WorldWideScience

Sample records for c3 plants

  1. Photosynthetic carbon assimilation in C3- and C4-plants

    International Nuclear Information System (INIS)

    The photosynthetic mechanisms of plants have become to be well understood by the use of radioactive and stable isotopes. This review included the distribution of 14C in photosynthetic intermediates by assimilation with 14CO2, resultant CO2 receptors, Calvin cycle, C4 photosynthetic pathway, differences between the photosynthetic pathway for C3-plants and that for C4-plants, photorespiration, glycolate pathway, the yield of photosynthetic quanta and the relationship between assimilation with 14CO2 and 13C values. Reference was made to the photosynthetic mechanism in 13C-NMR follow-up with 13CO2. (Chiba, N.)

  2. The effect of C3 and C4 plants for the magneticsusceptibility signal in soils

    Institute of Scientific and Technical Information of China (English)

    吕厚远; 刘东生

    2001-01-01

    To understand the origin of the ultrafine pedogenic components responsible for the magnetic susceptibility (MS) enhancement remains a major challenging problem in linking magnetic signal with paleoclimate. Here we examine the effect of the natural fires on the MS signal of both plants and modern soils and in particular the MS difference between C3 and C4 plant ashes and their influence on magnetic susceptibility. We also proved the influence of the different floral root systems on the MS signal of modern soils. We find that the C3 and C4 plants are different in their ability to enhance MS signal of modern soils. Increased MS signal of modern soils by C4 plants was much greater than that by C3 plants.

  3. Evolution of GOLDEN2-LIKE gene function in C3 and C4 plants

    OpenAIRE

    Wang, Peng; Fouracre, Jim; Kelly, Steven; Karki, Shanta; Gowik, Udo; Aubry, Sylvain; Shaw, Michael K.; Westhoff, Peter; Slamet-Loedin, Inez H.; Quick, W. Paul; Hibberd, Julian M.; Langdale, Jane A.

    2012-01-01

    A pair of GOLDEN2-LIKE transcription factors is required for normal chloroplast development in land plant species that encompass the range from bryophytes to angiosperms. In the C4 plant maize, compartmentalized function of the two GLK genes in bundle sheath and mesophyll cells regulates dimorphic chloroplast differentiation, whereas in the C3 plants Physcomitrella patens and Arabidopsis thaliana the genes act redundantly in all photosynthetic cells. To assess whether the cell-specific functi...

  4. Characteristics of C-4 photosynthesis in stems and petioles of C-3 flowering plants

    OpenAIRE

    Hibberd, J.M.; Quick, W.P.

    2002-01-01

    Most plants are known as C-3 plants because the first product of photosynthetic CO2 fixation is a three-carbon compound. C-4 plants, which use an alternative pathway in which the first product is a four-carbon compound, have evolved independently many times and are found in at least 18 families. In addition to differences in their biochemistry, photosynthetic organs of C-4 plants show alterations in their anatomy and ultrastructure. Little is known about whether the biochemical or anatomical ...

  5. Engineering the multigene pathways for CO 2 concentration mechanism and bypassing the photorespiration in C 3 plants

    OpenAIRE

    Kamble, Pratibha

    2014-01-01

    The present study shows an improvement in photosynthesis in C3 plants by two different approaches. The first approach is aimed to increasing the CO2 concentration in the proximity of Rubisco. The second approach is aimed at bypassing the ‘wasteful’ reaction of photorespiration in C3 plants. In both approaches, multiple transgene metabolic pathways are created and successfully introduced in C3 plants. With the help of multiple transgene metabolic pathways the final products such as CO2 is obse...

  6. Drought and Oxidative Load in the Leaves of C3 Plants: a Predominant Role for Photorespiration?

    OpenAIRE

    Noctor, Graham; VELJOVIC‐JOVANOVIC, SONJA; DRISCOLL, SIMON; NOVITSKAYA, LARISSA; Foyer, Christine H.

    2002-01-01

    Although active oxygen species are produced at high rates in both the chloroplasts and peroxisomes of the leaves of C3 plants, most attention has focused on the potentially damaging consequences of enhanced chloroplastic production in stress conditions such as drought. This article attempts to provide quantitative estimates of the relative contributions of the chloroplast electron transport chain and the glycolate oxidase reaction to the oxidative load placed on the photosynthetic leaf cell. ...

  7. The Coordination of Leaf Photosynthesis Links C and N Fluxes in C-3 Plant Species

    OpenAIRE

    Maire, Vincent; Martres, Pierre; Kattge, Jens; Gastal, Francois; Esser, Gerd; Fontaine, Sébastien; Soussana, Jean-François

    2012-01-01

    Photosynthetic capacity is one of the most sensitive parameters in vegetation models and its relationship to leaf nitrogen content links the carbon and nitrogen cycles. Process understanding for reliably predicting photosynthetic capacity is still missing. To advance this understanding we have tested across C-3 plant species the coordination hypothesis, which assumes nitrogen allocation to photosynthetic processes such that photosynthesis tends to be co-limited by ribulose-1,5-bisphosphate (R...

  8. A novel approach for the suppression of photorespiration in C 3 plants by gene transfer

    OpenAIRE

    Bari, Rafijul

    2004-01-01

    In the present study, a novel principle is proposed to increase the CO2 concentration in the vicinity of Rubisco thereby suppressing photorespiration in C3 plants. The pathway is derived from E. coli and converts the glycolate formed during photorespiration into glycerate. Three enzymatic activities are required: Glycolate dehydrogenase (GDH), Glyoxylate carboligase (GCL), and Tratronic semialdehyde reductase (TSR). In order to establish the pathway in the chloroplast of tobacco (Nicotiana ta...

  9. Mycorrhizal Symbiotic Efficiency on C3 and C4 Plants under Salinity Stress - A Meta-Analysis.

    Science.gov (United States)

    Chandrasekaran, Murugesan; Kim, Kiyoon; Krishnamoorthy, Ramasamy; Walitang, Denver; Sundaram, Subbiah; Joe, Manoharan M; Selvakumar, Gopal; Hu, Shuijin; Oh, Sang-Hyon; Sa, Tongmin

    2016-01-01

    A wide range of C3 and C4 plant species could acclimatize and grow under the impact of salinity stress. Symbiotic relationship between plant roots and arbuscular mycorrhizal fungi (AMF) are widespread and are well known to ameliorate the influence of salinity stress on agro-ecosystem. In the present study, we sought to understand the phenomenon of variability on AMF symbiotic relationship on saline stress amelioration in C3 and C4 plants. Thus, the objective was to compare varied mycorrhizal symbiotic relationship between C3 and C4 plants in saline conditions. To accomplish the above mentioned objective, we conducted a random effects models meta-analysis across 60 published studies. An effect size was calculated as the difference in mycorrhizal responses between the AMF inoculated plants and its corresponding control under saline conditions. Responses were compared between (i) identity of AMF species and AMF inoculation, (ii) identity of host plants (C3 vs. C4) and plant functional groups, (iii) soil texture and level of salinity and (iv) experimental condition (greenhouse vs. field). Results indicate that both C3 and C4 plants under saline condition responded positively to AMF inoculation, thereby overcoming the predicted effects of symbiotic efficiency. Although C3 and C4 plants showed positive effects under low (EC 8 ds/m) saline conditions, C3 plants showed significant effects for mycorrhizal inoculation over C4 plants. Among the plant types, C4 annual and perennial plants, C4 herbs and C4 dicot had a significant effect over other counterparts. Between single and mixed AMF inoculants, single inoculants Rhizophagus irregularis had a positive effect on C3 plants whereas Funneliformis mosseae had a positive effect on C4 plants than other species. In all of the observed studies, mycorrhizal inoculation showed positive effects on shoot, root and total biomass, and in nitrogen, phosphorous and potassium (K) uptake. However, it showed negative effects in sodium (Na

  10. Mycorrhizal Symbiotic Efficiency on C3 and C4 Plants under Salinity Stress – A Meta-Analysis

    Science.gov (United States)

    Chandrasekaran, Murugesan; Kim, Kiyoon; Krishnamoorthy, Ramasamy; Walitang, Denver; Sundaram, Subbiah; Joe, Manoharan M.; Selvakumar, Gopal; Hu, Shuijin; Oh, Sang-Hyon; Sa, Tongmin

    2016-01-01

    A wide range of C3 and C4 plant species could acclimatize and grow under the impact of salinity stress. Symbiotic relationship between plant roots and arbuscular mycorrhizal fungi (AMF) are widespread and are well known to ameliorate the influence of salinity stress on agro-ecosystem. In the present study, we sought to understand the phenomenon of variability on AMF symbiotic relationship on saline stress amelioration in C3 and C4 plants. Thus, the objective was to compare varied mycorrhizal symbiotic relationship between C3 and C4 plants in saline conditions. To accomplish the above mentioned objective, we conducted a random effects models meta-analysis across 60 published studies. An effect size was calculated as the difference in mycorrhizal responses between the AMF inoculated plants and its corresponding control under saline conditions. Responses were compared between (i) identity of AMF species and AMF inoculation, (ii) identity of host plants (C3 vs. C4) and plant functional groups, (iii) soil texture and level of salinity and (iv) experimental condition (greenhouse vs. field). Results indicate that both C3 and C4 plants under saline condition responded positively to AMF inoculation, thereby overcoming the predicted effects of symbiotic efficiency. Although C3 and C4 plants showed positive effects under low (EC 8 ds/m) saline conditions, C3 plants showed significant effects for mycorrhizal inoculation over C4 plants. Among the plant types, C4 annual and perennial plants, C4 herbs and C4 dicot had a significant effect over other counterparts. Between single and mixed AMF inoculants, single inoculants Rhizophagus irregularis had a positive effect on C3 plants whereas Funneliformis mosseae had a positive effect on C4 plants than other species. In all of the observed studies, mycorrhizal inoculation showed positive effects on shoot, root and total biomass, and in nitrogen, phosphorous and potassium (K) uptake. However, it showed negative effects in sodium (Na

  11. The effect of atmospheric CO2 concentration on carbon isotope fractionation in C3 land plants

    Science.gov (United States)

    Schubert, Brian A.; Jahren, A. Hope

    2012-11-01

    Because atmospheric carbon dioxide is the ultimate source of all land-plant carbon, workers have suggested that pCO2 level may exert control over the amount of 13C incorporated into plant tissues. However, experiments growing plants under elevated pCO2 in both chamber and field settings, as well as meta-analyses of ecological and agricultural data, have yielded a wide range of estimates for the effect of pCO2 on the net isotopic discrimination (Δδ13Cp) between plant tissue (δ13Cp) and atmospheric CO2 (δ13CCO2). Because plant stomata respond sensitively to plant water status and simultaneously alter the concentration of pCO2 inside the plant (ci) relative to outside the plant (ca), any experiment that lacks environmental control over water availability across treatments could result in additional isotopic variation sufficient to mask or cancel the direct influence of pCO2 on Δδ13Cp. We present new data from plant growth chambers featuring enhanced dynamic stabilization of moisture availability and relative humidity, in addition to providing constant light, nutrient, δ13CCO2, and pCO2 level for up to four weeks of plant growth. Within these chambers, we grew a total of 191 C3 plants (128 Raphanus sativus plants and 63 Arabidopsis thaliana) across fifteen levels of pCO2 ranging from 370 to 4200 ppm. Three types of plant tissue were harvested and analyzed for carbon isotope value: above-ground tissues, below-ground tissues, and leaf-extracted nC31-alkanes. We observed strong hyperbolic correlations (R ⩾ 0.94) between the pCO2 level and Δδ13Cp for each type of plant tissue analyzed; furthermore the linear relationships previously suggested by experiments across small (10-350 ppm) changes in pCO2 (e.g., 300-310 ppm or 350-700 ppm) closely agree with the amount of fractionation per ppm increase in pCO2 calculated from our hyperbolic relationship. In this way, our work is consistent with, and provides a unifying relationship for, previous work on carbon isotopes

  12. Construction and molecular analysis of genetically modified C 3 plants expressing a glycolate oxidizing pathway inside the chloroplast

    OpenAIRE

    Kebeish, Rashad Mohamed Ahmed

    2006-01-01

    Metabolism of glycolate via the photorespiratory pathway in C3 plants consumes not only ATP and reducing equivalents but results also in approximately 25% loss of the carbon from glycolate. In the present study, a novel biochemical pathway for the metabolism of glycolate was established in the chloroplast of Arabidopsis thaliana plants. The new pathway aims to increase the CO2 concentration in the vicinity of Rubisco thereby suppressing photorespiration in C3 plants. The pathway is derived fr...

  13. O2-insensitive photosynthesis in C3 plants: its occurrence and a possible explanation

    International Nuclear Information System (INIS)

    Leaves of C3 plants which exhibit a normal O2 inhibition of CO2 fixation at less than saturating light intensity were found to exhibit O2-insensitive photosynthesis at high light. This behavior was observed in Phaseolus vulgaris L., Xanthium strumarium L., and Scrophularia desertorum (Shaw.) Munz. O2-insensitive photosynthesis has been reported in nine other C3 species and usually occurred when the intercellular CO2 pressure was about double the normal pressure. A lack of O2 inhibition of photosynthesis was always accompanied by a failure of increased CO2 pressure to stimulate photosynthesis to the expected degree. O2-insensitive photosynthesis also occurred after plants had been water stressed. Under such conditions, however, photosynthesis became O2 and CO2 insensitive at physiological CO2 pressures. Postillumination CO2 exchange kinetics showed that O2 and CO2 insensitivity was not the result of elimination of photorespiration. It is proposed that O2 and CO2 insensitivity occurs when the concentration of phosphate in the chloroplast stroma cannot be both high enough to allow photophosphorylation and low enough to allow starch and sucrose synthesis at the rates required by the rest of the photosynthetic component processes. Under these conditions, the energy diverted to photorespiration does not adversely affect the potential for CO2 assimilation

  14. Analysis of carbon isotope in phytoliths from C3 and C4 plants and modern soils

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The analysis of carbon isotope in phytoliths from modern plants and surface soils in China shows that the values of carbon isotope are consistent with those from C3 and C4 plants,and the processes of photosynthesis of the original plants can be clearly identified by carbon isotope in phytoliths.The value of carbon isotope varied from -23.8‰ to -28‰,with the maximum distributed in the latitude zone from 34° N to 40° N in North China and East China areas,and the minimum in the Northeast China and South China regions.The values of carbon of phytoliths tend to increase from low to high and then reduce to low value again as the latitude increases.In the same latitude zone,the carbon isotope in phytoliths from grassland soil under the trees is obviously lower than that from grassland soil without any trees with the difference of 1‰-2‰.

  15. Role of C3 plant species on carbon dioxide and methane emissions in Mediterranean constructed wetland

    Directory of Open Access Journals (Sweden)

    Carmelo Maucieri

    2014-08-01

    Full Text Available C3 plant species are widely used to vegetate constructed wetlands (CW, but so far no information is available on their effect on CW CO2(eq balance in the Mediterranean climate. The aim of this research was to study carbon dioxide (CO2 and methane (CH4 emissions and CO2(eq budgets of CW horizontal sub-surface flow pilot-plant beds vegetated with Arundo donax L. and Phragmites australis (Cav. Trin. ex Steud. compared with an unvegetated bed in Sicily. The highest total plant biomass production was measured in the bed vegetated with A. donax (17.0 kg m–2, whereas P. australis produced 7.6 kg m–2. CO2 and CH4 emissions and showed significant correlation with average air temperature and solar radiation for each bed. The CO2 emission values ranged from 0.8±0.1 g m–2 d–1, for the unvegetated bed in April, to 24.9±0.6 g m–2 d–1 for the bed with P. australis in August. The average CO2 emissions of the whole monitored period were 15.5±7.2, 15.1±7.1 and 3.6±2.4 g m–2 d–1 for A. donax, P. australis and unvegetated beds respectively. The CH4 fluxes differed significantly over the monitored seasons, with the highest median value being measured during spring (0.963 g m–2 d–1. No statistical differences were found for CH4 flux among the studied beds. Cumulative estimated CH4 emissions during the study period (from April to December were 159.5, 134.1 and 114.7 g m–2 for A. donax, P. australis and unvegetated beds respectively. CO2(eq balance showed that the two vegetated beds act as CO2(eq sinks, while the unvegetated bed, as expected, acts as a CO2(eq source. Considering only the above-ground plant biomass in the CO2(eq budgets, P. australis and A. donax determined uptakes of 1.30 and 8.35 kg CO2(eq m–2 respectively.

  16. Extraction and radiochromatographic division of the early photosynthetic products of C3 plants

    International Nuclear Information System (INIS)

    A complete method for extraction, radiochromatographic separation and 14C balance of the early photosynthetic products in C3 plants (peach, apple, plum, grapevine and beans) was worked out on the basis of comparative tests of methods presented in literature and of results obtained by investigations carried out. It was established that in view of accomplishing high quality chromatogram an appropriate way to purify the extracts is to eliminate the lipids, pigments, soluble proteins and high molecular carbohydrates in a two-phase system of methanol (chlorophorm)-water (6:5, 5:5) and to block the cations by 0.1 M EDTA. Two-directional ascending chromatography was applied on FN 4 paper rinsed with 0,01 M EDTA and 2 M CH3COOH and solvents: for the first direction - 98% ethamol 1 M ammonium acetate pH 7,5: 0,1 M EDTA (75/30 l) by repeated ascending and for the second direction - butanol (propyonic acid) water (10/5/7) by threefold rinsing. Twenty-four 14C compounds were separated and identified, namely: sucrose diphosphates, uridine diphosphate-glucose, glucose-6-phosphate, glucose-1-phosphate, fructose-6-phosphate, phosphoglyceric acid, phosphoglycolic acid, phosphoenolpyruvic acid, dihydroacetone phosphate, aspartate glutamate, glycine, serine, alanine, citrate, malate, glycerate, glycolate, sorbitol, fructose, glucose, sucrose, maltose and rafinose. For a full 14C balance of the samples the radioactivity of starch, -1,4-glucosyleglucans, lipids, pigments and residues was determined. (author)

  17. A critical review on the improvement of photosynthetic carbon assimilation in C3 plants using genetic engineering.

    Science.gov (United States)

    Ruan, Cheng-Jiang; Shao, Hong-Bo; Teixeira da Silva, Jaime A

    2012-03-01

    Global warming is one of the most serious challenges facing us today. It may be linked to the increase in atmospheric CO2 and other greenhouse gases (GHGs), leading to a rise in sea level, notable shifts in ecosystems, and in the frequency and intensity of wild fires. There is a strong interest in stabilizing the atmospheric concentration of CO2 and other GHGs by decreasing carbon emission and/or increasing carbon sequestration. Biotic sequestration is an important and effective strategy to mitigate the effects of rising atmospheric CO2 concentrations by increasing carbon sequestration and storage capacity of ecosystems using plant photosynthesis and by decreasing carbon emission using biofuel rather than fossil fuel. Improvement of photosynthetic carbon assimilation, using transgenic engineering, potentially provides a set of available and effective tools for enhancing plant carbon sequestration. In this review, firstly different biological methods of CO2 assimilation in C3, C4 and CAM plants are introduced and three types of C4 pathways which have high photosynthetic performance and have evolved as CO2 pumps are briefly summarized. Then (i) the improvement of photosynthetic carbon assimilation of C3 plants by transgenic engineering using non-C4 genes, and (ii) the overexpression of individual or multiple C4 cycle photosynthetic genes (PEPC, PPDK, PCK, NADP-ME and NADP-MDH) in transgenic C3 plants (e.g. tobacco, potato, rice and Arabidopsis) are highlighted. Some transgenic C3 plants (e.g. tobacco, rice and Arabidopsis) overexpressing the FBP/SBPase, ictB and cytochrome c6 genes showed positive effects on photosynthetic efficiency and growth characteristics. However, over the last 28 years, efforts to overexpress individual, double or multiple C4 enzymes in C3 plants like tobacco, potato, rice, and Arabidopsis have produced mixed results that do not confirm or eliminate the possibility of improving photosynthesis of C3 plants by this approach. Finally, a prospect

  18. Changes in assimilation of C3 marsh plants by resident fishes in estuarine systems with distinct hydrogeomorphology features.

    OpenAIRE

    Adna Ferreira Garcia

    2015-01-01

    Although saltmarshes are widely recognized as important habitats providing shelter for estuarine organisms and protection against predators, there is still no consensus on the trophic value of marsh plants for estuarine food webs. We employed stable isotopes to evaluate differences in assimilation of nutrients derived from marsh plants with C3 (Juncus acutus, Scirpus maritimus, Scirpus olneyi) and C4 (Spartina densiflora) photosynthetic pathways by resident fishes in three estuaries with cont...

  19. Arctic herbivore diet can be inferred from stable carbon and nitrogen isotopes in C3 plants, faeces and wool

    DEFF Research Database (Denmark)

    Kristensen, Ditte; Kristensen, Erik; Forchhammer, Mads C.; Michelsen, Anders; Schmidt, Niels Martin

    2011-01-01

    The use of stable isotopes in diet analysis usually relies on the different photosynthetic pathways of C3 and C4 plants, and the resulting difference in carbon isotope signature. In the Arctic, however, plant species are exclusively C3, and carbon isotopes alone are therefore not suitable for...... studying arctic herbivore diets. In this study, we examined the potential of both stable carbon and nitrogen isotopes to reconstruct the diet of an arctic herbivore, here the muskox (Ovibos moschatus (Zimmermann, 1780)), in northeast Greenland. The isotope composition of plant communities and functional...... distinct. As a result, our examination mainly relied on stable nitrogen isotopes. The interpretation of stable isotopes from faeces was difficult because of the large uncertainty in diet–faeces fractionation, whereas isotope signatures from wool suggested that the muskox summer diet consists of around 80...

  20. Variations in carbon isotope ratios of C3 plants and distribution of C4 plants along an altitudinal transect on the eastern slope of Mount Gongga

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Variations in carbon isotopic ratios (δ 13C) of C3 plants and distribution of C4 plants were investigated along an altitudinal transect on the eastern slope of Mount Gongga, and the environmental effects on them were discussed. It is shown that plants with C4 photosynthetic pathway mainly occur at altitudes below 2100 m a.s.l., suggesting that the low summer temperature is responsible for the distributional pattern. In addition, δ 13C of C3 plants increases with elevation at the region above 2000 m a.s.l. with the characteristics of humid climate, and the increase rate in δ 13C for C3 plants is about 1.3‰ per kilometer. Temperature determines the altitudinal trend of δ 13C.

  1. Variations in carbon isotope ratios of C_3 plants and distribution of C_4 plants along an altitudinal transect on the eastern slope of Mount Gongga

    Institute of Scientific and Technical Information of China (English)

    LI JiaZhu; WANG GuoAn; LIU XianZhao; HAN JiaMao; LIU Min; LIU XiaoJuan

    2009-01-01

    Variations in carbon isotopic ratios (δ~(13)C) of C_3 plants and distribution of C_4 plants were investigated along an altitudinal transect on the eastern slope of Mount Gongga,and the environmental effects on them were discussed,it is shown that plants with C_4 photosynthetic pathway mainly occur at altitudes below 2100 m a.a.l.,suggesting that the low summer temperature is responsible for the distributional pattern.In addition,δ~(13)C of C_3 plants increases with elevation at the region above 2000 m a.s.l,with the characteristics of humid climate,and the increase rate in δ~(13)C for C_3 plants is about 1.3‰ per kilometer.Temperature determines the altitudinal trend of δ~(13)C.

  2. C3 and C4 plant species as energy sources and their potential impact on environment and climate

    International Nuclear Information System (INIS)

    Careful selection of crop species, among other aspects, is very helpful in enhancing energy production by way of increased biomass yields from agricultural land. A wide range of C3 and C4 plant species has been introduced and investigated for their environmental and climatic impact. The results indicate already that some perennial C4 crop species posses high yield potential, lower erosion-index, better CO2 reduction rates and need less fertiliser, water and chemicals. (Author)

  3. Simulation of leaf photosynthesis of C3 plants under fluctuating light and different temperatures

    DEFF Research Database (Denmark)

    Öztürk, Isik; Holst, Niels; Ottosen, Carl-Otto

    2012-01-01

    An induction-dependent empirical model was developed to simulate the C3 leaf photosynthesis under fluctuating light and different temperatures. The model also takes into account the stomatal conductance when the light intensity just exceeds the compensation point after a prolonged period of...... partial cloud cover and varying temperatures. The temporal course of observed photosynthesis rate and the carbon gain was compared to the simulation. The ability of the current model to predict the carbon assimilation rate was assessed using different statistical indexes. The model predictions were...

  4. Photosynthetic characteristics of an amphibious plant, Eleocharis vivipara: Expression of C4 and C3 modes in contrasting environments

    International Nuclear Information System (INIS)

    Eleocharis vivipara Link, a freshwater amphibious leafless plant belonging to the Cyperaceae can grow in both terrestrial and submersed aquatic conditions. Two forms of E. vivipara obtained from these contrasting environments were examined for the characteristics associated with C4 and C3 photosynthesis. In the terrestrial form, the culms, which are photosynthetic organs, possess a Kranz-type anatomy typical of C4 plants, and well-developed bundle-sheath cells contain numerous large chloroplasts. In the submersed form, the culms possess anatomical features characteristic of submersed aquatic plants, and the reduced bundle-sheath cells contain only a few small chloroplasts. 14C pulse-12C chase experiments showed that the terrestrial form and the submersed form fix carbon by way of the C4 pathway, with aspartate (40%) and malate (35%) as the main primary products, and by way of the C3 pathway, with 3-phosphoglyceric acid (53%) and sugar phosphates (14%) as the main primary products, respectively. The terrestrial form showed photosynthetic enzyme activities typical of the NAD-malic enzyme-C4 subtype, whereas the submersed form showed decreased activities of key C4 enzymes and an increased ribulose 1,5-bisphosphate carboxylase activity. These data suggest that this species can differentiate into the C4 mode under terrestrial conditions and into the C3 mode under submersed conditions

  5. Changes in assimilation of C3 marsh plants by resident fishes in estuarine systems with distinct hydrogeomorphology features.

    Directory of Open Access Journals (Sweden)

    Adna Ferreira Garcia

    2015-11-01

    Full Text Available Although saltmarshes are widely recognized as important habitats providing shelter for estuarine organisms and protection against predators, there is still no consensus on the trophic value of marsh plants for estuarine food webs. We employed stable isotopes to evaluate differences in assimilation of nutrients derived from marsh plants with C3 (Juncus acutus, Scirpus maritimus, Scirpus olneyi and C4 (Spartina densiflora photosynthetic pathways by resident fishes in three estuaries with contrasting hydrogeomorphology characteristics. Carbon (δ13C and nitrogen (δ15N stable isotope ratios of basal food sources (C3 and C4 marsh plants, macroalgae, seagrass and seston and estuarine resident fishes (Achirus garmani, Atherinella brasiliensis, Genidens genidens, Ctenogobius shufeldti, Jenynsia multidentata, Odonthestes argentinensis were analyzed in two choked lagoons (Tramandai-29°S, Patos-30°S and a coastal river (Chui-33°S. Average δ13C values of consumers were statistically significant higher in the two choked-type estuaries (Tramandaí: -16.11; Patos: -15.82 than in the coastal river (Chui: -24.32 (p0.292. SIAR mixing models revealed that the most assimilated basal food sources by consumers in the choked-type lagoon estuaries were a pool of 13C enriched food sources (macroalgae, C4 marsh and seagrass and seston (95% credibility interval: 0.38 to 0.80 and 0.00 to 0.54, respectively. In contrast, nutrients derived from C3-marsh plants were the main basal food source assimilated by estuarine resident fishes at the coastal river (0.33 to 0.87. These findings could be explained by the absence of extensive shallow embayments and a steeper slope at the coastal river that could promote higher transport of C3-marsh detritus and, consequently, higher assimilation by estuarine fishes. In contrast, detritus derived from C3 marsh plants could be trapped in the upper intertidal zone of choked-typed estuaries and, consequently, be less available for aquatic

  6. Phytoremediation of carbamazepine and its metabolite 10,11-epoxycarbamazepine by C3 and C4 plants.

    Science.gov (United States)

    Ryšlavá, Helena; Pomeislová, Alice; Pšondrová, Šárka; Hýsková, Veronika; Smrček, Stanislav

    2015-12-01

    The anticonvulsant drug carbamazepine is considered as an indicator of sewage water pollution: however, its uptake by plants and effect on metabolism have not been sufficiently documented, let alone its metabolite (10,11-epoxycarbamazepine). In a model system of sterile, hydroponically cultivated Zea mays (as C4 plant) and Helianthus annuus (as C3 plant), the uptake and effect of carbamazepine and 10,11-epoxycarbamazepine were studied in comparison with those of acetaminophen and ibuprofen. Ibuprofen and acetaminophen were effectively extracted from drug-supplemented media by both plants, while the uptake of more hydrophobic carbamazepine was much lower. On the other hand, the carbamazepine metabolite, 10,11-epoxycarbamazepine, was, unlike sunflower, willingly taken up by maize plants (after 96 h 88 % of the initial concentration) and effectively stored in maize tissues. In addition, the effect of the studied pharmaceuticals on the plant metabolism (enzymes of Hatch-Slack cycle, peroxidases) was followed. The activity of bound peroxidases, which could cause xylem vessel lignification and reduction of xenobiotic uptake, was at the level of control plants in maize leaves contrary to sunflower. Therefore, our results indicate that maize has the potential to remove 10,11-epoxycarbamazepine from contaminated soils. PMID:26310701

  7. Altered Carbon Isotope Discrimination of C3 Plants Under Very High pCO2 Levels

    Science.gov (United States)

    Panetta, R. J.; Schubert, B.; Jahren, H.

    2009-12-01

    Various modeling and proxy-based reconstructions of atmospheric pCO2 levels for the last 120 Ma have estimated RCO2 as high as 12x for the Early Cretaceous, generally decreasing into the Cenozoic, and decreasing further into the Quaternary. Multiple ecological studies to assess the effect of elevated CO2 on plant biomass and δ13C value have been spurred on by recent increases in greenhouse gases, however these studies typically grow plants under only slightly elevated CO2 levels (i.e., the twenty foremost studies published since 1990 involved 550 to 750 ppm pCO2, which equals RCO2 = 1.4 to 1.9x). In order to recreate the highest pCO2 environments of the last 120 Ma, we grew radish (Raphanus sativus L.) in growth chambers that maintained controlled environmental conditions and pCO2 levels ranging from ~5 to 11x that of today’s atmosphere (1791 to 4200 ppm); upon harvest we measured total biomass and stable carbon isotope ratio (δ13Cplant) in both above and below ground plant tissue. Unlike the 1:1 relationship between stable isotopes of atmospheric CO2 (δ13Catm) and δ13Cplant observed at lower pCO2 levels (i.e., RCO2 = 1x to 3x; Jahren et al., 2008), the δ13Cplant of biomass grown at more elevated RCO2 was dependent upon δ13Catm according to the linear relationship: δ13Cplant = 1.9(δ13Cplant) - 12.2 ‰ (r2 = 0.71). Concomitantly, we see a highly significant (p sativus L. from -27.0 to -28.0 ‰ at RCO2 = 5x to 11x, respectively. We will discuss possible mechanisms for changing isotope discrimination at very high pCO2 levels that may not be operative at lower concentrations. For example, we noted a striking reduction in the variability of biomass between plants grown at the same (very high) level of pCO2. This variability (calculated as the standard deviation of the log-transformed biomass data after Poorter and Garnier, 1996) decreased by 37 % (above-ground) and 48 % (below-ground) for plants grown at RCO2 > 5x compared to plants grown at RCO2 = 1x to 3x

  8. Influence of metabolites from the glycolate on the intensity of photosynthesis in C3 and C4-plants

    International Nuclear Information System (INIS)

    The experiments described are the result of the influence of photorespiratory metabolites on the intensity of photosynthesis in leaf discs from pisum (C3) and maize (C4) plants. Pisum protoplasts are also used. The discs are dried and exposed in a closed system in an atmosphere of 14CO2. Fixation of 14CO2 is determined in the reaction medium. The total radioactivity is measured. The inhibition of glycolate synthesis, photorespiration is accompanied by a rise in net photosynthesis. The positive effect of glycolic acid on photosynthesis is undoubtedly determined by the established stimulating action on the enzyme RuBPC (ribulosediphosphate carboxylase). (author)

  9. Effects of gaseous ammonia on intracellular pH values in leaves of C 3- and C 4-plants

    Science.gov (United States)

    Yin, Zu-Hua; Kaiser, Werner; Heber, Ulrich; Raven, John A.

    Responses of cytosolic and vacuolar pH to different concentrations (1.3-5.4 μmol NH 3 mol -1 gas or 0.940-3.825 mg NH 3 m -3 gas) of gaseous NH 3 were studied in experiments of 3 h duration by recording changes in fluorescence of pyranine and esculin in leaves of C 3 and C 4 plants. After a lag phase of 0.5-4 min, the uptake of NH 3 at 50-200 nmol m -2 leaf area s -1 increased pyranine fluorescence, indicating cytosolic alkalinization in leaves of Pelargonium zonale L. (C 3) and Amaranthus caudatus L. (C 4). A smaller increase in esculin fluorescence induced by NH 3 indicated some vacuolar alkalization in a Spinacia oleracea L. leaf. Photosynthesis and transpiration remained unchanged during exposure of illuminated leaves to NH 3 for up to 30 min (the maximum tested). CO 2 concentrations influenced the extent of cytosolic alkalinization. 500 μmol CO 2 mol -1 gas suppressed the NH 3-induced cytosolic alkalinization relative to that found in 16 μmol CO 2 mol -1 gas. The suppressing effect of CO 2 on NH 3-induced alkalization was larger in illuminated leaves of the C 4Amaranthus than the C 3Pelargonium. These results indicate that the alkaline pH shift caused by solution and protonation of NH 3 in aqueous leaf compartments is affected by assimilation of NH 3.

  10. Mesophyll conductance to CO2 and Rubisco as targets for improving intrinsic water use efficiency in C3 plants.

    Science.gov (United States)

    Flexas, J; Díaz-Espejo, A; Conesa, M A; Coopman, R E; Douthe, C; Gago, J; Gallé, A; Galmés, J; Medrano, H; Ribas-Carbo, M; Tomàs, M; Niinemets, Ü

    2016-05-01

    Water limitation is a major global constraint for plant productivity that is likely to be exacerbated by climate change. Hence, improving plant water use efficiency (WUE) has become a major goal for the near future. At the leaf level, WUE is the ratio between photosynthesis and transpiration. Maintaining high photosynthesis under water stress, while improving WUE requires either increasing mesophyll conductance (gm ) and/or improving the biochemical capacity for CO2 assimilation-in which Rubisco properties play a key role, especially in C3 plants at current atmospheric CO2 . The goals of the present analysis are: (1) to summarize the evidence that improving gm and/or Rubisco can result in increased WUE; (2) to review the degree of success of early attempts to genetically manipulate gm or Rubisco; (3) to analyse how gm , gsw and the Rubisco's maximum velocity (Vcmax ) co-vary across different plant species in well-watered and drought-stressed conditions; (4) to examine how these variations cause differences in WUE and what is the overall extent of variation in individual determinants of WUE; and finally, (5) to use simulation analysis to provide a theoretical framework for the possible control of WUE by gm and Rubisco catalytic constants vis-à-vis gsw under water limitations. PMID:26297108

  11. Evaluation of Efficiency in Steam Generator of C3 Power Plant at Cap Des Biches in Dakar

    Directory of Open Access Journals (Sweden)

    A. Kane

    2012-07-01

    Full Text Available The aim of the present study is to determine the efficiency of the power plant boiler steam C3 Cape deer and to evaluate the impact of it. We chose to calculate the return by the empirical formula of Martin which is based on two important parameters which are the temperature at the exit of the chimney and the ambient temperature. The calculation of these efficiencies allowed us to make comparative studies with data from the manufacturer and we have detected anomalies. On this basis we made a number of recommendations for improvement of the groups in normal, the application will lead to an optimization of the real exploitation of groups and a performance improvement. We gave various reasons for poor performance of steam generators and recommendations that can be used both in production efficiency on compliance with operating instructions. Solutions have been proposed after diagnosis with particular emphasis on compliance with operating instructions and maintenance schedule.

  12. The oxygen and carbon dioxide compensation points of C3 plants: possible role in regulating atmospheric oxygen.

    Science.gov (United States)

    Tolbert, N E; Benker, C; Beck, E

    1995-11-21

    The O2 and CO2 compensation points (O2 and CO2) of plants in a closed system depend on the ratio of CO2 and O2 concentrations in air and in the chloroplast and the specificities of ribulose bisphosphate carboxylase/oxygenase (Rubisco). The photosynthetic O2 is defined as the atmospheric O2 level, with a given CO2 level and temperature, at which net O2 exchange is zero. In experiments with C3 plants, the O2 with 220 ppm CO2 is 23% O2; O2 increases to 27% with 350 ppm CO2 and to 35% O2 with 700 ppm CO2. At O2 levels below the O2, CO2 uptake and reduction are accompanied by net O2 evolution. At O2 levels above the O2, net O2 uptake occurs with a reduced rate of CO2 fixation, more carbohydrates are oxidized by photorespiration to products of the C2 oxidative photosynthetic carbon cycle, and plants senesce prematurely. The CO2 increases from 50 ppm CO2 with 21% O2 to 220 ppm with 100% O2. At a low CO2/high O2 ratio that inhibits the carboxylase activity of Rubisco, much malate accumulates, which suggests that the oxygen-insensitive phosphoenolpyruvate carboxylase becomes a significant component of the lower CO2 fixation rate. Because of low global levels of CO2 and a Rubisco specificity that favors the carboxylase activity, relatively rapid changes in the atmospheric CO2 level should control the permissive O2 that could lead to slow changes in the immense O2 pool. PMID:11607591

  13. Quantifying uncertainty of past pCO2 determined from changes in C3 plant carbon isotope fractionation

    Science.gov (United States)

    Cui, Ying; Schubert, Brian A.

    2016-01-01

    Knowledge of the past concentrations of atmospheric CO2 level (pCO2) is critical to understanding climate sensitivity to changing pCO2. Towards this, a new proxy for pCO2 has been developed based on changes in carbon isotope fractionation (Δ13C) in C3 land plants. The accuracy of this approach has been validated against ice-core pCO2 records, suggesting the potential to apply this proxy to other geological periods; however, no thorough uncertainty assessment of the proxy has been conducted. Here, we first analyze the uncertainty in the model-curve fit through the experimental data using a bootstrap approach. Then, errors of the five input parameters for the proxy are evaluated using sensitivity analysis; these include the carbon isotope composition of atmospheric CO2 (δ13CCO2) and that of the plant material (δ13Corg) for two time periods, a reference time (t = 0) and the time period of interest (t), and the value of pCO2 at time t = 0. We then propagated the errors on the reconstructed pCO2 using a Monte Carlo random sampling approach that combined the uncertainties of the curve fitting and the five inputs for a scenario in which the reference time was the Holocene with a target period for the reconstructed pCO2 during the Cenozoic. We find that the error in the reconstructed pCO2(t) increases with increasing pCO2(t), yet remains stomata, liverwort, and paleosol proxies. The analysis presented here assumes that the paleoenvironment in which the plants grew is unknown and is determined to be the largest source of error in the reconstructed pCO2(t) levels; errors in pCO2(t) could be reduced provided independent determination of the paleoenvironmental conditions at the fossil site.

  14. Differential responses of C3 and CAM native Brazilian plant species to a SO2- and SPMFe-contaminated Restinga.

    Science.gov (United States)

    da Silva, Luzimar Campos; de Araújo, Talita Oliveira; Martinez, Carlos Alberto; de Almeida Lobo, Francisco; Azevedo, Aristéa Alves; Oliva, Marco Antonio

    2015-09-01

    Aiming to evaluate responses in terms of growth rates, physiological parameters, and degree of sensitivity to SO2 and SPMFe in Eugenia uniflora L. (Myrtaceae, a C3 species) and Clusia hilariana Schlecht (Clusiaceae, a CAM species); saplings were exposed to emissions from a pelletizing factory for 7 months. The species were distributed along a transect (200, 500, 800, 1400, and 1700 m away from the emission source), and analyses were performed after 71, 118, and 211 days of exposure to the pollutants. E. uniflora received higher superficial deposition of particulate iron. The highest total iron foliar contents were observed 200 m away from the emission source in both plant species, while the highest total sulfur foliar contents were observed 200 m away in C. hilariana and 800 m away in E. uniflora. E. uniflora presented decreased values of height growth rate, number of necrotic leaves, chlorophyll analysis (SPAD index) and transpiration, in relation to the distances from the emission source. C. hilariana showed decreased values of height growth rate, number of leaves, number of necrotic leaves, total ionic permeability, stomatal conductance, transpiration, net CO2 assimilation, and total dry matter, in relation to distances from the emission source. In relation to the days of exposure, both species presented increased number of necrotic leaves and foliar phytotoxicity index, and decreased values in the chlorophyll analysis. The two native plant species, both of which occur in the Brazilian Restinga, showed damage when exposed to emissions from an iron ore pelletizing factory. C. hilariana was considered the most sensitive species due to the decreased values in a higher number of variables after exposition. PMID:25956514

  15. Quantifying uncertainty of past pCO2 determined from changes in C3 plant carbon isotope fractionation

    Science.gov (United States)

    Cui, Ying; Schubert, Brian A.

    2016-01-01

    Knowledge of the past concentrations of atmospheric CO2 level (pCO2) is critical to understanding climate sensitivity to changing pCO2. Towards this, a new proxy for pCO2 has been developed based on changes in carbon isotope fractionation (Δ13C) in C3 land plants. The accuracy of this approach has been validated against ice-core pCO2 records, suggesting the potential to apply this proxy to other geological periods; however, no thorough uncertainty assessment of the proxy has been conducted. Here, we first analyze the uncertainty in the model-curve fit through the experimental data using a bootstrap approach. Then, errors of the five input parameters for the proxy are evaluated using sensitivity analysis; these include the carbon isotope composition of atmospheric CO2 (δ13CCO2) and that of the plant material (δ13Corg) for two time periods, a reference time (t = 0) and the time period of interest (t), and the value of pCO2 at time t = 0. We then propagated the errors on the reconstructed pCO2 using a Monte Carlo random sampling approach that combined the uncertainties of the curve fitting and the five inputs for a scenario in which the reference time was the Holocene with a target period for the reconstructed pCO2 during the Cenozoic. We find that the error in the reconstructed pCO2(t) increases with increasing pCO2(t), yet remains confidence for much of the Cenozoic and perhaps the majority of the last 400 million years, which is characterized by pCO2 levels generally less than 1000 ppmv. Towards this, an application of this uncertainty analysis is presented for the Paleogene (52-63 Ma) using published data. The resulting pCO2(t) levels calculated using this method average 470 +288/-147 ppmv (1σ, n = 75), and overlap with previous pCO2(t) estimates determined for this time period using stomata, liverwort, and paleosol proxies. The analysis presented here assumes that the paleoenvironment in which the plants grew is unknown and is determined to be the largest

  16. Quantitative sediment source attribution with compound-specific isotope analysis in a C3 plant-dominated catchment (central Switzerland)

    Science.gov (United States)

    Alewell, Christine; Birkholz, Axel; Meusburger, Katrin; Schindler Wildhaber, Yael; Mabit, Lionel

    2016-03-01

    As sediment loads impact freshwater systems and infrastructure, their origin in complex landscape systems is of crucial importance for sustainable management of agricultural catchments. We differentiated the sediment source contribution to a lowland river in central Switzerland by using compound-specific isotope analysis (CSIA). We found a clear distinction of sediment sources originating from forest and agricultural land use. Our results demonstrate that it is possible to reduce the uncertainty of sediment source attribution in: (i) using compound content (in our case, long-chain fatty acids; FAs) rather than soil organic matter content to transfer δ13C signal of FAs to soil contribution and (ii) restricting the investigation to the long-chain FAs (> C22 : 0) not to introduce errors due to aquatic contributions from algae and microorganisms. Results showed unambiguously that during base flow, agricultural land contributed up to 65 % of the suspended sediments, while forest was the dominant sediment source during high flow. This indicates that connectivity of sediment source areas within the river changes between base and high flow conditions. Uncertainty, which might occur in complex, large-scale studies due to undetected source attribution and/or CSSI signature degradation, is low because of limited data complexity in our study (i.e., two-three sources and two tracers). Our findings are the first published results highlighting (i) significant differences in compound-specific stable isotope (CSSI) signature of sediment sources from land uses dominated by C3 plant cultivation and (ii) the use of these differences to quantify sediment contribution to a small river.

  17. The effects of oxides of carbon and nitrogen emissions on the isotope and element abundances in foliage of C3 plants

    International Nuclear Information System (INIS)

    The carbon and nitrogen stable isotope abundance of C3 plants mango (Magnifera indica L), molave (Vitex parviflora Juss), talisay (Terminalia catappa L.) leaves harvested from sites with ambient air conditions and sites receiving air pollution contributions from coal-fired power plants were determined and compared. Isotope Ratio Mass Spectroscopy, IRMS was used to determine 13C and 15N in the samples. The elemental composition of the samples was determined using Inductively Coupled Plasma-Atomic Emission Spectrometry, ICP-AES. The 13C of the leaves grown in ambient air were found to fall within the range of -25.0 to -22.0 per mill and a close agreement with the literature values for the natural abundance of 13C in C3 plants (-27.0 to -21.0 per mill). The 13C abundance of plants obtained from sites polluted by coal-fired plants were sporadic from -35 to 24.0 per mille. The 15N abundance in leaves grown under ambient air condition (-1.0 to 2.0 per mille) were way below the 15N abundance of plants from coal-fired plant-polluted regions (16.0 to 17.5 per mille). Elemental exposition indicated no differences in element concentrations in leaves from ambient and polluted sites. Differences exist in the Ca, Mg, K ratios across species and are affected by seasonal variation. (author)

  18. Catalase is a sink for H2O2 and is indispensable for stress defence in C3 plants.

    OpenAIRE

    Willekens, H; Chamnongpol, S; Davey, M; Schraudner, M; Langebartels, C; Van Montagu, M; Inzé, D; Van Camp, W

    1997-01-01

    Hydrogen peroxide (H2O2) has been implicated in many stress conditions. Control of H2O2 levels is complex and dissection of mechanisms generating and relieving H2O2 stress is difficult, particularly in intact plants. We have used transgenic tobacco with approximately 10% wild-type catalase activity to study the role of catalase and effects of H2O2 stress in plants. Catalase-deficient plants showed no visible disorders at low light, but in elevated light rapidly developed white necrotic lesion...

  19. Online CO2 and H2 O oxygen isotope fractionation allows estimation of mesophyll conductance in C4 plants, and reveals that mesophyll conductance decreases as leaves age in both C4 and C3 plants.

    Science.gov (United States)

    Barbour, Margaret M; Evans, John R; Simonin, Kevin A; von Caemmerer, Susanne

    2016-05-01

    Mesophyll conductance significantly, and variably, limits photosynthesis but we currently have no reliable method of measurement for C4 plants. An online oxygen isotope technique was developed to allow quantification of mesophyll conductance in C4 plants and to provide an alternative estimate in C3 plants. The technique is compared to an established carbon isotope method in three C3 species. Mesophyll conductance of C4 species was similar to that in the C3 species measured, and declined in both C4 and C3 species as leaves aged from fully expanded to senescing. In cotton leaves, simultaneous measurement of carbon and oxygen isotope discrimination allowed the partitioning of total conductance to the chloroplasts into cell wall and plasma membrane versus chloroplast membrane components, if CO2 was assumed to be isotopically equilibrated with cytosolic water, and the partitioning remained stable with leaf age. The oxygen isotope technique allowed estimation of mesophyll conductance in C4 plants and, when combined with well-established carbon isotope techniques, may provide additional information on mesophyll conductance in C3 plants. PMID:26778088

  20. Detecting long-term metabolic shifts using isotopomers: CO2-driven suppression of photorespiration in C3 plants over the 20th century.

    Science.gov (United States)

    Ehlers, Ina; Augusti, Angela; Betson, Tatiana R; Nilsson, Mats B; Marshall, John D; Schleucher, Jürgen

    2015-12-22

    Terrestrial vegetation currently absorbs approximately a third of anthropogenic CO2 emissions, mitigating the rise of atmospheric CO2. However, terrestrial net primary production is highly sensitive to atmospheric CO2 levels and associated climatic changes. In C3 plants, which dominate terrestrial vegetation, net photosynthesis depends on the ratio between photorespiration and gross photosynthesis. This metabolic flux ratio depends strongly on CO2 levels, but changes in this ratio over the past CO2 rise have not been analyzed experimentally. Combining CO2 manipulation experiments and deuterium NMR, we first establish that the intramolecular deuterium distribution (deuterium isotopomers) of photosynthetic C3 glucose contains a signal of the photorespiration/photosynthesis ratio. By tracing this isotopomer signal in herbarium samples of natural C3 vascular plant species, crops, and a Sphagnum moss species, we detect a consistent reduction in the photorespiration/photosynthesis ratio in response to the ∼100-ppm CO2 increase between ∼1900 and 2013. No difference was detected in the isotopomer trends between beet sugar samples covering the 20th century and CO2 manipulation experiments, suggesting that photosynthetic metabolism in sugar beet has not acclimated to increasing CO2 over >100 y. This provides observational evidence that the reduction of the photorespiration/photosynthesis ratio was ca. 25%. The Sphagnum results are consistent with the observed positive correlations between peat accumulation rates and photosynthetic rates over the Northern Hemisphere. Our results establish that isotopomers of plant archives contain metabolic information covering centuries. Our data provide direct quantitative information on the "CO2 fertilization" effect over decades, thus addressing a major uncertainty in Earth system models. PMID:26644588

  1. Stable carbon isotopes of C3 plant resins and ambers record changes in atmospheric oxygen since the Triassic

    Science.gov (United States)

    Tappert, Ralf; McKellar, Ryan C.; Wolfe, Alexander P.; Tappert, Michelle C.; Ortega-Blanco, Jaime; Muehlenbachs, Karlis

    2013-11-01

    Estimating the partial pressure of atmospheric oxygen (pO2) in the geological past has been challenging because of the lack of reliable proxies. Here we develop a technique to estimate paleo-pO2 using the stable carbon isotope composition (δ13C) of plant resins-including amber, copal, and resinite-from a wide range of localities and ages (Triassic to modern). Plant resins are particularly suitable as proxies because their highly cross-linked terpenoid structures allow the preservation of pristine δ13C signatures over geological timescales. The distribution of δ13C values of modern resins (n = 126) indicates that (a) resin-producing plant families generally have a similar fractionation behavior during resin biosynthesis, and (b) the fractionation observed in resins is similar to that of bulk plant matter. Resins exhibit a natural variability in δ13C of around 8‰ (δ13C range: -31‰ to -23‰, mean: -27‰), which is caused by local environmental and ecological factors (e.g., water availability, water composition, light exposure, temperature, nutrient availability). To minimize the effects of local conditions and to determine long-term changes in the δ13C of resins, we used mean δ13C values (δ13Cmeanresin) for each geological resin deposit. Fossil resins (n = 412) are generally enriched in 13C compared to their modern counterparts, with shifts in δ13Cmeanresin of up to 6‰. These isotopic shifts follow distinctive trends through time, which are unrelated to post-depositional processes including polymerization and diagenesis. The most enriched fossil resin samples, with a δ13Cmeanresin between -22‰ and -21‰, formed during the Triassic, the mid-Cretaceous, and the early Eocene. Experimental evidence and theoretical considerations suggest that neither change in pCO2 nor in the δ13C of atmospheric CO2 can account for the observed shifts in δ13Cmeanresin. The fractionation of 13C in resin-producing plants (Δ13C), instead, is primarily influenced by

  2. Sensitivity of leaf photosynthesis to CO2 concentration is an invariant function for C3 plants: A test with experimental data and global applications

    Science.gov (United States)

    Luo, Yiqi; Sims, Daniel A.; Thomas, Richard B.; Tissue, David T.; Ball, J. Timothy

    1996-06-01

    Rising atmospheric CO2 concentration (Ca) may alter two components (sensitivity and acclimation) of global photosynthetic carbon influx into terrestrial ecosystems (PG). Most existing global models focus on long-term acclimation. We have developed a leaf-level function (ℒ) to quantify short-term increment of PG associated with sensitivity. The ℒ function is the normalized response of leaf photosynthesis to a small change in Ca and has been suggested to be an invariant function for C3 plants grown in diverse environments. This paper tests the hypothesis that ℒ is an invariant function. We calculated values of ℒ from 9 sets of experimental data which incorporated photosynthetic responses of 12 plant species to measurement conditions of light and temperature and to growth in different light, temperature, nitrogen, phosphorus, water stress, and CO2 concentration. Absolute rates of leaf photosynthesis differed by more than tenfold due to species differences and environmental variation. However, ℒ values derived from these data sets converged into a narrow range defined by two equations of the ℒ function, confirming that ℒ was insensitive to differences in photosynthetic capacity among species and between plants acclimated to different growth environments. Using the ℒ function, we predict that a yearly increase of 1.5 parts per million (ppm) in Ca will induce an increase in PG by 0.18 to 0.34 Gt (1 Gt = 1015 g) C yr-1 in 1993, provided that (1) PG = 120 Gt C yr-1, (2) 85% of PG is generated by C3 plant assimilation, and (3) the 1.5-ppm increase in Ca will not induce significant photosynthetic acclimation.

  3. Assessment of Waste Treatment Plant Lab C3V (LB-S1) Stack Sampling Probe Location for Compliance with ANSI/HPS N13.1-1999

    Energy Technology Data Exchange (ETDEWEB)

    Glissmeyer, John A.; Geeting, John GH

    2013-02-01

    This report documents a series of tests used to assess the proposed air sampling location in the Hanford Tank Waste Treatment and Immobilization Plant (WTP) Lab C3V (LB-S1) exhaust stack with respect to the applicable criteria regarding the placement of an air sampling probe. Federal regulations require that an air sampling probe be located in the exhaust stack in accordance with the criteria of American National Standards Institute/Health Physics Society (ANSI/HPS) N13.1-1999, Sampling and Monitoring Releases of Airborne Radioactive Substances from the Stack and Ducts of Nuclear Facilities. These criteria address the capability of the sampling probe to extract a sample that represents the effluent stream.

  4. Complement C3

    OpenAIRE

    Dinasarapu, Ashok Reddy; Chandrasekhar, Anjana; Sahu, Arvind; Subramaniam, Shankar

    2012-01-01

    Complement C3 is the central component of the human complement system. It is ~186 kDa in size, consisting of an α-chain (~110 kDa) and a β-chain (~75 kDa) that are connected by cysteine bridges. C3 in its native form is inactive. Cleavage of C3 into C3b (~177 kDa) and C3a (~9 kDa) is a crucial step in the complement activation cascade, which can be initiated by one or more of the three distinct pathways, called alternative, classical and lectin complement pathways. In the alternative pathway,...

  5. C3和C4植物寄主对华北地区棉铃虫越冬代和第一代的影响%Contribution of C3 and C4 host plants for the overwintering and 1st generation of Helicoverpa armigera(Hübner)in Northern China

    Institute of Scientific and Technical Information of China (English)

    叶乐夫; 付雪; 戈峰

    2011-01-01

    It is a key step for cotton bollworm (CBW) management to determine the ratio of moths of cotton bollworm originating from C3 and C4 host plants for the overwintering generation and their contribution to the next spring first generation in North China. In this study, the development times of larva from the female moths captured in wheat field in 2007 were observed systematically. Moreover, δ13C values in the wings of each female moth were tested with GC-MS apparatus to determine larval host plant type. Results showed that 53.1% of moths trapped during spring emergence (the overwintering generation CBW) came from larva grown in late autumn C3 host plants (cotton), 46.9% came from larva grown in late autumn C4 host plants (corn). 57.9% of eggs laid by the overwintering generation moths were determined as progeny of C3 phenotype via stable isotope examination on the wings of moth, individually. Significantly higher hatching rate were observed in the eggs laid by the moths from larva grown in C3 host plants than C4 host plants. Furthermore, about 63.7% first instar larva on spring wheat was determined as progeny of C3 phenotype moths. Moreover, about 47.9% larva at the third instar, 45.5% fourth instar larva, 46.9% fifth instar larva, 55.1% last instar larva of 1st generation of CBW originated from C3 host plants. The larva from first instar to third instar of moths from C3 phenotype develop quicker compared with from C4 phenotype. However, larva from fourth instar to sixth instar from C3 phenotype developed slowly than C4 phenotype. The larva originated from C3 phenotype displayed lower survival rate at lower instar larva and higher survival rate at higher instar larva while compared to the C4 phenotype progeny. In the whole, quicker development for lower instar larva with lower survival rate, and slower development for large larva with higher survival rate occurred during their larval developmental process, However, total developmental duration and

  6. Large-scale mRNA expression profiling in the common ice plant, Mesembryanthemum crystallinum, performing C3 photosynthesis and Crassulacean acid metabolism (CAM).

    Science.gov (United States)

    Cushman, John C; Tillett, Richard L; Wood, Joshua A; Branco, Joshua M; Schlauch, Karen A

    2008-01-01

    The common ice plant (Mesembryanthemum crystallinum L.) has emerged as a useful model for molecular genetic studies of Crassulacean acid metabolism (CAM) because CAM can be induced in this species by water deficit or salinity stress. Non-redundant sequence information from expressed sequence tag data was used to fabricate a custom oligonucleotide microarray to compare large-scale mRNA expression patterns in M. crystallinum plants conducting C(3) photosynthesis versus CAM. Samples were collected every 4 h over a 24 h time period at the start of the subjective second day from plants grown under constant light and temperature conditions in order to capture variation in mRNA expression due to salinity stress and circadian clock control. Of 8455 genes, a total of 2343 genes (approximately 28%) showed a significant change as judged by analysis of variance (ANOVA) in steady-state mRNA abundance at one or more time points over the 24 h period. Of these, 858 (10%) and 599 (7%) exhibited a greater than two-fold ratio (TFR) increase or decrease in mRNA abundance, respectively. Functional categorization of these TFR genes revealed that many genes encoding products that function in CAM-related C(4) acid carboxylation/decarboxylation, glycolysis/gluconeogenesis, polysaccharide, polyol, and starch biosynthesis/degradation, protein degradation, transcriptional activation, signalling, stress response, and transport facilitation, and novel, unclassified proteins exhibited stress-induced increases in mRNA abundance. In contrast, salt stress resulted in a significant decrease in transcript abundance for genes encoding photosynthetic functions, protein synthesis, and cellular biogenesis functions. Many genes with CAM-related functions exhibited phase shifts in their putative circadian expression patterns following CAM induction. This report establishes an extensive catalogue of gene expression patterns for future investigations aimed at understanding the complex, transcriptional

  7. Physiological and Growth Responses of C3 and C4 Plants to Reduced Temperature When Grown at Low CO2 of the Last Ice Age

    Institute of Scientific and Technical Information of China (English)

    Joy K. Ward; David A. Myers; Richard B. Thomas

    2008-01-01

    During the last Ice age, CO2 concentration ([CO2]) was 180-200 μmol/mol compared with the modern value of 380 μmol/mol,and global temperatures were ~8 ℃ cooler. Relatively little is known about the responses of C3 and C4 species to longterm exposure to glacial conditions. Here Abutilon theophrasti Medik. (C3) and Amaranthus retroflexus L. (C4) were grown at 200 μmol/mol CO2 with current (30/24 ℃) and glacial (22/16 ℃) temperatures for 22 d. Overall, the C4 species exhibited a large growth advantage over the C3 species at low [CO2]. However, this advantage was reduced at low temperature, where the C4 species produced 5× the total mass of the C3 species versus 14× at the high temperature.This difference was due to a reduction In C4 growth at low temperature, since the C3 species exhibited similar growth between temperatures. Physiological differences between temperatures were not detected for either species, although photorespirationlnet photosynthesis was reduced in the C3 species grown at low temperature, suggesting evidence of improved carbon balance at this treatment. This system suggests that C4 species had a growth advantage over C3 species during low [CO2] of the last ice age, although concurrent reductions in temperatures may have reduced this advantage.

  8. The soil microbial community composition and soil microbial carbon uptake are more affected by soil type than by different vegetation types (C3 and C4 plants) and seasonal changes

    Science.gov (United States)

    Griselle Mellado Vazquez, Perla; Lange, Markus; Gleixner, Gerd

    2016-04-01

    This study investigates the influence of different vegetation types (C3 and C4 plants), soil type and seasonal changes on the soil microbial biomass, soil microbial community composition and soil microbial carbon (C) uptake. We collected soil samples in winter (non-growing season) and summer (growing season) in 2012 from an experimental site cropping C3 and C4 plants for 6 years on two different soil types (sandy and clayey). The amount of phospholipid fatty acids (PLFAs) and their compound-specific δ13C values were used to determined microbial biomass and the flow of C from plants to soil microorganisms, respectively. Higher microbial biomass was found in the growing season. The microbial community composition was mainly explained by soil type. Higher amounts of SOC were driving the predominance of G+ bacteria, actinobacteria and cyclic G- bacteria in sandy soils, whereas root biomass was significantly related to the increased proportions of G- bacteria in clayey soils. Plant-derived C in G- bacteria increased significantly in clayey soils in the growing season. This increase was positively and significantly driven by root biomass. Moreover, changes in plant-derived C among microbial groups pointed to specific capabilities of different microbial groups to decompose distinct sources of C. We concluded that soil texture and favorable growth conditions driven by rhizosphere interactions are the most important factors controlling the soil microbial community. Our results demonstrate that a change of C3 plants vs. C4 plants has only a minor effect on the soil microbial community. Thus, such experiments are well suited to investigate soil organic matter dynamics as they allow to trace the C flow from plants into the soil microbial community without changing the community abundance and composition.

  9. Oxygen Requirement and Inhibition of C4 Photosynthesis . An Analysis of C4 Plants Deficient in the C3 and C4 Cycles

    OpenAIRE

    Maroco, J.P.; Ku, M.S.B.; Lea, P J; Dever, L.V.; Leegood, R C; Furbank, R.T.; Edwards, G. E.

    1998-01-01

    The basis for O2 sensitivity of C4 photosynthesis was evaluated using a C4-cycle-limited mutant of Amaranthus edulis (a phosphoenolpyruvate carboxylase-deficient mutant), and a C3-cycle-limited transformant of Flaveria bidentis (an antisense ribulose-1,5-bisphosphate carboxylase/oxygenase [Rubisco] small subunit transformant). Data obtained with the C4-cycle-limited mutant showed that atmospheric levels of O2 (20 kPa) caused increased inhibition of photosynthesis as a result of higher levels ...

  10. Reconstructing the response of C3 and C4 plants to decadal-scale climate change during the late Pleistocene in southern Illinois using isotopic analyses of calcified rootlets

    Science.gov (United States)

    Wang, Hongfang; Greenberg, S.E.

    2007-01-01

    The ??13C and ??18O values of well-preserved carbonate rhizoliths (CRs) provide detailed insights into changes in the abundance of C3 and C4 plants in response to approximately decadal-scale changes in growing-season climate. We performed stable isotope analyses on 35-40 CRs sampled at 1-cm intervals from an 18-cm-thick paleosol formed in southern Illinois during Wisconsin interstadial 2. Minimum ??13C values show little variation with depth, whereas maximum values vary dramatically, and average values show noticeable variability; maximum ??18O values vary less than the minimum ??18O values. These findings indicate that a diverse and stable C3 flora with a limited number of C4 grass species prevailed during this interval, and suggest that the maximum growing-season temperatures were relatively stable, but minimum growing-season temperatures varied considerably. Two general patterns characterize the relationships between the ??13C and ??18O values obtained from the 1-cm samples. In some cases, low ??13C values correspond to low ??18O values and high ??13C values correspond to high ??18O values, suggesting that cooler growing-season temperatures favored C3 and warmer growing-season temperatures favored C4 plants. In other cases, low ??13C values correspond to high ??18O values, likely suggesting that wetter growing-season conditions were favorable to C3 plants. The high density of well-preserved CRs in this paleosol provides a unique opportunity to study detailed ecological responses to high-resolution variability in growing-season climate. ?? 2006 University of Washington.

  11. Detecting long-term metabolic shifts using isotopomers: CO2-driven suppression of photorespiration in C3 plants over the 20th century

    OpenAIRE

    Ehlers, Ina; Augusti, Angela; Betson, Tatiana R.; Nilsson, Mats B.; Marshall, John D.; Schleucher, Jürgen

    2015-01-01

    Decadal-scale metabolic responses of plants to environmental changes, including the magnitude of the “CO2 fertilization” effect, are a major knowledge gap in Earth system models, in agricultural models, and for societal adaptation. We introduce intramolecular isotope distributions (isotopomers) as a methodology for detecting shifts in plant carbon metabolism over long times. Trends in a deuterium isotopomer ratio allow quantification of a biogeochemically relevant shift in the metabolism of C...

  12. Effects of Ontogeny on δ13C of Plant- and Soil-Respired CO2 and on Respiratory Carbon Fractionation in C3 Herbaceous Species.

    Science.gov (United States)

    Salmon, Yann; Buchmann, Nina; Barnard, Romain L

    2016-01-01

    Knowledge gaps regarding potential ontogeny and plant species identity effects on carbon isotope fractionation might lead to misinterpretations of carbon isotope composition (δ13C) of respired CO2, a widely-used integrator of environmental conditions. In monospecific mesocosms grown under controlled conditions, the δ13C of C pools and fluxes and leaf ecophysiological parameters of seven herbaceous species belonging to three functional groups (crops, forage grasses and legumes) were investigated at three ontogenetic stages of their vegetative cycle (young foliage, maximum growth rate, early senescence). Ontogeny-related changes in δ13C of leaf- and soil-respired CO2 and 13C/12C fractionation in respiration (ΔR) were species-dependent and up to 7‰, a magnitude similar to that commonly measured in response to environmental factors. At plant and soil levels, changes in δ13C of respired CO2 and ΔR with ontogeny were related to changes in plant physiological status, likely through ontogeny-driven changes in the C sink to source strength ratio in the aboveground plant compartment. Our data further showed that lower ΔR values (i.e. respired CO2 relatively less depleted in 13C) were observed with decreasing net assimilation. Our findings highlight the importance of accounting for ontogenetic stage and plant community composition in ecological studies using stable carbon isotopes. PMID:27010947

  13. Effects of Ontogeny on δ13C of Plant- and Soil-Respired CO2 and on Respiratory Carbon Fractionation in C3 Herbaceous Species.

    Directory of Open Access Journals (Sweden)

    Yann Salmon

    Full Text Available Knowledge gaps regarding potential ontogeny and plant species identity effects on carbon isotope fractionation might lead to misinterpretations of carbon isotope composition (δ13C of respired CO2, a widely-used integrator of environmental conditions. In monospecific mesocosms grown under controlled conditions, the δ13C of C pools and fluxes and leaf ecophysiological parameters of seven herbaceous species belonging to three functional groups (crops, forage grasses and legumes were investigated at three ontogenetic stages of their vegetative cycle (young foliage, maximum growth rate, early senescence. Ontogeny-related changes in δ13C of leaf- and soil-respired CO2 and 13C/12C fractionation in respiration (ΔR were species-dependent and up to 7‰, a magnitude similar to that commonly measured in response to environmental factors. At plant and soil levels, changes in δ13C of respired CO2 and ΔR with ontogeny were related to changes in plant physiological status, likely through ontogeny-driven changes in the C sink to source strength ratio in the aboveground plant compartment. Our data further showed that lower ΔR values (i.e. respired CO2 relatively less depleted in 13C were observed with decreasing net assimilation. Our findings highlight the importance of accounting for ontogenetic stage and plant community composition in ecological studies using stable carbon isotopes.

  14. Response of C3 and C4 plants to middle-Holocene climatic variation near the prairie-forest ecotone of Minnesota, U.S.A.

    Energy Technology Data Exchange (ETDEWEB)

    Tian, J; Brown, T A; Hu, F S; Stefanova, I; Nelson, D M

    2003-12-24

    Paleorecords of the middle Holocene (MH) from the North American midcontinent can offer insights into ecological responses to pervasive drought that may accompany future climatic warming. We analyzed MH sediments from West Olaf Lake (WOL) and Steel Lake (SL) in Minnesota to examine the effects of warm/dry climatic conditions on prairie-woodland ecosystems. Mineral composition and carbonate {delta}{sup 18}O were used to determine climatic variations, whereas pollen assemblages, charcoal {delta}{sup 13}C, and charcoal accumulation rates were used to reconstruct vegetation composition, C{sub 3} and C{sub 4} plant abundance, and fire. The ratio of aragonite:calcite at WOL and {delta}{sup 18}O at SL suggest that pronounced droughts occurred during the MH but that drought severity decreased with time. From charcoal {delta}{sup 13}C data we estimated that the MH abundance of C{sub 4} plants averaged 50% at WOL and 43% at SL. At WOL C{sub 4} abundance was negatively correlated with aragonite:calcite, suggesting that severe moisture deficits suppressed C{sub 4} plants in favor of weedy C{sub 3} plants (e.g., Ambrosia). As climate ameliorated C{sub 4} abundance increased (from {approx}33 to 66%) at the expense of weedy species, enhancing fuel availability and fire occurrence. In contrast, farther east at SL climate was cooler and wetter than at WOL, and C{sub 4} abundance showed no correlation with {delta}{sup 18}O-inferred aridity. Woody C{sub 3} plants (e.g., Quercus) were more abundant, biomass flammability lower, and fires less important at SL than at WOL. Our results suggest that C{sub 4} plants are adapted to warm/dry climatic conditions, but not to extreme droughts, and that the fire regime is controlled by biomass-climate interactions.

  15. C3 glomerulopathy: consensus report.

    OpenAIRE

    Lavin, Peter

    2013-01-01

    PUBLISHED C3 glomerulopathy is a recently introduced pathological entity whose original definition was glomerular pathology characterized by C3 accumulation with absent or scanty immunoglobulin deposition. In August 2012, an invited group of experts (comprising the authors of this document) in renal pathology, nephrology, complement biology, and complement therapeutics met to discuss C3 glomerulopathy in the first C3 Glomerulopathy Meeting. The objectives were to reach a consensus on: the ...

  16. Human complement component C3

    DEFF Research Database (Denmark)

    Behrendt, N

    1985-01-01

    The two common genetic variants of human C3, C3 S and C3 F, were purified and characterized by SDS-PAGE, agarose gel electrophoresis, isoelectric focusing and amino acid analysis. The difference in electrophoretic mobility between the two variants was conserved after purification, and by...... isoelectric focusing of the hemolytically active proteins, pI values of 5.86 and 5.81 were determined for C3 S and C3 F, respectively. Any difference in amino acid composition was too small to be detected by amino acid analysis, and the two proteins had the same molecular weight as determined by SDS-PAGE....

  17. Climate as the dominant control on C3 and C4 plant abundance in the Loess Plateau: Organic carbon isotope evidence from the last glacial-interglacial loess-soil sequences

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Abundance of C3 and C4 photosynthesis plants can be inferred relatively from stable carbon isotopic composition of organic matter in soils. The samples from five sequences of the last glacial-interglacial loess-soil in the Chinese Loess Plateau have been measured for organic carbon isotopic ratios (? 13Corg). The organic carbon isotope data show that relative abundance (or biomass) of C4 plants was increased ca. 40% for each sampling site from the last glacial maximum (LGM) to Holocene optimum, and increased southeastward on the Loess Plateau during both periods of LGM and Holocene. Statistic analyses on the steady maximumδ 13Corg values of Holocene soils and modern climatic data from the Loess Plateau and Inner Mongolia indicate that the C4 plant abundance increases with increasing temperature and decreasing precipitation. The C4 plant abundance is related much closer with mean April temperature and precipitation than annual. These results lead us to deduce following conclusions. First, temperature is the major factor for control on variations in C4 plant abundance in the Loess Plateau from the last glacial to interglacial. In the absence of favorable temperature condition, both of low moisture and low atmospheric CO2 concentration are insufficient to drive an expansion of the C4 plants in the plateau. Second, ? 13Corg in the loess-paleosol sequences, as a proxy of the relative abundance of C4 plants in the Loess Plateau, could not be used as an indicator of changes in the summer monsoon intensity unless the temperature had changed without great amplitude. Since all C4 plants are grasses, finally, the increase of the C4 plants supports that forest has not been dominant in the ecosystem on the Loess Plateau during Holocene although precipitation and atmospheric CO2 were largely increased relative to those during LGM.

  18. C3 degradation products (C3d) in normal pregnancy.

    OpenAIRE

    Jenkins, J. S.; Powell, R.J.

    1987-01-01

    Plasma C3 degradation products (C3d) were measured in 65 normal pregnancies and compared with those of non-pregnant women. No significant difference was detected between the two groups, although a difference had been previously reported. Plasma C3d estimations give an indication of complement activation and may be used as an indicator of disease activity in patients with systemic lupus erythematosus (SLE), irrespective of pregnancy.

  19. Complement component 3 (C3)

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003539.htm Complement component 3 (C3) To use the sharing features on this page, ... be some throbbing. Why the Test is Performed C3 and C4 are the most commonly measured complement components. A complement test may be used to monitor ...

  20. Update on C3 glomerulopathy.

    Science.gov (United States)

    Barbour, Thomas D; Ruseva, Marieta M; Pickering, Matthew C

    2016-05-01

    C3 glomerulopathy refers to a disease process in which abnormal control of complement activation, degradation or deposition results in predominant C3 fragment deposition within the glomerulus and glomerular damage. Recent studies have improved our understanding of its pathogenesis. The key abnormality is uncontrolled C3b amplification in the circulation and/or along the glomerular basement membrane. Family studies in which disease segregates with structurally abnormal complement factor H-related (CFHR) proteins demonstrate that abnormal CFHR proteins are important in some types of C3 glomerulopathy. This is currently thought to be due to the ability of these proteins to antagonize the major negative regulator of C3 activation, complement factor H (CFH), a process termed 'CFH de-regulation'. Recent clinicopathological cohort studies have led to further refinements in case definition, culminating in a 2013 consensus report, which provides recommendations regarding investigation and treatment. Early clinical experience with complement-targeted therapeutics, notably C5 inhibitors, has also now been published. Here, we summarize the latest developments in C3 glomerulopathy. PMID:25326473

  1. C3肾小球病%C3 glomerulopathy

    Institute of Scientific and Technical Information of China (English)

    位红兰

    2011-01-01

    Previous studies found that the pathogenesis of a variety of glomerulonephritis were associated with abnormal rePrevious studies found that the pathogenesis of a variety of glomerulonephritis were associated with abnormal regulation of the complement system,specifically,with dysregulation of the alternative pathway of the complement system.In recent years,clinicians have observed a group of glomerulonephritis which is characterized by glomerular deposits of C3 ,with no or only scanty glomerular deposits of immunoglobulin, and which pathogenesis may be related to genetic and acquired complement dysregulation.This group of glomerulonephritis was named C3 glomerulopathy,and was classified according to their clinical presentation and possible pathogenesis.This article summarized this group of glomerulonephritis and the relationship between dysregulation of the complement system and glomerular inflammation.%以往研究证实多种肾小球肾炎发病机制与补体系统,尤其是补体旁路途径调节异常相关.近年有作者发现一组免疫荧光染色单纯补体C3沿肾小球毛细血管拌沉积的肾小球肾炎,不伴或伴少量免疫球蛋白沉积,其发病机制可能与先天或后天获得性补体系统调节异常相关,该作者将这一组疾病统一命名为C3肾小球病,并根据其临床表现及可能的发病机制分为不同类别.本文就这类疾病作一综述,旨在关注补体在疾病发生中的作用机制,并提高对此类肾小球肾炎的认识.

  2. Glycine decarboxylase in C3, C4 and C3-C4 intermediate species.

    Science.gov (United States)

    Schulze, Stefanie; Westhoff, Peter; Gowik, Udo

    2016-06-01

    The glycine decarboxylase complex (GDC) plays a central role in photorespiration. GDC is localized in the mitochondria and together with serine hydroxymethyltransferase it converts two molecules of glycine to one molecule of serine, CO2 and NH3. Overexpression of GDC subunits in the C3 species Arabidopsis thaliana can increase the metabolic flux through the photorespiratory pathway leading to enhanced photosynthetic efficiency and consequently to an enhanced biomass production of the transgenic plants. Changing the spatial expression patterns of GDC subunits was an important step during the evolution of C3-C4 intermediate and likely also C4 plants. Restriction of the GDC activity to the bundle sheath cells led to the establishment of a photorespiratory CO2 pump. PMID:27038285

  3. Molecular basis of hereditary C3 deficiency.

    OpenAIRE

    Botto, M.; Fong, K. Y.; So, A K; Rudge, A; Walport, M.J. (Mark J.)

    1990-01-01

    Hereditary deficiency of complement component C3 in a 10-yr-old boy was studied. C3 could not be detected by RIA of serum from the patient. Segregation of C3 S and C3 F allotypes within the family confirmed the presence of a null gene for C3, for which the patient was homozygous. 30 exons have been characterized, spanning the entire beta chain of C3 and the alpha chain as far as the C3d region. Sequence analysis of the exons derived from the C3 null gene showed no abnormalities in the coding ...

  4. A Revised Mechanism for the Activation of Complement C3 to C3b

    OpenAIRE

    Rodriguez, Elizabeth; ,; Gor, Jayesh; Perkins, Stephen J.

    2014-01-01

    The solution structure of complement C3b is crucial for the understanding of complement activation and regulation. C3b is generated by the removal of C3a from C3. Hydrolysis of the C3 thioester produces C3u, an analog of C3b. C3b cleavage results in C3c and C3d (thioester-containing domain; TED). To resolve functional questions in relation to C3b and C3u, analytical ultracentrifugation and x-ray and neutron scattering studies were used with C3, C3b, C3u, C3c, and C3d, using the wild-type allo...

  5. Hydrogen isotope systematics in C3 and C4 saltmarsh plants: the importance of biochemical processes in controlling interspecies variation in n-alkane 2H/1H composition

    Science.gov (United States)

    Eley, Y.; Pedentchouk, N.

    2013-12-01

    Palaeohydrological studies have increasingly utilised the 2H/1H composition of leaf wax n-alkyl lipids to extract information from the geological record. Interpretation of the sedimentary biomarker δ2H signal, however, requires detailed understanding of the mechanisms controlling hydrogen isotope fractionation between source water and n-alkyl lipids (ɛl/w). The existence of large ranges in published n-alkyl δ2H and ɛl/w among modern plant species growing at a single location suggests that the lipid signal incorporated into the sedimentary record could be sensitive to relatively small-scale changes in vegetation assemblages. The mechanisms responsible for these interspecies differences are currently poorly constrained. Previous research has had limited success explaining n-alkyl δ2H by reference to physical processes controlling the movement of water inside/outside and within the leaf, while the relative importance of biochemical processes remains largely unexplored. This project aims to identify the mechanisms controlling interspecies variation in n-alkane 2H/1H among a range of C3 and C4 plants from a Norfolk saltmarsh in the UK. To distinguish between environmental, physical and biochemical controls, we conducted 2H/1H analysis of soil, xylem, and leaf waters and n-alkanes (i) across multiple sampling sites within the marsh, (ii) throughout the 2012 growth season, and (iii) at different times of the day. We also measured the 2H/1H of chloroplast phytol in 7 samples collected at the end of 2012. Leaf wax n-alkane δ2H varied among the sampled species by over 100‰ throughout the 2012 growth season. Environmental processes that could influence control source water 2H/1H did not fully account for this interspecies variation - soil water 2H/1H varied by only 35‰ with marsh sub-environment and exhibited site-specific seasonal shifts by no more than 31‰. Maximum interspecies variation in xylem water was 38‰, while leaf waters differed by only 29‰. We

  6. 日粮中C3、C4植物含量对牛肉品质和主要化学成分的影响%Effect of the amount of C3 or C4 plants in diets on the quality and main chemical components of beef

    Institute of Scientific and Technical Information of China (English)

    闫贵龙; 曹春梅; 刁其玉; 屠焰; 云强

    2010-01-01

    为探讨C3和C4植物在日粮中的含量对牛肉品质和主要化学成分的影响,本试验选用大豆粕、小麦麸、小麦、棉籽饼、苜蓿干草作为C3植物试验材料,选用黄贮玉米秸、玉米酒精糟、玉米作为C4植物试验材料,选用36头西门塔尔杂种公牛作为试验动物开展了肥育和屠宰试验.结果表明,日粮中C4植物含量对肥育牛增重、牛肉的脂肪酸、氨基酸(其中甘氨酸不确定除外)、水分含量以及牛肉的剪切力、蒸煮损失率、滴水损失率、大理石花纹评分和眼肌面积均没有显著的影响.日粮中C3植物含量对肥育牛增重、牛肉的脂肪酸(其中十七烷酸不确定除外)、氨基酸(其中丝氨酸和苏氨酸不确定除外)、水分含量以及牛肉的剪切力、蒸煮损失率、大理石花纹评分和眼肌面积也均没有显著的影响.

  7. 中国东北样带羊草群落C3和C4植物功能群生物量及其对环境变化的响应%The biomass of C3 and C4 plant function groups in Leymus chinensis communities and theirs response to environmental change along Northeast China transect

    Institute of Scientific and Technical Information of China (English)

    韩梅; 杨利民; 张永刚; 周广胜

    2006-01-01

    在全球动态植被模型的发展中,受限于人力、物力和财力使得在物种水平上的研究变得既不可能也无必要.植物功能群的划分是从生态学的,而不是系统发育的角度来相互比较地对待不同地区的植物,从而削减了植被变化研究中植物分类群的数量,已成为研究植被变化及生物多样性对生态系统功能作用的重要单位.植物的不同光合途径(C3、C4和CAM)从叶片组织结构到生理功能,从生态适应到地理分布均表现出对不同水、热、光环境的响应,是理想的植物功能群分类.为此,分析了中国东北样带以羊草(Leymus chinensis)为建群种或共建种的草原群落植物光合类型功能群生物量及其与群落初级生产力和环境变化的关系.结果表明:(1)C4植物生物量具有明显的变化规律,且对环境变化的响应显著,其变异性较高,更能反映样地间环境变化的差异;(2)C4与C3植物变化具有明显的互补性,并且多数C4植物常在逆境中起到更大作用,如干旱化、盐碱化和放牧干扰;(3)C4植物种类少,在所有调查样方中仅出现7种,占总出现种类的9.72%.这些特点说明C4植物可以考虑作为评估和预测我国温带草原植被及其生态系统变化的重要植物功能群.

  8. Genetics Home Reference: C3 glomerulopathy

    Science.gov (United States)

    Skip to main content Your Guide to Understanding Genetic Conditions Enable Javascript for addthis links to activate. ... Conditions Genes Chromosomes & mtDNA Resources Help Me Understand Genetics Home Health Conditions C3 glomerulopathy C3 glomerulopathy Enable ...

  9. Recent insights into C3 glomerulopathy

    OpenAIRE

    Barbour, Thomas D.; Pickering, Matthew C.; Cook, H. Terence

    2013-01-01

    C3 glomerulopathy’ is a recent disease classification comprising several rare types of glomerulonephritis (GN), including dense deposit disease (DDD), C3 glomerulonephritis (C3GN) and CFHR5 nephropathy. These disorders share the key histological feature of isolated complement C3 deposits in the glomerulus. A common aetiology involving dysregulation of the alternative pathway (AP) of complement has been elucidated in the past decade, with genetic defects and/or autoantibodies able to be ident...

  10. Photorespiration connects C3 and C4 photosynthesis.

    Science.gov (United States)

    Bräutigam, Andrea; Gowik, Udo

    2016-05-01

    C4 plants evolved independently more than 60 times from C3 ancestors. C4 photosynthesis is a complex trait and its evolution from the ancestral C3 photosynthetic pathway involved the modification of the leaf anatomy and the leaf physiology accompanied by changes in the expression of thousands of genes. Under high temperature, high light, and the current CO2 concentration in the atmosphere, the C4 pathway is more efficient than C3 photosynthesis because it increases the CO2 concentration around the major CO2 fixating enzyme Rubisco. The oxygenase reaction and, accordingly, photorespiration are largely suppressed. In the present review we describe a scenario for C4 evolution that not only includes the avoidance of photorespiration as the major driving force for C4 evolution but also highlights the relevance of changes in the expression of photorespiratory genes in inducing and establishing important phases on the path from C3 to C4. PMID:26912798

  11. Current concepts in C3 glomerulopathy

    OpenAIRE

    Thomas, S.; Ranganathan, D.; Francis, L.; Madhan, K.; John, G. T.

    2014-01-01

    Complement component 3 glomerulopathy (C3G) is a recently defined entity comprising of dense deposit disease and C3 glomerulonephritis. The key histological feature is the presence of isolated C3 deposits without immunoglobulins. Often masqueradng as some of the common glomerulonephritides this is a prototype disorder occurring from dysregulated alternate complement pathway with recently identified genetic defects and autoantibodies. We review the pathophysiology, clinical features, and diagn...

  12. Anaphylatoxin C3a receptors in asthma

    OpenAIRE

    Panettieri Reynold A; Ali Hydar

    2005-01-01

    Abstract The complement system forms the central core of innate immunity but also mediates a variety of inflammatory responses. Anaphylatoxin C3a, which is generated as a byproduct of complement activation, has long been known to activate mast cells, basophils and eosinophils and to cause smooth muscle contraction. However, the role of C3a in the pathogenesis of allergic asthma remains unclear. In this review, we examine the role of C3a in promoting asthma. Following allergen challenge, C3a i...

  13. Resource Conservation and Recovery Act, Part B Permit Application [for the Waste Isolation Pilot Plant (WIPP)]. Volume 2, Chapter C, Appendix C1--Chapter C, Appendix C3 (beginning), Revision 3

    Energy Technology Data Exchange (ETDEWEB)

    1993-03-01

    This volume contains appendices for the following: Rocky Flats Plant and Idaho National Engineering Laboratory waste process information; TRUPACT-II content codes (TRUCON); TRUPACT-II chemical list; chemical compatibility analysis for Rocky Flats Plant waste forms; chemical compatibility analysis for waste forms across all sites; TRU mixed waste characterization database; hazardous constituents of Rocky Flats Transuranic waste; summary of waste components in TRU waste sampling program at INEL; TRU waste sampling program; and waste analysis data.

  14. conformational complexity of complement component C3

    OpenAIRE

    Janssen, B.J.C.

    2007-01-01

    The complement system is an important part of the immune system and critical for the elimination of pathogens. In mammals the complement system consists of an intricate set of about 35 soluble and cell-surface plasma proteins. Central to complement is component C3, a large protein of 1,641 residues. Activation of C3 into C3b leads to several molecular and cellular responses, and to stimulation of the adaptive immune system. Chapter 1 gives an overview of the complement system, the central com...

  15. C3 polymorphism in beta-thalassemia.

    Science.gov (United States)

    Germenis, A; Kalantzi, M; Karamerou, A; Politi, C; Fertakis, A

    1984-01-01

    The distribution of phenotypes and gene frequencies of the third component of complement (C3) were studied in 106 beta-thalassemic patients and in 112 carriers of the beta-thalassemia trait. A statistically significant association was found between the C3F gene and homozygous beta-thalassemia. It can be suggested that this association may be related with the high incidence of infections encountered in these patients. PMID:6419525

  16. Self-association and domain rearrangements between complement C3 and C3u provide insight into the activation mechanism of C3

    OpenAIRE

    Li, Keying; Gor, Jayesh; Perkins, Stephen J.

    2010-01-01

    Abstract Component C3 is the central protein of the complement system. During complement activation, the thioester group in C3 is slowly hydrolysed to form C3u, then the presence of C3u enables the rapid conversion of C3 to functionally-active C3b. C3u shows functional similarities to C3b. To clarify this mechanism, the self-association properties and solution structures of C3 and C3u were determined using analytical ultracentrifugation and X-ray scattering. Sedimentation coefficie...

  17. conformational complexity of complement component C3

    NARCIS (Netherlands)

    Janssen, B.J.C.

    2007-01-01

    The complement system is an important part of the immune system and critical for the elimination of pathogens. In mammals the complement system consists of an intricate set of about 35 soluble and cell-surface plasma proteins. Central to complement is component C3, a large protein of 1,641 residues.

  18. The Development of the C3 Framework

    Science.gov (United States)

    Social Education, 2013

    2013-01-01

    Susan Griffin, executive director of NCSS, was chair of the Task Force of Professional Organizations that initiated and guided the development of "The College, Career, and Civic Life (C3) Framework for Social Studies State Standards", which will soon be released. In this interview with "Social Education", Susan explains how the…

  19. [Pulmonary calcification in C3H mice].

    Science.gov (United States)

    Yoshida, M; Uchida, K; Shigemura, M; Fujiwara, H; Kusano, N

    1985-10-01

    C3H mice including aged retired breeding females, aged virginal females, young virginal females and young males were examined for the incidence and severity of pulmonary calcification. Pulmonary calcification appeared in aged females, but not in young mice of either sex, and the lesions in aged breeders were more severe and frequent than in aged virgins. These results indicate that spontaneous pulmonary calcification is observed in aged females of the C3H strain. The findings of increased incidence and severity of pulmonary lesions in aged breeders suggest that pregnancy, delivery and lactation are important enhancing factors. Calcified lesions were also observed in kidney, heart, brain, ovary, choroid plexus, cornea and artery in the animals examined. PMID:4085573

  20. C3 Deficiency – A Case Report

    OpenAIRE

    Carreiro-Martins, P; Gaspar, A.; Rosado-Pinto, J.

    2006-01-01

    O sistema do complemento é um componente essencial do sistema imunitário inato, pelo que as deficiências de proteínas da sua complexa cascata podem ter consequências mais ou menos graves, de acordo com a importância do factor afectado. As complicações mais usuais das deficiências do complemento são infecções recorrentes a bactérias encapsuladas e distúrbios autoimunes. Os autores apresentam um caso clínico de deficiência do factor C3, situação extremamente rara, discutindo a fisiopatolo...

  1. Distinct associations of complement C3a and its precursor C3 with atherosclerosis and cardiovascular disease

    NARCIS (Netherlands)

    Hertle, E.; Greevenbroek, van M.M.J.; Arts, I.C.W.; Kallen, van der C.J.H.; Geijselaers, S.L.C.; Feskens, E.J.M.; Jansen, E.H.; Schalkwijk, C.G.; Stehouwer, C.D.A.

    2014-01-01

    Complement C3 is a novel risk factor for cardiovascular disease (CVD), but the underlying mechanism is currently unknown. We determined the associations of the anaphylatoxin C3a, the activation product of C3, and of C3 itself with estimates of atherosclerosis and CVD. We studied associations of C3a

  2. Molecular basis of polymorphisms of human complement component C3

    OpenAIRE

    1990-01-01

    C3 exhibits two common allotypic variants that may be separated by gel electrophoresis and are called C3 fast (C3 F) and C3 slow (C3 S). C3 F, the less common variant, occurs at appreciable frequencies only in Caucasoid populations (gene frequency = 0.20). An increased prevalence of the C3 F allele has been reported in patients with partial lipodystrophy, IgA nephropathy, and Indian childhood hepatic cirrhosis. Studies of the genomic organization of the human C3 gene led to the identification...

  3. Accelerated decay of C3b to iC3b when C3b is bound to the Cryptococcus neoformans capsule.

    OpenAIRE

    Pfrommer, G S; Dickens, S M; Wilson, M A; Young, B. J.; Kozel, T R

    1993-01-01

    Incubation of encapsulated and nonencapsulated Cryptococcus neoformans in normal human serum (NHS) leads to activation and binding of potentially opsonic fragments of complement component C3 to the yeast cells. Analysis of the molecular forms of C3 after incubation of encapsulated cryptococci in NHS showed that the percentage of bound C3 occurring as iC3b approached 100% after 8 min. The percentage of bound C3 occurring as iC3b on nonencapsulated cryptococci never exceeded 70%, even after 60 ...

  4. Generation of a C3c specific monoclonal antibody and assessment of C3c as a putative inflammatory marker derived from complement factor C3

    DEFF Research Database (Denmark)

    Palarasah, Yaseelan; Skjødt, Karsten; Brandt, Jette;

    2010-01-01

    complex (C5b-C9) and quantification of complement split products by precipitation-in-gel techniques (e.g. C3d). We have developed a mouse monoclonal antibody (mAb) that is able to detect fluid phase C3c without interference from other products generated from the complement component C3. The C3c specific m......Ab was tested in different ELISA combinations with various types of in vitro activated sera and with plasma or serum samples from factor I deficient patients. The specificity of the mAb was evaluated in immunoprecipitation techniques and by analysis of eluted fragments of C3 after immunoaffinity...... chromatography. The C3c mAb was confirmed to be C3c specific, as it showed no cross-reactivity with native (un-cleaved) C3, with C3b, iC3b, or with C3d. Also, no significant reaction was observed with C3 fragments in factor I deficient sera or plasma. This antibody forms the basis for the generation of a robust...

  5. Complement C3: an emerging risk factor in cardiometabolic disease

    OpenAIRE

    Hertle, E.; van Greevenbroek, M.M.J.; Stehouwer, C.D.A.

    2012-01-01

    C3 is the central component of the complement system and activation of C3 via any of the three major activation pathways—the classical, the lectin and the alternative pathways—results in initiation of the terminal complement pathway and release of the anaphylatoxin C3a. Both terminal pathway activation and signalling of C3a and its inactivation product C3a-desarg via the C3a receptor and C5a-like receptor 2, respectively, can induce inflammatory, immunomodulatory and metabolic responses. C3 h...

  6. Growth and N2-fixation of Dhaincha C-3/Sorghum C-4 and Dhaincha C-3/Sunflower C-3 intercropping systems using the 15N and 13C natural abundance method technique

    International Nuclear Information System (INIS)

    A field experiment on dhaincha C3 (Sesbania aculeata Pers), sunflower C3 (Helianthus annuus L.) and sorghum C4 (Sorghum bicolor L.) plants grown in monocropping and intercropping systems was conducted to evaluate seed yield, dry matter production, total N yield, land equivalent ratio (LER), intraspecific competition for soil N uptake, water use efficiency (WUE) and N2-fixation using the 15N natural abundance technique (δ 15N). Moreover, carbon isotope discrimination (Δ 13C) was determined to assess factors responsible for crop performance variability in the different cropping systems. (author)

  7. 雪铁龙C3 Picasso

    Institute of Scientific and Technical Information of China (English)

    孟颖梅

    2008-01-01

    认为C4 Picasso有点大?好,来个小点的,雪铁龙最近就推出了C3 Picasso这是个袖珍的MPV,车长比C4 Picasso短了大约510毫米,更适于城市的穿行。圆润的车身像个绿色大胶囊,宽阔的黑色进气口与黑眼圈的前雾灯显得很有趣。车头的雪铁龙标志不再是延伸的两列平行线,而是单独置于车头前方。前风挡很有特色,一直延伸到了车侧面,A柱被移到车前部的小侧窗后面,和前风挡连了起来。这种构造让驾驶员的前方视野大大拓宽,减轻了A柱对视线的影响。

  8. Interactions of complement receptor type 2 with C3d and factor H with C3u

    OpenAIRE

    Li, K

    2010-01-01

    Complement receptor type 2 (CR2, CD21) is a cell surface protein that links the innate and adaptive immune response through its binding to C3d, a cleavage fragment of the major complement component C3. Factor H (FH) is a major plasma protein that is the major regulator of the activity of C3b in the alternative pathway. FH binds to C3u, which is formed from C3 by hydrolysis, and C3u shows functional similarities to C3b. In this thesis, X-ray scattering, analytical ultracentrifug...

  9. Breakdown of C3 after complement activation. Identification of a new fragment C3g, using monoclonal antibodies

    OpenAIRE

    1982-01-01

    The physiological breakdown of C3 has been studied using monoclonal anti-C3 antibodies, and it has been found that the later stages of this process--the breakdown of C3bi--is more complex than had previously been recognized. C3bi is the reaction product produced from C3b by the action of factor I which, in the presence of factor H, produces a double cleavage in the alpha chain of C3b. It is here reported that, both on cells and in the fluid phase, the breakdown of C3bi in serum gives rise to ...

  10. Growth and N2-fixation of Dhaincha C-3/Sorghum C-4 and Dhaincha C-3/Sunflower C-3 intercropping systems using the 15N and 13C natural abundance method technique

    International Nuclear Information System (INIS)

    A field experiment on dhaincha C3 (Sesbania aculeata Pers), sunflower C3 (Helianthus annuus L.) and sorghum C4 (Sorghum bicolor L.) plants grown in monocropping and intercropping systems was conducted to evaluate seed yield, dry matter production, total N yield, land equivalent ratio (LER), intraspecific competition for soil N uptake, water use efficiency (WUE) and N2-fixation using the 15N natural abundance technique (δ 15N). Moreover, carbon isotope discrimination (Δ13C) was determined to assess factors responsible for crop performance variability in the different cropping systems. Intercropping of sesbania/sorghum showed greater efficiency over monocropping in producing dry matter, during the entire growth period, as indicated by the LERs (>1); whereas, the efficiency of producing dry matter in the sesbania /sunflower intercropping was similar to that in the monocropping system (LER=1). Moreover, sorghum plants (C4) was more competitive than sesbania (C3) for soil N uptake; whereas, sesbania seemed to be more competitive than its associated sunflower (C3). N uptake in the mixed stand of sesbania/sorghum was improved due to the increase in soil N uptake by the component sorghum and the higher root nodule activity of component sesbania without affecting the amount of N2 fixed. In both cropping systems, sesbania plants fixed almost the same amount of N2 (an average of 105 kg N/ha) although the number of rows in the mixed stand was 2/3 of that in the pure stand. This gives an advantage of the intercropping over sole cropping system with regards to N2-fixation. 13C discrimination in plant materials was found to be affected by plant species and the cropping system. Factors affected Δ13C in plants grown in the mixed stand relative to solely grown crops are discussed.(author)

  11. Molecular basis of complement C3 deficiency in guinea pigs.

    OpenAIRE

    Auerbach, H S; de Burger, R; Dodds, A.; Colten, H R

    1990-01-01

    In experiments to ascertain the biochemical basis of a genetically determined deficiency of the third component of complement (C3) in guinea pigs, we found that C3-deficient liver and peritoneal macrophages contain C3 messenger RNA of normal size (approximately 5 kb) and amounts, that this mRNA programs synthesis of pro-C3 in oocytes primed with liver RNA and in primary macrophage cultures. In each instance, heterodimeric native C3 protein was secreted with normal kinetics but the C3 protein ...

  12. Atomistic study on the structure and thermodynamic properties of Cr7C3, Mn7C3, Fe7C3

    International Nuclear Information System (INIS)

    The crystal structures and stabilities of Cr7C3, Mn7C3, Fe7C3 have been investigated using the interatomic potentials obtained by the lattice inversion method. The calculated structures of Cr7C3, Mn7C3 and Fe7C3 are proposed to be hexagonal with P63 mc space group and the calculated lattice constants are in basic agreement with the experimental data. The calculated cohesive energies indicate that the increase in the atomic number of the metal is accompanied by the decrease in the stability of its carbides. The phonon density of states and vibrational entropy related to dynamic phenomena are also evaluated. This work provides a new method for studying the properties of carbides with complex structure

  13. Candida albicans and Candida stellatoidea, in contrast to other Candida species, bind iC3b and C3d but not C3b.

    OpenAIRE

    Heidenreich, F; Dierich, M.P.

    1985-01-01

    It was demonstrated that complement-coated sheep erythrocytes bind to Candida albicans cells grown in serum-free RPMI 1640 medium. Testing of purified complement components proved that iC3b and C3d were responsible for the reaction, whereas C3b and C3b-H reacted only slightly if at all. Binding occurred only to C. albicans and C. stellatoidea, not to other species pathogenic to humans. There was evidence of a lectinlike nature of the effect.

  14. Fibronectin and serum amyloid P component stimulate C3b- and C3bi- mediated phagocytosis in cultured human monocytes

    OpenAIRE

    1983-01-01

    Fibronectin (FN) and serum amyloid P component (SAP) markedly enhance phagocytosis mediated by the C3b and C3bi receptors of cultured human monocytes but not of granulocytes. (The C3b and C3bi receptors of granulocytes can be activated by treatment of these phagocytes with PMA.) Activation of monocyte C3 receptors by FN is developmentally regulated: Freshly explanted monocytes respond to FN with a small increase in C3 receptor-mediated phagocytosis while monocytes matured in culture exhibit a...

  15. Efficacy of Targeted Complement Inhibition in Experimental C3 Glomerulopathy

    OpenAIRE

    Ruseva, Marieta M.; Peng, Tao; Lasaro, Melissa A.; Bouchard, Keith; Liu-Chen, Susan; Sun, Fang; Yu, Zhao-Xue; Marozsan, Andre; Wang, Yi; Pickering, Matthew C.

    2015-01-01

    C3 glomerulopathy refers to renal disorders characterized by abnormal accumulation of C3 within the kidney, commonly along the glomerular basement membrane (GBM). C3 glomerulopathy is associated with complement alternative pathway dysregulation, which includes functional defects in complement regulator factor H (FH). There is no effective treatment for C3 glomerulopathy. We investigated the efficacy of a recombinant mouse protein composed of domains from complement receptor 2 (CR2) and FH (CR...

  16. Mannan-binding lectin activates C3 and the

    DEFF Research Database (Denmark)

    Selander, B.; Martensson, U.; Weintraub, A.;

    2006-01-01

    Lectin pathway activation of C3 is known to involve target recognition by mannan-binding lectin (MBL) or ficolins and generation of classical pathway C3 convertase via cleavage of C4 and C2 by MBL-associated serine protease 2 (MASP-2). We investigated C3 activation in C2-deficient human sera and in...

  17. On the Y-chromosome haplogroup C3c classification.

    Science.gov (United States)

    Malyarchuk, Boris A; Derenko, Miroslava; Denisova, Galina

    2012-10-01

    As there are ambiguities in classification of the Y-chromosome haplogroup C3c, relatively frequent in populations of Northern Asia, we analyzed all three haplogroup-defining markers M48, M77 and M86 in C3-M217-individuals from Siberia, Eastern Asia and Eastern Europe. We have found that haplogroup C3c is characterized by the derived state at M48, whereas mutations at both M77 and M86 define subhaplogroup C3c1. The branch defined by M48 alone would belong to subhaplogroup C3c*, characteristic for some populations of Central and Eastern Siberia, such as Koryaks, Evens, Evenks and Yukaghirs. Subhaplogroup C3c* individuals could be considered as remnants of the Neolithic population of Siberia, based on the age of C3c*-short tandem repeat variation amounting to 4.5 ± 2.4 thousand years. PMID:22810113

  18. Climate and CO2 modulate the C3/C4 balance and δ13C signal in simulated vegetation

    Directory of Open Access Journals (Sweden)

    D. Jolly

    2009-08-01

    Full Text Available Climate and atmospheric CO2 effects on the balance between C3 and C4 plants have received conflicting interpretations based on the analysis of carbon isotopic fractionation (δ13C in sediments. But, climate and CO2 effects on the C3/C4 balance and δ13C signal are rarely addressed together. Here, we use a process-based model (BIOME4 to disentangle these effects. We simulated the vegetation response to climate and CO2 atmospheric concentration (pCO2 in two sites in which vegetation changed oppositely, with respect to C3 and C4 plants abundance, during the Last Glacial Maximum to Holocene transition. The C3/C4 balance and δ13C signal were primarily sensitive to temperature and CO2 atmospheric partial pressure. The simulated variations were in agreement with patterns observed in palaeorecords. Water limitation favoured C4 plants in case of large negative deviation in rainfall. Although a global parameter, pCO2 affected the δ13C signal differently from one site to the other because of its effects on the C3/C4 balance and on carbon isotopic fractionation in C3 and C4 plants. Simulated Plant functional types (PFT also differed in their composition and response from one site to the other. The C3/C4 balance involved different competing C3 and C4 PFT, and not homogeneous C3 and C4 poles as often assumed. Process-based vegetation modelling emphasizes the need to account for multiple factors when a palaeo-δ13C signal is used to reconstruct the C3/C4 balance.

  19. Downregulation of Complement C3 and C3aR Expression in Subcutaneous Adipose Tissue in Obese Women

    OpenAIRE

    Abhishek Gupta; Reza Rezvani; Marc Lapointe; Pegah Poursharifi; Picard Marceau; Sunita Tiwari; Andre Tchernof; Katherine Cianflone

    2014-01-01

    BACKGROUND: The central component of the complement system, C3, is associated with obesity, metabolic syndrome and cardiovascular disease however the underlying reasons are unknown. In the present study we evaluated gene expression of C3, the cleavage product C3a/C3adesArg and its cognate receptor C3aR in subcutaneous and omental adipose tissue in women. METHODS: Women (n = 140, 21-69 years, BMI 19.5-79 kg/m2) were evaluated for anthropometric and blood parameters, and adipose tissue gene exp...

  20. Staphylococcus aureus proteins Sbi and Efb recruit human plasmin to degrade complement C3 and C3b.

    Directory of Open Access Journals (Sweden)

    Tina K Koch

    Full Text Available Upon host infection, the human pathogenic microbe Staphylococcus aureus (S. aureus immediately faces innate immune reactions such as the activated complement system. Here, a novel innate immune evasion strategy of S. aureus is described. The staphylococcal proteins surface immunoglobulin-binding protein (Sbi and extracellular fibrinogen-binding protein (Efb bind C3/C3b simultaneously with plasminogen. Bound plasminogen is converted by bacterial activator staphylokinase or by host-specific urokinase-type plasminogen activator to plasmin, which in turn leads to degradation of complement C3 and C3b. Efb and to a lesser extend Sbi enhance plasmin cleavage of C3/C3b, an effect which is explained by a conformational change in C3/C3b induced by Sbi and Efb. Furthermore, bound plasmin also degrades C3a, which exerts anaphylatoxic and antimicrobial activities. Thus, S. aureus Sbi and Efb comprise platforms to recruit plasmin(ogen together with C3 and its activation product C3b for efficient degradation of these complement components in the local microbial environment and to protect S. aureus from host innate immune reactions.

  1. Distinct associations of complement C3a and its precursor C3 with atherosclerosis and cardiovascular disease. The CODAM study.

    Science.gov (United States)

    Hertle, Elisabeth; van Greevenbroek, Marleen M; Arts, Ilja C; van der Kallen, Carla J; Geijselaers, Stefan L; Feskens, Edith J; Jansen, Eugene H; Schalkwijk, Casper G; Stehouwer, Coen D

    2014-06-01

    Complement C3 is a novel risk factor for cardiovascular disease (CVD), but the underlying mechanism is currently unknown. We determined the associations of the anaphylatoxin C3a, the activation product of C3, and of C3 itself with estimates of atherosclerosis and CVD. We studied associations of C3a and C3 with carotid intima-media thickness (cIMT), ankle-arm blood pressure index (AAIx) and CVD in cross-sectional analyses among 545 participants of the Cohort on Diabetes and Atherosclerosis Maastricht (CODAM) study (62% men, 59.4 ± 6.9 years) and examined effect modification by smoking. We conducted linear and logistic regression analyses with adjustments for age, sex, glucose metabolism status, lipids, adiposity, renal function, blood pressure, pack-years smoked, physical activity, use of medication and investigated mediation by inflammation. C3a was independently associated with cIMT (β=0.032 mm, [95% confidence interval: 0.004; 0.060]) and AAIx (β=-0.022, [-0.043; -0.001]), but C3 was not. Effect modification by smoking was only observed for CVD (P(smoking*C3a)=0.008, P(smoking*C3)=0.018), therefore these associations were stratified for smoking behaviour. Both C3a (odds ratio [OR] =2.96, [1.15; 7.62]) and C3 (OR =1.98, [1.21; 3.22]) were independently associated with CVD in heavy smokers. The association of C3 with CVD was independent of C3a. Low-grade inflammation did partially explain the association of C3a with AAIx, but not the other observed associations. This suggests that C3a and C3 have distinct roles in pathways leading to CVD. C3a may promote atherosclerosis and additionally advance CVD in heavy smokers. Conversely, C3 may be associated with CVD in heavy smokers via pathways other than atherosclerosis. PMID:24500020

  2. Reduced apparent photorespiration by the C3-C4 intermediate species, Moricandia arvensis and Panicum milioides

    International Nuclear Information System (INIS)

    The CO2/O2 specificity factor of sucrose gradient purified ribulose 1,5-bisphosphate carboxylase/oxygenase from the C3-C4 intermediate plants Moricandia arvensis and Panicum milioides was similar to the respective values of the enzyme from the closely related C3 species, Moricandia foetida and Panicum laxum. Thus, the kinetic properties of this bifunctional enzyme do not explain the reduced rates of photorespiration exhibited by either of these intermediate species. Dark/light ratios for aminoacetonitrile-sensitive 14CO2 evolution during decarboxylation of exogenous [1-14C] glycine by leaf discs had values of 9.0 with M. arvensis and 11.8 with P. milioides. Similar results were obtained using [1-14C] glycolate as the exogenous photorespiratory substrate, with dark/light 14CO2 evolution ratios for the C3-C4 and C3 leaf discs averaging 6.6 and 2.0, respectively. The data suggest that P. milioides and M. arvensis are capable of a more efficient internal recycling of photorespiratory CO2 via ribulose bisphosphate carboxylase/oxygenase than closely related C3 plants, and that this may partially account for the reduced rates of apparent photorespiration by these intermediate species

  3. Die Rolle des Komplementfaktors C3 in der chronischen Herzinsuffizienz

    OpenAIRE

    Schenk, Andreas

    2010-01-01

    Vergangene Studien zeigten, dass das Komplementsystem bei myokardialer Ischämie und Reperfusion einen negativen Einfluss auf den Reperfusionsschaden hat. Der Einfluss des Komplementsystems auf die Entstehung und Progression der Herzinsuffizienz nach Myokardinfarkt ist allerdings bislang nicht untersucht. Diese Arbeit untersuchte deshalb in einem C3-Knockout(KO)-Modell pathophysiologische Auswirkungen des Komplementfaktors C3 auf die chronische Herzinsuffizienz. Bei Wildtyp- und C3-KO-Mäusen w...

  4. A revised mechanism for the activation of complement C3 to C3b: a molecular explanation of a disease-associated polymorphism.

    OpenAIRE

    Rodriguez, E.; Nan, R.; Li, K; Gor, J.; Perkins, S J

    2015-01-01

    The solution structure of complement C3b is crucial for the understanding of complement activation and regulation. C3b is generated by the removal of C3a from C3. Hydrolysis of the C3 thioester produces C3u, an analog of C3b. C3b cleavage results in C3c and C3d (thioester-containing domain; TED). To resolve functional questions in relation to C3b and C3u, analytical ultracentrifugation and x-ray and neutron scattering studies were used with C3, C3b, C3u, C3c, and C3d, using the wild-type allo...

  5. C3b complexation diversifies naturally processed T cell epitopes.

    OpenAIRE

    Cretin, François,; Serra, Vincent,; Villiers, Marie-Bernadette; Laharie, Anne-Marie; Marche, Patrice; Gabert, Françoise,

    2007-01-01

    International audience In addition to its well-established role in innate immunity, the complement component C3 is of critical importance in modulating the humoral response. In this study, we examined the effect of C3b linkage to tetanus toxin (TeNT) in the production of antigenic peptides inside human APC. We purified HLA-DR associated peptides isolated either from TeNT or TeNT-C3b pulsed cells. This study revealed that TeNT-C3b derived antigenic peptides are different and more numerous t...

  6. Activation and binding of C3 by Candida albicans.

    OpenAIRE

    Kozel, T R; Brown, R R; Pfrommer, G S

    1987-01-01

    Interaction with components of the complement system is an important aspect of the pathogenesis of infection by Candida albicans. The key role of C3 as an opsonic ligand and as an element in amplification of complement activation led us to examine several factors that influence the activation and binding of C3 cleavage fragments to the yeast. Activation and binding of C3 were determined by use of normal human serum containing 125I-labeled C3. Incubation of yeast-phase cells in 20% serum led t...

  7. Decreased circulating C3 levels and mesangial C3 deposition predict renal outcome in patients with IgA nephropathy.

    Directory of Open Access Journals (Sweden)

    Seung Jun Kim

    Full Text Available BACKGROUND AND AIMS: Mesangial C3 deposition is frequently observed in patients with IgA nephropathy (IgAN. However, the role of complement in the pathogenesis or progression of IgAN is uncertain. In this observational cohort study, we aimed to identify the clinical implications of circulating C3 levels and mesangial C3 deposition and to investigate their utility as predictors of renal outcomes in patients with IgAN. METHODS: A total of 343 patients with biopsy-proven IgAN were enrolled between January 2000 and December 2008. Decreased serum C3 level (hypoC3 was defined as C3 <90 mg/dl. The study endpoint was end-stage renal disease (ESRD and a doubling of the baseline serum creatinine (D-SCr. RESULTS: Of the patients, there were 66 patients (19.2% with hypoC3. During a mean follow-up of 53.7 months, ESRD occurred in 5 patients (7.6% with hypoC3 compared with 9 patients (3.2% with normal C3 levels (P = 0.11. However, 12 patients (18.2% with hypoC3 reached D-SCr compared with 17 patients (6.1% with normal C3 levels [Hazard ratio (HR, 3.59; 95% confidence interval (CI, 1.33-10.36; P = 0.018]. In a multivariable model in which serum C3 levels were treated as a continuous variable, hypoC3 significantly predicted renal outcome of D-SCr (per 1 mg/dl increase of C3; HR, 0.95; 95% CI, 0.92-0.99; P = 0.011. The risk of reaching renal outcome was significantly higher in patients with mesangial C3 deposition 2+ to 3+ than in patients without deposition (HR 9.37; 95% CI, 1.10-80.26; P = 0.04. CONCLUSIONS: This study showed that hypoC3 and mesangial C3 deposition were independent risk factors for progression, suggesting that complement activation may play a pathogenic role in patients with IgAN.

  8. Photorespiratory properties of protoplasts from C3-C4intermediate species of moricandia

    International Nuclear Information System (INIS)

    Protoplasts were isolated from leaves of the C3-C4 intermediate species, Moricandia arvensis (L.) DC. and Moricandia spinosa Pomel. Analysis by light and transmission electron microscopy indicated that these purified preparations contained both mesophyll protoplasts (MP) and bundle-sheath protoplasts (BSP). Conventional density gradient centrifugation procedures failed to yield separations of pure protoplasts from each cell-type. With these heterogeneous suspensions of MP and BSP, values measured for (i) the percentage inhibition of photosynthetic CO2 fixation by O2, (ii) the apparent K (CO2) of photosynthesis, and (iii) dark/light ratios of the rate of 14CO2 evolution during decarboxylation of exogenous [1-14C]glycine were not significantly different from those determined for protoplasts preparations from related or representative C3 plants, including M. foetida, Nicotiana tavacum, and Triticum aestivum. In contrast, previous comparisons with C3 species, using intact leaf tissue from M, arvensis, have shown a reduced sensitivity of new photosynethic to inhibition by O2 [Holaday et al., Plant Sci. Lett., 27 (1982) 181] and an enhanced capacity for the photosynthetic refixation of CO2 evolved during decarboxylation of exogenous photorespiratory substrates [Holbrook et al., Plant Physiol., 77 (1985) 578]. We conclude that these photosynthetic properties, associated with reduced photorespiration by M. arvensis and M. spinosa, are dependent upon the integrity of the anatomical and ultrastructural arrangement of bundle-sheath and mesophyll cells in these C3-C4intermediate species. (author)

  9. Stabilization/solidification on chromium (III) wastes by C(3)A and C(3)A hydrated matrix.

    Science.gov (United States)

    Li, Xiangguo; He, Chao; Bai, Yun; Ma, Baoguo; Wang, Guandong; Tan, Hongbo

    2014-03-15

    Hazardous wastes are usually used in the Portland cement production in order to save energy, costs and/or stabilize toxic substances and heavy metals inside the clinker. This work focus on the stabilization/solidification on chromium (III) wastes by C(3)A and C(3)A hydrated matrix. The immobilization rate of chromium in C(3)A and the leaching characteristics of the C(3)A hydrated matrixes containing chromium were investigated by ICP-AES. The results indicated that C(3)A had a good solidifying effect on chromium using the clinkering process, however, the Cr leaching content of Cr-doped C(3)A was higher than that of hydrated C(3)A matrix in Cr(NO(3))3 solution and was lower than that of the hydrated C(3)A matrix in K(2)CrO(4) solution, no matter the leachant was sulphuric acid & nitric acid or water. To explain this, C(3)A formation, chemical valence states of chromium in C(3)A, hydration products and Cr distribution in the C(3)A-gypsum hydrated matrixes were studied by XRD, XPS and FESEM-EDS. The investigation showed that part of Cr(3+) was oxidized to Cr(6+) in the clinkering process and identified as the chromium compounds Ca(4)Al(6)O(12)CrO(4) (3CaO·Al(20O(3)·CaCrO(4)), which resulted in the higher leaching of hydrated matrix of Cr-doped C(3)A. PMID:24468527

  10. Progress of C3 glomerulopathy%C3肾小球病研究进展

    Institute of Scientific and Technical Information of China (English)

    迟迪; 任立红

    2015-01-01

    C3肾小球病是一组以免疫荧光染色补体C3沿肾小球毛细血管袢沉积为主要病理改变的疾病,其C3沉积一般大于其他免疫球蛋白及补体激活经典途径成分(如C1 q、C4等)两个等级。C3肾小球病是新近认识的较为罕见的一组原发性肾小球疾病。该文综述C3肾小球病的病理特征、临床表现、诊断和治疗经过,以期提高临床对C3肾小球病的认识及重视。%C3 glomerulopathy is a group of diseases with immunofluorescence staining C3 along the glomerular capillary loops deposition,may be accompanied by other immunoglobulin deposition,but C3 sedi-mentary classic way was more than other immunoglobulin and complement activation ingredients ( such as C1q,C4). C3 glomerulopathy is a group of primary glomerular disease and relatively rare. This article mainly reviewed the pathological characteristic of C3 glomerulopathy,clinical manifestation,diagnosis and treatment, in order to improve clinical understanding of C3 glomerulopathy.

  11. The C3 Reference Model%C3参考模型

    Institute of Scientific and Technical Information of China (English)

    邱建雄; 文丹; 张河

    2004-01-01

    介绍了一种X3规范的通用框架结构C3RM.它是基于国际标准组织(ISO)、开放系统互连(OSI)、参考模型(RM)的一种通用结构.为了适应通信类型的作用,X3RM包含了ISO,OSI,RM,对所有物理作用的关键类型都包含了相似的结构,并利用应用层以整合的方式为所有作用类型提供命令和控制.X3RM充实了很多已有的模型结构,为相关规范的发展、模块间彼此协作的实现,以及保护在模块重复利用技术上的投资提供了一个系统框架.

  12. The pathogenic mechanism of C3 glomerulopathy and its countermeasures

    Directory of Open Access Journals (Sweden)

    Jin-quan WANG

    2015-01-01

    Full Text Available C3 glomerulopathy is a series of diseases of glomeruli mediated by abnormal activation of alternative complement pathway. A series of researches have revealed in recent years that there are diversity and multiplicity of pathogenic mechanism in the pathogenesis of C3 glomerulopathy. The pathogenic mechanism of C3 glomerulopathy may be different in different individuals and types of disease. Congenital genetic defects and/or acquired autoantibodies may be found in the same individual. Individualized therapy should be given to individual patient in order to target different pathogenic mechanisms. Chinese herbal medicine, Tripterygium wilfordii, shows promise as a potential therapeutic agent for C3 glomerulopathy. The pathogenic mechanism and countermeasures for C3 glomerulopathy have been reviewed in present paper. DOI: 10.11855/j.issn.0577-7402.2014.11.15

  13. The complement C3 protein family in invertebrates

    Directory of Open Access Journals (Sweden)

    M Nonaka

    2011-01-01

    Full Text Available Complement C3 plays a pivotal role in the innate immune system of mammals as the central component of the complement system essential for its activation mechanism and effecter function. C3 has a unique intra-chain thioester bond that is shared by some complement and non-complement proteins forming a thioester protein (TEP family. Phylogenetic analysis of TEP family genes of vertebrates and invertebrates revealed that the TEP family is divided into two subfamilies, the C3 subfamily and the alpha-2-macroglobulin (A2M subfamily. The establishment of the TEP genes and differentiation of them into the C3 and A2M subfamilies occurred prior to the divergence of Cnidaria and Bilateria, in a common ancestor of Eumetazoa more than 600 MYA. Since then the A2M subfamily has been retained by all metazoan lineages analyzed thus far. In contrast, the C3 subfamily has been retained only by deuterostomes and some protostomes, and has been lost in multiple protostome lineages. Although the direct functional analysis of the most invertebrate TEPs is still to be performed, conservation of the basic domain structure and functionally important residues for each molecule suggests that the basic function is also conserved. Functional analyses performed on a few invertebrate C3 support this conclusion. The gene duplication events that generated C4 and C5 from C3 occurred in a common ancestor of jawed vertebrates, indicating that invertebrate and cyclostome C3s represent the pre-duplication state. In addition to C3, complement Bf and MASP involved in the activation of C3 are also identified in Cnidaria and some invertebrates, indicating that the complement system is one of the most ancient innate immune systems of Eumetazoa.

  14. C3 and C4 biomass allocation responses to elevated CO2 and nitrogen: contrasting resource capture strategies

    Science.gov (United States)

    White, K.P.; Langley, J.A.; Cahoon, D.R.; Megonigal, J.P.

    2012-01-01

    Plants alter biomass allocation to optimize resource capture. Plant strategy for resource capture may have important implications in intertidal marshes, where soil nitrogen (N) levels and atmospheric carbon dioxide (CO2) are changing. We conducted a factorial manipulation of atmospheric CO2 (ambient and ambient + 340 ppm) and soil N (ambient and ambient + 25 g m-2 year-1) in an intertidal marsh composed of common North Atlantic C3 and C4 species. Estimation of C3 stem turnover was used to adjust aboveground C3 productivity, and fine root productivity was partitioned into C3-C4 functional groups by isotopic analysis. The results suggest that the plants follow resource capture theory. The C3 species increased aboveground productivity under the added N and elevated CO2 treatment (P 2 alone. C3 fine root production decreased with added N (P 2 (P = 0.0481). The C4 species increased growth under high N availability both above- and belowground, but that stimulation was diminished under elevated CO2. The results suggest that the marsh vegetation allocates biomass according to resource capture at the individual plant level rather than for optimal ecosystem viability in regards to biomass influence over the processes that maintain soil surface elevation in equilibrium with sea level.

  15. Degradation of C3a anaphylatoxins by rat mast cells

    International Nuclear Information System (INIS)

    Incubation of 125I-human C3a with rat peritoneal mast cells (RMC) causes extensive degradation of the ligand. Both cell-bound and free 125I-C3a (hu) was degraded by RMC, even at 00C, based on SDS-PAGE analysis. The authors examined several protease inhibitors for their ability to prevent degradation of 125I-C3a (hu). Degradation of 125I-C3a (hu) by RMC was not inhibited by leupeptin, antipain, elastatinal, pepstatin, α1-antitrypsin or EDTA. TPCK and TLCK were only partially effective. PMSF, chymostatin and SBTI were most effective in preventing 125I-C3a (hu) degradation. These latter compounds are effective inhibitors of the chymotrypsin-like enzyme chymase extracted from RMC, as is TPCK, based on hydrolysis of the substrate BTEE. Degradation of cell-bound ligand is totally prevented only by PMSF (or DFP). Therefore, 125I-C3a (hu) bound to the RMC appears to be degraded predominantly by chymase; however the cell-bound ligand is attacked by other surface proteases. Degradation of rat C3a by RMC was examined. After incubation with RMC, cell-bound and free 125I-C3a (rat) showed no evidence of degradation with or without inhibitors present. From these results, the authors conclude that chymase may not play a significant role in regulating anaphylatoxin activity. Furthermore, the authors propose that rat C3a is a preferred ligand for identifying receptors on mast cells because of its resistance to proteolysis

  16. The complement C3 protein family in invertebrates

    OpenAIRE

    Nonaka, M

    2011-01-01

    Complement C3 plays a pivotal role in the innate immune system of mammals as the central component of the complement system essential for its activation mechanism and effecter function. C3 has a unique intra-chain thioester bond that is shared by some complement and non-complement proteins forming a thioester protein (TEP) family. Phylogenetic analysis of TEP family genes of vertebrates and invertebrates revealed that the TEP family is divided into two subfamilies, the C3 subfamily and the al...

  17. Crystallographic evidence for deviating C3b structure?

    OpenAIRE

    Janssen, B.J.C.; Read, R.J.; Brunger, A. T.; Gros, P

    2007-01-01

    Activation of C3 into C3b is a critical step in the complement immune response against pathogenic, immunogenic and apoptotic particles. Ajees et al.1 report a crystal structure of C3b, which deviates from the one reported by Janssen et al.2 and Wiesmann et al.3. Analysis of the data deposited by Ajees et al.1 reveals features that are inconsistent with known physical properties of macromolecular structures and their diffraction data. Therefore, Ajees et al. do not provide substantial evidence...

  18. An observational investigation of the identity of B11244 (l-C3H+/C3H-)

    International Nuclear Information System (INIS)

    Pety et al. have reported the detection of eight transitions of a closed-shell, linear molecule (B11244) in observations toward the Horsehead photodissociation region (PDR), which they attribute to the l-C3H+ cation. Recent high-level ab initio calculations have called this assignment into question; the anionic C3H– molecule has been suggested as a more likely candidate. Here, we examine observations of the Horsehead PDR, Sgr B2(N), TMC-1, and IRC+10216 in the context of both l-C3H+ and C3H–. We find no observational evidence of Ka = 1 lines, which should be present were the carrier indeed C3H–. Additionally, we find a strong anticorrelation between the presence of known molecular anions and B11244 in these regions. Finally, we discuss the formation and destruction chemistry of C3H– in the context of the physical conditions in the regions. Based on these results, we conclude there is little evidence to support the claim that the carrier is C3H–.

  19. The interstellar chemistry of H2C3O isomers

    Science.gov (United States)

    Loison, Jean-Christophe; Agúndez, Marcelino; Marcelino, Núria; Wakelam, Valentine; Hickson, Kevin M.; Cernicharo, José; Gerin, Maryvonne; Roueff, Evelyne; Guélin, Michel

    2016-03-01

    We present the detection of two H2C3O isomers, propynal and cyclopropenone, toward various starless cores and molecular clouds, together with upper limits for the third isomer propadienone. We review the processes controlling the abundances of H2C3O isomers in interstellar media showing that the reactions involved are gas-phase ones. We show that the abundances of these species are controlled by kinetic rather than thermodynamic effects.

  20. The interstellar chemistry of H2C3O isomers

    OpenAIRE

    Loison, Jean-Christophe; Agúndez, Marcelino; Marcelino, Núria; Wakelam, Valentine; Hickson, Kevin M.; Cernicharo, José; Gerin, Maryvonne; Roueff, Evelyne; Guélin, Michel

    2016-01-01

    We present the detection of two H2C3O isomers, propynal and cyclopropenone, toward various starless cores and molecular clouds, together with upper limits for the third isomer propadienone. We review the processes controlling the abundances of H2C3O isomers in interstellar media showing that the reactions involved are gas-phase ones. We show that the abundances of these species are controlled by kinetic rather than thermodynamic effects.

  1. The interstellar chemistry of H2C3O isomers

    Science.gov (United States)

    Loison, Jean-Christophe; Agúndez, Marcelino; Marcelino, Núria; Wakelam, Valentine; Hickson, Kevin M.; Cernicharo, José; Gerin, Maryvonne; Roueff, Evelyne; Guélin, Michel

    2016-01-01

    We present the detection of two H2C3O isomers, propynal and cyclopropenone, toward various starless cores and molecular clouds, together with upper limits for the third isomer propadienone. We review the processes controlling the abundances of H2C3O isomers in interstellar media showing that the reactions involved are gas-phase ones. We show that the abundances of these species are controlled by kinetic rather than thermodynamic effects. PMID:27013768

  2. The interstellar chemistry of H2C3O isomers

    CERN Document Server

    Loison, Jean-Christophe; Marcelino, Núria; Wakelam, Valentine; Hickson, Kevin M; Cernicharo, José; Gerin, Maryvonne; Roueff, Evelyne; Guélin, Michel

    2015-01-01

    We present the detection of two H2C3O isomers, propynal and cyclopropenone, toward various starless cores and molecular clouds, together with upper limits for the third isomer propadienone. We review the processes controlling the abundances of H2C3O isomers in interstellar media showing that the reactions involved are gas-phase ones. We show that the abundances of these species are controlled by kinetic rather than thermodynamic effects.

  3. Design of Shibboleth-based Authorization in C3-Grid

    OpenAIRE

    Makedanz, Siegfried

    2007-01-01

    The D-Grid community project C3-Grid is in the process of building a Grid testbed with Shibboleth-based authentication und authorization. This testbed utilizes GridSphere, Globus Toolkit and metadata mechanisms specific to C3-Grid. Shibboleth will be integrated by way of GridShib's solution proposal for Teragrid Science Gateways. It shall be shown that portal-generated proxy certificates with embedded SAML statements, asserted by distributed Identity Providers, may be used for resource author...

  4. Draft Genome Sequence of Commercial Textile Dye-Decolorizing and -Degrading Bacillus subtilis Strain C3 Isolated in India

    Science.gov (United States)

    Kunadia, Khushbu; Nathani, Neelam M.; Kothari, Vishal; Kotadia, Rohit J.; Kothari, Charmy R.; Joshi, Anjali; Rank, Jalpa K.; Faldu, Priti R.; Shekar, M. Chandra; Viroja, Mitkumar J.; Patel, Priyank A.; Jadeja, Divyarajsinh; Reddy, Bhaskar; Pal Singh, Ravindra; Koringa, Prakash G.; Joshi, Chaitanya G.

    2016-01-01

    Bacillus subtilis C3, a commercial textile dye-decolorizing and -degrading bacterium, was isolated from the common effluent treatment plant (CEPT) of the Jetpur textile dyeing and printing industrial sector situated in the district of Rajkot, Gujarat, India. Here, we present the annotated 4.18-Mb draft genome sequence of B. subtilis C3, providing information about the metabolic pathways involved in decolorization and degradation of several commercial textile azo dyes. Thus, we confirm B. subtilis C3 as a potential candidate for bioremediation of textile effluents. PMID:26966205

  5. Current understanding of cellulose ethers impact on the hydration of C3A and C3A-sulphate systems

    OpenAIRE

    Pourchez, Jérémie; Grosseau, Philippe; Ruot, Bernard

    2009-01-01

    The impact of cellulose ethers (CE) on C3A hydration was examined to support the understanding of the retarding effect of CE on cement hydration. In this sense, we successively studied the CE adsorption on ettringite and calcium hydroaluminates, and then the CE influence during C3A hydration in presence or absence of calcium sulphate. We emphasized a phase-specific adsorption of CE depending on CE chemistry. Besides, in addition of CE, we highlighted a gradual slowing down of C3A dissolution ...

  6. Decreased Circulating C3 Levels and Mesangial C3 Deposition Predict Renal Outcome in Patients with IgA Nephropathy

    OpenAIRE

    Seung Jun Kim; Hyang Mo Koo; Beom Jin Lim; Hyung Jung Oh; Dong Eun Yoo; Dong Ho Shin; Mi Jung Lee; Fa Mee Doh; Jung Tak Park; Tae-Hyun Yoo; Shin-Wook Kang; Kyu Hun Choi; Hyeon Joo Jeong; Seung Hyeok Han

    2012-01-01

    BACKGROUND AND AIMS: Mesangial C3 deposition is frequently observed in patients with IgA nephropathy (IgAN). However, the role of complement in the pathogenesis or progression of IgAN is uncertain. In this observational cohort study, we aimed to identify the clinical implications of circulating C3 levels and mesangial C3 deposition and to investigate their utility as predictors of renal outcomes in patients with IgAN. METHODS: A total of 343 patients with biopsy-proven IgAN were enrolled betw...

  7. De novo C3 glomerulonephritis in a renal allograft.

    Science.gov (United States)

    Nahm, Ji Hae; Song, Seung Hwan; Kim, Yu Seun; Cheong, Hae-Il; Lim, Beom Jin; Kim, Beom Seok; Jeong, Hyeon Joo

    2016-01-01

    C3 glomerulonephritis (C3GN) is a recently described, rare glomerular disease characterized by predominant or sole glomerular C3 deposits. Morphologic features of C3GN are similar to those of dense deposit disease (DDD); however, ribbon-like intramembranous electron-dense deposits are absent in the former. We report a case of de novo C3GN in a renal allograft with morphologic transformation to DDD. A 6-year-old boy presented with congenital left renal agenesis and right ureteropelvic junction obstruction. The patient underwent pyeloplasty but experienced recurrent urinary tract infections. At the age of 22 years, he received a renal allograft from a living related donor. C3GN was diagnosed after 1 year of transplantation; initial histology showed minimal mesangiopathy and this progressed to mesangial proliferation and membranoproliferative features over the next 7 years. Serum creatinine levels were stabilized with anti-rejection treatments for combating repeated episodes of acute rejection; however, glomerular and tubular band-like electron-dense deposits became evident. PMID:26986539

  8. A Modified Thermal Time Model Quantifying Germination Response to Temperature for C3 and C4 Species in Temperate Grassland

    Directory of Open Access Journals (Sweden)

    Hongxiang Zhang

    2015-07-01

    Full Text Available Thermal-based germination models are widely used to predict germination rate and germination timing of plants. However, comparison of model parameters between large numbers of species is rare. In this study, seeds of 27 species including 12 C4 and 15 C3 species were germinated at a range of constant temperatures from 5 °C to 40 °C. We used a modified thermal time model to calculate germination parameters at suboptimal temperatures. Generally, the optimal germination temperature was higher for C4 species than for C3 species. The thermal time constant for the 50% germination percentile was significantly higher for C3 than C4 species. The thermal time constant of perennials was significantly higher than that of annuals. However, differences in base temperatures were not significant between C3 and C4, or annuals and perennial species. The relationship between germination rate and seed mass depended on plant functional type and temperature, while the base temperature and thermal time constant of C3 and C4 species exhibited no significant relationship with seed mass. The results illustrate differences in germination characteristics between C3 and C4 species. Seed mass does not affect germination parameters, plant life cycle matters, however.

  9. C3b/iC3b deposition on Streptococcus pneumoniae is not affected by HIV infection

    OpenAIRE

    Catherine Hyams; Jerry C H Tam; Brown, Jeremy S.; Gordon, Stephen B

    2010-01-01

    Streptococcus pneumoniae is a common cause of infection in both HIV positive patients and those with complement deficiencies. We hypothesised that HIV positive individuals might exhibit reduced opsonisation of pneumococcus with complement due to reduced levels of S. pneumoniae specific IgG. We discovered no difference in C3 deposition on S. pneumoniae between HIV positive or negative individuals, and furthermore C3 deposition remained unchanged as HIV progressed towards AIDS. We found no corr...

  10. Deposition of C3b and iC3b onto particulate activators of the human complement system. Quantitation with monoclonal antibodies to human C3

    OpenAIRE

    1985-01-01

    Monoclonal antibodies were used to determine the number and molecular form of C3 bound to particulate activators of the complement (C) system by human serum. Sheep erythrocytes (E) coated with IgM (EIgM) and IgG (EIgG) were used to study activation of the classical pathway (CP). Yeast (Y), rabbit erythrocytes (ER), and five species of bacteria (Escherichia coli, Staphylococcus aureus, Streptococcus pneumoniae type 3, Streptococcus pyogenes, and Hemophilus influenzae type b) were used to study...

  11. Glyphosate Resistance of C3 and C4 Weeds under Rising Atmospheric CO2.

    Science.gov (United States)

    Fernando, Nimesha; Manalil, Sudheesh; Florentine, Singarayer K; Chauhan, Bhagirath S; Seneweera, Saman

    2016-01-01

    The present paper reviews current knowledge on how changes of plant metabolism under elevated CO2 concentrations (e[CO2]) can affect the development of the glyphosate resistance of C3 and C4 weeds. Among the chemical herbicides, glyphosate, which is a non-selective and post-emergence herbicide, is currently the most widely used herbicide in global agriculture. As a consequence, glyphosate resistant weeds, particularly in major field crops, are a widespread problem and are becoming a significant challenge to future global food production. Of particular interest here it is known that the biochemical processes involved in photosynthetic pathways of C3 and C4 plants are different, which may have relevance to their competitive development under changing environmental conditions. It has already been shown that plant anatomical, morphological, and physiological changes under e[CO2] can be different, based on (i) the plant's functional group, (ii) the available soil nutrients, and (iii) the governing water status. In this respect, C3 species are likely to have a major developmental advantage under a CO2 rich atmosphere, by being able to capitalize on the overall stimulatory effect of e[CO2]. For example, many tropical weed grass species fix CO2 from the atmosphere via the C4 photosynthetic pathway, which is a complex anatomical and biochemical variant of the C3 pathway. Thus, based on our current knowledge of CO2 fixing, it would appear obvious that the development of a glyphosate-resistant mechanism would be easier under an e[CO2] in C3 weeds which have a simpler photosynthetic pathway, than for C4 weeds. However, notwithstanding this logical argument, a better understanding of the biochemical, genetic, and molecular measures by which plants develop glyphosate resistance and how e[CO2] affects these measures will be important before attempting to innovate sustainable technology to manage the glyphosate-resistant evolution of weeds under e[CO2]. Such information will be of

  12. 298 K rate coefficients for the reaction of OH with i - C3H7I, n - C3H7I and C3H8

    OpenAIRE

    Carl, S. A.; J. N. Crowley

    2001-01-01

    The kinetics of the title reactions were investigated using the laser photolysis - resonance fluorescence method, employing the sequential two-photon dissociation of NO2 in the presence of H2  as the OH source. The 298 K rate constant for OH + C3H8 was found to be (1.15 ± 0.1) × 10-12 cm3 s-1, in excellent agreement with the literature recommendation, and with a separate determination using HNO3  photolysis at 248 nm as the OH source. The 298 K rate constant...

  13. Glyphosate Resistance of C3 and C4 Weeds under Rising Atmospheric CO2

    Science.gov (United States)

    Fernando, Nimesha; Manalil, Sudheesh; Florentine, Singarayer K.; Chauhan, Bhagirath S.; Seneweera, Saman

    2016-01-01

    The present paper reviews current knowledge on how changes of plant metabolism under elevated CO2 concentrations (e[CO2]) can affect the development of the glyphosate resistance of C3 and C4 weeds. Among the chemical herbicides, glyphosate, which is a non-selective and post-emergence herbicide, is currently the most widely used herbicide in global agriculture. As a consequence, glyphosate resistant weeds, particularly in major field crops, are a widespread problem and are becoming a significant challenge to future global food production. Of particular interest here it is known that the biochemical processes involved in photosynthetic pathways of C3 and C4 plants are different, which may have relevance to their competitive development under changing environmental conditions. It has already been shown that plant anatomical, morphological, and physiological changes under e[CO2] can be different, based on (i) the plant’s functional group, (ii) the available soil nutrients, and (iii) the governing water status. In this respect, C3 species are likely to have a major developmental advantage under a CO2 rich atmosphere, by being able to capitalize on the overall stimulatory effect of e[CO2]. For example, many tropical weed grass species fix CO2 from the atmosphere via the C4 photosynthetic pathway, which is a complex anatomical and biochemical variant of the C3 pathway. Thus, based on our current knowledge of CO2 fixing, it would appear obvious that the development of a glyphosate-resistant mechanism would be easier under an e[CO2] in C3 weeds which have a simpler photosynthetic pathway, than for C4 weeds. However, notwithstanding this logical argument, a better understanding of the biochemical, genetic, and molecular measures by which plants develop glyphosate resistance and how e[CO2] affects these measures will be important before attempting to innovate sustainable technology to manage the glyphosate-resistant evolution of weeds under e[CO2]. Such information will be

  14. Engineering C4 photosynthesis into C3 chassis in the synthetic biology age.

    Science.gov (United States)

    Schuler, Mara L; Mantegazza, Otho; Weber, Andreas P M

    2016-07-01

    C4 photosynthetic plants outperform C3 plants in hot and arid climates. By concentrating carbon dioxide around Rubisco C4 plants drastically reduce photorespiration. The frequency with which plants evolved C4 photosynthesis independently challenges researchers to unravel the genetic mechanisms underlying this convergent evolutionary switch. The conversion of C3 crops, such as rice, towards C4 photosynthesis is a long-standing goal. Nevertheless, at the present time, in the age of synthetic biology, this still remains a monumental task, partially because the C4 carbon-concentrating biochemical cycle spans two cell types and thus requires specialized anatomy. Here we review the advances in understanding the molecular basis and the evolution of the C4 trait, advances in the last decades that were driven by systems biology methods. In this review we emphasise essential genetic engineering tools needed to translate our theoretical knowledge into engineering approaches. With our current molecular understanding of the biochemical C4 pathway, we propose a simplified rational engineering model exclusively built with known C4 metabolic components. Moreover, we discuss an alternative approach to the progressing international engineering attempts that would combine targeted mutagenesis and directed evolution. PMID:26945781

  15. Spatial distributions ofC3 and C4 grass functional types in the U.S. great plains and their despendency on inter-annual climate variability

    Science.gov (United States)

    Grassland ecosystems in North America are primarily composed of C3 and C4 plant functional types (PFTs) with their relative cover varying spatially and temporally. This study used 500-m MODIS surface reflectance products (MOD09A1) from 2000 to 2009 to extract an NDVI time series of C3 and C4 PFTs in...

  16. Screening for C3 deficiency in newborns using microarrays.

    Directory of Open Access Journals (Sweden)

    Magdalena Janzi

    Full Text Available BACKGROUND: Dried blood spot samples (DBSS from newborns are widely used in neonatal screening for selected metabolic diseases and diagnostic possibilities for additional disorders are continuously being evaluated. Primary immunodeficiency disorders comprise a group of more than one hundred diseases, several of which are fatal early in life. Yet, a majority of the patients are not diagnosed due to lack of high-throughput screening methods. METHODOLOGY/PRINCIPAL FINDINGS: We have previously developed a system using reverse phase protein microarrays for analysis of IgA levels in serum samples. In this study, we extended the applicability of the method to include determination of complement component C3 levels in eluates from DBSS collected at birth. Normal levels of C3 were readily detected in 269 DBSS from healthy newborns, while no C3 was detected in sera and DBSS from C3 deficient patients. CONCLUSIONS/SIGNIFICANCE: The findings suggest that patients with deficiencies of specific serum proteins can be identified by analysis of DBSS using reverse phase protein microarrays.

  17. Cytohistopathological correlation of C3 and C4 breast lesions

    International Nuclear Information System (INIS)

    Objective: To conduct an audit of smears in cytological categories C3 and C4 of fine-needle aspirates from breast lesions in comparison with histopathological diagnoses. Patients and Methods: Out of all patients referred to AFIP, Rawalpindi for aspiration of breast masses, those adjudged C3 and C4 were chosen for this study. History, clinical details and mammographic findings were noted. Aspirated smears were stained with hematoxyline and eosin as well as a Romanovsky dye. On excision or incision biopsy of these lesions, the cytological findings were compared with those on paraffin-embedded histological sections. Results: The total number of patients in these two categories was 54. Surgical specimens of 3 cases were found inadequate for assessment. Of the remaining 51 cases, 13 were categorised C3 and 38 C4. Sensitivity of 92%, specificity of 83% and accuracy of 90% were attained. Positive and negative predictive values were 95% and 77% respectively. Conclusion: Categories C3 and C4 are areas where the cytopathologist is in doubt as to the benign or malignant nature of a breast mass. High sensitivity, positive predictive value and accuracy, being the hallmarks of a good screening procedure, underscore the validity of the technique. (author)

  18. Defining the complement biomarker profile of c3 glomerulopathy

    DEFF Research Database (Denmark)

    Zhang, Yuzhou; Nester, Carla M; Martin, Bertha;

    2014-01-01

    , although a full description of the disease spectrum remains to be determined. This study sought to validate and define the association of complement dysregulation with C3G and to determine whether specific complement pathway abnormalities could inform disease definition. DESIGN, SETTING, PARTICIPANTS...

  19. Immunoglobulins and C3 in the P. brasiliensis granuloma

    Directory of Open Access Journals (Sweden)

    Lilian M. V. Biagioni

    1987-04-01

    Full Text Available The experimental model of paracoccidioidomycosis induced in mice by the intravenous injection of yeast-forms of P. brasiliensis (Bt2 strain; 1 x 10(6 viable fungi/animal was used to evaluate sequentially 2, 4, 8, 16 and 20 weeks after inoculation: 1. The presence of immunoglobulins and C3 in the pulmonary granuloma-ta, by direct immunofluorescence; 2. The humoral (immunodiffusion test and the cellular (footpad sweeling test immune response; 3. The histopathology of lesions. The cell-immune response was positive since week 2, showing a transitory depression at week 16. Specific antibodies were first detected at week 4 and peaked at week 16. At histology, epithelioid granulomas with numerous fungi and polymorphonuclear agreggates were seen. The lungs showed progressive involvement up to week 16, with little decrease at week 20. From week 2 on, there were deposits of IgG and C3 around fungal walls within the granulomas and IgG stained cells among the mononuclear cell peripheral halo. Interstitital immunoglobulins and C3 deposits in the granulomas were not letected. IgG and C3 seen to play an early an important role in. the host defenses against P. brasiliensis by possibly cooperating in the killing of parasites and blocking the antigenic diffusion.

  20. Zinc-induced Self-association of Complement C3b and Factor H

    OpenAIRE

    Nan, Ruodan; Tetchner, Stuart; Rodriguez, Elizabeth; Pao, Po-Jung; Gor, Jayesh; Lengyel, Imre; Perkins, Stephen J.

    2013-01-01

    The sub-retinal pigment epithelial deposits that are a hallmark of age-related macular degeneration contain both C3b and millimolar levels of zinc. C3 is the central protein of complement, whereas C3u is formed by the spontaneous hydrolysis of the thioester bridge in C3. During activation, C3 is cleaved to form active C3b, then C3b is inactivated by Factor I and Factor H to form the C3c and C3d fragments. The interaction of zinc with C3 was quantified using analytical ultracentrifugation and ...

  1. Pressure Effects on Product Channels of the Allyl Radical Reactions; C3H5+C3H5 and C3H5+CH3

    Science.gov (United States)

    Halpern, J. B.; N'Doumi, M.; Fahr, A.

    2011-12-01

    Relatively large hydrocarbon molecules (C4, C6 and larger) have been detected in several planetary environments. The mechanism for the formation of such large molecular species and detailed mechanism for their potential destruction are not well understood and are of considerable current interest. Previously we have studied the kinetics and product channels of small unsaturated hydrocarbon radical (C2 and C3s) reactions relevant to planetary atmospheric modeling. Reactions of C2 radicals (such as vinyl, H2CCH and ethynyl C2H) and C3 radicals (such as propargyl, HCCCH2) can affect the abundances of a large number of stable observable C3, C4, C5, C6 and larger molecules, including linear, aromatic and even poly aromatic molecules. Pressure-dependent product yields have been determined experimentally for the self- and cross-radical reactions performed at 298 K and at pressures between ~4 Torr (0.5 kPa) and 760 Torr (101 kPa). Final reaction products were quantitatively determined using a gas chromatograph with mass spectrometry/flame ionization detection (GC/MS/FID). In some cases complementary computational studies extended the pressure and temperature range of the experiments and provided valuable information on the complex reaction mechanisms. Theses studies provide a systematic framework so that important energetic and structural parameters for radical-radical reactions can be assessed. Here we report recent results for the allyl radical reactions H2CCCH3+ H2CCCH3 and H2CCCH3+CH3. For the allyl radical self-reaction, at high pressures the "head -to-head", combination channel forming 1,5-hexadiene is dominant with a combination/disproportionation = 1,5-hexadiene/propyne ratio of about 24 at 500 Torr (67 kPa, T=298K). At low pressures the ratio is substantially reduced to about 1.2 (at 0.3 kPa) and other major products are observed including allene, propene, 1-butene and propyne.

  2. The evolution and appearance of C3 duplications in fish originate an exclusive teleost c3 gene form with anti-inflammatory activity.

    Directory of Open Access Journals (Sweden)

    Gabriel Forn-Cuní

    Full Text Available The complement system acts as a first line of defense and promotes organism homeostasis by modulating the fates of diverse physiological processes. Multiple copies of component genes have been previously identified in fish, suggesting a key role for this system in aquatic organisms. Herein, we confirm the presence of three different previously reported complement c3 genes (c3.1, c3.2, c3.3 and identify five additional c3 genes (c3.4, c3.5, c3.6, c3.7, c3.8 in the zebrafish genome. Additionally, we evaluate the mRNA expression levels of the different c3 genes during ontogeny and in different tissues under steady-state and inflammatory conditions. Furthermore, while reconciling the phylogenetic tree with the fish species tree, we uncovered an event of c3 duplication common to all teleost fishes that gave rise to an exclusive c3 paralog (c3.7 and c3.8. These paralogs showed a distinct ability to regulate neutrophil migration in response to injury compared with the other c3 genes and may play a role in maintaining the balance between inflammatory and homeostatic processes in zebrafish.

  3. Relation of putative thioester bond in C3 to activation of the alternative pathway and the binding of C3b to biological targets of complement

    OpenAIRE

    1980-01-01

    The reaction of [14C]methylamine with native human C3 led to the stoichiometric incorporation of methylamine, loss of hemolytic activity, and the concomitant exposure of a sulfhydryl group that could be labeled with [14C]iodoacetamide. Both labeled sites were located in the C3d portion of the alpha-chain, which is known to contain the metastable binding of C3b. The methylamine-modified C3 [C3(CH3NH2)] was shown to exhibit many of the functional properties of C3b, although the C3a portion of t...

  4. Mapping of the C3d receptor (CR2)-binding site and a neoantigenic site in the C3d domain of the third component of complement.

    OpenAIRE

    LAMBRIS, J. D.; Ganu, V S; Hirani, S.; Müller-Eberhard, H. J.

    1985-01-01

    The C3d domain of C3 contains the site that binds to the C3d receptor (CR2) which is expressed on B lymphocytes. It also contains a neoantigenic determinant that is recognized by monoclonal antibody (mAb) 130 and is expressed when C3b is cleaved to iC3b and subsequently to C3dg or C3d. mAb 130 inhibits the binding of C3d to CR2. In this study, the locations of the CR2-binding site and of the neoantigen recognized by mAb 130 within the C3d domain were investigated. Treatment of human C3d with ...

  5. Eculizumab-induced reversal of dialysis-dependent kidney failure from C3 glomerulonephritis

    OpenAIRE

    Inman, Melissa; Prater, Ginnie; Fatima, Huma; Wallace, Eric

    2015-01-01

    C3 glomerulopathy (C3G) is characterized by C3 deposits with minimal immunoglobulin deposition caused by alternative complement pathway dysregulation. Unfortunately, no therapeutic intervention has consistently improved outcomes for patients with C3G. Eculizumab, a monoclonal antibody to C5, is currently the only approved complement-specific agent with some efficacy in the treatment of C3 glomerulonephritis (C3GN). Here, we describe a patient with acute crescentic C3GN with no identified comp...

  6. Improved analysis of C4 and C3 photosynthesis via refined in vitro assays of their carbon fixation biochemistry

    Science.gov (United States)

    Sharwood, Robert E.; Sonawane, Balasaheb V.; Ghannoum, Oula; Whitney, Spencer M.

    2016-01-01

    Plants operating C3 and C4 photosynthetic pathways exhibit differences in leaf anatomy and photosynthetic carbon fixation biochemistry. Fully understanding this underpinning biochemical variation is requisite to identifying solutions for improving photosynthetic efficiency and growth. Here we refine assay methods for accurately measuring the carboxylase and decarboxylase activities in C3 and C4 plant soluble protein. We show that differences in plant extract preparation and assay conditions are required to measure NADP-malic enzyme and phosphoenolpyruvate carboxylase (pH 8, Mg2+, 22 °C) and phosphoenolpyruvate carboxykinase (pH 7, >2mM Mn2+, no Mg2+) maximal activities accurately. We validate how the omission of MgCl2 during leaf protein extraction, lengthy (>1min) centrifugation times, and the use of non-pure ribulose-1,5-bisphosphate (RuBP) significantly underestimate Rubisco activation status. We show how Rubisco activation status varies with leaf ontogeny and is generally lower in mature C4 monocot leaves (45–60% activation) relative to C3 monocots (55–90% activation). Consistent with their >3-fold lower Rubisco contents, full Rubisco activation in soluble protein from C4 leaves (<5min) was faster than in C3 plant samples (<10min), with addition of Rubisco activase not required for full activation. We conclude that Rubisco inactivation in illuminated leaves primarily stems from RuBP binding to non-carbamylated enzyme, a state readily reversible by dilution during cellular protein extraction. PMID:27122573

  7. DEFECTIVE ENGRAFTMENT OF C3aR-/- HEMATOPOIETIC STEM PROGENITOR CELLS REVEALS A NOVEL ROLE OF THE C3a-C3aR AXIS IN BONE MARROW HOMING

    OpenAIRE

    Wysoczynski, Marcin; Reca, Ryan; Lee, HakMo; Wu, Wan; Ratajczak, Janina; Mariusz Z Ratajczak

    2009-01-01

    We reported that complement (C) becomes activated and cleaved in bone marrow (BM) during preconditioning for hematopoietic transplantation and the third C component (C3) cleavage fragments C3a and desArgC3a increase responsiveness of hematopoietic stem/progenitor cells (HSPCs) to stromal derived factor-1 (SDF-1). We also demonstrated that this homing promoting effect is not C3a receptor (C3aR) dependent. Herein, we report our new observation that transplantation of C3aR-/- HSPCs into lethally...

  8. Partial discharges and breakdown in C3F8

    International Nuclear Information System (INIS)

    Traditional search processes of gases or gas mixtures for replacing SF6 involve time consuming measurements of partial discharges and breakdown behaviour for several voltage waveforms and different field configurations. Recently a model for prediction of this behaviour for SF6 was described in literature. The model only requires basic properties of the gas such as the critical field strength and the effective ionization coefficient, which can be obtained by swarm parameter measurements, and thermodynamic properties, which can be calculated. In this paper, we show for the well-known and electronegative gas octafluoropropane (C3F8) that it is possible to transfer the model developed for SF6 to this gas to describe the breakdown behaviour of C3F8. Thus the model can be beneficial in the screening process of new insulation gases. (paper)

  9. Evaluation of EGM 2008 and EIGEN-6C3stat \

    Czech Academy of Sciences Publication Activity Database

    Kostelecký, J.; Klokočník, Jaroslav; Bezděk, Aleš

    -, č. 5 (2015), s. 3-12. ISSN 1810-8555 R&D Projects: GA ČR GA13-36843S Grant ostatní: GA MŠk(CZ)(CZ) CZ.1.05/1.1.00/02.0090 Institutional support: RVO:67985815 Keywords : gravity field evaluation * EGM 2008 * EIGEN-6C3stat Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  10. Free C_+ -actions on C^3 are translations

    OpenAIRE

    Kaliman, Shulim

    2002-01-01

    Let X' be a smooth contractible three-dimensional affine algebraic variety with a free algebraic C_+ -action on it such that S =X'// C_+ is smooth. We prove that X' is isomorphic to $S \\times \\C$ and the action is induced by a translation on the second factor. As a consequence we show that any free algebraic C_+ -action on C^3 is a translation in a suitable coordinate system.

  11. Astronomical identification of the C3H radical

    International Nuclear Information System (INIS)

    The C3H radical has been identified in the millimeter-wave spectra of IRC +10216 and TMC-1. In IRC +10216, four rotational transitions have been observed, three in the lower fine-structure ladder (2Pi1/2) and one in the upper (2Pi3/2), each a resolved or partially resolved lambda-doublet. In TMC-1, both lambda components of the lowest lying 3/2-1/2 transition of the 2Pi1/2 ladder have been observed, each with well-resolved hfs. In IRC +10216, the excitation of C3H is similar to that of SiCC: the rotational temperature Trot within the 2Pi1/2 ladder is low (8.5 K), because of rapid radiative decay, while Trot across the ladders is high (about 52 K), because interconnecting far-IR radiative transitions are only weakly permitted. The column density of C3H in IRC +10216 averaged over the estimated source diameter of 84 arcsec is 2.8 x 10 to the 13th/sq cm, an order of magnitude less than that of C2H and C4H. 10 references

  12. Astronomical identification of the C3H radical

    Science.gov (United States)

    Thaddeus, P.; Gottlieb, C. A.; Hjalmarson, A.; Johansson, L. E. B.; Irvine, W. M.; Friberg, P.; Linke, R. A.

    1985-07-01

    The C3H radical has been identified in the millimeter-wave spectra of IRC +10216 and TMC-1. In IRC +10216, four rotational transitions have been observed, three in the lower fine-structure ladder (2Pi1/2) and one in the upper (2Pi3/2), each a resolved or partially resolved lambda-doublet. In TMC-1, both lambda components of the lowest lying 3/2-1/2 transition of the 2Pi1/2 ladder have been observed, each with well-resolved hfs. In IRC +10216, the excitation of C3H is similar to that of SiCC: the rotational temperature Trot within the 2Pi1/2 ladder is low (8.5 K), because of rapid radiative decay, while Trot across the ladders is high (about 52 K), because interconnecting far-IR radiative transitions are only weakly permitted. The column density of C3H in IRC +10216 averaged over the estimated source diameter of 84 arcsec is 2.8 x 10 to the 13th/sq cm, an order of magnitude less than that of C2H and C4H.

  13. C2 photosynthesis generates about 3-fold elevated leaf CO2 levels in the C3–C4 intermediate species Flaveria pubescens

    OpenAIRE

    Keerberg, Olav; Pärnik, Tiit; Ivanova, Hiie; Bassüner, Burgund; Bauwe, Hermann

    2014-01-01

    Formation of a photorespiration-based CO2-concentrating mechanism in C3–C4 intermediate plants is seen as a prerequisite for the evolution of C4 photosynthesis, but it is not known how efficient this mechanism is. Here, using in vivo Rubisco carboxylation-to-oxygenation ratios as a proxy to assess relative intraplastidial CO2 levels is suggested. Such ratios were determined for the C3–C4 intermediate species Flaveria pubescens compared with the closely related C3 plant F. cronquistii and the ...

  14. Vibrational Level Structures of the Ground Electronic States of the C_3-Ar and C_3-Ne Complexes

    Science.gov (United States)

    Chen, Yi-Ren; Hsu, Yen-Chu

    2014-06-01

    The Heidelberg multiconfiguration time-dependent Hartree package was used. to calculate the vibrational level structures of the ground electronic states of the C_3-Ar and C_3-Ne complexes. The previously reported 4-D ab initio potentials were converted to 6-D potentials by adding the potential energies of the C-C symmetric and antisymmetric stretching vibrations of C_3. They were subsequently transformed from internal coordinates to Jacobi coordinates. The kinetic-energy operators were taken from Yang and Kühn. Preliminary results show that large amplitude motions occur in five coordinates: C-C-C bond angle, out-of-plane tilt angle, van der Waals stretch, van der Waals bend and one of the C-C bonds. G.A. Worth, M.H. Beck, A. Jäckle, H.-D. Meyer, F. Otto, M. Brill, and O. Vendrell, The MCTDH package, version 8.4, Heidelberg University, Heidelberg, Germany, 2011. Y. Yang and O. Kühn, Mol. Phys., 106, 2445 (2008)

  15. C-3 benzoic acid derivatives of C-3 deoxybetulinic acid and deoxybetulin as HIV-1 maturation inhibitors.

    Science.gov (United States)

    Liu, Zheng; Swidorski, Jacob J; Nowicka-Sans, Beata; Terry, Brian; Protack, Tricia; Lin, Zeyu; Samanta, Himadri; Zhang, Sharon; Li, Zhufang; Parker, Dawn D; Rahematpura, Sandhya; Jenkins, Susan; Beno, Brett R; Krystal, Mark; Meanwell, Nicholas A; Dicker, Ira B; Regueiro-Ren, Alicia

    2016-04-15

    A series of C-3 phenyl- and heterocycle-substituted derivatives of C-3 deoxybetulinic acid and C-3 deoxybetulin was designed and synthesized as HIV-1 maturation inhibitors (MIs) and evaluated for their antiviral activity and cytotoxicity in cell culture. A 4-subsituted benzoic acid moiety was identified as an advantageous replacement for the 3'3'-dimethylsuccinate moiety present in previously disclosed MIs that illuminates new aspects of the topography of the pharmacophore. The new analogs exhibit excellent in vitro antiviral activity against wild-type (wt) virus and a lower serum shift when compared with the prototypical HIV-1 MI bevirimat (1, BVM), the first MI to be evaluated in clinical studies. Compound 9a exhibits comparable cell culture potency toward wt virus as 1 (WT EC50=16nM for 9a compared to 10nM for 1). However, the potency of 9a is less affected by the presence of human serum, while the compound displays a similar pharmacokinetic profile in rats to 1. Hence 9a, the 4-benzoic acid derivative of deoxybetulinic acid, represents a new starting point from which to explore the design of a 2nd generation MI. PMID:26968652

  16. 儿童C3肾小球肾炎7例%C3 glomerulonephritis in 7 children

    Institute of Scientific and Technical Information of China (English)

    汪瑛; 林强; 朱赟; 徐琴英; 朱雪明; 王兴东; 李晓忠

    2013-01-01

    Objective To analyze the clinical characteristics of 7 pediatric patients with C3 glomerulonephritis (C3-GN).Methods The clinical manifestations,pathological features,therapies,prognosis of patients from Jun.2006 to Nov.2011 were analyzed retrospectively.Results All of the patients were presented as acute nephritic syndrome,and 4 patients with macroscopic hematuria,other 3 cases with severe proteinuria.Five patients with eyelid edema.All the patients showed decreased level of serum complement C3,while serum complement C4 was normal.Investigations showed elevation of 24 h urine protein,5 patients with elevated antistreptolysin O titers.Three patients with renal dysfunction.Isolated C3 deposition in mesangial and endothelial areas(+ +-+ + +) was confirmed by immunofluorescence.Light microscope revealed membrane proliferative glomerulonephritis and mesangial proliferative glomerulonephritis.Electron microscope showed swelling and hyperplasia of endothelial cells without electron-dense deposition or podocyte foot fusion.Based on conventional treatment,administration of immunosuppressant was performed in 3 patients with severe pathological changes.After a follow-up of 2 months to 5 years,the prognosis seems to be benign.Conclusions Children with C3-GN are usually presented as acute nephritic syndrome,characterized by isolate C3 deposition in immunofluorescence.Electron microscope showed lesion of endothelial cells,while no electron-dense deposits in mesangial and endothelial areas.The mechanism may be associated with dysregulation of alternative complement pathway,and seems had a good short-term prognosis.%目的 分析7例C3肾小球肾炎患儿的临床特点.方法 对2006年6月至2011年11月确诊为C3肾小球肾炎且有完整资料的7例患儿的临床表现、病理改变、疗效及预后进行回顾性分析.结果 临床表现:均以急性肾炎综合征起病,4例以肉眼血尿为首发表现,3例以大量蛋白尿为首发表现,5例患儿伴眼睑水肿;血C

  17. Simple birational extensions of the polynomial ring $\\C^{[3]}$

    OpenAIRE

    Kaliman, Sh.; Venereau, St.; Zaidenberg, M

    2001-01-01

    The Abhyankar-Sathaye Problem asks whether any biregular embedding of affine spaces $A^m_k\\to A^n_k$ can be rectified, that is, is equivalent to a linear embedding up to an automorphism of the target space. Here we study this problem for the embeddings $C^3 \\to C^4$ whose image $X$ is given in $C^4$ by an equation $p=f(x,y)u+g(x,y,z)=0$, where $f\\in C[x,y],$ $f\

  18. Formation of the initial C3 convertase of the alternative complement pathway. Acquisition of C3b-like activities by spontaneous hydrolysis of the putative thioester in native C3

    OpenAIRE

    1981-01-01

    Activation of the alternative pathway of complement commences with the formation of an initial fluid-phase C3 convertase. Treatment of C3 with the nucleophilic reagent methylamine has previously been shown to result in the cleavage of an intramolecular thioester bond and to induce C3b-like properties, including the ability to form a fluid-phase C3 convertase. This report examines the hypothesis that spontaneous hydrolysis of the thioester generates a derivative of C3 that is responsible for t...

  19. Inefficient binding of IgM immune complexes to erythrocyte C3b-C4b receptors (CR1) and weak incorporation of C3b-iC3b into the complexes

    DEFF Research Database (Denmark)

    Kávai, M; Rasmussen, J M; Baatrup, G;

    1988-01-01

    The binding of soluble complement-reacted IgM immune complexes (IC) to erythrocyte (E) C3b-C4b receptors (CR1) and the incorporation of C3b-iC3b into solid phase IgM-IC was investigated. The optimal binding of liquid phase IgM-IC to E-CR1 was obtained with IC formed at moderate antibody excess, but...... C. The binding of C3b-iC3b was determined by use of biotinylated F(ab')2 antibodies to C3b-C3c and avidin-coupled alkaline phosphatase. The incorporation of C3b-iC3b into solid-phase IgM-IC increased when increasing amounts of IgM antibody were reacted with the antigen. The binding reaction was slow......, reaching a maximum after about 2 h at 37 degrees C. The binding of C3b-iC3b to the IgM-IC was remarkably inefficient when compared to the incorporation into IgG-IC reacted with the same amounts of BSA-precipitating antibody....

  20. Beryllium-induced immune response in C3H mice

    International Nuclear Information System (INIS)

    Studies conducted at ITRI over the past several years have investigated whether Beagle dogs, monkeys, and mice are suitable models for human chronic beryllium-induced lung disease (CBD). Recent studies have focused on the histopathological and immunopathological changes occurring in A/J and C3H/HeJ mice acutely exposed by inhalation to Be metal. Lung lesions in both strains of mice included focal lymphocyte aggregates comprised primarily of B lymphocytes and lesser amounts of T-helper lymphocytes and microgranulomas consisting chiefly of macrophages and T-helper lymphocytes. The distribution of proliferating cells within the microgranulomas was similar to the distribution of T-helper cells. These results strongly suggested that A/J and C3H/HeJ mice responded to inhaled Be metal in a fashion similar to humans in terms of pulmonary lesions and the apparent in situ proliferation of T-helper cells. Results of these studies confirm lymphocyte involvement in the pulmonary response to inhaled Be metal

  1. Beryllium-induced immune response in C3H mice

    Energy Technology Data Exchange (ETDEWEB)

    Benson, J.M.; Bice, D.E.; Nikula, K.J. [and others

    1995-12-01

    Studies conducted at ITRI over the past several years have investigated whether Beagle dogs, monkeys, and mice are suitable models for human chronic beryllium-induced lung disease (CBD). Recent studies have focused on the histopathological and immunopathological changes occurring in A/J and C3H/HeJ mice acutely exposed by inhalation to Be metal. Lung lesions in both strains of mice included focal lymphocyte aggregates comprised primarily of B lymphocytes and lesser amounts of T-helper lymphocytes and microgranulomas consisting chiefly of macrophages and T-helper lymphocytes. The distribution of proliferating cells within the microgranulomas was similar to the distribution of T-helper cells. These results strongly suggested that A/J and C3H/HeJ mice responded to inhaled Be metal in a fashion similar to humans in terms of pulmonary lesions and the apparent in situ proliferation of T-helper cells. Results of these studies confirm lymphocyte involvement in the pulmonary response to inhaled Be metal.

  2. Investigation of Interaction of Vaccinia Virus Complement Control Protein and Curcumin with Complement Components C3 and C3b Using Quartz Crystal Microbalance with Dissipation Monitoring Technology

    OpenAIRE

    Kulkarni, Amod P.; Randall, Philippa J.; Murthy, Krishna; Kellaway, Lauriston A; Kotwal, Girish J.

    2010-01-01

    C3 and C3b, the components central to the complement activation, also play a damaging role in several inflammatory disorders. Vaccinia virus complement control protein (VCP) and curcumin (Cur) are natural compounds with different biological origins reported to regulate complement activation. However, both VCP and Cur have not been investigated for their interaction with the third component (C3) prior to it being converted to its activated form (C3b). These two compounds have also not been com...

  3. Improved analysis of C4 and C3 photosynthesis via refined in vitro assays of their carbon fixation biochemistry.

    Science.gov (United States)

    Sharwood, Robert E; Sonawane, Balasaheb V; Ghannoum, Oula; Whitney, Spencer M

    2016-05-01

    Plants operating C3 and C4 photosynthetic pathways exhibit differences in leaf anatomy and photosynthetic carbon fixation biochemistry. Fully understanding this underpinning biochemical variation is requisite to identifying solutions for improving photosynthetic efficiency and growth. Here we refine assay methods for accurately measuring the carboxylase and decarboxylase activities in C3 and C4 plant soluble protein. We show that differences in plant extract preparation and assay conditions are required to measure NADP-malic enzyme and phosphoenolpyruvate carboxylase (pH 8, Mg(2+), 22 °C) and phosphoenolpyruvate carboxykinase (pH 7, >2mM Mn(2+), no Mg(2+)) maximal activities accurately. We validate how the omission of MgCl2 during leaf protein extraction, lengthy (>1min) centrifugation times, and the use of non-pure ribulose-1,5-bisphosphate (RuBP) significantly underestimate Rubisco activation status. We show how Rubisco activation status varies with leaf ontogeny and is generally lower in mature C4 monocot leaves (45-60% activation) relative to C3 monocots (55-90% activation). Consistent with their >3-fold lower Rubisco contents, full Rubisco activation in soluble protein from C4 leaves (plant samples (extraction. PMID:27122573

  4. A rare Cervical Nerve Root, C2-C3 Schwannoma

    Directory of Open Access Journals (Sweden)

    Nilesh Chordia

    2014-04-01

    Full Text Available Schwannomas, neurilemmomas or neurinomas are benign nerve sheath tumors deriving from Schwann cells that occur in the head and neck region in 25-45% of cases 1 .About 10% of schwannoma that occur in the head and neck region generally originate from the vagus or sympathetic nervous system, those arising from C2 nerve root are extremely rare. 2 Preoperative imaging studies such as magnetic resonance imaging (MRI and computed tomography (CT are used to distinguish its location and origin. The treatment of schwannoma is surgical resection, with several surgical modalities have been introduced to preserve the neurological function. We present a rare case of Cervical nerve (C2-C3 root schwannoma of 70 years old male who presented with lateral neck swelling with no neurological deficit ,swelling which also had intervertebral part was removed successfully through neck incision with no post-operative neurological symptoms

  5. C3 generic workstation: Performance metrics and applications

    Science.gov (United States)

    Eddy, Douglas R.

    1988-01-01

    The large number of integrated dependent measures available on a command, control, and communications (C3) generic workstation under development are described. In this system, embedded communications tasks will manipulate workload to assess the effects of performance-enhancing drugs (sleep aids and decongestants), work/rest cycles, biocybernetics, and decision support systems on performance. Task performance accuracy and latency will be event coded for correlation with other measures of voice stress and physiological functioning. Sessions will be videotaped to score non-verbal communications. Physiological recordings include spectral analysis of EEG, ECG, vagal tone, and EOG. Subjective measurements include SWAT, fatigue, POMS and specialized self-report scales. The system will be used primarily to evaluate the effects on performance of drugs, work/rest cycles, and biocybernetic concepts. Performance assessment algorithms will also be developed, including those used with small teams. This system provides a tool for integrating and synchronizing behavioral and psychophysiological measures in a complex decision-making environment.

  6. Synthesis of the C3-C12 Fragment of Laulimalide

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyo Won; Hong, Joong Yeoun [Chungbuk National University, Cheongju (Korea, Republic of)

    2003-11-15

    We have reported the successful synthesis of the C3-C12 fragment of laulimalide using the introduction of a dihydropyran ring after the elongation of a side chain. Our on-going synthetic effort toward the synthesis of laulimalide will be reported in the near future. The antimiototic 20-membered macrolide laulimalide also known as fijanolide B, isolated from sea sponges such as Cacospongia mycofijiensis, Hyatella sp. Spongia mycofijiensis, and Fasciospongia rimosa, shows a potent biological activity against cell lines resistant to paclitaxel or epothilones since laulimalide binds to a site of microtubules in a mode distinct from taxoids. The stabilization of polymerization by laulimalide leads to the inhibition of miototic spindle and apoptosis of cells.

  7. Synthesis of paclitaxel-C3`-{sup 14}C

    Energy Technology Data Exchange (ETDEWEB)

    Walker, D.G.; Standridge, R.T.; Swigor, J.E. [Bristol-Myers-Squibb Co., Syracuse, NY (United States). Pharmaceutical Research Inst.

    1995-12-31

    Reductive cleavage of the C13 side chain of paclitaxel (3) followed by regioselective silylation gave 7-triethylsilybaccatin lll (6). Successive reaction of L-threonine methyl ester hydrochloride (7) with tertbutoxydiphenylchlorosilane, benzaldehyde-C7-{sup 14}C and acetoxyacetyl chloride/triethylamine gave a 92:8 ratio (NMR) of azetidinones in 57% yield from 7. Removal of the chiral auxiliary, and 3-O-triethylsilylation and N-benzoylation provided (3R,4S)-cis-1-benzoyl-3-O-(triethylsilyl)-4-phenylazetidin-2-one-C 4-{sup 14}C (18). Coupling of 18 and 6 followed by deprotection gave 1.12 g of paclitaxel-C3`-{sup 14}C having a specific activity of 16.4 mCi/mmol and a radiochemical purity of 96%. (Author).

  8. A complement receptor locus: genes encoding C3b/C4b receptor and C3d/Epstein-Barr virus receptor map to 1q32.

    Science.gov (United States)

    Weis, J H; Morton, C C; Bruns, G A; Weis, J J; Klickstein, L B; Wong, W W; Fearon, D T

    1987-01-01

    The alternative or classical pathways for complement system component C3 may be triggered by microorganisms and antigen-antibody complexes. In particular, an activated fragment of C3, C3b, covalently attaches to microorganisms or antigen-antibody complexes, which in turn bind to the C3b receptor, also known as complement receptor 1. The genes encoding the proteins that constitute the C3-activating enzymes have been cloned and mapped to a "complement activation" locus in the major histocompatibility complex, and we demonstrate in this study such a locus on the long arm of chromosome 1 at band 1q32. PMID:3782802

  9. Cleavage of Complement C3b to iC3b on the Surface of Staphylococcus aureus Is Mediated by Serum Complement Factor I

    OpenAIRE

    Cunnion, K. M.; Hair, P. S.; Buescher, E. S.

    2004-01-01

    Complement-mediated opsonization of Staphylococcus aureus bearing the dominant capsule serotypes, serotypes 5 and 8, remains incompletely understood. We have previously shown that complement plays a vital role in the efficient phagocytosis of a serotype 5 S. aureus strain and that the opsonic fragments of the central complement protein C3, C3b and iC3b, were present on the bacterial surface after incubation in human serum. In the present studies, C3b and iC3b were found on several serotype 5 ...

  10. Dynamic Structural Changes During Complement C3 Activation Analyzed by Hydrogen/Deuterium Exchange Mass Spectrometry

    OpenAIRE

    Schuster, Michael C.; Ricklin, Daniel; Papp, Krisztián; Molnar, Kathleen S.; Coales, Stephen J.; Hamuro, Yoshitomo; Sfyroera, Georgia; Chen, Hui; Winters, Michael S; Lambris, John D.

    2008-01-01

    Proteolytic cleavage of component C3 to C3b is a central step in the activation of complement. Whereas C3 is largely biologically inactive, C3b is directly involved in various complement activities. While the recently described crystal structures of C3 and C3b provide a molecular basis of complement activation, they do not reflect the dynamic changes that occur in solution. In addition, the available C3b structures diverge in some important aspects. Here we have utilized hydrogen/deuterium ex...

  11. The anaphylatoxin C3a downregulates the Th2 response to epicutaneously introduced antigen

    OpenAIRE

    Kawamoto, Seiji; Yalcindag, Ali; Laouini, Dhafer; Brodeur, Scott; Bryce, Paul; Lu, Bao; Humbles, Alison A.; Oettgen, Hans; Gerard, Craig; Geha, Raif S.

    2004-01-01

    Mechanical injury to the skin results in activation of the complement component C3 and release of the anaphylatoxin C3a. C3a binds to a seven-transmembrane G protein–coupled receptor, C3aR. We used C3aR–/– mice to examine the role of C3a in a mouse model of allergic inflammation induced by epicutaneous sensitization with OVA. C3aR–/– mice exhibited an exaggerated Th2 response to epicutaneous but not to intraperitoneal sensitization with OVA, as evidenced by significantly elevated levels of se...

  12. Interactions between conidia of Aspergillus fumigatus and human complement component C3.

    OpenAIRE

    Sturtevant, J E; Latgé, J P

    1992-01-01

    Activation and deposition of C3 on Aspergillus fumigatus conidia have been previously demonstrated. This study investigated in further detail the interactions between complement component C3 and the conidia of A. fumigatus. Immunoblotting and 125I-C3 binding studies showed that C3 deposition was rapid (less than 15 min) and parallel to the formation of iC3b. Immunoblotting experiments identified a 54- to 58-kDa conidial protein which binds human complement component C3 and/or a C3 fragment(s)...

  13. Glomerular C3c localization indicates ongoing immune deposit formation and complement activation in experimental glomerulonephritis.

    OpenAIRE

    Schulze, M.; Pruchno, C. J.; Burns, M.; Baker, P. J.; R. J. Johnson; Couser, W G

    1993-01-01

    In antibody-mediated glomerular disease, deposits of C3 (C3b) are common and are degraded by factor I to C3c and C3d. However, the kinetics of C3b degradation in glomerulonephritis have not been defined. To do this, we studied three models of complement-dependent glomerulonephritis with established C3 deposits (passive Heymann nephritis, cationized immunoglobulin G membranous nephropathy, and concanavalin A-anticoncanavalin A glomerulonephritis). C3b deposition was halted by administration of...

  14. Inhibition of neutrophil function by fluid phase C3b of complement.

    OpenAIRE

    Ogle, J D; Ogle, C K; Alexander, J. W.

    1983-01-01

    A high-molecular-weight fragment of C3 was isolated from normal human serum by column chromatography, was generated by incubation of serum at 37 degrees C with inulin, and was produced from highly purified C3 by limited digestion with trypsin. This product was shown to inhibit the antibacterial function of neutrophils by using Escherichia coli O75 as the main test organism. The inhibitor reacted with anti-C3b and anti-C3c, but not with anti-C3B (anti-native C3) or anti-C3a. The manner of prep...

  15. Investigation of dielectric properties of cold C3F8 mixtures and hot C3F8 gas as Substitutes for SF6

    Science.gov (United States)

    Wang, Xiaohua; Zhong, Linlin; Yan, Jing; Yang, Aijun; Han, Guohui; Han, Guiquan; Wu, Yi; Rong, Mingzhe

    2015-10-01

    In order to reduce the global warming potential resulting from SF6 widely used as an insulating and arc quenching medium, the substitutes need to be found. This paper focuses on different cold C3F8 mixtures (at room temperature) as an insulating gas and hot C3F8 gas (at temperatures of 300-3500 K) as an arc quenching medium, which seem to be a good replacement of SF6. Firstly, the dielectric properties, including the reduced ionization coefficient α / N, reduced electron attachment coefficient η / N and reduced critical electric field strength ( E / N)cr, of the cold C3F8-CF4, C3F8-CO2, C3F8-N2, C3F8-O2 and C3F8-Ar mixtures are calculated numerically using the two-term approximation of the Boltzmann equation. The dependence of such dielectric properties on the buffer gas proportion is investigated. Among the various C3F8 mixtures, the C3F8-N2 mixture has the lowest α / N and the C3F8-CF4 mixture has the largest η / N, and moreover, the C3F8-N2 mixture is the best insulator in terms of breakdown strength because it has the largest ( E / N)cr. Secondly, the ( E / N)cr of hot C3F8 at temperatures up to 3500 K and various pressures is determined and compared with that of hot SF6 gas. It is found that the hot C3F8 gas has much poorer dielectric performance than hot SF6 because the ( E / N)cr of C3F8 decreases significantly above room temperature.

  16. 补体C3C3 c和C3 d在IgA肾病肾组织中的表达%The expression of C3 complement and its breakdown components in glomeruli of lgA nephropathy

    Institute of Scientific and Technical Information of China (English)

    王自良; 张爱平; 刘鹏

    2008-01-01

    目的 阐明补体C3,C3c和C3 d分子在IgA肾病肾组织中的表达,探讨C3C3c和C3d在IgA肾病发病中的作用.方法 对36例IgA肾病和43例无IgA沉积的系膜增生性肾炎患者进行回顾性分析,对其肾组织进行抗人C3,C3c和C3 d抗体检查,在免疫荧光显微镜下观察C3C3c和C3 d在肾组织上各自的表达.结果 补体C3在IgA肾病组肾小球上的表达高于系膜增生性肾炎组患者.C3c和C3 d仅在IgA肾病上发现表达;它们的共同表达与肾脏病理损害有关(r=0.99176,P=0.0009).结论 补体C3C3c和C3 d在IgA肾病肾组织上高表达,而且C3c和C3 d共同表达与肾脏损害有关,可能是向终末性肾衰竭转化的标志.

  17. Synthesis of c-C3H2 in interstellar clouds

    International Nuclear Information System (INIS)

    The synthesis of c-C3H2 in interstellar clouds is exmained. It is argued that the reaction of C3H(+) with H2, which generates cyclic and linear isomers of C3H(3+), and dissociation recombination of these isomers produces c-C3H2 in interstellar clouds. Various ion-molecule reactions that could generate C3H(3+) in interstellar clouds are investigated. 20 references

  18. Detection of complement activation using monoclonal antibodies against C3d

    OpenAIRE

    Thurman, Joshua M.; Kulik, Liudmila; Orth, Heather; Wong, Maria; Renner, Brandon; Sargsyan, Siranush A.; Mitchell, Lynne M.; Hourcade, Dennis E.; Hannan, Jonathan P.; Kovacs, James M.; Coughlin, Beth; Woodell, Alex S.; Pickering, Matthew C.; Rohrer, Bärbel; Holers, V. Michael

    2013-01-01

    During complement activation the C3 protein is cleaved, and C3 activation fragments are covalently fixed to tissues. Tissue-bound C3 fragments are a durable biomarker of tissue inflammation, and these fragments have been exploited as addressable binding ligands for targeted therapeutics and diagnostic agents. We have generated cross-reactive murine monoclonal antibodies against human and mouse C3d, the final C3 degradation fragment generated during complement activation. We developed 3 monocl...

  19. Complement in Experimental Autoimmune Encephalomyelitis Revisited: C3 is Required for Development of Maximal Disease

    OpenAIRE

    Szalai, Alexander J.; Hu, Xianzhen; Adams, Jillian E.; Barnum, Scott R.

    2007-01-01

    Complement per se has been shown to play an important role in demyelinating disease but controversy remains regarding the role of C3 in the development and progression of experimental autoimmune encephalomyelitis (EAE), the animal model for multiple sclerosis. In this study we used C3-/- mice to confirm previous findings that C3 is required for full development of EAE. Furthermore, C3+/- mice (with serum C3 levels 50% that of wild type mice) developed EAE with a severity intermediate between ...

  20. Dsj meson decay in the C3P0 model

    International Nuclear Information System (INIS)

    the wave function, where the 3P0 model is the lowest order term of this expansion and represented by the Hamiltonian HFT. The next step is to introduce the bound-state corrections (orthogonality corrections) to this 'zero order' model. The Hamiltonian associated to this correction contains terms dependent on only one Δ, called the bound state kernel. A new model is introduced in order to correct the 3P0, which we call the C3P0 model. This description is a natural consequence of the constituent quark model scenario of hadronic states. In high energy collisions many new mesons have been discovered, in particular the enigmatic D+s1 (2317) and D+s1 (2460). The C3P0 model is applied for the Dsj mesons decay. The amplitudes and their respective decay rates are evaluated. (author)

  1. Genetic analysis of variations in the sugar chain composition at the C-3 position of soybean seed saponins

    OpenAIRE

    Takada, Yoshitake; Tayama, Ippei; Sayama, Takashi; Sasama, Hiroko; Saruta, Masayasu; Kikuchi, Akio; Ishimoto, Masao; Tsukamoto, Chigen

    2012-01-01

    Saponins are sterols or triterpene glycosides that are widely distributed in plants. The biosynthesis of soybean saponins is thought to involve many kinds of glycosyltransferases, which is reflected in their structural diversity. Here, we performed linkage analyses of the Sg-3 and Sg-4 loci, which may control the sugar chain composition at the C-3 sugar moieties of the soybean saponin aglycones soyasapogenols A and B. The Sg-3 locus, which controls the production of group A saponin Af, was ma...

  2. C3: A Collaborative Web Framework for NASA Earth Exchange

    Science.gov (United States)

    Foughty, E.; Fattarsi, C.; Hardoyo, C.; Kluck, D.; Wang, L.; Matthews, B.; Das, K.; Srivastava, A.; Votava, P.; Nemani, R. R.

    2010-12-01

    The NASA Earth Exchange (NEX) is a new collaboration platform for the Earth science community that provides a mechanism for scientific collaboration and knowledge sharing. NEX combines NASA advanced supercomputing resources, Earth system modeling, workflow management, NASA remote sensing data archives, and a collaborative communication platform to deliver a complete work environment in which users can explore and analyze large datasets, run modeling codes, collaborate on new or existing projects, and quickly share results among the Earth science communities. NEX is designed primarily for use by the NASA Earth science community to address scientific grand challenges. The NEX web portal component provides an on-line collaborative environment for sharing of Eearth science models, data, analysis tools and scientific results by researchers. In addition, the NEX portal also serves as a knowledge network that allows researchers to connect and collaborate based on the research they are involved in, specific geographic area of interest, field of study, etc. Features of the NEX web portal include: Member profiles, resource sharing (data sets, algorithms, models, publications), communication tools (commenting, messaging, social tagging), project tools (wikis, blogs) and more. The NEX web portal is built on the proven technologies and policies of DASHlink.arc.nasa.gov, (one of NASA's first science social media websites). The core component of the web portal is a C3 framework, which was built using Django and which is being deployed as a common framework for a number of collaborative sites throughout NASA.

  3. Carbon and oxygen isotope working standards from C3 and C4 photosynthates.

    Science.gov (United States)

    Spangenberg, Jorge E

    2006-09-01

    A preparation of organic working standards for the online measurement of 13C/12C and 18O/16O ratios in biological material is presented. The organic working standards are simple and inexpensive C3 and C4 carbohydrates (sugars or cellulose) from distinct geographic origin, including white sugar, toilet and XEROX papers from Switzerland, maize from Ivory Coast, cane sugar from Brazil, papyrus from Egypt, and the core of the stem of a Cyperus papyrus plant from Kenya. These photosynthetic products were compared with International Atomic Energy standards CH-3 and CH-6 and other calibration materials. The presented working standards cover a 15% range of 13C/12C ratios and 9% for 18O/16O, with a precision10. PMID:16870558

  4. Climate and CO2 modulate the C3-C4 balance and δ13C signal in simulated vegetation

    Directory of Open Access Journals (Sweden)

    D. Jolly

    2009-03-01

    Full Text Available Fossil pollen data and δ13C measurements from cores collected in peatbogs or lakes have shown major changes in the terrestrial vegetation during Late Quaternary. Although the effect of climate on the C3-C4 balance has been discussed for 50 years, the impact of a low atmospheric CO2 during the Last Glacial Maximum (LGM was emphasized recently and conflicting evidence exists. In this paper, we use a physiologically-based biome model (BIOME4 in an iterative mode to simulate vegetation response to changing mean climate conditions and atmospheric CO2 partial pressure (pCO2. In particular, we investigate the transition from LGM to present conditions in two sites which changed from either a C4- or a C3-dominated vegetation to the opposite pole, respectively at Kuruyange (Burundi and Lingtaï (Central Loess Plateau, China. The response of the C3-C4 balance and δ13C signal in the simulated vegetation are investigated. The results show that the vegetation is primarily sensitive to temperature and pCO2. Rainfall impacted the simulated variables below a threshold which decreased with higher pCO2. Climate and pCO2 interacted differently between the two sites showing indirect effects on the δ13C signal. Moreover, the plant functional types (PFTs differed in their composition and in their response between the two sites, emphasizing that the competition between C3 and C4 plants cannot be hardly considered as a simple binary scheme. Our results confirm the advantages of using process-based models to understand past vegetation changes and the need to take account of multiple drivers when the C3-C4 balance is reconstructed from a palaeo-δ13C signal.

  5. Comparative study of global warming effects during silicon nitride etching using C3F6O/O2 and C3F6/O2 gas mixtures

    Science.gov (United States)

    Kim, Ka Youn; Moon, Hock Key; Lee, Nae-Eung; Hong, Bo Han; Oh, Soo Ho

    2015-01-01

    C3F6 and C3F6 gases were investigated as replacement gases for SF6 used in display industry due to their low global warming potential and short lifetime. In the C3F6/O2 and C3F6/O2 capacitively coupled plasmas, Si3N4 etch conditions were varied by controlling process parameters. The global warming effects were quantified as million metric ton carbon equivalents (MMTCEs) obtained from the volumetric emission of by-product and etch gases. A lower MMTCE value and higher etch rate process with combination of high and low source frequencies, f HF (27.12 MHz)/ f LF (2 MHz), were observed for the C3F6/O2 chemistry than for the C3F6/O2 chemistry.

  6. Molecular Basis for Complement Recognition and Inhibition Determined by Crystallographic Studies of the Staphylococcal Complement Inhibitor (SCIN) Bound to C3c and C3b

    OpenAIRE

    Garcia, Brandon L.; Ramyar, Kasra X.; Tzekou, Apostolia; Ricklin, Daniel; McWhorter, William J.; Lambris, John D.; Geisbrecht, Brian V.

    2010-01-01

    The human complement system plays an essential role in innate and adaptive immunity by marking and eliminating microbial intruders. Activation of complement on foreign surfaces results in proteolytic cleavage of complement component 3 (C3) into the potent opsonin C3b, which triggers a variety of immune responses and participates in a self-amplification loop mediated by a multi-protein assembly known as the C3 convertase. The human pathogen Staphylococcus aureus has evolved a sophisticated and...

  7. Generation of Multiple Fluid-Phase C3b:Plasma Protein Complexes During Complement Activation. Possible Implications in C3 Glomerulopathies

    OpenAIRE

    Ramadass, Mahalakshmi; Ghebrehiwet, Berhane; Richard J. Smith; Kew, Richard R.

    2013-01-01

    The complement system is tightly regulated to safeguard against tissue damage that results from unwanted activation. The key step of C3 cleavage to C3b is regulated by multiple mechanisms that control the initiation and extent of activation. This study demonstrated that C3b:plasma protein complexes form in the fluid-phase during complement activation. Several different plasma proteins displayed a discrete high molecular SDS-resistant band when any of the three complement activating pathways w...

  8. The Embryotrophic Activity of Oviductal Cell-derived Complement C3b and iC3b, a Novel Function of Complement Protein in Reproduction

    OpenAIRE

    Lee, YL; Lee, KF; Lee, WM; Luk, JM; Yeung, WSB; Xu, JS; He, QY; Chiu, JF

    2004-01-01

    The oviduct-derived embryotrophic factor, ETF-3, enhances the development of trophectoderm and the hatching process of treated embryos. Monoclonal anti-ETF-3 antibody that abolishes the embryotrophic activity of ETF-3 recognized a 115-kDa protein from the conditioned medium of immortalized human oviductal cells. Mass spectrometry analysis showed that the protein was complement C3. Western blot analysis using an antibody against C3 confirmed the cross-reactivities between anti-C3 antibody with...

  9. Disaster Prevention Coastal Map Production by MMS & C3D

    Science.gov (United States)

    Hatake, Shuhei; Kohori, Yuki; Watanabe, Yasushi

    2016-06-01

    In March 2011, Eastern Japan suffered serious damage of Tsunami caused by a massive earthquake. In 2012, Ministry of Land, Infrastructure and Transport published "Guideline of setting assumed areas of inundation by Tsunami" to establish the conditions of topography data used for simulation of Tsunami. In this guideline, the elevation data prepared by Geographical Survey Institute of Japan and 2m/5m/10m mesh data of NSDI are adopted for land area, while 500m mesh data of Hydrographic and Oceanographic Department of Japan Coast Guard and sea charts are adopted for water area. These data, however, do not have continuity between land area and water area. Therefore, in order to study the possibility of providing information for coastal disaster prevention, we have developed an efficient method to acquire continuous topography over land and water including tidal zone. Land area data are collected by Mobile Mapping System (MMS) and water area depth data are collected by interferometry echo sounder (C3D), and both data are simultaneously acquired on a same boat. Elaborate point cloud data of 1m or smaller are expected to be used for realistic simulation of Tsunami waves going upstream around shoreline. Tests were made in Tokyo Bay (in 2014) and Osaka Bay (in 2015). The purpose the test in Osaka Bay is to make coastal map for disaster prevention as a countermeasure for predicted Nankai massive earthquake. In addition to Tsunami simulation, the continuous data covering land and marine areas are expected to be used effectively for maintenance and repair of aged port and river facilities, maintenance and investigation of dykes, and ecosystem preservation.

  10. Climate Change Communicators: The C3E3 Project

    Science.gov (United States)

    Sharif, H. O.; Joseph, J.

    2013-12-01

    The University of Texas at San Antonio (UTSA), San Antonio College (SAC), and the University of North Dakota (UND) have partnered with NASA to provide underrepresented undergraduates from UTSA, SAC, and other community colleges climate-related research and education experiences through the Climate Change Communication: Engineer, Environmental science, and Education (C3E3) project. The program aims to develop a robust response to climate change by providing K-16 climate change education; enhance the effectiveness of K-16 education particularly in engineering and other STEM disciplines by use of new instructional technologies; increase the enrollment in engineering programs and the number of engineering degrees awarded by showing engineering's usefulness in relation to the much-discussed contemporary issue of climate change; increase persistence in STEM degrees by providing student research opportunities; and increase the ethnic diversity of those receiving engineering degrees and help ensure an ethnically diverse response to climate change. Students participated in the second summer internship funded by the project. More than 60 students participated in guided research experiences aligned with NASA Science Plan objectives for climate and Earth system science and the educational objectives of the three institutions. The students went through training in modern media technology (webcasts), and in using this technology to communicate the information on climate change to others, especially high school students, culminating in production of webcasts on investigating the aspects of climate change using NASA data. Content developed is leveraged by NASA Earth observation data and NASA Earth system models and tools. Several departments are involved in the educational program.

  11. Conservation of structural and functional domains in complement component C3 of Xenopus and mammals.

    OpenAIRE

    Grossberger, D; Marcuz, A; Du Pasquier, L; LAMBRIS, J. D.

    1989-01-01

    The cDNA sequence and the deduced amino acid sequence of the Mr 34,000 C-terminal fragment of Xenopus laevis complement component C3 are presented. The sequence of Xenopus C3 has 57% nucleotide identity to the corresponding sequence of human C3 and approximately 49% amino acid identity to C3 from human, mouse, and rabbit. The Xenopus C3 sequence shows clusters of high and of low similarity to the mammalian C3 sequences. One of these regions of high similarity represents the domain of mammalia...

  12. Multiple forms of complement C3 in trout that differ in binding to complement activators.

    OpenAIRE

    Sunyer, J O; Zarkadis, I K; Sahu, A.; LAMBRIS, J. D.

    1996-01-01

    In all other species analyzed to date, the functionally active form of complement component C3 exists as the product of a single gene. We have now identified and characterized three functional C3 proteins (C3-1, C3-3, and C3-4) in trout that are the products of at least two distinct C3 genes. All three proteins are composed of an alpha-and a beta-chain and contain a thioester bond in the alpha-chain. However, they differ in their electrophoretic mobility, glycosylation, reactivity with monosp...

  13. C3 Glomerular Disease Pathogenesis%补体系统在C3肾小球病中的作用

    Institute of Scientific and Technical Information of China (English)

    尹梦笛; 李秋

    2016-01-01

    Objective C3 glomerulopathy describes a spectrum of disorders with glomerular pathology associated with C3 cleavage product deposition and with defective complement action and regulation. Kidney biopsies from these patients show glomerular accumulation or deposition of C3 cleavage fragments, but no or minor deposition of immunoglobulins.C3G is subdivided into C3G-DDD with specific dense deposits subforms and into C3 glomerulonephritis. C3G is considered to be the consequences of defective complement control and in particular deregulation of the alternative pathway, and complement system is associated with genetic variations and autoimmune factors. At present further studies are needed to clear the pathogenesis of the disease, identify the precise biological markers and develop effective treatments.%C3肾小球病是一组与C3裂解产物沉积及补体缺陷和/或失调相关的肾小球病。其肾活检特征性表现为免疫荧光染色C3沉积为主,不伴或伴少量其他免疫复合物沉积。C3肾小球病被认为是补体调控缺陷及旁路途径过度活化的结果,而补体调控异常与遗传变异和自身免疫有关。目前尚需进一步研究明确疾病的发病机制、找出精确的生物学标志物以及制定有效的治疗方法。

  14. Structural insight into the recognition of complement C3 activation products by integrin receptors

    DEFF Research Database (Denmark)

    Bajic, Goran

    2015-01-01

    associated with microbes and apoptotic or necrotic cells. Complement not only protects against pathogens but also maintains body homeostasis. Activation of complement leads to cleavage of the complement proteins C4, C3 and C5, and their fragments have effector functions through binding to pathogen surfaces...... small fragment C3a called anaphylatoxin. Complement leads to opsonization as the proteolytic fragment C3b becomes covalently linked to the activator surface through a reactive thioester. Self-surfaces are protected by complement regulators, whereas complement activation vividly amplifies on pathogens....... An important outcome of the regulators is the degradation of C3b to iC3b. Phagocytic receptor αMβ2 integrin (also called CR3, CD11b/CD18, or Mac-1) on leukocytes engages the opsonized activator subsequently to C3b cleavage into iC3b. Apoptotic cells activate complement leading to iC3b deposition and...

  15. Association of the porcine C3 gene with haemolytic complement activity in the pig

    OpenAIRE

    Mekchay Supamit; Ponsuksili Siriluck; Schellander Karl; Wimmers Klaus

    2003-01-01

    Abstract The complement component C3 plays an essential role in the activated complement system, which is involved in phagocytosis, inflammation and immunoregulation to destroy infectious microorganisms. The C3 molecule has more implications in the general defence mechanisms. In this study, the porcine C3 cDNA sequences including 5'- and 3'- flanking regions were determined and the polymorphisms in this gene were identified to carry out an association analysis between C3 and complement activi...

  16. Association of the porcine C3 gene with haemolytic complement activity in the pig

    OpenAIRE

    Mekchay, Supamit; Ponsuksili, Siriluck; Schellander, Karl; Wimmers, Klaus

    2003-01-01

    International audience The complement component C3 plays an essential role in the activated complement system, which is involved in phagocytosis, inflammation and immunoregulation to destroy infectious microorganisms. The C3 molecule has more implications in the general defence mechanisms. In this study, the porcine C3 cDNA sequences including $5'$- and $3'$- flanking regions were determined and the polymorphisms in this gene were identified to carry out an association analysis between C3 ...

  17. C3, factor B, alpha-1-antitrypsin in neonatal septicaemia with sclerema.

    OpenAIRE

    Pelet, B

    1980-01-01

    C3, factor B, and alpha-1-antitrypsin were determined in newborn infants with septicaemia and sclerema, associated with suspected infections, ABO or Rh incompatibility, and hyperbilirubinaemia of unknown origin, during and after treatment with exchange transfusion. Activation products from C3 and factor B, the clearance of the transfused C3, and its synthesis by the recipient were determined also. Infected newborn infants had low levels of C3 and factor B, but a normal amount of alpha-1-antit...

  18. Carbon isotope discrimination as a diagnostic tool for C4 photosynthesis in C3-C4 intermediate species

    Science.gov (United States)

    Alonso-Cantabrana, Hugo; von Caemmerer, Susanne

    2016-01-01

    The presence and activity of the C4 cycle in C3-C4 intermediate species have proven difficult to analyze, especially when such activity is low. This study proposes a strategy to detect C4 activity and estimate its contribution to overall photosynthesis in intermediate plants, by using tunable diode laser absorption spectroscopy (TDLAS) coupled to gas exchange systems to simultaneously measure the CO2 responses of CO2 assimilation (A) and carbon isotope discrimination (Δ) under low O2 partial pressure. Mathematical models of C3-C4 photosynthesis and Δ are then fitted concurrently to both responses using the same set of constants. This strategy was applied to the intermediate species Flaveria floridana and F. brownii, and to F. pringlei and F. bidentis as C3 and C4 controls, respectively. Our results support the presence of a functional C4 cycle in F. floridana, that can fix 12–21% of carbon. In F. brownii, 75–100% of carbon is fixed via the C4 cycle, and the contribution of mesophyll Rubisco to overall carbon assimilation increases with CO2 partial pressure in both intermediate plants. Combined gas exchange and Δ measurement and modeling is a powerful diagnostic tool for C4 photosynthesis. PMID:26862154

  19. Carbon isotope discrimination as a diagnostic tool for C4 photosynthesis in C3-C4 intermediate species.

    Science.gov (United States)

    Alonso-Cantabrana, Hugo; von Caemmerer, Susanne

    2016-05-01

    The presence and activity of the C4 cycle in C3-C4 intermediate species have proven difficult to analyze, especially when such activity is low. This study proposes a strategy to detect C4 activity and estimate its contribution to overall photosynthesis in intermediate plants, by using tunable diode laser absorption spectroscopy (TDLAS) coupled to gas exchange systems to simultaneously measure the CO2 responses of CO2 assimilation (A) and carbon isotope discrimination (Δ) under low O2 partial pressure. Mathematical models of C3-C4 photosynthesis and Δ are then fitted concurrently to both responses using the same set of constants. This strategy was applied to the intermediate species Flaveria floridana and F. brownii, and to F. pringlei and F. bidentis as C3 and C4 controls, respectively. Our results support the presence of a functional C4 cycle in F. floridana, that can fix 12-21% of carbon. In F. brownii, 75-100% of carbon is fixed via the C4 cycle, and the contribution of mesophyll Rubisco to overall carbon assimilation increases with CO2 partial pressure in both intermediate plants. Combined gas exchange and Δ measurement and modeling is a powerful diagnostic tool for C4 photosynthesis. PMID:26862154

  20. Carbon isotopic evidence from paleosols for mixed C 3/C 4 vegetation in the Bogota Basin, Colombia

    Science.gov (United States)

    Mora, Germán; Pratt, Lisa M.

    2002-04-01

    Pollen reconstructions in the Bogota basin (Colombia) indicate the expansion of tropical high-altitude grassland (paramo) at the expense of Andean forests during glacial intervals. The carbon isotopic composition (δ 13C) of soil organic matter (SOM) can be a useful indicator of changes in vegetation affecting grasslands because it distinguishes between two groups of grasses (C 3 and C 4) adapted to different ecological environments. Values of SOM δ 13C were determined in four weathering profiles containing both modern (Holocene) soils and paleosols formed during the Last Glacial Stage. These profiles are located along an altitudinal transect in the Bogota basin, extending from 2550 to 3100 m. Values of SOM δ 13C in the topsoil horizons reflect those of the native C 3 vegetation that currently dominates the ecosystems in the Colombian Andes. Although C 4 grasses are currently negligible in the basin, elevated SOM δ 13C values indicative of C 4 plants were found in two Holocene soils. Environmental changes or ancient agricultural activities could explain the increased abundance of these plants in the basin during the late Holocene. Isotopic values in the studied paleosols revealed the presence of a mixed C 3/C 4 vegetation in the basin during the Last Glacial Stage, thus indicating the expansion of C 4 grasses. We hypothesized that lowered pCO 2 and possibly reduced rainfall resulted in the colonization of the tropical Andes by lowland C 4 grasses despite of prevailing cooler temperatures.

  1. Complement system regulation and C3 glomerulopathy%补体系统调控异常与C3肾小球病

    Institute of Scientific and Technical Information of China (English)

    肖慧捷; 何瑞娟

    2013-01-01

    Complement system is a key system for immune surveillance and homeostasis. Excessive activation of complement system, especially the activation of alternative pathway may play a very important role in the pathogenesis of primary and secondary glomerulonephritis. C3 glomerulopathy is a newly named disease characterized by evident C3 deposition in the glomeruli with little or no immunoglobulin under immunofluorescence (IF). Its clinical and pathological manifestations vary a lot. The decreased plasma C3 and Factor H( FH) suggest that abnormal regulation of complement system plays an importment role in its pathogenesis. C3 glomerulopathy varies a lot as to its clinical manifestation, treatment and prognosis. The inhibition of excessive complement activation might be the key to treating C3 glomerulopathy.

  2. Hypomorphic variant of the slow allele of C3 associated with hypocomplementemia and hematuria.

    Science.gov (United States)

    McLean, R H; Bryan, R K; Winkelstein, J

    1985-05-01

    This report describes the first instance of a hypomorphic variant (C3*s) of the most common C3 allele, C3 Slow, which was detected in a four-year-old Caucasian boy with hematuria. Analysis of C3 phenotypes, as determined by agarose electrophoresis, showed a hypomorphic C3 Slow in the patient and a maternal aunt. Serum C3 concentration was significantly reduced in the patient and his mother (610 and 750 micrograms/ml; normal +/- 1 SD = 1,240 +/- 240 micrograms/ml) and was at the lower limits of normal in the affected aunt (770 micrograms/ml). The mother's phenotype was C3 S (? Ss) and she was the presumed carrier, since the father (C3 FS) had neither an abnormal C3 S band nor a low C3 concentration (980 micrograms/ml). Total hemolytic complement was significantly reduced only in the patient (19 units/ml; normal = 38 +/- 16). Hypomorphic C3 variants should be considered in the evaluation of decreased serum C3 levels. PMID:3993666

  3. Heme-heme magnetic interaction of cytochrome c3 studied by Mössbauer effect

    OpenAIRE

    Utuno, M.; Ôno, K.; Kimura, K.; Inokuchi, H; Yagi, T

    1980-01-01

    A Mössbauer effect study was carried out on cytochrome c3 to investigate the heme-heme magnetic interaction. Results observed in the spectrum of partially reduced cytochrome c3 at 4.2 K shows that a strongly enhanced heme-heme magnetic interaction exists between cytochrome c 3 molecules.

  4. 18 CFR 3c.3 - Reporting fraud, waste, abuse, and corruption and cooperation with official inquiries.

    Science.gov (United States)

    2010-04-01

    ... OF CONDUCT § 3c.3 Reporting fraud, waste, abuse, and corruption and cooperation with official inquiries. (a) Employees shall, in fulfilling the obligation of 5 CFR 2635.101(b)(11), report fraud, waste..., abuse, and corruption and cooperation with official inquiries. 3c.3 Section 3c.3 Conservation of...

  5. Liquid Robotics Wave Glider, Honey Badger (G3), 2015, C3

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Liquid Robotics Wave Glider, Honey Badger (G3), 2015, C3. C3 board number 8215 (not coated) appears as board_id=32, task_id=23. C3 board number 771 (coated) appears...

  6. The C3 Framework: One Year Later - an Interview with Kathy Swan

    Science.gov (United States)

    Social Education, 2014

    2014-01-01

    On September 17, 2013 (Constitution Day), the C3 Framework was released under the title "The College, Career and Civic Life (C3) Framework for Social Studies State Standards: Guidance for Enhancing the Rigor of K-12 Civics, Economics, Geography, and History." The C3 Project Director and lead writer was NCSS member Kathy Swan, who is…

  7. The AREVA customized chemical cleaning C3-concept as part of the steam generator asset management

    International Nuclear Information System (INIS)

    with various chemical cleaning methods and their world wide applications AREVA has developed the 'C3' Customized Chemical Cleaning concept. This concept covers the entire range of steam generator chemical cleaning. With this approach, also specific problems like removal of sludge piles from tube sheet can be adequately addressed. At European PWRs the above presented overall approach was applied successfully in 2009 and 2010. Prior to the chemical cleaning the steam generator status was investigated and evaluated in a common approach of all relevant AREVA departments. For example, as a result of one plant specific evaluation, a hard sludge problem was identified combined with denting indications mainly on the tube sheet. Based on this SG assessment and the expected amount of deposits an individually tailored and site specific cleaning approach was developed in close cooperation with the plant operator. Prior to the chemical cleaning an inner bundle lancing was performed to mechanically weaken the hard deposits, which allows deep penetration of the cleaning agent into the deposits. The chemical cleaning methodology for this site specific SG problem was the AREVA DART HT process selected from the C3 toolbox. The DART HT process allows an efficient removal of hard deposits, while keeping the average corrosion below 50 μm. After the chemical cleaning a subsequent tube sheet lancing was performed, effectively removing the chemically softened deposits. This approach removed the targeted amount of deposits, thus eliminating the hard sludge denting of tubes at the tube sheet. This paper describes the joint approach of the plant operator and AREVA for the on-site chemical cleaning to the improve steam generator condition. (authors)

  8. C3在迟发型超敏反应中的作用%Role of complement C3 in delayed-type hypersensitivity

    Institute of Scientific and Technical Information of China (English)

    裘毅刚; 陈月; 张丽芸; 陈政良

    2005-01-01

    目的探讨补体成分3(C3)在迟发型超敏反应(DTH)中的作用.方法用卵白蛋白(OVA)诱导C3基因敲除(C3-/-)和野生型(C3+/+)小鼠足垫部位的DTH,测量足垫厚度的变化,并对反应部位组织进行HE和免疫组化染色检测.分离小鼠脾脏T淋巴细胞,用巨噬细胞作为抗原提呈细胞,在体外分别用丝裂原和特异性抗原刺激,用3H-TdR掺入法评价T淋巴细胞的增殖活性.结果OVA诱导足垫DTH后,C3-/-小鼠足垫厚度和局部浸润单个核细胞的数量都显著低于C3+/+小鼠的,其中浸润的单个核细胞主要为CD4+T淋巴细胞.2种小鼠的T淋巴细胞对丝裂原刺激的反应相似,而已致敏C3-/-小鼠脾脏T细胞对特异性抗原再次刺激后的增殖反应显著低于C3+/+小鼠.结论C3缺陷明显影响DTH应答,提示C3在DTH中起了重要作用.

  9. Development of Predictive Thermodynamic Model for Liquefaction of Natural Gas Using the C3-Mr Refrigeration Process

    Directory of Open Access Journals (Sweden)

    Dagde, Kenneth, K.

    2012-11-01

    Full Text Available This paper presents a propane precooled mixed refrigerant (C3-MR liquefaction plant with 4 pressure levels of propane cooling operational in Nigeria and demonstrates the procedure for developing a thermodynamic model that predicts the liquefied natural gas (LNG production rate. The model prediction was validated with plant data with a maximum deviation of 3%. The thermodynamic efficiency of the natural gas liquefaction plant was estimated to be 45.1%. Simulations reveals that LNG production rate for the C3-MR plant depends on cooling water supply temperature (1 ͦC rise results to 92 tonnes per day of LNG loss, thermodynamic efficiency of the overall liquefaction process (1% drop results to 215 tonnes per day of LNG loss, LNG outlet temperature (1 ͦC decrease results to 108 tonnes per day of LNG loss, LNG production to feed gas supply ratio (1% rise results to 37 tonnes per day rise in LNG, thermal efficiency of gas turbine drivers (1% drop results to 277 tonnes per day of LNG loss, ambient air temperature (1 ͦC drop results to 67 tonnes per day of LNG increase and feed gas supply pressure.

  10. Extreme weather conditions reduce the CO2 fertilization effect in temperate C3 grasslands

    Science.gov (United States)

    Obermeier, Wolfgang; Lehnert, Lukas; Kammann, Claudia; Müller, Christoph; Grünhage, Ludger; Luterbacher, Jürg; Erbs, Martin; Yuan, Naiming; Bendix, Jörg

    2016-04-01

    The increase in atmospheric greenhouse gas concentrations from anthropogenic activities is the major driver of global climate change. The rising atmospheric carbon dioxide (CO2) concentrations may stimulate plant photosynthesis and, thus, cause a net sink effect in the global carbon cycle. As a consequence of an enhanced photosynthesis, an increase in the net primary productivity (NPP) of C3 plants (termed CO2 fertilization) is widely assumed. This process is associated with a reduced stomatal conductance of leaves as the carbon demand of photosynthesis is met earlier. This causes a higher water-use efficiency and, hence, may reduce water stress in plants exposed to elevated CO2 concentrations ([eCO2]). However, the magnitude and persistence of the CO2 fertilization effect under a future climate including more frequent weather extremes are controversial. To test the CO2 fertilization effect for Central European grasslands, a data set comprising 16 years of biomass samples and environmental variables such as local weather and soil conditions was analysed by means of a novel approach. The data set was recorded on a "Free Air Carbon dioxide Enrichment" (FACE) experimental site which allows to quantify the CO2 fertilization effect under naturally occurring climate variations. The results indicate that the CO2 fertilization effect on the aboveground biomass is strongest under local average environmental conditions. Such intermediate regimes were defined by the mean +/- 1 standard deviation of the long-term average in the respective variable three months before harvest. The observed CO2 fertilization effect was reduced or vanished under drier, wetter and hotter conditions when the respective variable exceeded the bounds of the intermediate regimes. Comparable conditions, characterized by a higher frequency of more extreme weather conditions, are predicted for the future by climate projections. Consequently, biogeochemical models may overestimate the future NPP sink

  11. In situ construction of g-C3N4/g-C3N4 metal-free heterojunction for enhanced visible-light photocatalysis.

    Science.gov (United States)

    Dong, Fan; Zhao, Zaiwang; Xiong, Ting; Ni, Zilin; Zhang, Wendong; Sun, Yanjuan; Ho, Wing-Kei

    2013-11-13

    The photocatalytic performance of the star photocatalyst g-C3N4 was restricted by the low efficiency because of the fast charge recombination. The present work developed a facile in situ method to construct g-C3N4/g-C3N4 metal-free isotype heterojunction with molecular composite precursors with the aim to greatly promote the charge separation. Considering the fact that g-C3N4 samples prepared from urea and thiourea separately have different band structure, the molecular composite precursors of urea and thiourea were treated simultaneously under the same thermal conditions, in situ creating a novel layered g-C3N4/g-C3N4 metal-free heterojunction (g-g CN heterojunction). This synthesis method is facile, economic, and environmentally benign using easily available earth-abundant green precursors. The confirmation of isotype g-g CN heterojunction was based on XRD, HRTEM, valence band XPS, ns-level PL, photocurrent, and EIS measurement. Upon visible-light irradiation, the photogenerated electrons transfer from g-C3N4 (thiourea) to g-C3N4 (urea) driven by the conduction band offset of 0.10 eV, whereas the photogenerated holes transfer from g-C3N4 (urea) to g-C3N4 (thiourea) driven by the valence band offset of 0.40 eV. The potential difference between the two g-C3N4 components in the heterojunction is the main driving force for efficient charge separation and transfer. For the removal of NO in air, the g-g CN heterojunction exhibited significantly enhanced visible light photocatalytic activity over g-C3N4 alone and physical mixture of g-C3N4 samples. The enhanced photocatalytic performance of g-g CN isotype heterojunction can be directly ascribed to efficient charge separation and transfer across the heterojunction interface as well as prolonged lifetime of charge carriers. This work demonstrated that rational design and construction of isotype heterojunction could open up a new avenue for the development of new efficient visible-light photocatalysts. PMID:24144400

  12. Activated Complement Component 3 (C3) Is Required for Ultraviolet Induction of Immunosuppression and Antigenic Tolerance

    OpenAIRE

    Hammerberg, Craig; Santosh K. Katiyar; Carroll, Michael C.; Cooper, Kevin D

    1998-01-01

    Complement component 3 (C3), a critical regulator of innate immunity, may also play a role in the regulation of cognate immunity, such as contact sensitivity responses. Because ultraviolet (UV) radiation also activates C3 in the skin, we determined whether the immunosuppressed state that results when a contact sensitizer is applied through UVB-exposed skin requires the presence and activation of C3. This question was addressed through the use of C3-deficient mice, blockade of C3 cleavage to C...

  13. Compstatin analog Cp40 inhibits complement dysregulation in vitro in C3 glomerulopathy

    OpenAIRE

    Zhang, Yuzhou; Shao, Dingwu; Ricklin, Daniel; Hilkin, Brieanna M.; Nester, Carla M.; Lambris, John D.; Smith, Richard J. H.

    2015-01-01

    C3 glomerulopathy (C3G) defines a group of untreatable ultra-rare renal diseases caused by uncontrolled activation of the alternative complement pathway. Nearly half of patients progress to end stage renal failure within 10 years. Cp40, a second-generation compstatin analog in clinical development, is a 14 amino-acid cyclic peptide that selectively inhibits complement activation in humans and non-human primates by binding to C3 and C3b. We hypothesized that by targeting C3 Cp40 would provide ...

  14. Complement C3 gene: Expression characterization and innate immune response in razor clam Sinonovacula constricta.

    Science.gov (United States)

    Peng, Maoxiao; Niu, Donghong; Wang, Fei; Chen, Zhiyi; Li, Jiale

    2016-08-01

    Complement component 3 (C3) is central to the complement system, playing an important role in immune defense, immune regulation and immune pathology. Several C3 genes have been characterized in invertebrates but very few in shellfish. The C3 gene was identified from the razor clam Sinonovacula constricta, referred to here as Sc-C3. It was found to be highly homologous with the C3 gene of Ruditapes decussatus. All eight model motifs of the C3 gene were found to be included in the thiolester bond and the C345C region. Sc-C3 was widely expressed in all healthy tissues with expression being highest in hemolymph. A significant difference in expression was revealed at the umbo larvae development stage. The expression of Sc-C3 was highly regulated in the hemolymph and liver, with a distinct response pattern being noted after a challenge with Micrococcus lysodeikticus and Vibrio parahemolyticus. It is therefore suggested that a complicated and unique response pathway may be present in S. constricta. Further, serum of S. constricta containing Sc-C3 was extracted. This was activated by LPS or bacterium for verification for function. The more obvious immune function of Sc-C3 was described as an effective membrane rupture in hemocyte cells of rabbit, V. parahemolyticus and Vibrio anguillarum. Thus, Sc-C3 plays an essential role in the immune defense of S. constricta. PMID:27231190

  15. Metal-free melem/g-C3N4 hybrid photocatalysts for water treatment.

    Science.gov (United States)

    Liu, Shizhen; Sun, Hongqi; O'Donnell, Kane; Ang, H M; Tade, Moses O; Wang, Shaobin

    2016-02-15

    In this study, graphitic carbon nitride was engineered to produce metal-free melem/g-C3N4 hybrid photocatalysts through a hydrothermal technique. It was revealed that the hydrothermal treatment of g-C3N4 could produce a hybrid structure of "thorn ball" liked melem on g-C3N4 layer at a high temperature, and was able to modify the photoelectronic properties of g-C3N4. The spectroscopic measurements implied that a melem/g-C3N4 hybrid has better light absorption and lower electron/hole recombination than pristine g-C3N4. Therefore, the melem/g-C3N4 photocatalysts can decompose methylene blue solution under artificial sunlight with a higher rate and also present good stability. PMID:26606376

  16. Premixed laminar C_3H_8- and C_3H_6-air stagnation flames: experiments and simulations with detailed kinetic models

    OpenAIRE

    Benezech, Laurent J.; Bergthorson, Jeffrey M.; Dimotakis, Paul E.

    2009-01-01

    A validation methodology based on the comparison of flame simulations relying on reacting-flow models with experiment is applied to C3 flames. The work reported targets the assessment of the modeled reactions and reaction rates relevant to C3-flame propagation in several detailed combustion kinetic models. A better knowledge of C3 hydrocarbon combustion chemistry is required before attempting to bridge the gap between the reasonably well-understood oxidation of C1–C2 hydrocarbons and the more...

  17. Neisseria meningitidis NalP cleaves human complement C3, facilitating degradation of C3b and survival in human serum

    OpenAIRE

    Del Tordello, Elena; Vacca, Irene; Ram, Sanjay; Rappuoli, Rino; Serruto, Davide

    2013-01-01

    The complement system is a crucial component of the innate immune response in humans. In this study, we report the characterization of an autotransporter protease of Neisseria meningitidis named NalP. We show that NalP is able to cleave the α-chain of the human complement factor C3 in a species-specific manner. As a consequence, the deposition of C3b on the bacterial surface is reduced and, in human serum, the NalP-generated C3b fragment is further degraded by host factors. Our results signif...

  18. The Tick-Over Theory Revisited: Formation and Regulation of the Soluble Alternative Complement C3 Convertase (C3(H2O)Bb)

    OpenAIRE

    Bexborn, Fredrik; Andersson, Per Ola; Chen, Hui; Nilsson, Bo; Ekdahl, Kristina N.

    2007-01-01

    The molecular interactions between the components of the C3 convertase of the alternative pathway (AP) of complement and its regulators, in both surface-bound and fluid-phase form, are still incompletely understood. The fact that the AP convertase is labile makes studies difficult to perform. According to the so called tick-over theory, hydrolyzed C3, called C3(H2O), forms the initial convertase in fluid phase together with factor B. In the present study, we have applied western blot analysis...

  19. The C3H-type zinc finger protein GDS1/C3H42 is a nuclear-speckle-localized protein that is essential for normal growth and development in Arabidopsis.

    Science.gov (United States)

    Kim, Dae Won; Jeon, Su Jeong; Hwang, Sung Min; Hong, Jong Chan; Bahk, Jeong Dong

    2016-09-01

    Eukaryotic C3H-type zinc finger proteins (Znfs) comprise a large family of regulatory proteins involved in many aspects of plant stress response, growth and development. However, compared to mammalian, only a few plant Znfs have been functionally characterized. Here, T-DNA inserted gds1 (growth, development and splicing 1) mutant, displayed abnormal growth throughout the lifecycle owing to the reduction of cell size and number. Inverse PCR analysis revealed that the abnormal growth was caused by the disruption of At3g47120, which encodes a C3H42 protein belonging to the C-X7-C-X5-C-X3-H class of the Znf family. GDS1 was ubiquitously transcribed, but shows high levels of expression in young seedling and unexpanded new leaves. In gds1, the transcripts of many growth- and development-related genes were down-regulated, and the auxin response was dramatically reduced. A fluorescence-based assay revealed that the GDS1 protein was localized to the nucleus, prominently in the speckle compartments. Its arginine/serine dipeptide-rich-like (RS-like) domain was essential for nuclear localization. In addition, the SR1, SRm102 and U1-70K components of the U1 spliceosome interacted with GDS1 in the nuclear speckle compartments. Taken together, these suggest that GDS1, a nuclear-speckle-associated Znf, might play a significant role in splicing during plant growth and development. PMID:27457991

  20. Species-dependent partitioning of C and N stable isotopes between arbuscular mycorrhizal fungi and their C3 and C4 hosts

    Czech Academy of Sciences Publication Activity Database

    Courty, P.-E.; Doubková, Pavla; Calabrese, S.; Niemann, H.; Lehmann, M. F.; Vosátka, Miroslav; Selosse,, M.-A.

    2015-01-01

    Roč. 82, Mar 2015 (2015), s. 52-61. ISSN 0038-0717 Institutional support: RVO:67985939 Keywords : arbuscular mycorrhizal symbiosis * carbon and nitrogen stable isotopes * C3 and C4 plants Subject RIV: EF - Botanics Impact factor: 3.932, year: 2014

  1. Lethal Infection of C3H/HeJ and C3H/SCID Mice with an Isolate of Leptospira interrogans Serovar Copenhageni

    OpenAIRE

    Nally, Jarlath E.; Fishbein, Michael C.; Blanco, David R.; Lovett, Michael A.

    2005-01-01

    Leptospira interrogans serovar Copenhageni strain RJ16441, a blood isolate from humans with the severe pulmonary form of leptospirosis, has previously been shown to cause fatal pulmonary hemorrhage in guinea pigs and asymptomatic chronic renal tubular colonization with urinary shedding in rats. In this study, RJ16441 caused lethal infection of both C3H/HeJ and C3H/SCID mice, but no hemorrhagic phenomena were observed.

  2. Factor H facilitates the clearance of GBM bound iC3b by controlling C3 activation in fluid phase

    OpenAIRE

    Paixão-Cavalcante, Danielle; Hanson, Steven; Botto, Marina; Cook, H. Terence; Pickering, Matthew C.

    2009-01-01

    Dense deposit disease (DDD) is strongly associated with the uncontrolled activation of the complement alternative pathway. Factor H (CFH)-deficient (Cfh −/−) mice spontaneously develop C3 deposition along the glomerular basement membrane (GBM) with subsequent development of glomerulonephritis with features of DDD, a lesion dependent on C3 activation. In order to understand the role of CFH in preventing renal damage associated with the dysregulation of the alternative pathway we administered p...

  3. Association of the porcine C3 gene with haemolytic complement activity in the pig

    Directory of Open Access Journals (Sweden)

    Mekchay Supamit

    2003-06-01

    Full Text Available Abstract The complement component C3 plays an essential role in the activated complement system, which is involved in phagocytosis, inflammation and immunoregulation to destroy infectious microorganisms. The C3 molecule has more implications in the general defence mechanisms. In this study, the porcine C3 cDNA sequences including 5'- and 3'- flanking regions were determined and the polymorphisms in this gene were identified to carry out an association analysis between C3 and complement activity traits. Porcine C3 gene has high homology with human C3. Five single nucleotide polymorphisms (SNPs and one microsatellite were detected in the porcine C3 gene. Haemolytic complement activity of alternative and classical pathways (ACH, CCP was measured in 416 F2 animals of a crossbred of Duroc × Berlin Miniature Pig, which were immunized with Mycoplasma, Aujeszky and PRRS vaccines. C3 markers were found to be significantly associated (P C3 with complement activity reinforces the importance of C3 as a candidate gene for natural resistance to microorganisms.

  4. Differential radiobiological effects of carboxyfullerene C3 on K562 and AHH-1 cells

    International Nuclear Information System (INIS)

    Objective: To investigate the application prospective of carboxyfullerene C3 as a radioprotectant or assistant for tumor radiotherapy. Methods: Different concentrations of C3 were incubated with K562 and AHH-1 cell, CCK-8 assay and trypan blue rejection test were performed to examine the influence of C3 on the cell viability. Annexin V/PI staining and flow cytometry assay were applied to assess the cell cycle and apoptosis after 7-ray irradiation. Results: C3 showed little toxicity to AHH-1 cell with the survival rate over 95%, but 600 mg/L of C3 markedly inhibited the growth of K562 cell (82%). Pretreatment of 100 mg/L C3 significantly increased the survival rate of AHH-1 cell after 4 Gy irradiation compared with the single radiation group(71.3% vs 90.3%), but decreased the apoptosis rate (26.3% vs 12.6%), while the survival rate of K562 cell was decreased and the apoptosis rate was elevated with the increase of C3 concentration. Moreover, the cell cycle analysis revealed the G2 phase block in AHH-1 cell after radiation exposure was mitigated by C3 pretreatment, but that in K562 cell was aggravated. Conclusions: C3 has good radioprotective effects on AHH-1 cells. For K562 cell, C3 could inhibit the cell proliferation, promote the radiation induced apoptosis and aggravate the G2 phase block. (authors)

  5. A Modified Thermal Time Model Quantifying Germination Response to Temperature for C 3 and C 4 Species in Temperate Grassland

    OpenAIRE

    Hongxiang Zhang; Yu Tian; Daowei Zhou

    2015-01-01

    Thermal-based germination models are widely used to predict germination rate and germination timing of plants. However, comparison of model parameters between large numbers of species is rare. In this study, seeds of 27 species including 12 C 4 and 15 C 3 species were germinated at a range of constant temperatures from 5 °C to 40 °C. We used a modified thermal time model to calculate germination parameters at suboptimal temperatures. Generally, the optimal germination temperature was higher...

  6. Soil Organic Matter \\delta 13C across the Great Plains grasslands: both rainfall and temperature control C3 vs. C4 productivity

    Science.gov (United States)

    von Fischer, J. C.; Tieszen, L. L.

    2004-12-01

    Grass species that dominate the Great Plains grasslands assimilate CO2 by one of two photosynthetic systems, C3 or C4, with the proportions of these types largely controlled by climate. Because C3 and C4 plants differ in their magnitudes of carbon isotope fractionation, regional and global scale biogeochemical analyses (e.g., isotopic inversion studies of CO2) depend on knowing the relative activity of these groups and how they vary with climate. However, regional analyses of C3/C4 proportions, such as Teeri and Stowe (1979), have measured species composition but not relative production. To quantify the relationship between climate and relative production, we have analyzed the carbon isotope composition of soil organic matter (SOM) from 75 native prairie relicts across the Great Plains and compared these values to long-term (30-year mean) climate data. Although temperature has long been recognized as a key determinant of C3 vs. C4 success because of its effects on photorespiration, we find that the timing of rainfall is an additional important predictor; increased rainfall in summer months leads to increased relative production of C4 species. This finding adds complexity to the dominant view that temperature alone controls C3/C4 balance, and suggests that regional scale biogeochemical studies should evaluate the degree to which rainfall is included as a predictor of C3 vs. C4 productivity.

  7. Enhanced Photocatalytic Performance of Luminescent g-C3N4 Photocatalyst in Darkroom.

    Science.gov (United States)

    Li, Huihui; Yin, Shu; Sato, Tsugio; Wang, Yuhua

    2016-12-01

    Graphitic-C3N4(g-C3N4), a low-cost visible-light-driven photocatalyst, was used for the photocatalytic oxidation of aqueous methylene blue (MB) in the dark with Sr4Al14O25:(Eu,Dy) assistance. The Sr4Al14O25:(Eu,Dy)/g-C3N4 photocatalysts were fabricated through the ultrasonic dispersion method. The commercial Sr4Al14O25:(Eu,Dy) phosphor was used as a long afterglow supplier for exciting g-C3N4 in the dark. The results demonstrated that the metal-free g-C3N4 photocatalyst could use the eye-visible long afterglow to photocatalytically decompose MB dyes in the dark. This work may expand the appealing application of g-C3N4 for the environmental cleanup. PMID:26880728

  8. Analysis of C3 deposition and degradation on Neisseria meningitidis and Neisseria gonorrhoeae.

    OpenAIRE

    Jarvis, G A

    1994-01-01

    The deposition and degradation of human complement component C3 on the cell surfaces of Neisseria meningitidis and Neisseria gonorrhoeae were studied. Bacteria were incubated in human serum, and ester-linked C3 fragments were analyzed by hydroxylamine release and immunoblot detection. Similar patterns of C3 degradation were found for both serum-resistant and serum-sensitive meningococcal strains of serogroups A, B, C, Y, and W135, as well as for serum-sensitive gonococcal strains and their si...

  9. A new role for complement C3: regulation of antigen processing through an inhibitory activity.

    OpenAIRE

    Villiers, Christian; Cretin, François,; Lefebvre, Nicole; Marche, Patrice; Villiers, Marie-Bernadette

    2008-01-01

    International audience Increasing evidence underlines the involvement of complement component C3 in the establishment of acquired immunity which appears to play a complex role and to act at different levels. As antigen proteolysis by antigen presenting cells is a key event in the control of antigen presentation efficiency, and consequently in the quality of the immune response, we investigated whether C3 could modulate this step. Our results demonstrate for the first time that C3 can inter...

  10. Activation, binding, and processing of complement component 3 (C3) by Blastomyces dermatitidis.

    OpenAIRE

    Zhang, M X; B. Klein(Ghent University, Ghent, Belgium)

    1997-01-01

    Complement plays a key role in phagocyte recognition and killing of Blastomyces dermatitidis, but little is known about how complement components interact with the yeast. We report the characteristics of activation, binding, and processing of C3 by B. dermatitidis. In pooled normal human serum (NHS), deposition of C3 on the yeast was detectable within 2 min, whereas in NHS containing MgEGTA, deposition was delayed by 6 min, indicating that the yeast activates C3 by both classical and alternat...

  11. The role of complement component C3b and its receptors in sperm-oocyte interaction.

    OpenAIRE

    Anderson, D. J.; Abbott, A F; Jack, R M

    1993-01-01

    Previous studies have shown that human sperm that have undergone the acrosome reaction express a unique tissue-specific variant of the complement component 3 (C3)-binding molecule membrane cofactor protein (MCP, CD46) and that damaged or dead sperm activate the alternative pathway of complement and bind C3 catabolites. In this study we provide evidence that MCP on sperm that have undergone the acrosome reaction specifically binds dimeric C3b and that human sperm acrosomal proteases released d...

  12. In vivo complement activation and binding of C3 to encapsulated Cryptococcus neoformans.

    OpenAIRE

    Truelsen, K; Young, T; Kozel, T R

    1992-01-01

    Tissues from mice infected with Cryptococcus neoformans were examined by immunofluorescence to determine the extent of deposition of complement component C3 on encapsulated cryptococci. The relative percentages of cryptococci in each tissue having readily visible C3 were greatest for liver and lung tissues, with the kidney tissue having the next highest percentage and the spleen having the lowest percentage. Binding of C3 fragments to cryptococci in brain tissue was essentially absent.

  13. Structural basis for the stabilization of the complement alternative pathway C3 convertase by properdin

    OpenAIRE

    Alcorlo, Martín; Tortajada, Agustín; Rodríguez de Córdoba, Santiago; Llorca, Oscar

    2013-01-01

    Complement is an essential component of innate immunity. Its activation results in the assembly of unstable protease complexes, denominated C3/C5 convertases, leading to inflammation and lysis. Regulatory proteins inactivate C3/C5 convertases on host surfaces to avoid collateral tissue damage. On pathogen surfaces, properdin stabilizes C3/C5 convertases to efficiently fight infection. How properdin performs this function is, however, unclear. Using electron microscopy we show that the N- and ...

  14. Collaborative Chronic Care Networks (C3Ns) to Transform Chronic Illness Care

    OpenAIRE

    Margolis, Peter A; Peterson, Laura E.; Seid, Michael

    2013-01-01

    Despite significant gains by pediatric collaborative improvement networks, the overall US system of chronic illness care does not work well. A new paradigm is needed: a Collaborative Chronic Care Network (C3N). A C3N is a network-based production system that harnesses the collective intelligence of patients, clinicians, and researchers and distributes the production of knowledge, information, and know-how over large groups of people, dramatically accelerating the discovery process. A C3N is a...

  15. Structural and friction characteristics of g-C3N4/PVDF composites

    International Nuclear Information System (INIS)

    Highlights: • The graphite-like carbon nitride (g-C3N4) was first used as filler to fill in polymer matrix for the modification of polymer. • The structure, morphology, and thermal properties of g-C3N4/PVDF composites were studied by XRD, FT-IR, SEM, TGA. • The friction characteristics of g-C3N4/PVDF composites were studied under dry sliding conditions. - Abstract: This paper introduced the preparation, structural, and friction characteristics of graphite-like carbon nitride (g-C3N4)/poly(vinylidene difluoride) (PVDF) composites. The g-C3N4/PVDF composites with different g-C3N4 contents were prepared via wet mixing and hot press molding technique. The structure, morphology, thermal properties, and friction characteristics were studied by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), thermo-gravimetric analysis (TGA), and universal micro-tribotester under dry sliding conditions. The XRD and FT-IR studies confirmed the incorporation of g-C3N4 into the PVDF matrix. The SEM results showed good dispersion of g-C3N4 in PVDF matrix. The “onset” temperature To of the composites increased with increasing the content of g-C3N4 filler, which confirmed the enhancement of thermal stability of the composites. The friction characteristics results indicated that small amount of g-C3N4 filler was not beneficial to reduce friction coefficient of the composite while large amount of filler had little effect on it. In addition, the g-C3N4 filler was beneficial to reduce wear loss of the composite, and the wear loss decreased with increasing the content of g-C3N4 filler

  16. Deposition and degradation of C3 on type III group B streptococci.

    OpenAIRE

    Campbell, J R; Baker, C J; Edwards, M S

    1991-01-01

    Antibody to the polysaccharide capsule of type III group B streptococci (GBS) and complement are essential to host defense against systemic infection in neonates. Interactions between C3 degradation products and specific neutrophil receptors mediate the attachment and ingestion of these organisms. To evaluate the influence of capsule on C3 disposition, we compared the C3 fragments released from a highly encapsulated clinical isolate (M861) with those from an unencapsulated mutant (COH 31-15) ...

  17. The chloroplast genome of a symbiodinium sp. clade C3 isolate

    KAUST Repository

    Barbrook, Adrian C.

    2014-01-01

    Dinoflagellate algae of the genus Symbiodinium form important symbioses within corals and other benthic marine animals. Dinoflagellates possess an extremely reduced plastid genome relative to those examined in plants and other algae. In dinoflagellates the plastid genes are located on small plasmids, commonly referred to as \\'minicircles\\'. However, the chloroplast genomes of dinoflagellates have only been extensively characterised from a handful of species. There is also evidence of considerable variation in the chloroplast genome organisation across those species that have been examined. We therefore characterised the chloroplast genome from an environmental coral isolate, in this case containing a symbiont belonging to the Symbiodinium sp. clade C3. The gene content of the genome is well conserved with respect to previously characterised genomes. However, unlike previously characterised dinoflagellate chloroplast genomes we did not identify any \\'empty\\' minicircles. The sequences of this chloroplast genome show a high rate of evolution relative to other algal species. Particularly notable was a surprisingly high level of sequence divergence within the core polypeptides of photosystem I, the reasons for which are currently unknown. This chloroplast genome also possesses distinctive codon usage and GC content. These features suggest that chloroplast genomes in Symbiodinium are highly plastic. © 2013 Adrian C. Barbrook.

  18. Structural transitions of complement component C3 and its activation products

    OpenAIRE

    Nishida, Noritaka; Walz, Thomas; Springer, Timothy A.

    2006-01-01

    Complement sensitizes pathogens for phagocytosis and lysis. We use electron microscopy to examine the structural transitions in the activation of the pivotal protein in the complement pathway, C3. In the cleavage product C3b, the position of the thioester domain moves ≈100 Å, which becomes covalently coupled to antigenic surfaces. In the iC3b fragment, cleavage in an intervening domain creates a long flexible linker between the thioester domain and the macroglobulin domain ring of C3. Studies...

  19. Mutants of complement component C3 cleaved by the C4-specific C1-s protease.

    OpenAIRE

    Mathias, P; Carrillo, C J; Zepf, N E; Cooper, N R; Ogata, R T

    1992-01-01

    To identify some of the structural features determining specific protease recognition of complement components C3 and C4, we used site-specific mutagenesis to construct mutants of murine C3 that are cleaved by the C4-specific C1-s protease. Insertion of three amino acid residues corresponding to residues at the C1-s cleavage site of human C4 into murine C3 at the analogous C3 convertase cleavage site was adequate to render the mutant protein susceptible to C1-s cleavage. In addition, insertio...

  20. Understanding the $\\rm C_3H_2$ cyclic-to-linear ratio in L1544

    CERN Document Server

    Sipilä, O; Caselli, P

    2016-01-01

    Aims. We aim to understand the high cyclic-to-linear $\\rm C_3H_2$ ratio ($32 \\pm 4$) observed toward L1544 by Spezzano et al. (2016). Methods. We combine a gas-grain chemical model with a physical model for L1544 to simulate the column densities of cyclic and linear $\\rm C_3H_2$ observed toward L1544. The most important reactions for the formation and destruction of both forms of $\\rm C_3H_2$ are identified, and their relative rate coefficients are varied to find the best match to the observations. Results. We find that the ratio of the rate coefficients of $\\rm C_3H_3^+ + e^- \\longrightarrow C_3H_2 + H$ for cyclic and linear $\\rm C_3H_2$ must be $\\sim 20$ in order to reproduce the observations, depending on the branching ratios assumed for the $\\rm C_3H_3^+ + e^- \\longrightarrow C_3H + H_2$ reaction. In current astrochemical networks it is assumed that cyclic and linear $\\rm C_3H_2$ are formed in a 1:1 ratio in the aforementioned reactions. Laboratory studies and/or theoretical calculations are needed to con...

  1. Epstein Barr virus/complement C3d receptor is an interferon alpha receptor.

    OpenAIRE

    Delcayre, A X; Salas, F.; Mathur, S; Kovats, K; Lotz, M.; Lernhardt, W

    1991-01-01

    Interferon alpha contains a sequence motif similar to the complement receptor type two (CR2/CD21) binding site on complement fragment C3d. Antibodies against a peptide with the CR2 binding sequence on C3d react with a peptide carrying the IFN alpha CR2 binding motif (residues 92-99) and with recombinant IFN alpha. The IFN alpha-derived peptide, as well as recombinant IFN alpha, inhibits C3bi/C3d interaction with CR2 on the Burkitt lymphoma Raji. The direct interaction of IFN alpha and CR2 is ...

  2. Growth characteristics of primary M7C3 carbide in hypereutectic Fe-Cr-C alloy.

    Science.gov (United States)

    Liu, Sha; Zhou, Yefei; Xing, Xiaolei; Wang, Jibo; Ren, Xuejun; Yang, Qingxiang

    2016-01-01

    The microstructure of the hypereutectic Fe-Cr-C alloy is observed by optical microscopy (OM). The initial growth morphology, the crystallographic structure, the semi-molten morphology and the stacking faults of the primary M7C3 carbide are observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The in-suit growth process of the primary M7C3 carbide was observed by confocal laser microscope (CLM). It is found that the primary M7C3 carbide in hypereutectic Fe-Cr-C alloy is irregular polygonal shape with several hollows in the center and gaps on the edge. Some primary M7C3 carbides are formed by layers of shell or/and consist of multiple parts. In the initial growth period, the primary M7C3 carbide forms protrusion parallel to {} crystal planes. The extending and revolving protrusion forms the carbide shell. The electron backscattered diffraction (EBSD) maps show that the primary M7C3 carbide consists of multiple parts. The semi-molten M7C3 carbide contains unmelted shell and several small-scale carbides inside, which further proves that the primary M7C3 carbide is not an overall block. It is believed that the coalescence of the primary M7C3 carbides is ascribed to the growing condition of the protrusion and the gap filling process. PMID:27596718

  3. C3larvin toxin, an ADP-ribosyltransferase from Paenibacillus larvae.

    Science.gov (United States)

    Krska, Daniel; Ravulapalli, Ravikiran; Fieldhouse, Robert J; Lugo, Miguel R; Merrill, A Rod

    2015-01-16

    C3larvin toxin was identified by a bioinformatic strategy as a putative mono-ADP-ribosyltransferase and a possible virulence factor from Paenibacillus larvae, which is the causative agent of American Foulbrood in honey bees. C3larvin targets RhoA as a substrate for its transferase reaction, and kinetics for both the NAD(+) (Km = 34 ± 12 μm) and RhoA (Km = 17 ± 3 μm) substrates were characterized for this enzyme from the mono-ADP-ribosyltransferase C3 toxin subgroup. C3larvin is toxic to yeast when expressed in the cytoplasm, and catalytic variants of the enzyme lost the ability to kill the yeast host, indicating that the toxin exerts its lethality through its enzyme activity. A small molecule inhibitor of C3larvin enzymatic activity was discovered called M3 (Ki = 11 ± 2 μm), and to our knowledge, is the first inhibitor of transferase activity of the C3 toxin family. C3larvin was crystallized, and its crystal structure (apoenzyme) was solved to 2.3 Å resolution. C3larvin was also shown to have a different mechanism of cell entry from other C3 toxins. PMID:25477523

  4. C3larvin Toxin, an ADP-ribosyltransferase from Paenibacillus larvae*

    Science.gov (United States)

    Krska, Daniel; Ravulapalli, Ravikiran; Fieldhouse, Robert J.; Lugo, Miguel R.; Merrill, A. Rod

    2015-01-01

    C3larvin toxin was identified by a bioinformatic strategy as a putative mono-ADP-ribosyltransferase and a possible virulence factor from Paenibacillus larvae, which is the causative agent of American Foulbrood in honey bees. C3larvin targets RhoA as a substrate for its transferase reaction, and kinetics for both the NAD+ (Km = 34 ± 12 μm) and RhoA (Km = 17 ± 3 μm) substrates were characterized for this enzyme from the mono-ADP-ribosyltransferase C3 toxin subgroup. C3larvin is toxic to yeast when expressed in the cytoplasm, and catalytic variants of the enzyme lost the ability to kill the yeast host, indicating that the toxin exerts its lethality through its enzyme activity. A small molecule inhibitor of C3larvin enzymatic activity was discovered called M3 (Ki = 11 ± 2 μm), and to our knowledge, is the first inhibitor of transferase activity of the C3 toxin family. C3larvin was crystallized, and its crystal structure (apoenzyme) was solved to 2.3 Å resolution. C3larvin was also shown to have a different mechanism of cell entry from other C3 toxins. PMID:25477523

  5. Constellation C3I Crew-Ground-Experimenter-Developer Collaboration Services Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Command, Control, Communications and Information (C3I) environment will be significantly different for Constellation than for Shuttle and International Space...

  6. Two Novel C3N4 Phases: Structural, Mechanical and Electronic Properties

    Directory of Open Access Journals (Sweden)

    Qingyang Fan

    2016-05-01

    Full Text Available We systematically studied the physical properties of a novel superhard (t-C3N4 and a novel hard (m-C3N4 C3N4 allotrope. Detailed theoretical studies of the structural properties, elastic properties, density of states, and mechanical properties of these two C3N4 phases were carried out using first-principles calculations. The calculated elastic constants and the hardness revealed that t-C3N4 is ultra-incompressible and superhard, with a high bulk modulus of 375 GPa and a high hardness of 80 GPa. m-C3N4 and t-C3N4 both exhibit large anisotropy with respect to Poisson’s ratio, shear modulus, and Young’s modulus. Moreover, m-C3N4 is a quasi-direct-bandgap semiconductor, with a band gap of 4.522 eV, and t-C3N4 is also a quasi-direct-band-gap semiconductor, with a band gap of 4.210 eV, with the HSE06 functional.

  7. ELISA for evaluating the incorporation of plasma derived complement split-products C3b/iC3b into solid-phase immune complexes

    DEFF Research Database (Denmark)

    Zimmermann-Nielsen, E; Svehag, S E; Thorlacius-Ussing, O;

    2001-01-01

    An ELISA that measures plasma derived complement (C) split-products C3b/iC3b deposited on solid-phase immune complexes during C activation is described. Plates are coated with BSA, anti-BSA and plasma is added. Deposited C3b/iC3b is then detected by biotinylated anti-C3c-antibodies, avidin......-alkaline phosphatase and para-nitrophenylphosphate. A novel feature is that the assay measures residual C activation capacity rather than in vivo generated C activation products. The assay was applied to plasma from 250 healthy blood donors. No difference in activation capacity of either the alternative (AP) or...... classical pathway (CP) with regard to age or gender was demonstrated. The total coefficient of variation was <5.7%. The ELISA procedure was compared to a standard hemolytic complement CH(50) assay using plasma from 23 out-patients with systemic lupus erythematosus (SLE). There was a weak correlation between...

  8. Monoclonal antibodies against complement 3 neoantigens for detection of immune complexes and complement activation. Relationship between immune complex levels, state of C3, and numbers of receptors for C3b.

    OpenAIRE

    Aguado, M. T.; LAMBRIS, J. D.; Tsokos, G C; de Burger, R; Bitter-Suermann, D.; Tamerius, J D; Dixon, F J; Theofilopoulos, A N

    1985-01-01

    C3-bearing immune complexes and C3 activation products were detected by using two monoclonal antibodies, one specific for a neoantigenic determinant on C3c and the other for C3d. To quantitate immune complexes, the anti-C3c or anti-C3d antibodies were fixed to microtiter plates and reacted with test plasma. The binding of C3-bearing immune complexes in this plasma was then measured with radioisotope- or enzyme-labeled anti-human IgG. To test for C3 breakdown products, solid-phase monoclonal a...

  9. C3 rho-inhibitor for targeted pharmacological manipulation of osteoclast-like cells.

    Directory of Open Access Journals (Sweden)

    Andrea Tautzenberger

    Full Text Available The C3 toxins from Clostridium botulinum (C3bot and Clostridium limosum (C3lim as well as C3-derived fusion proteins are selectively taken up into the cytosol of monocytes/macrophages where the C3-catalyzed ADP-ribosylation of Rho results in inhibition of Rho-signalling and characteristic morphological changes. Since the fusion toxin C2IN-C3lim was efficiently taken up into and inhibited proliferation of murine macrophage-like RAW 264.7 cells, its effects on RAW 264.7-derived osteoclasts were investigated. C2IN-C3lim was taken up into differentiated osteoclasts and decreased their resorption activity. In undifferentiated RAW 264.7 cells, C2IN-C3lim-treatment significantly decreased their differentiation into osteoclasts as determined by counting the multi-nucleated, TRAP-positive cells. This inhibitory effect was concentration- and time-dependent and most efficient when C2IN-C3lim was applied in the early stage of osteoclast-formation. A single-dose application of C2IN-C3lim at day 0 and its subsequent removal at day 1 reduced the number of osteoclasts in a comparable manner while C2IN-C3lim-application at later time points did not reduce the number of osteoclasts to a comparable degree. Control experiments with an enzymatically inactive C3 protein revealed that the ADP-ribosylation of Rho was essential for the observed effects. In conclusion, the results indicate that Rho-activity is crucial during the early phase of osteoclast-differentiation. Other bone cell types such as pre-osteoblastic cells were not affected by C2IN-C3lim. Due to their cell-type selective and specific mode of action, C3 proteins and C3-fusions might be valuable tools for targeted pharmacological manipulation of osteoclast formation and activity, which could lead to development of novel therapeutic strategies against osteoclast-associated diseases.

  10. Hyperglycemic conditions inhibit C3-mediated immunologic control of Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Hair Pamela S

    2012-03-01

    Full Text Available Abstract Background Diabetic patients are at increased risk for bacterial infections; these studies provide new insight into the role of the host defense complement system in controlling bacterial pathogens in hyperglycemic environments. Methods The interactions of complement C3 with bacteria in elevated glucose were assayed for complement activation to opsonic forms, phagocytosis and bacterial killing. C3 was analyzed in euglycemic and hyperglycemic conditions by mass spectrometry to measure glycation and structural differences. Results Elevated glucose inhibited S. aureus activation of C3 and deposition of C3b and iC3b on the bacterial surface. S. aureus-generated C5a and serum-mediated phagocytosis by neutrophils were both decreased in elevated glucose conditions. Interestingly, elevated glucose increased the binding of unactivated C3 to S. aureus, which was reversible on return to normal glucose concentrations. In a model of polymicrobial infection, S. aureus in elevated glucose conditions depleted C3 from serum resulting in decreased complement-mediated killing of E. coli. To investigate the effect of differing glucose concentration on C3 structure and glycation, purified C3 incubated with varying glucose concentrations was analyzed by mass spectrometry. Glycation was limited to the same three lysine residues in both euglycemic and hyperglycemic conditions over one hour, thus glycation could not account for observed changes between glucose conditions. However, surface labeling of C3 with sulfo-NHS-biotin showed significant changes in the surface availability of seven lysine residues in response to increasing glucose concentrations. These results suggest that the tertiary structure of C3 changes in response to hyperglycemic conditions leading to an altered interaction of C3 with bacterial pathogens. Conclusions These results demonstrate that hyperglycemic conditions inhibit C3-mediated complement effectors important in the immunological

  11. Prospects for improving CO2 fixation in C3-crops through understanding C4-Rubisco biogenesis and catalytic diversity.

    Science.gov (United States)

    Sharwood, Robert E; Ghannoum, Oula; Whitney, Spencer M

    2016-06-01

    By operating a CO2 concentrating mechanism, C4-photosynthesis offers highly successful solutions to remedy the inefficiency of the CO2-fixing enzyme Rubisco. C4-plant Rubisco has characteristically evolved faster carboxylation rates with low CO2 affinity. Owing to high CO2 concentrations in bundle sheath chloroplasts, faster Rubisco enhances resource use efficiency in C4 plants by reducing the energy and carbon costs associated with photorespiration and lowering the nitrogen investment in Rubisco. Here, we show that C4-Rubisco from some NADP-ME species, such as maize, are also of potential benefit to C3-photosynthesis under current and future atmospheric CO2 pressures. Realizing this bioengineering endeavour necessitates improved understanding of the biogenesis requirements and catalytic variability of C4-Rubisco, as well as the development of transformation capabilities to engineer Rubisco in a wider variety of food and fibre crops. PMID:27131319

  12. Heritability and expression of C4 photosynthesis in hybrids between C3-C4 and C4 Flaveria

    International Nuclear Information System (INIS)

    In general, leaves of C4 plants are considered to be more efficient at fixing atmospheric CO2 than those of C3 plants. Such efficiency in carbon assimilation is attributed to unique C4 features in anatomy, physiology and biochemistry of leaves. In these studies I investigated whether these C4 characteristics can be inherited and expressed in C3-C4 species through artificial hybridization with C4 species in genus Flaveria. The expression of C4 photosynthesis in the parent C4 parent F. brownii is influenced by the light intensity during growth. Characterization of these F1 hybrids demonstrates that several C4 traits are heritable. The expression of Kranz leaf anatomy, and the activities and/or quantities of key C4 enzymes in the F1 hybrids are intermediate between levels in the parents. Enzyme localization studies with isolated leaf mesophyll and bundle sheath protoplasts indicated that these hybrids lack a complete compartmentation of major photosynthetic enzymes, but they do exhibit a differential distribution of these enzymes between the two cell types. Furthermore, 14CO2 labeling experiments showed that they all possess a high degree of functional C4 photosynthesis, which may in part contribute to the reduced photorespiration observed in the F1 hybrids

  13. 人类补体C3研究进展%Advance in researches on the third component of complement(C3)

    Institute of Scientific and Technical Information of China (English)

    甘慧; 杨军; 孙萍; 王全立

    2004-01-01

    人类补体C3成分是补体激活的经典途径、替代途径以及甘露聚糖结合凝集素(MBL)途径三者的交汇点,是宿主防御机制中占据核心地位的特殊分子.补体C3与其裂解片段构成了人类补体系统的基础框架.现就近年来补体C3基因、蛋白、结合位点以及功能和应用相关的研究进展作一综述.

  14. Evolutionary implications of C3 -C4 intermediates in the grass Alloteropsis semialata.

    Science.gov (United States)

    Lundgren, Marjorie R; Christin, Pascal-Antoine; Escobar, Emmanuel Gonzalez; Ripley, Brad S; Besnard, Guillaume; Long, Christine M; Hattersley, Paul W; Ellis, Roger P; Leegood, Richard C; Osborne, Colin P

    2016-09-01

    C4 photosynthesis is a complex trait resulting from a series of anatomical and biochemical modifications to the ancestral C3 pathway. It is thought to evolve in a stepwise manner, creating intermediates with different combinations of C4 -like components. Determining the adaptive value of these components is key to understanding how C4 photosynthesis can gradually assemble through natural selection. Here, we decompose the photosynthetic phenotypes of numerous individuals of the grass Alloteropsis semialata, the only species known to include both C3 and C4 genotypes. Analyses of δ(13) C, physiology and leaf anatomy demonstrate for the first time the existence of physiological C3 -C4 intermediate individuals in the species. Based on previous phylogenetic analyses, the C3 -C4 individuals are not hybrids between the C3 and C4 genotypes analysed, but instead belong to a distinct genetic lineage, and might have given rise to C4 descendants. C3 A. semialata, present in colder climates, likely represents a reversal from a C3 -C4 intermediate state, indicating that, unlike C4 photosynthesis, evolution of the C3 -C4 phenotype is not irreversible. PMID:26524631

  15. Common evolutionary origin of alpha 2-macroglobulin and complement components C3 and C4

    DEFF Research Database (Denmark)

    Sottrup-Jensen, Lars; Stepanik, T M; Kristensen, Torsten;

    1985-01-01

    A comparison of the sequence of the subunit of human alpha 2-macroglobulin (alpha 2M; 1451 amino acid residues) with that of murine complement component pro-C3 (1639 amino acid residues) reveals eight extended regions of sequence similarity. These regions contain between 19% and 31% identically...... placed residues and account for 75% and 67%, respectively, of the polypeptide chains of alpha 2M and pro-C3. Published sequence data for complement component C4 show that segments of this protein match well with corresponding stretches in alpha 2M and pro-C3. It is proposed that alpha 2M, C3 and C4...... common gross structure. The quartets of basic residues in pro-C3 and pro-C4, at which cleavage takes place to produce the mature subunits of these proteins, and most of the residues forming the anaphylatoxin peptides of C3 and C4 (C3a and C4a) are absent in alpha 2M. In addition, C3 and C4 contain large...

  16. C3 functionalization of indolizines via In(iii)-catalyzed three-component reaction.

    Science.gov (United States)

    Jung, Youngeun; Kim, Ikyon

    2015-12-01

    Post-functionalization at the C3 position of indolizines via In(iii)-catalyzed three-component coupling reaction with amines and aldehydes allowed rapid access to a new class of indolizines with diverse functional groups at the C3 position in good to excellent yields. PMID:26380932

  17. Allele frequencies of the third component of complement (C3) in MS patients.

    OpenAIRE

    Bulman, D E; Armstrong, H; Ebers, G C

    1991-01-01

    No difference was found in the allele frequency of C3 (third component of complement) in 129 multiple sclerosis (MS) patients compared with both 69 controls or with similar reported controls from the published literature. An association cannot be confirmed between C3 and MS.

  18. Modulation of human B cell immunoglobulin secretion by the C3b component of complement.

    Science.gov (United States)

    Tsokos, G C; Berger, M; Balow, J E

    1984-02-01

    The human C3b component of complement was found to inhibit the differentiation of human B lymphocytes into immunoglobulin-secreting cells in vitro. Pokeweed mitogen (PWM)-induced plaque-forming cell (PFC) responses were inhibited by C3-coated zymosan particles and by purified human C3b. C3b inhibited the PWM-driven responses in a dose-dependent fashion, and it was necessary for C3b to be present in the early phases of the cultures. C3b acted directly on B cells rather than on helper T cells because it inhibited the PFC responses of MNC depleted of T cells and subsequently stimulated with a T cell-independent Epstein Barr virus mitogen. Furthermore, C3b failed to stimulate the generation of suppressor lymphocytes and/or monocytes that might have been responsible for the inhibition of B cell responses. Our results indicate that C3b or its fragments exert negative modulatory effects on human B lymphocyte responses. PMID:6228593

  19. Case report 530: Paget disease engrafted on congenitally fused cervical vertebrae (C3-C4)

    International Nuclear Information System (INIS)

    A case of Paget disease in congenitally fused C3 and 4 vertebral bodies is reported. Fusion of C3 and 4 and Paget disease as isolated findings in the cervical spine are both rare. The combination of the two is even rarer. The diagnosis was confirmed by a core biopsy of the lamina. (orig.)

  20. Final Hazard Categorization for the Remediation of the 116-C-3 Chemical Waste Tanks

    Energy Technology Data Exchange (ETDEWEB)

    T. M. Blakley; W. D. Schofield

    2007-09-10

    This final hazard categorization (FHC) document examines the hazards, identifies appropriate controls to manage the hazards, and documents the commitments for the 116-C-3 Chemical Waste Tanks Remediation Project. The remediation activities analyzed in this FHC are based on recommended treatment and disposal alternatives described in the Engineering Evaluation for the Remediation to the 116-C-3 Chemical Waste Tanks (BHI 2005e).

  1. Electronic and Rovibrational Quantum Chemical Analysis of C$_3$P$^-$: The Next Interstellar Anion?

    CERN Document Server

    Fortenberry, Ryan C

    2015-01-01

    C$_3$P$^-$ is analogous to the known interstellar anion C$_3$N$^-$ with phosphorus replacing the nitrogen in a simple step down the periodic table. In this work, it is shown that C$_3$P$^-$ is likely to possess a dipole-bound excited state. It has been hypothesized and observationally supported that dipole-bound excited states are an avenue through which anions could be formed in the interstellar medium. Additionally, C$_3$P$^-$ has a valence excited state that may lead to further stabilization of this molecule, and C$_3$P$^-$ has a larger dipole moment than neutral C$_3$P ($\\sim 6$ D vs. $\\sim 4$ D). As such, C$_3$P$^-$ is probably a more detectable astromolecule than even its corresponding neutral radical. Highly-accurate quantum chemical quartic force fields are also applied to C$_3$P$^-$ and its singly $^{13}$C substituted isotopologues in order to provide structures, vibrational frequencies, and spectroscopic constants that may aid in its detection.

  2. Electronic and rovibrational quantum chemical analysis of C3P-: the next interstellar anion?

    Science.gov (United States)

    Fortenberry, Ryan C.; Lukemire, Joseph A.

    2015-11-01

    C3P- is analogous to the known interstellar anion C3N- with phosphorus replacing nitrogen in a simple step down the periodic table. In this work, it is shown that C3P- is likely to possess a dipole-bound excited state. It has been hypothesized and observationally supported that dipole-bound excited states are an avenue through which anions could be formed in the interstellar medium. Additionally, C3P- has a valence excited state that may lead to further stabilization of this molecule, and C3P- has a larger dipole moment than neutral C3P (˜6 D versus ˜4 D). As such, C3P- is probably a more detectable astromolecule than even its corresponding neutral radical. Highly accurate quantum chemical quartic force fields are also applied to C3P- and its singly 13C substituted isotopologues in order to provide structures, vibrational frequencies, and spectroscopic constants that may aid in its detection.

  3. First-principles calculations on Mg/Al4C3 interfaces

    International Nuclear Information System (INIS)

    In order to explore the interfacial structure of Mg/Al4C3 interface and clarify the heterogeneous nucleation potential of Al4C3 particles in Mg melt. The atomic structure, bonding, and interfacial energy of Mg/Al4C3 interfaces were studied by first-principles calculations to analyze the sequence of Mg atoms onto the surface of Al4C3 (0 0 0 1) slab. Surface energy calculations show that the outmost layer of Al4C3 free surface having a preference of C atom termination. And polar covalent/ionic mixed bonds are formed across interface during the combination of Mg atoms with C-terminated Al4C3 surface. The calculated interfacial energy of Mg/Al4C3 interface is much smaller than that between α-Mg and magnesium melts, proving the excellent nucleation potency of Al4C3 particles for α-Mg grains from interfacial atomic structure and atomic bonding energy considerations.

  4. 26 CFR 1.669(c)-3A - Information requirements with respect to beneficiary.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 8 2010-04-01 2010-04-01 false Information requirements with respect to beneficiary. 1.669(c)-3A Section 1.669(c)-3A Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE... respect to beneficiary. (a) Information to be supplied by beneficiary—(1) Use of exact method....

  5. On localized tachyon condensation in C2/Zn and C3/Zn

    International Nuclear Information System (INIS)

    We study some aspects of localized tachyon condensation on non-supersymmetric orbifolds of the form C2/Zn and C3/Zn. We discuss the gauged linear sigma models for these orbifolds. We show how several features of the decay of orbifolds of C3 can be realised in terms of orbifolds of C2

  6. Unique role of the complement receptor CR1 in the degradation of C3b associated with immune complexes

    OpenAIRE

    1982-01-01

    The main finding of this paper is that CR1, the membrane receptor for C3b and C4b, together with C3b/C4b-inactivator (I), degrades C3b bound to immune complexes (C3b*). Two fragments are generated: C3c, which is released from the immune complexes, and C3d*. The C3c fragment released from the cell intermediate EAC1423b prepared with 125I-C3 was analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and radioautography. It has a 135,000 mol wt and contains disulfide bo...

  7. 补体C3促进HIV-1感染的作用%Complement C3-Mediated Enhancement of Human Immunodeficiency Virus Type 1 Infection

    Institute of Scientific and Technical Information of China (English)

    李鑫鑫; 徐元勇

    2015-01-01

    补体是天然免疫的重要组成部分.C3是补体经典途径、旁路途径及甘露糖结合凝集素(MBL)途径的共同通路,在补体清除1型人免疫缺陷病毒(HIV-1)的过程中发挥重要作用.同时,C3在促进病毒黏膜进入、传播与储存、感染免疫细胞等方面也起重要作用.

  8. Complement C3-Deficient Mice Fail to Display Age-Related Hippocampal Decline.

    Science.gov (United States)

    Shi, Qiaoqiao; Colodner, Kenneth J; Matousek, Sarah B; Merry, Katherine; Hong, Soyon; Kenison, Jessica E; Frost, Jeffrey L; Le, Kevin X; Li, Shaomin; Dodart, Jean-Cosme; Caldarone, Barbara J; Stevens, Beth; Lemere, Cynthia A

    2015-09-23

    The complement system is part of the innate immune response responsible for removing pathogens and cellular debris, in addition to helping to refine CNS neuronal connections via microglia-mediated pruning of inappropriate synapses during brain development. However, less is known about the role of complement during normal aging. Here, we studied the role of the central complement component, C3, in synaptic health and aging. We examined behavior as well as electrophysiological, synaptic, and neuronal changes in the brains of C3-deficient male mice (C3 KO) compared with age-, strain-, and gender-matched C57BL/6J (wild-type, WT) control mice at postnatal day 30, 4 months, and 16 months of age. We found the following: (1) region-specific and age-dependent synapse loss in aged WT mice that was not observed in C3 KO mice; (2) age-dependent neuron loss in hippocampal CA3 (but not in CA1) that followed synapse loss in aged WT mice, neither of which were observed in aged C3 KO mice; and (3) significantly enhanced LTP and cognition and less anxiety in aged C3 KO mice compared with aged WT mice. Importantly, CA3 synaptic puncta were similar between WT and C3 KO mice at P30. Together, our results suggest a novel and prominent role for complement protein C3 in mediating aged-related and region-specific changes in synaptic function and plasticity in the aging brain. Significance statement: The complement cascade, part of the innate immune response to remove pathogens, also plays a role in synaptic refinement during brain development by the removal of weak synapses. We investigated whether complement C3, a central component, affects synapse loss during aging. Wild-type (WT) and C3 knock-out (C3 KO) mice were examined at different ages. The mice were similar at 1 month of age. However, with aging, WT mice lost synapses in specific brain regions, especially in hippocampus, an area important for memory, whereas C3 KO mice were protected. Aged C3 KO mice also performed better on

  9. A novel polymorphism of human complement component C3 detected by means of a monoclonal antibody

    DEFF Research Database (Denmark)

    Koch, C; Behrendt, N

    1986-01-01

    A mouse monoclonal antibody, HAV 4-1, obtained after immunization of a BALB/c mouse with purified C3F, detected a novel genetic polymorphism of human complement component C3 in a simple immunoblotting system. The frequency of HAV 4-1-positive genes was 20.1%. Reactivity of HAV 4-1 was closely...... related to C3F, but certain individuals with the C3F allele did not react with HAV 4-1. Conversely, certain C3S homozygous individuals did react with HAV 4-1. The polymorphism detected by this monoclonal antibody is therefore different from the previously described polymorphism based on charge differences....

  10. C3 polymorphism in a Danish cystic fibrosis population and its possible association with antibody response

    DEFF Research Database (Denmark)

    Schiøtz, P O; Høiby, N; Morling, N;

    1978-01-01

    The C3 types of human serum are reported for a material of 113 Danish cystic fibrosis patients, age 0-30 years. The frequency of the C3F gene was 0.2832 which was significantly higher (p less than 0.0005) than the frequency found in a control group of 224 healthy babies (C3F = 0.1585). It also...... differed significantly (p less than 0.01) from the C3F gene frequency of 0.1780 found in 177 blood donors, age 20-24 years. A significant association between any of the C3 phenotypes and the most serious infection in cystic fibrosis, chronic mucoid P. aeruginosa infection, or the antibody response against...

  11. Rare bilateral C3 cervical spondylolysis:Report of four cases and a literature review

    Institute of Scientific and Technical Information of China (English)

    Huaiyu Tong; Hongzhen Jiang; Xinguang Yu; Yuanzheng Zhang

    2015-01-01

    Objective:To review and discuss the etiology, diagnosis and treatment C3 of bilateral cervical spondylolysis. Methods:This was a retrospective review of the clinical features, imaginge findings, and treatment of 4 cases of bilateral C3 cervical spondylolysis, with a review of the literature. Results:A 21‐year‐old woman, a 26‐year‐old man, a 14‐year‐old boy, and a 46‐year‐old man were diagnosed with bilateral C3 cervical spondylolysis. The patients had characteristic bilateral clefts between the articular pillar and the facets of C3, as well as spina bifida on CT. Although spondylolisthesis was not observed, spinal cord compression was definitive. All patients underwent posterior decompression with satisfactory results. Conclusions:C3 cervical spondylolysis is rare condition. The cause is most likely congenital. Diagnosis is dependent on characteristic radiological features. Surgical treatment is the first choice.

  12. A Graphitic-C3N4 "Seaweed" Architecture for Enhanced Hydrogen Evolution.

    Science.gov (United States)

    Han, Qing; Wang, Bing; Zhao, Yang; Hu, Chuangang; Qu, Liangti

    2015-09-21

    A seaweed-like graphitic-C3N4 (g-C3N4 "seaweed") architecture has been prepared by direct calcination of the freeze-drying-assembled, hydrothermally treated dicyandiamide fiber network. The seaweed network of mesoporous g-C3N4 nanofibers is favorable for light harvesting, charge separation and utilization of active sites, and has highly efficient photocatalytic behavior for water splitting. It exhibits a high hydrogen-evolution rate of 9900 μmol h(-1) g(-1) (thirty times higher than that of its g-C3N4 bulk counterpart), and a remarkable apparent quantum efficiency of 7.8% at 420 nm, better than most of the g-C3N4 nanostructures reported. This work presents a very simple method for designing and developing high-performance catalysts for hydrogen evolution. PMID:26212211

  13. Shock wave study of the thermal dissociations of C3F6 and c-C3F6. I. dissociation of hexafluoropropene.

    Science.gov (United States)

    Cobos, C J; Sölter, L; Tellbach, E; Troe, J

    2014-07-10

    The thermal dissociation of C3F6 was studied between 1330 and 2210 K in shock waves monitoring the UV absorption of CF2. CF2 yields of about 2.6 per parent C3F6 were obtained at reactant concentrations of 500-1000 ppm in the bath gas Ar. These yields dropped to about 1.8 when reactant concentrations were lowered to 60 ppm. The increase of the CF2 yield with increasing concentration was attributed to bimolecular reactions between primary and secondary dissociation products. Quantum-chemical and kinetic modeling calculations helped to estimate the contributions from the various primary dissociation steps. It was shown that the measurements correspond to unimolecular reactions in their falloff range. Falloff representations of the rate constants are given, leading to an overall high pressure rate constant k∞ = 2.0 × 10(17)(-104 kcal mol(-1)/RT) s(-1) and a relative rate of about 2/3:1/3 for the reactions C3F6 → CF3CF + CF2 versus C3F6 → C2F3 + CF3. PMID:24905383

  14. 298 K rate coefficients for the reaction of OH with i-C3H7I, n-C3H7I and C3H8

    Directory of Open Access Journals (Sweden)

    J. N. Crowley

    2001-09-01

    Full Text Available The kinetics of the title reactions were investigated using the laser photolysis - resonance fluorescence method, employing the sequential two-photon dissociation of NO2 in the presence of H2 as the OH source. The 298 K rate constant for OH + C3H8 was found to be (1.15±0.1 × 10-12 cm3 s-1, in excellent agreement with the literature recommendation, and with a separate determination using HNO3 photolysis at 248 nm as the OH source. The 298 K rate constants for OH + n-C3H7I and i-C3H7I were measured for the first time and found to be (1.47±0.08 and (1.22±0.06 × 10-12 cm3 s-1, respectively. The errors include an assessment of systematic error due to concentration measurement, which, for the propyl-iodides was minimised by on-line UV-absorption spectroscopy. The implications of these results for the reactive iodine budget of the marine boundary layer are discussed.

  15. Therapeutic control of complement activation at the level of the central component C3.

    Science.gov (United States)

    Ricklin, Daniel; Lambris, John D

    2016-06-01

    The increasing recognition of the complement system's association with diseases of the inflammatory spectrum and with biomaterial and transplant-related complications has generated growing interest in the therapeutic modulation of this innate immune cascade. As a central functional hub that largely drives the activation, amplification, and effector generation of the complement response, the plasma protein C3 has long been recognized as an attractive target. While pharmacological modulation of C3 activation may offer a powerful opportunity to interfere with or even prevent complement-driven pathologies, the development of C3 inhibitors has often been accompanied by concerns regarding the safety and feasibility of this approach. Although no C3-targeted inhibitors have thus far been approved for clinical use, several promising concepts and candidates have emerged in recent years. At the same time, experiences from preclinical development and clinical trials are slowly providing a more detailed picture of therapeutic complement inhibition at the level of C3. This review highlights the current therapeutic strategies to control C3 activation and discusses the possibilities and challenges on the road to bringing C3-targeted therapeutics to the clinic. PMID:26101137

  16. C3 glomerulonephritis: a new category of glomerulonephritis with etiopathogenic implications

    Directory of Open Access Journals (Sweden)

    Taborda Murillo, Alejandra

    2015-01-01

    Full Text Available Introduction: Glomerulonephritis with only deposits of C3 (GN-C3 could involve alteration on the complement alternative pathway.Objective: To describe retrospectively a series of GNC3 cases and to determine the frequency with which patients continue with renal alterations and/or hypocomplementemia. Methods: The 22 cases of GN-C3 diagnosed between 2004 and 2012 at the Department of Pathology, Faculty of Medicine, University of Antioquia (Medellin, Colombia were included. Their histological and clinical characteristics and their outcome were evaluated. Results: 14 patients were children and 12 were males. Mean age was 13 years (range: 3-65. Ten presented as a nephritic syndrome, seven as a rapidly progressive GN, three as acute renal failure, one as chronic renal failure, and one as a nephrotic-nephritic syndrome. The C3 fraction of complement was low in 21 cases. All biopsies showed proliferative GN. There was complete remission in eight patients, persistent urinalysis alterations in four, chronic renal failure in six, five of them end- stage. No follow-up was done in four. In nine patients follow-up determination of C3 serum levels was done; in all of them they normalized between 1 to 3 months after biopsy. Conclusions: GN-C3 can produce persistent or recurrent kidney alterations and end-stage renal disease. Long-term follow-up with repeated determinations of C3 is advisable.

  17. C3d enhanced DNA vaccination induced humoral immune response to glycoprotein C of pseudorabies virus

    International Nuclear Information System (INIS)

    Murine C3d were utilized to enhance immunogenicity of pseudorabies virus (PrV) gC DNA vaccination. Three copies of C3d and four copies of CR2-binding domain M284 were fused, respectively, to truncated gC gene encoding soluble glycoprotein C (sgC) in pcDNA3.1. BALB/c mice were, respectively, immunized with recombinant plasmids, blank vector, and inactivated vaccine. The antibody ELISA titer for sgC-C3d3 DNA was 49-fold more than that for sgC DNA, and the neutralizing antibody obtained 8-fold rise. Protection of mice from death after lethal PrV (316 LD5) challenge was augmented from 25% to 100%. Furthermore, C3d fusion increased Th2-biased immune response by inducing IL-4 production. The IL-4 level for sgC-C3d3 DNA immunization approached that for the inactivated vaccine. Compared to C3d, M28 enhanced sgC DNA immunogenicity to a lesser extent. In conclusion, we demonstrated that murine C3d fusion significantly enhanced gC DNA immunity by directing Th1-biased to a balanced and more effective Th1/Th2 response

  18. Differential freezing resistance and photoprotection in C3 and C4 eudicots and grasses.

    Science.gov (United States)

    Liu, Mei-Zhen; Osborne, Colin P

    2013-05-01

    Globally, C4 plants dominate hot, open environments, but this general pattern is underpinned by important differences in the biogeography of C4 lineages. In particular, the species richness of C4 Poaceae (grasses) increases strongly with increasing temperature, whereas that of the major C4 eudicot group Chenopodiaceae correlates positively with aridity. Freezing tolerance is a crucial determinant of biogeographical relationships with temperature and is mediated by photodamage and cellular disruption by desiccation, but little is known about differences between C4 families. This study hypothesized that there is a greater risk of freezing damage via these mechanisms in C4 Poaceae than Chenopodiaceae, that freezing protection differs between the taxonomic groups, and that freezing tolerance of species is linked to arid habitat preference. Chlorophyll fluorescence, water relations, and freezing injury were compared in four C3 and six C4 species of Poaceae and Chenopodiaceae from the same Mongolian flora. Contrary to expectations, freezing-induced leaf mortality and photodamage were lower in Poaceae than Chenopodiaceae species, and unrelated to photosynthetic pathway. The freezing resistance of Poaceae species resulted from constitutive protection and cold acclimation and an ability to protect the photosynthetic apparatus from photodamage. Freezing protection was associated with low osmotic potential and low tissue elasticity, and freezing damage was accompanied by electrolyte leakage, consistent with cell-membrane disruption by ice. Both Chenopodiaceae and Poaceae had the potential to develop cold acclimation and withstand freezing during the growing season, which conflicted with the hypothesis. Instead, freezing tolerance was more closely associated with life history and ecological preference in these Mongolian species. PMID:23599273

  19. Mesangial C3 deposition and decreased serum C3 levels in patients with IgA nephropathy%补体C3系膜区沉积与低C3血症在IgA肾病中的意义

    Institute of Scientific and Technical Information of China (English)

    章晓炎; 谢静远; 王伟铭; 王朝晖; 潘晓霞; 沈平雁; 徐静; 郝旭; 周琼秀

    2014-01-01

    目的 对IgA肾病(IgAN)患者的临床及病理资料进行分析,旨在探讨补体活化在IgAN中的意义,为临床治疗提供依据.方法 回顾性分析本院确诊的原发性IgAN患者,记录患者基线一般情况、临床指标、病理学检查及随访结果.根据免疫荧光下补体C3在系膜区沉积情况,分为阴性、弱阳性、强阳性3组,血C3降低组的定义为血清C3< 85 mg/dl.结果 本研究纳入528例患者,平均随访3年.肾组织C3沉积阴性组、弱阳性组、强阳性组患者分别为119例(22.5%)、164例(31.1%)和245例(46.4%);血C3降低组患者93例(21.7%),血C3正常组335例(78.3%);系膜区C3沉积与血清C3水平呈负相关(r=-0.209,P<0.01);不同肾组织C3沉积组间年龄、性别差异无统计学意义;随肾组织C3沉积加重,患者基线血肌酐、尿酸、血IgA水平升高,估算肾小球滤过率(eGFR)、体质量指数(BMI)降低(P<0.05),C3沉积较多的患者肾组织毛细血管内细胞增生和肾小管萎缩、肾间质纤维化更为严重(P< 0.05).与血C3正常组比较,血C3降低组患者白细胞、血红蛋白、三酰甘油、胆固醇、eGFR水平较低,而血肌酐水平较高(P<0.05).随访期间,共有54例患者进入终末期肾病(ESRD),血C3降低组ESRD发生率为23.7%,正常组为8.4%,Kaplan-Meier分析显示血C3降低组肾脏中位生存时间显著低于C3正常组[(145.0±22.5)个月比(150.8±17.0)个月,P<0.01].Cox回归分析显示,校正性别、年龄和临床指标(平均动脉压、eGFR、白蛋白、尿蛋白、血红蛋白水平)后,血清C3降低(HR=0.97,95%CI 0.96,0.99,P<0.01)为患者进入ESRD的独立危险因素.结论 IgAN患者存在不同程度补体系统活化,补体活化与患者基础肾功能及临床预后相关,血清C3下降为患者进入ESRD的独立危险因素,提示补体活化可能参与IgAN的进程.%Objective To explore the clinical significance of complement activation in IgA nephropathy (Ig

  20. Synthesis and propagation of complement C3 by microglia/monocytes in the aging retina.

    Directory of Open Access Journals (Sweden)

    Matt Rutar

    Full Text Available INTRODUCTION: Complement activation is thought to contribute to the pathogenesis of age-related macular degeneration (AMD, which may be mediated in part by para-inflammatory processes. We aimed to investigate the expression and localization of C3, a crucial component of the complement system, in the retina during the course of aging. METHODS: SD rats were born and reared in low-light conditions, and euthanized at post-natal (P days 100, 450, or 750. Expression of C3, IBA1, and Ccl- and Cxcl- chemokines was assessed by qPCR, and in situ hybridization. Thickness of the ONL was assessed in retinal sections as a measure of photoreceptor loss, and counts were made of C3-expressing monocytes. RESULTS: C3 expression increased significantly at P750, and correlated with thinning of the ONL, at P750, and up-regulation of GFAP. In situ hybridization showed that C3 was expressed by microglia/monocytes, mainly from within the retinal vasculature, and occasionally the ONL. The number of C3-expressing microglia increased significantly by P750, and coincided spatiotemporally with thinning of the ONL, and up-regulation of Ccl- and Cxcl- chemokines. CONCLUSIONS: Our data suggest that recruited microglia/monocytes contribute to activation of complement in the aging retina, through local expression of C3 mRNA. C3 expression coincides with age-related thinning of the ONL at P750, although it is unclear whether the C3-expressing monocytes are a cause or consequence. These findings provide evidence of activation of complement during natural aging, and may have relevance to cellular events underling the pathogenesis of age-related retinal diseases.

  1. Climate controls on C3 vs. C4 productivity in North American grasslands from carbon isotope composition of soil organic matter

    Science.gov (United States)

    von Fischer, J.C.; Tieszen, L.L.; Schimel, D.S.

    2008-01-01

    We analyzed the ??13 C of soil organic matter (SOM) and fine roots from 55 native grassland sites widely distributed across the US and Canadian Great Plains to examine the relative production of C3 vs. C4 plants (hereafter %C4) at the continental scale. Our climate vs. %C4 results agreed well with North American field studies on %C4, but showed bias with respect to %C4 from a US vegetation database (statsgo) and weak agreement with a physiologically based prediction that depends on crossover temperature. Although monthly average temperatures have been used in many studies to predict %C4, our analysis shows that high temperatures are better predictors of %C4. In particular, we found that July climate (average of daily high temperature and month's total rainfall) predicted %C4 better than other months, seasons or annual averages, suggesting that the outcome of competition between C3 and C4 plants in North American grasslands was particularly sensitive to climate during this narrow window of time. Root ??13 C increased about 1??? between the A and B horizon, suggesting that C 4 roots become relatively more common than C3 roots with depth. These differences in depth distribution likely contribute to the isotopic enrichment with depth in SOM where both C3 and C4 grasses are present. ?? 2008 The Authors Journal compilation ?? 2008 Blackwell Publishing Ltd.

  2. Effects of mannitol induced osmotic stress on proline accumulation, pigment degradation, photosynthetic abilities and growth characters in C3 rice and C4 sorghum

    Institute of Scientific and Technical Information of China (English)

    Suriyan CHA-UM; Souvanh THADAVONG; Chalermpol KIRDMANEE

    2009-01-01

    Osmotic stress is one of the most important abiotic factors which inhibit growth and development in both the vegetative and reproductive stages of many plant species. The aim of this investigation was to compare the biochemical and physiological responses in C3 rice and C4 sorghum to water deficit. Chlorophyll a (Chla), chlorophyll b (Chlb), total chlorophyll (TC) and total carotenoid (Cx+c) contents in both rice and sorghum seedlings under osmotic stress were adversely affected, related to increasing osmotic pressure in the culture media. In addition, the chlorophyll's fluorescence parameters and net photosynthetic rate (Pn) decreased, leading to growth reduction. Also, a positive correlation was found between physiological and biochemical data, while proline accumulation showed a negative relationship. The Chlb, Pn and fresh weight were maintained better in osmotic-stressed (-1.205 MPa) C4 sorghum seedlings than those in C3 rice seedlings. The growth and physiological responses of C3 rice and C4 sorghum decreased depending on the plant species, the osmotic pressure in the media and their interactions. Pigment content and Pn ability in C4 sorghum grown under mannitol-induced osmotic stress increased to a greater degree than in C3 rice, resulting in maintenance of growth.

  3. A rare case of complete C2–C3 dislocation with mild neurological symptoms

    OpenAIRE

    Machinis, Theofilos G.; Kostas N. Fountas; Kapsalaki, E. Z.; Kapsalakis, I.; Grigorian, A A.

    2006-01-01

    The authors report a rare case of complete C2–C3 dislocation with unexpectedly mild neurological symptoms in a 57 year old man involved in a motor vehicle accident, who had previously undergone posterior laminectomy from C3 through C7. A retrospective chart analysis and a thorough radiographic review were performed. X-rays and CT of the cervical spine demonstrated a complete dislocation at the C2–C3 level. Computed tomographic angiography revealed disruption of both vertebral arteries; howeve...

  4. Understanding the $\\rm C_3H_2$ cyclic-to-linear ratio in L1544

    OpenAIRE

    Sipilä, O.; Spezzano, S.; Caselli, P.

    2016-01-01

    Aims. We aim to understand the high cyclic-to-linear $\\rm C_3H_2$ ratio ($32 \\pm 4$) observed toward L1544 by Spezzano et al. (2016). Methods. We combine a gas-grain chemical model with a physical model for L1544 to simulate the column densities of cyclic and linear $\\rm C_3H_2$ observed toward L1544. The most important reactions for the formation and destruction of both forms of $\\rm C_3H_2$ are identified, and their relative rate coefficients are varied to find the best match to the observa...

  5. Thermomagnetic analysis of meteorites. 3: C3 and C4 chondrites

    Science.gov (United States)

    Herndon, J. M.; Rowe, M. W.; Larson, E. E.; Watson, D. E.

    1974-01-01

    Thermomagnetic analysis on all of the C3 and C4 chondrites, conducted under conditions of controlled oxygen fugacity, indicates the presence of a thermally unstable component in at least 5 of the C3 chondrites which upon heating results in magnetite production. This unstable component is most likely troilite (FeS). The presence of the unstable substance may affect the estimation of paleointensities in meteorites which contain it. Our results indicate that Grosnaja, Ornans, Kainsaz, Felix, and Warrenton are likely to be less complicated for paleointensity determinations than the other C3 chondrites. Both C4 chondrites should lead to reliable results.

  6. Early C3A hydration in the presence of different kinds of calcium sulfate.

    OpenAIRE

    Pourchet, Sylvie; Regnaud, Laure; Perez, Jean-Philippe; Nonat, André

    2009-01-01

    Hydration reactions of C3A with various amounts of calcium sulfate hemihydrate, gypsum or a mixture of two, were investigated by isothermal microcalorimetry, and a monitoring of the ionic concentrations of diluted suspensions. This study shows that sulfate type used modifies the early C3A-CaSO4 hydration products and the rate of this hydration. The fast initial AFm formation observed before ettringite precipitation in the C3A-gypsum system is avoided as soon as hemihydrate is present in the s...

  7. Analysis of cubic and orthorhombic C3A hydration in presence of gypsum and lime

    OpenAIRE

    Kirchheim, A. P.; Fernàndez-Altable, V.; Monteiro, P. J.; Dal Molin, D. C.; Casanova, I.

    2009-01-01

    Field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) have been used to study the microstructural changes and phase development that take place during the hydration of cubic (pure) and orthorhombic (Na-doped) tricalcium aluminate (C3A) and gypsum in the absence and presence of lime. The results demonstrate that important differences occur in the hydration of each C3A polymorph and gypsum when no lime is added; orthorhombic C3A reacts faster with gypsum than the cubi...

  8. Structural properties of the sesquicarbide superconductor La2C3 at high pressure

    OpenAIRE

    X Wang; Loa, I.; Syassen, K.; Kremer, R. K.; Simon, A; Hanfland, M; Ahn, K.

    2005-01-01

    The effect of pressure on the structural properties of lanthanum sesquicarbide La2C3 (T_c = 13 K) has been investigated at room temperature by angle-dispersive powder x-ray diffraction in a diamond anvil cell. The compound remains in the cubic Pu2C3-type structure at pressures up to at least 30 GPa. The corresponding equation of state parameters are reported and discussed in terms of phase stability of La2C3. Pressure-volume data of the impurity phase LaC2 are reported also for pressures up t...

  9. Detection of Interstellar C_2 and C_3 in the Small Magellanic Cloud

    OpenAIRE

    Welty, Daniel E.; Howk, J. Christopher; Lehner, Nicolas; Black, John H.

    2012-01-01

    We report the detection of absorption from interstellar C_2 and C_3 toward the moderately reddened star Sk 143, located in the near 'wing' region of the SMC, in optical spectra obtained with the ESO VLT/UVES. These detections of C_2 (rotational levels J=0-8) and C_3 (J=0-12) absorption in the SMC are the first beyond our Galaxy. The total abundances of C_2 and C_3 (relative to H_2) are similar to those found in diffuse Galactic molecular clouds -- as previously found for CH and CN -- despite ...

  10. Loss of Properdin Exacerbates C3 Glomerulopathy Resulting from Factor H Deficiency

    OpenAIRE

    Ruseva, Marieta M.; Vernon, Katherine A.; Lesher, Allison M; Schwaeble, Wilhelm J.; Youssif M Ali; Botto, Marina; Cook, Terence; Song, Wenchao; Stover, Cordula M.; Pickering, Matthew Caleb

    2012-01-01

    Complement factor H (CFH) is a negative regulator of the alternative pathway of complement, and properdin is the sole positive regulator. CFH-deficient mice (CFH−/−) develop uncontrolled C3 activation and spontaneous renal disease characterized by accumulation of C3 along the glomerular basement membrane, but the role of properdin in the pathophysiology is unknown. Here, we studied mice deficient in both CFH and properdin (CFH−/−.P−/−). Although CFH−/− mice had plasma depleted of both C3 and ...

  11. A novel third complement component C3 gene of Ciona intestinalis expressed in the endoderm at the early developmental stages

    OpenAIRE

    Hibino, T.; Nonaka, M

    2013-01-01

    The third complement component (C3) in ascidian was reported to function as an opsonin to enhance phagocytosis and as a chemotactic factor for phagocytes, indicating that ascidian C3 works in mesodermal cavity as a humoral factor like vertebrate C3s. In the basal Eumetazoa, Cnidaria lacking mesodermal tissues, C3 was reported to work in an endodermal cavity. Evolution of structure and function of C3 is still to be clarified. Here we report the identification of the third C3 gene, CiC3-3, in t...

  12. The structure of an alternate form of complement C3 that displays costimulatory growth factor activity for B lymphocytes

    OpenAIRE

    1994-01-01

    In this study, the structure of a novel 1.9-kb transcript coding for complement component 3 (C3) is described. This alternate C3 is identical to the 3' end of the C3 message beginning at position 3300 of the C3 cDNA. Its transcription appears to be driven by an alternate promoter located within intron 8 of the C3 gene. This alternate C3 message contains an open reading frame that may encode a 536-amino acid- long protein identical to the 3' part of the C3 alpha chain. The resulting protein co...

  13. Natural gas C3-C8 Hydrocarbon Enrichment Analysis Methods%天然气C3-C8烃类浓缩分析新方法

    Institute of Scientific and Technical Information of China (English)

    杨晓春; 王璋

    2015-01-01

    天然气形成的原因,但在一般情况下,天然气和油的成因是不同的,在天然气中,所用的有用信息数量不多。根据这一情况,自己配制了以C3—C8烃为主的天然气浓缩器,而当场就可以去井口搜集天然气的、浓缩的样品,在此基础上,形成了以天然气C3—C8烃为主的浓缩方法。对于该方法,能把天然气中的C3—C8烃类物质分析出来,从而完成了任务,即对天然气组分不多、气源相对不易,这是一个新的思路、方法,值得我们学习。%The causes of the formation of natural gas,but in general,the causes of natural gas an d oil are different,in natural gas,the small number of useful information.According to this situation,make myself a predominantly C3 - C8 hydrocarbon gas concentrator,and can go on the wellhead collecting gas,concentration of sample,on this basis,formed mainly gas C3 - C8 hydrocarbon enrichment method.For the method,can change the C3 - C8 hydrocarbons in natural gas analysis,so as to complete the task,namely a few components of natural gas,gas source is relatively difficult,this is a new train of thought,method and worth our learning.

  14. Complement-mediated solubilization of immune complexes and their interaction with complement C3 receptors

    DEFF Research Database (Denmark)

    Petersen, Ivan; Baatrup, Gunnar; Jepsen, H H;

    1985-01-01

    membrane attack complex do not participate in the reaction. Besides affecting the size and solubility of circulating IC the interaction with C factors influences the reactivities of the complexes towards fluid phase reactants and mediates the reversible binding of IC to cellular C3 receptors. Our knowledge...... of the cellular localization, expression and structure of the C3 receptors, especially the C3b (CR1) receptor, has been considerably extended in the last few years, whereas our understanding of the physiological role of these receptors is still fragmentary. However, it is becoming increasingly...... evident that impaired solubilization of IC in patients with compromised C function may permit the complexes to deviate from their normal pattern of interaction with C3 receptors probably influencing both the organ distribution and clearance of IC and thereby also their phlogistic potentials....

  15. Generation of tritiated methane using a CuO-Al4C3 bed

    International Nuclear Information System (INIS)

    With the supply of a constant flow rate of hydrogen with a constant tritium concentration to a CuO-Al4C3 bed at 573 K, methane with a constant radioactivity was generated at a high conversion ratio. Although tritiated methane was conventionally generated using a set of tritiated water vapor bubbler and an Al4C3 bed, its tritium radioactivity was limited by the saturated water vapor pressure and was dropped by a large decrease in density when water was vaporized. The present CuO-Al4C3 bed can substantially eliminate its limit because of the successive conversion from hydrogen to methane using a CuO-Al4C3 bed heated to 573 K. The difference in output between the ionization chamber and the gas chromatography was discussed based on the complete-mixing series-tank model. (author)

  16. Heterogeneity of the clinical manifestations and pathology features in C3 glomerulopathy

    Directory of Open Access Journals (Sweden)

    Jin-quan WANG

    2015-01-01

    Full Text Available C3 glomerulopathy is a kind of glomerular diseases mediated by abnormal activation of alternative complement pathway. As diversity and multiplicity of pathogenic mechanism, heterogeneity exists in the clinical manifestation and pathological features of C3 glomerulopathy. The clinical manifestation of the disease may be shown as abnormality in urine, hypertension, hematuria, nephrotic syndrome, nephritic syndrome, renal insufficiency, etc. Membranoproliferative glomerulonephritis, mesangial proliferation, crescent formation, focal segmental necrosis, diffuse hyperplasia and exudative lesions, etc may be found in renal biopsies. Also, the prognosis of C3 glomerulopathy is not uniform. The clinical manifestations and pathological features of C3 glomerulopathy were reviewed in the present paper. DOI: 10.11855/j.issn.0577-7402.2014.12.15

  17. Structure of Complement C3(H2O) Revealed By Quantitative Cross-Linking/Mass Spectrometry And Modeling*

    Science.gov (United States)

    Pellarin, Riccardo; Sali, Andrej; Barlow, Paul N.

    2016-01-01

    The slow but spontaneous and ubiquitous formation of C3(H2O), the hydrolytic and conformationally rearranged product of C3, initiates antibody-independent activation of the complement system that is a key first line of antimicrobial defense. The structure of C3(H2O) has not been determined. Here we subjected C3(H2O) to quantitative cross-linking/mass spectrometry (QCLMS). This revealed details of the structural differences and similarities between C3(H2O) and C3, as well as between C3(H2O) and its pivotal proteolytic cleavage product, C3b, which shares functionally similarity with C3(H2O). Considered in combination with the crystal structures of C3 and C3b, the QCMLS data suggest that C3(H2O) generation is accompanied by the migration of the thioester-containing domain of C3 from one end of the molecule to the other. This creates a stable C3b-like platform able to bind the zymogen, factor B, or the regulator, factor H. Integration of available crystallographic and QCLMS data allowed the determination of a 3D model of the C3(H2O) domain architecture. The unique arrangement of domains thus observed in C3(H2O), which retains the anaphylatoxin domain (that is excised when C3 is enzymatically activated to C3b), can be used to rationalize observed differences between C3(H2O) and C3b in terms of complement activation and regulation. PMID:27250206

  18. Structure of Complement C3(H2O) Revealed By Quantitative Cross-Linking/Mass Spectrometry And Modeling.

    Science.gov (United States)

    Chen, Zhuo A; Pellarin, Riccardo; Fischer, Lutz; Sali, Andrej; Nilges, Michael; Barlow, Paul N; Rappsilber, Juri

    2016-08-01

    The slow but spontaneous and ubiquitous formation of C3(H2O), the hydrolytic and conformationally rearranged product of C3, initiates antibody-independent activation of the complement system that is a key first line of antimicrobial defense. The structure of C3(H2O) has not been determined. Here we subjected C3(H2O) to quantitative cross-linking/mass spectrometry (QCLMS). This revealed details of the structural differences and similarities between C3(H2O) and C3, as well as between C3(H2O) and its pivotal proteolytic cleavage product, C3b, which shares functionally similarity with C3(H2O). Considered in combination with the crystal structures of C3 and C3b, the QCMLS data suggest that C3(H2O) generation is accompanied by the migration of the thioester-containing domain of C3 from one end of the molecule to the other. This creates a stable C3b-like platform able to bind the zymogen, factor B, or the regulator, factor H. Integration of available crystallographic and QCLMS data allowed the determination of a 3D model of the C3(H2O) domain architecture. The unique arrangement of domains thus observed in C3(H2O), which retains the anaphylatoxin domain (that is excised when C3 is enzymatically activated to C3b), can be used to rationalize observed differences between C3(H2O) and C3b in terms of complement activation and regulation. PMID:27250206

  19. Evaluation of Serum Complement C3 and C4 Levels as biomarkers for Systemic Lupus Erythromatosus

    Directory of Open Access Journals (Sweden)

    Fayez Muhammad Shaldoum*, Yousra Refaey Abdo Mohammed, Naglaa Mohamed El Wakeel and Abeer Saad Gawish

    2012-10-01

    Full Text Available Background: Systemic Lupus Erthematosis (SLE is a chronic autoimmune disorder that affects multiple organ systems and also affects the skin and oral mucosa, with the exact cause is unknown. Many hypotheses try to explain the role of the complement C3, C4 in the pathogenesis of SLE. The aim of this study is to determine levels of serum complement C3 and C4 in patient with SLE, so that we may explain its role in diagnosis and pathogenesis of the disease.Methods: Twenty patients were informed from outcome patients of Dermatology Unit in El-Azhar University suffering from SLE. All the patients included in this study fulfilled 4 or more of the American Rheumatism Association classification Criteria for SLE. Blood samples from These 20 SLE patients (18 females and 2 males aged from 20 to 45 years old were collected. Complement C3 and C4 were measured using radial immunodiffusion plates system technique. Clinical parameters such as Erythrocyte Sedimentation Rate (ESR, Total Protein (TPR, Serum Creatinine and Antinuclear Antibody (ANA of those patients were considered in order to compare and explain the data obtained for the levels of C3 and C4. The data were collected and statistically analyzed.Results: Most of patients were female 90% and only 10% male. Of all patients, 60% have low level of serum C4, 40% have normal level of serum C4, 25% have abnormal level of serum C3, and 75% have normal level of serum C3.Statistical analysis of the data on the correlation between C4, and disease activity revealed significant (P> 0.05 correlation, however no significant correlation was found between C3 and disease activity. Analysis on the correlation between C3 and C4 with TPR, S. creatinne, and ESR, showed no significant correlation. No significant relationship was also found between C3 and C4.All patients have had high TPR, S. creatinne and ESR. All patients have had positive ANA which is an important marker of SLE as an auto immune disease

  20. Identification of C3 beta chain as the human serum eosinophil cytotoxicity inhibitor

    OpenAIRE

    1991-01-01

    An eosinophil cytotoxicity inhibitor (ECI) was purified from serum of a human subject with severe allergic dermatitis. Molecular weight of the isolated polypeptide (75,000) and its NH2-terminal amino acid sequence identified it as the beta chain of the C3 complement component (apparently free, but perhaps attached to very small fragments of the alpha chain). Free beta chain, prepared from normal plasma by reduction of C3, inhibited both eosinophil cytotoxicity and neutrophil adherence functio...

  1. Hyperglycemic conditions inhibit C3-mediated immunologic control of Staphylococcus aureus

    OpenAIRE

    Hair Pamela S; Echague Charlene G; Rohn Reuben D; Krishna Neel K; Nyalwidhe Julius O; Cunnion Kenji M

    2012-01-01

    Abstract Background Diabetic patients are at increased risk for bacterial infections; these studies provide new insight into the role of the host defense complement system in controlling bacterial pathogens in hyperglycemic environments. Methods The interactions of complement C3 with bacteria in elevated glucose were assayed for complement activation to opsonic forms, phagocytosis and bacterial killing. C3 was analyzed in euglycemic and hyperglycemic conditions by mass spectrometry to measure...

  2. Activation of C3a receptor is required in cigarette smoke-mediated emphysema

    OpenAIRE

    Yuan, Xiaoyi; Shan, Ming; You, Ran; Frazier, Michael V.; Hong, Monica Jeongsoo; Wetsel, Rick A.; Drouin, Scott; SERYSHEV, ALEXANDER; MD, Li-zhen Song; Cornwell, Lorraine; Rossen, Roger D.; Corry, David B.; Kheradmand, Farrah

    2014-01-01

    Exposure to cigarette smoke can initiate sterile inflammatory responses in the lung and activate myeloid dendritic cells (mDCs) that induce differentiation of T helper type 1 (Th1) and Th17 cells in the emphysematous lungs. Consumption of complement proteins increases in acute inflammation, but the contribution of complement protein 3 (C3) to chronic cigarette smoke-induced immune responses in the lung is not clear. Here we show that following chronic exposure to cigarette smoke, C3 deficient...

  3. 17 CFR 270.6c-3 - Exemptions for certain registered variable life insurance separate accounts.

    Science.gov (United States)

    2010-04-01

    ... account which meets the requirements of paragraph (a) of Rule 6e-2 (17 CFR 270.6e-2) or paragraph (a) of Rule 6e-3(T) (17 CFR 270.6e-3(T)) and registers as an investment company under section 8(a) of the Act... registered variable life insurance separate accounts. 270.6c-3 Section 270.6c-3 Commodity and...

  4. Effect of Hypertriglyceridemia on Beta Cell Mass and Function in ApoC3 Transgenic Mice.

    Science.gov (United States)

    Liu, Yun-Zi; Cheng, Xiaoyun; Zhang, Ting; Lee, Sojin; Yamauchi, Jun; Xiao, Xiangwei; Gittes, George; Qu, Shen; Jiang, Chun-Lei; Dong, H Henry

    2016-07-01

    Hypertriglyceridemia results from increased production and decreased clearance of triglyceride-rich very low-density lipoproteins, a pathological condition that accounts for heightened risk of ischemic vascular diseases in obesity and type 2 diabetes. Despite its intimate association with insulin resistance, whether hypertriglyceridemia constitutes an independent risk for beta cell dysfunction in diabetes is unknown. Answering this fundamental question is stymied by the fact that hypertriglyceridemia is intertwined with hyperglycemia and insulin resistance in obese and diabetic subjects. To circumvent this limitation, we took advantage of apolipoprotein C3 (ApoC3)-transgenic mice, a model with genetic predisposition to hypertriglyceridemia. We showed that ApoC3-transgenic mice, as opposed to age/sex-matched wild-type littermates, develop hypertriglyceridemia with concomitant elevations in plasma cholesterol and non-esterified fatty acid levels. Anti-insulin and anti-glucagon dual immunohistochemistry in combination with morphometric analysis revealed that ApoC3-transgenic and wild-type littermates had similar beta cell and alpha cell masses as well as islet size and architecture. These effects correlated with similar amplitudes of glucose-stimulated insulin secretion and similar degrees of postprandial glucose excursion in ApoC3-transgenic versus wild-type littermates. Oil Red O histology did not visualize lipid infiltration into islets, correlating with the lack of ectopic triglyceride and cholesterol depositions in the pancreata of ApoC3-transgenic versus wild-type littermates. ApoC3-transgenic mice, despite persistent hypertriglyceridemia, maintained euglycemia under both fed and fasting conditions without manifestation of insulin resistance and fasting hyperinsulinemia. Thus, hypertriglyceridemia per se is not an independent risk factor for beta cell dysfunction in ApoC3 transgenic mice. PMID:27226540

  5. A novel application of g-C3N4 thin film in photoelectrochemical anticorrosion

    International Nuclear Information System (INIS)

    This study investigated the photo-to-current conversion properties and photoelectrochemical cathodic protection performance of g-C3N4 in 304 stainless steel under visible or white light illumination for the first time. The results showed that the g-C3N4 thin film could provide 304 stainless steel with very good cathodic protection in the presence of light irradiation. The application of this material represents a potential breakthrough in photoelectrochemical cathodic protection technology

  6. Ion-exchange chromatography separates activities synthesizing and degrading fructose 2,6-bisphosphate from C3 and C4 leaves but not from rat liver

    Science.gov (United States)

    Macdonald, F. D.; Chou, Q.; Buchanan, B. B.

    1987-01-01

    Fructose-6-phosphate,2-kinase and fructose-2,6-bisphosphatase were separated on the basis of charge from leaves of C3 (spinach, lettuce, and pea) and C4 (sorghum and amaranthus) plants but not from rat liver--a tissue known to contain a bifunctional enzyme with both activities. [2-32P]Fructose 2,6-bisphosphate binding experiments also suggest that the major forms of these activities reside on different proteins in leaves.

  7. Requirement of the C3HC4 zinc RING finger of the Arabidopsis PEX10 for photorespiration and leaf peroxisome contact with chloroplasts

    OpenAIRE

    Schumann, Uwe; Prestele, Jakob; O'Geen, Henriette; Brueggeman, Robert; Wanner, Gerhard; Gietl, Christine

    2007-01-01

    Plant peroxisomes perform multiple vital metabolic processes including lipid mobilization in oil-storing seeds, photorespiration, and hormone biosynthesis. Peroxisome biogenesis requires the function of peroxin (PEX) proteins, including PEX10, a C3HC4 Zn RING finger peroxisomal membrane protein. Loss of function of PEX10 causes embryo lethality at the heart stage. We investigated the function of PEX10 with conditional sublethal mutants. Four T-DNA insertion lines expressing pex10 with a dysfu...

  8. Transcript level of AKR1C3 is down-regulated in gastric cancer.

    Science.gov (United States)

    Frycz, Bartosz Adam; Murawa, Dawid; Borejsza-Wysocki, Maciej; Wichtowski, Mateusz; Spychała, Arkadiusz; Marciniak, Ryszard; Murawa, Paweł; Drews, Michał; Jagodziński, Paweł Piotr

    2016-04-01

    Steroid hormones have been shown to play a role in gastric carcinogenesis. Large amounts of steroid hormones are locally produced in the peripheral tissues of both genders. Type 5 of 17β-hydroxysteroid dehydrogenase, encoded by the AKR1C3 gene, plays a pivotal role in both androgen and estrogen metabolism, and its expression was found to be deregulated in different cancers. In this study we measured AKR1C3 transcript and protein levels in nontumoral and primary tumoral gastric tissues, and evaluated their association with some clinicopathological features of gastric cancer (GC). We found decreased levels of AKR1C3 transcript (p T3, T4, and G3 grades. We also determined the effect of the histone deacetylase inhibitor sodium butyrate (NaBu) on AKR1C3 expression in EPG 85-257 and HGC-27 GC cell lines. We found that NaBu elevates the levels of both AKR1C3 transcript and protein in the cell lines we investigated. Together, our results suggest that decreased expression of AKR1C3 may be involved in development of GC and can be restored by NaBu. PMID:27019068

  9. Evaluation of cervical body configuration from C3 to C7 in infants and children

    International Nuclear Information System (INIS)

    To obtain the findings of normal variant types of lower cervical body configuration for the purpose of differention ion from compression fracture. We retrospectively analysed simple true lateral radiographs of cervical spine from C3 to C7 in 157 pediatric patients who did not have definitive clinical symptoms of cervical spinal injury. We classified the variations of normal cervical spine into 5 types by their configuration. In case of rounded upper corner or anteriorly wedged type. We measured the height and the width of vertebral body to classify these types, and undertook ANOVA test and multiple range test to determine the correlation between the gross configuration and the measured values. Type 1 was similarly observed at each of C3 to C7 in age of 1-4 group but the frequency was markedly decreased in age of 5-8 group. Type 2a was frequently observed at both age groups, and its incidence increased considerably at C3 and C4 with advancing age. Type 2b was more frequently observed at C3 body and Type 3 was observed only at C3 body in age group 1-4. Type 4 was markedly increased at 5-8 age group. Type 2b and 3 were seen mostly at C3, but sometimes at C4 body. Height of body was statistically more significant than width of body in classification of type 2a, 2b and 3

  10. Thermomagnetic analysis of meteorites, 3. C3 and C4 chondrites

    Science.gov (United States)

    Herndon, J.M.; Rowe, M.W.; Larson, E.E.; Watson, D.E.

    1976-01-01

    Thermomagnetic analysis was made on samples of all known C3 and C4 chondrites in a controlled oxygen atmosphere. Considerable variation was noted in the occurrence of magnetic minerals, comparable to the variation observed earlier in the C2 chondrites. Magnetite was found as the only major magnetic phase in samples of only three C3 chondrites (2-4 wt.%) and the Karoonda C4 chondrite (7.7 wt.%). The magnetite content of these three C3 chondrites is only about one-third that observed in the C1 and C2 chondrites which were found to contain magnetite as the only magnetic phase. Five C3 chondrites were observed to undergo chemical change during heating, producing magnetite: this behavior is characteristic of troilite oxidation. Upper limits on initial magnetite content of about 1-9% were established for these meteorites. Samples of the remaining five C3 chondrites and the Coolidge C4 chondrite were found to contain both magnetite and metallic iron. In two samples, iron containing ???2% Ni was observed, while in the other four, the iron contained 6-8 wt.% Ni. In addition to containing both magnetite and iron metal, three of these samples reacted during heating to form additional magnetite. Variations in the magnetic mineralogy and, hence by inference bulk mineralogy, of C3 and C4 chondrites indicate a more complex genesis than is evident from whole-rock elemental abundance patterns. ?? 1976.

  11. Boron doped g-C3N4 with enhanced photocatalytic UO22+ reduction performance

    Science.gov (United States)

    Lu, Changhai; Chen, Rongyue; Wu, Xi; Fan, Meifeng; Liu, Yunhai; Le, Zhanggao; Jiang, Shujuan; Song, Shaoqing

    2016-01-01

    Tuning the band gap and absorption intensity of visible-light by element doping is an attractive strategy to enhance the photocatalytic activity of semiconductor materials. Here we doped boron into g-C3N4 to construct highly efficient photocatalysts (B-g-C3N4) for the photocatalytic reduction of UO22+. Characterization and photocatalysis tests showed the band gap of B-g-C3N4 was narrowed, and the absorption intensity of visible-light was enhanced with increasing the formed N-B-C (BCN) of B-g-C3N4, which is consistent with the trend of the photocatalytic performance of B-g-C3N4. The optimized B-g-C3N4 photocatalyst with BCN content of 1.01 at.% exhibited excellent removal efficiency of UO22+ and good photocatalytic stability. Therefore, these results may lead to a new strategy for exploring the advanced photocatalysts based on the carbon nanomaterials with abundant BCN for the photocatalytic reduction of U(VI) pollutant.

  12. Immune complex glomerulonephritis following bone marrow transplantation in C3 deficient mice.

    Directory of Open Access Journals (Sweden)

    Thomas R Welch

    Full Text Available BACKGROUND: The role of circulating complement in host defense and immune disease is well established. Although a number of cells and tissues are capable of synthesizing complement components locally, the importance of such local synthesis in immune disease has been difficult to establish. METHODOLOGY/PRINCIPAL FINDINGS: We used bone marrow transplantation (BMT between C3 knockout (C3KO and wild type (WT mice to construct animals that were discordant for systemic (hepatic and local (monocytic C3 synthetic capacity. An immune complex glomerulonephritis (GN was then induced using intraperitoneal injections of horse spleen apoferritin (HSA with a lipopolysaccharide (LPS adjuvant. All HSA/LPS animals developed a proliferative GN with glomerular infiltration by monocytes. By sensitive ELISA, monocyte C3 synthesis could be detected in C3KO animals transplanted with WT bone marrow cells. Despite this, there were no significant differences among groups of mice in measures of clinical (proteinuria, renal function or histologic (glomerular cellularity, crescents disease severity. CONCLUSIONS/SIGNIFICANCE: In this model of GN, local synthesis of C3 by infiltrating cells does not appear to be of pathologic importance.

  13. The Hydration and Carbonation of Tricalcium Aluminate (C3A) in the Presence of Heavy Metals

    Institute of Scientific and Technical Information of China (English)

    CHEN Quanyuan; C. D. Hills; M. Tyrer; I. Slipper

    2005-01-01

    The hydration of tricalcium aluminate (C3A) has a significant effect on the effectiveness of cement-based systems. In addition, the carbonation of hydration products of C3A is particularly important in respect of durability performance. The present work investigates the hydration and carbonation reactions of C3A and the changes induced by the presence of the heavy metal ions such as Zn2+, Pb2+, Cu2+ and Cr3+ by X-ray diffractometry (XRD). During hydration of C3A, gehlenite hydrate, hydrogarnet, calcium monoaluminate (C4AHx) and calcium carboaluminate were detected in C3A pastes except the Zn2+doped paste, where hydrogarnet did not form. The examinations revealed that heavy metals coexisted with gehlenite hydrate, calcium monoaluminate (C4AHx) and calcium carboaluminate, inhibiting the formation of hydrogarnet. Hydrating C3A was liable to be carbonated on exposure to air and carbon dioxide, especially in the presence of heavy metals, resulting in the formation of carboaluminate and/or calcium carbonate. The presence of heavy metals in-fluenced the polymorphism of calcium carbonate,ndicating that heavy metals could co-precipitate with calcium to form a carbonate solid solution.

  14. The g-C3 N4 /C2 N Nanocomposite: A g-C3 N4 -Based Water-Splitting Photocatalyst with Enhanced Energy Efficiency.

    Science.gov (United States)

    Wang, Huimin; Li, Xingxing; Yang, Jinlong

    2016-07-01

    Water-splitting photocatalysts with good energy efficiency are highly desirable, among which metal-free graphitic carbon nitride (g-C3 N4 ) is considered to be very promising and has been intensively studied in recent years. However, its practical application is hindered by the relatively low efficiencies of visible-light absorption and electron-hole separation. Herein, based on first-principles calculations, it is predicted that, by forming nanocomposites with another carbon nitride (C2 N), the energy efficiency of g-C3 N4 can be significantly improved. On one hand, C2 N has a wide, strong optical absorption in the visible-light region, which acts as a photosensitizer and enhances the photoabsorption efficiency of the composite photocatalyst. On the other hand, C2 N forms a type II heterojunction with g-C3 N4 , which leads to efficient separation of photogenerated electron-hole pairs through the chemical potential difference between the two components. These results provide a potential route to achieve highly efficient metal-free photocatalysts for water splitting. PMID:27110945

  15. A novel third complement component C3 gene of Ciona intestinalis expressed in the endoderm at the early developmental stages

    Directory of Open Access Journals (Sweden)

    T Hibino

    2013-04-01

    Full Text Available The third complement component (C3 in ascidian was reported to function as an opsonin to enhance phagocytosis and as a chemotactic factor for phagocytes, indicating that ascidian C3 works in mesodermal cavity as a humoral factor like vertebrate C3s. In the basal Eumetazoa, Cnidaria lacking mesodermal tissues, C3 was reported to work in an endodermal cavity. Evolution of structure and function of C3 is still to be clarified. Here we report the identification of the third C3 gene, CiC3-3, in the genome of an ascidian, Ciona intestinalis. Phylogenetic analysis using the entire amino acid sequences of Eumetazoan C3s indicated that CiC3-3 possess a closer relationship to vertebrate C3, C4 and C5 than other ascidian C3s. Although CiC3-3 retained the α-β processing site and 6 cysteine residues in the C3a region, it lacked the intra-molecular thioester bond and the catalytic histidine residue. Instead, CiC3-3 had a unique insertion of about 70 residues long Lys/Arg-rich sequence. CiC3-3 was expressed highly in the embryonic stages, but little in the adult in contradistinction to CiC3-1 and CiC3-2. The expression of CiC3-3 in early embryonic stages was restricted to endoderm similar to cnidarian C3s. Thus, the ascidian complement system could represent a unique evolutionary stage sharing a primitive endodermal function with Cnidaria, and newly developed humoral function with vertebrates.

  16. Uso de C3F8 no descolamento da membrana de Descemet pós-facectomia C3F8 use in Descemet detachment after cataract surgery

    Directory of Open Access Journals (Sweden)

    Abrahão da Rocha Lucena

    2006-06-01

    Full Text Available INTRODUÇÃO: O descolamento da membrana de Descemet é complicação rara, mas devastadora após facectomia. Algumas alternativas têm sido usadas para reposição da Descemet: bolha de ar, sutura com transfixação da córnea, viscoelástico associado com bolha de ar e gás SF6 ou C3F8. O transplante de córnea é o último recurso utilizado. OBJETIVO: Avaliar os resultados anatômicos e funcionais, do descolamento iatrogênico da membrana de Descemet, com uso de C3F8 (16% na câmara anterior em seis olhos pós-facectomia. MÉTODOS: Após colocação de 0,5 ml do gás em câmara anterior avaliou-se localização justa-estromal da membrana de Descemet em lâmpada de fenda. Os olhos com deslocamento superior/central eram orientados a ficar em decúbito elevado por dois dias e no caso do deslocamento inferior solicitamos decúbito dorsal com leve supraversão. RESULTADOS: A média de idade foi de 71,3 ± 9,3 anos, sendo quatro do sexo feminino e dois do sexo masculino. Todos os olhos tiveram sucesso com a colocação do C3F8, havendo aumento da pressão intra-ocular em um caso. O edema corneano regrediu a partir do segundo dia com resolução completa até o quarto dia. A acuidade visual melhorou em todos os casos logo após regressão do edema, sendo reavaliada quarenta e cinco dias depois. CONCLUSÃO: A introdução unicamente do gás C3F8 não expansivo para colar a membrana de Descemet é citado pela primeira vez na literatura brasileira. O restabelecimento da acuidade visual é rápida, o método é seguro, efetivo e de fácil execução, sendo realizado sob anestesia tópica.INTRODUCTION: Descemet's membrane detachment is a rare but serious complication following cataract surgery. Extensive detachments that affect the visual axis may result in poor vision and require penetrating corneal grafts. Some alternatives have been used to reattach Descemet's membrane: air bubble, transcorneal sutures and intracameral viscoelastic gel plus SF6 or C3F

  17. Recombinant acylation stimulating protein administration to C3-/- mice increases insulin resistance via adipocyte inflammatory mechanisms.

    Directory of Open Access Journals (Sweden)

    Mercedes Nancy Munkonda

    Full Text Available BACKGROUND: Complement 3 (C3, a key component of the innate immune system, is involved in early inflammatory responses. Acylation stimulating protein (ASP; aka C3adesArg, a C3 cleavage product, is produced in adipose tissue and stimulates lipid storage. We hypothesized that, depending on the diet, chronic ASP administration in C3(-/- mice would affect lipid metabolism and insulin sensitivity via an adaptive adipose tissue inflammatory response. METHODOLOGY/PRINCIPAL FINDINGS: C3(-/- mice on normal low fat diet (ND or high fat diet (HFD were chronically administered recombinant ASP (rASP for 25 days via an osmotic mini-pump. While there was no effect on food intake, there was a decrease in activity, with a relative increase in adipose tissue weight on ND, and a shift in adipocyte size distribution. While rASP administration to C3(-/- mice on a ND increased insulin sensitivity, on a HFD, rASP administration had the opposite effect. Specifically, rASP administration in C3(-/- HFD mice resulted in decreased gene expression of IRS1, GLUT4, SREBF1 and NFκB in muscle, and decreased C5L2 but increased JNK, CD36, CD11c, CCR2 and NFκB gene expression in adipose tissue as well as increased secretion of proinflammatory cytokines (Rantes, KC, MCP-1, IL-6 and G-CSF. In adipose tissue, although IRS1 and GLUT4 mRNA were unchanged, insulin response was reduced. CONCLUSION: The effects of chronic rASP administration are tissue and diet specific, rASP administration enhances the HFD induced inflammatory response leading to an insulin-resistant state. These results suggest that, in humans, the increased plasma ASP associated with obesity and cardiovascular disease could be an additional factor directly contributing to development of metabolic syndrome, insulin resistance and diabetes.

  18. Complement C3 deficiency attenuates chronic hypoxia-induced pulmonary hypertension in mice.

    Directory of Open Access Journals (Sweden)

    Eileen M Bauer

    Full Text Available Evidence suggests a role of both innate and adaptive immunity in the development of pulmonary arterial hypertension. The complement system is a key sentry of the innate immune system and bridges innate and adaptive immunity. To date there are no studies addressing a role for the complement system in pulmonary arterial hypertension.Immunofluorescent staining revealed significant C3d deposition in lung sections from IPAH patients and C57Bl6/J wild-type mice exposed to three weeks of chronic hypoxia to induce pulmonary hypertension. Right ventricular systolic pressure and right ventricular hypertrophy were increased in hypoxic vs. normoxic wild-type mice, which were attenuated in C3-/- hypoxic mice. Likewise, pulmonary vascular remodeling was attenuated in the C3-/- mice compared to wild-type mice as determined by the number of muscularized peripheral arterioles and morphometric analysis of vessel wall thickness. The loss of C3 attenuated the increase in interleukin-6 and intracellular adhesion molecule-1 expression in response to chronic hypoxia, but not endothelin-1 levels. In wild-type mice, but not C3-/- mice, chronic hypoxia led to platelet activation as assessed by bleeding time, and flow cytometry of platelets to determine cell surface P-selectin expression. In addition, tissue factor expression and fibrin deposition were increased in the lungs of WT mice in response to chronic hypoxia. These pro-thrombotic effects of hypoxia were abrogated in C3-/- mice.Herein, we provide compelling genetic evidence that the complement system plays a pathophysiologic role in the development of PAH in mice, promoting pulmonary vascular remodeling and a pro-thrombotic phenotype. In addition we demonstrate C3d deposition in IPAH patients suggesting that complement activation plays a role in the development of PAH in humans.

  19. Al4C3 Hydration Thermochemical Analysis for Burned Carbon-containing Refractories with Al

    Institute of Scientific and Technical Information of China (English)

    YANG Ding'ao; YU Zhiming; FAN Liuwu

    2003-01-01

    In this paper, X-ray diffractogram analysis and SEM observation of Al4 C3 formed at high temperature from carbon-containing refractories with Al have been carried out.Aluminum added to carbon-containing refractories reacts with C(s)to form Al4 C3(s) gradually during heating from 600 ℃ to 1200℃.It is considered that the interlocked structure of Al4 C3 plate crystals promotes the outstanding increase of hot modulus of rupture of carbon-containing refractories with Al. The HMOR of carbon-containing refractories added with Al additive from 0 to 5wt% increases by 2.8 times being from 6.5MPa to 18.2MPa.After a thermochemical calculation for hydration reaction processes of Al4 C3 and H2O(g), the equilibrium partial pressure chart of H2O(g)in H2O-Al4C3-Al(OH)3 system vs various temperatures has been attained . The H2O (g) partial pressure in the air needed for the Al4 C3 hydration reaction is no more than 10~18 atm at the temperature below 120℃.It is considered that the burned carbon-containing refractories with Al is extremely easy to hydrate and the cracking of burned carbon-containing refractories is generated because that the hydration expansion is 2.11 times during transforming from Al4 C3 to Al(OH)3.The fundamental measure against hydration of the refractories is to insulate the refractories from H2O(g)by various means such as pitch impregnation or other sealing materials.

  20. Mechanism of higher incidence of apoptosis by irradiation in C3H mouse macrophages

    International Nuclear Information System (INIS)

    Full text: The present study was performed to elucidate the mechanism underlying higher sensitivity of C3H mouse macrophages with respect to irradiation-induced apoptosis. Gamma-irradiation at a dose of 10 Gy induced significant apoptosis in peritoneal resident macrophages (PRMs) of C3H mice 4 hr after irradiation, but not three other strains of mice tested. The induction of apoptosis in PRMs of C3H mice increased in a dose-dependent manner up to 50 Gy, but in PRMs of B6 mice the percentage of apoptosis remained low even at a dose of 100 Gy. On the other hand, hydrogen peroxide induced apoptosis in PRMs of both strains at similar levels. Pretreatment of PRMs of C3H mice with buthionine sulfoximine or N-acetyl cysteine in order to alter the intracellular glutathione level significantly affected hydrogen peroxide-induced apoptosis but had no effect at all on irradiation-induced apoptosis. Sodium formate (a hydroxy radical scavenger) or deferoxamine mesylate (a potent iron chelater) had no effect on irradiation-induced apoptosis but Tiron, a cell permeable superoxide scavenger, significantly interfered with it. The enzymatic activity of superoxide dismutase in the cell lysate of PRMs was measured using a commercial assay kit. The activity of superoxide dismutase was much lower in PRMs of C3H mice than in those of B6 mice. These results suggest that the remarkable irradiation-induced apoptosis observed only in PRMs of C3H mice can be attributed to the lower superoxide dismutase activity and that superoxide among reactive oxygen species produced by ionizing radiation is an important molecule in irradiation-induced apoptosis in PRMs of C3H mice

  1. Detection of the photosynthesis protective mechanisms of C3 and C4 Crops from hyper spectral data%C3、C4作物的光保护机制差异的光谱探测研究

    Institute of Scientific and Technical Information of China (English)

    刘良云; 关琳琳; 彭代亮; 胡勇; 刘玲玲

    2012-01-01

    本文设计了大豆(C3作物)和玉米(C4作物)日变化光谱探测试验,提取了太阳光照条件下叶绿素荧光信号和光化学指数PRI.结果表明,首先大豆和玉米叶绿素荧光强度的日变化特征有较大差异,上午大豆的叶绿素荧光比例呈现快速增加的趋势,而玉米的叶绿素荧光未出现增加趋势;其次,下午高温胁迫条件下C3、C4叶绿素荧光光谱比值的变化差异显著,大豆在760 nm和688 nm波段的叶绿素荧光比值快速增加,而玉米未出现显著变化;最后,研究证实了C3作物中午受到强光抑制出现光合作用“午休”现象,即午后光合恢复后其光合效率快速增加,表现为C3作物的热耗散降低、PRI快速增加,而C4作物无“午休”现象,午后PRI增加较小.本文研究表明,强光和高温环境胁迫下C3、C4作物的叶绿素荧光和热耗散变化特征有较大差异,利用胁迫条件下的多时相、高光谱遥感数据,提取C3、C4作物的叶绿素荧光和PRI,有可能实现C3、C4作物的遥感分类目标.%The classification of C3 and C4 plant functional types has become an important issue in global change research, but the mechanism of using remote sensing data remains unclear. In this paper, a diurnal variation experiment was designed for soybean (C3 plant functional type) and maize (C4 plant functional type) to acquire canopy spectra under different illumination and temperature conditions, and chlorophyll fluorescence (ChlF) signals and photochemical reflectance index (PRI) were extracted from the canopy spectra. The results showed that: (1) the amplitudes of the diurnal variation in ChlF between soybean and maize were significantly different, as the relative ChlF of soybean increased rapidly under heat and high irradiance stresses in the afternoon, but the increasing trend was not found in maize; (2) there was also an apparent increase in the ratio f688/f760 of ChlF intensities of soybean in the afternoon, but

  2. C3b covalently bound to IgG demonstrates a reduced rate of inactivation by factors H and I

    OpenAIRE

    1984-01-01

    We have prepared C3b covalently linked to IgG via a hydroxylamine- sensitive bond between the C3b alpha' chain and sites predominantly, but not exclusively, located in the IgG heavy chain. This C3b species displays relative resistance to inactivation by factors H and I when compared with free C3b. This resistance appears to be due entirely to reduced affinity of C3b-IgG for factor H. Resistance to inactivation is not conferred on C3b by binding to another serum glycoprotein of similar size, c...

  3. Complement therapeutics in inflammatory diseases: promising drug candidates for C3-targeted intervention.

    Science.gov (United States)

    Mastellos, D C; Ricklin, D; Hajishengallis, E; Hajishengallis, G; Lambris, J D

    2016-02-01

    There is increasing appreciation that complement dysregulation lies at the heart of numerous immune-mediated and inflammatory disorders. Complement inhibitors are therefore being evaluated as new therapeutic options in various clinical translation programs and the first clinically approved complement-targeted drugs have profoundly impacted the management of certain complement-mediated diseases. Among the many members of the intricate protein network of complement, the central component C3 represents a 'hot-spot' for complement-targeted therapeutic intervention. C3 modulates both innate and adaptive immune responses and is linked to diverse immunomodulatory systems and biological processes that affect human pathophysiology. Compelling evidence from preclinical disease models has shown that C3 interception may offer multiple benefits over existing therapies or even reveal novel therapeutic avenues in disorders that are not commonly regarded as complement-driven, such as periodontal disease. Using the clinically developed compstatin family of C3 inhibitors and periodontitis as illustrative examples, this review highlights emerging therapeutic concepts and developments in the design of C3-targeted drug candidates as novel immunotherapeutics for oral and systemic inflammatory diseases. PMID:26332138

  4. Research on C3N4 Superhard Compound Thin Film and Its Application

    Institute of Scientific and Technical Information of China (English)

    Wu; Da-wei; Peng; Li-li; 等

    2003-01-01

    By combination of DC reactive magnetron sputtering with multiple arcplating, the alternating C3N4/TiN compound film is deposited onto HSS. The core level binding energy and contents of carbon and nitrogen are characterized by X-ray photoelectron spectrum. X-ray diffraction (XRD) shows that compound thin film contains hard crystalline phases of α-C3N4 and β-C3N4.The Knoop microhardness in the load range of 50.5-54.1GPa is measured. According to acoustic emission scratch test, the critical load values for the coating on HSS substrates are in the range of 40-80N. The metal coated with C3N4/TiN compound films has a great improvement in the resistance against corrosion. Many tests show that such a coating has a very high wearability. Compared with the uncoated and TiN coated tools, the C3N4/TiN coated tools have a much longer sutting life.

  5. Research on C3N4 Superhard Compound Thin Film and Its Application

    Institute of Scientific and Technical Information of China (English)

    Wu Da-wei; Peng Li-li; Lu Ning; Peng You-gui

    2003-01-01

    By combination of DC reactive magnetron sputtering with multiple arcplating, the alternating C3 N4/TiN compound film is deposited onto HSS. The core level binding energy and the contents of carbon and nitrogen are characterized by X-ray photoelectron spectrum. X-ray diffraction(XRD) shows that compound thin film contains hard crystalline phases of α-C3N4 and β-C3N4. The Knoop microhardness in the load range of 50.5-54.1 GPa is measured. According to acoustic emission scratch test, the critical load values for the coatings on HSS substrates are in the range of 40-80 N. The metal coated with C3N4/TiN compound films has a great improvement in the resistance against corrosion. Many tests show that such a coating has a very high wearability. Compared with the uncoated and TiN coated tools, the C3N4/TiN coated tools have a much longer cutting life.

  6. A previously unrecognized role of C3a in proteinuric progressive nephropathy.

    Science.gov (United States)

    Morigi, Marina; Locatelli, Monica; Rota, Cinzia; Buelli, Simona; Corna, Daniela; Rizzo, Paola; Abbate, Mauro; Conti, Debora; Perico, Luca; Longaretti, Lorena; Benigni, Ariela; Zoja, Carlamaria; Remuzzi, Giuseppe

    2016-01-01

    Podocyte loss is the initial event in the development of glomerulosclerosis, the structural hallmark of progressive proteinuric nephropathies. Understanding mechanisms underlying glomerular injury is the key challenge for identifying novel therapeutic targets. In mice with protein-overload induced by bovine serum albumin (BSA), we evaluated whether the alternative pathway (AP) of complement mediated podocyte depletion and podocyte-dependent parietal epithelial cell (PEC) activation causing glomerulosclerosis. Factor H (Cfh(-/-)) or factor B-deficient mice were studied in comparison with wild-type (WT) littermates. WT+BSA mice showed podocyte depletion accompanied by glomerular complement C3 and C3a deposits, PEC migration to capillary tuft, proliferation, and glomerulosclerosis. These changes were more prominent in Cfh(-/-) +BSA mice. The pathogenic role of AP was documented by data that factor B deficiency preserved glomerular integrity. In protein-overload mice, PEC dysregulation was associated with upregulation of CXCR4 and GDNF/c-Ret axis. In vitro studies provided additional evidence of a direct action of C3a on proliferation and CXCR4-related migration of PECs. These effects were enhanced by podocyte-derived GDNF. In patients with proteinuric nephropathy, glomerular C3/C3a paralleled PEC activation, CXCR4 and GDNF upregulation. These results indicate that mechanistically uncontrolled AP complement activation is not dispensable for podocyte-dependent PEC activation resulting in glomerulosclerosis. PMID:27345360

  7. High cervical C3-4 ′disc′ compression associated with basilar invagination

    Directory of Open Access Journals (Sweden)

    Goel Atul

    2008-01-01

    Full Text Available A 20-year-old male had torticollis and short neck since birth. He presented with symptom of progressive quadriparesis over a two-year period. Investigations revealed basilar invagination with marked rotation in the craniovertebral region and relatively large C3-4 region osteophytes. Serial MRI over two years showed persistent signal opposite C3-4 disc space suggestive of cord compression. Although the cord was humped over the odontoid process, there was no clear radiological evidence that the cord was compromised at this level. During surgery, instability was identified only at the craniovertebral region and not at the level of C3-4. Distraction of the lateral masses of atlas and axis and fixation using interarticular spacers and bone graft and direct screw implantation in the lateral mass of the atlas and pars of the axis resulted in reduction of the basilar invagination and of atlantoaxial dislocation. The patient had marked clinical recovery, despite the fact that no direct procedure was done for C3-4 disc decompression. The case suggests that C3-4 disc changes could be secondary to primary instability at the craniovertebral junction.

  8. Structure, electronic, mechanical and optical properties of ternary YAl3C3 carbide

    Science.gov (United States)

    Hussain, Altaf; Javed, Athar; Mehmood, Salman; Rasool, M. Nasir; Khan, Muhammad Azhar; Iqbal, Faisal

    2016-05-01

    The electronic structure, mechanical and optical properties of ternary yttrium aluminum carbide (YAl3C3) has been studied by first principles approach. The crystal structure and elastic properties are studied by using Vienna ab initio simulation package (VASP). An orthogonalized linear combination of atomic orbitals (OLCAO) method based on the density functional theory (DFT) is implemented to elucidate the electronic structure and optical properties of ternary YAl3C3 carbide. The YAl3C3 carbide exhibits a narrow indirect band gap, Eg=0.12 eV which shows its poor metallic and/or semiconductor behavior. The effective charge (Q*) calculation reveals more charge transfer from Al-sites as compared to Y-sites which indicates dominant ionic character of Al-sites. The analysis of structure and bond order (BO) calculations show that the Al-C bonds in the basal plane are much stronger as compared to Al-C bonds along the c-axis. The Al-C bonds lying in the basal plane have main contribution into the overall stiffness of YAl3C3 carbide. The effective mass of charge carriers (electrons and holes) and inter-band optical properties (complex dielectric function and optical conductivity) are also studied which show high degree of anisotropy in YAl3C3.

  9. Interactive Effects of Elevated CO2 and Growth Temperature on the Tolerance of Photosynthesis to Acute Heat Stress in C3 and C4 Species

    Institute of Scientific and Technical Information of China (English)

    E. William Hamilton Ⅲ; Scott A. Heckathorn; Puneet Joshi; Dan Wang; Deepak Barua

    2008-01-01

    Determining effects of elevated CO2 on the tolerance of photosynthesis to acute heat-stress (heat wave) is necessary for predicting plant responses to global warming, as photosynthesis is thermolabile and acute heat-stress and atmospheric CO2 will increase in the future. Few studies have examined this, and past results are variable, which may be due to methodological variation. To address this, we grew two C3 and two C4 species at current or elevated CO2 and three different growth temperatures (GT). We assessed photosynthetic thermotolerance in both unacclimated (basal tolerance) and preheat-stressed (preHS = acclimated) plants. In C3 species, basal thermotolerance of net photosynthesis (Pn) was increased In high CO2, but in C4 species, Pn thermotlerance was decreased by high CO2 (except Zea maya at low GT); CO2 effects in preHS plants were mostly small or absent, though high CO2 was detrimental in one C3 and one C4 species at warmer GT. Though high CO2 generally decreased stomatal conductance, decreases in Pn during heat stress were mostly due to non-stomatal effects. Photosystem II (PSII) efficiency was often decreased by high CO2 during heat stress, especially at high GT; CO2 effects on post-PSll electron transport were variable. Thus, high CO2 often affected photosynthetic theromotolerance, and the effects varied with photosynthetic pathway, growth temperature, and acclimation state. Most importantly, in heat-stressed plants at normal or warmer growth temperatures, high CO2 may often decrease, or not benefit as expected, tolerance of photosynthesis to acute heat stress. Therefore, interactive effects of elevated CO2 and warmer growth temperatures on acute heat tolerance may contribute to future changes in plant productivity, distribution, and diversity.

  10. Reduction of U(VI) and Toxic Metals by Desulfovibrio Cytochrome C3

    Energy Technology Data Exchange (ETDEWEB)

    Wall, Judy D

    2013-04-11

    The central objective of our proposed research was twofold: 1) to investigate the structure-function relationship of Desulfovibrio desulfuricans (now Desulfovibrio alaskensis G20) cytochrome c3 with uranium and 2) to elucidate the mechanism for uranium reduction in vitro and in vivo. Physiological analysis of a mutant of D. desulfuricans with a mutation of the gene encoding the type 1 tetraheme cytochrome c3 had demonstrated that uranium reduction was negatively impacted while sulfate reduction was not if lactate were the electron donor. This was thought to be due to the presence of a branched pathway of electron flow from lactate leading to sulfate reduction. Our experimental plan was to elucidate the structural and mechanistic details of uranium reduction involving cytochrome c3.

  11. Understanding the complement-mediated glomerular diseases: focus on membranoproliferative glomerulonephritis and C3 glomerulopathies.

    Science.gov (United States)

    Lionaki, Sophia; Gakiopoulou, Hara; Boletis, John N

    2016-09-01

    An enhanced understanding of the role of complement in the pathogenesis of membranoproliferative glomerulonephritis has led to reclassification of the latter into immunoglobulin-mediated and non-immunoglobulin-mediated disease. The new classification schema resulted in improved diagnostic clinical algorithms, while it brought into light again the diseases, which are characterized by the presence of glomerular deposits, composed predominantly by C3, in the absence of significant amounts of immunoglobulins in renal biopsy, namely, C3 glomerulopathies (dense deposit disease and C3 glomerulonephritis). Despite the lack of randomized controlled trials following the advances in the understanding of the pathogenetic pathways involved in membranoproliferative glomerulonephritis, it is important that the new mechanistic approach has opened new roads for the exploration and discovery of targeted therapies. PMID:27356907

  12. Analysis of cubic and orthorhombic C3A hydration in presence of gypsum and lime

    KAUST Repository

    Kirchheim, A. P.

    2009-02-26

    Field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) have been used to study the microstructural changes and phase development that take place during the hydration of cubic (pure) and orthorhombic (Na-doped) tricalcium aluminate (C3A) and gypsum in the absence and presence of lime. The results demonstrate that important differences occur in the hydration of each C3A polymorph and gypsum when no lime is added; orthorhombic C3A reacts faster with gypsum than the cubic phase, forming longer ettringite needles; however, the presence of lime slows down the formation of ettringite in the orthorhombic sample. Additional rheometric tests showed the possible effects on the setting time in these cementitious mixes.

  13. Nanoscale charge transport in cytochrome c3/DNA network: Comparative studies between redox-active molecules

    Science.gov (United States)

    Yamaguchi, Harumasa; Che, Dock-Chil; Hirano, Yoshiaki; Suzuki, Masayuki; Higuchi, Yoshiki; Matsumoto, Takuya

    2015-09-01

    The redox-active molecule of a cytochrome c3/DNA network exhibits nonlinear current-voltage (I-V) characteristics with a threshold bias voltage at low temperature and zero-bias conductance at room temperature. I-V curves for the cytochrome c3/DNA network are well matched with the Coulomb blockade network model. Comparative studies of the Mn12 cluster, cytochrome c, and cytochrome c3, which have a wide variety of redox potentials, indicate no difference in charge transport, which suggests that the conduction mechanism is not directly related to the redox states. The charge transport mechanism has been discussed in terms of the newly-formed electronic energy states near the Fermi level, induced by the ionic interaction between redox-active molecules with the DNA network.

  14. Polymorphism of newly discovered Ti4GaC3: A first-principles study

    International Nuclear Information System (INIS)

    The newly discovered MAX phase, Ti4GaC3, can exist in one of three polymorphs, α, β and γ, all with the space group P63/mmc. The Ti and Ga (underlined) atomic arrangements are, respectively, ABABACBCBC, ACACACACAC and ABCBACBABC. Herein first-principles calculations are used to investigate the phase stabilities, electronic structures, elastic properties and compressibilities of the three polymorphs. Since the α- to γ-phase transition only involves shuffling of the A-atoms, it occurs much more easily than those to β-Ti4GaC3 despite the fact that the latter is thermodynamically less stable than γ-Ti4GaC3. For α-Ti4GaC3, the total density of states, TDOS, around the Fermi energy, Ef, lies in a local minimum; for the two other polymorphs, the TDOS is near a local minimum. The electrons occupy all the bonding states for α-Ti4GaC3, but the bonding states are partially occupied for both β- and γ-Ti4GaC3. Both bond stiffness and bond angle play an important role in the compressibility. In general, with increasing pressure, all the bonds become shorter, and the rate of increase in bond stiffness also increases. The bulk moduli of the α-, β- and γ-polymorphs were calculated to be 178, 174 and 169 GPa, respectively. The corresponding theoretical densities are 5.14, 5.12 and 5.11 g cm-3.

  15. Rat prostatic steroid binding protein: characterisation of the Alu element upstream of the C3 genes.

    OpenAIRE

    Hurst, H C; Parker, M G

    1984-01-01

    We have characterised an Alu-like repetitive element found about 400 bp upstream of the gene encoding the C3 component of rat prostatic steroid binding protein and suggest, from comparisons with other published sequences, that it is an example of a third class of rodent Alu-equivalent sequences. Members of this class are 80-90 bp long, share greater than 90% sequence homology, and contain sequences resembling the RNA polymerase III bipartite promoter. The Alu type III element within the C3 ge...

  16. The Granular Chloride Channel ClC-3 Is Permissive For Insulin Secretion

    OpenAIRE

    Deriy, Ludmila V.; Gomez, Erwin A.; Jacobson, David A.; Wang, Xueqing; Hopson, Jessika A.; Liu, Xiang Y.; Zhang, Guangping; Bindokas, Vytautas P.; Philipson, Louis H.; Nelson, Deborah J.

    2009-01-01

    Insulin secretion from pancreatic β–cells is dependent on maturation and acidification of the secretory granule necessary for prohormone convertase cleavage of proinsulin. Previous studies in isolated β–cells revealed that acidification may be dependent on the granule membrane chloride channel ClC-3, in a step permissive for a regulated secretory response. In this study, immuno-electron microscopy of β–cells revealed colocalization of ClC-3 and insulin on secretory granules. Clc-3−/− mice as ...

  17. Note on thermodynamic instability of M4C3-type carbides of gallium group metals

    International Nuclear Information System (INIS)

    The paper deals with thermodynamic stability of hypothetical solid binary M4C3 carbides of gallium, indium and thallium. Heats of formation whose contribution to the stability of these compounds is dominant, were estimated by two independent methods: semiempirical theory of Miedema and empirical trends in the heats of formation of nitrides and carbides of Group III elements. Entropies were calculated with the use of the Cantor equation. The estimated values suggest that M4C3 carbides of gallium, indium and thallium are thermodynamically unstable with regard to their decomposition of elements. (Author)

  18. A study of immunoglobulins and complements (C3 &C4 in alopecia areata

    Directory of Open Access Journals (Sweden)

    Sharma R

    1995-01-01

    Full Text Available Estimation of serum Immunoglobulins (IgG, IgM and IgA and complements (C3 and C4 was carried out in 100 cases of alopecia areata as per method described by Mancini (1965.[1] Clinically patients were divided in two groups, alopecia areata circumscribed (group I and severe alopecia areata (group II. Significant decrease in levels of one or more Immunoglobulins were observed in most of the patients. However, Serum complements (C3 and C4 were within range of normal control values

  19. Shock wave study of the thermal dissociations of C3F6 and c-C3F6. II. dissociation of hexafluorocyclopropane and dimerization of CF2.

    Science.gov (United States)

    Cobos, C J; Sölter, L; Tellbach, E; Troe, J

    2014-07-10

    The thermal dissociation of c-C3F6 has been studied in shock waves over the range 620-1030 K monitoring the UV absorption of CF2. The reaction was studied close to its high-pressure limit, but some high-temperature falloff was accounted for. Quantum-chemical and kinetic modeling rationalized the experimental data. The reaction is suggested to involve the 1,3 biradical CF2CF2CF2 intermediate. CF2 formed by the dissociation of c-C3F6 dimerizes to C2F4. The measured rate of this reaction is also found to correspond to the falloff range. Rate constants for 2CF2 → C2F4 as a function of temperature and bath gas concentration [Ar] are given and shown to be consistent with literature values for the high-pressure rate constants from experiments at lower temperatures and dissociation rate constants obtained in the falloff range at higher temperatures. The onset of falloff at intermediate temperatures is analyzed. PMID:24905207

  20. Phenolic glycolipid-1 of Mycobacterium leprae binds complement component C3 in serum and mediates phagocytosis by human monocytes

    OpenAIRE

    1991-01-01

    Previous studies from this laboratory have demonstrated that Mycobacterium leprae, an obligate intracellular bacterial parasite, enters human mononuclear phagocytes via complement receptors on these host cells and bacterium-bound C3. The present study investigates the role of M. leprae surface molecules in C3 fixation and phagocytosis. By enzyme-linked immunosorbent assay, C3 binds selectively to phenolic glycolipid-1 (PGL-1), a major surface molecule of the leprosy bacillus. C3 fixation to P...

  1. Localization of the C3-Like ADP-Ribosyltransferase from Staphylococcus aureus during Bacterial Invasion of Mammalian Cells

    OpenAIRE

    Molinari, Gabriella; Rohde, Manfred; Wilde, Christian; Just, Ingo; Aktories, Klaus; Chhatwal, Gursharan S.

    2006-01-01

    The C3stau2 exoenzyme from Staphylococcus aureus is a C3-like ADP-ribosyltransferase which possesses no specific receptor-binding domain or translocation unit required for entry in target cells where its substrate is located. Here we show that C3stau2 can reach its target after invasion of staphylococci in eukaryotic cells without needing translocation.

  2. 26 CFR 1.280C-3 - Disallowance of certain deductions for qualified clinical testing expenses when section 28 credit...

    Science.gov (United States)

    2010-04-01

    ... 28(d)(2)). (b) Capitalization of qualified clinical testing expenses. In a case in which qualified... clinical testing expenses when section 28 credit is allowable. 1.280C-3 Section 1.280C-3 Internal Revenue... Not Deductible § 1.280C-3 Disallowance of certain deductions for qualified clinical testing...

  3. Stable Carbon Isotope Ratios of Individual Pollen Grains as a Proxy for C3- Versus C4-Grass Abundance in Paleorecords: A Validation Study

    Science.gov (United States)

    Nelson, D. M.; Hu, F.; Pearson, A.

    2007-12-01

    distinguishing C3 and C4 shifts. At 9 of the 10 sites C/N values indicate that surface-sediment organic matter was derived primarily from aquatic production. At the one site where organic matter was produced primarily by vascular plants the δ13C value (-29.3°) suggests organic matter derived exclusively from C3 plants. However, ~80% of the grasses on the landscape at this site are C4 grasses. The C3- like bulk-sediment δ13C value likely represents woody species, which comprise >90% of the pollen spectra. Thus δ13C analysis of single grains of grass pollen offers a new tool to classify grass pollen into two major functional groups and promises to advance our understanding of grassland ecology and evolution. Reference Nelson, D.M., Hu, F.S., Mikucki, J., Tian, J., and Pearson, A., 2007, Carbon isotopic analysis of individual pollen grains from C3 and C4 grasses using a spooling wire microcombustion interface: Geochimica et Cosmochimica Acta, v. 71, p. 4005-4014.

  4. 76 FR 44800 - Election of Reduced Research Credit Under Section 280C(c)(3)

    Science.gov (United States)

    2011-07-27

    ... rulemaking (REG-130200-08) was published in the Federal Register (74 FR 34523). No public hearing was...(c)(3) AGENCY: Internal Revenue Service (IRS), Treasury. ACTION: Final regulations. SUMMARY: This..., 2011. Applicability Date: For dates of applicability, see Sec. 1.280C- 4(c). FOR FURTHER...

  5. Complement component C3 and risk of age-related macular degeneration

    NARCIS (Netherlands)

    D.D.G. Despriet; C.M. van Duijn; B.A. Oostra; A.G. Uitterlinden; A. Hofman; A.F. Wright; J.B. ten Brink; A. Bakker; P.T.V.M. de Jong; J.R. Vingerling; A.A.B. Bergen; C.C.W. Klaver

    2009-01-01

    OBJECTIVE: To explore the association between polymorphisms in the complement component 3 (C3) gene and age-related macular degeneration (AMD), and to investigate the modifying effect of complement factor H (CFH) Y402H, LOC387715 A69S and smoking. DESIGN: Pooled data from the prospective, population

  6. Synthesis of 2-substituted tryptophans via a C3- to C2-alkyl migration

    Directory of Open Access Journals (Sweden)

    Michele Mari

    2014-08-01

    Full Text Available The reaction of 3-substituted indoles with dehydroalanine (Dha derivatives under Lewis acid-mediated conditions has been investigated. The formation of 2-substituted tryptophans is proposed to occur through a selective alkylative dearomatization–cyclization followed by C3- to C2-alkyl migration and rearomatization.

  7. The superfamily of C3b/C4b-binding proteins

    DEFF Research Database (Denmark)

    Kristensen, Torsten; D'Eustachio, P; Ogata, R T;

    1987-01-01

    The determination of primary structures by amino acid and nucleotide sequencing for the C3b-and/or C4b-binding proteins H, C4BP, CR1, B, and C2 has revealed the presence of a common structural element. This element is approximately 60 amino acids long and is repeated in a tandem fashion, commenci...

  8. 26 CFR 1.412(c)(3)-1 - Reasonable funding methods.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 5 2010-04-01 2010-04-01 false Reasonable funding methods. 1.412(c)(3)-1... Reasonable funding methods. (a) Introduction—(1) In general. This section prescribes rules for determining whether or not, in the case of an ongoing plan, a funding method is reasonable for purposes of section...

  9. Percutaneous CT-Guided Biopsy of C3 Vertebral Body: Modified Approach for an Old Procedure

    International Nuclear Information System (INIS)

    Percutaneous biopsy of upper cervical vertebrae is challenging due to the various critical structures in the location and often requires difficult trajectory such as transoral or paramaxillary approaches. The purpose of this manuscript is to illustrate the utility of head rotation in creating a potential space for direct percutaneous access to C3 vertebral body for safe biopsy.

  10. Complement protein C3 exacerbates prion disease in a mouse model of chronic wasting disease.

    Science.gov (United States)

    Michel, Brady; Ferguson, Adam; Johnson, Theodore; Bender, Heather; Meyerett-Reid, Crystal; Wyckoff, A Christy; Pulford, Bruce; Telling, Glenn C; Zabel, Mark D

    2013-12-01

    Accumulating evidence shows a critical role of the complement system in facilitating attachment of prions to both B cells and follicular dendritic cells and assisting in prion replication. Complement activation intensifies disease in prion-infected animals, and elimination of complement components inhibits prion accumulation, replication and pathogenesis. Chronic wasting disease (CWD) is a highly infectious prion disease of captive and free-ranging cervid populations that utilizes the complement system for efficient peripheral prion replication and most likely efficient horizontal transmission. Here we show that complete genetic or transient pharmacological depletion of C3 prolongs incubation times and significantly delays splenic accumulation in a CWD transgenic mouse model. Using a semi-quantitative prion amplification scoring system we show that C3 impacts disease progression in the early stages of disease by slowing the rate of prion accumulation and/or replication. The delayed kinetics in prion replication correlate with delayed disease kinetics in mice deficient in C3. Taken together, these data support a critical role of C3 in peripheral CWD prion pathogenesis. PMID:24038599

  11. Measurement of the figure of merit M for 1-C3F6/SF6 mixtures

    DEFF Research Database (Denmark)

    Christensen, Jørn Erik Berril; McAllister, Iain Wilson

    1997-01-01

    High precision measurements of the linear part of the Paschen curve are reported for 1-C3F6/SF6 mixtures. From these measurements, values for the pressure-reduced limiting electric field strength (E/p)lim and the associated figure of merit M are derived. These two parameters can be used to...

  12. Photocatalytic C−H Activation of Hydrocarbons over VO@g‑C3N4

    Science.gov (United States)

    A highly selective and sustainable method has beendeveloped for the oxidation of methyl arenes and their analogues.The VO@g-C3N4 catalyst is very efficient in the C−H activation andoxygen insertion reaction resulting in formation of the correspondingcarbonyl compounds and phenols...

  13. Crystal structure of the R2Ni22C3 compounds (R=Ce, La, Pr)

    International Nuclear Information System (INIS)

    The results of determination of the Ce2Ni22C3 (space group, Csub(mca), a=1.1384 (3), b=1.5024 (7), c=1.4671 (5) nm, V=2.5092 nm3, Z=8, N=216) compound crystal structure are presented. Monocrystal is surveyed in the automatic diffractometer ''Sintex P21'' (890 reflections, MOK-radiation, theta/20-method, graphite monochromator, 2thetasub(max)=110 deg). The atomic coordinates atoms are defined in an isotropic approximation up to R=0.082. The lattice cell parameters of the La2Ni22C3 and Pr2Ni22C3 isostructural compounds are refined, using the least square method, from diffraction diagrams, obtained using DRON-2.0 (FeKsub(α)-radiation) and are equal to a=1.145 (5), b=1.512 (4), c=1.463 (4) nm; a=1.138 (4), b=1.505 (3), c=1.459 (3) nm, respectively. Interatomic distances for Ce2Ni22C3 are presented

  14. Percutaneous CT-Guided Biopsy of C3 Vertebral Body: Modified Approach for an Old Procedure

    Energy Technology Data Exchange (ETDEWEB)

    Pua, Uei, E-mail: druei@yahoo.com [Tan Tock Seng Hospital, Department of Diagnostic Radiology (Singapore); Chan, Stephen Yung-Wei [Tan Tock Seng Hospital, Department of Anaesthesiology, Intensive Care and Pain Medicine (Singapore)

    2013-06-15

    Percutaneous biopsy of upper cervical vertebrae is challenging due to the various critical structures in the location and often requires difficult trajectory such as transoral or paramaxillary approaches. The purpose of this manuscript is to illustrate the utility of head rotation in creating a potential space for direct percutaneous access to C3 vertebral body for safe biopsy.

  15. Partial lipodystrophy, C3 nephritic factor and clinically inapparent mesangiocapillary glomerulonephritis.

    Science.gov (United States)

    Bennett, W M; Bardana, E J; Wuepper, K; Houghton, D; Border, W A; Götze, O; Schreiber, R

    1977-05-01

    A case of partial lipodystrophy with C3 nephritic factor was found to be associated with mesangiocapillary glomerulonephritis although all clinical parameters of renal function were normal. Diagnosis of mesangiocapillary glomerulonephritis required renal biopsy. Nephriti factor obtained from this patient was immunochemically related to nephritic factor isolated from the serum of patients with typical mesangiocapillary glomerulonephritis without partial lipodystrophy. PMID:860726

  16. Detection of Interstellar C_2 and C_3 in the Small Magellanic Cloud

    CERN Document Server

    Welty, Daniel E; Lehner, Nicolas; Black, John H

    2012-01-01

    We report the detection of absorption from interstellar C_2 and C_3 toward the moderately reddened star Sk 143, located in the near 'wing' region of the SMC, in optical spectra obtained with the ESO VLT/UVES. These detections of C_2 (rotational levels J=0-8) and C_3 (J=0-12) absorption in the SMC are the first beyond our Galaxy. The total abundances of C_2 and C_3 (relative to H_2) are similar to those found in diffuse Galactic molecular clouds -- as previously found for CH and CN -- despite the significantly lower average metallicity of the SMC. Analysis of the rotational excitation of C_2 yields an estimated kinetic temperature T_k ~ 25 K and a moderately high total hydrogen density n_H ~ 870 cm^-3 -- compared to the T_01 ~ 45 K and n_H ~ 85-300 cm^-3 obtained from H_2. The populations of the lower rotational levels of C_3 are consistent with an excitation temperature of about 34 K.

  17. The relationship between complement factor C3, APOE ε4, amyloid and tau in Alzheimer's disease.

    Science.gov (United States)

    Bonham, Luke W; Desikan, Rahul S; Yokoyama, Jennifer S

    2016-01-01

    Inflammation is becoming increasingly recognized as an important contributor to Alzheimer's disease (AD) pathogenesis. As a part of the innate immune system, the complement cascade enhances the body's ability to destroy and remove pathogens and has recently been shown to influence Alzheimer's associated amyloid and tau pathology. However, little is known in humans about the effects of the complement system and genetic modifiers of AD risk like the ε4 allele of apolioprotein E (APOE ε4) on AD pathobiology. We evaluated cerebrospinal fluid (CSF) protein levels from 267 individuals clinically diagnosed as cognitively normal, mild cognitive impairment, and AD. Using linear models, we assessed the relationship between APOE ε4 genotype, CSF Complement 3 (C3), CSF amyloid-β (amyloid) and CSF hyperphosphorylated tau (ptau). We found a significant interaction between APOE ε4 and CSF C3 on both CSF amyloid and CSF ptau. We also found that CSF C3 is only associated with CSF ptau after accounting for CSF amyloid. Our results support a conceptual model of the AD pathogenic cascade where a synergistic relationship between the complement cascade (C3) and APOE ε4 results in elevated Alzheimer's neurodegeneration and in turn, amyloid further regulates the effect of the complement cascade on downstream tau pathology. PMID:27357286

  18. Detection of vibronic bands of C$_3$ in a translucent cloud towards HD 169454

    CERN Document Server

    Schmidt, M R; Galazutdinov, G A; Zhao, D; Haddad, M A; Ubachs, W; Linnartz, H

    2014-01-01

    We report the detection of eight vibronic bands of C$_3$, seven of which have been hitherto unobserved in astrophysical objects, in the translucent cloud towards HD~169454. Four of these bands are also found towards two additional objects: HD~73882 and HD~154368. Very high signal-to-noise ratio ($\\sim$1000 and higher) and high resolving power ($R=80,000$) UVES-VLT spectra (Paranal, Chile) allow for detecting novel spectral features of C$_3$, even revealing weak perturbed features in the strongest bands. The work presented here provides the most complete spectroscopic survey of the so far largest carbon chain detected in translucent interstellar clouds. High-quality laboratory spectra of C$_3$ are measured using cavity ring-down absorption spectroscopy in a supersonically expanding hydrocarbon plasma, to support the analysis of the identified bands towards HD~169454. A column density of N(C$_3$) = $(6.6 \\pm 0.2) \\times 10^{12}$ cm$^{-2}$ is inferred and the excitation of the molecule exhibits two temperature c...

  19. Tame automorphisms of C^3 with multidegree of the form (3,d_2,d_3)

    OpenAIRE

    Karas, Marek

    2009-01-01

    In this note we prove that the sequence (3,d_2,d_3), where d_3>= d_2>= 3, is the multidegee of some tame automorphism of C^3, if and only if 3|d_2 or d_3 is a linaer combination of 3 and d_2 with coefficients in N.

  20. Synthesis of C3-symmetric tri(alkylamino) guests and their interaction with cyclodextrins

    Czech Academy of Sciences Publication Activity Database

    Bednaříková, T.; Tošner, Z.; Horský, Jiří; Jindřich, J.

    2015-01-01

    Roč. 81, 1-2 (2015), s. 141-152. ISSN 0923-0750 Institutional support: RVO:61389013 Keywords : cyclodextrin * supramolecular interactions * C3-symmetric guests Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 1.488, year: 2014

  1. [Modulation of Fcgamma and C3b receptor expression by marine bioglycans in mouse splenocytes].

    Science.gov (United States)

    Zaporozhets, T S

    2003-01-01

    Investigation of polysacharide immunomodulators of marine origin was performed--mitilane, alpha-1,4;1,6-D-glucane, isolated from midia Crenomytilus grayanus, and translam--beta-1,3;1,6-D-glucane isolated from marine algae Laminaria cichorioides were compared. Mechanisms of phagocytes cells activation were investigated. Dose-dependent ability of investigated bioglycanes to facilitate Fc gamma R [symbol: see text] C3bR expression at mice splenocytes was demonstrated in vivo and in vitro. The effect depended on immunomodulator type, incubation conditions, dose, period of incubation in vitro and by splenocytes population used for Fc gamma R and C3bR identification. It was shown that C3bR expression was more enhanced by immunomodulators than Fc gamma R expression. For Fc gamma R induction on lymphocytes membranes the presence of phagocytes cell (macrophages and neutrophils) is obligatory. Mitilane, containing alpha-1,4;1,6-D-glucane and some amount of protein is more effective in stimulation of membrane receptors expression than translam--beta-1,3;1,6-D-glucane. The results of investigation demonstrates the possibility to use marine bioglicanes as activators of Fc gamma R and C3bR activity, that is the base for control of pathological processes, related to immune system. PMID:12914116

  2. Characterization of Al–Al4C3 nanocomposites produced by mechanical milling

    International Nuclear Information System (INIS)

    In this work, a mixture of Al–C–Al4C3 nanopowder previously synthesized by mechanical milling and subsequent thermal treatment was used to reinforce the Al matrix. The nanocomposites were fabricated via high-energy ball milling and subsequent sintering process for different periods of time at 550 °C. Hardness and compression tests were performed to evaluate the mechanical properties of the nanocomposites in the as-milled and sintered conditions. According to the results the reinforcement located in the grain boundaries is responsible for the brittle behavior observed in the nanocomposites during the compression test. The combined effect of sintering and precipitation mechanisms produced an evident increase of the strength of the Al matrix at a relatively short sintering time. By using the Rietveld method the crystallite size and microstrain measurements were determined and correlated with the microhardness values. For the proper characterization of the nanoparticles present in the Al matrix, atomic force microscopy and high resolution electron microscopy were used. - Highlights: • Nanostructured Al4C3 reinforcement was fabricated via mechanical milling and heat treatment. • We found a significant increase of the mechanical properties at short sintering times. • The formation of Al4C3 with during sintering time restricted the excessive growth of the crystallite. • Al4C3 located in the grain boundaries causes brittle fracture observed in compression tests. • There is a correlation between, crystallite size and microstrain values with microhardness

  3. Photorespiratory properties of total leaf protoplasts isolated from C3-C4 intermediate species of MORICANDIA

    International Nuclear Information System (INIS)

    In comparison to C3 species, intact leaf tissue of M. arvensis (C3-C4) exhibits a reduced sensitivity of photosynthesis to inhibition by O2 and an enhanced capacity for the refixation of 14CO2 evolved during decarboxylation of exogenous [1-14C]glycine. In contrast, purified protoplast preparations from leaves of M. arvensis and M. spinosa (C3-C4), containing 8.4 +/- 0.6% (S.E) bundle-sheath protoplasts and approx. 90% mesophyll protoplasts, showed no significant differences from protoplasts of the C3 species, M. foetida and Triticum aestivum with respect to the following parameters: (a) percentage O2-inhibition of photosynthetic 14CO2 fixation; (b) apparent Km(CO2) of photosynthesis; and (c) dark/light ratios of 14CO2 evolution during metabolism of exogenous [1-14C]glycine. It was concluded that the structural arrangement of mesophyll and bundle-sheath cells and organelles in situ in leaf tissue of M. arvensis and M. spinosa is of importance in facilitating reduced apparent photorespiration in these intermediate species by enhanced recycling of CO2

  4. DIBENZODIOXOCIN STRUCTURES INVOLVING P-HYDROXYPHENYL UNITS IN C3H DOWN-REGULATED LIGNINS

    Science.gov (United States)

    We previously reported that downregulation of the gene encoding 4-coumarate 3-hydroxylase (C3H) in alfalfa markedly increased the proportion of p-hydroxyphenyl (H) units relative to the normally dominant guaiacyl (G) and syringyl (S) units, as determined by 2D 13C-1H correlative NMR methods, thioaci...

  5. From orphan drugs to adopted therapies: Advancing C3-targeted intervention to the clinical stage.

    Science.gov (United States)

    Mastellos, Dimitrios C; Reis, Edimara S; Yancopoulou, Despina; Hajishengallis, George; Ricklin, Daniel; Lambris, John D

    2016-10-01

    Complement dysregulation is increasingly recognized as an important pathogenic driver in a number of clinical disorders. Complement-triggered pathways intertwine with key inflammatory and tissue destructive processes that can either increase the risk of disease or exacerbate pathology in acute or chronic conditions. The launch of the first complement-targeted drugs in the clinic has undeniably stirred the field of complement therapeutic design, providing new insights into complement's contribution to disease pathogenesis and also helping to leverage a more personalized, comprehensive approach to patient management. In this regard, a rapidly expanding toolbox of complement therapeutics is being developed to address unmet clinical needs in several immune-mediated and inflammatory diseases. Elegant approaches employing both surface-directed and fluid-phase inhibitors have exploited diverse components of the complement cascade as putative points of therapeutic intervention. Targeting C3, the central hub of the system, has proven to be a promising strategy for developing biologics as well as small-molecule inhibitors with clinical potential. Complement modulation at the level of C3 has recently shown promise in preclinical primate models, opening up new avenues for therapeutic intervention in both acute and chronic indications fueled by uncontrolled C3 turnover. This review highlights recent developments in the field of complement therapeutics, focusing on C3-directed inhibitors and alternative pathway (AP) regulator-based approaches. Translational perspectives and considerations are discussed, particularly with regard to the structure-guided drug optimization and clinical advancement of a new generation of C3-targeted peptidic inhibitors. PMID:27353192

  6. Global modeling of the C1-C3 alkyl nitrates using STOCHEM-CRI

    Science.gov (United States)

    Khan, M. A. H.; Cooke, M. C.; Utembe, S. R.; Morris, W. C.; Archibald, A. T.; Derwent, R. G.; Jenkin, M. E.; Orr-Ewing, A. J.; Higgins, C. M.; Percival, C. J.; Leather, K. E.; Shallcross, D. E.

    2015-12-01

    The atmospheric global budget and distribution of C1-C3 alkyl nitrates have been investigated using a global three-dimensional chemistry transport model, STOCHEM-CRI. Alkyl nitrates (RONO2) are significant NOx reservoir species and the more detailed VOC oxidation mechanism (CRI v2-R5) leads to greater photochemical production. RONO2 are significant sources of NOx in regions remote from NOx sources. The study shows that the global burden and the atmospheric life-time of C1-C3 alkyl nitrates are 113 Gg and 9-10 days, respectively, which are in excellent agreement with estimates established by previous studies. The abundance of alkyl nitrates have been found to be higher in the continental atmosphere, with CH3ONO2 mixing ratios up to 20 ppt over the Amazon rainforest. Up to 15, 10, 2, and 5 ppt of modelled CH3ONO2, C2H5ONO2, n-C3H7ONO2 and i-C3H7ONO2 have been found in the northern hemisphere over regions with large anthropogenic emissions of NOx and VOCs. The combination of atmospheric production and long-range transport led to high alkyl nitrate levels at high latitudes. The model performance for C1-C3 alkyl nitrates was established using observations from nine flights and nine field campaigns. The comparison shows a tendency towards model under-prediction of the observations, particularly in the southern hemispheric marine boundary layer, possibly due to the absence of oceanic production mechanisms and air-sea exchange processes in the model. The discrepancies between model and observed seasonal cycles, especially of CH3ONO2, in both hemispheres are discussed.

  7. Conformational states of a bacterial α2-macroglobulin resemble those of human complement C3.

    Directory of Open Access Journals (Sweden)

    David Neves

    Full Text Available α(2 macroglobulins (α(2Ms are broad-spectrum protease inhibitors that play essential roles in the innate immune system of eukaryotic species. These large, multi-domain proteins are characterized by a broad-spectrum bait region and an internal thioester, which, upon cleavage, becomes covalently associated to the target protease, allowing its entrapment by a large conformational modification. Notably, α(2Ms are part of a larger protein superfamily that includes proteins of the complement system, such as C3, a multi-domain macromolecule which is also characterized by an internal thioester-carrying domain and whose activation represents the pivotal step in the complement cascade. Recently, α(2M/C3-like genes were identified in a large number of bacterial genomes, and the Escherichia coli α(2M homolog (ECAM was shown to be activated by proteases. In this work, we have structurally characterized ECAM by electron microscopy and small angle scattering (SAXS techniques. ECAM is an elongated, flexible molecule with overall similarities to C3 in its inactive form; activation by methylamine, chymotrypsin, or elastase induces a conformational modification reminiscent of the one undergone by the transformation of C3 into its active form, C3b. In addition, the proposed C-terminus of ECAM displays high flexibility and different conformations, and could be the recognition site for partner macromolecules. This work sheds light on a potential bacterial defense mechanism that mimics structural rearrangements essential for activation of the complement cascade in eukaryotes, and represents a possible novel target for the development of antibacterials.

  8. Research of evaluation system for C3I information fusion%C3I信息融合测试评估系统研究

    Institute of Scientific and Technical Information of China (English)

    刘云翔; 江力斯; 林捷

    2008-01-01

    测试评估系统在C3I信息融合的发展过程中起着极其重要的作用.讨论了信息融合系统评估的一般理论、方法,给出了一些用于定量评估的性能指标的定义和测试评估系统的构建方法及过程,并基于软总线结构进行了软件设计.该评估系统具有操作方便、灵活性好、通用性强等特点.通过实例分析,使得该评估系统的可靠性和实用性得到了验证.

  9. The use of C3d as a means of monitoring clinical activity in systemic lupus erythematosus and rheumatoid arthritis.

    OpenAIRE

    Morrow, W J; Williams, D. J.; Ferec, C.; Casburn-Budd, R; Isenberg, D. A.; Paice, E; Snaith, M L; Youinou, P; Le Goff, P

    1983-01-01

    Plasma samples from 44 patients with systemic lupus erythematosus (SLE) and 43 with rheumatoid arthritis (RA) were assayed for C3d, a breakdown product of the third component of complement (C3), which was also measured in parallel. Levels of C3d varied in direct proportion with disease activity in RA, whereas C3 showed little change. Although C3d values also increased with worsening clinical condition in SLE, this trend was not considered to be sufficiently clear to be useful and did not prov...

  10. The receptor for complement component C3a mediates protection from intestinal ischemia-reperfusion injuries by inhibiting neutrophil mobilization

    OpenAIRE

    Wu, Mike C. L.; Brennan, Faith H; Lynch, Jason P. L.; Mantovani, Susanna; Phipps, Simon; Wetsel, Rick A.; Ruitenberg, Marc J.; Taylor, Stephen M.; Woodruff, Trent M.

    2013-01-01

    C3a is a key complement activation fragment, yet its neutrophil-expressed receptor (C3aR) still has no clearly defined role. In this study, we used a neutrophil-dependent mouse model of intestinal ischemia-reperfusion (IR) injury to explore the role of C3aR in acute tissue injuries. C3aR deficiency worsened intestinal injury, which corresponded with increased numbers of tissue-infiltrating neutrophils. Circulating neutrophils were significantly increased in C3aR−/− mice after intestinal ische...

  11. Negative Regulation of Pulmonary Th17 Responses by C3a Anaphylatoxin during Allergic Inflammation in Mice

    OpenAIRE

    Hoyong Lim; Young Uk Kim; Drouin, Scott M.; Stacey Mueller-Ortiz; Kyoungah Yun; Eva Morschl; Wetsel, Rick A.; Yeonseok Chung

    2012-01-01

    Activation of complement is one of the earliest immune responses to exogenous threats, resulting in various cleavage products including anaphylatoxin C3a. In addition to its contribution to host defense, C3a has been shown to mediate Th2 responses in animal models of asthma. However, the role of C3a on pulmonary Th17 responses during allergic inflammation remains unclear. Here, we show that mice deficient in C3a receptor (C3aR) exhibited (i) higher percentages of endogenous IL-17-producing CD...

  12. Activation of the complement system by Cryptococcus neoformans leads to binding of iC3b to the yeast.

    OpenAIRE

    Kozel, T R; Pfrommer, G S

    1986-01-01

    The complement system plays a key role in resistance to cryptococcosis. In the present study, we examined several factors that influence the binding of C3 cleavage fragments to Cryptococcus neoformans. Binding of C3 was determined by using normal human serum supplemented with 125I-labeled C3. Incubation of encapsulated cryptococci in 20% serum led to the binding of approximately 3.2 X 10(6) molecules of C3 to each cell. The binding of C3 was markedly inhibited by heating the serum at 56 degre...

  13. Zinc-induced self-association of complement C3b and Factor H: implications for inflammation and age-related macular degeneration.

    OpenAIRE

    Nan, R.; Tetchner, S; Rodriguez, E.; Pao, P. J.; Gor, J.; Lengyel, I; Perkins, S J

    2013-01-01

    The sub-retinal pigment epithelial deposits (sRPEds) that are a hallmark of age-related macular degeneration (AMD) contain both C3b and mM levels of zinc. C3 is the central protein of complement, while C3u is formed by the spontaneous hydrolysis of the thioester bridge in C3. During activation, C3 is cleaved to form active C3b, then C3b is inactivated by Factor I and Factor H to form the C3c and C3d fragments. The interaction of zinc with C3 was quantified using analytical ultracentrifugation...

  14. Step 1: Human System Integration (HSI) FY05 Pilot-Technology Interface Requirements for Command, Control, and Communications (C3)

    Science.gov (United States)

    2005-01-01

    The document provides the Human System Integration(HSI) high-level functional C3 HSI requirements for the interface to the pilot. Description includes (1) the information required by the pilot to have knowledge C3 system status, and (2) the control capability needed by the pilot to obtain C3 information. Fundamentally, these requirements provide the candidate C3 technology concepts with the necessary human-related elements to make them compatible with human capabilities and limitations. The results of the analysis describe how C3 operations and functions should interface with the pilot to provide the necessary C3 functionality to the UA-pilot system. Requirements and guidelines for C3 are partitioned into three categories: (1) Pilot-Air Traffic Control (ATC) Voice Communications (2) Pilot-ATC Data Communications, and (3) command and control of the unmanned aircraft (UA). Each requirement is stated and is supported with a rationale and associated reference(s).

  15. C3-Luc Cells Are an Excellent Model for Evaluation of Cellular Immunity following HPV16L1 Vaccination.

    Directory of Open Access Journals (Sweden)

    Li-Li Li

    Full Text Available C3 and TC-1 are the two model cell lines most commonly used in studies of vaccines and drugs against human papillomavirus (HPV infection. Because C3 cells contain both the HPV16 E and L genes, but TC-1 cells contain only the HPV16 E genes, C3 cells are usually used as the model cell line in studies targeting the HPV16 L protein. However, expression of the L1 protein is difficult to detect in C3 cells using common methods. In our study, Short tandem repeat analysis (STR was used to demonstrate that C3 cells are indeed derived from mice, PCR results show that HPV16 L1, E6 and E7 genes were detected in C3 genomic DNA, and RT-PCR results demonstrated that L1 transcription had occurred in C3 cells. However, the expression of C3 protein was not found in the results of western blot and immunohistochemistry (IHC. Growth and proliferation of C3 were inhibited by mice spleen lymphocytes that had been immunized with a vaccine against HPV16L1. The luciferase gene was integrated into C3 cells, and it was confirmed that addition of the exogenous gene had no effect on C3 cells by comparing cell growth and tumor formation with untransformed cells. Cells stably expressing luciferase (C3-luc were screened and subcutaneously injected into the mice. Tumors became established and were observed using a Spectrum Pre-clinical in Vivo Imaging System. Tumor size of mice in the different groups at various time points was calculated by counting photons. The sensitivity of the animals to the vaccine was quantified by statistical comparison. Ten or 30 days following injection of the C3-luc cells, tumor size differed significantly between the PBS and vaccine groups, indicating that C3 cells were susceptible to vaccination even after tumors were formed in vivo.

  16. Anthracycline resistance mediated by reductive metabolism in cancer cells: The role of aldo-keto reductase 1C3

    Energy Technology Data Exchange (ETDEWEB)

    Hofman, Jakub; Malcekova, Beata; Skarka, Adam; Novotna, Eva; Wsol, Vladimir, E-mail: wsol@faf.cuni.cz

    2014-08-01

    Pharmacokinetic drug resistance is a serious obstacle that emerges during cancer chemotherapy. In this study, we investigated the possible role of aldo-keto reductase 1C3 (AKR1C3) in the resistance of cancer cells to anthracyclines. First, the reducing activity of AKR1C3 toward anthracyclines was tested using incubations with a purified recombinant enzyme. Furthermore, the intracellular reduction of daunorubicin and idarubicin was examined by employing the transfection of A549, HeLa, MCF7 and HCT 116 cancer cells with an AKR1C3 encoding vector. To investigate the participation of AKR1C3 in anthracycline resistance, we conducted MTT cytotoxicity assays with these cells, and observed that AKR1C3 significantly contributes to the resistance of cancer cells to daunorubicin and idarubicin, whereas this resistance was reversible by the simultaneous administration of 2′-hydroxyflavanone, a specific AKR1C3 inhibitor. In the final part of our work, we tracked the changes in AKR1C3 expression after anthracycline exposure. Interestingly, a reciprocal correlation between the extent of induction and endogenous levels of AKR1C3 was recorded in particular cell lines. Therefore, we suggest that the induction of AKR1C3 following exposure to daunorubicin and idarubicin, which seems to be dependent on endogenous AKR1C3 expression, eventually might potentiate an intrinsic resistance given by the normal expression of AKR1C3. In conclusion, our data suggest a substantial impact of AKR1C3 on the metabolism of daunorubicin and idarubicin, which affects their pharmacokinetic and pharmacodynamic behavior. In addition, we demonstrate that the reduction of daunorubicin and idarubicin, which is catalyzed by AKR1C3, contributes to the resistance of cancer cells to anthracycline treatment. - Highlights: • Metabolism of anthracyclines by AKR1C3 was studied at enzyme and cellular levels. • Anthracycline resistance mediated by AKR1C3 was demonstrated in cancer cells. • Induction of AKR1C3

  17. Anthracycline resistance mediated by reductive metabolism in cancer cells: The role of aldo-keto reductase 1C3

    International Nuclear Information System (INIS)

    Pharmacokinetic drug resistance is a serious obstacle that emerges during cancer chemotherapy. In this study, we investigated the possible role of aldo-keto reductase 1C3 (AKR1C3) in the resistance of cancer cells to anthracyclines. First, the reducing activity of AKR1C3 toward anthracyclines was tested using incubations with a purified recombinant enzyme. Furthermore, the intracellular reduction of daunorubicin and idarubicin was examined by employing the transfection of A549, HeLa, MCF7 and HCT 116 cancer cells with an AKR1C3 encoding vector. To investigate the participation of AKR1C3 in anthracycline resistance, we conducted MTT cytotoxicity assays with these cells, and observed that AKR1C3 significantly contributes to the resistance of cancer cells to daunorubicin and idarubicin, whereas this resistance was reversible by the simultaneous administration of 2′-hydroxyflavanone, a specific AKR1C3 inhibitor. In the final part of our work, we tracked the changes in AKR1C3 expression after anthracycline exposure. Interestingly, a reciprocal correlation between the extent of induction and endogenous levels of AKR1C3 was recorded in particular cell lines. Therefore, we suggest that the induction of AKR1C3 following exposure to daunorubicin and idarubicin, which seems to be dependent on endogenous AKR1C3 expression, eventually might potentiate an intrinsic resistance given by the normal expression of AKR1C3. In conclusion, our data suggest a substantial impact of AKR1C3 on the metabolism of daunorubicin and idarubicin, which affects their pharmacokinetic and pharmacodynamic behavior. In addition, we demonstrate that the reduction of daunorubicin and idarubicin, which is catalyzed by AKR1C3, contributes to the resistance of cancer cells to anthracycline treatment. - Highlights: • Metabolism of anthracyclines by AKR1C3 was studied at enzyme and cellular levels. • Anthracycline resistance mediated by AKR1C3 was demonstrated in cancer cells. • Induction of AKR1C3

  18. Phenology of Australian temperate grasslands: linking near-surface phenology to C3/C4 community composition

    Science.gov (United States)

    Watson, C. J.

    2015-12-01

    Vegetation phenology is relatively well-studied in northern hemisphere temperate biomes, but limited research has been conducted on phenological drivers and responses in Australian temperate ecosystems. Australian temperate grasslands represent a broad range of plant communities from exotic pastures to native grasslands, but all are important for food security (livestock grazing) and biodiversity retention. Climate predictions for temperate Australia include higher temperatures, altered rainfall frequency/seasonality, increased drought severity and more regular wildfires. The ecosystem response to these climatic factors is unknown, and the need to improve the monitoring of these highly dynamic grassland systems at a landscape scale is acute. The aim of this research is to use high-frequency phenological data to improve the identification of grassland functional types and ultimately use this to improve the inter-annual monitoring of dynamic grassland systems. We use hourly repeat photography and the Green Chromatic Coordinate vegetation index to characterize the vegetative phenology of several native and exotic grassland communities. Monthly vegetation surveys allow us to correlate plant functional groups with indicator features on the phenology profile. C4-dominated grasslands are characterized by a consistent low greenness during winter, the commencement of greening in late spring/early summer and the retention of green vegetation throughout the summer. Exotic C4 grasslands can be distinguished from native ecosystems by their early-spring flush of annual grasses and forbs prior to the primary greening in late spring/early summer. Native C3 grasslands are more variable in response to rainfall and exhibit multiple greening/browning cycles within the year. They tend to green up earlier in the spring and brown off rapidly in response to high temperatures and low rainfall. Exotic C3 grasslands also green up in early spring but exhibit a more traditional unimodal

  19. Advances in research of complement component 3%C3研究进展

    Institute of Scientific and Technical Information of China (English)

    余新沛; 陈政良

    2004-01-01

    C3是3条补体激活途径的交汇点,系机体防御体系[档但其活化失调则会导致组织细胞损害,且其与病原体相互作用为微生物逃避补体攻击提供了可能.因此,深入了解C3的分子结构及其与其它蛋白、病原体、细胞的相互作用,对补体系统研究以及补体相关疾病和感染性疾病的治疗均有重要意义.

  20. Dark Matter Search Results from the PICO-2L C$_3$F$_8$ Bubble Chamber

    CERN Document Server

    Amole, C; Asner, D M; Baxter, D; Behnke, E; Bhattacharjee, P; Borsodi, H; Bou-Cabo, M; Brice, S J; Broemmelsiek, D; Clark, K; Collar, J I; Cooper, P S; Crisler, M; Dahl, C E; Daley, S; Das, M; Debris, F; Dhungana, N; Farine, J; Felis, I; Filgas, R; Fines-Neuschild, M; Girard, F; Giroux, G; Hai, M; Hall, J; Harris, O; Jackson, C M; Jin, M; Krauss, C B; Lafrenière, M; Laurin, M; Lawson, I; Levine, I; Lippincott, W H; Mann, E; Martin, J P; Maurya, D; Mitra, P; Neilson, R; Noble, A J; Plante, A; Podviianiuk, R B; Priya, S; Robinson, A E; Ruschman, M; Scallon, O; Seth, S; Sonnenschein, A; Starinski, N; Štekl, I; Vàzquez-Jaùregui, E; Wells, J; Wichoski, U; Zacek, V; Zhang, J

    2015-01-01

    New data are reported from the operation of a 2-liter C$_3$F$_8$ bubble chamber in the 2100 meter deep SNOLAB underground laboratory, with a total exposure of 211.5 kg-days at four different recoil energy thresholds ranging from 3.2 keV to 8.1 keV. These data show that C3F8 provides excellent electron recoil and alpha rejection capabilities at very low thresholds, including the first observation of a dependence of acoustic signal on alpha energy. Twelve single nuclear recoil event candidates were observed during the run. The candidate events exhibit timing characteristics that are not consistent with the hypothesis of a uniform time distribution, and no evidence for a dark matter signal is claimed. These data provide the most sensitive direct detection constraints on WIMP-proton spin-dependent scattering to date, with significant sensitivity at low WIMP masses for spin-independent WIMP-nucleon scattering.

  1. Inseparability of colours through dynamical breaking of SUsub(C)(3)

    International Nuclear Information System (INIS)

    A class of feasible quark field models based on the assumption that the quarks are the only carriers of colours is discussed. The forces between quarks are described by local but non-linear interaction between quark fields. Such models are much closer than QCD to the - so far very successful - naive quark model with colours. It is shown that inseparability and localization of colours, which are two basic conditions of quark confinement, are of dynamical nature. In particular, inseparability is simply incompatible with rigorous SUsub(C)(3) invariance. Therefore, explicit dynamical SUsub(C)(3) breaking is proposed in such a form that makes only the white currents strictly conserved. The resulting field equations imply manifest inseparability of colours. (author)

  2. Radioprotection of C3H mice by recombinant human interleukin-1α

    International Nuclear Information System (INIS)

    High doses of rHIL-1 protected C3H/HeN mice against lethal radiation damage. The optimum time of radioprotection was found when this cytokine was administered at 4 h and at 20 h before irradiation. The dose reduction factors when the IL-1 was administered at those times were about 1.30. The radio-protection at the optimum times was also observed in the cell kinetic behaviour of GM-CFC in the bone marrow. In previous studies it was reported that less radioprotection was found in C3H/HeN mice pretreated with IL-1. This may not be the case with a higher dose of IL-1. (author)

  3. Dark Matter Search Results from the PICO-2L C3F8 Bubble Chamber

    Energy Technology Data Exchange (ETDEWEB)

    Amole, C.; Ardid, M.; Asner, David M.; Baxter, D.; Behnke, E.; Bhattacharjee, P. S.; Borsodi, H.; Bou-Cabo, M.; Brice, S. J.; Broemmelsiek, D.; Clark, K.; Collar, J. I.; Cooper, P. S.; Crisler, M.; Dahl, C. E.; Daley, S.; Das, Madhusmita; Debris, F.; Dhungana, N.; Farine, J.; Felis, I.; Filgas, R.; Fines-Neuschild, M.; Girard, Francoise; Giroux, G.; Hai, M.; Hall, Jeter C.; Harris, O.; Jackson, C. M.; Jin, M.; Krauss, C. B.; Lafreniere, M.; Laurin, M.; Lawson, I.; Levine, I.; Lippincott, W. H.; Mann, E.; Martin, J. P.; Maurya, D.; Mitra, Pitam; Neilson, R.; Noble, A. J.; Plante, A.; Podviianiuk, R. B.; Priya, S.; Robinson, A. E.; Ruschman, M.; Scallon, O.; Seth, S.; Sonnenschein, Andrew; Starinski, N.; Stekl, I.; Vazquez-Jauregui, E.; Wells, J.; Wichoski, U.; Zacek, V.; Zhang, J.

    2015-06-12

    New data are reported from the operation of a 2-liter C3F8 bubble chamber in the 2100 meter deep SNOLAB underground laboratory, with a total exposure of 211.5 kg-days at four different recoil energy thresholds ranging from 3.2 keV to 8.1 keV. These data show that C3F8 provides excellent electron recoil and alpha rejection capabilities at very low thresholds, including the rst observation of a dependence of acoustic signal on alpha energy. Twelve single nuclear recoil event candidates were observed during the run. The candidate events exhibit timing characteristics that are not consistent with the hypothesis of a uniform time distribution, and no evidence for a dark matter signal is claimed. These data provide the most sensitive direct detection constraints on WIMP-proton spin-dependent scattering to date, with signicant sensitivity at low WIMP masses for spin-independent WIMP-nucleon scattering.

  4. Morphometric studies with attached mouse C3H/10T 1/2 cells

    International Nuclear Information System (INIS)

    Studies of in vitro transformation using the Syrian hamster embryo cell system and the mouse C3H/10T 1/2 cell system form an integral part of this laboratory's activities. As part of the studies with the mouse cell line we have monitored the behavior of these cells in culture in order to ascertain those variables which might influence the expression of transformation. The study of transformed cells versus normal cells could lead to insight into an earlier definition of transformation that the clonal morphological change currently in use. This present report details the changes in cellular morphology with time in culture of normal mouse C3H/10T 1/2 cells from early passages (9 to 13) and x-ray transformed cells which have been maintained in culture for three years

  5. Low Serum Complement C3 Levels at Diagnosis of Renal ANCA-Associated Vasculitis Is Associated with Poor Prognosis

    Science.gov (United States)

    Augusto, Jean-François; Langs, Virginie; Demiselle, Julien; Lavigne, Christian; Brilland, Benoit; Duveau, Agnès; Poli, Caroline; Chevailler, Alain; Croue, Anne; Tollis, Frederic; Sayegh, Johnny; Subra, Jean-François

    2016-01-01

    Background Recent studies have demonstrated the key role of the complement alternative pathway (cAP) in the pathophysiology of experimental ANCA-associated vasculitis (AAV). However, in human AAV the role of cAP has not been extensively explored. In the present work, we analysed circulating serum C3 levels measured at AAV onset and their relation to outcomes. Methods We conducted a retrospective observational cohort study including 45 consecutive patients with AAV diagnosed between 2000 and 2014 with serum C3 measurement at diagnosis, before immunosuppressive treatment initiation. Two groups were defined according to the median serum C3 level value: the low C3 group (C3C3 level group (C3≥120 mg/dL). Patient and renal survivals, association between C3 level and renal pathology were analysed. Results Serum complement C3 concentration remained in the normal range [78–184 mg/dL]. Compared with the high C3 level, the patients in the low C3 level group had lower complement C4 concentrations (P = 0.008) and lower eGFR (P = 0.002) at diagnosis. The low C3 level group had poorer patient and death-censored renal survivals, compared with the high C3 level group (P = 0.047 and P = 0.001, respectively). We observed a significant negative correlation between C3 levels and the percentage of glomeruli affected by cellular crescent (P = 0.017, r = -0.407). According to the Berden et al renal histologic classification, patients in the crescentic/mixed category had low C3 levels more frequently (PC3 level, long term renal survival was significantly greater in the high C3 level group than in the low C3 level group (100% vs 40.7% at 6 years, p = 0.046). No relationship between serum C4 and renal outcome was observed. Conclusion A Low C3 serum level in AAV patients at diagnosis is associated with worse long-term patient and renal survival. PMID:27391243

  6. C3PO: A Network and Application Framework for Spontaneous and Ephemeral Social Networks

    OpenAIRE

    Boutet, Antoine; Frenot, Stephane; Laforest, Frederique; Launay, Pascale; Le Sommer, Nicolas; Maheo, Yves; Reimert, Damien

    2015-01-01

    The C3PO project promotes the development of new kind of social networks called Spontaneous and Ephemeral Social Networks (SESNs) dedicated to happenings such as cultural or sport events. SESNs rely on both opportunistic networks formed dynamically by the mobile devices of event attendees, and on an event-based communication model. Therefore, user can exchange digital contents with the other members of their SESNs, even without Internet access. This paper presents the framework developed in t...

  7. Relationships between C3b receptor (CR1) activity of erythrocytes and positive Coombs' tests.

    OpenAIRE

    Inada, Y.; Kamiyama, M; Kanemitsu, T; Clark, W S; Asai, Y

    1986-01-01

    Although positive direct Coombs' tests occur in most patients with active systemic lupus erythematosus (SLE), haemolytic anaemic associated with antibody to erythrocytes (E) occurs in less than 10%. Our studies show an association between positive direct Coombs' tests and both the presence of circulating immune complexes and diminished activity of the C3b receptor (CR1) of E. Data presented in this report suggest that in vivo binding of immune complexes and complement by the CR1 of E results ...

  8. C3A Cell Behaviors on Micropatterned Chitosan? Collagen?Gelatin Membranes

    OpenAIRE

    Yu, Bo-Yi; Chou, Pei-Hsun; Chen, Chang-An; Yi-ming SUN; Kung, Shieh-Shiuh

    2007-01-01

    Abstract The influence of the properties and surface micropatterning of chitosan?collagen?gelatin (CCG) blended membranes on C3A cell's activities has been investigated. It is aimed to guide the cell growth and improve the growth rate in vitro for the application in tissue engineering. Masters with micropatterns are prepared on stainless steel plates by photolithography. The CCG membranes with surface micropatterns are then fabricated by soft lithography and dry?wet phase inversion...

  9. Tame automorphisms of C^3 with multidegree of the form (p_1,p_2,d_3)

    OpenAIRE

    Karaś, Marek

    2009-01-01

    Let d_3 >= p_2 > p_1 >= 3 be integers such that p_1,p_2 are prime numbers. In this paper we show that the sequence (p_1,p_2,d_3) is the multidegree of some tame automorphisms of C^3 if and only if d_3 is in p_1*N+p_2*N, i.e. if and only if d_3 is a linear combination of p_1 and p_2 with coefficients in N.

  10. Characterization of a C3 Deoxygenation Pathway Reveals a Key Branch Point in Aminoglycoside Biosynthesis.

    Science.gov (United States)

    Lv, Meinan; Ji, Xinjian; Zhao, Junfeng; Li, Yongzhen; Zhang, Chen; Su, Li; Ding, Wei; Deng, Zixin; Yu, Yi; Zhang, Qi

    2016-05-25

    Apramycin is a clinically interesting aminoglycoside antibiotic (AGA) containing a highly unique bicyclic octose moiety, and this octose is deoxygenated at the C3 position. Although the biosynthetic pathways for most 2-deoxystreptamine-containing AGAs have been well characterized, the pathway for apramycin biosynthesis, including the C3 deoxygenation process, has long remained unknown. Here we report detailed investigation of apramycin biosynthesis by a series of genetic, biochemical and bioinformatical studies. We show that AprD4 is a novel radical S-adenosyl-l-methionine (SAM) enzyme, which uses a noncanonical CX3CX3C motif for binding of a [4Fe-4S] cluster and catalyzes the dehydration of paromamine, a pseudodisaccharide intermediate in apramycin biosynthesis. We also show that AprD3 is an NADPH-dependent reductase that catalyzes the reduction of the dehydrated product from AprD4-catalyzed reaction to generate lividamine, a C3' deoxygenated product of paromamine. AprD4 and AprD3 do not form a tight catalytic complex, as shown by protein complex immunoprecipitation and other assays. The AprD4/AprD3 enzyme system acts on different pseudodisaccharide substrates but does not catalyze the deoxygenation of oxyapramycin, an apramycin analogue containing a C3 hydroxyl group on the octose moiety, suggesting that oxyapramycin and apramycin are partitioned into two parallel pathways at an early biosynthetic stage. Functional dissection of the C6 dehydrogenase AprQ shows the crosstalk between different AGA biosynthetic gene clusters from the apramycin producer Streptomyces tenebrarius, and reveals the remarkable catalytic versatility of AprQ. Our study highlights the intriguing chemistry in apramycin biosynthesis and nature's ingenuity in combinatorial biosynthesis of natural products. PMID:27120352

  11. Synthesis and Antiproliferative Activity of C3' and B-ring Modified Paclitaxel Analogs

    OpenAIRE

    Hodge, Mathis

    2007-01-01

    The natural product, paclitaxel, has made tremendous contributions in supplying the arsenal of anticancer therapeutics, and was FDA approved for clinical use in 1992. In order to design simplified analogs, the conformation that paclitaxel adopts when binding to tubulin has been the subject of ongoing studies. Much evidence has led to a T-taxol proposal and a C3' constrained analog has been designed and synthesized as a test of this conformation. In the search for more active analogs, a number...

  12. Contribution of the Federal Republic of Germany to chapter C.3/C.4

    International Nuclear Information System (INIS)

    The paper refers to chapters C.3 and C.4 of the WG 5C report. Different modes of international FBR activities are examined according to the aspects such as ownership, operation, electricity supply, and safeguards. Examples of realization of international FBR development are given. Three aspects are examined as the main potential incentives for internationalization i.e. environment, economics, non-proliferation; some problems are revealed. Aspects of collocation and internationalization in connection with FBRs are investigated based on 3 concepts

  13. Improvement in photocatalytic H2 evolution over g-C3N4 prepared from protonated melamine

    International Nuclear Information System (INIS)

    Highlights: • Porous g-C3N4 samples (pm-g-C3N4) were prepared by sintering protonated melamine. • Condensation degree of pm-g-C3N4 turns larger with increasing calcination temperature. • The protonation may reduce recombination of photogenerated carriers in pm-g-C3N4. • The highest hydrogen evolution rate of 417 μmol h−1 g−1 was achieved over pm-g-C3N4. - Abstract: Porous g-C3N4 (pm-g-C3N4) samples were prepared by sintering protonated melamine. Photocatalytic activities for H2 production over the g-C3N4 samples were evaluated under visible-light irradiation. Specific surface areas and condensation degree of the g-C3N4 samples prepared from protonated melamine turn larger as the calcination temperatures increase (400 °C, 450 °C, 500 °C, 550 °C, and 580 °C for 1 h). Also, their bandgaps are narrowed and PL peak red shifts, and thus their photocatalytic activities are enhanced. Compared with the reference g-C3N4 samples synthesized by sintering melamine without any protonation (m-g-C3N4), the pm-g-C3N4 samples exhibit better photocatalytic performances, owing to larger specific surface area, less recombination of photogenerated carriers and higher degree of condensation. By optimizing the preparation parameters and the amount of Pt cocatalyst, the highest hydrogen evolution rate of 417 μmol h−1 g−1 was achieved over the pm-g-C3N4 samples synthesized at 550 °C for 2 h, when irradiated by 300-W Xe lamp with a cutoff filter (λ ≥ 420 nm)

  14. Dark Matter Limits From a 2L C3F8 Filled Bubble Chamber

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, Alan Edward [Univ. of Chicago, IL (United States)

    2015-12-01

    The PICO-2L C3F8 bubble chamber search forWeakly Interacting Massive Particle (WIMP) dark matter was operated in the SNOLAB underground laboratory at the same location as the previous CF3I lled COUPP-4kg detector. Neutron calibrations using photoneutron sources in C3F8 and CF3I lled calibration bubble chambers were performed to verify the sensitivity of these target uids to dark matter scattering. This data was combined with similar measurements using a low-energy neutron beam at the University of Montreal and in situ calibrations of the PICO-2L and COUPP-4kg detectors. C3F8 provides much greater sensitivity to WIMP-proton scattering than CF3I in bubble chamber detectors. PICO-2L searched for dark matter recoils with energy thresholds below 10 keV. Radiopurity assays of detector materials were performed and the expected neutron recoil background was evaluated to be 1.6+0:3

  15. Absolute-rate coefficient for C3+(2s→2p) electron-impact excitation

    International Nuclear Information System (INIS)

    We have measured the absolute-rate coefficient for electron-impact excitation (EIE) of C3+(2s 2S1/2→2p 2P1/2,3/2) for energies near threshold. A delayed coincidence technique with inclined beams was used. Radiation from the excited ions was detected using an optical system that subtends slightly over π steradians. At an ion-rest-frame energy of 10.10 eV the measured rate coefficient was (7.79±2.10)x10-8 cm3 s-1 and the measured cross section was (4.15±1.12)x10-16 cm2. The uncertainties quoted here represent the total experimental uncertainty, statistical and systematic, at a confidence level considered to be equivalent to a statistical 90% confidence level. Good agreement is found with other measurements. Agreement is not good with Coulomb-Born with exchange and two-state close-coupling calculations, both of which fall outside our 90% confidence limits. Nine-state close-coupling calculations are in better agreement. However, the calculations lie at the extreme edge of our uncertainty limits. Taking into account previous measurements of EIE in C3+ and also a measurement of EIE in Li-like Be+ that falls significantly below theory at threshold, there is a suggestion that the C3+(2s→2p) EIE rate coefficient near threshold may fall slightly below presently accepted values

  16. C3 coefficients for the alkali atoms interacting with a graphene layer and carbon nanotube

    International Nuclear Information System (INIS)

    We evaluate separation dependent van der Waals dispersion (C3) coefficients for the interactions of the Li, Na, K and Rb atoms with a graphene layer and with a single walled carbon nanotube (CNT) using the hydrodynamic and Dirac models. The results from both the models are evaluated using accurate values of the dynamic polarizabilities of the above alkali atoms. Accountability of accurate dynamic polarizabilities of the alkali atoms to determine the C3 coefficients are accentuated by comparing the obtained coefficients using the precise values of the dynamic dipole polarizabilities against the values estimated from the single oscillator approximation that are generally used in the earlier calculations. For a practical description of the atom–surface interaction potentials, the C3 coefficients are given for a wide range of separation distances between the considered ground states of the atoms and the wall surfaces and also for different nanotube radii. The coefficients for the graphene layer are fitted to a logistic function of the separation distance. For CNT, we find a paraboloid kind of fit dependence both on the separation distances and radii of the CNT. (paper)

  17. Laboratory detection of the C3N an C4H free radicals

    Science.gov (United States)

    Gottlieb, C. A.; Gottlieb, E. W.; Thaddeus, P.; Kawamura, H.

    1983-01-01

    The millimeter-wave spectra of the linear carbon chain free radicals C3N and C4H, first identified in IRC + 10216 and hitherto observed only in a few astronomical sources, have been detected with a Zeeman-modulated spectrometer in laboratory glow discharges through low pressure flowing mixtures of N2 + HC3N and He + HCCH, respectively. Four successive rotational transitions between 168 and 198 GHz have been measured for C3N, and five rotational transitions between 143 and 200 GHz for C4H; each is a well-resolved spin doublet owing to the unpaired electron present in both species. Precise values for the rotational, centrifugal distortion, and spin doubling constants have been obtained, which, with hyperfine constants derived from observations of the lower rotational transitions in the astronomical source TMC 1, allow all the rotational transitions of C3N and C4H at frequencies less than 300 GHz to be calculated to an absolute accuracy exceeding 1 ppm.

  18. Scleral depressed vitreous shaving, 360 laser, and perfluoropropane (C 3 F 8 for retinal detachment

    Directory of Open Access Journals (Sweden)

    Vivek Chaturvedi

    2014-01-01

    Full Text Available Purpose : To review the characteristics and outcomes of patients who underwent pars plana vitrectomy (PPV with scleral depressed vitreous shaving, 360 degree peripheral endolaser, and 14% C3F8 gas for rhegmatogenous retinal detachment (RRD. Materials and Methods : A retrospective review of a consecutive series of patients who underwent primary repair of RRD by PPV with scleral depressed vitreous shaving, 360 degree peripheral endolaser, and 14% perfluoropropane (C 3 F 8 was conducted. Patients with less than 3 months follow-up, previous retinal surgery, and higher than grade B proliferative vitreoretinopathy were excluded. Results : Ninety-one eyes were included in the study. The mean age was 60.1 years. The mean follow-up was 13.7 months. The macula was detached in 63% (58/91 of the eyes. The reattachment rate after one surgical procedure was 95% (86/91 while overall reattachment rate was 100%. There was no statistically significant difference between reattachment rates of superior, nasal/temporal, or inferior RRDs. The mean final best corrected visual acuity (BCVA was 20/40. Of all the patients, 66% of patients with macula-off RRDs had a final BCVA of 20/40 or better. Conclusions: PPV with scleral depressed vitreous shaving, 360 degree peripheral endolaser, and 14% C 3 F 8 leads to successful anatomical reattachment with visual improvement in patients with primary RRD.

  19. In folio study of carbonic anhydrase and Rubisco activities in higher C3 plants using 18O and mass spectrometry

    International Nuclear Information System (INIS)

    This document studies the effects of a mild water stress and carbonic anhydrase activity by ethoxyzolamide (EZA) on the diffusion of CO2 in leaves, by 18O labelling of O2 and of CO2 associated to mass spectrometry. (A.B.). 5 refs., 2 figs

  20. Differential Mobility of Pigment-Protein Complexes in Granal and Agranal Thylakoid Membranes of C-3 and C-4 Plants

    Czech Academy of Sciences Publication Activity Database

    Kirchhoff, H.; Sharpe, R.M.; Herbstová, Miroslava; Yarbrough, R.; Edwards, G.E.

    2013-01-01

    Roč. 161, č. 1 (2013), s. 497-507. ISSN 0032-0889 Institutional support: RVO:60077344 Keywords : Photosystem-II * Photosynthetic membranes * Electron tomography Subject RIV: ED - Physiology Impact factor: 7.394, year: 2013

  1. Potential of knowledge discovery using workflows implemented in the C3Grid

    Science.gov (United States)

    Engel, Thomas; Fink, Andreas; Ulbrich, Uwe; Schartner, Thomas; Dobler, Andreas; Fritzsch, Bernadette; Hiller, Wolfgang; Bräuer, Benny

    2013-04-01

    With the increasing number of climate simulations, reanalyses and observations, new infrastructures to search and analyse distributed data are necessary. In recent years, the Grid architecture became an important technology to fulfill these demands. For the German project "Collaborative Climate Community Data and Processing Grid" (C3Grid) computer scientists and meteorologists developed a system that offers its users a webinterface to search and download climate data and use implemented analysis tools (called workflows) to further investigate them. In this contribution, two workflows that are implemented in the C3Grid architecture are presented: the Cyclone Tracking (CT) and Stormtrack workflow. They shall serve as an example on how to perform numerous investigations on midlatitude winterstorms on a large amount of analysis and climate model data without having an insight into the data source, program code and a low-to-moderate understanding of the theortical background. CT is based on the work of Murray and Simmonds (1991) to identify and track local minima in the mean sea level pressure (MSLP) field of the selected dataset. Adjustable thresholds for the curvature of the isobars as well as the minimum lifetime of a cyclone allow the distinction of weak subtropical heat low systems and stronger midlatitude cyclones e.g. in the Northern Atlantic. The user gets the resulting track data including statistics about the track density, average central pressure, average central curvature, cyclogenesis and cyclolysis as well as pre-built visualizations of these results. Stormtrack calculates the 2.5-6 day bandpassfiltered standard deviation of the geopotential height on a selected pressure level. Although this workflow needs much less computational effort compared to CT it shows structures that are in good agreement with the track density of the CT workflow. To what extent changes in the mid-level tropospheric storm track are reflected in trough density and intensity

  2. Reduced graphene oxide wrapped Cu2O supported on C3N4: An efficient visible light responsive semiconductor photocatalyst

    Science.gov (United States)

    Ganesh Babu, S.; Vinoth, R.; Surya Narayana, P.; Bahnemann, Detlef; Neppolian, B.

    2015-10-01

    Herein, Cu2O spheres were prepared and encapsulated with reduced graphene oxide (rGO). The Cu2O-rGO-C3N4 composite covered the whole solar spectrum with significant absorption intensity. rGO wrapped Cu2O loading caused a red shift in the absorption with respect to considering the absorption of bare C3N4. The photoluminescence study confirms that rGO exploited as an electron transport layer at the interface of Cu2O and C3N4 heterojunction. Utmost, ˜2 fold synergistic effect was achieved with Cu2O-rGO-C3N4 for the photocatalytic reduction of 4-nitrophenol to 4-aminophenol in comparison with Cu2O-rGO and C3N4. The Cu2O-rGO-C3N4 photocatalyst was reused for four times without loss in its activity.

  3. Reduced graphene oxide wrapped Cu2O supported on C3N4: An efficient visible light responsive semiconductor photocatalyst

    Directory of Open Access Journals (Sweden)

    S. Ganesh Babu

    2015-10-01

    Full Text Available Herein, Cu2O spheres were prepared and encapsulated with reduced graphene oxide (rGO. The Cu2O–rGO–C3N4 composite covered the whole solar spectrum with significant absorption intensity. rGO wrapped Cu2O loading caused a red shift in the absorption with respect to considering the absorption of bare C3N4. The photoluminescence study confirms that rGO exploited as an electron transport layer at the interface of Cu2O and C3N4 heterojunction. Utmost, ∼2 fold synergistic effect was achieved with Cu2O–rGO–C3N4 for the photocatalytic reduction of 4-nitrophenol to 4-aminophenol in comparison with Cu2O–rGO and C3N4. The Cu2O–rGO–C3N4 photocatalyst was reused for four times without loss in its activity.

  4. The Complement C3a Receptor Contributes to Melanoma Tumorigenesis by Inhibiting Neutrophil and CD4+ T Cell Responses.

    Science.gov (United States)

    Nabizadeh, Jamileh A; Manthey, Helga D; Steyn, Frederik J; Chen, Weiyu; Widiapradja, Alexander; Md Akhir, Fazrena N; Boyle, Glen M; Taylor, Stephen M; Woodruff, Trent M; Rolfe, Barbara E

    2016-06-01

    The complement peptide C3a is a key component of the innate immune system and a major fragment produced following complement activation. We used a murine model of melanoma (B16-F0) to identify a hitherto unknown role for C3a-C3aR signaling in promoting tumor growth. The results show that the development and growth of B16-F0 melanomas is retarded in mice lacking C3aR, whereas growth of established melanomas can be arrested by C3aR antagonism. Flow cytometric analysis showed alterations in tumor-infiltrating leukocytes in the absence of C3aR. Specifically, neutrophils and CD4(+) T lymphocyte subpopulations were increased, whereas macrophages were reduced. The central role of neutrophils was confirmed by depletion experiments that reversed the tumor inhibitory effects observed in C3aR-deficient mice and returned tumor-infiltrating CD4(+) T cells to control levels. Analysis of the tumor microenvironment showed upregulation of inflammatory genes that may contribute to the enhanced antitumor response observed in C3aR-deficient mice. C3aR deficiency/inhibition was also protective in murine models of BRAF(V600E) mutant melanoma and colon and breast cancer, suggesting a tumor-promoting role for C3aR signaling in a range of tumor types. We propose that C3aR activation alters the tumor inflammatory milieu, thereby promoting tumor growth. Therapeutic inhibition of C3aR may therefore be an effective means to trigger an antitumor response in melanoma and other cancers. PMID:27183625

  5. Isolation of lymphocyte membrane complement receptor type two (the C3d receptor) and preparation of receptor-specific antibody.

    OpenAIRE

    LAMBRIS, J. D.; Dobson, N J; Ross, G D

    1981-01-01

    A glycoprotein binding complement component C3d was isolated from media used for culture of Raji human lymphoblastoid cells. Analysis by sodium dodecyl sulfate/polyacrylamide gel electrophoresis and gas/liquid chromatography indicated that the C3d-binding glycoprotein consisted of a single polypeptide chain with extensive intrachain disulfide bonds, a molecular weight of 72,000, and several different bound carbohydrates. Several lines of evidence indicated that this medium-derived C3d-binding...

  6. Evasion of Complement-Mediated Lysis and Complement C3 Deposition Are Regulated by Francisella tularensis Lipopolysaccharide O Antigen1

    OpenAIRE

    Clay, Corey D.; Soni, Shilpa; Gunn, John S.; Schlesinger, Larry S.

    2008-01-01

    The bacterium Francisella tularensis (Ft) is a potential weapon of bioterrorism when aerosolized. Macrophage infection is necessary for disease progression and efficient phagocytosis by human macrophages requires serum opsonization by complement. Microbial complement activation leads to surface deposition of a highly regulated protein complex resulting in opsonization or membrane lysis. The nature of complement component C3 deposition, i.e., C3b (opsonization and lysis) or C3bi (opsonization ...

  7. Genetic and intervention studies implicating complement C3 as a major target for the treatment of periodontitis1

    OpenAIRE

    Maekawa, Tomoki; Abe, Toshiharu; Hajishengallis, Evlambia; Hosur, Kavita B.; DeAngelis, Robert A.; Ricklin, Daniel; Lambris, John D.; Hajishengallis, George

    2014-01-01

    Chronic periodontitis is induced by a dysbiotic microbiota and leads to inflammatory destruction of tooth-supporting connective tissue and bone. The third component of complement, C3, is a point of convergence of distinct complement activation mechanisms but its involvement in periodontitis was not previously addressed. We investigated this question using two animal species models, namely, C3-deficient or wild-type mice and non-human primates (NHP) locally treated with a potent C3 inhibitor (...

  8. Pneumococcal polysaccharides complexed with C3d bind to human B lymphocytes via complement receptor type 2.

    OpenAIRE

    Griffioen, A W; Rijkers, G T; Janssens-Korpela, P; Zegers, B J

    1991-01-01

    The immunoregulatory function of the complement system has been the focus of many investigations. In particular, fragments of complement factor C3 have been shown to play a role in B-lymphocyte activation and proliferation, lymphokine production, and the generation of in vitro antibody production. Purified pneumococcal polysaccharides (PS) can induce direct activation of C3 via the alternative pathway. Using sera of C1q-deficient patients and healthy subjects, we demonstrated that C3d, a spli...

  9. Elevated atmospheric CO2 triggers compensatory feeding by root herbivores on a C3 but not a C4 grass.

    Directory of Open Access Journals (Sweden)

    Scott N Johnson

    Full Text Available Predicted increases in atmospheric carbon dioxide (CO2 concentrations often reduce nutritional quality for herbivores by increasing the C:N ratio of plant tissue. This frequently triggers compensatory feeding by aboveground herbivores, whereby they consume more shoot material in an attempt to meet their nutritional needs. Little, however, is known about how root herbivores respond to such changes. Grasslands are particularly vulnerable to root herbivores, which can collectively exceed the mass of mammals grazing aboveground. Here we provide novel evidence for compensatory feeding by a grass root herbivore, Sericesthis nigrolineata, under elevated atmospheric CO2 (600 µmol mol(-1 on a C3 (Microlaena stipoides but not a C4 (Cymbopogon refractus grass species. At ambient CO2 (400 µmol mol(-1 M. stipoides roots were 44% higher in nitrogen (N and 7% lower in carbon (C concentrations than C. refractus, with insects performing better on M. stipoides. Elevated CO2 decreased N and increased C:N in M. stipoides roots, but had no impact on C. refractus roots. Root-feeders displayed compensatory feeding on M. stipoides at elevated CO2, consuming 118% more tissue than at ambient atmospheric CO2. Despite this, root feeder biomass remained depressed by 24%. These results suggest that compensatory feeding under elevated atmospheric CO2 may make some grass species particularly vulnerable to attack, potentially leading to future shifts in the community composition of grasslands.

  10. Inhibition of in vitro natural killer activity by the third component of complement: role for the C3a fragment.

    OpenAIRE

    Charriaut, C; Senik, A; Kolb, J P; Barel, M; Frade, R

    1982-01-01

    Purified human native third component of complement, C3, was found to inhibit in vitro natural killer (NK) cell cytotoxicity in both mouse and human systems. The effect was dose and time dependent, a 50% inhibition being reached with 190 nM C3 (35 micrograms/ml) added during the NK assay or after a 30-min preincubation of the effector cells with this C3 concentration. C3 was shown to act at the effector-cell population level because pretreatment of the target cells did not modify the NK lysis...

  11. gp72, the 72 kilodalton glycoprotein, is the membrane acceptor site for C3 on Trypanosoma cruzi epimastigotes

    OpenAIRE

    1985-01-01

    We examined the interaction of complement component C3 with surface molecules on Trypanosoma cruzi. Five- to six-fold more C3 was bound to epimastigotes (Epi) than to metacyclic trypomastigotes (CMT) of strain M88. Epi and CMT were surface iodinated, then incubated in C8-deficient serum, and detergent lysates were applied to anti-C3 antibody that had been coupled to Sepharose. We found that 9.20-10.24% of applied 125I- Epi protein bound to anti-C3-sepharose, compared to 2.64% binding of 125I-...

  12. Identification of OprF as a Complement Component C3 Binding Acceptor Molecule on the Surface of Pseudomonas aeruginosa

    OpenAIRE

    Mishra, Meenu; Ressler, Adam; Schlesinger, Larry S.; Wozniak, Daniel J.

    2015-01-01

    Pseudomonas aeruginosa is a versatile opportunistic pathogen that can cause devastating persistent infections. Complement is a highly conserved pathway of the innate immune system, and its role in the first line of defense against pathogens is widely appreciated. One of the earliest events in the complement cascade is the conversion of C3 to C3a and C3b, the latter typically binds to one or more acceptor molecules on the pathogen surface. We previously demonstrated that complement C3b binding...

  13. Molecular cloning and expression analysis of Pleurodeles waltl complement component C3 under normal physiological conditions and environmental stresses

    OpenAIRE

    Gueguinou, Nathan; Huin-Schohn, Cécile; Ouzren-Zarhloul, Nassima; Ghislin, Stéphanie; Frippiat, Jean-Pol

    2014-01-01

    C3 is a component of the complement system that plays a central role in immunity, development and tissue regeneration. In this study, we isolated the C3 cDNA of the Iberian ribbed newt Pleurodeles waltl. This cDNA encodes a 1637 amino acid protein with an estimated molecular mass of 212.5. kDa. The deduced amino acid sequence showed that P. waltl C3 contains all the conserved domains known to be critical for C3 function. Quantitative real-time PCR (qRT-PCR) demonstrated that under normal phys...

  14. Classical complement pathway activation by antipneumococcal antibodies leads to covalent binding of C3b to antibody molecules.

    OpenAIRE

    Brown, E J; Berger, M.; Joiner, K A; Frank, M. M.

    1983-01-01

    We have examined whether or not a physical relationship exists between antipneumococcal antibodies (Ab) and C3b when Ab activate the classical complement pathway on the surface of pneumococci (Pn). After sensitization with 125I-labeled Ab, Pn were sequentially incubated with purified C1, C4, C2, and biotinylated C3. Ab molecules were then eluted from Pn, and C3b-associated molecules were purified on avidin-Sepharose. Both 125I-labeled immunoglobulin G (IgG) and [125I]IgM bound to C3b; the ass...

  15. Photoelectrochemical Conversion from Graphitic C3N4 Quantum Dot Decorated Semiconductor Nanowires.

    Science.gov (United States)

    An, Tiance; Tang, Jing; Zhang, Yueyu; Quan, Yingzhou; Gong, Xingao; Al-Enizi, Abdullah M; Elzatahry, Ahmed A; Zhang, Lijuan; Zheng, Gengfeng

    2016-05-25

    Despite the recent progress of developing graphitic carbon nitride (g-C3N4) as a metal-free photocatalyst, the synthesis of nanostructured g-C3N4 has still remained a complicated and time-consuming approach from its bulk powder, which substantially limits its photoelectrochemical (PEC) applications as well as the potential to form composites with other semiconductors. Different from the labor-intensive methods used before, such as exfoliation or assistant templates, herein, we developed a facile method to synthesize graphitic C3N4 quantum dots (g-CNQDs) directly grown on TiO2 nanowire arrays via a one-step quasi-chemical vapor deposition (CVD) process in a homemade system. The as-synthesized g-CNQDs uniformly covered over the surface of TiO2 nanowires and exhibited attractive photoluminescence (PL) properties. In addition, compared to pristine TiO2, the heterojunction of g-CNQD-decorated TiO2 nanowires showed a substantially enhanced PEC photocurrent density of 3.40 mA/cm(2) at 0 V of applied potential vs Ag/AgCl under simulated solar light (300 mW/cm(2)) and excellent stability with ∼82% of the photocurrent retained after over 10 h of continuous testing, attributed to the quantum and sensitization effects of g-CNQDs. Density functional theory calculations were further carried out to illustrate the synergistic effect of TiO2 and g-CNQD. Our method suggests that a variety of g-CNQD-based composites with other semiconductor nanowires can be synthesized for energy applications. PMID:27149607

  16. Acylation stimulating protein, complement C3 and lipid metabolism in ketosis-prone diabetic subjects.

    Directory of Open Access Journals (Sweden)

    Yan Liu

    Full Text Available Ketosis-prone diabetes (KPDM is new-onset diabetic ketoacidosis without precipitating factors in non-type 1 diabetic patients; after management, some are withdrawn from exogenous insulin, although determining factors remain unclear.Twenty KPDM patients and twelve type 1 diabetic patients (T1DM, evaluated at baseline, 12 and 24 months with/without insulin maintenance underwent a standardized mixed-meal tolerance test (MMTT for 2 h.At baseline, triglyceride and C3 were higher during MMTT in KPDM vs. T1DM (p<0.0001 with no differences in non-esterified fatty acids (NEFA while Acylation Stimulating Protein (ASP tended to be higher. Within 12 months, 11 KPDM were withdrawn from insulin treatment (KPDM-ins, while 9 were maintained (KPDM+ins. NEFA was lower in KPDM-ins vs. KPDM+ins at baseline (p = 0.0006, 12 months (p<0.0001 and 24 months (p<0.0001 during MMTT. NEFA in KPDM-ins decreased over 30-120 minutes (p<0.05, but not in KPDM+ins. Overall, C3 was higher in KPDM-ins vs KPDM+ins at 12 months (p = 0.0081 and 24 months (p = 0.0019, while ASP was lower at baseline (p = 0.0024 and 12 months (p = 0.0281, with a decrease in ASP/C3 ratio.Notwithstanding greater adiposity in KPDM-ins, greater NEFA decreases and lower ASP levels during MMTT suggest better insulin and ASP sensitivity in these patients.

  17. Synthesis and antitumor evaluation of C3/C3 fluoroquinolone dimers (I): Tethered with a fused heterocyclic s-triazolo[2,1-b][1,3,4]thiadiazole

    Institute of Scientific and Technical Information of China (English)

    Guo

    2010-01-01

    Five C3/C3 fluoroquinolone dimers tethered with a fused heterocyclic ring of s-triazolo[2,1-b][1,3,4]thiadiazole derived from antibacterial quinolones were synthesized and characterized, and their in vitro antitumor activity against L1210, CHO cell lines was evaluated via the respective IC50 values.

  18. Complement C3 and C-reactive protein levels in patients with coronary artery disease%冠心病患者血清C3和CRP的水平分析

    Institute of Scientific and Technical Information of China (English)

    顾万建; 张春兵; 薛亚晶

    2007-01-01

    目的 了解C3、CRP与冠心病(CAN)的相关性.方法 测定40名病人(经冠状动脉造影术确诊为典型冠心病)及40名年龄、性别相当的正常对照人群的血清C3、CRP、CHO、TG、HDL、LDL及空腹血糖水平.结果 病人组的C3、CRP水平明显高于正常对照组(C3分别为2.94g/l和1.43g/1,P<0.001;CRP分别为19.32mg/l和5.71m/l,P=0.005).通过包括C3、CRP、CHO、TG、HDL、LDL及空腹血糖等参数的相关分析,C3与冠心病是独立相关的.结论 CAD病人血清C3和CRP水平是升高的,且C3比CRP具有更好的相关性.

  19. A C3 Symmetric Nitrate Complex with a Thiophene-Based Tripodal Receptor

    OpenAIRE

    Işiklan, Muhammet; Saeed, Musabbir A.; Pramanik, Avijit; Wong, Bryan M.; Fronczek, Frank R.; Hossain, Alamgir

    2011-01-01

    A thiophene-based tripodal receptor has been synthesized and its complexes with nitrate and iodide have determined by single-crystal X-ray analysis. In the nitrate complex, one nitrate is encapsulated in a selective orientation forming a C3 symmetric complex, which is bonded to three protonated secondary amines with six NH···O bonds. The anion is coordinated in a plane perpendicular to the principal rotation axis passing through the tertiary nitrogen of the receptor and the nitrogen of the en...

  20. Using 501c3 Foundations in the Care of Cleft and Craniofacial Children.

    Science.gov (United States)

    Smith, Kevin S; Henry, Byron T

    2016-05-01

    This article relates to the use of 501c3 foundations in the care of patients with cleft and craniofacial disorders. Both authors are medical directors and founders of foundations that serve these children: A Smile for a Child Foundation was set up to help children locally; Free to Smile was set up as an international missions foundation. This article explores the advantages and disadvantages of each type of foundation as well as the struggles and successes foundations face to help children locally and internationally. PMID:27150307

  1. Detection of hypoxic cells in a C3H mouse mammary carcinoma using the comet assay.

    OpenAIRE

    Olive, P. L.; Horsman, M R; C. Grau; Overgaard, J.

    1997-01-01

    The comet assay was used to estimate radiobiological hypoxic fraction across a full range of tumour oxygenations in C3H mammary tumours implanted into the feet of female CDF1 mice. Tumours were either clamped before irradiation or mice were allowed to breath air, 100% oxygen, carbogen or carbon monoxide for 5-35 min before and during exposure to 15 Gy. For the alkaline comet assay, tumours were excised after irradiation and individual tumour cells were analysed for DNA single-strand breaks. H...

  2. C2—(C3—)Continuous Interpolation Spline Curve and Surface

    Institute of Scientific and Technical Information of China (English)

    方逵; 谭建荣; 等

    1998-01-01

    Free-formed or sculptured surfaces in engineering products are frequently constructed from a set of measured 3D data points.C2-(C3-)continuity approach is important in this field.This paper presents a method of rectangular interpolation of given 3D data array which is regularly arranged.The interpolation surface which is constructed by tensor product has dsirable properties(second-order or third-order continuity,locality)and is implemented and adjusted easily,Higher order continuity methods are also briefly discussed.

  3. Classification of thermal stresses and calculation of the C3 stress index in component fatigue analysis

    International Nuclear Information System (INIS)

    The ASME Boiler and Pressure Vessel Code Section III requires the evaluation of secondary stresses due to thermal transient loadings. At gross structural or material discontinuities it is especially critical to determine this stress correctly since it is tied directly to the penalty factor, Ke, on the alternating stress. This paper will provide a method by which the secondary thermal stress can be extracted from the total thermal stress in NB-3200 piping component analysis. Two examples are provided which illustrate the method and the potential benefits. In addition there is a discussion of how the C3 stress index of NB-3600 can be justifiably reduced using these same methods

  4. Synthesis and antitumor evaluation of fluoroquinolone C3 fused heterocycles (Ⅱ): From triazolothiadiazines to pyrazolotriazoles

    Institute of Scientific and Technical Information of China (English)

    Guo Qiang Hu; Wen Long Huang; Li Li Hou; Yong Yang; Lei Yi; Song Qiang Xie; Guo Qiang Wang; Nan Nan Duan; Tie Yao Chao; Xiao Yi Wen

    2011-01-01

    To further expand an effective modified route for the shift from an antibacterial fluoroquinolone (FQ) to an antitumor FQ, two series of title compounds based on an isostere of the FQ C3 carboxylic group with two fused heterocyclic rings, [l,2,4]triazolo[3,4-6][l,3,4]thiadiazine and pyrazolo[5,l-c][l,2,4]triazole, respectively, were designed and synthesized starting from the current antibacterial FQs, and their in vitro antitumor activity against L1210, CHO cell lines were evaluated via their respective IC50 values.

  5. Adsorption behavior of conjugated {C}3-oligomers on Si(100) and HOPG surfaces

    CERN Document Server

    Mahieu, G; Stiévenard, Didier; Krzeminski, Christophe; Delerue, Christophe; Roncali, Jean; Martineau, C; 10.1021/la026907n

    2012-01-01

    A pi-conjugated {C}3h-oligomer involving three dithienylethylene branches bridged at the meta positions of a central benzenic core has been synthesized and deposited either on the Si(100) surface or on the HOPG surface. On the silicon surface, scanning tunneling microscopy allows the observation of isolated molecules. Conversely, by substituting the thiophene rings of the oligomers with alkyl chains, a spontaneous ordered film is observed on the HOPG surface. As the interaction of the oligomers is different with both surfaces, the utility of the Si(100) surface to characterize individual oligomers prior to their use into a 2D layer is discussed.

  6. Clinical significance of serum C3 level in patients with liver diseases%肝病患者血清补体C3检测的临床意义

    Institute of Scientific and Technical Information of China (English)

    邱国华; 高媛娇; 申戈; 路遥; 张璐; 王琳; 李明慧; 谢尧

    2012-01-01

    目的 研究血清补体C3水平与不同类型肝病进程之间的关系.方法 检测1060例肝病患者的血清补体C3浓度,按其病情分组,并进行组间比较.结果 急性肝炎组、慢性肝炎组、肝细胞癌组、肝硬化组和重型肝炎组,其补体C3水平依次降低.急性肝炎组补体C3水平在正常值范围内,重型肝炎组的补体C3水平最低.肝细胞癌组补体C3水平较肝硬化组增高.肝硬化及肝细胞癌合并自发性腹膜炎(SBP)的补体C3水平较未合并SBP组低,差异具有统计学意义(P<0.05).结论 血清补体C3水平与肝病类型密切相关,可以预测疾病的预后,具有重要的临床意义.%Objective To investigate whether serum complement C3 concentrations have prognostic relevance for patients with different stages of liver diseases. Methods Total of 1060 cases were reviewed which were divided into different groups according to pathogenetic conditions ( acute hepatitis, chronic hepatitis, severe hepatitis, liver cirrhosis and hepatocellular carcinoma ). Serum complement C3 concentrations were analysed and compared among each group, respectively. Results In acute hepatitis, chronic hepatitis, liver cirrhosis, HCC and severe hepatitis groups, the levels of serum complement C3 decreased in order. The level of complement C3 was within nomal range in acute hepatitis group and the lowest in severe hepatitis group, which increased in HCC group compared with liver cirrhosis group. The levels of complement C3 in cirrhosis and HCC groups with spontaneous bacterial peritonitis ( SBP ) were lower than patients without SBP, and there were significant differences. Conclusions The level of serum complement C3 is an important index to evaluate the liver function of patients with liver diseases and is closely related to the type of liver diseases which could predict the prognosis of the diseases.

  7. BiOBr/protonated graphitic C3N4 heterojunctions: Intimate interfaces by electrostatic interaction and enhanced photocatalytic activity

    International Nuclear Information System (INIS)

    Highlights: • BiOBr/pg-C3N4 was prepared by an electrostatically-driven in-situ growth method. • BiOBr/pg-C3N4 exhibited a superior visible-light activity and stability. • The efficient separation of charges due to the intimate interface of BiOBr/pg-C3N4. - Abstract: In this work, enhanced photocatalytic activity of BiOBr/graphitic C3N4 heterojunctions for degradation of Rhodamine B (RhB) were obtained by the protonation pretreatment of graphitic C3N4 with hydrochloric acid. A possibly electrostatic interaction between protonated graphitic C3N4 (pg-C3N4) and BiOBr provided a closely intimate interface in the heterojunction, which was demonstrated by the results of scanning electron microscopy (SEM) and transmission electron microscopy (TEM). This tight coupling was favorable for the charge transfer between pg-C3N4 and BiOBr, and therefore promoted the effective separation of photogenerated electron–hole pairs. The effect of composition in heterojunctions on photocatalytic activity was investigated, and the optimal photocatalyst with a BiOBr/pg-C3N4 mass ratio of 7:3 showed a superior activity, which was 35.03 and 33.72 times higher than that over pg-C3N4 and BiOBr, respectively. Radical trap experiments confirmed that the holes and superoxide radical species were the main reactive species in the RhB photodegradation process. Moreover, the stability of BiOBr/pg-C3N4 heterojunction was also tested and the RhB degradation efficiency declined by only 9.6% after seven successive cycles

  8. 补体C3与心房纤颤关系的临床研究%Clinical study on relationship between complement C3 and atrial fibrillation

    Institute of Scientific and Technical Information of China (English)

    熊祖员

    2010-01-01

    目的 研究补体C3与心房纤颤(房颤)的关系.方法 采用免疫速率散射比浊法对56例房颤患者和35例正常对照组进行了血清C3水平测定.结果 房颤患者血清补体C3水平明显高于正常对照组(P<0.05),持续性房颤C3水平明显高于阵发性房颤组(P<0.05).结论 血清C3水平增高可能是房颤的发生和持续重要危险因素之一.

  9. Formation and characterization of classical pathway C3 convertase of complement system in vitro%补体经典激活途径C3转化酶的体外组装及活性观察

    Institute of Scientific and Technical Information of China (English)

    邹强; 郑萍; 谢佩蓉; 李华; 郭波

    2002-01-01

    目的体外组装包含人C4分子的补体经典激活途径C3转化酶,并对其转化酶活性及衰变特性进行观察.方法利用豚鼠血清功能纯C1、C2及溶血中间体EAC4hu体外组装经典途径C3转化酶,观察不同C1、C2用量及孵育温度对C3转化酶形成和自发性衰变的影响,以及人红细胞膜抽提蛋白对C3转化酶衰变的影响.结果高剂量和低剂量的C1均会影响C3转化酶的形成,增加C2用量可增加C3转化酶的形成数量,C3转化酶的自发性衰变随孵育温度的升高而加速,人红细胞膜抽提蛋白可抑制C3转化酶的自发性衰变过程.结论C1、C2用量及孵育温度是影响C3转化酶形成和自发性衰变的主要因素,体外组装的补体经典激活途径C3转化酶可应用于相关补体调控蛋白的活性检测.

  10. Postoperative Atypical Hemolytic Uremic Syndrome Associated with Complement C3 Mutation

    Directory of Open Access Journals (Sweden)

    Eiji Matsukuma

    2014-01-01

    Full Text Available Atypical hemolytic uremic syndrome (aHUS can be distinguished from typical or Shiga-like toxin-induced HUS. The clinical outcome is unfavorable; up to 50% of affected patients progress to end-stage renal failure and 25% die during the acute phase. Multiple conditions have been associated with aHUS, including infections, drugs, autoimmune conditions, transplantation, pregnancy, and metabolic conditions. aHUS in the nontransplant postsurgical period, however, is rare. An 8-month-old boy underwent surgical repair of tetralogy of Fallot. Neurological disturbances, acute renal failure, thrombocytopenia, and microangiopathic hemolytic anemia developed 25 days later, and aHUS was diagnosed. Further evaluation revealed that his complement factor H (CFH level was normal and that anti-FH antibodies were not detected in his plasma. Sequencing of his CFH, complement factor I, membrane cofactor protein, complement factor B, and thrombomodulin genes was normal. His ADAMTS-13 (a disintegrin-like and metalloprotease with thrombospondin-1 repeats 13 activity was also normal. However, he had a potentially causative mutation (R425C in complement component C3. Restriction fragment length polymorphism analysis revealed that his father and aunt also had this mutation; however, they had no symptoms of aHUS. We herein report a case of aHUS that developed after cardiovascular surgery and was caused by a complement C3 mutation.

  11. Dark Matter Search Results from the PICO-2L C3F8 Bubble Chamber

    Science.gov (United States)

    Amole, C.; Ardid, M.; Asner, D. M.; Baxter, D.; Behnke, E.; Bhattacharjee, P.; Borsodi, H.; Bou-Cabo, M.; Brice, S. J.; Broemmelsiek, D.; Clark, K.; Collar, J. I.; Cooper, P. S.; Crisler, M.; Dahl, C. E.; Daley, S.; Das, M.; Debris, F.; Dhungana, N.; Farine, J.; Felis, I.; Filgas, R.; Fines-Neuschild, M.; Girard, F.; Giroux, G.; Hai, M.; Hall, J.; Harris, O.; Jackson, C. M.; Jin, M.; Krauss, C. B.; Lafrenière, M.; Laurin, M.; Lawson, I.; Levine, I.; Lippincott, W. H.; Mann, E.; Martin, J. P.; Maurya, D.; Mitra, P.; Neilson, R.; Noble, A. J.; Plante, A.; Podviianiuk, R. B.; Priya, S.; Robinson, A. E.; Ruschman, M.; Scallon, O.; Seth, S.; Sonnenschein, A.; Starinski, N.; Štekl, I.; Vázquez-Jáuregui, E.; Wells, J.; Wichoski, U.; Zacek, V.; Zhang, J.; PICO Collaboration

    2015-06-01

    New data are reported from the operation of a 2 liter C3F8 bubble chamber in the SNOLAB underground laboratory, with a total exposure of 211.5 kg days at four different energy thresholds below 10 keV. These data show that C3F8 provides excellent electron-recoil and alpha rejection capabilities at very low thresholds. The chamber exhibits an electron-recoil sensitivity of 98.2 %. These data also include the first observation of a dependence of acoustic signal on alpha energy. Twelve single nuclear recoil event candidates were observed during the run. The candidate events exhibit timing characteristics that are not consistent with the hypothesis of a uniform time distribution, and no evidence for a dark matter signal is claimed. These data provide the most sensitive direct detection constraints on WIMP-proton spin-dependent scattering to date, with significant sensitivity at low WIMP masses for spin-independent WIMP-nucleon scattering.

  12. Postoperative atypical hemolytic uremic syndrome associated with complement c3 mutation.

    Science.gov (United States)

    Matsukuma, Eiji; Imamura, Atsushi; Iwata, Yusuke; Takeuchi, Takamasa; Yoshida, Yoko; Fujimura, Yoshihiro; Fan, Xinping; Miyata, Toshiyuki; Kuwahara, Takashi

    2014-01-01

    Atypical hemolytic uremic syndrome (aHUS) can be distinguished from typical or Shiga-like toxin-induced HUS. The clinical outcome is unfavorable; up to 50% of affected patients progress to end-stage renal failure and 25% die during the acute phase. Multiple conditions have been associated with aHUS, including infections, drugs, autoimmune conditions, transplantation, pregnancy, and metabolic conditions. aHUS in the nontransplant postsurgical period, however, is rare. An 8-month-old boy underwent surgical repair of tetralogy of Fallot. Neurological disturbances, acute renal failure, thrombocytopenia, and microangiopathic hemolytic anemia developed 25 days later, and aHUS was diagnosed. Further evaluation revealed that his complement factor H (CFH) level was normal and that anti-FH antibodies were not detected in his plasma. Sequencing of his CFH, complement factor I, membrane cofactor protein, complement factor B, and thrombomodulin genes was normal. His ADAMTS-13 (a disintegrin-like and metalloprotease with thrombospondin-1 repeats 13) activity was also normal. However, he had a potentially causative mutation (R425C) in complement component C3. Restriction fragment length polymorphism analysis revealed that his father and aunt also had this mutation; however, they had no symptoms of aHUS. We herein report a case of aHUS that developed after cardiovascular surgery and was caused by a complement C3 mutation. PMID:25431709

  13. Dark Matter Search Results from the PICO-2L C3F8 Bubble Chamber.

    Science.gov (United States)

    Amole, C; Ardid, M; Asner, D M; Baxter, D; Behnke, E; Bhattacharjee, P; Borsodi, H; Bou-Cabo, M; Brice, S J; Broemmelsiek, D; Clark, K; Collar, J I; Cooper, P S; Crisler, M; Dahl, C E; Daley, S; Das, M; Debris, F; Dhungana, N; Farine, J; Felis, I; Filgas, R; Fines-Neuschild, M; Girard, F; Giroux, G; Hai, M; Hall, J; Harris, O; Jackson, C M; Jin, M; Krauss, C B; Lafrenière, M; Laurin, M; Lawson, I; Levine, I; Lippincott, W H; Mann, E; Martin, J P; Maurya, D; Mitra, P; Neilson, R; Noble, A J; Plante, A; Podviianiuk, R B; Priya, S; Robinson, A E; Ruschman, M; Scallon, O; Seth, S; Sonnenschein, A; Starinski, N; Štekl, I; Vázquez-Jáuregui, E; Wells, J; Wichoski, U; Zacek, V; Zhang, J

    2015-06-12

    New data are reported from the operation of a 2 liter C3F8 bubble chamber in the SNOLAB underground laboratory, with a total exposure of 211.5 kg days at four different energy thresholds below 10 keV. These data show that C3F8 provides excellent electron-recoil and alpha rejection capabilities at very low thresholds. The chamber exhibits an electron-recoil sensitivity of 98.2%. These data also include the first observation of a dependence of acoustic signal on alpha energy. Twelve single nuclear recoil event candidates were observed during the run. The candidate events exhibit timing characteristics that are not consistent with the hypothesis of a uniform time distribution, and no evidence for a dark matter signal is claimed. These data provide the most sensitive direct detection constraints on WIMP-proton spin-dependent scattering to date, with significant sensitivity at low WIMP masses for spin-independent WIMP-nucleon scattering. PMID:26196790

  14. En bloc resection of a C2-C3 upper cervical chordoma: Technical note

    Directory of Open Access Journals (Sweden)

    Alexander G Weil

    2015-01-01

    Full Text Available Background: Recently, en bloc spondylectomy for upper cervical chordomas has been reported. Most authors utilize the combined approaches (e.g., transoral tumor resection with anterior column reconstruction and primary pharyngeal closure without up-front flap repair. However, the 60% incidence of posterior pharyngeal wall dehiscence delays oral intake, typically requires an additional surgery (e.g. free-flap, and delays radiation therapy. Methods: Here, we demonstrate the efficacy of en bloc C2-C3 spondylectomy for the treatment of upper cervical chordomas utilizing a combined transoral followed by posterior approach. We used a novel anterior de-epithelialized submental island flap (SIF as an underlay graft between the pharyngeal wall and cage/hardware to prevent pharyngeal wound dehiscence. Results: Despite a small pharyngeal fistula, the construct healed and the patient was disease-free 40 months later. Conclusion: En bloc C2-C3 spondylectomy for the treatment of an upper cervical chordoma typically requires a combined transoral and posterior approaches. This required utilization of an anterior SIF to promote adequate wound healing. This maneuver avoided incurring the typical complications of combined approaches (e.g. transoral tumor resection with anterior column reconstruction and primary pharyngeal closure without up-front flap repair.

  15. Measurement of dielectronic recombination for C3+ in a known external electric field

    International Nuclear Information System (INIS)

    Dielectronic recombination (DR) is the dominant recombination mechanism for many ions in high temperature (Te approx-gt 1 x 104 K), low density (ne approx-lt 1x1016 cm-3) plasmas. Because electric fields (generated by the plasma or by the motion of the ions traveling through a magnetic field) can significantly enhance the DR process, measurements are needed of DR in fields of known strength. We have used an inclined beams arrangement and a photon/recombine-ion coincidence technique to measure the C3+ DR rate coefficient through the 2s-2p core transition in an electric field of 12 V cm-1. Our preliminary result of (4.0 ±1.8)x10-10 cm3sec-1, at the 90 percent confidence level, is about 7 times larger than calculated zero field values. Our new value agrees well with a previous measurement from this laboratory. At the 90 percent confidence level, our new measurement appears not to agree with present calculations which include the effects of an external electric field. Our measurement is larger than theoretically predicted and is consistent with the suggestion of experiments (which had large uncertainties in their electric field strengths) that theoretical calculations underestimate field enhanced DR in Li-like, low Z ions. Progress towards measurements of the C3+ DR rate coefficient at other field strengths will also be reported

  16. The Copernicus Climate Change Service (C3S): A European Answer to Climate Change

    Science.gov (United States)

    Thepaut, Jean-Noel

    2016-04-01

    Copernicus is the European Commission's flagship Earth observation programme that delivers freely accessible operational data and information services. ECMWF has been entrusted to operate two key parts of the Copernicus programme, which will bring a consistent standard to the measurement, forecasting and prediction of atmospheric conditions and climate change: • The Copernicus Atmosphere Monitoring Service, CAMS, provides daily forecasts detailing the makeup composition of the atmosphere from the ground up to the stratosphere. • The Copernicus Climate Change Service (C3S) (in development) will routinely monitor and analyse more than 20 essential climate variables to build a global picture of our climate, from the past to the future, as well as developing customisable climate indicators for relevant economic sectors, such as energy, water management, agriculture, insurance, health…. C3S has now taken off and a number of proof-of-concept sectoral climate services have been initiated. This paper will focus on the description and expected outcome of these proof-of-concept activities as well as the definition of a roadmap towards a fully operational European Climate Change Service.

  17. Modeling of C3 I system in laser countermeasure weapon system

    Institute of Scientific and Technical Information of China (English)

    CHEN Chang-xi; GUO Li-hong

    2008-01-01

    With the spectrum extended in modem Electronic War, Laser Countermeasure Weapon will be re-quested in order to snatch up and keep the Electromagnetism-Power in war field. If Command, Control, Com-munications and Intelligence called Double-Army-Power-Implement is applied to general design of Laser Coun-termeasure Weapon System, the efficiency of Weapon System can be greatly improved. The Object-Oriented a-nalysis and design approach based on UML for C3I system architecture was put forward, by which logical archi-tecture described by class diagrams and behavior diagrams can be developed through Object-Oriented analysis,and physical architecture described by component diagrams and deployment diagrams can be developed through Object-Oriented design. The framework of Modeling based UML was firstly set forth, the high process of Com-mand, Control, Intelligence, Surveillance, Reconnaissance and UML Architecture was utilized., Then the Modeling process was particularly discussed through following the core ideology and basic principle of RUP(Rational Unified Process). Next, a series of diagrams of UML diagram which include Activity diagrams, Use Case diagrams, Sequence diagrams, Package diagrams and Class diagrams of system analysis, Component dia-grams, and Deployment diagrams of system design are illustrated in the process of Modeling of C3I system soft-ware. Lastly, some problems that should be noticed in the Modeling process, merit and demerit of model, next works were also put forward.

  18. First Principles Investigation of the C3 Coefficients for Molecular Adsorption on Transition Metal Surfaces

    Science.gov (United States)

    Kara, Abdelkader; Matos, Jeronimo; Yildirim, Handan

    2015-03-01

    C6 coefficients are used to investigate the strength of the long-range interactions for weakly interacting dimers as a function of separation distance. These coefficients are useful both as a measure for the accuracy of the various van der Waals (vdW) inclusive methods as well as reference for use in large-scale molecular dynamics simulations. In the case of molecule-surface interaction, the C3 coefficient is the counterpart to the C6 coefficient that is used for testing the interaction of dimers. We will present the results of the vdW inclusive density functional theory (DFT) calculations evaluating the C3 coefficients for the adsorption of M/X(110) and X(111), with X: Ag, Au, Cu, Pt, Pd, Ni, Rh and M: Benzene, Thiophene, Sexithiophene, Pentacene and Olympicene, as described by the PBE exchange-correlation functional and the self-consistent vdW-DF, optimized vdW-DFs and vdW-DF2 functionals. Work supported by the U.S. Department of Energy Basic Energy Science under Contract No. DE-FG02-11ER16243.

  19. Bound and continuum states of molecular anions C2H- and C3N-

    Science.gov (United States)

    Harrison, Stephen; Tennyson, Jonathan

    2011-02-01

    Recently a number of molecular anions, closed-shell linear carbon chains of the form CnH- and CnN-, have been detected in space. The molecules C2H- and C3N- are investigated by using the R-matrix method to consider electron scattering from the corresponding neutral targets. Initial target calculations are conducted and refined in order to produce target state characteristics similar to the experimental data. A number of different scattering models are tested including static exchange and close-coupling models, and the use of Hartree-Fock or natural orbitals in the close-coupling calculations. The calculations concentrate on bound and resonances states for the anions as well as eigenphase sums, elastic cross-sections and electronic excitation cross-sections for electron collisions with the neutral. It is found that electronic resonances are all too high in energy to be important for anion formation in the interstellar medium. However, C3N-, unlike C2H-, supports a number of very weakly bound excited states, which may well provide the route to electron attachment for this system.

  20. Genetic variants of complement component 3 (C3) in DR4 positive and DR4 negative rheumatoid arthritis.

    OpenAIRE

    Thomson, W; Dyer, P A; Sanders, P A; Grennan, D M

    1986-01-01

    C3 allotypes were defined in 86 Caucasoid patients with rheumatoid arthritis living in the north west of England and in 80 local, healthy controls. C3 allotype and phenotype frequencies were similar in RA (whether DR4 positive or negative) and control groups.

  1. Human plasma complement C3 is independently associated with coronary heart disease, but only in heavy smokers (the CODAM study)

    NARCIS (Netherlands)

    Greevenbroek, van M.M.J.; Jacobs, M.; Kallen, van der C.J.H.; Blaak, E.E.; Jansen, E.H.J.M.; Schalkwijk, C.G.; Feskens, E.J.M.; Stehouwer, C.D.A.

    2012-01-01

    Background - Complement C3 is an emerging risk factor for coronary heart disease (CHD) and is particularly increased in the metabolic syndrome. A direct effect of smoking on structure and function of complement C3 has been suggested. Hypothesis - Smoking behavior may affect the cardiovascular risk t

  2. Analysis of C3 suggests three periods of positive selection events and different evolutionary patterns between fish and mammals.

    Directory of Open Access Journals (Sweden)

    Fanxing Meng

    Full Text Available BACKGROUND: The third complement component (C3 is a central protein of the complement system conserved from fish to mammals. It also showed distinct characteristics in different animal groups. Striking features of the fish complement system were unveiled, including prominent levels of extrahepatic expression and isotypic diversity of the complement components. The evidences of the involvement of complement system in the enhancement of B and T cell responses found in mammals indicated that the complement system also serves as a bridge between the innate and adaptive responses. For the reasons mentioned above, it is interesting to explore the evolutionary process of C3 genes and to investigate whether the huge differences between aquatic and terrestrial environments affected the C3 evolution between fish and mammals. METHODOLOGY/PRINCIPAL FINDINGS: Analysis revealed that these two groups of animals had experienced different evolution patterns. The mammalian C3 genes were under purifying selection pressure while the positive selection pressure was detected in fish C3 genes. Three periods of positive selection events of C3 genes were also detected. Two happened on the ancestral lineages to all vertebrates and mammals, respectively, one happened on early period of fish evolutionary history. CONCLUSIONS/SIGNIFICANCE: Three periods of positive selection events had happened on C3 genes during history and the fish and mammals C3 genes experience different evolutionary patterns for their distinct living environments.

  3. Spin-forbidden and spin-allowed cyclopropenone (c-H2C3O) formation in interstellar medium

    International Nuclear Information System (INIS)

    Three proposed mechanisms of cyclopropenone (c-H2C3O) formation from neutral species are studied using high-level electronic structure methods in combination with nonadiabatic transition state and collision theories to deduce the likelihood of each reaction mechanism under interstellar conditions. The spin-forbidden reaction involving the singlet electronic state of cyclopenylidene (c-C3H2) and the triplet state of atomic oxygen is studied using nonadiabatic transition state theory to predict the rate constant for c-H2C3O formation. The spin-allowed reactions of c-C3H2 with molecular oxygen and acetylene with carbon monoxide were also investigated. The reaction involving the ground electronic states of acetylene and carbon monoxide has a very large reaction barrier and is unlikely to contribute to c-H2C3O formation in interstellar medium. The spin-forbidden reaction of c-C3H2 with atomic oxygen, despite the high probability of nonadiabatic transition between the triplet and singlet states, was found to have a very small rate constant due to the presence of a small (3.8 kcal mol–1) reaction barrier. In contrast, the spin-allowed reaction between c-C3H2 and molecular oxygen is found to be barrierless, and therefore can be an important path to the formation of c-H2C3O molecule in interstellar environment.

  4. Structural, electronic, and magnetic properties of iron carbide Fe7C3 phases from first-principles theory

    NARCIS (Netherlands)

    Fang, C.M.; Van Huis, M.A.; Zandbergen, H.W.

    2009-01-01

    The iron carbide Fe7C3 exhibits two types of basic crystal structures, an orthorhombic (o-) form and a hexagonal (h-) one. First-principles calculations have been performed for the basic Fe7C3 forms and for the related θ-Fe3C cementite phase. Accurate total-energy calculations show that the stabilit

  5. Visible-light-induced blue MoO3–C3N4 composite with enhanced photocatalytic activity

    International Nuclear Information System (INIS)

    Highlights: • Novel MoO3–C3N4 composite was prepared by a mixing-calcination method. • The MoO3–C3N4 composite shows remarkably enhanced absorption of visible light. • The MoO3–C3N4 composite shows superior visible-light photocatalytic activity. - Abstract: Composite photocatalyst of blue MoO3/g-C3N4 (denoted as MoO3–C3N4) was prepared by a simple mixing-calcination method. The obtained MoO3–C3N4 composite contains a low amount of molybdenum blue and shows remarkably enhanced absorption of visible light and high efficiency for the degradation of methylene blue dye (MB) under visible light. The enhancement of visible light photocatalytic activity in MoO3–C3N4 is attributed to the synergetic effect: (i) the strong and wide absorption of visible light, (ii) the high separation and easy transfer of photogenerated electron–hole pairs at the heterojunction interfaces derived from the match of band position between the g-C3N4 and MoO3

  6. Unique structure of iC3b resolved at a resolution of 24 Å by 3D-electron microscopy

    OpenAIRE

    Alcorlo, Martin; Martínez-Barricarte, Ruben; Fernández, Francisco J.; Rodríguez-Gallego, César; Round, Adam; Vega, M. Cristina; Harris, Claire L.; de Cordoba, Santiago Rodríguez; Llorca, Oscar

    2011-01-01

    Activation of C3, deposition of C3b on the target surface, and subsequent amplification by formation of a C3-cleaving enzyme (C3-convertase; C3bBb) triggers the effector functions of complement that result in inflammation and cell lysis. Concurrently, surface-bound C3b is proteolyzed to iC3b by factor I and appropriate cofactors. iC3b then interacts with the complement receptors (CR) of the Ig superfamily, CR2 (CD21), CR3 (CD11b/CD18), and CR4 (CD11c/CD18) on leukocytes, down-modulating infla...

  7. Impact of the common genetic associations of age-related macular degeneration upon systemic complement component C3d levels.

    Directory of Open Access Journals (Sweden)

    Tina Ristau

    Full Text Available Age-related macular degeneration (AMD is a common condition that leads to severe vision loss and dysregulation of the complement system is thought to be associated with the disease. To investigate associations of polymorphisms in AMD susceptibility genes with systemic complement activation, 2655 individuals were genotyped for 32 single nucleotide polymorphisms (SNPs in or near 23 AMD associated risk genes. Component 3 (C3 and its catabolic fragment C3d were measured in serum and AMD staging was performed using multimodal imaging. The C3d/C3 ratio was calculated and associations with environmental factors, SNPs and various haplotypes of complement factor H (CFH genes and complement factor B (CFB genes were analyzed. Linear models were built to measure the influence of genetic variants on the C3d/C3 ratio. The study cohort included 1387 patients with AMD and 1268 controls. Higher C3d/C3 ratios were found for current smoker (p = 0.002, higher age (p = 1.56 × 10(-7, AMD phenotype (p = 1.15 × 10(-11 and the two SNPs in the C3 gene rs6795735 (p = 0.04 and rs2230199 (p = 0.04. Lower C3d/C3 ratios were found for diabetes (p = 2.87 × 10(-6, higher body mass index (p = 1.00 × 10(-13, the SNPs rs1410996 (p = 0.0001, rs800292 (p = 0.003, rs12144939 (p = 4.60 × 10(-6 in CFH, rs4151667 (p = 1.01 × 10(-5 in CFB and individual haplotypes in CFH and CFB. The linear model revealed a corrected R-square of 0.063 including age, smoking status, gender, and genetic polymorphisms explaining 6.3% of the C3d/C3 ratio. After adding the AMD status the corrected R-square was 0.067. In conclusion, none of the evaluated genetic polymorphisms showed an association with increased systemic complement activation apart from two SNPs in the C3 gene. Major genetic and non-genetic factors for AMD were not associated with systemic complement activation.

  8. Identification of an additional class of C3-binding membrane proteins of human peripheral blood leukocytes and cell lines.

    Science.gov (United States)

    Cole, J L; Housley, G A; Dykman, T R; MacDermott, R P; Atkinson, J P

    1985-02-01

    Proteins binding the third component of complement (C3) were isolated by affinity chromatography from surface-labeled solubilized membranes of human peripheral blood cells and cell lines. The isolated molecules were subjected to NaDodSO4/PAGE, and autoradiographs of these gels indicated that C3-binding proteins could be divided into three groups based on Mr: (i) gp200, an approximately 200,000 Mr molecule previously identified as the C3b/C4b receptor or CR1; (ii) gp140, an approximately 140,000 Mr molecule previously identified as the C3d receptor or CR2; and (iii) gp45-70, a heretofore unrecognized group of 45,000-70,000 Mr C3-binding molecules. The cell distribution, Mr, antigenic cross-reactivity, and specificity of gp45-70 were examined. Erythrocytes have no detectable gp45-70, but all leukocyte populations examined possess this group of molecules. On neutrophils and mononuclear phagocytes, CR1 is the predominant C3-binding glycoprotein, but gp45-70 is present on both cell populations and on macrophage and neutrophil cell lines. B plus null cells, chronic lymphocytic leukemia cells, and an Epstein-Barr virus-transformed B-cell line possess CR1, CR2, and gp45-70. On T cells and T-cell lines gp45-70 is the predominant or, in some cases, the only C3-binding protein isolated. gp45-70 is structurally characterized as a broad band or doublet with a mean Mr that is slightly different for each cell population. gp45-70 binds iC3, C3b, and C4b, but not C3d, indicating that the binding region is probably within the C3c portion of C3b. A polyclonal antibody to CR1 and monoclonal antibodies to CR1 and CR2 do not immunoprecipitate gp45-70. While gp45-70 has not been previously characterized on human cells, a C3b-binding glycoprotein of similar Mr is present on rabbit alveolar macrophages. We conclude that gp45-70 is an additional group of membrane proteins present on human leukocytes that possess ligand-binding activity for C3b. PMID:3871945

  9. Cellular basis of the immunohematologic defects observed in short-term semiallogeneic B6C3F1→C3H chimeras: evidence for host-versus-graft reaction initiated by radioresistant T cells

    International Nuclear Information System (INIS)

    Lethally irradiated C3Hf mice reconstituted with a relatively low dose (2 x 106) of B6C3F1 bone marrow cells (B6C3F1→C3Hf chimeras) frequently manifest immunohematologic deficiencies during the first month following injection of bone marrow cells. They show slow recovery of antibody-forming potential to sheep red blood cells (SRBC) as compared to that observed in syngeneic (C3Hf→C3Hf or B6C3F1→B6C3F1) chimeras. They also show a deficiency of B-cell activity as assessed by antibody response to SRBC following further reconstitution with B6C3F1-derived thymus cells 1 week after injection of bone marrow cells. A significant fraction of B6C3F1→C3Hf chimeras was shown to manifest a sudden loss of cellularity of spleens during the second week following injection of bone marrow cells even though cellularity was restored to the normal level within 1 week. The splenic mononuclear cells recovered from such chimeras almost invariably showed strong cytotoxicity against target cells expressing donor-type specific H-2 antigens (H-2/sup b/) when assesed by 51Cr-release assay in vitro. The effector cells responsible for the observed anti-donor specific cytotoxicity were shown to be residual host-derived T cells. These results indicate strongly that residual host T cells could develop anti-donor specific cytotoxicity even after exposure to a supralethal dose (1050 R) of radiation and that the immunohematologic disturbances observed in shortterm F1 to parent bone marrow chimeras (B6C3F1→C3Hf) were due to host-versus-graft reaction (HVGR) initiated by residual host T cells. The implication of these findings on the radiobiological nature of the residual T cells and the persistence of potentially anti-donor reactive T-cell clones in long-surviving allogeneic bone marrow chimeras was discussed

  10. Corrosion performance of bi-layer Ni/Cr2C3-NiCr HVAF thermal spray coating

    Science.gov (United States)

    Sadeghimeresht, E.; Markocsan, N.; Nylén, P.; Björklund, S.

    2016-04-01

    The corrosion behavior of three HVAF thermal spray coating systems (A: single-layer Ni, B: single-layer Cr2C3-NiCr coatings, and C: bi-layer Ni/Cr2C3-NiCr coating) was comparatively studied using immersion, salt spray, and electrochemical tests. Polarization and EIS results showed that the corrosion behavior of Cr2C3-NiCr coatings in 3.5 wt.% NaCl solution was significantly improved by adding the intermediate layer of Ni. It was illustrated that the polarization resistance of the bi-layer Ni/Cr2C3-NiCr and single-layer Cr2C3-NiCr coatings were around 194 and 38 kΩ cm2, respectively. Microstructure analysis revealed that the bond coating successfully prevented the corrosion propagation toward the coating.

  11. A review on g-C3N4 for photocatalytic water splitting and CO2 reduction

    Science.gov (United States)

    Ye, Sheng; Wang, Rong; Wu, Ming-Zai; Yuan, Yu-Peng

    2015-12-01

    Solar fuel generation through water splitting and CO2 photoreduction is an ideal route to provide the renewable energy sources and mitigate global warming. The main challenge in photocatalysis is finding a low-cost photocatalyst that can work efficiently to split water into hydrogen and reduce CO2 to hydrocarbon fuels. Metal-free g-C3N4 photocatalyst shows great potentials for solar fuel production. In this mini review, we summarize the most current advances on novel design idea and new synthesis strategy for g-C3N4 preparation, insightful ideas on extending optical absorption of pristine g-C3N4, overall water splitting and CO2 photoreduction over g-C3N4 based systems. The research challenges and perspectives on g-C3N4 based photocatalysts were also suggested.

  12. Sonochemical Synthesis of CdS/C3N4 Composites with Efficient Photocatalytic Performance Under Visible Light Irradiation.

    Science.gov (United States)

    Chai, Bo; Wang, Xing

    2016-02-01

    The CdS/C3N4 composites with efficient photocatalytic performance under visible light irradiation were synthesized by a facile sonochemical route. The as-prepared CdS/C3N4 composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution trans- mission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance absorption spectra (DRS), fourier transform infrared spectroscopy (FTIR) and photoluminescence spectra (PL). The photocatalytic degradation of rhodamine B (RhB) by the CdS/C3N4 composites was explored and optimized, suggesting the optimal amount of CdS in the composites was 50 wt%. The significantly enhanced photocatalytic activity of CdS/C3N4 composites could be attributed to the effectively interfacial transfer of photogenerated charge carriers between CdS and C3N4, which restrained the recombination of electron-hole pairs. PMID:27433724

  13. Grain refinement of AZ91D magnesium alloy by a new Mg–50%Al4C3 master alloy

    International Nuclear Information System (INIS)

    A novel and simple method for preparing Mg–50%Al4C3 (hereafter in wt.%) master alloy has been developed by powder in-situ synthesis process under argon atmosphere. X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDS) results show the existence of Al4C3 particles in this master alloy. After adding 1.8% Mg–50%Al4C3 master alloy, the average grain size of α-Mg decreased from 360 μm to 154 μm. Based on the DTA test results and calculation of the planar disregistry between Al4C3 and α-Mg, Al4C3 particles located in the central regions of magnesium grains can act as the heterogeneous nucleus of primary α-Mg phase

  14. Roles for NHERF1 and NHERF2 on the regulation of C3a receptor signaling in human mast cells.

    Directory of Open Access Journals (Sweden)

    Hariharan Subramanian

    Full Text Available BACKGROUND: The anaphylatoxin C3a binds to the G protein coupled receptor (GPCR, C3aR and activates divergent signaling pathways to induce degranulation and cytokine production in human mast cells. Adapter proteins such as the Na(+/H(+ exchange regulatory factor (NHERF1 and NHERF2 have been implicated in regulating functions of certain GPCRs by binding to the class I PDZ (PSD-95/Dlg/Zo1 motifs present on their cytoplasmic tails. Although C3aR possesses a class I PDZ motif, the possibility that it interacts with NHERF proteins to modulate signaling in human mast cells has not been determined. METHODOLOGY/PRINCIPAL FINDINGS: Using reverse transcription PCR and Western blotting, we found that NHERF1 and NHERF2 are expressed in human mast cell lines (HMC-1, LAD2 and CD34(+-derived primary human mast cells. Surprisingly, however, C3aR did not associate with these adapter proteins. To assess the roles of NHERFs on signaling downstream of C3aR, we used lentiviral shRNA to stably knockdown the expression of these proteins in human mast cells. Silencing the expression of NHERF1 and NHERF2 had no effect on C3aR desensitization, agonist-induced receptor internalization, ERK/Akt phosphorylation or chemotaxis. However, loss of NHERF1 and NHERF2 resulted in significant inhibition of C3a-induced mast cell degranulation, NF-κB activation and chemokine production. CONCLUSION/SIGNIFICANCE: This study demonstrates that although C3aR possesses a class I PDZ motif, it does not associate with NHERF1 and NHERF2. Surprisingly, these proteins provide stimulatory signals for C3a-induced degranulation, NF-κB activation and chemokine generation in human mast cells. These findings reveal a new level of complexity for the functional regulation of C3aR by NHERFs in human mast cells.

  15. The functional significance of C3-C4 intermediate traits in Heliotropium L. (Boraginaceae): gas exchange perspectives.

    Science.gov (United States)

    Vogan, Patrick J; Frohlich, Michael W; Sage, Rowan F

    2007-10-01

    We demonstrate for the first time the presence of species exhibiting C3-C4 intermediacy in Heliotropium (sensu lato), a genus with over 100 C3 and 150 C4 species. CO2 compensation points (Gamma) and photosynthetic water-use efficiencies (WUEs) were intermediate between C3 and C4 values in three species of Heliotropium: Heliotropium convolvulaceum (Gamma = 20 micromol CO2 mol(-1) air), Heliotropium racemosum (Gamma = 22 micromol mol(-1)) and Heliotropium greggii (Gamma = 17 micromol mol(-1)). Heliotropium procumbens may also be a weak C3-C4 intermediate based on a slight reduction in Gamma (48.5 micromol CO2 mol(-1)) compared to C3Heliotropium species (52-60 micromol mol(-1)). The intermediate species H. convolvulaceum, H. greggii and H. racemosum exhibited over 50% enhancement of net CO2 assimilation rates at low CO2 levels (200-300 micromol mol(-1)); however, no significant differences in stomatal conductance were observed between the C3 and C3-C4 species. We also assessed the response of Gamma to variation in O2 concentration for these species. Heliotropium convolvulaceum, H. greggii and H. racemosum exhibited similar responses of Gamma to O2 with response slopes that were intermediate between the responses of C3 and C4 species below 210 mmol O2 mol(-1) air. The presence of multiple species displaying C3-C4 intermediate traits indicates that Heliotropium could be a valuable new model for studying the evolutionary transition from C3 to C4 photosynthesis. PMID:17727423

  16. Negative regulation of pulmonary Th17 responses by C3a anaphylatoxin during allergic inflammation in mice.

    Directory of Open Access Journals (Sweden)

    Hoyong Lim

    Full Text Available Activation of complement is one of the earliest immune responses to exogenous threats, resulting in various cleavage products including anaphylatoxin C3a. In addition to its contribution to host defense, C3a has been shown to mediate Th2 responses in animal models of asthma. However, the role of C3a on pulmonary Th17 responses during allergic inflammation remains unclear. Here, we show that mice deficient in C3a receptor (C3aR exhibited (i higher percentages of endogenous IL-17-producing CD4(+ T cells in the lungs, (ii higher amounts of IL-17 in the bronchoalveolar lavage fluid, and (iii more neutrophils in the lungs than wild-type mice when challenged with intranasal allergens. Moreover, adoptive transfer experiments showed that the frequencies of antigen-specific IL-17-producing CD4(+ T cells were significantly higher in the lungs and bronchial lymph nodes of C3aR-deficient recipients than those of wild-types recipients. Bone-marrow reconstitution study indicated that C3aR-deficiency on hematopoietic cells was required for the increased Th17 responses. Furthermore, C3aR-deficient mice exhibited increased percentages of Foxp3(+ regulatory T cells; however, depletion of these cells minimally affected the induction of antigen-specific Th17 cell population in the lungs. Neutralization of IL-17 significantly reduced the number of neutrophils in bronchoalveolar lavage fluid of C3aR-deficient mice. Our findings demonstrate that C3a signals negatively regulate antigen-specific Th17 responses during allergic lung inflammation and the size of Foxp3(+ regulatory T cell population in the periphery.

  17. 补体C3基因多态性与相关疾病研究进展%Research Progress of Complement Component 3 (C3) Gene Polymorphism with Related Diseases

    Institute of Scientific and Technical Information of China (English)

    翟瑞燕; 王长法; 仲跻峰; 安利国

    2010-01-01

    在补体各成分中,补体第三组分(C3)在血清中含量最高,是补体系统的核心.C3在功能上不仅处于补体经典途径、甘露糖结合凝集素途径和补体旁路途径三条激活途径的汇合点,还是C3b依赖的阳性反馈环路的基础;而且C3裂解片段及其结合蛋白复杂多样,在免疫防御、免疫调控以及免疫病理中发挥着重要的作用.当C3基因发生突变或缺失时会造成C3缺陷性疾病,常伴发免疫性疾病及反复细菌感染,患者对病原菌感染的易感性显著增加.论文概述了C3基因结构及其多态性以及其与机体易感性的关联性.

  18. Comparion of Complement Activity and C3 Content of Chicken and Mammals%鸡与哺乳动物补体活性与C3含量的比较

    Institute of Scientific and Technical Information of China (English)

    马雪云; 高淑霞; 牛钟相

    2006-01-01

    本文研究了不同动物血清补体水平及其补体C3含量的差异.采取成年鸡、猪、羊、牛、豚鼠五种动物的新鲜血清,测定其补体总活性;生化合成C3α链N端21肽,免疫家兔,制备抗鸡C3抗体,用来测定不同动物血清中C3含量.结果表明,抗鸡C3抗体能够与各种哺乳动物血清中的补体C3发生特异性反应,可以用来测定各种动物血清中的C3含量,测定结果为:鸡血清中的C3含量为0.34士0.005 mg/mL、猪1.47±0.008 mg/mL、山羊1.70±0.005mg/mL、牛1.78±0.007 mg/mL、豚鼠4.18±0.008 mg/mL,其中鸡血清中补体总活性和C3含量都远远低于哺乳动物,差异极显著(P<0.01).

  19. Deficiencia congénita de complemento: C3 y C4: Comunicación de un caso clínico Congenital deficiency of the C3 and C4 fractions of complement: A clinical report

    Directory of Open Access Journals (Sweden)

    ALEXIS STRICKLER P

    2006-06-01

    Full Text Available La deficiencia congénita del 3er constituyente del Complemento (C3 es extremadamente rara, y se expresa clínicamente como un defecto de la inmunidad humoral. Se comunica un caso de deficiencia C3 y C4 en un lactante de sexo femenino de 1 año de edad, hijo de padres consanguíneos, que presentó un cuadro de meningoencefalitis aguda de etiología no precisada, con secuela neurológica severa e infecciones bacterianas recurrentes, respiratorias y urinarias, septicemia y osteomielitis, con respuesta parcial a antimicrobianos. El estudio de inmunidad humoral y celular (subpoblaciones linfocitarias, inmunoglobulinas séricas y subclases de IgG fue normal, demostrándose déficit de C3 y C4 con CH50 ausente en la niña y cifras bajas de C3 y C4, cercanas al 50% del valor normal en ambos padresCongenital deficiency of C3 fraction of the complement is a very rare condition. Clinically it is expressed as a deficiency of the humoral immunity. We report a case of C3 and C4 deficiency in a 1 year old infant girl. Her parents have a high consanguinity. She presented an acute meningoencephalitis of unknown etiology, and she evolved with severe neurological damage, and recurrent respiratory and urinary bacterial infections, sepsis and osteomielitis, with partial response to antimicrobials. The tests to investigate humoral and cellular immune response (lymphocyte subpopulations, serum immunoglobulins and subtypes of IgG were normal. The patient had a deficit of C3 and C4, mainly C3, with absence of CH50. Both of her parents had C3 and C4 about 50% of normal values, and CH50 slightly under the normal values

  20. The Copernicus Climate Change Service (C3S): Open Access to a Climate Data Store

    Science.gov (United States)

    Thepaut, Jean-Noel; Dee, Dick

    2016-04-01

    In November 2014, The European Centre for Medium-range Weather Forecasts (ECMWF) signed an agreement with the European Commission to deliver two of the Copernicus Earth Observation Programme Services on the Commission's behalf. The ECMWF delivered services - the Copernicus Climate Change Service (C3S) and Atmosphere Monitoring Service (CAMS) - will bring a consistent standard to how we monitor and predict atmospheric conditions and climate change. They will maximise the potential of past, current and future earth observations - ground, ocean, airborne, satellite - and analyse these to monitor and predict atmospheric conditions and in the future, climate change. With the wealth of free and open data that the services provide, they will help business users to assess the impact of their business decisions and make informed choices, delivering a more energy efficient and climate aware economy. These sound investment decisions now will not only stimulate growth in the short term, but reduce the impact of climate change on the economy and society in the future. C3S is in its proof of concept phase and through its Climate Data Store will provide • global and regional climate data reanalyses; • multi-model seasonal forecasts; • customisable visual data to enable examination of wide range of scenarios and model the impact of changes; • access to all the underlying data, including climate data records from various satellite and in-situ observations. In addition, C3S will provide key indicators on climate change drivers (such as carbon dioxide) and impacts (such as reducing glaciers). The aim of these indicators will be to support European adaptation and mitigation policies in a number of economic sectors. At the heart of the Service is the provision of open access to a one stop shop (the Climate Data Store) of climate data and modelling, analysing more than 20 Essential Climate Variables to build a global picture of our past, present and future climate and developing

  1. Comparison of physiological and anatomical changes of C3 (Oryza sativa [L.]) and C4 (Echinochloa crusgalli [L.]) leaves in response to drought stress

    Science.gov (United States)

    Hamim, Hamim; Banon, Sri; Dorly, Dorly

    2016-01-01

    The experiment aimed to analyse the different response of C3 (Oryza sativa L.) and C4 (Echinochloa crusgalli L.) species to drought stress based on physiological and anatomical properties. Seeds of rice (Oryza sativa) and Echinochloa (Echinochloa crusgalli) were grown in 15 cm (D) pot for 6 weeks under well-watered conditions. After 6 weeks the plants were divided into two groups, (1) well-watered which were watered daily, and (2) drought stress which were withheld from watering for 6 days. After 6 days of drought, the plants were then re-watered to analyse plant recovery. During drought period, the plants were analysed for growth, leaf relative water content (RWC), photosynthesis, and leaf anatomy. Drought stress significantly reduced leaf RWC of both species, but the reduction was bigger in rice than in Echinochloa. The maximum efficiency of photosynthesis (Fv/Fm) was decrease significantly in response to drought stress by about 48.04% in rice, while it was only 34.40% in Echinochloa. Anatomical analysis showed drought treatment tended to reduce leaf thickness in the area of bulliform cell, major- as well as intervein and xylem diameter, more in Echinochloa than in rice, suggesting that the decrease of vein and xylem diameter is among the anatomical parameters that is important to overcome from drought stress in Echinochloa. The number of chloroplast in the mesophyll cell and bundle sheath cell (BSC) was different between these two species, where in Echinochloa chloroplast was found in both mesophyll as well as BSC, while in rice it was only found in mesophyll cell, confirmed that Echinochloa is a C4 and rice is a C3 species. Interestingly, in Echinochloa, the number of chloroplast was significantly increased due to drought stress in BSC, but not in mesophyll cell. The number of starch granules also dramatically increased in response to drought in the mesophyll cells of rice and Echinochloa, and in the bundle sheath cell of Echinochloa which indicate that C3

  2. Binding of complement component C3b to glycoprotein gC of herpes simplex virus type 1: mapping of gC-binding sites and demonstration of conserved C3b binding in low-passage clinical isolates.

    OpenAIRE

    Friedman, H M; Glorioso, J C; Cohen, G H; Hastings, J C; Harris, S L; Eisenberg, R J

    1986-01-01

    The sites on glycoprotein gC of herpes simplex virus type 1 (HSV-1) which bind complement component C3b were evaluated by using anti-gC monoclonal antibodies and mutants which have alterations at defined regions of the glycoprotein. Monoclonal antibodies were incubated with HSV-1-infected cells in a competitive assay to block C3b binding. Each of 12 different monoclonals, which recognize the four major antigenic sites of gC, completely inhibited C3b binding. With this approach, no one antigen...

  3. To Reduce the Dry Gas Contents of Components above C3 in the Catalytic Cracking%降低催化裂化干气中C3以上组分含量

    Institute of Scientific and Technical Information of China (English)

    李晓伟

    2014-01-01

    介绍了洛阳石化第一套催化干气中C3以上组分含量的现状,通过分析,找出要因,通过持续对要因进行工艺调整和设备防护,将干气中C3以上组分含量控制在1.5%以内,有效的降低了C3以上组分含量含量,并且增加了企业的经济效益.

  4. JRC Copernicus Climate Change Service (C3S) F4P platform

    Science.gov (United States)

    Gobron, Nadine; Adams, Jennifer; Cappucci, Fabrizio; Lanconelli, Christian; Morgan, Olivier; Mota, Bernado; Robustelli, Monica

    2016-07-01

    This paper presents the Climate Change Copernicus Service (C3S) fitness-for-purpose (F4P) platform which is actually developed at the Joint Research Centre. This platform aims at monitoring several Earth Observation (EO) land Essential Climate Variables (ECVs) accuracies by assessing their compliance against GCOS criteria. One component uses a quality 3-D radiative transfer modelled-based approach for assessing 1) the ground-based measurements protocols traditionally used to validate EO products and 2) several space retrieval algorithms. In the second module, we propose an automatic review of their quality at global and regional scale and present new metrics, such as the Gamma Index, to check GCOS criteria compliance, including the stability assessment.

  5. Molecular Structure and Bonding in Plutonium Carbides: A Theoretical Study of PuC3.

    Science.gov (United States)

    Molpeceres, Germán; Rayón, Víctor M; Barrientos, Carmen; Largo, Antonio

    2016-04-14

    The most relevant species of plutonium tricarbide were characterized using theoretical methods. The global minimum is predicted to be a fan structure where the plutonium atom is bonded to a quasi-linear C3 unit. A rhombic isomer, shown to be a bicyclic species with transannular C-C bonding, lies about 39 kJ/mol above the fan isomer. A linear PuCCC isomer and a three-membered ring CPuC2 isomer were found to be higher in energy (150 and 195 kJ/mol, respectively, above the predicted global minimum). The possible processes for the formation of these species are discussed, and the IR spectra were predicted to help in possible experimental detection. The nature of the Pu-C interaction has been analyzed in terms of a topological analysis of the electronic density, showing that Pu-C bonding is essentially ionic with a certain degree of covalent character. PMID:27010701

  6. Synthesis and Antiproliferative Activity of C-3 Functionalized Isobenzofuran-1(3H-ones

    Directory of Open Access Journals (Sweden)

    Fabrício Marques de Oliveira

    2013-02-01

    Full Text Available A series of thirteen C-3 functionalized isobenzofuran-1(3H-ones (phtalides was synthesized via condensation, aromatization, and acetylation reactions. NMR (one and two dimensional experiments, IR, and mass spectrometry analysis allowed confirmation of the identity of the synthesized compounds. The substances were submitted to in vitro bioassays against U937 (lymphoma and K562 (myeloid leukemia cancer cell lines using the MTT cytotoxicity assay. Some derivatives inhibited 90% of cell viability at 100 µM. Also, two phtalides presented biological activity superior than that of etoposide (VP16, a commercial drug used as a positive control in the assays. In silico drug properties of the evaluated compounds were calculated and the results are discussed.

  7. 全新风格毕加索 CITROEN C3 PICASSO

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    在我的记忆里好像C3 Picasso推出并不是很长的时间,不过雪铁龙又推出了这款车型外观小变化的升级版本。前脸的变化最为明显,其实整个前脸的改动都集中在了前保险杠的区域里。新的中网设计很符合雪铁龙最新家族特征,让那个双立人徽标融合在了中网的镀铬饰件上。

  8. Structural properties of a holmium iron carbide interstitial compound, Ho2Fe17C3-x

    International Nuclear Information System (INIS)

    X-ray diffractometric studies were performed on a single-crystalline specimen of the Ho2Fe17C3-x intermetallic alloy. Its crystal data (for x > 2) are a = 8.521 (2), c = 8.309 (2) angstrom, V = 522.5 angstrom 3, hexagonal space group P63/mmc. The crystal structure, solved by direct methods, was refined to a final agreement factor R of 0.045. The atoms are distributed in two layers perpendicular to the z axis: while one is composed only of iron atoms forming regular hexagonal nets, the insertion of carbons in the second layer deforms the hexagonal nets which contain holmium atoms in their centers. 19 refs., 3 figs., 2 tabs

  9. Relationship between misonidazole toxicity and core temperature in C3H mice

    International Nuclear Information System (INIS)

    A single intraperitoneal injection of the radiation sensitizer misonidazole at doses greater than 0.5 mg/g was found to produce a transient hypothermic response in C3H mice. An increase in the acute toxicity of this drug was demonstrated when the animal core temperature was maintained at a normal 35 to 370C by placing the mice in a warmed environment immediately following injection of the drug. The LD/sub 50/3 days/ dose of misonidazole was determined to be 1.48 mg/g for mice allowed to become hypothermic following injection but 0.77 mg/g for mice maintained at a normal core temperature following injection

  10. The Effect of Ginkgo Biloba Extract on Hypoxic Fraction of C3H Mouse Fibrosarcoma

    International Nuclear Information System (INIS)

    Purpose : To investigate the effect of Ginkgo biloba extract (GBE) on hypoxic cell fraction and metabolic status in fibrosarcoma (FSa II) of C3H mouse. Materials and Methods : Fibrosarcoma (Fsa II), 6mm in diameter, growing in the right hind leg muscle of C3H mouse was used for estimation of hypoxic cell fraction using comparison of TCD50. Radiation was given one hour after administration of GBE (100 mg/Kg, i.p.) with or without priming dose of GBE (100 mg/Kg, i.p.) given 24 hours earlier. Radiation was also given under air breathing condition or clamp hypoxia without GBE as controls. 31P NMR spectroscopy was performed before and one hour after administration of GBE with or without priming dose of GBE. Results : TCD50/120's were 81.7(77.7-86.0) Gy when irradiated under clamped hypoxia, 69.6 (66.8-72.5) Gy under air breathing condition,67.5(64.1-71.1) Gy with a single dose of GBE (100 mg/kg) given one hour before irradiation, and 62.2(59.1-65.5) Gy with two doses of GBE given at 25 hours and one hour before irradiation. The hypoxic cell fractions, estimated from TCD50/120's were 1.6% under air breathing condition, 7.2% after single dose of GBE, and 2.7% after two doses of GBE. Metabolic status of tumor, probably by increasing the blood flow and delivery of oxygen and nutrients, resulting in increased radiosensitivity of tumor

  11. Reclassification of membranoproliferative glomerulonephritis: Identification of a new GN: C3GN.

    Science.gov (United States)

    Salvadori, Maurizio; Rosso, Giuseppina

    2016-07-01

    This review revises the reclassification of the membranoproliferative glomerulonephritis (MPGN) after the consensus conference that by 2015 reclassified all the glomerulonephritis basing on etiology and pathogenesis, instead of the histomorphological aspects. After reclassification, two types of MPGN are to date recognized: The immunocomplexes mediated MPGN and the complement mediated MPGN. The latter type is more extensively described in the review either because several of these entities are completely new or because the improved knowledge of the complement cascade allowed for new diagnostic and therapeutic approaches. Overall the complement mediated MPGN are related to acquired or genetic cause. The presence of circulating auto antibodies is the principal acquired cause. Genetic wide association studies and family studies allowed to recognize genetic mutations of different types as causes of the complement dysregulation. The complement cascade is a complex phenomenon and activating factors and regulating factors should be distinguished. Genetic mutations causing abnormalities either in activating or in regulating factors have been described. The diagnosis of the complement mediated MPGN requires a complete study of all these different complement factors. As a consequence, new therapeutic approaches are becoming available. Indeed, in addition to a nonspecific treatment and to the immunosuppression that has the aim to block the auto antibodies production, the specific inhibition of complement activation is relatively new and may act either blocking the C5 convertase or the C3 convertase. The drugs acting on C3 convertase are still in different phases of clinical development and might represent drugs for the future. Overall the authors consider that one of the principal problems in finding new types of drugs are both the rarity of the disease and the consequent poor interest in the marketing and the lack of large international cooperative studies. PMID:27458560

  12. Reclassification of membranoproliferative glomerulonephritis: Identification of a new GN: C3GN

    Science.gov (United States)

    Salvadori, Maurizio; Rosso, Giuseppina

    2016-01-01

    This review revises the reclassification of the membranoproliferative glomerulonephritis (MPGN) after the consensus conference that by 2015 reclassified all the glomerulonephritis basing on etiology and pathogenesis, instead of the histomorphological aspects. After reclassification, two types of MPGN are to date recognized: The immunocomplexes mediated MPGN and the complement mediated MPGN. The latter type is more extensively described in the review either because several of these entities are completely new or because the improved knowledge of the complement cascade allowed for new diagnostic and therapeutic approaches. Overall the complement mediated MPGN are related to acquired or genetic cause. The presence of circulating auto antibodies is the principal acquired cause. Genetic wide association studies and family studies allowed to recognize genetic mutations of different types as causes of the complement dysregulation. The complement cascade is a complex phenomenon and activating factors and regulating factors should be distinguished. Genetic mutations causing abnormalities either in activating or in regulating factors have been described. The diagnosis of the complement mediated MPGN requires a complete study of all these different complement factors. As a consequence, new therapeutic approaches are becoming available. Indeed, in addition to a nonspecific treatment and to the immunosuppression that has the aim to block the auto antibodies production, the specific inhibition of complement activation is relatively new and may act either blocking the C5 convertase or the C3 convertase. The drugs acting on C3 convertase are still in different phases of clinical development and might represent drugs for the future. Overall the authors consider that one of the principal problems in finding new types of drugs are both the rarity of the disease and the consequent poor interest in the marketing and the lack of large international cooperative studies.

  13. The Effect of Ginkgo Biloba Extract on Hypoxic Fraction of C3H Mouse Fibrosarcoma

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Chul Koo; Yi, Chun Ja; Ha, Sung Whan; Park, Charn Il [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1995-09-15

    Purpose : To investigate the effect of Ginkgo biloba extract (GBE) on hypoxic cell fraction and metabolic status in fibrosarcoma (FSa II) of C3H mouse. Materials and Methods : Fibrosarcoma (Fsa II), 6mm in diameter, growing in the right hind leg muscle of C3H mouse was used for estimation of hypoxic cell fraction using comparison of TCD{sub 50}. Radiation was given one hour after administration of GBE (100 mg/Kg, i.p.) with or without priming dose of GBE (100 mg/Kg, i.p.) given 24 hours earlier. Radiation was also given under air breathing condition or clamp hypoxia without GBE as controls. {sup 31}P NMR spectroscopy was performed before and one hour after administration of GBE with or without priming dose of GBE. Results : TCD{sub 50/120's} were 81.7(77.7-86.0) Gy when irradiated under clamped hypoxia, 69.6 (66.8-72.5) Gy under air breathing condition,67.5(64.1-71.1) Gy with a single dose of GBE (100 mg/kg) given one hour before irradiation, and 62.2(59.1-65.5) Gy with two doses of GBE given at 25 hours and one hour before irradiation. The hypoxic cell fractions, estimated from TCD50/120's were 1.6% under air breathing condition, 7.2% after single dose of GBE, and 2.7% after two doses of GBE. Metabolic status of tumor, probably by increasing the blood flow and delivery of oxygen and nutrients, resulting in increased radiosensitivity of tumor.

  14. Mechanistic aspects of initiation and promotion in C3H/10T1/2 cells.

    Science.gov (United States)

    Boreiko, C J

    1985-01-01

    The transformation of C3H/10T1/2 cells can be made to proceed through discrete stages of initiation and promotion. Studies of the effect of cell density upon focus formation in cultures treated with MNNG and TPA suggest that initiation by MNNG is due to a relatively infrequent, irreversible event induced by a single carcinogen treatment. In contrast, promotion appears to be a reversible process requiring multiple treatments with TPA over a protracted period of time. Some evidence suggests that promotion may entail the induction of phenotypic changes which impart a growth advantage to phenotypically unstable "initiated" cell populations. The actual cellular mechanism(s) for most of the phenomena observed in C3H/10T1/2 cultures have eluded precise definition and widely divergent hypotheses have been advanced to explain transformation, initiation, and promotion. Conceivably there are multiple mechanisms responsible for each of these phenomenon. Some agents may transform by a multistage mechanism whereas others may exert their effects in a more direct fashion. Some of the foci produced by promotion may be the result of simple selective processes, others the product of more complex inductive events. Variations would thus be expected between laboratories working with different protocols and agents. As demonstrated by the possible involvement of an MCA residue in transformation, it is also apparent that fundamental technical aspects of this conceptually simple cell transformation system are poorly understood. While it is natural to develop mechanistic models based on quantitative observations of transformation, a limited understanding of the basic cell culture variables which modulate both the induction and expression of transformation dictate that caution be exercised in extrapolating the significance of such models to in vivo carcinogenesis. PMID:4053071

  15. Apolipoprotein C3 polymorphisms, cognitive function and diabetes in Caribbean origin Hispanics.

    Directory of Open Access Journals (Sweden)

    Caren E Smith

    Full Text Available Apolipoprotein C3 (APOC3 modulates triglyceride metabolism through inhibition of lipoprotein lipase, but is itself regulated by insulin, so that APOC3 represents a potential mechanism by which glucose metabolism may affect lipid metabolism. Unfavorable lipoprotein profiles and impaired glucose metabolism are linked to cognitive decline, and all three conditions may decrease lifespan. Associations between apolipoprotein C3 (APOC3 gene polymorphisms and impaired lipid and glucose metabolism are well-established, but potential connections between APOC3 polymorphisms, cognitive decline and diabetes deserve further attention.We examined whether APOC3 single nucleotide polymorphisms (SNPs m482 (rs2854117 and 3u386 (rs5128 were related to cognitive measures, whether the associations between cognitive differences and genotype were related to metabolic differences, and how diabetes status affected these associations. Study subjects were Hispanics of Caribbean origin (n = 991, aged 45-74 living in the Boston metropolitan area.Cognitive and metabolic measures differed substantially by type II diabetes status. In multivariate regression models, APOC3 m482 AA subjects with diabetes exhibited lower executive function (P = 0.009, Stroop color naming score (P = 0.014 and Stroop color-word score (P = 0.022 compared to AG/GG subjects. APOC3 m482 AA subjects with diabetes exhibited significantly higher glucose (P = 0.032 and total cholesterol (P = 0.028 compared to AG/GG subjects. APOC3 3u386 GC/GG subjects with diabetes exhibited significantly higher triglyceride (P = 0.004, total cholesterol (P = 0.003 and glucose (P = 0.016 compared to CC subjects.In summary, we identified significant associations between APOC3 polymorphisms, impaired cognition and metabolic dysregulation in Caribbean Hispanics with diabetes. Further research investigating these relationships in other populations is warranted.

  16. Hepatitis B virus X protein binding to hepsin promotes C3 production by inducing IL-6 secretion from hepatocytes.

    Science.gov (United States)

    Zhang, Mingming; Gu, Jianxin; Zhang, Chunyi

    2016-02-16

    Hepatitis B virus (HBV) X protein (HBx) is an important effector for HBV-associated pathogenesis. In this study, we identified hepsin as an HBx-interacting protein and investigated the effects of hepsin on HBx-mediated complement component 3 (C3) secretion in hepatocytes. In vivo and in vitro binding between HBx and hepsin was confirmed by co-immunoprecipitation and Glutathione S-transferase pull-down assays. HBx synergized with hepsin to promote C3 production by potentiating interleukin-6 (IL-6) secretion. Knockdown of endogenous hepsin attenuated C3 and IL-6 secretion induced by HBx in hepatic cells. In addition, levels of hepsin protein correlated positively with C3 expression in human non-tumor liver tissues. Further exploration revealed that HBx and hepsin increased C3 promoter activity by up-regulating the expression and phosphorylation of the transcription factor CAAT/enhancer binding protein beta (C/EBP-β), which binds to the IL-6/IL-1 response element in the C3 promoter. HBx and hepsin synergistically enhanced IL-6 mRNA levels and promoter activity by increasing the nuclear translocation of nuclear factor kappaB (NF-κB). Our findings show for the first time that binding between HBx and hepsin promotes C3 production by inducing IL-6 secretion in hepatocytes. PMID:26760961

  17. LegC3, an effector protein from Legionella pneumophila, inhibits homotypic yeast vacuole fusion in vivo and in vitro.

    Directory of Open Access Journals (Sweden)

    Terry L Bennett

    Full Text Available During infection, the intracellular pathogenic bacterium Legionella pneumophila causes an extensive remodeling of host membrane trafficking pathways, both in the construction of a replication-competent vacuole comprised of ER-derived vesicles and plasma membrane components, and in the inhibition of normal phagosome:endosome/lysosome fusion pathways. Here, we identify the LegC3 secreted effector protein from L. pneumophila as able to inhibit a SNARE- and Rab GTPase-dependent membrane fusion pathway in vitro, the homotypic fusion of yeast vacuoles (lysosomes. This vacuole fusion inhibition appeared to be specific, as similar secreted coiled-coiled domain containing proteins from L. pneumophila, LegC7/YlfA and LegC2/YlfB, did not inhibit vacuole fusion. The LegC3-mediated fusion inhibition was reversible by a yeast cytosolic extract, as well as by a purified soluble SNARE, Vam7p. LegC3 blocked the formation of trans-SNARE complexes during vacuole fusion, although we did not detect a direct interaction of LegC3 with the vacuolar SNARE protein complexes required for fusion. Additionally, LegC3 was incapable of inhibiting a defined synthetic model of vacuolar SNARE-driven membrane fusion, further suggesting that LegC3 does not directly inhibit the activity of vacuolar SNAREs, HOPS complex, or Sec17p/18p during membrane fusion. LegC3 is likely utilized by Legionella to modulate eukaryotic membrane fusion events during pathogenesis.

  18. Structural features of the human C3 gene: Intron/exon organization, transcriptional start site, and promoter region sequence

    International Nuclear Information System (INIS)

    The third component of human complement (C3) is a key molecule in the activation of the complement cascade. C3 cDNA fragments were used to identify seven cosmid clones that covered all but 1 kilobase pair (kb) of the C3 gene. The remainder of the gene was cloned by using the polymerase chain reaction. These clones were used to identify the interon/exon boundaries and to map the gene. The C3 gene is 42 kb in length and comprises 41 exons ranging in size from 52 to 213 base pairs (bp). The transcription start site was identified by primer extension, and approximately 1 kb of DNA upstream of this site was sequenced. Putative TATA and CAAT boxes were identified along with a number of regions that shared homology with known regulatory sequences. These include responsive elements for interferon-γ, interleukin-6, nuclear factor kB, estrogen, glucocorticoids and thyroid hormone. Several of these agents have been shown to affect C3 synthesis and mRNA levels. The sizes of the exons in C3 were compared to those of C4 and α2-macroglobulin (α2M). Thirty-nine of 41 exons in C4 were found to be of similar size to the analogous ones in C3, and two-thirds of those in α2M were also similarly sized, supporting the hypothesis that these genes arose from a common ancestor

  19. Histopathological Correlation of Atypical (C3 and Suspicious (C4 Categories in Fine Needle Aspiration Cytology of the Breast

    Directory of Open Access Journals (Sweden)

    Prashant Goyal

    2013-01-01

    Full Text Available Introduction. According to the National Cancer Institute (NCI guidelines in 1996, breast lesions are categorized as C1 to C5 on fine needle aspiration (FNA cytology. Very few studies are available in the English literature analyzing histopathology outcome of C3 (atypical, probably benign and C4 (suspicious, probably malignant lesions. Our study aims to correlate FNA cytology of breast lump diagnosed as C3 and C4 lesion with histopathological examination. Methods. During a period of 2 years, 59 cases of C3 and 26 cases of C4 were retrieved from total 1093 cases of breast FNA. All the cases were reviewed by two cytopathologists independently. The final 24 cases of C3 and 16 cases of C4 categories were correlated with histopathological diagnosis. Result. Among C3 category, 37.5% revealed malignant findings, whereas of C4 category, 87.5% were malignant on histopathology. This difference was statistically significant (P=0.0017. Sensitivity, specificity, positive predictive values, and negative predictive value of C4 category in diagnosing breast malignancy were 60.8%, 88.2%, 87.5%, and 62.5%, respectively. Conclusion. Although FNAC is simple, safe, cost-effective and accurate method for diagnosis of breast masses, one must be aware of its limitations particularly in C3 and C4 categories. Also, since both these categories carry different probabilities of malignancy and thus different management, we therefore, support maintaining C3 and C4 categories.

  20. Enhanced visible light photocatalytic hydrogen evolution of sulfur-doped polymeric g-C3N4 photocatalysts

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Sulfur-doped g-C3N4 was prepared using thiourea as sulfur source. • The sulfur-doped g-C3N4 shows significantly enhanced H2 evolution activity. • The doped sulfur species plays key roles in the improvement of H2 production. • Photocatalytic mechanism is proposed based on the experimental results. • The mechanism is confirmed by PL spectra and transient photocurrent curves. - Abstract: Visible light-activated sulfur-doped g-C3N4 photocatalysts were successfully synthesized using thiourea as sulfur source. The obtained photocatalysts were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microcopy, ultraviolet–visible diffuse reflection spectroscopy, X-ray photoelectron spectroscopy, photoluminescence spectroscopy and transient photocurrent response. The sulfur-doped g-C3N4 photocatalysts show beneficial effects on visible light absorption, electron–hole pair generation and separation. The sulfur species doped in the samples was identified as S2− to replace N atoms in the g-C3N4 framework. The photocatalytic activities of the sulfur-doped g-C3N4 under visible light were evaluated by hydrogen evolution from water splitting in aqueous solution containing methanol. The sulfur-doped g-C3N4 photocatalyst showed the highest photocatalytic performance with H2 evolution rate of 12.16 μmol h−1, about 6 times higher than un-doped g-C3N4. It can be concluded that the sulfur species play a vital role and act as active sites in the photocatalytic reaction. This novel sulfur-doped g-C3N4 can be potentially used in energy and environmental applications

  1. Reduced graphene oxide wrapped Cu2O supported on C3N4: An efficient visible light responsive semiconductor photocatalyst

    OpenAIRE

    S. Ganesh Babu; R.Vinoth; P. Surya Narayana; Detlef Bahnemann; B. Neppolian

    2015-01-01

    Herein, Cu2O spheres were prepared and encapsulated with reduced graphene oxide (rGO). The Cu2O–rGO–C3N4 composite covered the whole solar spectrum with significant absorption intensity. rGO wrapped Cu2O loading caused a red shift in the absorption with respect to considering the absorption of bare C3N4. The photoluminescence study confirms that rGO exploited as an electron transport layer at the interface of Cu2O and C3N4 heterojunction. Utmost, ∼2 fold synergistic effect was achieved with C...

  2. Acute local inflammation alters synthesis, distribution, and catabolism of third component of complement (C3) in rabbits.

    OpenAIRE

    Manthei, U; Strunk, R. C.; Giclas, P. C.

    1984-01-01

    In order to evaluate the basis for changes in plasma concentrations of the third component of complement (C3) during inflammation, we injected purified radiolabeled C3 into normal New Zealand White rabbits and into rabbits with turpentine-induced pleurisy. In the normal animals, C3 was distributed between the intravascular compartment (75%) and the extravascular space (25%), with an exchange rate of 1.8 +/- 0.1% of the plasma pool per hour. The fractional catabolic rate (FCR) was 2.7 +/- 0.3%...

  3. Identification of an additional class of C3-binding membrane proteins of human peripheral blood leukocytes and cell lines.

    OpenAIRE

    Cole, J L; Housley, G A; Dykman, T R; MacDermott, R P; Atkinson, J P

    1985-01-01

    Proteins binding the third component of complement (C3) were isolated by affinity chromatography from surface-labeled solubilized membranes of human peripheral blood cells and cell lines. The isolated molecules were subjected to NaDodSO4/PAGE, and autoradiographs of these gels indicated that C3-binding proteins could be divided into three groups based on Mr: (i) gp200, an approximately 200,000 Mr molecule previously identified as the C3b/C4b receptor or CR1; (ii) gp140, an approximately 140,0...

  4. Signaling through C5a receptor and C3a receptor diminishes function of murine natural regulatory T cells

    OpenAIRE

    Kwan, Wing-hong; Van der Touw, William; Paz-Artal, Estela; Li, Ming O.; Heeger, Peter S.

    2013-01-01

    Thymus-derived (natural) CD4+ FoxP3+ regulatory T cells (nT reg cells) are required for immune homeostasis and self-tolerance, but must be stringently controlled to permit expansion of protective immunity. Previous findings linking signals transmitted through T cell–expressed C5a receptor (C5aR) and C3a receptor (C3aR) to activation, differentiation, and expansion of conventional CD4+CD25− T cells (T conv cells), raised the possibility that C3aR/C5aR signaling on nT reg cells could physiologi...

  5. Tunable far-IR laser spectroscopy of jet-cooled carbon clusters - The nu-2 bending vibration of C3

    Science.gov (United States)

    Schmuttenmaer, C. A.; Cohen, R. C.; Pugliano, N.; Heath, J. R.; Cooksy, A. L.

    1990-01-01

    Seven rovibrational transitions of the (01/1/0)-(00/0/0) fundamental bending band of C3 have been measured with high precision with the use of a tunable far-infrared laser spectrometer. The C3 molecules were produced by laser vaporization of a graphite rod and cooled in a supersonic expansion. The astrophysically important nu-2 fundamental frequency is determined to be 63.416529(40)/cm. These measurements provide the basis for studies of C3 in the interstellar medium with far-infrared astronomy.

  6. Cooperation between MASP-1 and MASP-2 in the generation of C3 convertase through the MBL pathway

    DEFF Research Database (Denmark)

    Møller-Kristensen, Mette; Thiel, Steffen; Sjöholm, A;

    2007-01-01

    The complement system is an important part of the innate immune system. Three pathways, the classical, the alternative and the lectin pathway, lead to the cleavage of complement factor C3, a central event in the activation of the complement system. We investigated the deposition of C3b (solid-pha....... Our results demonstrate a function of the orphan protease MASP-1 by providing evidence that this enzyme collaborates with MASP-2 in the generation of C3 convertase, a process observable at high serum concentration, but not at low serum concentration...

  7. Effects of different elevated CO2 concentrations on chlorophyll contents, gas exchange, water use efficiency, and PSII activity on C3 and C4 cereal crops in a closed artificial ecosystem.

    Science.gov (United States)

    Wang, Minjuan; Xie, Beizhen; Fu, Yuming; Dong, Chen; Hui, Liu; Guanghui, Liu; Liu, Hong

    2015-12-01

    Although terrestrial CO2 concentrations [CO2] are not expected to reach 1000 μmol mol(-1) (or ppm) for many decades, CO2 levels in closed systems such as growth chambers and greenhouses can easily exceed this concentration. CO2 levels in life support systems (LSS) in space can exceed 10,000 ppm (1 %). In order to understand how photosynthesis in C4 plants may respond to elevated CO2, it is necessary to determine if leaves of closed artificial ecosystem grown plants have a fully developed C4 photosynthetic apparatus, and whether or not photosynthesis in these leaves is more responsive to elevated [CO2] than leaves of C3 plants. To address this issue, we evaluated the response of gas exchange, water use efficiency, and photosynthetic efficiency of PSII by soybean (Glycine max (L.) Merr., 'Heihe35') of a typical C3 plant and maize (Zea mays L., 'Susheng') of C4 plant under four CO2 concentrations (500, 1000, 3000, and 5000 ppm), which were grown under controlled environmental conditions of Lunar Palace 1. The results showed that photosynthetic pigment by the C3 plants of soybean was more sensitive to elevated [CO2] below 3000 ppm than the C4 plants of maize. Elevated [CO2] to 1000 ppm induced a higher initial photosynthetic rate, while super-elevated [CO2] appeared to negate such initial growth promotion for C3 plants. The C4 plant had the highest ETR, φPSII, and qP under 500-3000 ppm [CO2], but then decreased substantially at 5000 ppm [CO2] for both species. Therefore, photosynthetic down-regulation and a decrease in photosynthetic electron transport occurred by both species in response to super-elevated [CO2] at 3000 and 5000 ppm. Accordingly, plants can be selected for and adapt to the efficient use of elevated CO2 concentration in LSS. PMID:25869633

  8. Leaf physiological processes strongly affect δH2 values of leaf wax n-alkanes in C3 and C4 grasses.

    Science.gov (United States)

    Gamarra, Bruno; Sachse, Dirk; Kahmen, Ansgar

    2013-04-01

    Leaf wax n-alkanes are naturally synthesized saturated hydrocarbons. They are synthesized as part of plant leaf cuticle as a mechanism to prevent water losses. Two of the most important features of n-alkanes are their enormous environmental persistence and terrestrial ubiquity making them a solid and reliable long-term and large-scale biomarker. Their hydrogen isotopic composition (δH2) of leaf wax n-alkanes has been traditionally related to precipitation. Leaf wax n-alkanes and their δH2 values have thus been celebrated as biomarkers to reconstruct hydrological changes. δH2 values of leaf wax n-alkanes are yet to be fully comprehended. They are basically determined by three mechanisms: (1) The δH2 value of the plant source water (2) leaf water evaporative enrichment in H2 and (3) biosynthetic fractionation and depletion in H2during their biosynthesis from leaf water. Out of these three, the exact degree by which the evaporative H2-enrichment of leaf water influences the δH2 values of leaf wax n-alkanes is still unknown. We conducted an experiment where we tested and quantified the effects of leaf water evaporative H2-enrichment on the leaf wax n-alkane δH2 values of different grass species. We grew 12 C3 and C4 grass species under controlled environmental conditions in growth chambers. The plants were exposed to 3 different levels of air relative humidity (45, 65 and 85%). These treatments were to generate different degrees of leaf water H2-enrichment in the plants. The goal of our experiment was to determine by what degree the different levels of leaf water H2-enrichment influence the δH2 values of the different C3 and C4 grass species. Additional measurements of gas exchange, evapotranspiration and leaf length and area accompanied the isotopic analysis in order to explain species variability. Our experiments showed that leaf water evaporative H2-enrichment has a critical impact on leaf wax n-alkane δH2 values of all studied plants. The magnitude was

  9. Pyrosequencing reveals the influence of elevated atmospheric CO2 on the composition of archaeal communities in the rhizosphere of C3 and C4 crops

    Science.gov (United States)

    Nelson, D. M.; Cann, I. K.; Mackie, R. I.

    2008-12-01

    The projected increase in atmospheric CO2 concentrations throughout the 21st century is likely to increase aboveground and belowground plant productivity and cause changes in the quantity and quality of plant root exudates, although plants using C4 photosynthesis are likely to be only affected during times of drought (Leakey et al., 2006, Plant Physiology, 140, 779). Evidence is emerging from molecular tools that these changes may influence the abundance and composition of soil microbial communities that regulate key soil processes, such as nitrogen cycling (Lesaulnier et al., 2008, Environmental Microbiology, 10, 926). However, most molecular tools are not well-suited for comparing multiple samples at great sequencing depth, which is critical when considering soil microbial communities of high diversity. To overcome these limitations we used pyrosequencing and quantitative PCR (qPCR) of two genes (the V3 region of 16S rDNA and the amoA gene) to examine intra- and inter-treatment variability in the abundance and composition of microbial communities in the rhizosphere of soybean (C3) and maize (C4) grown in field conditions under ambient (~380 ppm) and elevated (~550 ppm) CO2 using FACE (free-air concentration enrichment) technology during the 2006 growing season in central Illinois. We specifically focused on archaeal communities because of their key role in nitrification (Leininger et al., 2006, Nature, 442, 806). The majority (>97%) of recovered sequences were from members of the phylum Crenarchaeota. Principle component analysis of sequence results from the V3 and amoA genes indicated significant (p<0.05) differences in the composition of rhizosphere archaeal communities between ambient and elevated CO2 beneath soybean, but not maize. qPCR suggested no significant difference in the abundance of archaea between treatments for soybean and maize. The lack of response of archaeal community composition beneath maize to elevated CO2 is consistent with relatively high

  10. Biological Function of the Guanine Nucleotide Exchange Factor C3G%鸟嘌呤核苷酸交换因子C3G生物学功能研究进展

    Institute of Scientific and Technical Information of China (English)

    吴国金; 安输; 杨洋; 刘莹; 徐天瑞; 郭晓汐

    2016-01-01

    Crk SH3域结合鸟嘌呤核苷酸交换因子[v-Crk sarcoma virus CT10 oncogene homolog (avian) SH3-domain-binding guanine nucleotide exchange factor,C3G]属于鸟嘌呤核苷酸交换因子(guanine nucleotide exchange factors,GEFs),是一种在细胞内普遍表达的蛋白质分子.C3G激活小GTP酶并参与各种信号所触发的通路,对哺乳动物胚胎发育和许多组织的细胞功能来说,都是必不可少的.C3G参与细胞的黏附和迁移,细胞连接的维持,突起的生长等需要细胞骨架重构重要生物功能的调控.在细胞信号转导通路中,C3G的功能不仅依赖其催化活性,更重要的是,C3G在不同细胞类型中与不同的蛋白质相互作用,从而激活相应的信号转导通路.该文总结了目前C3G研究的最新进展,并概述了C3G的不同表达亚型对癌症、心脏病的影响及其生物功能背后的分子作用机制.对C3G及其相互作用蛋白质的研究将为卵巢癌、心脏病等疾病的诊断和治疗提供重要的科学依据.

  11. Identification and Antagonism Study of a Novel Chitinase-producing Bacterium Burkholderia Sp.C3 against Phytopathogenic Fungi

    Institute of Scientific and Technical Information of China (English)

    金虹; TAO Yong

    2006-01-01

    Through a modified agar well diffusion assay, antagonism of a novel chitinase-producing strain C3 against the phytopathogenic fungi including Phoma wasabiae Yokogi,Heterostrophus, Exserohilum Turcicum, Curwularia (Walk) Boed, Thantephorus cucumris, Fusarium graminearum was tested. The data showed that the crude cxtracts of strain C3 had stable antifungal activity in the range of pH 5.0 to pH 8.0. The active components were heat labile and sensitive to proteinase K. A series of experiments supported that the compound responsible for inhibitory activity appeared to be ehitinase. The 16s rDNA analysis indicated that C3 was subject to genus Burkholderia. Pbenotypic characterization of C3 was also consisted with the result of molecular identification.

  12. Atomically Thin Mesoporous Nanomesh of Graphitic C3N4 for High-Efficiency Photocatalytic Hydrogen Evolution.

    Science.gov (United States)

    Han, Qing; Wang, Bing; Gao, Jian; Cheng, Zhihua; Zhao, Yang; Zhang, Zhipan; Qu, Liangti

    2016-02-23

    Delamination of layer materials into two-dimensional single-atom sheets has induced exceptional physical properties, including large surface area, ultrahigh intrinsic carrier mobility, pronounced changes in the energy band structure, and other properties. Here, atomically thin mesoporous nanomesh of graphitic carbon nitride (g-C3N4) is fabricated by solvothermal exfoliation of mesoporous g-C3N4 bulk made from thermal polymerization of freeze-drying assembled Dicyandiamide nanostructure precursor. With the unique structural advantages for aligned energy levels, electron transfer, light harvesting, and the richly available reaction sites, the as-prepared monolayer of mesoporous g-C3N4 nanomesh exhibits a superior photocatalytic hydrogen evolution rate of 8510 μmol h(-1) g(-1) under λ > 420 nm and an apparent quantum efficiency of 5.1% at 420 nm, the highest of all the metal-free g-C3N4 nanosheets photocatalysts. PMID:26766237

  13. Structure and electronic structure of S-doped graphitic C3N4 investigated by density functional theory

    Institute of Scientific and Technical Information of China (English)

    Chen Gang; Gao Shang-Peng

    2012-01-01

    The structures of the heptazine-based graphitic C3N4 and the S-doped graphitic C3N4 are investigated by using the density functional theory with a semi-empirical dispersion correction for the weak long-range interaction between layers.The corrugated structure is found to be energetically favorable for both the pure and the S-doped graphitic C3N4.The S doptant is prone to substitute the N atom bonded with only two nearest C atoms.The band structure calculation reveals that this kind of S doping causes a favorable red shift of the light absorption threshold and can improve the electroconductibility and the photocatalytic activity of the graphitic C3N4.

  14. Differential C3NET reveals disease networks of direct physical interactions

    Directory of Open Access Journals (Sweden)

    Markowetz Florian

    2011-07-01

    Full Text Available Abstract Background Genes might have different gene interactions in different cell conditions, which might be mapped into different networks. Differential analysis of gene networks allows spotting condition-specific interactions that, for instance, form disease networks if the conditions are a disease, such as cancer, and normal. This could potentially allow developing better and subtly targeted drugs to cure cancer. Differential network analysis with direct physical gene interactions needs to be explored in this endeavour. Results C3NET is a recently introduced information theory based gene network inference algorithm that infers direct physical gene interactions from expression data, which was shown to give consistently higher inference performances over various networks than its competitors. In this paper, we present, DC3net, an approach to employ C3NET in inferring disease networks. We apply DC3net on a synthetic and real prostate cancer datasets, which show promising results. With loose cutoffs, we predicted 18583 interactions from tumor and normal samples in total. Although there are no reference interactions databases for the specific conditions of our samples in the literature, we found verifications for 54 of our predicted direct physical interactions from only four of the biological interaction databases. As an example, we predicted that RAD50 with TRF2 have prostate cancer specific interaction that turned out to be having validation from the literature. It is known that RAD50 complex associates with TRF2 in the S phase of cell cycle, which suggests that this predicted interaction may promote telomere maintenance in tumor cells in order to allow tumor cells to divide indefinitely. Our enrichment analysis suggests that the identified tumor specific gene interactions may be potentially important in driving the growth in prostate cancer. Additionally, we found that the highest connected subnetwork of our predicted tumor specific network

  15. Choroidal neovascularization is inhibited via an intraocular decrease of inflammatory cells in mice lacking complement component C3

    OpenAIRE

    Xue Tan; Katsuhito Fujiu; Ichiro Manabe; Junko Nishida; Reiko Yamagishi; Ryozo Nagai; Yasuo Yanagi

    2015-01-01

    In early age-related macular degeneration (AMD), complement component C3 can be observed in drusen, which is the accumulation of material beneath the retinal pigment epithelium. The complement pathways, via the activation of C3, can upregulate the expression of cytokines and their receptors and the recruitment of inflammatory leukocytes, both of which play an important role in the development of choroidal neovascularization (CNV) in exudative AMD. Laser-induced CNV lesions were found to be si...

  16. C3d fragment of complement interacts with laminin and binds to basement membranes of glomerulus and trophoblast

    OpenAIRE

    1986-01-01

    Two mouse monoclonal antibodies generated against human placental homogenate were found to react specifically with human complement component C3. In immunofluorescence of human tissues, these antibodies gave a bright linear staining outlining the glomerular basement membrane of the adult kidney and the trophoblast basement membrane of placenta. An identical staining pattern was observed with a rabbit C3d antiserum which also prevented binding of the monoclonal antibodies to tissue sections. O...

  17. Structure of Compstatin in Complex with Complement Component C3c Reveals a New Mechanism of Complement Inhibition

    OpenAIRE

    Janssen, B.J.C.; Halff, E.F.; LAMBRIS, J. D.; Gros, P

    2007-01-01

    Undesired complement activation is a major cause of tissue injury in various pathological conditions and contributes to several immune complex diseases. Compstatin, a 13-residue peptide, is an effective inhibitor of the activation of complement component C3 and thus blocks a central and crucial step in the complement cascade. The precise binding site on C3, the structure in the bound form, and the exact mode of action of compstatin are unknown. Here we present the crystal structure of compsta...

  18. Regulation of C3a Receptor Signaling in Human Mast Cells by G Protein Coupled Receptor Kinases

    OpenAIRE

    Qiang Guo; Hariharan Subramanian; Kshitij Gupta; Hydar Ali

    2011-01-01

    BACKGROUND: The complement component C3a activates human mast cells via its cell surface G protein coupled receptor (GPCR) C3aR. For most GPCRs, agonist-induced receptor phosphorylation leads to receptor desensitization, internalization as well as activation of downstream signaling pathways such as ERK1/2 phosphorylation. Previous studies in transfected COS cells overexpressing G protein coupled receptor kinases (GRKs) demonstrated that GRK2, GRK3, GRK5 and GRK6 participate in agonist-induced...

  19. Reibergrama para la evaluación de la síntesis intratecal de C3c

    Directory of Open Access Journals (Sweden)

    Dorta-Contreras Alberto Juan

    2006-01-01

    Full Text Available INTRODUCCIÓN: El diagrama de las razones de Reiber o reibergrama cobra cada día mayores usos para la caracterización de la síntesis intratecal de proteínas. El reibergrama fue definido para las clases mayores de inmunoglobulinas pero luego ha sido utilizado para evaluar otras proteínas basado en la teoría de la difusión molecular/velocidad de flujo del líquido cefalorraquídeo (LCR. MÉTODO: El C3c, producto de la degradación del factor del complemento C3 y con una masa molecular de 145 KDa, se acerca a las características moleculares de la IgG para las leyes de la difusión de Fick. Se asume las constantes de la IgG en la fórmula de Reiber para evaluar la síntesis intratecal de C3c así como su correspondiente reibergrama. Se estudiaron 27 pacientes y 27 controles a los que se les dosificó albúmina y C3c en suero y LCR por inmunodifusión radial. RESULTADOS: Con el reibergrama propuesto para el C3c se evaluaron estos pacientes. Se comprueba la validez de este reibergrama para distintas condiciones de barrera con o sin síntesis intratecal de C3c. CONCLUSION: El reibergrama y su fórmula correspondiente propuesto para la C3c puede ser usado para la evaluación de la síntesis intratecal de C3c.

  20. Protective efficacy of P7C3-S243 in the 6-hydroxydopamine model of Parkinson’s disease

    OpenAIRE

    De Jesús-Cortés, Héctor; Miller, Adam D.; Jeremiah K Britt; DeMarco, Anthony J; De Jesús-Cortés, Mayralis; Stuebing, Emily; Naidoo, Jacinth; Vázquez-Rosa, Edwin; Morlock, Lorraine; Williams, Noelle S.; Ready, Joseph M.; Narayanan, Nandakumar S.; Pieper, Andrew A.

    2015-01-01

    BACKGROUND There are currently no therapeutic options for patients with Parkinson’s disease that prevent or slow the death of dopaminergic neurons. We have recently identified the novel P7C3 class of neuroprotective molecules that blocks neuron cell death. AIMS The aim of this study was to determine whether treatment with highly active members of the P7C3 series blocks dopaminergic neuron cell death and associated behavioral and neurochemical deficits in the rat 6-hydroxydopamine (6-OHDA) mod...