全文获取类型
收费全文 | 28042篇 |
免费 | 1428篇 |
国内免费 | 213篇 |
专业分类
耳鼻咽喉 | 362篇 |
儿科学 | 516篇 |
妇产科学 | 275篇 |
基础医学 | 3735篇 |
口腔科学 | 721篇 |
临床医学 | 1841篇 |
内科学 | 7288篇 |
皮肤病学 | 545篇 |
神经病学 | 2322篇 |
特种医学 | 965篇 |
外科学 | 4557篇 |
综合类 | 116篇 |
预防医学 | 804篇 |
眼科学 | 584篇 |
药学 | 1823篇 |
中国医学 | 73篇 |
肿瘤学 | 3156篇 |
出版年
2023年 | 185篇 |
2022年 | 342篇 |
2021年 | 612篇 |
2020年 | 304篇 |
2019年 | 456篇 |
2018年 | 579篇 |
2017年 | 489篇 |
2016年 | 597篇 |
2015年 | 608篇 |
2014年 | 767篇 |
2013年 | 974篇 |
2012年 | 1646篇 |
2011年 | 1778篇 |
2010年 | 946篇 |
2009年 | 834篇 |
2008年 | 1550篇 |
2007年 | 1734篇 |
2006年 | 1653篇 |
2005年 | 1799篇 |
2004年 | 1700篇 |
2003年 | 1681篇 |
2002年 | 1594篇 |
2001年 | 550篇 |
2000年 | 540篇 |
1999年 | 569篇 |
1998年 | 409篇 |
1997年 | 307篇 |
1996年 | 285篇 |
1995年 | 252篇 |
1994年 | 211篇 |
1993年 | 194篇 |
1992年 | 373篇 |
1991年 | 304篇 |
1990年 | 282篇 |
1989年 | 279篇 |
1988年 | 264篇 |
1987年 | 245篇 |
1986年 | 243篇 |
1985年 | 196篇 |
1984年 | 158篇 |
1983年 | 133篇 |
1982年 | 64篇 |
1981年 | 79篇 |
1980年 | 71篇 |
1979年 | 106篇 |
1978年 | 80篇 |
1977年 | 55篇 |
1974年 | 73篇 |
1972年 | 55篇 |
1969年 | 62篇 |
排序方式: 共有10000条查询结果,搜索用时 281 毫秒
71.
Sadahisa Okamoto Yuichiro Inatomi Toshiro Yonehara Yoichiro Hashimoto Teruyuki Hirano Makoto Uchino 《Clinical neurology》2006,46(5):307-311
In order to determine predictive factors of early seizures (ES) after acute stroke and to estimate prognosis, we retrospectively examined clinical data of 1,743 consecutive patients with acute ischemic stroke. The subjects were divided into two groups; an ES group (19 patients) and a non-ES group (1,724 patients). Multivariate statistical analysis revealed that the NIH-Stroke Scale score on admission (/10, OR, 1.1: 95% CI 1.04 to 1.13) and positive past history of cerebrovascular disease or brain injury (OR, 3.85: 95% CI 1.49 to 9.95) are significant factors to predict ES. There was no significant difference in the outcome between the two groups. A recurrence of seizures, after follow up for 4 to 40 months, was observed only in one patient with a history of ES. 相似文献
72.
Endogenous tumor necrosis factor exerts its protective function intracellularly against the cytotoxicity of exogenous tumor necrosis factor. 总被引:5,自引:0,他引:5
T Okamoto N Watanabe N Yamauchi Y Tsuji N Tsuji Y Itoh H Neda Y Niitsu 《Cancer research》1992,52(19):5278-5281
Based on the findings that expression of endogenous tumor necrosis factor (enTNF), which is not present in TNF-susceptible cells, was generally observed in TNF-resistant cells and that TNF gene transfection gives rise to TNF resistance, the assumption was made that enTNF may be a protective protein against the cytotoxicity of exogenous TNF. However, it remains unknown whether the protection by enTNF is exerted in an intracellular or extracellular (autocrine) manner. We therefore transfected a nonsecretory human TNF gene (pTNF delta pro) into highly TNF-sensitive mouse tumorigenic fibroblasts (L-M cells) and investigated their TNF susceptibility. The transfectants expressed enTNF which was not secreted into the medium and acquired an appreciable degree of resistance to exogenous TNF. A significant increase in the manganous superoxide dismutase level was also noted in the transfectants. These findings suggest that enTNF exerts its protective function intracellularly by inducing manganous superoxide dismutase production. 相似文献
73.
Makoto Kamada Kenji Ohsaka Susumu Nagamine Hidemitsu Kakihata 《The Japanese Journal of Thoracic and Cardiovascular Surgery》2003,51(10):552-556
Acute aortic dissection complicated with acute myocardial infarction (AMI) is the most fatal situation. We experienced the
successful treatment for acute type A aortic dissection complicated with inferior AMI following aortic valve replacement (AVR).
A 60-year-old man had had AVR for aortic regurgitation. Sixteen months after the AVR, he had a sudden onset of severe chest
pain with complete atrioventricular block. Immediately, temporary pacing and cardiac catheterization were conducted, showing
the occlusion of the right coronary artery due to acute type A aortic dissection. On his way to our hospital, direct current
shock was conducted 3 times for ventricular fibrillation. We replaced the ascending aorta combined with coronary artery bypass
grafting and the postoperative course was uneventful. The key to treat acute aortic dissection complicated with AMI is early
accurate diagnosis, prompt temporary pacing for bradycardia, defibrillation for lethal arrhythmia and insertion of a perfusion
catheter if possible. These preoperative hemodynamic stabilization gives us the chance to save these patients. 相似文献
74.
Endogenous tumor necrosis factor functions as a resistant factor against hyperthermic cytotoxicity. 总被引:4,自引:0,他引:4
Y Tsuji N Watanabe T Okamoto N Tsuji H Sasaki S Akiyama N Yamauchi Y Niitsu 《Cancer research》1992,52(22):6258-6262
One of the mechanisms of cytotoxicity by tumor necrosis factor (TNF) is the induction of reactive oxygen molecules. Cells producing endogenous tumor necrosis factor (enTNF) show resistance to the cytotoxicity of exogenous TNF by scavenging the reactive oxygen molecules. The intracellular hydroxyl radical production is also known to be involved in the heat-induced cytotoxicity. In the present study, we therefore examined the possibility that enTNF may act as a protective protein against the heat-induced cytotoxicity in a manner similar to that of exogenous TNF. Heat-sensitive L-M (mouse tumorigenic fibroblast) cells, originally expressing no enTNF, were transfected with a human TNF expression vector to produce enTNF. The stable transfectants showed apparent resistance to heat treatment. Conversely, when HeLa (human uterine cervical cancer) cells, originally producing an appreciable amount of enTNF, were transfected with an antisense TNF mRNA expression vector to inhibit enTNF synthesis, their heat sensitivity was enhanced. Furthermore, L-M cells which were transfected with nonsecretory human TNF expression vector also acquired resistance to heat treatment. In these cells, heat resistance correlated well with expression of enTNF and intracellular levels of manganous superoxide dismutase. These results indicate that enTNF exerts its intracellular protective effect against the heat-induced cytotoxicity by scavenging reactive oxygen with induced manganous superoxide dismutase in a manner similar to that found in cells treated with exogenous TNF. 相似文献
75.
Yusuke Kishikawa Daiki Masaki Yurinosuke Kitabayashi Naosuke Tani Akira Hirogane Kenji Fukui 《Nihon Arukōru Yakubutsu Igakkai zasshi》2003,38(5):434-439
In order to find useful information for the establishment of new treatment method to alcohol dependence, we investigated the change of the body image of patients with alcohol dependence before and after the treatment. HABIT (Haga Body Image Test), a questionnaire about body image developed in department of psychiatry in Kyoto Prefectural University of Medicine, was used to examine the change of body image between pre- and post-3-month conventional treatment program in 46 patients with alcohol dependence hospitalized into special institutions for treatment of the disease in Kyoto. Patients with poor outcome of the treatment showed improvement of body image on visceral function, feeling of appetite and outward appearance, while patients with good outcome indicated no significant change in these aspects. This finding likely suggests that the treatment would result in good outcome in patients having stable feeling of physical health, and the cognitive treatment approach about these aspects of body image should be performed on the patients with poor treatment outcome. On the other hand, the body image about motor function showed significantly higher score in the patients approach for the patients with poor outcome to become aware of their physical activity would be effective. 相似文献
76.
Aortic arch replacement with proximal first technique. 总被引:2,自引:0,他引:2
Yuji Miyamoto Kenji Onishi Masataka Mitsuno Koichi Toda Masao Yoshitatsu Kazuo Abe 《Annals of thoracic and cardiovascular surgery》2003,9(6):389-393
BACKGROUND: Deep hypothermic circulatory arrest (DHCA) without retrograde cerebral perfusion (RCP) has a strict time limit. We modified a surgical technique for anastomosis to shorten the period of DHCA and unilateral cerebral perfusion (UCP). METHODS: Between March 1993 and August 2001, retrospective analysis was done on 23 consecutive patients, who underwent aortic arch replacement with branches. The patients were divided into two groups: DHCA group and UCP group. The DHCA group, in which DHCA alone and without additional cerebral perfusion was performed, comprised of nine patients. Proximal aortic anastomosis was performed first during systemic cooling; then both the brachiocephalic artery and left carotid artery were reconstructed with the branches of the artificial graft during circulatory arrest; thereafter, cerebral and coronary perfusions were resumed. The UCP group, in which DHCA was not used but right hemisphere perfusion during deep hypothermia was performed when the origin of brachiocephalic artery was safely clamped, consisted of 14 patients. RESULTS: Mean time of DHCA was 18.8+/-4.2 minutes and that of right hemisphere perfusion time was 11.0+/-3.8 minutes, respectively. Twenty-one patients survived the surgery (91.3%), and two (8.7%) died during hospitalization. Transient cerebral complication occurred in four patients in the DHCA group and all recovered. Logistic regression analysis revealed that DHCA was the only parameter to significantly influence temporary neurological dysfunction. There was no other significant difference between the two groups. CONCLUSION: With our modified and simple surgical technique for aortic arch repair, we were able to successfully shorten the DHCA time and right hemisphere perfusion time. However, because DHCA was the only parameter to significantly influence temporary neurological dysfunction, some form of continuous cerebral perfusion at deep hypothermia may be a safer method to preserve cerebral function. 相似文献
77.
Masahito Minakawa Kenji Takahashi Norihiro Kondo Masaharu Hatakeyama Toshihiko Kuga Ikuo Fukuda 《The Japanese Journal of Thoracic and Cardiovascular Surgery》2003,51(11):582-587
Objective: Reoperative coronary bypass grafting is at high risk. Particularly in redo cases where the patent graft is running near
the midline of the sternum, the graft may be exposed to injury by a median sternotomy and subsequent dissection. Whereas,
off-pump bypass grafting from the left axillary artery or descending thoracic artery by a left thoracotomy approach is safe
for preventing graft damage.Methods: From March 1998 to February 2002, we performed off-pump coronary artery bypass grafting by a left thoracotomy approach in
9 patients. The left axillary artery was used as the inflow vessel in 4 cases, and the descending thoracic, aorta in 5.Results: The radial artery was anastomosed proximally to the axillary artery in 4 cases and the descending thoracic aorta in one
case. The saphenous vein graft was anastomosed, proximally to the descending thoracic aorta in 4 cases. Transdiaphragmatic
minimally invasive bypass grafting for the right coronary artery was simultaneously performed in 3 cases. Postoperative cardiac
events were ventricular arrhythmia in 6 cases and supraventricular arrhythmia in 3 cases. There was no damage to the patent
grafts. Postoperative coronary angiography performed, in 8 cases revealed all the grafts to be patent without stenosis. Cardiac
symptoms were not found after the operation in any of the cases.Conclusions: These procedures can prevent the injury to patent grafts caused by a median sternotomy, and will be one of the useful strategies
for reoperative off-pump coronary artery bypass grafting. 相似文献
78.
A Konno N Terada Y Okamoto 《ORL; journal for oto-rhino-laryngology and its related specialties》1987,49(4):206-213
To investigate the responses of nasal vessels, divided into resistance and capacitance vessels, to a beta-receptor agonist in human, mucosal blood flow of the inferior turbinate and nasal airway resistance were measured when 1.5 mg terbutaline was applied topically. Mucosal blood flow was measured by the hydrogen clearance method just beneath the site where terbutaline in physiological saline (0.02 ml) was applied on an extremely localized area of the nasal mucosa. Nasal airway resistance of the ipsilateral and contralateral nasal cavities was measured separately by anterior rhinomanometry when terbutaline in normal saline (0.1 ml) was sprayed in the unilateral nasal cavity. Topical application of terbutaline elicited neither a significant increase of mucosal blood flow of the inferior turbinate nor an increase of nasal airway resistance. beta-Receptors seem not to be as densely distributed both in the resistance vessels and in the capacitance vessels as to cause vasodilatation by their activation in the nasal mucosa. 相似文献
79.
PAF (1 ug/kg) injected intravenously (i.v.) into anesthetized rabbits resulted in marked loss of circulating platelets and leukocytes. Administration of FR-900452 1-methyl-3-(1-(5-methylthiomethyl-6-oxo-3-(2-oxo-3-cyclopenten-1-y lidene)- 2-piperazinyl) ethyl)-2-indolinone, a specific PAF inhibitor, at a dose of 10 mg/kg i.v. with 10 min prior to the PAF injection significantly prevented both changes. On the other hand, PAF has been considered as a mediator of endotoxin shock. Therefore, in order to determine whether endogenous PAF contributes to the occurrence of thrombocytopenia or leukopenia in endotoxin shock, we assessed the effect of FR-900452 on the thrombocytopenia and the leukopenia following bolus i.v. injection of E.coli endotoxin (0.03 mg/kg) in rabbits. As a result, pretreatment with the compound (10 mg/kg, i.v.) significantly reduced the thrombocytopenia at 60 and 180 min after the endotoxin injection. In contrast, FR-900452 did not reduced the leukopenia at any time of after endotoxin. These results indicate that PAF might be involved in the occurrence of thrombocytopenia in rabbit endotoxemia and the contribution of PAF to the leukopenia is much less extent than that to the thrombocytopenia. 相似文献
80.
Kenji Yoshimi Masatoshi Takeda Tsuyoshi Nishimura Takashi Kudo Yu Nakamura Kunitoshi Tada Nobuyoshi Iwata 《Brain research》1991,560(1-2):149-158
Changes in MAP2 and clathrin immunoreactivity were studied in gerbil hippocampus after transient cerebral ischemia. MAP2 immuno-reactivity decreased significantly by 1 h in the subiculum-CA1 and CA2 areas which correspond to reactive change, while no decrease was observed in CA1 until day 4. Before the initiation of delayed neuronal death, MAP2 immunoreactivity was not changed in CA1. On the other hand clathrin immunoreactivity increased in the pyramidal cell layer of CA1 by 3 h after ischemia and remained high for 2 days. Clathrin immunoreactivity in the pyramidal cell layer of CA1 diminished after delayed neuronal death. The transient change of clathrin was noted especially in CA1 in the period prior to delayed neuronal death. These results imply an abnormal change in clathrin turnover after ischemia, which may participate in the pathogenesis of delayed neuronal death. 相似文献