全文获取类型
收费全文 | 560篇 |
免费 | 31篇 |
国内免费 | 5篇 |
出版年
2023年 | 15篇 |
2022年 | 28篇 |
2021年 | 16篇 |
2020年 | 12篇 |
2019年 | 22篇 |
2018年 | 25篇 |
2017年 | 9篇 |
2016年 | 7篇 |
2015年 | 21篇 |
2014年 | 14篇 |
2013年 | 30篇 |
2012年 | 18篇 |
2011年 | 14篇 |
2010年 | 17篇 |
2009年 | 19篇 |
2008年 | 8篇 |
2007年 | 19篇 |
2006年 | 22篇 |
2005年 | 11篇 |
2004年 | 17篇 |
2003年 | 12篇 |
2002年 | 20篇 |
2001年 | 14篇 |
2000年 | 15篇 |
1999年 | 9篇 |
1998年 | 14篇 |
1997年 | 11篇 |
1996年 | 7篇 |
1995年 | 13篇 |
1994年 | 9篇 |
1993年 | 8篇 |
1992年 | 6篇 |
1991年 | 4篇 |
1990年 | 5篇 |
1989年 | 7篇 |
1988年 | 5篇 |
1987年 | 6篇 |
1986年 | 9篇 |
1985年 | 7篇 |
1984年 | 15篇 |
1983年 | 7篇 |
1982年 | 6篇 |
1981年 | 10篇 |
1980年 | 7篇 |
1979年 | 7篇 |
1978年 | 4篇 |
1977年 | 5篇 |
1976年 | 4篇 |
1973年 | 2篇 |
1969年 | 1篇 |
排序方式: 共有596条查询结果,搜索用时 15 毫秒
81.
Activation of hypothalamic RIP‐Cre neurons promotes beiging of WAT via sympathetic nervous system 下载免费PDF全文
Baile Wang Ang Li Xiaomu Li Philip WL Ho Donghai Wu Xiaoqi Wang Zhuohao Liu Kelvin KL Wu Sonata SY Yau Aimin Xu Kenneth KY Cheng 《EMBO reports》2018,19(4)
Activation of brown adipose tissue (BAT) and beige fat by cold increases energy expenditure. Although their activation is known to be differentially regulated in part by hypothalamus, the underlying neural pathways and populations remain poorly characterized. Here, we show that activation of rat‐insulin‐promoter‐Cre (RIP‐Cre) neurons in ventromedial hypothalamus (VMH) preferentially promotes recruitment of beige fat via a selective control of sympathetic nervous system (SNS) outflow to subcutaneous white adipose tissue (sWAT), but has no effect on BAT. Genetic ablation of APPL2 in RIP‐Cre neurons diminishes beiging in sWAT without affecting BAT, leading to cold intolerance and obesity in mice. Such defects are reversed by activation of RIP‐Cre neurons, inactivation of VMH AMPK, or treatment with a β3‐adrenergic receptor agonist. Hypothalamic APPL2 enhances neuronal activation in VMH RIP‐Cre neurons and raphe pallidus, thereby eliciting SNS outflow to sWAT and subsequent beiging. These data suggest that beige fat can be selectively activated by VMH RIP‐Cre neurons, in which the APPL2–AMPK signaling axis is crucial for this defending mechanism to cold and obesity. 相似文献
82.
α-黑色素细胞刺激素对白细胞介素-1β发热的解热机理研究 总被引:5,自引:0,他引:5
本研究观察了α-黑色素细胞刺激素(α-MSH)对家兔白细胞介素-1β(IL-1β)发热效应及下丘脑组织腺苷环-磷酸(cAMP)含量的影响;同时观察了下丘本外培养过程中,α-MSH对IL-1β刺激下丘脑释放cAMP的影响。结果显示:α-MSH能显著降低IL-1β引起的体温升高(P〈0.05);同时抑制下丘脑组织cAMP含量的增高(P〈0.01)。IL-1β与下丘脑组织培养,其上清液的cAMP含量明显 相似文献
83.
Twenty days after bilateral adrenalectomy (ADX) or immediately after the last of three 6-h long immobilization periods, the levels of hypothalamic and neurohypophyseal L-[35S]Cys-labeled arginine vasopressin (AVP), oxytocin (OT), and somatostatin-14 (SRIF) (only stressed animals) were measured simultaneously in male Wistar rats, after third ventricular administration of the labeled precursor, via guide-cannulae. The acetic acid-extracted labeled peptide fractions were purified by two sequential HPLC steps. After a 4 h period of labeling, only L-[35S]Cys-AVP was selectively increased in the hypothalami of ADX-ized rats, compared to the sham-operated animals, possibly reflecting a significant activation of the paraventricular parvocellular (PVC) AVP/corticotropin-releasing factor (CRF) neurons. The increased accumulation of neurohypophyseal L-[35S]Cys-labeled AVP and OT in these animals, without changes in the endogenous levels of these peptides, as measured by UV absorbance, also suggests a moderate activation of the magnocellular (MGC) AVP and OT neurons, as a consequence of adrenal insufficiency. In response to immobilization stress, levels of L-[35S]Cys-OT were selectively increased in the hypothalami and corresponding neurohypophyses, 2 h and 4 h after receiving the label, concomitantly with a statistically significant reduction in the stores of OT in the neural lobes. AVP and SRJF biosynthesis remained unaffected by immobilization; the neurohypophyseal AVP stores likewise remained unchanged. These observations suggest the selective activation of MGC-OT neurons in response to chronic immobilization stress. Selective increases in hypothalamic L-[35S]Cys-AVP in ADX-ized rats, and in hypothalamic L-[35S]Cys-OT in chronically stress-immobilized rats, are presented as a measure of PVC-AVP/CRF and MGC-OT neuronal activation, respectively. 相似文献
84.
85.
86.
87.
P.-F. Ferrari S. Lowther H. Tidbury P. Greengrass C. A. Wilson R. W. Horton 《Cellular and molecular neurobiology》1999,19(6):775-784
1.Rat hypothalamic 5-hydroxytryptamine (5-HT) and 5-hydroxyindole acetic acid (5-HIAA) concentrations are transiently sexually differentiated in the second week postpartum (pp), with higher levels in the female. In this report we investigate the possibility that 5-HT receptors may also exhibit sexual dimorphism in the neonatal period.2.5-HT1A and 5-HT2A receptors were quantitated by radioligand binding of [3H]ketanserin and [3H]8-OH DPAT, respectively, in hypothalamus and amygdala from male and female rats at days 8–16 pp.3.There was no sexual dimorphism or change in the density of 5-HT2A binding in hypothalamus or amygdala over days 8–16 pp. There was also no sexual dimorphism of 5-HT1A receptors.4.There was an increase in 5-HT1A receptor density in both the hypothalamus and the amygdala. In the hypothalamus, but not the amygdala, this increase was interrupted on day 14 by a decrease in 5-HT1A receptors, which we suggest may be of physiological significance in modifying the eventual pattern of adult agonistic activity.5.The results suggest that the sexual dimorphism in 5-HT turnover is predominantly presynaptic, relating to altered synthesis and/or release, and is not of sufficient magnitude or duration to produce adaptive responses in postsynaptic 5-HT1A or 5-HT2A receptors. 相似文献
88.
本文用脑室灌注和Fura2测定细胞内游离钙技术观察了地塞米松(dexamethasone,DEX)对家兔乙二醇双(2氨基乙醚)四乙酸性发热效应和下丘脑细胞内游离钙浓度([Ca2+]i)的影响,借此深入探讨地塞米松解热作用的中枢机制。结果发现:脑室灌注乙二醇双(2氨基乙醚)四乙酸(06nmol)引起家兔结肠温度明显升高,静脉注射地塞米松(5mg/kg)显著抑制家兔乙二醇双(2氨基乙醚)四乙酸性发热,地塞米松(60~120μmol/L)并不影响下丘脑细胞内[Ca2+]i,而事先脑室灌注抑制基因转录的放线菌素D(3nmol)则完全取消了地塞米松对乙二醇双(2氨基乙醚)四乙酸性发热的解热作用。这些结果提示:地塞米松显著抑制家兔乙二醇双(2氨基乙醚)四乙酸性发热,其机制与地塞米松激活脑内某些基因的表达有关,而与下丘脑神经细胞跨膜钙离子流无关。 相似文献
89.
Naked mole-rats (Heterocephalus glaber) are eusocial rodents that live in large subterranean colonies including a single breeding female and 1-3 breeding males; all other members of the colony, known as subordinates, are reproductively suppressed. We recently found that naked mole-rats lack many of the sex differences in the brain and spinal cord commonly found in other rodents. Instead, neural morphology is influenced by breeding status, such that breeders, regardless of sex, have more neurons than subordinates in the ventromedial nucleus of the hypothalamus (VMH), and larger overall volumes of the bed nucleus of the stria terminalis (BST), paraventricular nucleus (PVN) and medial amygdala (MeA). To begin to understand how breeding status influences brain morphology, we examined the distribution of androgen receptor (AR) immunoreactivity in gonadally intact breeders and subordinates of both sexes. All animals had AR+ nuclei in many of the same regions positive for AR in other mammals, including the VMH, BST, PVN, MeA, and the ventral portion of the premammillary nucleus (PMv). We also observed diffuse labeling throughout the preoptic area, demonstrating that distribution of the AR protein in presumptive reproductive brain nuclei is well-conserved, even in a species that exhibits remarkably little sexual dimorphism. In contrast to other rodents, however, naked mole-rats lacked AR+ nuclei in the suprachiasmatic nucleus and hippocampus. Males had more AR+ nuclei in the MeA, VMH, and PMv than did females. Surprisingly, breeders had significantly fewer AR+ nuclei than subordinates in all brain regions examined (VMH, BST, PVN, MeA, and PMv). Thus, social status is strongly correlated with AR immunoreactivity in this eusocial species. 相似文献
90.
Environmental and social factors have important effects on aggressive behaviors. We examined the effect of reproductive experience on aggression in a biparental species of mouse, Peromyscus californicus. Estrogens are important in mediating aggressive behavior so we also examined estrogen receptor expression and c-fos for insights into possible mechanisms of regulation. Parental males were significantly more aggressive than virgin males, but no significant differences in estrogen receptor alpha or beta expression were detected. Patterns of c-fos following aggression tests suggested possible parallels with maternal aggression. Parental males had more c-fos positive cells in the medial amygdala, and medial preoptic area relative to virgin males. The medial preoptic area is generally considered to be relatively less important for male-male aggression in rodents, but is known to have increased activity in the context of maternal aggression. We also demonstrated through habituation-dishabituation tests that parental males show exaggerated investigation responses to chemical cues from a male intruder, suggesting that heightened sensory responses may contribute to increased parental aggression. These data suggest that, in biparental species, reproductive experience leads to the onset of paternal aggression that may be analogous to maternal aggression. 相似文献