全文获取类型
收费全文 | 6600篇 |
免费 | 280篇 |
国内免费 | 59篇 |
专业分类
耳鼻咽喉 | 50篇 |
儿科学 | 138篇 |
妇产科学 | 20篇 |
基础医学 | 233篇 |
口腔科学 | 18篇 |
临床医学 | 709篇 |
内科学 | 502篇 |
皮肤病学 | 3篇 |
神经病学 | 2284篇 |
特种医学 | 633篇 |
外科学 | 560篇 |
综合类 | 912篇 |
预防医学 | 184篇 |
眼科学 | 34篇 |
药学 | 481篇 |
1篇 | |
中国医学 | 52篇 |
肿瘤学 | 125篇 |
出版年
2023年 | 51篇 |
2022年 | 214篇 |
2021年 | 245篇 |
2020年 | 203篇 |
2019年 | 155篇 |
2018年 | 168篇 |
2017年 | 210篇 |
2016年 | 246篇 |
2015年 | 216篇 |
2014年 | 417篇 |
2013年 | 419篇 |
2012年 | 424篇 |
2011年 | 459篇 |
2010年 | 399篇 |
2009年 | 383篇 |
2008年 | 345篇 |
2007年 | 325篇 |
2006年 | 304篇 |
2005年 | 268篇 |
2004年 | 210篇 |
2003年 | 136篇 |
2002年 | 96篇 |
2001年 | 106篇 |
2000年 | 95篇 |
1999年 | 77篇 |
1998年 | 63篇 |
1997年 | 51篇 |
1996年 | 53篇 |
1995年 | 51篇 |
1994年 | 46篇 |
1993年 | 32篇 |
1992年 | 35篇 |
1991年 | 30篇 |
1990年 | 39篇 |
1989年 | 25篇 |
1988年 | 41篇 |
1987年 | 31篇 |
1986年 | 25篇 |
1985年 | 44篇 |
1984年 | 41篇 |
1983年 | 12篇 |
1982年 | 22篇 |
1981年 | 18篇 |
1980年 | 18篇 |
1979年 | 25篇 |
1978年 | 14篇 |
1977年 | 10篇 |
1976年 | 10篇 |
1974年 | 6篇 |
1972年 | 7篇 |
排序方式: 共有6939条查询结果,搜索用时 0 毫秒
41.
R. Pontes F. Junqueira M. Paiva M. Ferreira N. Oliveira V. Costa 《Revista espa?ola de anestesiología y reanimación》2021,68(2):103-106
Intracranial subdural hematoma is a rare, but potentially lethal complication of neuraxial procedures. Considering the high frequency of neuraxial techniques in the obstetric population, parturients are more susceptible to this fearful complication. The diagnosis is often masked and delayed because it shares similar clinical characteristics with posdural puncture headache, with headache being the most common symptom. This case report describes a timely diagnosis and successful management of an intracranial subdural hematoma, after unintentional dural puncture during labour epidural analgesia. Postpartum headache following epidural analgesia, remains a clinical challenge for the caring team, requiring a close follow-up and awareness for non-benign causes that require prompt management, avoiding devastating consequences. 相似文献
42.
IntroductionThe recurrent laryngeal nerve (RLN) originates from the Vagus nerve intrathoracically. It passes through the tracheoesophageal groove (TEG) in the neck and different variations in this section were observed. The RLN is at highest risk for injury during the thyroid surgery. Therefore, it is important to know variations to decrease the injury effectively.Presentation of caseA 50 years-old woman with no thyroid related complaints except for enlargement of the thyroid gland in recent 12-months that annoyed her during neck movement and for aesthetic features. Medical, surgical, drugs, irradiation history, laboratory data, and physical examination was unremarkable except for multi-lobulated enlarged thyroid gland. The CT scanning study revealed intrathoracic extension of the gland. Patient underwent total thyroidectomy with suspicious diagnosis of multinodular goiter which was confirmed later by pathologic study. Intraoperative exploration of the right RLN discovered an intracranial branch originating from the recurrent laryngeal trunk just beneath the inferior thyroid artery (ITA) at the level of the nerve intersection. The branch then passed laterally about 1 cm and penetrated in ipsilateral carotid sheath.DiscussionThe RLN has different anatomical variations in either the right or the left side of the neck. However extra-laryngeal nerve branching is the most common variation but other seldom variations including the non-RLN, and intracranial branch should be mentioned by surgeon intraoperatively.ConclusionTo decrease iatrogenic injuries to RLN and its associated nerve branches knowledge of the nerve anatomy is mandatory for surgeon to prevent morbid side effects. 相似文献
43.
Barbiturates are used clinically as anaesthetics and to reduce raised intracranial pressure. One side effect is hypotension, usually ascribed to a depression of cardiac contractility, while their effects on the resistance vessels are more controversial: both vasodilation and vasoconstriction have been described. This study analyzes the effects of thiopental on basal vascular tone in the cat skeletal muscle. We found that total resistance increased by almost 20% at low (50mol/l) and decreased down to about 50% of control at high (350 mol/l) plasma concentrations of thiopental. The vasoconstriction dominated in the large arterioles (i.d. >25 m) and the vasodilation in the small arterioles (i.d. <25 m). A dosedependent inhibition of myogenic vascular reactivity (here defined as the maximum resistance increase to a transient rise in transmural pressure) coincided with the vasodilation. Autoregulation of blood flow was depressed by thiopental. During vasoconstriction there was a net transcapillary fluid absorption and during vasodilation a net fluid filtration. The fluid movements could be ascribed to variations in capillary hydrostatic pressure. If applicable to the cerebral circulation these results suggest that thiopental at high plasma concentrations might induce, instead of reduce, interstitial brain oedema. 相似文献
44.
E. Herting O. Gefeller Ch. P. Speer K. Harms H. L. Halliday T. Curstedt B. Robertson 《European journal of pediatrics》1994,153(11):842-849
Within a randomized European multicentre trial the time of onset, severity and progression of intracerebral haemorrhages (ICH) were investigated prospectively by serial cranial ultrasonography in 343 ventilated infants with severe respiratory distress syndrome (RDS) following instillation of single or multiple doses of a natural porcine surfactant (Curosurf). In 148/343 infants (43%) ICH was diagnosed (grade I or II: 22%, grade III or IV: 21%). In 26 cases (8%) ICH was present on the ultrasound scan prior to surfactant instillation at a median age of 6h. Incidence and severity of ICH was similar after single- or multiple-dose surfactant treatment. Using a logistic regression model the following risk factors predictive of ICH were defined: low birth weight, allocation to certain hospitals, vaginal delivery, Apgar score6, rectal temperature on admission 36°C, primary anaemia, acidosis prior to treatment, RDS grade IV in pre-treatment chest films and poor response to surfactant treatmentOur study provides supportive evidence that multiple doses of Curosurf do not increase the risk for ICH as compared to single-dose administration.A preliminary report of this work was presented at 8th International Workshop on Surfactant Replacement, Oslo, Norway, May 21 1993. The study was supported by grants of the German government (BMFT 93 607 27) and the German Research Council (Deutsche Forschungsgemeinschaft He 2072: 1–2). The surfactant used in the trial was prepared ang tested in Stockholm with the skilful technical assistance of Elin Arvesen, Bim Linderholm. Eva Lundberg, Gunhild Nilsson and Petru Popa (supported by the Swedish Medical Research Council (Project No. 3351) and Oscar II:s Jubileumsfond)Dedicated to the memory of Edgar (Eddi) Laufkötter, one of the most active trial collaborators, who died under tragic circumstances on April 10, 1994. 相似文献
45.
Moyamoya病发生、发展及转归实验研究 总被引:4,自引:2,他引:2
目的研究Moyamoya病的发生、发展及转归过程。方法建立Moyamoya病的实验动物模型。结果颈动脉逐渐狭窄或闭塞的过程是内弹力纤维变性、断裂后,中膜平滑肌细胞沿断裂处向内膜游走、深入增生的过程。早期,因侧支循环血管建立不完善,脑组织缺血、缺氧出现多灶性脑软化坏死。随时间延长,脑内大量小动脉及毛细血管代偿性增生,其血管壁腔大壁薄,形成异网。同时5个粟粒状或囊状动脉瘤.蛛网膜下腔、脑室内及脑实质内有小的出血灶。结论Moyamoya病临床表现早期以缺血性脑血管病为主,后期以出血性脑血管病为主,是由Moyamoya病理的演变过程所决定的,是疾病的发展规律。 相似文献
46.
P. W. Hanlo R. H. J. M. Gooskens J. A. J. Faber R. J. A. Peters A. A. M. Nijhuis W. P. Vandertop C. A. F. Tulleken J. Willemse 《Child's nervous system》1996,12(4):200-209
The treatment of choice in progressive hydrocephalus is drainage of cerebrospinal fluid in order to reduce elevated intracranial pressure (ICP). Defining the right moment for surgical intervention, however, in a hydrocephalic infant on the basis of clinical signs alone can be a difficult task. Clinical signs of raised ICP are known to be unreliable and sometimes even misleading. In the present study, the relationship between long-term anterior fontanelle pressure (AFP) measurements and clinical signs was investigated in 37 infants with hydrocephalus. The decision as to whether to operate or not was based on clinical signs alone; AFP values were not taken into account. There was an overall difference between the non-operated group and the preoperative measurements in the operated group, and also between the preoperative and the postoperative measurements in the latter, in regard to both AFP measurements and clinical signs. Almost all preoperative AFP values were increased. The direct correlation () between most individual clinical signs and AFP levels, however, was low (=0.15–0.41). The clinical sign tense fontanelle showed the best correlation with the AFP levels (=0.75). Furthermore, using logistic regression analysis, no combination of clinical signs could be found which reliably predicted the AFP. The relationship between the AFP pressure variables and clinical signs was also examined. The pathological A-waves occurred only in the presence of raised (baseline) AFP, a situation in which considerably more frequent B-waves were observed as well. It was concluded that clinical signs of raised ICP in infantile hydrocephalus are not very reliable and AFP monitoring can therefore provide valuable information on intracranial dynamics in patients with dubious neurological manifestations of progressive hydrocephalus. 相似文献
47.
Oh Kee Kwon Kyu-Chang Wang Chong Jai Kim In-One Kim Je G. Chi Byung-Kyu Cho 《Child's nervous system》1996,12(10):633-636
Primary spinal cord primitive neuroectodermal tumor (PNET) is a rare entity. In all, 13 cases have been reported in the literature, including 3 with intracranial seeding. A 3-month-old girl with involvement of the spinal cord below the mid-thoracic level is described. The brain MRI revealed findings indicative of seeding along the intracranial subarachnoid space. Biopsy, duraplasty and removal of laminotomy flap were done. In spite of a good response to the first cycle of postoperative 8-drugs-in-a-day chemotherapy, further treatment was refused. She died 21 days after the onset of leg weakness, which reveals the rapid progression of untreated cases. To our knowledge, this is the first case of spinal cord PNET with parenchymal involvement that has been described in an infant. 相似文献
48.
Summary In patients with severe brain lesions monitoring of the intracranial pressure as well as monitoring of cerebral blood flow can be of clinical value. While at the moment there is no atraumatic method for measuring cerebral blood flow in man, it is recommended to measure blood flow velocity with the ultrasound Doppler technic in the common carotid artery. On theoretical grounds a positive correlation between cerebral blood flow and blood flow velocity can be expected and the observations presented show that such a correlation exists in normal controls and in neurological patients. In many neurological patients the flow velocity in the common carotid artery decreases with increasing intracranial pressure. This suggests that the autoregulation is disturbed. The demonstration of such a disturbance can have clinical implications.
Zusammenfassung Bei Patienten mit ernsten Läsionen im Gehirn kann Monitoring von sowohl intercraniellem Druck als auch der zerebralen Blutdurchströmung für die Klinik von Bedeutung sein. Da im Moment keine atraumatische Methode für die Messung der zerebralen Blutdurchströmung besteht, wird anempfohlen, die Durchströmungsgeschwindigkeit mit der Ultraschall-Doppler-Technik in der Arteria carotis communis zu messen. Theoretisch kann eine positive Korrelation zwischen der zerebralen Blutdurchströmung und der Strömungsgeschwindigkeit erwartet werden.Die beschriebenen Ergebnisse zeigen, daß tatsächlich ein solcher Zusammenhang besteht, sowohl bei gesunden Versuchspersonen als auch bei neurologischen Patienten.Bei vielen dieser Patienten nimmt die Durchströmungsgeschwindigkeit in der Arteria carotis communis ab bei einer Zunahme des intracraniellen Druckes. Dies suggeriert eine gestörte Autoregulation. Das Aufzeigen einer solchen Störung kann klinische Bedeutung haben.相似文献
49.
Depression and anhedonia are two major symptoms of cocaine withdrawal in humans. Hence, pharmacological treatments effective in depression might also alleviate the symptoms of cocaine withdrawal. In the present study, the effects of acute and repeated administration of a tricyclic antidepressant, desmethylimipramine (DMI), were investigated in naive and cocaine-withdrawing rats. An animal model of cocaine withdrawal was used that employs the elevation in intracranial self-stimulation (ICSS) thresholds following the termination of prolonged periods of cocaine self-administration as a measure of an animal's anhedonic state. The influence of chronic DMI treatment on-adrenergic receptor binding and affinity was also correlated with the behavioral signs of cocaine withdrawal. Neither acute nor repeated DMI treatment influenced reward functions in rats that were not undergoing cocaine withdrawal. However, repeated DMI treatment significantly down-regulated-adrenergic receptors, and shortened the duration of the post-cocaine anhedonia (elevation in thresholds). Furthermore, the magnitude of the-adrenergic receptor down-regulation correlated significantly with the degree of effectiveness of DMI treatment in reversing the post-cocaine anhedonia. However, chronic DMI treatment did reduce the amount of cocaine self-administered by the animals. The reversal of the post-cocaine anhedonia in this animal model of cocaine withdrawal by chronic DMI treatment demonstrates the potential usefulness of the model in identifying new pharmacotherapies for cocaine withdrawal. In addition, the results indicate that tricyclic antidepressants may be able to ameliorate some of the symptoms of cocaine withdrawal. 相似文献
50.
Primary intracranial arachnoidal cysts 总被引:1,自引:1,他引:0
I. Pascual-Castroviejo M. C. Roche A. Martinez Bermejo J. Arcas M. Garcia Blazquez 《Child's nervous system》1991,7(5):257-263
Sixty-seven cases (41 males and 26 females) of arachnoidal cysts in children under 11 years are reported. About 53% of cases were diagnosed before 1 year of life. Thirty-one (42.2%) were supratentorial (interhemispheric 9, temporal fossa 10, convexity 5, sylvian fissure 3, supra- and/or retrosellar 4); 31 (46.2%) infratentorial (supra- and/or retrocerebellar 22, foramen of Magendie 3, quadrigeminal cistern 5, pontocerebellar 1); 5 (7.5%) supra-and infratentorial. Macrocephaly was the presenting symptom in 48 cases (71.5%). Associated features were frequent: cranial asymmetry in 24; aqueductal stenosis in 10; agenesis of corpus callosum in 8; deficient cerebellar lobullation in 4; Chiari I malformation in 2; neurofibromatosis type 1 with dysgenetic zones of the brain in 1; arteriovenous malformation in 1. Diagnosis was made at autopsy in six cases in the days before computed tomography and magnetic resonance: three patients had a cyst in the supra-and retrocerebellar midline; two had a cyst in the quadrigeminal cistern and the sixth was a rare case with the cyst passing from the posterior fossa to the left lateral ventricle through a hole in the basal surface of the brain. Small and some middle-sized cysts were not treated. Big and some middle-sized cysts were usually treated by cysto- and/or ventriculoperitoneal shunts. Arachnoidal cysts of the quadrigeminal cistern usually present with aqueductal stenosis and have to be treated with ventriculoperitoneal shunt. Craniotomy and fenestration of the cysts were performed in some cases with good results. The average mental level of these children is usually moderately low. 相似文献