全文获取类型
收费全文 | 2604篇 |
免费 | 261篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 42篇 |
妇产科学 | 80篇 |
基础医学 | 360篇 |
口腔科学 | 49篇 |
临床医学 | 277篇 |
内科学 | 599篇 |
皮肤病学 | 8篇 |
神经病学 | 444篇 |
特种医学 | 78篇 |
外科学 | 327篇 |
综合类 | 25篇 |
预防医学 | 151篇 |
眼科学 | 79篇 |
药学 | 178篇 |
中国医学 | 2篇 |
肿瘤学 | 180篇 |
出版年
2023年 | 18篇 |
2022年 | 22篇 |
2021年 | 64篇 |
2020年 | 44篇 |
2019年 | 52篇 |
2018年 | 58篇 |
2017年 | 49篇 |
2016年 | 57篇 |
2015年 | 62篇 |
2014年 | 92篇 |
2013年 | 130篇 |
2012年 | 214篇 |
2011年 | 189篇 |
2010年 | 96篇 |
2009年 | 91篇 |
2008年 | 163篇 |
2007年 | 141篇 |
2006年 | 174篇 |
2005年 | 156篇 |
2004年 | 182篇 |
2003年 | 155篇 |
2002年 | 104篇 |
2001年 | 47篇 |
2000年 | 28篇 |
1999年 | 44篇 |
1998年 | 28篇 |
1997年 | 25篇 |
1996年 | 20篇 |
1995年 | 16篇 |
1994年 | 15篇 |
1993年 | 12篇 |
1992年 | 20篇 |
1991年 | 15篇 |
1990年 | 12篇 |
1989年 | 22篇 |
1988年 | 19篇 |
1987年 | 22篇 |
1986年 | 24篇 |
1985年 | 18篇 |
1984年 | 23篇 |
1983年 | 12篇 |
1982年 | 10篇 |
1981年 | 12篇 |
1980年 | 11篇 |
1979年 | 12篇 |
1978年 | 9篇 |
1976年 | 10篇 |
1975年 | 10篇 |
1974年 | 16篇 |
1971年 | 8篇 |
排序方式: 共有2887条查询结果,搜索用时 31 毫秒
1.
Clinical Spectrum of Capillary Malformation–Arteriovenous Malformation Syndrome Presenting to a Pediatric Dermatology Practice: A Retrospective Study
下载免费PDF全文
![点击此处可从《Pediatric dermatology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Nicole A. Weitz M.D. Christine T. Lauren M.D. Gerald G. Behr M.D. June K. Wu M.D. Jessica J. Kandel M.D. Philip M. Meyers M.D. Sally Sultan M.D. Kwame Anyane‐Yeboa M.D. Kimberly D. Morel M.D. Maria C. Garzon M.D. 《Pediatric dermatology》2015,32(1):76-84
Capillary malformation–arteriovenous malformation syndrome (CM‐AVM) is an autosomal dominant disorder caused by RASA1 mutations. The prevalence and phenotypic spectrum are unknown. Evaluation of patients with multiple CMs is challenging because associated AVMs can be life threatening. The objective of this study was to describe the clinical characteristics of children presenting with features of CM‐AVM to an academic pediatric dermatology practice. After institutional review board approval was received, a retrospective chart review was performed of patients presenting between 2009 and 2012 with features of CM‐AVM. We report nine cases. Presenting symptoms ranged from extensive vascular stains and cardiac failure to CMs noted incidentally during routine skin examination. All demonstrated multiple CMs, two had Parkes Weber syndrome, and two had multiple infantile hemangiomas. Seven patients had family histories of multiple CMs; three had family histories of large, atypical CMs. Six had personal or family histories of AVMs. Genetic evaluation was recommended for all and was pursued by six families; four RASA1 mutations were identified, including one de novo. Consultations with neurology, cardiology, and orthopedics were recommended. Most patients (89%) have not required treatment to date. CM‐AVM is an underrecognized condition with a wide clinical spectrum that often presents in childhood. Further evaluation may be indicated in patients with multiple CMs. This study is limited by its small and retrospective nature. 相似文献
2.
Edbert B Hsu Tamara L Thomas Eric B Bass Dianne Whyne Gabor D Kelen Gary B Green 《BMC medical education》2006,6(1):19-9
Background
Although training and education have long been accepted as integral to disaster preparedness, many currently taught practices are neither evidence-based nor standardized. The need for effective evidence-based disaster training of healthcare staff at all levels, including the development of standards and guidelines for training in the multi-disciplinary health response to major events, has been designated by the disaster response community as a high priority. We describe the application of systematic evidence-based consensus building methods to derive educational competencies and objectives in criteria-based preparedness and response relevant to all hospital healthcare workers. 相似文献3.
Philippe Cattin Hitendu Dave Jürg Grünenfelder Gabor Szekely Marko Turina Gregor Zünd 《European journal of cardio-thoracic surgery》2004,25(5):786-790
OBJECTIVES: To characterize remaining coronary artery motion of beating pig hearts after stabilization with an 'Octopus' using an optical remote analysis technique. METHODS: Three pigs (40, 60 and 65 kg) underwent full sternotomy after receiving general anesthesia. An 8-bit high speed black and white video camera (50 frames/s) coupled with a laser sensor (60 microm resolution) were used to capture heart wall motion in all three dimensions. Dopamine infusion was used to deliberately modulate cardiac contractility. Synchronized ECG, blood pressure, airway pressure and video data of the region around the first branching point of the left anterior descending (LAD) coronary artery after Octopus stabilization were captured for stretches of 8 s each. Several sequences of the same region were captured over a period of several minutes. Computerized off-line analysis allowed us to perform minute characterization of the heart wall motion. RESULTS: The movement of the points of interest on the LAD ranged from 0.22 to 0.81 mm in the lateral plane (x/y-axis) and 0.5-2.6 mm out of the plane (z-axis). Fast excursions (>50 microm/s in the lateral plane) occurred corresponding to the QRS complex and the T wave; while slow excursion phases (<50 microm/s in the lateral plane) were observed during the P wave and the ST segment. The trajectories of the points of interest during consecutive cardiac cycles as well as during cardiac cycles minutes apart remained comparable (the differences were negligible), provided the hemodynamics remained stable. Inotrope-induced changes in cardiac contractility influenced not only the maximum excursion, but also the shape of the trajectory. Normal positive pressure ventilation displacing the heart in the thoracic cage was evident by the displacement of the reference point of the trajectory. CONCLUSIONS: The movement of the coronary artery after stabilization appears to be still significant. Minute characterization of the trajectory of motion could provide the substrate for achieving motion cancellation for existing robotic systems. Velocity plots could also help improve gated cardiac imaging. 相似文献
4.
Jean-yves Gillon Pierre-Alain Vitte Francoise Lemonnier Gabor Kato 《Drug development research》1994,32(1):42-49
Medifoxamine, an antidepressant agent which has an original chemical structure, has been shown through in vitro studies, utilising radioligand binding in tissue homogenates, to bind with moderately high affinity to 5-HT1c and 5-HT2 receptor subtypes and to 5-HT uptake sites (IC50 950, 980, and 1,500 nM, respectively). It has been shown to bind in vivo to rat brain 5-HT2 receptors after acute treatment with high dose (50 mg/kg, i.e., 133.9 μmol/kg). After 14 days continuous treatment with low dose (20 mg/kg, 53.6 μmol/kg), a decrease in the capacity of [3H]-5-HT uptake and a dose-dependent down-regulation of 5-HT2 receptors in rat cerebral cortex were observed. These results indicate that medifoxamine, which has been shown previously to act through dopaminergic systems, interacts also with central serotonergic neurotransmission and particularly with the 5-HT2 receptors, which could contribute to its antidepressant effect. 相似文献
5.
Sabine Elisabeth Gabor Heiko Renner Alfred Maier Freyja Maria Smolle Jüttner 《European journal of cardio-thoracic surgery》2005,28(3):502-503
A 21-year-old female with chronic membranoproliferative nephritis was admitted for suspected esophageal disruption and asthma after severe, prolonged vomiting. At the time of admission she presented with dyspnea, tachypnea, arterial hypotension and tachycardia. Physical examination showed discrete signs of ectopic air at the neck and distended cervical veins. CT-scan of the chest showed severe mediastinal emphysema with compression of the right atrium. After cervical mediastinotomy the cardiorespiratory parameters normalized immediately. Esophagoscopy showed multiple longitudinal mucosal tears between 25 and 45 cm; fluoroscopically, there was no leakage of contrast medium. Following conservative treatment the patient recovered completely and was discharged on day 8. 相似文献
6.
S Gabor M Woltsche A Maier F M Smolle-Jüttner 《European journal of cardio-thoracic surgery》2003,23(1):131-133
A 88-year-old male patient presented with fever, singultus and retrosternal pain. After 8 days of antibiotic therapy not resulting in clinical improvement, he suddenly developed a pneumopericardium. Contrast swallow and endoscopy showed intrapericardial perforation of a benign gastric ulcer. Excision of the ulcer and suturing of both the stomach and the diaphragm as well as lavage of the pericardium were done over a left thoracotomy. The patient recovered uneventfully. 相似文献
7.
Activity-dependent facilitation is a mechanism of associative synaptic plasticity that contributes to classical conditioning in Aplysia. Previous studies of activity-dependent facilitation in the mechanosensory neurons of Aplysia suggested that the Ca2+ influx during paired spike activity enhances the transmitter-stimulated, cAMP-dependent, presynaptic facilitation in these cells. Moreover, paired activity was found to potentiate the activation of the adenylate cyclase by transmitter. It was therefore proposed that the Ca2+/calmodulin-sensitive cyclase may serve as a site of interaction between the inputs from the conditioned and unconditioned stimuli. These studies were carried out to test whether a Ca2+/calmodulin-sensitive adenylate cyclase in the Aplysia CNS has the properties necessary to mediate such an associative interaction. Three lines of evidence indicate that the same cyclase molecules that are sensitive to Ca2+/calmodulin are also stimulated by receptor to facilitatory transmitter via the stimulatory G-protein, Gs: First, calmodulin inhibitors reduced stimulation of the cyclase by facilitatory transmitter. When membranes had been preexposed to one of these inhibitors, trifluoperazine, the addition of exogenous calmodulin partially reversed the inhibition. Second, when Gs had been activated by GTP gamma S, so that it persistently activated the catalytic unit of the cyclase, stimulation of the cyclase by Ca2+ was greatly amplified, suggesting that the two inputs interact in activating a common population of the enzyme. Third, solubilized cyclase activity that bound to calmodulin-Sepharose in a Ca(2+)-dependent manner was stimulated by Gs, which had been partially purified from Aplysia CNS, as well as by Ca2+/calmodulin. Having demonstrated dual activation of the cyclase, we have explored the dependence of cyclase activation on the temporal pattern of Ca2+ and transmitter addition. Optimal activation required that a pulse of Ca2+ temporally overlap the addition of facilitatory transmitter. These several results suggested that the dually regulated adenylate cyclase might underlie the temporal requirements for effective classical conditioning in this system. 相似文献
8.
9.
Selective elimination of mRNAs in vivo: complementary oligodeoxynucleotides promote RNA degradation by an RNase H-like activity. 总被引:29,自引:11,他引:18
下载免费PDF全文
![点击此处可从《Proceedings of the National Academy of Sciences of the United States of America》网站下载免费的PDF全文](/ch/ext_images/free.gif)
P Dash I Lotan M Knapp E R Kandel P Goelet 《Proceedings of the National Academy of Sciences of the United States of America》1987,84(22):7896-7900
Oligodeoxynucleotides lead to translation arrest of complementary mRNAs in the wheat germ translation system by a degradation of the mRNA. In an attempt to develop an effective reverse genetic approach in vivo, we demonstrate that injection of short (15- to 30-nucleotide) oligonucleotides into Xenopus oocytes leads to complete degradation of both injected and endogenous mRNAs by means of an RNase H-like activity. 相似文献
10.