1,725 research outputs found
Centaur AC-8 Postflight Guidance Analysis
Centaur AC-8 postflight guidance and control analysi
Intracranial Injection of Gammagard, a Human IVIg, Modulates the Inflammatory Response of the Brain and Lowers A\u3cem\u3eβ\u3c/em\u3e in APP/PS1 Mice Along a Different Time Course than Anti-A\u3cem\u3eβ\u3c/em\u3e Antibodies
Gammagard IVIg is a therapeutic approach to treat Alzheimer\u27s disease currently in phase 3 clinical trials. Despite the reported efficacy of the approach the mechanism of action is poorly understood. We have previously shown that intracranial injection of anti-Aβ antibodies into the frontal cortex and hippocampus reveals important information regarding the time course of events once the agent is in the brain. In the current study we compared IVIg, mouse-pooled IgG, and the anti-Aβ antibody 6E10 injected intracranially into the frontal cortex and hippocampus of 7-month-old APP/PS1 mice. We established a time course of events ranging from 1 to 21 d postinjection.
IVIg and pooled mouse IgG both significantly reduced Aβ deposition to the same degree as the 6E10 anti-Aβ antibody; however, the clearance was much slower to occur, happening between the 3 and 7 d time points. In contrast, as we have previously shown, Aβ reductions were apparent with the 6E10 anti-Aβ group at the 1 d time point. Also, neuroinflammatory profiles were significantly altered by the antibody treatments. APP/PS1 transgenic mice at 7 months of age typically exhibit an M2a inflammatory phenotype. All antibody treatments stimulated an M2b response, yet anti-Aβ antibody was a more rapid change. Because the neuroinflammatory switch occurs before the detectable reductions in amyloid deposition, we hypothesize that the IVIg and pooled mouse IgG act as immune modulators and this immune modulation is responsible for the reductions in amyloid pathology
Understanding light quanta: First quantization of the free electromagnetic field
The quantization of the electromagnetic field in vacuum is presented without
reference to lagrangean quantum field theory. The equal time commutators of the
fields are calculated from basic principles. A physical discussion of the
commutators suggest that the electromagnetic fields are macroscopic emergent
properties of more fundamental physical system: the photons
ОПРЕДЕЛЕНИЕ ОРГАНИЧЕСКИХ КИСЛОТ, УГЛЕВОДОВ И ПОДСЛАСТИТЕЛЕЙ В ПИЩЕВЫХ ПРОДУКТАХ И БИОЛОГИЧЕСКИ АКТИВНЫХ ДОБАВКАХ МЕТОДОМ ВЫСОКОЭФФЕКТИВНОЙ ЖИДКОСТНОЙ ХРОМАТОГРАФИИ
The content of organic acids and carbohydrates in samples of wine, juice, dairy products, dietary supplements was revealed by reverse-phase high performance liquid chromatography (HPLC). Organic acids (oxalic acid, tartaric acid, formic acid, malic acid, lactic acid, acetic acid, citric acid, succinic acid, fumaric acid, propionic acid) was determined by using spectrophotometric detection, carbohydrates (glucose, lactose, maltose, mannose, sucrose, fructose) and sweeteners (xylitol, sorbitol) - with refractometric detection. The limits of detection of organic acids in liquid samples were 0.05-2.8 mg / l, in solid 0.7-3.1%. The detection limits for carbohydrates and sweeteners in liquid samples were 0.1-0.6 g/ l, in solid samples of 0.1-0.6 %. Samples or their solutions were purified from interfering organic impurities on solid phase extraction cartridges (SPE) C18, then were analyzed by HPLC.Key words: RP HPLC, spectrophotometric detection, refractometric detection, organic acids, carbohydrates and sweeteners, food, solid-phase extraction(Russian)DOI: http://dx.doi.org/10.15826/analitika.2013.17.2.011A.M. Zaharova*, L.A. Kartsova**, I.L. Greenstein**Company "Analyte", St. Petersburg, Russian Federation**St. Petersburg State University, St. Petersburg, Russian FederationМетодом обращенно-фазовой высокоэффективной жидкостной хроматографии (ОФ ВЭЖХ) выявлено содержание органических кислот и углеводов в пробах вина, сока, молочных продуктов, биологически активных добавках. Органические кислоты (щавелевая, винная, муравьиная, яблочная, молочная, уксусная, лимонная, янтарная, фумаровая, пропионовая) определяли с использованием спектрофотометрического детектирования; углеводы (глюкоза, лактоза, мальтоза, манноза, сахароза, фруктоза) и подсластители (ксилитол, сорбитол) - с рефрактометрическим детектированием. Пределы обнаружения органических кислот в жидких пробах составили 0.05-2.8 мг/л; в твёрдых - 4.10-5-2.10-3 % мас. Пределы обнаружения углеводов и подсластителей в жидких пробах - 0.1-0.6 г/л, в твердых - 0.1-0.6 % мас. Анализируемые пробы или их растворы очищали от мешающих органических примесей на картриджах для твердофазной экстракции (ТФЭ).Ключевые слова:ОФ ВЭЖХ, спектрофотометрическое детектирование, рефрактометрическое детектирование, органические кислоты, углеводы и подсластители, пищевые продукты, твердофазная экстракция.DOI: http://dx.doi.org/10.15826/analitika.2013.17.2.01
Assessment of Selected Reef Sites in Northern and South-Central Belize, Including Recovery from Bleaching and Hurricane Disturbances (Stony Corals, Algae and Fish)
The condition of coral. algal. and fish populations in fore reefs. patch reefs, and coral reef ridges was investigated at 13 sites along the northern and south-central Belize barrier reef during May 1999, documenting effects of the 1998 warming episode and Hurricane Mitch. We found high percentages of partial, or even complete, colony mortality of major reef-builders (Acropora palmata, the Montastraea annuluris species complex and Agaricia tenuifolia) that were rarely censused as recruits. A. tenuifolia, formerly a space-dominant coral in reef ridges, had incurred nearly 100% mortality after bleaching. Nearly 45% of the M. annurluris complex was still discolored (50% had been bleached in January 1999) on some south-central patch reefs where the total (recent + old) partial mortality exceeded 60% of colony surfaces. Although turf algae dominated patch reefs and coral reef ridges, macroalgae were quite prevalent representing \u3e30% cover at six sites. Parrotfish densities exceeded surgeontishes at most sites (11/13). Consistent patterns of lower partial-colony mortality of stony corals and greater fish densities and sizes near and within the Hol Chan Marine Reserve highlight the ecological benefits of protected areas for the maintenance of reef corals and attendant fish populations
EPR before EPR: a 1930 Einstein-Bohr thought experiment revisited
In 1930 Einstein argued against consistency of the time-energy uncertainty
relation by discussing a thought experiment involving a measurement of mass of
the box which emitted a photon. Bohr seemingly triumphed over Einstein by
arguing that the Einstein's own general theory of relativity saves the
consistency of quantum mechanics. We revisit this thought experiment from a
modern point of view at a level suitable for undergraduate readership and find
that neither Einstein nor Bohr was right. Instead, this thought experiment
should be thought of as an early example of a system demonstrating nonlocal
"EPR" quantum correlations, five years before the famous
Einstein-Podolsky-Rosen paper.Comment: 11 pages, revised, accepted for publication in Eur. J. Phy
Multiple Current States of Two Phase-Coupled Superconducting Rings
The states of two phase-coupled superconducting rings have been investigated.
Multiple current states have been revealed in the dependence of the critical
current on the magnetic field. The performed calculations of the critical
currents and energy states in a magnetic field have made it possible to
interpret the experiment as the measurement of energy states into which the
system comes with different probabilities because of the equilibrium and
non-equilibrium noises upon the transition from the resistive state to the
superconducting state during the measurement of the critical currentComment: 5 pages, 5 figure
Transition from an M1 to a Mixed Neuroinflammatory Phenotype Increases Amyloid Deposition in APP/PS1 Transgenic Mice
BACKGROUND: The polarization to different neuroinflammatory phenotypes has been described in early Alzheimer\u27s disease, yet the impact of these phenotypes on amyloid-beta (Aβ) pathology remains unknown. Short-term studies show that induction of an M1 neuroinflammatory phenotype reduces Aβ, but long-term studies have not been performed that track the neuroinflammatory phenotype.
METHODS: Wild-type and APP/PS1 transgenic mice aged 3 to 4 months received a bilateral intracranial injection of adeno-associated viral (AAV) vectors expressing IFNγ or green fluorescent protein in the frontal cortex and hippocampus. Mice were sacrificed 4 or 6 months post-injection. ELISA measurements were used for IFNγ protein levels and biochemical levels of Aβ. The neuroinflammatory phenotype was determined through quantitative PCR. Microglia, astrocytes, and Aβ levels were assessed with immunohistochemistry.
RESULTS: AAV expressing IFNγ induced an M1 neuroinflammatory phenotype at 4 months and a mixed phenotype along with an increase in Aβ at 6 months. Microglial staining was increased at 6 months and astrocyte staining was decreased at 4 and 6 months in mice receiving AAV expressing IFNγ.
CONCLUSIONS: Expression of IFNγ through AAV successfully induced an M1 phenotype at 4 months that transitioned to a mixed phenotype by 6 months. This transition also appeared with an increase in amyloid burden suggesting that a mixed phenotype, or enhanced expression of M2a and M2c markers, could contribute to increasing amyloid burden and disease progression
An analysis of spectra in the Red Rectangle nebula
This paper presents an analysis of a series of spectra in the Red Rectangle
nebula. Only the reddest part of the spectra can safely be attributed to light
from the nebula, and indicates Rayleigh scattering by the gas, in conformity
with the large angles of scattering involved and the proximity of the star. In
the blue, light from HD44179, refracted or scattered in the atmosphere,
dominates the spectra. This paper questions the reliability of ground-based
observations of extended objects in the blue.Comment: 25 figure
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