首页 | 官方网站   微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   84509篇
  免费   6917篇
  国内免费   4147篇
医药卫生   95573篇
  2024年   150篇
  2023年   861篇
  2022年   1605篇
  2021年   2320篇
  2020年   2278篇
  2019年   2041篇
  2018年   1863篇
  2017年   2282篇
  2016年   2793篇
  2015年   2610篇
  2014年   4975篇
  2013年   4427篇
  2012年   5375篇
  2011年   6099篇
  2010年   5292篇
  2009年   5112篇
  2008年   4967篇
  2007年   5439篇
  2006年   5235篇
  2005年   5034篇
  2004年   3980篇
  2003年   3520篇
  2002年   2972篇
  2001年   2821篇
  2000年   2271篇
  1999年   1724篇
  1998年   1489篇
  1997年   1299篇
  1996年   794篇
  1995年   686篇
  1994年   609篇
  1993年   348篇
  1992年   324篇
  1991年   262篇
  1990年   261篇
  1989年   222篇
  1988年   228篇
  1987年   197篇
  1986年   164篇
  1985年   140篇
  1984年   94篇
  1983年   66篇
  1982年   79篇
  1981年   56篇
  1980年   57篇
  1979年   41篇
  1978年   43篇
  1977年   19篇
  1976年   16篇
  1975年   13篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
3.
Over the last 40 years, the incidence and prevalence of gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) have continued to increase. Compared to other epithelial neoplasms in the same organ, GEP-NENs exhibit indolent biological behavior, resulting in more chances to undergo surgery. However, the role of surgery in high-grade or advanced GEP-NENs is still controversial. Surgery is associated with survival improvement of well-differentiated high-grade GEP-NENs, whereas poorly differentiated GEP-NENs that may benefit from resection require careful selection based on Ki67 and other tissue biomarkers. Additionally, surgery also plays an important role in locally advanced and metastatic disease. For locally advanced GEP-NENs, isolated major vascular involvement is no longer an absolute contraindication. In the setting of metastatic GEP-NENs, radical intended surgery is recommended for patients with low-grade and resectable metastases. For unresectable metastatic disease, a variety of surgical approaches, including cytoreduction of liver metastasis, liver transplantation, and surgery after neoadjuvant treatment, show survival benefits. Primary tumor resection in GEP-NENs with unresectable metastatic disease is associated with symptom control, prolonged survival, and improved sensitivity toward systemic therapies. Although there is no established neoadjuvant or adjuvant strategy, increasing attention has been given to this emerging research area. Some studies have reported that neoadjuvant therapy effectively reduces tumor burden, improves the effectiveness of subsequent surgery, and decreases surgical complications.  相似文献   
4.
5.
Introduction: In men, lower urinary tract symptoms (LUTS) are primarily attributed to benign prostatic hyperplasia (BPH). Therapeutic options are targeted to relax prostate smooth muscle and/or reduce prostate enlargement.

Areas covered: This article reviews the major preclinical and clinical data on PDE5 inhibitors with a specific focus on tadalafil. It includes details of the role of the nitric oxide (NO)-cyclic guanosine monophosphate (cGMP) – PDE5 pathway in the LUT organs (bladder and prostate) in addition to the available data on tadalafil in patients with LUTS secondary to BPH with or without erectile dysfunction (ED).

Expert opinion: Preclinical and clinical data have clearly demonstrated that PDE5 inhibitors induce bladder and prostate relaxation, which contributes to the improvement seen in storage symptoms in both animal models of bladder and prostate hypercontractility. Tadalafil is effective both as a monotherapy and add-on therapy in patients with LUTS secondary to BPH. Furthermore, as LUTS-BPH and ED are urological disorders that commonly coexist in aging men, tadalafil is more advantageous than α1-adrenoceptors and should be used as the first option. Tadalafil is a safe and tolerable therapy and unlike α1- adrenoceptors and 5-alpha reductase inhibitors, which can cause sexual dysfunctions, tadalafil improves sexual function.  相似文献   

6.
7.
BACKGROUND Minimally invasive surgery for gastric cancer(GC) has gained widespread use as a safe curative procedure especially for early GC.AIM To determine risk factors for postoperative complications after minimally invasive gastrectomy for GC.METHODS Between January 2009 and June 2019, 1716 consecutive patients were referred to our division for primary GC. Among them, 1401 patients who were diagnosed with both clinical and pathological Stage Ⅲ or lower GC and underwent robotic gastrectomy(RG) or laparoscopic gastrectomy(LG) were enrolled. Retrospective chart review and multivariate analysis were performed for identifying risk factors for postoperative morbidity.RESULTS Morbidity following minimally invasive gastrectomy was observed in 7.5% of the patients. Multivariate analyses demonstrated that non-robotic minimally invasive surgery, male gender, and an operative time of ≥ 360 min were significant independent risk factors for morbidity. Therefore, morbidity was compared between RG and LG. Accordingly, propensity-matched cohort analysis revealed that the RG group had significantly fewer intra-abdominal infectious complications than the LG group(2.5% vs 5.9%, respectively; P = 0.038), while no significant differences were noted for other local or systemic complications.Multivariate analyses of the propensity-matched cohort revealed that non-robotic minimally invasive surgery [odds ratio = 2.463(1.070–5.682); P = 0.034] was a significant independent risk factor for intra-abdominal infectious complications.CONCLUSION The findings showed that robotic surgery might improve short-term outcomes following minimally invasive radical gastrectomy by reducing intra-abdominal infectious complications.  相似文献   
8.
Non-clear cell renal cell carcinoma is a very rare malignancy that includes several histological subtypes. Each subtype may need to be addressed separately regarding prognosis and treatment; however, no Phase III clinical trial data exist. Thus, treatment recommendations for patients with non-clear cell metastatic RCC (mRCC) remain unclear. We present first prospective data on choice of first- and second-line treatment in routine practice and outcome of patients with papillary mRCC. From the prospective German clinical cohort study (RCC-Registry), 99 patients with papillary mRCC treated with systemic first-line therapy between December 2007 and May 2017 were included. Prospectively enrolled patients who had started first-line treatment until May 15, 2016, were included into the outcome analyses (n = 82). Treatment was similar to therapies used for clear cell mRCC and consisted of tyrosine kinase inhibitors, mechanistic target of rapamycin inhibitors and recently checkpoint inhibitors. Median progression-free survival from start of first-line treatment was 5.4 months (95% confidence interval [CI], 4.1–9.2) and median overall survival was 12.0 months (95% CI, 8.1–20.0). At data cutoff, 73% of the patients died, 6% were still observed, 12% were lost to follow-up, and 9% were alive at the end of the individual 3-year observation period. Despite the lack of prospective Phase III evidence in patients with papillary mRCC, our real-world data reveal effectiveness of systemic clear cell mRCC therapy in papillary mRCC. The prognosis seems to be inferior for papillary compared to clear cell mRCC. Further studies are needed to identify drivers of effectiveness of systemic therapy for papillary mRCC.  相似文献   
9.
miRNAs是一类长度约为20~25个核苷酸,参与基因调控表达的内源性非编码RNA。miR-149作为miRNAs的重要成员,在多种肿瘤中表达异常,其表达水平与肿瘤细胞增殖、转移、凋亡、耐药、患者的早期诊断及预后密切相关。因此,miR-149有望成为新一类抗肿瘤治疗的靶点。  相似文献   
10.
目的探讨接受选择性淋巴结照射(ENI)的食管鳞癌患者预后和失败模式。方法回顾性分析2005年1月至2012年12月河北医科大学第四医院收治的179例符合入组条件的食管鳞癌患者,分析肿瘤局部相关因素预测患者预后的价值,分析影响患者近期疗效、预后的影响因素,并对影响患者总生存率(OS)、无进展生存率(PFS)和复发的指标分别进行单因素和多因素分析。结果全组患者1、3、5年OS和PFS分别为77.1%、40.1%、26.0%和62.6%、30.6%、20.3%。多因素分析结果显示声音嘶哑、cN分期、cTNM分期、GTV-横径(GTV-D)和GTV-体积/长度(GTV-V/L)为影响患者OS的独立性影响因素(P<0.05);声音嘶哑、cTNM分期和近期疗效为影响患者PFS的独立性影响因素(P<0.05)。全组有75例(41.9%)患者出现复发,61例(34.1%)远处转移,其中19例(10.6%)为合并复发和远处转移。75例复发患者中64例(85.3%)患者为单纯食管复发,4例(5.3%)为单纯淋巴结复发,另7例(9.3%)患者为食管合并淋巴结复发。治疗后达完全缓解(CR)的63例患者中有18例患者出现复发,其中仅有2例患者出现淋巴结复发;logistic多因素分析结果显示患者周边组织/器官受侵、GTV-D和近期疗效为影响患者复发的独立性影响因素(P<0.05)。结论食管鳞癌患者接受ENI确实可行,其失败主要模式仍为食管复发;治疗前声音嘶哑、GTV-D和GTV-V/L较大、临床分期较晚和近期疗效不佳为患者预后较差的指标;肿瘤周边组织受侵、GTV-D和近期疗效是影响患者失败的独立性因素。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司    京ICP备09084417号-23

京公网安备 11010802026262号