全文获取类型
收费全文 | 7640篇 |
免费 | 424篇 |
国内免费 | 33篇 |
专业分类
耳鼻咽喉 | 77篇 |
儿科学 | 303篇 |
妇产科学 | 168篇 |
基础医学 | 725篇 |
口腔科学 | 186篇 |
临床医学 | 590篇 |
内科学 | 1722篇 |
皮肤病学 | 181篇 |
神经病学 | 495篇 |
特种医学 | 189篇 |
外科学 | 1564篇 |
综合类 | 118篇 |
一般理论 | 3篇 |
预防医学 | 287篇 |
眼科学 | 232篇 |
药学 | 673篇 |
中国医学 | 37篇 |
肿瘤学 | 547篇 |
出版年
2024年 | 6篇 |
2023年 | 77篇 |
2022年 | 172篇 |
2021年 | 389篇 |
2020年 | 214篇 |
2019年 | 263篇 |
2018年 | 366篇 |
2017年 | 235篇 |
2016年 | 296篇 |
2015年 | 269篇 |
2014年 | 413篇 |
2013年 | 466篇 |
2012年 | 758篇 |
2011年 | 712篇 |
2010年 | 393篇 |
2009年 | 359篇 |
2008年 | 427篇 |
2007年 | 453篇 |
2006年 | 390篇 |
2005年 | 324篇 |
2004年 | 250篇 |
2003年 | 189篇 |
2002年 | 150篇 |
2001年 | 44篇 |
2000年 | 43篇 |
1999年 | 46篇 |
1998年 | 29篇 |
1997年 | 25篇 |
1996年 | 22篇 |
1995年 | 19篇 |
1994年 | 14篇 |
1993年 | 16篇 |
1992年 | 41篇 |
1991年 | 32篇 |
1990年 | 20篇 |
1989年 | 18篇 |
1988年 | 17篇 |
1987年 | 20篇 |
1986年 | 16篇 |
1985年 | 23篇 |
1984年 | 11篇 |
1983年 | 10篇 |
1982年 | 5篇 |
1981年 | 8篇 |
1980年 | 4篇 |
1979年 | 9篇 |
1978年 | 4篇 |
1977年 | 11篇 |
1976年 | 4篇 |
1974年 | 3篇 |
排序方式: 共有8097条查询结果,搜索用时 0 毫秒
1.
Richard Kim Elaine Tan Emily Wang Amit Mahipal Dung-Tsa Chen Biwei Cao Fadzai Masawi Cindy Machado James Yu Dae Won Kim 《The oncologist》2020,25(12):e1893-e1899
Lessons Learned
- The combination of trametinib and sorafenib has an acceptable safety profile, albeit at doses lower than approved for monotherapy.
- Maximum tolerated dose is trametinib 1.5 mg daily and sorafenib 200 mg twice daily.
- The limited anticancer activity observed in this unselected patient population does not support further exploration of trametinib plus sorafenib in patients with hepatocellular carcinoma.
2.
Derivation and spontaneous differentiation of human embryonic stem cells 总被引:16,自引:0,他引:16 下载免费PDF全文
Embryonic stem (ES) cells are unique cells derived from the inner cell mass of the mammalian blastocyst. These cells are immortal and pluripotent, retain their developmental potential after prolonged culture, and can be continuously cultured in an undifferentiated state. Many in vitro differentiation systems have been developed for mouse ES cells, including reproducible methods for mouse ES cell differentiation into haematopoietic and neural precursors, cardiomyocytes, insulin‐secreting cells, endothelial cells and various other cell types. The derivation of new human ES cell lines provides the opportunity to develop unique models for developmental research and for cell therapies. In this review we consider the derivation and spontaneous differentiation of human ES cells. 相似文献
3.
Andrew Cooper Amit Joglekar Neill Adhikari 《Canadian Medical Association journal》2003,169(8):785-787
4.
Amit Badhwar Thomas L Forbes Marge B Lovell Alison A Dungey Sarah D McCarter Jeffrey R Scott Guy DeRose Kenneth A Harris Richard F Potter 《Canadian journal of surgery》2004,47(5):352-358
BACKGROUND: Ischemic preconditioning (IPC) has been found in animals to have a protective effect against future ischemic injury to muscle tissue. Such injury is unavoidable during some surgical procedures. To determine whether chronic ischemia in the lower extremities would imitate IPC and reduce ischemic injury during vascular surgery, we designed a controlled clinical study. PATIENTS AND METHODS: Two groups of patients at a university-affiliated medical centre with chronic lower-extremity ischemia served as models of IPC: 6 patients awaiting femoral distal bypass (FDB) and 4 scheduled for aortobifemoral (ABF) bypass grafting for aortoiliac occlusive disease. Seven patients undergoing elective open repair of an infrarenal abdominal aortic aneurysm (AAA) were chosen as non-IPC controls. Three hematologic indicators of skeletal-muscle injury, lactate dehydrogenase (LDH), creatine kinase (CK) and myoglobin, were measured before placement of the proximal clamp, during surgical ischemia, immediately upon reperfusion, 15 minutes after and 1 hour after reperfusion, and during the first, second and third postoperative days. RESULTS: Baseline markers of skeletal-muscle injury were similar in all groups. In postreperfusion samples, concentrations of muscle-injury markers were significantly lower in the 2 PC groups than in the control group. For example, at day 2, LDH levels were increased by about 30% over baseline measures in the elective AAA (control) group, whereas levels in the FDB and ABF groups remained statistically unchanged from baseline. Myoglobin in controls had increased by 977%, but only by 160% in the FDB and 528% in the ABF groups. CK levels, in a similar trend, were 1432% higher in the control group and only 111% (FDB) and 1029% (ABF) in the study groups. Taken together, these data represent a significant level of protection. CONCLUSIONS: Patients with chronic lower-extremity ischemia suffered less severe ischemic injury after a period of acute ischemia than those with acute ischemia alone. Ischemic preconditioning is one proposed mechanism to help explain this protective effect. 相似文献
5.
Amit Dang MBBS Gaurav Garg Padmanabh V. Rataboli MD 《The International journal of eating disorders》2009,42(4):385-386
Nocturnal Sleep‐Related Eating Disorder (NSRED) is a well‐documented sleeping disorder where the person is reported to experience bizarre eating behavior during sleep. Although various causes are implicated in this disorder, role of drugs cannot be ruled out. Here we narrate an interesting rare case report of a drug‐induced new onset NSRED, where a 45‐year‐old man on zolipdem performed an unexpected and bizarre eating behavior during somnambulistic state, type of which has not been reported earlier in the literature. The case falls under even rarer category as such behavior in sleep is reported mainly in woman. © 2008 by Wiley Periodicals, Inc. Int J Eat Disord 2009 相似文献
6.
Phospho-akt expression is associated with a favorable outcome in non-small cell lung cancer. 总被引:3,自引:0,他引:3
Amit Shah William A Swain Donna Richardson John Edwards Duncan J Stewart Catherine M Richardson Daniel E B Swinson Dipika Patel J Louise Jones Kenneth J O'Byrne 《Clinical cancer research》2005,11(8):2930-2936
Akt, a Serine/Threonine protein kinase, mediates growth factor-associated cell survival. Constitutive activation of Akt (phosphorylated Akt, P-Akt) has been observed in several human cancers, including lung cancer and may be associated with poor prognosis and chemotherapy and radiotherapy resistance. The clinical relevance of P-Akt in non-small cell lung cancer (NSCLC) is not well described. In the present study, we examined 82 surgically resected snap-frozen and paraffin-embedded stage I to IIIA NSCLC samples for P-Akt and Akt by Western blotting and for P-Akt by immunohistochemistry. P-Akt protein levels above the median, measured using reproducible semiquantitative band densitometry, correlated with a favorable outcome (P = 0.007). Multivariate analysis identified P-Akt as a significant independent favorable prognostic factor (P = 0.004). Although associated with a favorable prognosis, high P-Akt levels correlated with high tumor grade (P = 0.02). Adenocarcinomas were associated with low P-Akt levels (P = 0.039). Akt was not associated with either outcome or clinicopathologic variables.Cytoplasmic (CP-Akt) and nuclear (NP-Akt) P-Akt tumor cell staining was detected in 96% and 42% of cases, respectively. Both CP-Akt and NP-Akt correlated with well-differentiated tumors (P = 0.008 and 0.017, respectively). NP-Akt also correlated with nodal metastases (P = 0.022) and squamous histology (P = 0.037).These results suggest P-Akt expression is a favorable prognostic factor in NSCLC. Immunolocalization of P-Akt, however, may be relevant as NP-Akt was associated with nodal metastases, a known poor prognostic feature in this disease. P-Akt may be a potential novel therapeutic target for the management of NSCLC. 相似文献
7.
Sandeep Nijhawan Mukul Rastogi Ashish Joshi Atul Shende Manish Tandon Dinesh Singla Amit Mathur Subhash Nepalia Ramesh Roop Rai 《Digestive endoscopy》2007,19(2):80-82
Background: Ingestion of coins is a common clinical problem in children. Many of the coins are ferromagnetic and can be retrieved with the help of a magnet. We describe the use of a novel endoscopic accessory for removing ferromagnetic coins. Material and methods: Two magnet discs of 1.5 cm diameter were joined to a 200 cm steel wire of 0.75 mm thickness with a terminal 5 cm spring. A Teflon tube (160 cm, 7 F) was used along with this instrument as a sleeve. The use of this accessory was analyzed prospectively in subjects presenting with a history of coin ingestion. The time taken for removal of coins, complications during the procedure and failure rate was noted. Effect of the magnet on cardiac rhythm was also noted during the procedure. Results: A total of 55 children (mean age 5.1 ± 2.3 years) with coin ingestion presented over a period of 1 year. Forty‐four coins were ferromagnetic. All ferromagnetic coins were removed successfully. Mean time for removal was 68 ± 22 s. No complications were encountered. Conclusion: The novel magnetic instrument is precise, safe and quick for the removal of ferromagnetic coins under direct vision. 相似文献
8.
9.
The effects of naltrexone (NTX) on the acquisition of ethanol drinking was assessed in rats. NTX (0, 2.5, 5.0, or 10.0 mg/kg) was administered to rats presented with an ascending series of ethanol concentrations (2%, 4%, 6%, and 8% v/v) and water. The 2.5 and 10 mg/kg doses of NTX attenuated the acquisition of voluntary drinking of 8% ethanol, but the 5.0 mg/kg dose of NTX had no effect on ethanol intake. The acquisition paradigm was repeated in experiment 2 with naïve animals that received 0, 5.0, or 7.5 mg/kg of NTX. Neither dose of NTX affected ethanol intake, preference for alcohol, or water intake. Total fluid intake was suppressed in the NTX groups, but only on the second presentations of the 2% and 6% concentrations of ethanol. We suggest that the 2.5 and 10 mg/kg doses of NTX may have attenuated the acquisition of ethanol drinking by at least two different behavioral mechanisms. 相似文献
10.