全文获取类型
收费全文 | 23094篇 |
免费 | 1182篇 |
国内免费 | 156篇 |
专业分类
耳鼻咽喉 | 187篇 |
儿科学 | 536篇 |
妇产科学 | 187篇 |
基础医学 | 3072篇 |
口腔科学 | 543篇 |
临床医学 | 1490篇 |
内科学 | 5990篇 |
皮肤病学 | 385篇 |
神经病学 | 2096篇 |
特种医学 | 844篇 |
外科学 | 3797篇 |
综合类 | 95篇 |
预防医学 | 684篇 |
眼科学 | 457篇 |
药学 | 1524篇 |
中国医学 | 56篇 |
肿瘤学 | 2489篇 |
出版年
2023年 | 134篇 |
2022年 | 224篇 |
2021年 | 479篇 |
2020年 | 238篇 |
2019年 | 371篇 |
2018年 | 499篇 |
2017年 | 403篇 |
2016年 | 488篇 |
2015年 | 527篇 |
2014年 | 632篇 |
2013年 | 814篇 |
2012年 | 1328篇 |
2011年 | 1498篇 |
2010年 | 824篇 |
2009年 | 694篇 |
2008年 | 1345篇 |
2007年 | 1529篇 |
2006年 | 1456篇 |
2005年 | 1550篇 |
2004年 | 1519篇 |
2003年 | 1474篇 |
2002年 | 1375篇 |
2001年 | 376篇 |
2000年 | 347篇 |
1999年 | 400篇 |
1998年 | 340篇 |
1997年 | 267篇 |
1996年 | 241篇 |
1995年 | 248篇 |
1994年 | 194篇 |
1993年 | 176篇 |
1992年 | 260篇 |
1991年 | 250篇 |
1990年 | 193篇 |
1989年 | 220篇 |
1988年 | 189篇 |
1987年 | 168篇 |
1986年 | 159篇 |
1985年 | 147篇 |
1984年 | 104篇 |
1983年 | 96篇 |
1982年 | 67篇 |
1981年 | 63篇 |
1980年 | 57篇 |
1979年 | 65篇 |
1978年 | 42篇 |
1974年 | 33篇 |
1971年 | 43篇 |
1970年 | 31篇 |
1969年 | 32篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Spermidine/Spermine N-Acetyltransferase, a New Biochemical Marker for Epithelial Proliferation in Rat Bladder 总被引:4,自引:4,他引:0
Isao Matsui-Yuasa Shuzo Otani Yoshihisa Yano Nobuyasu Takada Masa-Aki Shibata Shoji Fukushima 《Cancer science》1992,83(10):1037-1040
We examined the activity of spermidine/spermine N 1 -acetyltransferase (SAT), a rate-limiting enzyme of the biodegradation of polyamines, in N -butyl- N -(4–hydroxybutyI)nitrosamine-induced transitional cell carcinoma (TCC) and melamine-induced papillomatosis of rat bladder, and compared the activity to that of ornithine decarboxylase (ODC). Both activities were higher in both lesions than in control rats. The difference between SAT and ODC activities in cancerous tissue and papillomatosis was not significant. Cells stained for proliferating cell nuclear antigen (PCNA) were abundant in papillomatosis. TCC had areas with much PCNA. The results indicated that an elevation of SAT activity occurs in both reversible and irreversible proliferation of bladder epithelium and could be important in bladder carcinogenesis. 相似文献
82.
83.
Genetic alteration in carcinoid tumors of the lung. 总被引:1,自引:0,他引:1
Kenji Sugio Toshihiro Osaki Tsunehiro Oyama Mitsuhiro Takenoyama Takeshi Hanagiri Masaru Morita Koji Yamazaki Akira Nagashima Hisashi Nakahashi Yoshihiko Maehara Kosei Yasumoto 《Annals of thoracic and cardiovascular surgery》2003,9(3):149-154
Surgically resected specimens of 13 carcinoid tumors of the lung including nine typical carcinoids and four atypical carcinoids, and eight salivary gland type carcinomas (six mucoepidermoid carcinomas and two adenoid cystic carcinomas) were analyzed regarding p53 expression, loss of heterozygosity (LOH) in chromosome 3p, 9p, and K-ras mutation. The overexpression of p53 was identified in four atypical carcinoid tumors, one mucoepidermoid carcinoma, and one adenoid cystic carcinoma, however, none of typical carcinoids showed p53 immunoreactivity. LOH in 3p14 was demonstrated in three of seven informative cases in all tumors. LOH in 9p was demonstrated in two of five informative cases in all tumors. Two of three cases with LOH at 3p14 had a poor prognosis, one of which also had LOH at 9p. No mutation of the K-ras gene was observed in any of these tumors. These data thus indicate that p53 overexpression might distinguish atypical carcinoid tumors from typical tumors and might therefore be useful as an adjunct modality in the differential diagnosis of pulmonary carcinoid tumors. The presence of LOH at 3p14 or 9p may thus help to identify lung cancer patients with a poor prognosis. 相似文献
84.
Koichiroh Nandate Kenji Muranaka Koichi Shinohara Kazuyoshi Ishida Hiroko Ishida Katsuhiro Seo Hiroshi Takeshita 《Journal of anesthesia》1997,11(2):117-120
We retrospectively reviewed the records of 250 consecutive patients undergoing coronary artery bypass graft surgery (CABG)
from January 1994 through January 1996 to determine the incidence of persistent postoperative neurological dysfunction after
CABG and to compare normothermic and moderate hypothermic cardiopulmonary bypass (CPB). Normothermic CPB was used in 128 patients
(36°–37°C) and hypothermic CPB (27°–28°C) in 122 patients. Postoperative neurological dysfunction included focal motor deficits,
delayed recovery of consciousness (>24h) after surgery, and seizures within 1 week postoperatively. Persistent neurological
dysfunction was diagnosed if complete resolution had not occurred within 10 days of surgery. The incidence of persistent postoperative
neurological dysfunction was 4.1% in the hypothermic CPB group and 2.3% in the normothermic CPB group. There were no statistically
significant differences between the two groups (P=NS). These results suggest that normothermic CPB did not increase the incidence of persistent postoperative neurological
dysfunction compared to hypothermic CPB. 相似文献
85.
86.
Daisuke Morioka Mureo Kasahara Yasutsugu Takada Yasumasa Shirouzu Kaoru Taira Seisuke Sakamoto Kenji Uryuhara Hiroto Egawa Hiroshi Shimada Koichi Tanaka 《Liver transplantation》2005,11(11):1332-1342
To address the current role of liver transplantation (LT) for urea cycle disorders (UCDs), we reviewed the worldwide English literature on the outcomes of LT for UCD as well as 13 of our own cases of living donor liver transplantation (LDLT) for UCD. The total number of cases was 51, including our 13 cases. The overall cumulative patient survival rate is presumed to be more than 90% at 5 years. Most of the surviving patients under consideration are currently doing well with satisfactory quality of life. One advantage of LDLT over deceased donor liver transplantation (DDLT) is the opportunity to schedule surgery, which beneficially affects neurological consequences. Auxiliary partial orthotopic liver transplantation (APOLT) is no longer considered significant for the establishment of gene therapies or hepatocyte transplantation but plays a significant role in improving living liver donor safety; this is achieved by reducing the extent of the hepatectomy, which avoids right liver donation. Employing heterozygous carriers of the UCDs as donors in LDLT was generally acceptable. However, male hemizygotes with ornithine transcarbamylase deficiency (OTCD) must be excluded from donor candidacy because of the potential risk of sudden-onset fatal hyperammonemia. Given this possibility as well as the necessity of identifying heterozygotes for other disorders, enzymatic and/or genetic assays of the liver tissues in cases of UCDs are essential to elucidate the impact of using heterozygous carrier donors on the risk or safety of LDLT donor-recipient pairs. In conclusion, LT should be considered to be the definitive treatment for UCDs at this stage, although some issues remain unresolved. 相似文献
87.
T Oka A Okuyama H Fujisue H Itatani Y C Park A Wakabayashi M Takada T Uemura K Kori N Kanbara 《Hinyokika kiyo. Acta urologica Japonica》1987,33(8):1157-1161
At Kanbara Hospital, 187 patients with urolithiasis have been treated by extracorporeal shock-wave lithotripsy (ESWL) since the first ESWL treatment in December, 1986. Some cases in which ESWL could not be performed easily were experienced. These difficulties were analyzed retrospectively and some problems in the ESWL treatment are discussed. 相似文献
88.
Near-infrared spectroscopy for monitoring cerebral ischemia during selective cerebral perfusion. 总被引:3,自引:0,他引:3
Kazumasa Orihashi Taijiro Sueda Kenji Okada Katsuhiko Imai 《European journal of cardio-thoracic surgery》2004,26(5):907-911
OBJECTIVE: To minimize the neurological complications following cardiovascular surgery, it is essential to prevent an occurrence of cerebrovascular embolism and to detect and solve cerebral malperfusion without delay in the operating theater. Although we have introduced near-infrared spectroscopy (NIRS) monitoring for the purpose of detecting cerebral malperfusion, no criterion has been available. We searched for this criterion by examining the relationship of sustained drop in the regional oxygen saturation (rSO2) of the frontal lobes to the occurrence of neurological events. METHODS: The 59 consecutive patients undergoing aortic surgery with selective cerebral perfusion (SCP) were examined. The rSO2 was monitored throughout the surgery and the durations of drops in rSO2 to below 55% and those below 60% were determined for each patient. The durations of rSO2 drop and other surgery-related parameters were compared between the patients in whom neurological events occurred and those without such events. RESULTS: A total of 16 cases (27.1%) presented with neurological events. Newly developed cerebral infarction was documented in 6 of these 16 cases. Operation time and the durations for which rSO2 dropped were significantly longer for the 16 patients with neurological events than for the 43 patients without events (Op time: 546.8 versus 448.1 min, P=0.0064; rSO2 below 60%: 141.2 versus 49.8 min, P=0.0032; rSO2 below 55%: 66.6 versus 10.6 min, P=0.0011), while there was no significant difference in age, bypass time, aortic clamping time, SCP time, and circulatory arrest time between the two groups. In the 3 patients with infarcts suggestive to hypoperfusion, sustained decrease in rSO2 was observed, while it was not significant in the remaining 3 patients with infarcts suggestive to embolism. Among the 53 patients without infarction, transient neurological events occurred more frequently in patients with sustained drop in rSO2 below 55% for over 5 min (44.4% versus 5.7%, P=0.0014). CONCLUSIONS: A sustained drop in rSO2 during aortic surgery is closely related to the occurrence of neurological events following surgery. We recommend that recovery of drop in rSO2 below 55% should be addressed without delay. However, use of NIRS is limited for detecting embolic events or hypoperfusion in the basilar region. 相似文献
89.
90.
We report a case of cortical reflex myoclonus in adult onset Huntington's disease (HD). The patient is a 51-year-old woman. Chorea and myoclonus were observed on her face and extremities. Neurophysiological tests showed C reflex and abnormal waves preceding myoclonus by jerk-locked back averaging method but no giant somatosensory evoked potential. Gene analysis revealed the prolongation of CAG repeats (13/44) in IT15 gene. Oral administration of clonazepam was transiently effective for myoclonus. We should inscribe that the cortical reflex myoclonus may exceptionally manifest in HD. 相似文献