全文获取类型
收费全文 | 16732篇 |
免费 | 767篇 |
国内免费 | 141篇 |
专业分类
耳鼻咽喉 | 124篇 |
儿科学 | 379篇 |
妇产科学 | 162篇 |
基础医学 | 1732篇 |
口腔科学 | 538篇 |
临床医学 | 902篇 |
内科学 | 4377篇 |
皮肤病学 | 203篇 |
神经病学 | 1340篇 |
特种医学 | 687篇 |
外科学 | 3389篇 |
综合类 | 49篇 |
现状与发展 | 1篇 |
一般理论 | 1篇 |
预防医学 | 463篇 |
眼科学 | 355篇 |
药学 | 964篇 |
中国医学 | 35篇 |
肿瘤学 | 1939篇 |
出版年
2023年 | 98篇 |
2022年 | 210篇 |
2021年 | 339篇 |
2020年 | 180篇 |
2019年 | 251篇 |
2018年 | 325篇 |
2017年 | 250篇 |
2016年 | 338篇 |
2015年 | 352篇 |
2014年 | 485篇 |
2013年 | 559篇 |
2012年 | 888篇 |
2011年 | 985篇 |
2010年 | 633篇 |
2009年 | 565篇 |
2008年 | 947篇 |
2007年 | 1001篇 |
2006年 | 899篇 |
2005年 | 946篇 |
2004年 | 934篇 |
2003年 | 904篇 |
2002年 | 852篇 |
2001年 | 426篇 |
2000年 | 420篇 |
1999年 | 353篇 |
1998年 | 261篇 |
1997年 | 189篇 |
1996年 | 167篇 |
1995年 | 140篇 |
1994年 | 143篇 |
1993年 | 137篇 |
1992年 | 266篇 |
1991年 | 212篇 |
1990年 | 207篇 |
1989年 | 229篇 |
1988年 | 167篇 |
1987年 | 164篇 |
1986年 | 154篇 |
1985年 | 157篇 |
1984年 | 105篇 |
1983年 | 104篇 |
1982年 | 44篇 |
1979年 | 59篇 |
1978年 | 45篇 |
1977年 | 51篇 |
1974年 | 38篇 |
1972年 | 45篇 |
1970年 | 39篇 |
1969年 | 41篇 |
1968年 | 47篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
62.
Pharmacologic preconditioning effects: Prostaglandin E1 induces heat-shock proteins immediately after ischemia/reperfusion of the mouse liver 总被引:1,自引:0,他引:1
Ken-ichi Matsuo M.D. Shinji Togo M.D. Ph.D. Hitoshi Sekido M.D. Ph.D. Tomoyuki Morita M.D. Ph.D. Masako Kamiyama Ph.D. Daisuke Morioka M.D. Ph.D. Toru Kubota M.D. Ph.D. Yasuhiko Miura M.D. Ph.D. Kuniya Tanaka M.D. Ph.D. Takashi Ishikawa M.D. Ph.D. Yasushi Ichikawa M.D. Ph.D. Itaru Endo M.D. Ph.D. Hitoshi Goto M.D. Ph.D. Hiroyuki Nitanda M.D. Ph.D. Yasushi Okazaki M.D. Ph.D. Yoshihide Hayashizaki M.D. Ph.D. Hiroshi Shimada M.D. Ph.D. 《Journal of gastrointestinal surgery》2005,9(6):758-768
Prostaglandin E1 (PGE1) has several potential therapeutic effects, including cytoprotection, vasodilation, and inhibition of platelet aggregation. This study investigates the protective action of PGE1 against hepatic ischemia/reperfusion injury in vivo using a complementary DNA microarray. PGE1 or saline was continuously administered intravenously to mice in which the left lobe of the liver was made ischemic for 30 minutes and then reperfused. Livers were harvested 0, 10, and 30 minutes postreperfusion. Messenger RNA was extracted, and the samples were labeled with two different fluorescent dyes and hybridized to the RIKEN set of 18,816 full-length enriched mouse complementary DNA microarrays. Serum alanine aminotransferase and aspartate aminotransferase levels at 180 minutes postreperfusion were significantly lower in the PGE1-treated group than in the saline-treated group. The cDNA microarray analysis revealed that the genes encoding heat-shock protein (HSP) 70, glucose-regulated protein 78, HSP86, and glutathione S-transferase were upregulated at the end of the ischemic period (0 minutes postreperfusion) in the PGE1 group. Our results suggested that PGE1 induces HSPs immediately after ischemia reperfusion. HSPs might therefore play an important role in the protective effects of PGE1 against ischemia/reperfusion injury of the liver. 相似文献
63.
Tomomi Iwashita Kazuo Kitazawa Jun-Ichi Koyama Hisashi Nagashima Toru Koyama Yuichiro Tanaka Kazuhiro Hongo Hiroshi Okudera Kazufumi Okamoto 《Journal of clinical neuroscience》2007,14(1):68-71
A patient with cerebral deep sinus thrombosis, which was not diagnosed on the first examination, is reported. A 46-year-old woman presented with headache and vomiting. Neurological examination and a brain computed tomography (CT) scan showed no obvious abnormal findings. The patient suffered disturbed consciousness on the day after the examination, and was admitted to our emergency centre. A CT scan and magnetic resonance imaging revealed an ischaemic lesion in the left basal ganglia, suggesting deep sinus occlusion. Anticoagulant therapy was administered. One day after admission, a CT scan showed a haematoma and severe brain swelling in the same region. Cerebral angiography demonstrated a straight sinus occlusion. Intracranial pressure was not controlled with hypothermia, and the patient died 25 days after admission. Review of the initial CT scan revealed subtle, early findings of deep venous thrombosis that were missed on first examination. 相似文献
64.
The present study was designed to investigate whether or not arginine vasopressin (AVP) is released from magnocellular neurons within the median eminence (ME) in vivo. Urethane-anesthetized adult male Wistar rats were equipped with a microdialysis probe aimed at the supraoptic (SON) or paraventricular nucleus (PVN), a push-pull perfusion probe resting in the ME, and a blood microdialysis probe within the jugular vein. Dialysis of the SON (but not the PVN) with Ringer's solution containing 56 mmol l−1 K+ resulted in an increase in AVP release within the ME (to 492 ± 192% of release during basal conditions,P < 0.05) and into blood (to 138 ± 9%,P < 0.01) whereby the release probably occurred from axonal swellings and nerve terminals of supraoptic neurons which project through the internal zone of the ME to the posterior pituitary. The calculated amount of AVP released into the extracellular fluid of the ME was high enough (approximately 1 pg/μ1) to hypothesize that the neuropeptide could enter the portal blood capillaries in physiologically relevant concentrations. Taken together, the present study indicates that activation of magnocellular neurons is accompanied by release of AVP within the median eminence. We assume that AVP released in this way might mediate a communication between the hypothalamic-neurohypophysial system and the hypothalamic-pituitary-adrenal axis in response to selected stressful stimuli. 相似文献
65.
Yoko Kubota Teruhiro Nakada Kyoichi Imai Hidetoshi Yamanaka Hideki Sakai Yutaka Saito Yukio Tomaru Koichi Kitamura Osamu Sugano Isoji Sasagawa 《The Prostate》1995,26(1):50-54
There have only been a few studies of chemo-endocrine therapy compared with endocrine therapy alone in newly diagnosed prostate cancer patients. We assessed the effects of these two therapies by comparing long-term survival rates. One hundred and twenty-nine patients were entered in this study between November 1977 and March 1992. Seventy-seven patients were treated with endocrine therapy alone. Other 52 patients received chemo-endocrine therapy, which included orchiectomy and/or diethylstilbestrol diphosphate (DES-DP) plus Cisplatin, with or without other cytotoxic agents. All patients had bone metastasis at the beginning of the study. There was a significant difference in survival between patients who received endocrine therapy and chemo-endocrine therapy (P = 0.0078). That is, survival rate was superior for the chemoendocrine therapy patients throughout the entire follow-up period. These data suggest that early chemo-endocrine therapy containing Cisplatin, with or without maintenance chemotherapy, is a potentially effective treatment for newly diagnosed metastatic prostate cancer and is worth further investigation via a randomized trial. 相似文献
66.
K Okamoto K Kubota E Kawada H Kurabayashi T Shirakura 《Nihon Ronen Igakkai zasshi. Japanese journal of geriatrics》1991,28(5):693-696
A 70-year-old man was admitted to our hospital because of fever and progressive dyspnea in December 1989. He was already diagnosed as having erythrocytosis secondary to pulmonary fibrosis 4 years previously and the values of his hematocrit (Ht) were maintained between 44.5 and 62.9% by repeated phlebotomy. Immediately after admission, severe diarrhea developed and the Ht value was 61.5%. Around 1:30 a.m. of the 3rd hospital day, he developed disturbance of consciousness. In addition, the serum levels of LDH, CPK, aldolase, and myoglobin of muscle origin increased markedly and the Ht value showed 78.5%. While the level of consciousness was gradually restored by 600 ml phlebotomy and 1,500 ml saline infusion, dysarthria and hemiplegia became evident. The Ht value early in the morning of the 3rd hospital day was reduced to 59.4%. Although cranial CT and MRI performed 74 days and 15 months, respectively, after the onset of the symptoms failed to reveal any abnormal shadow, he was clinically suspected to have cerebral infarction. These findings emphasize that abrupt increase in Ht or blood viscosity is a possible factor triggering cerebral infarction, and adequate control of Ht value is recommended for the prevention of such a condition in the aged. 相似文献
67.
Ki-67-determined growth fraction versus standard staging and grading parameters in colorectal carcinoma. A multivariate analysis. 总被引:4,自引:0,他引:4
BACKGROUND. The antibody Ki-67 binds to nuclei in all cell cycle phases except GO and can be used to measure growth fraction. Because proliferative activity has been linked to prognosis in neoplasia, the authors analyzed 100 cases of colorectal carcinoma, each with 3 or more years of follow-up, using Ki-67 immunostaining. METHODS. The Ki-67-positive nuclear area and total nuclear area of carcinoma cells in 20 microscopic fields were measured by computed morphometry. A Ki-67 score (percent positive nuclear area x 100) was calculated. The following characteristics also were recorded for each case: patient age and sex, tumor site and size, modified Dukes' stage, spread beyond bowel wall, lymph node status, tumor grade, histologic type, extramural venous spread, tumor growth pattern, fibrosis, lymphocytic infiltration, and mitotic rate. RESULTS. Ki-67 scores ranged from 1 to 90 (mean, 34.6). Ki-67 scores were higher in Stage A disease (versus Stage B, C, and D disease) but were not associated with survival. Survival curves differed by stage, lymph node metastases, infiltrative growth pattern, lymphocytic infiltration, fibrosis, extramural venous spread, and tumor grade in a univariate analysis. The infiltrative growth pattern (P = 0.04) and lymphocytic infiltration (P = 0.003) were features associated independently with survival after adjusting for modified Dukes' stage. Furthermore, the lack of a significant lymphocytic infiltrate was associated with a death rate 3.4 times greater than that occurring in patients with Stage B disease with a significant infiltrate. CONCLUSIONS. The authors conclude that proliferative activity in colorectal carcinoma as measured by Ki-67 immunostaining was not associated with prognosis. 相似文献
68.
69.
The integrity of the sensory nervous system in the anal canals of chronically constipated children was investigated using
evoked potential techniques examining cerebral and spinal evoked potentials from the lower extremities and anal canal. Stimulation
of the posterior tibial nerve produced no significant difference in the parameters of spinal and cerebral evoked potentials
between 18 controls and 12 chronically constipated chidren. However, stimulation of the anal canal resulted in evoked potentials
related to the age and/or consciousness level of the control children. Reproducible cerebral responses were obtained only
from nine of these control children, all aged over 4 years, who were examined while awake without sedatives. A typical response
was characterized by a polyphasic wave occurring with an onset latency of 79.4± 27.7ms (mean ±SD). In the 12 chronically constipated
children, the 5 sedated patients examined while asleep did not show any reproducible potential, as in the controls. However,
in the remaining 7 children examined while awake, the occurrence of the anal canal evoked potential was significantly reduced,
and only two exhibited a cerebral response. These findings suggest that rectal mucosal perception of the intraluminal stimuli
might be disturbed in some children with chronic constipation. 相似文献
70.
Toshimichi Hasegawa Yuko Tazuke Yasuhiro Iwasaki Osamu Monta Junichi Sumimura Hiroshi Koyama Toru Dezawa 《Surgery today》1997,27(12):1191-1194
We report herein the case of a premature infant with esophageal atresia (EA) and a tracheoesophageal fistula (TEF) associated
with cardiac anomalies who was successfully treated by an early ligation of the TEF following gastrostomy, and delayed repair
of the esophagus. A 1212-g male was born prematurely at 31 gestational weeks, at which time he was diagnosed as having EA
with TEF and patent ductus arteriosus (PDA), ventricular septal defect (VSD), and atrial septal defect (ASD). A gastrostomy
was initially performed but following extubation he gradually became tachypneic. A chest roentogenogram revealed atelectasis
and ground-glass appearance, and reintubation was required. Ligation of the TEF was performed 53h after his birth. Following
the improvement of his respiratory condition through ventilatory support and the intratracheal administration of pulmonary
surfactant, he underwent repair of the esophagus on the 6th day of life. Postoperatively, he suffered from heart failure,
but was treated with peritoneal dialysis and pharmacological closure of the PDA. Weaning the infant from the ventilator proved
difficult, but it was finally achieved when he had reached a weight of 2268g at 3 months of age by enteral feeding. Our experience
of this case demonstrates that early ligation of TEF should be performed for a premature infant with EA and TEF before respiratory
distress syndrome (RDS) has developed. If a gastrostomy is required to prevent gastric distention, it should be followed by
simultaneous or immediate ligation of the TEF. 相似文献