全文获取类型
收费全文 | 8895篇 |
免费 | 453篇 |
国内免费 | 86篇 |
专业分类
耳鼻咽喉 | 32篇 |
儿科学 | 149篇 |
妇产科学 | 90篇 |
基础医学 | 1102篇 |
口腔科学 | 189篇 |
临床医学 | 537篇 |
内科学 | 2672篇 |
皮肤病学 | 257篇 |
神经病学 | 819篇 |
特种医学 | 385篇 |
外科学 | 1508篇 |
综合类 | 21篇 |
预防医学 | 240篇 |
眼科学 | 86篇 |
药学 | 502篇 |
中国医学 | 15篇 |
肿瘤学 | 830篇 |
出版年
2023年 | 52篇 |
2022年 | 86篇 |
2021年 | 197篇 |
2020年 | 130篇 |
2019年 | 174篇 |
2018年 | 184篇 |
2017年 | 127篇 |
2016年 | 172篇 |
2015年 | 164篇 |
2014年 | 265篇 |
2013年 | 292篇 |
2012年 | 450篇 |
2011年 | 542篇 |
2010年 | 303篇 |
2009年 | 257篇 |
2008年 | 484篇 |
2007年 | 523篇 |
2006年 | 511篇 |
2005年 | 527篇 |
2004年 | 518篇 |
2003年 | 572篇 |
2002年 | 547篇 |
2001年 | 228篇 |
2000年 | 213篇 |
1999年 | 203篇 |
1998年 | 154篇 |
1997年 | 111篇 |
1996年 | 104篇 |
1995年 | 76篇 |
1994年 | 65篇 |
1993年 | 69篇 |
1992年 | 128篇 |
1991年 | 89篇 |
1990年 | 80篇 |
1989年 | 103篇 |
1988年 | 80篇 |
1987年 | 89篇 |
1986年 | 60篇 |
1985年 | 61篇 |
1984年 | 56篇 |
1983年 | 47篇 |
1982年 | 28篇 |
1981年 | 22篇 |
1980年 | 18篇 |
1979年 | 35篇 |
1978年 | 25篇 |
1977年 | 38篇 |
1976年 | 17篇 |
1968年 | 21篇 |
1967年 | 16篇 |
排序方式: 共有9434条查询结果,搜索用时 656 毫秒
1.
2.
3.
Taisuke Inada Satoshi Fukushima Masayuki Murai Masatoshi Jinnin Azusa Miyashita Satoshi Nakahara Junji Yamashita Jun Aoi Shinichi Masuguchi Hironobu Ihn 《The Journal of dermatology》2015,42(2):198-201
miRNA‐221 (miR‐221) is known to be abnormally expressed in many human cancers. The serum levels of miR‐221 have been reported as a tumor marker for malignant melanoma (MM). We hypothesized that the hair shaft miR‐221 levels may be increased in patients with MM. We therefore assessed the possibility that hair shaft miR‐221 levels could be a marker for MM. The hair shaft miR‐221 levels were significantly higher in patients with MM than controls. The rates of increased hair shaft miR‐221 levels above the cut‐off value were comparable to those of serum 5‐S‐CD, which is a tumor marker commonly used for MM. Measurements of the hair shaft miR‐221 levels could have potential clinical value in the detection of MM. This is the first report investigating the hair shaft levels of an miRNA in patients with MM. Our investigations offer new insight into the relationship between miR‐221 and MM, and may provide a new, non‐invasive way to screen for melanoma. 相似文献
4.
5.
Salvage of a failed valgus osteotomy for nonunion
of an unstable pertrochanteric fracture is reported.
A valgus intertrochanteric osteotomy was performed for a
failed sliding hip screw fixation of an unstable
pertrochanteric fracture at another institution. Four months
following osteotomy, the fracture was still un-united with
two distal screws of the hip plate broken and a coxa vara
deformity. Reconstruction was performed with a nine-hole
95° angle blade plate and cancellous bone graft, because the
insufficient fixation of the distal fragment was considered to
be the main reason for failure. The osteotomy was healed at
six months post-surgery and the patient reported complete
resolution of symptoms. Intertrochanteric valgus osteotomy
is an effective procedure for mal-union and non-union of
pertrochanteric fracture but stable fixation is required for a
good result. The blade of the angle plate offers good purchase
of the proximal fragment and secures it under rotational
and bending stresses. We recommend that distal fragments
should be fixed with at least seven cortices for this
type of osteotomy. 相似文献
6.
Studies on the mechanisms underlying beta-adrenoceptor-mediated relaxation of rat abdominal aorta. 总被引:1,自引:0,他引:1
Mechanisms underlying beta-adrenoceptor (beta-AR)-mediated vascular relaxation were studied in the isolated rat abdominal aorta. In the endothelium-denuded helical preparations, a non-selective beta-AR agonist isoprenaline elicited a concentration-dependent relaxation. In the absence of beta-AR antagonists, isoprenaline-induced relaxation was not practically affected by an adenylyl cyclase inhibitor SQ 22,536 (300 microM), but was strongly diminished by high-KCl (80 mM). Isoprenaline-induced relaxation in the presence of SQ 22,536 was significantly diminished by iberiotoxin (IbTx, 0.1 microM), but was not affected by 4-aminopyridine (4-AP, 3 mM). Isoprenaline-induced relaxation was not also affected by SQ 22,536 (300 microM) even in the presence of CGP20712A (a beta(1)-selective antagonist) and ICI-118,551 (a beta(2)-selective antagonist) (0.1 microM for each), but was strongly diminished by high-KCl. By contrast, SQ 22,536-resistant, isoprenaline-induced relaxation in the presence of CGP20712A plus ICI-118,551 was not affected by IbTx (0.1 microM), but was inhibited significantly by 4-AP (3 mM). These results suggest that in rat abdominal aortic smooth muscle: 1) both beta(1)-/beta(2)-AR- and beta(3)-AR-mediated relaxations substantially involve cAMP-independent mechanisms; 2) beta(1)-/beta(2)-AR-mediated, cAMP-independent relaxant mechanisms are partly attributed to the large-conductance, Ca (2+)-sensitive K(+) (MaxiK, BK) channel whereas beta(3)-AR-mediated relaxant mechanisms are attributed to K(v) channel. 相似文献
7.
Akira Sawaki Nobumasa Mizuno Kuniyuki Takahashi Tsuneya Nakamura Masahiro Tajika Hiroki Kawai Toshifumi Isaka Hiroshi Imaoka Yasuyuki Okamoto Masatoshi Aoki Hiroyuki Inoue Ahmed AS Salem Yasushi Yatabe Kenji Yamao 《Digestive endoscopy》2006,18(1):40-44
Background: Gastrointestinal stromal tumors (GIST) are one of the most common mesenchymal tumors of the gastrointestinal tract. GIST are defined by positive immunohistochemical staining for KIT or CD34 and thus are generally diagnosed after surgery. Because small GIST are rarely diagnosed before surgery, the clinical course of these small tumors is not clear. The aim of the present study was to follow changes in size and configuration of small GIST that were pathologically confirmed using endoscopic ultrasonography‐guided fine‐needle aspiration biopsy (EUS‐FNAB). Methods: Between July 1997 and December 2003, 16 tumors in 16 patients (10 men and 6 women) with an immunohistochemical diagnosis of GIST were regularly followed in our hospital. The median patient age when EUS‐FNAB was performed was 62 years (range 26–82 years) and the median follow‐up period was 4.9 years (range 0.5–9.6 years). Results: Fourteen tumors showed no remarkable changes in size and shape during follow up compared with the initial diagnosis. Two tumors enlarged: one tumor approximately doubled its diameter in 8 years and the other tumor increased from 1.8 cm at diagnosis to up to 10 cm after only 2 years. Doubling time of the latter tumor was calculated as 3.1 months. Conclusions: We conclude that EUS‐FNAB might be a good modality for final diagnosis of GIST without surgery, and that GIST without rapid growth on follow up can be endoscopically followed. 相似文献
8.
9.
The role of hypertension and antihypertensive drugs in cardiovascular complications was evaluated in 380 elderly people living in the Tokyo Metropolitan Gerontology Center. The subjects were classified into four groups according to the presence or absence of hypertension and their antihypertensive treatment, and followed up prospectively for 5 years from 1979 to 1984. The average age of each group was 74 to 76 years. Cerebrovascular disease was observed in 19.3% of male hypertensives and 10.1% of male normotensives (p = 0.078). The drug treated group revealed no cerebral hemorrhage and less cerebral infarction. This tendency was not observed in females. Ischemic heart disease was prevalent in the drug treated group (10.9% vs 4.5%, p = 0.023) irrespective of blood pressure level. Risk factors such as body mass index, skinfold thickness, serum cholesterol, albumin, creatinine, blood urea nitrogen and uric acid at entry were elevated in the drug treated group. Diuretics were used in 92% of the drug treated group; in 53% as monotherapy and in 39% as combination therapy with other antihypertensive agents. The metabolic effect of diuretics may increase the incidence of ischemic heart disease in the elderly. We might conclude that hypertension in the aged accelerates cerebrovascular complications, and that antihypertensive treatment is effective even in this group. However, the wide use of diuretics could increase the incidence of ischemic heart disease. Careful selection of antihypertensive drugs as well as dose adjustment are needed in the treatment of elderly hypertensives. 相似文献
10.
Preoperative concurrent chemotherapy and radiation therapy followed by surgery for esophageal cancer. 总被引:1,自引:0,他引:1
Masahiko Yano Masatoshi Inoue Hitoshi Shiozaki 《Annals of thoracic and cardiovascular surgery》2002,8(3):123-130
Currently, the most promising strategy to improve the prognosis of advanced esophageal cancer is preoperative chemoradiation (CRT) followed by surgery. The superiority of CRT over radiation therapy alone has been demonstrated by several randomized studies. Many phase II studies of CRT followed by surgery have shown that the pathologic complete response (CR) rate ranges from 17 to 40%, and the median survival time (MST) is 12 to 31.3 months. Five randomized trials have compared preoperative CRT followed by surgery with surgery alone for resectable esophageal cancer, and four of them did not find any significant survival benefit for the combined treatment group. There are several issues in interpreting these findings, such as the quality of the surgery, the accuracy of the preoperative staging, the statistical power and design of the trials. Until comprehensive evaluation can be done, the standard therapy for resectable esophageal cancer should be considered to be surgery alone. The histological response in the resected specimen correlates well with the prognosis. Patients with pathologic CR display significantly better survival than those with microscopic residual cancer cells in the resected specimens. These findings suggest that more potent regimens leading to higher pathologic CR rates should improve the prognosis. Chemotherapy or radiation therapy sensitivity testing needs to be established. If accurate prediction of the response is possible prior to therapy, non-responders can be excluded. Cell cycle-related genes, apoptosis-related genes, and drug metabolizing genes have been investigated in many pilot studies and need to be evaluated by large-scale clinical studies. At present, pathologic CR can not be accurately diagnosed before surgery. Endoscopic biopsy is also unreliable for the diagnosis. In the future, new diagnostic tools such as positron emission tomography scanning, a sensitivity test or molecular markers may enable accurate diagnosis of pathologic CR to guide the choice of treatment strategies for individual patients. 相似文献