Phonon-Induced Enhancement of Photon Entanglement in Quantum Dot-Cavity Systems.

We report on simulations of the degree of polarization entanglement of photon pairs simultaneously emitted from a quantum dot-cavity system that demand revisiting the role of phonons. Since coherence is a fundamental precondition for entanglement and phonons are known to be a major source of decoherence, it seems unavoidable that phonons can only degrade entanglement. In contrast, we demonstrate that phonons can cause a degree of entanglement that even surpasses the corresponding value for the phonon-free case.

Emission-Frequency Separated High Quality Single-Photon Sources Enabled by Phonons.

We demonstrate theoretically that the single-photon purity of photons emitted from a quantum dot exciton prepared by phonon-assisted off-resonant excitation can be significantly higher in a wide range of parameters than that obtained by resonant preparation for otherwise identical conditions. Despite the off-resonant excitation, the brightness stays on a high level. These surprising findings exploit the fact that the phonon-assisted preparation is a two-step process where phonons first lead to a relaxation between laser-dressed states while high exciton occupations are reached only with a delay to the laser pulse maximum by adiabatically undressing the dot states.

Oxidation of cholesterol in synaptosomes and mitochondria isolated from rat brains.

Cholesterol and alpha-tocopherol oxidations were studied in brain subcellular fractions isolated from cerebral hemispheres of 4-month-old, male Fischer 344 rats. The fractions were suspended in buffered media (pH 7.4, 37 degrees C0 and oxidized by adding (i) ferrous iron (Fe2+) with or without ascorbate or (ii) peroxynitrite (an endogenous oxidant produced by the reaction of superoxide and nitric oxide).

Analysis of hydroxy and keto cholesterols in oxidized brain synaptosomes.

A rapid method for the simultaneous determination of cholesterol and its oxidation products as well as alpha-to-copherol and tocopherolquinone in brain subcellular fractions is described. The samples are saponified and extracted with hexane. It is not necessary to remove cholesterol in the sample before analyzing for oxysterols.

Features of the polarity of the Golgi apparatus of frog photoreceptors: studies with lectins and with Brefeldin A.

The cis-trans polarity of the Golgi apparatus is important in Golgi functioning in glycosylation, sorting and other processes. The present work extends our prior studies on the polarity of the Golgi apparatus of frog (Rana) rod photoreceptors. We demonstrate that Golgi structures with the morphology and distribution of cis elements show the heaviest deposition of osmium.

Infradian modulation of liver nucleic acid and lipid content of adult female Lewis/S rats.

Infradian modulation with periods of 168 h and 120 h characterizes the RNA, DNA and lipid content of the liver in adult female Lewis/S rats. Multilinear analysis shows that the fit of an infradian cosine curve with these periods is statistically significant below the 5% level (P = 0.011; P = 0.

Circadian stage-dependent effect of ACTH and melatonin on protein synthesis by rat adrenal cells.

The objective of the present study was to determine the circadian effects of melatonin and two different ACTH preparations: a synthetic heptadecapeptide with adrenocorticotrophic action (Synchrodyn 1-17, HOE 433) and a natural ACTH (Acthar, Armour). Both ACTH preparations acted in a circadian stage-dependent fashion affecting the MESOR and the amplitude of total protein synthesis of rat adrenal cells. The results also indicated interaction of melatonin with the rhythmic action of ACTH.

Lead-dependent deposits in diverse synaptic vesicles: suggestive evidence for the presence of anionic binding sites.

We have observed electron dense deposits dependent on incubation of aldehyde-fixed tissues with lead ions within synaptic vesicles of several types of neurons that differ in the neurotransmitters utilized and in the secretory granules of the adrenal medulla. Evidently, vesicle components that can interact with lead ions are widespread. A plausible explanation for the occurrence of the deposits is the presence of anionic binding sites within the vesicles.

Rhythmic pineal-hypophyseal-adrenal intermodulations ex vivo.

To assess circadian and circaseptan rhythmic intermodulation, female mice, kept on regimens of 12 hr light (L) alternating with 12 hr of darkness (D) (LD 12:12) were sampled for 1-13 days at six circadian stages. Pineals were removed and homogenized with 0.9% NaCl.

More on the circadian melatonin rhythm in pineals from domesticated B6D2F1 mice.

For melatonin (a chronomodulator of adrenal cortical function, immune phenomena and carcinogenesis), a circadian rhythm is demonstrated in aqueous pineal homogenate of domesticated B6D2F1 mice. Domestication as such does not eliminate a mechanism of cephalo-adrenal coordination.

Chronobiologic lead study cost-effectively assesses circadian-circaseptan intermodulation in murine pineal melatonin content.

The investment into the design of a study is usually and unfortunately proportional to the available information, i.e. the less one knows the more one is tempted to skimp and perform a minimal 'pilot' study.

Cell contact- and shape-dependent regulation of vinculin synthesis in cultured fibroblasts.

Recent studies have demonstrated the fundamental role of cell-substrate contacts and changes in cell shape in the regulation of cell growth, motility and differentiation, but the molecular basis for these phenomena is poorly understood. Because of the involvement of cytoskeletal networks in cell morphogenesis and contact formation, it is of interest that the expression of genes encoding several cytoskeletal proteins is markedly affected by changes in cell contacts and configuration. Because most of these phenomena involve changes in the form, extent or topology of cell contacts, we sought to determine whether the expression of components directly involved in the formation of cell-cell or cell-substrate contacts is affected by the respective cellular interactions.

Corticotropin specifically stimulates the uptake and intracellular movements of sterol carrier protein in adrenals.

Sterol carrier protein (SCP), also known as liver fatty acid binding protein, is a major adrenal protein localized in the cytosol and inner mitochondrial membrane. SCP is synthesized in liver and intestine and then rapidly secreted into blood, where it associates primarily with the high density lipoprotein fraction. Studies using steroidogenesis inhibitors showed that corticotropin has a specific effect on the uptake of SCP and its movement with cholesterol to the inner mitochondrial membrane.

Osteosynthesis of subtrochanteric fractures. A review of different methods.

The authors analysed the long-term results of 72 subtrochanteric fractures treated surgically over a period of 13 years. The case material was subdivided according to type of fracture and method of osteosynthesis and the results were evaluated with a view to ascertaining the best method of treatment in each type of fracture. The best results were obtained with osteosynthesis using an angled nail plate.

Rotatory subluxation of the atlanto-axial joint.

Twelve cases of rotatory subluxation of the atlanto-axial joint are presented. The pathogenesis of this lesion is discussed, in particular why it is prevalent in children. The radiographic and clinical features are described.

Plasma and synovial fluid concentrations of isoxicam in meniscectomized patients.

Concentrations of isoxicam in the plasma and synovial fluid of 7 patients were investigated by means of high-pressure liquid chromatography. The samples were collected after 7 days' treatment with a single 200 mg isoxicam capsule taken each morning. A highly significant correlation was found (r = 0.

Uptake of calcium by the endoplasmic reticulum of the frog photoreceptor.

We studied retinal photoreceptors of Rana pipiens by using techniques designed to investigate calcium localization. Particularly useful were methods in which intracellular sites of calcium uptake were detected by incubation of saponin-treated isolated retinas in calcium-containing media, with oxalate present as a trapping agent. With these procedures, cell compartments accumulate deposits, which can be shown to contain calcium by x-ray microanalysis.

Intramitochondrial movement of adrenal sterol carrier protein with cholesterol in response to corticotropin.

Sterol carrier protein (SCP) is a highly abundant, ubiquitous, low molecular weight protein that has a rapid turnover and multifunctional roles in lipid metabolism and transport. It is also known as the fatty acid-binding protein. These and other characteristics led to studies on the possible role of SCP in mediation of steroidogenic responses of the adrenal gland to corticotropin.

Distribution of membrane cholesterol of adrenal cortical cells after corticotropin stimulation.

Membrane cholesterol in adrenal cortical cells is enriched in the plasma membrane. Stimulation of isolated adrenal cortical cells with corticotropin leads to the production of corticosterone. At high levels of corticotropin, cholesterol for corticosterone synthesis arises by hydrolysis of cellular cholesteryl ester, whereas at lower levels of corticotropin cholesteryl ester levels are unchanged from control values and there is a decrease in plasma-membrane cholesterol levels.

Pineal modulation of ACTH 1-17 effect upon murine corticosterone production.

In tests of corticosterone production in vitro, aqueous pineal homogenate (APH) modulates the effect of a short-chain ACTH analogue, ACTH 1-17, added to adrenals from different circadian stages. Adrenal and pineal glands from female B6D2F1 mice, standardized on staggered LD 12:12 regimens, were obtained at the same clock-hour from each room, in order to cover 6 different circadian stages. Adrenals from each circadian stage were bisected and incubated with APH from the same circadian stage (isophasic incubation) or from one of the other 5 circadian stages (heterophasic incubation).

Circadian pineal modulation of pituitary effect on murine corticosterone in vitro.

An old controversy is resolved as a novel effect: In a rhythmic fashion, aqueous pineal homogenate (APH) enhances, attenuates or leaves unaffected the production of corticosterone by mouse adrenals incubated with pituitary media. All glands stem from the same circadian stage in these (isophasic) studies on 72 female CD2F1 mice, standardized for two weeks in L 0600-1800 and D 1800-0600. Every 4 hours during a 24-hour span, 12 mice were killed.

Hypothalamic and pituitary periodicity demonstrated by isolated rat adrenal cells.

Rats were maintained under standardized conditions of food and water ad libitum and a lighting schedule of 12 h light/we h dark for seven days. Animals were sacrificed at 0500 and 1700 h and tissues were removed and washed. Isolated intact adrenal and pituitary cells were prepared by collagenase treatment.

Formation and isolation of delta 5-3-ketosteroids using a purified rat liver alcohol dehydrogenase.

3 beta-Hydroxy-5-androsten-17-one is converted to 5-androstene-3, 17-dione by rat liver alcohol dehydrogenase (ADH). We have reported on the purity of the enzyme which is eluted with pyrazole as a single homogeneous protein using an AMP-agarose affinity column. Rat liver ADH can oxidize hydroxyl groups not only at 3 beta-, but also at 3 alpha-, and 17 beta-positions to a lesser extent; thus it is a pure mammalian enzyme with multifunctional activity for steroids.