全文获取类型
收费全文 | 21976篇 |
免费 | 1366篇 |
国内免费 | 129篇 |
专业分类
耳鼻咽喉 | 201篇 |
儿科学 | 577篇 |
妇产科学 | 550篇 |
基础医学 | 3459篇 |
口腔科学 | 331篇 |
临床医学 | 1796篇 |
内科学 | 5540篇 |
皮肤病学 | 550篇 |
神经病学 | 2441篇 |
特种医学 | 464篇 |
外科学 | 1954篇 |
综合类 | 83篇 |
一般理论 | 11篇 |
预防医学 | 1676篇 |
眼科学 | 434篇 |
药学 | 1513篇 |
中国医学 | 54篇 |
肿瘤学 | 1837篇 |
出版年
2024年 | 32篇 |
2023年 | 276篇 |
2022年 | 617篇 |
2021年 | 978篇 |
2020年 | 497篇 |
2019年 | 770篇 |
2018年 | 801篇 |
2017年 | 610篇 |
2016年 | 694篇 |
2015年 | 742篇 |
2014年 | 1018篇 |
2013年 | 1170篇 |
2012年 | 1807篇 |
2011年 | 1869篇 |
2010年 | 1034篇 |
2009年 | 932篇 |
2008年 | 1458篇 |
2007年 | 1483篇 |
2006年 | 1366篇 |
2005年 | 1260篇 |
2004年 | 1078篇 |
2003年 | 995篇 |
2002年 | 834篇 |
2001年 | 92篇 |
2000年 | 58篇 |
1999年 | 120篇 |
1998年 | 148篇 |
1997年 | 112篇 |
1996年 | 86篇 |
1995年 | 79篇 |
1994年 | 48篇 |
1993年 | 50篇 |
1992年 | 37篇 |
1991年 | 26篇 |
1990年 | 32篇 |
1989年 | 27篇 |
1988年 | 20篇 |
1987年 | 24篇 |
1986年 | 26篇 |
1985年 | 15篇 |
1984年 | 10篇 |
1983年 | 14篇 |
1982年 | 13篇 |
1981年 | 16篇 |
1980年 | 15篇 |
1978年 | 7篇 |
1975年 | 8篇 |
1974年 | 6篇 |
1971年 | 9篇 |
1966年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 21 毫秒
31.
32.
A. J. Lawrence Elena Krstew Bevyn Jarrott 《Naunyn-Schmiedeberg's archives of pharmacology》1997,355(2):303-308
The present study has employed in vitro electrophysiology and radioligand binding assays to determine whether dopamine and
adenosine receptors interact with each other on rat vagal afferent neurons. Preincubation of the isolated rat nodose ganglion
with the adenosine A2a agonists CGS 21680 or DPMA (Both 1 μM) resulted in a functional antagonism of the ability of dopamine to depolarise the preparation.
Specifically, the concentration-response curve to dopamine was significantly shifted to the right in the presence of CGS 21680
and DPMA. On the other hand, adenosine itself, A1 and A3 receptor agonists and ATP were all incapable of modulating the electrophysiological response to dopamine. In contrast to
the nodose ganglion, CGS 21680 did not significantly affect the ability of the dopamine D2 ligands quinpirole or raclopride to displace [125I]NCQ298 binding to dopamine D2 receptors in membranes prepared from rat dorsal brain stem. These data indicate the presence of an interaction between high
affinity adenosine A2 receptors and dopamine D2 receptors on the soma of rat vagal afferent neurons, whereas the situation in the brain stem remains less clear.
Received: 17 September 1996 / Accepted: 20 October 1996 相似文献
33.
Acute psychotropic effects of bilateral subthalamic nucleus stimulation and levodopa in Parkinson's disease. 总被引:9,自引:0,他引:9
Aurélie Funkiewiez Claire Ardouin Paul Krack Valérie Fraix Nadège Van Blercom Jing Xie Elena Moro Alim-Louis Benabid Pierre Pollak 《Movement disorders》2003,18(5):524-530
High-frequency deep brain stimulation (DBS) of the subthalamic nucleus (STN) improves the motor symptoms of Parkinson's disease (PD). Opposite changes in mood, such as mania or depression, have been reported after surgery, but it is not known whether these side effects are specifically related to STN DBS. To learn whether STN DBS also influences the limbic loop, we investigated acute subjective psychotropic effects related to levodopa or bilateral STN DBS. After a median postoperative follow-up of 12 months, 50 PD patients completed the Addiction Research Center Inventory (ARCI), assessing subjective psychotropic effects in four conditions: off-drug/on-stimulation; off-drug/off-stimulation; on-drug/off-stimulation; and on-drug/on-stimulation. Both levodopa and STN DBS improved all the ARCI subscales, indicating subjective feelings of well being, euphoria, increase in motivation, and decrease in fatigue, anxiety, and tension. A suprathreshold dose of levodopa was significantly more effective than STN DBS, using the same electrical parameters as for chronic stimulation, on four of the five ARCI subscales. We concluded that 1) both STN DBS and levodopa have synergistic acute beneficial psychotropic effects in PD, 2) the psychotropic effects of both treatments need to be considered in the long-term management of chronic STN DBS, and 3) the results indicate an involvement of the limbic STN in mood disorders of PD. 相似文献
34.
Kaija Mikkola Elena Kushnerenko Eino Partanen Silve Serenius-Sirve Jaana Leip?l? Minna Huotilainen Vineta Fellman 《Clinical neurophysiology》2007,118(7):1494-1502
OBJECTIVE: In our previous study, auditory event-related potentials (AERPs) in preterm 1-year-old children had a positive deflection at 150-350 ms that correlated positively with their 2-year neurodevelopmental outcome. In a study of the same subjects at age 5, our aim was to assess AERPs and their relationship to neuropsychological test results. METHODS: Preterm small (SGA, n=13), appropriate for gestational age (AGA, n=15), and control (n=13) children were assessed with an Easy paradigm presenting a large frequency change accompanied with occasional novel sounds, and a Challenging paradigm presenting small frequency and duration changes with a rapid rate. The preterm children underwent neurocognitive tests. RESULTS: Easy paradigm. The P1 response to frequency deviant was smaller and MMN larger in the preterm than in the control children. Challenging paradigm. The P1 response to standard, frequency, and duration deviants was smaller in the preterm than in the control children. The N2 response to frequency deviant was larger in the preterm than in the control children. AGA and SGA children had similar AERPs. The P1, N2, and MMN amplitudes correlated with verbal IQ and NEPSY language subtests. CONCLUSIONS: Small P1 response(s) appears to be typical for preterm children. SIGNIFICANCE: Small P1 response in preterm children may suggest altered primary auditory processing. 相似文献
35.
Caroline F Rowland Julian M Pine Elena V M Lieven Anna L Theakston 《J. Speech Lang. Hear. Res.》2005,48(2):384-404
Many current generativist theorists suggest that young children possess the grammatical principles of inversion required for question formation but make errors because they find it difficult to learn language-specific rules about how inversion applies. The present study analyzed longitudinal spontaneous sampled data from twelve 2-3-year-old English speaking children and the intensive diary data of 1 child (age 2;7 [years;months] to 2;11) in order to test some of these theories. The results indicated significantly different rates of error use across different auxiliaries. In particular, error rates differed across 2 forms of the same auxiliary subtype (e.g., auxiliary is vs. are), and auxiliary DO and modal auxiliaries attracted significantly higher rates of errors of inversion than other auxiliaries. The authors concluded that current generativist theories might have problems explaining the patterning of errors seen in children's questions, which might be more consistent with a constructivist account of development. However, constructivists need to devise more precise predictions in order to fully explain the acquisition of questions. 相似文献
36.
37.
Nontraumatic intracerebral hemorrhage in young adults 总被引:3,自引:0,他引:3
We reviewed our experience with 72 patients, aged 15 to 45 years, who were hospitalized for nontraumatic intracerebral hemorrhages (ICHs) between 1978 and 1985. Evaluation included arteriography in 61 patients. Computed tomography demonstrated 41 lobar, 11 putaminal, four thalamic, four pontine, four intraventricular, two caudate, two midbrain, two cerebellar, one globus pallidum, and one corpus callosum hemorrhage. Forty-three patients, with either progressive neurologic deterioration, arteriovenous malformations (AVMs), or saccular aneurysms underwent surgery. The overall in-hospital survival, including those patients treated medically, was 87.5%. A presumed cause for the ICH was found in 55 (76.4%) patients. The main causes were ruptured arteriovenous malformations (21), hypertension (11), ruptured saccular aneurysms (seven), and sympathomimetic drug abuse (five). Surgical explorations demonstrated a necrotizing angiitis in one patient and arteriovenous malformations in two patients who had negative arteriograms. Young patients with nontraumatic ICHs represent a heterogeneous group. A cause can be established in most patients. Arteriovenous malformations account for less than one third of the hemorrhages in young adults, and other causes should be sought. 相似文献
38.
Vincenzo De Giorgi MD Daniela Massi MD Elisa Trez MD Camilla Salvini MD Elena Quercioli MD Paolo Carli MD 《Dermatologic surgery》2003,29(9):965-967
In dermoscopy, the correct recognition of the single parameters is fundamental to achieve great diagnostic accuracy, but the scarce morphologic expression of a parameter may lead to diagnostic errors. We report the case of a 27-year-old white man presenting a pigmented lesion of the back, which was present since puberty. Clinical examination revealed on the back the presence of a flat, gray-blue lesion and at the periphery a small dark-brown papule. An assessment of the lesion by means of dermoscopy was performed. The purpose of this report was to analyze the Blue Hue in dermoscopy with its histopathologic correlates, starting with the discussion of a clinical case. 相似文献
39.
40.
Nadejda Lermontova Nikolai Lukoyanov Tatyana Serkova Elena Lukoyanova Sergei Bachurin 《Molecular and chemical neuropathology / sponsored by the International Society for Neurochemistry and the World Federation of Neurology and research groups on neurochemistry and cerebrospinal fluid》1998,33(1):51-61
Effects of tacrine (1,2,3,4-tetrahydro-9-aminoacridine) on memory deficits in rats treated with ethylcholine aziridinium ion (AF64A) were studied using active avoidance test in the two-way shuttle box. Neurotoxin AF64A injected at a dose of 6 nmol (icv, bilaterally) causes nonspecific tissue damage in hippocampal fields CA2 and CA3. Two weeks after treatment with 6 nmol, AF64A active avoidance performance of toxin-treated rats was significantly deteriorated compared to vehicle-treated animals estimated in learning test (68±3.5 and 83±3.2% of correct responses, respectively;p<0.01) and in retention test (53±5 and 76±3.6%, respectively;p<0.01). Under these conditions, chronic treatment with tacrine at a daily dose of 1 mg/kg for 12–14 d reverses the effect of AF64A on the active avoidance performance both in learning (78±3.2%) and retention (72±4%) tests. It is supposed that behavioral effects of tacrine considerably depend on a severity of neurodegeneration in the hippocampus. 相似文献