全文获取类型
收费全文 | 106293篇 |
免费 | 7952篇 |
国内免费 | 5418篇 |
专业分类
耳鼻咽喉 | 1001篇 |
儿科学 | 1795篇 |
妇产科学 | 935篇 |
基础医学 | 9793篇 |
口腔科学 | 1641篇 |
临床医学 | 12149篇 |
内科学 | 12051篇 |
皮肤病学 | 1187篇 |
神经病学 | 4531篇 |
特种医学 | 4151篇 |
外国民族医学 | 17篇 |
外科学 | 10100篇 |
综合类 | 23052篇 |
现状与发展 | 22篇 |
一般理论 | 31篇 |
预防医学 | 10591篇 |
眼科学 | 1746篇 |
药学 | 12014篇 |
134篇 | |
中国医学 | 6562篇 |
肿瘤学 | 6160篇 |
出版年
2024年 | 260篇 |
2023年 | 987篇 |
2022年 | 2786篇 |
2021年 | 4120篇 |
2020年 | 3366篇 |
2019年 | 2662篇 |
2018年 | 3334篇 |
2017年 | 3330篇 |
2016年 | 3200篇 |
2015年 | 4819篇 |
2014年 | 6102篇 |
2013年 | 7172篇 |
2012年 | 9077篇 |
2011年 | 9150篇 |
2010年 | 8158篇 |
2009年 | 6964篇 |
2008年 | 7347篇 |
2007年 | 7012篇 |
2006年 | 6133篇 |
2005年 | 4993篇 |
2004年 | 3708篇 |
2003年 | 3166篇 |
2002年 | 2548篇 |
2001年 | 2056篇 |
2000年 | 1670篇 |
1999年 | 1064篇 |
1998年 | 622篇 |
1997年 | 556篇 |
1996年 | 423篇 |
1995年 | 325篇 |
1994年 | 331篇 |
1993年 | 212篇 |
1992年 | 200篇 |
1991年 | 174篇 |
1990年 | 121篇 |
1989年 | 109篇 |
1988年 | 120篇 |
1987年 | 100篇 |
1986年 | 82篇 |
1985年 | 63篇 |
1984年 | 59篇 |
1983年 | 23篇 |
1982年 | 44篇 |
1980年 | 28篇 |
1971年 | 27篇 |
1970年 | 26篇 |
1968年 | 43篇 |
1966年 | 22篇 |
1949年 | 23篇 |
1947年 | 25篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
Donor bone grafts are an important aspect of orthopaedic surgery. The use of plain film as a pathological screening tool before
donor bone dispatch has revealed “lytic” lesions in proximal humeri. Donor demographics did not support the diagnosis of myeloma
and subsequent computed tomography (CT) scans of these bones identified the lesions as air, not pathology. In total, 27 long
bones were scanned and 100% (27/27 cases) exhibited air within the trabecular bone. Three distinct patterns were found: ovoid,
linear/branching, and broad channel. A longitudinal course of CT scans was performed to identify at which stage air appeared
within the bone. Pre-retrieval, preprocessing, and postprocessing scans revealed that air originated between the retrieval
and preprocessing stages of donor bone preparation. There may be multiple aetiology of this phenomenon, including bone retrieval
and natural decomposition. 相似文献
42.
隐匿阴茎的分类和手术治疗 总被引:13,自引:0,他引:13
目的:探讨隐匿阴茎的分类和手术治疗方法。方法:手术治疗33例隐匿阴茎患者,年龄l岁3个月-25岁,平均6.2岁。根据Bergeson(1993)的隐匿阴茎的分类标准,埋藏阴茎29例,蹼状阴茎2例,束缚阴茎2例。结果:术后随访2个月-1年,所有患者术后阴茎外观满意,阴茎皮肤与阴茎体附着正常。结论:对隐匿阴茎不能指望青春期发育时耻骨前脂肪组织减少或简单行包茎松解术就能得到解决,正确的分类和恰当的手术治疗才能取得良好效果。 相似文献
43.
F. D’Angelo M. Giudici M. Molina G. Margaria 《Journal of orthopaedics and traumatology》2005,6(3):111-116
Abstract
The femoral neck fracture is actually the most important traumatic event in the elderly, because of its high rate and terrible
complications. We reviwed clinical records of 314 patients treated in our institution with a bipolar implant for femoral neck
fracture. At a mean follow-up of 5 years, 15 patients (4.8%) were lost to followup so data for 299 patients was studied to
identity factors associated with mortality. Ten predictor variables were examined: age, sex, waiting time for surgery, pulmonary
dysfunction, fracture etiology, and comorbidity with ischemic heart disease, and heart failure, hypertension, cerebrovascular
disease, and chronic renal failure. Cumulative mortality rate during the first 6 months was 19% (55 of 299 patients) and in
the first year it was 25% (76 of 299). At logistic regression analysis, mortality was associated with age, male gender, waiting
period for surgery and presence of neoplastic disease or pathological fracture.
Waiting for surgery was a significant factor for mortality at 6, 12 and 24 months: patients surgically treated in the first
24 hours had lower mortality than those who waited longer. The risk of mortality in the first 6 months doubled for an age
increase of 12 years, while mortality within 2 years doubled for an age increase of 9 years. Although the motality rate after
surgery for femoral neck fracture was high in the first year (25%), it dropped off in successive years to levels observed
in a healthy population. Thus, we agree with the literature that femoral fracture is a risk factor for survival only in the
first year after trauma, above all in the elderly. 相似文献
44.
45.
46.
目的通过检测子宫内膜异位症(EMs)患者血清及腹腔液中血小板衍生生长因子(PDGF)、血管细胞粘附分子-(VCAM-1)浓度,探讨PDGF和VCAM-1在EMs发病中的作用。方法选取手术后病理证实为EMs的40例患者为EMs组,其中I~II期17例,III~IV23例;非EMs组20例作为对照组。应用酶联免疫吸附法(ELISA)检测血清及腹腔液中PDGF和VCAM-1水平。结果EMs组血清及腹腔液中PDGF、VCAM-1水平均明显高于对照组(P<0.01)。随EMs期别的增加,其血清和腹腔液中PDGF、VCAM-1含量呈上升趋势;EMsIII~IV期水平显著高于I~II期(P<0.05)。EMs患者PDGF与VCAM-1呈正相关性(P<0.05)。结论EMs患者PDGF、VCAM-1表达水平升高,在EMs的发生发展中具有重要作用。 相似文献
47.
曹厚德 《中国医疗器械信息》2007,13(11)
受印度尼西亚WIDYA MANDALA CATHOLIC UNIVERSITY校长Ami Soewandi教授的邀请,上海医疗器械高等专科学校副校长、上海理工大学医疗器械学院副院长张学龙教授,于2007年7月19日~23日参加在Surabaya希莱顿(Sheraton)大酒店召开的印度尼西亚"全国第6次技术设计与应用研讨会",并在会议开幕式上作关于"全方位产学研合作面向市场培养医疗器械类人才"的主题报告,反响热烈。 相似文献
48.
49.
The regulation of interleukin 6 (IL-6) expression in the B-lymphocyte-supporting murine stromal cell line BMS2 has been examined in response to exogenous cytokines and chemical agents. Kinetic analyses of IL-6 mRNA induction and decay are presented together with analysis of the IL-6 biological activity. The cytokines tumor necrosis factor, interleukin 1 (alpha and beta), and transforming growth factor beta, as well as forskolin and dibutyryl cyclic AMP, all induce a transient rise in the steady-state level of IL-6 mRNA and an increased release of IL-6 protein. To study its regulation at the chromatin level, the murine IL-6 genomic gene has been cloned. Induction of IL-6 expression correlates with increased DNA nicking, consistent with increased topoisomerase I and endogenous nuclease activity. This finding is supported by kinetic analyses using camptothecin, a topoisomerase I inhibitor. We conclude that IL-6 regulation in murine stromal cells capable of supporting B-lymphopoiesis is comparable to that observed in human diploid fibroblasts. 相似文献
50.
Christian Foged Christer Halldin Christian Loc’h Bernard Mazière Stefan Pauli Mariannick Maziére Holger C. Hansen Tetsuya Suhara Carl-Gunnar Swahn Per Karlsson Lars Farde 《European journal of nuclear medicine and molecular imaging》1997,24(10):1261-1267
NNC 13-8241 has recently been labelled with iodine-123 and developed as a metabolically stable benzodiazepine receptor ligand
for single-photon emission computed tomography (SPECT) in monkeys and man. NNC 13-8199 is a bromo-analogue of NNC 13-8241.
This partial agonist binds selectively and with subnanomolar affinity to the benzodiazepine receptors. We prepared 76Br labelled NNC 13-8199 from the trimethyltin precursor by the chloramine-T method. Carbon-11 labelled NNC 13-8199 was synthesised
by N-alkylation of the nitrogen of the amide group with [11C]methyl iodide. Positron emission tomography (PET) examination with the two radioligands in monkeys demonstrated a high uptake
of radioactivity in the occipital, temporal and frontal cortex. In the study with [76Br]NNC 13-8199, the monkey brain uptake continued to increase until the time of displacement with flumazenil at 215 min after
injection. For both radioligands the radioactivity in the cortical brain regions was markedly reduced after displacement with
flumazenil. More than 98% of the radioactivity in monkey plasma represented unchanged radioligand 40 min after injection.
The low degree of metabolism indicates that NNC 13-8199 is metabolically much more stable than hitherto developed PET radioligands
for imaging of benzodiazepine receptors in the primate brain. [76Br]NNC 13-8199 has potential as a radioligand in human PET studies using models where a slow metabolism is an advantage.
Received 19 April and in revised form 10 June 1997 相似文献