全文获取类型
收费全文 | 40220篇 |
免费 | 2599篇 |
国内免费 | 576篇 |
专业分类
耳鼻咽喉 | 762篇 |
儿科学 | 601篇 |
妇产科学 | 565篇 |
基础医学 | 6965篇 |
口腔科学 | 745篇 |
临床医学 | 3233篇 |
内科学 | 8160篇 |
皮肤病学 | 1538篇 |
神经病学 | 3030篇 |
特种医学 | 2392篇 |
外科学 | 5117篇 |
综合类 | 230篇 |
现状与发展 | 1篇 |
一般理论 | 9篇 |
预防医学 | 1677篇 |
眼科学 | 935篇 |
药学 | 3486篇 |
中国医学 | 505篇 |
肿瘤学 | 3444篇 |
出版年
2023年 | 189篇 |
2022年 | 638篇 |
2021年 | 1392篇 |
2020年 | 738篇 |
2019年 | 985篇 |
2018年 | 1166篇 |
2017年 | 952篇 |
2016年 | 1381篇 |
2015年 | 2008篇 |
2014年 | 2345篇 |
2013年 | 2555篇 |
2012年 | 3790篇 |
2011年 | 3621篇 |
2010年 | 2168篇 |
2009年 | 1864篇 |
2008年 | 2528篇 |
2007年 | 2280篇 |
2006年 | 2026篇 |
2005年 | 1787篇 |
2004年 | 1490篇 |
2003年 | 1322篇 |
2002年 | 1161篇 |
2001年 | 790篇 |
2000年 | 694篇 |
1999年 | 559篇 |
1998年 | 247篇 |
1997年 | 202篇 |
1996年 | 141篇 |
1995年 | 131篇 |
1994年 | 89篇 |
1993年 | 79篇 |
1992年 | 185篇 |
1991年 | 211篇 |
1990年 | 141篇 |
1989年 | 166篇 |
1988年 | 154篇 |
1987年 | 147篇 |
1986年 | 121篇 |
1985年 | 109篇 |
1984年 | 79篇 |
1983年 | 82篇 |
1982年 | 47篇 |
1981年 | 48篇 |
1980年 | 45篇 |
1979年 | 73篇 |
1978年 | 73篇 |
1977年 | 68篇 |
1976年 | 44篇 |
1974年 | 42篇 |
1973年 | 46篇 |
排序方式: 共有10000条查询结果,搜索用时 421 毫秒
91.
92.
Financial Implications of Pancreas Transplant Complications: A Business Case for Quality Improvement
J. A. Cohn M. J. Englesbe Y. M. Ads J. L. Paruch S. J. Pelletier T. H. Welling C. J. Sonnenday J. C. Magee J. D. Punch D. A. Campbell Jr . R. S. Sung 《American journal of transplantation》2007,7(6):1656-1660
We quantified the financial implications of surgical complications following pancreas transplantation. We reviewed medical and financial records of 49 pancreas transplant recipients at the University of Michigan Health System (UMHS) between 1/6/2002 and 11/22/2004. The association of donor, transplant recipient and financial variables was assessed. The median costs to UMHS of procedures and follow-up were $92,917 for recipients without surgical complications versus $108,431 when a surgical complication occurred, a difference of $15,514 (p = 0.03). Median reimbursement by the payer was $17,363 higher in patients with a surgical complication (p = 0.001). Similar trends (higher insurer costs) were noted when stratifying by payer (public and private) and specific procedure (SPK and PAK). All parties (patient, physician, payer and medical center) should benefit from quality improvement, with payers having a financial interest in pancreas transplant surgical quality initiatives. 相似文献
93.
Soo Jeong Lim Jin Chul Paeng Sung Jin Kim Sang Yoon Kim Heuiran Lee Dae Hyuk Moon 《Journal of nuclear medicine》2007,48(3):398-404
Increased expression of the sodium iodide symporter (NIS) is required for effective radioiodine treatment and reporter gene imaging of breast cancer. We investigated the effect of retinoic acid on adenovirus-mediated expression of the human NIS gene in the MCF-7 breast cancer cell line. METHODS: The MCF-7 cell line was infected with recombinant adenovirus carrying the human NIS gene (Rad-NIS). Levels of NIS messenger RNA (mRNA) and protein expression and radioiodine ((125)I) uptake were measured to evaluate adenovirus-mediated NIS gene expression in wild-type and Rad-NIS-infected MCF-7 cells after treatment with all-trans-retinoic acid (ATRA; 10(-8)-10(-6) mol/L). RESULTS: The transduction efficiency of adenovirus in MCF-7 cells at a multiplicity of infection (MOI) of 50 was >60%. After incubation with 10(-6) mol/L ATRA, the mRNA level in Rad-NIS-infected MCF-7 cells increased to 118.5 times that of wild-type MCF-7 cells, whereas the mRNA level in wild-type MCF-7 cells showed only a 2.1-fold increase. Western blot, immunocytochemical staining, and flow cytometry analyses showed that NIS protein expression in MCF-7 cells infected with Rad-NIS increased after ATRA treatment. With ATRA treatment, the amount of (125)I uptake increased in a dose-dependent manner (P < 0.001). The (125)I uptake in wild-type MCF-7 cells increased 3.1-, 5.5-, and 7.6-fold with treatment with 10(-8), 10(-7), and 10(-6) mol/L ATRA, respectively. Rad-NIS-infected cells showed a 4.0-fold increase in (125)I uptake. Treatment of Rad-NIS-infected cells with 10(-8), 10(-7), and 10(-6) mol/L ATRA increased (125)I uptake by 4.9-, 8.2-, and 27.6-fold, respectively, compared with wild-type MCF-7 cells. The level of NIS expression in Rad-NIS-infected MCF-7 cells treated with 10(-6) mol/L ATRA (245.0 +/- 13.7 pmol/10(6) cells) was much greater than the sum of the expression levels seen in ATRA-treated wild-type cells and Rad-NIS-infected wild-type cells. CONCLUSION: Retinoic acid increases adenovirus-mediated NIS expression in MCF-7 cells. Our results indicate that improved efficiency of NIS gene therapy or reporter imaging in breast cancer may be possible with retinoic acid treatment. 相似文献
94.
Si Chan Sung Yun Hee Chang Jong Soo Woo 《European journal of cardio-thoracic surgery》2007,31(4):742-743
We developed a technique of translocation of the pulmonary artery anterior to the ascending aorta without transection of the aorta in the repair of tetralogy of Fallot with absent pulmonary valve. Our technique includes detachment of the main pulmonary artery (MPA) from the pulmonary annulus, vertical division of the MPA, anterior translocation of the pulmonary artery with patch augmentation between the vertically divided MPA. 相似文献
95.
96.
97.
98.
K. L. Brayman M. K. Guidinger C. M. Sommers R. S. Sung 《American journal of transplantation》2007,7(Z1):1359-1375
Kidney and pancreas transplantation in 2005 improved in quantity and outcome quality, despite the increasing average age of kidney graft recipients, with 56% aged 50 or older. Geography and ABO blood type contribute to the discrepancy in waiting time among the deceased donor (DD) candidates. Allocation policy changes are decreasing the median times to transplant for pediatric recipients. Overall, 6% more DD kidney transplants were performed in 2005 with slight increases in standard criteria donors (SCD) and expanded criteria donors (ECD). The largest increase (39%) was in donation after cardiac death (DCD) from non‐ECD donors. These DCD, non‐ECD kidneys had equivalent outcomes to SCD kidneys. 1‐, 3‐ and 5‐year unadjusted graft survival was 91%, 80% and 70% for non‐ECD‐DD transplants, 82%, 68% and 53% for ECD‐DD grafts, and 95%, 88% and 80% for living donor kidney transplants. In 2005, 27% of patients were discharged without steroids compared to 3% in 1999. Acute rejection decreased to 11% in 2004. There was a slight increase in the number of simultaneous pancreas‐kidney transplants (895), with fewer pancreas after kidney transplants (343 from 419 in 2004), and a stable number of pancreas alone transplants (129). Pancreas underutilization appears to be an ongoing issue. 相似文献
99.
Performance measurement of the microPET focus 120 scanner. 总被引:6,自引:0,他引:6
Jin Su Kim Jae Sung Lee Ki Chun Im Su Jin Kim Seog-Young Kim Dong Soo Lee Dae Hyuk Moon 《Journal of nuclear medicine》2007,48(9):1527-1535
The microPET Focus 120 scanner is a third-generation animal PET scanner dedicated to rodent imaging. Here, we report the results of scanner performance testing. METHODS: A (68)Ge point source was used to measure energy resolution, which was determined for each crystal and averaged. Spatial resolution was measured using a (22)Na point source with a nominal size of 0.25 mm at the system center and various off-center positions. Absolute sensitivity without attenuation was determined by extrapolating the data measured using an (18)F line source and multiple layers of absorbers. Scatter fraction and counting rate performance were measured using 2 different cylindric phantoms simulating rat and mouse bodies. Sensitivity, scatter fraction, and noise equivalent counting rate (NECR) experiments were repeated under 4 different conditions (energy window, 250 approximately 750 keV or 350 approximately 650 keV; coincidence window, 6 or 10 ns). A performance phantom with hot-rod inserts of various sizes was scanned, and several animal studies were also performed. RESULTS: Energy resolution at a 511-keV photopeak was 18.3% on average. Radial, tangential, and axial resolution of images reconstructed with the Fourier rebinning (FORE) and filtered backprojection (FBP) algorithms were 1.18 (radial), 1.13 (tangential), and 1.45 mm full width at half maximum (FWHM) (axial) at center and 2.35 (radial), 1.66 (tangential), and 2.00 mm FWHM (axial) at a radial offset of 2 cm. Absolute sensitivities at transaxial and axial centers were 7.0% (250 approximately 750 keV, 10 ns), 6.7% (250 approximately 750 keV, 6 ns), 4.0% (350 approximately 650 keV, 10 ns), and 3.8% (350 approximately 650 keV, 6 ns). Scatter fractions were 15.9% (mouse phantom) and 35.0% (rat phantom) for 250 approximately 750 keV and 6 ns. Peak NECR was 869 kcps at 3,242 kBq/mL (mouse phantom) and 228 kcps at 290 kBq/mL (rat phantom) at 250 approximately 750 keV and 6 ns. Hot-rod inserts of 1.6-mm diameter were clearly identified, and animal studies illustrated the feasibility of this system for studies of whole rodents and mid-sized animal brains. CONCLUSION: The results of this independent field test showed the improved physical characteristics of the F120 scanner over the previous microPET series systems. This system will be useful for imaging studies on small rodents and brains of larger animals. 相似文献
100.
Kwan Chang Kim Kwang Ree Cho Yong-Jin Kim Dae-Won Sohn Ki-Bong Kim 《European journal of cardio-thoracic surgery》2007,31(2):261-266
OBJECTIVE: We evaluated the long-term results of the Cox-Maze III procedure (CM-III) for persistent atrial fibrillation (AF) associated with rheumatic mitral valve (MV) disease. METHODS: We analyzed 127 patients who underwent the CM-III combined with a rheumatic MV procedure between 1994 and 2004. In-hospital mortalities were excluded from the study. RESULTS: There were 10 late deaths and the mean follow-up duration was 7.1+/-2.8 years (range, 13 months to 11.5 years). Normal sinus rhythm was restored in 88.2% (112/127) after the CM-III. Right atrial contractility was demonstrable in 100% (112/112) and left atrial contractility in 68.8% (77/112) of the patients restored to sinus rhythm. Fifteen patients never regained sinus rhythm after the CM-III (AF treatment failure). Permanent pacemakers were implanted in 4.7% (6/127) of the patients during the follow-up. Late recurrence of AF developed in 34 of 112 patients at 44+/-27 months postoperatively, and sinus rhythm was restored in 29 of 34 patients by administration of an antiarrhythmic medication. Independent risk factors for late AF recurrence were longer duration of AF (>60 months) (odds ratio (OR)=2.758, p=0.025), increased left atrial size (OR=1.113, p=0.004). Freedom from AF recurrence was 93% at 1-year, 82% at 3 years, 71% at 5 years, and 63% at 7 years. Risk factors for AF treatment failure were longer duration of AF (>60 months) (p<0.001) and increased patient age (p=0.030). A higher prevalence of significant late tricuspid regurgitation was observed in patients with AF treatment failure and those with late AF recurrence. CONCLUSIONS: The CM-III for persistent AF associated with rheumatic MV disease demonstrated a progressively decreased cure rate during the follow-up period. Early surgical therapy, aggressive left atrial reduction, and correction of tricuspid regurgitation at the time of surgery may increase the long-term success rate. 相似文献