全文获取类型
收费全文 | 54351篇 |
免费 | 3633篇 |
国内免费 | 277篇 |
专业分类
耳鼻咽喉 | 530篇 |
儿科学 | 1969篇 |
妇产科学 | 1386篇 |
基础医学 | 8111篇 |
口腔科学 | 799篇 |
临床医学 | 5217篇 |
内科学 | 12360篇 |
皮肤病学 | 1181篇 |
神经病学 | 5944篇 |
特种医学 | 1143篇 |
外科学 | 4470篇 |
综合类 | 298篇 |
现状与发展 | 1篇 |
一般理论 | 43篇 |
预防医学 | 5056篇 |
眼科学 | 879篇 |
药学 | 4096篇 |
中国医学 | 137篇 |
肿瘤学 | 4641篇 |
出版年
2024年 | 91篇 |
2023年 | 684篇 |
2022年 | 1447篇 |
2021年 | 2450篇 |
2020年 | 1407篇 |
2019年 | 1807篇 |
2018年 | 1983篇 |
2017年 | 1601篇 |
2016年 | 1766篇 |
2015年 | 1921篇 |
2014年 | 2495篇 |
2013年 | 3125篇 |
2012年 | 4604篇 |
2011年 | 4606篇 |
2010年 | 2456篇 |
2009年 | 2088篇 |
2008年 | 3490篇 |
2007年 | 3476篇 |
2006年 | 3151篇 |
2005年 | 2880篇 |
2004年 | 2645篇 |
2003年 | 2361篇 |
2002年 | 2124篇 |
2001年 | 265篇 |
2000年 | 214篇 |
1999年 | 268篇 |
1998年 | 350篇 |
1997年 | 288篇 |
1996年 | 201篇 |
1995年 | 186篇 |
1994年 | 188篇 |
1993年 | 146篇 |
1992年 | 101篇 |
1991年 | 97篇 |
1990年 | 71篇 |
1989年 | 81篇 |
1988年 | 77篇 |
1987年 | 69篇 |
1986年 | 68篇 |
1985年 | 66篇 |
1984年 | 87篇 |
1983年 | 69篇 |
1982年 | 80篇 |
1981年 | 66篇 |
1980年 | 62篇 |
1979年 | 31篇 |
1978年 | 34篇 |
1977年 | 34篇 |
1976年 | 26篇 |
1973年 | 21篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Anna Di Landro Lorenzo Marchesi Luigi Naldi Teresio Motta Tullio Cainelli 《Pediatric dermatology》1997,14(6):449-452
Abstract: Hypopigmented mycosis fungoides is a variant of mycosis fungoides characterized by the presence of hypopigmented patches as the sole manifestation of the disease. It has been described aimost always in young black or dark-skinned patients. The only white patient described was a 64-year-oid woman who not oniy had hypopigmented lesions, but also nodular lesions with lymphadenopathy. We describe hypopigmented lesions arising in a white boy 12 years of age, born in northern Italy, without any foreign ancestors. The microscopic alterations, with epidermotropism, the immunoiogic markers, the negativity of T-cell receptor gene rearrangement, and the good response to PUVA therapy correspond to the main findings in black patients with this disease. Long-term follow-up of these patients is important to obtain better knowledge of the natural history of the disorder, Hypopigmented mycosis fungoides must now be included in the differential diagnosis of hypopigmented macular lesions not only in black or dark-skinned patients but also in white patients. 相似文献
72.
Anna P Basu Prashant Kumar Anita M Devlin Christopher J O'Brien 《European journal of paediatric neurology》2007,11(4):240-242
A 15-week old male infant presented with bilateral lower motor neuron facial palsy of unknown cause. Subsequently his growth deteriorated and he developed progressively worsening cough and wheeze. A diagnosis of cystic fibrosis was confirmed and hypovitaminosis A detected. Improvement of the facial palsy was noted following standard management of cystic fibrosis including vitamin A supplementation. 相似文献
73.
Gregory P Crucian Anna M Barrett David W Burks Alonso R Riestra Heidi L Roth Ronald L Schwartz William J Triggs Dawn Bowers William Friedman Melvin Greer Kenneth M Heilman 《Journal of the International Neuropsychological Society》2003,9(7):1078-1087
Deficits in visual-spatial ability can be associated with Parkinson's disease (PD), and there are several possible reasons for these deficits. Dysfunction in frontal-striatal and/or frontal-parietal systems, associated with dopamine deficiency, might disrupt cognitive processes either supporting (e.g., working memory) or subserving visual-spatial computations. The goal of this study was to assess visual-spatial orientation ability in individuals with PD using the Mental Rotations Test (MRT), along with other measures of cognitive function. Non-demented men with PD were significantly less accurate on this test than matched control men. In contrast, women with PD performed similarly to matched control women, but both groups of women did not perform much better than chance. Further, mental rotation accuracy in men correlated with their executive skills involving mental processing and psychomotor speed. In women with PD, however, mental rotation accuracy correlated negatively with verbal memory, indicating that higher mental rotation performance was associated with lower ability in verbal memory. These results indicate that PD is associated with visual-spatial orientation deficits in men. Women with PD and control women both performed poorly on the MRT, possibly reflecting a floor effect. Although men and women with PD appear to engage different cognitive processes in this task, the reason for the sex difference remains to be elucidated. 相似文献
74.
Caroline F Rowland Julian M Pine Elena V M Lieven Anna L Theakston 《J. Speech Lang. Hear. Res.》2005,48(2):384-404
Many current generativist theorists suggest that young children possess the grammatical principles of inversion required for question formation but make errors because they find it difficult to learn language-specific rules about how inversion applies. The present study analyzed longitudinal spontaneous sampled data from twelve 2-3-year-old English speaking children and the intensive diary data of 1 child (age 2;7 [years;months] to 2;11) in order to test some of these theories. The results indicated significantly different rates of error use across different auxiliaries. In particular, error rates differed across 2 forms of the same auxiliary subtype (e.g., auxiliary is vs. are), and auxiliary DO and modal auxiliaries attracted significantly higher rates of errors of inversion than other auxiliaries. The authors concluded that current generativist theories might have problems explaining the patterning of errors seen in children's questions, which might be more consistent with a constructivist account of development. However, constructivists need to devise more precise predictions in order to fully explain the acquisition of questions. 相似文献
75.
William F Astle Vivian E Hill Anna L Ells Nguyen Thi Thanh Chi Elaine Martinovic 《Journal of AAPOS》2003,7(5):339-344
BACKGROUND: Congenital absence of the inferior rectus muscle is a rare cause of apparent inferior rectus palsy especially in the absence of associated cranial facial anomalies. METHODS: We report three cases of isolated congenital absence of the inferior rectus muscle and its successful surgical management. RESULTS: Failure of the normal embryologic development of the mesodermal complex around the eye can lead to agenesis of the extraocular muscles. In apparent palsies of the inferior rectus muscle and no definite cause, a high index of suspicion and orbital imaging can confirm the diagnosis of congenitally absent inferior rectus preoperatively. Surgical correction may involve inferior transposition of the horizontal rectus muscles. CONCLUSIONS: Although rare, congenital absence of the inferior rectus muscle is a possible cause of apparent inferior rectus muscle palsy particularly in the absence of another identifiable cause. Strabismus surgery in conjunction with intramuscular botulinum toxin injection can offer significant improvement in function and cosmesis of these patients. 相似文献
76.
Janina Rafalowska Anna Fidzianska Dorota Dziewulska Aleksandra Podlecka Grazyna Maria Szpak Hubert Kwiecinski 《Neuropathology》2004,24(1):16-20
In the present study, morphological examination of patients from two unrelated Polish families with CADASIL was performed. Using light microscopy, there were evident changes characteristic to the disease. On electron microscopy, deposits of granular osmiophillic material (GOM) were found not only in cerebral arteries and veins but also in cerebral capillaries and vessels of the internal organs. These findings indicate that pathological process in CADASIL is generalized and involves also small vessels devoid of smooth muscle cells. Therefore, we propose to consider a replacement for the name CADASIL that better reflects the morphological picture of the disease like, for example, cerebral autosomal dominant vasculopathy with subcortical infarcts and leukoencephalopathy (CADVaSIL) or, to preserve the commonly known acronym, cerebral autosomal dominant angiopathy with subcortical infarcts and leukoencephalopathy. 相似文献
77.
PURPOSE: Although the angle of deviation in patients with congenital esotropia has been shown to increase during the early preoperative period, few data exist regarding this change in other forms of childhood esotropia. The primary objective of this study was to investigate whether the angle of deviation increases with time in patients with acquired nonaccommodative esotropia (ANAET). METHODS: The medical records of all children whose ANAET was diagnosed at East Tennessee State University College of Medicine from August 1, 1995, through October 1, 2001, were retrospectively reviewed. All patients were assessed for any change in the amount of their strabismic angle and associated risk factors. RESULTS: Eighty-two patients with ANAET were identified, and all except 3 underwent more than one examination. Of the 79 children who underwent more than one examination, 26 (32.9%) displayed an angle increase of > or =10 prism diopters (PD) during a median follow-up period of 2.9 months. The ANAET of those patients whose angle increased by > or =10 PD was diagnosed (28.4 months of age vs 45.5 months of age, P =.003), and they underwent surgery (35.9 months of age vs 53.3 months of age, P =.003) at a significantly younger median age than those whose angle increased <10 PD. CONCLUSIONS: The angle of deviation of approximately one third of patients with ANAET in this study increased at least 10 PD in the early preoperative period. This increase occurs more often in younger patients and underscores the importance of performing serial measurements of the deviating angle before surgical intervention is undertaken. 相似文献
78.
79.
Anna Szymańska Elżbieta Korobowicz Wiesław Gołąbek 《European archives of oto-rhino-laryngology》2006,263(7):657-660
Nasopharyngeal angiofibromas occur predominantly in males in their puberty and adolescence; the incidence in other age groups and in women is exceptional. This report describes a case of a 57-year-old woman with nasopharyngeal angiofibroma presenting typical radiological findings in computed tomography, MR imaging and angiography. The tumour was successfully removed and histopathological examination confirmed the diagnosis. In 6 years follow-up the patient is free of symptoms. 相似文献
80.
Felice Cardillo Piccolino Giovanni Calabria Anna Polizzi Mauro Fioretto 《Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie》1989,227(4):335-339
Two young brothers were bilaterally affected by pigmentary glaucoma and extensive symmetrical changes of the retinal pigment epithelium (RPE). Fundus changes consisted in widespread salt-and-pepper RPE mottling and pigment clumping, sparing only the peripapillary and foveal areas. During the course of 4 years, one of the two patients suffered multiple, recurrent, exudative and hemorrhagic detachments of the RPE that involved the midperiphery and posterior pole. No exudative lesions appeared in the brother. The medical history and systemic laboratory tests were noncontributory in both patients. The ERG was normal and the EOG subnormal. Dark adaptation was delayed and showed an elevation of the scotopic threshold. These cases seem to support the hypothesis that the RPE is also involved in the pigmentary dispersion syndrome. An inherited defect could affect the pigment epithelium in both the anterior and posterior segments of the eye. The multifocal subretinal exudative pattern that occurred in one of our patients has not been previously observed in hereditary disorders of the RPE.Presented at the XVIth Meeting of the Club Jules Gonin, Bruges, 4–8 September 1988 相似文献