全文获取类型
收费全文 | 211163篇 |
免费 | 2937篇 |
国内免费 | 147篇 |
专业分类
耳鼻咽喉 | 1630篇 |
儿科学 | 7492篇 |
妇产科学 | 3705篇 |
基础医学 | 21088篇 |
口腔科学 | 3691篇 |
临床医学 | 14889篇 |
内科学 | 40095篇 |
皮肤病学 | 1588篇 |
神经病学 | 19351篇 |
特种医学 | 9623篇 |
外科学 | 34068篇 |
综合类 | 2527篇 |
一般理论 | 13篇 |
预防医学 | 20696篇 |
眼科学 | 3387篇 |
药学 | 11417篇 |
中国医学 | 758篇 |
肿瘤学 | 18229篇 |
出版年
2023年 | 238篇 |
2022年 | 515篇 |
2021年 | 1402篇 |
2020年 | 743篇 |
2019年 | 1103篇 |
2018年 | 22993篇 |
2017年 | 18037篇 |
2016年 | 20255篇 |
2015年 | 1933篇 |
2014年 | 2340篇 |
2013年 | 2630篇 |
2012年 | 9982篇 |
2011年 | 24011篇 |
2010年 | 20481篇 |
2009年 | 12961篇 |
2008年 | 21903篇 |
2007年 | 24126篇 |
2006年 | 3034篇 |
2005年 | 4572篇 |
2004年 | 5402篇 |
2003年 | 6158篇 |
2002年 | 4116篇 |
2001年 | 442篇 |
2000年 | 534篇 |
1999年 | 370篇 |
1998年 | 479篇 |
1997年 | 419篇 |
1996年 | 283篇 |
1995年 | 284篇 |
1994年 | 238篇 |
1993年 | 165篇 |
1992年 | 138篇 |
1991年 | 166篇 |
1990年 | 172篇 |
1989年 | 112篇 |
1988年 | 96篇 |
1987年 | 79篇 |
1986年 | 65篇 |
1985年 | 80篇 |
1984年 | 73篇 |
1983年 | 74篇 |
1982年 | 67篇 |
1981年 | 50篇 |
1980年 | 101篇 |
1978年 | 44篇 |
1977年 | 48篇 |
1974年 | 39篇 |
1938年 | 60篇 |
1932年 | 56篇 |
1930年 | 46篇 |
排序方式: 共有10000条查询结果,搜索用时 156 毫秒
91.
Dan Greitz 《Child's nervous system》2007,23(5):487-489
Objective This study aims to question the generally accepted cerebrospinal fluid (CSF) bulk flow theory suggesting that the CSF is exclusively
absorbed by the arachnoid villi and that the cause of hydrocephalus is a CSF absorption deficit. In addition, this study aims
to briefly describe the new hydrodynamic concept of hydrocephalus and the rationale for endoscopic third ventriculostomy (ETV)
in communicating hydrocephalus.
Critique The bulk flow theory has proven incapable of explaining the pivotal mechanisms behind communicating hydrocephalus. Thus, the
theory is unable to explain why the ventricles enlarge, why the CSF pressure remains normal and why some patients improve
after ETV.
Hydrodynamic concept of hydrocephalus Communicating hydrocephalus is caused by decreased intracranial compliance increasing the systolic pressure transmission into
the brain parenchyma. The increased systolic pressure in the brain distends the brain towards the skull and simultaneously
compresses the periventricular region of the brain against the ventricles. The final result is the predominant enlargement
of the ventricles and narrowing of the subarachnoid space. The ETV reduces the increased systolic pressure in the brain simply
by venting ventricular CSF through the stoma. The patent aqueduct in communicating hydrocephalus is too narrow to vent the
CSF sufficiently. 相似文献
92.
Christian Waydhas Dieter Nast-Kolb Steffen Ruchholtz 《European journal of trauma and emergency surgery》2007,33(2):170-175
Abstract
Objective: To define the diagnostic accuracy of clinical examination in patients with impaired consciousness or endotracheal intubation
to detect pelvic ring fractures and to identify those with severe bleeding.
Methods: Included in this prospective data collection with retrolective data analysis were a consecutive series of blunt trauma victims
with either a Glasgow Coma Scale ≤ 13 or tracheal intubation. Clinical examination comprised testing for stability of the
iliac wings.
Results: From 784 subjects (injury severity score 23.3 ± 17.4) 93 patients (11.9%) were found to have a pelvic ring fracture. Clinical
instability of the pelvic ring was found in 42 patients. There was only one false positive. Fifty-two fractures could not
be identified by clinical examination, including nine fractures (17%) that required surgical fracture stabilization (sensitivity
of clinical examination 44.1%). Seventeen fractures (18.3%) were associated with a blood loss larger than 20% of circulating
blood volume. Sixteen of those were identified by clinical instability of the pelvic ring (sensitivity 94.1%, specificity
97.0%, positive predictive value 38.1%, negative predictive value 99.9%).
Conclusions: Clinical examination for stability of the pelvis in this selected group of patients missed a significant number of pelvic
ring fractures including fractures that require surgical stabilization. The finding of a clinically unstable identifies most
of the patients with the pelvic ring fracture being a major source of bleeding. A stable pelvis makes pelvic ring fracture
as being the source of bleeding quite unlikely. 相似文献
93.
Francisco Jose Martinez-Guijarro Eduardo Soriano Jose Antonio del Rio Carlos Lopez-Garcia 《Brain research》1991,547(2)
An antibody against the calcium binding protein parvalbumin selectively labels a set of neurons in the cerebral cortex of lizards. Golgi-like immunostained bipolar, multipolar and pyramid-like neurons appear mainly located in the inner plexiform layers. Parvalbumin-immunoreactive (PARV-IR) puncta are concentrated in the cell layer of the dorsal and dorsomedial cortices showing a basket-like distribution. The morphology and distribution of PARV-IR neurons and puncta overlap GABA-immunostaining in the cerebral cortex of lizards. Thus, it is likely that PARV-IR neurons are a subset of the cortical GABAergic neurons of lizards. 相似文献
94.
Background
Reports on childhood cancer survivors estimated cumulative probability of developing secondary neoplasms vary from 3,3% to 25% at 25 years from diagnosis, and the risk of developing another cancer to several times greater than in the general population. 相似文献95.
Alcides José Branco Filho William Kondo Luis Sérgio Nassif Mariana Jorge Garcia Rafael de Almeida Tirapelle Carlos Marcelo Dotti 《JSLS, Journal of the Society of Laparoendoscopic Surgeons》2006,10(3):326-331
BACKGROUND: Gastrogastric fistula is a communication between the proximal gastric pouch and the distal gastric remnant, rarely described in the realm of bariatric procedures. The aim of this study was to review the existing literature about this topic and to demonstrate its laparoscopic treatment. METHODS: An extensive literature review found several articles reporting this complication. However, no citation was found describing the steps of the laparoscopic management of this situation. RESULTS: Gastrogastric fistula occurs in up to 6% of Roux-en-Y gastric bypasses. Two theories exist for fistula formation: (1) it is a technical complication derived from the incomplete division of the stomach during the creation of the pouch, and (2) it occurs after a staple-line failure, developing a leak with an abscess, which then drains into the distal stomach forming the fistula. Early symptoms include fever, tachycardia, and abdominal pain. Failure in weight loss is a late clinical sign observed in these patients. Diagnosis is based on radiologic study, upper endoscopy and computed tomography. When identified in the acute postoperative course, laparoscopic treatment is easy. Chronic fistulas are difficult to manage, and the laparoscopic approach is an alternative to open surgery. CONCLUSIONS: Gastrogastric fistula is a possible complication of Roux-en-Y gastric bypass and its laparoscopic treatment is feasible. 相似文献
96.
97.
98.
99.
100.
Birgitta Malmberg Göran Kecklund Björn Karlson Roger Persson Per Flisberg Palle Ørbaek 《BMC health services research》2010,10(1):239