全文获取类型
收费全文 | 1530篇 |
免费 | 96篇 |
国内免费 | 56篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 71篇 |
妇产科学 | 11篇 |
基础医学 | 181篇 |
口腔科学 | 25篇 |
临床医学 | 161篇 |
内科学 | 333篇 |
皮肤病学 | 51篇 |
神经病学 | 85篇 |
特种医学 | 321篇 |
外科学 | 114篇 |
综合类 | 27篇 |
一般理论 | 2篇 |
预防医学 | 75篇 |
眼科学 | 5篇 |
药学 | 144篇 |
中国医学 | 7篇 |
肿瘤学 | 67篇 |
出版年
2023年 | 4篇 |
2021年 | 13篇 |
2020年 | 10篇 |
2019年 | 10篇 |
2018年 | 23篇 |
2016年 | 7篇 |
2015年 | 15篇 |
2014年 | 20篇 |
2013年 | 59篇 |
2012年 | 36篇 |
2011年 | 32篇 |
2010年 | 43篇 |
2009年 | 69篇 |
2008年 | 28篇 |
2007年 | 67篇 |
2006年 | 41篇 |
2005年 | 37篇 |
2004年 | 26篇 |
2003年 | 30篇 |
2002年 | 29篇 |
2001年 | 34篇 |
2000年 | 40篇 |
1999年 | 39篇 |
1998年 | 80篇 |
1997年 | 86篇 |
1996年 | 107篇 |
1995年 | 62篇 |
1994年 | 63篇 |
1993年 | 58篇 |
1992年 | 24篇 |
1991年 | 28篇 |
1990年 | 35篇 |
1989年 | 58篇 |
1988年 | 48篇 |
1987年 | 45篇 |
1986年 | 52篇 |
1985年 | 47篇 |
1984年 | 16篇 |
1983年 | 18篇 |
1982年 | 14篇 |
1981年 | 13篇 |
1980年 | 13篇 |
1979年 | 12篇 |
1978年 | 20篇 |
1977年 | 15篇 |
1976年 | 13篇 |
1975年 | 14篇 |
1974年 | 6篇 |
1971年 | 4篇 |
1966年 | 3篇 |
排序方式: 共有1682条查询结果,搜索用时 31 毫秒
1.
Hypocretin/orexin selectively increases dopamine efflux within the prefrontal cortex: involvement of the ventral tegmental area. 总被引:4,自引:0,他引:4
Hypocretins (HCRTs) modulate a variety of behavioral and physiological processes, in part via interactions with multiple ascending modulatory systems. Further, HCRT efferents from the lateral hypothalamus innervate midbrain dopamine (DA) nuclei, and DA cell bodies express HCRT receptors. Combined, these observations suggest that HCRT may influence behavioral state and/or state-dependent processes via modulation of DA neurotransmission. The current studies used in vivo microdialysis in the unanesthetized rat to first characterize the effect of intracerebroventricular infusion of HCRT-1 (0.07, 0.7 nmol) on extracellular levels of DA within the prefrontal cortex (PFC) and nucleus accumbens (Acc). Electroencephalographic/electromyographic measures of sleep-wake state were collected along with select behavioral measures (eg locomotor activity, grooming). HCRT-1 dose-dependently increased PFC dialysate DA levels, and these increases were closely correlated with increases in time spent awake. In contrast, Acc DA levels were unaffected. Additional studies examined whether HCRT-1 acts directly within the ventral tegmental area (VTA) to selectively increase PFC DA efflux and modulate behavioral state. Unilateral infusion of HCRT-1 (0.1, 1.0 nmol) within the VTA increased PFC, but not Acc, DA levels. Importantly, intra-VTA infusion of HCRT-1 increased the time spent awake and grooming. Moreover, HCRT-induced increases in both time spent awake and time spent grooming were significantly correlated with post-infusion PFC DA levels. The current observations predict a prominent modulatory influence of HCRT on PFC-dependent cognitive and affective processes that results, in part, from actions within the VTA. Additionally, these observations suggest that the activation of VTA DA neurons contributes to the behavioral state-modulatory actions of HCRT. 相似文献
2.
3.
4.
The hypothesis that benzodiazepine-induced hyperphagia is due to a specific enhancement of the palatability of foods has been supported by previous ‘taste reactivity’ studies of affective (hedonic and aversive) reactions to taste palatability. Diazepam and chlordiazepoxide enhance hedonic reactions of rats (rhythmic tongue protrusions, etc.) to sweet tastes in a receptor-specific fashion. A role for brainstem circuits has been indicated by a previous demonstration of the persistence of the taste reactivity enhancement by diazepam after midbrain decerebration. The present study examined whether benzodiazepine brainstem receptors are the chief substrates for palatability enhancement even in intact brains. We compared the effectiveness of benzodiazepine microinjections to elicit feeding and enhance hedonic reactions when delivered into either the lateral ventricle (forebrain) or the fourth ventricle (brainstem) of rats. The results show diazepam is reliably more effective at eliciting feeding and enhancing positive hedonic reactions to oral sucrose when microinjections are made in the fourth ventricle than in the lateral ventricle. We conclude that brainstem neural systems containing benzodiazepine-GABA receptors are likely to be the chief substrates for benzodiazepine-induced palatability enhancement. 相似文献
5.
6.
Leonidas JC; Berdon WE; Valderrama E; Neveling U; Schuval S; Weiss SJ; Hilfer C; Godine L 《Radiology》1996,198(2):377
7.
The direct enhancement of positive palatability by chlordiazepoxide is antagonized by Ro 15-1788 and CGS 8216 总被引:1,自引:0,他引:1
In a previous study, it was found that positive, palatability-dependent consummatory reactions in rats to intraorally infused tastes were facilitated by chlordiazepoxide (10 mg/kg). In contrast, the rats' more neutral or aversive reactions to these tastes were not facilitated by chlordiazepoxide. This suggested that chlordiazepoxide might selectively enhance the positive palatability of tastes. This effect was replicated in the present experiment, and in addition, the benzodiazepine antagonists Ro 15-1788 and CGS 8216 were found to counteract the enhancement of positive ingestive reactions produced by chlordiazepoxide. These antagonist effects generally suggest that the benzodiazepine receptor complex may be involved in making tastes more palatable after chlordiazepoxide administration. 相似文献
8.
OBJECTIVE: To review the technique, indications, and common imaging findings regarding saline infusion sonohysterography. METHODS: The literature on saline infusion sonohysterography was reviewed. Pertinent images from our institution are presented to illustrate common imaging findings. RESULTS: From the literature review, we summarize the various clinical scenarios in which saline infusion sonohysterography is useful and give examples from our clinical practice. CONCLUSIONS: Saline infusion sonohysterography is a useful procedure for evaluation of endometrial and subendometrial abnormalities. 相似文献
9.
JC Sitek† M Loeb‡ JR Ronnevig¶ 《Journal of the European Academy of Dermatology and Venereology》2007,21(7):891-896
BACKGROUND: Since 1997, a number of trials have shown promising results in treating generalized vitiligo with narrowband ultraviolet B (UVB) both in adults and children. However, there is little knowledge concerning the duration and permanency of the treatment-induced repigmentation. OBJECTIVE: Our main objective was to perform a follow-up trial of successfully treated patients receiving narrowband UVB for generalized vitiligo. METHODS: We have investigated to what degree the treatment-induced repigmentation remains stable for up to 2 years post-treatment. We performed an initial open trial including 31 patients with generalized vitiligo. They received narrowband UVB thrice weekly for up to 12 months. Patients experiencing > 75% repigmentation were defined responders and were included in the follow-up trial. Responders were followed every 6 months for up to 2 years after cessation of treatment. We observed the pigmentation status and registered any changes indicating loss of pigmentation and relapse. RESULTS: Eleven of the 31 treated patients were included in the follow-up trial. Six patients had relapse and five patients had stable response 24 months after cessation of treatment. Four out of six relapses were within 6 months post-treatment. CONCLUSION: In our study population of 31 patients with generalized vitiligo, five patients (16%) experienced > 75% stable repigmentation 2 years after cessation of a treatment programme of up to 1 years narrowband UVB therapy. 相似文献
10.
Ongoing pregnancies after intracytoplasmic injection using cryopreserved testicular spermatozoa 总被引:4,自引:2,他引:2
Perraguin-Jayot S; Audebert A; Emperaire JC; Parneix I 《Human reproduction (Oxford, England)》1997,12(12):2706-2709
We report two clinical pregnancies occurring after intracytoplasmic sperm
injection (ICSI) using cryopreserved spermatozoa obtained from testicular
biopsy, made in two different infertility situations in our clinic. The
first patient showed a secretory azoospermia associated with elevated serum
follicular stimulating hormone (FSH) level and spermiogenesis maturation
arrest. The second patient was affected by azoospermia resulting from
bilateral epididymal obstruction. Spermatozoa present in the wet
preparation of testicular biopsy made on the day of scrotal exploration
were cryopreserved within the testicular tissue for both men.
Intracytoplasmic injections were performed at a later date, using
spermatozoa prepared from frozen-thawed tissues. In each case, three
embryos were obtained and transferred in utero. The transfers resulted in a
twin pregnancy for the first case, and in a singleton pregnancy for the
second. Living foetuses were seen in the ultrasound scan at the 7th week
and both pregnancies are proceeding to date beyond 30 weeks without
complications.
相似文献