全文获取类型
收费全文 | 5123篇 |
免费 | 280篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 31篇 |
儿科学 | 363篇 |
妇产科学 | 81篇 |
基础医学 | 441篇 |
口腔科学 | 180篇 |
临床医学 | 323篇 |
内科学 | 1136篇 |
皮肤病学 | 268篇 |
神经病学 | 294篇 |
特种医学 | 124篇 |
外科学 | 743篇 |
综合类 | 186篇 |
预防医学 | 245篇 |
眼科学 | 308篇 |
药学 | 438篇 |
中国医学 | 13篇 |
肿瘤学 | 239篇 |
出版年
2023年 | 38篇 |
2022年 | 76篇 |
2021年 | 170篇 |
2020年 | 75篇 |
2019年 | 152篇 |
2018年 | 191篇 |
2017年 | 131篇 |
2016年 | 158篇 |
2015年 | 166篇 |
2014年 | 214篇 |
2013年 | 224篇 |
2012年 | 387篇 |
2011年 | 448篇 |
2010年 | 234篇 |
2009年 | 177篇 |
2008年 | 247篇 |
2007年 | 284篇 |
2006年 | 207篇 |
2005年 | 196篇 |
2004年 | 170篇 |
2003年 | 142篇 |
2002年 | 159篇 |
2001年 | 109篇 |
2000年 | 114篇 |
1999年 | 90篇 |
1998年 | 41篇 |
1997年 | 19篇 |
1996年 | 20篇 |
1995年 | 35篇 |
1994年 | 17篇 |
1992年 | 69篇 |
1991年 | 64篇 |
1990年 | 41篇 |
1989年 | 37篇 |
1988年 | 53篇 |
1987年 | 39篇 |
1986年 | 32篇 |
1985年 | 38篇 |
1984年 | 27篇 |
1983年 | 23篇 |
1979年 | 22篇 |
1977年 | 15篇 |
1975年 | 16篇 |
1974年 | 26篇 |
1973年 | 15篇 |
1972年 | 27篇 |
1971年 | 19篇 |
1970年 | 15篇 |
1969年 | 16篇 |
1968年 | 18篇 |
排序方式: 共有5413条查询结果,搜索用时 31 毫秒
91.
92.
93.
Background: Conventional oral dosage forms exhibit poor/low bioavailability due to incomplete release of drug and short residence time at the absorption site. Gastro-retentive drug delivery system (GRDDS) is particularly used to improve bioavailability of the drugs, which have narrow absorption window down in the levels of gastrointestinal tract and also to treat local disorders.Purpose: The purpose of this review is to describe the utility of the nanofibers as gastro-retentive dosage form. From last few decades, formulation scientists have put extensive efforts to develop suitable gastro-retentive drug delivery system, which is appropriate for commercialization. Current approaches used for preparation of gastro-retentive drug delivery system offers limited functional features to control the floating behavior. Recently, an extensive research has been developed to improve the gastric residence time by using nanofibers, which ultimately leads to the increased bioavailability of the drug. Multiple functional features and unique properties of nanofibers improve its gastro retention.Conclusion: Nanofiber system provides stomach-specific drug release for longer duration; moreover, increased local action of the drug due to prolonged contact time with the gastric mucosa. Thus, the nanofiber system promises to be the potential approach for gastric retention drug delivery system. 相似文献
94.
David A. Talan Sukhjit S. Takhar Anusha Krishnadasan William R. Mower Daniel J. Pallin Manish Garg Jon Femling Richard E. Rothman Johanna C. Moore Alan E. Jones Frank Lovecchio Jonathan Jui Mark T. Steele Amy M. Stubbs William K. Chiang Gregory J. Moran 《Annals of emergency medicine》2021,77(1):32-43
95.
Mehtani Rohit Garg Shankey Kajal Kamal Soni Shiv Lal Premkumar Madhumita 《Metabolic brain disease》2022,37(5):1291-1307
Metabolic Brain Disease - Patients with liver disease often have alteration of neurological status which requires admission to an intensive care unit. Patients with acute liver failure (ALF),... 相似文献
96.
Garg SK Walker AJ Hoff HK D'Souza AO Gottlieb PA Chase HP 《Diabetes technology & therapeutics》2004,6(1):9-15
This study compared external insulin pump treatment using insulin lispro or insulin aspart with multiple daily injections (MDI; four or more injections per day) using insulin glargine and insulin lispro or insulin aspart. An electronic database was used to retrieve various parameters of glycemic control for 515 adult patients with type 1 diabetes. An insulin pump was used by 216 patients, and 299 patients were taking insulin glargine for at least 6 months. The mean age (approximately 33 years), duration of diabetes (approximately 16 years), and duration of treatment (approximately 12 months) were similar for both the pump and insulin glargine groups. The mean (+/-SEM) A1C values were significantly reduced in both groups from the baseline to the end of the study (7.7 +/- 0.1% to 7.5 +/- 0.1% for the pump group and 8.0 +/- 0.1% to 7.7 +/- 0.1% for the insulin glargine group, P< 0.001) with similar weight gain (P> 0.05) in both groups. The insulin glargine group significantly reduced basal insulin intake at follow-up. The premeal boluses were similar throughout the study for both groups. The subjects reporting severe hypoglycemic episodes were similar in the two groups; however, there were 12 cases of diabetic ketoacidosis reported in the pump group and none in the insulin glargine group. Patients with type 1 diabetes can achieve similar glycemic control using insulin glargine with premeal insulin lispro or by using an external infusion pump with insulin lispro or insulin aspart. However, costs and episodes of diabetic ketoacidosis are significantly higher for insulin pump users. 相似文献
97.
Extracorporeal membrane oxygenation (ECMO) is a highly invasive therapy for intractable neonatal respiratory failure, and serious complications may occur with increasing duration of bypass. Weaning from bypass is empirical at present. Thus, there is a need to accurately predict when infants can be successfully decannulated. We hypothesized that pulmonary mechanics would reflect lung recovery and, therefore, predict successful weaning from ECMO. We measured pulmonary mechanics daily in 22 neonates, at gestational age of 37.8 +/- 0.6 weeks (SE) requiring ECMO for severe respiratory failure (oxygen index 66 +/- 6). Pulmonary resistance (Rpul), dynamic compliance (Cdyn), and tidal volume (VT) were measured. Rpul did not predict lung recovery. Cdyn within 24 hours of starting ECMO was 0.3 +/- 0.04 ml/cm H2O. Cdyn within 24 hours of weaning from ECMO was 1.2 +/- 0.09 ml/cm H2O (p less than 0.001). All 22 infants had Cdyn greater than 0.6 ml/cm H2O at the time of decannulation, but four infants (20 percent) with Cdyn less than 0.6 ml/cm H2O could not be weaned from ECMO within 20 hours (p less than 0.01). Thus, a minimum Cdyn of 0.6 ml/cm H2O is associated with successful weaning from ECMO. Cdyn of 0.8 ml/cm H2O provided better overall discrimination between those who could be successfully weaned from ECMO. We conclude that serial measurement of dynamic pulmonary compliance predicts successful weaning from ECMO. 相似文献
98.
Ae-Young Her Eun-Seok Shin Joo Myung Lee Scot Garg Joon-Hyung Doh Chang-Wook Nam Bon-Kwon Koo 《The international journal of cardiovascular imaging》2018,34(9):1339-1347
There is limited data on the efficacy of paclitaxel-coated balloon (PCB) compared to stents for de novo coronary lesions. The purpose of this study was to compare the efficacy of PCB treatment with stent implantation for de novo coronary lesions after successful plain old balloon angioplasty (POBA) guided by fractional flow reserve (FFR). In 200 patients scheduled for elective percutaneous coronary intervention (PCI) for de novo lesions, FFR was measured after POBA (POBA–FFR). If POBA–FFR was ≥?0.75, patients were treated with PCB (PCB group, n?=?78) or stent (Stent group, n?=?73). If POBA–FFR was <?0.75, stent was implanted as planned (Reference group, n?=?42). The primary endpoint was late lumen loss at 9 months and the secondary endpoint was adverse cardiac events (cardiac death, myocardial infarction, target lesion thrombosis, or repeat revascularization) at 12 months follow-up. There was no between-group differences in the POBA–FFR (0.87?±?0.05 in PCB, 0.89?±?0.06 in stent, p?=?0.101). At 9 months, late lumen loss was significantly lower in the PCB group compared to the Stent group (0.05?±?0.33 vs. 0.59?±?0.76 mm, p?<?0.001). Adverse cardiac events were not different between the PCB, Stent and Reference groups (2.6, 5.5, and 9.5% respectively; p?=?0.430 for PCB vs. Stent group; p?=?0.229 for the reference vs. both other groups). PCB treatment guided by POBA–FFR showed excellent 9 months angiographic and functional results, as well as comparable 12 months clinical outcomes, compared with stent implantation for de novo coronary lesions. 相似文献
99.
Nilay Kumar Ambarish Pandey Neetika Garg Emmanuel Sampene Carl J. Lavie 《Mayo Clinic proceedings. Mayo Clinic》2018,93(9):1185-1190
Objective
To ascertain whether temporal and geographic interest in seeking cardiovascular disease (CVD) information online follows seasonal and geographic patterns similar to those observed in real-world data.Methods
We searched Google Trends for popular search terms relating to CVD. Relative search volumes (RSVs) were obtained for the period January 4, 2004, to April 19, 2014, for the United States and Australia. We compared average RSVs by month and season and used cosinor analysis to test for seasonal variation in RSVs. We also assessed correlations between state-level RSVs and CVD burden using an ecological correlational design.Results
RSVs were 15% higher in the United States and 45% higher in Australia for winter compared with summer (P<.001 for difference for both). In the United States, RSVs were 36% higher in February compared with August, while in Australia, RSVs were 75% higher in August compared with January. On cosinor analysis, we found a significant seasonal variability in RSVs, with winter peaks and summer troughs for both the United States and Australia (P<.001 for zero amplitude test for both). We found a significant correlation between state-level RSVs and mortality from CVD (r=0.62; P<.001), heart disease (r=0.58; P<.001), coronary heart disease (r=0.48; P<.001), heart failure (r=0.51; P<.001), and stroke (r=0.60; P<.001).Conclusion
Google search query volumes related to CVD follow strong seasonal patterns with winter peaks and summer troughs. There is moderate to strong positive correlation between state-level search query volumes and burden of CVD mortality. 相似文献100.