全文获取类型
收费全文 | 20944篇 |
免费 | 1085篇 |
国内免费 | 92篇 |
专业分类
耳鼻咽喉 | 243篇 |
儿科学 | 492篇 |
妇产科学 | 392篇 |
基础医学 | 2685篇 |
口腔科学 | 1120篇 |
临床医学 | 1547篇 |
内科学 | 5164篇 |
皮肤病学 | 380篇 |
神经病学 | 1821篇 |
特种医学 | 388篇 |
外科学 | 3256篇 |
综合类 | 205篇 |
一般理论 | 7篇 |
预防医学 | 1646篇 |
眼科学 | 463篇 |
药学 | 1201篇 |
中国医学 | 91篇 |
肿瘤学 | 1020篇 |
出版年
2024年 | 18篇 |
2023年 | 147篇 |
2022年 | 346篇 |
2021年 | 708篇 |
2020年 | 371篇 |
2019年 | 577篇 |
2018年 | 710篇 |
2017年 | 448篇 |
2016年 | 461篇 |
2015年 | 600篇 |
2014年 | 877篇 |
2013年 | 1037篇 |
2012年 | 1726篇 |
2011年 | 1736篇 |
2010年 | 962篇 |
2009年 | 867篇 |
2008年 | 1465篇 |
2007年 | 1518篇 |
2006年 | 1345篇 |
2005年 | 1282篇 |
2004年 | 1105篇 |
2003年 | 921篇 |
2002年 | 913篇 |
2001年 | 169篇 |
2000年 | 118篇 |
1999年 | 146篇 |
1998年 | 190篇 |
1997年 | 138篇 |
1996年 | 96篇 |
1995年 | 89篇 |
1994年 | 88篇 |
1993年 | 70篇 |
1992年 | 89篇 |
1991年 | 61篇 |
1990年 | 57篇 |
1989年 | 58篇 |
1988年 | 51篇 |
1987年 | 44篇 |
1986年 | 42篇 |
1985年 | 42篇 |
1984年 | 46篇 |
1983年 | 41篇 |
1982年 | 44篇 |
1981年 | 37篇 |
1980年 | 22篇 |
1979年 | 22篇 |
1978年 | 27篇 |
1977年 | 27篇 |
1976年 | 18篇 |
1973年 | 18篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
Sergio J Canovas Eric Lim Fernando Hornero Jose Montero 《European journal of cardio-thoracic surgery》2003,23(4):639-641
Left ventricular free wall rupture is a dramatic complication after myocardial infarction. We present our experience with the simple, expedient technique of patch glue repair without extracorporeal circulation. Access is obtained via median sternotomy. Evacuation of blood and haematoma is undertaken and a Goretex patch exceeding the size of infarct is fashioned. The patch is applied to the epicardium using enbrucrilate surgical glue instilled with gentle pressure against the beating heart. We performed this technique on 17 patients from 1993 to 2001, with a operative (30-day) mortality of 23.5% with a post-discharge survival of 85% at 2.2 years. 相似文献
33.
Fernando Alfonso 《Journal of the American College of Cardiology》2007,50(7):650-1; author reply 651
34.
Cranial sutures and craniometric points detected on MRI 总被引:2,自引:0,他引:2
Cotton F Rozzi FR Vallee B Pachai C Hermier M Guihard-Costa AM Froment JC 《Surgical and radiologic anatomy : SRA》2005,27(1):64-70
The main goal of the study was to determine on MRI the cranial sutures, the craniometric points and craniometric measurements, and to correlate these results with classical anthropometric measurements. For this purpose, we reviewed 150 cerebral MRI examinations considered as normal (Caucasian population aged 2049 years). For each examination we individualized 11 craniometric landmarks (Glabella, Bregma, Lambda, Opisthocranion, Opisthion, Basion, Inion, Porion, Infra-orbital, Eurion) and three measurements. Measurements were also calculated independently on 498 dry crania (Microscribe 3-DX digitizer). To validate the MRI procedure, we measured four dry crania by MRI and with compass or digital caliper gauges. Cranial sutures always appeared without signal (black), whatever the MRI sequence used, and they are better visualized with a 5 mm slice thickness (compact bone overlapping). Slice dynamic analysis and multiplanar reformatting allowed the detection of all craniometric points, some of these being more difficult to detect than others (Porion, Infra-orbital). The measurements determined by these points were as follows: VertexBasion height=135.66±6.56 mm; EurionEurion width=141.17±5.19 mm; GlabellaOpisthocranion length=181.94±6.40 mm. On the midline T1-weighted sagittal image, all median craniometric landmarks can be individualized and the GlabellaOpisthocranion length, VertexBasion height and parenchyma indices can be calculated. Craniometric points and measurements between these points can be estimated with a standard cerebral MRI examination, with results that are similar to anthropometric data. 相似文献
35.
36.
Colgin LL Kubota D Brucher FA Jia Y Branyan E Gall CM Lynch G 《Journal of neurophysiology》2004,92(6):3385-3398
Spontaneous negative-going potentials occurring at an average frequency of 0.7 Hz were recorded from the dentate gyrus of slices prepared from the temporal hippocampus of young adult rats. These events (here termed "dentate waves") in several respects resembled the dentate spikes described for freely moving rats during immobile behaviors and slow-wave sleep. Action potentials were observed on the descending portion of the in vitro waves and, as expected from this, whole cell recordings established that the waves were composed of depolarizing currents. Dentate waves appeared to be locally generated within the granule cell layer and were greatly reduced by antagonists of AMPA-type glutamate receptors or by lesions to the entorhinal cortex. Simultaneous recordings indicated that the waves were often synchronized in the inner and outer blades of the dentate gyrus. Knife cuts through the perforant path and the commissural/associational system did not eliminate synchronization, leaving electrotonic propagation via gap junctions as its probable cause. In accord with this, cuts that separated the two blades of the dentate eliminated synchronization between them, and a compound that inhibits gap junctions reduced wave activity. Dentate waves were regularly accompanied by sharp waves in field CA3 and were reduced in size by the acetylcholinesterase inhibitor, physostigmine. It is hypothesized that dentate waves occur when spontaneous glutamate release from dentate afferents produces action potentials in neighboring granule cells that then summate electrotonically into a population event; once initiated, the waves propagate, again electrotonically, and thereby engage a significant portion of the granule cell population. 相似文献
37.
Allele-Specific PCR Method Based on pncA and oxyR Sequences for Distinguishing Mycobacterium bovis from Mycobacterium tuberculosis: Intraspecific M. bovis pncA Sequence Polymorphism 总被引:1,自引:0,他引:1 下载免费PDF全文
Luz Elena Espinosa de los Monteros Juan Carlos Galn Montserrat Gutirrez Sofía Samper Juan F. García Marín Carlos Martín Lucas Domínguez Luis de Rafael Fernando Baquero Enrique Gmez-Mampaso Jesús Blzquez 《Journal of clinical microbiology》1998,36(1):239-242
An allele-specific amplification method based on two genetic polymorphisms to differentiate Mycobacterium tuberculosis from Mycobacterium bovis was tested. Based on the differences found at position 169 in the pncA genes from M. tuberculosis and M. bovis, a PCR system which was able to differentiate most of the 237 M. tuberculosis complex isolates tested in one of the two species was developed. All 121 M. tuberculosis strains showed the expected base (cytosine) at position 169. Most of the M. bovis isolates had a guanine at the cited position. Nevertheless, 18 of the 116 M. bovis isolates, all of them goat isolates, showed the pncA polymorphism specific to M. tuberculosis. These results suggest that goat M. bovis may be the nicotinamidase-missing link at the origin of the M. tuberculosis species. Based on the polymorphism found at position 285 in the oxyR gene, the same system was used to differentiate M. tuberculosis from M. bovis. In this case, DNAs from all 121 M. tuberculosis isolates had the expected base (guanine) at this position. In addition, all 116 M. bovis isolates, including those from goats, showed the identical polymorphism (adenine). The oxyR allele-specific amplification method can differentiate M. bovis from M. tuberculosis, is rapid (results can be obtained in less than 3 h), and is easy to perform. 相似文献
38.
Antonio López-Beltrán Alfonso S. Calañas Pilar Jimena Alberto L. Escudero Telma R. Campello Manuel Muñoz-Torres Fernando Escobar-Jiménez Rafael E. Carvia F. F. Nogales 《Virchows Archiv : an international journal of pathology》1997,431(2):149-151
Three further cases of mature benign cystic teratomas of the ovary associated with virilization are added to the three previously
reported in the literature. They were found in postmenopausal, obese, diabetic women aged 52, 61, and 67 years. The patients
presented with hirsutism and voice changes and clitoromegaly was present in one. Testosterone and androstenedione levels were
elevated but promptly regressed after removal of the tumours. Histologically, sheets of stromal luteinized cells were found
peripherally at the interface between the neoplasm and ovarian tissue. Luteinization of ovarian stroma induced by an unknown
factor related to diabetes mellitus is the origin of the virilization.
Received: 8 January 1997 / Accepted: 28 February 1997 相似文献
39.
Gómez-Román JJ Del Valle CE Zarrabeitia MT Martínez JC Goñi FZ Lera RM Cuevas J Val-Bernal JF 《Pathology international》2005,55(9):580-584
Bronchioloalveolar carcinoma is a distinctive subtype of pulmonary adenocarcinoma, without effective therapy, although there have recently been some attempts to use lung transplantation. However, a high post-transplantation local recurrence rate is described with some controversy regarding the possible involved mechanisms, the main possibilities being the lymphatic spread and aerosolization. Presented herein is a case of a bilateral lung transplantation for a bilateral and pneumonic form of non-mucinous bronchioloalveolar carcinoma in a 43-year-old woman. The histological analysis of mediastinal lymph nodes during surgery did not show neoplastic cells. Thirty-five months after transplantation several nodular opacities in donor lungs were detected. Three pulmonary wedge resections were performed showing a non-mucinous bronchioloalveolar carcinoma with the same histological characteristics as the primary. Again, the mediastinal lymph nodes were tumor free. A complete microsatellites molecular analysis was performed to compare the primary and recurrent carcinoma using capillary electrophoresis, showing that the recurrent tumor was generated in a recipient cellular clone. The absence of lymph node metastasis and the molecular evidence of the recipient origin of the neoplasm supports the contamination of the new lungs at the time of implantation as being the reason for the high incidence of recurrence after lung transplantation in this kind of disease. 相似文献
40.