全文获取类型
收费全文 | 10839篇 |
免费 | 1246篇 |
国内免费 | 237篇 |
专业分类
耳鼻咽喉 | 30篇 |
儿科学 | 43篇 |
妇产科学 | 191篇 |
基础医学 | 439篇 |
口腔科学 | 136篇 |
临床医学 | 1189篇 |
内科学 | 1211篇 |
皮肤病学 | 50篇 |
神经病学 | 104篇 |
特种医学 | 181篇 |
外国民族医学 | 49篇 |
外科学 | 822篇 |
综合类 | 1468篇 |
预防医学 | 305篇 |
眼科学 | 81篇 |
药学 | 1094篇 |
11篇 | |
中国医学 | 406篇 |
肿瘤学 | 4512篇 |
出版年
2024年 | 27篇 |
2023年 | 265篇 |
2022年 | 332篇 |
2021年 | 727篇 |
2020年 | 657篇 |
2019年 | 561篇 |
2018年 | 536篇 |
2017年 | 610篇 |
2016年 | 544篇 |
2015年 | 584篇 |
2014年 | 870篇 |
2013年 | 806篇 |
2012年 | 694篇 |
2011年 | 783篇 |
2010年 | 544篇 |
2009年 | 591篇 |
2008年 | 539篇 |
2007年 | 458篇 |
2006年 | 383篇 |
2005年 | 338篇 |
2004年 | 282篇 |
2003年 | 221篇 |
2002年 | 157篇 |
2001年 | 138篇 |
2000年 | 141篇 |
1999年 | 106篇 |
1998年 | 82篇 |
1997年 | 59篇 |
1996年 | 49篇 |
1995年 | 52篇 |
1994年 | 35篇 |
1993年 | 23篇 |
1992年 | 21篇 |
1991年 | 10篇 |
1990年 | 15篇 |
1989年 | 8篇 |
1988年 | 10篇 |
1987年 | 9篇 |
1986年 | 6篇 |
1985年 | 13篇 |
1984年 | 7篇 |
1983年 | 12篇 |
1982年 | 3篇 |
1981年 | 7篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1977年 | 1篇 |
1976年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
11.
《Journal of thoracic oncology》2021,16(10):1694-1704
IntroductionIn patients with NSCLC, the prognostic significance of the tumor microenvironment (TME) immune composition has been revealed using single- or dual-marker staining on sequential tissue sections. Although these studies reveal that relative abundance and localization of immune cells are important parameters, deeper analyses of the NSCLC TME are necessary to refine the potential application of these findings to clinical care. Currently, the complex spatial relationships between cells of the NSCLC TME and potential drivers contributing to its immunologic composition remain unknown.MethodsWe used multispectral quantitative imaging on the lung adenocarcinoma TME in 153 patients with resected tumors. On a single slide per patient, we evaluated the TME with markers for CD3, CD8, CD14, CD19, major histocompatibility complex II (MHCII), cytokeratin, and 4′,6-diamidino-2-phenylindole (DAPI). Image analysis, including tissue segmentation, phenotyping, and spatial localization, was performed.ResultsSpecimens wherein greater than or equal to 5% of lung cancer cells expressed MHCII (MHCIIhi TME) had increased levels of CD4+ and CD8+ T cells and CD14+ cell infiltration. In the MHCIIhi TME, the immune infiltrate was closer to cancer cells and expressed an activated phenotype. Morphologic image analysis revealed cancer cells in the MHCIIhi TME more frequently interfaced with CD4+ and CD8+ T cells. Patients with an MHCIIhi TME experienced improved overall survival (p = 0.046).ConclusionsLung cancer cell-specific expression of MHCII associates with levels of immune cell infiltration, spatial localization, and activation status within the TME. This suggests that cancer cell-specific expression of MHCII may represent a biomarker for the immune system’s recognition and activation against the tumor. 相似文献
12.
Quang Ngoc Nguyen Linh Dieu Vuong Van-Long Truong To Van Ta Nam Trung Nguyen Hung Phi Nguyen Ha Hoang Chu 《Pathology, research and practice》2019,215(5):885-892
Genetic and epigenetic alterations importantly contribute to the pathogenesis of lung cancer. In the study, we measured the frequency and distribution of molecular abnormalities of EGFR as well as the aberrant promoter methylations of BRCA1, MGMT, MLH1, and RASSF1A in Vietnamese lung adenocarcinomas. We investigated the association between genetic and epigenetic alteration, and between each abnormality with clinicopathologic parameters. Somatic EGFR mutation that was found in 49/139 (35.3%) lung adenocarcinomas showed a significant association with young age, female gender, and non-smokers. EGFR overexpression was identified in 82 tumors (59.0%) and statistical relationships with EGFR or BRCA1 methylation but not EGFR mutation. In addition, EGFR, BRCA1, MGMT, MLH1, and RASSF1A methylations were found in 33 (23.7%), 41 (29.5%), 46 (33.1%), 28 (20.1%), and 41 (29.5%) cases of a total of 139 lung adenocarcinomas, respectively. The RASSF1A methylation was found to be linked to the smoking habit. Methylations in MGMT and RASSF1A were also found to correlate with metastasis status. Furthermore, the distribution of EGFR mutation and that of BRCA1, MGMT or RASSF1A methylation were significantly exclusive in lung adenocarcinomas. The main finding of our study demonstrate that epigenetic abnormalities might play a critical role for the lung tumorigenesis in patients with smoking history and metastasis, and partly affect the predictive value of EGFR mutations through blocking expression due to promoter EGFR hypermethylation. Mutually exclusive distribution of genetic and epigenetic alterations reflects differently biological characteristics in the etiology of lung adenocarcinomas. 相似文献
13.
《Journal of pharmaceutical sciences》2019,108(11):3521-3523
We make the case for why continuous pharmaceutical manufacturing is essential, what the barriers are, and how to overcome them. To overcome them, government action is needed in terms of tax incentives or regulatory incentives that affect time. 相似文献
14.
Dysregulated activation of the MET tyrosine kinase receptor is implicated in the development of solid tumors and can arise through several mechanisms, including gene amplification, overexpression of the receptor and/or its ligand hepatocyte growth factor (HGF), and the acquisition of activating mutations. The most common activating mutations cause exon 14 to be skipped during MET mRNA splicing. This in-frame deletion, known as MET exon 14, results in production of a shortened receptor that lacks a juxtamembrane domain but retains affinity for HGF. However, the negative regulatory function located within this protein sequence is lost, leading to receptor accumulation on the cell surface and prolonged activation by HGF. MET mutations causing exon 14 skipping appear to be true oncogenic drivers and occur in patients and tumors with distinct characteristics.Increasing evidence suggests that tumors carrying such mutations are sensitive to MET inhibition, raising the hope that selective MET inhibitors will provide patients with optimal anticancer activity with minimal toxicity.We discuss the prospects for selective MET inhibitors in the treatment of non-small cell lung cancer harboring MET exon 14 skipping. 相似文献
15.
《Journal of thoracic oncology》2020,15(1):138-143
IntroductionEGFR mutated (EGFRm) NSCLC tumors occasionally express programmed cell death ligand 1 (PD-L1), although frequency and clinical relevance are not fully characterized. We report PD-L1 expression in patients with EGFRm advanced NSCLC and association with clinical outcomes following treatment with osimertinib or comparator EGFR tyrosine kinase inhibitors in the FLAURA trial (phase III, NCT02296125).MethodsOf 231 tissue blocks available from the screened population (including EGFRm-positive and -negative samples), 197 had sufficient tissue for PD-L1 testing using the SP263 (Ventana, Tucson, Arizona) immunohistochemical assay. Tumor cell (TC) staining thresholds of PD-L1 TC greater than or equal to 1%, TC greater than or equal to 25%, and TC greater than or equal to 50% were applied. Progression-free survival (PFS) was investigator-assessed, per Response Evaluation Criteria in Solid Tumor, version 1.1, according to PD-L1 expressors (TC ≥ 1%) or negatives (TC < 1%) in randomized patients.ResultsPD-L1 staining was successful in 193 of 197 patient formalin-fixed paraffin-embedded blocks; of these, 128 of 193 were EGFRm-positive and 106 of 128 patients were randomized to treatment (osimertinib: 54; comparator: 52). At the PD-L1 TC greater than or equal to 25% threshold, 8% (10 of 128) of EGFRm-positive tumors expressed PD-L1 versus 35% (23 of 65) of EGFRm-negative tumors. With the TC greater than or equal to 1% threshold, 51% (65 of 128) versus 68% (44 of 65) were mutation-positive and –negative, respectively, and with the TC greater than or equal to 50% threshold, 5% (7 of 128) versus 28% (18 of 65), were mutation-positive and -negative, respectively. For PD-L1 expressors (TC ≥ 1%), median PFS was 18.4 months with osimertinib and 6.9 months with comparator (hazard ratio = 0.30; 95% confidence interval: 0.15–0.60). For PD-L1–negative patients (TC < 1%), median PFS was 18.9 months with osimertinib and 10.9 months with comparator (hazard ratio = 0.37; 95% confidence interval: 0.17–0.74).ConclusionsClinical benefit with osimertinib was unaffected by PD-L1 expression status. 相似文献
16.
Apatinib, an oral small molecular receptor tyrosine kinase inhibitor (TKI) developed first in China, exerts antiangiogenic and antineoplastic function through selectively binding and inhibiting vascular endothelial growth
factor receptor 2 (VEGFR-2). In this study, we aimed to explore the efficacy and safety profile of apatinib
monotherapy, or combined with chemotherapy or endothelial growth factor receptor (EGFR)-TKI in heavily
pretreated non-small cell lung cancer (NSCLC) patients with brain metastases. We performed a retrospective
analysis for relapsed NSCLC patients with brain metastases from our institute, who received apatinib
(250 mg or 500 mg p.o. qd) monotherapy, or combination with EGFR-TKI or chemotherapy as second or
more line systemic therapy until disease progression or unacceptable toxicity occurred. The objective response
rate (ORR), disease control rate (DCR), median progression-free survival (mPFS), median overall survival
(mOS), and safety were analyzed. A total of 26 eligible patients were included: 24 patients diagnosed with
adenocarcinoma, 2 with squamous carcinoma, and 14 patients harboring EGFR sensitizing mutations. The
mPFS and mOS were 4.93 (range, 0.27−32.91; 95% CI 3.64−6.22) and 14.70 (range, 0.27−32.91; 95% CI
0.27−43.60) months for the whole group. The ORR and DCR were 7.7% (2/26) and 69.2% (18/26) for the
entire lesions, and 7.7% (2/26) and 79.6% (20/26) for brain metastases, respectively. Compared with patients
who received apatinib monotherapy, patients who received apatinib combination treatment had more favorable
mPFS (11.77 vs. 2.27 months, p<0.05) and mOS (24.03 vs. 6.07 months, p<0.05). Treatment-related toxicities
were tolerable including grade 1/2 hypertension, hand-and-foot syndrome, fatigue, nausea, liver dysfunction,
myelosuppression, skin rash, and palpitation. In conclusion, apatinib exhibited high activity and good tolerance
for NSCLC patients with brain metastasis, and it might become a potential choice for metastatic brain tumors
in NSCLC patients. 相似文献
17.
《European journal of surgical oncology》2020,46(6):1118-1123
AimTo investigate the impact of circumferential tumour location on neoadjuvant chemoradiotherapy (CRT) response and its prognostic value for locally advanced rectal cancer (LARC) patients after CRT and surgery.MethodsA retrospective study was performed on 486 patients with LARC who received neoadjuvant CRT and surgical treatment. The rate of pathological complete response (pCR) and survival among patients with anteriorly, laterally, and posteriorly located tumours were compared. Logistic regression was performed to identify pCR predictors.ResultsThe anterior tumours exhibited the highest pCR rate of 26.7%, which was slightly higher than the 20.0% and 12.3% for lateral and posterior tumours, respectively (P = 0.006). The 5-year Overall survival (OS) rates after CRT were similar among the anterior, lateral, and posterior groups (anterior vs lateral vs posterior: 81.1% vs 89.9% vs 84.1%, P = 0.6368). Multivariate analysis revealed that the circumferential tumour location, post-CRT serum CEA and post-CRT tumour thickness measured by MRI were independently correlated with achieving pCR.ConclusionThis study is the first, to the best of our knowledge, to show that anterior LARC exhibited the highest pCR rate after neoadjuvant CRT. Patients with anterior rectal cancers do not have different prognoses from those with non-anterior cancers if they undergo neoadjuvant CRT. 相似文献
18.
Stuart J. Dilley Tracey J. Weiland Robert O’Brien Neil J. Cunningham Julian E. Van Dijk Rosie M. Mahoney 《Teaching and learning in medicine》2015,27(1):71-79
Theory: Immersive simulation is a common mode of education for medical students. Observation of clinical simulations prior to participation is believed to be beneficial, though this is often a passive process. Active observation may be more beneficial. Hypotheses: The hypothesis tested in this study was that the active use of a simple checklist during observation of an immersive simulation would result in better participant performance in a subsequent scenario compared with passive observation alone. Methods: Medical students were randomized to either passive or active (with checklist) observation of an immersive simulation involving cardiac arrest prior to participating in their own simulation. Performance measures included time to cardiopulmonary resuscitation (CPR) and time to defibrillation and were compared between first and second scenarios as well as between passive and active observers. Results: Seventy-nine simulations involving 232 students were conducted. Mean time to CPR was 18 seconds (SD = 11.6) for those using the checklist and 24 seconds (SD = 15.8) for those who observed passively (M difference = 6 seconds), t(35) = 1.46, p =.153. Time to defibrillation was 94 seconds (SD = 26.4) for those using the checklist and 92 seconds (SD = 23.8) for those who observed passively (M difference = –2 seconds), t(38) =.21, p =.837. Time to CPR was 24 seconds (SD = 15.8) for passive observers and 31 seconds (SD = 21.0; M difference = 7 seconds), t(35) = 1.13, p =.265, for their first scenario counterparts. Time to CPR was 18 seconds (SD = 11.6) for active observers and 36 seconds (SD = 26.2; M difference = 18 seconds), t(24) = 2.81, p =.010, for their first scenario counterparts. Time to defibrillation was 92 seconds (SD = 23.8) for passive observers and 125 seconds (SD = 32.2; M difference = 33 seconds), t(33) = 3.63, p =.001, for their first scenario counterparts. Time to defibrillation was 94 seconds (SD = 26.4) for the active observers and 132 seconds (SD = 52.9; M difference = 38 seconds), t(28) =.46, p =.008, for their first scenario counterparts. Conclusions: Observation alone leads to improved performance in the management of a simulated cardiac arrest. The active use of a simple skills-based checklist during observation did not appear to improve performance over passive observation alone. 相似文献
19.
高龄妊娠是指孕妇妊娠年龄≥35岁,近年来其发生率不断增高,已经逐步成为目前我国围产医学关注的热点问题。针对高龄妊娠中的生殖遗传问题,需特别关注女性的生育力下降的情况,其自然流产发生率升高,胎儿染色体异常和胎儿结构畸形的发生率增加,这就更加强调了产前筛查和诊断的重要性,以及需要关注常常与高龄妊娠相伴随的男性高龄生育的问题。做好上述问题的咨询和管理是完成高质量高龄妊娠围产保健的关键。 相似文献
20.
肝内胆管癌(ICC)恶性程度高,症状隐匿,早期症状不明显,由于缺乏有效的筛查,确诊时多处于进展期,大多失去手术切除机会。目前,根治性手术仍是惟一可以使病人获得长期生存的治疗方式,但存在切除率低、术后易复发等难题。新辅助治疗能缩小原有病灶及转移的淋巴结,提高R0切除率,对于无法切除的局部晚期ICC,新辅助治疗可使局部进展的ICC降期为可切除,也可改善肝移植病人的预后。但目前对ICC行新辅助治疗的潜在效用仍存在争议。 相似文献