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81.
Rando Tuvikene Kalle Truus Marju Robal Olga Volobujeva Enn Mellikov Tõnis Pehk Andres Kollist Tiiu Kailas Merike Vaher 《Journal of applied phycology》2010,22(1):51-63
The structure and composition of galactan from Furcellaria lumbricalis (furcellaran) were investigated in connection with rheological specificities, gel structure, and extraction conditions. The
polysaccharide was characterized by 13C nuclear magnetic resonance (13C-NMR) and Fourier transform infrared spectroscopy, inductively coupled plasma-optical emission spectrometry, electrothermal
atomization atomic absorption spectrometry, and gel permeation chromatography methods. The microstructure of polymer gels
was studied using a cryofixation method in combination with freeze-drying and scanning electron microscopy (SEM) techniques.
The undersulfated furcellaran backbone consists mainly of 3,6-anhydro-d-galactose (28.5–30.1%) and galactose residues, the latter being partly sulfated in positions 4 and 6, which give rise to
some specific properties of the gel. Also, residues of 6-O-methyl-d-galactose as a minor component are found to be present. The water-extracted furcellaran with the average molecular weight
about 290 kDa is rich in nitrogen, calcium, magnesium, and potassium, while the sodium content is rather low. The low sulfur
content (5.3%) and 13C-NMR spectra refer to an undersulfated nature of this galactan. The extraction of seaweeds in low concentration alkaline
solutions (instead of water) leads to a significant increase of the minimum size of the galactan particles and the value of
gel strength (more than 12 times for Rb-containing gels). The properties of the gel are dependent on specific tentacle-like
structure units present in furcellaran gels established by a high-resolution SEM. 相似文献
82.
McNeela EA Burke A Neill DR Baxter C Fernandes VE Ferreira D Smeaton S El-Rachkidy R McLoughlin RM Mori A Moran B Fitzgerald KA Tschopp J Pétrilli V Andrew PW Kadioglu A Lavelle EC 《PLoS pathogens》2010,6(11):e1001191
Pneumolysin (PLY) is a key Streptococcus pneumoniae virulence factor and potential candidate for inclusion in pneumococcal subunit vaccines. Dendritic cells (DC) play a key role in the initiation and instruction of adaptive immunity, but the effects of PLY on DC have not been widely investigated. Endotoxin-free PLY enhanced costimulatory molecule expression on DC but did not induce cytokine secretion. These effects have functional significance as adoptive transfer of DC exposed to PLY and antigen resulted in stronger antigen-specific T cell proliferation than transfer of DC exposed to antigen alone. PLY synergized with TLR agonists to enhance secretion of the proinflammatory cytokines IL-12, IL-23, IL-6, IL-1β, IL-1α and TNF-α by DC and enhanced cytokines including IL-17A and IFN-γ by splenocytes. PLY-induced DC maturation and cytokine secretion by DC and splenocytes was TLR4-independent. Both IL-17A and IFN-γ are required for protective immunity to pneumococcal infection and intranasal infection of mice with PLY-deficient pneumococci induced significantly less IFN-γ and IL-17A in the lungs compared to infection with wild-type bacteria. IL-1β plays a key role in promoting IL-17A and was previously shown to mediate protection against pneumococcal infection. The enhancement of IL-1β secretion by whole live S. pneumoniae and by PLY in DC required NLRP3, identifying PLY as a novel NLRP3 inflammasome activator. Furthermore, NLRP3 was required for protective immunity against respiratory infection with S. pneumoniae. These results add significantly to our understanding of the interactions between PLY and the immune system. 相似文献
83.
Julie E Norville Ratmir Derda Saurabh Gupta Kelly A Drinkwater Angela M Belcher Andres E Leschziner Thomas F KnightJr 《Journal of biological engineering》2010,4(1):17
Background
BioBrick standard biological parts are designed to make biological systems easier to engineer (e.g. assemble, manipulate, and modify). There are over 5,000 parts available in the Registry of Standard Biological Parts that can be easily assembled into genetic circuits using a standard assembly technique. The standardization of the assembly technique has allowed for wide distribution to a large number of users -- the parts are reusable and interchangeable during the assembly process. The standard assembly process, however, has some limitations. In particular it does not allow for modification of already assembled biological circuits, addition of protein tags to pre-existing BioBrick parts, or addition of non-BioBrick parts to assemblies. 相似文献84.
85.
Andres Meos Tiiu Jüriado Vallo Matto Ain Raal 《Biological trace element research》2011,140(2):244-251
Trace metal contamination is a major environmental and health problem virtually in all countries. The present study was aimed
to estimate the lead content of pot marigold (Calendula officinalis L.) inflorescences and leaves collected from a nonpolluted test field. The lead content in dry pot marigold inflorescences
was 9.34 ± 0.79 μg/g, in dry leaves 11.57 ± 0.47 μg/g, and in soil 0.649 ± 0.012 μg/g. The distance of pot marigold collection
beds (30–220 m from the motorway) had no effect on lead content. There was a strong positive correlation between the amount
of precipitations and lead content of pot marigold leaves but not inflorescences indicating the soil as primarily the source
of increased lead content. In conclusion, no effect of motorway vicinity was found for pot marigold inflorescences or leaves
lead content; however, as a precaution, it is not recommended to collect the plants during or just after showers. 相似文献
86.
Comprehensive gene expression analysis by transcript profiling 总被引:20,自引:0,他引:20
Donson J Fang Y Espiritu-Santo G Xing W Salazar A Miyamoto S Armendarez V Volkmuth W 《Plant molecular biology》2002,48(1-2):75-97
87.
Fractionation of diluted Hevea brasiliensis latex on iso-osmotic Ficoll density gradients by sedimentation produces a sharp acid phosphatase-rich lutoid band at the density of ca1.04 g/cm3. Polyphenol oxidase (PPO) is not exclusively located in the Frey-Wyssling complexes as shown earlier by others; its distribution is variable. A complete separation of acid phosphatase and PPO activities can be obtained by flotation in a Ficoll density gradient. Ethephon stimulation of the tree reduces the acid phosphatase and PPO activities. A transient change in lutoid density soon after stimulation is observed. The occurrence of some new enzyme activities and their subcellular localization are reported. 相似文献
88.
Jon M. Massman Andres Gordillo Robenzon E. Lorenzana Rex Bernardo 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2013,126(1):13-22
Maize (Zea mays L.) breeders evaluate many single-cross hybrids each year in multiple environments. Our objective was to determine the usefulness of genomewide predictions, based on marker effects from maize single-cross data, for identifying the best untested single crosses and the best inbreds within a biparental cross. We considered 479 experimental maize single crosses between 59 Iowa Stiff Stalk Synthetic (BSSS) inbreds and 44 non-BSSS inbreds. The single crosses were evaluated in multilocation experiments from 2001 to 2009 and the BSSS and non-BSSS inbreds had genotypic data for 669 single nucleotide polymorphism (SNP) markers. Single-cross performance was predicted by a previous best linear unbiased prediction (BLUP) approach that utilized marker-based relatedness and information on relatives, and from genomewide marker effects calculated by ridge-regression BLUP (RR-BLUP). With BLUP, the mean prediction accuracy (r MG) of single-cross performance was 0.87 for grain yield, 0.90 for grain moisture, 0.69 for stalk lodging, and 0.84 for root lodging. The BLUP and RR-BLUP models did not lead to r MG values that differed significantly. We then used the RR-BLUP model, developed from single-cross data, to predict the performance of testcrosses within 14 biparental populations. The r MG values within each testcross population were generally low and were often negative. These results were obtained despite the above-average level of linkage disequilibrium, i.e., r 2 between adjacent markers of 0.35 in the BSSS inbreds and 0.26 in the non-BSSS inbreds. Overall, our results suggested that genomewide marker effects estimated from maize single crosses are not advantageous (compared with BLUP) for predicting single-cross performance and have erratic usefulness for predicting testcross performance within a biparental cross. 相似文献
89.
Thioredoxin-interacting protein (Txnip) knockout (TKO) mice exhibit impaired response to fasting. Herein, we showed that activation of adenine monophosphate-activated protein kinase and cellular AMP levels were diminished in the heart and soleus muscle but not in gastrocnemius muscle of fasting TKO mice. Similarly, glycogen content in fasted TKO mice was increased in oxidative muscles but was not different in glycolytic muscles. These data suggest Txnip deficiency has a higher impact on oxidative muscle than glycolytic muscles and provide new insights into the metabolic role of Txnip. 相似文献
90.
The land crab Gecarcinus quadratus is an engineering species that controls nutrient cycling in tropical forests. Factors regulating their coastal distribution are not fully understood. We quantified land crab distribution during the dry season at Sirena Field Station in Corcovado National Park, Costa Rica, and found that land crab burrow density decreases with increasing distance from the ocean. Leaf litter depth and tree seedling density are negatively correlated with land crab burrow density. Burrows are strongly associated with sand substrate and burrow density is comparatively low in clay substrate. Results suggest that G. quadratus is limited to a narrow coastal zone with sand substrate, and this distribution could have profound effects on plant community structure. 相似文献