全文获取类型
收费全文 | 384354篇 |
免费 | 34935篇 |
国内免费 | 15348篇 |
专业分类
耳鼻咽喉 | 3600篇 |
儿科学 | 10872篇 |
妇产科学 | 3682篇 |
基础医学 | 58412篇 |
口腔科学 | 9342篇 |
临床医学 | 32420篇 |
内科学 | 56786篇 |
皮肤病学 | 7152篇 |
神经病学 | 25932篇 |
特种医学 | 9724篇 |
外国民族医学 | 155篇 |
外科学 | 48344篇 |
综合类 | 54336篇 |
现状与发展 | 78篇 |
一般理论 | 4篇 |
预防医学 | 15049篇 |
眼科学 | 5956篇 |
药学 | 38908篇 |
125篇 | |
中国医学 | 11922篇 |
肿瘤学 | 41838篇 |
出版年
2024年 | 518篇 |
2023年 | 5342篇 |
2022年 | 7550篇 |
2021年 | 14666篇 |
2020年 | 13159篇 |
2019年 | 12842篇 |
2018年 | 12948篇 |
2017年 | 13547篇 |
2016年 | 13891篇 |
2015年 | 15188篇 |
2014年 | 24203篇 |
2013年 | 25818篇 |
2012年 | 21910篇 |
2011年 | 25126篇 |
2010年 | 20780篇 |
2009年 | 20273篇 |
2008年 | 20552篇 |
2007年 | 20133篇 |
2006年 | 18369篇 |
2005年 | 16404篇 |
2004年 | 14088篇 |
2003年 | 12091篇 |
2002年 | 9686篇 |
2001年 | 8465篇 |
2000年 | 7203篇 |
1999年 | 6187篇 |
1998年 | 5715篇 |
1997年 | 5280篇 |
1996年 | 4804篇 |
1995年 | 4278篇 |
1994年 | 3971篇 |
1993年 | 3191篇 |
1992年 | 2879篇 |
1991年 | 2561篇 |
1990年 | 2074篇 |
1989年 | 1928篇 |
1988年 | 1835篇 |
1987年 | 1500篇 |
1986年 | 1522篇 |
1985年 | 2017篇 |
1984年 | 1829篇 |
1983年 | 1327篇 |
1982年 | 1412篇 |
1981年 | 1172篇 |
1980年 | 1028篇 |
1979年 | 842篇 |
1978年 | 606篇 |
1977年 | 512篇 |
1976年 | 508篇 |
1975年 | 280篇 |
排序方式: 共有10000条查询结果,搜索用时 343 毫秒
41.
目的:探讨健脾益肾方对非小细胞肺癌(NSCLC)细胞体外增殖凋亡的作用。方法:人NSCLC细胞系A549分为四组:空白对照组(仅加入细胞培养液)、阴性对照组(加入细胞,不进行中药处理)、实验组(加细胞加中药处理)。荧光定量PCR和Western blot分别检测Survivin、Bcl-2和Caspase-3的mRNA和蛋白表达。MTT检测细胞增殖;流式细胞术检测细胞凋亡。结果:与空白对照组相比,阴性对照组细胞在24、48、72 h的吸光度值明显升高,细胞凋亡率下降,Survivin和Bcl-2 mRNA和蛋白相对表达量上调,Caspase-3 mRNA和蛋白相对表达量下调,组间比较差异有统计学意义(P<0.05);而健脾益肾方处理的实验组24、48、72 h的吸光度值均显著降低,细胞凋亡率显著上升,Survivin和Bcl-2 mRNA和蛋白相对表达量下调,Caspase-3 mRNA和蛋白相对表达量上调,与空白对照组相比差异有统计学意义(P<0.05)。结论:健脾益肾方可通过下调Survivin和Bcl-2、上调Caspase-3表达诱导NSCLC细胞凋亡,并抑制肿瘤细胞的增殖,进而抑制NSCLC的发展。 相似文献
42.
Rupa Narayan MD Traci M. Blonquist MS Ashkan Emadi MD PhD Robert P. Hasserjian MD Meghan Burke BS Christopher Lescinskas BS Donna S. Neuberg ScD Andrew M. Brunner MD Gabriela Hobbs MD Hanno Hock MD PhD Steven L. McAfee MD Yi-Bin Chen MD Eyal Attar MD Timothy A. Graubert MD Christina Bertoli MSN Jenna A. Moran MSN Meghan K. Bergeron MSN Julia E. Foster MSN Aura Y. Ramos BSN Tina T. Som BSN Megan K. Vartanian BSN RN Jennifer L. Story LPN Kristin McGregor MS Molly Macrae BS Tanya Behnan BS Margaret C. Wey PhD Jessica Rae BSN Frederic I. Preffer PhD Patricia Lesho BA Vu H. Duong MD Mason L. Mann BA Karen K. Ballen MD Christine Connolly BS Philip C. Amrein MD Amir T. Fathi MD 《Cancer》2020,126(6):1264-1273
43.
Brittney H. Cotta Margaret F. Meagher Aaron Bradshaw Stephen T. Ryan Gerant Rivera-Sanfeliz 《Expert review of anticancer therapy》2019,19(4):301-308
Introduction: Percutaneous renal mass biopsy has evolved over the last decade with improvements on previous pitfalls including low tissue yield, high non-diagnostic rates, and complications. As understanding of tumor biology and natural history of renal cortical neoplasms has improved, percutaneous renal mass biopsy is poised to have an expanding role in an area characterized by individualized management and refined risk stratification.
Areas covered: This review summarizes the evolution of renal mass biopsy to its current state with respect to outcomes, indications, and clinical guidelines.
Expert opinion: With improved understanding of differential biological potential of renal cortical neoplasms combined with technical improvements in diagnostic yield and accuracy, utilization of renal mass biopsy is becoming an important adjunct to patient care in a broad range of clinical scenarios, including active surveillance, thermal ablation, and use of primary systemic therapy in localized and advanced settings. 相似文献
44.
Xiying Fan Glen A. Bjerke Kent Riemondy Li Wang Rui Yi 《Molecular carcinogenesis》2019,58(12):2241-2253
MicroRNAs (miRNAs) play important roles in prostate cancer development. However, it remains unclear how individual miRNAs contribute to the initiation and progression of prostate cancer. Here we show that a basal layer‐enriched miRNA is required for prostate tumorigenesis. We identify miR‐205 as the most highly expressed miRNA and enriched in the basal cells of the prostate. Although miR‐205 is not required for normal prostate development and homeostasis, genetic deletion of miR‐205 in a Pten null tumor model significantly compromises tumor progression and does not promote metastasis. In Pten null basal cells, loss of miR‐205 attenuates pAkt levels and promotes cellular senescence. Furthermore, although overexpression of miR‐205 in prostate cancer cells with luminal phenotypes inhibits cell growth in both human and mouse, miR‐205 has a minimal effect on the growth of a normal human prostate cell line. Taken together, we have provided genetic evidence for a requirement of miR‐205 in the progression of Pten null‐induced prostate cancer. 相似文献
45.
Noreen M. Walsh Heinz Kutzner Luis Requena Lorenzo Cerroni 《Journal of cutaneous pathology》2019,46(9):698-708
We review the spectrum of cutaneous disorders associated with inflammatory and neoplastic plasmacytic pathology. Because plasma cells are derived from B‐lymphocytes our overview includes discussion of certain lymphoplasmacytic proliferations. It is structured along histopathological lines, addressing conditions characterized by (a) cutaneous plasma cell infiltrates, (b) deposits of plasma cell products or their derivatives in the skin and (c) miscellaneous, poorly understood cutaneous complications of plasmacytic disorders. Lesions arising primarily in the skin and those due to cutaneous involvement by multisystem disorders are addressed. The range includes a spectrum of tumefactive and circulatory manifestations. We highlight key clinical and pathological features of the different conditions and outline recent advances in our understanding of these entities. By emphasizing the dermatopathological characteristics of this spectrum of disorders we hope to hone the diagnostic accuracy of practitioners in the field. 相似文献
46.
Effects of the Clearing the Lung and Dissipating Phlegm Method in the Treatment of Acute Exacerbation of Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis 下载免费PDF全文
Tao Zhang Yao-Hui Li Gai-Xia Liu Xiu-Lin Tang 《World Journal of Traditional Chinese Medicine》2019,(1)
Objective: The objective of this study is to evaluate the efficacy and safety of the clearing the lung and dissipating phlegm method in the treatment of acute exacerbation of chronic obstructive pulmonary disease(COPD) and to provide evidence for the treatment of the disease. Materials and Methods: Literature was searched from the United States National Library of Medicine(PubMed), Embase, Cochrane Library, China National Knowledge Infrastructure, Wanfang Database(Wanfang), and the Full?Text Database of Chinese Scientific and Technical Periodicals(VIP).A comprehensive collection was made of randomized controlled trials(RCTs) before June 2018, in which the treatment groups used either the clearing the lung and dissipating phlegm formulas only or combined it with routine Western medicine therapy, and the control group adopted routine Western medicine therapy only for the acute exacerbation of COPD. The Cochrane risk of bias method was used to evaluate the quality of the literature. The data were analyzed and retrieved independently by two reviewers before meta?analysis was carried out with RevMan 5.3 software to evaluate the primary outcome measures, including the total clinical effective rate, and the secondary outcome measures such as the pulmonary function(forced vital capacity [FVC], forced expiratory volume in the 1 s [FEV1], percentage of FEV1 [FEV1%], and FEV1/FVC)and blood gases(PaO_2 and PaCo_2). Results: A total of 13 RCTs involving 990 patients(496 in the treatment group and 494 in the control group)were included in this study. Meta?analysis revealed significant difference in the efficacy of the group that adopted solely the routine Western medicine method and the group that combined the Western medicine with the clearing the lung and dissipating phlegm method. Outcome measures including the pulmonary function(FVC, FEV1, FEV1%, and FEV1/FVC) and the blood gases(PaO_2 and PaCo_2) were significantly improved as compared to the control group(P 0.00001). However, adverse effects in the treatment group using combined traditional Chinese medicine were not reported due to the short observation time of the study. Conclusion: The clearing the lung and dissipating phlegm method can improve the efficacy in the treatment of acute exacerbation of COPD, the outcome measures of the pulmonary function and the blood gases,as well as the life quality of the patients. However, due to the fact that the existing studies are generally of poor quality in which randomization and its implementation were not properly carried out, more high?quality RCTs are necessary to confirm the findings of this study. 相似文献
47.
《Journal of vascular and interventional radiology : JVIR》2020,31(2):286-293
PurposeTo evaluate tumor and ablation zone morphology and densitometry related to tumor recurrence in participants with Stage IA non–small cell lung cancer undergoing radiofrequency ablation in a prospective, multicenter trial.Materials and MethodsForty-five participants (median 76 years old; 25 women; 20 men) from 16 sites were followed for 2 years (December 2006 to November 2010) with computed tomography (CT) densitometry. Imaging findings before and after ablation were recorded, including maximum CT attenuation (in Hounsfield units) at precontrast and 45-, 90-, 180-, and 300-s postcontrast.ResultsEvery 1-cm increase in the largest axial diameter of the ablation zone at 3-months’ follow-up compared to the index tumor reduced the odds of 2-year recurrence by 52% (P = .02). A 1-cm difference performed the best (sensitivity, 0.56; specificity, 0.93; positive likelihood ratio of 8). CT densitometry precontrast and at 45 seconds showed significantly different enhancement patterns in a comparison among pretreated lung cancer (delta = +61.2 HU), tumor recurrence (delta = +57 HU), and treated tumor/ablation zone (delta [change in attenuation] = +16.9 HU), (P < .0001). Densitometry from 45 to 300 s was also different among pretreated tumor (delta = −6.8 HU), recurrence (delta = −11.2 HU), and treated tumor (delta = +12.1 HU; P = .01). Untreated and residual tumor demonstrated washout, whereas treated tumor demonstrated increased attenuation.ConclusionsAn ablation zone ≥1 cm larger than the initial tumor, based on 3-month follow-up imaging, is recommended to decrease odds of recurrence. CT densitometry can delineate tumor versus treatment zones. 相似文献
48.
49.
There is a sharp difference in how one views TCR structure–function–behaviour dependent on whether its recognition of major histocompatibility complex‐encoded restriction elements (R) is germline selected or somatically generated. The generally accepted or Standard model is built on the assumption that recognition of R is by the V regions of the αβ TCR, which is not driven by allele specificity, whereas the competing model posits that recognition of R is allele‐specific. The establishing of allele‐specific recognition of R by the TCR would rule out the Standard model and clear the road to a consideration of a competing construct, the Tritope model. Here, the case for allele‐specific recognition (germline selected) is detailed making it obvious that the Standard model is untenable. 相似文献
50.
Aliyah Hussein Kiran Sran Imran Ali Janine Woellner Helen Wilcox Stephen D. Marks Helen Jones Chris Callaghan 《Pediatric transplantation》2020,24(4)
Transplant ureteric stent insertion reduces the incidence of MUCs, but it is not known whether routine PSRGU is needed to detect unmasked MUCs. This study evaluated whether routine PSRGU in the pRTR is a useful tool to identify MUCs before they become clinically apparent. A retrospective analysis was undertaken of the clinical outcomes following elective stent removal from pediatric kidney‐only transplant recipients at two London centers between 2012 and 2016. Our policy was to perform PSRGU either routinely or urgently if there were concerning symptoms or biochemical evidence of renal allograft dysfunction. Elective stent removal was performed in 86% (97 of 113 pRTR), and 75 (77%) of whom had routine PSRGU at a median (IQR) of 6 (2‐8) days after stent removal. There were changes to management in 3 (4%) of pRTR with PSRGU identifying no MUC. Nineteen patients (25%) had urgent PSRGU, most commonly due to renal allograft dysfunction, at a median (IQR) of 5.5 (2.7‐12.3) days after stent removal. Of these, two pRTR required ureteric intervention. For our current practice of removing transplant stents at 4‐6 weeks post‐transplantation, our study has found no evidence to support routine PSRGU after elective stent removal. 相似文献