全文获取类型
收费全文 | 3649篇 |
免费 | 243篇 |
国内免费 | 26篇 |
专业分类
耳鼻咽喉 | 63篇 |
儿科学 | 80篇 |
妇产科学 | 80篇 |
基础医学 | 526篇 |
口腔科学 | 81篇 |
临床医学 | 417篇 |
内科学 | 672篇 |
皮肤病学 | 57篇 |
神经病学 | 377篇 |
特种医学 | 118篇 |
外科学 | 385篇 |
综合类 | 28篇 |
一般理论 | 3篇 |
预防医学 | 256篇 |
眼科学 | 54篇 |
药学 | 343篇 |
中国医学 | 10篇 |
肿瘤学 | 368篇 |
出版年
2023年 | 33篇 |
2022年 | 82篇 |
2021年 | 131篇 |
2020年 | 67篇 |
2019年 | 82篇 |
2018年 | 114篇 |
2017年 | 91篇 |
2016年 | 101篇 |
2015年 | 116篇 |
2014年 | 108篇 |
2013年 | 202篇 |
2012年 | 262篇 |
2011年 | 284篇 |
2010年 | 120篇 |
2009年 | 133篇 |
2008年 | 169篇 |
2007年 | 161篇 |
2006年 | 168篇 |
2005年 | 149篇 |
2004年 | 138篇 |
2003年 | 132篇 |
2002年 | 105篇 |
2001年 | 68篇 |
2000年 | 84篇 |
1999年 | 83篇 |
1998年 | 41篇 |
1997年 | 18篇 |
1996年 | 21篇 |
1994年 | 14篇 |
1993年 | 17篇 |
1992年 | 41篇 |
1991年 | 40篇 |
1990年 | 50篇 |
1989年 | 40篇 |
1988年 | 33篇 |
1987年 | 38篇 |
1986年 | 39篇 |
1985年 | 47篇 |
1984年 | 21篇 |
1980年 | 12篇 |
1979年 | 16篇 |
1978年 | 17篇 |
1977年 | 12篇 |
1976年 | 11篇 |
1975年 | 12篇 |
1974年 | 18篇 |
1973年 | 12篇 |
1972年 | 17篇 |
1971年 | 14篇 |
1970年 | 13篇 |
排序方式: 共有3918条查询结果,搜索用时 0 毫秒
1.
2.
Molecular determinants of cetuximab efficacy. 总被引:17,自引:0,他引:17
Daniel Vallb?hmer Wu Zhang Michael Gordon Dong Yun Yang Jim Yun Oliver A Press Katrin E Rhodes Andy E Sherrod Syma Iqbal Kathleen D Danenberg Susan Groshen Heinz-Josef Lenz 《Journal of clinical oncology》2005,23(15):3536-3544
PURPOSE: To investigate whether mRNA expression levels of cyclin D1 (CCND1), cyclooxygenase 2 (Cox-2), epidermal growth factor receptor (EGFR), interleukin 8 (IL-8), and vascular endothelial growth factor (VEGF), all members of the EGFR signaling pathway, are associated with clinical outcome in patients with EGFR-expressing metastatic colorectal cancer (CRC) treated with cetuximab. PATIENTS AND METHODS: Thirty-nine patients with metastatic CRC, refractory to both irinotecan and oxaliplatin, were enrolled on IMCL-0144 and treated with single-agent cetuximab. The intratumoral mRNA levels of CCND1, Cox-2, EGFR, IL-8, and VEGF were assessed from paraffin-embedded tissue samples using laser-capture microdissection and quantitative real-time polymerase chain reaction. RESULTS: There were 21 women and 18 men with a median age of 64 years (range, 35 to 83 years). Higher gene expression levels of VEGF were associated with resistance to cetuximab (P = .038; Kruskal-Wallis test). The combination of low gene expression levels of Cox-2, EGFR, and IL-8 was significantly associated with overall survival (13.5 v 2.3 months; P = .028; log-rank test). Both findings were independent of skin toxicity that was itself significantly correlated to survival. Patients with a lower mRNA amount of EGFR had a longer overall survival compared with patients that had a higher mRNA amount (7.3 v 2.2 months; P = .09; log-rank test). Patients with lower expression of Cox-2 had a significantly higher rate of grade 2 to 3 skin reactions under cetuximab treatment. CONCLUSION: This pilot study suggests that gene expression levels of Cox-2, EGFR, IL-8, and VEGF in patients with metastatic CRC may be useful markers of clinical outcome in single-agent cetuximab treatment. 相似文献
3.
Joerg Lindenmann Veronika Matzi Alfred Maier Freyja-Maria Smolle-Juettner 《European journal of cardio-thoracic surgery》2007,31(2):322-324
We report a pitfall deriving from the assumption of metastatic disease based upon seemingly identical histology in a pulmonary lesion and in the esophagus. In a 60-year-old patient, cT1 esophageal squamous cell carcinoma was found. One of the two pulmonary nodules was histologically diagnosed as metastasis. When esophageal perforation occurred during palliative therapy, esophagectomy became necessary together with the right lower lobectomy for the removal of the remaining pulmonary lesion. Definitive histology showed pT1N0 cancer of the esophagus, primary esophageal sarcoma and pT4N0 bronchogenic carcinoma. The other pulmonary lesion was re-evaluated and defined as intralobar M1 of bronchogenic carcinoma. 相似文献
4.
5.
Jens Garbade Andreas Schubert Ardawan Julian Rastan Dominik Lenz Thomas Walther Jan Fritz Gummert Stefan Dhein Friedrich-Wilhelm Mohr 《European journal of cardio-thoracic surgery》2005,28(5):685-691
OBJECTIVE: Recent studies have demonstrated that transplanted bone marrow-derived stem cells (BMCs) possess a broad differentiation potential and are able to form new cardiomyocytes. However, the identity of BMCs as true cardiomyocytes is still ambiguous. Therefore, we investigated the fate of transplanted fluorescence labeled BMCs and cardiomyocytes in co-culture. METHODS: For cell tracking we used two different fluorescent probes, Vybrant/DiO and Vybrant/DiI. BMCs were taken from human sternal marrow, purified using a Ficoll-gradient-centrifugation, treated with 5-azacytidine and stained with Vybrant/DiO. Furthermore, isolated spontaneous beating cardiomyocytes of neonatal rats (CM) were labeled with Vybrant/DiI. Thereafter, the BMCs were transplanted into CM-cultures and investigated on day 1, 4, 7, 14 and 28 using two-color fluorescence phenotyping by laser-scanning-cytometry (LSC). Two-color positive cells were harvested by patch-clamp technique and beta-MHC mRNA expression was analyzed by single-cell PCR. RESULTS: Two different morphological phenotypes were observed by LSC. First, isolated DiO labeled BMCs without contact or with direct cell contact to DiI labeled CMs. Second, some BMCs and CMs were double positive for DiO/DiI spontaneously forming hybrids. This population increased by 18% from day 1 to 4 and decreased only slightly until day 28. Additionally, few two-color positive cell formations expressed both human and rat specific beta-MHC mRNA as well as only human beta-MHC mRNA indicating that cell-fusion and transdifferentiation has occurred. CONCLUSION: These observations provide in vitro evidence for spontaneous cell fusion and transdifferentiation of BMCs in co-culture, raising the possibility that the observed phenomenons may contribute to development or maintenance of these cell types. 相似文献
6.
J Dabernig B Shilov O Schumacher C Lenz W Dabernig J Schaff 《Journal of plastic, reconstructive & aesthetic surgery》2006,59(2):142-147
We present our experience in functional reconstruction of the Achilles tendon with large tissue defects following after trauma and infection. To cover the skin defect and to reconstruct the Achilles tendon we used the free tensor fasciae latae (TFL) flap. From 1997 to 2003 six males, ranging from 22 to 71 (average 38.6) years, underwent this reconstructive procedure. All of them had sustained a trauma with following loss of the tendon and of the overlying tissue. After initial debridements the reconstruction with a tensor fascia latae free flap was performed. To achieve a strong distal fascia lata attachment to the calcaneal bone, we developed a special method of fixation. After vertical osteotomy in the calcaneus the distal part of the fascia flap was introduced between the bone segments, which were fixed together with a spongiosa screw. For functional outcome, it was important to fix the foot in a 90 degrees position with tension on the vascularised fascia lata. The range of motion of the ankle of the reconstructed foot showed 93.7% in comparison to the normal foot. No flap failure occurred in any of the six patients. Simultaneous soft-tissue and function restoration of the foot with TFL free flap is in our opinion an optimal one-stage reconstructive procedure. 相似文献
7.
Ch. Madl G. Grimm R. Mallek B. Schneeweiß W. Druml A. N. Laggner K. Lenz 《Intensive care medicine》1992,18(4):245-246
In the presence of ascites ultrasound is not appropriate to distinguish between gallbladder perforation and acute acalculous cholecystitis. However, the correct and early diagnosis of gallbladder perforation is important for the treatment and prognosis. We report 4 critically ill patients with ascites. All patients had evidence of gallbladder perforation by ultrasound and underwent cholecystectomy: 2 patients had gallbladder perforation, but 2 had acalculous cholecystitis without perforation. markedly elevated serum alkaline phosphatase was the only discriminating finding indicating gallbladder perforation. 相似文献
8.
9.
First Amsterdam, then Bethesda, now Melbourne? 总被引:13,自引:0,他引:13
Heinz-Josef Lenz 《Journal of clinical oncology》2005,23(27):6445-6449
10.
P Lenz 《Physics in medicine and biology》1992,37(2):311-324
Tumours are examined in a simple sandwich structure which gives the samples a well defined shape and volume. Collimated light is scattered by the sample and analysed using a goniometer. It is found that tumours can be optically characterized by only two parameters. In phantoms, composed in order to approach closely the optical properties of tumours, a relationship is established experimentally between these parameters and the penetration depth. Using this relationship the penetration depth in tumours can be determined for 630 nm and 680 nm wavelength light. 相似文献