD16 activates the tyrosine kinase pathway, which induces the tyrosine phosphorylation of several substrates, including the ζ subunit and the phospholipase C γ-1 and γ-2 isoforms. Here we show that CD 16 stimulation of either peripheral blood NK cells, leukemic NK cells, or Jurkat transformants expressing a CD16:ζ:γ receptor complex, results in the tyrosine phosphorylation of a 70 kDa ζ-associated protein (pp70). Similarly, a 70-kDa ζ-associated phosphoprotein in T cells has been shown to be a tyrosine kinase (ZAP-70). Peptide mapping analysis indicates that the 70-kDa ζ-associated phosphoproteins from T cells and NK cells are structurally indistinguishable. We conclude that the CD16:ζ:γ complex may use a ZAP-70-related non-receptor tyrosine kinase, in the CD16 signaling cascade leading to NK cell activation. 相似文献
96.
Romano Maurizio; Dri Pietro; Dadalt Liviana; Patriarca Pierluigi; Baralle Francisco E. 《Blood》1997,90(10):4126-4134
97.
P E Romano 《Annals of ophthalmology》1988,20(10):365-6, 370
98.
José I. Bilbao Manuel Ruza Jesús M. Longo Francisco Mansilla Antonio Picardi Vanessa de Villa Fernando Pardo Jesús Sola Jorge Quiroga 《Cardiovascular and interventional radiology》1994,17(4):210-213
Posttransplant lymphoproliferative disorders are infrequent tumors related to chronic immunosuppressive therapy. We present a liver transplant recipient who developed such a tumor in the porta hepatis that provoked obstruction of the entire portal triad. Treatment consisted of systemic chemotherapy, percutaneous dilatation, and placement of Wallstent endoprostheses across both biliary and portal vein stenoses. The patient died 3 weeks later of pneumonia and sepsis. At necropsy, the tumor was completely necrosed and the prostheses in both the common bile duct and the portal vein were patent. 相似文献
99.
Egidio L. Romano res Soyano Ramón F. Montaño Murray Ratcliffe Marilyn Olson Guillermo Suarez Nelly Martínez and Geoffrey Worstey 《Vox sanguinis》1994,66(3):194-199
Thirteen infants, 10 with A-O and 3 with B-O hemolytic disease of the newborn (ABO-HDN), were treated with synthetic A or B blood group trisaccharides (ATS, BTS) which cause dissociation of maternal antibody bound to infant red cells. The clinical outcome was compared with that of a control group of 21 infants treated with phototherapy during the preceding year. Exchange transfusion was required in 2 out of 13 infants in the experimental group and in 7 in the control group. A randomized prospective controlled study is necessary to confirm these results. 相似文献
100.
Mutations Affecting the Rossman Fold of Isoleucyl-tRNA Synthetase Are Correlated with Low-Level Mupirocin Resistance in Staphylococcus aureus
下载免费PDF全文
![点击此处可从《Antimicrobial agents and chemotherapy》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Martin Antonio Neil McFerran Mark J. Pallen 《Antimicrobial agents and chemotherapy》2002,46(2):438-442
The isoleucyl-tRNA synthetase (ileS) gene was sequenced in toto from 9 and in part from 31 Staphylococcus aureus strains with various degrees of susceptibility to mupirocin. All strains for which the mupirocin MIC was greater than 8 microg/ml contained point mutations affecting the Rossman fold via Val-to-Phe changes at either residue 588 (V588F) or residue 631 (V631F). The importance of the V588F mutation was confirmed by an allele-specific PCR survey of 32 additional strains. Additional mutations of uncertain significance were found in residues clustered on the surface of the IleS protein. 相似文献