988 resultados para Brown family.
Resumo:
The analysis of the mass spectrum and the calculation of the strong decay of P-wave charmonium states strongly purport to explain the newly observed X(3915) and X(4350) as new members in the P-wave charmonium family, i.e., chi'(c0) for X(3915) and chi ''(c2) for X(4350). Under the P-wave charmonium assignment to X(3915) and X(4350), the J(PC) quantum numbers of X(3915) and X(4350) must be 0(++) and 2(++) respectively, which provide important criteria to test the P-wave charmonium explanation for X(3915) and X(4350) proposed by this Letter. The decay behavior of the remaining two P-wave charmonium states with the second radial excitation is predicted, and an experimental search for them is suggested.
Resumo:
Fucoidan fractions from the brown seaweed Chorda filum were studied using solvolytic desulfation.Methylation analysis and NMR spectroscopy were applied for native and desulfated polysaccharides.Homefucan sulfate from C.filum was shown to contain poly-a-(1-3)-fucopyranoside backbone with a high degree of branching,mainly of a-(1-2)-linked single units.Some fucopyranose residues are sulfated at O-4(mainly) and O-2 positions.Some a-(1-3)-linked fucose residues were shown by NMR to be 2-O-acetylated.The 1H and 13C NMR spectra of desulfated,deaceylated fucan were complerely assigned.THe spectral data obtained correspond to a quasiregular polysaccharide structure with a branched hexasaccharide repeating unit.Other fucoidan frations from C.filum have more complex carbohydrate composition and give rather complex methvlation patterns.
Resumo:
The ecological interaction of brown algae are important as these macroalgae are common and often keystone members in many benthic marine communities.This review highlights their chemical interactions,particularly with potential herbivores,but also with fouling oranganisms,with potential pathogens,with each other as gametes,and with their microenvironments when they are spores.Phlorotannins,which are phenolic compounds unique to brown algae,have been studied hesvily in many of these respects and sre highlightes here.This includes recent controversy about their roles as defences against herbivory,as well as new understanding of their roles in primary cellular functions that may,in many instances,be more important than ,and which at least have to be considered in convert with,any possible ecological functions.Brown algae have also been useful models for testing theoties about the evolution of and ecological constraints on chemical defence.Furthermore,their mocroscopic motile gametes and spores have the ability to react to their chemical environments behavirourally.
Resumo:
In this paper, marine brown algae Laminaria japonica was chemically modified by crosslinking with epichlorohydrin (EC1 and EC2), or oxidizing by potassium permanganate (PC), or crosslinking with glutaraldehyde (GA), or only washed by distilled water (DW). They were used for equilibrium sorption uptake studies with Cd2+, Cu2+, Ni2+ and Zn2+.
Resumo:
In this paper, marine brown algae Laminaria japonica was chemically modified by crosslinking with epichlorohydrin (EC1 and EC2), or oxidizing by potassium permanganate (PC), or crosslinking with glutaraldehyde (GA), or only washed by distilled water (DW). They were used for equilibrium sorption uptake studies with Cd2+, Cu2+, Ni2+ and Zn2+. The experimental data have been analyzed using Langmuir, Freundlich and Redlich-Peterson isotherms. The results showed that the biosorption equilibrium was well described by both the Langmuir and Redlich-Peterson isotherms.
Resumo:
A novel solid solution Ce6MoO15 was achieved. Their structure and oxide ionic conductivity were studied. Based on Ce6MoO15, rare earth element substitution on cerium site shows that all resulting oxides enhance the conductivity further, and have high oxide-ion conductivity, which may be a kind of promising material for SOFCs.
Resumo:
Two new brominated selinane sesquiterpenes, 1-bromoselin-4(14), 11-diene (1) and 9-bromoselin-4(14), 11-diene (2), one known cadinane sesquiterpene, cadalene (3), and four known selinane sesquiterpenes, alpha-selinene (4), beta-selinene (5), beta-dictyopterol (6), and cyperusol C (7), were isolated from a sample of marine brown alga Dictyopteris divaricata collected off the coast of Yantai (China). Their structures were established by detailed MS and NMR spectroscopic analysis, as well as comparison with literature data.
Resumo:
Mariculture of the brown alga Hizikia fusiformis (Harvey) Okamura as an export-oriented human food has been there more for than 20 years in China. It is now one of the five major farmed algal species along the Chinese coast. Stable and sufficient supply of young seedlings for scaling up the cultivation has been a problem throughout the farming history of this species due to the unique dioecious life cycle and relatively short time window of sexual reproduction in nature. These two factors led to a practical difficulty in obtaining zygotes at identical developmental stage in viable amounts for seedling production. A key solution to this problem is to control the synchronization of the receptacle development and to realize the simultaneous discharge of male and female gametes, such that the fertilization rate could be greatly enhanced. Focusing on one of the farmed populations in this report, we present our results on mass production of seedlings using the synchronization technique on a large scale performed in 2007. Totally 5.5 hundred million embryos were obtained from 100 kg female sporophytes. The seedlings were raised up to 3.5 mm in length in greenhouse tanks over a month and were further grown in open sea for over 3 months at two experimental sites. The success of mass production of seedlings in this alga helped to lay the basis for future trials in other species in the genus of Sargassum that have identical life cycle.