全文获取类型
收费全文 | 2314篇 |
免费 | 202篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 49篇 |
儿科学 | 103篇 |
妇产科学 | 19篇 |
基础医学 | 270篇 |
口腔科学 | 28篇 |
临床医学 | 246篇 |
内科学 | 339篇 |
皮肤病学 | 38篇 |
神经病学 | 149篇 |
特种医学 | 337篇 |
外科学 | 273篇 |
综合类 | 64篇 |
一般理论 | 2篇 |
预防医学 | 213篇 |
眼科学 | 98篇 |
药学 | 148篇 |
中国医学 | 1篇 |
肿瘤学 | 141篇 |
出版年
2021年 | 37篇 |
2019年 | 29篇 |
2018年 | 51篇 |
2017年 | 22篇 |
2016年 | 31篇 |
2015年 | 27篇 |
2014年 | 56篇 |
2013年 | 69篇 |
2012年 | 77篇 |
2011年 | 104篇 |
2010年 | 79篇 |
2009年 | 72篇 |
2008年 | 84篇 |
2007年 | 87篇 |
2006年 | 83篇 |
2005年 | 88篇 |
2004年 | 98篇 |
2003年 | 76篇 |
2002年 | 61篇 |
2001年 | 55篇 |
2000年 | 55篇 |
1999年 | 42篇 |
1998年 | 50篇 |
1997年 | 33篇 |
1996年 | 38篇 |
1995年 | 41篇 |
1994年 | 41篇 |
1993年 | 30篇 |
1992年 | 43篇 |
1991年 | 45篇 |
1990年 | 59篇 |
1989年 | 57篇 |
1988年 | 55篇 |
1987年 | 46篇 |
1986年 | 51篇 |
1985年 | 39篇 |
1984年 | 29篇 |
1983年 | 28篇 |
1982年 | 33篇 |
1981年 | 24篇 |
1980年 | 24篇 |
1979年 | 22篇 |
1978年 | 23篇 |
1977年 | 20篇 |
1976年 | 29篇 |
1975年 | 22篇 |
1973年 | 22篇 |
1972年 | 23篇 |
1968年 | 24篇 |
1967年 | 24篇 |
排序方式: 共有2518条查询结果,搜索用时 15 毫秒
1.
Vasopressin (AVP) receptor binding within hypothalamic sites was compared between cycling and lactating female golden hamsters. The density of AVP receptor binding was analyzed by quantitative autoradiography within the ventrolateral hypothalamus and dorsomedial hypothalamic nucleus. Lactation was correlated with a disappearance of AVP receptor binding within the ventrolateral hypothalamus. In contrast, lactation was associated with a two- to three-fold increase in the density of AVP receptor binding within the dorsomedial hypothalamic nucleus. These results suggest that AVP receptor binding within the ventrolateral hypothalamus is responsive to gonadal hormones in female golden hamsters. However, the increase in binding observed within the dorsomedial hypothalamus may be related to other neurobiological changes associated with lactation. 相似文献
2.
Early glottic carcinoma, specifically stage I or II, can be treated with endoscopic excision, radiation therapy, or open partial laryngectomy. Over the past two decades, this topic has received intensive interest, and controversies have often focused on techniques and outcomes comparing the use of endoscopic excision versus radiation therapy. This article will discuss philosophy, techniques, and outcomes of resection using the endoscopic approach to early glottic carcinoma. Optimization through appropriate instrumentation, staging, and technical details are critical to postoperative oncologic and vocal outcomes. The reader must remember that over 90% of T1 lesions and approximately 75% of T2 lesions are curable, and therefore adherence to the principles described below is important to achieve these outcomes. 相似文献
3.
Acute appendicitis: CT and US correlation in 100 patients 总被引:19,自引:1,他引:18
4.
Perforated colorectal neoplasms: correlation of clinical, contrast enema, and CT examinations 总被引:2,自引:0,他引:2
Hulnick DH; Megibow AJ; Balthazar EJ; Gordon RB; Surapenini R; Bosniak MA 《Radiology》1987,164(3):611-615
Results of clinical, contrast enema (CE), and computed tomographic (CT) examinations in 39 patients with perforated colorectal neoplasms were retrospectively reviewed. Twenty patients were toxemic at initial presentation, but in only four patients was the diagnosis of perforated colorectal neoplasm initially suspected clinically. CE study was performed in 22 patients and enabled the diagnosis of perforated neoplasm in 11 cases, neoplasm alone in eight, and neither neoplasm nor perforation in three. CT was performed in 38 patients and enabled the diagnosis of perforated neoplasm in 36; pericolic phlegmon but no mass lesion was evident in two. In 16 patients, CT also demonstrated metastatic disease. Because of its reliability in establishing the diagnosis and staging the extent of the inflammatory and neoplastic disease, CT is indicated in cases of suspected or proved perforated colorectal neoplasm and in cases in which CE study findings are indeterminate or suggestive of perforated neoplasm. 相似文献
5.
6.
7.
Steenbergen EJ; Verhagen OJ; van Leeuwen EF; van den Berg H; von dem Borne AE; van der Schoot CE 《Blood》1995,86(2):692-702
Crosslineage T-cell receptor delta (TCR delta) rearrangements are widely used as tumor markers for the follow up of minimal residual disease in childhood B-precursor acute lymphoblastic leukemia (ALL) by polymerase chain reaction (PCR). The major drawback of this approach is the risk of false-negative results due to clonal evolution. We investigated the stability of V delta 2D delta 3 rearrangements in a group of 56 childhood B-precursor ALL patients by PCR and Southern blot analysis. At the PCR level, V delta 2D delta 3-to-J alpha rearranged subclones (one pathway for secondary TCR delta recombination) were demonstrated in 85.2% of V delta 2D delta 3-positive patients tested, which showed that small subclones are present in the large majority of patients despite apparently monoclonal TCR delta Southern blot patterns. Sequence analysis of V delta 2D delta 3J alpha rearrangements showed a biased J alpha gene usage, with HAPO5 and J alpha F in 26 of 32 and 6 of 32 clones, respectively. Comparison of V delta 2D delta 3 rearrangement status between diagnosis and first relapse showed differences in seven of eight patients studied. In contrast, from first relapse onward, no clonal changes were observed in six patients studied. To investigate the occurrence of crosslineage TCR delta rearrangements in normal B and T cells, fluorescence-activated cell sorter-sorted peripheral blood CD19+/CD3- and CD19-/CD3+ cell populations from three healthy donors were analyzed. V delta 2D delta 3 rearrangements were detected at low frequencies in both B and T cells, which suggests that V delta 2-to-D delta 3 joining also occurs during normal B-cell differentiation. A model for crosslineage TCR delta rearrangements in B-precursor ALL is deduced that explains the observed clonal changes between diagnosis and relapse and is compatible with multistep leukemogenesis of B-precursor ALL. 相似文献
8.
Respiratory symptoms and lung function in relation to passive smoking: a comparative study of American and French women 总被引:3,自引:0,他引:3
F Kauffmann D W Dockery F E Speizer B G Ferris 《International journal of epidemiology》1989,18(2):334-344
Results are reported from a parallel analysis of the association of passive smoking with respiratory symptoms and lung function (FEV1, FVC and FEV1/FVC) in 2220 US and 3855 French women from the general population examined over the same time period using similar methods. Age, city, educational level, occupational exposure and height (for lung function) were taken into account. In the US survey, being a never smoker married to a current or former smoker was significantly associated only with wheezing compared to being a true never smoker. A borderline significant association between passive smoking and dyspnoea was observed among women older than 40 in the French survey. No association was observed with cough or phlegm production. Passive smoking was significantly related to lower FVC and FEV1 values among French women 40 years or more, even among those without a history of wheeze or asthma. However, even among US women older than 40 years of age, there was no significant association between passive smoking and level of lung function. Better housing conditions, higher divorce rates, more frequent exposure to passive smoking in childhood, and different selection factors for active smoking in the US compared to France might explain the lack of association of current spousal smoking habits with lower lung function in American women. 相似文献
9.
10.
C A Wilson E Stefánsson L Klombers L D Hubbard S C Kaufman F L Ferris 《American journal of ophthalmology》1988,106(2):131-134
We measured retinal vessel diameter before and after panretinal photocoagulation in 59 eyes with diabetic retinopathy and moderate to severe optic disk neovascularization. Treatment significantly reduced mean arteriolar and venular diameter. The diameter of the retinal arterioles after treatment correlated significantly with the amount of regression in disk neovascularization. Eyes with large diameter vessels after treatment usually had little or no regression of proliferative retinopathy, whereas regression was more frequently seen in eyes with smaller diameter vessels after treatment. 相似文献