全文获取类型
收费全文 | 18238篇 |
免费 | 1677篇 |
国内免费 | 244篇 |
专业分类
耳鼻咽喉 | 46篇 |
儿科学 | 948篇 |
妇产科学 | 346篇 |
基础医学 | 2545篇 |
口腔科学 | 183篇 |
临床医学 | 4451篇 |
内科学 | 814篇 |
皮肤病学 | 47篇 |
神经病学 | 4270篇 |
特种医学 | 196篇 |
外科学 | 488篇 |
综合类 | 1471篇 |
现状与发展 | 1篇 |
一般理论 | 9篇 |
预防医学 | 3264篇 |
眼科学 | 56篇 |
药学 | 609篇 |
12篇 | |
中国医学 | 232篇 |
肿瘤学 | 171篇 |
出版年
2024年 | 81篇 |
2023年 | 597篇 |
2022年 | 493篇 |
2021年 | 773篇 |
2020年 | 832篇 |
2019年 | 814篇 |
2018年 | 721篇 |
2017年 | 729篇 |
2016年 | 666篇 |
2015年 | 712篇 |
2014年 | 936篇 |
2013年 | 1575篇 |
2012年 | 833篇 |
2011年 | 883篇 |
2010年 | 702篇 |
2009年 | 771篇 |
2008年 | 811篇 |
2007年 | 891篇 |
2006年 | 733篇 |
2005年 | 648篇 |
2004年 | 618篇 |
2003年 | 521篇 |
2002年 | 453篇 |
2001年 | 343篇 |
2000年 | 289篇 |
1999年 | 283篇 |
1998年 | 294篇 |
1997年 | 233篇 |
1996年 | 229篇 |
1995年 | 173篇 |
1994年 | 156篇 |
1993年 | 170篇 |
1992年 | 127篇 |
1991年 | 123篇 |
1990年 | 87篇 |
1989年 | 82篇 |
1988年 | 89篇 |
1987年 | 90篇 |
1986年 | 75篇 |
1985年 | 71篇 |
1984年 | 82篇 |
1983年 | 39篇 |
1982年 | 64篇 |
1981年 | 60篇 |
1980年 | 48篇 |
1979年 | 41篇 |
1978年 | 23篇 |
1977年 | 30篇 |
1976年 | 18篇 |
1974年 | 10篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
101.
Klinefelter syndrome is a common cause for mental retardation of unknown etiology among prepubertal males 总被引:1,自引:0,他引:1
Klinefelter syndrome (KS) has not typically been associated with mental retardation (MR), however, in recent years a growing body of evidence suggested that KS boys often experience language deficits and academic difficulties. In this study, we screened DNA samples from 1205 patients originally referred for fragile X syndrome (FRAX) testing, because of MR of unknown etiology and detected 8 KS patients. A similar number of males in the same age group were found to have FRAX; 3 of them had a family history of FRAX. Based on these findings, KS might be the most common cause of MR of unknown etiology among prepubertal males. Because of the significant benefits of early recognition and treatment of KS, we emphasize the importance of cytogenetic testing of all prepubertal males with cognitive impairment even without dysmorphic features. 相似文献
102.
The delivery of mental health services, particularly psychotherapy and other psychosocial care, is being increasingly limited by financial constraints. We briefly review three trends that will play an increasingly important role in the delivery of mental health services in large organizations such as health maintenance organizations. These are (a) an increasing role for self-help and bibliotherapy interventions, both in traditional and electronic formats; (b) mental health services being offered in settings other than mental health specialty clinics; and (c) an increased emphasis on mechanisms for improving the quality and type of services offered, including quality improvement methods and pay-for-performance. 相似文献
103.
Petros M Pavlopoulos Anastasia E Konstantinidou Emmanuel Agapitos Panagiotis Davaris 《Clinical genetics》1998,54(6):512-516
Roberts syndrome (RS) is a rare autosomal recessive disorder characterized primarily by symmetric reduction anomalies of all limbs, growth retardation and craniofacial abnormalities. Most RS patients are reported to present a typical abnormality of their constitutive heterochromatin, accompanied by abnormal cytological growth characteristics. We present an extremely severe case of an RS fetus, karyotypically documented, with a clinical presentation including growth deficiency, tetraphocomelia, frontal meningocele, craniofacial abnormalities and penile enlargement with hypospadias. Nuclear morphometrical analysis in tissues of various organs revealed a reduced nuclear size in RS as compared to normal controls, and statistically significant differences in morphometric parameters related to the nuclear shape. Immunohistochemical study of the same organs showed a reduced expression of proliferating cell nuclear antigen in the presented case, thus indicating a decreased cell proliferation rate in RS. Our results reconfirm previously reported findings in cultured fibroblasts of RS cases, thereby reinforcing on a histologic level, the hypothesis that reduced cell proliferation may be involved in the growth retardation and the reduction abnormalities observed in RS. 相似文献
104.
Sonia Ehrlich Tania Bustos Inder J. Paika Aubrey Milunsky John M. Opitz 《American journal of medical genetics. Part A》1983,15(2):261-263
Some variation in the phenotype of patients with dup(18q) is recognized. Our patient has the phenotype described for dup(18qter). 相似文献
105.
Familial partial trisomy 5p resulting from segregation of an insertional translocation 总被引:1,自引:0,他引:1
A case of duplication of segment p13-p15 of the short arm of chromosome 5 as the result of an insertional translocation in a mentally retarded girl with congenital anomalies is reported. Some of the apparently balanced carriers of the inverted insertion showed minor congenital anomalies. 相似文献
106.
1978—1987年北京市十六所大学本科生因精神疾病休学、退学情况分析 总被引:9,自引:2,他引:9
本文对北京市十六所大学十年来因精神疾病休学、退学的资料进行了分析。结果表明,因精神疾病休学率有所上升,精神疾病是大学生因病休、退学的主要原因,其中以神经症为主。因精神疾病的休退学率以二、三年级学生,及理工科大学学生最高。 相似文献
107.
父母离异子女精神卫生问题调查 总被引:12,自引:0,他引:12
目的 :了解父母离异后单亲家庭子女的精神卫生状况 ,探讨其预防措施。方法 :选择天津市和平区中小学中的 12个班级 486名学生进行调查。生活在单亲家庭中的青少年 49人 ,将其组成研究组 ,采用 1∶1配对的方法组成对照组。研究组和对照组使用自制的一般情况调查表、修订的艾森克个性问卷(EPQ)、自尊量表 (SES)、Achenbach氏儿童行为量表和自制的学习成绩评定表进行评定。结果 :研究组和对照组存在各种精神卫生问题分别占 98%及 14 3 % (P <0 0 1)。两组比较单亲组性格内向 (分别为 2 8 6% ,12 2 % )、外向 ( 3 8 8% ,18 4% ) ;自尊心强 ( 2 6 5 % ,14 3 % )、自尊心差 ( 2 6 5 % ,4 1% ) ;早熟( 4 0 8% ,6 1% )、冷漠 ( 4 2 9% ,2 1% )、交往不良 ( 3 4 7% ,4 1% )、敌意 ( 12 2 %、 2 1% )和违纪行为( 2 8 6% ,2 1% ) ,均显著高于双亲家庭子女组。结论 :单亲家庭子女存在较多的精神卫生问题 ,应有针对性的进行干预。 相似文献
108.
Adrien JL Rossignol-Deletang N Martineau J Couturier G Barthelemy C 《Developmental psychobiology》2001,39(2):124-136
Based on the Piagetian framework, this study examined regulation of cognitive activity and developmental communication profiles and their interrelationship in groups of autistic, mentally retarded, and normal children of comparable overall, verbal, and oculo-manual developmental ages (from 6 to 24 months). Regulation of activity was assessed with both an object permanence test and an original behavior grid, and development of communication skills with the Guidetti-Tourrette scales (French adaptation of the Seibert-Hogan scales). The results showed evidence of certain types of dysregulation of cognitive activity and a general delay in communication ability in autistic children compared to the other two groups. Moreover, although the intensity of some of these disorders decreased in relation to the developmental levels of social interaction and joint attention in normal children, they were related to both high and low levels of development of social interaction only in autistic children. These findings raise the hypothesis of a relationship between a disorder of disengaging from an activity and developmental levels of social interaction noted at two transitory periods of early development (12 and 24 months) only in children with autism. Developmental and neuropsychological interpretations of this particular pattern are proposed. 相似文献
109.
Ana Grangeia Miguel Leão Carla P. Moura 《American journal of medical genetics. Part A》2020,182(1):25-28
Wiedemann‐Steiner syndrome (WSS) is a rare genetic disorder characterized by growth retardation, facial dysmorphism, hypertrichosis cubiti and neurodevelopment delay. It is caused by pathogenic variants in the KMT2A gene. This report describes two unrelated Portuguese patients, age 11 and 17 years, with a phenotype concordant with WSS and clinical and molecular diagnosis of WSS by the identification of two novel frameshift variants in the KMT2A gene. This work also highlights the presence of certain clinical features in patients with growth retardation and development delay and should draw attention to the diagnosis of WSS, when hirsutism, particularly hypertrichosis cubiti is present. 相似文献
110.