全文获取类型
收费全文 | 115584篇 |
免费 | 7553篇 |
国内免费 | 2270篇 |
专业分类
耳鼻咽喉 | 1710篇 |
儿科学 | 1783篇 |
妇产科学 | 3014篇 |
基础医学 | 16977篇 |
口腔科学 | 2465篇 |
临床医学 | 11382篇 |
内科学 | 21441篇 |
皮肤病学 | 2868篇 |
神经病学 | 7688篇 |
特种医学 | 5252篇 |
外国民族医学 | 6篇 |
外科学 | 15407篇 |
综合类 | 4396篇 |
现状与发展 | 8篇 |
一般理论 | 27篇 |
预防医学 | 6083篇 |
眼科学 | 2592篇 |
药学 | 9988篇 |
20篇 | |
中国医学 | 2241篇 |
肿瘤学 | 10059篇 |
出版年
2023年 | 929篇 |
2022年 | 2547篇 |
2021年 | 4014篇 |
2020年 | 2221篇 |
2019年 | 2810篇 |
2018年 | 3532篇 |
2017年 | 2651篇 |
2016年 | 3139篇 |
2015年 | 4663篇 |
2014年 | 5682篇 |
2013年 | 6541篇 |
2012年 | 9682篇 |
2011年 | 9097篇 |
2010年 | 5500篇 |
2009年 | 4751篇 |
2008年 | 6665篇 |
2007年 | 6361篇 |
2006年 | 5806篇 |
2005年 | 5270篇 |
2004年 | 4682篇 |
2003年 | 4281篇 |
2002年 | 3680篇 |
2001年 | 3121篇 |
2000年 | 2804篇 |
1999年 | 2201篇 |
1998年 | 895篇 |
1997年 | 698篇 |
1996年 | 621篇 |
1995年 | 550篇 |
1994年 | 493篇 |
1993年 | 365篇 |
1992年 | 1032篇 |
1991年 | 891篇 |
1990年 | 809篇 |
1989年 | 739篇 |
1988年 | 665篇 |
1987年 | 670篇 |
1986年 | 529篇 |
1985年 | 458篇 |
1984年 | 346篇 |
1983年 | 301篇 |
1982年 | 169篇 |
1981年 | 180篇 |
1980年 | 139篇 |
1979年 | 284篇 |
1978年 | 229篇 |
1977年 | 142篇 |
1976年 | 154篇 |
1975年 | 152篇 |
1974年 | 159篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Tumor metastasis to the pancreas is a rare but recognized cause of acute pancreatitis. Autopsy series have reported a 24-40% of pancreatic involvement in small cell lung cancer. However, only a very few cases of tumor-induced acute pancreatitis have been described. Budd-Chiari syndrome complicating lung cancer is a rarely reported condition. We report a 68-year-old woman with extensive small cell lung cancer with the unusual initial presentation of both acute pancreatitis and acute Budd-Chiari syndrome. This patient suffered from progressive epigastralgia for 3 weeks. Severe epigastralgia with radiation to back and progressive jaundice developed 2 days prior to admission. After admission, the liver enlarged rapidly and the ascites increased markedly. Chest roentgenogram showed a mass lesion over the left lower lung field. Poorly differentiated carcinoma cells were found in ascites and bone marrow. The patient died on the ninth day of hospitalization before chemotherapy was initiated. Prompt diagnosis of extensive-stage small cell lung cancer may allow early chemotherapy treatment which favorably influences recovery when the pancreatitis is mild. Although prolonged survival might have been expected had this patient recovered from pancreatitis and received chemotherapy, diagnosis was delayed due to difficulty in immunohistochemical diagnosis of the tumor and the unusual clinical presentation. The use of stains employing antibodies against neurofilament and neuron-specific enolase cell antigens is important for early diagnosis of poorly differentiated metastatic tumor cells. 相似文献
72.
Following an encephalopathic illness, a 13-year-old Chinese boy had a partial form of Klüver-Bucy syndrome with emotional disturbance, recent memory loss, hypersexuality, and polyphagia. Other unusual features included narcolepsy, polydipsia, and polyuria. Virologic studies failed to incriminate the etiologic agent, including herpes simplex virus. Brain biopsy of the frontal lobe demonstrated Alzheimer type II astrocytosis. 相似文献
73.
Chang Y Jung Hyo S Choi Jin S Ju Hyo S Park Tae G Kwon Yong C Bae Dong K Ahn 《The journal of pain》2006,7(10):747-756
The present study investigated the role of central metabotropic glutamate receptors (mGluRs) in interleukin-1beta (IL-1beta)-induced mechanical allodynia and mirror-image mechanical allodynia in the orofacial area. Experiments were carried out on male Sprague-Dawley rats weighing 230 to 280 g. After administration of 0.01, 0.1, 1, or 10 pg of IL-1beta into a subcutaneous area of the vibrissa pad, we examined the withdrawal behavioral responses produced by 10 successive trials of an air-puff ramp pressure applied ipsilaterally or contralaterally to the IL-1beta injection site. Subcutaneous injection of IL-1beta produced mechanical allodynia and mirror-image mechanical allodynia in the orofacial area. Intracisternal administration of CPCCOEt, a mGluR1 antagonist, or MPEP, a mGluR5 antagonist, reduced IL-1beta-induced mechanical allodynia and mirror-image mechanical allodynia. Intracisternal administration of APDC, a group II mGluR agonist, or L-AP4, a group III mGluR agonist, reduced both IL-1beta-induced mechanical allodynia and mirror-image mechanical allodynia. The antiallodynic effect, induced by APDC or L-AP4, was blocked by intracisternal pretreatment with LY341495, a group II mGluR antagonist, or CPPG, a group III mGluR antagonist. These results suggest that groups I, II, and III mGluRs differentially modulated IL-1beta-induced mechanical allodynia, as well as mirror-image mechanical allodynia, in the orofacial area. PERSPECTIVE: Central group I mGluR antagonists and groups II and III mGluR agonists modulate IL-1beta-induced mechanical allodynia and mirror-image mechanical allodynia in the orofacial area. Therefore, the central application of group I mGluR antagonists or groups II and III mGluR agonists might be of therapeutic value in treating pain disorder. 相似文献
74.
The effect of body position (right and left lateral decubitus positions) on arterial oxygen tension (PaO2) and the relationship between this postural effect on gas exchange and pulmonary function were evaluated in 21 patients who had unilateral pleural effusions without roentgenographic and bronchoscopic evidence of bronchopulmonary disorders. Our results indicated that a positional influence on gas exchange existed in these patients. We failed to find a consistent relationship between the size of effusion estimated by chest roentgenogram and alterations in PaO2 during different positions. Postural change did affect gas exchange in the patients with unilateral pleural effusions and this postural effect on gas exchange was highly correlated with their FEV1 and FVC. This may be of clinical significance in managing such patients. 相似文献
75.
1例脊髓空洞症侧脑室延髓池内分流术的护理 总被引:1,自引:0,他引:1
1 病例介绍病人,男,34岁,左下肢步态不稳10年,加重伴酸麻、隐痛1年,于2004年4月入院.入院时精神欠佳,生活不能完全自理,左上肢肱二腱、肱三腱反射和下肢膝反射亢进,右上肢肱二腱、肱三腱反射减弱,右前臂及手部触觉消失,左下肢膝关节以下触觉、位置觉、浅感觉消失.MRI示脊髓空洞症.术前检查未发现手术禁忌证,行全身麻醉下环枕畸形减压、侧脑室延髓池内分流术.手术顺利,术中输红细胞悬液400 mL,放置皮下引流管1根,术后恢复好,无并发症发生,病人生活上基本自理,出院随访1年,情况良好.…… 相似文献
76.
Cannabis remains the most widely used illegal drug in the United States. This update examines the available literature on neuroimaging studies of the brains of cannabis users. The majority of studies examining the acute effects of delta-9-tetrahydrocannabinol (THC) administration used PET methods and concluded that administration of THC leads to increased activation in frontal and paralimbic regions and the cerebellum. These increases in activation are broadly consistent with the behavioral effects of the drug. Although there is only equivocal evidence that chronic cannabis use might result in structural brain changes, blood-oxygenation-level-dependent-fMRI studies in chronic users consistently show alterations, or neuroadaptation, in the activation of brain networks responsible for higher cognitive functions. It is not yet certain whether these changes are reversible with abstinence. Given the high prevalence of cannabis use among adolescents, studies are needed to evaluate whether cannabis use might affect the developing brain. Considerable further work, employing longitudinal designs, is also required to determine whether cannabis use causes permanent functional alterations in the brains of adults. 相似文献
77.
A study on the pathologic findings after recession and resection of extraocular muscles in rabbits was performed. Fibrosis of the extraocular muscles increased with time, which showed no difference between the recessed and resected muscles. Inflammation and foreign body reaction decreased with time, which showed no difference between the recessed and resected muscles. Adhesions of extraocular muscles to the sclera were observed from one month after the operation. The resected muscles showed milder adhesion to the sclera than the recessed ones. The operated extraocular muscles showed atrophies at one month, which showed no difference between the recessed and resected muscles. According to our results, when reoperation is needed, fibrosis of the extraocular muscles after recession and resection should be considered when making a decision on the amount of muscle to be recessed and resected. 相似文献
78.
The clinical and ultrasonographic (US) features of 15 cases of mesenteric or omental cyst are herein described. This series included seven male and eight female patients, whose age ranged from 2–89 years. Correct clinical diagnosis was made in two children only, but preoperative US examination accurately demonstrated the lesion in 11 of 13 patients (85%). These cystic lesions usually had a thin wall, internal septations, and fluid content with sedimentation. Enteric duplication cysts had a relatively thick wall merging with the muscle layer of bowel loop, and multiloculation was noted mainly with cystic lymphangiomas or pseudocysts. The diagnostic and surgical management of these lesions are briefly reviewed and their US appearance is illustrated. 相似文献
79.
Taylor Moran-Gates Christopher Grady Young Shik Park Ross J Baldessarini Frank I Tarazi 《European neuropsychopharmacology》2007,17(6-7):448-455
The atypical antipsychotic risperidone is often prescribed to pediatric patients with neuropsychiatric disorders, though its effects on the developing brain remain unclear. Accordingly, we studied the effects of repeated treatment of risperidone on dopamine receptors in brain regions of juvenile rat. Levels of dopamine receptors (D(1), D(2), D(3), D(4)) in forebrain regions of juvenile rats were quantified after 3 weeks of treatment with three different doses of risperidone (0.3, 1.0 and 3.0 mg/kg) and compared findings to those in adult rats treated with risperidone (3.0 mg/kg/day) previously. Risperidone (at 1.0 and 3.0 mg/kg/day) increased levels of D(1) receptors in nucleus accumbens and caudate-putamen of juvenile, but not adult rats. Conversely, all three doses of risperidone dose-dependently increased D(2) labeling in medial prefrontal cortex and hippocampus, and D(4) receptor in nucleus accumbens, caudate-putamen and hippocampus of juvenile animals as well as in adults. Only the high dose of risperidone (3.0 mg/kg) increased D(2) receptors in caudate-putamen in both juvenile and adult brain. D(3) receptors were not altered by risperidone in any brain region at any dose or age. The findings indicate dose-dependent effects of risperidone on dopamine receptors in developing animals, and that juvenile animals are more sensitive than adults to the cerebral effects of risperidone. 相似文献