全文获取类型
收费全文 | 46380篇 |
免费 | 4152篇 |
国内免费 | 49篇 |
专业分类
耳鼻咽喉 | 528篇 |
儿科学 | 1317篇 |
妇产科学 | 1063篇 |
基础医学 | 5974篇 |
口腔科学 | 1057篇 |
临床医学 | 5379篇 |
内科学 | 8787篇 |
皮肤病学 | 704篇 |
神经病学 | 4901篇 |
特种医学 | 2052篇 |
外国民族医学 | 4篇 |
外科学 | 6338篇 |
综合类 | 817篇 |
一般理论 | 34篇 |
预防医学 | 4431篇 |
眼科学 | 1177篇 |
药学 | 3135篇 |
3篇 | |
中国医学 | 72篇 |
肿瘤学 | 2808篇 |
出版年
2021年 | 591篇 |
2019年 | 560篇 |
2018年 | 653篇 |
2017年 | 558篇 |
2016年 | 561篇 |
2015年 | 674篇 |
2014年 | 889篇 |
2013年 | 1419篇 |
2012年 | 1960篇 |
2011年 | 2067篇 |
2010年 | 1174篇 |
2009年 | 1039篇 |
2008年 | 1848篇 |
2007年 | 2061篇 |
2006年 | 1937篇 |
2005年 | 1835篇 |
2004年 | 1795篇 |
2003年 | 1674篇 |
2002年 | 1703篇 |
2001年 | 1530篇 |
2000年 | 1549篇 |
1999年 | 1367篇 |
1998年 | 548篇 |
1997年 | 515篇 |
1996年 | 498篇 |
1995年 | 475篇 |
1994年 | 417篇 |
1993年 | 356篇 |
1992年 | 1157篇 |
1991年 | 1164篇 |
1990年 | 1093篇 |
1989年 | 1099篇 |
1988年 | 916篇 |
1987年 | 1036篇 |
1986年 | 957篇 |
1985年 | 967篇 |
1984年 | 767篇 |
1983年 | 622篇 |
1982年 | 400篇 |
1981年 | 367篇 |
1980年 | 376篇 |
1979年 | 700篇 |
1978年 | 525篇 |
1977年 | 446篇 |
1976年 | 463篇 |
1975年 | 396篇 |
1974年 | 520篇 |
1973年 | 455篇 |
1972年 | 383篇 |
1971年 | 363篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Seth D. Friedman PhD Sandra L. Poliachik PhD Randolph K. Otto MD Gregory T. Carter MD Christopher B. Budech BA Thomas D. Bird MD Daniel G. Miller MD PhD Dennis W.W. Shaw MD 《Muscle & nerve》2014,49(2):257-260
Introduction: Magnetic resonance imaging of muscle shows short tau‐inversion recovery (STIR) brightness in autosomal dominant facioscapulohumeral muscular dystrophy (FSHD1) suggestive of active inflammation/injury. We measured the longitudinal stability/progression of this potential disease biomarker. Methods: Nine subjects underwent calf MRI imaging over 2 years. Two radiologists evaluated qualitative muscle changes. Results: In 3/9 subjects, calf muscles demonstrated moderate/severe STIR hyperintensity at Time 1 that had progressed to fatty replacement 2 years later (Time 2). In the remaining subjects, moderate/severe muscle STIR abnormalities, when present, were consistent between exams. Mild STIR+ elevations had roughly similar patterns between exams. Conclusions: Moderate/severe STIR hyperintensities often foreshadow fatty replacement over a 2‐year interval. Whether longer time courses are required to observe muscle degeneration and fatty replacement in some subjects remains to be explored. Muscle Nerve 49 : 257–260, 2014 相似文献
72.
The induction by ultrasound (US) of petechiae and hemorrhages in mouse intestine was examined with injection of gas body-based contrast agents. Production of petechiae in the intestinal wall was enhanced by contrast agents for both continuous and pulsed (10 micros pulses repeated at 1 kHz) exposure relative to a gas body-free blank. For pulsed exposure with 10 mL/kg of Albunex, apparent thresholds for peak negative pressure amplitude were 0.42 MPa at 0.4 MHz, 0.85 MPa at 1.09 MHz and 2.3 MPa at 2.4 MHz. Results at these frequencies were the same for 10-11 cycle pulses with fixed duty cycle (0.01). Thresholds for hemorrhage into the intestinal lumen were not appreciably enhanced by added Albunex, and appear to be compatible with previously reported lithotripsy data when duty factor differences are considered. The agents PESDA, Optison and Levovist had lower thresholds (for example, 1.8 MPa for Levovist) than Albunex at 2.3 MHz, and yielded more petechiae. The thresholds for petechiae induction by US with contrast agents encroach upon the exposure range relevant to diagnostic US practice. 相似文献
73.
The Affordable Care Act seeks to overhaul the US health care system by providing insurance for more Americans, improving the quality of health care delivery, and reducing health care expenditures. Although the law's intent is clear, its implementation and effect on patient care remains largely undefined. Herein, we discuss major components of the Affordable Care Act, including the proposed insurance expansion, payment and delivery system reforms (e.g., bundled payments and Accountable Care Organizations), and other reforms relevant to the field of urologic oncology. We also discuss how these proposed reforms may affect patients with urologic cancers. 相似文献
74.
Kirsten J. Sasaki Aarathi Cholkeri-Singh Suela Sulo Charles E. Miller 《JSLS, Journal of the Society of Laparoendoscopic Surgeons》2014,18(4)
Background and Objectives:
In our clinical experience, there seemed to be a correlation between cervical stump bleeding and adenomyosis. Therefore, we wanted to conduct a study to determine whether there was an actual correlation and to identify other risk factors for persistent bleeding after a laparoscopic supracervical hysterectomy.Methods:
The study included women who underwent laparoscopic supracervical hysterectomy from January 1, 2003, through December 31, 2012. Data were collected on age, postmenopausal status, body mass index (BMI), uterine weight, indication for hysterectomy, concomitant bilateral salpingo-oophorectomy (BSO), presence of endometriosis, surgical ablation of the endocervix, adenomyosis, presence of endocervix in the specimen, and postoperative bleeding.Results:
The study included 256 patients, of whom 187 had no postoperative bleeding after the operation, 40 had bleeding within 12 weeks, and 29 had bleeding after 12 weeks. The 3 groups were comparable in BMI, postmenopausal status, uterine weight, indication for hysterectomy, BSO, surgical ablation of the endocervix, adenomyosis, and the presence of endocervix. However, patients who had postoperative bleeding at more than 12 weeks were significantly younger (P = .002) and had a higher rate of endometriosis (P < .001).Conclusions:
Risks factors for postoperative bleeding from the cervical stump include a younger age at the time of hysterectomy and the presence of endometriosis. Therefore, younger patients and those with endometriosis who desire to have no further vaginal bleeding may benefit from total hysterectomy over supracervical hysterectomy. All patients who are undergoing supracervical hysterectomy should be counseled about the possible alternatives, benefits, and risks, including continued vaginal bleeding from the cervical stump and the possibility of requiring future treatment and procedures. 相似文献75.
76.
77.
Yang J Bohl CE Nair VA Mustafa SM Hong SS Miller DD Dalton JT 《The Journal of pharmacology and experimental therapeutics》2006,317(1):402-408
Proper management of prostate cancer patients is highly dependent on the spread of the disease. High expression levels of the androgen receptor (AR) in prostate tumor offer a target for identifying cancer metastasis. We investigated the use of nonsteroidal AR ligands for receptor-mediated imaging as a diagnostic tool for prostate cancer staging. Compound S-26 [S-3-(4-fluorophenoxy)-2-hydroxy-2-methyl-N-(4-cyano-3-iodophenyl)-propionamide]was identified from a series of iodinated ether-linked derivatives of bicalutamide due to its high-AR binding affinity of 3.3 nM (which is similar to testosterone and approximately 25% of the binding affinity of dihydrotestosterone) in an in vitro competitive binding assay using rat prostate cytosol. Furthermore, S-26 exhibited a greater binding affinity (K(i) = 4.4 nM) in a whole-cell binding assay using COS-7 cells transfected with human AR than testosterone (K(i) = 32.9 nM) and dihydrotestosterone (K(i) = 45.4 nM). We also confirmed that sex hormone-binding globulin (SHBG), a plasma protein that binds steroids with high affinity, does not bind with S-26. Cotransfection studies with the estrogen, progesterone, and glucocorticoid receptor indicated that S-26 does not cross-react with other members of the steroid hormone receptor family. The nonsteroidal structure, high-AR binding affinity, specificity, and lack of binding to SHBG indicate that S-26 exhibits favorable properties for further development as an imaging agent for prostate cancer. 相似文献
78.
79.
D L Miller M S Allen C Deschamps V F Trastek P C Pairolero 《Mayo Clinic proceedings. Mayo Clinic》1992,67(5):462-464
Solitary pulmonary nodules continue to challenge all diagnostic skills. Herein we describe video-assisted thoracic surgical intervention, a new, minimally invasive technique that aids physicians in obtaining a definitive histologic diagnosis in a select group of patients with an indeterminate solitary pulmonary nodule. 相似文献
80.
Mohamed Magdy Ibrahim MD Jennifer Bond PhD Andrew Bergeron BA Kyle J. Miller BA Tosan Ehanire BA Carlos Quiles MD Elizabeth R. Lorden MS Manuel A. Medina MD Mark Fisher MD Bruce Klitzman PhD M. Angelica Selim MD Kam W. Leong PhD Howard Levinson MD 《Wound repair and regeneration》2014,22(6):755-764
Hypertrophic scar (HSc) contraction following burn injury causes contractures. Contractures are painful and disfiguring. Current therapies are marginally effective. To study pathogenesis and develop new therapies, a murine model is needed. We have created a validated immune‐competent murine HSc model. A third‐degree burn was created on dorsum of C57BL/6 mice. Three days postburn, tissue was excised and grafted with ear skin. Graft contraction was analyzed and tissue harvested on different time points. Outcomes were compared with human condition to validate the model. To confirm graft survival, green fluorescent protein (GFP) mice were used, and histologic analysis was performed to differentiate between ear and back skin. Role of panniculus carnosus in contraction was analyzed. Cellularity was assessed with 4′,6‐diamidino‐2‐phenylindole. Collagen maturation was assessed with Picro‐sirius red. Mast cells were stained with Toluidine blue. Macrophages were detected with F4/80 immune. Vascularity was assessed with CD31 immune. RNA for contractile proteins was detected by quantitative real‐time polymerase chain reaction (qRT‐PCR). Elastic moduli of skin and scar tissue were analyzed using a microstrain analyzer. Grafts contracted to ~45% of their original size by day 14 and maintained their size. Grafting of GFP mouse skin onto wild‐type mice, and analysis of dermal thickness and hair follicle density, confirmed graft survival. Interestingly, hair follicles disappeared after grafting and regenerated in ear skin configuration by day 30. Radiological analysis revealed that panniculus carnosus doesn't contribute to contraction. Microscopic analyses showed that grafts show increase in cellularity. Granulation tissue formed after day 3. Collagen analysis revealed increases in collagen maturation over time. CD31 stain revealed increased vascularity. Macrophages and mast cells were increased. qRT‐PCR showed up‐regulation of transforming growth factor beta, alpha smooth muscle actin, and rho‐associated protein kinase 2 in HSc. Tensile testing revealed that human skin and scar tissues are tougher than mouse skin and scar tissues. 相似文献