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Common Substrate (common + substrate)
Selected AbstractsA compact microstrip UWB BPF with nonuniformly short-circuited CPW resonatorMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 1 2010H. Chen Abstract A novel and compact ultra-wideband bandpass filter using hybrid microstrip/coplanar waveguide is presented. The proposed filter consists of a single coplanar waveguide with nonuniformly short-circuited resonator, which is broadside-coupled to two microstrip open-circuited stubs on the other side of a common substrate. The measured results show that the filter has a good performance, including a low insertion loss, a group delay variation of less than 0.25 ns within the passband, stop-band of up to 18.8 GHz at high frequencies, and an out-of-band rejection level of below ,16.5 dB from 11.4 to 18.8 GHz. ©2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 216,218, 2010; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/mop.24859 [source] An ultra-wideband bandpass filter using hybrid structure of microstrip and CPWMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 10 2009Xun Luo Abstract An ultra-wideband (UWB) bandpass filter is proposed based on the hybrid structure of microstrip and coplanar waveguide (CPW). First, the detached-mode resonator is formed on the CPW layer, which composes a quarter-wavelength (,/4) multiple-mode resonator (MMR) with a short-stub and a ,/4 single-mode resonator. Then, two ,/4 microstrip open-stubs on the top side of the common substrate are introduced for bandwidth enhancement to meet the UWB passband limit. Quasi-elliptic function response and UWB operation are achieved. The simulated and measured results show an excellent agreement. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2470,2473, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24658 [source] A compact dual-port, dual-band planar microstrip antennaMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 4 2002A. Gadzina Abstract A compact dual-band, dual-port planar microstrip antenna is described. Its main properties are wide bandwidth, high and constant gain at both frequency bands, and a simple planar structure, which results from etching all patches onto a common substrate. As an example of application an antenna for GSM900/1800 has been realized and described with measured data. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 34: 302,305, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10443 [source] Functional genomics of phosphate antiport systems of plastidsPHYSIOLOGIA PLANTARUM, Issue 4 2003Ulf-Ingo Flügge Plant cells require a co-ordination of metabolism between their major compartments, the plastids and the cytosol, in particular as certain metabolic pathways are confined to either compartments. The inner envelope membrane of the plastids forms the major barrier for metabolite exchange and is the site for numerous transport proteins, which selectively catalyse metabolite exchanges characteristic for green and/or non-green tissues. This report is focused on the molecular biology, evolution and physiological function of the family of phosphate translocators (PT) from plastids. Until now, four distinct subfamilies have been identified and characterized, which all share inorganic phosphate as common substrate, but have different spectra of counter exchange substrates to fulfil the metabolic needs of individual cells and tissues. The PTs are named after their main transported substrate, triose phosphate (TPT), phosphoenolpyruvate (PPT), glucose 6-phosphate (GPT) and xylulose 5-P (XPT). All PTs belong to the TPT/nucleotide sugar transporter (NST) superfamily, which includes yet uncharacterized PT homologues from plants and other eukaryotes. Transgenic plants or mutants with altered transport activity of some of the PTs have been generated or isolated. The analysis of these plant lines revealed new insights in the co-ordination and flexibility of plant metabolism. [source] Chinese medicine Banxia-houpu decoction regulates c-fos expression in the brain regions in chronic mild stress model in ratsPHYTOTHERAPY RESEARCH, Issue 3 2004Weiyun Zhang Abstract Banxia-houpu decoction is a safe and effective traditional Chinese medicinal formula used in the treatment of mild and manic-depressive disorders for centuries. There has been increasing interest in its therapeutic application in depression. However, the mechanisms behind behavioural changes are still poorly understood. Chronic mild stress (CMS)-induced preference behaviour change has been used as a model to predict the clinical ef,cacy of many types of antidepressant treatment. Both EtOH and water extracts (AE and WE) of Banxia-houpu decoction exhibited a signi,cantly increased sucrose intake in the CMS model in rats, but there was no effect in unstressed animals. In the present study, it was found that the c-fos expression in cerebral cortex, hippocampus and striatum corpora were very high in the CMS model in rats. WE and AE at a dose of 130 mg/kg exhibited a signi,cantly decreased c-fos expression in the cerebral regions in CMS model in rats, respectively. The former was more potent than the latter. However, no signi,cant changes in the c-fos expression were observed in unstressed rats treated with the decoction. Fluoxetine not only signi,cantly reduced c-fos expression in all regions in the CMS model in rats, but only showed a marked decrease in c-fos expression in the hippocampus in unstressed animals. A different molecular mechanism of Banxia-houpu decoction and ,uoxetine may be implied. The cerebral cortex, hippocampus and striatum conpora might be important structural substrates in the central nervous system mediating the section of the Banxia-houpu decoction on preference behaviour in CMS-induced rats, and fos protein might be the common substrate of the signal transduction process of the decoction. Copyright © 2004 John Wiley & Sons, Ltd. [source] Structural and functional organization of Complex I in the mitochondrial respiratory chainBIOFACTORS, Issue 1-4 2003Cristina Bianchi Abstract Metabolic flux control analysis of NADH oxidation in bovine heart submitochondrial particles revealed high flux control coefficients for both Complex I and Complex III, suggesting that the two enzymes are functionally associated as a single enzyme, with channelling of the common substrate, Coenzyme Q. This is in contrast with the more accepted view of a mobile diffusable Coenzyme Q pool between these enzymes. Dilution with phospholipids of a mitochondrial fraction enriched in Complexes I and III, with consequent increased theoretical distance between complexes, determines adherence to pool behavior for Coenzyme Q, but only at dilution higher than 1:5 (protein:phospholipids), whereas, at lower phospholipid content, the turnover of NADH cytochrome c reductase is higher than expected by the pool equation. [source] Litter Decomposition Within the Canopy and Forest Floor of Three Tree Species in a Tropical Lowland Rain forest, Costa RicaBIOTROPICA, Issue 3 2010Catherine L. Cardelús ABSTRACT The rain forest canopy hosts a large percentage of the world's plant biodiversity, which is maintained, in large part, by internal nutrient cycling. This is the first study to examine the effects of site (canopy, forest floor) and tree species (Dipteryx panamensis, Lecythis ampla, Hyeronima alchorneoides) on decay rates of a common substrate and in situ leaf litter in a tropical forest in Costa Rica. Decay rates were slower for both substrates within the canopy than on the forest floor. The slower rate of mass loss of the common substrate in the canopy was due to differences in microclimate between sites. Canopy litter decay rates were negatively correlated with litter lignin:P ratios, while forest floor decay rates were negatively correlated with lignin concentrations, indicating that the control of litter decay rates in the canopy is P availability while that of the forest floor is carbon quality. The slower cycling rates within the canopy are consistent with lower foliar nutrient concentrations of epiphytes compared with forest floor-rooted plants. Litter decay rates, but not common substrate decay rates, varied among tree species. The lack of variation in common substrate decay among tree species eliminated microclimatic variation as a possible cause for differences in litter decay and points to variation in litter quality, nutrient availability and decomposer community of tree species as the causal factors. The host tree contribution to canopy nutrient cycling via litter quality and inputs may influence the quality and quantity of canopy soil resources. Abstract in Spanish is available at http://www.blackwell-synergy.com/loi/btp [source] Modification of epithelial cell barrier permeability and intercellular junctions by Clostridium sordellii lethal toxinsCELLULAR MICROBIOLOGY, Issue 7 2006Catherine Boehm Summary Clostridium sordellii lethal toxin (LT) is a glucosyltransferase which inactivates small GTPases from the Rho and Ras families. In the present work, we studied the effects of two variants, LT82 and LT9048, on the integrity of epithelial cell barrier using polarized MCCD (Mouse Cortical Collecting Duct) and MDCK (Madin-Darby Canine Kidney) cells. Our results demonstrate for the first time that LTs have very limited effects on tight junctions. In contrast, we show that both toxins modified the paracellular permeability within 2,4 h. Concomitantly LT82 and LT9048 induced a disorganization of basolateral actin filaments, without modifying apical actin. Both toxins mainly altered adherens junctions by removing E-cadherin-catenin complexes from the membrane to the cytosol. Similar effects on adherens junctions have been observed with other toxins, which directly or indirectly depolymerize actin. Thereby, Rac, a common substrate of both LTs, might play a central role in LT-dependent adherens junction alteration. Here, we show that adherens junction perturbation induced by LTs results neither from a direct effect of toxins on adherens junction proteins nor from an actin-independent Rac pathway, but rather from a Rac-dependent disorganization of basolateral actin cytoskeleton. This further supports that a dynamic equilibrium of cortical actin filaments is essential for functional E-cadherin organization in epithelia. [source] Trophic interactions in the methanogenic microbial community of low-temperature terrestrial ecosystemsFEMS MICROBIOLOGY ECOLOGY, Issue 1 2005O.R. Kotsyurbenko Abstract The formation of methane in various ecosystems is due to the functioning of an anaerobic community, which combines trophically different groups of microorganisms. The methanogenic microbial community is a complex biological system, which responds to low temperatures by changes in its trophic structure resulting in redistributing matter flows. The enhanced activity of homoacetogenic bacteria at low temperature plays a significant role in this redistribution. Due to their relatively high growth rates and metabolic versatility, homoacetogens can successfully compete with fermenting bacteria and hydrogenotrophic methanogenic archaea for common substrates. The concentration of hydrogen is an important regulatory factor in the psychroactive methanogenic community. At low temperature methanogenic archaea possessing a higher affinity for hydrogen than homoacetogens provide for interspecies H2 transport in syntrophic reactions of fatty acid decomposition. The formation of a balanced community at low temperature is a longtime process. Cold terrestrial ecosystems are dominated by psychroactive (psychrotolerant) microorganisms, which can grow over a wide range of ambient temperatures. [source] Raised water temperature lowers diversity of hyporheic aquatic hyphomycetesFRESHWATER BIOLOGY, Issue 2 2008FELIX BÄRLOCHER Summary 1. The hyporheic zone of a permanent first-order stream was divided into a treatment and a control section using a 1 m deep sheet-metal barrier. During a 4-month pre-treatment period, water temperatures in two transects of the two sections were not different. Upon heating, the water temperature in the treatment transect increased by an average of 4.3 °C over values in the control transect. 2. Eleven bimonthly core samples were taken from a treatment and a control transect, and recovered CPOM was classified as twigs, wood, grass, roots, cedar and deciduous leaves. 3. In both transects, twigs were the most common and deciduous leaves the least common substrates. The number of leaf fragments declined significantly in the heat-treated transect. 4. Diversity and frequencies of occurrence of aquatic hyphomycetes were highest on leaves and lowest on grass and wood. On leaves, their frequency of occurrence was higher in control than in treatment samples. 5. Preliminary results with amplified and cloned 18S DNA sequences revealed many fungal taxa with high affinities to Basidiomycota, particularly to Limnoperdon incarnatum. 6. By itself, higher water temperature due to global warming is likely to lower the availability of substrates for, and therefore the occurrence of, aquatic hyphomycetes. [source] Divergent Reactivity of 2-Azetidinone-Tethered Allenols with Electrophilic Reagents: Controlled Ring Expansion versus SpirocyclizationADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 4 2010Benito Alcaide Abstract A dual reactivity of 2-azetidinone-tethered allenols may occur by judicious choice of the electrophilic reagents, namely halogenating versus selenating reagents. Using common substrates, structurally different compounds, namely tetramic acids (from N -bromosuccinimide) or spirocyclic seleno-,-lactams (from N -phenylselenophthalimide), can be readily synthesized by these divergent protocols. [source] Growth-Promoting Nitrogen Nutrition Affects Flavonoid Biosynthesis in Young Apple (Malus domestica Borkh.) LeavesPLANT BIOLOGY, Issue 6 2005T. Strissel Abstract: Enhanced shoot growth and a decrease in flavonoid concentration in apple trees grown under high nitrogen (N) supply was observed in previous studies, along with increasing scab susceptibility of cultivar "Golden Delicious" after high N nutrition. Several hypotheses have suggested that there is a trade-off between primary and secondary metabolism because of competition for common substrates, but nothing is known about regulation at the enzyme level. In this study, a set of experiments was performed to elucidate the effect of N nutrition on the activities of key enzymes involved in flavonoid biosynthesis (phenylalanine ammonia-lyase [PAL], chalcone synthase/chalcone isomerase [CHS/CHI}, flavanone 3-hydroxylase [FHT], flavonol synthase [FLS], dihydroflavonol 4-reductase [DFR]) and the accumulation of different groups of phenylpropanoids. The inhibition of flavonoid accumulation by high N nutrition could be confirmed, but the influence of N supply on the flavonoid enzymes CHS/CHI, FHT, DFR, and FLS was not evident. However, PAL activity seems to be downregulated, thus forming a bottleneck resulting in a generally decreased flavonoid accumulation. Furthermore, the response of the scab-resistant cultivar "Rewena" to high N nutrition was not as strong as that of the susceptible cultivar "Golden Delicious". [source] Polysomnography in patients with post-traumatic stress disorderPSYCHIATRY AND CLINICAL NEUROSCIENCES, Issue 3 2010Sinan Yetkin MD Aims:, The purpose of the present study was to investigate sleep structure in post-traumatic stress disorder (PTSD) patients with and without any psychiatric comorbidities. The relationship between sleep variables and measurements of clinical symptom severity were also investigated. Methods:, Sleep patterns of 24 non-medicated male PTSD patients and 16 age- and sex-matched normal controls were investigated on polysomnography on two consecutive nights. Six PTSD-only patients and 15 PTSD patients with major depressive disorder (MDD) were also compared to normal controls. Sleep variables were correlated with PTSD symptoms. Results:, Compared to the normal controls, the PTSD patients with MDD had difficulty initiating sleep, poor sleep efficiency, decreased total sleep time, decreased slow wave sleep (SWS), and a reduced rapid eye movement (REM) sleep latency. The PTSD patients without any comorbid psychiatric disorders had moderately significant disturbances of sleep continuity, and decreased SWS, but no abnormalities of REM sleep. REM sleep latency was inversely proportional to the severity of startle response. SWS was found to be inversely correlated with the severity of psychogenic amnesia. Conclusions:, PTSD patients have disturbance of sleep continuity, and SWS deficit, without the impact of comorbid depression on sleep. The relationship between SWS and the inability to recall an important aspect of trauma may indicate the role of sleep in the consolidation of traumatic memories. The relationship between the severity of the startle response and REM latency may suggest that REM sleep physiology shares common substrates with the symptoms of PTSD. [source] Zero valent iron as an electron-donor for methanogenesis and sulfate reduction in anaerobic sludgeBIOTECHNOLOGY & BIOENGINEERING, Issue 7 2005Srilakshmi Karri Abstract Zero valent iron (ZVI) is a reactive media commonly utilized in permeable reactive barriers (PRBs). Sulfate reducing bacteria are being considered for the immobilization of heavy metals in PRBs. The purpose of this study was to evaluate the potential of ZVI as an electron donor for sulfate reduction in natural mixed anaerobic cultures. The ability of methanogens to utilize ZVI as an electron-donor was also explored since these microorganisms often compete with sulfate reducers for common substrates. Four grades of ZVI of different particle sizes (1.120, 0.149, 0.044, and 0.010 mm diameter) were compared as electron donor in batch bioassays inoculated with anaerobic bioreactor sludge. Methanogenesis was evaluated in mineral media lacking sulfate. Sulfate reduction was evaluated in mineral media containing sulfate and the specific methanogenic inhibitor, 2-bromoethane sulfonate. ZVI contributed to significant increases in methane production and sulfate reductioncompared to endogenous substrate controls. The rates of methane formation or sulfate reduction were positively correlated with the surface area of ZVI. The highest rates of 0.310 mmol CH4 formed/mol Fe0·day and 0.804 mmol SO reduced/ mol Fe0·day were obtained with the finest grade of ZVI (0.01 mm). The results demonstrate that ZVI is readily utilized as a slow-release electron donor for methanogenesis and sulfate reduction in anaerobic sludge; and therefore, has a promising potential in bioremediation applications. © 2005 Wiley Periodicals, Inc. [source] | |||||||||||||