bluuebunny/crossref_metadata_2025_split huggingface dataset:
Antioxidant activity and hepatoprotective potential of agaro-oligosaccharides in vitro and in vivo
Authors: Chen Haimin , Yan Xiaojun , Zhu Peng , Lin Jing 
Published: December 2006

Abstract

Background
Agaro-oligosaccharides derived from red seaweed polysaccharide have been reported to possess antioxidant activity. In order to assess the live protective effects of agar-oligosaccharides, we did both in vitro and in vivo studies based on own-made agaro-oligosaccharides, and the structural information of this oligosaccharide was also determined.

Method
Structure of agaro-oligosaccharides prepared with acid hydrolysis on agar was confirmed by matrix-assisted ultraviolet laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS) and NMR. The antioxidant effect of agaro-oligosaccharides on intracellular reactive oxygen species (ROS) was assessed by 2', 7'-dichlorofluorescin diacetate. Carbon tetrachloride was used to induce liver injury, some index including SOD, GSH-Px, MDA, AST, ALT were examined to determine the hepatoprotective effect of agaro-oligosaccharides.

Results
Agaro-oligosaccharides we got were composed of odd polymerizations with molecular weights ranged from 500 to 2500. Results from intracellular test indicated that agaro-oligosaccharides could significantly scavenge the level of oxidants in the hepatocytes, more beneficially, also associated with the improvement of cell viability In vivo studies of the antioxidant effects on tissue peroxidative damage induced by carbon tetrachloride in rat model indicated that agaro-oligosaccharides could elevate the activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and decrease the level of malondialdehyde (MDA), glutamate oxaloacetate transaminase (AST), glutamic pyruvic transaminase (ALT) significantly. At 400 mg/kg, MDA level reduced 44 % and 21 % in liver and heart, SOD and GSH-Px increased to highest in liver and serum, while ALT level decreased 22.16 % in serum.

Conclusion
Overall, the results of the present study indicate that agaro-oligosaccharides can exert their in vitro and in vivo hepatoprotective effect through scavenging oxidative damage induced by ROS.
Analysis of gene expression and chemoresistance of CD133+ cancer stem cells in glioblastoma
Authors: Liu Gentao , Yuan Xiangpeng , Zeng Zhaohui , Tunici Patrizia , Ng Hiushan , Abdulkadir Iman R , Lu Lizhi , Irvin Dwain , Black Keith L , Yu John S 
Published: December 2006

Abstract

Background
Recently, a small population of cancer stem cells in adult and pediatric brain tumors has been identified. Some evidence has suggested that CD133 is a marker for a subset of leukemia and glioblastoma cancer stem cells. Especially, CD133 positive cells isolated from human glioblastoma may initiate tumors and represent novel targets for therapeutics. The gene expression and the drug resistance property of CD133 positive cancer stem cells, however, are still unknown.

Results
In this study, by FACS analysis we determined the percentage of CD133 positive cells in three primary cultured cell lines established from glioblastoma patients 10.2%, 69.7% and 27.5%, respectively. We also determined the average mRNA levels of markers associated with neural precursors. For example, CD90, CD44, CXCR4, Nestin, Msi1 and MELK mRNA on CD133 positive cells increased to 15.6, 5.7, 337.8, 21.4, 84 and 1351 times, respectively, compared to autologous CD133 negative cells derived from cell line No. 66. Additionally, CD133 positive cells express higher levels of BCRP1 and MGMT mRNA, as well as higher mRNA levels of genes that inhibit apoptosis. Furthermore, CD133 positive cells were significantly resistant to chemotherapeutic agents including temozolomide, carboplatin, paclitaxel (Taxol) and etoposide (VP16) compared to autologous CD133 negative cells. Finally, CD133 expression was significantly higher in recurrent GBM tissue obtained from five patients as compared to their respective newly diagnosed tumors.

Conclusion
Our study for the first time provided evidence that CD133 positive cancer stem cells display strong capability on tumor's resistance to chemotherapy. This resistance is probably contributed by the CD133 positive cell with higher expression of on BCRP1 and MGMT, as well as the anti-apoptosis protein and inhibitors of apoptosis protein families. Future treatment should target this small population of CD133 positive cancer stem cells in tumors to improve the survival of brain tumor patients.
Selective Epoxidation of Cyclohexene by a Square-planar Ru Complex Immobilized into Mesoporous Silicate FSM-16
Authors: Okumura Takeshi , Takagi Hideki , Funahashi Yasuhiro , Ozawa Tomohiro , Fukushima Yoshiaki , Jitsukawa Koichro , Masuda Hideki 
Published: December 2006

Abstract
The Ru complex, [RuII(babp)(dmso)2] (1) (H2babp = 6,6′-bis(benzoylamino)-2,2′-bipyridine), was immobilized into mesoporous silicate FSM-16. The heterogeneous catalyst demonstrated a more selective epoxidation compared with the homogeneous 1.
Transformations of N-Allyl-N-(phenylethynyl)arenesulfonamides into 2,2-Disubstituted 4-Pentenenitriles through Aza-Claisen Rearrangement that Follows Carbomagnesiation
Authors: Yasui Hiroto , Yorimitsu Hideki , Oshima Koichiro 
Published: December 2006

Abstract
Treatment of N-allyl-N-(phenylethynyl)arenesulfonamides with Grignard reagents under copper catalysis resulted in carbomagnesiation across the alkynyl parts. The carbomagnesiations yielded 2-magnesio-3-aza-1,5-hexadienes, which underwent the aza-Claisen rearrangement upon heating. The rearrangement followed by elimination of the arenesulfonyl groups provided 2,2-disubstituted 4-pentenenitriles.
Chiral Scandium-catalyzed Highly Stereoselective Ring-opening of meso-Epoxides with Thiols
Authors: Ogawa Chikako , Wang Naiwei , Kobayashi Shu 
Published: December 2006

Abstract
The desymmetrization of meso-epoxides with thiols proceeded smoothly in dichloromethane or dichloroethane in the presence of a catalytic amount of a chiral scandium complex consisting of Sc(OTf)3 and chiral bipyridine 1, to afford the corresponding sulfides in high yields with high enantioselectivities.
Iron(III) Chloride-catalyzed Reductive Etherification of Carbonyl Compounds with Alcohols
Authors: Iwanami Katsuyuki , Yano Kentaro , Oriyama Takeshi 
Published: December 2006

Abstract
A facile reductive etherification of carbonyl compounds can be performed by the reaction with alcohols and triethylsilane catalyzed by iron(III) chloride. The corresponding alkyl ethers are obtained in good to excellent yields under mild reaction conditions.
Incidence and Economic Burden of Osteoporosis-Related Fractures in the United States, 2005–2025
Authors: Burge Russel , Dawson-Hughes Bess , Solomon Daniel H , Wong John B , King Alison , Tosteson Anna 
Published: December 2006

Abstract
This study predicts the burden of incident osteoporosis-related fractures and costs in the United States, by sex, age group, race/ethnicity, and fracture type, from 2005 to 2025. Total fractures were &gt;2 million, costing nearly $17 billion in 2005. Men account for &gt;25% of the burden. Rapid growth in the disease burden is projected among nonwhite populations.
Introduction: The aging of the U.S. population will likely lead to greater prevalence of osteoporosis. Policy makers require precise projections of the disease burden by demographic subgroups and skeletal sites to effectively target osteoporosis intervention and treatment programs.
Materials and Methods: A state transition Markov decision model was used to estimate total incident fractures and costs by age, sex, race/ethnicity, and skeletal site for the U.S. population ≥50 years of age for 2005–2025.
Results: More than 2 million incident fractures at a cost of $17 billion are predicted for 2005. Total costs including prevalent fractures are more than $19 billion. Men account for 29% of fractures and 25% of costs. Total incident fractures by skeletal site were vertebral (27%), wrist (19%), hip (14%), pelvic (7%), and other (33%). Total costs by fracture type were vertebral (6%), hip (72%), wrist (3%), pelvic (5%), and other (14%). By 2025, annual fractures and costs are projected to rise by almost 50%. The most rapid growth is estimated for people 65–74 years of age, with an increase &gt;87%. An increase of nearly 175% is projected for Hispanic and other subpopulations.
Conclusions: Osteoporosis prevention, treatment, and education efforts should address all skeletal sites, not just hip and vertebral, and appropriate attention is warranted for men and diverse race/ethnicity subgroups.
Topochemical investigation on phenolic deposits in the vessels of afzelia (Afzelia spp.) and merbau (Intsia spp.) heartwood
Authors: Koch Gerald , Richter Hans-Georg , Schmitt Uwe 
Published: December 2006

Abstract
The topochemical distribution of phenolic deposits in the vessels of afzelia (Afzelia spp.) and merbau (Intsia spp.) heartwood was investigated by means of cellular UV microspectrophotometry (UMSP) to characterise the chemical composition and synthesis by pit membrane-associated enzymes. UV absorbance spectra of the deposits attached to the vessel walls of merbau are characterised by a distinct maximum at a wavelength of 368 nm representing the UV absorbance of pure robinetin (C15H10O7). Deposits in the vessels of afzelia display a typical spectrum of kaempferol (C15H10O2) with two distinct maxima at 270 and 350 nm. The pit membranes and pit canals of associated vessel and parenchyma cells are impregnated by these compounds. These results verify the assumption that the synthesis of deposits in afzelia and merbau is regulated by pit membrane-associated enzymes.
Application of scanning UV microspectrophotometry for the topochemical detection of lignin within individual cell walls of brown-rotted Scots pine (Pinus sylvestris L.) sapwood
Authors: Irbe Ilze , Noldt Guna , Koch Gerald , Andersone Ingeborga , Andersons Bruno 
Published: December 2006

Abstract
Brown rotted Scots pine (Pinus sylvestris) sapwood was studied using scanning UV microspectrophotometry. Wood blocks were exposed to the fungus Coniophora puteana (Schum.: Fr.) Karst. (BAM Ebw.15) for 6, 8, 10, 30, and 50 days. No wood weight loss was detected in the initial decay periods. On the other hand, point analyses of lignin distribution in wood cells revealed higher absorbance after 6–10 days of decay, which we interpret as an increase in the absorption coefficient of lignin due to its oxidative modification by the fungus. Uneven wood degradation occurred in the later periods (30 and 50 days), with both significantly decayed and visually sound cells observed. The decayed cells showed a higher absorbance at 280 nm, although the apparently sound cells were also degraded to a lower extent. Degradation of lignin-rich compounds in middle lamellae and cell corners was not observed during fungal attack.
Influence of overexpression of a gibberellin 20-oxidase gene on the kinetics of xylem cell development in hybrid poplar (Populus tremula L. and P. tremuloides Michx.)
Authors: Dünisch Oliver , Fladung Matthias , Nakaba Satoshi , Watanabe Yoko , Funada Ryo 
Published: December 2006

AbstractGibberellins (GAs) are important regulators of shoot growth in trees. We studied the kinetics of xylem formation in hybrid poplar (Populus tremulaL.×P. tremuloidesMichx.) in which the key regulatory gene gibberellin acid 20 oxidase (GA20-oxidase) isolated fromArabidopsisis overexpressed. Increments in the height and radius of shoots were registered by high-resolution laser measurements. The anatomical and chemical structure of mature xylem cells was studied by light electron microscopy and UV spectrophotometry. Transgenic plants showed an increase in height growth, but a lower speed of cell elongation during primary growth compared to wild-type plants. During the first year of growth, transgenic plants showed a higher radius increment, an increase in the period of cell expansion of vessels and fibres and their final size, and a higher lignin content of the compound middle lamella between fibres compared to wild-type plants. In contrast, during the third year of growth, only a slight increase in the period of cell expansion of fibre cells was observed in transgenic compared to wild-type plants. Analyses of GA20-oxidase expression in leaves and shoots of 6-month- and 3-year-old plants of three different independent transgenic lines revealed a decrease in its expression only in shoots but not in leaves of the 3-year-old plants. The results indicate that overexpression of the GA20-oxidase gene in young shoots of transgenic poplar predominately affects cell expansion, while no GA20-oxidase expression was observed in shoots of 3-year-old transgenic plants, resulting in wild-type xylem cell development.
Decay resistance of anhydride-modified Corsican pine sapwood exposed to the brown rot fungus Coniophora puteana
Authors: Hill Callum A.S. , Hale Michael D. , Ormondroyd Graham A. , Kwon Jin H. , Forster Simon C. 
Published: December 2006

Abstract
Corsican pine (Pinus nigra) sapwood was chemically modified with acetic or hexanoic anhydride to a variety of weight gains. The modified wood was exposed to the brown rot fungus Coniophora puteana, and the relationship between weight loss due to decay and weight percentage gain, or degree of hydroxyl substitution, was determined in a 16-week exposure test. The effect of exposure time and the strain of C. puteana upon the decay protection threshold of acetylated Corsican pine was also examined.
Extraction of iron compounds from wood from the Vasa
Authors: Almkvist Gunnar , Persson Ingmar 
Published: December 2006

Abstract
In 2000, salt precipitates were found on surfaces of the Swedish warship Vasa, accompanied by low pH values, partly as a result of oxidation of accumulated sulfur compounds. One hypothesis is that oxidation of the sulfur compounds was catalysed by the large amounts of diverse iron compounds present in the wood. It is therefore of interest to develop a method to extract the iron compounds and simultaneously neutralise the acids. The iron compounds could be extracted using an aqueous solution of ethylenediimino-bis(2-hydroxy-4-methylphenyl)acetic acid (EDDHMA) or diethylenetriamine penta-acetic acid (DTPA) at alkaline pH, leaving only small amounts of iron compounds. The polyethylene glycol (PEG) used as the conservation agent, salts and other water-soluble compounds were co-extracted. The extraction rate was enhanced by stirring and by higher concentrations of the chelator, but diffusion of compounds through the wood was the most important factor for the overall extraction efficiency. Extraction of iron compounds from deep inside the wood is time-consuming and may take years. The results from this study imply that aqueous extraction with strong chelators at relatively high pH, 9–11, effectively removes iron compounds and neutralises the acids present. Although the results are promising, it is still too early to start major re-conservation of Vasa wood using extraction, as all the effects on the wood are not known, but such studies are in progress.
High-consistency ozonation of hardwood kraft pulp
Authors: Tran Ai Van 
Published: December 2006

Abstract
At present, ozone is one of the main chemicals in elemental chlorine-free (ECF) and totally chlorine-free (TCF) bleaching sequences. High consistency (HC) and medium consistency (MC) technologies are in use. This study shows that HC ozonation of hardwood kraft pulp, as expressed by the overall kappa number encompassing both hexenuronic acid groups and residual lignin, is a two-phase path. The reaction rate of the first phase is two- to three-fold higher than that of the second phase. We propose that the first phase is due to ozonation of both hexenuronic acid groups and residual lignin, whereas the second phase involves only residual lignin. The fiber width and wall thickness were relatively unchanged during ozonation. These results are in contrast to the “shrinking core kinetic model” frequently discussed in the context of HC ozonation. The development of pulp brightness and the decrease in pulp viscosity with the ozonation time are well correlated with the overall kappa number or the kappa number due to residual lignin alone.
Measurement of Helium Generation in AISI 304 Reflector and Blanket Assemblies after Long-term Irradiation in EBR-II
Authors: Garner FA , Oliver BM , Greenwood LR , Porter DL , Allen T 
Published: December 2006

Abstract
Five hexagonal ducts constructed from AISI 304 stainless steel in the annealed state were removed from rows 8–14 of the EBR-II fast reactor after many years of irradiation to study the effect of atomic displacement rate on void swelling. For this objective it was important to assure that the observed differences in void swelling were not strongly influenced by variations in helium/dpa ratio. The two major contributions to helium production arise from the nickel and boron content of the steel. However, the boron content was unspecified and therefore unknown, but it was determined from an unirradiated archive duct by converting a well-defined fraction to helium and then measuring the helium content using isotopic dilution mass spectrometry. The same technique was used to measure the total helium in the irradiated duct specimens. After separating the boron contribution from the total measured helium it was possible to determine the contribution from various fast and thermal neutron interactions with the other major elements in the steel and compare the helium generation with predicted values. One important conclusion of the study is that the range of He/dpa ratios over the five subassemblies was not very large, allowing the observed changes in swelling to be attributed primarily to variations in displacement rate and temperature.
A New Biaxial Tension Test Fixture for Uniaxial Testing Machine—A Validation for Hyperelastic Behavior of Rubber-like Materials
Authors: Brieu M. , Diani J. , Bhatnagar N. 
Published: December 2006

Abstract
A new mechanism for a biaxial tension test is developed for loading an in-plane specimen simultaneously in two principal directions. This mechanism can be adapted to any uniaxial tension test machine and thereby it reduces the cost of conducting tests on expensive machines. It provides a uniform state of equibiaxial tension necessary for procedure characterizing the biaxial loading of any material system and particularly for understanding the hyperelastic behavior law of rubber-like materials for large deformations. The mechanism can also be utilized for evaluating an interaction coefficient of anisotropic or orthotropic materials like reinforced composites that can help in characterizing and predicting failure behavior. As a sample case, the experimental results obtained by this new mechanism are validated with the existing models for two rubber-like materials undergoing hyperelasticity.
Alteration of normal cellular profiles in the scleractinian coral (Pocillopora damicornis) following laboratory exposure to fuel oil
Authors: Rougée Luc , Downs Craig A. , Richmond Robert H. , Ostrander Gary K. 
Published: December 2006

Abstract
Petroleum contamination from oil spills is a continuing threat to our ocean's fragile ecosystems. Herein, we explored the effects of the water-soluble fraction of crude oil on a stony coral, Pocillopora damicornis (Linneaeus 1758). We developed methods for exposing corals to various concentrations of crude oil and for assessing the potential molecular responses of the corals. Corals were exposed to water-accommodated fraction solutions, and appropriate cellular biomarkers were quantified. When compared to the “healthy” control specimens, exposed corals exhibited shifts in biomarker concentrations that were indicative of a shift from homeostasis. Significant changes were seen in cytochrome P450 1-class, cytochrome P450 2-class, glutathione-S-transferase-pi, and cnidarian multixenobiotic resistance protein-1 biomarkers, which are involved the cellular response to, and manipulation and excretion of, toxic compounds, including polycyclic aromatic hydrocarbons. A shift in biomarkers necessary for porphyrin production (e.g., protoporphyrinogen oxidase IX and ferrochelatase) and porphyrin destruction (e.g., heme oxygenase-1 and invertebrate neuroglobin homologue) illustrates only one of the cellular protective mechanisms. The response to oxidative stress was evaluated through measurements of copper/zinc superoxide dismutase-1 and DNA glycosylase MutY homologue-1 concentrations. Likewise, changes in heat shock protein 70 and small heat shock proteins indicated an adjustment in the cellular production of proteins. Finally, the results of this laboratory study were nearly identical to what we observed previously among corals of a different species, Porites lobata, exposed to an oil spill in the field after the grounding of the Merchant Vessel Kyowa Violet.
Phototoxicity of oil sands–derived polycyclic aromatic compounds to japanese medaka (Oryzias latipes) embryos
Authors: Farwell Andrea J. , Nero Vincent , Croft Melanie , Rhodes Spencer , Dixon D. George 
Published: December 2006

AbstractAlkylated polycyclic aromatic compounds (PACs), which are rich in dibenzothiophenes, are present in natural and reclaimed aquatic environments in the oil sands region of northern Alberta (Canada). An oil sands–derived PAC extract has been shown to induce signs of blue sac disease in Japanese medaka (Oryzias latipes) embryos. Information regarding exposure to and effects of oil sands PACs is available, but little of this information concerns the impact of modifying factors. The present study focuses on the effect of simulated solar radiation on oil sands–derived PAC toxicity to Japanese medaka embryos. Photomodification of the oil sands PAC extract caused reduced toxicity with an increase in the duration of ultraviolet (UV) exposure. Generally, mortality and developmental endpoints and, to a lesser extent, growth were affected by photomodification. Coexposures of the PAC mixture and UV caused slight increases in toxicity for mortality and embryonic developmental endpoints at the longest duration of UV exposure tested (16 h). Based on the modest phototoxicity of the oil sands PAC extract to Japanese medaka embryos, enhanced toxicity associated with UV irradiation may not be a concern for embryos of fish species that are common to the oil sands region. However, testing the effects of differing levels of UV irradiation on larval fish and invertebrates that may differ in their PAC bioaccumulation would improve our understanding concerning the importance of UV irradiation as a modifying factor in oil sands environmental risk assessment.