全文获取类型
收费全文 | 174502篇 |
免费 | 914篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 1121篇 |
儿科学 | 6612篇 |
妇产科学 | 3001篇 |
基础医学 | 16385篇 |
口腔科学 | 1529篇 |
临床医学 | 12286篇 |
内科学 | 30519篇 |
皮肤病学 | 657篇 |
神经病学 | 16367篇 |
特种医学 | 8898篇 |
外科学 | 28665篇 |
综合类 | 2306篇 |
预防医学 | 18033篇 |
眼科学 | 2720篇 |
药学 | 9408篇 |
中国医学 | 626篇 |
肿瘤学 | 16284篇 |
出版年
2019年 | 20篇 |
2018年 | 21927篇 |
2017年 | 17363篇 |
2016年 | 19508篇 |
2015年 | 886篇 |
2014年 | 775篇 |
2013年 | 738篇 |
2012年 | 6896篇 |
2011年 | 20941篇 |
2010年 | 18773篇 |
2009年 | 11469篇 |
2008年 | 19427篇 |
2007年 | 21618篇 |
2006年 | 466篇 |
2005年 | 2089篇 |
2004年 | 3297篇 |
2003年 | 4273篇 |
2002年 | 2419篇 |
2001年 | 251篇 |
2000年 | 395篇 |
1999年 | 150篇 |
1998年 | 192篇 |
1997年 | 196篇 |
1996年 | 83篇 |
1995年 | 95篇 |
1994年 | 92篇 |
1993年 | 55篇 |
1992年 | 36篇 |
1991年 | 82篇 |
1990年 | 121篇 |
1989年 | 74篇 |
1988年 | 51篇 |
1987年 | 38篇 |
1986年 | 21篇 |
1985年 | 28篇 |
1984年 | 18篇 |
1983年 | 20篇 |
1982年 | 24篇 |
1980年 | 39篇 |
1974年 | 19篇 |
1970年 | 19篇 |
1969年 | 20篇 |
1968年 | 17篇 |
1939年 | 20篇 |
1938年 | 60篇 |
1937年 | 25篇 |
1935年 | 22篇 |
1934年 | 30篇 |
1932年 | 56篇 |
1930年 | 46篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
Nicolas Beysard Bertrand Yersin Pascal Meylan Olivier Hugli Pierre-Nicolas Carron 《Internal and emergency medicine》2018,13(2):251-256
The morbidity and mortality of the 2014–2015 influenza season were more important than those in previous years. We assessed the impact of the 2014–2015 influenza season on the length of stay (LOS) and workload in an academic emergency department (ED). This is a monocentric retrospective study. The database of the microbiology laboratory was used to identify influenza nasal swabs performed during the influenza seasons from 2010 to 2015. Patients admitted to the ED during these periods were identified through the administrative database and cross-checked with patients who underwent an influenza nasal swab in the ED. Median LOS was used to estimate the impact of the isolation procedures on ED LOS. Bed occupancy rate and mean LOS in the ED were calculated as proxy of the ED workload. During the 2014–2015 influenza season, 55.9% of ED patients (n = 123) with confirmed influenza were hospitalised. In terms of workload, despite that influenza patients represented only 2.2% of all ED patients during the season, they occupied 28% of ED beds with respiratory isolation during the delay to realise and obtain the test results, as well as during the delay before being discharged home or transferred to a hospital ward. The median ED LOS for influenza-confirmed patients was significantly longer in comparison with all ED patients (21.6 h vs 4.0 for ambulatory patients and 24.7 h vs 12.3 for hospitalised patients). The 2014–2015 influenza season had significant consequences in terms of ED LOS and bed use. It dramatically increased the workload in the ED. 相似文献
992.
Qun He Ye Wang Yan Li Yurun Zhang Peng Lin Fang Yang Xiaobing Fu Jie Li H. Fisher Raymond Li Ling Willi McFarland 《AIDS and behavior》2008,12(1):93-96
Men who have sex with men (MSM) may account for an increasing proportion of China’s HIV epidemic, but remain difficult to access for epidemiological studies due to high stigma. We compare the composition of two samples of MSM obtained in Guangzhou, China. The first survey, conducted in 2004, recruited MSM through convenience sampling. The second survey in 2006 used long-chain referral recruitment in the context of respondent-driven sampling. Compared to convenience sampling, the long-chain referral method included higher proportions of subgroups of MSM thought to be at elevated risk for HIV infection and more difficult to reach, including internal migrants and those engaging in commercial sex. Long-chain referral also recruited more MSM who were under 25 years, unemployed, and had lower education. We conclude that long-chain referral recruitment will be more effective in tracking the leading edge of the epidemic among MSM in China than convenience sampling. 相似文献
993.
Ian T. MacQueen Melinda Maggard-Gibbons Gina Capra Laura Raaen Jesus G. Ulloa Paul G. Shekelle Isomi Miake-Lye Jessica M. Beroes Susanne Hempel 《Journal of general internal medicine》2018,33(2):191-199
Background
Rural areas have historically struggled with shortages of healthcare providers; however, advanced communication technologies have transformed rural healthcare, and practice in underserved areas has been recognized as a policy priority. This systematic review aims to assess reasons for current providers’ geographic choices and the success of training programs aimed at increasing rural provider recruitment.Methods
This systematic review (PROSPERO: CRD42015025403) searched seven databases for published and gray literature on the current cohort of US rural healthcare practitioners (2005 to March 2017). Two reviewers independently screened citations for inclusion; one reviewer extracted data and assessed risk of bias, with a senior systematic reviewer checking the data; quality of evidence was assessed using the GRADE approach.Results
Of 7276 screened citations, we identified 31 studies exploring reasons for geographic choices and 24 studies documenting the impact of training programs. Growing up in a rural community is a key determinant and is consistently associated with choosing rural practice. Most existing studies assess physicians, and only a few are based on multivariate analyses that take competing and potentially correlated predictors into account. The success rate of placing providers-in-training in rural practice after graduation, on average, is 44% (range 20–84%; N = 31 programs). We did not identify program characteristics that are consistently associated with program success. Data are primarily based on rural tracks for medical residents.Discussion
The review provides insight into the relative importance of demographic characteristics and motivational factors in determining which providers should be targeted to maximize return on recruitment efforts. Existing programs exposing students to rural practice during their training are promising but require further refining. Public policy must include a specific focus on the trajectory of the healthcare workforce and must consider alternative models of healthcare delivery that promote a more diverse, interdisciplinary combination of providers.994.
Epidemiology of anaphylaxis in the united states 总被引:2,自引:0,他引:2
Anaphylaxis is a potentially life-threatening allergic reaction characterized by a syndrome of dermatologic and systemic signs
and symptoms, at times including cardiovascular collapse from distributive shock. Although it is recognized that the incidence
of anaphylaxis is increasing, the extent of its prevalence, both from individual causes and in toto, remains unclear. Common
causes include pharmacologic agents, such as antibiotics and radiocontrast media, as well as foods, insect stings, and latex
exposure. The available literature suffers from methodologic shortcomings, limiting the accuracy of estimated prevalence.
However, current data suggest that there are approximately 1500 annual deaths from anaphylaxis, and between 2.8 million and
42.7 million Americans are at risk of experiencing an episode of anaphylaxis during their lives. 相似文献
995.
Wendling D Tisserand G Griffond V Saccomani C Toussirot E 《Clinical rheumatology》2008,27(9):1205-1206
A 72-year-old man, treated with a 60-mg intravenous infusion of pamidronate for shoulder hand syndrome, developed after few hours an acute pseudogout arthritis of his right knee. Diagnosis was confirmed by synovial fluid analysis and was associated with hypocalcemia. Only a few cases are reported in the literature. The mechanism of this potential side effect remains speculative. 相似文献
996.
Stephen J. Hanna Oz Barakat Simon Watkin 《Journal of hepato-biliary-pancreatic sciences》2004,11(3):190-192
We report the case of a 54-year old woman who presented with a persistent right lower lobe pneumonia followed by cholelithoptysis, 11 months after a laparoscopic cholecystectomy. It is postulated that this was a result of the formation of a subphrenic abscess secondary to intraoperative spillage of gallstones. It is concluded that spillage of gallstones at laparoscopic cholecystectomy is not as benign as previously thought and that efforts to prevent spillage should include scrupulous operative technique, especially in the presence of gallbladder inflammation, and especial care when removing the gallbladder from the abdominal cavity. 相似文献
997.
Brundell S Tsopelas C Chatterton B Touloumtzoglou J Blefari C Hewett PJ 《Diseases of the colon and rectum》2003,46(5):637-642
INTRODUCTION: We have reported previously on an in vitro model to examine tumor cell adherence to metal and plastic laparoscopic ports and to port sites through which they had been passed. This demonstrated that increased numbers of tumor cells were found both on metal ports compared with plastic ports and on the port sites through which metal ports had passed. In this study, the in vivo adherence of such cells to ports and port sites was investigated.
METHODS: LIM 1215 tumor cells were injected under direct vision into the pelvises of 16 30-kg female pigs (range, 15–70 × 106 cells). A total of 12 ports were inserted through each anterior abdominal wall (6 metal and 6 plastic), and these were either left in situ for 30 minutes (nondisplaced) or were removed twice and replaced through the original wound (displaced).
RESULTS: Increasing the tumor cell inoculum resulted in increased deposition of tumor cells on both ports (P = 0.002) and on the port sites (P = 0.017). Significantly more tumor cells adhered to metal ports than to plastic ports (P = 0.04), although this failed to reach significance for the sites through which metal ports had been passed (P = 0.066). Although displacement of ports did not increase the number of tumor cells that adhered to ports (P = 0.45), this did result in more tumor cells being deposited on the port sites (P = 0.01).
CONCLUSIONS: These data suggest that minimizing the number of tumor cells within the abdominal cavity, using plastic ports, and securing ports to prevent inadvertent displacement would be expected to reduce the number of tumor cells deposited in port sites during operative laparoscopy. This may be beneficial in reducing the incidence of port-site metastases after laparoscopic surgery for gastrointestinal malignancies. 相似文献
998.
Antonio De Sisti Joelci Tonet Sonia Marrakchi Denis Raguin Robert Frank 《Journal of interventional cardiac electrophysiology》2008,22(3):189-193
Limited information is available on the efficacy of cryoablation in the coronary venous system in humans. A patient with a lateral accessory pathway was referred to our center after several unsuccessful endocardial and epicardial (within the coronary sinus) attempts using standard radiofrequency energy. Ablation was subsequently performed successfully by applying cryoenergy distally into the coronary sinus, using a temperature of -50 degrees C and a freezing application time of 45 s. There were no complications. Angiography of the left coronary circumflex artery and coronary venous system was performed at 12 months follow-up using cardiac multislice computed tomography, and no coronary stenosis or anatomic anomaly was found. Neither pre-excitation or any arrhythmia recurred during follow-up. This experience suggests that ablating in the distal coronary sinus can be safely performed using cryoenergy. 相似文献
999.
Insulin aspart (NovoLog, NovoRapid), a rapid-acting human insulin analog, provides more rapid absorption than regular human insulin after subcutaneous administration. In most randomized, nonblind clinical trials in patients with type 1 diabetes mellitus, insulin aspart administered immediately before meals resulted in significantly lower mean glycosylated hemoglobin (HbA1c) levels than regular human insulin (usually administered 30 minutes before a meal). Insulin aspart also significantly improved postprandial glycemic control compared with regular human insulin. The efficacy of insulin aspart was similar to that of insulin lispro when administered to patients with type 1 diabetes mellitus via continuous subcutaneous infusion in a randomized, nonblind trial. Preliminary data from randomized, nonblind trials suggest insulin aspart had a trend towards lower HbA1c levels compared with regular human insulin in patients with type 2,diabetes mellitus. Biphasic insulin aspart (30% soluble [rapid-acting] and 70% protamine-bound insulin aspart [BIAsp30]) [NovoLog Mix 70/30, NovoMix 30(2)] generally provided significantly better postprandial glucose control than a similar mixture of biphasic regular human insulin (BHI30) in a randomized, nonblind trial in patients with type 1 or 2 diabetes mellitus. However, the long-term efficacy of BIAsp30 was similar to that of BHI30 after 2 years in a randomized, nonblind trial in patients with type 2 diabetes mellitus. Patients with type 1 or 2 diabetes mellitus reported greater treatment satisfaction with insulin aspart or BIAsp30 than with regular human insulin or BHI30. The overall incidence of hypoglycemia with insulin aspart was lower than, or similar to, that of regular human insulin. Moreover, insulin aspart tended to be associated with a lower occurrence of nocturnal hypoglycemia and severe hypoglycemic events than regular human insulin. Conclusion: The standard preparation of insulin aspart has the potential to better mimic the physiological response to meals than regular human insulin. Insulin aspart when combined with a suitable basal insulin improved overall glycemic control and led to a similar or lower number of hypoglycemic episodes compared with a similar regular human insulin regimen. Insulin aspart was generally as effective and well tolerated as insulin lispro when administered by continuous subcutaneous infusion in a single comparative trial. The efficacy of biphasic insulin aspart has been documented in a small number of trials. Both insulin aspart and biphasic insulin aspart provide for flexible and convenient administration. Insulin aspart is now well established as an effective and convenient means of providing glycemic control which offers clinical and practical advantages over regular human insulin. 相似文献
1000.
Expression of vascular endothelial growth factor and receptor flk-1 in colon cancer liver metastases
Jun Cheng Richard E. Slavin Jennifer A. Gallagher Guojing Zhu Thomas R. Biehl Lee L. Swanstrom Paul D. Hansen 《Journal of hepato-biliary-pancreatic sciences》2004,11(3):164-170