全文获取类型
收费全文 | 4413篇 |
免费 | 226篇 |
国内免费 | 19篇 |
专业分类
耳鼻咽喉 | 30篇 |
儿科学 | 69篇 |
妇产科学 | 99篇 |
基础医学 | 658篇 |
口腔科学 | 74篇 |
临床医学 | 372篇 |
内科学 | 976篇 |
皮肤病学 | 57篇 |
神经病学 | 473篇 |
特种医学 | 127篇 |
外科学 | 591篇 |
综合类 | 23篇 |
一般理论 | 2篇 |
预防医学 | 244篇 |
眼科学 | 105篇 |
药学 | 377篇 |
中国医学 | 15篇 |
肿瘤学 | 366篇 |
出版年
2023年 | 19篇 |
2022年 | 45篇 |
2021年 | 70篇 |
2020年 | 58篇 |
2019年 | 70篇 |
2018年 | 93篇 |
2017年 | 62篇 |
2016年 | 77篇 |
2015年 | 100篇 |
2014年 | 110篇 |
2013年 | 170篇 |
2012年 | 245篇 |
2011年 | 240篇 |
2010年 | 170篇 |
2009年 | 116篇 |
2008年 | 227篇 |
2007年 | 251篇 |
2006年 | 266篇 |
2005年 | 237篇 |
2004年 | 215篇 |
2003年 | 173篇 |
2002年 | 172篇 |
2001年 | 108篇 |
2000年 | 120篇 |
1999年 | 113篇 |
1998年 | 54篇 |
1997年 | 41篇 |
1996年 | 37篇 |
1995年 | 31篇 |
1994年 | 27篇 |
1993年 | 26篇 |
1992年 | 87篇 |
1991年 | 73篇 |
1990年 | 84篇 |
1989年 | 92篇 |
1988年 | 79篇 |
1987年 | 74篇 |
1986年 | 62篇 |
1985年 | 60篇 |
1984年 | 33篇 |
1983年 | 21篇 |
1982年 | 15篇 |
1981年 | 18篇 |
1980年 | 19篇 |
1979年 | 24篇 |
1978年 | 14篇 |
1977年 | 20篇 |
1976年 | 12篇 |
1975年 | 13篇 |
1974年 | 25篇 |
排序方式: 共有4658条查询结果,搜索用时 0 毫秒
1.
2.
3.
Hyo-Chang Kim Seok-Gu Kang Pil-Woo Huh Do Sung Yoo Kyoung Suok Cho Dal Soo Kim 《Journal of clinical neuroscience》2007,14(11):1135-1139
Pituitary abscess is a rare and potentially lethal condition. Pituitary abscess in a pregnant woman has not been previously described. A 38-year-old pregnant woman (34 weeks gestation) with a pituitary mass complained of a progressive headache and sudden visual impairment. She was afebrile and had no inflammatory symptoms on admission. On MRI, the preoperative diagnosis was pituitary adenoma with sphenoid sinusitis. She underwent an uncomplicated transsphenoidal procedure for removal of the pituitary mass. The next day, labor commenced and a healthy preterm baby was delivered. Pathologic examination of the intrasellar mass showed polymorphonuclear cells, debris and no tumor cells. The sellar contents were cultured and Streptococcus viridans was grown. To our knowledge this is the first case of pituitary abscess reported during pregnancy. Although the patient was pregnant, the transsphenoidal approach was safe for the mother and the fetus. Surgical drainage and antibiotic therapy are required for the definitive treatment of this condition. 相似文献
4.
A. P. Dei Tos Paola Dal Cin 《Virchows Archiv : an international journal of pathology》1997,431(2):83-94
Soft tissue tumours represent a heterogeneous group of mesenchymal lesions, and their classification is the subject of continuous
debate. Chromosome analysis, molecular cytogenetics and molecular assays may become increasingly useful in diagnosis, and
this review summarises advances in the cytogenetic characterisation and classification of soft tissue tumours. Among the group
of fibrous lesions, superficial fibromatosis exhibits trisomy 8. This genomic change is also observed in desmoid fibromatosis
in association with trisomy 20. Trisomy 11 is the most frequently observed chromosomal aberration in congenital fibrosarcoma.
Dermatofibrosarcoma protuberans and giant cell fibroblastoma share a translocation t(17;22), which supports the concept of
the existence of a common differentiation pathway. Adipose tissue tumours is the group in which integration of genetics and
pathology has been most fruitful. Ordinary lipomas cytogenetically show an abnormal karyotype in about half the cases. Genomic
changes of the 11q13 region are observed in hibernoma. Lipoblastoma exhibits a specific 8q rearrangement in 8q11-q13. Loss
of material from the region 16q13-qter and 13q deletions are observed in spindle cell/pleomorphic lipomas. The well-differentiated
liposarcoma/atypical lipoma group is characterised karyotypically by the presence of one extra ring and/or extra giant chromosome
marker. Myxoid and round cell liposarcoma share the same characteristic chromosome change: t(12;16)(q13;p11) in most cases.
In the group of smooth muscle lesions most data are derived from uterine leiomyomas, which can be subclassified cytogenetically
into seven different types. Half of all leiomyomas are chromosomally normal; the other half have one of six possible consistent
chromosome changes. Alveolar rhabdomyosarcoma is characterised cytogenetically by two variant translocations t(2;13)(q35;q14)
and t(1;13)(p36;q14). Among tenosynovial tumours, the localised type of giant cell tumour of tendon sheath exhibits two different
karyotypic changes. One involves 1p11 in a translocation with chromosome 2 or with another chromosome. A second type involves
16q24. Synovial sarcoma is characterised cytogenetically by a translocation occurring between chromosome 18 and presumably
two adjacent loci on the X chromosome. In neural tumours, abnormalities of chromosome 22 have been reported in benign schwannomas
and perineuriomas. Malignant peripheral nerve sheath tumours exist in two main forms: sporadic and associated with the NF-1
syndrome. Karyotypes are very complex, but chromosomes 17q and 22q are very often involved. Clear cell sarcoma is characterised
cytogenetically and molecularly by a translocation t(12;22)(q13;q12). The Ewing’s sarcoma/peripheral neuroectodermal tumour
category shows a central karyotypic anomaly represented by the translocation t(11;22). The two variants t(21;22) and t(7;22)
are found in some cases. Among cartilaginous lesion, the most frequently described anomaly is the t(9;22)(q22;q12) in extraskeletal
myxoid chondrosarcoma. Intra-abdominal desmoplastic small round cell tumour is characterised by a t(11;22)(p13;q12).
Received: 5 February 1997 / Accepted: 24 February 1997 相似文献
5.
Osteopenia of the tibia and femur caused by an external fixator in the tibia was studied in 14 rabbits. Eight rabbits were treated with a complete unilateral external fixator in one tibia, whereas the other tibia served as control. The other 6 animals had one leg operated on with inserting of all the pins but without the frame. This technique was chosen to compare osteopenia caused by stress protection and the effect of the pins. After 6 weeks, we found a 7 percent reduction in the bone mineral content in the tibial diaphyseal segment between the pins of the external fixator and no bone loss in the tibia that were operated on with only pins. In the femurs, there was a smaller decrease in the bone mineral content: respectively 3.2 percent (complete frame) and 2.9 percent (only pins). On all the operated on tibiae, there was an increase in the bone mineral content around the pins both proximally and distally. 相似文献
6.
Claudio Babiloni Giuliano Binetti Emanuele Cassetta Gloria Dal Forno Claudio Del Percio Florinda Ferreri Raffaele Ferri Giovanni Frisoni Koichi Hirata Bartolo Lanuzza Carlo Miniussi Davide V Moretti Flavio Nobili Guido Rodriguez Gian Luca Romani Serenella Salinari Paolo M Rossini 《Clinical neurophysiology》2006,117(2):252-268
OBJECTIVE: The present study tested the hypothesis that cortical electroencephalographic (EEG) rhythms. change across normal elderly (Nold), mild cognitive impairment (MCI), and Alzheimer's disease (AD) subjects as a function of the global cognitive level. METHODS: Resting eyes-closed EEG data were recorded in 155 MCI, 193 mild AD, and 126 age-matched Nold subjects. EEG rhythms of interest were delta (2-4 Hz), theta (4-8 Hz), alpha 1 (8-10.5 Hz), alpha 2 (10.5-13 Hz), beta 1 (13-20 Hz), and beta 2 (20-30 Hz). EEG cortical sources were estimated by LORETA. RESULTS: Occipital delta and alpha 1 sources in parietal, occipital, temporal, and 'limbic' areas had an intermediate magnitude in MCI subjects compared to mild AD and Nold subjects. These five EEG sources presented both linear and nonlinear (linear, exponential, logarithmic, and power) correlations with the global cognitive level (as revealed by mini mental state examination score) across all subjects. CONCLUSIONS: Cortical EEG rhythms change in pathological aging as a function of the global cognitive level. SIGNIFICANCE: The present functional data on large populations support the 'transitional hypothesis' of a shadow zone across normality, pre-clinical stage of dementia (MCI), and AD. 相似文献
7.
The masseter muscle often has been implicated as a primary cause of postreduction displacement of the fractured zygomatic complex. However, this contention has never been proved. This study compared masseter muscle force in 10 male controls with that in 10 male patients who had sustained unilateral zygomaticomaxillary complex (ZMC) fractures. Calculation of muscle force was based on measured bite force, electromyogram, and radiographic determination of muscle vectors. It was found that the masseter muscle in patients with ZMC fractures developed significantly less force than masseter muscle in controls. Following fracture, the masseter force slowly increased, but at 4 weeks following surgery the majority of patients were still well below control levels. The results of this study cast uncertainty on the role of the masseter muscle in postreduction displacement of the fractured ZMC. 相似文献
8.
9.
10.
Laser energy can be used for a variety of neoplastic diseases including benign tumors, early stage malignancies, and advanced carcinomas, either with curative intent or for palliation. Nd:YAG laser photocoagulation of 168 colorectal adenomas allowed a complete eradication in 70% of cases, after a mean follow-up of 22 months. Advanced and obstructing tumors were treated with Nd:YAG laser to recanalize the lumen. In the upper gastrointestinal tract the recanalization of the lumen by means of laser photocoagulation improved the quality of life and survival. In fact, in our series of 308 patients treated, 1-year survival was 23% in recanalized patients and 7% in nonrecanalized patients. In the lower gastrointestinal tract, 289 cancer patients were treated and an amelioration of symptoms related to the obstruction was obtained in 93%. The current indication for photodynamic therapy is mainly the treatment of flat or ulcerative early stage tumors in the esophagus and stomach of high risk patients. Out of 17 patients treated, 14 were locally cured. 相似文献