89 research outputs found
Acetogenin and Prenylated Flavonoids from Helminthostachys zeylanica with Inhibitory Activity on Superoxide Generation and Elastase Release by Neutrophils
One new acetogenin, 6-hydroxy-8-pentadecyloxocane-2,7-dione (1), and four new prenylated flavonoids, 4 '' a,5 '',6 '',7 '',8 '',8 '' a-hexahydro-5,3',4'-trihydroxy-5 '',5 '',8 '' a-trimethyl-4H-chromeno[2 '',3 '': 7,6] flavone (2), 4 '' a,5 '',6 '',7 '',8 '',8 '' a-hexahydro5,3', 4',-trihydroxy-5 '',5 '',8 '' a-trimethyl-4Hchromeno[2 '', 3 '': 7,8] flavone (3), 2-(3,4-dihydroxyphenyl)6-((2,2-dimethyl-6-methylenecyclohexyl) methyl)-5,7-dihydroxy-chroman-4-one (4), and 2-(3,4-dihydroxy-2-[(2,6,6-trimethylcyclohex-2-enyl) methyl] phenyl)-3,5,7-trihydroxy-4H-chromen-4-one (5), together with six known compounds, were isolated and purified from the rhizomes of Helminthostachys zeylanica by column chromatography and high performance liquid chromatography (HPLC) via bioactivity-guided fractionation isolation. The structures of the new isolates were elucidated by spectroscopic methods. Compounds 1, 3, and 5 showed inhibitory activities on either superoxide anion generation or elastase release by human neutrophils in response to formyl-L-methionyl-L-leucyl-L-phenylalanine/cytochalasin B (FMLP/CB)
Transformation of β-Ni(OH)2to NiO nano-sheets via surface nanocrystalline zirconia coating: Shape and size retention
Shape and size of the synthesized NiO nano-sheets were retained during transformation of sheet-like β-Ni(OH)2to NiO at elevated temperatures via nano-sized zirconia coating on the surface of β-Ni(OH)2. The average grain size was 6.42 nm after 600 °C treatment and slightly increased to 10 nm after 1000 °C treatment, showing effective sintering retardation between NiO nano-sheets. The excellent thermal stability revealed potential application at elevated temperatures, especially for high temperature catalysts and solid-state electrochemical devices
Prunella vulgaris: A comprehensive review of chemical constituents, pharmacological effects and clinical applications.
Prunella vulgaris (PV) is a perennial herb belonging to the Labiate family and is widely distributed in northeastern Asian countries such as Korea, Japan, and China. It is reported to display diverse biological activities including anti-microbial, anti-cancer, and anti-inflammation as determined by in vitro or in vivo studies. So far, about 200 compounds have been isolated from PV plant and majority of these have been characterized mainly as triterpenoids, sterols and flavonoids, followed by coumarins, phenylpropanoids, polysaccharides and volatile oils. This review summarizes and analyzes the current knowledge on the chemical constituents, pharmacological activities, mechanisms of action and clinical applications of the PV plant including its potential as a future medicinal plant. Although some of the chemical constituents of the PV plant and their mechanism of action have been investigated the biological activities of many of these remain unknown and further clinical trials are required to further enhance its reputation as a medicinal plant
The global burden of cancer attributable to risk factors, 2010–19: a systematic analysis for the Global Burden of Disease Study 2019
BACKGROUND: Understanding the magnitude of cancer burden attributable to potentially modifiable risk factors is crucial for development of effective prevention and mitigation strategies. We analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 to inform cancer control planning efforts globally. METHODS: The GBD 2019 comparative risk assessment framework was used to estimate cancer burden attributable to behavioural, environmental and occupational, and metabolic risk factors. A total of 82 risk–outcome pairs were included on the basis of the World Cancer Research Fund criteria. Estimated cancer deaths and disability-adjusted life-years (DALYs) in 2019 and change in these measures between 2010 and 2019 are presented. FINDINGS: Globally, in 2019, the risk factors included in this analysis accounted for 4·45 million (95% uncertainty interval 4·01–4·94) deaths and 105 million (95·0–116) DALYs for both sexes combined, representing 44·4% (41·3–48·4) of all cancer deaths and 42·0% (39·1–45·6) of all DALYs. There were 2·88 million (2·60–3·18) risk-attributable cancer deaths in males (50·6% [47·8–54·1] of all male cancer deaths) and 1·58 million (1·36–1·84) risk-attributable cancer deaths in females (36·3% [32·5–41·3] of all female cancer deaths). The leading risk factors at the most detailed level globally for risk-attributable cancer deaths and DALYs in 2019 for both sexes combined were smoking, followed by alcohol use and high BMI. Risk-attributable cancer burden varied by world region and Socio-demographic Index (SDI), with smoking, unsafe sex, and alcohol use being the three leading risk factors for risk-attributable cancer DALYs in low SDI locations in 2019, whereas DALYs in high SDI locations mirrored the top three global risk factor rankings. From 2010 to 2019, global risk-attributable cancer deaths increased by 20·4% (12·6–28·4) and DALYs by 16·8% (8·8–25·0), with the greatest percentage increase in metabolic risks (34·7% [27·9–42·8] and 33·3% [25·8–42·0]). INTERPRETATION: The leading risk factors contributing to global cancer burden in 2019 were behavioural, whereas metabolic risk factors saw the largest increases between 2010 and 2019. Reducing exposure to these modifiable risk factors would decrease cancer mortality and DALY rates worldwide, and policies should be tailored appropriately to local cancer risk factor burden
An innovative a-Si : H p-i-n based X-ray medical image detector for low dosage and long exposure applications
An innovative hydrogenated amorphous silicon (a-Si:H) p-i-n photodiode based X-ray detector for medical imaging applications was developed in this work, and the improvements of the device were also discussed. The detector consists of an a-Si:H p-i-n photodiode and a stacked dielectric layer, such as silicon nitride (SiNx), deposited on p-layer of this p-i-n diode (n-i-p-SiNx), as the major charge storage element. The detector operates as a capacitor, formed by this dielectric layer, in parallel with a reverse-biased p-i-n diode during the detection cycle. Consequently, the capacitance, for accumulating the photon-converted charges, of the p-i-n diode was enlarged by this stacked dielectric layer without decreasing the active area of the detector. As a result, the dynamic range, linearity and data retention capability of this novel detector are significantly improved. In particular, the photo sensitivity and charge storage capability of this novel detector can be separately optimized, and the drastically improved data retention, due to the high density and long release time of the trapped electrons in p-layer of the p-i-n diode, could facilitate this novel detector to be employed in the low dosage flux and long exposure applications. (C) 2003 Elsevier Science B.V. All rights reserved
A new convertible authenticated encryption scheme with message linkages
In this article, we present an authenticated encryption scheme with message linkages used to deliver a large message. To protect the receiver's benefit, the receiver can easily convert the signature into an ordinary one that can be verified by anyone. Several feasible attacks will be discussed, and the security analysis will prove that none of them can successfully break the proposed scheme. (c) 2006 Elsevier Ltd. All rights reserved
Operating principles and performance of a novel A-Si : H P-I-N-based X-ray detector for medical image applications
This work develops a novel hydrogenated amorphous silicon (a-Si:H) p-i-n photodiode-based. X-ray detector aimed at medical image applications. The new detector consists of an a-Si:H p-i-n photodiode and a stacked dielectric layer, deposited on the p-layer (n-i-p-SiNx) or the n-layer (p-i-n-SiNx) of the p-i-n photodiode, as the main charge storage element. This detector operates as a capacitor and is connected in parallel to a reverse-biased p-i-n photodiode during the detection cycle to accumulate photon-converted charges. The junction capacitance (C-j) of the p-i-n diode was enhanced by this stacked dielectric. layer without reducing the active area of the detector. The design of the charge storage capacity and the photon-charge transfer efficiency can be optimized separately for various applications. Moreover, the linearity, dynamic range of operation, and data retention capacity of the detector were found to be markedly improved by the enlarged capacitance in the detector. The operating principles and performance of this novel device are discussed, and the corresponding control sequence of the switch of the device array is also addressed. The experimental results proved that this novel structure is valid and can be applied to construct effectively a two-dimensional detection array, offering considerable advantages of the novel device in X-ray medical image applications
Comprehensive Flight Dynamics Activities and Enhancement for KOMPSAT-3 Mission Operations
Inhibitors of protein and RNA synthesis block the cytotoxic effects of non-steroidal antiestrogens
10.1016/0167-4889(95)00017-MBiochimica et Biophysica Acta - Molecular Cell Research12662215-222BAMR
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