全文获取类型
收费全文 | 83篇 |
免费 | 17篇 |
出版年
2019年 | 3篇 |
2016年 | 1篇 |
2015年 | 2篇 |
2014年 | 4篇 |
2013年 | 8篇 |
2012年 | 7篇 |
2011年 | 6篇 |
2010年 | 3篇 |
2009年 | 7篇 |
2008年 | 4篇 |
2007年 | 5篇 |
2006年 | 6篇 |
2005年 | 2篇 |
2004年 | 3篇 |
2003年 | 3篇 |
2001年 | 1篇 |
2000年 | 3篇 |
1999年 | 4篇 |
1998年 | 2篇 |
1997年 | 4篇 |
1996年 | 1篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1991年 | 1篇 |
1989年 | 2篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1981年 | 2篇 |
1979年 | 1篇 |
1977年 | 3篇 |
1975年 | 2篇 |
1965年 | 1篇 |
排序方式: 共有100条查询结果,搜索用时 15 毫秒
1.
Basolateral plasma membrane localization of ouabain-sensitive sodium transport sites in the secretory epithelium of the avian salt gland
下载免费PDF全文
![点击此处可从《The Journal of cell biology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The distribution of Na+ pump sites (Na+-K+-ATPase) in the secretory epithelium of the avian salt gland was demonstrated by freeze-dry autoradiographic analysis of [(3)H] ouabain binding sites. Kinetic studies indicated that near saturation of tissue binding sites occurred when slices of salt glands from salt-stressed ducks were exposed to 2.2 μM ouabain (containing 5 μCi/ml [(3)H]ouabain) for 90 min. Washing with label-free Ringer's solution for 90 min extracted only 10% of the inhibitor, an amount which corresponded to ouabain present in the tissue spaces labeled by [(14)C]insulin. Increasing the KCl concentration of the incubation medium reduced the rate of ouabain binding but not the maximal amount bound. In contrast to the low level of ouabain binding to salt glands of ducks maintained on a freshwater regimen, exposure to a salt water diet led to a more than threefold increase in binding within 9-11 days. This increase paralleled the similar increment in Na+-K+-ATPase activity described previously. [(3)H]ouabain binding sites were localized autoradiographically to the folded basolateral plasma membrane of the principal secretory cells. The luminal surfaces of these cells were unlabeled. Mitotically active peripheral cells were also unlabeled. The cell-specific pattern of [(3)H]ouabain binding to principal secretory cells and the membrane-specific localization of binding sites to the nonluminal surfaces of these cells were identical to the distribution of Na+-K+-ATPase as reflected by the cytochemical localization of ouabain-sensitive and K+-dependent nitrophenyl phosphatase activity. The relationship between the nonluminal localization of Na+-K+-ATPase and the possible role of the enzyme n NaCl secretion is considered in the light of physiological data on electrolyte transport in salt glands and other secretory epithelia. 相似文献
2.
Acidified 2,2-dimethoxypropane (DMP), used as an alternative to regular fixation and dehydration methods for insects, was found to be the only successful means of preparing the sugarbeet root maggot larva, Tetanops myopaeformis (R?der) (Diptera:Otitidae), for the scanning electron microscope. No morphological changes were evident when DMP treated sugarbeet root maggot adults were compared to fresh (unfixed) adults and glutaraldehyde-osmium tetroxide fixed adults. The method has been used with success on several gropus of insects. Acidified CMP is quickly hydrolyzed by water in tissue to acetone and methanol. DMP is advantageous in that it penetrates water impermeable cuticles rapidly and saves several steps and time in the fixation and dehydration process. 相似文献
3.
Intercellular communication in the rat anterior pituitary gland: an in vivo and in vitro study 总被引:3,自引:1,他引:2
下载免费PDF全文
![点击此处可从《The Journal of cell biology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The concept of "stimulus-secretion coupling" suggested by Douglas and co-workers to explain the events related to monamine discharge by the adrenal medulla (5, 7) may be applied to other endocrine tissues, such as adrenal cortex (36), pancreatic islets (4), and magnocellular hypothalamic neurons (6), which exhibit a similar ion-dependent process of hormone elaboration. In addition, they share another feature, that of joining neighbor cells via membrane junctions (12, 26, and Fletcher, unpublished observation). Given this, and the reports that hormone secretion by the pars distalis also involves a secretagogue-induced decrease in membrane bioelectric potential accompanied by a rise in cellular [Ca++] (27, 34, 41), it was appropriate to test the possibility that cells of the anterior pituitary gland are united by junctions. 相似文献
4.
Jarle W. Bjerke 《分类学与生物多样性》2013,11(1):45-47
A new sorediate lichen, Menegazzia hypernota Bjerke, is described from New Zealand. This new species is characterised by convex, crescent‐shaped to fabi‐form soralia that are occasionally associated with perforations; apothecia with 2‐spored asci; the small perforations; the numerous secondary lobules; the presence of inconspicuous, yellow spots in the internal cavity; and fumarprotocetraric acid as principal medullary constituent. Menegazzia caliginosa, a species associated with M. hypernota, is reported for the first time from the Auckland Islands. 相似文献
5.
Tyler JW Robinson Melody Pai Jeff C Liu Frederick Vizeacoumar Thomas Sun Sean E Egan Alessandro Datti Jing Huang Eldad Zacksenhaus 《Cell cycle (Georgetown, Tex.)》2013,12(18):3013-3024
Triple-negative breast cancer (TNBC) represents an aggressive subtype, for which radiation and chemotherapy are the only options. Here we describe the identification of disulfiram, an FDA-approved drug used to treat alcoholism, as well as the related compound thiram, as the most potent growth inhibitors following high-throughput screens of 3185 compounds against multiple TNBC cell lines. The average IC50 for disulfiram was ~300 nM. Drug affinity responsive target stability (DARTS) analysis identified IQ motif-containing factors IQGAP1 and MYH9 as direct binding targets of disulfiram. Indeed, knockdown of these factors reduced, though did not completely abolish, cell growth. Combination treatment with 4 different drugs commonly used to treat TNBC revealed that disulfiram synergizes most effectively with doxorubicin to inhibit cell growth of TNBC cells. Disulfiram and doxorubicin cooperated to induce cell death as well as cellular senescence, and targeted the ESA+/CD24-/low/CD44+ cancer stem cell population. Our results suggest that disulfiram may be repurposed to treat TNBC in combination with doxorubicin. 相似文献
6.
This study was conducted to examine the psycho-emotional effects of repeated oral exposure to capsaicin, the principal active component of chili peppers. Each rat received 1 mL of 0.02% capsaicin into its oral cavity daily, and was subjected to behavioural tests following 10 daily administrations of capsaicin. Stereotypy counts and rostral grooming were significantly increased, and caudal grooming decreased, in capsaicin-treated rats during the ambulatory activity test. In elevated plus maze test, not only the time spent in open arms but also the percent arm entry into open arms was reduced in capsaicin-treated rats compared with control rats. In forced swim test, although swimming duration was decreased, struggling increased in the capsaicin group, immobility duration did not differ between the groups. Repeated oral capsaicin did not affect the basal levels of plasma corticosterone; however, the stress-induced elevation of plasma corticosterone was prolonged in capsaicin treated rats. Oral capsaicin exposure significantly increased c-Fos expression not only in the nucleus tractus of solitarius but also in the paraventricular nucleus. Results suggest that repeated oral exposure to capsaicin increases anxiety-like behaviours in rats, and dysfunction of the hypothalamic-pituitary-adrenal axis may play a role in its pathophysiology. 相似文献
7.
8.
Kan Chen Wanlu Cao Juan Li Dave Sprengers Pratika Y Hernanda Xiangdong Kong Luc JW van der Laan Kwan Man Jaap Kwekkeboom Herold J Metselaar Maikel P Peppelenbosch Qiuwei Pan 《Molecular medicine (Cambridge, Mass.)》2015,21(1):792-802
As uncontrolled cell proliferation requires nucleotide biosynthesis, inhibiting enzymes that mediate nucleotide biosynthesis constitutes a rational approach to the management of oncological diseases. In practice, however, results of this strategy are mixed and thus elucidation of the mechanisms by which cancer cells evade the effect of nucleotide biosynthesis restriction is urgently needed. Here we explored the notion that intrinsic differences in cancer cell cycle velocity are important in the resistance toward inhibition of inosine monophosphate dehydrogenase (IMPDH) by mycophenolic acid (MPA). In short-term experiments, MPA treatment of fast-growing cancer cells effectively elicited G0/G1 arrest and provoked apoptosis, thus inhibiting cell proliferation and colony formation. Forced expression of a mutated IMPDH2, lacking a binding site for MPA but retaining enzymatic activity, resulted in complete resistance of cancer cells to MPA. In nude mice subcutaneously engrafted with HeLa cells, MPA moderately delayed tumor formation by inhibiting cell proliferation and inducing apoptosis. Importantly, we developed a lentiviral vector–based Tet-on label-retaining system that enables to identify, isolate and functionally characterize slow-cycling or so-called label-retaining cells (LRCs) in vitro and in vivo. We surprisingly found the presence of LRCs in fast-growing tumors. LRCs were superior in colony formation, tumor initiation and resistance to MPA as compared with fast-cycling cells. Thus, the slow-cycling compartment of cancer seems predominantly responsible for resistance to MPA. 相似文献
9.
Fife MS Gutierrez A Ogilvie EM Stock CJ Samuel JM Thomson W Mack LF Lewis CM Woo P 《Arthritis research & therapy》2006,8(5):R148-5
Juvenile idiopathic arthritis (JIA) is the most common cause of chronic childhood disability and encompasses a number of disease
subgroups. In this study we have focused on systemic JIA (sJIA), which accounts for approximately 11% of UK JIA cases. This
study reports the investigation of three members of the IL10 gene family as candidate susceptibility loci in children with
sJIA. DNA from 473 unaffected controls and 172 patients with sJIA was genotyped for a single nucleotide polymorphism (SNP)
in IL19 and IL20 and two SNPs in IL10. We examined evidence for association of the four SNPs by single marker and haplotype
analysis. Significant differences in allele frequency were observed between cases and controls, for both IL10-1082 (p = 0.031)
and IL20-468 (p = 0.028). Furthermore, examination of the haplotypes of IL10-1082 and IL20-468 revealed greater evidence for
association (global p = 0.0006). This study demonstrates a significant increased prevalence of the low expressing IL10-1082
genotype in patients with sJIA. In addition, we show a separate association with an IL20 polymorphism, and the IL10-1082A/IL20-468T
haplotype. The two marker 'A-T' haplotype confers an odds ratio of 2.24 for sJIA. This positive association suggests an important
role for these cytokines in sJIA pathogenesis. 相似文献
10.
S. Bokhorst G. K. Phoenix J. W. Bjerke T. V. Callaghan F. Huyer‐Brugman M. P. Berg 《Global Change Biology》2012,18(3):1152-1162
Extreme weather events can have negative impacts on species survival and community structure when surpassing lethal thresholds. Extreme winter warming events in the Arctic rapidly melt snow and expose ecosystems to unseasonably warm air (2–10 °C for 2–14 days), but returning to cold winter climate exposes the ecosystem to lower temperatures by the loss of insulating snow. Soil animals, which play an integral part in soil processes, may be very susceptible to such events depending on the intensity of soil warming and low temperatures following these events. We simulated week‐long extreme winter warming events – using infrared heating lamps, alone or with soil warming cables – for two consecutive years in a sub‐Arctic dwarf shrub heathland. Minimum temperatures were lower and freeze‐thaw cycles were 2–11 times more frequent in treatment plots compared with control plots. Following the second event, Acari populations decreased by 39%; primarily driven by declines of Prostigmata (69%) and the Mesostigmatic nymphs (74%). A community‐weighted vertical stratification shift occurred from smaller soil dwelling (eu‐edaphic) Collembola species dominance to larger litter dwelling (hemi‐edaphic) species dominance in the canopy‐with‐soil warming plots compared with controls. The most susceptible groups to these winter warming events were the smallest individuals (Prostigmata and eu‐edaphic Collembola). This was not apparent from abundance data at the Collembola taxon level, indicating that life forms and species traits play a major role in community assembly following extreme events. The observed shift in soil community can cascade down to the micro‐flora affecting plant productivity and mineralization rates. Short‐term extreme weather events have the potential to shift community composition through trait composition with potentially large consequences for ecosystem development. 相似文献