全文获取类型
收费全文 | 50924篇 |
免费 | 2678篇 |
国内免费 | 423篇 |
专业分类
耳鼻咽喉 | 537篇 |
儿科学 | 961篇 |
妇产科学 | 1432篇 |
基础医学 | 6208篇 |
口腔科学 | 1870篇 |
临床医学 | 3885篇 |
内科学 | 14085篇 |
皮肤病学 | 1035篇 |
神经病学 | 4381篇 |
特种医学 | 1409篇 |
外科学 | 7708篇 |
综合类 | 341篇 |
一般理论 | 10篇 |
预防医学 | 2844篇 |
眼科学 | 792篇 |
药学 | 2852篇 |
中国医学 | 197篇 |
肿瘤学 | 3478篇 |
出版年
2023年 | 337篇 |
2022年 | 467篇 |
2021年 | 1652篇 |
2020年 | 881篇 |
2019年 | 1285篇 |
2018年 | 1734篇 |
2017年 | 1157篇 |
2016年 | 1272篇 |
2015年 | 1472篇 |
2014年 | 1988篇 |
2013年 | 2614篇 |
2012年 | 4041篇 |
2011年 | 4000篇 |
2010年 | 2286篇 |
2009年 | 2006篇 |
2008年 | 3407篇 |
2007年 | 3544篇 |
2006年 | 3298篇 |
2005年 | 3264篇 |
2004年 | 2962篇 |
2003年 | 2709篇 |
2002年 | 2400篇 |
2001年 | 443篇 |
2000年 | 362篇 |
1999年 | 437篇 |
1998年 | 439篇 |
1997年 | 383篇 |
1996年 | 329篇 |
1995年 | 314篇 |
1994年 | 253篇 |
1993年 | 204篇 |
1992年 | 206篇 |
1991年 | 155篇 |
1990年 | 149篇 |
1989年 | 124篇 |
1988年 | 94篇 |
1987年 | 79篇 |
1986年 | 104篇 |
1985年 | 100篇 |
1984年 | 96篇 |
1983年 | 76篇 |
1982年 | 107篇 |
1981年 | 68篇 |
1980年 | 74篇 |
1979年 | 52篇 |
1978年 | 63篇 |
1977年 | 44篇 |
1976年 | 41篇 |
1974年 | 33篇 |
1973年 | 38篇 |
排序方式: 共有10000条查询结果,搜索用时 578 毫秒
91.
J A San Román I Vilacosta J Zamorano C Almería F J Cortés E Iturralde L Sánchez Harguindey 《Revista espa?ola de cardiología》1992,45(3):219-221
Three cases with suspected pulmonary artery embolism are presented, in which transesophageal echocardiography showed a mass in the right pulmonary artery consistent with thrombus. The relevant diagnostic contributions of transesophageal echocardiography are discussed. 相似文献
92.
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
93.
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
94.
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
95.
黄芪注射液对严重创伤患者的免疫调节 总被引:1,自引:0,他引:1
目的 探讨黄芪注射液对严重创伤患者的免疫调节作用。方法 选择 5 0例严重创伤患者 (ISS ,创伤严重度评分≥16 ) ,检测应用黄芪注射液 ( 4 0ml)前后T淋巴细胞亚群血清IL 2及可溶性白介素 2受体 (SIL 2R)。结果 严重创伤患者伤后IL 2、CD4 +和CD4 +/CD8+减低 ,而SIL 2R和CD8+升高 ,黄芪治疗组在伤后 14d血中IL 2、T淋巴细胞CD4 +亚群、CD4 +/CD8+降低及SIL 2R、CD8+升高程度均低于治疗前 ,P <0 .0 5。结论 严重创伤患者伤后细胞免疫功能明显抑制 ,应用黄芪注射液可以增加机体免疫功能 相似文献
96.
Mono- and bi-allelic expression of insulin-like growth factor II gene in human muscle tumors 总被引:4,自引:1,他引:3
Pedone Paolo V.; Tirabosco Roberto; Cavazzana Andrea O.; Ungaro Paola; Basso Giuseppe; Luksch Roberto; Carli Modesto; Bruni Carmelo B.; Frunzio Rodolfo; Riccio Andrea 《Human molecular genetics》1994,3(7):1117-1121
Insulin-like growth factor II (IGF-II) is a mitogen for manycell types and an important modulator of muscle growth and differentiation.IGF-II gene is prevalently expressed during prenatal developmentand its gene activity is regulated by genomic imprinting, inthat the allele inherited from the father is active and theallele inherited from the mother is inactive in most normaltissues. IGF-II expression is activated in several types ofhuman neoplasms and an alteration of IGF-II imprinting has beendescribed in BeckwithWiedemann syndrome and Wilms' tumour.Here we show that monoallelic expression of IGF-II gene is conservedin normal adult muscle tissue whereas two or more copies ofactive IGF-II alleles, arising by either relaxation of imprintingor duplication of the active allele, are found in 9 out of 11(82%) rhabdomyo-sarcomas retaining heterozygosity at 11p15,regardless of the histological subtype. Since IGF-II has beenindicated as an autocrine growth factor for rhabdomyosarcomacells, these findings strongly suggest that acquisition of adouble dosage of active IGF-II gene is an important step forthe initiation or progression of rhabdomyosarcoma tumorigenesis.Among different types of muscle tumors, relaxation of imprintingseems to arise prevalently in rhabdomyosarcomas, since we havedetected only one case of partial reactivation of the maternalIGF-II allele out of 7 lelomyosarcomas tested. 相似文献
97.
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
98.
Antonio F. Govoni M.D 《Clinical imaging》1992,16(4):285
99.
Ana Sánchez-Romero Israel Oliver David Costa Albina Orduña Javier Lacueva Francisco Pérez-Vicente Antonio Arroyo Rafael Calpena 《Clinical & translational oncology》2006,8(4):294-295
Lung cancer is the most prevalent malignancy in western countries and most of the patients present at advanced stages, but
single splenic metastasis is exceptional instead. We report on a case of a seventy-three-year old male presenting with non-hemoptoic
productive cough, constitutional syndrome and pain in the left lower quadrant. Physical examination and complementary radiological
and hystologycal procedures revealed the presence of an adenocarcinoma of the left lung with probable splenic metastasis.
The patient underwent splenectomy, which confirmed the diagnose of splenic metastasis of lung adenocarcinoma and, secondly,
lung resection was performed. Topics about lung cancer metastasis are discussed. 相似文献
100.
Alfonso Fasano Antonio E Elia Arianna Guidubaldi Pietro A Tonali Anna Rita Bentivoglio 《Movement disorders》2007,22(4):564-566
We report a case of cervical dystonia occurring in a 33-year-old without personal history of movement disorder but with family history of essential tremor, primigravid, primiparous woman at 1 weeks' amenorrhea, resolved completely after delivery in the course of 3 months. Dystonia never recurred in the following 5 years. Several neurological disorders are known to occur or worsen during pregnancy. As far as we know, this is the second reported case of dystonia occurring during pregnancy, thus confirming that dystonia gravidarum represents a new entity and should be considered in women of reproductive age affected by dystonia, especially when presenting with rapid-onset cervical dystonia. 相似文献