全文获取类型
收费全文 | 20989篇 |
免费 | 1068篇 |
国内免费 | 156篇 |
专业分类
耳鼻咽喉 | 192篇 |
儿科学 | 391篇 |
妇产科学 | 193篇 |
基础医学 | 2889篇 |
口腔科学 | 422篇 |
临床医学 | 1321篇 |
内科学 | 5611篇 |
皮肤病学 | 362篇 |
神经病学 | 1920篇 |
特种医学 | 766篇 |
外科学 | 3372篇 |
综合类 | 87篇 |
预防医学 | 577篇 |
眼科学 | 482篇 |
药学 | 1411篇 |
中国医学 | 48篇 |
肿瘤学 | 2169篇 |
出版年
2023年 | 116篇 |
2022年 | 101篇 |
2021年 | 454篇 |
2020年 | 226篇 |
2019年 | 356篇 |
2018年 | 458篇 |
2017年 | 382篇 |
2016年 | 466篇 |
2015年 | 485篇 |
2014年 | 626篇 |
2013年 | 764篇 |
2012年 | 1291篇 |
2011年 | 1458篇 |
2010年 | 780篇 |
2009年 | 660篇 |
2008年 | 1292篇 |
2007年 | 1483篇 |
2006年 | 1367篇 |
2005年 | 1484篇 |
2004年 | 1426篇 |
2003年 | 1394篇 |
2002年 | 1303篇 |
2001年 | 312篇 |
2000年 | 249篇 |
1999年 | 327篇 |
1998年 | 302篇 |
1997年 | 235篇 |
1996年 | 200篇 |
1995年 | 205篇 |
1994年 | 167篇 |
1993年 | 147篇 |
1992年 | 178篇 |
1991年 | 152篇 |
1990年 | 143篇 |
1989年 | 166篇 |
1988年 | 144篇 |
1987年 | 112篇 |
1986年 | 96篇 |
1985年 | 89篇 |
1984年 | 83篇 |
1983年 | 73篇 |
1982年 | 51篇 |
1981年 | 47篇 |
1980年 | 47篇 |
1979年 | 40篇 |
1978年 | 30篇 |
1977年 | 24篇 |
1976年 | 29篇 |
1975年 | 23篇 |
1974年 | 23篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Kimiyoshi Ozawa Kenji Hashimoto Takashi Kishimoto Eiji Shimizu Hiroshi Ishikura Masaomi Iyo 《Neuropsychopharmacology》2006,59(6):546-554
BACKGROUND: Maternal viral infection is associated with increased risk for schizophrenia. It is hypothesized that the maternal immune response to viruses may influence fetal brain development and lead to schizophrenia. METHODS: To mimic a viral infection, the synthetic double strand RNA polyriboinosinic-polyribocytidilic acid (poly I:C) was administered into pregnant mice. Behavioral evaluations (thigmotaxis, methamphetamine [MAP]-induced hyperactivity, novel-object recognition test [NORT]), sensorimotor gating (prepulse inhibition [PPI]), and biochemical evaluation of the dopaminergic function of the offspring of phosphate-buffered saline (PBS)-treated dams (PBS-mice) and that of poly I:C-treated dams (poly I:C-mice) were examined. RESULTS: In juveniles, no difference was found between the poly I:C-mice and PBS-mice. However, in adults, the poly I:C-mice exhibited attenuated thigmotaxis, greater response in MAP-induced (2 mg/kg) hyperlocomotion, deficits in PPI, and cognitive impairment in NORT compared with the PBS-mice. Cognitive impairment in the adult poly I:C-mice could be improved by subchronic administration of clozapine (5.0 mg/kg) but not haloperidol (.1 mg/kg). Increased dopamine (DA) turnover and decreased receptor binding of D2-like receptors, but not D1-like receptors, in the striatum were found in adult poly I:C-mice. CONCLUSIONS: Prenatal poly I:C administration causes maturation-dependent increased subcortical DA function and cognitive impairment in the offspring, indicating a neurodevelopmental animal model of schizophrenia. 相似文献
92.
Jiro Okochi Kenji Toba Tai Takahashi Kozo Matsubayashi Masanori Nishinaga Ryutaro Takahashi Takashi Ohrui 《Geriatrics & Gerontology International》2006,6(4):223-227
Background: The aim of this study is to construct a simple screening test for the risk of falls in community-dwelling elder persons.
Methods: A total of 1378 community-dwelling people aged 65 years and older in five different communities in Japan were asked to answer a self rated questionnaire including 22 items covering physical, cognitive, emotional and social aspects of functioning and environmental factors. At a six-month follow-up, the outcome of fall occurrence and the number of falls was ascertained by social workers, health visitors or nurses.
Results: Five out of 22 items were selected using a logistic regression model. Using this five-item version, a screening test was constructed, and at the best cut-off point, the sensitivity and specificity were 68% and 70%, respectively. The validity of this scale was tested on persons with cognitive dysfunction.
Conclusion: The simplicity and the predictive validity of the screening test support the use of this test in health check ups or general outpatient facilities. 相似文献
Methods: A total of 1378 community-dwelling people aged 65 years and older in five different communities in Japan were asked to answer a self rated questionnaire including 22 items covering physical, cognitive, emotional and social aspects of functioning and environmental factors. At a six-month follow-up, the outcome of fall occurrence and the number of falls was ascertained by social workers, health visitors or nurses.
Results: Five out of 22 items were selected using a logistic regression model. Using this five-item version, a screening test was constructed, and at the best cut-off point, the sensitivity and specificity were 68% and 70%, respectively. The validity of this scale was tested on persons with cognitive dysfunction.
Conclusion: The simplicity and the predictive validity of the screening test support the use of this test in health check ups or general outpatient facilities. 相似文献
93.
Koichi Tanaka Kazue Ozawa Satoshi Teramukai Yasutsugu Takada Hiroto Egawa Satoshi Kaihara Yasuhiro Fujimoto Yasuhiro Ogura Mureo Kasahara Masako Ono Hiroshi Sato Kenji Takai Masanori Fukushima Nagahiro Minato 《Liver transplantation》2006,12(5):792-800
The primed status of T cells is markedly different among liver transplant recipients, due to a lifetime of antigen exposure and reduced thymopoiesis by aging, and diseases. This study aims to characterize the preoperative immunological status of CD8+ T cell subpopulations and relate it to the outcome for liver transplant recipients. We classified 112 liver transplant recipients into 5 groups, based on hierarchical clustering of the CD8+CD45 isoform proportion of T cells. In Groups I and II (pediatric), the naive T cell proportion was more than 50%. In adult recipients, Group III was characterized by a naive T cell proportion of 50%, Group IV had the greatest effector/memory T cells (EM), and Group V had the greatest proportion of effector T cells. In Groups IV and V, the effector T cell proportion was considerably higher, and was accompanied by marked downregulation of the CD27+CD28+ subsets and upregulation of interferon gamma (IFN)-gamma, tumor necrosis factor-alpha, and perforin expression. Group V recipients tended to be complicated postoperatively, with a significantly reduced survival rate (1 yr, 66.8%) and markedly reduced Eastern Cooperative Oncology Group performance status. 相似文献
94.
Shinji Homma Kenji Satoh Hitoshi Matsuo Minoru Yagi Jun Hasegawa Tomoyuki Maruta Naozumi Watanabe Tsuneo Iiai Katsuyoshi Hatakeyama 《Journal of Smooth Muscle Research》2004,40(6):271-280
Electrogastrograms (EGGs) were recorded in patients both before and after receiving proximal gastrectomy plus jejunal interposition (PGJI) or just after receiving total gastrectomy plus jejunal interposition (TGJI). Intraluminal pressure was also recorded in some postoperative patients. The EGG 3 cpm component (2.5-4.9 cpm) remained after PGJI, but subsequently decreased with a significant reduction in the preoperative to postoperative ratio of the 3 cpm components (P<0.05). The mean frequency of the 3 cpm components increased significantly after PGJI (P<0.05) and its instability factor increased. The EGG 10 cpm components became relatively dominant compared to other frequency components in 2 out of 8 of patients having PGJI but the mean amplitude of 10 cpm decreased. In TGJI patients, only the 10 cpm component was conspicuous in EGG as in the case of total gastrectomy and Roux en Y anastomosis procedures. The spectral frequencies of intraluminal pressure in the interposed jejunum were similar to the EGG of 10 cpm components both in the case of PGJI and TGJI patients. In conclusion, surface EGG could record the electrical activities of the interposed jejunum more easily in patients having had TGJI than in PGJI. 相似文献
95.
96.
97.
98.
Masashi Kimura M.D. Kenji Shirakura M.D. Atsushi Hasegawa M.D. Yasukazu Kobayashi M.D. Eiichi Udagawa M.D. 《Arthroscopy》1992,8(4):419-423
An arthroscopic and anatomical investigation was performed to define the abnormal conditions of the popliteal tendon area in a lateral meniscus. Arthroscopic findings for 100 patients and anatomical observations of 10 amputated knees were analyzed. Five of the 10 dissected menisci were also examined histologically. Menisco-tibial coronary ligaments were classified into two types, as follows: type I--a coronary ligament covering an entire popliteal tendon beneath the meniscus; type II--a popliteal tendon visible beneath the meniscus through defects of the coronary ligament. Twenty-one of 100 cases were classified as type I, and 79 were classified as type II. Three of the 10 anatomical dissections were type I, and the remaining 7 were type II. Menisci in which the type I coronary ligaments were thought to be torn and menisci with type II coronary ligaments showed a rather marked mobility, but no conclusion could be reached. 相似文献
99.
Sixty-four patients with persistent asthma receiving 200 to 800 μ g of fluticasone propionate daily were enrolled in this switchover study. The patients applied a tulobuterol patch 2 mg every 24 hours for 4 weeks followed by inhalation of salmeterol 100 μ g bid for 4 weeks. The mean values for morning and evening peak expiratory flow improved significantly compared with baseline during the 4 weeks of tulobuterol patch treatment. Further improvement was seen on switching to salmeterol treatment, which was significant even in the first week, and continued until the final week of the study. Use of salmeterol alone resulted in a significant increase in the percentage of forced expiratory volume in 1 second %FEV1 from baseline, with 51% of patients feeling that the treatment was effective (vs. 37% on tulobuterol). These data suggest that salmeterol can achieve better control in asthmatic patients after switching from using tulobuterol patches. 相似文献
100.
Kenji Kihara Shinichi Ueno Masahiko Sakoda Takashi Aikou 《Liver transplantation》2005,11(12):1574-1580
Recent studies have shown that hyperbaric oxygen therapy (HBOT) reduces neutrophil endothelial adherence in venules and also blocks the progressive arteriolar vasoconstriction associated with ischemia-reperfusion (I-R) injury in the extremities and the brain. In order to elucidate the effects of HBOT after I-R in digestive organs, particularly in the liver, we evaluated the following: 1) the relationship between timing of HBOT and tissue damage; and 2) HBOT's effects on neutrophil sequestration. Using a hepatic I-R (45 minute) model in male rats, survival rate, liver tissue damage, and neutrophil accumulation within the sinusoids in the HBOT-treated group (Group H) were compared to those in the nontreated group (Group C). For the HBOT-treated group, HBOT was administered as 100% oxygen, at 2.5 atm absolute, for 60 minutes. When HBOT was given 30 minute after I-R, the survival rate was much better in Group H than in Group C. HBOT performed within 3 hours of I-R markedly suppressed increases in the malondialdehyde level in tissues of the liver and lessened the congestion in the sinusoids. In addition, HBOT just after I-R caused decreased number of cells stained by the naphthol AS-D chloroacetate esterase infiltrating into the sinusoids. HBOT 3 hours after reperfusion, however, showed no clear effects upon neutrophil sequestration compared to Group C. These results indicate that HBOT performed within 3 hours of I-R alleviates hepatic dysfunction and improves the survival rate after I-R. Herein, we propose 1 possible mechanism for these beneficial effects: early HBOT given before neutrophil-mediated injury phase may suppress the accumulation of neutrophils after I-R. In conclusion, we believe that the present study should lead to an improved understanding of HBOT's potential role in hepatic surgery. 相似文献