全文获取类型
收费全文 | 988篇 |
免费 | 55篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 43篇 |
儿科学 | 40篇 |
妇产科学 | 65篇 |
基础医学 | 60篇 |
口腔科学 | 65篇 |
临床医学 | 69篇 |
内科学 | 186篇 |
皮肤病学 | 27篇 |
神经病学 | 57篇 |
特种医学 | 49篇 |
外科学 | 265篇 |
综合类 | 11篇 |
预防医学 | 27篇 |
眼科学 | 24篇 |
药学 | 28篇 |
中国医学 | 2篇 |
肿瘤学 | 33篇 |
出版年
2023年 | 11篇 |
2022年 | 11篇 |
2021年 | 25篇 |
2020年 | 17篇 |
2019年 | 16篇 |
2018年 | 28篇 |
2017年 | 19篇 |
2016年 | 45篇 |
2015年 | 43篇 |
2014年 | 43篇 |
2013年 | 54篇 |
2012年 | 76篇 |
2011年 | 62篇 |
2010年 | 44篇 |
2009年 | 37篇 |
2008年 | 68篇 |
2007年 | 91篇 |
2006年 | 90篇 |
2005年 | 59篇 |
2004年 | 71篇 |
2003年 | 46篇 |
2002年 | 35篇 |
2001年 | 14篇 |
2000年 | 7篇 |
1999年 | 10篇 |
1998年 | 4篇 |
1997年 | 3篇 |
1996年 | 2篇 |
1995年 | 4篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1982年 | 1篇 |
1978年 | 1篇 |
1960年 | 1篇 |
排序方式: 共有1051条查询结果,搜索用时 15 毫秒
1.
2.
3.
Abdülmuttalip Keser Murat Bozkurt Omer Faruk Taner Mithat Akan Omer Sens?z 《Nordisk plastikkirurgisk forening [and] Nordisk klubb for handkirurgi》2004,38(5):257-260
The various methods of prefabricating flaps include vascular induction through staged transfer; pretransfer delay, expansion, and grafting; the use of alloplastic materials; and tissue bioengineering. In this experimental study, vascular induction was used to provide an axial vascular pedicle to randomly nourished tissue. Twenty-six New Zealand rabbits, ages and weights ranging between 6 months-1 year and 1.5-3.5 kg, respectively, were used. The sex difference was not considered. The deep inferior epigastric artery and vein were used to carry blood and were placed into a segment of femur to prefabricate the bone. Four weeks later, the viability of the segment of bone prefabricated by new axial pedicle was shown by scintigraphic study, and the new axial pedicle was ready for free transfer. 相似文献
4.
First branchial cleft fistula is a rare congenital malformation of the head and neck with an incidence of less than 10% of all branchial cleft defects. We herein report a 15-year-old girl who had a cystic mass in the postauricular region with an external opening on the posterior face of the earlobe. Surgical exploration revealed that a second sinus tract was passing through the conchal cartilage without going beyond the skin of the external acoustic meatus. The mass and the tract were excised along with the opening on the earlobe as well as the skin island surrounding the opening. The case was treated surgically with success .The significance of our case was the location of external opening on the earlobe. 相似文献
5.
Lavanya Yohanathan Cristina C. Campioli Omar Y. Mousa Kymberly Watt Daniel Z. P. Friedman Vijay Shah Resham Ramkissoon Alexander S. Hines Patrick S. Kamath Raymund R. Razonable Andrew D. Badley Erin S. DeMartino Michael J. Joyner Rondell Graham Paschalis Vergidis Doug A. Simonetto William Sanchez Timucin Taner Julie K. Heimbach Elena Beam Michael D. Leise 《American journal of transplantation》2021,21(8):2890-2894
Current guidelines recommend deferring liver transplantation (LT) in patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection until clinical improvement occurs and two PCR tests collected at least 24 hours apart are negative. We report a case of an 18-year-old, previously healthy African-American woman diagnosed with COVID-19, who presents with acute liver failure (ALF) requiring urgent LT in the context of SARS-CoV-2 polymerase chain reaction (PCR) positivity. The patient was thought to have acute Wilsonian crisis on the basis of hemolytic anemia, alkaline phosphatase:bilirubin ratio <4, AST:ALT ratio >2.2, elevated serum copper, and low uric acid, although an unusual presentation of COVID-19 causing ALF could not be excluded. After meeting criteria for status 1a listing, the patient underwent successful LT, despite ongoing SARS-CoV-2 PCR positivity. Remdesivir was given immediately posttransplant, and mycophenolate mofetil was withheld initially and the SARS-CoV-2 PCR test eventually became negative. Three months following transplantation, the patient has made a near-complete recovery. This case highlights that COVID-19 with SARS-CoV-2 PCR positivity may not be an absolute contraindication for transplantation in ALF. Criteria for patient selection and timing of LT amid the COVID-19 pandemic need to be validated in future studies. 相似文献
6.
In dentistry, acrylates have been used for preparing denture bases for 50 years. Although polymethylmethacrylates (PMMA) are known to be an ideal base material, they possess some undesirable mechanical properties, especially their impact strength and tensile strength, which appear to be unsatisfactory for some applications. Additives and fibers have therefore been used to enhance and improve these properties over the last two decades. The present article describes the mechanical properties, impact and tensile strength of PMMA reinforced with chopped ultra-high molecular weight polyethylene fiber (6 mm long). It was found that, although the processing involved for high loading of fibers into the PMMA was difficult, the resulting improvement of impact strength was substantial. 相似文献
7.
Highly efficient ex vivo gene transfer to the transplanted heart by means of hypothermic perfusion with a low dose of adenoviral vector 总被引:1,自引:0,他引:1
Pellegrini C Jeppsson A Taner CB O'Brien T Miller VM Tazelaar HD McGregor CG 《The Journal of thoracic and cardiovascular surgery》2000,119(3):493-500
BACKGROUND: Hypothermic conditions required for donor heart preservation may reduce gene-transfer efficiency. Experiments were designed to determine whether a perfusion technique could improve the efficiency of gene transfer to donor hearts. METHODS: An adenoviral vector encoding beta-galactosidase (3.5 x 10(8) plaque-forming units) was infused into explanted rat hearts under 4 conditions (each n = 6): (1) the virus was diluted in 350 microL of University of Wisconsin solution and infused as a high-pressure bolus into the coronary arteries of donor hearts through the aortic root; (2) the virus was diluted in 5 mL of University of Wisconsin solution and circulated by means of a peristaltic pump (flow, 0.75 mL/min) through the vasculature of the donor heart for 30 minutes; (3) 5 mL of viral solution was circulated as for group 2 for 15 minutes; and (4) 5 mL of viral solution was circulated for 5 minutes at a flow rate of 2.4 mL/min. Transduced hearts were transplanted into the abdomen of syngeneic rats, and transgene expression was assessed by means of immunoassay 4 days later. RESULTS: The median beta-galactosidase content was (1) 45.0 ng/mg protein (25th-75th percentile, 33-73 ng/mg), (2) 640 ng/mg protein (25th-75th percentile, 614-878 ng/mg), (3) 493.8 ng/mg protein (25th-75th percentile, 456-527 ng/mg), and (4) 503.3 ng/mg protein (25th-75th percentile, 475-562 ng/mg; P <.01 for group 2 vs group 1, and P <.05 for groups 3 and 4 vs group 1). Transgene expression was predominantly in myocytes and favored the subepicardial region of the right ventricle. CONCLUSION: Hypothermic perfusion of the donor heart with an adenoviral vector resulted in efficient transgene expression compared with that induced by a single bolus injection. 相似文献
8.
9.
Gastric emptying time measurement by radionuclide study, although quite informative, is rarely remembered in clinical practice. We presented a patient with brittle diabetes who had multiple emergency admissions due to hypoglycemia under routinely prescribed insulin therapy. She had severe gastroparesis, which was determined by scintigraphic gastric emptying study (gastric half-emptying time = 260 min for a mixed meal). She had not presented to the emergency service for two years because of only a slight change the timing of her insulin administration time (after meal instead of before meal) in the light of gastric-emptying study. 相似文献
10.
The added value of the apparent diffusion coefficient calculation to magnetic resonance imaging in the differentiation and grading of malignant brain tumors 总被引:14,自引:0,他引:14
Bulakbasi N Guvenc I Onguru O Erdogan E Tayfun C Ucoz T 《Journal of computer assisted tomography》2004,28(6):735-746
OBJECTIVE: ADC calculation can improve the diagnostic efficacy of MR imaging in brain tumor grading and differentiation. METHODS: Apparent diffusion coefficient (ADC) values and ratios of 33 low-grade (23 astrocytomas, 10 oligodendrogliomas) and 40 high-grade (25 metastases and 15 high-grade astrocytomas) malignant tumors were prospectively evaluated. RESULTS: Tumoral ADC values (r=-0.738, P <0.000) and ratios (r=-0.746, P < 0.000) were well correlated with higher degree of malignancy and quite effective in grading of malignant brain tumors (P < 0.000). By using cutoff values of 0.99 for tumoral ADC value and 1.22 for normalized ADC ratio, the sensitivity of MR imaging could be increased from 72.22% to 93.75% and 90.63%, the specificity from 81.08% to 92.68% and 90.24%, PPV from 78.79% to 90.91% and 87.88%, and NPV from 75.00% to 95.00% and 92.50%, respectively. CONCLUSION: ADC calculation was quite effective in grading of malignant brain tumors but not in differentiation of them and added more information to conventional contrast-enhanced MR imaging. 相似文献