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1.
J P Plummer 《Experientia》1979,35(11):1534-1535
In view of the number of workers who have confirmed the presence of cutaneous nerves beneath acupuncture points, a plea is made not to dismiss them too lightly or hastily at this point in the search for the mechanisms of acupuncture.  相似文献   
2.
Summary In view of the number of workers who have confirmed the presence of cutaneous nerves beneath acupuncture points, a plea is made not to dismiss them too lightly or hastily at this point in the search for the mechanisms of acupuncture.  相似文献   
3.
Summary The addition of insulin (10 U) to a suspension of isolated hepatocytes in Krebs-Ringer bicarbonate solution. causes an increase in the negative electrophoretic mobility of the cells from –1.68 m sec–1 V–1 cm to 2.26 m sec–1 V–1 cm. This observation supports the findings by other workers that the binding of insulin to its receptor leads to a marked change in the membrane.Acknowledgment. We wish to thank the Medical Research Council for the provision of the microelectrophoresis apparatus and initial running costs of the project.  相似文献   
4.
M R Plummer  P Hess 《Nature》1991,351(6328):657-659
N-type calcium channels are thought to be expressed specifically in neuronal cells and to have a dominant role in the control of neurotransmitter release from sympathetic neurons. But their unitary properties are poorly understood and the separation of neuronal Ca2+ current into components carried by N-type or L-type Ca2+ channels is controversial. Here we show that individual N-type Ca2+ channels in sympathetic neurons can carry two kinetically distinct components of current, one that is rapidly transient and one that is long lasting. The mechanism that gives rise to these two components is unexpected for Ca2+ channels: a test depolarization elicits either a rapidly inactivating, single short burst with an average duration of 40 ms, or sustained, noninactivating channel activity lasting for over 1 s. The switching between inactivating and noninactivating activity is a slow process, the occurrence of each type of unitary kinetic behaviour remaining statistically correlated over several seconds. Variable coupling of inactivation in N-type Ca2+ channels could be an effective mechanism for the modulation of neuronal excitability and synaptic plasticity.  相似文献   
5.
Zusammenfassung Durch Umsetzung des Methyl-Reserpates (Ic) mit Diazomethan in Gegenwart von Fluoborsäure wird 18-O-Methylreserpsäure-methylester (Id) gewonnen. Reaktion des 18-O-p-Brombenzolsulfonylreserpsäure-methylesters (Ie) mit Methanol und Triäthylamin führt dagegen zum isomeren 18-epi-Methyläther (IIa). Diese Produkte, und besonders ihre wasserlöslichen Hydrochloride, besitzen ausgeprägte sedative Eigenschaften mit schnellem Wirkungseintritt; sie sind aber nicht hypotensiv wirksam.  相似文献   
6.
RNASEL Arg462Gln variant is implicated in up to 13% of prostate cancer cases   总被引:13,自引:0,他引:13  
RNASEL (encoding ribonuclease L) has recently been proposed as a candidate for the hereditary prostate cancer (HPC1) gene. We determined that the RNASEL variant Arg462Gln has three times less enzymatic activity than the wildtype and is significantly associated with prostate cancer risk (P = 0.007). At least one copy of the mutated allele that causes this substitution is carried by nearly 60% of the men in our study. Men that are heterozygous with respect to the mutated allele have 50% greater risk of prostate cancer than non-carriers, and homozygotes have more than double the risk.  相似文献   
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8.
Prior studies use a linear adaptive expectations model to describe how analysts revise their forecasts of future earnings in response to current forecast errors. However, research shows that extreme forecast errors are less likely than small forecast errors to persist in future years. If analysts recognize this property, their marginal forecast revisions should decrease with the forecast error's magnitude. Therefore, a linear model is likely to be unsatisfactory at describing analysts' forecast revisions. We find that a non‐linear model better describes the relation between analysts' forecast revisions and their forecast errors, and provides a richer theoretical framework for explaining analysts' forecasting behaviour. Our results are consistent with analysts' recognizing the permanent and temporary nature of forecast errors of differing magnitudes. Copyright © 2000 John Wiley & Sons, Ltd.  相似文献   
9.
Zusammenfassung Es wird die Synthese und Pharmakologie eines neuen blutdrucksenkenden Mittels,cis-Cinnamyl-guanidinsulfat, beschrieben.  相似文献   
10.
Exposure of rare-earth films to hydrogen can induce a metal-insulator transition, accompanied by pronounced optical changes. This 'switchable mirror' effect has received considerable attention from theoretical, experimental and technological points of view. Most systems use polycrystalline films, but the synthesis of yttrium-based epitaxial switchable mirrors has also been reported. The latter form an extended self-organized ridge network during initial hydrogen loading, which results in the creation of micrometre-sized triangular domains. Here we observe homogeneous and essentially independent optical switching of individual domains in epitaxial switchable mirrors during hydrogen absorption. The optical switching is accompanied by topographical changes as the domains sequentially expand and contract; the ridges block lateral hydrogen diffusion and serve as a microscopic lubricant for the domain oscillations. We observe the correlated changes in topology and optical properties using in situ atomic force and optical microscopy. Single-domain phase switching is not observed in polycrystalline films, which are optically homogeneous. The ability to generate a tunable, dense pattern of switchable pixels is of technological relevance for solid-state displays based on switchable mirrors.  相似文献   
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