全文获取类型
收费全文 | 5680篇 |
免费 | 425篇 |
国内免费 | 33篇 |
专业分类
耳鼻咽喉 | 45篇 |
儿科学 | 273篇 |
妇产科学 | 158篇 |
基础医学 | 743篇 |
口腔科学 | 83篇 |
临床医学 | 518篇 |
内科学 | 1245篇 |
皮肤病学 | 124篇 |
神经病学 | 324篇 |
特种医学 | 126篇 |
外国民族医学 | 1篇 |
外科学 | 786篇 |
综合类 | 230篇 |
一般理论 | 5篇 |
预防医学 | 412篇 |
眼科学 | 119篇 |
药学 | 474篇 |
中国医学 | 24篇 |
肿瘤学 | 448篇 |
出版年
2023年 | 56篇 |
2022年 | 141篇 |
2021年 | 213篇 |
2020年 | 115篇 |
2019年 | 185篇 |
2018年 | 220篇 |
2017年 | 122篇 |
2016年 | 164篇 |
2015年 | 156篇 |
2014年 | 207篇 |
2013年 | 296篇 |
2012年 | 397篇 |
2011年 | 354篇 |
2010年 | 213篇 |
2009年 | 199篇 |
2008年 | 288篇 |
2007年 | 319篇 |
2006年 | 323篇 |
2005年 | 264篇 |
2004年 | 252篇 |
2003年 | 192篇 |
2002年 | 159篇 |
2001年 | 101篇 |
2000年 | 109篇 |
1999年 | 98篇 |
1998年 | 38篇 |
1997年 | 35篇 |
1996年 | 25篇 |
1994年 | 19篇 |
1992年 | 52篇 |
1991年 | 60篇 |
1990年 | 61篇 |
1989年 | 36篇 |
1988年 | 41篇 |
1987年 | 42篇 |
1986年 | 43篇 |
1985年 | 45篇 |
1984年 | 24篇 |
1983年 | 19篇 |
1981年 | 29篇 |
1980年 | 23篇 |
1979年 | 36篇 |
1978年 | 28篇 |
1977年 | 24篇 |
1975年 | 22篇 |
1974年 | 23篇 |
1973年 | 35篇 |
1972年 | 26篇 |
1971年 | 30篇 |
1969年 | 21篇 |
排序方式: 共有6138条查询结果,搜索用时 15 毫秒
991.
Rana Ghandehari-Alavijeh Dina Zohrabi Marziyeh Tavalaee 《Human fertility (Cambridge, England)》2019,22(2):145-151
Reduced sperm motility (asthenozoospermia) accounts for a significant percentage of male infertility and numerous factors have been suggested to explain this phenomenon among which hypoxic and inflammatory markers are the least studied. Therefore, the aim of this study was to assess the main molecular markers involved in hypoxia (P53 and HIF-1α) and inflammation (TNF-α) pathways in infertile men with asthenozoospermia. Expression of these markers were assessed by qRT-PCR, and analysis of data show that mean of hypoxia markers (P53, HIF-1α) and also TNF- α were significantly higher in infertile men with asthenozoospermia compared to fertile men (p?0.05). Unlike TNF-α, significant negative correlations were observed between expression of P53 (r?=?–0.568; p?=?0.002) and HIF-1α (r?=?–0.403; p?=?0.046) with sperm motility. In addition, a significant negative correlation was observed between expression of P53 with sperm concentration (r?=?–0.576; p?0.001). In addition, a significant positive correlation was observed between hypoxia markers (P53, HIF-1α) and TNF-α (p?0.01). However, no significant relation was observed between TNF-α and semen parameters. Taken together, the results of this study suggest the involvement of hypoxia pathway is more pronounced than the inflammatory pathway in asthenozoospermia. 相似文献
992.
Vanessa Bacal Urvi Rana Daniel I. McIsaac Innie Chen 《Journal of minimally invasive gynecology》2019,26(1):40-52
The objective of this study was to address the efficacy of transversus abdominis plane (TAP) blocks in pain management among women who undergo elective hysterectomy for benign pathology in both open and minimally invasive surgeries. We performed a systematic review by searching for bibliographic citations from Medline, Embase, and Cochrane Library. MeSH headings for TAP blocks and hysterectomy were combined and restricted to the English language. We included randomized controlled trials comparing TAP blocks with placebo or no block in patients who underwent elective hysterectomy. Pain was measured using a visual analog scale (VAS) on a scale of 0 to 100. We calculated pooled mean differences in VAS and total morphine consumption at 2 and 24 hours by performing a random effects meta-analysis. Fourteen studies met the inclusion criteria, comprising 855 participants. At 2 hours mean VAS scores for patients who underwent TAP blocks were significantly lower after both total abdominal hysterectomy (TAH) (mean difference, ?14.97; 95% confidence interval [CI], ?20.35 to ?9.59) and total laparoscopic hysterectomy (TLH; mean difference, ?18.16; 95% CI, ?34.78 to ?1.53) compared with placebo or no block. Pain scores at 24 hours for patients who underwent TAP blocks were significantly lower after both TAH (?10.09; 95% CI, ?17.35 to ?2.83) and TLH (?9.12; 95% CI, ?18.12 to ?.13) compared with placebo or no block. Mean difference in morphine consumption was ?9.53?mg (95% CI, ?15.43 to ?3.63) for TAH and ?3.15?mg (95% CI, ?8.41 to 2.12) for TLH. In conclusion, TAP blocks provide significant postoperative early and delayed pain control compared with placebo or no block among women who undergo hysterectomy. There was reduced morphine consumption among patients who underwent TAH but not TLH. (Registration: International Prospective Register of Systematic Reviews ID: CRD42016036791.) 相似文献
993.
994.
Rana R. McKay Peter Vu Laurence K. Albiges Xun Lin Ronit Simantov Jennifer S. Temel Toni K. Choueiri 《Clinical genitourinary cancer》2019,17(6):443-450.e1
BackgroundThe relationship between weight change during treatment and survival remains poorly characterized in patients with metastatic renal cell carcinoma (mRCC).Patients and MethodsIn this retrospective analysis we included 3311 patients with mRCC treated in phase II/III first-line or second-line targeted therapy clinical trials and assessed the effect of weight change on overall survival (OS), progression-free survival (PFS), and objective response rate (ORR) at 6 and 12 weeks from treatment initiation. Weight change was defined as weight loss (≥5% reduction), weight gain (≥2% increase), or stable weight from baseline. Survival analyses were performed using the Kaplan–Meier method and adjusted for known prognostic factors using Cox regression multivariable analysis.ResultsOverall, 1916 (58%) had stable weight, 936 (28%) had weight loss, and 459 (14%) had weight gain at 12 weeks. Patients with weight loss at 12 weeks had inferior OS compared with those with stable weight (hazard ratio [HR], 1.494; 95% confidence interval [CI], 1.322-1.688; P < .0001; median OS 18.7 vs. 26.9 months), and shorter PFS (HR, 1.315; 95% CI, 1.189-1.455; P < .0001; median PFS, 7.2 vs. 10.1 months). The ORRs for patients with weight loss, stable weight, and weight gain at 12 weeks were 23.4% (n = 219/936), 32.1% (n = 615/1916), and 35.9% (n = 165/459), respectively (adjusted odds ratio, 0.715; P = .03). Findings were consistent at 6 weeks. Adverse events were similar between groups.ConclusionWe showed that mRCC patients who experience weight loss during treatment have worse outcomes compared with patients with stable weight at 6 and 12 weeks of treatment. Weight loss at 6 weeks from treatment initiation might be an early clinical biomarker of worse survival and might provide prognostic utility. 相似文献
995.
996.
997.
998.
Rajesh Vijayvergiya Ramalingam Vadivelu Sachin Mahajan Sandeep S Rana Manphool Singhal 《World journal of cardiology》2015,7(9):579-582
Constrictive pericarditis (CP) is an inflammatory disease of pericardium. Pericardial calcification in X-ray provides a clue for the diagnosis of CP. An extensive “eggshell” type of calcification is rarely seen in CP. We hereby report a case of CP with eggshell calcification of pericardium, encircling whole of the heart. A need for multimodality imaging and hemodynamic assessment followed by surgical pericardiectomy is discussed. 相似文献
999.
Rajesh Verma Sunita Kakkar Biju Vasudevan Vandana Rana Debdeep Mitra Shekar Neema 《Indian journal of dermatology》2015,60(2):188-190
A 51-year-old male presented with blackish discoloration of nails of 10 months duration. Examination revealed black dystrophic left thumb finger nail. Detailed examination showed a mass under the dystrophic nail. Hutchinson sign was positive. Histopathology revealed characteristic features of melanoma. A detailed evaluation revealed no features of local or distant metastasis. The entire lesion was then removed surgically along with disarticulation at the interphalangeal joint. Resection-free margin was confirmed. This case is being reported for the rare occurrence of subungual melanoma in the Indian population and also for presentation with a long history of lesion with no evidence of metastasis. 相似文献
1000.
Al Hussainy R Verbeek J van der Born D Braker AH Leysen JE Knol RJ Booij J Herscheid JK 《Journal of medicinal chemistry》2011,54(10):3480-3491
Here we describe the design, synthesis, and pharmacological profile of 5-HT(1A) receptor ligands related to 1 (WAY-100635). The cyclohexyl moiety in 1 and its O-desmethylated analogue 3 were replaced by the bridgehead iodinated bridge-fused rings: adamantyl, cubyl, bicyclo[2.2.2]octyl, or bicyclo[2.2.1]heptyl. All analogues displayed a (sub)nanomolar affinity for the 5-HT(1A) receptor in vitro. Compounds 6b and 7b appeared to be selective for this receptor over other relevant receptors and could easily be iodinated with radioactive iodine-123. In humane hepatocytes, [(123)I]6b showed a low propensity for amide hydrolysis and a stable carbon-iodine bond. The biodistribution of [(123)I]6b and [(123)I]7b in rats revealed that the carbon-iodine bond was also stable in vivo. Unfortunately, the brain uptake and the specificity for both radioligands were significantly lower than those of the parent molecule 1. In conclusion, the designed tracers are not suitable for SPECT imaging. 相似文献