6,004 research outputs found
On the Polarization of H-alpha Lines Scattered by Neutral Hydrogen in Active Galactic Nuclei
Raman scattering by atomic hydrogen converts the UV continuum around
Ly into optical continuum around H, and the basic atomic physics
has been discussed in several works on symbiotic stars. We propose that the
same process may operate in active galactic nuclei (AGN) and calculate the
linear polarization of the broad emission lines Raman-scattered by a high
column neutral hydrogen compnent. The conversion efficiency of the Raman
scattering process is discussed and the expected scattered flux is computed
using the spectral energy distribution of an AGN given by a typical power law.
The high column H {\sc i} component in AGN is suggested by many observations
encompassing radio through UV and X-ray ranges. When the neutral hydrogen
component with a column density is present around the
active nucleus, it is found that the scattered H is characterized by a
very broad width and that the strength of the polarized flux
is comparable to that of the electron-scattered flux expected from a
conventional unified model of narrow line AGN. The width of the scattered flux
is mainly determined by the column density of the neutral scatterers where the
total scattering optical depth becomes of order unity. The asymmetry in the
Raman scattering cross section around Ly introduces red asymmetric
polarized profiles around H. The effects of the blended Ly and O
{\sc vi} 1034 doublet are also investigated. We briefly discuss the
spectropolarimetric observations performed on the Seyfert galaxy IRAS
110548-1131 and the narrow line radio galaxy Cyg A.Comment: 11 pages, 6 figures, accepted for publication in MNRA
A label-free quantitative shotgun proteomics analysis of rice grain development
<p>Abstract</p> <p>Background</p> <p>Although a great deal of rice proteomic research has been conducted, there are relatively few studies specifically addressing the rice grain proteome. The existing rice grain proteomic researches have focused on the identification of differentially expressed proteins or monitoring protein expression patterns during grain filling stages.</p> <p>Results</p> <p>Proteins were extracted from rice grains 10, 20, and 30 days after flowering, as well as from fully mature grains. By merging all of the identified proteins in this study, we identified 4,172 non-redundant proteins with a wide range of molecular weights (from 5.2 kDa to 611 kDa) and <it>pI </it>values (from pH 2.9 to pH 12.6). A Genome Ontology category enrichment analysis for the 4,172 proteins revealed that 52 categories were enriched, including the carbohydrate metabolic process, transport, localization, lipid metabolic process, and secondary metabolic process. The relative abundances of the 1,784 reproducibly identified proteins were compared to detect 484 differentially expressed proteins during rice grain development. Clustering analysis and Genome Ontology category enrichment analysis revealed that proteins involved in the metabolic process were enriched through all stages of development, suggesting that proteome changes occurred even in the desiccation phase. Interestingly, enrichments of proteins involved in protein folding were detected in the desiccation phase and in fully mature grain.</p> <p>Conclusion</p> <p>This is the first report conducting comprehensive identification of rice grain proteins. With a label free shotgun proteomic approach, we identified large number of rice grain proteins and compared the expression patterns of reproducibly identified proteins during rice grain development. Clustering analysis, Genome Ontology category enrichment analysis, and the analysis of composite expression profiles revealed dynamic changes of metabolisms during rice grain development. Interestingly, we detected that proteins involved in glycolysis, TCA-cycle, lipid metabolism, and proteolysis accumulated at higher levels in fully mature grain compared to grain developing stages, suggesting that the accumulation of these proteins during the desiccation stage may be associated with the preparation of proteins required in germination.</p
Naphthalimide Trifluoroacetyl Acetonate: A Hydrazine-Selective Chemodosimetric Sensor
The trifluoroacetyl acetonate naphthalimide derivative 1 has been synthesized in good yield. In acetonitrile solution, compound 1 reacts selectively with hydrazine (NH2NH2) to give a five-membered ring. This leads to OFF-ON fluorescence with a maximum intensity at 501 nm as well as easily discernible color changes. Based on a readily discernible and reproducible 3.9% change in overall fluorescence intensity, the limit of detection for 1 is 3.2 ppb (0.1 mu M), which is below the accepted limit for hydrazine set by the U.S. Environmental Protection Agency (EPA). Compound 1 is selective for hydrazine over other amines, including NH4OH, NH2OH, ethylenediamine, methylamine, n-butylamine, piperazine, dimethylamine, triethylamine, pyridine, and is not perturbed by environmentally abundant metal ions. When supported on glass-backed silica gel TLC plates, compound 1 acts as a fluorimetric and colorimetric probe for hydrazine vapor at a partial pressure of 9.0 mm Hg, with selectivity over other potentially interfering volatile analytes, including ammonia, methylamine, n-butylamine, formaldehyde, acetaldehyde, H2O2, HCl, and CO2 being observed. Probe 1 can also be used for the detection of hydrazine in HeLa cells and does so without appreciable interference from other biologically abundant amines and metal ions.U.S. National Science Foundation CHE-1057904Robert A. Welch Foundation F-1018CRI project grant from National Research Foundation of Korea (NRF)Korea government (MSIP) 2009-0081566Chemistr
Frauenerwerbstätigkeit in Südkorea: die Benachteiligung von Frauen im Arbeitsleben
Südkorea hat in den vergangenen Jahrzehnten eine rasante wirtschaftliche und gesellschaftliche Entwicklung erlebt. Ein ökonomisch rückständiges und politisch noch nicht gefestigtes Land entwickelte sich in kurzer Zeit zu einer Industrienation. Im Zuge der Transformation von einer Agrargesellschaft über eine moderne Industriegesellschaft hin zu einer Dienstleistungsgesellschaft hat die Frauenerwerbstätigkeit in Südkorea deutlich zugenommen und stellt eine der bedeutendsten soziostrukturellen Entwicklungstendenzen der jüngsten Geschichte des Landes dar. Ausschlaggebend hierfür sind sozioökonomische Entwicklungen und Veränderungen im Bildungsbereich sowie in der Familienstruktur. Die Zunahme der Frauenerwerbsarbeit ist zugleich Ursache und Wirkung der Strukturveränderungen auf dem Arbeitsmarkt und in der Familie. Als wichtiger Faktor für die Zunahme der Frauenerwerbstätigkeit ist insbesondere die Verbesserung der Bildungschancen anzuführen. Die Ausbildung ist eine der zentralen Determinanten für die beruflichen Chancen im Erwerbssystem. Allgemein hat sich das Bildungsniveau der südkoreanischen Bevölkerung in den letzten beiden Jahrzehnten wesentlich verbessert. "Das Erziehungssystem in Südkorea hat den Aufschwung der koreanischen Industrie erst möglich gemacht"
Role of Myokines in Regulating Skeletal Muscle Mass and Function
Loss of skeletal muscle mass and strength has recently become a hot research topic with the extension of life span and an increasingly sedentary lifestyle in modern society. Maintenance of skeletal muscle mass is considered an essential determinant of muscle strength and function. Myokines are cytokines synthesized and released by myocytes during muscular contractions. They are implicated in autocrine regulation of metabolism in the muscle as well as in the paracrine/endocrine regulation of other tissues and organs including adipose tissue, the liver, and the brain through their receptors. Till date, secretome analysis of human myocyte culture medium has revealed over 600 myokines. In this review article, we summarize our current knowledge of major identified and characterized myokines focusing on their biological activity and function, particularly in muscle mass and function
Back Extensor Strengthening Exercise and Backpack Wearing Treatment for Camptocormia in Parkinson's Disease: A Retrospective Pilot Study
Objective
To investigate the effect of a conservative treatment regime in Parkinson's disease patients with camptocormia.
Methods
Nine patients with Parkinson's disease were included in a retrospective pilot study of the value of back extensor strengthening exercise. Six inpatients received a 30-minute treatment, twice daily for 5 weeks, being treated on average for 34 days; while three outpatients visited the clinic and were educated for home exercise and backpack wearing treatment. Outpatients should be scheduled to visit the outpatient department to check physical status every 2–4 weeks for an average of 3 months.
Results
All patients except one showed statistically significant improvements in activities of daily living (ADL) and motor symptoms, as measured by flexion angle at standing posture, Unified Parkinson's Disease Rating Scale (UPDRS) II and III, and modified Hoehn-Yahr staging.
Conclusion
Conservative treatment is effective in postural correction of camptocormia in Parkinson's disease, as well as improvement in ADL and motor symptoms
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