首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   5955篇
  免费   382篇
  国内免费   10篇
耳鼻咽喉   66篇
儿科学   314篇
妇产科学   106篇
基础医学   729篇
口腔科学   190篇
临床医学   618篇
内科学   1341篇
皮肤病学   89篇
神经病学   480篇
特种医学   629篇
外科学   573篇
综合类   95篇
一般理论   10篇
预防医学   393篇
眼科学   95篇
药学   282篇
  1篇
中国医学   9篇
肿瘤学   327篇
  2021年   42篇
  2018年   59篇
  2017年   51篇
  2016年   69篇
  2015年   59篇
  2014年   112篇
  2013年   165篇
  2012年   202篇
  2011年   242篇
  2010年   141篇
  2009年   120篇
  2008年   182篇
  2007年   232篇
  2006年   252篇
  2005年   208篇
  2004年   219篇
  2003年   214篇
  2002年   193篇
  2001年   168篇
  2000年   207篇
  1999年   149篇
  1998年   92篇
  1997年   77篇
  1996年   87篇
  1995年   120篇
  1994年   84篇
  1993年   86篇
  1992年   170篇
  1991年   154篇
  1990年   174篇
  1989年   190篇
  1988年   157篇
  1987年   150篇
  1986年   166篇
  1985年   144篇
  1984年   112篇
  1983年   99篇
  1982年   62篇
  1981年   59篇
  1980年   55篇
  1979年   87篇
  1978年   69篇
  1977年   46篇
  1976年   59篇
  1975年   51篇
  1974年   44篇
  1973年   56篇
  1972年   51篇
  1971年   41篇
  1970年   40篇
排序方式: 共有6347条查询结果,搜索用时 15 毫秒
1.
Two examples of localized primary amyloid tumor of the breast are presented, including one patient with metachronous bilateral lesions. Our findings and review of the literature indicate that this rare lesion occurs predominantly in elderly females and can be mammographically and clinically confused with carcinoma. Fine-needle aspiration biopsy can be a useful procedure to make a preliminary diagnosis. Congo red staining with prior potassium permanganate incubation confirmed the AL type of amyloid in our two cases; this might be the predominant type in the localized form involving the breast. Immunofluorescence studies demonstrated IgA, with kappa and lambda light-chain deposition within the amyloid foci in one case, and intracytoplasmic IgG with both light chains within plasma cells and amyloid deposits of the second case. Ultrastructural examination of one of the cases showed characteristic findings of straight, nonbranching fibrils of 4-9 nm, diagnostic of amyloid. From our findings and a review of the literature, we conclude that amyloid tumors of the breast can occur in three separate settings: secondary amyloidosis, systemic or multiple myeloma associated amyloidosis, and as a localized primary type having a benign course.  相似文献   
2.
Systemic disease may present first in the foot. The authors present a case in which the marrow of resected bone tissue from a phalanx showed the changes of chronic lymphocytic leukemia (CLL). Subsequent blood examination confirmed this diagnosis.  相似文献   
3.
4.
Immunosuppressed persons are at greater risk of developing malignancies. In human immunodeficiency virus (HIV) immunosuppression the most common oral cancers are Kaposi's sarcoma and non-Hodgkin's lymphoma. Squamous cell carcinoma has also been reported to be associated with HIV disease. Kaposi's sarcoma is the most frequent neoplastic disease in acquired immunodeficiency syndrome and is by far the most common in the head and neck area. This article reviews the prevalence, clinical features, and management of these diseases in HIV infection.  相似文献   
5.
The beStent is a new stainless steel, balloon-expandable mesh stent which has a unique serpentine design. Rotation of the unique low stress junctions upon expansion leads to orthogonal locking of the wires, maximizing radial strength and assuring zero shortening. The stent has delineating gold markers which assure precise positioning. We aim to present the initial acute results in a pilot registry for stent evaluation. Two hundred eighty-four stents were used in a total of 217 patients (age 57.9 ± 3.10 years; 178 males; 39 females) in seven centers, for variable indications. Stents of 15-, 25-, and 35-mm length were used. The arteries treated were the left anterior descending (n = 112, 42%), circumflex (n = 54, 20.2%), right coronary (n = 95, 35.5%), left main (n = 1, 0.4%), and vein graft (n = 5, 1.9%). Lesion types were: A in 42 patients (16.5%); B1 in 53 patients (20.7%); B2 in 81 patients (31.8%); and C in 79 patients (31%). One hundred fifty-nine patients required one stent, 40 patients required two stents, and 18 patients required three or more stents. Anticoagulation protocol included procedural heparin with aspirin with/without ticlopidine. Smooth angiographie results were obtained in all cases with no plaque herniation. Acute angiographic success was obtained in 97% of the patients, and acute clinical success in 95% of the patients. Complications within 30 days were: 3 deaths (1.4%) (2 noncardiac); 2 (0.9%) myocardial infarctions; and 2 (0.9%) stent thromboses. Therefore, the beStent is useful in treatment of complex lesions of variable length and complexity, providing excellent acute results with a low complication rate, in spite of unfavorable basic clinical and angiographie characteristics.  相似文献   
6.
We have identified a secreted glycoprotein with an apparent molecular weight of 39,000 that is inhibited by estrogens and stimulated by antiestrogens in the MCF-7 human breast cancer cell line. The protein was detected within 24 h of hormone treatment with inhibition occurring at concentrations as low as 10(-11) M estradiol and stimulation occurring with antiestrogens. When phenol red, which has been found to have estrogenic activity, is removed from the tissue culture medium, no inhibition of cell growth or induction of the Mr 39,000 protein is seen with antiestrogens. A 6-fold decrease in the amount secreted in the presence of estrogens is seen under these conditions. The induction was specific in that growth inhibition by several other means did not induce expression of the Mr 39,000 protein. The Mr 39,000 protein has been identified as a glycoprotein complex that can be resolved into four polypeptides with two major components that migrate in the pH range of 5.5 to 6.3 by two-dimensional gel electrophoresis. This protein is the first evidence that estrogens inhibit a specific protein and it may prove useful as a marker of antiestrogen-induced growth arrest in breast cancer.  相似文献   
7.
Rats with unilateral 6-hydroxydopamine lesions of substantia nigra rotate (circle) when placed, undrugged, in the environment in which they have previously been treated with apomorphine. This conditioned rotation, like the unconditioned rotation which acutely follows the administration of apomorphine, is directed away from the side with the lesion, i.e., the rotation is contralateral. Here, rats that had been administered apomorphine weeks earlier were tested, in a crossover design, for the expression of conditioned rotation following treatment with saline and with alpha-methyltyrosine. When administered four hours prior to testing, 100 mg/kg alpha-methyltyrosine significantly antagonized the expression of classically conditioned rotation. In a second group of animals, alpha-methyltyrosine had no effect on the unconditioned rotation induced by 0.05 mg/kg apomorphine.  相似文献   
8.
Truncus Arteriosus With Patent Ductus Arteriosus and Normal Aortic Arch   总被引:1,自引:0,他引:1  
In hearts with a common arterial trunk (truncus arteriosus), there is almost always an inverse development of the aortic arch and the ductus arteriosus. Truncus with a normal aortic arch and a patent ductus is a rare echocardiographic and surgical finding. In this report, we describe 2 neonates in whom truncus arteriosus with a normal aortic arch and a medium or large patent ductus was diagnosed by preoperative echocardiography (without catheterization) and confirmed intraoperatively.  相似文献   
9.
In summary, we have described two patients with CRMO and psoriasis, and have reviewed the musculoskeletal manifestations associated with pustular eruptions of the palms and soles. In view of the frequent occurrence of PPP in patients with CRMO, we suggest that the occurrence of psoriasis in our two patients is more than coincidence, and that noninfectious, inflammatory lesions of bone may be another musculoskeletal manifestation of psoriasis. This rare association, as well as the association of PPP with disorders associated with new bone formation, may shed new insights on the relatively common finding of periosteal elevation associated with psoriatic arthritis and the occasional severe juxta-articular osteolytic destructive bone lesions seen in psoriatic arthritis.  相似文献   
10.
We report a patient with alcohol-induced necrotizing pancreatitis who developed a severe ileus followed by incarceration of a portion of the transverse colon within a ventral hernia. Laparotomy 9 days after the onset of symptoms revealed infarction of the transverse colon and infection of the pancreas. This is the first report of a case of acute pancreatitis that led to a strangulated ventral hernia of the colon. We believe that the enteric organisms that infected the pancreas originated in the incarcerated transverse colon.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号