Impaired pH Homeostasis in Arabidopsis Lacking the Vacuolar Dicarboxylate Transporter and Analysis of Carboxylic Acid Transport across the Tonoplast1

Science.gov (United States)

Hurth, Marco Alois; Suh, Su Jeoung; Kretzschmar, Tobias; Geis, Tina; Bregante, Monica; Gambale, Franco; Martinoia, Enrico; Neuhaus, H. Ekkehard

2005-01-01

Arabidopsis (Arabidopsis thaliana) mutants lacking the tonoplastic malate transporter AttDT (A. thaliana tonoplast dicarboxylate transporter) and wild-type plants showed no phenotypic differences when grown under standard conditions. To identify putative metabolic changes in AttDT knock-out plants, we provoked a metabolic scenario connected to an increased consumption of dicarboxylates. Acidification of leaf discs stimulated dicarboxylate consumption and led to extremely low levels of dicarboxylates in mutants. To investigate whether reduced dicarboxylate concentrations in mutant leaf cells and, hence, reduced capacity to produce OH− to overcome acidification might affect metabolism, we measured photosynthetic oxygen evolution under conditions where the cytosol is acidified. AttDT::tDNA protoplasts showed a much stronger inhibition of oxygen evolution at low pH values when compared to wild-type protoplasts. Apparently citrate, which is present in higher amounts in knock-out plants, is not able to replace dicarboxylates to overcome acidification. To raise more information on the cellular level, we performed localization studies of carboxylates. Although the total pool of carboxylates in mutant vacuoles was nearly unaltered, these organelles contained a lower proportion of malate and fumarate and a higher proportion of citrate when compared to wild-type vacuoles. These alterations concur with the observation that radioactively labeled malate and citrate are transported into Arabidopsis vacuoles by different carriers. In addition, wild-type vacuoles and corresponding organelles from AttDT::tDNA mutants exhibited similar malate channel activities. In conclusion, these results show that Arabidopsis vacuoles contain at least two transporters and a channel for dicarboxylates and citrate and that the activity of AttDT is critical for regulation of pH homeostasis. PMID:15728336

2-Phenylimidazolium hemi(benzene-1,3-dicarboxylate monohydrate

Directory of Open Access Journals (Sweden)

Wen-Yu Zhang

2011-08-01

Full Text Available The asymmetric unit of the title compound, C9H9N2+·0.5C8H4O4−·H2O, contains one 2-phenylimidazolium cation, half a benzene-1,3-dicarboxylate anion and one water molecule. In the crystal, components are connected by N—H...O and O—H...O hydrogen-bonding interactions into a three-dimensional network.

Thermoset coatings from epoxidized sucrose soyate and blocked, bio-based dicarboxylic acids.

Science.gov (United States)

Kovash, Curtiss S; Pavlacky, Erin; Selvakumar, Sermadurai; Sibi, Mukund P; Webster, Dean C

2014-08-01

A new 100% bio-based thermosetting coating system was developed from epoxidized sucrose soyate crosslinked with blocked bio-based dicarboxylic acids. A solvent-free, green method was used to block the carboxylic acid groups and render the acids miscible with the epoxy resin. The thermal reversibility of this blocking allowed for the formulation of epoxy-acid thermoset coatings that are 100% bio-based. This was possible due to the volatility of the vinyl ethers under curing conditions. These systems have good adhesion to metal substrates and perform well under chemical and physical stress. Additionally, the hardness of the coating system is dependent on the chain length of the diacid used, making it tunable. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Gas adsorption properties of highly porous metal-organic frameworks containing functionalized naphthalene dicarboxylate linkers.

Science.gov (United States)

Sim, Jaeung; Yim, Haneul; Ko, Nakeun; Choi, Sang Beom; Oh, Youjin; Park, Hye Jeong; Park, SangYoun; Kim, Jaheon

2014-12-28

Three functionalized metal-organic frameworks (MOFs), MOF-205-NH2, MOF-205-NO2, and MOF-205-OBn, formulated as Zn4O(BTB)4/3(L), where BTB is benzene-1,3,5-tribenzoate and L is 1-aminonaphthalene-3,7-dicarboxylate (NDC-NH2), 1-nitronaphthalene-3,7-dicarboxylate (NDC-NO2) or 1,5-dibenzyloxy-2,6-naphthalenedicarboxylate (NDC-(OBn)2), were synthesized and their gas (H2, CO2, or CH4) adsorption properties were compared to those of the un-functionalized, parent MOF-205. Ordered structural models for MOF-205 and its derivatives were built based on the crystal structures and were subsequently used for predicting porosity properties. Although the Brunauer-Emmett-Teller (BET) surface areas of the three MOF-205 derivatives were reduced (MOF-205, 4460; MOF-205-NH2, 4330; MOF-205-NO2, 3980; MOF-205-OBn, 3470 m(2) g(-1)), all three derivatives were shown to have enhanced H2 adsorption capacities at 77 K and CO2 uptakes at 253, 273, and 298 K respectively at 1 bar in comparison with MOF-205. The results indicate the following trend in H2 adsorption: MOF-205 < MOF-205-NO2 < MOF-205-NH2 < MOF-205-OBn. MOF-205-OBn showed good ideal adsorbed solution theory (IAST) selectivity values of 6.5 for CO2/N2 (15/85 in v/v) and 2.7 for CO2/CH4 (50/50 in v/v) at 298 K. Despite the large reduction (-22%) in the surface area, MOF-205-OBn displayed comparable total volumetric CO2 (at 48 bar) and CH4 (at 35 bar) storage capacities with those of MOF-205 at 298 K: MOF-205-OBn, 305 (CO2) and 112 (CH4) cm(3) cm(-3), and for MOF-205, 307 (CO2) and 120 (CH4) cm(3) cm(-3), respectively.

Effect of counting system dead time on thyroid uptake measurements

International Nuclear Information System (INIS)

Simpkin, D.J.

1984-01-01

Equations are derived and the results of numerical calculations shown that illustrate the effect of counting system dead time on measured thyroid uptake of radioiodine. It is predicted that the observed uptake is higher than the true uptake due to system dead time. This is shown for both paralyzing and nonparalyzing dead time. The effect of increasing the administered activity is shown to increase the measured uptake, in a manner predicted by the paralyzable and nonparalyzable dead time models

Determination of low-molecular-weight dicarboxylic acids in atmospheric aerosols by injection-port derivatization and gas chromatography-mass spectrometry.

Science.gov (United States)

Hsu, Ching-Lin; Ding, Wang-Hsien

2009-12-15

A rapid and environmental-friendly injection-port derivatization with gas chromatography-mass spectrometry (GC-MS) method was developed to determine selected low-molecular weight (LMW) dicarboxylic acids (from C2 to C10) in atmospheric aerosol samples. The parameters related to the derivatization process (i.e., type of ion-pair reagent, injection-port temperature and concentration of ion-pair reagent) were optimized. Tetrabutylammonium hydroxide (TBA-OH) 20 mM in methanol gave excellent yield for di-butyl ester dicarboxylate derivatives at injection-port temperature at 300 degrees C. Solid-phase extraction (SPE) method instead of rotary evaporation was used to concentrate analytes from filter extracts. The recovery from filter extracts ranged from 78 to 95% with relative standard deviation (RSD) less than 12%. Limits of quantitation (LOQs) ranged from 25 to 250 pg/m(3). The concentrations of di-carboxylated C2-C5 and total C6-C10 in particles of atmospheric aerosols ranged from 91.9 to 240, 11.3 to 56.7, 9.2 to 49.2, 8.7 to 35.3 and n.d. to 37.8 ng/m(3), respectively. Oxalic acid (C2) was the dominant LMW-dicarboxylic acids detected in aerosol samples. The quantitative results were comparable to the results obtained by the off-line derivatization.

pH-metric studies on the mixed ligand-chelates of oxovanadium(IV) with 2,2'-bipyridyl and dicarboxylic or hydroxy acids

International Nuclear Information System (INIS)

Jain, A.K.; Kumari, V.; Chaturvedi, G.K.

1978-01-01

The interaction of vanadyl ion with 2,2'-bipyridyl and some dicarboxylic or hydroxy acids (where dicarboxylic acid = oxalic (OX), malonic (MALN), phthalic (PHA), maleic (MAL) acids; hydroxy acids salicylic (SA), 5-sulfosalicylic (5-SSA), mandelic (MAND) and glycollic (HG) acids was studied potentiometrically. pH-titrations of the reaction mixtures containing vanadyl sulphate, 2,2'-bipyridyl and one of the dicarboxylic or hydroxy acids (OX, MALN, PHA, MAL, SA, 5-SSA, MAND and HG acids) in equimolar ratio exhibited the formation of 1:1:1 mixed ligand chelates. The formation constants of the resulting biligand chelates were calculated, at 35 + -1 0 and 45 + -1 0 and also the thermodynamic functions viz. ΔF, ΔH and ΔS (μ=0.1M KNO 3 ) (auth.)

Determination of low-molecular-weight dicarboxylic acids in atmospheric aerosols by injection-port derivatization and gas chromatography-mass spectrometry

Science.gov (United States)

Ding, W.; Hsu, C.

2008-12-01

Currently, the investigations on aerosol water-soluble organic compounds (WSOCs) formed by burning biomass have become increasingly concerned with the role of these compounds in atmospheric chemistry and their effect on climate, because they have great potential to influence cloud formation, precipitation, and climate on both global and regional scales. Of these compounds, low-molecular weight (LMW) dicarboxylic acids (from C2 to C10) have attracted the most interest because of their properties as specific tracers for the burning of biomass. In this study, a modified injection-port derivatization and gas chromatography - mass spectrometry method was developed and evaluated for rapid determination of LMW dicarboxylic acids in atmospheric aerosol samples. The parameters related to the derivatization process (i.e., type of ion-pair reagent, injection-port temperature and concentration of ion-pair reagent) were optimized. Tetrabutylammonium hydroxide (TBA-OH) dissolved in methanol used as the ion-pair solution gave excellent yield for di-butyl ester low-molecular weight derivatives. Solid-phase extraction method instead of rotary evaporation was used to concentrate analytes from filter extracts. The recovery from filter extracts ranged from 67 to 86% with relative standard deviation (RSD) less than 13%. The concentrations of dicarboxylated C2, C3, C4, C5 and C6-C10 in atmospheric aerosols ranged from 91-240 ng/m3, 11-56 ng/m3, 12-49 ng/m3, 8-35 ng/m3 and n.d. to 17 ng/m3, respectively. Oxalic (C2) acid was the dominant dicarboxylic acids detected in aerosol samples. The total concentrations of the LMW dicarboxylic acids (from C2 to C10) correspond to 2.2 to 2.6% of the total aerosol mass.

Elevated sacroilac joint uptake ratios in systemic lupus erythematosus

International Nuclear Information System (INIS)

De Smet, A.A.; Mahmood, T.; Robinson, R.G.; Lindsley, H.B.

1984-01-01

Sacroiliac joint radiographs and radionuclide sacroiliac joint uptake ratios were obtained on 14 patients with active systemic lupus erythematosus. Elevated joint ratios were found unilaterally in two patients and bilaterally in seven patients when their lupus was active. In patients whose disease became quiescent, the uptake ratios returned to normal. Two patients had persistently elevated ratios with continued clinical and laboratory evidence of active lupus. Mild sacroiliac joint sclerosis and erosions were detected on pelvic radiographs in these same two patients. Elevated quantitative sacroiliac joint uptake ratios may occur as a manifestation of active systemic lupus erythematosus

Modelling water uptake efficiency of root systems

Science.gov (United States)

Leitner, Daniel; Tron, Stefania; Schröder, Natalie; Bodner, Gernot; Javaux, Mathieu; Vanderborght, Jan; Vereecken, Harry; Schnepf, Andrea

2016-04-01

Water uptake is crucial for plant productivity. Trait based breeding for more water efficient crops will enable a sustainable agricultural management under specific pedoclimatic conditions, and can increase drought resistance of plants. Mathematical modelling can be used to find suitable root system traits for better water uptake efficiency defined as amount of water taken up per unit of root biomass. This approach requires large simulation times and large number of simulation runs, since we test different root systems under different pedoclimatic conditions. In this work, we model water movement by the 1-dimensional Richards equation with the soil hydraulic properties described according to the van Genuchten model. Climatic conditions serve as the upper boundary condition. The root system grows during the simulation period and water uptake is calculated via a sink term (after Tron et al. 2015). The goal of this work is to compare different free software tools based on different numerical schemes to solve the model. We compare implementations using DUMUX (based on finite volumes), Hydrus 1D (based on finite elements), and a Matlab implementation of Van Dam, J. C., & Feddes 2000 (based on finite differences). We analyse the methods for accuracy, speed and flexibility. Using this model case study, we can clearly show the impact of various root system traits on water uptake efficiency. Furthermore, we can quantify frequent simplifications that are introduced in the modelling step like considering a static root system instead of a growing one, or considering a sink term based on root density instead of considering the full root hydraulic model (Javaux et al. 2008). References Tron, S., Bodner, G., Laio, F., Ridolfi, L., & Leitner, D. (2015). Can diversity in root architecture explain plant water use efficiency? A modeling study. Ecological modelling, 312, 200-210. Van Dam, J. C., & Feddes, R. A. (2000). Numerical simulation of infiltration, evaporation and shallow

Task-specific enhancement of short-term, but not long-term, memory by class I metabotropic glutamate receptor antagonist 1-aminoindan-1,5-dicarboxylic acid in rats

DEFF Research Database (Denmark)

Christoffersen, G.R.J.; Christensen, Lone H.; Harrington, Nicholas R.

1999-01-01

Metabotropic glutamate receptors; Class I antagonist; 1-aminoindan-1,5-dicarboxylic acid; spatial learning; contextual conditioning; rats......Metabotropic glutamate receptors; Class I antagonist; 1-aminoindan-1,5-dicarboxylic acid; spatial learning; contextual conditioning; rats...

pH-metric studies on the mixed ligand-chelates of oxovanadium(IV) with 2,2'-bipyridyl and dicarboxylic or hydroxy acids

Energy Technology Data Exchange (ETDEWEB)

Jain, A K; Kumari, V; Chaturvedi, G K [Agra Coll. (India)

1978-12-01

The interaction of vanadyl ion with 2,2'-bipyridyl and some dicarboxylic or hydroxy acids (where dicarboxylic acid = oxalic (OX), malonic (MALN), phthalic (PHA), maleic (MAL) acids; hydroxy acids salicylic (SA), 5-sulfosalicylic (5-SSA), mandelic (MAND) and glycollic (HG) acids was studied potentiometrically. pH-titrations of the reaction mixtures containing vanadyl sulphate, 2,2'-bipyridyl and one of the dicarboxylic or hydroxy acids (OX, MALN, PHA, MAL, SA, 5-SSA, MAND and HG acids) in equimolar ratio exhibited the formation of 1:1:1 mixed ligand chelates. The formation constants of the resulting biligand chelates were calculated, at 35/sup +/-1/sup 0/ and 45/sup +/-1/sup 0/ and also the thermodynamic functions viz. ..delta..F, ..delta..H and ..delta..S (..mu..=0.1M KNO/sub 3/) (auth.).

Uptake of Alkylamines on Dicarboxylic Acids Relevant to Secondary Organic Aerosol Formation

Science.gov (United States)

Marrero-Ortiz, W.; Secrest, J.; Zhang, R.

2017-12-01

Aerosols play a critical role in climate directly by scattering and absorbing solar radiation, and indirectly by functioning as cloud condensation nuclei (CCN); both represent the largest uncertainties in climate predictions. New particle formation contributes significantly to CCN production; however, the mechanisms related to particle nucleation and growth processes are not well understood. Organic acids are atmospherically abundant, and their neutralization by low molecular weight amines may result in the formation of stable low volatility aminium salt products contributing to the growth of secondary organic aerosols and even the alteration of the aerosol properties. The acid-base neutralization of particle phase succinic acid and tartaric acid by low molecular weight aliphatic amines, i.e. methylamine, dimethylamine, and trimethylamine, has been investigated by employing a low-pressure fast flow reactor at 298K with an ion drift - chemical ionization mass spectrometer (ID-CIMS). The heterogeneous uptake is time dependent and influenced by organic acids functionality, alkylamines basicity, and steric effect. The implications of our results to atmospheric nanoparticle growth will be discussed.

Gallium-67 uptake by the thyroid associated with progressive systemic sclerosis

International Nuclear Information System (INIS)

Sjoberg, R.J.; Blue, P.W.; Kidd, G.S.

1989-01-01

Although thyroidal uptake of gallium-67 has been described in several thyroid disorders, gallium-67 scanning is not commonly used in the evaluation of thyroid disease. Thyroidal gallium-67 uptake has been reported to occur frequently with subacute thyroiditis, anaplastic thyroid carcinoma, and thyroid lymphoma, and occasionally with Hashimoto's thyroiditis and follicular thyroid carcinoma. A patient is described with progressive systemic sclerosis who, while being scanned for possible active pulmonary involvement, was found incidentally to have abnormal gallium-67 uptake only in the thyroid gland. Fine needle aspiration cytology of the thyroid revealed Hashimoto's thyroiditis. Although Hashimoto's thyroiditis occurs with increased frequency in patients with progressive systemic sclerosis, thyroidal uptake of gallium-67 associated with progressive systemic sclerosis has not, to our knowledge, been previously described. Since aggressive thyroid malignancies frequently are imaged by gallium-67 scintigraphy, fine needle aspiration cytology of the thyroid often is essential in the evaluation of thyroidal gallium-67 uptake

Gallium-67 uptake by the thyroid associated with progressive systemic sclerosis

Energy Technology Data Exchange (ETDEWEB)

Sjoberg, R.J.; Blue, P.W.; Kidd, G.S.

1989-01-01

Although thyroidal uptake of gallium-67 has been described in several thyroid disorders, gallium-67 scanning is not commonly used in the evaluation of thyroid disease. Thyroidal gallium-67 uptake has been reported to occur frequently with subacute thyroiditis, anaplastic thyroid carcinoma, and thyroid lymphoma, and occasionally with Hashimoto's thyroiditis and follicular thyroid carcinoma. A patient is described with progressive systemic sclerosis who, while being scanned for possible active pulmonary involvement, was found incidentally to have abnormal gallium-67 uptake only in the thyroid gland. Fine needle aspiration cytology of the thyroid revealed Hashimoto's thyroiditis. Although Hashimoto's thyroiditis occurs with increased frequency in patients with progressive systemic sclerosis, thyroidal uptake of gallium-67 associated with progressive systemic sclerosis has not, to our knowledge, been previously described. Since aggressive thyroid malignancies frequently are imaged by gallium-67 scintigraphy, fine needle aspiration cytology of the thyroid often is essential in the evaluation of thyroidal gallium-67 uptake.

3,6-Dithiaoctane-1,8-dicarboxylic acid and its metal complexes

NARCIS (Netherlands)

Bellaart, A.C.; Verbeek, J.L.

1969-01-01

A soln. contg. 1.5 g 3,6-dithiaoctane-1,8-dicarboxylic acid (HL) in 20 ml H2O was treated with 1.8 g Ag2O for 20 min on a boiling water bath to give H[AgL2], m.p. 115-16 Deg (uncor.). A structure is proposed on the basis of ir spectral studies and elec. cond. measurements. H[CuL2] was similarly

Identification of a single sinusoidal bile salt uptake system in skate liver

International Nuclear Information System (INIS)

Fricker, G.; Hugentobler, G.; Meier, P.J.; Kurz, G.; Boyer, J.L.

1987-01-01

To identify the sinusoidal bile acid uptake system(s) of skate liver, photoaffinity labeling and kinetic transport studies were performed in isolated plasma membranes as well as intact hepatocytes. In both preparations photoaffinity labeling with the photolabile bile salt derivative revealed the presence of a predominant bile salt binding polypeptide with an apparent molecular weight of 54,000. The [ 3 H]-labeling of this polypeptide was inhibited by taurocholate and cholate in a concentration-dependent manner and was virtually abolished by 1 mM of the anion transport inhibitor 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid. Kinetic studies of hepatic uptake with taurocholate, cholate, and the photoreactive bile salt derivative indicated the involvement of a single transport system, and all three substrates mutually competed with the uptake of each other. Finally, irreversible inhibition of the bile salt uptake system of photoaffinity labeling of hepatocytes with high concentrations of photolabile derivative reduced the V max but the K m of taurocholate uptake. These findings strongly indicate that a single polypeptide with an apparent molecular weight of 54,000 is involved in sinusoidal bile salt uptake into skate hepatocytes. These findings contrast with similar studies in rat liver that implicate both a 54,000- and 48,000-K polypeptide in bile salt uptake and are consistent with a single Na + -independent transport mechanism for hepatic bile salt uptake in this primitive vertebrate

Synthesis and characterization of Mg-Al-layered double hydroxides intercalated with cubane-1,4-dicarboxylate anions.

Science.gov (United States)

Rezvani, Zolfaghar; Arjomandi Rad, Farzad; Khodam, Fatemeh

2015-01-21

In the present work, Mg2Al-layered double hydroxide (LDH) intercalated with cubane-1,4-dicarboxylate anions was prepared from the reaction of solutions of Mg(ii) and Al(iii) nitrate salts with an alkaline solution of cubane-1,4-dicarboxylic acid by using the coprecipitation method. The successful preparation of a nanohybrid of cubane-1,4-dicarboxylate(cubane-dc) anions with LDH was confirmed by powder X-ray diffraction, FTIR spectroscopy and thermal gravimetric analysis (TGA). The increase in the basal spacing of LDHs from 8.67 Å to 13.40 Å shows that cubane-dc anions were successfully incorporated into the interlayer space. Thermogravimetric analyses confirm that the thermal stability of the intercalated cubane-dc anions is greater than that of the pure form before intercalation because of host-guest interactions involving hydrogen bonds. The interlayer structure, hydrogen bonding, and subsequent distension of LDH compounds containing cubane-dc anions were shown by molecular simulation. The RDF (radial distribution function), mean square displacement (MSD), and self-diffusion coefficient were calculated using the trajectory files on the basis of molecular dynamics (MD) simulations, and the results indicated that the cubane-dc anions were more stable when intercalated into the LDH layers. A good agreement was obtained between calculated and measured X-ray diffraction patterns and between experimental and calculated basal spacings.

Plant-uptake of uranium: Hydroponic and soil system studies

Science.gov (United States)

Ramaswami, A.; Carr, P.; Burkhardt, M.

2001-01-01

Limited information is available on screening and selection of terrestrial plants for uptake and translocation of uranium from soil. This article evaluates the removal of uranium from water and soil by selected plants, comparing plant performance in hydroponic systems with that in two soil systems (a sandy-loam soil and an organic-rich soil). Plants selected for this study were Sunflower (Helianthus giganteus), Spring Vetch (Vicia sativa), Hairy Vetch (Vicia villosa), Juniper (Juniperus monosperma), Indian Mustard (Brassica juncea), and Bush Bean (Phaseolus nanus). Plant performance was evaluated both in terms of the percent uranium extracted from the three systems, as well as the biological absorption coefficient (BAC) that normalized uranium uptake to plant biomass. Study results indicate that uranium extraction efficiency decreased sharply across hydroponic, sandy and organic soil systems, indicating that soil organic matter sequestered uranium, rendering it largely unavailable for plant uptake. These results indicate that site-specific soils must be used to screen plants for uranium extraction capability; plant behavior in hydroponic systems does not correlate well with that in soil systems. One plant species, Juniper, exhibited consistent uranium extraction efficiencies and BACs in both sandy and organic soils, suggesting unique uranium extraction capabilities.

The 'glial' glutamate transporter, EAAT2 (Glt-1) accounts for high affinity glutamate uptake into adult rodent nerve endings.

Science.gov (United States)

Suchak, Sachin K; Baloyianni, Nicoletta V; Perkinton, Michael S; Williams, Robert J; Meldrum, Brian S; Rattray, Marcus

2003-02-01

The excitatory amino acid transporters (EAAT) removes neurotransmitters glutamate and aspartate from the synaptic cleft. Most CNS glutamate uptake is mediated by EAAT2 into glia, though nerve terminals show evidence for uptake, through an unknown transporter. Reverse-transcriptase PCR identified the expression of EAAT1, EAAT2, EAAT3 and EAAT4 mRNAs in primary cultures of mouse cortical or striatal neurones. We have used synaptosomes and glial plasmalemmal vesicles (GPV) from adult mouse and rat CNS to identify the nerve terminal transporter. Western blotting showed detectable levels of the transporters EAAT1 (GLAST) and EAAT2 (Glt-1) in both synaptosomes and GPVs. Uptake of [3H]D-aspartate or [3H]L-glutamate into these preparations revealed sodium-dependent uptake in GPV and synaptosomes which was inhibited by a range of EAAT blockers: dihydrokainate, serine-o-sulfate, l-trans-2,4-pyrrolidine dicarboxylate (PDC) (+/-)-threo-3-methylglutamate and (2S,4R )-4-methylglutamate. The IC50 values found for these compounds suggested functional expression of the 'glial, transporter, EAAT2 in nerve terminals. Additionally blockade of the majority EAAT2 uptake sites with 100 micro m dihydrokainate, failed to unmask any functional non-EAAT2 uptake sites. The data presented in this study indicate that EAAT2 is the predominant nerve terminal glutamate transporter in the adult rodent CNS.

Development of cesium 137 plant uptake predicting model using geographical information systems

International Nuclear Information System (INIS)

Lomonos, O.V.

2002-01-01

Soil-plant system is a critical component of food chain in processes of Cs 137 migration. In this component it is possible to decrease greatly Cs 137 uptake in food chain. Development of Cs 137 migration model in soil-plant system enable to determine amount of Cs 137 in plant uptake and evaluate agricultural produce accordance with modern ecological requirements. Also this model can help with management of agricultural production. Geographical information systems (GIS) have a wide propagation in radioecology at present time. Models using GIS have several advantages: relative simplicity of evaluation, visualization of evaluated results etc. As a result, plots with possible Cs 137 uptake increasing could be easily discovered. Physical decay, Cs 137 sorption and fixation by soil, Cs 137 vertical migration in soil profile and plant uptake are the main components of the Cs 137 migration model in soil-plant system. Content of biologically available Cs 137 calculated taking into account all of these components. Using GIS with Cs 137 migration model in soil-plant system lets efficiently discover those factors that have major influence on Cs 137 plant uptake increasing. This model improves agricultural production on territories, which polluted by Cs 137

Application of novel catalytic-ceramic-filler in a coupled system for long-chain dicarboxylic acids manufacturing wastewater treatment.

Science.gov (United States)

Wu, Suqing; Qi, Yuanfeng; Fan, Chunzhen; He, Shengbing; Dai, Bibo; Huang, Jungchen; Zhou, Weili; Gao, Lei

2016-02-01

To gain systematic technology for long-chain dicarboxylic acids (LDCA) manufacturing wastewater treatment, catalytic micro-electrolysis (CME) coupling with adsorption-biodegradation sludge (AB) process was studied. Firstly, novel catalytic-ceramic-filler was prepared from scrap iron, clay and copper sulfate solution and packed in the CME reactor. To remove residual n-alkane and LDCA, the CME reactor was utilized for LDCA wastewater pretreatment. The results revealed that about 94% of n-alkane, 98% of LDCA and 84% of chemical oxygen demand (COD) were removed by the aerated CME reactor at the optimum hydraulic retention time (HRT) of 3.0 h. In this process, catalysis from Cu and montmorillonites played an important role in improving the contaminants removal. Secondly, to remove residual COD in the wastewater, AB process was designed for the secondary biological treatment, about 90% of the influent COD could be removed by biosorption, bio-flocculation and biodegradation effects. Finally, the effluent COD (about 150 mg L(-1)) discharged from the coupled CME-AB system met the requirement of the national discharged standard (COD ≤ 300 mg L(-1)). All of these results suggest that the coupled CME-AB system is a promising technology due to its high-efficient performance, and has the potential to be applied for the real LDCA wastewater treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

A novel one-dimensional chain built of vanadyl ions and pyrazine-2,5-dicarboxylate

NARCIS (Netherlands)

Lankelma, M.; de Boer, J.; Ferbinteanu, M.; Dantas Ramos, A.L.; Tanasa, R.; Rothenberg, G.; Tanase, S.

2015-01-01

We present a new coordination polymer, {[VO(pzdc)(H2O)(2)] H2O}(n), built from vanadyl and pyrazine-2,5-dicarboxylate (pzdc) ions. It consists of a one-dimensional chain of vanadyl ions linked by pzdc ions. The carboxylate groups show monodentate coordination, while the pyrazine ring is present both

Cyclohexane-1,2-dicarboxylic acid diisononyl ester and metabolite effects on rat epididymal stromal vascular fraction differentiation of adipose tissue

Energy Technology Data Exchange (ETDEWEB)

Campioli, Enrico [Research Institute of the McGill University Health Centre (Canada); Department of Medicine, McGill University, Montréal, Québec (Canada); Duong, Tam B. [Research Institute of the McGill University Health Centre (Canada); Deschamps, François [Synthèse AptoChem Inc., Montréal, Québec (Canada); Papadopoulos, Vassilios, E-mail: vassilios.papadopoulos@mcgill.ca [Research Institute of the McGill University Health Centre (Canada); Department of Medicine, McGill University, Montréal, Québec (Canada); Department of Biochemistry, McGill University, Montréal, Québec (Canada); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec (Canada)

2015-07-15

Plastics are generally mixed with additives like plasticizers to enhance their flexibility, pliability, and elasticity proprieties. Plasticizers are easily released into the environment and are absorbed mainly through ingestion, dermal contact, and inhalation. One of the main classes of plasticizers, phthalates, has been associated with endocrine and reproductive diseases. In 2002, 1,2-cyclohexane dicarboxylic acid diisononyl ester (DINCH) was introduced in the market for use in plastic materials and articles intended to come into contact with food, and it received final approval from the European Food Safety Authority in 2006. At present, there is limited knowledge about the safety and potential metabolic and endocrine-disrupting properties of DINCH and its metabolites. The purpose of this study was to evaluate the biological effects of DINCH and its active metabolites, cyclohexane-1,2-dicarboxylic acid (CHDA) and cyclohexane-1,2-dicarboxylic acid mono isononyl ester (MINCH), on rat primary stromal vascular fraction (SVF) of adipose tissue. DINCH and its metabolite, CHDA, were not able to directly affect SVF differentiation. However, exposure of SVF to 50 μM and 100 μM concentrations of MINCH affected the expression of Cebpa and Fabp4, thus inducing SVF preadipocytes to accumulate lipids and fully differentiate into mature adipocytes. The effect of MINCH was blocked by the specific peroxisome proliferator-activated receptor (PPAR)-α antagonist, GW6471. Taken together, these results suggest that MINCH is a potent PPAR-α agonist and a metabolic disruptor, capable of inducing SVF preadipocyte differentiation, that may interfere with the endocrine system in mammals. - Highlights: • DINCH and CHDA did not affect the adipogenesis of the SVF. • MINCH affected the adipogenesis of the SVF. • MINCH effect was blocked by the specific PPAR-α antagonist GW6471. • MINCH exerted a similar effect as MEHP on SVF adipogenesis. • DINCH/MINCH are potential metabolic

Molecular and cellular characterisation of the zinc uptake (Znu) system of Nostoc punctiforme.

Science.gov (United States)

Hudek, Lee; Pearson, Leanne A; Michalczyk, Agnes; Neilan, Brett A; Ackland, M Leigh

2013-11-01

Metal homoeostasis in cyanobacteria is based on uptake and export systems that are controlled by their own regulators. This study characterises the zinc uptake (Znu) system in Nostoc punctiforme. The system was found to comprise of three subunits in an ACB operon: a Zn(2+)-binding protein (ZnuA18), a transmembrane domain (ZnuB) and an ATPase (ZnuC). These proteins are encoded within the znu operon regulated by a zinc uptake transcription repressor (Zur). Interestingly, a second Zn(2+)-binding protein (ZnuA08) was also identified at a distal genomic location. Interactions between components of the ZnuACB system were investigated using knockouts of the individual genes. The znuA08(-), znuA18(-), znuB(-) and znuC(-) mutants displayed overall reduced znuACB transcript levels, suggesting that all system components are required for normal expression of znu genes. Zinc uptake assays in the Zn(2+)-binding protein mutant strains showed that the disruption of znuA18 had a greater negative effect on zinc uptake than disruption of znuA08. Complementation studies in Escherichia coli indicated that both znuA08 and znuA18 were able to restore zinc uptake in a znuA(-) mutant, with znuA18 permitting the highest zinc uptake rate. The N. punctiforme zur was also able to complement the E. coli zur(-) mutant. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

A convenient preparation of 9 H -carbazole-3,6-dicarbonitrile and 9 H -carbazole-3,6-dicarboxylic acid

KAUST Repository

Weselinski, Lukasz Jan; Luebke, Ryan; Eddaoudi, Mohamed

2014-01-01

,6-dicarboxylic acid. Both compounds are versatile and fine-tunable organic building blocks and therefore offer potential in material science, medicinal and supramolecular chemistry. © Georg Thieme Verlag Stuttgart New York.

1,1′-Binaphthyl-2,2′-dicarboxylic acid–urea (1/1

Directory of Open Access Journals (Sweden)

Edwin Weber

2008-10-01

Full Text Available In the title co-crystal, C22H14O4·CH4N2O, the 1,1′-binaphthyl-2,2′-dicarboxylic acid (BNDA and urea molecules are connected via a system of hydrogen bonds into a chiral two-dimensional polymeric structure parallel to the (001 plane. As the crystal is centrosymmetric, it consists of alternately stacked BNDA–urea layers of opposite chirality. The urea H atoms trans to the C=O group are bonded in a chelating mode [R12(6] to the carbonyl O atom from one of the carboxylic acid groups which, in turn, acts as the donor of an O—H...O hydrogen bond to another urea molecule. The [010] chains thus formed are further connected via an R22(8 hydrogen-bond motif formed between urea and the second carboxylic acid group of BNDA.

O-alkylation of disodium salt of diethyl 3,4-dihydroxythiophene-2,5-dicarboxylate with 1,2-dichloroethane catalyzed by ionic type phase transfer catalyst and potassium iodide

Energy Technology Data Exchange (ETDEWEB)

Lu, Huasheng; Yin, Hengbo; Wang, Aili; Shen, Jun; Yan, Xiaobo; Liu, Yumin; Zhang, Changhua [Jiangsu University, Zhenjiang (China)

2014-01-15

Diethyl 3,4-ethylenedioxy thiophene-2,5-dicarboxylate was efficiently synthesized via the O-alkylation of disodium salt of diethyl 3,4-dihydroxy thiophene-2,5-dicarboxylate with 1,2-dichloroethane over ionic type phase transfer catalysts, such as tetrabutyl ammonium bromide and benzyl triethyl ammonium chloride. The ionic type phase transfer catalysts showed higher catalytic activities than the nonionic type phase transfer catalysts, such as triethylamine, pyridine, 18-crown-6, and polyethylene glycol 400/600, in the O-alkylation reaction. The conversion of the disodium salt of more than 97% and the selectivity of diethyl 3,4-ethylenedioxy thiophene-2,5-dicarboxylate of more than 98% were achieved when the O-alkylation reaction was synergistically catalyzed by tetrabutyl ammonium bromide and potassium iodide.

Differentiation of DctA and DcuS function in the DctA/DcuS sensor complex of Escherichia coli: function of DctA as an activity switch and of DcuS as the C4-dicarboxylate sensor.

Science.gov (United States)

Steinmetz, Philipp Aloysius; Wörner, Sebastian; Unden, Gottfried

2014-10-01

The C4-dicarboxylate responsiveness of the sensor kinase DcuS is only provided in concert with C4-dicarboxylate transporters DctA or DcuB. The individual roles of DctA and DcuS for the function of the DctA/DcuS sensor complex were analysed. (i) Variant DctA(S380D) in the C4-dicarboxylate site of DctA conferred C4-dicarboxylate sensitivity to DcuS in the DctA/DcuS complex, but was deficient for transport and for growth on C4-dicarboxylates. Consequently transport activity of DctA is not required for its function in the sensor complex. (ii) Effectors like fumarate induced expression of DctA/DcuS-dependent reporter genes (dcuB-lacZ) and served as substrates of DctA, whereas citrate served only as an inducer of dcuB-lacZ without affecting DctA function. (iii) Induction of dcuB-lacZ by fumarate required 33-fold higher concentrations than for transport by DctA (Km  = 30 μM), demonstrating the existence of different fumarate sites for both processes. (iv) In titration experiments with increasing dctA expression levels, the effect of DctA on the C4-dicarboxylate sensitivity of DcuS was concentration dependent. The data uniformly show that C4-dicarboxylate sensing by DctA/DcuS resides in DcuS, and that DctA serves as an activity switch. Shifting of DcuS from the constitutive ON to the C4-dicarboxylate responsive state, required presence of DctA but not transport by DctA. © 2014 John Wiley & Sons Ltd.

Molecular distributions of dicarboxylic acids, ketocarboxylic acids and α-dicarbonyls in biomass burning aerosols: implications for photochemical production and degradation in smoke layers

Directory of Open Access Journals (Sweden)

A. Hoffer

2010-03-01

Full Text Available Aerosols in the size class <2.5 μm (6 daytime and 9 nighttime samples were collected at a pasture site in Rondônia, Brazil, during the intensive biomass burning period of 16–26 September 2002 as part of the Large-Scale Biosphere-Atmosphere Experiment in Amazonia – Smoke, Aerosols, Clouds, Rainfall and Climate (LBA-SMOCC. Homologous series of dicarboxylic acids (C2–C11 and related compounds (ketocarboxylic acids and α-dicarbonyls were identified using gas chromatography (GC and GC/mass spectrometry (GC/MS. Among the species detected, oxalic acid was found to be the most abundant, followed by succinic, malonic and glyoxylic acids. Average concentrations of total dicarboxylic acids, ketocarboxylic acids and α-dicarbonyls in the aerosol samples were 2180, 167 and 56 ng m−3, respectively. These are 2–8, 3–11 and 2–16 times higher, respectively, than those reported in urban aerosols, such as in 14 Chinese megacities. Higher ratios of dicarboxylic acids and related compounds to biomass burning tracers (levoglucosan and K+ were found in the daytime than in the nighttime, suggesting the importance of photochemical production. On the other hand, higher ratios of oxalic acid to other dicarboxylic acids and related compounds normalized to biomass burning tracers (levoglucosan and K+ in the daytime provide evidence for the possible degradation of dicarboxylic acids (≥C3 in this smoke-polluted environment. Assuming that these and related compounds are photo-chemically oxidized to oxalic acid in the daytime, and given their linear relationship, they could account for, on average, 77% of the formation of oxalic acid. The remaining portion of oxalic acid may have been directly emitted from biomass burning as suggested by a good correlation with the biomass burning tracers (K+, CO and ECa and organic carbon (OC. However, photochemical production from other precursors could not be excluded.

Mining the Sinorhizobium meliloti transportome to develop FRET biosensors for sugars, dicarboxylates and cyclic polyols.

Directory of Open Access Journals (Sweden)

Alexandre Bourdès

Full Text Available Förster resonance energy transfer (FRET biosensors are powerful tools to detect biologically important ligands in real time. Currently FRET bisosensors are available for twenty-two compounds distributed in eight classes of chemicals (two pentoses, two hexoses, two disaccharides, four amino acids, one nucleobase, two nucleotides, six ions and three phytoestrogens. To expand the number of available FRET biosensors we used the induction profile of the Sinorhizobium meliloti transportome to systematically screen for new FRET biosensors.Two new vectors were developed for cloning genes for solute-binding proteins (SBPs between those encoding FRET partner fluorescent proteins. In addition to a vector with the widely used cyan and yellow fluorescent protein FRET partners, we developed a vector using orange (mOrange2 and red fluorescent protein (mKate2 FRET partners. From the sixty-nine SBPs tested, seven gave a detectable FRET signal change on binding substrate, resulting in biosensors for D-quinic acid, myo-inositol, L-rhamnose, L-fucose, β-diglucosides (cellobiose and gentiobiose, D-galactose and C4-dicarboxylates (malate, succinate, oxaloacetate and fumarate. To our knowledge, we describe the first two FRET biosensor constructs based on SBPs from Tripartite ATP-independent periplasmic (TRAP transport systems.FRET based on orange (mOrange2 and red fluorescent protein (mKate2 partners allows the use of longer wavelength light, enabling deeper penetration of samples at lower energy and increased resolution with reduced back-ground auto-fluorescence. The FRET biosensors described in this paper for four new classes of compounds; (i cyclic polyols, (ii L-deoxy sugars, (iii β-linked disaccharides and (iv C4-dicarboxylates could be developed to study metabolism in vivo.

Isoguvacine binding, uptake, and release: relation to the GABA system

Energy Technology Data Exchange (ETDEWEB)

White, W F; Snodgrass, S R

1983-06-01

Isoguvacine (1,2,3,6-tetrahydropyridine-4-carboxylic acid) is a GABA (gamma-aminobutyric acid) agonist with limited conformational flexibility. In these studies we investigated the binding, uptake, and release of (3H) isoguvacine by use of tissue preparations of rat CNS, comparing the results with similar studies of (3H)GABA. The results from these investigations indicate that isoguvacine binds to membrane preparations of rat forebrain with pharmacological characteristics similar to the post-synaptic GABA recognition site; that it is transported into synaptosomal preparations by an uptake system similar to the high-affinity GABA uptake system; and that recently accumulated isoguvacine is released in a Ca2+-dependent manner and by heteroexchange with external GABA. The ability of isoguvacine and gamma-hydroxybutyric acid to decrease the K+-stimulated Ca2+-dependent release process was also investigated. The results indicate that isoguvacine interactions have many of the biochemical features of GABA synaptic function, isoguvacine being, however, less potent than GABA.

Identification and Functional Characterization of a Tonoplast Dicarboxylate Transporter in Tomato (Solanum lycopersicum)

OpenAIRE

Liu, Ruiling; Li, Boqiang; Qin, Guozheng; Zhang, Zhanquan; Tian, Shiping

2017-01-01

Acidity plays an important role in flavor and overall organoleptic quality of fruit and is mainly due to the presence of organic acids. Understanding the molecular basis of organic acid metabolism is thus of primary importance for fruit quality improvement. Here, we cloned a putative tonoplast dicarboxylate transporter gene (SlTDT) from tomato, and submitted it to the NCBI database (GenBank accession number: KC733165). SlTDT protein contained 13 putative transmembrane domains in silico analys...

Crystal structure and luminescence of complexes of Eu(III) and Tb(III) with furan-2,5-dicarboxylate

NARCIS (Netherlands)

Akerboom, S.; Fu, W.T.; Lutz, M.; Bouwman, E.

2012-01-01

Four new Ln(III) complexes (Ln = Eu, Tb) with furan-2,5-dicarboxylic acid (H2FDA) as a ligand have been synthesized and characterized in the solid state. Luminescence studies indicate that the compounds exhibit line-like luminescence characteristic of the lanthanide centre upon excitation in the

The plant homolog to the human sodium/dicarboxylic cotransporter is the vacuolar malate carrier.

Science.gov (United States)

Emmerlich, Vera; Linka, Nicole; Reinhold, Thomas; Hurth, Marco A; Traub, Michaela; Martinoia, Enrico; Neuhaus, H Ekkehard

2003-09-16

Malate plays a central role in plant metabolism. It is an intermediate in the Krebs and glyoxylate cycles, it is the store for CO2 in C4 and crassulacean acid metabolism plants, it protects plants from aluminum toxicity, it is essential for maintaining the osmotic pressure and charge balance, and it is therefore involved in regulation of stomatal aperture. To fulfil many of these roles, malate has to be accumulated within the large central vacuole. Many unsuccessful efforts have been made in the past to identify the vacuolar malate transporter; here, we describe the identification of the vacuolar malate transporter [A. thaliana tonoplast dicarboxylate transporter (AttDT)]. This transporter exhibits highest sequence similarity to the human sodium/dicarboxylate cotransporter. Independent T-DNA [portion of the Ti (tumor-inducing) plasmid that is transferred to plant cells] Arabidopsis mutants exhibit substantially reduced levels of leaf malate, but respire exogenously applied [14C]malate faster than the WT. An AttDT-GFP fusion protein was localized to vacuole. Vacuoles isolated from Arabidopsis WT leaves exhibited carbonylcyanide m-chlorophenylhydrazone and citrate inhibitable malate transport, which was not stimulated by sodium. Vacuoles isolated from mutant plants import [14C]-malate at strongly reduced rates, confirming that this protein is the vacuolar malate transporter.

Optical Absorption, Stability and Structure of NpO2+ Complexes with Dicarboxylic Acids

International Nuclear Information System (INIS)

Guoxin Tian; Linfeng Rao

2006-01-01

Complexation of NpO2+ with oxalic acid (OX),2,2'-oxydiacetic acid (ODA), 2,2'-iminodiacetic acid (IDA) and 2,2'-thiodiacetic acid (TDA), has been studied using spectrophotometry in1 M NaClO4. Both the position and the intensity of the absorption band of NpO2+ at 980 nm are affected by the formation of NpO2+/dicarboxylate complexes, providing useful information on the complexation strength, the coordination mode and the structure of the complexes

Crystallographic aspects of hydrated salts of 4,6-diaminopyrimidine with the first five dicarboxylic acids

Czech Academy of Sciences Publication Activity Database

Matulková, I.; Andreoni, R.; Císařová, I.; Němec, I.; Fábry, Jan

2017-01-01

Roč. 232, č. 6 (2017), s. 471-484 ISSN 2194-4946 R&D Projects: GA ČR GA14-05506S Institutional support: RVO:68378271 Keywords : crystal structure analysis * 4,6-diaminopyrimidine * dicarboxylic acids * hydrogen-bonding * vibrational spectroscopy * X-ray diffraction Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 3.179, year: 2016

Potentiometric studies on ternary complexes involving some divalent transition metal ions, gallic acid and biologically abundant aliphatic dicarboxylic acids in aqueous solutions

Directory of Open Access Journals (Sweden)

Abdelatty Mohamed Radalla

2015-06-01

Full Text Available Formation of binary and ternary complexes of the divalent transition metal ions, Cu2+, Ni2+, Co2+ and Zn2+ with gallic acid and the biologically important aliphatic dicarboxylic acids (adipic, succinic, malic, malonic, maleic, tartaric and oxalic acids were investigated by means of the potentiometric technique at 25 °C and I = 0.10 mol dm−3 NaNO3. The acid-base properties of the ligands were investigated and discussed. The acidity constants of gallic acid and aliphatic dicarboxylic acids were determined and used for determining the stability constants of the binary and ternary complexes formed in the aqueous medium under the above experimental conditions. The formation of the different 1:1 and 1:2 binary complexes and 1:1:1 ternary complexes are inferred from the corresponding potentiometric pH-metric titration curves. The ternary complex formation was found to occur in a stepwise manner. The stability constants of these binary and ternary systems were calculated. The values of Δ log K, percentage of relative stabilization (%R.S. and log X were evaluated and discussed. The concentration distribution of the various complex species formed in solution was evaluated and discussed. The mode of chelation of ternary complexes formed was ascertained by conductivity measurements.

Coligand-regulated assembly, fluorescence, and magnetic properties of Co(II) and Cd(II) complexes with a non-coplanar dicarboxylate

International Nuclear Information System (INIS)

Xin, Ling-Yun; Liu, Guang-Zhen; Ma, Lu-Fang; Wang, Li-Ya

2013-01-01

A non-coplanar dicarboxylate ndca (H 2 ndca=5-norbornene-2,3-dicarboxylic acid), combining with various dipyridyl-typed tectons, constructs six Cd(II)/Co(II) coordination polymers under hydrothermal conditions, namely [Co(ndca)(H 2 O)] n (1), ([Co(ndca)(bpe)(H 2 O)]·H 2 O) n (2), [Co(ndca)(bpa) 0.5 (H 2 O)] n (3), [Cd(ndca)(bpe)(H 2 O)] n (4), ([Cd(ndca)(bpa)(H 2 O)]·0.5H 2 O) n (5), and ([Cd(ndca)(bpp) (H 2 O)]·H 2 O) n (6) (bpe=1,2-di(4-pyridyl)ethylene, bpa=1,2-bi(4-pyridyl)ethane, and bpp=1,3-bis(4-pyridyl)propane). All these compounds contain various metal(II)–carboxylate motifs, including carboxylate binuclear (2, 4, 5), carboxylate chain (1, 6) and carboxylate layer (3), which are further extended by dipyridyl-typed coligands to afford a vast diversity of the structures with 2D pyknotic layers (1, 6), 2D open layer (5), 2D→3D interpenetrated networks (2,4), and 3D pillared-layer framework (3), respectively. In addition, fluorescent spectra of Cd(II) complexes and magnetic properties of Co(II) complexes are also given. - Graphical abstract: Six various cadmium(II)/cobalt(II)–organic frameworks were constructed by 5-norbornene-2,3-dicarboxylic acid and different bis(pyridine) rod-like tectons, and Cd (II) complexes exhibit blue–violet emissions, whereas Co (II) complexes show antiferromagnetic behaviours. Display Omitted

Variation for N Uptake System in Maize: Genotypic Response to N Supply

KAUST Repository

Garnett, Trevor; Plett, Darren; Conn, Vanessa; Conn, Simon; Rabie, Huwaida; Rafalski, J. Antoni; Dhugga, Kanwarpal; Tester, Mark A.; Kaiser, Brent N.

2015-01-01

An understanding of the adaptations made by plants in their nitrogen (N) uptake systems in response to reduced N supply is important to the development of cereals with enhanced N uptake efficiency (NUpE). Twenty seven diverse genotypes of maize (Zea mays, L.) were grown in hydroponics for 3 weeks with limiting or adequate N supply. Genotypic response to N was assessed on the basis of biomass characteristics and the activities of the nitrate (NO−3) and ammonium (NH+4) high-affinity transport systems. Genotypes differed greatly for the ability to maintain biomass with reduced N. Although, the N response in underlying biomass and N transport related characteristics was less than that for biomass, there were clear relationships, most importantly, lines that maintained biomass at reduced N maintained net N uptake with no change in size of the root relative to the shoot. The root uptake capacity for both NO−3 and NH+4 increased with reduced N. Transcript levels of putative NO−3 and NH+4 transporter genes in the root tissue of a subset of the genotypes revealed that predominately ZmNRT2 transcript levels responded to N treatments. The correlation between the ratio of transcripts of ZmNRT2.2 between the two N levels and a genotype's ability to maintain biomass with reduced N suggests a role for these transporters in enhancing NUpE. The observed variation in the ability to capture N at low N provides scope for both improving NUpE in maize and also to better understand the N uptake system in cereals.

Variation for N Uptake System in Maize: Genotypic Response to N Supply

KAUST Repository

Garnett, Trevor

2015-11-09

An understanding of the adaptations made by plants in their nitrogen (N) uptake systems in response to reduced N supply is important to the development of cereals with enhanced N uptake efficiency (NUpE). Twenty seven diverse genotypes of maize (Zea mays, L.) were grown in hydroponics for 3 weeks with limiting or adequate N supply. Genotypic response to N was assessed on the basis of biomass characteristics and the activities of the nitrate (NO−3) and ammonium (NH+4) high-affinity transport systems. Genotypes differed greatly for the ability to maintain biomass with reduced N. Although, the N response in underlying biomass and N transport related characteristics was less than that for biomass, there were clear relationships, most importantly, lines that maintained biomass at reduced N maintained net N uptake with no change in size of the root relative to the shoot. The root uptake capacity for both NO−3 and NH+4 increased with reduced N. Transcript levels of putative NO−3 and NH+4 transporter genes in the root tissue of a subset of the genotypes revealed that predominately ZmNRT2 transcript levels responded to N treatments. The correlation between the ratio of transcripts of ZmNRT2.2 between the two N levels and a genotype\\'s ability to maintain biomass with reduced N suggests a role for these transporters in enhancing NUpE. The observed variation in the ability to capture N at low N provides scope for both improving NUpE in maize and also to better understand the N uptake system in cereals.

Urinary concentrations of cyclohexane-1,2-dicarboxylic acid monohydroxy isononyl ester, a metabolite of the non-phthalate plasticizer di(isononyl)cyclohexane-1,2-dicarboxylate (DINCH), and markers of ovarian response among women attending a fertility center

Energy Technology Data Exchange (ETDEWEB)

Mínguez-Alarcón, Lidia, E-mail: lminguez@hsph.harvard.edu [Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston (United States); Souter, Irene [Vincent Obstetrics and Gynecology, Massachusetts General Hospital and Harvard Medical School, Boston (United States); Chiu, Yu-Han [Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston (United States); Williams, Paige L. [Department of Epidemiology, and Harvard T.H. Chan School of Public Health, Boston (United States); Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston (United States); Ford, Jennifer B. [Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston (United States); Ye, Xiaoyun; Calafat, Antonia M. [National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta (United States); Hauser, Russ [Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston (United States); Department of Epidemiology, and Harvard T.H. Chan School of Public Health, Boston (United States); Vincent Obstetrics and Gynecology, Massachusetts General Hospital and Harvard Medical School, Boston (United States)

2016-11-15

Di(isononyl)cyclohexane-1,2-dicarboxylate (DINCH), a non-phthalate plasticizer, was introduced commercially in 2002 as an alternative to ortho-phthalate esters because of its favorable toxicological profile. However, the potential health effects from DINCH exposure remain largely unknown. We explored the associations between urinary concentrations of metabolites of DINCH on markers of ovarian response among women undergoing in vitro fertilization (IVF) treatments. Between 2011 and 2015, 113 women enrolled a prospective cohort study at the Massachusetts General Hospital Fertility Center and provided up to two urine samples prior to oocyte retrieval. The urinary concentrations of two DINCH metabolites, cyclohexane-1,2-dicarboxylic acid monohydroxy isononyl ester (MHiNCH) and cyclohexane-1,2-dicarboxylic acid monocarboxyisooctyl ester (MCOCH), were quantified by isotope dilution tandem mass spectrometry. We used generalized linear mixed models to evaluate the association between urinary metabolite concentrations and markers of ovarian response, accounting for multiple IVF cycles per woman via random intercepts. On average, women with detectable urinary MHiNCH concentrations, as compared to those below LOD, had a lower estradiol levels (−325 pmol/l, p=0.09) and number of retrieved oocytes (−1.8, p=0.08), with a stronger association among older women. However, urinary MHiNCH concentrations were unrelated to mature oocyte yield and endometrial wall thickness. In conclusion, we found suggestive negative associations between urinary MHiNCH concentrations and peak estradiol levels and number of total oocyte yields. This is the first study evaluating the effect of DINCH exposure on human reproductive health and raises the need for further experimental and epidemiological studies to better understand the potential effects of this chemical on health. - Highlights: • Women with detectable urinary MHiNCH concentrations had a lower estradiol levels and number of retrieved

Urinary concentrations of cyclohexane-1,2-dicarboxylic acid monohydroxy isononyl ester, a metabolite of the non-phthalate plasticizer di(isononyl)cyclohexane-1,2-dicarboxylate (DINCH), and markers of ovarian response among women attending a fertility center

International Nuclear Information System (INIS)

Mínguez-Alarcón, Lidia; Souter, Irene; Chiu, Yu-Han; Williams, Paige L.; Ford, Jennifer B.; Ye, Xiaoyun; Calafat, Antonia M.; Hauser, Russ

2016-01-01

Di(isononyl)cyclohexane-1,2-dicarboxylate (DINCH), a non-phthalate plasticizer, was introduced commercially in 2002 as an alternative to ortho-phthalate esters because of its favorable toxicological profile. However, the potential health effects from DINCH exposure remain largely unknown. We explored the associations between urinary concentrations of metabolites of DINCH on markers of ovarian response among women undergoing in vitro fertilization (IVF) treatments. Between 2011 and 2015, 113 women enrolled a prospective cohort study at the Massachusetts General Hospital Fertility Center and provided up to two urine samples prior to oocyte retrieval. The urinary concentrations of two DINCH metabolites, cyclohexane-1,2-dicarboxylic acid monohydroxy isononyl ester (MHiNCH) and cyclohexane-1,2-dicarboxylic acid monocarboxyisooctyl ester (MCOCH), were quantified by isotope dilution tandem mass spectrometry. We used generalized linear mixed models to evaluate the association between urinary metabolite concentrations and markers of ovarian response, accounting for multiple IVF cycles per woman via random intercepts. On average, women with detectable urinary MHiNCH concentrations, as compared to those below LOD, had a lower estradiol levels (−325 pmol/l, p=0.09) and number of retrieved oocytes (−1.8, p=0.08), with a stronger association among older women. However, urinary MHiNCH concentrations were unrelated to mature oocyte yield and endometrial wall thickness. In conclusion, we found suggestive negative associations between urinary MHiNCH concentrations and peak estradiol levels and number of total oocyte yields. This is the first study evaluating the effect of DINCH exposure on human reproductive health and raises the need for further experimental and epidemiological studies to better understand the potential effects of this chemical on health. - Highlights: • Women with detectable urinary MHiNCH concentrations had a lower estradiol levels and number of retrieved

Determination of submicromolar amounts of uranium(VI) by compleximetric titration with pyridine-2,6-dicarboxylic acid

International Nuclear Information System (INIS)

Marsh, S.F.; Betts, M.R.; Rein, J.E.

1980-01-01

Uranium(VI) is selectively determined by a compleximetric titration with pyridine-2,6-dicarboxylic acid, using arsenazo-I indicator and hexamethylenetetramine buffer at pH 4.9. Cyclohexanediaminetetraacetic acid and diethylenetriaminepentaacetic acid provide masking of interfering metal ions. A probe colorimeter apparatus is recommended for end-point detection. The relative standard deviation is 0.6% for 0.17-0.76 μmol of uranium. (Auth.)

Determination of submicromolar amounts of uranium(VI) by compleximetric titration with pyridine-2,6-dicarboxylic acid

Energy Technology Data Exchange (ETDEWEB)

Marsh, S F; Betts, M R; Rein, J E [Los Alamos Scientific Lab., NM (USA)

1980-10-01

Uranium(VI) is selectively determined by a compleximetric titration with pyridine-2,6-dicarboxylic acid, using arsenazo-I indicator and hexamethylenetetramine buffer at pH 4.9. Cyclohexanediaminetetraacetic acid and diethylenetriaminepentaacetic acid provide masking of interfering metal ions. A probe colorimeter apparatus is recommended for end-point detection. The relative standard deviation is 0.6% for 0.17-0.76 ..mu..mol of uranium.

PC based Thyroid uptake system for the National Health System

International Nuclear Information System (INIS)

Arista Romeo, Eduardo; Ateche Diaz, Raul; Alonso Abad, Dolores

2003-01-01

a measurement detection system is presented to be used in Iodine Thyroid Uptake Studies. It consists of three elements the detector with its collimator, a blind measurement module and the application software. The measurements module communications through a RS-232 serial interface to the PC where the applications software Detect resides. The software was designed according to the principles ob object oriented programming using C++ language. It automatically fixes spectrometric measurement parameters and besides patient measurement also performs statistical analysis of a batch of samples, It possesses a Paradox database with all information of measured patients and an on line help with the system options

Self-nanoemulsifying drug delivery system for enhanced bioavailability and improved hepatoprotective activity of biphenyl dimethyl dicarboxylate.

Science.gov (United States)

El-Laithy, Hanan M

2008-07-01

Biphenyl Dimethyl Dicarboxylate (BDD) is insoluble in aqueous solution and the bioavailability after oral administration is low. Self-nanoemulsifying drug delivery system (SNEDDS) containing BDD has been successfully prepared using carefully selected ingredients which are less affected by pH and ionic strength changes to improve its bioavailability. SNEDDS is an isotropic mixture of lipid, surfactant, and cosurfactant which are spontaneously emulsified in aqueous medium under gentle digestive motility in the gastrointestinal tract. Pseudo ternary phase diagrams composed of various excipients were plotted to identify self -nano -emulsifying area. Droplet size changes upon dilution with aqueous media and in vitro release of BDD from SNEDDS in 0.1N HCl and phosphate buffer (pH 7.4) were studied and compared with commercial chinese pilules and Pennel capsules. The hepatoprotective activity upon oral administration of SNEDDS against carbon tetrachloride-induced oxidative stress in albino rats was assessed by measuring biochemical parameters like serum glutamic oxalacetate transaminase (SGOT), serum glutamic pyruvate transaminase (SGPT) and lactate dehydrogenase (LDH). Results showed that using a proper ratio of Tween 80 to Transcutol as surfactant and co-surfactant respectively and Miglyol 812 as oil to surfactants mixture resulted in production of infinitely diluted formulations in nano droplet size range. BDD self nano emulsified formula composed of 20% Miglyol 812, 60% Tween 80 and 20% Transcutol released 99% of the drug very rapidly within 10-15 minutes regardless of the pH condition. The oral absorption and bioavailability of BDD self nano emulsified formula in albino rats were significantly enhanced (P<0.01) with an average improvement of 1.7 and 6-folds that of commercial chinese pilules and Pennel capsules respectively. This improvement was also confirmed histopathologically in chemically injured rats and by the significant decrease in elevated liver enzymes

Coligand-regulated assembly, fluorescence, and magnetic properties of Co(II) and Cd(II) complexes with a non-coplanar dicarboxylate

Energy Technology Data Exchange (ETDEWEB)

Xin, Ling-Yun [College of Chemistry and Chemical Engineering, Luoyang Normal University, Luoyang 471022 (China); Liu, Guang-Zhen, E-mail: gzliuly@126.com [College of Chemistry and Chemical Engineering, Luoyang Normal University, Luoyang 471022 (China); Ma, Lu-Fang [College of Chemistry and Chemical Engineering, Luoyang Normal University, Luoyang 471022 (China); Wang, Li-Ya [College of Chemistry and Chemical Engineering, Luoyang Normal University, Luoyang 471022 (China); College of Chemistry and Pharmacy Engineering, Nanyang Normal University, Nanyang 473061 (China)

2013-10-15

A non-coplanar dicarboxylate ndca (H{sub 2}ndca=5-norbornene-2,3-dicarboxylic acid), combining with various dipyridyl-typed tectons, constructs six Cd(II)/Co(II) coordination polymers under hydrothermal conditions, namely [Co(ndca)(H{sub 2}O)]{sub n} (1), ([Co(ndca)(bpe)(H{sub 2}O)]·H{sub 2}O){sub n} (2), [Co(ndca)(bpa){sub 0.5}(H{sub 2}O)]{sub n} (3), [Cd(ndca)(bpe)(H{sub 2}O)]{sub n} (4), ([Cd(ndca)(bpa)(H{sub 2}O)]·0.5H{sub 2}O){sub n} (5), and ([Cd(ndca)(bpp) (H{sub 2}O)]·H{sub 2}O){sub n} (6) (bpe=1,2-di(4-pyridyl)ethylene, bpa=1,2-bi(4-pyridyl)ethane, and bpp=1,3-bis(4-pyridyl)propane). All these compounds contain various metal(II)–carboxylate motifs, including carboxylate binuclear (2, 4, 5), carboxylate chain (1, 6) and carboxylate layer (3), which are further extended by dipyridyl-typed coligands to afford a vast diversity of the structures with 2D pyknotic layers (1, 6), 2D open layer (5), 2D→3D interpenetrated networks (2,4), and 3D pillared-layer framework (3), respectively. In addition, fluorescent spectra of Cd(II) complexes and magnetic properties of Co(II) complexes are also given. - Graphical abstract: Six various cadmium(II)/cobalt(II)–organic frameworks were constructed by 5-norbornene-2,3-dicarboxylic acid and different bis(pyridine) rod-like tectons, and Cd (II) complexes exhibit blue–violet emissions, whereas Co (II) complexes show antiferromagnetic behaviours. Display Omitted.

Thermodynamics of formation of cadmium dicarboxylate and carboxylate mixed complexes with benzimidazole

Energy Technology Data Exchange (ETDEWEB)

Kharitonov, G V; Bolotov, V M; Kharitonova, R I [Voronezhskij Tekhnologicheskij Inst. (USSR)

1980-01-01

Thermodynamic parameters of the mixed complexing of cadmium propionate, butyrate, valerate, succinate, maleinate and malate with benzimidazole in 20 % aqUeous-ethanol solution of 0.1 M KNO/sub 3/ are studied using polarographic method. It is shown that stability of mixed complexes of cadmium carboxylates with benzimidazole is connected with the process enthalpy and is determined by covalency of the metal-carboxylate bond. Increasing length of hydrocarbon chain of acyl group of monobasic acids hampers amine coordination with central complexing agent (..delta..S<0). The presence of dicarboxylate-ion in the inner coordination sphere decreases the enthalpy and increases the entropy of the process (..delta..S>0).

Measurement of the iodine uptake by the thyroid: comparative analysis between the gamma camera system with 'pinhole' collimator and 13S002 system

International Nuclear Information System (INIS)

Silva, Carlos Borges da; Mello, Rossana Corbo R. de; Rebelo, Ana Maria O.

2002-01-01

The thyroid uptake measurements are common in medical uses and are considered a direct and precise form of diagnostic, however, different results have been observed as measurements of thyroid uptake are taken using distinct equipment. This study attempts to find the cause of the differences between a thyroid uptake probe and a gamma camera. These discrepancies can be associated to the different patients samples, equipment's problems or operator procedures errors. This work presents the results of comparative uptake measurements performed in a neck phantom and a 4-hour thyroid uptake study in 40 patients, using a Gamma Camera Ohio Nuclear model Sigma 410 with a pinhole collimator and Nuclear Medicine System model 13S002, developed by Instituto de Engenharia Nuclear. The results observed show that in spite of non satisfactory results commented in literature, both the System 13S002 and System Gamma Camera Ohio can be used in uptake thyroid diagnostic with statistical confidence degree of 99 %. (author)

Uptake and localisation of lead in the root system of Brassica juncea

International Nuclear Information System (INIS)

Meyers, Donald E.R.; Auchterlonie, Graeme J.; Webb, Richard I.; Wood, Barry

2008-01-01

The uptake and distribution of Pb sequestered by hydroponically grown (14 days growth) Brassica juncea (3 days exposure; Pb activities 3.2, 32 and 217 μM) was investigated. Lead uptake was restricted largely to root tissue. Examination using scanning transmission electron microscopy-energy dispersive spectroscopy revealed substantial and predominantly intracellular uptake at the root tip. Endocytosis of Pb at the plasma membrane was not observed. A membrane transport protein may therefore be involved. In contrast, endocytosis of Pb into a subset of vacuoles was observed, resulting in the formation of dense Pb aggregates. Sparse and predominantly extracellular uptake occurred at some distance from the root tip. X-ray photoelectron spectroscopy confirmed that the Pb concentration was greater in root tips. Heavy metal rhizofiltration using B. juncea might therefore be improved by breeding plants with profusely branching roots. Uptake enhancement using genetic engineering techniques would benefit from investigation of plasma membrane transport mechanisms. - The sites of Pb sequestration within the root system of hydroponically grown Brassica juncea were identified

Microbial Transformation of Dicarboxylic Acids by Airborne Bacteria

Science.gov (United States)

Cote, V.; Ariya, P.

2004-05-01

Organic aerosols are assumed to be key players in driving climatic changes and can cause health problems for human. Dicarboxylic acids (DCA) include a large fraction of identified important class of organic aerosols. In addition to direct sources, DCA are partly formed as the result of ozonolysis of terpenes and cyclic alkenes. Previous works in our laboratory show that airborne fungi collected from urban and suburban air play an important role in the transformation of severals organic aerosols such as DCA. Our present study focuses on understanding the potential chemical transformation induced by airborne bacteria and on identification of the transformation products. Airborne bacteria have been collected using a biosampler and cultivated on a solid media. Each bacterial colony is being tested by HPLC for their ability to transform DCA in liquid cultures. Also, GC-MS, SPME and NMR are being used to identify the metabolites generated from the transformation. We will present our preliminary results and we will discuss the application of bacterial activities on the chemical transformation of organics in atmosphere.

Chemical characteristics of dicarboxylic acids and related organic compounds in PM2.5 during biomass-burning and non-biomass-burning seasons at a rural site of Northeast China.

Science.gov (United States)

Cao, Fang; Zhang, Shi-Chun; Kawamura, Kimitaka; Liu, Xiaoyan; Yang, Chi; Xu, Zufei; Fan, Meiyi; Zhang, Wenqi; Bao, Mengying; Chang, Yunhua; Song, Wenhuai; Liu, Shoudong; Lee, Xuhui; Li, Jun; Zhang, Gan; Zhang, Yan-Lin

2017-12-01

Fine particulate matter (PM2.5) samples were collected using a high-volume air sampler and pre-combusted quartz filters during May 2013 to January 2014 at a background rural site (47 ∘ 35 N, 133 ∘ 31 E) in Sanjiang Plain, Northeast China. A homologous series of dicarboxylic acids (C 2 -C 11 ) and related compounds (oxoacids, α-dicarbonyls and fatty acids) were analyzed by using a gas chromatography (GC) and GC-MS method employing a dibutyl ester derivatization technique. Intensively open biomass-burning (BB) episodes during the harvest season in fall were characterized by high mass concentrations of PM2.5, dicarboxylic acids and levoglucosan. During the BB period, mass concentrations of dicarboxylic acids and related compounds were increased by up to >20 times with different factors for different organic compounds (i.e., succinic (C 4 ) acid > oxalic (C 2 ) acid > malonic (C 3 ) acid). High concentrations were also found for their possible precursors such as glyoxylic acid (ωC 2 ), 4-oxobutanoic acid, pyruvic acid, glyoxal, and methylglyoxal as well as fatty acids. Levoglucosan showed strong correlations with carbonaceous aerosols (OC, EC, WSOC) and dicarboxylic acids although such good correlations were not observed during non-biomass-burning seasons. Our results clearly demonstrate biomass burning emissions are very important contributors to dicarboxylic acids and related compounds. The selected ratios (e.g., C 3 /C 4 , maleic acid/fumaric acid, C 2 /ωC 2 , and C 2 /levoglucosan) were used as tracers for secondary formation of organic aerosols and their aging process. Our results indicate that organic aerosols from biomass burning in this study are fresh without substantial aging or secondary production. The present chemical characteristics of organic compounds in biomass-burning emissions are very important for better understanding the impacts of biomass burning on the atmosphere aerosols. Copyright © 2017 Elsevier Ltd. All rights reserved.

Photoluminescence properties of lanthanide-organic frameworks (LnOFs) with thiophene-2,5-dicarboxylate and acetate

Energy Technology Data Exchange (ETDEWEB)

Han, Jing; Wei, Qing; Xie, Gang; Chen, Sanping [Key Lab. of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest Univ., Xi' an, Shaanxi (China); Zhang, Sheng [Key Lab. of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest Univ., Xi' an, Shaanxi (China); College of Chemistry and Chemical Engineering, Baoji Univ. of Arts and Science, Baoji, Shaanxi (China)

2017-07-17

S-heterocyclic dicarboxylic acid, thiophene-2,5-dicarboxylic acid (H{sub 2}TDC), was employed to construct a series of lanthanide-organic frameworks (LnOFs) with coligand acetate, formulated as [Ln(TDC)(OAc)(H{sub 2}O)]{sub n} [Ln = Eu (1), Tb (2), Gd (3), Dy (4), Sm (5)] under hydrothermal conditions. Structure analysis reveals that 1-5 have dinuclear 3D metal organic frameworks (MOFs), in which TDC{sup 2-} and OAc{sup -} display (κ{sup 1}-κ{sup 1})-(κ{sup 1}-κ{sup 1})-μ{sub 4} and (κ{sup 2}-κ{sup 1})-μ{sub 2} coordination fashions, respectively. The dehydrated products of all compounds show high thermal stability above 410 C. As for 1, 2, 4, and 5, the photoluminescence analyses exhibit characteristic luminescence emission bands of the corresponding lanthanide ions in the visible region. In particular, compound 2 displays bright green luminescence in the solid state with {sup 5}D{sub 4} lifetime of 0.510 ms and relative high overall quantum yield of 16 %, based on an ideal energy gap between the lowest triplet state energy level of H{sub 2}TDC ligand and the {sup 5}D{sub 4} state energy level of Tb{sup 3+}. The energy transfer mechanisms in compounds 1 and 2 were also discussed. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Microbial and 'de novo' transformation of dicarboxylic acids by three airborne fungi

International Nuclear Information System (INIS)

Cote, Valerie; Kos, Gregor; Mortazavi, Roya; Ariya, Parisa A.

2008-01-01

Micro-organisms and organic compounds of biogenic or anthropogenic origins are important constituents of atmospheric aerosols, which are involved in atmospheric processes and climate change. In order to investigate the role of fungi and their metabolisation activity, we collected airborne fungi using a biosampler in an urban location of Montreal, Quebec, Canada (45 o 28' N, 73 o 45' E). After isolation on Sabouraud dextrose agar, we exposed isolated colonies to dicarboxylic acids (C 2 -C 7 ), a major group of organic aerosols and monitored their growth. Depending on the acid, total fungi numbers varied from 35 (oxalic acid) to 180 CFU/mL (glutaric acid). Transformation kinetics of malonic acid, presumably the most abundant dicarboxylic acid, at concentrations of 0.25 and 1.00 mM for isolated airborne fungi belonging to the genera Aspergillus, Penicillium, Eupenicillium, and Thysanophora with the fastest transformation rate are presented. The initial concentration was halved within 4.5 and 11.4 days. Other collected fungi did not show a significant degradation and the malonic acid concentration remained unchanged (0.25 and 1.00 mM) within 20 days. Degradation of acid with formation of metabolites was followed using high performance liquid chromatography-ultraviolet detection (HPLC/UV) and gas chromatography-mass spectrometry (GC/MS), as well as monitoring of 13 C labelled malonic acid degradation with solid-state nuclear magnetic resonance spectroscopy (NMR). Using GC/MS we identified two processes driving chemical modifications of organic aerosol solutions: (I) formation of metabolites within several days, and (II) rapid release (≤ 2 min) of organic molecules from fungal species upon the insertion of taxa in organic aerosol solutions. Metabolites included aromatic compounds and alcohols (e.g. trimethylbenzene and butanol). Potential atmospheric implications of our results are discussed

Characterization of cadmium uptake in Lactobacillus plantarum and isolation of cadmium and manganese uptake mutants

Energy Technology Data Exchange (ETDEWEB)

Hao, Z.; Reiske, H.R.; Wilson, D.B.

1999-11-01

Two different Cd{sup 2+} uptake systems were identified in Lactobacillus plantarum. One is a high-affinity, high-velocity Mn{sup 2+} uptake system which also takes up Cd{sup 2+} and is induced by Mn{sup 2+} starvation. The calculated K{sub m} and V{sub max} are 0.26 {mu}M and 3.6 {mu}mol g of dry cell{sup {minus}1} min{sup {minus}1}, respectively. Unlike Mn{sup 2+} uptake, which is facilitated by citrate and related tricarboxylic acids, Cd{sup 2+} uptake is weakly inhibited by citrate. Cd{sup 2+} and Mn{sup 2+} are competitive inhibitors of each other, and the affinity of the system for Cd{sup 2+} is higher than that for Mn{sup 2+}. The other Cd{sup 2+} uptake system is expressed in Mn{sup 2+}-sufficient cells, and no K{sub m} can be calculated for it because uptake is nonsaturable. Mn{sup 2+} does not compete for transport through this system, nor does any other tested cation, i.e., Zn{sup 2+}, Cu{sup 2+}, Co{sup 2+}, Mg{sup 2+}, Ca{sup 2+}, Fe{sup 2+}, or Ni{sup 2+}. Both systems require energy, since uncouplers completely inhibit their activities. Two Mn{sup 2+}-dependent L. plantarum mutants were isolated by chemical mutagenesis and ampicillin enrichment. They required more than 5,000 times as much Mn{sup 2+} for growth as the parental strain. Mn{sup 2+} starvation-induced Cd{sup 2+} uptake in both mutants was less than 5% the wild-type rate. The low level of long-term Mn{sup 2+} or Cd{sup 2+} accumulation by the mutant strains also shows that the mutations eliminate the high-affinity Mn{sup 2+} and Cd{sup 2+} uptake system.

Unmasking the Role of Uptake Transporters for Digoxin Uptake Across the Barriers of the Central Nervous System in Rat

Directory of Open Access Journals (Sweden)

Kunal S Taskar

2017-03-01

Full Text Available The role of uptake transporter (organic anion–transporting polypeptide [Oatp] in the disposition of a P-glycoprotein (P-gp substrate (digoxin at the barriers of central nervous system, namely, the blood-brain barrier (BBB, blood-spinal cord barrier (BSCB, and brain-cerebrospinal fluid barrier (BCSFB, was studied using rat as a preclinical species. In vivo chemical inhibition of P-gp and Oatp was achieved using elacridar and rifampicin, respectively. Our findings show that (1 digoxin had a low brain-to-plasma concentration ratio (B/P (0.07 in rat; (2 in the presence of elacridar, the B/P of digoxin increased by about 12-fold; (3 rifampicin administration alone did not change the digoxin B/P significantly when compared with digoxin B/P alone; (4 rifampicin administration along with elacridar resulted only in 6-fold increase in the B/P of digoxin; (5 similar fold changes and trends were seen with the spinal cord-to-plasma concentration ratio of digoxin, indicating the similarity between BBB and the BSCB; and (6 unlike BBB and BSCB, the presence of rifampicin further increased the cerebrospinal fluid-to-plasma concentration ratio (CSF/P for digoxin, suggesting a differential orientation of the uptake transporters at the BCSFB (CSF to blood compared with the BBB (blood to brain. The observations for digoxin uptake, at least at the BBB and the BSCB, advocate the importance of uptake transporters (Oatps. However, the activity of such uptake transporters became evident only after inhibition of the efflux transporter (P-gp.

Cadmium uptake by cocoa trees in agroforestry and monoculture systems under conventional and organic management.

Science.gov (United States)

Gramlich, A; Tandy, S; Andres, C; Chincheros Paniagua, J; Armengot, L; Schneider, M; Schulin, R

2017-02-15

Cadmium (Cd) uptake by cocoa has recently attracted attention, after the European Union (EU) decided to establish values for tolerable Cd concentrations in cocoa products. Bean Cd concentrations from some cocoa provenances, especially from Latin America, were found to exceed these values. Cadmium uptake by cocoa is expected not only to depend on a variety of soil factors, but also on plant and management factors. In this study, we investigated the influence of different production systems on Cd uptake by cocoa in a long-term field trial in the Alto Beni Region of Bolivia, where cocoa trees are grown in monocultures and in agroforestry systems, both under organic and conventional management. Leaf, fruits and roots of two cultivars were sampled from each production system along with soil samples collected around these trees. Leaf, pod husk and bean samples were analysed for Cd, iron (Fe) and zinc (Zn), the roots for mycorrhizal abundance and the soil samples for 'total' and 'available' Cd, Fe and Zn as well as DGT-available Cd and Zn, pH, organic matter, texture, 'available' phosphorus (P) and potassium (K). Only a small part of the variance in bean and pod husk Cd was explained by management, soil and plant factors. Furthermore, the production systems and cultivars alone had no significant influence on leaf Cd. However, we found lower Cd leaf contents in agroforestry systems than in monocultures when analysed in combination with DGT-available soil Cd, cocoa cultivar and soil organic matter. Overall, this model explained 60% of the variance of the leaf Cd concentrations. We explain lower leaf Cd concentrations in agroforestry systems by competition for Cd uptake with other plants. The cultivar effect may be explained by cultivar specific uptake capacities or by a growth effect translating into different uptake rates, as the cultivars were of different size. Copyright © 2016 Elsevier B.V. All rights reserved.

Competitive solvent extraction of alkaline-earth cations into chloroform by lipophilic acyclic polyether dicarboxylic acids

International Nuclear Information System (INIS)

Kang, S.I.; Czech, A.; Czech, B.P.; Stewart, L.E.; Bartsch, R.A.

1985-01-01

Competitive solvent extraction of alkaline-earth cations from aqueous solutions into chloroform by a series of lipophilic acyclic polyether dicarboxylic acids is reported. The influence of polyether chain length and of terminal carboxylic acid group variation upon extraction selectivity and efficiency is assessed. In the competitive extraction of concentrated magnesium, calcium, strontium and barium chloride solutions, one complexing agent exhibits pronounced selectivity for barium with Ba 2+ /S 2+ = 50, Ba 2+ /Ca 2+ = 250, and no detectable Mg 2+ extraction. 20 references, 3 figures, 1 table

Uptake of [N-Me-3H]-choline by synaptosomes from the central nervous system of Locusta migratoria

International Nuclear Information System (INIS)

Breer, H.

1982-01-01

The accumulation of 3H-choline by isolated synaptosomes from the central nervous system of locust was studied at concentrations varying from 0.05 to 40 microM. Kinetic analysis of the saturable process revealed a high-affinity and a low-affinity system. The high-affinity uptake was competitively inhibited by hemicholinium-3 and was absolutely dependent on external sodium. Elevated potassium concentrations inhibited choline uptake. The choline uptake by insect synaptosomes was found to be remarkably resistant to a variety of metabolic inhibitors. The reduced choline uptake under depolarizing conditions (high potassium concentration or veratridine) in the absence of calcium implies that electrochemical gradients are important for high-affinity choline uptake. Depolarization of preloaded synaptosomes under appropriate conditions resulted in a significant release of newly accumulated choline radioactivity

Thyroid uptake software

International Nuclear Information System (INIS)

Alonso, Dolores; Arista, Eduardo

2003-01-01

The DETEC-PC software was developed as a complement to a measurement system (hardware) able to perform Iodine Thyroid Uptake studies. The software was designed according to the principles of Object oriented programming using C++ language. The software automatically fixes spectrometric measurement parameters and besides patient measurement also performs statistical analysis of a batch of samples. It possesses a PARADOX database with all information of measured patients and a help system with the system options and medical concepts related to the thyroid uptake study

Use of imidazole 4,5-dicarboxylic acid in vanadium speciation

International Nuclear Information System (INIS)

Banerjee, D.; Mondal, B.C.; Das, D.; Das, A.K.

2003-01-01

A new resin has been synthesized by fictionalization of polystyrene-divinylbenzene (8 %) with imidazole 4,5-dicarboxylic acid through -N=N- bonding. The resulting resin has been characterized by elemental analysis, thermogravimetric analysis, infrared spectroscopy, hydrogen ion capacity and metal ion capacity. The speciation study of vanadium has been studied by using this resin and the maximum exchange capacity was found to be 0.45 mmol g -1 for V 4+ and that for V 5+ was 1.57 mmol g -1 at pH 3 for both. The eluents malonic acid and sodium hydroxide have been used for the selective separation of vanadium(IV) and vanadium(V) species respectively. The effects of diverse ions on the sorption and recovery of each species have been studied. Finally, the developed method has been applied for the speciation and determination of these two species in natural water samples. (author)

Zn-Al LAYERED DOUBLE HYDROXIDE PILLARED BY DIFFERENT DICARBOXYLATE ANIONS

Directory of Open Access Journals (Sweden)

S. Gago

2004-12-01

Full Text Available Zn-Al layered double hydroxides (LDHs intercalated by terephthalate (TPH and biphenyl-4,4'-dicarboxylate (BPH anions have been synthesized by direct co-precipitation from aqueous solution. The Zn/Al ratio in the final materials was 1.8. The products were characterized by powder X-ray diffraction, thermogravimetric analysis, FTIR and FT Raman spectroscopy, and MAS NMR spectroscopy. The basal spacing for the TPH-LDH intercalate was 14.62 Å, indicating that the guest anions stack to form a monolayer with the aromatic rings perpendicular to the host layers. For the LDH intercalate containing BPH anions, a basal spacing of at least 19.2 Å would be expected if the anions adopted an arrangement similar to that for the TPH anions. The observed spacing was 18.24 Å, suggesting that the anions are tilted slightly with respect to the host layers.

Arsenic-phosphorus interactions in the soil-plant-microbe system: Dynamics of uptake, suppression and toxicity to plants.

Science.gov (United States)

Anawar, Hossain M; Rengel, Zed; Damon, Paul; Tibbett, Mark

2018-02-01

High arsenic (As) concentrations in the soil, water and plant systems can pose a direct health risk to humans and ecosystems. Phosphate (Pi) ions strongly influence As availability in soil, its uptake and toxicity to plants. Better understanding of As(V)-Pi interactions in soils and plants will facilitate a potential remediation strategy for As contaminated soils, reducing As uptake by crop plants and toxicity to human populations via manipulation of soil Pi content. However, the As(V)-Pi interactions in soil-plant systems are complex, leading to contradictory findings among different studies. Therefore, this review investigates the role of soil type, soil properties, minerals, Pi levels in soil and plant, Pi transporters, mycorrhizal association and microbial activities on As-Pi interactions in soils and hydroponics, and uptake by plants, elucidate the key mechanisms, identify key knowledge gaps and recommend new research directions. Although Pi suppresses As uptake by plants in hydroponic systems, in soils it could either increase or decrease As availability and toxicity to plants depending on the soil types, properties and charge characteristics. In soil, As(V) availability is typically increased by the addition of Pi. At the root surface, the Pi transport system has high affinity for Pi over As(V). However, Pi concentration in plant influences the As transport from roots to shoots. Mycorrhizal association may reduce As uptake via a physiological shift to the mycorrhizal uptake pathway, which has a greater affinity for Pi over As(V) than the root epidermal uptake pathway. Copyright © 2017 Elsevier Ltd. All rights reserved.

Characterization of cesium uptake mediated by a potassium transport system of bacteria in a soil conditioner

International Nuclear Information System (INIS)

Zhang, Pengyao; Idota, Yoko; Yano, Kentaro; Negishi, Masayuki; Kawabata, Hideaki; Arakawa, Hiroshi; Ogihara, Takuo; Morimoto, Kaori; Tsuji, Akira

2014-01-01

We found that bacteria in a commercial soil conditioner sold in Ishinomaki, Miyagi, exhibited concentrative and saturable cesium ion (Cs + ) uptake in the natural range of pH and temperature. The concentration of intracellular Cs + could be condensed at least a few times higher compared with the outside medium of the cells. This uptake appeared to be mediated by a K + transport system, since Cs + uptake was dose-dependently inhibited by potassium ion (K + ). Eadie-Hofstee plot analysis indicated that the Cs + uptake involved a single saturable process. The maximum uptake amount (J max ) was the same in the presence and absence of K + , suggesting that Cs + and K + uptakes were competitive with respect to each other. These bacteria might be useful for bioremediation of cesium-contaminated soil. (author)

27-Hydroxycholesterol impairs neuronal glucose uptake through an IRAP/GLUT4 system dysregulation

Science.gov (United States)

Mateos, Laura; Maioli, Silvia; Ali, Zeina; Gulyás, Balázs; Winblad, Bengt; Savitcheva, Irina

2017-01-01

Hypercholesterolemia is associated with cognitively deteriorated states. Here, we show that excess 27-hydroxycholesterol (27-OH), a cholesterol metabolite passing from the circulation into the brain, reduced in vivo brain glucose uptake, GLUT4 expression, and spatial memory. Furthermore, patients exhibiting higher 27-OH levels had reduced 18F-fluorodeoxyglucose uptake. This interplay between 27-OH and glucose uptake revealed the engagement of the insulin-regulated aminopeptidase (IRAP). 27-OH increased the levels and activity of IRAP, countered the IRAP antagonist angiotensin IV (AngIV)–mediated glucose uptake, and enhanced the levels of the AngIV-degrading enzyme aminopeptidase N (AP-N). These effects were mediated by liver X receptors. Our results reveal a molecular link between cholesterol, brain glucose, and the brain renin-angiotensin system, all of which are affected in some neurodegenerative diseases. Thus, reducing 27-OH levels or inhibiting AP-N maybe a useful strategy in the prevention of the altered glucose metabolism and memory decline in these disorders. PMID:28213512

Evaluation of uptake and systemicity of 14C - fosthiazate in tomato (Lycopersicon esculentum L.)

International Nuclear Information System (INIS)

Mukherjee, Santanu; Srivastava, Anjana; Kumar, Surendra; Srivastava, P.C.

2009-01-01

Nematodes are round worm species that are found in almost all habitats. Beneficial species are usually referred to free living nematodes, other nematode species are parasitic and harmful to plants, animals and humans. Soil provides an excellent habitat for nematodes. Plant parasitic nematodes may live within plant roots or inhabit in the rhizosphere. The percent yield loss due to root knot nematodes in vegetable crops has been studied under All India Co-ordinated Research Project (Nematodes). The fosthiazate is a new compound incorporated in the market. The uptake and systemicity of fosthiazate in intact tomato plants was studied through 14 C-labeled fosthiazate in presence and absence of DNP. It was found that fosthiazate function as a systemic nematicide in tomato, the accumulation rate of fosthiazate was found higher in roots and shoots part upto 15 hrs. uptake period and after that accumulation slowly becomes saturated in the absence of DNP. In the presence of DNP (10 -2 mM) the amount of fosthiazate in roots as well as shoots was found to be decreased with respect to the uptake time.There was more inhibition on the uptake of fosthiazate in shoots than roots by DNP. (author)

Morphology and phase transformations of tin oxide nanostructures synthesized by the hydrothermal method in the presence of dicarboxylic acids

International Nuclear Information System (INIS)

Zima, Tatyana; Bataev, Ivan

2016-01-01

A new approach to the synthesis of non-stoichiometric tin oxide structures with different morphologies and the phase compositions has been evaluated. The nanostructures were synthesized by hydrothermal treatment of the mixtures of dicarboxylic acids ― aminoterephthalic or oxalic ― with nanocrystalline SnO 2 powder, which was obtained via the sol-gel technology. The products were characterized by Raman and IR spectroscopy, SEM, HRTEM, and XRD analysis. It was shown that the controlled addition of a dicarboxylic acid leads not only to a change in the morphology of the nanostructures, but also to SnO 2 –SnO 2 /Sn 3 O 4 –Sn 3 O 4 –SnO phase transformations. A single-phase Sn 3 O 4 in the form of the well-separated hexagonal nanoplates and mixed SnO 2 /Sn 3 O 4 phases in the form of hierarchical flower-like structures were obtained in the presence of organic additives. The effects of concentration, redox activity of the acids and heat treatment on the basic characteristics of the synthesized tin oxide nanostructures and phase transformations in the synthesized materials are discussed. - Graphical abstract: The controlled addition of aminoterephthalic or oxalic acid leads not only to a change in the morphology of the nanostructures, but also to SnO 2 –SnO 2 /Sn 3 O 4 –Sn 3 O 4 –SnO phase transformations. - Highlights: • A new approach to the synthesis of non-stoichiometric tin oxide structures is studied. • Tin oxide structures are synthesized via hydrothermal method with dicarboxylic acids. • Morphology and phase composition are changed with redox activity and dosage of acid. • The redox activity of acid has an effect on ratio of SnO and SnO 2 in crystal structure. • A pure phase Sn 3 O 4 nanoplates and SnO 2 /Sn 3 O 4 hierarchical structures are formed.

Synthesis, structures and properties of a series of manganese coordination complexes constructed from dicarboxylic fluorene derivatives

Energy Technology Data Exchange (ETDEWEB)

Li Xing, E-mail: lixing@nbu.edu.cn [State Key Laboratory Base of Novel Functional Materials and Preparation Science, Faculty of Materials Science and Chemical Engineering, Ningbo University, Ningbo, Zhejiang, 315211 (China); Zhao Xiuhua; Bing Yue; Zha Meiqin; Xie Hongzhen; Guo Zhiyong [State Key Laboratory Base of Novel Functional Materials and Preparation Science, Faculty of Materials Science and Chemical Engineering, Ningbo University, Ningbo, Zhejiang, 315211 (China)

2013-01-15

Assembly reactions of 9,9-diethylfluorene-2,7-dicarboxylic acid (H{sub 2}DFDC) and Mn(CH{sub 3}COO){sub 2}{center_dot}4H{sub 2}O or MnCl{sub 2}{center_dot}4H{sub 2}O by tuning of various secondary ligands such as 2,2 Prime -bipyridine (2,2 Prime -bpy), 4,4 Prime -bipyridine (4,4 Prime -bpy) or 1,3-bis(4-pyridyl)propane) (bpp), gave rise to four complexes {l_brace} [Mn{sub 2}(DFDC){sub 2}(DMF){sub 2}]{center_dot}H{sub 2}O{r_brace} {sub n} (1), [Mn(DFDC)(2,2 Prime -bpy)]{sub n} (2), {l_brace} [Mn{sub 2}(DFDC){sub 2}(4,4 Prime -bpy){sub 2}]{center_dot}2CH{sub 3}OH{r_brace} {sub n} (3), and {l_brace} [Mn{sub 4}(DFDC){sub 4}(bpp){sub 2}(CH{sub 3}OH){sub 3} (H{sub 2}O){sub 3}]{center_dot}3(CH{sub 3}OH){center_dot}3(H{sub 2}O){r_brace} {sub n} (4). Single crystal X-ray diffraction analysis reveal that complex 1 is three dimensional structure with rhombic channels filled by guest water molecules; 2 presents a close-packed structure with high thermal stability; 3 exhibits a three dimensional framework with micro-porous channels filled by guest methanol molecules and 4 is a two-dimensional structure. The photoluminescent properties of 1-4 have been studied, respectively, showing that the Mn(II) ions, accessorial organic ligands or crystal structures exert important influences on the photoluminescence emissions of H{sub 2}DFDC ligands. Thermogravimetric analysis show that the complexes have remarkably high thermal stability. Magnetic susceptibility measurements have been finished and discussed for the complexes. - Graphical abstract: Assembly of 9,9-diethylfluorene-2,7-dicarboxylic acid and Mn(II) salts by tuning of various accessorial ligands resulted in four manganese complexes with different topological frameworks. Highlights: Black-Right-Pointing-Pointer Four manganese complexes based on 9,9-diethylfluorene-2,7-dicarboxylic acid were obtained. Black-Right-Pointing-Pointer The complexes were structurally characterized by single-crystal X-ray diffraction. Black

Relative Water Uptake as a Criterion for the Design of Trickle Irrigation Systems

Science.gov (United States)

Communar, G.; Friedman, S. P.

2008-12-01

Previously derived analytical solutions to the 2- and 3-dimensional water flow problems describing trickle irrigation are not being widely used in practice because those formulations either ignore root water uptake or refer to it as a known input. In this lecture we are going to describe a new modeling approach and demonstrate its applicability for designing the geometry of trickle irrigation systems, namely the spacing between the emitters and drip lines. The major difference between our and previous modeling approaches is that we refer to the root water uptake as to the unknown solution of the problem and not as to a known input. We postulate that the solution to the steady-state water flow problem with a root sink that is acting under constant, maximum suction defines un upper bound to the relative water uptake (water use efficiency) in actual transient situations and propose to use it as a design criterion. Following previous derivations of analytical solutions we assume that the soil hydraulic conductivity increases exponentially with its matric head, which allows the linearization of the Richards equation, formulated in terms of the Kirchhoff matric flux potential. Since the transformed problem is linear, the relative water uptake for any given configuration of point or line sources and sinks can be calculated by superposition of the Green's functions of all relevant water sources and sinks. In addition to evaluating the relative water uptake, we also derived analytical expressions for the steam functions. The stream lines separating the water uptake zone from the percolating water provide insight to the dependence of the shape and extent of the actual rooting zone on the source- sink geometry and soil properties. A minimal number of just 3 system parameters: Gardner's (1958) alfa as a soil type quantifier and the depth and diameter of the pre-assumed active root zone are sufficient to characterize the interplay between capillary and gravitational effects on

Relevance of Peptide Uptake Systems to the Physiology and Virulence of Streptococcus agalactiae

OpenAIRE

Samen, Ulrike; Gottschalk, Birgit; Eikmanns, Bernhard J.; Reinscheid, Dieter J.

2004-01-01

Streptococcus agalactiae is a major cause of invasive infections in human newborns. To satisfy its growth requirements, S. agalactiae takes up 9 of the 20 proteinogenic amino acids from the environment. Defined S. agalactiae mutants in one or several of four putative peptide permease systems were constructed and tested for peptide uptake, growth in various media, and expression of virulence traits. Oligopeptide uptake by S. agalactiae was shown to be mediated by the ABC transporter OppA1-F, w...

A convenient preparation of 9 H -carbazole-3,6-dicarbonitrile and 9 H -carbazole-3,6-dicarboxylic acid

KAUST Repository

Weselinski, Lukasz Jan

2014-01-23

A catalytic, high yielding and scalable procedure for the synthesis of 9H-carbazole-3,6-dicarbonitrile has been developed. Subsequent hydrolysis of the dinitrile in the presence of a catalytic copper species (i.e., CuI) yields 9H-carbazole-3,6-dicarboxylic acid. Both compounds are versatile and fine-tunable organic building blocks and therefore offer potential in material science, medicinal and supramolecular chemistry. © Georg Thieme Verlag Stuttgart New York.

Synthesis and characterization of Cis-5-Norbornene-2, 3-dicarboxylic anhydride-chitosan

International Nuclear Information System (INIS)

Ku Marshilla Ku Ishak; Zulkifli Ahmad; Hazizan Mohd Akil

2009-01-01

Chitosan was chemically modified with bulky structure, cis-5-norbornene-2, 3-dicarboxylic anhydride and the characteristic of this modified chitosan was studied. The resulting material was analyzed by FTIR, TGA, DSC, XRD and SEM to study the effect of N-acylation to the polysaccharide structure. FTIR results show that the anhydride monomer was successfully bound to amine group of chitosan. Thermal analysis of the modified structure provides the chitosan fibers with thermal stability while XRD and SEM show the lost of crystallinity of modified chitosan. XRD of modified chitosan shows broader peak pattern and a considerable increase in a dimension while SEM of chitosan presented the single particle morphology while norbornene-chitosan shows aggromolarate behaviour due to the hydrophobic nature of norbornene pendant group which induced aggromolaration of the particles in modified structure.(author)

Hydrogen uptake by Azolla-Anabaena

International Nuclear Information System (INIS)

Ruschel, A.P.; Freitas, J.R. de; Silva, P.M.

1984-01-01

The hydrogen uptake in the Azolla-Anabaena system is studied. Tritium is used as tracer. Plants are incubated under different atmosphere composition: a) Air + 3 H 2 ; b) Air + CO 2 + 3 H 2 + CO; c) Air + 3 H 2 + CO; d) Air + CO 2 + 3 H 2 + CO to study the pathway of absorbed hydrogen in the Azolla - Anabaena system. Azolla-Anabaena showed greater hydrogen uptake under argonium atmosphere than under air. Carbon monoxide decreased hydrogen uptake. There are evidences of recycling of the hydrogen evolved through notrogenease. (Author) [pt

Synthetic nanoparticles camouflaged with biomimetic erythrocyte membranes for reduced reticuloendothelial system uptake

International Nuclear Information System (INIS)

Rao, Lang; Xu, Jun-Hua; Cai, Bo; Liu, Huiqin; Li, Ming; Jia, Yan; Xiao, Liang; Guo, Shi-Shang; Liu, Wei; Zhao, Xing-Zhong

2016-01-01

Suppression of the reticuloendothelial system (RES) uptake is one of the most challenging tasks in nanomedicine. Coating stratagems using polymers, such as poly(ethylene glycol) (PEG), have led to great success in this respect. Nevertheless, recent observations of immunological response toward these synthetic polymers have triggered a search for better alternatives. In this work, natural red blood cell (RBC) membranes are camouflaged on the surface of Fe 3 O 4 nanoparticles for reducing the RES uptake. In vitro macrophage uptake, in vivo biodistribution and pharmacokinetic studies demonstrate that the RBC membrane is a superior alternative to the current gold standard PEG for nanoparticle ‘stealth’. Furthermore, we systematically investigate the in vivo potential toxicity of RBC membrane-coated nanoparticles by blood biochemistry, whole blood panel examination and histology analysis based on animal models. The combination of synthetic nanoparticles and natural cell membranes embodies a novel and biomimetic nanomaterial design strategy and presents a compelling property of functional materials for a broad range of biomedical applications. (paper)

Exogenous hydrogen sulfide eliminates spatial memory retrieval impairment and hippocampal CA1 LTD enhancement caused by acute stress via promoting glutamate uptake.

Science.gov (United States)

He, Jin; Guo, Ruixian; Qiu, Pengxin; Su, Xingwen; Yan, Guangmei; Feng, Jianqiang

2017-05-14

Acute stress impairs the hippocampus-dependent spatial memory retrieval, and its synaptic mechanisms are associated with hippocampal CA1 long-term depression (LTD) enhancement in the adult rats. Endogenous hydrogen sulfide (H 2 S) is recognized as a novel gasotransmitter and has the neural protective roles. However, very little attention has been paid to understanding the effects of H 2 S on spatial memory retrieval impairment. We observed the protective effects of NaHS (a donor of H 2 S) against spatial memory retrieval impairment caused by acute stress and its synaptic mechanisms. Our results showed that NaHS abolished spatial memory retrieval impairment and hippocampal CA1 LTD enhancement caused by acute stress, but not by glutamate transporter inhibitor l-trans-pyrrolidine-2,4-dicarboxylic (tPDC), indicating that the activation of glutamate transporters is necessary for exogenous H 2 S to exert its roles. Moreover, NaHS restored the decreased glutamate uptake in the hippocampal CA1 synaptosomal fraction caused by acute stress. Dithiothreitol (DTT, a disulfide reducing agent) abolished a decrease in the glutamate uptake caused by acute stress, and NaHS eradicated the decreased glutamate uptake caused by 5,5'-dithio-bis(2-nitrobenzoic)acid (DTNB, a thiol oxidizing agent), collectively, revealing that exogenous H 2 S increases glutamate uptake by reducing disulfide bonds of the glutamate transporters. Additionally, NaHS inhibited the increased expression level of phosphorylated c-Jun-N-terminal kinase (JNK) in the hippocampal CA1 region caused by acute stress. The JNK inhibitor SP600125 eliminated spatial memory retrieval impairment, hippocampal CA1 LTD enhancement and the decreased glutamate uptake caused by acute stress, indicating that exogenous H 2 S exerts these roles by inhibiting the activation of JNK signaling pathway. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

Enantio-selective molecular dynamics of (±)-o,p-DDT uptake and degradation in water-sediment system.

Science.gov (United States)

Ali, Imran; Alharbi, Omar M L; Alothman, Zeid A; Alwarthan, Abdulrahman

2018-01-01

Enantio-selective molecular dynamics of (±)-o,p-DDT uptake and degradation in water-sediment system is described. Both uptake and degradation processes of (-)-o,p-DDT were slightly higher than (+)-o,p-DDT enantiomer. The optimized parameters for uptake were 7.0μgL -1 concentration of o,p-DDT, 60min contact time, 5.0pH, 6.0gL -1 amount of reverine sediment and 25°C temperature. The maximum degradation of both (-)- and (+)-o,p-DDT was obtained with 16 days, 0.4μgL -1 concentration of o,p-DDT, pH 7 and 35°C temperature. Both uptake and degraded process followed first order rate reaction. Thermodynamic parameters indicated exothermic nature of uptake and degradation processes. Both uptake and degradation were slightly higher for (-)-enantiomer in comparison to (+)-enantiomer of o,p-DDT. It was concluded that both uptake and degradation processes are responsible for the removal of o,p-DDT from nature but uptake plays a crucial role. The percentage degradations of (-)- and (+)-o,p-DDT were 30.1 and 29.5, respectively. This study may be useful to manage o,p-DDT contamination of our earth's ecosystem. Copyright © 2017. Published by Elsevier Inc.

Crystal growth and physical characterization of picolinic acid cocrystallized with dicarboxylic acids

Science.gov (United States)

Somphon, Weenawan; Haller, Kenneth J.

2013-01-01

Pharmaceutical cocrystals are multicomponent materials containing an active pharmaceutical ingredient with another component in well-defined stoichiometry within the same unit cell. Such cocrystals are important in drug design, particularly for improving physicochemical properties such as solubility, bioavailability, or chemical stability. Picolinic acid is an endogenous metabolite of tryptophan and is widely used for neuroprotective, immunological, and anti-proliferative effects within the body. In this paper we present cocrystallization experiments of a series of dicarboxylic acids, oxalic acid, succinic acid, DL-tartaric acid, pimelic acid, and phthalic acid, with picolinic acid. Characterization by FT-IR and Raman spectroscopy, DSC and TG/DTG analysis, and X-ray powder diffraction show that new compounds are formed, including a 1:1 picolinium tartrate monohydrate, a 2:1 monohydrate adduct of picolinic acid and oxalic acid, and a 2:1 picolinic acid-succinic acid monohydrate cocrystal.

Radiosynthesis of dimethyl-2-[{sup 18}F]-(fluoromethyl)-6-methyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate for L-type calcium channel imaging

Energy Technology Data Exchange (ETDEWEB)

Sadeghpour, H. [Nuclear Medicine Research Group, Agricultural, Medical and Industrial Research School (AMIRS), Karaj (Iran); Faculty of Pharmacy and Pharmaceutical Sciences Research Center, Tehran Univ. of Medical Sciences, Tehran (Iran); Jalilian, A.R.; Akhlaghi, M.; Mirzaei, M. [Nuclear Medicine Research Group, Agricultural, Medical and Industrial Research School (AMIRS), Karaj (Iran); Shafiee, A. [Faculty of Pharmacy and Pharmaceutical Sciences Research Center, Tehran Univ. of Medical Sciences, Tehran (Iran); Miri, R. [Medicinal and Natural Products Chemistry Research Center, Shiraz Univ. of Medical Sciences, Shiraz (Iran)

2008-07-01

Dimethyl 2-(fluoromethyl)-6-methyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate 4a, a fluorinated nifedipine analog, has been shown to elicit significant calcium channel blocker activity using a guinea pig ileal longitudinal smooth muscle model. In order to perform biological studies for detection of L-type calcium channel distribution, we decided to prepare the [{sup 18}F]-labeled compound. The latter compound was prepared in no-carrier-added (n.c.a.) form from dimethyl 2-(bromomethyl)-6-methyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate 2 in one step at 80 C in Kryptofix[222]/K[{sup 18}F]F and acetonitrile as a solvent in 15 min. Column chromatography afforded the radiochemically pure compound in 20 min. Radiochemical purity of the {sup 18}F-nifedipine was determined by RTLC and HPLC (> 98%) and specific activity of 21-48 GBq/{mu}mol (EOB). (orig.)

Dynamics of pesticide uptake into plants: From system functioning to parsimonious modeling

DEFF Research Database (Denmark)

Fantke, Peter; Wieland, Peter; Wannaz, Cedric

2013-01-01

Dynamic plant uptake models are suitable for assessing environmental fate and behavior of toxic chemicals in food crops. However, existing tools mostly lack in-depth analysis of system dynamics. Furthermore, no existing model is available as parameterized version that is easily applicable for use...

An exposure system for measuring nasal and lung uptake of vapors in rats

Energy Technology Data Exchange (ETDEWEB)

Dahl, A.R.; Brookins, L.K.; Gerde, P. [National Inst. for Working Life, Solna (Sweden)

1995-12-01

Inhaled gases and vapors often produce biological damage in the nasal cavity and lower respiratory tract. The specific site within the respirator tract at which a gas or vapor is absorbed strongly influences the tissues at risk to potential toxic effects; to predict or to explain tissue or cell specific toxicity of inhaled gases or vapors, the sites at which they are absorbed must be known. The purpose of the work reported here was to develop a system for determining nose and lung absorption of vapors in rats, an animal commonly used in inhalation toxicity studies. In summary, the exposure system described allows us to measure in the rate: (1) nasal absorption and desorption of vapors; (2) net lung uptake of vapors; and (3) the effects of changed breathing parameters on vapor uptake.

SYNTHESIS AND CHARACTERIZATION OF NEW THERMALLY STABLE POLYAMIDES BASED ON 2,5-PYRIDINE DICARBOXYLIC ACID AND AROMATIC DIAMINES

OpenAIRE

FAGHIHI, KHALIL

2009-01-01

Six new thermally stable polyamides 3a-f were synthesized through the polycondensation reaction of 2,5-pyridine dicarboxylic acid 1 with six different derivatives of aromatic diamines 2a-f in amedium consisting of N-methyl-2-pyrrolidone, triphenyl phosphite, calcium chloride and pyridine. The polycondensation reaction produced a series of novel polyamides containing pyridyl moieties in the main chain in high yield with inherent viscosities between 0.50-0.82 dL/g. The resulting polymers were f...

Temperature dependences of saturated vapor pressure and the enthalpy of vaporization of n-pentyl esters of dicarboxylic acids

Science.gov (United States)

Portnova, S. V.; Krasnykh, E. L.; Levanova, S. V.

2016-05-01

The saturated vapor pressures and enthalpies of vaporization of n-pentyl esters of linear C2-C6 dicarboxylic acids are determined by the transpiration method in the temperature range of 309.2-361.2 K. The dependences of enthalpies of vaporization on the number of carbon atoms in the molecule and on the retention indices have been determined. The predictive capabilities of the existing calculation schemes for estimation of enthalpy of vaporization of the studied compounds have been analyzed.

Uptake of proline by the scutellum of germinating barley grain

International Nuclear Information System (INIS)

Vaeisaenen, E.; Sopanen, T.

1986-01-01

Scutella separated from germinating grains of barley (Hordeum vulgare L. cv Himalaya) took up 1 millimolar L-[ 14 C]proline at an initial rate of about 6.5 micromoles gram -1 fresh weight hour -1 (pH 5, 30 0 C). The uptake had a pH optimum at 5. The bulk of the uptake (93%) was via carrier-mediated active transport. All of the 19 L-amino acids tested at 10 millimolar concentration inhibited the mediated uptake of 1 millimolar proline, the inhibitions varying from 18 to 76%. By studying how large a fraction of the mediated uptake was inhibitable by asparagine, alanine, glutamine, and leucine, the mediated uptake was shown to be due to three components. Two of these are most probably attributable to the two nonspecific uptake systems proposed earlier to act in the uptake of glutamine and leucine. The third component was not inhibited by glutamine, asparagine, or alanine, but was inhibited by unlabeled proline and leucine. The uptake by this system was apparently carrier-mediated active transport. D-Proline inhibited this system as strongly as L-proline. Nine of the 16 L-amino tested at 50 millimolar concentrations did not inhibit the uptake of 1 millimolar proline by this system. Valine, leucine, isoleucine, and the basic amino acids were inhibitory, but in spite of this, they did not appear to be taken up by this system. It seems therefore that in addition to two nonspecific amino acid uptake systems the scutella have an uptake system which is specific for proline. It is likely that this proline-specific system accounts for the bulk of proline uptake in a germinating grain

Root water uptake and lateral interactions among root systems in a temperate forest

Science.gov (United States)

Agee, E.; He, L.; Bisht, G.; Gough, C. M.; Couvreur, V.; Matheny, A. M.; Bohrer, G.; Ivanov, V. Y.

2016-12-01

A growing body of research has highlighted the importance of root architecture and hydraulic properties to the maintenance of the transpiration stream under water limitation and drought. Detailed studies of single plant systems have shown the ability of root systems to adjust zones of uptake due to the redistribution of local water potential gradients, thereby delaying the onset of stress under drying conditions. An open question is how lateral interactions and competition among neighboring plants impact individual and community resilience to water stress. While computational complexity has previously hindered the implementation of microscopic root system structure and function in larger scale hydrological models, newer hybrid approaches allow for the resolution of these properties at the plot scale. Using a modified version of the PFLOTRAN model, which represents the 3-D physics of variably saturated soil, we model root water uptake in a one-hectare temperate forest plot under natural and synthetic forcings. Two characteristic hydraulic architectures, tap roots and laterally sprawling roots, are implemented in an ensemble of simulations. Variations of root architecture, their hydraulic properties, and degree of system interactions produce variable local response to water limitation and provide insights on individual and community response to changing meteorological conditions. Results demonstrate the ability of interacting systems to shift areas of active uptake based on local gradients, allowing individuals to meet water demands despite competition from their peers. These results further illustrate how inter- and intra-species variations in root properties may influence not only individual response to water stress, but also help quantify the margins of resilience for forest ecosystems under changing climate.

Uptake of nuclides by plants

International Nuclear Information System (INIS)

Greger, Maria

2004-04-01

This review on plant uptake of elements has been prepared to demonstrate how plants take up different elements. The work discusses the nutrient elements, as well as the general uptake and translocation in plants, both via roots and by foliar absorption. Knowledge of the uptake by the various elements within the periodic system is then reviewed. The work also discusses transfer factors (TF) as well as difficulties using TF to understand the uptake by plants. The review also focuses on species differences. Knowledge necessary to understand and calculate plant influence on radionuclide recirculation in the environment is discussed, in which the plant uptake of a specific nuclide and the fate of that nuclide in the plant must be understood. Plants themselves determine the uptake, the soil/sediment determines the availability of the nuclides and the nuclides themselves can interact with each other, which also influences the uptake. Consequently, it is not possible to predict the nuclide uptake in plants by only analysing the nuclide concentration of the soil/substrate

Uptake of nuclides by plants

Energy Technology Data Exchange (ETDEWEB)

Greger, Maria [Stockholm Univ. (Sweden). Dept. of Botany

2004-04-01

This review on plant uptake of elements has been prepared to demonstrate how plants take up different elements. The work discusses the nutrient elements, as well as the general uptake and translocation in plants, both via roots and by foliar absorption. Knowledge of the uptake by the various elements within the periodic system is then reviewed. The work also discusses transfer factors (TF) as well as difficulties using TF to understand the uptake by plants. The review also focuses on species differences. Knowledge necessary to understand and calculate plant influence on radionuclide recirculation in the environment is discussed, in which the plant uptake of a specific nuclide and the fate of that nuclide in the plant must be understood. Plants themselves determine the uptake, the soil/sediment determines the availability of the nuclides and the nuclides themselves can interact with each other, which also influences the uptake. Consequently, it is not possible to predict the nuclide uptake in plants by only analysing the nuclide concentration of the soil/substrate.

Effect of root temperature on the uptake and metabolism of anions by the root system of Zea mays L. I. Uptake of sulphate by resistant and non-resistant plants

Energy Technology Data Exchange (ETDEWEB)

Holobrada, M; Mistrik, I; Kolek, J [Institute of Experimental Biology and Ecology of the Slovak Academy of Sciences, Bratislava (Czechoslovakia)

1980-01-01

The effect of root temperature upon the uptake of /sup 35/S-sulfate by intact 21 days old maize roots was discussed. The plant roots grown at 20 degC were cooled in steps down to 15 degC or 5 degC. The rate of /sup 35/S uptake was studied both in the whole root system and separately in the individual roots (primary seminal root, seminal adventitious roots and nodal roots). Differences were ascertained at lower uptakes by various root samples from resistant and nonresistant maize cultivars.

Can European eco-innovation policies accelerate the uptake of product-service systems?

NARCIS (Netherlands)

Tan, A.R.; Diaz Lopez, F.J.; Mudgal, S.; Tukker, A.

2013-01-01

Despite the apparent potential of product-service systems (PSS) as a more profitable, resource efficient and socially responsible form of eco-innovation, there has seemingly been limited uptake of this type of business model. A current gap in the literature is that most of the available academic

Two three-dimensional coordination polymers of lead(II) with iminodiacetate and naphthalene-dicarboxylate anions: Synthesis, characterization and luminescence behavior

Energy Technology Data Exchange (ETDEWEB)

Hazari, Debdoot; Jana, Swapan Kumar [Department of Chemistry and Chemical Technology, Vidyasagar University, Midnapore 721 102, West Bengal (India); Fleck, Michel [Institute of Mineralogy and Crystallography, University of Vienna, Geozentrum, Althanstr. 9, A-1090 Vienna (Austria); Zangrando, Ennio [Department of Chemical and Pharmaceutical Sciences, University of Trieste, 34127 Trieste (Italy); Dalai, Sudipta, E-mail: sudipta@mail.vidyasagar.ac.in [Department of Chemistry and Chemical Technology, Vidyasagar University, Midnapore 721 102, West Bengal (India)

2014-11-15

Two lead(II) compounds [Pb{sub 3}(idiac){sub 3}(phen){sub 2}(H{sub 2}O)]·2(H{sub 2}O) (1) and [Pb(ndc)]{sub n} (2), where H{sub 2}idiac=iminodiacetic acid, phen=1,10-phenanthroline and H{sub 2}ndc=naphthalene-2,6-dicarboxylic acid, have been synthesized and structurally characterized. Single crystal X-ray diffraction analysis showed that compound 1 is a discrete trinuclear complex (of two-fold symmetry) which evolves to a supramolecular 3D network via π–π interactions, while in compound 2 the naphthalene dicarboxylate anion act as a linker to form a three dimensional architecture, where the anion adopts a bis-(bidentate bridging) coordination mode connecting four Pb(II) centers. The photoluminescence property of the two complexes has been studied. - graphical abstract: Two new topologically different 1D coordination polymers formed by Pb{sub 4} clusters have been synthesized and characterized by x-ray analysis. The luminescence and thermal properties have been studied. - Highlights: • 1 is a trinuclear complex of Pb(II) growing to 3D network via weak interactions. • In 1, layers of (4,4) rhomboidal topology are identified. • In 2, the ndc anion adopts interesting bis-(bidentate bridging) coordination. • In 2, network is reinforced by C–H…π-ring interactions between the ndc rings.

Site-specific ligation of anthracene-1,8-dicarboxylates to an Mn12 core: a route to the controlled functionalisation of single-molecule magnets.

Science.gov (United States)

Pacchioni, Mirko; Cornia, Andrea; Fabretti, Antonio C; Zobbi, Laura; Bonacchi, Daniele; Caneschi, Andrea; Chastanet, Guillaume; Gatteschi, Dante; Sessoli, Roberta

2004-11-21

A novel single-molecule magnet of the Mn12 family, [Mn12O12(O2CC6H5)8(L)4(H2O)4].8CH2Cl2, has been synthesised by site-specific ligand exchange using a tailor-made dicarboxylate (L2-), which leads to selective occupation of axial binding sites.

Salt and cocrystals of sildenafil with dicarboxylic acids: solubility and pharmacokinetic advantage of the glutarate salt.

Science.gov (United States)

Sanphui, Palash; Tothadi, Srinu; Ganguly, Somnath; Desiraju, Gautam R

2013-12-02

Sildenafil is a drug used to treat erectile dysfunction and pulmonary arterial hypertension. Because of poor aqueous solubility of the drug, the citrate salt, with improved solubility and pharmacokinetics, has been marketed. However, the citrate salt requires an hour to reach its peak plasma concentration. Thus, to improve solubility and bioavailability characteristics, cocrystals and salts of the drug have been prepared by treating aliphatic dicarboxylic acids with sildenafil; the N-methylated piperazine of the drug molecule interacts with the carboxyl group of the acid to form a heterosynthon. Salts are formed with oxalic and fumaric acid; salt monoanions are formed with succinic and glutaric acid. Sildenafil forms cocrystals with longer chain dicarboxylic acids such as adipic, pimelic, suberic, and sebacic acids. Auxiliary stabilization via C-H···O interactions is also present in these cocrystals and salts. Solubility experiments of sildenafil cocrystal/salts were carried out in 0.1N HCl aqueous medium and compared with the solubility of the citrate salt. The glutarate salt and pimelic acid cocrystal dissolve faster than the citrate salt in a two hour dissolution experiment. The glutarate salt exhibits improved solubility (3.2-fold) compared to the citrate salt in water. Solubilities of the binary salts follow an inverse correlation with their melting points, while the solubilities of the cocrystals follow solubilities of the coformer. Pharmacokinetic studies on rats showed that the glutarate salt exhibits doubled plasma AUC values in a single dose within an hour compared to the citrate salt. The high solubility of glutaric acid, in part originating from the strained conformation of the molecule and its high permeability, may be the reason for higher plasma levels of the drug.

Cadmium uptake by cocoa trees in agroforestry and monoculture systems under conventional and organic management

OpenAIRE

Gramlich, A.; Tandy, S.; Andres, C.; Chincheros Paniagua, J.; Armengot, L.; Schneider, M.; Schulin, R.

2016-01-01

Cadmium(Cd) uptake by cocoa has recently attracted attention, after the European Union (EU) decided to establish values for tolerable Cd concentrations in cocoa products. Bean Cd concentrations from some cocoa provenances, especially from Latin America, were found to exceed these values. Cadmium uptake by cocoa is expected not only to depend on a variety of soil factors, but also on plant and management factors. In this study, we investigated the influence of different production systems on C...

Dipropyl 3,6-diphenyl-1,2-dihydro-1,2,4,5-tetrazine-1,2-dicarboxylate.

Science.gov (United States)

Rao, Guo-Wu; Hu, Wei-Xiao

2003-05-01

The title compound, C(22)H(24)N(4)O(4), was prepared from propyl chloroformate and 3,6-diphenyl-1,2-dihydro-s-tetrazine. This reaction yields the title compound rather than dipropyl 3,6-diphenyl-1,4-dihydro-s-tetrazine-1,4-dicarboxylate. The 2,3-diazabutadiene group in the central six-membered ring is not planar; the C=N double-bond length is 1.285 (2) A, and the average N-N single-bond length is 1.401 (3) A, indicating a lack of conjugation. The ring has a twist conformation, in which adjacent N atoms lie +/- 0.3268 (17) A from the plane of the ring. The molecule has twofold crystallographic symmetry.

Characterization of the biotin uptake system encoded by the biotin-inducible bioYMN operon of Corynebacterium glutamicum

Science.gov (United States)

2012-01-01

Background The amino acid-producing Gram-positive Corynebacterium glutamicum is auxotrophic for biotin although biotin ring assembly starting from the precursor pimeloyl-CoA is still functional. It possesses AccBC, the α-subunit of the acyl-carboxylases involved in fatty acid and mycolic acid synthesis, and pyruvate carboxylase as the only biotin-containing proteins. Comparative genome analyses suggested that the putative transport system BioYMN encoded by cg2147, cg2148 and cg2149 might be involved in biotin uptake by C. glutamicum. Results By comparison of global gene expression patterns of cells grown with limiting or excess supply of biotin or with dethiobiotin as supplement replacing biotin revealed that expression of genes coding for enzymes of biotin ring assembly and for the putative uptake system was regulated according to biotin availability. RT-PCR and 5'-RACE experiments demonstrated that the genes bioY, bioM, and bioN are transcribed from one promoter as a single transcript. Biochemical analyses revealed that BioYMN catalyzes the effective uptake of biotin with a concentration of 60 nM biotin supporting a half-maximal transport rate. Maximal biotin uptake rates were at least five fold higher in biotin-limited cells as compared to cells grown with excess biotin. Overexpression of bioYMN led to an at least 50 fold higher biotin uptake rate as compared to the empty vector control. Overproduction of BioYMN alleviated biotin limitation and interfered with triggering L-glutamate production by biotin limitation. Conclusions The operon bioYMN from C. glutamicum was shown to be induced by biotin limitation. Transport assays with radio-labeled biotin revealed that BioYMN functions as a biotin uptake system. Overexpression of bioYMN affected L-glutamate production triggered by biotin limitation. PMID:22243621

Characterization of the biotin uptake system encoded by the biotin-inducible bioYMN operon of Corynebacterium glutamicum.

Science.gov (United States)

Schneider, Jens; Peters-Wendisch, Petra; Stansen, K Corinna; Götker, Susanne; Maximow, Stanislav; Krämer, Reinhard; Wendisch, Volker F

2012-01-13

The amino acid-producing Gram-positive Corynebacterium glutamicum is auxotrophic for biotin although biotin ring assembly starting from the precursor pimeloyl-CoA is still functional. It possesses AccBC, the α-subunit of the acyl-carboxylases involved in fatty acid and mycolic acid synthesis, and pyruvate carboxylase as the only biotin-containing proteins. Comparative genome analyses suggested that the putative transport system BioYMN encoded by cg2147, cg2148 and cg2149 might be involved in biotin uptake by C. glutamicum. By comparison of global gene expression patterns of cells grown with limiting or excess supply of biotin or with dethiobiotin as supplement replacing biotin revealed that expression of genes coding for enzymes of biotin ring assembly and for the putative uptake system was regulated according to biotin availability. RT-PCR and 5'-RACE experiments demonstrated that the genes bioY, bioM, and bioN are transcribed from one promoter as a single transcript. Biochemical analyses revealed that BioYMN catalyzes the effective uptake of biotin with a concentration of 60 nM biotin supporting a half-maximal transport rate. Maximal biotin uptake rates were at least five fold higher in biotin-limited cells as compared to cells grown with excess biotin. Overexpression of bioYMN led to an at least 50 fold higher biotin uptake rate as compared to the empty vector control. Overproduction of BioYMN alleviated biotin limitation and interfered with triggering L-glutamate production by biotin limitation. The operon bioYMN from C. glutamicum was shown to be induced by biotin limitation. Transport assays with radio-labeled biotin revealed that BioYMN functions as a biotin uptake system. Overexpression of bioYMN affected L-glutamate production triggered by biotin limitation.

Human papillomavirus vaccine uptake among individuals with systemic inflammatory diseases.

Directory of Open Access Journals (Sweden)

Candace H Feldman

Full Text Available The human papillomavirus (HPV vaccine is safe and efficacious in patients with systemic inflammatory diseases (SID who have higher rates of persistent HPV infection. We compared HPV vaccine uptake among SID and non-SID patients.Using a U.S. insurance claims database (2006-2012, we identified individuals 9-26 years with ≥2 SID diagnosis codes ≥7 days apart with ≥12 months of continuous enrollment prior to the second code (index date. We matched SID patients by age, sex and index date to randomly selected non-SID subjects and selected those with ≥24 months of post-index date continuous follow-up. We also identified a non-SID subcohort with ≥1 diagnosis code for asthma. We defined initiation as ≥1 HPV vaccination claim after 2007, and completion as 3 claims. We used multivariable logistic regression to assess uptake in females 11-26 years comparing SID, non-SID and asthma cohorts, adjusting for demographics, region, comorbidities, and healthcare utilization.We identified 5,642 patients 9-26 years with SID and 20,643 without. The mean age was 18.1 years (SD 4.9. We identified 1,083 patients with asthma; the mean age was 17.2 (SD 5.1. Among females, 20.6% with SID, 23.1% without SID and 22.9% with asthma, received ≥1 HPV vaccine. In our adjusted models, the odds of receipt of ≥1 vaccine was 0.87 times lower in SID (95% CI 0.77-0.98 compared to non-SID and did not differ for 3 vaccines (OR 1.03, 95% CI 0.83-1.26. The odds of initiation and completion were not statistically different between SID and non-SID asthma cohorts.In this nationwide cohort, HPV vaccine uptake was extremely low. Despite the heightened risk of persistent HPV infection among those with SID, no increase in HPV vaccine uptake was observed. Public health efforts to promote HPV vaccination overall are needed, and may be particularly beneficial for those at higher risk.

The role and uptake of private health insurance in different health care systems: are there lessons for developing countries?

Science.gov (United States)

Odeyemi, Isaac Ao; Nixon, John

2013-01-01

Social and national health insurance schemes are being introduced in many developing countries in moving towards universal health care. However, gaps in coverage are common and can only be met by out-of-pocket payments, general taxation, or private health insurance (PHI). This study provides an overview of PHI in different health care systems and discusses factors that affect its uptake and equity. A representative sample of countries was identified (United States, United Kingdom, The Netherlands, France, Australia, and Latvia) that illustrates the principal forms and roles of PHI. Literature describing each country's health care system was used to summarize how PHI is utilized and the factors that affect its uptake and equity. In the United States, PHI is a primary source of funding in conjunction with tax-based programs to support vulnerable groups; in the UK and Latvia, PHI is used in a supplementary role to universal tax-based systems; in France and Latvia, complementary PHI is utilized to cover gaps in public funding; in The Netherlands, PHI is supplementary to statutory private and social health insurance; in Australia, the government incentivizes the uptake of complementary PHI through tax rebates and penalties. The uptake of PHI is influenced by age, income, education, health care system typology, and the incentives or disincentives applied by governments. The effect on equity can either be positive or negative depending on the type of PHI adopted and its role within the wider health care system. PHI has many manifestations depending on the type of health care system used and its role within that system. This study has illustrated its common applications and the factors that affect its uptake and equity in different health care systems. The results are anticipated to be helpful in informing how developing countries may utilize PHI to meet the aim of achieving universal health care.

Can European sustainability and innovation policies accelerate the uptake of product-service systems?

NARCIS (Netherlands)

Tan, A.R.; Diaz Lopez, F.J.; Mudgal, S.; Tukker, A.

2013-01-01

This review paper presents preliminary results from on-going research on PSS policies in Europe. Despite the apparent potential of product-service systems (PSS) as more profitable, resource efficient and socially responsible, there has seemingly been limited uptake of this type of business model. A

Naphthalene Bis(4,8-diamino-1,5-dicarboxyl)amide Building Block for Semiconducting Polymers.

Science.gov (United States)

Eckstein, Brian J; Melkonyan, Ferdinand S; Manley, Eric F; Fabiano, Simone; Mouat, Aidan R; Chen, Lin X; Facchetti, Antonio; Marks, Tobin J

2017-10-18

We report a new naphthalene bis(4,8-diamino-1,5-dicarboxyl)amide (NBA) building block for polymeric semiconductors. Computational modeling suggests that regio-connectivity at the 2,6- or 3,7-NBA positions strongly modulates polymer backbone torsion and, therefore, intramolecular π-conjugation and aggregation. Optical, electrochemical, and X-ray diffraction characterization of 3,7- and 2,6-dithienyl-substituted NBA molecules and corresponding isomeric NBA-bithiophene copolymers P1 and P2, respectively, reveals the key role of regio-connectivity. Charge transport measurements demonstrate that while the twisted 3,7-NDA-based P1 is a poor semiconductor, the planar 2,6-functionalized NBA polymers (P2-P4) exhibit ambipolarity, with μ e and μ h of up to 0.39 and 0.32 cm 2 /(V·s), respectively.

Transport of acidic amino acids by human jejunal brush-border membrane vesicles

International Nuclear Information System (INIS)

Rajendran, V.M.; Harig, J.M.; Adams, M.B.; Ramaswamy, K.

1987-01-01

This study characterizes the transport of radiolabeled acidic amino acids into brush-border membrane vesicles prepared from human jejunum. The uptakes of L-glutamic, L-aspartic, and D-aspartic acids were stimulated by a Na + gradient. Concentrative uptake (resulting in an overshoot phenomenon) of these dicarboxylic amino acids occurred when there was an outward K + gradient. In addition, increasing K + gradients resulted in enhanced uptake of L-glutamic acid. This K + requirement is somewhat specific as Rb + and Cs + could enhance uptake to a limited extent, whereas Li + and choline + showed no enhancement. The presence of a K + gradient did not affect the affinity of the carrier system for L-glutamic acid but it did increase the V/sub max/. The presence of extravesicular anions having differing membrane permeabilities did not altar L-glutamic acid uptake indicating an absence of an effect of membrane potential on the transport process. Finally, the human transport system for L-glutamic acid appears to be specific for acidic amino acids as demonstrated by inhibition studies. The studies demonstrate a transport system in human jejunum specific for acidic amino acids that is energized by an inward Na + gradient and an outward K + gradient

Genome-based analysis of heme biosynthesis and uptake in prokaryotic systems.

Science.gov (United States)

Cavallaro, Gabriele; Decaria, Leonardo; Rosato, Antonio

2008-11-01

Heme is the prosthetic group of many proteins that carry out a variety of key biological functions. In addition, for many pathogenic organisms, heme (acquired from the host) may constitute a very important source of iron. Organisms can meet their heme demands by taking it up from external sources, by producing the cofactor through a dedicated biosynthetic pathway, or both. Here we analyzed the distribution of proteins specifically involved in the processes of heme biosynthesis and heme uptake in 474 prokaryotic organisms. These data allowed us to identify which organisms are capable of performing none, one, or both processes, based on the similarity to known systems. Some specific instances where one or more proteins along the pathways had unusual modifications were singled out. For two key protein domains involved in heme uptake, we could build a series of structural models, which suggested possible alternative modes of heme binding. Future directions for experimental work are given.

Methanogenic Paraffin Biodegradation: Alkylsuccinate Synthase Gene Quantification and Dicarboxylic Acid Production.

Science.gov (United States)

Oberding, Lisa K; Gieg, Lisa M

2018-01-01

Paraffinic n -alkanes (>C 17 ) that are solid at ambient temperature comprise a large fraction of many crude oils. The comparatively low water solubility and reactivity of these long-chain alkanes can lead to their persistence in the environment following fuel spills and pose serious problems for crude oil recovery operations by clogging oil production wells. However, the degradation of waxy paraffins under the anoxic conditions characterizing contaminated groundwater environments and deep subsurface energy reservoirs is poorly understood. Here, we assessed the ability of a methanogenic culture enriched from freshwater fuel-contaminated aquifer sediments to biodegrade the model paraffin n -octacosane (C 28 H 58 ). Compared with that in controls, the consumption of n -octacosane was coupled to methane production, demonstrating its biodegradation under these conditions. Smithella was postulated to be an important C 28 H 58 degrader in the culture on the basis of its high relative abundance as determined by 16S rRNA gene sequencing. An identified assA gene (known to encode the α subunit of alkylsuccinate synthase) aligned most closely with those from other Smithella organisms. Quantitative PCR (qPCR) and reverse transcription qPCR assays for assA demonstrated significant increases in the abundance and expression of this gene in C 28 H 58 -degrading cultures compared with that in controls, suggesting n -octacosane activation by fumarate addition. A metabolite analysis revealed the presence of several long-chain α,ω-dicarboxylic acids only in the C 28 H 58 -degrading cultures, a novel observation providing clues as to how methanogenic consortia access waxy hydrocarbons. The results of this study broaden our understanding of how waxy paraffins can be biodegraded in anoxic environments with an application toward bioremediation and improved oil recovery. IMPORTANCE Understanding the methanogenic biodegradation of different classes of hydrocarbons has important

Candida antartica lipase-catalyzed hydrolysis of 4-substituted bis(ethoxycarbonylmethyl) 1,4-dihydropyridine-3,5-dicarboxylates as the key step in the synthesis of optically active dihydropyridines

NARCIS (Netherlands)

Sobolev, A.; Franssen, M.C.R.; Makarova, N.; Duburs, G.; Groot, de Æ.

2001-01-01

Prochiral bis(ethoxycarbonylmethyl) substituted 4-aryl-1,4-dihydropyridine-3,5-dicarboxylates were hydrolyzed enantioselectively by Candida antarctica lipase B (Novozym 435). The enantiomeric excesses varied from 68 to 93°depending on the substituent at position 4. In some cases, the e.e. could be

Morita-Baylis-Hillman Route to Dimethyl 2,3-Dihydrobenzo[b]oxepine-2,4- dicarboxylates and Methyl 2-(2-Carbomethoxybenzo[b]furan-3-yl)propanoates from Salicylaldehydes

International Nuclear Information System (INIS)

Ahn, Sang Hyun; Jang, Seung Soon; Kim, Young Keun; Lee, Kee Jung

2012-01-01

A new synthetic method for dimethyl 2,3-dihydrobenzo[b]oxepine-2,4-dicarboxylates and methyl 2-(2- carbomethoxybenzo[b]furan-3-yl)propanoates by an intramolecular conjugate displacement reaction or an S N 2 reaction of acetates of Morita-Baylis-Hillman adducts of methyl (2-formylphenoxy)acetates has been described

A review and model assessment of 32P and 33P uptake to biota in freshwater systems

International Nuclear Information System (INIS)

Smith, J.T.; Bowes, M.J.; Cailes, C.R.

2011-01-01

Bioaccumulation of key short-lived radionuclides such as 131 I and 32,33 P may be over-estimated since concentration ratios (CRs) are often based on values for the corresponding stable isotope which do not account for radioactive decay during uptake via the food chain. This study presents estimates for bioaccumulation of radioactive phosphorus which account for both radioactive decay and varying ambient levels of stable P in the environment. Recommended interim CR values for radioactive forms of P as a function of bioavailable stable phosphorus in the water body are presented. Values of CR are presented for three different trophic levels of the aquatic food chain; foodstuffs from all three trophic levels may potentially be consumed by humans. It is concluded that current recommended values of the CR are likely to be significantly over-estimated for radioactive phosphorus in many freshwater systems, particularly lowland rivers. Further research is recommended to field-validate these models and assess their uncertainty. The relative importance of food-chain uptake and direct uptake from water are also assessed from a review of the literature. It can be concluded that food-chain uptake is the dominant accumulation pathway in fish and hence accumulation factors for radioactive phosphorus in farmed fish are likely to be significantly lower than those for wild fish. - Highlights: → A model is developed for radiophosphorus uptake to fish. → Concentration ratios for 32,33 P in fish may be over-estimated in freshwater systems. → New recommended values for 32,33 P concentration ratios are given. → Farmed fish are likely to have much lower 32,33 P uptake than wild fish.

Gallium-67 uptake in meningeal sarcoidosis

International Nuclear Information System (INIS)

Ayres, J.G.; Hicks, B.H.; Maisey, M.N.

1986-01-01

A case of sarcoidosis limited to the central nervous system is described in which the diagnosis was suggested by high Ga-67 uptake in the cranial and spinal meninges. The diagnosis was confirmed by meningeal biopsy. Treatment with oral corticosteroids resulted in clinical improvement and marked reduction in Ga-67 uptake in the meninges. This is the first reported case of the central nervous system sarcoid diagnosed by Ga-67 imaging

Photo and Thermal Behavior of New Reinforced Polyamide-nanocomposite Montmorillonite on 2,3-Pyrazin Dicarboxylic Acid

Science.gov (United States)

Faghihi, Khalil; Samiei, Mojtaba; Hajibeygi, Mohsen

2012-06-01

Two new samples of reinforce polyamidemontmorillonite nanocomposites were synthesized by a convenient solution intercalation technique. Polyamide (PA) 3 as a source of polymer matrix was synthesized by the direct polycondensation reaction of pyrazine 2,3-dicarboxylic acid 1 with 4,4'-diamino diphenyl ether 2 in the presence of triphenyl phosphite (TPP), CaCl2, pyridine and N-methyl-2-pyrrolidone (NMP). The resulting nanocomposite films were characterized by Fourier transform infrared spectra (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). The results showed that organo-modified clay was dispersed homogeneously in PA matrix. TGA indicated an enhancement of thermal stability of new nanocomposites compared with the pure polymer.

catena-Poly[[[tetraaquazinc(II]-μ-4,4′-bipyridine-κ2N:N′] benzene-1,4-dicarboxylate

Directory of Open Access Journals (Sweden)

Ming-Bo Ruan

2009-07-01

Full Text Available In the title compound, {[Zn(C10H8N2(H2O4](C8H4O4}n, the ZnII atoms, lying on a twofold rotation axis, are bridged by 4,4′-bipyridine ligands, resulting in a linear chain along the b axis. In the chain, the ZnII atom adopts a slightly distorted octahedral coordination geometry involving four water molecules at the equatorial positions. The noncoordinated benzene-1,4-dicarboxylate anion, which is also located on a twofold rotation axis, bridges adjacent chains through O—H...O hydrogen bonds, forming a three-dimensional supramolecular network.

Research into esterification of mixture of lower dicarboxylic acids by 2-ethylhexan-1-ol in the presence of p-toluensulfonic acid

OpenAIRE

Melnyk, Stepan; Melnyk, Yuriy; Nykulyshyn, Irena; Shevchuk, Liliya

2017-01-01

Regularities of esterification of the mixture of lower dicarboxylic acids (succinic, glutaric, adipic) by 2-ethylhexan-1-ol in the presence of catalysts – p-toluensulfonic and sulfuric acids under non-stationary conditions were studied. It was found that in the presence of mineral acid, the reaction flows at a lower rate. Application of benzene as a substance that facilitates separation of water, formed in the esterification reaction, makes it possible, due to a lower reaction temperature, to...

Morita-Baylis-Hillman Route to Dimethyl 2,3-Dihydrobenzo[b]oxepine-2,4- dicarboxylates and Methyl 2-(2-Carbomethoxybenzo[b]furan-3-yl)propanoates from Salicylaldehydes

Energy Technology Data Exchange (ETDEWEB)

Ahn, Sang Hyun; Jang, Seung Soon; Kim, Young Keun; Lee, Kee Jung [Hanyang University, Seoul (Korea, Republic of)

2012-01-15

A new synthetic method for dimethyl 2,3-dihydrobenzo[b]oxepine-2,4-dicarboxylates and methyl 2-(2- carbomethoxybenzo[b]furan-3-yl)propanoates by an intramolecular conjugate displacement reaction or an S{sub N}2 reaction of acetates of Morita-Baylis-Hillman adducts of methyl (2-formylphenoxy)acetates has been described.

Human Papillomavirus Vaccine Uptake among Individuals with Systemic Inflammatory Diseases

Science.gov (United States)

Feldman, Candace H.; Hiraki, Linda T.; Lii, Huichuan; Seeger, John D.; Kim, Seoyoung C.

2015-01-01

Objectives The human papillomavirus (HPV) vaccine is safe and efficacious in patients with systemic inflammatory diseases (SID) who have higher rates of persistent HPV infection. We compared HPV vaccine uptake among SID and non-SID patients. Methods Using a U.S. insurance claims database (2006–2012), we identified individuals 9–26 years with ≥2 SID diagnosis codes ≥7 days apart with ≥12 months of continuous enrollment prior to the second code (index date). We matched SID patients by age, sex and index date to randomly selected non-SID subjects and selected those with ≥24 months of post-index date continuous follow-up. We also identified a non-SID subcohort with ≥1 diagnosis code for asthma. We defined initiation as ≥1 HPV vaccination claim after 2007, and completion as 3 claims. We used multivariable logistic regression to assess uptake in females 11–26 years comparing SID, non-SID and asthma cohorts, adjusting for demographics, region, comorbidities, and healthcare utilization. Results We identified 5,642 patients 9–26 years with SID and 20,643 without. The mean age was 18.1 years (SD 4.9). We identified 1,083 patients with asthma; the mean age was 17.2 (SD 5.1). Among females, 20.6% with SID, 23.1% without SID and 22.9% with asthma, received ≥1 HPV vaccine. In our adjusted models, the odds of receipt of ≥1 vaccine was 0.87 times lower in SID (95% CI 0.77–0.98) compared to non-SID and did not differ for 3 vaccines (OR 1.03, 95% CI 0.83–1.26). The odds of initiation and completion were not statistically different between SID and non-SID asthma cohorts. Conclusions In this nationwide cohort, HPV vaccine uptake was extremely low. Despite the heightened risk of persistent HPV infection among those with SID, no increase in HPV vaccine uptake was observed. Public health efforts to promote HPV vaccination overall are needed, and may be particularly beneficial for those at higher risk. PMID:25692470

Mechanisms of DNA uptake by cells

Energy Technology Data Exchange (ETDEWEB)

Lacks, S.A.

1977-01-01

Three categories of cellular uptake of DNA can be distinguished. First, in the highly transformable bacteria, such as Diplococcus pneumoniae, Haemophilus influenzae and Bacillus subtilis, elaborate mechanisms of DNA transport have evolved, presumably for the purpose of genetic exchange. These mechanisms can introduce substantial amounts of DNA into the cell. Second, methods have been devised for the forced introduction of DNA by manipulation of bacterial cells under nonphysiological conditions. By such means small but significant amounts of DNA have been introduced into various bacteria, including Escherichia coli. Third, mammalian cells are able to take up biologically active DNA. This has been most clearly demonstrated with viral DNA, although the mechanism of uptake is not well understood. The intention, here, is to survey current understanding of the various mechanisms of DNA uptake. A review of experience with the bacterial systems may throw some light on the mammalian system and lead to suggestions for enhancing DNA uptake by mammalian cells.

Rational design and enantioselective synthesis of (1R,4S,5R,6S)-3-azabicyclo[3.3.0]octane-4,6-dicarboxylic acid - a novel inhibitor at human glutamate transporter subtypes 1, 2, and 3

DEFF Research Database (Denmark)

Bunch, Lennart; Nielsen, Birgitte; Jensen, Anders A.

2006-01-01

The natural product kainic acid is used as template for the rational design of a novel conformationally restricted (S)-glutamic acid (Glu) analogue, (1R,4S,5R,6S)-3-azabicyclo[3.3.0]octane-4,6-dicarboxylic acid (1a). The target structure 1a was synthesized from commercially available (S)-pyroglut......The natural product kainic acid is used as template for the rational design of a novel conformationally restricted (S)-glutamic acid (Glu) analogue, (1R,4S,5R,6S)-3-azabicyclo[3.3.0]octane-4,6-dicarboxylic acid (1a). The target structure 1a was synthesized from commercially available (S...

Metaiodobenzylguanidine (MIBG) uptake in Parkinson's disease also decreases at thyroid

International Nuclear Information System (INIS)

Matsui, Hideaki; Udaka, Fukashi; Oda, Masaya; Tamura, Akiko; Kubori, Tamotsu; Nishinaka, Kazuto; Kameyama, Masakuni

2005-01-01

Decreased cardiac metaiodobenzylguanidine (MIBG) uptake was reported in Parkinson's disease and this contributes to the differential diagnosis between Parkinson's disease and other forms of parkinsonism such as multiple system atrophy. However, decreased MIBG uptake of the thyroid has not been demonstrated. The objective of this study was to compare MIBG uptake of the thyroid among Parkinson's disease, multiple system atrophy and controls. Twenty-six patients with Parkinson's disease, 11 patients with multiple system atrophy and 14 controls were examined in this study. Planar images were taken 15 minutes (early images) and 3 hours (late images) after intravenous injection of 111 MBq 123 I-MIBG. MIBG uptake of the thyroid on early images decreased significantly in Parkinson's disease compared to controls (p<0.0001) and multiple system atrophy (p=0.018). MIBG uptake of the thyroid on early images decreased significantly also in multiple system atrophy compared to controls (p=0.027). On late images, thyroid uptake differed significantly only between Parkinson's disease and controls (p=0.010). Our study is the first to demonstrate decreased MIBG uptake of the thyroid in Parkinson's disease. Sympathetic nervous denervation of Parkinson's disease occurred not only in the heart but also in the thyroid. (author)

Biochemistry of an olfactory purinergic system: dephosphorylation of excitatory nucleotides and uptake of adenosine

Energy Technology Data Exchange (ETDEWEB)

Trapido-Rosenthal, H G; Carr, W E; Gleeson, R A

1987-10-01

The olfactory organ of the spiny lobster, Panulirus argus, is composed of chemosensory sensilla containing the dendrites of primary chemosensory neurons. Receptors on these dendrites are activated by the nucleotides AMP, ADP, and ATP but not by the nucleoside adenosine. It is shown here that the lobster chemosensory sensilla contain enzymes that dephosphorylate excitatory nucleotides and an uptake system that internalizes the nonexcitatory dephosphorylated product adenosine. The uptake of (/sup 3/H)-adenosine is saturable with increasing concentration, linear with time for up to 3 h, sodium dependent, insensitive to moderate pH changes and has a Km of 7.1 microM and a Vmax of 5.2 fmol/sensillum/min (573 fmol/micrograms of protein/min). Double-label experiments show that sensilla dephosphorylate nucleotides extracellularly; /sup 3/H from adenine-labeled AMP or ATP is internalized, whereas 32P from phosphate-labeled nucleotides is not. The dephosphorylation of AMP is very rapid; /sup 3/H from AMP is internalized at the same rate as /sup 3/H from adenosine. Sensillar 5'-ectonucleotidase activity is inhibited by ADP and the ADP analog alpha, beta-methylene ADP. Collectively, these results indicate that the enzymes and the uptake system whereby chemosensory sensilla of the lobster inactivate excitatory nucleotides and clear adenosine from extracellular spaces are very similar to those present in the internal tissues of vertebrates, where nucleotides have many neuroactive effects.

Measuring the actual I-131 thyroid uptake curve with a collar detector system: a feasibility study

Energy Technology Data Exchange (ETDEWEB)

Brinks, Peter; Van Gils, Koen; Dickerscheid, Dennis B.M.; Habraken, Jan B.A. [Department of Medical Physics, St. Antonius Hospital, Nieuwegein (Netherlands); Kranenborg, Ellen; Lavalaye, Jules [Department of Nuclear Medicine, St. Antonius Hospital, Nieuwegein (Netherlands)

2017-06-15

Radionuclide therapy using I-131 is commonly used for the treatment of benign thyroid diseases. The therapeutic dose to be administered is calculated based on the type of disease, the volume of the thyroid, and the measured uptake percentage. This methodology assumes a similar biological half-life of iodine, whereas in reality a large variation in biological half-life is observed. More knowledge about the actual biological half-life of iodine for individual patients will improve the quantification of the delivered radiation dose during radioiodine therapy and could aid the evaluation of the success of the therapy. In this feasibility study we used a novel measurement device [Collar Therapy Indicator (CoTI)] to measure the uptake curve of patients undergoing I-131 radioiodine therapy. The CoTI device is a light-weight wearable device that contains two independent gamma radiation detectors that are placed in a collar. By comparing results of thyroid uptake measurements with results obtained with a gamma camera, the precision of the system is demonstrated. Additionally, for three patients the uptake curve is measured during 48 h of admission in the hospital. The presented results demonstrate the feasibility of the new measurement device to measure the uptake curve during radioiodine therapy. (orig.)

Tuning different kinds of entangled metal-organic frameworks by modifying the spacer group of aliphatic dicarboxylate ligands and the reactant ratio.

Science.gov (United States)

Yang, Jin-Xia; Zhai, Ji-Quan; Zhang, Xin; Qin, Ye-Yan; Yao, Yuan-Gen

2016-01-14

Taking advantage of the conformational flexibility of the bpp ligand and aliphatic dicarboxylic acids, six interesting entangled coordination polymers, {[Cd(fum)(bpp)(H2O)]·(H2O)}n (), {[Cd(fum)(bpp)2]·(H2O)5}n (), {[Cd2(suc)1.5(bpp)2(NO3)(H2O)2]·6H2O}n (), {[Cd(suc)(bpp)2]·(H2O)1.5}n (), {[Cd2(glu)2(bpp)3]·10H2O}n (), and {Cd(adp)(bpp)(H2O)}n () have been prepared and structurally characterized (bpp = 1,3-bi(4-pyridyl)propane, fum = fumaric, suc = succinate, glu = glutaric, adp = adipic). Compounds and are comprised of undulated 2D 4(4)-sql networks. In the structure of compound , two identical undulated layers are parallelly interpenetrated with each other to give a 2D → 2D interpenetrating framework. For , the dangling arms projected from 2D layers are intercalated into the neighboring sheets, producing a 2D → 3D polythreading framework. Compound shows a rare example of a 2D self-penetrating framework with a (3,4)-connected (4(2)·6(3)·8)(4(2)·6) topology. Compound presents an unusual 2D self-threading network with a novel 4-connected {4(2)·6(3)·8} topology. Compound displays a 3D self-penetrating system based on a 2D → 3D parallel polycatenation array. Compound exhibits an unprecedented 3D self-penetrating structure having both 1D + 1D → 1D polycatenation and 3D + 3D → 3D interpenetration characteristics. A comparison of these six compounds demonstrates that both the different spacer lengths of the aliphatic dicarboxylates and reactant ratios appear to play a significant role in the assembly of entangled frameworks. In addition, thermal stabilities and photoluminescence properties of have been examined in the solid state at room temperature.

Stimulatory effect of insulin on glucose uptake by muscle involves the central nervous system in insulin-sensitive mice.

Science.gov (United States)

Coomans, Claudia P; Biermasz, Nienke R; Geerling, Janine J; Guigas, Bruno; Rensen, Patrick C N; Havekes, Louis M; Romijn, Johannes A

2011-12-01

Insulin inhibits endogenous glucose production (EGP) and stimulates glucose uptake in peripheral tissues. Hypothalamic insulin signaling is required for the inhibitory effects of insulin on EGP. We examined the contribution of central insulin signaling on circulating insulin-stimulated tissue-specific glucose uptake. Tolbutamide, an inhibitor of ATP-sensitive K(+) channels (K(ATP) channels), or vehicle was infused into the lateral ventricle in the basal state and during hyperinsulinemic-euglycemic conditions in postabsorptive, chow-fed C57Bl/6J mice and in postabsorptive C57Bl/6J mice with diet-induced obesity. Whole-body glucose uptake was measured by d-[(14)C]glucose kinetics and tissue-specific glucose uptake by 2-deoxy-d-[(3)H]glucose uptake. During clamp conditions, intracerebroventricular administration of tolbutamide impaired the ability of insulin to inhibit EGP by ∼20%. In addition, intracerebroventricular tolbutamide diminished insulin-stimulated glucose uptake in muscle (by ∼59%) but not in heart or adipose tissue. In contrast, in insulin-resistant mice with diet-induced obesity, intracerebroventricular tolbutamide did not alter the effects of insulin during clamp conditions on EGP or glucose uptake by muscle. Insulin stimulates glucose uptake in muscle in part through effects via K(ATP) channels in the central nervous system, in analogy with the inhibitory effects of insulin on EGP. High-fat diet-induced obesity abolished the central effects of insulin on liver and muscle. These observations stress the role of central insulin resistance in the pathophysiology of diet-induced insulin resistance.

The Assessment of I-131 Internal Doses of Nuclear Medicine Workers in Korea Using Thyroid uptake system

International Nuclear Information System (INIS)

Bahn, Young Kag; Oh, Gi Back; Lee, Chang Ho; Lee, Jong Doo; Yeom, Yu Sun; Hwang, Young Muk

2012-01-01

There are possibilities the radiation workers could intake the radiation when workers deal with radiation-materials. Therefore, internal radiation doses of radiation workers need to be assessed. Although an application of the nuclear medicine is continuously increased in Korea, there is not a proper tool and form to monitor the internal doses of nuclear medicine workers. However, it is possible to attain the internal doses of I-131 to evaluate using thyroid uptake and well count system. In this study, we measured and evaluated the I-131 internal doses of nuclear medicine workers in Korea using thyroid uptake and well count system and performed an air sampling

Alternative plasticizer, 4-cyclohexene-1,2-dicarboxylic acid dinonyl ester, for blood containers with protective effects on red blood cells and improved cold resistance.

Science.gov (United States)

Morishita, Yuki; Nomura, Yusuke; Fukui, Chie; Fujisawa, Ayano; Watanabe, Kayo; Fujimaki, Hideo; Kumada, Hidefumi; Inoue, Kaoru; Morikawa, Tomomi; Takahashi, Miwa; Kawakami, Tsuyoshi; Sakoda, Hideyuki; Mukai, Tomokazu; Yuba, Toshiyasu; Inamura, Ken-Ichi; Tanoue, Akito; Miyazaki, Ken-Ichi; Chung, Ung-Il; Ogawa, Kumiko; Yoshida, Midori; Haishima, Yuji

2018-04-01

Di (2-ethylhexyl) phthalate (DEHP), a typical plasticizer used for polyvinyl chloride (PVC), is eluted from PVC-made blood containers and protects against red blood cell (RBC) hemolysis. However, concerns have arisen regarding the reproductive and developmental risks of DEHP in humans, and the use of alternative plasticizers for medical devices has been recommended worldwide. In this study, we propose that the use of a novel plasticizer, 4-cyclohexene-1,2-dicarboxylic acid dinonyl ester (DL9TH), could help produce more useful and safe blood containers. PVC sheet containing DL9TH and di (2-ethylhexyl) 4-cyclohexene-1,2-dicarboxylate (DOTH) provides comparable or superior protective effects to RBCs relative to PVC sheet containing DEHP or di-isononyl-cyclohexane-1,2-dicarboxylate (DINCH ® , an alternative plasticizer that has been used in PVC sheets for blood containers). The total amount of plasticizer eluted from DOTH/DL9TH-PVC sheets is nearly the same as that eluted from DEHP-PVC sheets. In addition, DOTH/DL9TH-PVC has better cold resistance than DEHP- and DINCH ® -PVC sheets. In vitro and in vivo tests for biological safety based on International Organization for Standardization guidelines (10993 series) suggest that the DOTH/DL9TH-PVC sheet can be used safely. Subchronic toxicity testing of DL9TH in male rats in accordance with the principles of Organisation for Economic Co-operation and Development Test Guideline 408 showed that DL9TH did not induce adverse effects up to the highest dose level tested (717 mg/kg body weight/day). There were no effects on testicular histopathology and sperm counts, and no indications of endocrine effects: testosterone, thyroid-stimulating hormone, follicle-stimulating hormone, and 17β-estradiol were unchanged by the treatment, compared with the control group. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1052-1063, 2018. © 2017 Wiley Periodicals, Inc.

The role and uptake of private health insurance in different health care systems: are there lessons for developing countries?

Directory of Open Access Journals (Sweden)

Odeyemi IA

2013-03-01

Full Text Available Isaac AO Odeyemi,1 John Nixon21Senior Director and Head of Health Economics and Outcomes Research, Astellas Pharma UK Ltd, Chertsey, UK; 2Teaching Associate in Health Economics, Department of Economics and Related Studies, University of York, York, UKBackground: Social and national health insurance schemes are being introduced in many developing countries in moving towards universal health care. However, gaps in coverage are common and can only be met by out-of-pocket payments, general taxation, or private health insurance (PHI. This study provides an overview of PHI in different health care systems and discusses factors that affect its uptake and equity.Methods: A representative sample of countries was identified (United States, United Kingdom, The Netherlands, France, Australia, and Latvia that illustrates the principal forms and roles of PHI. Literature describing each country's health care system was used to summarize how PHI is utilized and the factors that affect its uptake and equity.Results: In the United States, PHI is a primary source of funding in conjunction with tax-based programs to support vulnerable groups; in the UK and Latvia, PHI is used in a supplementary role to universal tax-based systems; in France and Latvia, complementary PHI is utilized to cover gaps in public funding; in The Netherlands, PHI is supplementary to statutory private and social health insurance; in Australia, the government incentivizes the uptake of complementary PHI through tax rebates and penalties. The uptake of PHI is influenced by age, income, education, health care system typology, and the incentives or disincentives applied by governments. The effect on equity can either be positive or negative depending on the type of PHI adopted and its role within the wider health care system.Conclusion: PHI has many manifestations depending on the type of health care system used and its role within that system. This study has illustrated its common applications

Synthesis and Preclinical Evaluation of Radioiodinated Hypericin Dicarboxylic Acid as a Necrosis Avid Agent in Rat Models of Induced Hepatic, Muscular, and Myocardial Necroses.

Science.gov (United States)

Li, Jindian; Zhang, Jian; Yang, Shengwei; Jiang, Cuihua; Zhang, DongJian; Jin, Qiaomei; Wang, Qin; Wang, Cong; Ni, Yicheng; Yin, Zhiqi; Song, Shaoli

2016-01-04

Myocardial infarction (MI) leads to substantial morbidity and mortality around the world. Accurate assessment of myocardial viability is essential to assist therapies and improve patient outcomes. (131)I-hypericin dicarboxylic acid ((131)I-HDA) was synthesized and evaluated as a potential diagnostic agent for earlier assessment of myocardium viability compared to its preceding counterpart (131)I-hypericin ((131)I-Hyp) with strong hydrophobic property, long plasma half-life, and high uptake in mononuclear phagocyte system (MPS). Herein, HDA was synthesized and characterized, and self-aggregation constant Kα was analyzed by spectrophotometry. Plasma half-life was determined in healthy rats by γ-counting. (131)I-HDA and (131)I-Hyp were prepared with iodogen as oxidant. In vitro necrosis avidity of (131)I-HDA and (131)I-Hyp was evaluated in necrotic cells induced by hyperthermia. Biodistribution was determined in rat models of induced necrosis using γ-counting, autoradiography, and histopathology. Earlier imaging of necrotic myocardium to assess myocardial viability was performed in rat models of reperfused myocardium infarction using single photon emission computed tomography/computed tomography (SPECT/CT). As a result, the self-aggregation constant Kα of HDA was lower than that of Hyp (105602 vs 194644, p HDA displayed a shorter blood half-life compared with (131)I-Hyp (9.21 vs 31.20 h, p HDA relative to that with (131)I-Hyp (5.48 vs 4.63, p HDA showed a higher necrotic-viable myocardium ratio (7.32 vs 3.20, p HDA achieved imaging of necrotic myocardium at 6 h postinjection (p.i.) with SPECT/CT, earlier than what (131)I-Hyp did. Therefore, (131)I-HDA may serve as a promising necrosis-avid diagnostic agent for earlier imaging of necrotic myocardium compared with (131)I-Hyp. This may support further development of radiopharmaceuticals ((123)I and (99m)Tc) based on HDA for SPECT/CT of necrotic myocardium.

Multiple pathways for uptake of paraquat, methylglyoxal bis(guanylhydrazone), and polyamines

Energy Technology Data Exchange (ETDEWEB)

Byers, T.L.; Kameji, R.; Rannels, D.E.; Pegg, A.E.

1987-06-01

The uptake of polyamines, methylglyoxal bis(guanylhydrazone) (MGBG), and paraquat (N,N-dimethyl-4,4'-bipyridylium) into control Chinese hamster ovary (CHO) cells and a mutant CHO cell line selected for resistance to the toxicity of MGBG was examined. In contrast to control CHO cells, the mutant cells had no detectable uptake of (/sup 14/C)-MGBG or any of the polyamines. There was no difference between the two cell lines in the uptake of ..cap alpha..-aminoisobutyric (/sup 3/H-AIB), which indicates that there was no general change in membrane transport processes. The mutant cells were also found to be resistant to the toxicity of paraquat and to have a reduced capability to take up the herbicide. This finding confirms that the uptake of paraquat is necessary for the toxicity of this compound and that the paraquat is taken up by a transport system that also transports MGBG. Competition experiments showed that an excess of unlabeled paraquat inhibited uptake of MGBG and, to a lesser extent, uptake of putrescine and spermidine, but no inhibitory action on spermine uptake could be detected. Studies with type II cells isolated from rat lung also demonstrated uptake of paraquat and spermidine, but paraquat was only a weak inhibitor of spermidine uptake in this system. These results suggest that there may be multiple systems for the uptake of MGBG and polyamines and that paraquat is taken up by at least one but not by all of these systems.

Multiple pathways for uptake of paraquat, methylglyoxal bis(guanylhydrazone), and polyamines

International Nuclear Information System (INIS)

Byers, T.L.; Kameji, R.; Rannels, D.E.; Pegg, A.E.

1987-01-01

The uptake of polyamines, methylglyoxal bis(guanylhydrazone) (MGBG), and paraquat [N,N-dimethyl-4,4'-bipyridylium] into control Chinese hamster ovary (CHO) cells and a mutant CHO cell line selected for resistance to the toxicity of MGBG was examined. In contrast to control CHO cells, the mutant cells had no detectable uptake of [ 14 C]-MGBG or any of the polyamines. There was no difference between the two cell lines in the uptake of α-aminoisobutyric ( 3 H-AIB), which indicates that there was no general change in membrane transport processes. The mutant cells were also found to be resistant to the toxicity of paraquat and to have a reduced capability to take up the herbicide. This finding confirms that the uptake of paraquat is necessary for the toxicity of this compound and that the paraquat is taken up by a transport system that also transports MGBG. Competition experiments showed that an excess of unlabeled paraquat inhibited uptake of MGBG and, to a lesser extent, uptake of putrescine and spermidine, but no inhibitory action on spermine uptake could be detected. Studies with type II cells isolated from rat lung also demonstrated uptake of paraquat and spermidine, but paraquat was only a weak inhibitor of spermidine uptake in this system. These results suggest that there may be multiple systems for the uptake of MGBG and polyamines and that paraquat is taken up by at least one but not by all of these systems

A one-dimensional ladder-like coordination polymer: poly[[hexa-aqua-bis(μ-5-nitro-benzene-1,3-dicarboxyl-ato-κO,O',O'')(μ-oxalato-κO,O':O'',O''')diyttrium(III)] trihydrate].

Science.gov (United States)

Fu, Zhong; Lin, Ying; Zhou, Yun-You; Zhang, Hong-Tao

2007-12-06

In the crystal structure of the title one-dimensional coordination polymer, [Y(2)(C(8)H(3)NO(6))(2)(C(2)O(4))(H(2)O)(6)]·3H(2)O, each Y(III) ion is bridged to its neighbours by two 5-nitro-benzene-1,3-dicarboxyl-ate (nbdc) dianions and one oxalate dianion (located on an inversion centre) to form a ladder-like polymeric structure. The two carboxylate groups of nbdc assume different modes of coordination, one is chelating whereas the other is monodentate. Three water mol-ecules coordinate to the Y(III) ion to complete an eight-coordinate distorted dodecahedral geometry. The ladder-like polymers are assembled together by hydrogen bonding and π-π stacking [centrio-centriod distance = 3.819 (9) Å] in the crystal structure.

Dynamics of Short-Term Phosphorus Uptake by Intact Mycorrhizal and Non-mycorrhizal Maize Plants Grown in a Circulatory Semi-Hydroponic Cultivation System.

Science.gov (United States)

Garcés-Ruiz, Mónica; Calonne-Salmon, Maryline; Plouznikoff, Katia; Misson, Coralie; Navarrete-Mier, Micaela; Cranenbrouck, Sylvie; Declerck, Stéphane

2017-01-01

A non-destructive cultivation system was developed to study the dynamics of phosphorus (Pi) uptake by mycorrhizal and non-mycorrhizal maize plantlets. The system consisted of a plant container connected via silicon tubes to a glass bottle containing a nutrient solution supplemented with Pi. The nutrient solution is pumped with a peristaltic pump to the upper part of the container via the silicon tubes and the solution percolate through the plantlet container back into the glass bottle. Pi is sampled from the glass bottle at regular intervals and concentration evaluated. Maize plantlets were colonized by the AMF Rhizophagus irregularis MUCL 41833 and Pi uptake quantified at fixed intervals (9, 21, and 42 h) from the depletion of the Pi in the nutrient solution flowing through the plantlets containers. Plants and fungus grew well in the perlite substrate. The concentration of Pi in the bottles followed an almost linear decrease over time, demonstrating a depletion of Pi in the circulating solution and a concomitant uptake/immobilization by the plantlet-AMF associates in the containers. The Pi uptake rate was significantly increased in the AMF-colonized plantlets (at 9 and 21 h) as compared to non-colonized plantlets, although no correlation was noticed with plant growth or P accumulation in shoots. The circulatory semi-hydroponic cultivation system developed was adequate for measuring Pi depletion in a nutrient solution and by corollary Pi uptake/immobilization by the plant-AMF associates. The measurements were non-destructive so that the time course of Pi uptake could be monitored without disturbing the growth of the plant and its fungal associate. The system further opens the door to study the dynamics of other micro and macro-nutrients as well as their uptake under stressed growth conditions such as salinity, pollution by hydrocarbon contaminants or potential toxic elements.

Dynamics of Short-Term Phosphorus Uptake by Intact Mycorrhizal and Non-mycorrhizal Maize Plants Grown in a Circulatory Semi-Hydroponic Cultivation System

Directory of Open Access Journals (Sweden)

Mónica Garcés-Ruiz

2017-08-01

Full Text Available A non-destructive cultivation system was developed to study the dynamics of phosphorus (Pi uptake by mycorrhizal and non-mycorrhizal maize plantlets. The system consisted of a plant container connected via silicon tubes to a glass bottle containing a nutrient solution supplemented with Pi. The nutrient solution is pumped with a peristaltic pump to the upper part of the container via the silicon tubes and the solution percolate through the plantlet container back into the glass bottle. Pi is sampled from the glass bottle at regular intervals and concentration evaluated. Maize plantlets were colonized by the AMF Rhizophagus irregularis MUCL 41833 and Pi uptake quantified at fixed intervals (9, 21, and 42 h from the depletion of the Pi in the nutrient solution flowing through the plantlets containers. Plants and fungus grew well in the perlite substrate. The concentration of Pi in the bottles followed an almost linear decrease over time, demonstrating a depletion of Pi in the circulating solution and a concomitant uptake/immobilization by the plantlet-AMF associates in the containers. The Pi uptake rate was significantly increased in the AMF-colonized plantlets (at 9 and 21 h as compared to non-colonized plantlets, although no correlation was noticed with plant growth or P accumulation in shoots. The circulatory semi-hydroponic cultivation system developed was adequate for measuring Pi depletion in a nutrient solution and by corollary Pi uptake/immobilization by the plant-AMF associates. The measurements were non-destructive so that the time course of Pi uptake could be monitored without disturbing the growth of the plant and its fungal associate. The system further opens the door to study the dynamics of other micro and macro-nutrients as well as their uptake under stressed growth conditions such as salinity, pollution by hydrocarbon contaminants or potential toxic elements.

Uptake mechanism for iodine species to black carbon.

Science.gov (United States)

Choung, Sungwook; Um, Wooyong; Kim, Minkyung; Kim, Min-Gyu

2013-09-17

Natural organic matter (NOM) plays an important role in determining the fate and transport of iodine species such as iodide (I(-)) and iodate (IO3(-)) in groundwater system. Although NOM exists as diverse forms in environments, prior iodine studies have mainly focused on uptake processes of iodide and iodate to humic materials. This study was conducted to determine the iodide and iodate uptake potential for a particulate NOM (i.e., black carbon [BC]). A laboratory-produced BC and commercial humic acid were used for batch experiments to compare their iodine uptake properties. The BC exhibited >100 times greater uptake capability for iodide than iodate at low pH of ~3, while iodide uptake was negligible for the humic acid. The uptake properties of both solids strongly depend on the initial iodine aqueous concentrations. After uptake reaction of iodide to the BC, X-ray absorption fine structure spectroscopy results indicated that the iodide was converted to electrophilic species, and iodine was covalently bound to carbon atom in polycyclic aromatic hydrocarbons present in the BC. The computed distribution coefficients (i.e., Kd values) suggest that the BC materials retard significantly the transport of iodide at low pH in environmental systems containing even a small amount of BC.

Autonomic nervous system activation mediates the increase in whole-body glucose uptake in response to electroacupuncture

DEFF Research Database (Denmark)

Benrick, Anna; Kokosar, Milana; Hu, Min

2017-01-01

was higher after EA in controls and women with PCOS. Plasma serotonin levels and homovanillic acid, markers of vagal activity, decreased in both controls and patients with PCOS. Adipose tissue expression of pro-nerve growth factor (proNGF) decreased, and the mature NGF/proNGF ratio increased after EA in PCOS...... of EA increases whole-body glucose uptake by activation of the sympathetic and partly the parasympathetic nervous systems, which could have important clinical implications for the treatment of insulin resistance.-Benrick, A., Kokosar, M., Hu, M., Larsson, M., Maliqueo, M., Marcondes, R. R., Soligo, M......., Protto, V., Jerlhag, E., Sazonova, A., Behre, C. J., Højlund, K., Thorén, P., Stener-Victorin, E. Autonomic nervous system activation mediates the increase in whole-body glucose uptake in response to electroacupuncture....

pH-Dependent Uptake of Fumaric Acid in Saccharomyces cerevisiae under Anaerobic Conditions

NARCIS (Netherlands)

Jamalzadeh, E.; Verheijen, P.J.; Heijnen, J.J.; Van Gulik, W.M.

2011-01-01

Microbial production of C4 dicarboxylic acids from renewable resources has gained renewed interest. The yeast Saccharomyces cerevisiae is known as a robust microorganism and is able to grow at low pH, which makes it a suitable candidate for biological production of organic acids. However, a

Normal cerebral FDG uptake during childhood

International Nuclear Information System (INIS)

London, Kevin; Howman-Giles, Robert

2014-01-01

Current understanding of cerebral FDG uptake during childhood originates from a small number of studies in patients with neurological abnormalities. Our aim was to describe cerebral FDG uptake in a dataset of FDG PET scans in children more likely to represent a normal population. We reviewed cerebral FDG PET scans in children up to 16 years of age with suspected/proven extracranial malignancies and the following exclusions: central nervous system metastases, previous malignancies, previous chemotherapy or radiotherapy, development of cerebral metastases during therapy, neurological conditions, taking antiepileptic medication or medications likely to interfere with cerebral metabolism, and general anaesthesia within 24 h. White matter, basal ganglia, thalamus and the cerebellar cortex were analysed using regional SUV max , and the cerebral cortex, basal ganglia, thalamus and cerebellum were analysed using a regional relative uptake analysis in comparison to maximal cortical uptake. Scans from 30 patients (age range 11 months to 16 years, mean age 10 years 5 months) were included. All regions showed increasing SUV max with age. The parietal, occipital, lateral temporal and medial temporal lobes showed lower rates of increasing FDG uptake causing changing patterns of regional FDG uptake during childhood. The cortical regions showing the most intense uptake in early childhood were the parietal and occipital lobes. At approximately 7 years of age these regions had relatively less uptake than the frontal lobes and at approximately 10 years of age these regions had relatively less uptake than the thalamus. Relative FDG uptake in the brain has not reached an adult pattern by 1 year of age, but continues to change up to 16 years of age. The changing pattern is due to different regional rates of increasing cortical FDG uptake, which is less rapid in the parietal, occipital and temporal lobes than in the frontal lobes. (orig.)

Normal cerebral FDG uptake during childhood

Energy Technology Data Exchange (ETDEWEB)

London, Kevin [The Children' s Hospital at Westmead, Department of Nuclear Medicine, Sydney, NSW (Australia); University of Sydney, Discipline of Paediatrics and Child Health, Sydney Medical School, Sydney, NSW (Australia); Howman-Giles, Robert [The Children' s Hospital at Westmead, Department of Nuclear Medicine, Sydney, NSW (Australia); University of Sydney, Disciplines of Imaging and Paediatrics and Child Health, Sydney Medical School, Sydney, NSW (Australia)

2014-04-15

Current understanding of cerebral FDG uptake during childhood originates from a small number of studies in patients with neurological abnormalities. Our aim was to describe cerebral FDG uptake in a dataset of FDG PET scans in children more likely to represent a normal population. We reviewed cerebral FDG PET scans in children up to 16 years of age with suspected/proven extracranial malignancies and the following exclusions: central nervous system metastases, previous malignancies, previous chemotherapy or radiotherapy, development of cerebral metastases during therapy, neurological conditions, taking antiepileptic medication or medications likely to interfere with cerebral metabolism, and general anaesthesia within 24 h. White matter, basal ganglia, thalamus and the cerebellar cortex were analysed using regional SUV{sub max}, and the cerebral cortex, basal ganglia, thalamus and cerebellum were analysed using a regional relative uptake analysis in comparison to maximal cortical uptake. Scans from 30 patients (age range 11 months to 16 years, mean age 10 years 5 months) were included. All regions showed increasing SUV{sub max} with age. The parietal, occipital, lateral temporal and medial temporal lobes showed lower rates of increasing FDG uptake causing changing patterns of regional FDG uptake during childhood. The cortical regions showing the most intense uptake in early childhood were the parietal and occipital lobes. At approximately 7 years of age these regions had relatively less uptake than the frontal lobes and at approximately 10 years of age these regions had relatively less uptake than the thalamus. Relative FDG uptake in the brain has not reached an adult pattern by 1 year of age, but continues to change up to 16 years of age. The changing pattern is due to different regional rates of increasing cortical FDG uptake, which is less rapid in the parietal, occipital and temporal lobes than in the frontal lobes. (orig.)

A local renal renin-angiotensin system activation via renal uptake of prorenin and angiotensinogen in diabetic rats.

Science.gov (United States)

Tojo, Akihiro; Kinugasa, Satoshi; Fujita, Toshiro; Wilcox, Christopher S

2016-01-01

The mechanism of activation of local renal renin-angiotensin system (RAS) has not been clarified in diabetes mellitus (DM). We hypothesized that the local renal RAS will be activated via increased glomerular filtration and tubular uptake of prorenin and angiotensinogen in diabetic kidney with microalbuminuria. Streptozotocin (STZ)-induced DM and control rats were injected with human prorenin and subsequently with human angiotensinogen. Human prorenin uptake was increased in podocytes, proximal tubules, macula densa, and cortical collecting ducts of DM rats where prorenin receptor (PRR) was expressed. Co-immunoprecipitation of kidney homogenates in DM rats revealed binding of human prorenin to the PRR and to megalin. The renal uptake of human angiotensinogen was increased in DM rats at the same nephron sites as prorenin. Angiotensin-converting enzyme was increased in podocytes, but decreased in the proximal tubules in DM rats, which may have contributed to unchanged renal levels of angiotensin despite increased angiotensinogen. The systolic blood pressure increased more after the injection of 20 μg of angiotensinogen in DM rats than in controls, accompanied by an increased uptake of human angiotensinogen in the vascular endothelium. In conclusion, endocytic uptake of prorenin and angiotensinogen in the kidney and vasculature in DM rats was contributed to increased tissue RAS and their pressor response to angiotensinogen.

New model concepts for dynamic plant uptake and mass flux estimates in the soil-plant-air system

DEFF Research Database (Denmark)

Rein, Arno; Bauer-Gottwein, Peter; Trapp, Stefan

2010-01-01

in environmental systems at different scales. Feedback mechanisms between plants and hydrological systems can play an important role. However, they have received little attention to date. Here, a new model concept for dynamic plant uptake models applying analytical matrix solutions is presented, which can...

Spatiotemporal variation of nitrate uptake kinetics within the maize (Zea mays L.) root system is associated with greater nitrate uptake and interactions with architectural phenes.

Science.gov (United States)

York, Larry M; Silberbush, Moshe; Lynch, Jonathan P

2016-06-01

Increasing maize nitrogen acquisition efficiency is a major goal for the 21st century. Nitrate uptake kinetics (NUK) are defined by I max and K m, which denote the maximum uptake rate and the affinity of transporters, respectively. Because NUK have been studied predominantly at the molecular and whole-root system levels, little is known about the functional importance of NUK variation within root systems. A novel method was created to measure NUK of root segments that demonstrated variation in NUK among root classes (seminal, lateral, crown, and brace). I max varied among root class, plant age, and nitrate deprivation combinations, but was most affected by plant age, which increased I max, and nitrate deprivation time, which decreased I max K m was greatest for crown roots. The functional-structural simulation SimRoot was used for sensitivity analysis of plant growth to root segment I max and K m, as well as to test interactions of I max with root system architectural phenes. Simulated plant growth was more sensitive to I max than K m, and reached an asymptote near the maximum I max observed in the empirical studies. Increasing the I max of lateral roots had the largest effect on shoot growth. Additive effects of I max and architectural phenes on nitrate uptake were observed. Empirically, only lateral root tips aged 20 d operated at the maximum I max, and simulations demonstrated that increasing all seminal and lateral classes to this maximum rate could increase plant growth by as much as 26%. Therefore, optimizing I max for all maize root classes merits attention as a promising breeding goal. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Sudden increase in atmospheric concentration reveals strong coupling between shoot carbon uptake and root nutrient uptake in young walnut trees

International Nuclear Information System (INIS)

Delaire, M.; Sigogne, M.; Beaujard, F.; Frak, E.; Adam, B.; Le Roux, X.

2005-01-01

Short-term effects of a sudden increase in carbon dioxide concentration on nutrient uptake by roots during vegetative growth was studied in young walnut trees. Rates of carbon dioxide uptake and water loss by individual trees were determined by a branch bag method from three days before and six days after carbon dioxide concentration was increased. Nutrient uptake rates were measured concurrently by a hydroponic recirculating nutrient solution system. Carbon dioxide uptake rates increased greatly with increasing atmospheric carbon dioxide; nutrient uptake rates were proportional to carbon dioxide uptake rates, except for the phosphorus ion. Daily water loss rates were only slightly affected by elevated carbon dioxide. Overall, it was concluded that in the presence of non-limiting supplies of water and nutrients, root nutrient uptake and shoot carbon assimilation are strongly coupled in the short term in young walnut trees despite the important carbon and nutrient storage capacities od woody species. 45 refs., 7 figs

Ruthenium water oxidation catalysts containing the non-planar tetradentate ligand, biisoquinoline dicarboxylic acid (biqaH2).

Science.gov (United States)

Scherrer, Dominik; Schilling, Mauro; Luber, Sandra; Fox, Thomas; Spingler, Bernhard; Alberto, Roger; Richmond, Craig J

2016-12-06

Two ruthenium complexes containing the tetradentate ligand [1,1'-biisoquinoline]-3,3'-dicarboxylic acid, and 4-picoline or 6-bromoisoquinoline as axial ligands have been prepared. The complexes have been fully characterised and initial studies on their potential to function as molecular water oxidation catalysts have been performed. Both complexes catalyse the oxidation of water in acidic media with Ce IV as a stoichiometric chemical oxidant, although turnover numbers and turnover frequencies are modest when compared with the closely related Ru-bda and Ru-pda analogues. Barriers for the water nucleophilic attack and intermolecular coupling pathways were obtained from density functional theory calculations and the crucial influence of the ligand framework in determining the most favourable reaction pathway was elucidated from a combined analysis of the theoretical and experimental results.

(2,2'-Bipyridine-4,4'-dicarboxylic acid-κ2N,N')chlorido(2,2':6',2''-terpyridyl-κ3N,N',N'')ruthenium(II) perchlorate ethanol monosolvate monohydrate

DEFF Research Database (Denmark)

Nielsen, Anne; McKenzie, Christine Joy; Bond, Andrew David

2012-01-01

,4 '-dicarboxylic acid ligands, with interplanar separations of 3.65 (1) and 3.72 (1) angstrom. Three O atoms of the perchlorate ion are each disordered equally over two positions. The hydroxy group of the ethanol molecule is also disordered over two sites with refined occupancies of 0.794 (9) and 0.206 (9)....

Crystal engineering of novel cocrystals of a triazole drug with 1,4-dicarboxylic acids.

Science.gov (United States)

Remenar, Julius F; Morissette, Sherry L; Peterson, Matthew L; Moulton, Brian; MacPhee, J Michael; Guzmán, Héctor R; Almarsson, Orn

2003-07-16

Cocrystals of the poorly soluble antifungal drug cis-itraconazole (1) with 1,4-dicarboxylic acids have been prepared. The crystal structure of the succinic acid cocrystal with 1 was determined to be a trimer by single-crystal X-ray. The trimer is comprised of two molecules of 1 oriented in antiparallel fashion to form a pocket with a triazole at either end. The extended succinic acid molecule fills the pocket, bridging the triazole groups through hydrogen-bonding interactions rather than interacting with the more basic piperazine nitrogens. The solubility and dissolution rate of some of the cocrystals are approximately the same as those of the amorphous drug in the commercial formulation and are much higher than those for the crystalline free base. The results suggest that cocrystals of drug molecules have the possibility of achieving the higher oral bioavailability common for amorphous forms of water-insoluble drugs while maintaining the long-term chemical and physical stability that crystal forms provide.

Syntheses, structures and magnetic properties of four coordination polymers based on nitrobenzene dicarboxylate and various N-donor coligands

International Nuclear Information System (INIS)

Li, Gui-Lian; Yin, Wei-Dong; Liu, Guang-Zhen; Ma, Lu-Fang; Wang, Li-Ya

2014-01-01

Four new coordination polymers ([Ni(4-Nbdc)(bpa)(H 2 O)]) n (1), ([Co(4-Nbdc)(bpp) (H 2 O)]) n (2), ([Ni(4-Nbdc)(bpp)(H 2 O)]·H 2 O) n (3), and ([Mn 2 (3-Nbdc) 2 (bib) 3 ]·2H 2 O) n (4) (4-Nbdc=4-nitrobenzene-1,2-dicarboxylate, 3-Nbdc=3-nitrobenzene-1,2-dicarboxylate, bpa=1,2-bi(4-pyridyl)ethane, bpp=1,3-bis(4-pyridyl)propane, and bib=1,4-bis(1-imidazoly)benzene), were synthesized by hydrothermal reactions, and characterized by single-crystal X-ray diffractions, elemental analysis, FT-IR, PXRD, TGA and magnetic analysis. Complexes 1 and 2 display quasi-trapezoidal chain and brick-wall layer, and both of them contain metal–carboxylate binuclear units. Complexes 3 and 4 exhibit three-dimensional frameworks with the (6 6 ) dia topology and (4 4 .6 10 .8)(4 4 .6 2 ) fsc topology, and both of them contain metal–carboxylate chains. The carboxyl groups with syn-anti coordination mode mediate effectively the weak ferromagnetic coupling interaction within Ni(II)–carboxylate binuclear in 1 (J=1.27 cm −1 ) and Ni(II)–carboxylate chain in 3 (J=1.44 cm −1 ), respectively, and the carboxyl groups with anti-anti coordination mode leads to the classic antiferromagnetic coupling interaction within Mn(II)–carboxylate chain in 4 (J=−0.77 cm −1 ). - Highlights: • Four novel coordination polymers were hydrothermally synthesized. • 1 is 1D quasi-trapezoidal chain and 2 is brick-wall layer both with dinuclear units. • 3 and 4 show 3D frameworks both with 1D metal–carboxylate chains. • 1 and 3 exhibit ferromagnetic coupling, while 4 shows antiferromagnetic coupling

Molecular and polymeric uranyl and thorium hybrid materials featuring methyl substituted pyrazole dicarboxylates and heterocyclic 1,3-diketones

Science.gov (United States)

Carter, Korey P.; Kerr, Andrew T.; Taydakov, Ilya V.; Cahill, Christopher L.

2018-02-01

A series of seven novel f-element bearing hybrid materials have been prepared from either methyl substituted 3,4 and 4,5-pyrazoledicarboxylic acids, or heterocyclic 1,3- diketonate ligands using hydrothermal conditions. Compounds 1, [UO2(C6H4N2O4)2(H2O)], and 3, [Th(C6H4N2O4)4(H2O)5]·H2O feature 1-Methyl-1H-pyrazole-3,4-dicarboxylate ligands (SVI-COOH 3,4), whereas 2, [UO2(C6H4N2O4)2(H2O)], and 4, [Th(C6H5N2O4)(OH)(H2O)6]2·2(C6H5N2O4)·3H2O feature 1-Methyl-1H-pyrazole-4,5-dicarboxylate moieties (SVI-COOH 4,5). Compounds 5, [UO2(C13H15N4O2)2(H2O)]·2H2O and 6, [UO2(C11H11N4O2)2(H2O)]·4.5H2O feature 1,3-bis(4-N1-methyl-pyrazolyl)propane-1,3-dione and 1,3-bis(4-N1,3-dimethyl-pyrazolyl)propane-1,3-dione respectively, whereas the heterometallic 7, [UO2(C11H11N4O2)2(CuCl2)(H2O)]·2H2O is formed by using 6 as a metalloligand starting material. Single crystal X-ray diffraction indicates that all coordination to either [UO2]2+ or Th(IV) metal centers is through O-donation as anticipated. Room temperature, solid-state luminescence studies indicate characteristic uranyl emissive behavior for 1 and 2, whereas those for 5 and 6 are weak and poorly resolved.

The effect of hydrate promoters on gas uptake.

Science.gov (United States)

Xu, Chun-Gang; Yu, Yi-Song; Ding, Ya-Long; Cai, Jing; Li, Xiao-Sen

2017-08-16

Gas hydrate technology is considered as a promising technology in the fields of gas storage and transportation, gas separation and purification, seawater desalination, and phase-change thermal energy storage. However, to date, the technology is still not commercially used mainly due to the low gas hydrate formation rate and the low gas uptake. In this study, the effect of hydrate promoters on gas uptake was systematically studied and analyzed based on hydrate-based CH 4 storage and CO 2 capture from CO 2 /H 2 gas mixture experiments. Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR) and gas chromatography (GC) were employed to analyze the microstructures and gas compositions. The results indicate that the effect of the hydrate promoter on the gas uptake depends on the physical and chemical properties of the promoter and gas. A strong polar ionic promoter is not helpful towards obtaining the ideal gas uptake because a dense hydrate layer is easily formed at the gas-liquid interface, which hinders gas diffusion from the gas phase to the bulk solution. For a weak polar or non-polar promoter, the gas uptake depends on the dissolution characteristics among the different substances in the system. The lower the mutual solubility among the substances co-existing in the system, the higher the independence among the substances in the system; this is so that each phase has an equal chance to occupy the hydrate cages without or with small interactions, finally leading to a relatively high gas uptake.

Rational design, synthesis, and pharmacological evaluation of 2-azanorbornane-3-exo,5-endo-dicarboxylic acid

DEFF Research Database (Denmark)

Bunch, Lennart; Liljefors, Tommy; Greenwood, Jeremy R

2003-01-01

conformationally restricted (S)-glutamic acid (Glu) analogue intended as a mimic of the folded Glu conformation. The synthesis of 1 was completed in its racemic form in eight steps from commercially available starting materials. As a key step, the first facially selective hydroboration of a 5-methylidene[2......The design and synthesis of conformationally restricted analogues of alpha-amino acids is an often used strategy in medicinal chemistry research. Here we present the rational design, synthesis, and pharmacological evaluation of 2-azanorbornane-3-exo,5-endo-dicarboxylic acid (1), a novel...... studies on native 2-amino-3-(3-hydroxy-5-methyl-4-isoxazolyl)propionic acid (AMPA) (IC(50) > 300 microM, [(3)H]AMPA) or kainic acid (IC(50) > 160 microM, [(3)H]kainic acid) receptors nor in binding studies on the cloned iGluR5,6 subtypes (IC(50) > 300 microM, [(3)H]kainic acid)....

Chemical characterization of composites developed from glycerol and dicarboxylic acids rein forced with piassava fiber

International Nuclear Information System (INIS)

Miranda, Cleidiene S.; Oliveira, Jamerson C.; Guimaraes, Danilo H.; Jose, Nadia M.; Carvalho, Ricardo F.

2011-01-01

In search of alternative technologies that enable the use of products with lower environmental impact, This study aims to develop a composite polymer-based piassava fiber. The sludge, waste and byproduct of commercial uses currently being used as reinforcement in polymer matrices, due to presence of lignocellulosic materials. The matrix polymer used was synthesized from glycerol with dicarboxylic acids, in order to open future perspectives on the use of glycerin generated from purified biodiesel production plastics. Composites with 2, 5, 10 wt% of piassava fiber cut into 5 mm raw and treated were obtained a mixture of solution. The materials were characterized by TGA, DSC, XRD and SEM. It was observed that the material under study is promising for the industrial market, because it has good compatibility with natural fibers allowing wider application of fiber natural and glycerol, producing semicrystalline composites and with good thermal properties. (author)

Mechanism of Uptake of Trace Elements by Plants

International Nuclear Information System (INIS)

Broda, E.

1965-01-01

MECHANISM OF UPTAKE OF TRACE ELEMENTS BY PLANTS (EXPERIMENTS WlTH RADIOZINC). Some authors have assumed that the uptake of (essential or non-essential) trace elements by plants is due to active transport, and therefore needs metabolic energy. In our laboratory it has been found that the uptake of zinc (“6”5Zn) by chlorella and barley roots is, in the main, a passive process, and is based largely on ion exchange. In these experiments the Zn system contrasted sharply with actively transporting systems, e. g. the K system, although the extent of accumulation may be similar: (1) decouplers (DNP, azide) or anaerobiosis do not depress the uptake of Zn: (2) plants killed by grinding, freezing or alcohol treatment take up more Zn than living plants: (3) the temperature coefficient of the Zn uptake is small: (4) many ions compete with Zn, i.e. the uptake is unspecific. We have measured - primarily with dead cells, where equilibria are reached easily - the competition of several foreign ions with radiozinc at fixed pH (usually 6). These values have been compared with analogous values obtained with radiozinc (and verified with radiocopper) in respect to cation exchange resins. It is concluded from the sequence of the different ions that the active sites in the cells are mainly carboxyl groups. Probably most of the ‘exchanger’ consists of carbohydrate derivatives in the cell wall, i.e. in the ‘free space’, However, both by Langmuir analysis of the observed ‘uptake isotherm’ and by radiochemical work with partly blocked material, sites with anomalous affinity to Zn have been demonstrated. These may be imidazol groups in the proteins known to bind zinc strongly by complexation. (author)

SUBSTRATE UPTAKE AND UTILIZATION BY A MARINE ULTRAMICROBACTERIUM

NARCIS (Netherlands)

SCHUT, F; JANSEN, M; GOMES, TMP; GOTTSCHAL, JC; HARDER, W; PRINS, RA

A facultatively oligotrophic ultramicrobacterium (strain RB2256) isolated from an Alaskan fjord by extinction dilution in seawater, was grown in batch culture and under single- and dual-substrate-limitation of alanine and glucose in a chemostat. The nature of the uptake systems, and the uptake

The effect of root temperature on the uptake and metabolism of anions by the root system of Zea mays L. I

International Nuclear Information System (INIS)

Holobrada, M.; Mistrik, I.; Kolek, J.

1980-01-01

The effect of root temperature upon the uptake of 35 S-sulfate by intact 21 days old maize roots was discussed. The plant roots grown at 20 degC were cooled in steps down to 15 degC or 5 degC. The rate of 35 S uptake was studied both in the whole root system and separately in the individual roots (primary seminal root, seminal adventitious roots and nodal roots). Differences were ascertained at lower uptakes by various root samples from resistant and nonresistant maize cultivars. (author)

Luminescence recognition of different organophosphorus pesticides by the luminescent Eu(III)-pyridine-2,6-dicarboxylic acid probe

Energy Technology Data Exchange (ETDEWEB)

Azab, Hassan A., E-mail: azab2@yahoo.com [Chemistry Department, Faculty of Science, Suez Canal University, Ismailia 41522 (Egypt); Duerkop, Axel [Institute of Analytical Chemistry, Chemo and Biosensors, Regensburg University, D-93040 Regensburg (Germany); Anwar, Z.M.; Hussein, Belal H.M.; Rizk, Moustafa A.; Amin, Tarek [Chemistry Department, Faculty of Science, Suez Canal University, Ismailia 41522 (Egypt)

2013-01-08

Highlights: Black-Right-Pointing-Pointer Europium (III) luminescence quenching has been used for sensing organophosphorous pesticides. Black-Right-Pointing-Pointer Four guest pesticides chlorfenvinphos, malathion, azinphos, and paraxon ethyl were used. Black-Right-Pointing-Pointer A sensitive rapid, cheap direct method for the determination of the pesticides has been developed. Black-Right-Pointing-Pointer The method was applied to the determination of the OPs in tap, river, mineral, and waste waters. - Abstract: Luminescence quenching of a novel long lived Eu(III)-pyridine-2,6-dicarboxylic acid probe of 1:2 stoichiometric ratio has been studied in 0.10 volume fraction ethanol-water mixture at pH 7.5 (HEPES buffer) in the presence of the organophosphorus pesticides chlorfenvinphos (P1), malathion (P2), azinphos (P3), and paraxon ethyl (P4). The luminescence intensity of Eu(III)-(PDCA){sub 2} probe decreases as the concentration of the pesticide increases. It was observed that the quenching due to P3 and P4 proceeds via both diffusional and static quenching processes. Direct methods for the determination of the pesticides under investigation have been developed using the luminescence quenching of Eu(III)-pyridine-2,6-dicarboxylic acid probe in solution. The linear range for determination of the selected pesticides is 1.0-35.0 {mu}M. The detection limits were 0.24-0.55 {mu}M for P3, P4, and P1 and 2.5 {mu}M for P2, respectively. The binding constants (K), and thermodynamic parameters of the OPs with Eu(III)-(PDCA){sub 2} were evaluated. Positive and negative values of entropy ({Delta}S) and enthalpy ({Delta}H) changes for Eu(III)-(PDCA){sub 2}-P1 ternary complex were calculated. As the waters in this study do not contain the above mentioned OPs over the limit detectable by the method, a recovery study was carried out after the addition of the adequate amounts of the organophosphorus pesticides under investigation.

Benzene-1,3-dicarboxylic acid 2,5-dimethylpyrrole derivatives as multiple inhibitors of bacterial Mur ligases (MurC-MurF).

Science.gov (United States)

Perdih, Andrej; Hrast, Martina; Barreteau, Hélène; Gobec, Stanislav; Wolber, Gerhard; Solmajer, Tom

2014-08-01

Enzymes catalyzing the biosynthesis of bacterial peptidoglycan represent traditionally a collection of highly selective targets for novel antibacterial drug design. Four members of the bacterial Mur ligase family-MurC, MurD, MurE and MurF-are involved in the intracellular steps of peptidoglycan biosynthesis, catalyzing the synthesis of the peptide moiety of the Park's nucleotide. In our previous virtual screening campaign, a chemical class of benzene-1,3-dicarboxylic acid 2,5-dimethylpyrrole derivatives exhibiting dual MurD/MurE inhibition properties was discovered. In the present study we further investigated this class of compounds by performing inhibition assays on all four Mur ligases (MurC-MurF). Furthermore, molecular dynamics (MD) simulation studies of one of the initially discovered compound 1 were performed to explore its geometry as well as its energetic behavior based on the Linear Interaction Energy (LIE) method. Further in silico virtual screening (VS) experiments based on the parent active compound 1 were conducted to optimize the discovered series. Selected hits were assayed against all Escherichia coli MurC-MurF enzymes in biochemical inhibition assays and molecules 10-14 containing benzene-1,3-dicarboxylic acid 2,5-dimethylpyrrole coupled with five member-ring rhodanine moiety were found to be multiple inhibitors of the whole MurC-MurF cascade of bacterial enzymes in the micromolar range. Steady-state kinetics studies suggested this class to act as competitive inhibitors of the MurD enzyme towards d-Glu. These compounds represent novel valuable starting point in the development of novel antibacterial agents. Copyright © 2014 Elsevier Ltd. All rights reserved.

Basic Description of the Lymphatic System from the Perspective of SLN Uptake of Radioactive Tracers. Chapter 2

International Nuclear Information System (INIS)

Pasqualini, R.; Janevik-Ivanovska, E.

2015-01-01

The lymphatic system is part of the circulatory system. It is closely associated with the cardiovascular system because it includes a network of vessels that contributes to liquid transportation throughout the body. This circulatory system is essential for the maintenance of interstitial fluid balance, uptake of dietary fat and for body defence against invasion by disease causing agents. Lymph nodes, which contain large numbers of B and T lymphocytes and macrophages, are located along lymphatic pathways. They have two primary functions: filtering and digesting potentially harmful particles from lymph before returning it to the bloodstream and contributing to the immune surveillance provided by lymphocytes and macrophages. In their function of filtering particles or cell debris, lymph nodes may collect cancer cells that are breaking and travelling away from the primary tumour. The spread of some forms of cancer usually follows an orderly progression, spreading first to regional lymph nodes, then the next rank of lymph nodes and so on. Therefore, the first lymph node (the SLN) is more likely than other lymph nodes to contain cancer cells. If a suitable radioactive tracer, generally a nanocolloid or a dye, is administrated in the proximity of the tumour site, it will travel through the lymphatic system and be trapped in the SLN, allowing its localization using an appropriate probe or by visual determination. The size and the charge of the radioactive tracer will mainly influence the extent of radioactivity remaining at the site of injection, the rate of diffusion into the lymphatic vessels and the uptake in the SLN. Knowledge of the physiology of the lymphatic system will help to identify factors influencing the diffusion and uptake mechanism of radioactive tracers in the lymph nodes and will assist in the design of more efficient and selective SLN seeking drugs. (author)

Arsenic uptake by Lemna minor in hydroponic system.

Science.gov (United States)

Goswami, Chandrima; Majumder, Arunabha; Misra, Amal Kanti; Bandyopadhyay, Kaushik

2014-01-01

Arsenic is hazardous and causes several ill effects on human beings. Phytoremediation is the use of aquatic plants for the removal of toxic pollutants from external media. In the present research work, the removal efficiency as well as the arsenic uptake capacity of duckweed Lemna minor has been studied. Arsenic concentration in water samples and plant biomass were determined by AAS. The relative growth factor of Lemna minor was determined. The duckweed had potential to remove as well as uptake arsenic from the aqueous medium. Maximum removal of more than 70% arsenic was achieved atinitial concentration of 0.5 mg/1 arsenic on 15th day of experimental period of 22 days. Removal percentage was found to decrease with the increase in initial concentration. From BCF value, Lemna minor was found to be a hyperaccumulator of arsenic at initial concentration of 0.5 mg/L, such that accumulation decreased with increase in initial arsenic concentration.

Electron uptake by iron-oxidizing phototrophic bacteria

Energy Technology Data Exchange (ETDEWEB)

Bose, A; Gardel, EJ; Vidoudez, C; Parra, EA; Girguis, PR

2014-02-26

Oxidation-reduction reactions underlie energy generation in nearly all life forms. Although most organisms use soluble oxidants and reductants, some microbes can access solid-phase materials as electron-acceptors or -donors via extracellular electron transfer. Many studies have focused on the reduction of solid-phase oxidants. Far less is known about electron uptake via microbial extracellular electron transfer, and almost nothing is known about the associated mechanisms. Here we show that the iron-oxidizing photoautotroph Rhodopseudomonas palustris TIE-1 accepts electrons from a poised electrode, with carbon dioxide as the sole carbon source/electron acceptor. Both electron uptake and ruBisCo form I expression are stimulated by light. Electron uptake also occurs in the dark, uncoupled from photosynthesis. Notably, the pioABC operon, which encodes a protein system essential for photoautotrophic growth by ferrous iron oxidation, influences electron uptake. These data reveal a previously unknown metabolic versatility of photoferrotrophs to use extracellular electron transfer for electron uptake.

A coordination polymer of CdII with benzene-1,3-dicarboxylate and 1,4-bis[1-(2-pyridylmethylbenzimidazol-2-yl]butane

Directory of Open Access Journals (Sweden)

Wei-Ping Zhang

2009-11-01

Full Text Available The title CdII coordination polymer, catena-poly[[{1,4-bis[1-(2-pyridylmethylbenzimidazol-2-yl]butane}cadmium(II]-μ-benzene-1,3-dicarboxylato], [Cd(C8H4O4(C30H28N6]n, was obtained by reaction of CdCO3, benzene-1,3-dicarboxylic acid (H2btc and 1,4-bis[1-(2-pyridylmethylbenzimidazol-2-yl]butane (L. The CdII cation is six-coordinated by an N2O4-donor set. L acts as a bidentate ligand and btc anions link CdII centers into a chain propagating parallel to [010].

Pyridine 2,4-Dicarboxylic Acid Suppresses Tomato Seedling Growth

Directory of Open Access Journals (Sweden)

Sotirios Fragkostefanakis

2018-01-01

Full Text Available Pyridine 2,4-dicarboxylic acid is a structural analog of 2-oxoglutarate and is known to inhibit 2-oxoglutare-dependent dioxygenases. The effect of this inhibitor in tomato seedlings grown in MS media supplied with various concentrations of PDCA was investigated, resulting in shorter roots and hypocotyls in a dose-dependent manner. The partial inhibition of growth in roots was more drastic compared to hypocotyls and was attributed to a decrease in the elongation of root and hypocotyl cells. Concentrations of 100 and 250 μM of PDCA decreased hydroxyproline content in roots while only the 250 μM treatment reduced the hydroxyproline content in shoots. Seedlings treated with 100 μM PDCA exhibited enhanced growth of hypocotyl and cotyledon cells and higher hydroxyproline content resulting in cotyledons with greater surface area. However, no alterations in hypocotyl length were observed. Prolyl 4 hydroxylases (P4Hs are involved in the O-glycosylation of AGPs and were also highly expressed during seedling growth. Moreover PDCA induced a decrease in the accumulation of HRGPs and particularly in AGPs-bound epitopes in a dose dependent-manner while more drastic reduction were observed in roots compared to shoots. In addition, bulged root epidermal cells were observed at the high concentration of 250 μM which is characteristic of root tissues with glycosylation defects. These results indicate that PDCA induced pleiotropic effects during seedling growth while further studies are required to better investigate the physiological significance of this 2-oxoglutarate analog. This pharmacological approach might be used as a tool to better understand the physiological significance of HRGPs and probably P4Hs in various growth and developmental programs in plants.

Pyridine 2,4-dicarboxylic acid suppresses tomato seedling growth

Science.gov (United States)

Fragkostefanakis, Sotirios; Kaloudas, Dimitrios; Kalaitzis, Panagiotis

2018-01-01

Pyridine 2,4-dicarboxylic acid is a structural analogue of 2-oxoglutarate and is known to inhibit 2-oxoglutare-dependent dioxygenases. The effect of this inhibitor in tomato seedlings grown in MS media supplied with various concentrations of PDCA was investigated, resulting in shorter roots and hypocotyls in a dose-dependent manner. The partial inhibition of growth in roots was more drastic compared to hypocotyls and was attributed to a decrease in the elongation of root and hypocotyl cells. Concentrations of 100 and 250 μΜ of PDCA decreased hydroxyproline content in roots while only the 250 μΜ treatment reduced the hydroxyproline content in shoots. Seedlings treated with 100 μΜ PDCA exhibited enhanced growth of hypocotyl and cotyledon cells and higher hydroxyproline content resulting in cotyledons with greater surface area. However, no alterations in hypocotyl length were observed. Prolyl 4 hydroxylases (P4Hs) are involved in the O-glycosylation of AGPs and were also highly expressed during seedling growth. Moreover PDCA induced a decrease in the accumulation of HRGPs and particularly in AGPs-bound epitopes in a dose dependent-manner while more drastic reduction were observed in roots compared to shoots. In addition, bulged root epidermal cells were observed at the high concentration of 250 μΜ which is characteristic of root tissues with glycosylation defects. These results indicate that PDCA induced pleiotropic effects during seedling growth while further studies are required to better investigate the physiological significance of this 2-oxoglutarate analogue. This pharmacological approach might be used as a tool to better understand the physiological significance of HRGPs and probably P4Hs in various growth and developmental programs in plants.

A unified approach to model uptake kinetics of trace elements in complex aqueous – solid solution systems

International Nuclear Information System (INIS)

Thien, Bruno M.J.; Kulik, Dmitrii A.; Curti, Enzo

2014-01-01

Highlights: • There are several models able to describe trace element partitioning in growing minerals. • To describe complex systems, those models must be embedded in a geochemical code. • We merged two models into a unified one suitable for implementation in a geochemical code. • This unified model was tested against coprecipitation experimental data. • We explored how our model reacts to solution depletion effects. - Abstract: Thermodynamics alone is usually not sufficient to predict growth-rate dependencies of trace element partitioning into host mineral solid solutions. In this contribution, two uptake kinetic models were analyzed that are promising in terms of mechanistic understanding and potential for implementation in geochemical modelling codes. The growth Surface Entrapment Model (Watson, 2004) and the Surface Reaction Kinetic Model (DePaolo, 2011) were shown to be complementary, and under certain assumptions merged into a single analytical expression. This Unified Uptake Kinetics Model was implemented in GEMS3K and GEM-Selektor codes ( (http://gems.web.psi.ch)), a Gibbs energy minimization package for geochemical modelling. This implementation extends the applicability of the unified uptake kinetics model to accounting for non-trivial factors influencing the trace element partitioning into solid solutions, such as the changes in aqueous solution composition and speciation, or the depletion effects in closed geochemical systems

Static magnetic field reduced exogenous oligonucleotide uptake by spermatozoa using magnetic nanoparticle gene delivery system

International Nuclear Information System (INIS)

Katebi, Samira; Esmaeili, Abolghasem; Ghaedi, Kamran

2016-01-01

Spermatozoa could introduce exogenous oligonucleotides of interest to the oocyte. The most important reason of low efficiency of sperm mediated gene transfer (SMGT) is low uptake of exogenous DNA by spermatozoa. The aim of this study was to evaluate the effects of static magnetic field on exogenous oligonucleotide uptake of spermatozoa using magnetofection method. Magnetic nanoparticles (MNPs) associated with the labeled oligonucleotides were used to increase the efficiency of exogenous oligonucleotide uptake by rooster spermatozoa. We used high-field/high-gradient magnet (NdFeB) to enhance and accelerate exogenous DNA sedimentation at the spermatozoa surface. Flow cytometry analysis was performed to measure viability and percentage of exogenous oligonucleotide uptake by sperm. Flow cytometry analysis showed a significant increase in exogenous oligonucleotide uptake by rooster spermatozoa (P<0.001) when spermatozoa were incubated in exogenous oligonucleotide solution and MNPs. However, by applying static magnetic field during magnetofection method, a significant decrease in exogenous oligonucleotide uptake was observed (P<0.05). Findings of this study showed that MNPs were effective to increase exogenous oligonucleotide uptake by rooster spermatozoa; however unlike others studies, static magnetic field, was not only ineffective to enhance exogenous oligonucleotide uptake by rooster spermatozoa but also led to reduction in efficiency of magnetic nanoparticles in gene transfer. - Highlights: • Core/shell type Iron oxide nanoparticles were used as a novel and efficient method. • This method increases exogenous DNA uptake by rooster spermatozoa. • Static magnetic field decreased DNA uptake by rooster spermatozoa.

Static magnetic field reduced exogenous oligonucleotide uptake by spermatozoa using magnetic nanoparticle gene delivery system

Energy Technology Data Exchange (ETDEWEB)

Katebi, Samira; Esmaeili, Abolghasem, E-mail: aesmaeili@sci.ui.ac.ir; Ghaedi, Kamran

2016-03-15

Spermatozoa could introduce exogenous oligonucleotides of interest to the oocyte. The most important reason of low efficiency of sperm mediated gene transfer (SMGT) is low uptake of exogenous DNA by spermatozoa. The aim of this study was to evaluate the effects of static magnetic field on exogenous oligonucleotide uptake of spermatozoa using magnetofection method. Magnetic nanoparticles (MNPs) associated with the labeled oligonucleotides were used to increase the efficiency of exogenous oligonucleotide uptake by rooster spermatozoa. We used high-field/high-gradient magnet (NdFeB) to enhance and accelerate exogenous DNA sedimentation at the spermatozoa surface. Flow cytometry analysis was performed to measure viability and percentage of exogenous oligonucleotide uptake by sperm. Flow cytometry analysis showed a significant increase in exogenous oligonucleotide uptake by rooster spermatozoa (P<0.001) when spermatozoa were incubated in exogenous oligonucleotide solution and MNPs. However, by applying static magnetic field during magnetofection method, a significant decrease in exogenous oligonucleotide uptake was observed (P<0.05). Findings of this study showed that MNPs were effective to increase exogenous oligonucleotide uptake by rooster spermatozoa; however unlike others studies, static magnetic field, was not only ineffective to enhance exogenous oligonucleotide uptake by rooster spermatozoa but also led to reduction in efficiency of magnetic nanoparticles in gene transfer. - Highlights: • Core/shell type Iron oxide nanoparticles were used as a novel and efficient method. • This method increases exogenous DNA uptake by rooster spermatozoa. • Static magnetic field decreased DNA uptake by rooster spermatozoa.

Thyroid uptake test

International Nuclear Information System (INIS)

Ganatra, R.D.

1992-01-01

The uptake of radioiodine by the thyroid gland is altered by the iodine content of diet or drugs. American diet has a high iodine content because each slice of the white bread contains nearly 150μg of iodine due to the bleaching process employed in the production of the bread. This carrier content of iodine reduces the uptake so much, that the normal American uptakes are usually three to four times lower than the uptakes in the developing countries. The other drawback of the thyroid uptake test is that it is affected by the iodine containing drugs. Anti-diarrhoea medications are quire common in the developing countries and many of them contain iodine moiety. Without a reliable drug history, a low thyroid uptake value may lead to a misleading conclusion

Nutrient uptake from liquid digestate using ornamental aquatic macrophytes (Canna indica, Iris pseudacorus, Typha latifolia) in a constructed wetland system

Science.gov (United States)

Ediviani, W.; Priadi, C. R.; Moersidik, S. S.

2018-05-01

Indonesia has implemented energy recovery from organic (food) waste by anaerobic digestion method, but the digestate was commonly treated only by composting, and still as a separated treatment (not integrated into a resource recovery system). Whilst not getting any pretreatment, the digestate was disposed to the environment and then act as a pollutant. Yet it contains nutrients which could be recovered as a nutrient source for plants. The study was about how ornamental aquatic macrophytes could uptake nitrogen from liquid digestate in a constructed wetland method. Canna indica, Iris pseudacorus, and Typha latifolia were the experimented ornamental aquatic macrophytes used to uptake the nutrient (nitrogen—N) from liquid digestate. The study showed that the highest N uptake was done by C. indica (25.1%) which has the highest biomass increment as well (80.5%). Effluent quality improvement also shown by N removal by C. indica (68.5—76.4% TN), I. pseudacorus (61.8—71.3% TN), and T. latifolia (61.6—74.5%). This research proved that C. indica has the performance for the N uptake, best N removal efficiency, with a great growth rate as well. This system using C. indica could also improve the water quality of the effluent and add the aesthetic of environment.

Comparison between Arabidopsis and Rice for Main Pathways of K+ and Na+ Uptake by Roots

OpenAIRE

Nieves-Cordones, Manuel; Mart?nez, Vicente; Benito, Bego?a; Rubio, Francisco

2016-01-01

K+ is an essential macronutrient for plants. It is acquired by specific uptake systems located in roots. Although the concentrations of K+ in the soil solution are widely variable, K+ nutrition is secured by uptake systems that exhibit different affinities for K+. Two main systems have been described for root K+ uptake in several species: the high-affinity HAK5-like transporter and the inward-rectifier AKT1-like channel. Other unidentified systems may be also involved in root K+ uptake, a...

Gbu Glycine Betaine Porter and Carnitine Uptake in Osmotically Stressed Listeria monocytogenes Cells

Science.gov (United States)

Mendum, Mary Lou; Smith, Linda Tombras

2002-01-01

The food-borne pathogen Listeria monocytogenes grows actively under high-salt conditions by accumulating compatible solutes such as glycine betaine and carnitine from the medium. We report here that the dominant transport system for glycine betaine uptake, the Gbu porter, may act as a secondary uptake system for carnitine, with a Km of 4 mM for carnitine uptake and measurable uptake at carnitine concentrations as low as 10 μM. This porter has a Km for glycine betaine uptake of about 6 μM. The dedicated carnitine porter, OpuC, has a Km for carnitine uptake of 1 to 3 μM and a Vmax of approximately 15 nmol/min/mg of protein. Mutants lacking either opuC or gbu were used to study the effects of four carnitine analogs on growth and uptake of osmolytes. In strain DP-L1044, which had OpuC and the two glycine betaine porters Gbu and BetL, triethylglycine was most effective in inhibiting growth in the presence of glycine betaine, but trigonelline was best at inhibiting growth in the presence of carnitine. Carnitine uptake through OpuC was inhibited by γ-butyrobetaine. Dimethylglycine inhibited both glycine betaine and carnitine uptake through the Gbu porter. Carnitine uptake through the Gbu porter was inhibited by triethylglycine. Glycine betaine uptake through the BetL porter was strongly inhibited by trigonelline and triethylglycine. These results suggest that it is possible to reduce the growth of L. monocytogenes under osmotically stressful conditions by inhibiting glycine betaine and carnitine uptake but that to do so, multiple uptake systems must be affected. PMID:12406761

Vanadium uptake and an effect of vanadium treatment on 18F-labeled water movement in a cowpea plant by positron emitting tracer imaging system (PETIS)

International Nuclear Information System (INIS)

Furukawa, J.; Yokota, H.; Tanoi, K.; Ueoka, S.; Nakanishi, T.M.; Uchida, H.; Tsuji, A.

2001-01-01

Real time vanadate (V 5+ ) uptake imaging in a cowpea plant by positron emitting tracer imaging system (PETIS) is presented. Vanadium-48 was produced by bombarding a Sc foil target with 50 MeV α-particles at Takasaki Ion Accelerators for Advanced Radiation application (TIARA) AVF cyclotron. Then 48 V was added to the culture solution to investigate the V distribution in a cowpea plant. The real time uptake of the 48 V was monitored by PETIS. Distribution of 48 V in a whole plant was measured after 3, 6 and 20 hours of V treatment by Bio-imaging Analyzer System (BAS). After the 20 hour treatment, vanadate was detected at the up-ground part of the plant. To know the effect of V uptake on plant activity, 18 F-labeled water uptake was analyzed by PETIS. When a cowpea plant was treated with V for 20 hours before 18 F-labeled water uptake experiment, the total amount of 18 F-labeled water absorption ws drastically decreased. Results suggest the inhibition of water uptake was mainly caused by the vanadate already moved to the up-ground part of the plant. (author)

Syntheses, structures and magnetic properties of four coordination polymers based on nitrobenzene dicarboxylate and various N-donor coligands

Energy Technology Data Exchange (ETDEWEB)

Li, Gui-Lian; Yin, Wei-Dong; Liu, Guang-Zhen; Ma, Lu-Fang [College of Chemistry and Chemical Engineering, Luoyang Normal University, Luoyang 471022, Henan (China); Wang, Li-Ya, E-mail: gzliuly@126.com [College of Chemistry and Chemical Engineering, Luoyang Normal University, Luoyang 471022, Henan (China); College of Chemistry and Pharmacy Engineering, Nanyang Normal University, Nanyang 473061, Henan (China)

2014-12-15

Four new coordination polymers ([Ni(4-Nbdc)(bpa)(H{sub 2}O)]){sub n} (1), ([Co(4-Nbdc)(bpp) (H{sub 2}O)]){sub n} (2), ([Ni(4-Nbdc)(bpp)(H{sub 2}O)]·H{sub 2}O){sub n} (3), and ([Mn{sub 2}(3-Nbdc){sub 2}(bib){sub 3}]·2H{sub 2}O){sub n} (4) (4-Nbdc=4-nitrobenzene-1,2-dicarboxylate, 3-Nbdc=3-nitrobenzene-1,2-dicarboxylate, bpa=1,2-bi(4-pyridyl)ethane, bpp=1,3-bis(4-pyridyl)propane, and bib=1,4-bis(1-imidazoly)benzene), were synthesized by hydrothermal reactions, and characterized by single-crystal X-ray diffractions, elemental analysis, FT-IR, PXRD, TGA and magnetic analysis. Complexes 1 and 2 display quasi-trapezoidal chain and brick-wall layer, and both of them contain metal–carboxylate binuclear units. Complexes 3 and 4 exhibit three-dimensional frameworks with the (6{sup 6}) dia topology and (4{sup 4}.6{sup 10}.8)(4{sup 4}.6{sup 2}) fsc topology, and both of them contain metal–carboxylate chains. The carboxyl groups with syn-anti coordination mode mediate effectively the weak ferromagnetic coupling interaction within Ni(II)–carboxylate binuclear in 1 (J=1.27 cm{sup −1}) and Ni(II)–carboxylate chain in 3 (J=1.44 cm{sup −1}), respectively, and the carboxyl groups with anti-anti coordination mode leads to the classic antiferromagnetic coupling interaction within Mn(II)–carboxylate chain in 4 (J=−0.77 cm{sup −1}). - Highlights: • Four novel coordination polymers were hydrothermally synthesized. • 1 is 1D quasi-trapezoidal chain and 2 is brick-wall layer both with dinuclear units. • 3 and 4 show 3D frameworks both with 1D metal–carboxylate chains. • 1 and 3 exhibit ferromagnetic coupling, while 4 shows antiferromagnetic coupling.

Luminescence recognition of different organophosphorus pesticides by the luminescent Eu(III)–pyridine-2,6-dicarboxylic acid probe

International Nuclear Information System (INIS)

Azab, Hassan A.; Duerkop, Axel; Anwar, Z.M.; Hussein, Belal H.M.; Rizk, Moustafa A.; Amin, Tarek

2013-01-01

Highlights: ► Europium (III) luminescence quenching has been used for sensing organophosphorous pesticides. ► Four guest pesticides chlorfenvinphos, malathion, azinphos, and paraxon ethyl were used. ► A sensitive rapid, cheap direct method for the determination of the pesticides has been developed. ► The method was applied to the determination of the OPs in tap, river, mineral, and waste waters. - Abstract: Luminescence quenching of a novel long lived Eu(III)–pyridine-2,6-dicarboxylic acid probe of 1:2 stoichiometric ratio has been studied in 0.10 volume fraction ethanol–water mixture at pH 7.5 (HEPES buffer) in the presence of the organophosphorus pesticides chlorfenvinphos (P1), malathion (P2), azinphos (P3), and paraxon ethyl (P4). The luminescence intensity of Eu(III)–(PDCA) 2 probe decreases as the concentration of the pesticide increases. It was observed that the quenching due to P3 and P4 proceeds via both diffusional and static quenching processes. Direct methods for the determination of the pesticides under investigation have been developed using the luminescence quenching of Eu(III)–pyridine-2,6-dicarboxylic acid probe in solution. The linear range for determination of the selected pesticides is 1.0–35.0 μM. The detection limits were 0.24–0.55 μM for P3, P4, and P1 and 2.5 μM for P2, respectively. The binding constants (K), and thermodynamic parameters of the OPs with Eu(III)–(PDCA) 2 were evaluated. Positive and negative values of entropy (ΔS) and enthalpy (ΔH) changes for Eu(III)–(PDCA) 2 –P1 ternary complex were calculated. As the waters in this study do not contain the above mentioned OPs over the limit detectable by the method, a recovery study was carried out after the addition of the adequate amounts of the organophosphorus pesticides under investigation.

Plant uptake of dual-labeled organic N biased by inorganic C uptake

DEFF Research Database (Denmark)

Rasmussen, Jim; Sauheitl, Leopold; Eriksen, Jørgen

2010-01-01

glycine or CO2-3 , but found no differences in uptake rates between these C-sources. The uptake of inorganic C to the shoot tissue was higher for maize grown in full light compared to shading, which indicates a passive uptake of inorganic C with water. We conclude that uptake of inorganic C produced...

Design and synthesis of four coordination polymers generated from 2,2'-biquinoline-4,4'-dicarboxylate and aromatic bidentate ligands

International Nuclear Information System (INIS)

Ye Junwei; Zhang Ping; Ye Kaiqi; Zhang Hongyu; Jiang Shimei; Ye Ling; Yang Guangdi; Wang Yue

2006-01-01

Four coordination polymers [Zn(bqdc)(phen)] n (1), [Zn(bqdc)(bpy)(H 2 O)] n (2), [Mn(bqdc)(bpy)(H 2 O) 2 ] n (3) and [Mn(bqdc)(phen)(H 2 O) 2 ] n (4) (H 2 bqdc=2,2'-biquinoline-4,4'-dicarboxylic acid, phen=1,10-phenanthroline and bpy=2,2'-bipyridyl) have been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction. Crystal data for 1: monoclinic system, C2/c, a=14.141(3)A, b=10.021(2)A, c=18.511(4)A, β=103.78(3) o , V=2547.6(9)A 3 , Z=4. Crystal data for 2: monoclinic system, p2 1 /n, a=13.656(3)A, b=10.015(2)A, c=19.127(4)A, β=107.13(7) o , V=2500.1(9)A 3 , Z=4. Crystal data for 3: monoclinic system, C2/c, a=14.5050(8)A, b=15.1932(8)A, c=12.7549(6)A, β=116.8010(11) o , V=2508.9(2)A 3 , Z=4. Crystal data for 4: monoclinic system, C2/c, a=14.1732(17)A, b=16.115(3)A, c=12.809(3)A, β=117.04(3) o , V=2605.7(8)A 3 , Z=4. Single helix-like chains exist in 1. The supramolecular structure of 1 exhibits extended two-dimensional network while 2-4 display extended three-dimensional architectures based on interchain hydrogen bonding and π-π interactions. Compounds 1 and 2 show blue photoluminescence under UV light suggesting that they may be employed to develop luminescent materials. Compounds 3 and 4 show interesting magnetic behaviors

The relevance of parametric U-uptake models in ESR age calculations

International Nuclear Information System (INIS)

Gruen, Rainer

2009-01-01

In the ESR dating three basic parametric U-uptake models have been applied for dating teeth: early U-uptake (EU: closed system), linear U-uptake (LU) and recent U-uptake (RU, it is assumed that the dose rate contribution of U in the dental tissues is zero). In many ESR dating publications it is still assumed that samples comply with one or the other parametric U-uptake model calculation or that their correct age lies somewhere between EU and LU. Observations of the spatial distribution of uranium in dental tissues show that it is difficult to predict any relationships between the relative uptake in the dental tissues. Combined U-series/ESR age estimates can give insights into the actual U-uptake. An evaluation of published data shows that for cave sites, a significant number of results fall outside the EU and LU bracket, while for open air sites, the majority of data are outside this bracket, particularly showing greatly delayed U-uptake. This may be due to changes in the hydrological system, leading to erosion which exposes the open air site. U-leaching has also been observed on samples from open air sites, in which case any reasonable age calculation is impossible.

Bicyclists' Uptake of Traffic-Related Air Pollution: Effects of the Urban Transportation System

Science.gov (United States)

2014-10-27

While bicyclists and other active travelers obtain health benefits from increased physical activity, they also risk uptake of traffic-related air pollution. But pollution uptake by urban bicyclists is not well understood due to a lack of direct measu...

Heavy metal uptake of Geosiphon pyriforme

Energy Technology Data Exchange (ETDEWEB)

Scheloske, Stefan E-mail: stefan.scheloske@mpi-hd.mpg.de; Maetz, Mischa; Schuessler, Arthur

2001-07-01

Geosiphon pyriforme represents the only known endosymbiosis between a fungus, belonging to the arbuscular mycorrhizal (AM) fungi, and cyanobacteria (blue-green algae). Therefore we use Geosiphon as a model system for the widespread AM symbiosis and try to answer some basic questions regarding heavy metal uptake or resistance of AM fungi. We present quantitative micro-PIXE measurements of a set of heavy metals (Cu, Cd, Tl, Pb) taken up by Geosiphon-cells. The uptake is studied as a function of the metal concentration in the nutrient solution and of the time Geosiphon spent in the heavy metal enriched medium. The measured heavy metal concentrations range from several ppm to some hundred ppm. Also the influence of the heavy metal uptake on the nutrition transfer of other elements will be discussed.

Selenium Uptake and Volatilization by Marine Algae

Science.gov (United States)

Luxem, Katja E.; Vriens, Bas; Wagner, Bettina; Behra, Renata; Winkel, Lenny H. E.

2015-04-01

Selenium (Se) is an essential trace nutrient for humans. An estimated one half to one billion people worldwide suffer from Se deficiency, which is due to low concentrations and bioavailability of Se in soils where crops are grown. It has been hypothesized that more than half of the atmospheric Se deposition to soils is derived from the marine system, where microorganisms methylate and volatilize Se. Based on model results from the late 1980s, the atmospheric flux of these biogenic volatile Se compounds is around 9 Gt/year, with two thirds coming from the marine biosphere. Algae, fungi, and bacteria are known to methylate Se. Although algal Se uptake, metabolism, and methylation influence the speciation and bioavailability of Se in the oceans, these processes have not been quantified under environmentally relevant conditions and are likely to differ among organisms. Therefore, we are investigating the uptake and methylation of the two main inorganic Se species (selenate and selenite) by three globally relevant microalgae: Phaeocystis globosa, the coccolithophorid Emiliania huxleyi, and the diatom Thalassiosira oceanica. Selenium uptake and methylation were quantified in a batch experiment, where parallel gas-tight microcosms in a climate chamber were coupled to a gas-trapping system. For E. huxleyi, selenite uptake was strongly dependent on aqueous phosphate concentrations, which agrees with prior evidence that selenite uptake by phosphate transporters is a significant Se source for marine algae. Selenate uptake was much lower than selenite uptake. The most important volatile Se compounds produced were dimethyl selenide, dimethyl diselenide, and dimethyl selenyl sulfide. Production rates of volatile Se species were larger with increasing intracellular Se concentration and in the decline phase of the alga. Similar experiments are being carried out with P. globosa and T. oceanica. Our results indicate that marine algae are important for the global cycling of Se

Structural modulation and luminescent properties of four Cd{sup II} coordination architectures based on 3-(pyridin-4-yl)-5-(pyrazin-2-yl)-1H-1,2,4-triazole and flexible/rigid dicarboxylate ligands

Energy Technology Data Exchange (ETDEWEB)

Xia, Liang; Dong, Wen-Wen, E-mail: dongww1@126.com; Ye, Xiao; Zhao, Jun; Li, Dong-Sheng, E-mail: lidongsheng1@126.com

2016-10-15

To systematically investigate the influence of the flexible or rigid auxiliary ligands on the structures and properties of transition metal compounds, we synthesized four new d{sup 10} coordination polymers (CPs) from 3-(pyridin-4-yl)-5-(pyrazin-2-yl)-1H-1,2,4-triazole (4-Hpzpt) and flexible/rigid dicarboxylate ligands, [Cd(4-pzpt){sub 2}]{sub n} (1), [Cd{sub 3}(4-pzpt){sub 2}(suc){sub 2}]{sub n} (2), [Cd{sub 2}(4-Hpzpt)(nbc){sub 2}(H{sub 2}O)]{sub n} (3) and ([Cd{sub 2}(4-pzpt){sub 2}(tfbdc)(H{sub 2}O){sub 4}]·H{sub 2}O){sub n} (4) (H{sub 2}suc=1,2-ethanedicarboxylic acid, H{sub 2}nbc=hthalene-1,4-dicarboxylic acid, H{sub 2}tfbdc =2,3,5,6-tetrafluoroterephthalic acid). Single crystal X-ray analysis indicates that compound 1 shows a 4{sup 4}-sql layer, which is extended to a 3D network via nonclassical C–H{sup …}N hydrogen bonds. Compound 2 possesses a 6-connected pcu-4{sup 12}0.6{sup 3} net composed of trinuclear Cd{sup II}-clusters. Compound 3 represents a rare 3D (3,4,4,5)-connected topology with a Schläfli symbol of (4·6·7)(4·5{sup 3}·7{sup 2})(5{sup 3}·6·7·9)(4{sup 2}·5{sup 5}·6·7{sup 2}). Compound 4 exhibits a 2D+2D→2D parallel interpenetrated 6{sup 3}-hcb network. The adjacent 2D networks are interdigitated with each other to form the resulting 3D supramolecular architecture through classical O–H{sup …}N and O–H{sup …}O hydrogen bonds. Structural diversities indicate that the nature of flexible/rigid-dicarboxlates plays crucial roles in modulating structures of these compounds. Moreover, the luminescent properties of them have been briefly investigated. - Graphical abstract: Four new Cd{sup II} coordination architectures constructed from the primary ligand 4-Hpzpt and flexible/rigid dicarboxylate coligands. Structural diversities indicate that the nature of flexible/rigid-dicarboxlates plays crucial roles in modulating structures of these compounds. And more, the thermal stability and luminescence are discussed. - Highlights: �

Uranium uptake by hydroponically cultivated crop plants

Energy Technology Data Exchange (ETDEWEB)

Soudek, Petr; Petrova, Sarka [Laboratory of Plant Biotechnologies, Joint Laboratory of Institute of Experimental Botany AS CR, v.v.i. and Crop Research Institute, v.v.i., Rozvojova 263, 162 05 Prague 6 (Czech Republic); Benesova, Dagmar [Laboratory of Plant Biotechnologies, Joint Laboratory of Institute of Experimental Botany AS CR, v.v.i. and Crop Research Institute, v.v.i., Rozvojova 263, 162 05 Prague 6 (Czech Republic); Faculty of Environment Technology, Institute of Chemical Technology, Technicka 5, 166 28 Prague 6 (Czech Republic); Dvorakova, Marcela [Laboratory of Plant Biotechnologies, Joint Laboratory of Institute of Experimental Botany AS CR, v.v.i. and Crop Research Institute, v.v.i., Rozvojova 263, 162 05 Prague 6 (Czech Republic); Vanek, Tomas, E-mail: vanek@ueb.cas.cz [Laboratory of Plant Biotechnologies, Joint Laboratory of Institute of Experimental Botany AS CR, v.v.i. and Crop Research Institute, v.v.i., Rozvojova 263, 162 05 Prague 6 (Czech Republic)

2011-06-15

Hydroponicaly cultivated plants were grown on medium containing uranium. The appropriate concentrations of uranium for the experiments were selected on the basis of a standard ecotoxicity test. The most sensitive plant species was determined to be Lactuca sativa with an EC{sub 50} value about 0.1 mM. Cucumis sativa represented the most resistant plant to uranium (EC{sub 50} = 0.71 mM). Therefore, we used the uranium in a concentration range from 0.1 to 1 mM. Twenty different plant species were tested in hydroponic solution supplemented by 0.1 mM or 0.5 mM uranium concentration. The uranium accumulation of these plants varied from 0.16 mg/g DW to 0.011 mg/g DW. The highest uranium uptake was determined for Zea mays and the lowest for Arabidopsis thaliana. The amount of accumulated uranium was strongly influenced by uranium concentration in the cultivation medium. Autoradiography showed that uranium is mainly localized in the root system of the plants tested. Additional experiments demonstrated the possibility of influencing the uranium uptake from the cultivation medium by amendments. Tartaric acid was able to increase uranium uptake by Brassica oleracea and Sinapis alba up to 2.8 times or 1.9 times, respectively. Phosphate deficiency increased uranium uptake up to 4.5 times or 3.9 times, respectively, by Brassica oleracea and S. alba. In the case of deficiency of iron or presence of cadmium ions we did not find any increase in uranium accumulation. - Highlights: > The uranium accumulation in twenty different plant species varied from 0.160 to 0.011 mg/g DW. > Uranium is mainly localized in the root system. > Tartaric acid was able to increase uranium uptake by Brassica oleracea and Sinapis alba. > The phosphates deficiency increase the uranium uptake.

Uranium uptake by hydroponically cultivated crop plants

International Nuclear Information System (INIS)

Soudek, Petr; Petrova, Sarka; Benesova, Dagmar; Dvorakova, Marcela; Vanek, Tomas

2011-01-01

Hydroponicaly cultivated plants were grown on medium containing uranium. The appropriate concentrations of uranium for the experiments were selected on the basis of a standard ecotoxicity test. The most sensitive plant species was determined to be Lactuca sativa with an EC 50 value about 0.1 mM. Cucumis sativa represented the most resistant plant to uranium (EC 50 = 0.71 mM). Therefore, we used the uranium in a concentration range from 0.1 to 1 mM. Twenty different plant species were tested in hydroponic solution supplemented by 0.1 mM or 0.5 mM uranium concentration. The uranium accumulation of these plants varied from 0.16 mg/g DW to 0.011 mg/g DW. The highest uranium uptake was determined for Zea mays and the lowest for Arabidopsis thaliana. The amount of accumulated uranium was strongly influenced by uranium concentration in the cultivation medium. Autoradiography showed that uranium is mainly localized in the root system of the plants tested. Additional experiments demonstrated the possibility of influencing the uranium uptake from the cultivation medium by amendments. Tartaric acid was able to increase uranium uptake by Brassica oleracea and Sinapis alba up to 2.8 times or 1.9 times, respectively. Phosphate deficiency increased uranium uptake up to 4.5 times or 3.9 times, respectively, by Brassica oleracea and S. alba. In the case of deficiency of iron or presence of cadmium ions we did not find any increase in uranium accumulation. - Highlights: → The uranium accumulation in twenty different plant species varied from 0.160 to 0.011 mg/g DW. → Uranium is mainly localized in the root system. → Tartaric acid was able to increase uranium uptake by Brassica oleracea and Sinapis alba. → The phosphates deficiency increase the uranium uptake.

Characterization of taurine binding, uptake, and release in the rat hypothalamus

International Nuclear Information System (INIS)

Hanretta, A.T.

1985-01-01

The neurotransmitter criteria of specific receptors, inactivation, and release were experimentally examined for taurine in the hypothalamus. Specific membrane binding and synaptosomal uptake of taurine both displayed high affinity and low affinity systems. The neurotransmitter criterion of release was studied in superfused synaptosomes. Exposure of synaptosomes which had been preloaded with a concentration of [ 3 H]taurine in the high affinity uptake range (1.5 μM) to either 56 mM K + or 100 μM veratridine evoked a Ca 2+ -independent release. Exposure of synaptosomes which had been preloaded with a concentration of [ 3 H]taurine in the low affinity uptake range (2 mM) to 56 mM K + induced a Ca 2+ -independent release, whereas 100 + M veratridine did not, either in the presence or absence of Ca 2+ . Based on these results, as well as other observations, a model is proposed in which the high affinity uptake system is located on neuronal membranes and the low affinity uptake system is located on glial membranes. The mechanisms of binding, uptake, and release in relation to the cellular location of each are discussed. We conclude that the neurotransmitter criterion of activation by re-uptake is satisfied for taurine in the hypothalamus. However, the failure to demonstrate both a specific taurine receptor site and a Ca 2+ -dependent evoked release, necessitates that we conclude that taurine appears not to function as a hypothalamic neurotransmitter, at least not in the classical sense

Static magnetic field reduced exogenous oligonucleotide uptake by spermatozoa using magnetic nanoparticle gene delivery system

Science.gov (United States)

Katebi, Samira; Esmaeili, Abolghasem; Ghaedi, Kamran

2016-03-01

Spermatozoa could introduce exogenous oligonucleotides of interest to the oocyte. The most important reason of low efficiency of sperm mediated gene transfer (SMGT) is low uptake of exogenous DNA by spermatozoa. The aim of this study was to evaluate the effects of static magnetic field on exogenous oligonucleotide uptake of spermatozoa using magnetofection method. Magnetic nanoparticles (MNPs) associated with the labeled oligonucleotides were used to increase the efficiency of exogenous oligonucleotide uptake by rooster spermatozoa. We used high-field/high-gradient magnet (NdFeB) to enhance and accelerate exogenous DNA sedimentation at the spermatozoa surface. Flow cytometry analysis was performed to measure viability and percentage of exogenous oligonucleotide uptake by sperm. Flow cytometry analysis showed a significant increase in exogenous oligonucleotide uptake by rooster spermatozoa (Prooster spermatozoa; however unlike others studies, static magnetic field, was not only ineffective to enhance exogenous oligonucleotide uptake by rooster spermatozoa but also led to reduction in efficiency of magnetic nanoparticles in gene transfer.

Reversible uptake of molecular oxygen by heteroligand Co(II)-L-α-amino acid-imidazole systems: equilibrium models at full mass balance.

Science.gov (United States)

Pająk, Marek; Woźniczka, Magdalena; Vogt, Andrzej; Kufelnicki, Aleksander

2017-09-19

The paper examines Co(II)-amino acid-imidazole systems (where amino acid = L-α-amino acid: alanine, asparagine, histidine) which, when in aqueous solutions, activate and reversibly take up dioxygen, while maintaining the structural scheme of the heme group (imidazole as axial ligand and O 2 uptake at the sixth, trans position) thus imitating natural respiratory pigments such as myoglobin and hemoglobin. The oxygenated reaction shows higher reversibility than for Co(II)-amac systems with analogous amino acids without imidazole. Unlike previous investigations of the heteroligand Co(II)-amino acid-imidazole systems, the present study accurately calculates all equilibrium forms present in solution and determines the [Formula: see text]equilibrium constants without using any simplified approximations. The equilibrium concentrations of Co(II), amino acid, imidazole and the formed complex species were calculated using constant data obtained for analogous systems under oxygen-free conditions. Pehametric and volumetric (oxygenation) studies allowed the stoichiometry of O 2 uptake reaction and coordination mode of the central ion in the forming oxygen adduct to be determined. The values of dioxygen uptake equilibrium constants [Formula: see text] were evaluated by applying the full mass balance equations. Investigations of oxygenation of the Co(II)-amino acid-imidazole systems indicated that dioxygen uptake proceeds along with a rise in pH to 9-10. The percentage of reversibility noted after acidification of the solution to the initial pH ranged within ca 30-60% for alanine, 40-70% for asparagine and 50-90% for histidine, with a rising tendency along with the increasing share of amino acid in the Co(II): amino acid: imidazole ratio. Calculations of the share of the free Co(II) ion as well as of the particular complex species existing in solution beside the oxygen adduct (regarding dioxygen bound both reversibly and irreversibly) indicated quite significant values for the

Nitrogen and Phosphorus Plant Uptake During Periods with no Photosynthesis Accounts for About Half of Global Annual Uptake

Science.gov (United States)

Riley, W. J.; Zhu, Q.; Tang, J.

2017-12-01

Uncertainties in current Earth System Model (ESM) predictions of terrestrial carbon-climate feedbacks over the 21st century are as large as, or larger than, any other reported natural system uncertainties. Soil Organic Matter (SOM) decomposition and photosynthesis, the dominant fluxes in this regard, are tightly linked through nutrient availability, and the recent Coupled Model Inter-comparison Project 5 (CMIP5) used for climate change assessment had no credible representations of these constraints. In response, many ESM land models (ESMLMs) have developed dynamic and coupled soil and plant nutrient cycles. Here we quantify terrestrial carbon cycle impacts from well-known observed plant nutrient uptake mechanisms ignored in most current ESMLMs. In particular, we estimate the global role of plant root nutrient competition with microbes and abiotic process at night and during the non-growing season using the ACME land model (ALMv1-ECA-CNP) that explicitly represents these dynamics. We first demonstrate that short-term nutrient uptake dynamics and competition between plants and microbes are accurately predicted by the model compared to 15N and 33P isotopic tracer measurements from more than 20 sites. We then show that global nighttime and non-growing season nitrogen and phosphorus uptake accounts for 46 and 45%, respectively, of annual uptake, with large latitudinal variation. Model experiments show that ignoring these plant uptake periods leads to large positive biases in annual N leaching (globally 58%) and N2O emissions (globally 68%). Biases these large will affect modeled carbon cycle dynamics over time, and lead to predictions of ecosystems that have overly open nutrient cycles and therefore lower capacity to sequester carbon.

Studies on the evaluation of renal function in hydronephrosis with 99mTc-DMSA renal uptake

International Nuclear Information System (INIS)

Takeda, Masayuki; Katayama, Yasushi; Takahashi, Hitoshi; Sato, Shotaro

1988-01-01

99m Tc-dimercaptosuccinic acid renal uptake (DMSA uptake) was measured in patients with hydronephrosis and we obtained the following conclusions. 1. Grades of hydronephrosis on IVP according to Oka's classification were compared with DMSA uptake. In 73 adult patients, the grade of hydronephrosis paralleled DMSA uptake well, but in 20 children it did not. 2. The changes of DMSA uptake pre- and post-nephrostomy were measured in 21 kidneys in 19 cases with congenital hydronephrosis. DMSA uptake of 7 infantile kidneys significantly increased post-nephrostomy, but in the cases over 1 year old significantly decreased after nephrostomy. DMSA uptake of the contralateral kidney significantly increased after nephrostomy in infants, but it did not change in the group over 1 year old. 3. In 15 kidneys of 13 cases with nephrostomy, DMSA uptake during closure and after opening of the nephrostomy catheter and DMSA uptake due to the radioisotope (RI) accumulated in the renal collecting system were measured. In the group over 1 year old, DMSA uptake decreased after opening nephrostomy nearly all and the extent of the decrease almost agreed with DMSA uptake due to RI accumulated in the renal collecting system. But in infants, DMSA uptake increased after opening nephrostomy in most cases and the extent of the change in DMSA uptake did not agree with DMSA uptake due to RI accumulated in the renal collecting system. (author)

Systemic perfusion: a method of enhancing relative tumor uptake of radiolabeled monoclonal antibodies

Energy Technology Data Exchange (ETDEWEB)

Wahl, R.L.; Piko, C.R.; Beers, B.A.; Geatti, O.; Johnson, J.; Sherman, P. (Michigan Univ., Ann Arbor, MI (USA). Dept. of Internal Medicine)

1989-01-01

The authors evaluated the feasibility of systemic vascular perfusion with saline (mimicking plasmapheresis) as a method to enhance tumor-specific monoclonal antibody (MoAb) tumor/background ratios. Perfusion in rats dropped whole-body 5G6.4 levels significantly at both perfusion times. The drop in whole-body radioactivity with perfusion was significantly greater for the animals perfused at 4 h post i.v. 5G6.4 antibody injection (48.3 +- 5.1%) than for those perfused at 24h post i.v. antibody injection (32.9 +- 2.9%). In the nude mice with ovarian cancer xenografts, gamma camera images of tumors were visually and quantitatively by computer image analysis enhanced by perfusion, with a 2.33-fold greater decline in whole body uptake than in the tumor. These studies show that much background antibody radioactivity can be removed using whole-body perfusion with saline, that the decline in whole body activity is larger with 4 than 24h perfusion and that tumor imaging can be enhanced by this approach. This and similar approaches that increase relative tumor antibody uptake such as plasmapheresis may be useful in imaging and therapy with radiolabeled antibodies.

Determination of maximum physiologic thyroid uptake and correlation with 24-hour RAI uptake value

International Nuclear Information System (INIS)

Duldulao, M.; Obaldo, J.

2007-01-01

Full text: In hyperthyroid patients, thyroid uptake values are overestimated, sometimes approaching or exceeding 100%. This is physiologically and mathematically impossible. This study was undertaken to determine the maximum physiologic thyroid uptake value through a proposed simple method using a gamma camera. Methodology: Twenty-two patients (17 females and 5 males), with ages ranging from 19-61 y/o (mean age ± SD; 41 ± 12), with 24-hour uptake value of >50%, clinically hyperthyroid and referred for subsequent radioactive iodine therapy were studied. The computed maximum physiologic thyroid uptake was compared with the 24-hour uptake using the paired Student t-test and evaluated using linear regression analysis. Results: The computed physiologic uptake correlated poorly with the 24-hour uptake value. However, in the male subgroup, there was no statistically significant difference between the two (p=0.77). Linear regression analysis gives the following relationship: physiologic uptake (%) = 77.76 - 0.284 (24-hour RAI uptake value). Conclusion: Provided that proper regions of interest are applied with correct attenuation and background subtraction, determination of physiologic thyroid uptake may be obtained using the proposed method. This simple method may be useful prior to I-131 therapy for hyperthyroidism especially when a single uptake determination is performed. (author)

Human-centered design of the human-system interfaces of medical equipment: thyroid uptake system

International Nuclear Information System (INIS)

Monteiro, Jonathan K.R.; Farias, Marcos S.; Santos, Isaac J.A. Luquetti; Monteiro, Beany G.

2013-01-01

Technology plays an important role in modern medical centers, making healthcare increasingly complex, relying on complex technical equipment. This technical complexity is particularly noticeable in the nuclear medicine. Poorly design human-system interfaces can increase the risks for human error. The human-centered approach emphasizes the development of the equipment with a deep understanding of the users activities, current work practices, needs and abilities of the users. An important concept of human-centered design is that the ease-of-use of the equipment can be ensured only if users are actively incorporated in all phases of the life cycle of design process. Representative groups of users are exposed to the equipment at various stages in development, in a variety of testing, evaluation and interviewing situations. The users feedback obtained is then used to refine the design, with the result serving as input to the next interaction of design process. The limits of the approach are that the users cannot address any particular future needs without prior experience or knowledge about the equipment operation. The aim of this paper is to present a methodological framework that contributes to the design of the human-system interfaces, through an approach related to the users and their activities. A case study is described in which the methodological framework is being applied in development of new human-system interfaces of the thyroid uptake system. (author)

Self-microemulsifying drug delivery system for improving the bioavailability of huperzine A by lymphatic uptake

Directory of Open Access Journals (Sweden)

Fang Li

2017-05-01

Full Text Available Huperzine A (Hup-A is a poorly water-soluble drug with low oral bioavailability. A self-microemulsifying drug delivery system (SMEDDS was used to enhance the oral bioavailability and lymphatic uptake and transport of Hup-A. A single-pass intestinal perfusion (SPIP technique and a chylomicron flow-blocking approach were used to study its intestinal absorption, mesenteric lymph node distribution and intestinal lymphatic uptake. The value of the area under the plasma concentration–time curve (AUC of Hup-A SMEDDS was significantly higher than that of a Hup-A suspension (P<0.01. The absorption rate constant (Ka and the apparent permeability coefficient (Papp for Hup-A in different parts of the intestine suggested a passive transport mechanism, and the values of Ka and Papp of Hup-A SMEDDS in the ileum were much higher than those in other intestinal segments. The determination of Hup-A concentration in mesenteric lymph nodes can be used to explain the intestinal lymphatic absorption of Hup-A SMEDDS. For Hup-A SMEDDS, the values of AUC and maximum plasma concentration (Cmax of the blocking model were significantly lower than those of the control model (P<0.05. The proportion of lymphatic transport of Hup-A SMEDDS and Hup-A suspension were about 40% and 5%, respectively, suggesting that SMEDDS can significantly improve the intestinal lymphatic uptake and transport of Hup-A.

Uranium uptake history, open-system behaviour and uranium-series ages of fossil Tridacna gigas from Huon Peninsula, Papua New Guinea

Science.gov (United States)

Ayling, Bridget F.; Eggins, Stephen; McCulloch, Malcolm T.; Chappell, John; Grün, Rainer; Mortimer, Graham

2017-09-01

Molluscs incorporate negligible uranium into their skeleton while they are living, with any uranium uptake occurring post-mortem. As such, closed-system U-series dating of molluscs is unlikely to provide reliable age constraints for marine deposits. Even the application of open-system U-series modelling is challenging, because uranium uptake and loss histories can affect time-integrated uranium distributions and are difficult to constrain. We investigate the chemical and isotopic distribution of uranium in fossil Tridacna gigas (giant clams) from Marine Isotope Stage (MIS) 5e (128-116 ka) and MIS 11 (424-374 ka) reefs at Huon Peninsula in Papua New Guinea. The large size of the clams enables detailed chemical and isotopic mapping of uranium using LA-ICPMS and LA-MC-ICPMS techniques. Within each fossil Tridacna specimen, marked differences in uranium concentrations are observed across the three Tridacna growth zones (outer, inner, hinge), with the outer and hinge zones being relatively enriched. In MIS 5e and MIS 11 Tridacna, the outer and hinge zones contain approximately 1 ppm and 5 ppm uranium respectively. In addition to uptake of uranium, loss of uranium appears prevalent, especially in the MIS 11 specimens. The effect of uranium loss is to elevate measured [230Th/238U] values with little effect on [234U/238U] values. Closed-system age estimates are on average 50% too young for the MIS 5e Tridacna, and 25% too young for the MIS 11 Tridacna. A complex, multi-stage uptake and loss history is interpreted for the fossil Tridacna and we demonstrate that they cannot provide independent, reliable geochronological controls on the timing of past reef growth at Huon Peninsula.

Circadian rhythm in ''1''5O-labeled water uptake manner of a soybean plant by PETIS (Positron Emitting Tracer Imaging System)

International Nuclear Information System (INIS)

Nakanishi, Tomoko M.; Yokota, Harumi; Tanoi, Keitaro; Furukawa, Jun; Ikeue, Natsuko; Ookuni, Yoko; Uchida, Hiroshi; Tsuji, Atsunori

2001-01-01

We present a circadian rhythm of water uptake manner in a soybean plant through realtime imaging of water, labeled with 15 O. Nitrogen gas was irradiated with deuterons accelerated by a cyclotron at Hamamatsu Photonics Co. to produce 15 O-labeled water. Then the 15 O-labeled water was supplied to a soybean plant from the root and the realtime water uptake amount was measured for 20 min by Positron Emitting Tracer Imaging System (PETIS). All the targeting positions for the measurements were stems, two points at an internode between root and the first leaves, between the first leaves and the first trifoliates and between the first trifoliates and the second trifoliates. The water uptake amount was gradually increased and showed its maximum at around 13:00, especially at the basal part of the stem. Then the water uptake activity was gradually decreased until 17:00. The water amount taken up by a plant at 13:00 was about 40% higher than that at 17:00. (author)

Synthesis and luminescent spectroscopy of lanthanide complexes with dimethylpyridine-2,6-dicarboxylate (dmpc)

Energy Technology Data Exchange (ETDEWEB)

Taha, Ziyad A., E-mail: tahaz33@just.edu.jo [Department of Applied Chemical Sciences, Faculty of Arts and Sciences, Jordan University of Science and Technology, Irbid 22110 (Jordan); Ajlouni, Abdulaziz M.; Hijazi, Ahmed K. [Department of Applied Chemical Sciences, Faculty of Arts and Sciences, Jordan University of Science and Technology, Irbid 22110 (Jordan); Al-Rawashdeh, Nathir A. [Department of Applied Chemical Sciences, Faculty of Arts and Sciences, Jordan University of Science and Technology, Irbid 22110 (Jordan); Department of Chemistry, United Arab Emirates University, Al Ain 15551 (United Arab Emirates); Al-Hassan, Khader A.; Al-Haj, Yaser A. [Department of Chemistry, Faculty of Science, Yarmouk University, 1163 Irbid (Jordan); Ebqa' ai, Mohammad A. [Al-Qunfudah Center For Scientific Research, Umm Al-Qura University, College in Al-Qunfudah, Makkah (Saudi Arabia); Altalafha, Ammar Y. [Department of Chemistry, Faculty of Science, Yarmouk University, 1163 Irbid (Jordan)

2015-05-15

A series of lanthanide complexes with the general formulae [Ln(dmpc)(NO{sub 3}){sub 2}(H{sub 2}O){sub 2}]NO{sub 3} (Ln=Pr, Nd, Sm, Eu, Gd, Tb, Dy, and Er) and [La(dmpc)(NO{sub 3}){sub 2}(H{sub 2}O){sub 2}]NO{sub 3} were prepared by direct reaction between hydrated lanthanide(III) nitrate and dimethylpyridine-2,6-dicarboxylate (dmpc) in a 1:1 M ratio in ethylacetate–chloroform mixture. The luminescence properties of the dmpc and its Ln(III) complexes were investigated in solid state and in methanol, DMF and DMSO solutions. The Tb–dmpc, Eu–dmpc, Sm–dmpc and Dy–dmpc complexes exhibit characteristic luminescence of Tb(III), Eu(III), Sm(III) and Dy(III) ions indicating energy transfer from the dmpc to the Ln(III) ions. Scavenging activities of the dmpc and its Ln(III) complexes on DPPH{sup •} free radical were investigated in DMSO solution at a different concentrations ranges. - Highlights: • Nine new lanthanide complexes with dmpc ligand are prepared and characterized. • Ln–dmpc {Ln=Eu, Tb, Sm, Dy} complexes exhibit characteristic emissions of Ln ions. • The solvent effect on the luminescence intensity is investigated. • The antioxidant activity of the dmpc is enhanced upon complexation with lanthanide.

Uptake of gold nanoparticles in primary human endothelial cells

DEFF Research Database (Denmark)

Klingberg, Henrik; Oddershede, Lene B.; Löschner, Katrin

2015-01-01

Gold nanoparticles (AuNPs) are relevant in nanomedicine for drug delivery in the vascular system, where endothelial cells are the first point of contact. We investigated the uptake of 80 nm AuNPs in primary human umbilical vein endothelial cells (HUVECs) by flow cytometry, 3D confocal microscopy......–3 or more particles. Pre-treatment with chlorpromazine inhibited the AuNP-uptake in HUVECs, indicating that internalisation occurred mainly by clathrin-mediated endocytosis. Cell activation by exposure to tumour necrosis factor or lipopolysaccharide had a slight or no effect on the uptake of Au...

Ocean carbon uptake and storage

International Nuclear Information System (INIS)

Tilbrook, Bronte

2007-01-01

Full text: The ocean contains about 95% of the carbon in the atmosphere, ocean and land biosphere system, and is of fundamental importance in regulating atmospheric carbon dioxide concentrations. In the 1990s an international research effort involving Australia was established to determine the uptake and storage of anthropogenic C02 for all major ocean basins. The research showed that about 118 of the 244 + 20 billion tons of the anthropogenic carbon emitted through fossil fuel burning and cement production has been stored in the ocean since preindustrial times, thus helping reduce the rate of increase in atmospheric C02. The research also showed the terrestrial biosphere has been a small net source of C02 (39 ± 28 billion tons carbon) to the atmosphere over the same period. About 60% of the total ocean inventory of the anthropogenic C02 was found in the Southern Hemisphere, with most in the 30 0 S to 50 0 S latitude band. This mid-latitude band is where surface waters are subducted as Mode and Intermediate waters, which is a major pathway controlling ocean C02 uptake. High storage (23% of the total) also occurs in the North Atlantic, associated with deep water formation in that basin. The ocean uptake and storage is expected to increase in the coming decades as atmospheric C02 concentrations rise. However, a number of feedback mechanisms associated with surface warming, changes in circulation, and biological effects are likely to impact on the uptake capacity. The accumulation or storage-of the C02 in the ocean is also the major driver of ocean acidification with potential to disrupt marine ecosystems. This talk will describe the current understanding of the ocean C02 uptake and storage and a new international research strategy to detect how the ocean uptake and storage will evolve on interannual through decadal scales. Understanding the ocean response to increasing atmospheric C02 will be a key element in managing future C02 increases and establishing

Uptake of cadmium from hydroponic solutions by willows (Salix spp ...

African Journals Online (AJOL)

DR. NJ TONUKARI

2011-11-16

Nov 16, 2011 ... which indicated that cadmium uptake across the plasma membrane was ... to cadmium pollution in water-soil-plant systems because .... plants were separated into roots and shoots, blotted dry with paper tissue .... Analysis of the kinetic constants for cadmium uptake ..... proteins (Welch and Norvell, 1999).

Bacterial uptake of photosynthetic carbon from freshwater phytoplankton

International Nuclear Information System (INIS)

Coveney, M.F.

1982-01-01

Microheterotrophic uptake of algal extracellular products was studied in two eutrophic lakes in southern Sweden. Size fractionation was used in H 14 CO 3 uptake experiments to measure 14 C fixation in total particulate, small particulate and dissolved organic fractions. Carbon fixed in algal photosynthesis was recovered as dissolved and small particulate 14 C, representing excretion and bacterial uptake of algal products. Estimated gross extracellular release was low in these eutrophic systems, 1 to 7% of total 14 C uptake per m 2 lake surface. From 28 to 80 % of 14 C released was recovered in the small particulate fraction after ca. 4h incubation.This percentage was uniform within each depth profile, but varied directly with in situ water temperature. Laboratory time-series incubations indicated steady state for the pool of algal extracellular products on one occasion, while increasing pool size was indicated in the remaining two experiments. Uptake of photosynthetic carbon to small particles in situ was 32 to 95% of estimted heterotrophic bacterial production (as dark 14 CO 2 uptake) on four occasions. While excretion apparently was not an important loss of cabon for phytoplankton, it may have represented an important carbon source for planktonic bacteria. (author)

Physiological conditions and uptake of inorganic carbon-14 by plant roots

International Nuclear Information System (INIS)

Amiro, B.D.; Ewing, L.L.

1992-01-01

The uptake of inorganic 14 C by bean plant roots was measured. The plants were grown in a nutrient solution culture at pH 6 and a NaH 14 CO 3 tracer was added to the growth medium. Photosynthesis and transpiration were varied by exposing the aerial portions of the plants to different atmospheric CO 2 concentrations, humidities and light levels in a cuvette system. Leaf concentrations of 14 C were measured at the end of the experiments using liquid scintillation counting. Plant uptake of 14 C via the roots was independent of the photosynthetic rate and, in most cases, could be predicted by knowing the transpiration rate and the nutrient solution concentration. However, when a less efficient root-medium aeration system was used, 14 C uptake was greater than that predicted using transpiration, a phenomenon observed by other researchers. This contrasted to results of another experiment where the measured uptake of iodine was much slower than that predicted using transpiration. Knowledge of transpiration rates is useful in predicting inorganic carbon uptake via the roots and in estimating 14 C transport from contaminated soils to biota. Also, the independence of the uptake from photosynthesis and ambient CO 2 concentrations suggests that future increases in atmospheric CO 2 concentrations may not have a direct effect on root uptake of soil carbon. (author)

Systemic uptake and clearance of chloroform by hairless rats following dermal exposure. I. Brief exposure to aqueous solutions.

Science.gov (United States)

Islam, M S; Zhao, L; Zhou, J; Dong, L; McDougal, J N; Flynn, G L

1996-06-01

The systemic uptake of chloroform from dilute aqueous solutions into live hairless rats under conditions simulating dermal environmental exposure was studied. Whole blood was sampled during a 30-min immersion of an animal within water containing a known concentration of chloroform and then for 5.5 h following its removal from the bath. The amount of chloroform systemically absorbed was determined by comparing the AUCs of the blood concentration vs. time plots from dermal exposure to that obtained after i.v. infusion (for a period of 30 min) of an aqueous solution containing a known amount of chloroform (positive control). Although dermal data implied two-compartment disposition characteristics, i.v. infusion data fit best to a three-compartment disposition. Linear pharmacokinetics was observed both by i.v. administration and percutaneous absorption at the dose levels studied. Chloroform was detected in the rat blood as early as 4 min following exposure. Our findings suggest that about 10.2 mg of chloroform was systemically absorbed after dermal exposure of a rat to an aqueous solution of 0.44 mg/ml. This amount is substantially higher than the predictions of mathematical risk-models put forth by some investigators. However, when expressed as the "effective" permeability coefficient (Kpeff), close agreement was noticed between our value and those estimated by others using physiologically based pharmacokinetic (PBPK) models. Also, in terms of Kpeff, reasonable agreement existed between our and another investigator's past estimates of uptake based on depletion of bath level of chloroform and the actual uptake measured in our current experiments. The estimated onset of systemic entry seen here is entirely consistent with our estimate of how long it takes to establish the diffusion gradient across the stratum corneum based on tape stripping.

Uptake and depuration of pharmaceuticals in aquatic invertebrates

International Nuclear Information System (INIS)

Meredith-Williams, Melanie; Carter, Laura J.; Fussell, Richard; Raffaelli, David; Ashauer, Roman; Boxall, Alistair B.A.

2012-01-01

The uptake and depuration of a range of pharmaceuticals in the freshwater shrimp (Gammarus pulex) and the water boatman (Notonecta glauca) was studied. For one compound, studies were also done using the freshwater snail Planobarius corneus. In G. pulex, bioconcentration factors (BCFs) ranged from 4.6 to 185,900 and increased in the order moclobemide < 5-fluoruracil < carbamazepine < diazepam < carvedilol < fluoxetine. In N. glauca BCFs ranged from 0.1 to 1.6 and increased in the order 5-fluorouracil < carbamazepine < moclobemide < diazepam < fluoxetine < carvedilol. For P. corneus, the BCF for carvedilol was 57.3. The differences in degree of uptake across the three organisms may be due to differences in mode of respiration, behaviour and the pH of the test system. BCFs of the pharmaceuticals for each organism were correlated to the pH-corrected liposome–water partition coefficient of the pharmaceuticals. - Highlights: ► One of the first studies exploring the uptake of pharmaceuticals into aquatic invertebrates. ► Data presented on uptake, depuration rates and bioconcentration for a range of pharmaceuticals. ► Uptake is correlated with the pH-corrected liposome–water partition coefficient. ► Findings can be used to better predict impacts of pharmaceuticals on the aquatic environment. - The factors affecting the degree of uptake of pharmaceuticals into aquatic invertebrates were studied. The results indicate that species traits such as respiration and behaviour of the organisms and pH-corrected liposome–water partition coefficients are important factors in determining pharmaceutical uptake.

Cloning, expression, and characterization of cadmium and manganese uptake genes from Lactobacillus plantarum

Energy Technology Data Exchange (ETDEWEB)

Hao, Z.; Chen, S.; Wilson, D.B.

1999-11-01

An Mn{sup 2+} and Cd{sup 2+} uptake gene, mntA, was cloned from Lactobacillus plantarum ATCC 14917 into Escherichia coli. Its expression conferred on E. coli cells increased Cd{sup 2+} sensitivity as well as energy-dependent Cd{sup 2+} uptake activity. Both transcription and translation of mntA were induced by Mn{sup 2+} starvation in L. plantarum, as indicated by reverse transcriptase PCR and immunoblotting. Two Cd{sup 2+} uptake systems have been identified in L. plantarum: one is a high-affinity Mn{sup 2+} and Cd{sup 2+} uptake system that is expressed in Mn{sup 2+}-starved cells, and the other is a nonsaturable Cd{sup 2+} uptake system that is expressed in Cd{sup 2+}-sufficient cells. MntA was not detected in an Mn{sup 2+}-dependent mutant of L. plantarum which had lost high-affinity Mn{sup 2+} and Cd{sup 2+} uptake activity. The results suggest that mntA is the gene encoding the high-affinity Mn{sup 2+} and Cd{sup 2+} transporter. On the basis of its predicted amino acid sequence, MntA belongs to the family of P-type cation-translocating ATPases. The topology and potential Mn{sup 2+}- and Cd{sup 2+}-binding sites of MntA are discussed. A second clone containing a low-affinity Cd{sup 2+} transport system was also isolated.

In situ synthesis of Prussian blue nanoparticles within a biocompatible reverse micellar system for in vivo Cs"+ uptake

International Nuclear Information System (INIS)

Lavaud, Cyril; Kajdan, Marilyn; Long, Jerome; Larionova, Joulia; Guari, Yannick; Compte, Elsa; Maurel, Jean-Claude; Him, Josephine Lai Kee; Bron, Patrick; Oliviero, Erwan

2017-01-01

A new highly stable Prussian blue reverse micellar system comprising ultra-small Prussian blue nanoparticles in Aonyss (Peceolt, b-sitosterol, lecithin, ethanol and water) acts as an in vivo Cs"+ uptake agent presenting higher efficiency compared to commercially available Prussian blue treatment with a significant dose effect. (authors)

Thyroid Scan and Uptake

Medline Plus

Full Text Available ... for a thyroid scan is 30 minutes or less. Thyroid Uptake You will be given radioactive iodine (I-123 or I-131) in liquid or capsule form to swallow. The thyroid uptake will begin several hours to 24 hours later. Often, two separate uptake ...

Kinetic parameters of silicon uptake by rice cultivars

Directory of Open Access Journals (Sweden)

Priscila Oliveira Martins

2012-02-01

Full Text Available Silicon is considered an important chemical element for rice, because it can improve tolerance to biotic and abiotic stress. However, in many situations no positive effect of silicon was observed, probably due to genetic factors. The objective of this research was to monitor Si uptake kinetics and identify responses of rice cultivars in terms of Si uptake capacity and use. The experiment was carried out in a greenhouse of the São Paulo State University (UNESP, Brazil. The experiment was arranged in a completely randomized, factorial design with three replications. that consisted of two rice cultivars and two Si levels. Kinetic parameters (Vmax, Km, and Cmin, root morphology variables, dry matter yield, Si accumulation and levels in shoots and roots, uptake efficiency, utilization efficiency, and root/shoot ratio were evaluated. Higher Si concentrations in the nutrient solution did not increase rice dry matter. The development of the low-affinity silicon uptake system of the rice cultivar 'Caiapó' was better than of 'Maravilha'.

Barium coordination polymers based on fluorinated and fluorine-free benzene-dicarboxylates: Mechanochemical synthesis and spectroscopic characterization

Science.gov (United States)

Al-Terkawi, Abdal-Azim; Scholz, Gudrun; Emmerling, Franziska; Kemnitz, Erhard

2018-05-01

A series of new Ba-based coordination polymers (CPs) were mechanochemically synthesized by milling Ba-hydroxide samples with perfluorinated and fluorine-free benzene-dicarboxylic acids, including tetrafluoroisophthalic acid (H2mBDC-F4), tetrafluorophthalic acid (H2oBDC-F4), isophthalic acid (H2mBDC) and phthalic acid (H2oBDC). The new fluorinated CPs: [Ba(mBDC-F4)·0.5H2O] (1) and [Ba(oBDC-F4)·1.5H2O] (2) are compared to their nonfluorinated counterparts: [Ba(mBDC)·2.5H2O] (3), and [Ba(oBDC)·1H2O] (4). These materials are thoroughly characterized using powder X-ray diffraction. The products obtained by milling are all hydrated but vary in their water contents. Compositions and local structures are investigated by elemental analysis, thermal analysis, MAS NMR and attenuated total reflection-infrared spectroscopy. These materials exhibit high thermal stabilities but small surface areas that remain unchanged even after thermal treatments.

2,1,3-benzothiadiazole-5,6-dicarboxylic imide - A versatile building block for additive- and annealing-free processing of organic solar cells with effi ciencies exceeding 8%

KAUST Repository

Nielsen, Christian Bergenstof

2014-12-15

A new photoactive polymer comprising benzo[1,2-b:3,4-b′:5,6-d′]trithiophene and 2,1,3-benzothiadiazole-5,6-dicarboxylic imide is reported. The synthetic design allows for alkyl chains to be introduced on both electron-rich and electron-deficient components, which in turn allows for rapid optimization of the alkyl chain substitution pattern. Consequently, the optimized polymer shows a maximum efficiency of 8.3% in organic photovoltaic devices processed in commercially viable fashion without solvent additives, annealing, or device engineering.

2,1,3-benzothiadiazole-5,6-dicarboxylic imide - A versatile building block for additive- and annealing-free processing of organic solar cells with effi ciencies exceeding 8%

KAUST Repository

Nielsen, Christian Bergenstof; Ashraf, Raja Shahid; Treat, Neil D.; Schroeder, Bob C.; Donaghey, Jenny E.; White, Andrew J P; Stingelin, Natalie; McCulloch, Iain

2014-01-01

A new photoactive polymer comprising benzo[1,2-b:3,4-b′:5,6-d′]trithiophene and 2,1,3-benzothiadiazole-5,6-dicarboxylic imide is reported. The synthetic design allows for alkyl chains to be introduced on both electron-rich and electron-deficient components, which in turn allows for rapid optimization of the alkyl chain substitution pattern. Consequently, the optimized polymer shows a maximum efficiency of 8.3% in organic photovoltaic devices processed in commercially viable fashion without solvent additives, annealing, or device engineering.

Luminescence of uranyl ion complexed with 2,6-pyridine dicarboxylic acid as ligand in acetonitrile medium. Observation of co-luminescence

Energy Technology Data Exchange (ETDEWEB)

Maji, Siuli; Kumar, Satendra; Sankaran, Kannan [Indira Ghandi Centre for Atomic Research, Tamil Nadu (India). Materials Chemistry Div.

2017-10-01

Luminescence from UO{sub 2}{sup 2+} (uranyl ion) complexed with 2,6-pyridine dicarboxylic acid (PDA) has been studied using acetonitrile (MeCN) as solvent between pH 1.0 and 6.0. The enhancement in luminescence intensity because of sensitization by PDA in the non-aqueous environment provided by the MeCN is found to be one order better than in aqueous medium. The luminescence is further enhanced by about four times following the addition of Y{sup 3+}; a process known as co-luminescence. This is the first study on co-luminescence of uranyl ion in its PDA complex. Lifetime studies indicate the presence of two species having different micro-environments. Formations of both intra and inter molecular complexes are believed to be responsible for enhancement due to co-luminescence.

Luminescence of uranyl ion complexed with 2,6-pyridine dicarboxylic acid as ligand in acetonitrile medium. Observation of co-luminescence

International Nuclear Information System (INIS)

Maji, Siuli; Kumar, Satendra; Sankaran, Kannan

2017-01-01

Luminescence from UO_2"2"+ (uranyl ion) complexed with 2,6-pyridine dicarboxylic acid (PDA) has been studied using acetonitrile (MeCN) as solvent between pH 1.0 and 6.0. The enhancement in luminescence intensity because of sensitization by PDA in the non-aqueous environment provided by the MeCN is found to be one order better than in aqueous medium. The luminescence is further enhanced by about four times following the addition of Y"3"+; a process known as co-luminescence. This is the first study on co-luminescence of uranyl ion in its PDA complex. Lifetime studies indicate the presence of two species having different micro-environments. Formations of both intra and inter molecular complexes are believed to be responsible for enhancement due to co-luminescence.

Distribution of 3H-GABA uptake sites in the nematode Ascaris

International Nuclear Information System (INIS)

Guastella, J.; Stretton, A.O.

1991-01-01

The distribution of uptake sites for the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) in the nematode Ascaris suum was examined by autoradiography of 3H-GABA uptake. Single neural processes in both the ventral and dorsal nerve cords were labeled with 3H-GABA. Serial section analysis identified the cells of origin of these processes as the RMEV-like and RMED-like neurons. These cells belong to a set of four neurons in the nerve ring, all of which are labeled by 3H-GABA. 3H-GABA labeling of at least two other sets of cephalic neurons was seen. One of these pairs consists of medium-sized lateral ganglia neurons, located at the level of the amphid commissure bundle. A second pair is located in the lateral ganglia at the level of the deirid commissure bundle. The position and size of these lateral ganglia cells suggest that they are the GABA-immunoreactive lateral ganglia cells frequently seen in whole-mount immunocytochemical preparations. Four neuronal cell bodies located in the retrovesicular ganglion were also labeled with 3H-GABA. These cells, which are probably cholinergic excitatory motor neurons, do not contain detectable GABA-like immunoreactivity. Heavy labeling of muscle cells was also observed. The ventral and dorsal nerve cord inhibitory motor neurons, which are known to contain GABA-like immunoreactivity, were not labeled above background with 3H-GABA. Together with the experiments reported previously, these results define three classes of GABA-associated neurons in Ascaris: (1) neurons that contain endogenous GABA and possess a GABA uptake system; (2) neurons that contain endogenous GABA, but that either lack a GABA uptake system or possess a GABA uptake system of low activity; (3) neurons that possess a GABA uptake system, but that lack endogenous GABA

Chromium speciation, bioavailability, uptake, toxicity and detoxification in soil-plant system: A review.

Science.gov (United States)

Shahid, Muhammad; Shamshad, Saliha; Rafiq, Marina; Khalid, Sana; Bibi, Irshad; Niazi, Nabeel Khan; Dumat, Camille; Rashid, Muhammad Imtiaz

2017-07-01

Chromium (Cr) is a potentially toxic heavy metal which does not have any essential metabolic function in plants. Various past and recent studies highlight the biogeochemistry of Cr in the soil-plant system. This review traces a plausible link among Cr speciation, bioavailability, phytouptake, phytotoxicity and detoxification based on available data, especially published from 2010 to 2016. Chromium occurs in different chemical forms (primarily as chromite (Cr(III)) and chromate (Cr(VI)) in soil which vary markedly in term of their biogeochemical behavior. Chromium behavior in soil, its soil-plant transfer and accumulation in different plant parts vary with its chemical form, plant type and soil physico-chemical properties. Soil microbial community plays a key role in governing Cr speciation and behavior in soil. Chromium does not have any specific transporter for its uptake by plants and it primarily enters the plants through specific and non-specific channels of essential ions. Chromium accumulates predominantly in plant root tissues with very limited translocation to shoots. Inside plants, Cr provokes numerous deleterious effects to several physiological, morphological, and biochemical processes. Chromium induces phytotoxicity by interfering plant growth, nutrient uptake and photosynthesis, inducing enhanced generation of reactive oxygen species, causing lipid peroxidation and altering the antioxidant activities. Plants tolerate Cr toxicity via various defense mechanisms such as complexation by organic ligands, compartmentation into the vacuole, and scavenging ROS via antioxidative enzymes. Consumption of Cr-contaminated-food can cause human health risks by inducing severe clinical conditions. Therefore, there is a dire need to monitor biogeochemical behavior of Cr in soil-plant system. Copyright © 2017 Elsevier Ltd. All rights reserved.

Amino Acid Transporters and Release of Hydrophobic Amino Acids in the Heterocyst-Forming Cyanobacterium Anabaena sp. Strain PCC 7120

Directory of Open Access Journals (Sweden)

Rafael Pernil

2015-04-01

Full Text Available Anabaena sp. strain PCC 7120 is a filamentous cyanobacterium that can use inorganic compounds such as nitrate or ammonium as nitrogen sources. In the absence of combined nitrogen, it can fix N2 in differentiated cells called heterocysts. Anabaena also shows substantial activities of amino acid uptake, and three ABC-type transporters for amino acids have been previously characterized. Seven new loci encoding predicted amino acid transporters were identified in the Anabaena genomic sequence and inactivated. Two of them were involved in amino acid uptake. Locus alr2535-alr2541 encodes the elements of a hydrophobic amino acid ABC-type transporter that is mainly involved in the uptake of glycine. ORF all0342 encodes a putative transporter from the dicarboxylate/amino acid:cation symporter (DAACS family whose inactivation resulted in an increased uptake of a broad range of amino acids. An assay to study amino acid release from Anabaena filaments to the external medium was set up. Net release of the alanine analogue α-aminoisobutyric acid (AIB was observed when transport system N-I (a hydrophobic amino acid ABC-type transporter was engaged in the uptake of a specific substrate. The rate of AIB release was directly proportional to the intracellular AIB concentration, suggesting leakage from the cells by diffusion.

Identification and Functional Characterization of a Tonoplast Dicarboxylate Transporter in Tomato (Solanum lycopersicum).

Science.gov (United States)

Liu, Ruiling; Li, Boqiang; Qin, Guozheng; Zhang, Zhanquan; Tian, Shiping

2017-01-01

Acidity plays an important role in flavor and overall organoleptic quality of fruit and is mainly due to the presence of organic acids. Understanding the molecular basis of organic acid metabolism is thus of primary importance for fruit quality improvement. Here, we cloned a putative tonoplast dicarboxylate transporter gene ( SlTDT ) from tomato, and submitted it to the NCBI database (GenBank accession number: KC733165). SlTDT protein contained 13 putative transmembrane domains in silico analysis. Confocal microscopic study using green fluorescent fusion proteins revealed that SlTDT was localized on tonoplast. The expression patterns of SlTDT in tomato were analyzed by RT-qPCR. The results indicated that SlTDT expressed in leaves, roots, flowers and fruits at different ripening stages, suggesting SlTDT may be associated with the development of different tissues. To further explore the function of SlTDT , we constructed both overexpression and RNAi vectors and obtained transgenic tomato plants by agrobacterium-mediated method. Gas chromatography-mass spectrometer (GC-MS) analysis showed that overexpression of SlTDT significantly increased malate content, and reduced citrate content in tomato fruit. By contrast, repression of SlTDT in tomato reduced malate content of and increased citrate content. These results indicated that SlTDT played an important role in remobilization of malate and citrate in fruit vacuoles.

Three new 5-fold interpenetrating diamondoid frameworks constructed by rigid diimidazole and dicarboxylate ligands

Science.gov (United States)

Huo, Jianqiang; Yan, Shuai; Li, Haiqiang; Yu, Donghui; Arulsamy, Navamoney

2018-03-01

A series of three-dimensional coordination polymers, namely, [Cd(BIMB)(SCA)]n (1), [M(BIMB)(trans-CHDC)]n (2, M = Cd2+; 3, M = Co2+), where BIMB = 1,4-di(1H-imidazol-1-yl)benzene, SCA2- = succinate dianion, CHDC2- = cyclohexane-1,4-dicarboxylate dianion) are synthesized hydro/solvatothermal methods. The products are characterized by elemental analysis and single-crystal X-ray diffraction data. Both the dianion and BIMB bridge different pairs of the metal ions, the three complexes are polymeric and their three-dimensional topology feature a diamond-like metal-organic framework (MOF). Owing to the length of the two bridging ligands, moderate size voids are formed in the diamondoid networks. However, the voids are filled by mutual interpenetration of four independent equivalent frameworks in a 5-fold interpenetrating architecture, and there is no sufficient void volume available for any guest molecules. The phase purity and thermal stability of the compounds are verified by powder X-ray diffraction (PXRD) and thermogravimetric (TG) data. The solid-state fluorescence spectra for the 3d10 Cd2+ MOF's 1 and 2 reveal significant enhancement in their emission intensities in comparison to the non-metallated BIMB. The enhanced emission is attributed to perturbation of intra-ligand emission states due to Cd2+ coordination.

Three PbII coordination polymers based on 2-(pyridin-2-yl)-1H-imidazole-4,5-dicarboxylic acid: Syntheses, crystal structures, and fluorescent properties

International Nuclear Information System (INIS)

Yu, Xiao-Yang; Xin, Rui; Gao, Wei-Ping; Wang, Na; Zhang, Xiao; Yang, Yan-Yan; Qu, Xiao-Shu

2013-01-01

Three lead coordination polymers, [PbCl(C 10 H 6 N 3 O 4 )(H 2 O)·H 2 O] n (1), [Pb(C 10 H 6 N 3 O 4 ) 2 (H 2 O)] n (2) and [Pb 3 (C 10 H 5 N 3 O 4 ) 3 ] n (3) (C 10 H 7 N 3 O 4 =2-(pyridin-2-yl)-1H-imidazole-4,5-dicarboxylic acid), have been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction. In 1, Cl anions connected neighboring wave-like 2D layers, which are constructed with left- and right-handed helical chains, into a 3D network structure with a (6 3 )(6 5 ·8) topology. In 2, Pb cations are linked into a 3D 6 6 network with left- and right-handed helixes by μ 2 -bridging C 10 H 6 N 3 O 4 − ligands. In 3, C 10 H 5 N 3 O 4 2− ligands link Pb 6 O 12 clusters into a 3D (4 12 ·6 3 ) network. Their fluorescent properties were also investigated. - Graphical abstract: Three 3D lead compounds based on 2-(pyridin-2-yl)-1H-imidazole-4,5-dicarboxylic acid have been hydrothermally synthesized. Four new coordination modes of the organic ligand are first reported. Display Omitted - Highlights: • Three new Pb(II) complexes have been synthesized and characterized. • Left- and right-handed helical chains can be found in the 3D networks of 1 and 2. • Pb 6 O 12 clusters are connected into (4 12 ·6 3 ) network in 3

Accumulation of phenanthrene by roots of intact wheat (Triticum acstivnm L. seedlings: passive or active uptake?

Directory of Open Access Journals (Sweden)

Jiang Ting-Hui

2010-03-01

Full Text Available Abstract Background Polycyclic aromatic hydrocarbons (PAHs are of particular concern due to their hydrophobic, recalcitrant, persistent, potentially carcinogenic, mutagenic and toxic properties, and their ubiquitous occurrence in the environment. Most of the PAHs in the environment are present in surface soil. Plants grown in PAH-contaminated soils or water can become contaminated with PAHs because of their uptake. Therefore, they may threaten human and animal health. However, the mechanism for PAHs uptake by crop roots is little understood. It is important to understand exactly how PAHs are transported into the plant root system and into the human food chain, since it is beneficial in governing crop contamination by PAHs, remedying soils or waters polluted by PAHs with plants, and modeling potential uptake for risk assessment. Results The possibility that plant roots may take up phenanthrene (PHE, a representative of PAHs, via active process was investigated using intact wheat (Triticum acstivnm L. seedlings in a series of hydroponic experiments. The time course for PHE uptake into wheat roots grown in Hoagland solution containing 5.62 μM PHE for 36 h could be separated into two periods: a fast uptake process during the initial 2 h and a slow uptake component thereafter. Concentration-dependent PHE uptake was characterized by a smooth, saturable curve with an apparent Km of 23.7 μM and a Vmax of 208 nmol g-1 fresh weight h-1, suggesting a carrier-mediated uptake system. Competition between PHE and naphthalene for their uptake by the roots further supported the carrier-mediated uptake system. Low temperature and 2,4-dinitrophenol (DNP could inhibit PHE uptake equally, indicating that metabolism plays a role in PHE uptake. The inhibitions by low temperature and DNP were strengthened with increasing concentration of PHE in external solution within PHE water solubility (7.3 μM. The contribution of active uptake to total absorption was almost 40

Carbonation and CO2 uptake of concrete

International Nuclear Information System (INIS)

Yang, Keun-Hyeok; Seo, Eun-A; Tae, Sung-Ho

2014-01-01

This study developed a reliable procedure to assess the carbon dioxide (CO 2 ) uptake of concrete by carbonation during the service life of a structure and by the recycling of concrete after demolition. To generalize the amount of absorbable CO 2 per unit volume of concrete, the molar concentration of carbonatable constituents in hardened cement paste was simplified as a function of the unit content of cement, and the degree of hydration of the cement paste was formulated as a function of the water-to-cement ratio. The contribution of the relative humidity, type of finishing material for the concrete surface, and the substitution level of supplementary cementitious materials to the CO 2 diffusion coefficient in concrete was reflected using various correction factors. The following parameters varying with the recycling scenario were also considered: the carbonatable surface area of concrete crusher-runs and underground phenomena of the decreased CO 2 diffusion coefficient and increased CO 2 concentration. Based on the developed procedure, a case study was conducted for an apartment building with a principal wall system and an office building with a Rahmen system, with the aim of examining the CO 2 uptake of each structural element under different exposure environments during the service life and recycling of the building. As input data necessary for the case study, data collected from actual surveys conducted in 2012 in South Korea were used, which included data on the surrounding environments, lifecycle inventory database, life expectancy of structures, and recycling activity scenario. Ultimately, the CO 2 uptake of concrete during a 100-year lifecycle (life expectancy of 40 years and recycling span of 60 years) was estimated to be 15.5%–17% of the CO 2 emissions from concrete production, which roughly corresponds to 18%–21% of the CO 2 emissions from the production of ordinary Portland cement. - Highlights: • CO 2 uptake assessment approach owing to the

Isopycnal mixing by mesoscale eddies significantly impacts oceanic anthropogenic carbon uptake

Science.gov (United States)

Gnanadesikan, Anand; Pradal, Marie-Aude; Abernathey, Ryan

2015-06-01

Anthropogenic carbon dioxide uptake varies across Earth System Models for reasons that have remained obscure. When varied within a single model, the lateral eddy mixing coefficient ARedi produces a range of uptake similar to the modeled range. The highest uptake, resulting from a simulation with a constant ARedi of 2400 m2/s, simulates 15% more historical carbon uptake than a model with ARedi = 400 m2/s. A sudden doubling in carbon dioxide produces a 21% range in carbon uptake across the models. Two spatially dependent representations of ARedi produce uptake that lies in the middle of the range of constant values despite predicting very large values in the subtropical gyres. One-dimensional diffusive models of the type used for integrated assessments can be fit to the simulations, with ARedi accounting for a substantial fraction of the effective vertical diffusion. Such models, however, mask significant regional changes in stratification and biological carbon storage.

Uptake of oxytetracycline and its phytotoxicity to alfalfa (Medicago sativa L.)

International Nuclear Information System (INIS)

Kong, W.D.; Zhu, Y.G.; Liang, Y.C.; Zhang, J.; Smith, F.A.; Yang, M.

2007-01-01

A series of experiments were conducted in a hydroponic system to investigate the uptake of oxytetracycline (OTC) and its toxicity to alfalfa (Medicago sativa L.). OTC inhibited alfalfa shoot and root growth by up to 61% and 85%, respectively. The kinetics of OTC uptake could be well described by Michaelis-Menten equation with V max of 2.25 μmol g -1 fresh weight h -1 , and K m of 0.036 mM. The uptake of OTC by alfalfa was strongly inhibited by the metabolic inhibitor, 2,4-DNP (2,4-dinitrophenol), at pH 3.5 and 6.0, but not by the aquaporin competitors, glycerol and Ag + . OTC uptake, however, was significantly inhibited by Hg 2+ , suggesting that the inhibition of influx was due to general cellular stress rather than the specific action of Hg 2+ on aquaporins. Results from the present study suggested that OTC uptake into alfalfa is an energy-dependent process. - Plant uptake of antibiotic oxytetracycline is energy-dependent

Diselenolane-mediated cellular uptake.

Science.gov (United States)

Chuard, Nicolas; Poblador-Bahamonde, Amalia I; Zong, Lili; Bartolami, Eline; Hildebrandt, Jana; Weigand, Wolfgang; Sakai, Naomi; Matile, Stefan

2018-02-21

The emerging power of thiol-mediated uptake with strained disulfides called for a move from sulfur to selenium. We report that according to results with fluorescent model substrates, cellular uptake with 1,2-diselenolanes exceeds uptake with 1,2-dithiolanes and epidithiodiketopiperazines with regard to efficiency as well as intracellular localization. The diselenide analog of lipoic acid performs best. This 1,2-diselenolane delivers fluorophores efficiently to the cytosol of HeLa Kyoto cells, without detectable endosomal capture as with 1,2-dithiolanes or dominant escape into the nucleus as with epidithiodiketopiperazines. Diselenolane-mediated cytosolic delivery is non-toxic (MTT assay), sensitive to temperature but insensitive to inhibitors of endocytosis (chlorpromazine, methyl-β-cyclodextrin, wortmannin, cytochalasin B) and conventional thiol-mediated uptake (Ellman's reagent), and to serum. Selenophilicity, the extreme CSeSeC dihedral angle of 0° and the high but different acidity of primary and secondary selenols might all contribute to uptake. Thiol-exchange affinity chromatography is introduced as operational mimic of thiol-mediated uptake that provides, in combination with rate enhancement of DTT oxidation, direct experimental evidence for existence and nature of the involved selenosulfides.

Is there a strategy I iron uptake mechanism in maize?

Science.gov (United States)

Li, Suzhen; Zhou, Xiaojin; Chen, Jingtang; Chen, Rumei

2018-04-03

Iron is a metal micronutrient that is essential for plant growth and development. Graminaceous and nongraminaceous plants have evolved different mechanisms to mediate Fe uptake. Generally, strategy I is used by nongraminaceous plants like Arabidopsis, while graminaceous plants, such as rice, barley, and maize, are considered to use strategy II Fe uptake. Upon the functional characterization of OsIRT1 and OsIRT2 in rice, it was suggested that rice, as an exceptional graminaceous plant, utilizes both strategy I and strategy II Fe uptake systems. Similarly, ZmIRT1 and ZmZIP3 were identified as functional zinc and iron transporters in the maize genome, along with the determination of several genes encoding Zn and Fe transporters, raising the possibility that strategy I Fe uptake also occurs in maize. This mini-review integrates previous reports and recent evidence to obtain a better understanding of the mechanisms of Fe uptake in maize.

[Long-Term Inhibition of FNA on Aerobic Phosphate Uptake and Variation of Phosphorus Uptake Properties of the Sludge].

Science.gov (United States)

Ma, Juan; Li, Lu; Yu, Xiao-jun; Sun, Lei-jun; Sun, Hong-wei; Chen, Yong-zhi

2015-10-01

An alternating anaerobic/oxic ( An/O) sequencing batch reactor (SBR) was employed to investigate the long-term inhibitory effect of free nitrous acid (FNA) on aerobic phosphorus uptake performance and variation of phosphorus uptake properties of the sludge by adding nitrite. The reactor was started up under the condition of 21-23 degrees C. The results showed that FNA had no impact on phosphate release and uptake capacities of the sludge. However, the specific phosphate release/uptake rates was found to be higher. As FNA concentration (measure by HNO2-N) was lower than 0.53 x 10(-3) mg x L(-1), phosphorus removal efficiency of the system was higher than 96.9%. When the FNA concentration was increased to 0.99 x 10(-3) mg x L(-1), 1.46 x 10(-3) mg x L(-1) and 1.94 x 10(-3) mg x L(-1), the phosphorus removal performance deteriorated rapidly. The phosphorus removal efficiency was recovered to 64.42%, 67.33% and 44.14% after 50, 12 and 30 days, respectively, which implied the deterioration of phosphorus removal performance caused by FNA inhibition could be recovered and long-term acclimation could shorten the recovery process. Notably, increasing nitrite consumption appeared during aerobic phase with the concentration of FNA below 1.46 x 10(-3) mg x L(-1). It was also observed that the phosphorus uptake properties of the sludge varied after long-term inhibition. Nitrate and nitrite type anoxic phosphorus uptake capacity was increased by 3.35 and 3.86 times, respectively, suggesting long-term dosing FNA may facilitate the denitrifying of polyphosphate in organisms utilizing nitrite as electron acceptor. Moreover, long-term acclimation favored sludge settling.

Coupling of Groundwater Transport and Plant Uptake Models

DEFF Research Database (Denmark)

Rein, Arno; Bauer-Gottwein, Peter; Trapp, Stefan

2010-01-01

in environmental systems at different scale. Feedback mechanisms between plants and hydrological systems can play an important role, however having received little attention to date. Here, a new model concept for dynamic plant uptake models applying analytical matrix solutions is presented, which can be coupled...

Dynamic plant uptake modelling and mass flux estimation

DEFF Research Database (Denmark)

Rein, Arno; Bauer-Gottwein, Peter; Trapp, Stefan

2011-01-01

in environmental systems at different scales. Feedback mechanisms between plants and hydrological systems can play an important role. However, they have received little attention to date. Here, a new model concept for dynamic plant uptake models applying analytical matrix solutions is presented, which can...

Retinal uptake and release of (/sup 3/H)DABA

Energy Technology Data Exchange (ETDEWEB)

Bauer, B; Ehinger, B [Lund Univ. (Sweden)

1978-03-01

The uptake of (/sup 3/H)DABA was studied in rat, guinea-pig and cat retinas in vivo and in rabbit retinas both in vivo and in vitro by autoradiography. (/sup 3/H)DABA was preferentially accumulated by a type of amacrine cell but after brief incubation or shortly after intravitreal injections there was not only a neuronal uptake but also a glial one. In guinea-pigs the glial labelling in vivo was significant also after 4 hr. The glial uptake (rabbits) was found to be saturable and temperature dependent as expected for an active uptake mechanism. The Ksub(m) of DABA uptake was 2.11 x 10/sup -5/ m and Vsub(max) 2.38 x 10/sup -5/ mol/mg/min. GABA competitively inhibited the DABA uptake. The uptake was not statistically significantly influenced by OMEGA-amino acids such as glycine, ..beta..-alanine, ..cap alpha..-alanine or epsilon-aminocaproic acid. The effect of different stimuli on the spontaneous efflux of radioactivity from (/sup 3/H)DABA preloaded rabbit retinas was studied with (/sup 3/H)DABA localized to neurons. Light flashes evoked a small but not statistically significant increased release whereas 40mM-K/sup +/ evoked an immediate and large increase. Unlabelled DABA, GABA and ..beta..-alanine (10/sup -5/M) increased the spontaneous efflux of (/sup 3/H)DABA but not glycine. It is concluded that there is in the retina of rats, guinea-pigs, cats, and rabbits, a glial high affinity uptake mechanism in addition to the neuronal uptake. DABA seems to be transported by the same mechanism as GABA in both systems. The DABA seems to be better retained in neurons than in glia in rats, cats and rabbits, which allows it to be used as a neuronal marker.

Cases of diffusely increased 18F FDG uptake in bone marrow

International Nuclear Information System (INIS)

Suga, Kazuyoshi; Kawakami, Yasuhiko; Matsunaga, Naofumi

2009-01-01

A whole body imaging of 18 F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT provides assessment of FDG uptake in bone marrow and other systemic organs. Diffuse increase of FDG uptake in bone marrow can be associated with leukocytosis, infection, anemia, administration of granulocyte-colony stimulating factor or erythropoietin. and cytokine-producing neoplasms and myeloproliferative syndromes, and etc, and this finding can be an important sign indicative of hyper-metabolism in hemopoietic tissue associated by various etiology. Diffuse increase of FDG uptake in bone marrow affect on FDG uptake in other organs or primary lesions, and must be differentiated from diffuse bone marrow involvement of malignant tumors. In this paper, we report cases of diffuse increase of FDG uptake in bone marrow experienced in our hospital, and discuss the mechanisms and diagnostic importance of this finding, by referring to the published literatures. (author)

Physiological and tumoral uptake of 68Ga-DOTATATE. Standardized uptake values and challenges in interpretation

International Nuclear Information System (INIS)

Kuyumcu, Serkan; Oezkan, Zeynep Goezde; Sanli, Yasemin; Yilmaz, Ebru; Mudun, Ayse; Adalet, Isik; Unal, Seher

2013-01-01

The objective of this study is to determine the range of standardized uptake value (SUV) max of 68Ga-DOTA-tyr3-octreotate (DOTATATE) in normal organs and tumoral lesions and establish uptake unrelated to neuroendocrine tumors (NET). One hundred and twenty patients (57 men, 63 women), who underwent 68 Ga-DOTATATE positron emission tomography (PET)/CT imaging in our institution were analyzed. Patients were indicated for 68 Ga-DOTATATE PET/CT imaging to detect primary tumor or metastasis of suspected or previously known NET, to determine somatostatin receptor (SSTR) positivity and to detect occult source of ectopic Cushing syndrome. Normal range of uptake was calculated for the organs that were proven to have no pathology by either conventional radiological imaging or clinical follow-up, using SUV max as a semiquantitative measure. Uptake and tumor to background (T/B) ratios of tumoral lesions in liver, pancreas, bone, brain and lymph nodes were calculated. Uptakes due to lesions unrelated to NET were also documented. Significant uptake was found in spleen, kidneys, adrenal glands, liver and pituitary gland with mean SUV max of 24.67, 14.30, 13.73, 9.12 and 9.74 respectively. Uptake was measured separately for the pancreatic head and body separately, however, besides a slightly heterogeneous uptake; the difference was not statistically significant. Uptake in the tumoral lesions had high (T/B) ratios with mean SUV max of 28.72, 25.21, 18.28, 34.73 and 12.59 for liver, pancreas, bone, brain and lymph nodes, respectively. Incidental benign tumoral lesions were detected in 3 patients (2.5%) which were meningioma and fibrous dysplasia demonstrating significant and breast fibroadenoma demonstrating mild 68 Ga-DOTATATE uptake. Non-neoplastic processes were detected in 4 patients (14.1%), including postsurgical inflammation, reactive lymph nodes, arthritis and demonstrated faint to mild 68 Ga-DOTATATE uptake, with the exception of significant uptake in accessory spleen. 68 Ga

Validation of the measurement detection system for thyroid uptake (DETEC-PC)

International Nuclear Information System (INIS)

Alonso Abad, Dolores; Arista Romeu, Eduardo; Bolanos Perez, Lourdes; Arteche Diaz, Raul; Alonso Abad, Ariel

2008-01-01

Diseases caused by a malfunction of the Thyroid gland are very common. Any general hospital assists dozens of such cases weekly and there are some places where these diseases are endemic. A measurement detection system was designed and developed to allow carrying out Thyroid Uptakes functional studies. It has been taken in account the requirements of easiness of use and the good medical practices. The system consists of a Personal Computer connected with a radiometric block based on a UnI052 board, for the acquisition of counts to be processed. The application software is responsible for the control and monitoring of the equipment operation as well as the statistical analysis. It also includes a database where the information of the patient under study is stored. The software was designed according to the principles of Object Oriented Programming (OOP) with a graphic user interface (GUI) under 'MS-Windows' environment. The software has several functions that allow making important quality controls about the correct operation of the system. Quality control tests, according to international standards, have been performed to the equipment. The tests of acceptance, of reference, of routine and of operational or daily control were made. They showed a satisfactory performance under real conditions of operation. Then, the metrological certification was obtained. This is the requirement necessary for doing the case study for obtaining the Medical Registration, which certifies the introduction in the National System of Health. (author)

{sup 18}F-FDG uptake at the surgical margin after hepatic resection: Patterns of uptake and differential diagnosis

Energy Technology Data Exchange (ETDEWEB)

Peungjesada, Silanath [University New Mexico, Department of Radiology, Albuquerque, NM (United States); Aloia, Thomas A. [University of Texas MD Anderson Cancer Center, Department of Surgical Oncology, Unit 444, Houston, TX (United States); Fox, Patricia [University of Texas MD Anderson Cancer Center, Department of Biostatistics, Unit 1411, Houston, TX (United States); Chasen, Beth [University of Texas MD Anderson Cancer Center, Department of Nuclear Medicine, Unit 1483, Houston, TX (United States); Shin, Sooyoung; Loyer, Evelyne M. [University of Texas MD Anderson Cancer Center, Department of Diagnostic Radiology, Unit 1473, Houston, TX (United States); Baiomy, Ali [Cairo University, National Cancer Center, Cairo (Egypt)

2015-08-15

To evaluate the patterns of {sup 18}F-FDG uptake at the surgical margin after hepatectomy to identify features that may differentiate benign and malignant uptake. Patients who had undergone a PET/CT after hepatectomy were identified. Delay between resection and PET/CT, presence of uptake at the surgical margin, pattern of uptake, and maximal standardized value were recorded. The PET/CT findings were correlated with contrast-enhanced CT or MRI. There were 26 patients with increased 18F-FDG uptake; uptake was diffuse in seven and focal in 19. Diffuse uptake was due to inflammation in all cases. Focal uptake was due to recurrence in 12 and inflammation in seven cases. Defining a focal pattern only as a positive for malignancy yielded 100 % sensitivity, 87 % specificity, 37 % false positive rate. As expected, SUV{sub max} was significantly higher for recurrence than inflammation, but did overlap. Contrast-enhanced CT allowed differentiation between malignant and benign uptake in all cases. F-FDG uptake after hepatectomy does not equate to recurrence and yields a high false positive rate. Diffuse uptake did not require additional evaluation in our sample. Focal uptake, however, may be due to recurrence; differentiating benign and malignant nodular uptake relies on optimal contrast-enhanced CT or MRI. (orig.)

Functionalization of LDPE and mLLDPE via grafting trans-ethylene-1,2-dicarboxylic acid by reactive extrusion

Directory of Open Access Journals (Sweden)

2010-03-01

Full Text Available An investigation was made of grafting trans-ethylene-1,2-dicarboxylic acid (TEDA onto metallocene-linear low-density polyethylene (mLLDPE and low-density polyethylene (LDPE in the course of reactive extrusion. The initiator was 1,3-bis-(tert-butyl-peroxyisopropylbenzene. The graft efficiency of TEDA has been shown to increase with increasing initiator concentration, irrespective of polyethylene type. The graft values for LDPE were higher than for mLLDPE over the initiator concentration range (0.05 to 0.4 wt%. The rheological properties of mLLDPE were found to undergo more tangible changes during functionalization than those of LDPE. These changes were caused by side reactions, mainly macromolecular crosslinking. It has been established that some carboxyl groups get transformed to anhydride groups in the grafted product. The concentration of end double bonds reduces, but intramolecular unsaturation in both polyethylenes increases. Data are presented on thermal and stress-strain (mechanical properties of virgin and functionalized polymers, as well as rheological and viscoelastic properties of their melts.

Comparison between Arabidopsis and Rice for Main Pathways of K(+) and Na(+) Uptake by Roots.

Science.gov (United States)

Nieves-Cordones, Manuel; Martínez, Vicente; Benito, Begoña; Rubio, Francisco

2016-01-01

K(+) is an essential macronutrient for plants. It is acquired by specific uptake systems located in roots. Although the concentrations of K(+) in the soil solution are widely variable, K(+) nutrition is secured by uptake systems that exhibit different affinities for K(+). Two main systems have been described for root K(+) uptake in several species: the high-affinity HAK5-like transporter and the inward-rectifier AKT1-like channel. Other unidentified systems may be also involved in root K(+) uptake, although they only seem to operate when K(+) is not limiting. The use of knock-out lines has allowed demonstrating their role in root K(+) uptake in Arabidopsis and rice. Plant adaptation to the different K(+) supplies relies on the finely tuned regulation of these systems. Low K(+)-induced transcriptional up-regulation of the genes encoding HAK5-like transporters occurs through a signal cascade that includes changes in the membrane potential of root cells and increases in ethylene and reactive oxygen species concentrations. Activation of AKT1 channels occurs through phosphorylation by the CIPK23/CBL1 complex. Recently, activation of the Arabidopsis HAK5 by the same complex has been reported, pointing to CIPK23/CBL as a central regulator of the plant's adaptation to low K(+). Na(+) is not an essential plant nutrient but it may be beneficial for some plants. At low concentrations, Na(+) improves growth, especially under K(+) deficiency. Thus, high-affinity Na(+) uptake systems have been described that belong to the HKT and HAK families of transporters. At high concentrations, typical of saline environments, Na(+) accumulates in plant tissues at high concentrations, producing alterations that include toxicity, water deficit and K(+) deficiency. Data concerning pathways for Na(+) uptake into roots under saline conditions are still scarce, although several possibilities have been proposed. The apoplast is a significant pathway for Na(+) uptake in rice grown under salinity

Comparison between Arabidopsis and Rice for Main Pathways of K+ and Na+ Uptake by Roots

Science.gov (United States)

Nieves-Cordones, Manuel; Martínez, Vicente; Benito, Begoña; Rubio, Francisco

2016-01-01

K+ is an essential macronutrient for plants. It is acquired by specific uptake systems located in roots. Although the concentrations of K+ in the soil solution are widely variable, K+ nutrition is secured by uptake systems that exhibit different affinities for K+. Two main systems have been described for root K+ uptake in several species: the high-affinity HAK5-like transporter and the inward-rectifier AKT1-like channel. Other unidentified systems may be also involved in root K+ uptake, although they only seem to operate when K+ is not limiting. The use of knock-out lines has allowed demonstrating their role in root K+ uptake in Arabidopsis and rice. Plant adaptation to the different K+ supplies relies on the finely tuned regulation of these systems. Low K+-induced transcriptional up-regulation of the genes encoding HAK5-like transporters occurs through a signal cascade that includes changes in the membrane potential of root cells and increases in ethylene and reactive oxygen species concentrations. Activation of AKT1 channels occurs through phosphorylation by the CIPK23/CBL1 complex. Recently, activation of the Arabidopsis HAK5 by the same complex has been reported, pointing to CIPK23/CBL as a central regulator of the plant’s adaptation to low K+. Na+ is not an essential plant nutrient but it may be beneficial for some plants. At low concentrations, Na+ improves growth, especially under K+ deficiency. Thus, high-affinity Na+ uptake systems have been described that belong to the HKT and HAK families of transporters. At high concentrations, typical of saline environments, Na+ accumulates in plant tissues at high concentrations, producing alterations that include toxicity, water deficit and K+ deficiency. Data concerning pathways for Na+ uptake into roots under saline conditions are still scarce, although several possibilities have been proposed. The apoplast is a significant pathway for Na+ uptake in rice grown under salinity conditions, but in other plant species

Relationship between nitrate reductase and nitrate uptake in phytoplankton in the Peru upwelling region

International Nuclear Information System (INIS)

Blasco, D.; MacIsaac, J.J.; Packard, T.T.; Dugdale, R.C.

1984-01-01

Nitrate reductase (NR) activity and 15 NO 3 - uptake in phytoplankton were compared under different environmental conditions on two cruises in the upwelling region off Peru. The NR activity and NO 3 - uptake rates responded differently to light and nutrients and the differences led to variations in the uptake: reductase ratio. Analysis of these variations suggests that the re-equilibration time of the two processes in response to environmental perturbation is an important source of variability. The nitrate uptake system responds faster than the nitrate reductase system. Considering these differences in response time the basic differences in the two processes, and the differences in their measurement, the authors conclude that the Nr activity measures the current nitrate-reducing potential, which reflects NO 3 - assimilation before the sampling time, while 15 NO 3 - uptake measures NO 3 - assimilation in the 6-h period following sampling

Tl-201 per rectum scintigraphy in chronic liver disease: assessment of Tl-201 uptake indices

International Nuclear Information System (INIS)

Moon, Won Jin; Choi, Yun Young; Cho, Suk Shin; Lee, Min Ho

1999-01-01

Heart to liver ratio on Tl-201 per rectal scintigraphy (shunt index) is known to be useful in the assessment of portal systemic shunt. We assessed Tl-201 uptake pattern and early liver/heart uptake rate of Tl-201 and correlated with shunt index in patients with chronic active hepatitis (CAH) and liver cirrhosis (LC). Fifty eight patients with biopsy-proven chronic liver disease (35 with CAH, 23 with LC) underwent Tl-201 per rectum scintigraphy after instillation of 18.5 MBq of Tl-201 into the upper rectum. We evaluated hepatic uptake (type 1: homogeneous, 2: inhomogeneous segmental, 3: inhomogeneous nonsegmental) and extrahepatic uptake of spleen, heart and kidney (grade 0: no uptake, 1: less than liver, 2: equal to liver, 3: greater than liver). We measured the early liver/heart uptake rate (the slope of the liver to heart uptake ratio for 10 mim) and shunt index (heart to liver uptake ratio). Tl-201 uptake pattern and early liver/heart uptake rate of Tl-201 was correlated with the pathologic diagnosis and shunt index. Hepatic uptake patterns of type 1 and 2 were dominant in CAH (CAH: 27/35, LC: 8/23), and type 3 in LC (CAH: 8/35, LC: 15/23)(p<0.005). The grades of extrahepatic uptake were higher in LC than in CAH (spleen: p<0.001, other soft tissue: p<0.005). The early liver/heart uptake rate of CAH (0.110±0.111) was significantly higher than that of LC (0.014±0.090)(p<0.001). The sensitivity and specificity of the early liver/heart uptake rate were 77.7% and 67.7% in differentiating LC from CAH. There was negative correlation between early liver/heart uptake rate and shunt index (r=-0.3347, p<0.01). Hepatic and extrahepatic uptake pattern and early liver/heart uptake rate on Tl-201 per rectum scintigraphy are useful in the assessment of portal systemic shunt in patients with chronic liver disease

Modulating the Global Response Regulator, LuxO of V. cholerae Quorum Sensing System Using a Pyrazine Dicarboxylic Acid Derivative (PDCApy: An Antivirulence Approach

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M. Hema

2017-10-01

Full Text Available Vibrio cholerae is a Gram-negative pathogen which causes acute diarrhoeal disease, cholera by the expression of virulence genes through quorum sensing (QS mechanism. The QS circuit of V. cholerae is controlled by the global quorum regulator, LuxO, which at low cell density (LCD state produces major virulence factors such as, toxin co-regulated pilus (TCP and cholera toxin (CT to mediate infection. On the contrary, at the high cell density (HCD state the virulent genes are downregulated and the vibrios are detached from the host intestinal epithelial cells, promoted by HapA protease. Hence, targeting the global regulator LuxO would be a promising approach to modulate the QS to curtail V. cholerae pathogenesis. In our earlier studies, LuxO targeted ligand, 2,3 pyrazine dicarboxylic acid (PDCA and its derivatives having desired pharmacophore properties were chemically synthesized and were shown to have biofilm inhibition as well as synergistic activity with the conventionally used antibiotics. In the present study, the QS modulatory effect of the PDCA derivative with pyrrolidine moiety designated as PDCApy against the V. cholerae virulence gene expression was analyzed at various growth phases. The data significantly showed a several fold reduction in the expression of the genes, tcp and ct whereas the expression of hapR was upregulated at the LCD state. In addition, PDCApy reduced the adhesion and invasion of the vibrios onto the INT407 intestinal cell lines. Collectively, our data suggest that PDCApy could be a potential QS modulator (QSM for the antivirulence therapeutic approach.

Tumor grade-related thallium-201 uptake in chondrosarcomas

International Nuclear Information System (INIS)

Kaya, G.C.; Demir, Y.; Ozkal, S.

2010-01-01

Diagnosis of low-grade chondrosarcoma, especially discrimination between enchondroma and low-grade chondrosarcoma, may be difficult pathologically. The aim of this study was to evaluate the value of thallium-201 (Tl-201) scintigraphy in the diagnosis of chondrosarcoma and to investigate whether there was a correlation between Tl-201 uptake and tumor grade. We retrospectively evaluated 121 patients with pathologically proven bone and soft tissue tumors diagnosed between the years 1999 and 2007. All patients were followed by the Bone and Soft Tissue Tumor Working Group in our hospital. Twenty-three patients, mean age 44±15 (range 17-72) years, with a diagnosis of cartilaginous tumors were included. Increased Tl-201 uptake at the lesion sites greater than background was evaluated as malignant tumor. For the pathologic classification, a grading system (grade 1-3) based on the histopathologic findings was used. Pearson correlation coefficient was used to determine whether there was any correlation between Tl-201 uptake and tumor grade in chondrosarcoma. There were 7 enchondromas and 16 chondrosarcomas. Four of 16 patients with chondrosarcoma had lesions pathologically classified as grade 3, 5 as grade 2, and 7 had grade 1 chondrosarcoma. Increased Tl-201 uptake was observed in all patients with grade 3 chondrosarcoma and 2 patients with grade 2 chondrosarcoma. Of 10 patients with chondrosarcoma, 3 grade 2 chondrosarcomas and 7 grade 1 chondrosarcomas, there was no Tl-201 uptake in the tumor region. A significant correlation was found between Tl-201 uptake and tumor grade in chondrosarcoma (p=0.002, r=0.71). Only a few reports in literature have demonstrated false negative results in low-grade chondrosarcoma. Tl-201 uptake was related to tumor grade in chondrosarcoma. If there is a possibility of chondrosarcoma, Tl-201 scintigraphy should be reported with caution. (author)

Uptake of oxytetracycline and its phytotoxicity to alfalfa (Medicago sativa L.)

Energy Technology Data Exchange (ETDEWEB)

Kong, W D [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Zhu, Y G [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Liang, Y C [Ministry of Agriculture Key Laboratory of Plant Nutrition and Nutrient Cycling, Institute of Soils and Fertilizers, Chinese Academy of Agricultural Sciences, Beijing 100081 (China); Zhang, J [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Smith, F A [Soil and Land Systems, School of Earth and Environmental Sciences, University of Adelaide, DP 636, Adelaide, SA 5005 (Australia); Yang, M [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China)

2007-05-15

A series of experiments were conducted in a hydroponic system to investigate the uptake of oxytetracycline (OTC) and its toxicity to alfalfa (Medicago sativa L.). OTC inhibited alfalfa shoot and root growth by up to 61% and 85%, respectively. The kinetics of OTC uptake could be well described by Michaelis-Menten equation with V {sub max} of 2.25 {mu}mol g{sup -1} fresh weight h{sup -1}, and K {sub m} of 0.036 mM. The uptake of OTC by alfalfa was strongly inhibited by the metabolic inhibitor, 2,4-DNP (2,4-dinitrophenol), at pH 3.5 and 6.0, but not by the aquaporin competitors, glycerol and Ag{sup +}. OTC uptake, however, was significantly inhibited by Hg{sup 2+}, suggesting that the inhibition of influx was due to general cellular stress rather than the specific action of Hg{sup 2+} on aquaporins. Results from the present study suggested that OTC uptake into alfalfa is an energy-dependent process. - Plant uptake of antibiotic oxytetracycline is energy-dependent.

Novel one-pot synthesis of dicarboxylic acids mediated alginate-zirconium biopolymeric complex for defluoridation of water.

Science.gov (United States)

Prabhu, Subbaiah Muthu; Meenakshi, Sankaran

2015-04-20

The present investigation explains the fluoride removal from aqueous solution using alginate-zirconium complex prepared with respective dicarboxylic acids like oxalic acid (Ox), malonic acid (MA) and succinic acid (SA) as a medium. The complexes viz., alginate-oxalic acid-zirconium (Alg-Ox-Zr), alginate-malonic acid-zirconium (Alg-MA-Zr) and alginate-succinic acid-zirconium (Alg-SA-Zr) were synthesized and studied for fluoride removal. The synthesized complexes were characterized by FTIR, XRD, SEM with EDAX and mapping images. The effects of various operating parameters were optimized. The result showed that the maximum removal of fluoride 9653mgF(-)/kg was achieved by Alg-Ox-Zr complex at acidic pH in an ambient atmospheric condition. Equilibrium data of Alg-Ox-Zr complex was fitted well with Freundlich isotherm. The calculated values of thermodynamic parameters indicated that the fluoride adsorption is spontaneous and endothermic in nature. The mechanism of fluoride removal behind Alg-Ox-Zr complex has been proposed in detail. The suitability of the Alg-Ox-Zr complex has been tested with the field sample collected in a nearby fluoride endemic area. Copyright © 2014 Elsevier Ltd. All rights reserved.

Dermal uptake of phthalates from clothing: comparison of model to human participant results

DEFF Research Database (Denmark)

Morrison, Glenn; Weschler, Charles J.; Bekö, Gabriel

2016-01-01

In this research, we extend a model of transdermal uptake of phthalates to include a layer of clothing. When compared with experimental results, this model better estimates dermal uptake of diethylphthalate (DEP) and di-n-butylphthalate (DnBP) than a previous model. It also demonstrates that uptake...... is sensitive to both the gap between skin and clothing and the time clothing is allowed to adsorb phthalates. The model predictions are consistent with the observation that exposed clothing increases dermal uptake when compared with uptake observed in bare-skin participants. Extension of this model beyond...... the cotton-phthalate system will be challenging until data on partition coefficients are quantified for other combinations of SVOCs, fabric materials and environmental conditions....

Concentrations of higher dicarboxylic acids C5–C13 in fresh snow samples collected at the High Alpine Research Station Jungfraujoch during CLACE 5 and 6

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K. Sieg

2009-03-01

Full Text Available Samples of freshly fallen snow were collected at the high alpine research station Jungfraujoch (Switzerland in February and March 2006 and 2007, during the Cloud and Aerosol Characterization Experiments (CLACE 5 and 6. In this study a new technique has been developed and demonstrated for the measurement of organic acids in fresh snow. The melted snow samples were subjected to solid phase extraction and resulting solutions analysed for organic acids by HPLC-MS-TOF using negative electrospray ionization. A series of linear dicarboxylic acids from C5 to C13 and phthalic acid, were identified and quantified. In several samples the biogenic acid pinonic acid was also observed. In fresh snow the median concentration of the most abundant acid, adipic acid, was 0.69 μg L−1 in 2006 and 0.70 μg L−1 in 2007. Glutaric acid was the second most abundant dicarboxylic acid found with median values of 0.46 μg L−1 in 2006 and 0.61 μg L−1 in 2007, while the aromatic acid phthalic acid showed a median concentration of 0.34 μg L−1 in 2006 and 0.45 μg L−1 in 2007. The concentrations in the samples from various snowfall events varied significantly, and were found to be dependent on the back trajectory of the air mass arriving at Jungfraujoch. Air masses of marine origin showed the lowest concentrations of acids whereas the highest concentrations were measured when the air mass was strongly influenced by boundary layer air.

One-step green synthesis of non-hazardous dicarboxyl cellulose flocculant and its flocculation activity evaluation

International Nuclear Information System (INIS)

Zhu, Hangcheng; Zhang, Yong; Yang, Xiaogang; Liu, Hongyi; Shao, Lan; Zhang, Xiumei; Yao, Juming

2015-01-01

The waste management of used flocculants is a thorny issue in the field of wastewater treatment. To natural cellulose based flocculants, utilization of hazardous cellulose solvent and simplification of synthetic procedure are the two urgent problems needing to be further improved. In this work, a series of natural dicarboxyl cellulose flocculants (DCCs) were one-step synthesized via Schiff-base route. The cellulose solvent (NaOH/Urea solution) was utilized during the synthesis process. The full-biodegradable flocculants avoid causing secondary pollution to environment. The chemical structure and solution property of the DCC products were characterized by FT-IR, 1 H NMR, 13 C NMR, TGA, FESEM, charge density and ζ-potential. Kaolin suspension and effluent from paper mill were selected to evaluate the flocculation activity of the DCCs. Their flocculation performance was compared with that of commercial cationic polyacrylamide and poly aluminium chloride flocculants. The positive results showed that the NaOH/Urea solvent effectively promoted the dialdehyde cellulose (DAC) conversion to DCC in the one-step synthesis reaction. The DCCs with the carboxylate content more than 1 mmol/g exhibited steady flocculation performance to kaolin suspension in the broad pH range from 4 to 10. Its flocculation capacity to the effluent from paper mill also showed excellent

Excitatory amino acid-stimulated uptake of 22Na+ in primary astrocyte cultures

International Nuclear Information System (INIS)

Kimelberg, H.K.; Pang, S.; Treble, D.H.

1989-01-01

In this study we have found that L-glutamic acid, as well as being taken up by a Na+-dependent mechanism, will stimulate the uptake of 22Na+ by primary astrocyte cultures from rat brain in the presence of ouabain. By simultaneously measuring the uptake of 22Na+ and L-3H-glutamate a stoichiometry of 2-3 Na+ per glutamate was measured, implying electrogenic uptake. Increasing the medium K+ concentration to depolarize the cells inhibited L-3H-glutamate uptake, while calculations of the energetics of the observed L-3H-glutamate accumulation also supported an electrogenic mechanism of at least 2 Na+:1 glutamate. In contrast, kinetic analysis of the Na+ dependence of L-3H-glutamate uptake indicated a stoichiometry of Na+ to glutamate of 1:1, but further analysis showed that the stoichiometry cannot be resolved by purely kinetic studies. Studies with glutamate analogs, however, showed that kainic acid was a very effective stimulant of 22Na+ uptake, but 3H-kainic acid showed no Na+ -dependent uptake. Furthermore, while L-3H-glutamate uptake was very sensitive to lowered temperatures, glutamate-stimulated 22Na+ uptake was relatively insensitive. These results indicate that glutamate-stimulated uptake of 22Na+ in primary astrocytes cultures cannot be explained solely by cotransport of Na+ with glutamate, and they suggest that direct kainic acid-type receptor induced stimulation of Na+ uptake also occurs. Since both receptor and uptake effects involve transport of Na+, accurate measurements of the Na+ :glutamate stoichiometry for uptake can only be done using completely specific inhibitors of these 2 systems

Glycine uptake by microvillous and basal plasma membrane vesicles from term human placentae.

Science.gov (United States)

Dicke, J M; Verges, D; Kelley, L K; Smith, C H

1993-01-01

Like most amino acids, glycine is present in higher concentrations in the fetus than in the mother. Unlike most amino acids, animal studies suggest fetal concentrations of glycine are minimally in excess of those required for protein synthesis. Abnormal glycine utilization has also been demonstrated in small-for-gestational age human fetuses. The mechanism(s) of glycine uptake in the human placenta are unknown. In other mammalian cells glycine is a substrate for the A, ASC and Gly amino acid transport systems. In this study human placental glycine uptake was characterized using microvillous and basal plasma membrane vesicles each prepared from the same placenta. In both membranes glycine uptake was mediated predominantly by the sodium-dependent A system. Competitive inhibition studies suggest that in microvillous vesicles the small percentage of sodium-dependent glycine uptake not inhibited by methylaminoisobutyric acid (MeAIB) shares a transport system with glycine methyl ester and sarcosine, substrates of the Gly system in other tissues. In addition there are mediated sodium-independent and non-selective transport mechanisms in both plasma membranes. If fetal glycine availability is primarily contingent upon the common and highly regulated A system, glycine must compete with many other substrates potentially resulting in marginal fetal reserves, abnormal utilization and impaired growth.

Quantification of radionuclide uptake levels for primary bone tumors

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Hasford Francis

2015-04-01

Full Text Available The purpose of the study is to quantify the level of uptake of administered radionuclide in primary bone tumors for patients undergoing bone scintigraphy. Retrospective study on 48 patient's scintigrams to quantify the uptake levels of administered radiopharmaceuticals was performed in a nuclear medicine unit in Ghana. Patients were administered with activity ranging between 0.555 and 1.110 MBq (15–30 mCi, and scanned on Siemens e.cam SPECT system. Analyses on scintigrams were performed with Image J software by drawing regions of interest (ROIs over identified hot spots (pathologic sites. Nine skeletal parts namely cranium, neck, shoulder, sacrum, sternum, vertebra, femur, ribcage, and knee were considered in the study, which involved 96 identified primary tumors. Radionuclide uptakes were quantified in terms of the estimated counts of activity per patient for identified tumor sites. Average normalized counts of activity (nGMC per patient ranged from 5.2759 ± 0.6590 cts/mm2/MBq in the case of cranium tumors to 72.7569 ± 17.8786 cts/mm2/MBq in the case of ribcage tumors. The differences in uptake levels could be attributed to different mechanisms of Tc-99m MDP uptake in different types of bones, which is directly related to blood flow and degree of osteoblastic activity. The overall normalized count of activity for the 96 identified tumors was estimated to be 23.0350 ± 19.5424 cts/mm2/MBq. The study revealed highest uptake of activity in ribcage and least uptake in cranium. Quantification of radionuclide uptakes in tumors is important and recommended in assessing patient's response to therapy, doses to critical organs and in diagnosing tumors.

Active uptake of substance P carboxy-terminal heptapeptide (5-11) into rat brain and rabbit spinal cord slices

Energy Technology Data Exchange (ETDEWEB)

Nakata, Y; Kusaka, Y; Yajima, H; Segawa, T

1981-12-01

We previously reported that nerve terminals and glial cells lack an active uptake system capable of terminating transmitter action of substance P (SP). In the present study, we demonstrated the existence of an active uptake system for SP carboxy-terminal heptapeptide, (5-11)SP. When the slices from either rat brain or rabbit spinal cord were incubated with (3H)(5-11)SP, the uptake of (5-11)SP into slices was observed. The uptake system has the properties of an active transport mechanism: it is dependent on temperature and sensitive to hypoosmotic treatment and is inhibited by ouabain and dinitrophenol (DNP). In the brain, (5-11)SP was accumulated by means of a high-affinity and a low-affinity uptake system. The Km and the Vmax values for the high-affinity system were 4.20 x 10(-8) M and 7.59 fmol/10 mg wet weight/min, respectively, whereas these values for the low-affinity system were 1.00 x 10(-6) M and 100 fmol/10 mg wet weight/min, respectively. In the spinal cord, there was only one uptake system, with a Km value of 2.16 x 10(-7) M and Vmax value of 26.2 fmol/10 mg wet weight/min. These results suggest that when SP is released from nerve terminals, it is hydrolysed into (5-11)SP before or after acting as a neurotransmitter, which is in turn accumulated into nerve terminals. Therefore, the uptake system may represent a possible mechanism for the inactivation of SP.

Nitrogen uptake efficiency of irrigated wheat in Egypt

International Nuclear Information System (INIS)

Abdel Monem, M.A.S.

2000-01-01

Egypt's current wheat production would be impossible without N fertilizers, the consumption of which has increased more than 75% in the last 20 years. The efficiency of uptake of applied N is low, and better management of both fertilizer and irrigation is needed to improve N recovery by crops and reduce losses from the plant/soil system. Field trials were conducted over a 3-year period, on Egypt's three main soil types: old irrigated land of the Nile valley, newly reclaimed sandy and calcareous soils, and salt-affected soil of the north delta. The responses of wheat cultivars to N, and patterns of N uptake and N loss, as affected by irrigation regime, were examined using 15 N. Cultivar Sakha 69 was more responsive to applied N and assimilated N more efficiently than other varieties under different soil types. Nitrogen loss from the sandy soil was as high as 57% whereas average loss in the clay soil was 17%. A higher water table in the salt-affected soil negatively affected N uptake. Irrigation with 75% of the required water for wheat had no effect on yield or N-uptake. (author)

Uptake of uranium from sea water by microalgae

International Nuclear Information System (INIS)

Sakaguchi, Takashi; Horikoshi, Takao; Nakajima, Akira

1978-01-01

The uptake of uranium from aqueous systems especially from sea water by various microalgae was investigated. The freshwater microalgae, Chlorella regularis, Scenedesmus bijuga, Scenedesmus chloreloides, Scenedesmus obliquus, Chlamydomonas angulosa, Chlamydomonas reinhardtii, accumulated relatively large amounts of uranium from the solution containing uranium only. The concentration factors of the above mentioned algae were: Chlorella regularis 3930, Chlamydomonas 2330 - 3400, Scenedesmus 803 - 1920. The uptake of uranium from sea water by Chlorella regularis was inhibited markedly by the co-existence of carbonate ions. Chlorella cells could take up a great quantity of uranium from decarbonated sea water. The uptake of uranium was affected by the pH of sea water, and the amount of uranium absorbed was maximum at pH 5. The experiment was carried out to screen marine microalgae which have the ability to accumulate a large amount of uranium from sea water. The uptake of uranium from sea water by marine microalgae of different species turned out to be in the following decreasing order: Synechococcus > Chlamydomonas >> Chlorella > Dunaliella > Platymonas > Calothrix > Porphyridium. The amount of uranium absorbed differed markedly with different species of marine microalgae. (author)

Thyroid uptake of I-131 during anti-thyroid drug treatment

International Nuclear Information System (INIS)

Hoque, M.; Alam, F.; Haque, F.S.; Karim, M.A.; Fariduddin, M.

2004-01-01

Hyperthyroidism is a global ailment and its treatment is very promising either by ant-thyroid drug or by radioiodine. Iodine-131 uptake test is very important for evaluation of hyperthyroid in respect to its therapy and to exclude thyroiditis. This study was performed to observe the thyroid uptake pattern during intake of anti-thyroid medicine and workout the possibility to start I-131 therapy just after withdraw of antithyroid drug without waiting few days. In this study total 252 patient's I-131 uptake test is performed. Among the patient 135 (53.57%) were female, 117 (64.43%) were male. All this patients were hyperthyroid both clinically and biochemically. Thyroid uptake was taken to all patients at 24 hours after oral administration of 5 to 10 micro-curie of I -131. Uptake was taken by an uptake system and recorded as percentage uptake. These patients are grouped into three categories. Group-A-newly diagnosed cases, who have not taken antithyroid drug or I-131 therapy, there were 82 patients in this group, and their mean uptake was 37.12 ±18.5%. Group B - this group of patients were studied during intake of antithyroid medicine, there were 130 patients in this group and their mean uptake was 34.34±16.0%. Group-B patients were further divided in two sub-groups, patients having antithyroid drug for 1 to 3 weeks (group-B 1), group B1 have mean uptake 37±21% and those were taking antithyroid for 3 weeks to 2 years (group-B2), group B2 have uptake 34.34±20%. Group C- these patients are taken from those patients who had withdrawn antithyroid drug for 3 days to 3 months, there were 40 such patients. Group C further divided into two sub-group, group-C1 (stopped for 3-10 days) and group C2 (stopped for 11 days to 3 months). Group C1 had mean uptake 38±16% and group C2 had mean uptake 35±19%. From this study it is observed that Iodine-131 uptake percentage of untreated hyperthyroid; during antithyroid drug treatment and after withdraw of antithyroid drug almost

Thyroid Scan and Uptake

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Full Text Available ... for a thyroid scan is 30 minutes or less. Thyroid Uptake You will be given radioactive iodine ( ... for each thyroid uptake is five minutes or less. top of page What will I experience during ...

Thyroid Scan and Uptake

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Full Text Available ... Scan and Uptake Thyroid scan and uptake uses small amounts of radioactive materials called radiotracers, a special ... is a branch of medical imaging that uses small amounts of radioactive material to diagnose and determine ...

Thyroid Scan and Uptake

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Full Text Available ... uptake measurements are obtained at different times. For example, you may have uptake measurements at four to ... medicine procedures can be time consuming. It can take several hours to days for the radiotracer to ...

Thyroid Scan and Uptake

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Full Text Available ... known as a thyroid uptake. It is a measurement of thyroid function, but does not involve imaging. ... eating can affect the accuracy of the uptake measurement. Jewelry and other metallic accessories should be left ...

Thyroid Scan and Uptake

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Full Text Available ... Uptake? A thyroid scan is a type of nuclear medicine imaging. The radioactive iodine uptake test (RAIU) ... of thyroid function, but does not involve imaging. Nuclear medicine is a branch of medical imaging that ...

Thyroid Scan and Uptake

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Full Text Available ... radioactive iodine uptake test (RAIU) is also known as a thyroid uptake. It is a measurement of ... potential to identify disease in its earliest stages as well as a patient’s immediate response to therapeutic ...

Imaging analysis of direct alanine uptake by rice seedlings

International Nuclear Information System (INIS)

Nihei, Naoto; Masuda, Sayaka; Rai, Hiroki; Nakanishi, Tomoko M.

2008-01-01

We presented alanine, a kind of amino acids, uptake by a rice seedling to study the basic mechanism of the organic fertilizer effectiveness in organic farming. The rice grown in the culture solution containing alanine as a nitrogen source absorbed alanine approximately two times faster than that grown with NH 4 + from analysis of 14 C-alanine images by Imaging Plate method. It was suggested that the active transport ability of the rice seeding was induced in roots by existence of alanine in the rhizosphere. The alanine uptake images of the rice roots were acquired every 5 minutes successively by the real-time autoradiography system we developed. The analysis of the successive images showed that alanine uptake was not uniform throughout the root but especially active at the root tip. (author)

Thyroid Scan and Uptake

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Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Thyroid Scan and Uptake Thyroid scan and uptake uses ...

Uptake of antibiotics by human polymorphonuclear leukocyte cytoplasts

International Nuclear Information System (INIS)

Hand, W.L.; King-Thompson, N.L.

1990-01-01

Enucleated human polymorphonuclear leukocytes (PMN cytoplasts), which have no nuclei and only a few granules, retain many of the functions of intact neutrophils. To better define the mechanisms and intracellular sites of antimicrobial agent accumulation in human neutrophils, we studied the antibiotic uptake process in PMN cytoplasts. Entry of eight radiolabeled antibiotics into PMN cytoplasts was determined by means of a velocity gradient centrifugation technique. Uptakes of these antibiotics by cytoplasts were compared with our findings in intact PMN. Penicillin entered both intact PMN and cytoplasts poorly. Metronidazole achieved a concentration in cytoplasts (and PMN) equal to or somewhat less than the extracellular concentration. Chloramphenicol, a lipid-soluble drug, and trimethoprim were concentrated three- to fourfold by cytoplasts. An unusual finding was that trimethroprim, unlike other tested antibiotics, was accumulated by cytoplasts more readily at 25 degrees C than at 37 degrees C. After an initial rapid association with cytoplasts, cell-associated imipenem declined progressively with time. Clindamycin and two macrolide antibiotics (roxithromycin, erythromycin) were concentrated 7- to 14-fold by cytoplasts. This indicates that cytoplasmic granules are not essential for accumulation of these drugs. Adenosine inhibited cytoplast uptake of clindamycin, which enters intact phagocytic cells by the membrane nucleoside transport system. Roxithromycin uptake by cytoplasts was inhibited by phagocytosis, which may reduce the number of cell membrane sites available for the transport of macrolides. These studies have added to our understanding of uptake mechanisms for antibiotics which are highly concentrated in phagocytes

Quantitative clinical uptake measurements using conjugate counting

International Nuclear Information System (INIS)

Lathrop, K.A.; Bartlett, R.D.; Chen, C.T.; Chou, J.S.; Faulhaber, P.F.; Harper, P.V.; Stark, V.J.

1986-01-01

While the use of conjugate counting for determination of organ uptake in human subjects has been extensively described, in the present study the determination of the organ uptake of ortho-iodohippurate presented several opportunities for validation of the in vivo counting data. Ortho-iodohippurate is distributed in the extracellular space, is largely extracted on each pass through the kidneys, and is not significantly deiodinated in vivo. Thus, the kidney uptake rate should be proportional to the blood level, the appearance rate of activity in the bladder is equal to the disappearance rate from the kidneys, and direct measurement of activity in the urine after voiding provides an internal standard for imaging measurements of bladder activity. Since the activity levels in the kidneys, bladder, and remainder of the body changed fairly rapidly, especially in the first 20 to 30 minutes following injection, posterior images of the trunk including kidneys and bladder were obtained continuously using a gamma camera fitted with a diverging collimator for 30 minutes and then at intervals for several hours. Simultaneous conjugate counting determinations were made using a whole body scanning system previously described at these meetings. Imaging data corrected for decay and adjacent background were fitted by least squares methods to curves representing a sum of exponentials, and the curves were normalized to the conjugate uptake measurements. The uptake curves of the kidneys and bladder matched well with the direct measurements of the urinary excretion. Data were collected in 16 normal subjects, and the estimated absorbed dose was calculated for the kidneys, the bladder and the remainder of the body for seven radioisotopes of iodine. 4 references, 6 figures, 2 tables

Increased muscle glucose uptake during contractions

DEFF Research Database (Denmark)

Ploug, Thorkil; Galbo, Henrik; Richter, Erik

1984-01-01

We reinvestigated the prevailing concept that muscle contractions only elicit increased muscle glucose uptake in the presence of a so-called "permissive" concentration of insulin (Berger et al., Biochem. J. 146: 231-238, 1975; Vranic and Berger, Diabetes 28: 147-163, 1979). Hindquarters from rats...... in severe ketoacidosis were perfused with a perfusate containing insulin antiserum. After 60 min perfusion, electrical stimulation increased glucose uptake of the contracting muscles fivefold. Also, subsequent contractions increased glucose uptake in hindquarters from nondiabetic rats perfused for 1.5 h......-methylglucose uptake increased during contractions and glucose uptake was negative at rest and zero during contractions. An increase in muscle transport and uptake of glucose during contractions does not require the presence of insulin. Furthermore, glucose transport in contracting muscle may only increase if glycogen...

Thyroid Scan and Uptake

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Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... of nuclear medicine imaging. The radioactive iodine uptake test (RAIU) is also known as a thyroid uptake. ...

Reduction of the influence of the liver uptake to the myocardial uptake on technetium-99m myocardial SPECT. Usefulness and problems of a mask processing method

Energy Technology Data Exchange (ETDEWEB)

Takaki, Akihiro; Okada, Kazuhiro; Urata, Johji; Matsuda, Hirofumi; Takao, Yuji [Saiseikai Kumamoto Hospital (Japan)

1999-07-01

The aim of this study is to evaluate the usefulness of a mask processing method for obtaining the true myocardial tracer distribution by eliminating the influence of the liver uptake to the myocardial uptake on myocardial SPECT images by using technetium-99m ({sup 99m}Tc) blood flow agents. A SPECT imaging was performed with a two-head SPECT system (GCA-7200A/DI) in both phantom and clinical studies. The mask processing method was applied to the reconstructed and projection images. The phantom consisted of heart, lung, liver and spine. A defect was located in the inferior wall of the left ventricle and other parts of the heart and liver were filled with {sup 99m}Tc solution. For clinical study 10 patients with difficulty in the interpretation of the inferior wall were selected for the evaluation of usefulness of the mask method. In the phantom study, the mask processing method applied to the reconstructed images was able to remove the overlapped liver from the heart, but was not able to remove the influence of the liver uptake to the myocardial uptake. Nevertheless, the mask processing method applied to the projection images successfully eliminated not only the overlapped liver but also the influence of the liver uptake to the myocardial uptake. In the clinical study, the liver uptake could be removed from the uptake in the inferior wall in 8 of 10 patients with the mask processing methods. In 2 patients, the overlapped liver uptake could not be eliminated from the uptake in the inferior wall because the distance between the liver and heart was too short. The mask processing method applied to the projection images was thought to be superior to that applied to the reconstruction images in both phantom and clinical studies. The mask processing method, especially applied to the projection images, seems to be useful for the elimination of the liver uptake from the inferior wall of the myocardium on myocardial SPECT images using {sup 99m}Tc blood flow agents. (author)

Reduction of the influence of the liver uptake to the myocardial uptake on technetium-99m myocardial SPECT. Usefulness and problems of a mask processing method

International Nuclear Information System (INIS)

Takaki, Akihiro; Okada, Kazuhiro; Urata, Johji; Matsuda, Hirofumi; Takao, Yuji

1999-01-01

The aim of this study is to evaluate the usefulness of a mask processing method for obtaining the true myocardial tracer distribution by eliminating the influence of the liver uptake to the myocardial uptake on myocardial SPECT images by using technetium-99m ( 99m Tc) blood flow agents. A SPECT imaging was performed with a two-head SPECT system (GCA-7200A/DI) in both phantom and clinical studies. The mask processing method was applied to the reconstructed and projection images. The phantom consisted of heart, lung, liver and spine. A defect was located in the inferior wall of the left ventricle and other parts of the heart and liver were filled with 99m Tc solution. For clinical study 10 patients with difficulty in the interpretation of the inferior wall were selected for the evaluation of usefulness of the mask method. In the phantom study, the mask processing method applied to the reconstructed images was able to remove the overlapped liver from the heart, but was not able to remove the influence of the liver uptake to the myocardial uptake. Nevertheless, the mask processing method applied to the projection images successfully eliminated not only the overlapped liver but also the influence of the liver uptake to the myocardial uptake. In the clinical study, the liver uptake could be removed from the uptake in the inferior wall in 8 of 10 patients with the mask processing methods. In 2 patients, the overlapped liver uptake could not be eliminated from the uptake in the inferior wall because the distance between the liver and heart was too short. The mask processing method applied to the projection images was thought to be superior to that applied to the reconstruction images in both phantom and clinical studies. The mask processing method, especially applied to the projection images, seems to be useful for the elimination of the liver uptake from the inferior wall of the myocardium on myocardial SPECT images using 99m Tc blood flow agents. (author)

An intermolecular Diels-Alder cycloaddition under various condition between 1,3-cyclohexadiene and 7-oxabicyclo[2.2.1]hepta-2,5-diene-2,3-dicarboxylate

Directory of Open Access Journals (Sweden)

Özgür Yılmaz

2017-10-01

Full Text Available The reaction between 1,3-cyclohexadiene and dimethyl 7-oxabicyclo[2.2.1]hepta-2,5-diene-2,3-dicarboxylate both without a catalyst and with different catalysts, in both atmospheric and at high pressure, over 20 days were studied. At the end of the reactions, different products (retro Diels-Alder addition product 5 and Diels-Alder addition product 6 were obtained in different yields. When we look at the percentage of the addition product, it is observed that the yield of reaction at high pressure in water is the highest. All structures of these products were characterized by 1H-NMR, 13C-NMR, MS, and IR spectroscopy.

Downregulation of taurine uptake in multidrug resistant Ehrlich ascites tumor cells

DEFF Research Database (Denmark)

Poulsen, K A; Litman, Thomas; Eriksen, J

2002-01-01

In daunorubicin resistant Ehrlich ascites tumor cells (DNR), the initial taurine uptake was reduced by 56% as compared to the parental, drug sensitive Ehrlich cells. Kinetic experiments indicated that taurine uptake in Ehrlich cells occurs via both high- and low-affinity transporters. The maximal...... rate constant for the initial taurine uptake was reduced by 45% (high-affinity system) and 49% (low affinity system) in the resistant subline whereas the affinity of the transporters to taurine was unchanged. By immunoblotting we identified 3 TauT protein bands in the 50-70 kDa region. A visible...... reduction in the intensity of the band with the lowest molecular weight was observed in resistant cells. Quantitative RT-PCR indicated a significant reduction in the amount of taurine transporter mRNA in the resistant cells. Drug resistance in DNR Ehrlich cells is associated with overexpression of the mdr1...

Uptake of extracellular DNA: Competence induced pili in natural transformation of Streptococcus pneumoniae

Science.gov (United States)

Muschiol, Sandra; Balaban, Murat; Normark, Staffan; Henriques-Normark, Birgitta

2015-01-01

Transport of DNA across bacterial membranes involves complex DNA uptake systems. In Gram-positive bacteria, the DNA uptake machinery shares fundamental similarities with type IV pili and type II secretion systems. Although dedicated pilus structures, such as type IV pili in Gram-negative bacteria, are necessary for efficient DNA uptake, the role of similar structures in Gram-positive bacteria is just beginning to emerge. Recently two essentially very different pilus structures composed of the same major pilin protein ComGC were proposed to be involved in transformation of the Gram-positive bacterium Streptococcus pneumoniae – one is a long, thin, type IV pilus-like fiber with DNA binding capacity and the other one is a pilus structure that was thicker, much shorter and not able to bind DNA. Here we discuss how competence induced pili, either by pilus retraction or by a transient pilus-related opening in the cell wall, may mediate DNA uptake in S. pneumoniae. PMID:25640084

Uptake of 14C-labelled chloroquine and an 125I-labelled chloroquine analogue in some polypeptide hormone producing cell systems

International Nuclear Information System (INIS)

Dencker, L.; Lindquist, N.G.; Tjaelve, H.

1976-01-01

After the injection of 14 C-labelled chloroquine and the 125 I-labelled chloroquine analogue 4-(3 1 -dimethylaminopropylamino)-7-iodoquinoline [ 125 I]DAPQ into mice, rats and a monkey the distribution of the radioactivity was studied by autoradiographical methods. A high and persistent uptake occurred in some endocrine cell systems, such as the pancreatic islets, the hypophysis, the adrenal medulla and the thyroid (in cells that were probably identical with the parafollicular cells). The melanin-containing tissues were the only ones which showed a higher uptake and retention of radioactivity. The above mentioned endocrine cells and the melanocytes have a common embryological origin and common morphological and cytochemical characteristics. They have been called the APUD (Amine Precursor Uptake and Decarboxylation)-cell series. It is proposed that the polypeptide hormone producing cells and the melanocytes may use a similar mechanism for accumulating chloroquine and (as shown earlier) also some other drugs such as nicotine, alprenolol, local anesthetics and atropine. These drugs however, accumulate stronger within the melanocytes and become bound to the melanin for a long time. The ability to accumulate these drugs may be considered another characteristic of the APUD-cell series. (author)

Relationship between nitrate reductase and nitrate uptake in phytoplankton in the Peru upwelling region

International Nuclear Information System (INIS)

Blasco, D.; MacIsaac, J.J.; Packard, T.T.; Dugdale, R.C.

1984-01-01

Nitrate reductase (NR) activity and 15 NO 3 - uptake in phytoplankton were compared under different environmental conditions on two cruises in the upwelling region off Peru. The NR activity and NO 3 - uptake rates responded differently to light and nutrients and the differences led to variations in the uptake:reductase ratio. Analysis of these variations suggests that the re-equilibration time of the two processes in response to environmental perturbation is an important source of variability. The nitrate uptake system responds faster than the nitrate reductase system. Considering these differences in response time, the basic differences in the two processes, and the differences in their measurement, the authors conclude that the NR activity measures the current nitrate-reducing potential, which relfects NO 3 - assimilation before the sampling time, while 15 NO 3 - uptake measures NO 3 - assimilation in the 6-h period following sampling. Thus, considering the sampling time as a point of reference, the former is a measure of the past and the latter is a measure of the future

Radioiodine uptake in inactive pulmonary tuberculosis

International Nuclear Information System (INIS)

Bakheet, S.M.; Powe, J.; Al Suhaibani, H.; Hammami, M.M.; Bazarbashi, M.

1999-01-01

Radioiodine may accumulate at sites of inflammation or infection. We have seen such accumulation in six thyroid cancer patients with a history of previously treated pulmonary tuberculosis. We also review the causes of false-positive radioiodine uptake in lung infection/inflammation. Eight foci of radioiodine uptake were seen on six iodine-123 diagnostic scans. In three foci, the uptake was focal and indistinguishable from thyroid cancer pulmonary metastases from thyroid cancer. In the remaining foci, the uptake appeared nonsegmental, linear or lobar, suggesting a false-positive finding. The uptake was unchanged, variable in appearance or non-persistent on follow-up scans and less extensive than the fibrocystic changes seen on chest radiographs. In the two patients studied, thyroid hormone level did not affect the radioiodine lung uptake and there was congruent gallium-67 uptake. None of the patients had any evidence of thyroid cancer recurrence or of reactivation of tuberculosis and only two patients had chronic intermittent chest symptoms. Severe bronchiectasis, active tuberculosis, acute bronchitis, respiratory bronchiolitis, rheumatoid arthritis-associated lung disease and fungal infection such as Allescheria boydii and aspergillosis can lead to different patterns of radioiodine chest uptake mimicking pulmonary metastases. Pulmonary scarring secondary to tuberculosis may predispose to localized radioiodine accumulation even in the absence of clinically evident active infection. False-positive radioiodine uptake due to pulmonary infection/inflammation should be considered in thyroid cancer patients prior to the diagnosis of pulmonary metastases. (orig.)

Dicarboxylic acids and levoglucosan in aerosols from Indo-Gangetic Plain: Inferences from day night variability during wintertime.

Science.gov (United States)

Sorathia, Fena; Rajput, Prashant; Gupta, Tarun

2018-05-15

This study assesses daytime and nighttime atmospheric abundance and molecular distribution of dicarboxylic acids (DCA: C 2 -C 10 ) and biomass burning tracers (levoglucosan and biomass burning derived potassium: K + BB ) in PM 10 (particulate matter with aerodynamic diameter≤10μm) from an urban location, Kanpur (in central Indo-Gangetic Plain: IGP) during wintertime (December 2015-February 2016). In this study, PM 10 varied from 130 to 242 and 175-388μgm -3 during daytime and nighttime, respectively. The average ratios of OC/EC (day: 12.3; night: 9.3) and WSOC/OC (day: 0.74; night: 0.48) were relatively high during daytime (OC: organic carbon; EC: elemental carbon; WSOC: water-soluble organic carbon). Strong linear correlations (R 2 ≥0.6; pformation involving aqueous-phase chemistry. Strong linear correlations of C 2 with C 3 and C 4 plausibly suggest that C 2 can have predominant formation pathways via decomposition of higher congeners of DCA. Overall, strong linear correlations of C 2 with levoglucosan and sulphate suggest that biomass burning emission and secondary transformations are predominant sources of DCA over IGP during wintertime. Copyright © 2017 Elsevier B.V. All rights reserved.

Ethanol intake and 3H-serotonin uptake I: A study in Fawn-Hooded rats

International Nuclear Information System (INIS)

Daoust, M.; Compagnon, P.; Legrand, E.; Boucly, P.

1991-01-01

Ethanol intake and synaptosomal 3 H-serotonin uptake were studied in male Fawn-Hooded and Sprague-Dawley rats. Fawn-Hooded rats consumed more alcohol and more water than Sprague-Dawley rats. Plasma alcohol levels of Sprague-Dawley rats were not detectable but were about 5 mg/dl in Fawn-Hooded rats. Ethanol intake increased the Vmax of serotonin uptake in Fawn-Hooded rats in hippocampus and cortex, but not in thalamus. In Fawn-Hooded rats, serotonin uptake (Vmax) was higher than in Sprague-Dawley rats cortex. Ethanol intake reduced the Vmax of serotonin uptake in Fawn-Hooded rats in hippocampus and cortex. In cortex, the carrier affinity for serotonin was increased in alcoholized Fawn-Hooded rats. These results indicate that synaptosomal 3 H-serotonin uptake is affected by ethanol intake. In Fawn-Hooded rats, high ethanol consumption is associated with high serotonin uptake. In rats presenting high serotonin uptake, alcoholization reduces 3 H-serotonin internalization in synaptosomes, indicating a specific sensitivity to alcohol intake of serotonin uptake system

Nutrient uptake efficiency of Gracilaria chilensis and Ulva lactuca in an IMTA system with the red abalone Haliotis rufescens

Directory of Open Access Journals (Sweden)

Juan Macchiavello

2014-07-01

Full Text Available The current study examined the nutrient uptake efficiency of Ulva lactuca and Gracilaria chilensis cultivated in tanks associated with the wastewater of a land-based abalone culture. The experiments evaluated different seaweed stocking densities (1200, 1900, 2600, and 3200 g m-2 and water exchange rates (60, 80, 125, and 250 L h-1. The results show that both U. lactuca and G. chilensis were efficient in capturing and removing all of the inorganic nutrients originating from the abalone cultivation for all of the tested conditions. Furthermore, an annual experiment was performed with U. lactuca, cultivated at a stocking density of 1900 g m-2 and at a water exchanged rate of 125 L h-1, in order to evaluate seasonal changes in the nutrient uptake efficiency, productivity, and growth rate associated with the wastewater of a land-based abalone culture. The results confirmed high uptake efficiency during the entire year, equivalent to a 100% removal of the NH4, NO3, and PO4 produced by the land-based abalone culture. The growth rate and productivity of U. lactuca presented a marked seasonality, increasing from fall until summer and varying from 0.5 ± 0.2% to 2.6 ± 0.2% d-1 and 10 ± 6.1% to 73.6 ± 8.4% g m-2 d-1 for sustainable growth rate and productivity, respectively. We conclude that there is sufficient evidence that demonstrates the high possibility of changing the traditional monoculture system of abalone in Chile, to a sustainable integrated multi-trophic aquaculture system, generating positive environmental externalities, including the use of U. lactuca as a biofiltration unit.

Uptake of technetium from seawater by red abalone Haliotis rufescens

International Nuclear Information System (INIS)

Spies, R.B.

1975-01-01

Technetium accumulation from seawater by the abalone Haliotis rufescens was studied with 95 Tc. Concentration factors, uptake rates, steady state concentrations, and biological half-lives were determined experimentally for whole-body uptake. Whole-body concentration factors ranged from 135 to 205; biological half-life was 60 days. Changes in concentration factors were determined for six tissues during the uptake period. The highest activities were in the order of: digestive gland>gill>kidneys>heart>gonad>columnar muscle. Dead shells accumulated little activity compared to shells of living abalone. Gills and digestive system appear to be the routes of entry. Autoradiography shows that of the muscular tissues the outer edge of the foot and epipodium are the most active and the edible columnar muscle the least active. (author)

Impact of Silver and Iron Nanoparticle Exposure on Cholesterol Uptake by Macrophages

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Jonathan H. Shannahan

2015-01-01

Full Text Available Macrophages are central to the development of atherosclerosis by absorbing lipids, promoting inflammation, and increasing plaque deposition. Nanoparticles (NPs are becoming increasingly common in biomedical applications thereby increasing exposure to the immune and vascular systems. This project investigated the influence of NPs on macrophage function and specifically cholesterol uptake. Macrophages were exposed to 20 nm silver NPs (AgNPs, 110 nm AgNPs, or 20 nm Fe3O4 NPs for 2 h and NP uptake, cytotoxicity, and subsequent uptake of fluorescently labeled cholesterol were assessed. Macrophage uptake of NPs did not induce cytotoxicity at concentrations utilized (25 μg/mL; however, macrophage exposure to 20 nm AgNPs reduced subsequent uptake of cholesterol. Further, we assessed the impact of a cholesterol-rich environment on macrophage function following NP exposure. In these sets of experiments, macrophages internalized NPs, exhibited no cytotoxicity, and altered cholesterol uptake. Alterations in the expression of scavenger receptor-B1 following NP exposure, which likely influences cholesterol uptake, were observed. Overall, NPs alter cholesterol uptake, which may have implications in the progression of vascular or immune mediated diseases. Therefore, for the safe development of NPs for biomedical applications, it is necessary to understand their impact on cellular function and biological interactions in underlying disease environments.

Root uptake of transuranic elements

International Nuclear Information System (INIS)

Schulz, R.K.

1977-01-01

The uptake of elements by plant roots is one of the important pathways of entry of many elements into the food chain of man. Data are cited showing plutonium concentration ratios, plant/soil, ranging from 10 -10 to 10 -3 . Concentration ratios for americium range from 10 -7 to 10 +1 . Limited experiments with curium and neptunium indicate that root uptake of curium is similar to that of americium and that plant uptake of neptunium is substantially larger than that of curium and americium. The extreme ranges of concentration ratios cited for plutonium and americium are due to a number of causes. Experimental conditions such as very intensive cropping will lead to abnormally high concentration ratios. In some experiments, addition of chelating agents markedly increased plant root uptake of transuranic elements. Particle size and composition of the source material influenced uptake of the transuranics by plants. Translocation within the plant, and soil factors such as pH and organic matter content, all affect concentration ratios

Extracellular enzymes facilitate electron uptake in biocorrosion and bioelectrosynthesis.

Science.gov (United States)

Deutzmann, Jörg S; Sahin, Merve; Spormann, Alfred M

2015-04-21

to have a significant impact not only on fundamental microbial and biogeochemical processes but also on applied bioelectrochemical systems, such as microbial electrosynthesis and biocorrosion. This study provides a simple mechanistic explanation for frequently observed fast electron uptake kinetics in microbiological systems without a direct transfer: free, cell-derived enzymes can interact with cathodic surfaces and catalyze the formation of intermediates that are rapidly consumed by microbial cells. This electron transfer mechanism likely plays a significant role in various microbial electron transfer reactions in the environment. Copyright © 2015 Deutzmann et al.

The E. coli pET expression system revisited-mechanistic correlation between glucose and lactose uptake.

Science.gov (United States)

Wurm, David Johannes; Veiter, Lukas; Ulonska, Sophia; Eggenreich, Britta; Herwig, Christoph; Spadiut, Oliver

2016-10-01

Therapeutic monoclonal antibodies are mainly produced in mammalian cells to date. However, unglycosylated antibody fragments can also be produced in the bacterium Escherichia coli which brings several advantages, like growth on cheap media and high productivity. One of the most popular E. coli strains for recombinant protein production is E. coli BL21(DE3) which is usually used in combination with the pET expression system. However, it is well known that induction by isopropyl β-D-1-thiogalactopyranoside (IPTG) stresses the cells and can lead to the formation of insoluble inclusion bodies. In this study, we revisited the pET expression system for the production of a novel antibody single-chain variable fragment (scFv) with the goal of maximizing the amount of soluble product. Thus, we (1) investigated whether lactose favors the recombinant production of soluble scFv compared to IPTG, (2) investigated whether the formation of soluble product can be influenced by the specific glucose uptake rate (q s,glu) during lactose induction, and (3) determined the mechanistic correlation between the specific lactose uptake rate (q s,lac) and q s,glu. We found that lactose induction gave a much greater amount of soluble scFv compared to IPTG, even when the growth rate was increased. Furthermore, we showed that the production of soluble protein could be tuned by varying q s,glu during lactose induction. Finally, we established a simple model describing the mechanistic correlation between q s,lac and q s,glu allowing tailored feeding and prevention of sugar accumulation. We believe that this mechanistic model might serve as platform knowledge for E. coli.

Traits affecting early season nitrogen uptake in nine legume species

Directory of Open Access Journals (Sweden)

Elana Dayoub

2017-02-01

Full Text Available Legume crops are known to have low soil N uptake early in their life cycle, which can weaken their ability to compete with other species, such as weeds or other crops in intercropping systems. However, there is limited knowledge on the main traits involved in soil N uptake during early growth and for a range of species. The objective of this research was to identify the main traits explaining the variability among legume species in soil N uptake and to study the effect of the soil mineral N supply on the legume strategy for the use of available N sources during early growth. Nine legume species were grown in rhizotrons with or without N supply. Root expansion, shoot and root biomass, nodule establishment, N2 fixation and mineral soil N uptake were measured. A large interspecific variability was observed for all traits affecting soil N uptake. Root lateral expansion and early biomass in relation to seed mass were the major traits influencing soil N uptake regardless of the level of soil N availability. Fenugreek, lentil, alfalfa, and common vetch could be considered weak competitors for soil N due to their low plant biomass and low lateral root expansion. Conversely, peanut, pea, chickpea and soybean had a greater soil N uptake. Faba bean was separated from other species having a higher nodule biomass, a higher N2 fixation and a lower seed reserve depletion. Faba bean was able to simultaneously fix N2 and take up soil N. This work has identified traits of seed mass, shoot and root biomass, root lateral expansion, N2 fixation and seed reserve depletion that allowing classification of legume species regarding their soil N uptake ability during early growth.

Effect of aliphatic, monocarboxylic, dicarboxylic, heterocyclic and sulphur-containing amino acids on Leishmania spp. chemotaxis.

Science.gov (United States)

Diaz, E; Zacarias, A K; Pérez, S; Vanegas, O; Köhidai, L; Padrón-Nieves, M; Ponte-Sucre, A

2015-11-01

In the sand-fly mid gut, Leishmania promastigotes are exposed to acute changes in nutrients, e.g. amino acids (AAs). These metabolites are the main energy sources for the parasite, crucial for its differentiation and motility. We analysed the migratory behaviour and morphological changes produced by aliphatic, monocarboxylic, dicarboxylic, heterocyclic and sulphur-containing AAs in Leishmania amazonensis and Leishmania braziliensis and demonstrated that L-methionine (10-12 m), L-tryptophan (10-11 m), L-glutamine and L-glutamic acid (10-6 m), induced positive chemotactic responses, while L-alanine (10-7 m), L-methionine (10-11 and 10-7 m), L-tryptophan (10-11 m), L-glutamine (10-12 m) and L-glutamic acid (10-9 m) induced negative chemotactic responses. L-proline and L-cysteine did not change the migratory potential of Leishmania. The flagellum length of L. braziliensis, but not of L. amazonensis, decreased when incubated in hyperosmotic conditions. However, chemo-repellent concentrations of L-alanine (Hypo-/hyper-osmotic conditions) and L-glutamic acid (hypo-osmotic conditions) decreased L. braziliensis flagellum length and L-methionine (10-11 m, hypo-/hyper-osmotic conditions) decreased L. amazonensis flagellum length. This chemotactic responsiveness suggests that Leishmania discriminate between slight concentration differences of small and structurally closely related molecules and indicates that besides their metabolic effects, AAs play key roles linked to sensory mechanisms that might determine the parasite's behaviour.

Using the North Dakota Immunization Information System to determine adolescent vaccination rates and uptake.

Science.gov (United States)

LoMurray, Keith; Sander, Molly

2011-01-01

We described the uptake and coverage rates of meningococcal conjugate vaccine (MCV4); tetanus-diphtheria-acellular pertussis vaccine (Tdap); and quadrivalent human papillomavirus vaccine (HPV4) in North Dakota using the North Dakota Immunization Information System (NDIIS). We analyzed all available MCV4, Tdap, and HPV4 doses given after vaccine licensure and through December 31, 2009, obtained from the NDIIS to identify trends and patterns in vaccine administration. We analyzed all data by administration date, age group, and health-care provider type. We also calculated missed opportunities to complete all recommended vaccines among vaccinated adolescents. For adolescents aged 13-17 years, 69.2% had > or = 1 dose of Tdap and 62.8% had > or = 1 dose of MCV4. Of females aged 13-17 years, 42.8% initiated the HPV4 vaccination series and 24.9% received > or = 3 HPV4 doses. Only 48.7% of males aged 13-17 years received both Tdap and MCV4 at the same visit, and only 11.5% of females aged 13-17 years received Tdap, MCV4, and HPV4 doses at the first visit. The NDIIS is useful in tracking adolescent vaccine uptake. The immunization rates for all three routinely recommended adolescent vaccines are rising in North Dakota, although at different paces. Providers should be educated about the importance of not missing opportunities to vaccinate, and school-based vaccination clinics should be used to reach adolescents who are less likely to have preventive care visits.

Gastrointestinal uptake of cadmium and zinc by a marine teleost Acanthopagrus schlegeli

International Nuclear Information System (INIS)

Zhang Li; Wang Wenxiong

2007-01-01

Gastrointestinal metal uptake represents a potential route for metal bioaccumulation in marine fish. Drinking of seawater for osmoregulation causes constant waterborne exposure of the gastrointestinal tract. Tissue specific Cd and Zn accumulation and distribution were investigated in juvenile black sea bream (Acanthopagrus schlegeli) exposed to waterborne Cd (5.7 nM) and Zn (2.6 nM) for 4 h-7 days. The intestine accumulated a large portion of the Cd (43-58%) and Zn (18-28%), and had the highest Cd (>1.0 nmol g -1 ) and Zn (>1.8 nmol g -1 ) concentrations of all body fractions, suggesting that the intestines were the major uptake sites for these waterborne metals. Among all the segments of the gastrointestinal tract, the anterior intestine played the most important role in Cd and Zn uptake. A gastrointestinal injection assay was conducted to distinguish waterborne metal uptake by the intestines and the gills. The intestine contained over 90% of the Cd in the body after depuration for 3-7 days, suggesting that little waterborne Cd entered the rest of the body through the intestine, and that Cd may exert its toxic effects on the gastrointestinal system. In contrast, intestine retained less than 20% of the total Zn after depuration, suggesting that Zn tended to be transported from the intestine to the internal tissues via the cardiovascular system. The uptake kinetics of waterborne Cd and Zn by the intestines and the gills were determined as a first-order and saturated pattern, respectively, over a wide range of ambient metal concentrations (6.2 nM-4.5 μM for Cd, and 13 nM-15 μM for Zn). An in vitro intestinal perfusion assay investigated the effects of intestinal metal composition and drinking rate on uptake. The presence of EDTA significantly reduced intestinal Zn uptake to 11%, while cysteine improved it by 59%. The intestinal Cd and Zn uptake rates were unaffected by the perfusion rate

The role of receptor topology in the vitamin D3 uptake and Ca"2"+ response systems

International Nuclear Information System (INIS)

Morrill, Gene A.; Kostellow, Adele B.; Gupta, Raj K.

2016-01-01

The steroid hormone, vitamin D_3, regulates gene transcription via at least two receptors and initiates putative rapid response systems at the plasma membrane. The vitamin D receptor (VDR) binds vitamin D_3 and a second receptor, importin-4, imports the VDR-vitamin D_3 complex into the nucleus via nuclear pores. Here we present evidence that the Homo sapiens VDR homodimer contains two transmembrane (TM) helices ("3"2"7E – D"3"4"2), two TM “half-helix” ("2"6"4K − N"2"7"6), one or more large channels, and 16 cholesterol binding (CRAC/CARC) domains. The importin-4 monomer exhibits 3 pore-lining regions ("2"2"6E – L"2"5"1; "7"6"8V – G"7"8"3; "8"7"6S – A"8"9"1) and 16 CRAC/CARC domains. The MEMSAT algorithm indicates that VDR and importin-4 may not be restricted to cytoplasm and nucleus. VDR homodimer TM helix-topology predicts insertion into the plasma membrane, with two 84 residue C-terminal regions being extracellular. Similarly, MEMSAT predicts importin-4 insertion into the plasma membrane with 226 residue extracellular N-terminal regions and 96 residue C-terminal extracellular loops; with the pore-lining regions contributing gated Ca"2"+ channels. The PoreWalker algorithm indicates that, of the 427 residues in each VDR monomer, 91 line the largest channel, including two vitamin D_3 binding sites and residues from both the TM helix and “half-helix”. Cholesterol-binding domains also extend into the channel within the ligand binding region. Programmed changes in bound cholesterol may regulate both membrane Ca"2"+ response systems and vitamin D_3 uptake as well as receptor internalization by the endomembrane system culminating in uptake of the vitamin D_3-VDR-importin-4 complex into the nucleus.

A two-dimensional simulation model of phosphorus uptake including crop growth and P-response

NARCIS (Netherlands)

Mollier, A.; Willigen, de P.; Heinen, M.; Morel, C.; Schneider, A.; Pellerin, S.

2008-01-01

Modelling nutrient uptake by crops implies considering and integrating the processes controlling the soil nutrient supply, the uptake by the root system and relationships between the crop growth response and the amount of nutrient absorbed. We developed a model that integrates both dynamics of maize

Circadian rhythm in ''1''5O-labeled water uptake manner of a soybean plant by PETIS (Positron Emitting Tracer Imaging System)

Energy Technology Data Exchange (ETDEWEB)

Nakanishi, Tomoko M.; Yokota, Harumi; Tanoi, Keitaro; Furukawa, Jun; Ikeue, Natsuko; Ookuni, Yoko [Tokyo Univ. (Japan). Graduate School of Agricultural and Life Sciences; Uchida, Hiroshi; Tsuji, Atsunori

2001-05-01

We present a circadian rhythm of water uptake manner in a soybean plant through realtime imaging of water, labeled with {sup 15}O. Nitrogen gas was irradiated with deuterons accelerated by a cyclotron at Hamamatsu Photonics Co. to produce {sup 15}O-labeled water. Then the {sup 15}O-labeled water was supplied to a soybean plant from the root and the realtime water uptake amount was measured for 20 min by Positron Emitting Tracer Imaging System (PETIS). All the targeting positions for the measurements were stems, two points at an internode between root and the first leaves, between the first leaves and the first trifoliates and between the first trifoliates and the second trifoliates. The water uptake amount was gradually increased and showed its maximum at around 13:00, especially at the basal part of the stem. Then the water uptake activity was gradually decreased until 17:00. The water amount taken up by a plant at 13:00 was about 40% higher than that at 17:00. (author)

New aspects of cellular thallium uptake: Tl+-Na+-2Cl--cotransport is the central mechanism of ion uptake

International Nuclear Information System (INIS)

Sessler, M.J.; Maul, F.D.; Hoer, G.; Munz, D.L.; Geck, P.

1986-01-01

Cellular uptake mechanisms of 201 Tl + were studied in Ehrlich mouse ascites tumor cells. 201 Tl + phases the cell membrane of tumor cells using three transport systems: the ATPase, the Tl + -Na + -2Cl - -cotransport, and the Ca ++ -dependent ion channel. In the case of 201 Tl + the main route for entering the cells was the cotransport, its importance increasing with the age of the cells; in parallel, the ATPase activity was reduced. In contrast, the transport capacities of the ATPase and the cotransport were of the same magnitude in the case of 42 K + and 86 Rb + . This change in ion distribution was not brought about by varying velocity relations but by changing the number of transport systems in the cell membrane. There was no relationship between transport rates and diameters of the ions. 201 Tl + distribution is proportional to that of K + with a higher intracellular concentration of about 30%. Under physiological conditions the cotransport was reversible suggesting the ability to regulate steady state during varying extracellular ion concentrations. Cells and medium were two compartments, kinetically seen. Due to the significant difference of transport capacities between the three systems with the respective ions the term ''potassium-thallium-analogy'' may be misleading as it erroneously assumes identical uptake conditions. (orig.) [de

Surface modification of solid lipid nanoparticles for oral delivery of curcumin: Improvement of bioavailability through enhanced cellular uptake, and lymphatic uptake.

Science.gov (United States)

Baek, Jong-Suep; Cho, Cheong-Weon

2017-08-01

Curcumin has been reported to exhibit potent anticancer effects. However, poor solubility, bioavailability and stability of curcumin limit its in vivo efficacy for the cancer treatment. Solid lipid nanoparticles (SLN) are a promising delivery system for the enhancement of bioavailability of hydrophobic drugs. However, burst release of drug from SLN in acidic environment limits its usage as oral delivery system. Hence, we prepared N-carboxymethyl chitosan (NCC) coated curcumin-loaded SLN (NCC-SLN) to inhibit the rapid release of curcumin in acidic environment and enhance the bioavailability. The NCC-SLN exhibited suppressed burst release in simulated gastric fluid while sustained release was observed in simulated intestinal fluid. Furthermore, NCC-SLN exhibited increased cytotoxicity and cellular uptake on MCF-7 cells. The lymphatic uptake and oral bioavailability of NCC-SLN were found to be 6.3-fold and 9.5-fold higher than that of curcumin solution, respectively. These results suggest that NCC-SLN could be an efficient oral delivery system for curcumin. Copyright © 2017 Elsevier B.V. All rights reserved.

Toward a transport-based analysis of nutrient spiraling and uptake in streams

Science.gov (United States)

Runkel, Robert L.

2007-01-01

Nutrient addition experiments are designed to study the cycling of nutrients in stream ecosystems where hydrologic and nonhydrologic processes determine nutrient fate. Because of the importance of hydrologic processes in stream ecosystems, a conceptual model known as nutrient spiraling is frequently employed. A central part of the nutrient spiraling approach is the determination of uptake length (SW), the average distance traveled by dissolved nutrients in the water column before uptake. Although the nutrient spiraling concept has been an invaluable tool in stream ecology, the current practice of estimating uptake length from steady-state nutrient data using linear regression (called here the "SW approach") presents a number of limitations. These limitations are identified by comparing the exponential SW equation with analytical solutions of a stream solute transport model. This comparison indicates that (1) SW, is an aggregate measure of uptake that does not distinguish between main channel and storage zone processes, (2) SW, is an integrated measure of numerous hydrologie and nonhydrologic processes-this process integration may lead to difficulties in interpretation when comparing estimates of SW, and (3) estimates of uptake velocity and areal uptake rate (Vf and U) based on S W, are not independent of system hydrology. Given these findings, a transport-based approach to nutrient spiraling is presented for steady-state and time-series data sets. The transport-based approach for time-series data sets is suggested for future research on nutrient uptake as it provides a number of benefits, including the ability to (1) separately quantify main channel and storage zone uptake, (2) quantify specific hydrologic and nonhydrologic processes using various model parameters (process separation), (3) estimate uptake velocities and areal uptake rates that are independent of hydrologic effects, and (4) use short-term, non-plateau nutrient additions such that the effects of

Biotransformation of 5-hydroxy-methylfurfural into 2,5-furan-dicarboxylic acid by bacterial isolate using thermal acid algal hydrolysate.

Science.gov (United States)

Yang, Chu-Fang; Huang, Ci-Ruei

2016-08-01

Thermal acid hydrolysis is often used to deal with lignocellulosic biomasses, but 5-hydroxy-methylfurfural (5-HMF) formed during hydrolysis deeply influences downstream fermentation. 2,5-Furan-dicarboxylic acid (FDCA), which is in the list of future important biomass platform molecules can be obtained using 5-HMF biotransformation. Based on the connection between 5-HMF removal in acid hydrolysate and FDCA production, the optimum thermal acid hydrolysis condition for macroalgae Chaetomorpha linum was established. Potential microbes capable of transforming 5-HMF into FDCA were isolated and characterized under various parameters and inoculated into algal hydrolysate to perform 5-HMF biotransformation. The optimum hydrolysis condition was to apply 0.5M HCl to treat 3% algal biomass under 121°C for 15min. Isolated Burkholderia cepacia H-2 could transform 2000mg/L 5-HMF at the initial pH of 7 at 28°C and 1276mg/L FDCA was received. Strain B. cepacia H-2 was suitable for treating the algal hydrolysate without dilution, receiving 989.5mg/L FDCA. Copyright © 2016 Elsevier Ltd. All rights reserved.

Policies for biosimilar uptake in Europe: An overview.

Science.gov (United States)

Moorkens, Evelien; Vulto, Arnold G; Huys, Isabelle; Dylst, Pieter; Godman, Brian; Keuerleber, Simon; Claus, Barbara; Dimitrova, Maria; Petrova, Guenka; Sović-Brkičić, Ljiljana; Slabý, Juraj; Šebesta, Robin; Laius, Ott; Karr, Allan; Beck, Morgane; Martikainen, Jaana E; Selke, Gisbert W; Spillane, Susan; McCullagh, Laura; Trifirò, Gianluca; Vella Bonanno, Patricia; Mack, Asbjørn; Fogele, Antra; Viksna, Anita; Władysiuk, Magdalena; Mota-Filipe, Helder; Meshkov, Dmitry; Kalaba, Marija; Mencej Bedrač, Simona; Fürst, Jurij; Zara, Corrine; Skiöld, Peter; Magnússon, Einar; Simoens, Steven

2017-01-01

Across European countries, differences exist in biosimilar policies, leading to variations in uptake of biosimilars and divergences in savings all over Europe. The aim of this article is to provide an overview of different initiatives and policies that may influence the uptake of biosimilars in different European countries. Recommendations will be formulated on how to create sustainable uptake. An overview of policies on biosimilars was obtained via a questionnaire, supplemented with relevant articles. Topics were organized in five themes: availability, pricing, reimbursement, demand-side policies, and recommendations to enhance uptake. In all countries studied, biological medicines are available. Restrictions are mainly dependent on local organization of the healthcare system. Countries are willing to include biosimilars for reimbursement, but for commercial reasons they are not always marketed. In two thirds of countries, originator and biosimilar products may be subjected to internal reference pricing systems. Few countries have implemented specific incentives targeting physicians. Several countries are implementing pharmacist substitution; however, the scope and rules governing such substitution tend to vary between these countries. Reported educational policies tend to target primarily physicians, whereas fewer initiatives were reported for patients. Recommendations as proposed by the different country experts ranged from the need for information and communication on biosimilars to competitive pricing, more support for switching and guidance on substitution. Most countries have put in place specific supply-side policies for promoting access to biosimilars. To supplement these measures, we propose that investments should be made to clearly communicate on biosimilars and educate stakeholders. Especially physicians need to be informed on the entry and use of biosimilars in order to create trust. When physicians are well-informed on the treatment options, further

Radioiodine uptake by plants from soils

International Nuclear Information System (INIS)

Sabova, T.

1976-01-01

The uptake and accumulation of radioiodine by wheat, maize and peas from various types of soil have been studied. The uptake depends on the type of soil, on its content of organic matter and on the amount of fertilizer. Radioiodine is mainly accumulated in the roots. Accumulation in above-ground plant parts decreases in the following order: wheat, maize, peas. Uptake was highest from humus and clay soils and lowest from black and meadow soils. Application of chloride fertilizer or carrier iodine lead to an increase of radioiodine uptake in the whole plant. (author)

Uptake, translocation, and toxicity of gold nanorods in maize

Science.gov (United States)

Moradi Shahmansouri, Nastaran

Nanomaterials are widely used in many different products, such as electronics, cosmetics, industrial goods, biomedical uses, and other material applications. The heavy emission of nanomaterials into the environment has motived increasing concern regarding the effects on ecosystems, food chains, and, human health. Plants can tolerate a certain amount of natural nanomaterials, but large amounts of ENMs released from a variety of industries could be toxic to plants and possibly threaten the ecosystem. Employing phytoremediation as a contamination treatment method may show promise. However a pre-requisite to successful treatment is a better understanding of the behavior and effects of nanomaterials within plant systems. This study is designed to investigate the uptake, translocation, bioavailability, and toxicity of gold nanorods in maize plants. Maize is an important food and feed crop that can be used to understand the potential hazardous effects of nanoparticle uptake and distribution in the food chain. The findings could be an important contribution to the fields of phytoremediation, agri-nanotechnology, and nanoparticle toxicity on plants. In the first experiment, hydroponically grown maize seedlings were exposed to similar doses of commercial non-coated gold nanorods in three sizes, 10x34 nm, 20x75 nm, and 40x96 nm. The three nanorod species were suspended in solutions at concentrations of 350 mg/l, 5.8 mg/l, and 14 mg/l, respectively. Maize plants were exposed to all three solutions resulting in considerably lower transpiration and wet biomass than control plants. Likewise, dry biomass was reduced, but the effect is less pronounced than that of transpiration and wet biomass. The reduced transpiration and water content, which eventually proved fatal to exposed plants, were most likely a result of toxic effect of gold nanorod, which appeared to physically hinder the root system. TEM images proved that maize plants can uptake gold particles and accumulate them in

Effect of microorganisms on the uptake of radionuclides by plant, application of the plant-microorganism complex system to the phytoremediation

International Nuclear Information System (INIS)

Soshi, Takayuki; Enomoto, Shuichi; Yamaguchi, Isamu

2003-01-01

Effects of the microorganisms to the uptake of radionuclides by host plant of endophyte (Neotyphodium lolii) to perennial ryegrass, rice pathogenic fungi Gibberella fujikuroi to rice, Fusarium species that is symbiotic to tomato was monitored using the multitracer technique. Perennial ryegrass colonized by endophyte showed lower uptake rate rather than the plant without endophyte. Gibberella fujikuroi was able to increase the uptake of radionuclides (Cs, Sr, Mn, Zn and Co) by rice via infection. Uptake rate of Mn and Co by infected rice plant was elevated to almost two times as that of non-infected plant. The effect of five nonpathogenic strains of F. oxysporum, F. spio rycopersici (N.P.F.) isolated from tomato rhizosphere was analyzed. Each strain shows uptake enhancement of some radionuclide by plant. At least one strain shows critical enhancement of the uptake of Sr and Cs both. (author)

Insulin resistance and maximal oxygen uptake

DEFF Research Database (Denmark)

Seibaek, Marie; Vestergaard, Henrik; Burchardt, Hans

2003-01-01

BACKGROUND: Type 2 diabetes, coronary atherosclerosis, and physical fitness all correlate with insulin resistance, but the relative importance of each component is unknown. HYPOTHESIS: This study was undertaken to determine the relationship between insulin resistance, maximal oxygen uptake......, and the presence of either diabetes or ischemic heart disease. METHODS: The study population comprised 33 patients with and without diabetes and ischemic heart disease. Insulin resistance was measured by a hyperinsulinemic euglycemic clamp; maximal oxygen uptake was measured during a bicycle exercise test. RESULTS......: There was a strong correlation between maximal oxygen uptake and insulin-stimulated glucose uptake (r = 0.7, p = 0.001), and maximal oxygen uptake was the only factor of importance for determining insulin sensitivity in a model, which also included the presence of diabetes and ischemic heart disease. CONCLUSION...

OXYGEN UPTAKE KINETICS IN SPORT, EXERCISE AND MEDICINE

Directory of Open Access Journals (Sweden)

David C. Poole

2005-03-01

Full Text Available The objective of the book is to discuss the principal determinants of oxygen uptake dynamics which is essential to developing exercise performance and improving quality of life for patients, especially those with cardio-respiratory diseases. A broad review of the current knowledge about this relatively less studied field is provided by this book. Incidentally, it updates the reader about how a person can use his/her aerobic energy system more effectively in order to fatigue gradually and be able to endure more physical activity. It also discusses the effects of exercise training in speeding up oxygen uptake kinetics, and the effects of ageing and a selection of conditions in slowing oxygen dynamics and declining exercise capacity.

The effect of nucleotides and adenosine on stimulus-evoked glutamate release from rat brain cortical slices

OpenAIRE

Bennett, Gillian C; Boarder, Michael R

2000-01-01

Evidence has previously been presented that P1 receptors for adenosine, and P2 receptors for nucleotides such as ATP, regulate stimulus-evoked release of biogenic amines from nerve terminals in the brain. Here we investigated whether adenosine and nucleotides exert presynaptic control over depolarisation-elicited glutamate release.Slices of rat brain cortex were perfused and stimulated with pulses of 46 mM K+ in the presence of the glutamate uptake inhibitor L-trans-pyrrolidine-2,4-dicarboxyl...

Quantitative uptake of colloidal particles by cell cultures

Energy Technology Data Exchange (ETDEWEB)

Feliu, Neus [Department of Physics, Philipps University Marburg, Marburg (Germany); Department for Clinical Science, Intervention and Technology (CLINTEC),Karolinska Institutet, Stockholm (Sweden); Hühn, Jonas; Zyuzin, Mikhail V.; Ashraf, Sumaira; Valdeperez, Daniel; Masood, Atif [Department of Physics, Philipps University Marburg, Marburg (Germany); Said, Alaa Hassan [Department of Physics, Philipps University Marburg, Marburg (Germany); Physics Department, Faculty of Science, South Valley University (Egypt); Escudero, Alberto [Department of Physics, Philipps University Marburg, Marburg (Germany); Instituto de Ciencia de Materiales de Sevilla, CSIC — Universidad de Sevilla, Seville (Spain); Pelaz, Beatriz [Department of Physics, Philipps University Marburg, Marburg (Germany); Gonzalez, Elena [Department of Physics, Philipps University Marburg, Marburg (Germany); University of Vigo, Vigo (Spain); Duarte, Miguel A. Correa [University of Vigo, Vigo (Spain); Roy, Sathi [Department of Physics, Philipps University Marburg, Marburg (Germany); Chakraborty, Indranath [Department of Chemistry, University of Illinois at Urbana Champaign, Urbana, IL (United States); Lim, Mei L.; Sjöqvist, Sebastian [Department for Clinical Science, Intervention and Technology (CLINTEC),Karolinska Institutet, Stockholm (Sweden); Jungebluth, Philipp [Department of Thoracic Surgery, Thoraxklinik, Heidelberg University, Heidelberg (Germany); Parak, Wolfgang J., E-mail: wolfgang.parak@physik.uni-marburg.de [Department of Physics, Philipps University Marburg, Marburg (Germany); CIC biomaGUNE, San Sebastian (Spain)

2016-10-15

The use of nanotechnologies involving nano- and microparticles has increased tremendously in the recent past. There are various beneficial characteristics that make particles attractive for a wide range of technologies. However, colloidal particles on the other hand can potentially be harmful for humans and environment. Today, complete understanding of the interaction of colloidal particles with biological systems still remains a challenge. Indeed, their uptake, effects, and final cell cycle including their life span fate and degradation in biological systems are not fully understood. This is mainly due to the complexity of multiple parameters which need to be taken in consideration to perform the nanosafety research. Therefore, we will provide an overview of the common denominators and ideas to achieve universal metrics to assess their safety. The review discusses aspects including how biological media could change the physicochemical properties of colloids, how colloids are endocytosed by cells, how to distinguish between internalized versus membrane-attached colloids, possible correlation of cellular uptake of colloids with their physicochemical properties, and how the colloidal stability of colloids may vary upon cell internalization. In conclusion three main statements are given. First, in typically exposure scenarios only part of the colloids associated with cells are internalized while a significant part remain outside cells attached to their membrane. For quantitative uptake studies false positive counts in the form of only adherent but not internalized colloids have to be avoided. pH sensitive fluorophores attached to the colloids, which can discriminate between acidic endosomal/lysosomal and neutral extracellular environment around colloids offer a possible solution. Second, the metrics selected for uptake studies is of utmost importance. Counting the internalized colloids by number or by volume may lead to significantly different results. Third, colloids

Controls on thallium uptake during hydrothermal alteration of the upper ocean crust

Science.gov (United States)

Coggon, Rosalind M.; Rehkämper, Mark; Atteck, Charlotte; Teagle, Damon A. H.; Alt, Jeffrey C.; Cooper, Matthew J.

2014-11-01

Hydrothermal circulation is a fundamental component of global biogeochemical cycles. However, the magnitude of the high temperature axial hydrothermal fluid flux remains disputed, and the lower temperature ridge flank fluid flux is difficult to quantify. Thallium (Tl) isotopes behave differently in axial compared to ridge flank systems, with Tl near-quantitatively stripped from the intrusive crust by high temperature hydrothermal reactions, but added to the lavas during low temperature reaction with seawater. This contrasting behavior provides a unique approach to determine the fluid fluxes associated with axial and ridge flank environments. Unfortunately, our understanding of the Tl isotopic mass balance is hindered by poor knowledge of the mineralogical, physical and chemical controls on Tl-uptake by the ocean crust. Here we use analyses of basaltic volcanic upper crust from Integrated Ocean Drilling Program Hole U1301B on the Juan de Fuca Ridge flank, combined with published analyses of dredged seafloor basalts and upper crustal basalts from Holes 504B and 896A, to investigate the controls on Tl-uptake by mid-ocean ridge basalts and evaluate when in the evolution of the ridge flank hydrothermal system Tl-uptake occurs. Seafloor basalts indicate an association between basaltic uptake of Tl from cold seawater and uptake of Cs and Rb, which are known to partition into K-rich phases. Although there is no clear relationship between Tl and K contents of seafloor basalts, the data do not rule out the incorporation of at least some Tl into the same minerals as the alkali elements. In contrast, we find no relationship between the Tl content and either the abundance of secondary phyllosilicate minerals, or the K, Cs or Rb contents in upper crustal basalts. We conclude that the uptake of Tl and alkali elements during hydrothermal alteration of the upper crust involves different processes and/or mineral phases compared to those that govern seafloor weathering. Furthermore

Nutrient Uptake and Metabolism Along a Large Scale Tropical Physical-Chemical Gradient

Science.gov (United States)

Tromboni, F.; Neres-Lima, V.; Saltarelli, W. A.; Miwa, A. C. P.; Cunha, D. G. F.

2016-12-01

Nutrient spiraling is a whole-system approach for estimating nutrient uptake that can be used to assess aquatic ecosystems' responses to environmental change and anthropogenic impacts. Historically research on nutrient dynamic uptake in streams has focused on single nutrient dynamics and only rarely the stoichiometric uptake has been considered and linked to carbon metabolism driven by autotrophic and heterotrophic production. We investigated the relationship between uptake of phosphate (PO43-), nitrate (NO3-) ammonium (NH4+) and total dissolve nitrogen (DIN)/ PO43-; and gross primary production (GPP), respiration (R), and net ecosystem productivity (NEP) in six relatively pristine streams with differences regarding canopy cover and physical characteristics, located in a large scale gradient from tropical Atlantic Forest to an Atlantic forest/Cerrado (Brazilian Savanna) transition. We carried out whole stream instantaneous additions of PO43-, NO3- and NH4+ added to each stream in combination, using the TASCC (Tracer Additions for Spiraling Curve Characterization) method. Metabolism measurements were performed in the same streams right after uptake was measured, using one-station open channel method and re-aeration estimations for those sites. We found different background concentrations in the streams located in the Atlantic forest compared with the transition area with Cerrado. In general PO43- and NO3- uptake increased with the decreasing of canopy cover, while a positive relation with background concentration better explained NH4+uptake. DIN/PO43- uptake increased with increasing R and NEP. Little work on functional characteristics of pristine streams has been conducted in this region and this work provides an initial characterization on nitrogen and phosphorus dynamics as well as their stoichiometric uptake in streams.

Physiological FDG uptake in the palatine tonsils

International Nuclear Information System (INIS)

Kawabe, Joji; Okamura, Terue; Shakudo, Miyuki

2001-01-01

In clinical F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) studies of the head and neck region, remarkable symmetric tonsillar FDG uptake is sometimes observed. We determined the incidence and degree of tonsillar FDG uptake and investigated the significance of tonsillar FDG uptake. Between June 1998 and August 1998, we obtained informed consent from 17 patients who were scheduled to undergo a FDG-PET study for their own disease (11 men and 6 women; aged 22 to 77 yr) and who did not have head and neck disease to perform FDG-PET scanning of the head and neck region in addition to their target organs. The incidence and degree of tonsillar FDG uptake were determined. Remarkable tonsillar FDG uptake was found in 9 patients. The SUVs of these FDG uptakes ranged from 2.48 to 6.75, with a mean of 4.29±1.20 (SD). Tonsillar FDG uptakes in the remaining 8 patients were not remarkable, and their SUVs ranged from 1.93 to 3.31, with a mean of 2.46±0.45. Head and neck disease does not appear to have been responsible for the increase in tonsillar FDG uptake. Differences among tonsillar FDG uptake in these 17 patients without head and neck disease appear to reflect differences in activity of ''physiological'' inflammation of the palatine tonsils. (author)

Thyroidal radioisotope uptake in euthyroid cats : a comparison between 131I and 99MTcO4

Directory of Open Access Journals (Sweden)

N. Lambrechts

1997-07-01

Full Text Available Two thyroidal evaluation systems in euthyroid cats (n = 12 were compared. A single, confirmed hyperthyroid cat was included for interest. Firstly, thyroidal uptake of an intravenous bolus of approximately 111 MBq (3 mCi 99MTcO4- was estimated by using a scintillation camera and calculating the ratio of thyroid to salivary activities at 20 min and 4 h. Thyroid to salivary activity ratios were 1:1 at 20 min and 2:1 at 4 h. Two discrete areas of salivary uptake were identified, namely a parotid/mandibular complex and a more rostral buccal/sublingual complex. These results were compared to radioiodine uptake of an oral dose of approximately 0.925 MBq (25 mCi 131I using a standard thyroid uptake system, measured at 1, 2, 4, 6, 8, 10, 12, 24 and 48 h after administration. Mean radioiodine thyroidal uptake started at 33 % at 1 h, stabilised at 21 % between 4 and 24 h, and dropped to 18 % at 48 h. There was a significant correlation between the early thyroid:salivary ratio of the parotid/mandibular complex and the radioiodine uptake at 12 h.

Barriers to cervical cancer screening uptake among rural women in ...

African Journals Online (AJOL)

[5] Among Asian-American women, psychosocial ... poorly-trained personnel were health system-related barriers. In sub-Saharan ... explored the religious and cultural barriers to cervical screening ... perceived barriers to screening uptake.

Testing a structural model of young driver willingness to uptake Smartphone Driver Support Systems.

Science.gov (United States)

Kervick, Aoife A; Hogan, Michael J; O'Hora, Denis; Sarma, Kiran M

2015-10-01

There is growing interest in the potential value of using phone applications that can monitor driver behaviour (Smartphone Driver Support Systems, 'SDSSs') in mitigating risky driving by young people. However, their value in this regard will only be realised if young people are willing to use this technology. This paper reports the findings of a study in which a novel structural model of willingness to use SDSSs was tested. Grounded in the driver monitoring and Technology Acceptance (TA) research literature, the model incorporates the perceived risks and gains associated with potential SDSS usage and additional social cognitive factors, including perceived usability and social influences. A total of 333 smartphone users, aged 18-24, with full Irish driving licenses completed an online questionnaire examining willingness or Behavioural Intention (BI) to uptake a SDSS. Following exploratory and confirmatory factor analyses, structural equation modelling indicated that perceived gains and social influence factors had significant direct effects on BI. Perceived risks and social influence also had significant indirect effects on BI, as mediated by perceived gains. Overall, this model accounted for 72.5% of the variance in willingness to uptake SDSSs. Multi-group structural models highlighted invariance of effects across gender, high and low risk drivers, and those likely or unlikely to adopt novel phone app technologies. These findings have implications for our understanding of the willingness of young drivers to adopt and use SDSSs, and highlight potential factors that could be targeted in behavioural change interventions seeking to improve usage rates. Copyright © 2015 Elsevier Ltd. All rights reserved.

The industrial logistic surface: Displaying the impact of energy policy on uptake of new technologies

International Nuclear Information System (INIS)

Mathews, John A.; Baroni, Paolo

2013-01-01

Two processes are widely viewed as fundamental to the transition from conventional fossil-fuelled energy systems to renewable powered systems that is under way. There is firstly the progressive reduction in costs as investment, or production/energy generating capacity, grows. To see the uptake itself we need a second process, captured as a logistic curve (or S-shaped curve) that depicts the uptake of the new technology as an industrial substitution process unfolding over time. In this paper we put these two processes together, deriving a single expression that depicts uptake as a function of both cumulative investment and time, where the key parameter can be related to the learning coefficient. We display this expression in the form of a 3-dimensional surface that we dub the Logistic Industrial Surface. It is applied to a real case involving cost reduction and logistic uptake of solar PV (photovoltaic) cells. In this specific case, we estimate the learning curve involved and on this basis calculate that (for an initial time period) early in the trajectory a cost reduction of 8.7% would be associated with an increase in investment of 10%, leading to an increase in uptake by 4.35%; whereas a cost reduction of 44% (corresponding to a doubling of investment) would lead to a more rapid uptake of 41.95%. We claim that this is the first demonstration in the literature of a direct connection between investment levels, cost reductions and consequent levels of uptake according to logistic industrial dynamics. - Highlights: • We derive an expression which combines learning curves with logistic uptake. • This expression is termed an ILS (industrial logistic surface). • We illustrate the ILS through different investment schedules. • We apply the new framework to the case of solar PV cost reductions and uptake. • We demonstrate the workings of the ILS with a numerical example

Kinetics and autoradiography of high affinity uptake of serotonin by primary astrocyte cultures

International Nuclear Information System (INIS)

Katz, D.M.; Kimelberg, H.K.

1985-01-01

Primary astrocyte cultures prepared from the cerebral cortices of neonatal rats showed significant accumulation of serotonin (5-hydroxytryptamine; [ 3 H]-5-HT). At concentrations in the range of 0.01 to 0.7 microM [ 3 H]-5-HT, this uptake was 50 to 85% Na+ dependent and gave a Km of 0.40 +/- 0.11 microM [ 3 H]-5-HT and a Vmax of 6.42 +/- 0.85 (+/- SEM) pmol of [ 3 H]-5-HT/mg of protein/4 min for the Na+-dependent component. In the absence of Na+ the uptake was nonsaturable. Omission of the monoamine oxidase inhibitor pargyline markedly reduced the Na+-dependent component of [ 3 H]-5-HT uptake but had a negligible effect on the Na+-independent component. This suggest significant oxidative deamination of serotonin after it has been taken up by the high affinity system, followed by release of its metabolite. The authors estimated that this system enabled the cells to concentrate [ 3 H]-5-HT up to 44-fold at an external [ 3 H]-5-HT concentration of 10(-7) M. Inhibition of [ 3 H]-5-HT uptake by a number of clinically effective antidepressants was also consistent with a specific high affinity uptake mechanism for 5-HT, the order of effectiveness of inhibition being chlorimipramine greater than fluoxetine greater than imipramine = amitriptyline greater than desmethylimipramine greater than iprindole greater than mianserin. Uptake of [ 3 H]-5-HT was dependent on the presence of Cl- as well as Na+ in the medium, and the effect of omission of both ions was nonadditive. Varying the concentration of K+ in the media from 1 to 50 mM had a limited effect on [ 3 H]-5-HT uptake

Characterization of uptake and translocation of radioactive herbicides in a parasitic-host system

International Nuclear Information System (INIS)

Diaz S, Jorge; Lopez G, Francisca; Garcia T, Luis

1999-01-01

Uptake and translocation of [14C]-propyzamide applied to the sunflower seed by coating or soaking, of [14C]-imazapyr and [14C]-glyphosate both applied at post emergence, were studied in sunflower (Helianthus annuus L.) parasitising or not by nodding broom rape (Orobanche cumana Wallr.). Sunflower seed absorbed 9.8 and 3.4% of [14C]-propyzamide applied by coating or soaking, respectively, and less than 1% was translocated to the nodding broom rape. In sunflower plants infested and not infested with nodding broom rape, nearly 90% of [14C]-imazapyr was absorbed and 26% was translocated to the parasitic weed. Uptake of [14C]-glyphosate was similar (50%) for infested or not infested sunflower plants and only the 6% was translocated to the nodding broom rape

Uptake of benzyladenine by excised watermelon cotyledons.

Science.gov (United States)

Lampugnani, M G; Fantelli, R; Longo, G P; Longo, C P; Rossi, G

1981-07-01

The uptake of 8-[(14)C]N(6)-benzyladenine (BA) was studied in excised watermelon (Citrullus vulgaris Schrad.) cotyledons 24 hours after the start of imbibition. The passive nature of this uptake is suggested by the following evidence: (a) no sign of saturation on increasing external concentration of BA; (b) no decrease in uptake under conditions that inhibit ATP synthesis; (c) no change in amount of radioactivity absorbed when cotyledons are frozen and thawed before the uptake test. About two-thirds of the radioactivity taken up is released after 12 hours of washing. If the washing is performed at 2 C very little radioactivity is released.There seems to be a correlation between the level of radioactivity (i.e. of BA + derivatives) present in the cotyledons and the magnitude of hormonal responses that are observed four days after uptake. This relationship holds regardless of whether a given level of radioactivity has been reached after a short period of uptake or after a long period of uptake followed by washing.

Can tumor uptake Tc-99m MDP ?

International Nuclear Information System (INIS)

Yand Shun, Fang; Yao, Ming; Zeng, Jun; Shi Zhen, Yu; Zhao Lan, Xiang; Dong Qiang, Gang

2003-01-01

To explore the mechanism of technetium-99m-methylene diphosphonate (MDP) uptake within tumor through analyze a distribution of Tc-99m MDP in mice bearing tumor cell lines. Methods: The uptake of Tc-99m MDP was analyzed in seven human tumor cell lines ( SPC-A1 adenocarcinoma of lung cancer, Bcap-37 Breast cancer, T-24 Bladder cancer, SKOV3 Ovary carcinoma, Hela-229 Cervical carcinoma, SCI-OS Osteosarcoma, SCI-375 Melanoma) and mouse Lewis lung cancer cell line. They were transplanted into athymic mice, SCID nude mice and C57BL/6 mice, respectively. Approximately 10(6) cells of each cell line were injected subcutaneously into a right chest of mouse. After 4 and 5 weeks, the Tc-99m MDP scintigraphy were determined 6 hours after tail vein injection of 74MBq in 0.05ml every mouse. Result: Biodistribution and tumor uptake MDP was different in the various cell types investigated. According to the Region Ratio program of Siemens Power Macintosh 9500 Computer System, region of interests (RIOs) placed on a small part of the tumor and horizontal copied to left background (T/B) and thoracic spine (T/N) of mice in Tc-99m MDP imaging. The average cpm/pixel ratios were calculated by standardized uptake measure (SUM) and determined the tumor-positive value (T/B) greater than or equal to 1.2. T/B of cell lines were sorted from higher to lower as follows: SCI-OS, Lewis, SKOV3, SCI-375, T-24, SPC-A1, Bcap-37, Hela-229. T/N: SCI-OS, SKOV3, T-24, SCI-375, Lewis, SPC-A1, Bcap-37, Hela-229. The biodistribution data of 99Tcm-MDP in SPC-A1 tumor-bearing BALB/c nude mice were given as ID/g and represent the means D (n=13) in 30 hours after injection of Tc-99m MDP. ID/g of major tissue were sorted from higher to lower as follows: thoracic spine, lumbar, ribs, kidneys, the center of tumor, the ulcer of tumor, the surrounding of tumor, lymph node, blood, lungs, heart, liver. Conclusions: Most of tumor can uptake Tc-99m MDP including human adenocarcinoma. The uptake rate in the center tissue of

Seasonal temperatures have more influence than nitrogen fertilizer rates on cucumber yield and nitrogen uptake in a double cropping system

Energy Technology Data Exchange (ETDEWEB)

Guo Ruiying; Li Xiaolin [College of Resources and Environmental Sciences, China Agricultural University, No. 2 Yuanmingyuan Xilu, Haidian District, Beijing 100094 (China); Christie, Peter [College of Resources and Environmental Sciences, China Agricultural University, No. 2 Yuanmingyuan Xilu, Haidian District, Beijing 100094 (China); Agricultural and Environmental Science Department, Queen' s University Belfast, Belfast BT9 5PX (United Kingdom); Chen Qing [College of Resources and Environmental Sciences, China Agricultural University, No. 2 Yuanmingyuan Xilu, Haidian District, Beijing 100094 (China)], E-mail: qchen@cau.edu.cn; Zhang Fusuo [College of Resources and Environmental Sciences, China Agricultural University, No. 2 Yuanmingyuan Xilu, Haidian District, Beijing 100094 (China)

2008-02-15

Two-year greenhouse cucumber experiments were conducted to investigate seasonal effects on fruit yield, dry matter allocation, and N uptake in a double-cropping system with different fertilizer management. Seasonal effects were much greater than fertilizer effects, and winter-spring (WS) cucumber attained higher fruit yields and N uptake than autumn-winter (AW) cucumber due to lower cumulative air temperatures during fruit maturation in the AW season. Fertilizer N application and apparent N loss under recommended N management (Nmr) decreased by 40-78% and 33-48% without yield loss compared to conventional N management (Nmt) over four growing seasons. However, there were no seasonal differences in N recommendations, taking into consideration seasonal differences in crop N demand, critical nutrient supply in the root zone and N mineralization rate. - Nitrogen inputs can be reduced to minimize N losses to the environment while maintaining yields but N recommendations must reflect seasonal temperature effects.

Seasonal temperatures have more influence than nitrogen fertilizer rates on cucumber yield and nitrogen uptake in a double cropping system

International Nuclear Information System (INIS)

Guo Ruiying; Li Xiaolin; Christie, Peter; Chen Qing; Zhang Fusuo

2008-01-01

Two-year greenhouse cucumber experiments were conducted to investigate seasonal effects on fruit yield, dry matter allocation, and N uptake in a double-cropping system with different fertilizer management. Seasonal effects were much greater than fertilizer effects, and winter-spring (WS) cucumber attained higher fruit yields and N uptake than autumn-winter (AW) cucumber due to lower cumulative air temperatures during fruit maturation in the AW season. Fertilizer N application and apparent N loss under recommended N management (Nmr) decreased by 40-78% and 33-48% without yield loss compared to conventional N management (Nmt) over four growing seasons. However, there were no seasonal differences in N recommendations, taking into consideration seasonal differences in crop N demand, critical nutrient supply in the root zone and N mineralization rate. - Nitrogen inputs can be reduced to minimize N losses to the environment while maintaining yields but N recommendations must reflect seasonal temperature effects

Synthesis and characterization of zinc-organic frameworks with 1,4-benzenedicarboxylic acid and azobenzene-4,4'-dicarboxylic acid

Science.gov (United States)

Nguyen, Van Hung; Phuong Thuy Nguyen, Ngoc; Tuyet Nhung Nguyen, Thi; Thanh Thuy Le, Thi; Nghiem Le, Van; Chinh Nguyen, Quoc; Quang Ton, That; Hoang Nguyen, Thai; Phuong Thoa Nguyen, Thi

2011-06-01

The solvothermal reactions of 1,4-bezenedicarboxylic acid (H2BDC) or azobenzene-4,4'-dicarboxylic acid (H2ABD) with zinc ions/clusters lead to the formation of four crystalline materials. All of these compounds were characterized by x-ray diffraction, optical microscopy, thermo-gravimetric analysis and nitrogen adsorption. Block-shaped crystals (BZ1) with various shapes and sizes were obtained at H2BDC:Zn mole ratio of 1:1 and H2BDC concentration of 0.1 M. At more dilute H2BDC concentration of 0.01 M and H2BDC:Zn mole ratio of 1 : 4, the reaction product was cubic crystals (BZ2) with a size of 250 μm. In the H2ABD system, flat-plate-like crystals (AZ1) were obtained at H2ABD:Zn mole ratio of 1 : 1 and H2ABD concentration of 0.01 M. Meanwhile, thick-block-like crystals (AZ2) were formed at the same H2ABD:Zn mole ratio but at 0.004 M H2ABD. The Langmuir surface area (SLang) of the materials was remarkable, enhanced by diluting the reaction solution. For the compounds synthesized in N,N'-dimethylformamide (DMF), SLang increased from 304.6 m2 g-1 for BZ1 to 2631 m2 g-1 for BZ2 and from 475.8 m2 g-1 for AZ1 to 3428 m2 g-1 for AZ2. Meanwhile, BZ2 synthesized in N,N'-diethylformamide (BZ2/DEF) got the highest SLang of 4330 m2 g-1. Both AZ2 and BZ2 materials were stable up to 400 °C.

Gastric gallium-67 uptake in gastritis

International Nuclear Information System (INIS)

Yeh, E.L.; Tisdale, P.L.; Zielonka, J.S.

1983-01-01

Even though Ga-67 imaging has been used widely in the diagnosis of malignant as well as inflammatory lesions, its uptake in the stomach has been reported in the literature mainly in gastric lymphoma and carcinoma. As shown in this case, intense gastric uptake of the radionuclide may be seen in common gastritis without malignancy. Perhaps the benign gastric uptake of Ga-67 deserves more emphasis

Simple mass transport model for metal uptake by marine macroalgae growing at different rates

Energy Technology Data Exchange (ETDEWEB)

Rice, D.L.

1984-01-01

Although algae growing at different rates may exhibit different concentrations of a given metal, such differences in algal chemistry may or may not reflect actual effects of environmental growth factors on the kinetics of metal uptake. Published data on uptake of rubidium, cadmium, and manganese by the green seaweed Ulva fasciata Delile grown at different rates in open system sea water was interpreted using the model. Differences in exposure time to sea water of relatively old and relatively young thalli were responsible for significant decreases in algal rubidium and cadmium concentrations with increases in specific growth rate. The biomass-specific growth rates of uptake of these two metals did not vary with growth rate. Both algal concentrations and specific rates of uptake of manganese increase significantly with increasing growth rate, thus indicating a distinct link between the kinetics of manganese uptake and metabolic rate. Under some circumstances, seaweed bioassay coupled with an interpretive model may provide the only reasonable approach to the study of chemical uptake-growth phenomena. In practice, if the residence time of sea water in culture chambers is sufficiently low to preclude pseudo-closed system artifacts, differences in trace metal concentrations between input and output sea water may be difficult to detect. In the field and in situ experiments based on time-series monitoring of changes in the water chemistry would be technically difficult or perhaps impossible to perform. 13 references, 1 figure.

Contextual factors associated with uptake of breast and cervical cancer screening: A systematic review of the literature.

Science.gov (United States)

Plourde, Natasha; Brown, Hilary K; Vigod, Simone; Cobigo, Virginie

2016-01-01

Existing research on barriers to breast and cervical cancer screening uptake has focused primarily on socio-demographic characteristics of individuals. However, contextual factors, such as service organization, as well as healthcare providers' training and practices, are more feasibly altered to increase health service use. The objective of the authors in this study was to perform a critical systematic review of the literature to identify contextual factors at the provider- and system-level that were associated with breast and cervical cancer screening uptake. Studies published from 2000 to 2013 were identified through PubMed and PsycInfo. Methodologic quality was assessed, and studies were examined for themes related to provider- and system-level factors associated with screening uptake. Thirteen studies met the inclusion criteria. Findings revealed a positive association between patients' receipt of provider recommendation and uptake of breast and cervical cancer screening. Uptake was also higher among patients of female providers. Facilities with flexible appointment times and reminders had higher mammography and Pap test uptake. Similarly, greater organizational commitment to quality and performance had higher breast and cervical cancer screening rates. Knowledge provided in this review could be used in future research to inform the development of public health policy and clinical programs to improve screening uptake.

Evaluation of uptake and distribution of gold nanoparticles in solid tumors

Science.gov (United States)

England, Christopheri G.; Gobin, André M.; Frieboes, Hermann B.

2015-11-01

Although nanotherapeutics offer a targeted and potentially less toxic alternative to systemic chemotherapy in cancer treatment, nanotherapeutic transport is typically hindered by abnormal characteristics of tumor tissue. Once nanoparticles targeted to tumor cells arrive in the circulation of tumor vasculature, they must extravasate from irregular vessels and diffuse through the tissue to ideally reach all malignant cells in cytotoxic concentrations. The enhanced permeability and retention effect can be leveraged to promote extravasation of appropriately sized particles from tumor vasculature; however, therapeutic success remains elusive partly due to inadequate intra-tumoral transport promoting heterogeneous nanoparticle uptake and distribution. Irregular tumor vasculature not only hinders particle transport but also sustains hypoxic tissue kregions with quiescent cells, which may be unaffected by cycle-dependent chemotherapeutics released from nanoparticles and thus regrow tumor tissue following nanotherapy. Furthermore, a large proportion of systemically injected nanoparticles may become sequestered by the reticulo-endothelial system, resulting in overall diminished efficacy. We review recent work evaluating the uptake and distribution of gold nanoparticles in pre-clinical tumor models, with the goal to help improve nanotherapy outcomes. We also examine the potential role of novel layered gold nanoparticles designed to address some of these critical issues, assessing their uptake and transport in cancerous tissue.

The role of receptor topology in the vitamin D3 uptake and Ca{sup 2+} response systems

Energy Technology Data Exchange (ETDEWEB)

Morrill, Gene A., E-mail: gene.morrill@einstein.yu.edu; Kostellow, Adele B.; Gupta, Raj K.

2016-09-02

The steroid hormone, vitamin D{sub 3}, regulates gene transcription via at least two receptors and initiates putative rapid response systems at the plasma membrane. The vitamin D receptor (VDR) binds vitamin D{sub 3} and a second receptor, importin-4, imports the VDR-vitamin D{sub 3} complex into the nucleus via nuclear pores. Here we present evidence that the Homo sapiens VDR homodimer contains two transmembrane (TM) helices ({sup 327}E – D{sup 342}), two TM “half-helix” ({sup 264}K − N{sup 276}), one or more large channels, and 16 cholesterol binding (CRAC/CARC) domains. The importin-4 monomer exhibits 3 pore-lining regions ({sup 226}E – L{sup 251}; {sup 768}V – G{sup 783}; {sup 876}S – A{sup 891}) and 16 CRAC/CARC domains. The MEMSAT algorithm indicates that VDR and importin-4 may not be restricted to cytoplasm and nucleus. VDR homodimer TM helix-topology predicts insertion into the plasma membrane, with two 84 residue C-terminal regions being extracellular. Similarly, MEMSAT predicts importin-4 insertion into the plasma membrane with 226 residue extracellular N-terminal regions and 96 residue C-terminal extracellular loops; with the pore-lining regions contributing gated Ca{sup 2+} channels. The PoreWalker algorithm indicates that, of the 427 residues in each VDR monomer, 91 line the largest channel, including two vitamin D{sub 3} binding sites and residues from both the TM helix and “half-helix”. Cholesterol-binding domains also extend into the channel within the ligand binding region. Programmed changes in bound cholesterol may regulate both membrane Ca{sup 2+} response systems and vitamin D{sub 3} uptake as well as receptor internalization by the endomembrane system culminating in uptake of the vitamin D{sub 3}-VDR-importin-4 complex into the nucleus.

Uptake of myocardial imaging agents by rejected hearts

International Nuclear Information System (INIS)

Bergsland, J.; Carr, E.A.; Carroll, M.; Wright, J.W.; Feldman, M.J.; Massucci, J.; Bhayana, J.N.; Gona, J.M.

1985-01-01

Technetium 99 m pyrophosphate, Gallium 67 and Thallium 201 uptakes were measured in heterotopically transplanted rat hearts. Five days after transplantation, Technetium 99 m pyrophosphate, and Gallium 67 uptakes were significantly higher in allogeneic grafts than in syngeneic grafts. At an early stage of rejection (three days after transplantation), only Technetium 99 m pyrophosphate uptake in the left ventricle of allogeneic grafts showed a significant difference (p less than 0.04). At five days, Thallium 201 uptake was significantly lower in allo- than syngeneic grafts. There was a positive correlation between radionuclide uptake and histologic degree of rejection for Technetium 99 m pyrophosphate and Gallium 67 while Thallium 201 uptake correlated negatively. Analysis of variance revealed that hearts with no or minimal rejection had statistically different uptakes than hearts with mild to moderate rejection. These results suggest that uptake of imaging agents might be useful in the diagnosis of rejection of the transplanted heart

Material properties that predict preservative uptake for silicone hydrogel contact lenses.

Science.gov (United States)

Green, J Angelo; Phillips, K Scott; Hitchins, Victoria M; Lucas, Anne D; Shoff, Megan E; Hutter, Joseph C; Rorer, Eva M; Eydelman, Malvina B

2012-11-01

To assess material properties that affect preservative uptake by silicone hydrogel lenses. We evaluated the water content (using differential scanning calorimetry), effective pore size (using probe penetration), and preservative uptake (using high-performance liquid chromatography with spectrophotometric detection) of silicone and conventional hydrogel soft contact lenses. Lenses grouped similarly based on freezable water content as they did based on total water content. Evaluation of the effective pore size highlighted potential differences between the surface-treated and non-surface-treated materials. The water content of the lens materials and ionic charge are associated with the degree of preservative uptake. The current grouping system for testing contact lens-solution interactions separates all silicone hydrogels from conventional hydrogel contact lenses. However, not all silicone hydrogel lenses interact similarly with the same contact lens solution. Based upon the results of our research, we propose that the same material characteristics used to group conventional hydrogel lenses, water content and ionic charge, can also be used to predict uptake of hydrophilic preservatives for silicone hydrogel lenses. In addition, the hydrophobicity of silicone hydrogel contact lenses, although not investigated here, is a unique contact lens material property that should be evaluated for the uptake of relatively hydrophobic preservatives and tear components.

Uptake and transport of chromium in plants

International Nuclear Information System (INIS)

Ramachandran, V.; D'souza, T.J.; Mistry, K.B.

1980-01-01

The uptake of chromium, an important soil and water pollutant, by five different plant species was examined in nutrient culture experiments using chromium-51 as a tracer. The concentration in aerial tissues of both trivalent and hexavalent forms of chromium was the greatest in peas followed by beans, tomato and the cereals over identical uptake periods. The uptake of 51 Cr 3+ was, in general, greater than 51 CrO 4 2- . Studies with bean plants indicated that shoot uptake of both forms of chromium decreased with increasing pH and salt concentration of the external solution. Concentrations of 10 -4 M and 10 -5 M DNP inhibited 51 Cr uptake by bean shoots. (author)

Radioiodine uptake measurements in thyroid

International Nuclear Information System (INIS)

Kadireshn, A.; Kapur, S.C.; Samuel, J.R.; Mahajan, M.K.

1988-01-01

Evaluation of thyroid function can be carried out by measuring the uptake of orally administered radioactive iodine. The results of the thyroid uptake measurements for the period 1982-1987 in Christian Medical College, Ludhiana are presented here. About 3000 patients were screened during the analysis period. (author)

Highly sensitive optical sensor that detects Hg"2"+ and Cu"2"+ by immobilizing dicarboxylate 1,5-diphenyl-3-thiocarbazone on surface functionalized PVA microspheres

International Nuclear Information System (INIS)

Bai, Xue; Gu, Haixin; Hua, Zulin; Dai, Zhangyan; Yang, Bei; Li, Yulong

2015-01-01

Highlights: • PVA microspheres were chosen as carrier and DDT groups were chosen as chromophores. • The DDT–PVA microspheres could detect Hg"2"+ and Cu"2"+ simultaneously within 120 s. • The DDT–PVA microspheres had excellent detection for Hg"2"+ and Cu"2"+ ions. • The DDT–PVA microspheres had preeminent selectivity and reusability. - Abstract: A novel optical sensor to detect Hg"2"+ and Cu"2"+ is prepared by immobilizing a synthesized dicarboxylate 1,5-diphenyl-3-thiocarbazone (DDT) group on functionalized polyvinyl alcohol (PVA) microspheres. This optical sensor is successfully fabricated by extensive characterization with Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Its colorimetric properties, selectivity, sensitivity, and reversibility are investigated as well. In this sensing system, DDT–PVA selectively recognized multiple heavy metal ions, as indicated by the changes in color from orange to scarlet for Hg"2"+ and from orange to gray for Cu"2"+. In particular, this optical sensor exhibits the most apparent color changes at pH levels of 12 and 2. Hence, Hg"2"+ and Cu"2"+ can be detected in aqueous solution at minimum detection limits of 0.053 and 0.132 μM, respectively, with a UV-vis spectrometer. Furthermore, the sensor can be regenerated by ethylene diamine tetraacetic acid and reused several times. Therefore, the optical sensor can detect Hg"2"+ because of its selectivity, sensitivity, and reversibility.

Foliar uptake of cesium from the water column by aquatic macrophytes

Energy Technology Data Exchange (ETDEWEB)

Pinder, J.E. [Savannah River Ecology Laboratory, University of Georgia, Drawer E, Aiken, SC 29801 (United States); Hinton, T.G. [Savannah River Ecology Laboratory, University of Georgia, Drawer E, Aiken, SC 29801 (United States)]. E-mail: thinton@srel.edu; Whicker, F.W. [Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO 80523-1618 (United States)

2006-07-01

The probable occurrence and rate of foliar absorption of stable cesium ({sup 133}Cs) from the water column by aquatic macrophyte species was analyzed following the addition of {sup 133}Cs into a small reservoir near Aiken, South Carolina, USA. An uptake parameter u (10{sup 3} L kg{sup -1} d{sup -1}) and a loss rate parameter k (d{sup -1}) were estimated for each species using time series of {sup 133}Cs concentrations in the water and plant tissues. Foliar uptake, as indicated by rapid increases in plant concentrations following the {sup 133}Cs addition, occurred in two floating-leaf species, Brasenia schreberi and Nymphaea odorata, and two submerged species, Myriophyllum spicatum and Utricularia inflata. These species had values of u {>=} 0.75 x 10{sup 3} L kg{sup -1} d{sup -1}. Less evidence for foliar uptake was observed in three emergent species, including Typha latifolia. Ratios of u to k for B. schreberi, M. spicatum, N. odorata and U. inflata can be used to estimate concentration ratios (CR) at equilibrium, and these estimates were generally within a factor of 2 of the CR for {sup 137}Cs for these species in the same reservoir. This correspondence suggests that foliar uptake of Cs was the principal absorption mechanism for these species. Assessments of: (1) the prevalence of foliar uptake of potassium, rubidium and Cs isotopes by aquatic macrophytes and (2) the possible importance of foliar uptake of Cs in other lentic systems are made from a review of foliar uptake studies and estimation of comparable u and k values from lake studies involving Cs releases.

Octreotide Uptake in Parathyroid Adenoma

Directory of Open Access Journals (Sweden)

Seyhan Karaçavuş

2012-08-01

Full Text Available The patient with a history of bone pain and muscle weakness, was thought to have oncogenic osteomalacia as a result of biochemical investigations and directed to Nuclear Medicine Department for a whole-body bone scintigraphy and 111In-octreotide scintigraphy. There was no focal pathologic tracer uptake, but generalized marked increase in skeletal uptake on bone scintigraphy. Octreotide scintigraphy showed accumulation of octreotide in the region of the left lobe of the thyroid gland in the neck. Thereafter, parathyroid scintigraphy was performed with technetium-99m labeled metroxy-isobutyl-isonitryl (99mTc-MIB and MIBI scan demonstrated radiotracer uptake at the same location with octreotide scintigraphy. The patient underwent left inferior parathyroidectomy and histopathology confirmed a parathyroid adenoma. Somatostatin receptor positive parathyroid adenoma may show octreotide uptake. Octreotide scintigraphy may be promising and indicate a possibility of using somatostatin analogues for the medical treatment of somatostatin receptor positive parathyroid tumors. (MIRT 2012;21:77-79

Effects of polyamine inhibitors on zinc uptake by COMMA-1D mammary epithelial cells

Energy Technology Data Exchange (ETDEWEB)

Allen, J.C.; Haedrich, L.H. (North Carolina State Univ., Raleigh (United States))

1991-03-15

Zn uptake or transport is stimulated by glucocorticoids in many types of epithelial cells, including the COMMA-1D mouse mammary cell line. The current objective was to determine whether polyamines also mediate glucocorticoid stimulation of Zn-uptake. Initially, cells grown in lactogenic hormone supplemented-media had approximately 65% greater {sup 65}Zn-uptake over 24 h than cells in nonsupplemented growth media (GM). {sup 65}Zn-uptake from HM with 10{sup {minus}5}M methylglyoxal-bis(guanylhydrazone) (MGBG) (s-adenosyl-methionine decarboxylase inhibitor to block polyamine synthesis) added was less than from GM. Exogenous spermidine added to the MGBG-HM media increased {sup 65}Zn-uptake. However, up to 10mM difluoromethylornithine (DFMO), a more specific inhibitor of sperimidine synthesis, had no significant effect on 24-h {sup 65}Zn-uptake by cells in HM. In GM, DFMO caused a slight dose-dependent decrease in {sup 65}Zn-uptake over the range 10{sup {minus}6} to 5 {times} 10{sup 3}M. Also, with 8 h of incubation, DFMO tended to decrease {sup 65}Zn-uptake in HM-stimulated cells. These data cannot yet distinguish between the possibilities that DFMO is inactivated during the 24-h incubation or that the dramatic effects of MGBG on {sup 65}Zn-uptake in these mammary-derived cells is not related to its inhibition of polyamine synthesis. Because COMMA-1D cells alter Zn uptake in response to lactogenic hormones and MGBG, the model system is suitable for further studies of the mechanisms of zinc transport in epithelia.

The uptake of 131I by some hydroponically grown crops

International Nuclear Information System (INIS)

Asprer, G.A.; Lansangan, L.M.; de la Paz, L.R.

1982-01-01

Biologically labelled vegetables which include kangkong and sweet potato tops were grown hydroponically in a modified Hoagland-Arnon nutrient solution containing radioiodine with 0.5% non-radioactive Nal solution as the medium. The crops considered in this study are commonly eaten by Filipinos. The concentration of the solution as well as the uptake in the plant system were determined at various time intervals. The extent of radioiodine uptake through air-water-plant pathway is one of the parameters needed for calculating the dose that the general populace could be exposed to, due to radioactivity in the environment. (author)

Aquaporins and root water uptake

Science.gov (United States)

Water is one of the most critical resources limiting plant growth and crop productivity, and root water uptake is an important aspect of plant physiology governing plant water use and stress tolerance. Pathways of root water uptake are complex and are affected by root structure and physiological res...

Cell uptake survey of pegylated nanographene oxide.

Science.gov (United States)

Vila, M; Portolés, M T; Marques, P A A P; Feito, M J; Matesanz, M C; Ramírez-Santillán, C; Gonçalves, G; Cruz, S M A; Nieto, A; Vallet-Regi, M

2012-11-23

Graphene and more specifically, nanographene oxide (GO) has been proposed as a highly efficient antitumoral therapy agent. Nevertheless, its cell uptake kinetics, its influence in different types of cells and the possibility of controlling cellular internalization timing, is still a field that remains unexplored. Herein, different cell types have been cultured in vitro for several incubation periods in the presence of 0.075 mg ml(-1) pegylated GO solutions. GO uptake kinetics revealed differences in the agent's uptake amount and speed as a function of the type of cell involved. Osteoblast-like cells GO uptake is higher and faster without resulting in greater cell membrane damage. Moreover, the dependence on the commonly used PEG nature (number of branches) also influences the viability and cell uptake speed. These facts play an important role in the future definition of timing parameters and selective cell uptake control in order to achieve an effective therapy.

Cell uptake survey of pegylated nanographene oxide

International Nuclear Information System (INIS)

Vila, M; Nieto, A; Vallet-Regi, M; Portolés, M T; Feito, M J; Matesanz, M C; Ramírez-Santillán, C; Marques, P A A P; Gonçalves, G; Cruz, S M A

2012-01-01

Graphene and more specifically, nanographene oxide (GO) has been proposed as a highly efficient antitumoral therapy agent. Nevertheless, its cell uptake kinetics, its influence in different types of cells and the possibility of controlling cellular internalization timing, is still a field that remains unexplored. Herein, different cell types have been cultured in vitro for several incubation periods in the presence of 0.075 mg ml −1 pegylated GO solutions. GO uptake kinetics revealed differences in the agent’s uptake amount and speed as a function of the type of cell involved. Osteoblast-like cells GO uptake is higher and faster without resulting in greater cell membrane damage. Moreover, the dependence on the commonly used PEG nature (number of branches) also influences the viability and cell uptake speed. These facts play an important role in the future definition of timing parameters and selective cell uptake control in order to achieve an effective therapy. (paper)

Nanoparticle synthesis and delivery by an aerosol route for watermelon plant foliar uptake

Science.gov (United States)

Wang, Wei-Ning; Tarafdar, Jagadish C.; Biswas, Pratim

2013-01-01

An aerosol process was developed for synthesis and delivery of nanoparticles for living watermelon plant foliar uptake. This is an efficient technique capable of generating nanoparticles with controllable particle sizes and number concentrations. Aerosolized nanoparticles were easily applied to leaf surfaces and enter the stomata via gas uptake, avoiding direct interaction with soil systems, eliminating potential ecological risks. The uptake and transport of nanoparticles inside the watermelon plants were investigated systematically by various techniques, such as elemental analysis by inductively coupled plasma mass spectrometry and plant anatomy by transmission electron microscopy. The results revealed that certain fractions of nanoparticles ( d p watermelon plants. The particle size and number concentration played an important role in nanoparticle translocation inside the plants. In addition, the nanoparticle application method, working environment, and leaf structure are also important factors to be considered for successful plant foliar uptake.

UPTAKE OF HEAVY METALS IN BATCH SYSTEMS BY A RECYCLED IRON-BEARING MATERIAL

Science.gov (United States)

An iron-bearing material deriving from surface finishing operations in the manufacturing of cast-iron components demonstrates potential for removal of heavy metals from aqueous waste streams. Batch isotherm and rate experiments were conducted for uptake of cadmium, zinc, and lead...

Cephalopod vision involves dicarboxylic amino acids: D-aspartate, L-aspartate and L-glutamate.

Science.gov (United States)

D'Aniello, Salvatore; Spinelli, Patrizia; Ferrandino, Gabriele; Peterson, Kevin; Tsesarskia, Mara; Fisher, George; D'Aniello, Antimo

2005-03-01

In the present study, we report the finding of high concentrations of D-Asp (D-aspartate) in the retina of the cephalopods Sepia officinalis, Loligo vulgaris and Octopus vulgaris. D-Asp increases in concentration in the retina and optic lobes as the animal develops. In neonatal S. officinalis, the concentration of D-Asp in the retina is 1.8+/-0.2 micromol/g of tissue, and in the optic lobes it is 5.5+/-0.4 micromol/g of tissue. In adult animals, D-Asp is found at a concentration of 3.5+/-0.4 micromol/g in retina and 16.2+/-1.5 micromol/g in optic lobes (1.9-fold increased in the retina, and 2.9-fold increased in the optic lobes). In the retina and optic lobes of S. officinalis, the concentration of D-Asp, L-Asp (L-aspartate) and L-Glu (L-glutamate) is significantly influenced by the light/dark environment. In adult animals left in the dark, these three amino acids fall significantly in concentration in both retina (approx. 25% less) and optic lobes (approx. 20% less) compared with the control animals (animals left in a diurnal/nocturnal physiological cycle). The reduction in concentration is in all cases statistically significant (P=0.01-0.05). Experiments conducted in S. officinalis by using D-[2,3-3H]Asp have shown that D-Asp is synthesized in the optic lobes and is then transported actively into the retina. D-aspartate racemase, an enzyme which converts L-Asp into D-Asp, is also present in these tissues, and it is significantly decreased in concentration in animals left for 5 days in the dark compared with control animals. Our hypothesis is that the dicarboxylic amino acids, D-Asp, L-Asp and L-Glu, play important roles in vision.

Genome-scale model-driven strain design for dicarboxylic acid production in Yarrowia lipolytica.

Science.gov (United States)

Mishra, Pranjul; Lee, Na-Rae; Lakshmanan, Meiyappan; Kim, Minsuk; Kim, Byung-Gee; Lee, Dong-Yup

2018-03-19

Recently, there have been several attempts to produce long-chain dicarboxylic acids (DCAs) in various microbial hosts. Of these, Yarrowia lipolytica has great potential due to its oleaginous characteristics and unique ability to utilize hydrophobic substrates. However, Y. lipolytica should be further engineered to make it more competitive: the current approaches are mostly intuitive and cumbersome, thus limiting its industrial application. In this study, we proposed model-guided metabolic engineering strategies for enhanced production of DCAs in Y. lipolytica. At the outset, we reconstructed genome-scale metabolic model (GSMM) of Y. lipolytica (iYLI647) by substantially expanding the previous models. Subsequently, the model was validated using three sets of published culture experiment data. It was finally exploited to identify genetic engineering targets for overexpression, knockout, and cofactor modification by applying several in silico strain design methods, which potentially give rise to high yield production of the industrially relevant long-chain DCAs, e.g., dodecanedioic acid (DDDA). The resultant targets include (1) malate dehydrogenase and malic enzyme genes and (2) glutamate dehydrogenase gene, in silico overexpression of which generated additional NADPH required for fatty acid synthesis, leading to the increased DDDA fluxes by 48% and 22% higher, respectively, compared to wild-type. We further investigated the effect of supplying branched-chain amino acids on the acetyl-CoA turn-over rate which is key metabolite for fatty acid synthesis, suggesting their significance for production of DDDA in Y. lipolytica. In silico model-based strain design strategies allowed us to identify several metabolic engineering targets for overproducing DCAs in lipid accumulating yeast, Y. lipolytica. Thus, the current study can provide a methodological framework that is applicable to other oleaginous yeasts for value-added biochemical production.

99mTc-DPD uptake in juvenile arthritis

International Nuclear Information System (INIS)

Stender Hansen, E.; Holm, I.E.; Buenger, C.; Knudsen, V.; Noer, I.; Bach Christensen, S.

1986-01-01

Unilateral arthritis of the knee was induced in mongrel puppies by intraarticular injections of 1% Carragheenan. Bone metabolism was studied by a scintimetric technique on static 99m Tc-diphosphonate bone scans every 2nd week during the induction of arthritis for 3 months and monthly in a postarthritic phase of another 3 months. Changes in uptake of radionuclide were present after 2 weeks. The induction phase was characterized by a decreased uptake in the calcification layer of the juxta-articular growth plates and a moderately increased epiphyseal uptake. The postarthritic phase was characterized by normalization of growth plate uptake and a marked increase in epiphyseal uptake. Using contact autoradiography, the epiphyseal uptake was seen mainly in a narrow subchondral and subsynovial bone layer, around bone cysts and osteophytes, whereas central epiphyseal bone was osteopenic with decreased uptake of tracer. The study suggests that the early scintigraphic appearance of juvenile non-suppurative arthritis may be an overall decrease in uptake of 99m Tc-diphosphonate due to a depression of growth plate metabolism. (author)

Introduction and uptake of new medical technologies in the Australian health care system: a qualitative study.

Science.gov (United States)

Gallego, Gisselle; Casey, Robert; Norman, Richard; Goodall, Stephen

2011-10-01

The aim of this study was to explore the views and perceptions of stakeholders about the current national health technology assessment process conducted by the Medical Services Advisory Committee (MSAC) and its role in the uptake and diffusion of new medical technologies in Australia. Data collection occurred over a nine month period (August 2008-April 2009). Twenty in-depth, semi-structured interviews were conducted with individuals from four stakeholders groups: (i) MSAC members and evaluators, (ii) academic and health technology assessment experts, (iii) medical industry representatives and (iv) medical specialists. Interviews were digitally recorded, transcribed verbatim and coded using a constant comparative method. Respondents expressed a consensus opinion that the MSAC process is generally fair and transparent, and has been increasingly so over time. The process was described as "flexible" and "intuitive" yet also "idiosyncratic" due to the nature of the technologies being appraised. Approval by MSAC was generally reported to be increasingly important once a technology becomes more widely used. While successful MSAC approval was felt to be important for widespread distribution of a new technology, it was viewed more as a "facilitator of the uptake of new technologies" as opposed to a primary "driver" of technology uptake. Instead, other factors were identified as providing the actual impetus for the uptake of new technologies, with MSAC approval and reimbursement eventually helping facilitate more widespread diffusion. MSAC's decision making process is perceived as fair but with room for improvement. Its role in the uptake and diffusion of new medical technologies in Australia is limited. MSAC does not act as a barrier to significant market penetration of new procedures and medical technologies. However reimbursement is a trigger for increased use. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Policies for biosimilar uptake in Europe: An overview

Science.gov (United States)

Vulto, Arnold G.; Huys, Isabelle; Dylst, Pieter; Godman, Brian; Keuerleber, Simon; Claus, Barbara; Dimitrova, Maria; Petrova, Guenka; Sović-Brkičić, Ljiljana; Slabý, Juraj; Šebesta, Robin; Laius, Ott; Karr, Allan; Beck, Morgane; Martikainen, Jaana E.; Selke, Gisbert W.; Spillane, Susan; McCullagh, Laura; Trifirò, Gianluca; Vella Bonanno, Patricia; Mack, Asbjørn; Fogele, Antra; Viksna, Anita; Władysiuk, Magdalena; Mota-Filipe, Helder; Meshkov, Dmitry; Kalaba, Marija; Mencej Bedrač, Simona; Fürst, Jurij; Zara, Corrine; Skiöld, Peter; Magnússon, Einar; Simoens, Steven

2017-01-01

Background Across European countries, differences exist in biosimilar policies, leading to variations in uptake of biosimilars and divergences in savings all over Europe. Objectives The aim of this article is to provide an overview of different initiatives and policies that may influence the uptake of biosimilars in different European countries. Recommendations will be formulated on how to create sustainable uptake. Methods An overview of policies on biosimilars was obtained via a questionnaire, supplemented with relevant articles. Topics were organized in five themes: availability, pricing, reimbursement, demand-side policies, and recommendations to enhance uptake. Results In all countries studied, biological medicines are available. Restrictions are mainly dependent on local organization of the healthcare system. Countries are willing to include biosimilars for reimbursement, but for commercial reasons they are not always marketed. In two thirds of countries, originator and biosimilar products may be subjected to internal reference pricing systems. Few countries have implemented specific incentives targeting physicians. Several countries are implementing pharmacist substitution; however, the scope and rules governing such substitution tend to vary between these countries. Reported educational policies tend to target primarily physicians, whereas fewer initiatives were reported for patients. Recommendations as proposed by the different country experts ranged from the need for information and communication on biosimilars to competitive pricing, more support for switching and guidance on substitution. Conclusions Most countries have put in place specific supply-side policies for promoting access to biosimilars. To supplement these measures, we propose that investments should be made to clearly communicate on biosimilars and educate stakeholders. Especially physicians need to be informed on the entry and use of biosimilars in order to create trust. When physicians

Policies for biosimilar uptake in Europe: An overview.

Directory of Open Access Journals (Sweden)

Evelien Moorkens

Full Text Available Across European countries, differences exist in biosimilar policies, leading to variations in uptake of biosimilars and divergences in savings all over Europe.The aim of this article is to provide an overview of different initiatives and policies that may influence the uptake of biosimilars in different European countries. Recommendations will be formulated on how to create sustainable uptake.An overview of policies on biosimilars was obtained via a questionnaire, supplemented with relevant articles. Topics were organized in five themes: availability, pricing, reimbursement, demand-side policies, and recommendations to enhance uptake.In all countries studied, biological medicines are available. Restrictions are mainly dependent on local organization of the healthcare system. Countries are willing to include biosimilars for reimbursement, but for commercial reasons they are not always marketed. In two thirds of countries, originator and biosimilar products may be subjected to internal reference pricing systems. Few countries have implemented specific incentives targeting physicians. Several countries are implementing pharmacist substitution; however, the scope and rules governing such substitution tend to vary between these countries. Reported educational policies tend to target primarily physicians, whereas fewer initiatives were reported for patients. Recommendations as proposed by the different country experts ranged from the need for information and communication on biosimilars to competitive pricing, more support for switching and guidance on substitution.Most countries have put in place specific supply-side policies for promoting access to biosimilars. To supplement these measures, we propose that investments should be made to clearly communicate on biosimilars and educate stakeholders. Especially physicians need to be informed on the entry and use of biosimilars in order to create trust. When physicians are well-informed on the treatment

Studies on the uptake of 14C-neostigmine in the isolated rat diaphragm

International Nuclear Information System (INIS)

Helleberg, L.

1976-01-01

The uptake process of 14 C-neostigmine in striated muscles was studied using the isolated rat diaphragm. Hemidiaphragms were incubated with 3x10 -7 M 14 C-neostigmine at 37deg in Krebs-Ringer solution containing 11 mM glucose and aerated with oxygen:carbon dioxide (95:5 v/v %). The uptake, which is expressed as the muscle-to-medium concentration ratio, was 1.41, after 3 hours, after which the rate of uptake diminished and became equal to that of inulin. The uptake which showed partial saturation, was decreased by some tertiary and quarternary amines, metabolic inhibitors, potassium and in an atmosphere of nitrogen. Neostigmine accumulated in all parts of the muscle without preference for the end plate zone. The half-time for the efflux was about 30 min. The phrenic nerve-diaphragm preparation became desensitized to the effect of 3x10 -7 M neostigmine after 2-3 hours. It is suggested that the uptake of neostigmine is mediated via a specialized carrier transport system. (author)

Ethnic background and human papillomavirus vaccine uptake in Denmark

DEFF Research Database (Denmark)

de Casadevante, Victoria Fernández; Cantarero-Arévalo, Lourdes; Cuesta, Julita Gil

2016-01-01

Aim: We examined ethnicity-related differences in the uptake of a temporary free-of-charge HPV vaccine (HPVV) catch-up programme offered in Denmark from August 2012 to December 2013 to women born from 1985-1992 and compared it with the previous self-payment system in place. Methods: We conducted...... a nationwide retrospective cohort study. We performed logistic regression analyses to examine the relationship between ethnic background and HPV vaccine (HPVV) programme initiation. Results: The free programme increased the vaccination uptake from 16% to 75%. Descendants (Denmark-born women with both parents...... than others. The integration process (as related to use of health services) occurs over many years where differences between the different population groups seem to vanish....

21 CFR 868.1730 - Oxygen uptake computer.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Oxygen uptake computer. 868.1730 Section 868.1730...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1730 Oxygen uptake computer. (a) Identification. An oxygen uptake computer is a device intended to compute the amount of oxygen consumed by a...

Ethanol intake and 3H-serotonin uptake II: A study in alcoholic patients using platelets 3H-paroxetine binding

International Nuclear Information System (INIS)

Daoust, M.; Boucly, P.; Ernouf, D.; Breton, P.; Lhuintre, J.P.

1991-01-01

The kinetic parameters of 3 H-paroxetine binding and 3 H-serotonin uptake were studied in platelets of alcoholic patients. There was no difference between alcoholic and non alcoholic subjects in 3 H-paroxetine binding. When binding and 3 H-serotonin uptake were studied, in the same plasma of the same subjects, the Vmax of serotonin uptake was increased in alcoholics. The data confirm the involvement of serotonin uptake system in alcohol dependance and suggest that serotonin uptake and paroxetine binding sites may be regulated independently in this pathology

Deciphering relationships between in-stream travel times, nutrient concentrations, and uptake through analysis of hysteretic and non-hysteretic kinetic behavior

Science.gov (United States)

Covino, T. P.; Bowden, W. B.; Gooseff, M. N.; Wollheim, W. M.; McGlynn, B. L.; Whittinghill, K. A.; Wlostowski, A. N.; Herstand, M. R.

2012-12-01

Understanding the relationship between solute travel time, concentration, and nutrient uptake remains a central question in watershed hydrology and biogeochemistry. Theoretical understanding predicts that nutrient uptake should increase as in-stream solute travel time lengthens and/or as concentration increases; however, results from field-based studies have been contradictory. We used a newly developed approach, Tracer Additions for Spiraling Curve Characterization (TASCC), to investigate relationships between solute travel time, nutrient concentration, and nutrient uptake across a range of stream types. This approach allows us to quantify in-stream nutrient uptake across a range of travel times and nutrient concentrations using single instantaneous injections (slugs) of conservative and non-conservative tracers. In some systems we observed counter-clockwise hysteresis loops in the relationship between nutrient uptake and concentration. Greater nutrient uptake on the falling limb of tracer breakthrough curves indicates stronger uptake for a given concentration at longer travel times. However, in other systems we did not observe hysteresis in these relationships. Lack of hysteresis indicates that nutrient uptake kinetics were not influenced by travel time travel time. Here we investigate the potential roles of travel time and in-stream flowpaths that could be responsible for hysteretic behavior.

Heavy metals and their radionuclides uptake by Bacillus Licheniformis

International Nuclear Information System (INIS)

Ramadan, A.A.; Ahmed, M.M.; Abo-state, M.A.M.; Sarhan, M.; Faroqe, M.

2007-01-01

Bacillus licheniformis is a gram positive spore forming bacterium. Different concentrations of cobalt affected the ability of Co uptake and growth of Bacillus licheniformis. As the concentration increased, both the uptake and growth were decreased. Maximum Co uptake was found at ph 7.0, while for growth was ph 8.0. The optimum temperature for uptake and growth was 40 degree C and 20% inoculum size represents the maximum cobalt uptake by Bacillus licheniformis. Also, maximum uptake was recorded after 72 hours, incubation period. As the concentration of cesium was increased till 400 mg/l, the uptake was also increased. The optimum cesium uptake and growth was at ph 8.0. The optimum growth was at 45 degree C while Cs uptake was found at 35 degree C and 15% inoculum size represented the maximum Cs uptake. After 72 hour incubation period, maximum Cs uptake was recorded. Generally, Bacillus licheniformis removed more than 80% of Co and 50% of Cs from the broth medium. Addition of clay to Bacillus licheniformis increased both Co or Cs uptake. Bacillus licheniformis was gamma resistant and 10 KGy reduced the viability by 5.3 log cycles. The irradiated and non-irradiated cultures can grow on 500 or 700 mg Co or Cs. Bacillus licheniformis removed 99.32% of the Co radionuclides and 99.28% of Cs radionuclides

Correlation between 5-Minute {sup 99m}Tc-Pertechnetate Uptake and 24-Hour {sup 131}I Uptake in Patients with Thyroid Disease

Energy Technology Data Exchange (ETDEWEB)

Lee, Chan Woo; Won, Kyu Chang; Yoon, Hyun Dae; Cho, In Ho; Kim, Tae Nyeun; Shin, Dong Gu; Lee, Hyoung Woo; Shim, Bong Sup; Lee, Hyun Woo [Yeungnam University School of Medicine, Daegu (Korea, Republic of)

1992-07-15

The 20-minute {sup 99m}Tc-pertechnetate uptake became readily available for routine use and it replaced {sup 131}I for thyroid imaging. However measuring thyroid uptake during a 5-minute minimizes pertechnetate uptake by the salivary glands and presence of contaminated saliva from those glands in to the pharynx and esophagus. A study was carried out to determine the suitability of the utility of a 5-minute and 20-minute interval from administration of {sup 99m}Tc-pertechnetate to imaging and uptake measurement as a replacement for the 24 hour standard originally established with {sup 131}I, and to evaluate the relationship between 5-minute {sup 99m}Tc-pertechnetate uptake and other thyroid functions. A 5-minute and 20-minute uptake of {sup 99m}Tc-pertechnetate were measured in 70 patients with thyroid disease at Yeungnam University Hospital from March 1, 1991 to Feb. 29, 1992. The results were as follows. 1) The 5-minute {sup 99m}Tc-pertechnetate uptake in Graves' disease, Hashimoto's thyroiditis, simple goiter non toxic nodular goiter, subacute thyroiditis and euthyroid were 18.2%, 14.6%, 2.8%, 3.2%, 1.2% and 1.1%, respectively. There was a significant difference between the mean of the euthyroid group and the mean of the Graves' disease. So differentiation between them can be easily made. 2) The 5 minute {sup 99m}Tc- pertechnetate thyroid uptake was well correlated with 24 hour {sup 131}I thyroid uptake (r=0.75, p<0.001). These data provided an equation for estimating the 24 hour uptake of iodide given the 5 minute pertechnetate uptake: Estimated 24-hour '1{sup 31}I thyroid Uptake = 7.188{sup *}In (5 minute {sup 99m}Tc-Pertechnetate uptake)+16.94 3) The 20-minute {sup 99m}Tc-pertechnetate thyroid uptake was well correlated with 24-hour {sup 131}I uptake (r=0.72, p<0.001) and 5-minute {sup 99m}Tc-pertechnetate thyroid uptake (r=0.96, p<0.001). 4) In the Graves' disease, The 5-minute {sup 99m}Tc-pertechnetate thyroid uptake was well

Characterization of (/sup 3/H)5-hydroxytryptamine uptake within rat cerebrovascular tree

Energy Technology Data Exchange (ETDEWEB)

Amenta, F.; Rossi, M. de; Mione, M.C.; Geppetti, P.

1985-06-07

The in vitro uptake of tritiated serotonin ((/sup 3/H)5HT) was studied in a preparation of rat extracerebral arteries. The uptake of (/sup 3/H)5HT was time- and temperature-dependent and of high affinity; linear regression analysis gave a Ksub(m) value of 6.48 X 10/sup 7/ M for the specific uptake. Histoautoradiographic studies showed the highest density of silver grains at the level of the adventitial-medial border of the basilar artery. Fluoxetine inhibited the accumulation of silver grains within the adventitial-medial border in the blood vessel studied. The present data further support the view that a neuronal serotonergic system may play a role in the control of blood flow in the cerebrovascular tree.

Increased FDG bone marrow uptake after intracoronary progenitor cell therapy

Energy Technology Data Exchange (ETDEWEB)

Doebert, N.; Menzel, C.; Diehl, M.; Hamscho, N.; Zaplatnikov, K.; Gruenwald, F. [Dept. of Nuclear Medicine, Univ. of Frankfurt (Germany)

2005-02-01

Patients with coronary artery disease who undergo FDG PET for therapy monitoring after intracoronary progenitor cell infusion (PCT) show an increased bone marrow uptake in some cases. Aim of the study was to evaluate the systemic bone marrow glucose metabolism in this patient group after PCT. Patients, methods: FDG bone marrow uptake (BMU), measured as standardized uptake value (SUVmax) in the thoracic spine, was retrospectively evaluated in 23 control patients who did not receive PCT and in 75 patients who received PCT 3{+-}2.2 days before PET scanning. Five out of them were pretreated with granulocyte colony-stimulating factor (G-CSF) 5 days prior to PCT and 10{+-}1.2 days before PET scanning. In 39 patients who received only PCT without G-CSF and underwent PET therapy monitoring 4 months later, baseline and follow up bone marrow uptake were measured. Leucocytes, C-reactive protein (CRP) levels and the influence of nicotine consumption were compared with the BMU. Results: In patients (n=70) who received PCT without G-CSF, BMU media (1.3) was slightly, but significantly higher than in the controls (1.0) (p=0.02) regardless nicotine consumption. BMU did not change significantly 4 months later (1.2) (p=0.41, n.s.). After G-CSF pretreatment, patients showed a significantly higher bone marrow uptake (3.7) compared to patients only treated with PCT (1.3) (p=0.023). Leucocyte blood levels were significantly higher in patients with a BMU {>=}2.5 compared to patients with a bone marrow SUVmax<2.5 (p<0.001). CRP values did not correlate with the BMU (rho -0.02, p=0.38). Conclusion: Monitoring PCT patients, a slightly increased FDG BMU may be observed which remains unchanged for several months. Unspecific bone marrow reactions after PCT may be associated with increased leucocyte blood levels and play a role in the changed systemic glucose BMU. In addition, pretreatment with G-CSF shows an intense amplitifcation of BMU. (orig.)

Clinical meaning of hot uptake on bone scan in symptomatic accessory navicular bones

International Nuclear Information System (INIS)

Chong, Ari; Ha, Jung Min; Lee, Jun Young

2016-01-01

We analyzed clinical factors related to uptake on a Tc-99 m HDP bone scan of the accessory navicular (AN). We retrospectively reviewed patients who had been examined by an orthopedic surgeon and underwent bone scan due to suspected symptomatic AN. A three-point grading system was used to evaluate uptake on bone scan. Relationships between grade, symptoms, age, gender, symptom duration, and bone size were analyzed. In total, 73 ANs (30 asymptomatic, 43 symptomatic) were enrolled. The majority of asymptomatic ANs had no uptake but some had grade 1 (n = 8) or 2 (n = 2) uptake. All asymptomatic ANs with uptake remained asymptomatic during follow-up. For the asymptomatic ANs, larger bones showed a higher grade. With a cut-off value of size ≤6.8 mm, there is no chance of uptake. All symptomatic ANs showed uptake on bone scan. For symptomatic ANs, larger size and shorter pain duration were related to a higher grade. Age, gender, and left-/right-sideness were not related to grade. Multiple regressions revealed that only uptake grade, not size or symptom duration, was the significant risk factor for a symptomatic AN. With a cut-off value of grade <1, a symptomatic AN could be ruled out with a negative predictive value of 100 %. Bone scanning is useful for symptomatic ANs with a high negative predictive value. Higher grade is related to larger size and shorter pain duration. For asymptomatic ANs, grade was related to size but did not predict symptom development

Clinical meaning of hot uptake on bone scan in symptomatic accessory navicular bones

Energy Technology Data Exchange (ETDEWEB)

Chong, Ari; Ha, Jung Min; Lee, Jun Young [Chosun University Hospital, Gwangju (Korea, Republic of)

2016-12-15

We analyzed clinical factors related to uptake on a Tc-99 m HDP bone scan of the accessory navicular (AN). We retrospectively reviewed patients who had been examined by an orthopedic surgeon and underwent bone scan due to suspected symptomatic AN. A three-point grading system was used to evaluate uptake on bone scan. Relationships between grade, symptoms, age, gender, symptom duration, and bone size were analyzed. In total, 73 ANs (30 asymptomatic, 43 symptomatic) were enrolled. The majority of asymptomatic ANs had no uptake but some had grade 1 (n = 8) or 2 (n = 2) uptake. All asymptomatic ANs with uptake remained asymptomatic during follow-up. For the asymptomatic ANs, larger bones showed a higher grade. With a cut-off value of size ≤6.8 mm, there is no chance of uptake. All symptomatic ANs showed uptake on bone scan. For symptomatic ANs, larger size and shorter pain duration were related to a higher grade. Age, gender, and left-/right-sideness were not related to grade. Multiple regressions revealed that only uptake grade, not size or symptom duration, was the significant risk factor for a symptomatic AN. With a cut-off value of grade <1, a symptomatic AN could be ruled out with a negative predictive value of 100 %. Bone scanning is useful for symptomatic ANs with a high negative predictive value. Higher grade is related to larger size and shorter pain duration. For asymptomatic ANs, grade was related to size but did not predict symptom development.

What hinders the uptake of computerized decision support systems in hospitals? A qualitative study and framework for implementation.

Science.gov (United States)

Liberati, Elisa G; Ruggiero, Francesca; Galuppo, Laura; Gorli, Mara; González-Lorenzo, Marien; Maraldi, Marco; Ruggieri, Pietro; Polo Friz, Hernan; Scaratti, Giuseppe; Kwag, Koren H; Vespignani, Roberto; Moja, Lorenzo

2017-09-15

Advanced Computerized Decision Support Systems (CDSSs) assist clinicians in their decision-making process, generating recommendations based on up-to-date scientific evidence. Although this technology has the potential to improve the quality of patient care, its mere provision does not guarantee uptake: even where CDSSs are available, clinicians often fail to adopt their recommendations. This study examines the barriers and facilitators to the uptake of an evidence-based CDSS as perceived by diverse health professionals in hospitals at different stages of CDSS adoption. Qualitative study conducted as part of a series of randomized controlled trials of CDSSs. The sample includes two hospitals using a CDSS and two hospitals that aim to adopt a CDSS in the future. We interviewed physicians, nurses, information technology staff, and members of the boards of directors (n = 30). We used a constant comparative approach to develop a framework for guiding implementation. We identified six clusters of experiences of, and attitudes towards CDSSs, which we label as "positions." The six positions represent a gradient of acquisition of control over CDSSs (from low to high) and are characterized by different types of barriers to CDSS uptake. The most severe barriers (prevalent in the first positions) include clinicians' perception that the CDSSs may reduce their professional autonomy or may be used against them in the event of medical-legal controversies. Moving towards the last positions, these barriers are substituted by technical and usability problems related to the technology interface. When all barriers are overcome, CDSSs are perceived as a working tool at the service of its users, integrating clinicians' reasoning and fostering organizational learning. Barriers and facilitators to the use of CDSSs are dynamic and may exist prior to their introduction in clinical contexts; providing a static list of obstacles and facilitators, irrespective of the specific implementation

Microbial production of branched-chain dicarboxylate 2-methylsuccinic acid via enoate reductase-mediated bioreduction.

Science.gov (United States)

Wang, Jian; Yang, Yaping; Zhang, Ruihua; Shen, Xiaolin; Chen, Zhenya; Wang, Jia; Yuan, Qipeng; Yan, Yajun

2018-01-01

2-Methylsuccinic acid (2-MSA) is a C5 branched-chain dicarboxylate that serves as an attractive synthon for the synthesis of polymers with extensive applications in coatings, cosmetic solvents and bioplastics. However, the lack of natural pathways for 2-MSA biosynthesis has limited its application as a promising bio-replacement. Herein, we conceived a non-natural three-step biosynthetic route for 2-MSA, via employing the citramalate pathway in combination with enoate reductase-mediated bioreduction of the pathway intermediate citraconate. First, over-expression of codon-optimized citramalate synthase variant CimA* from Methanococcus jannaschii, endogenous isopropylmalate isomerase EcLeuCD and enoate reductase YqjM from Bacillus subtilis allowed the production of 2-MSA in Escherichia coli for the first time, with a titer of 0.35g/L in shake flask experiments. Subsequent screening of YqjM-like enoate reductases of different bacterial origins enabled identification and characterization of a new NAD(P)H-dependent enoate reductase KpnER from Klebsiella pneumoniae, which exhibited higher activity towards citraconate than YqjM. Incorporation of KpnER into the 2-MSA biosynthetic pathway led to 2-MSA production improvement to a titer of 0.96g/L in aerobic condition. Subsequent optimizations including cofactor regeneration, microaerobic cultivation and host strain engineering, boosted 2-MSA titer to 3.61g/L with a molar yield of 0.36 in shake flask experiments. This work established a promising platform for 2-MSA bioproduction, which enabled the highest titer of 2-MSA production in microbial hosts so far. Copyright © 2017 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Role of polyhydroxybutyrate in mitochondrial calcium uptake

Science.gov (United States)

Smithen, Matthew; Elustondo, Pia A.; Winkfein, Robert; Zakharian, Eleonora; Abramov, Andrey Y.; Pavlov, Evgeny

2013-01-01

Polyhydroxybutyrate (PHB) is a biological polymer which belongs to the class of polyesters and is ubiquitously present in all living organisms. Mammalian mitochondrial membranes contain PHB consisting of up to 120 hydroxybutyrate residues. Roles played by PHB in mammalian mitochondria remain obscure. It was previously demonstrated that PHB of the size similar to one found in mitochondria mediates calcium transport in lipid bilayer membranes. We hypothesized that the presence of PHB in mitochondrial membrane might play a significant role in mitochondrial calcium transport. To test this, we investigated how the induction of PHB hydrolysis affects mitochondrial calcium transport. Mitochondrial PHB was altered enzymatically by targeted expression of bacterial PHB hydrolyzing enzyme (PhaZ7) in mitochondria of mammalian cultured cells. The expression of PhaZ7 induced changes in mitochondrial metabolism resulting in decreased mitochondrial membrane potential in HepG2 but not in U87 and HeLa cells. Furthermore, it significantly inhibited mitochondrial calcium uptake in intact HepG2, U87 and HeLa cells stimulated by the ATP or by the application of increased concentrations of calcium to the digitonin permeabilized cells. Calcium uptake in PhaZ7 expressing cells was restored by mimicking calcium uniporter properties with natural electrogenic calcium ionophore - ferutinin. We propose that PHB is a previously unrecognized important component of the mitochondrial calcium uptake system. PMID:23702223

Uranium uptake of Vetiveria zizanioides (L.) Nash

International Nuclear Information System (INIS)

Luu Viet Hung; Maslov, O.D.; Trinh Thi Thu My; Phung Khac Nam Ho; Dang Duc Nhan

2010-01-01

Uranium uptake of vetiver grass (Vetiveria zizanioides (L.) Nash) from Eutric Fluvisols (AK), Albic Acrisols (BG), Dystric Fluvisols (HP) and Ferralic Acrisols (TC) in northern Vietnam is assessed. The soils were mixed with aqueous solution of uranyl nitrate to make soils contaminated with uranium at 0, 50, 100, 250 mg/kg before planting the grass. The efficiency of uranium uptake by the grass was assessed based on the soil-to-plant transfer factor (TF U , kg·kg -1 ). It was found that the TF U values are dependent upon the soils properties. CEC facilitates the uptake and the increased soil pH could reduce the uptake and translocation of uranium in the plant. Organic matter content, as well as iron and potassium, inhibits the uranium uptake of the grass. It was revealed that the lower fertile soil, the higher uranium uptake. The translocation of uranium in root for all the soil types studied is almost higher than that in its shoot. It seems that vetiver grass could potentially be used for the purpose of phytoremediation of soils contaminated with uranium

Monocyte transferrin-iron uptake in hereditary hemochromatosis

International Nuclear Information System (INIS)

Sizemore, D.J.; Bassett, M.L.

1984-01-01

Transferrin-iron uptake by peripheral blood monocytes was studied in vitro to test the hypothesis that the relative paucity of mononuclear phagocyte iron loading in hereditary hemochromatosis results from a defect in uptake of iron from transferrin. Monocytes from nine control subjects and 17 patients with hemochromatosis were cultured in the presence of 59Fe-labelled human transferrin. There was no difference in 59Fe uptake between monocytes from control subjects and monocytes from patients with hemochromatosis who had been treated by phlebotomy and who had normal body iron stores. However, 59Fe uptake by monocytes from iron-loaded patients with hemochromatosis was significantly reduced compared with either control subjects or treated hemochromatosis patients. It is likely that this was a secondary effect of iron loading since iron uptake by monocytes from treated hemochromatosis patients was normal. Assuming that monocytes in culture reflect mononuclear phagocyte iron metabolism in vivo, this study suggests that the relative paucity of mononuclear phagocyte iron loading in hemochromatosis is not related to an abnormality in transferrin-iron uptake by these cells

Phosphorus uptake by decomposing leaf detritus: effect of microbial biomass and activity

Energy Technology Data Exchange (ETDEWEB)

Mulholland, P J; Elwood, J W; Newbold, J D; Webster, J R; Ferren, L A; Perkins, R E

1984-12-01

The dominant energy source in small woodland streams is the allochthonous input of leaves. Utilization of this energy source by stream biota establishes the patterns of secondary productivity and nutrient uptake in these ecosystems. Although leaf inputs support much of the production of macroinvertebrates and higher consumers in streams, microbes are the critical link between these organisms and the leaf resource, much of which is undigestible by higher organisms. A number of studies have indicated that stream macroinvertebrates preferentially select leaves with greater levels of microbial activity. Rates of microbial activity associated with decomposing leaves were shown to be dependent on the supply of P in one woodland stream. In other streams, leaf decomposition has been shown to be nutrient limited as well. Thus, as in many other ecosystems, maintenance of high levels of production in streams is dependent on retention and efficient recycling of nutrients. Uptake of P by microbes colonizing leaves is an important mechanism for nutrient retention in small woodland streams. In these systems, numerous debris collections efficiently retard downstream movement of particulate materials, especially decomposing leaves. Uptake of dissolved, easily transportable forms of P by microbes attached to decomposing leaves increases P retention in streams. The more rapid the rate of P uptake onto decomposing leaves for a given P supply, the shorter the P uptake length and the more times an atom of P is utilized within a given stream reach. In this study the authors examined the temporal patterns of P uptake during the early stages of leaf decomposition in streams. Patterns of P uptake were compared to patterns of other measurements of microbial activity to identify the effect of microbial succession or conditioning of leaves on P uptake. 22 references, 1 figure, 2 tables.

Hg uptake in ureteral obstructions

International Nuclear Information System (INIS)

Desgrez, J.P.; Bourguignon, M.; Raynaud, C.; CEA, 91 - Orsay

1976-01-01

In the presence of a total obstruction the results obtained with the Hg uptake test, as indeed with other functional tests, inform on the value of the kidney function at the time but have no prognostic value where repair possibilities are concerned. Some preliminary results seem to show however that very soon after the obstacle is removed, by the 10th or 15th day perhaps, quantitative functional tests may once more be used to evaluate the functional prognosis. This would mean that by waiting about two weeks after the disappearance of a total obstruction the Hg uptake test may again be used in all confidence. In order to check this deduction, which is based on slender evidence but which nevertheless has important practical implications, the measurement of the Hg uptake rate during the days following removal of the obstacle appears essential. In long-standing partial obstructions the Hg uptake rate gives an accurate assessment of the functional balance and helps considerably in the choice of therapy [fr

Effect of environmental temperature on radioiodine uptake by the thyroid gland of rats during ontogenetic development

International Nuclear Information System (INIS)

Samel, M.

1975-01-01

Radioiodine uptake by the thyroid gland of young rats, aged 1 to 30 days, was studied at nest temperature (35degC) and at the temperature of the animal room (24degC). In animals younger than two weeks 131 I uptake was significantly lower at 24degC than at nest temperature. In older animals, these temperature differences did not result in significantly different uptake values. It is suggested that short-term cold does not activate the pituitary-thyroid gland axis in younger animals with unstable body temperature, and that functional changes in the circulatory system might be responsible for the differences observed in 131 I uptake. (author)

Uptake of dissolved inorganic and organic nitrogen by the benthic toxic dinoflagellate Ostreopsis cf. ovata.

Science.gov (United States)

Jauzein, Cécile; Couet, Douglas; Blasco, Thierry; Lemée, Rodolphe

2017-05-01

Environmental factors that shape dynamics of benthic toxic blooms are largely unknown. In particular, for the toxic dinoflagellate Ostreopsis cf. ovata, the importance of the availability of nutrients and the contribution of the inorganic and organic pools to growth need to be quantified in marine coastal environments. The present study aimed at characterizing N-uptake of dissolved inorganic and organic sources by O. cf. ovata cells, using the 15 N-labelling technique. Experiments were conducted taking into account potential interactions between nutrient uptake systems as well as variations with the diel cycle. Uptake abilities of O. cf. ovata were parameterized for ammonium (NH 4 + ), nitrate (NO 3 - ) and N-urea, from the estimation of kinetic and inhibition parameters. In the range of 0 to 10μmolNL -1 , kinetic curves showed a clear preference pattern following the ranking NH 4 + >NO 3 - >N-urea, where the preferential uptake of NH 4 + relative to NO 3 - was accentuated by an inhibitory effect of NH 4 + concentration on NO 3 - uptake capabilities. Conversely, under high nutrient concentrations, the preference for NH 4 + relative to NO 3 - was largely reduced, probably because of the existence of a low-affinity high capacity inducible NO 3 - uptake system. Ability to take up nutrients in darkness could not be defined as a competitive advantage for O. cf. ovata. Species competitiveness can also be defined from nutrient uptake kinetic parameters. A strong affinity for NH 4 + was observed for O. cf. ovata cells that may partly explain the success of this toxic species during the summer season in the Bay of Villefranche-sur-mer (France). Copyright © 2017 Elsevier B.V. All rights reserved.

Measuring the serotonin uptake site using [3H]paroxetine--a new serotonin uptake inhibitor

International Nuclear Information System (INIS)

Gleiter, C.H.; Nutt, D.J.

1988-01-01

Serotonin is an important neurotransmitter that may be involved in ethanol preference and dependence. It is possible to label the serotonin uptake site in brain using the tricyclic antidepressant imipramine, but this also binds to other sites. We have used the new high-affinity uptake blocker paroxetine to define binding to this site and report it to have advantages over imipramine as a ligand

Kinetic Uptake Studies of Powdered Materials in Solution

Directory of Open Access Journals (Sweden)

Mohamed H. Mohamed

2015-06-01

Full Text Available Challenges exist for the study of time dependent sorption processes for heterogeneous systems, especially in the case of dispersed nanomaterials in solvents or solutions because they are not well suited to conventional batch kinetic experiments. In this study, a comparison of batch versus a one-pot setup in two variable configurations was evaluated for the study of uptake kinetics in heterogeneous (solid/solution systems: (i conventional batch method; (ii one-pot system with dispersed adsorbent in solution with a semi-permeable barrier (filter paper or dialysis tubing for in situ sampling; and (iii one-pot system with an adsorbent confined in a semi-permeable barrier (dialysis tubing or filter paper barrier with ex situ sampling. The sorbent systems evaluated herein include several cyclodextrin-based polyurethane materials with two types of phenolic dyes: p-nitrophenol and phenolphthalein. The one-pot kinetics method with in situ (Method ii or ex situ (Method iii sampling described herein offers significant advantages for the study of heterogeneous sorption kinetics of highly dispersed sorbent materials with particles sizes across a range of dimensions from the micron to nanometer scale. The method described herein will contribute positively to the development of advanced studies for heterogeneous sorption processes where an assessment of the relative uptake properties is required at different experimental conditions. The results of this study will be advantageous for the study of nanomaterials with significant benefits over batch kinetic studies for a wide range of heterogeneous sorption processes.

Seasonal dynamics of 60Co uptake by freshwater algae under natural conditions

International Nuclear Information System (INIS)

Koulikov, N.V.; Trapeznikov, A.V.

1988-08-01

The data presented in the present report show that the values of 60 Co uptake coefficient in freshwater algae under naturel conditions can change 5-6 times depending on seasons, reaching maximum values in summer. Specific activity of the radionuclide in water can be essentially changed depending on the nuclear power plant operation mode. In such a nonequilibrium system it is rather questionable to use the uptake coefficient as a constant parameter for the determination of the radionuclide specific activity in water [fr

Disruption of Lipid Uptake in Astroglia Exacerbates Diet-Induced Obesity

NARCIS (Netherlands)

Gao, Yuanqing; Layritz, Clarita; Legutko, Beata; Eichmann, Thomas O.; Laperrousaz, Elise; Moullé, Valentine S.; Cruciani-Guglielmacci, Celine; Magnan, Christophe; Luquet, Serge; Woods, Stephen C.; Eckel, Robert H.; Yi, Chun-Xia; Garcia-Caceres, Cristina; Tschöp, Matthias H.

2017-01-01

Neuronal circuits in the brain help to control feeding behavior and systemic metabolism in response to afferent nutrient and hormonal signals. Although astrocytes have historically been assumed to have little relevance for such neuroendocrine control, we investigated whether lipid uptake via

Radioactive iodine uptake: deriving new message from an old test

International Nuclear Information System (INIS)

Gonzales, R.R.; Magboo, M.L.C.; San Luis, T.O.L.

1993-01-01

92 patients with elevated 4 hour RAIU were divided into two groups and analyzed. Group I consisted of 42 patients with rapid iodine trapping and organification (4 hour>24 hour). Group II consisted of 50 patients with progressively increasing RAIU (24 hour>4 hour). Analysis of the clinical manifestations of both groups by using the J. Crooks Scoring System showed that 37 patients (88%) in group I belonged to the toxic group while only 7 (14%) of patients in group II showed clear signs and symptoms of thyrotoxicosis. Independent 2-tailed t-test between the Crooks score of both groups showed significant difference (t=8.42). The uptake pattern of both groups showed significant differences in their uptake levels at p value<0.001. All of the patients in group I received antithyroid regimen while in group II, 26 patients (56%) were given thyroid hormone preparations and only 16 (32%) patients received anti-thyroid drugs. In the final analysis, patterns wherein the 4 hour uptake is higher than the 24 hour uptake are highly associated with hyperthyroidism. Those with sustained elevations of the 4 hour and the 24 hour RAIU should merit good correlation between the clinical and thyroid hormone level before initiating any treatment regimen. (author). 8 refs.; 8 tabs

Lipoprotein lipase: genetics, lipid uptake, and regulation.

Science.gov (United States)

Merkel, Martin; Eckel, Robert H; Goldberg, Ira J

2002-12-01

Lipoprotein lipase (LPL) regulates the plasma levels of triglyceride and HDL. Three aspects are reviewed. 1) Clinical implications of human LPL gene variations: common mutations and their effects on plasma lipids and coronary heart disease are discussed. 2) LPL actions in the nervous system, liver, and heart: the discussion focuses on LPL and tissue lipid uptake. 3) LPL gene regulation: the LPL promoter and its regulatory elements are described.

Effects of cultivation conditions on the uptake of arsenite and arsenic chemical species accumulated by Pteris vittata in hydroponics.

Science.gov (United States)

Hatayama, Masayoshi; Sato, Takahiko; Shinoda, Kozo; Inoue, Chihiro

2011-03-01

The physiological responses of the arsenic-hyperaccumulator, Pteris vittata, such as arsenic uptake and chemical transformation in the fern, have been investigated. However, a few questions remain regarding arsenic treatment in hydroponics. Incubation conditions such as aeration, arsenic concentration, and incubation period might affect those responses of P. vittata in hydroponics. Arsenite uptake was low under anaerobic conditions, as previously reported. However, in an arsenite uptake experiment, phosphorous (P) starvation-dependent uptake of arsenate was observed under aerobic conditions. Time course-dependent analysis of arsenite oxidation showed that arsenite was gradually oxidized to arsenate during incubation. Arsenite oxidation was not observed in any of the control conditions, such as exposure to a nutrient solution or to culture medium only, or with the use of dried root; arsenite oxidation was only observed when live root was used. This result suggests that sufficient aeration allows the rhizosphere system to oxidize arsenite and enables the fern to efficiently take up arsenite as arsenate. X-ray absorption near edge structure (XANES) analyses showed that long-duration exposure to arsenic using a hydroponic system led to the accumulation of arsenate as the dominant species in the root tips, but not in the whole roots, partly because up-regulation of arsenate uptake by P starvation of the fern was caused and retained by long-time incubation. Analysis of concentration-dependent arsenate uptake by P. vittata showed that the uptake switched from a high-affinity transport system to a low-affinity system at high arsenate concentrations, which partially explains the increased arsenate abundance in the whole root. Copyright © 2010 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Rapid adaptation of activated sludge bacteria into a glycogen accumulating biofilm enabling anaerobic BOD uptake.

Science.gov (United States)

Hossain, Md Iqbal; Paparini, Andrea; Cord-Ruwisch, Ralf

2017-03-01

Glycogen accumulating organisms (GAO) are known to allow anaerobic uptake of biological oxygen demand (BOD) in activated sludge wastewater treatment systems. In this study, we report a rapid transition of suspended activated sludge biomass to a GAO dominated biofilm by selective enrichment using sequences of anaerobic loading followed by aerobic exposure of the biofilm to air. The study showed that within eight weeks, a fully operational, GAO dominated biofilm had developed, enabling complete anaerobic BOD uptake at a rate of 256mg/L/h. The oxygen uptake by the biofilm directly from the atmosphere had been calculated to provide significant energy savings. This study suggests that wastewater treatment plant operators can convert activated sludge systems readily into a "passive aeration" biofilm that avoids costly oxygen transfer to bulk wastewater solution. The described energy efficient BOD removal system provides an opportunity to be coupled with novel nitrogen removal processes such as anammox. Copyright © 2016. Published by Elsevier Ltd.

Piezoelectric crystal microbalance measurements of enthalpy of sublimation of C2-C9 dicarboxylic acids

Science.gov (United States)

Dirri, F.; Palomba, E.; Longobardo, A.; Zampetti, E.

2016-02-01

We present here a novel experimental set-up that is able to measure the enthalpy of sublimation of a given compound by means of piezoelectric crystal microbalances (PCMs). The PCM sensors have already been used for space measurements, such as for the detection of organic and non-organic volatile species and refractory materials in planetary environments. In Earth atmospherics applications, PCMs can be also used to obtain some physical-chemical processes concerning the volatile organic compounds (VOCs) present in atmospheric environments. The experimental set-up has been developed and tested on dicarboxylic acids. In this work, a temperature-controlled effusion cell was used to sublimate VOC, creating a molecular flux that was collimated onto a cold PCM. The VOC recondensed onto the PCM quartz crystal, allowing the determination of the deposition rate. From the measurements of deposition rates, it has been possible to infer the enthalpy of sublimation of adipic acid, i.e. ΔHsub : 141.6 ± 0.8 kJ mol-1, succinic acid, i.e. 113.3 ± 1.3 kJ mol-1, oxalic acid, i.e. 62.5 ± 3.1 kJ mol-1, and azelaic acid, i.e. 124.2 ± 1.2 kJ mol-1. The results obtained show an accuracy of 1 % for succinic, adipic, and azelaic acid and within 5 % for oxalic acid and are in very good agreement with previous works (within 6 % for adipic, succinic, and oxalic acid and within 11 % or larger for azelaic acid).

Predominant contribution of L-type amino acid transporter to 4-borono-2-18F-fluoro-phenylalanine uptake in human glioblastoma cells

International Nuclear Information System (INIS)

Yoshimoto, Mitsuyoshi; Kurihara, Hiroaki; Honda, Natsuki; Kawai, Keiichi; Ohe, Kazuyo; Fujii, Hirofumi; Itami, Jun; Arai, Yasuaki

2013-01-01

Introduction: 4-Borono-2- 18 F-fluoro-phenylalanine ( 18 F-FBPA) has been used to anticipate the therapeutic effects of boron neutron capture therapy (BNCT) with 4-borono-L-phenylalanine (BPA). Similarly, L-[methyl- 11 C]-methionine ( 11 C-MET), the most popular amino acid PET tracer, is a possible candidate for this purpose. We investigated the transport mechanism of 18 F-FBPA and compared it with that of 14 C-MET in human glioblastoma cell lines. Methods: Uptake of 18 F-FBPA and 14 C-MET was examined in A172, T98G, and U-87MG cells using 2-aminobicyclo-(2.2.1)-heptane-2-carboxylic acid (a system L-specific substrate), 2-(methylamino)-isobutyric acid (a system A-specific substrate), and BPA. Gene expression was analyzed by quantitative real time polymerase chain reaction. Results: System L was mainly involved in the uptake of 18 F-FBPA (74.5%–81.1% of total uptake) and 14 C-MET (48.3%–59.4%). System A and ASC also contributed to the uptake of 14 C-MET. Inhibition experiments revealed that BPA significantly decreased the uptake of 18 F-FBPA, whereas 31%–42% of total 14 C-MET uptake was transported by BPA non-sensitive transporters. In addition, 18 F-FBPA uptake correlated with LAT1 and total LAT expressions. Conclusion: This study demonstrated that 18 F-FBPA was predominantly transported by system L in human glioblastoma cells compared to 14 C-MET. Although further studies are needed to elucidate the correlation between 18 F-FBPA uptake and BPA content in tumor tissues, 18 F-FBPA is suitable for the selection of patients who benefit from BNCT with BPA

A study of 32P-phosphate uptake in a plant by a real-time RI imaging system

International Nuclear Information System (INIS)

Yamawaki, M.; Kanno, S.; Ishibashi, H.; Noda, A.; Hirose, A.; Tanoi, K.; Nakanishi, T.M.

2011-01-01

It is very important to visualize the process of nutrient absorption and distribution to study the physiological activity of the plant. We developed a real-time radioisotope (RI) imaging system, where RI tracers were applied to the plant sample. This system allowed the quantitative measurement concerning the uptake of nutrients labeled with radioisotopes, such as 45 Ca, 35 S, 32 P and 14 C as long as several days. The β-rays emitted from the sample were converted to light by a CsI(Tl) scintillator and were guided to a highly sensitive CCD camera. The scintillator surface was covered with an Al plate to avoid LED light penetration but allow selected β-ray penetration. We employed Lotus japonicus for the plant sample and observed the 32 P-phosphate absorption in roots and the accumulation to the aboveground part of the plant. The environment condition of daytime and night was simulated by the ON/OFF of LED timer and the accumulation manner of the 32 P-phosphate in roots and leaves during daytime and night was analyzed. The accumulation of 32 P-phosphate in leaves was highly dependant on light irradiation and higher when the LEDs was turned on, whereas the absorption of 32 P-phosphate in root was higher when the LEDs was turned off. The transfer function concerning the transportation of phosphate within the plant during the developmental stage was obtained from the analysis of 32 P uptake images. We are now trying to get specific moving images of each radioisotope when two kinds of isotopes, such as 32 P and 32 S, were applied at the same time to the plant, through an image analysis. (orig.)

P-32 uptake in lentic algae

International Nuclear Information System (INIS)

Strange, J.R.; Williamson, G.D.; Fletcher, D.J.

1975-01-01

A study of the Flat Creek Embayment of Lake Sidney Lanier near Gainesville, Georgia revealed three genera of algae, Chlorococcum, Fragillaria and Nostoc, to be prominent in this eutrophic region of the lake. The algae was grown in phosphate-rich media and subsequently labelled with P-32. All species incorporated luxury amounts of phosphorus as determined by the uptake of P-32. The results indicate that the P-32 uptake is proportional to the surface-per-volume ratio. The higher surface-per-volume ratio resulted in greater uptake of P-32

Sulfocerebrosides upregulate liposome uptake in human astrocytes without inducing a proinflammatory response.

Science.gov (United States)

Suesca, Elizabeth; Alejo, Jose Luis; Bolaños, Natalia I; Ocampo, Jackson; Leidy, Chad; González, John M

2013-07-01

Astrocytes are involved in the pathogenesis of demyelinating diseases, where they actively regulate the secretion of proinflammatory factors, and trigger the recruitment of immune cells in the central nervous system (CNS). Antigen presentation of myelin-derived proteins has been shown to trigger astrocyte response, suggesting that astrocytes can directly sense demyelination. However, the direct response of astrocytes to lipid-debris generated during demyelination has not been investigated. The lipid composition of the myelin sheath is distinct, presenting significant amounts of cerebrosides, sulfocerebrosides (SCB), and ceramides. Studies have shown that microglia are activated in the presence of myelin-derived lipids, pointing to the possibility of lipid-induced astrocyte activation. In this study, a human astrocyte cell line was exposed to liposomes enriched in each myelin lipid component. Although liposome uptake was observed for all compositions, astrocytes had augmented uptake for liposomes containing sulfocerebroside (SCB). This enhanced uptake did not modify their expression of human leukocyte antigen (HLA) molecules or secretion of chemokines. This was in contrast to changes observed in astrocyte cells stimulated with IFNγ. Contrary to human monocytes, astrocytes did not internalize beads in the size-range of liposomes, indicating that liposome uptake is lipid specific. Epifluorescence microscopy corroborated that liposome uptake takes place through endocytosis. Soluble SCB were found to partially block uptake of liposomes containing this same lipid. Endocytosis was not decreased when cells were treated with cytochalasin D, but it was decreased by cold temperature incubation. The specific uptake of SCB in the absence of a proinflammatory response indicates that astrocytes may participate in the trafficking and regulation of sulfocerebroside metabolism and homeostasis in the CNS. Copyright © 2013 International Society for Advancement of Cytometry.

Reduction of FDG uptake in brown adipose tissue in clinical patients by a single dose of propranolol

Energy Technology Data Exchange (ETDEWEB)

Soederlund, Veli [Karolinska University Hospital, Department of Radiology, Stockholm (Sweden); Larsson, Stig A. [Karolinska University Hospital, Department of Nuclear Medicine, Stockholm (Sweden); Jacobsson, Hans [Karolinska University Hospital, Department of Radiology, Stockholm (Sweden); Karolinska University Hospital, Department of Nuclear Medicine, Stockholm (Sweden)

2007-07-15

Uptake in brown adipose tissue (hibernating fat) is sometimes seen at FDG-PET examinations. Despite a characteristic appearance, this may hide clinically relevant uptake. Stimulation of the sympathetic nervous system increases glucose uptake of brown fat. We now re-examine patients with brown fat activity that could disguise tumour uptake after pre-treatment with propranolol (a non-selective {beta}-blocker) in order to reduce the uptake. Our first examinations of this kind are reported. Eleven patients with strong brown fat uptake were studied. There was a mean of 5 days (range 2-8) between the examinations. At the second examination, 80 mg of propranolol was given orally 2 h before FDG administration. In addition to visual evaluation of the brown fat uptake, SUV assessments of the uptake in brown fat, lung, heart, liver, spleen and bone marrow were made. All patients showed complete or almost complete disappearance of the brown fat activity at the second examination (p < 0.001) both upon visual evaluation and when comparing SUVs. In seven patients there was also uptake in a known or strongly suspected malignancy, which remained unchanged between the examinations. Beyond an insignificant decrease in the myocardial uptake, there was no redistribution to the various examined organs at the second examination. Pre-treatment with a single dose of propranolol blocks the FDG uptake in brown adipose tissue, thereby increasing the specificity of the examination. The tumour uptake seems not to be impaired. (orig.)

Elucidating the mechanisms of nickel compound uptake: A review of particulate and nano-nickel endocytosis and toxicity

Energy Technology Data Exchange (ETDEWEB)

Muñoz, Alexandra; Costa, Max, E-mail: Max.Costa@nyumc.org

2012-04-01

Nickel (Ni) is a worldwide pollutant and contaminant that humans are exposed to through various avenues resulting in multiple toxic responses — most alarming is its clear carcinogenic nature. A variety of particulate Ni compounds persist in the environment and can be distinguished by characteristics such as solubility, structure, and surface charge. These characteristics influence cellular uptake and toxicity. Some particulate forms of Ni are carcinogenic and are directly and rapidly endocytized by cells. A series of studies conducted in the 1980s observed this process, and we have reanalyzed the results of these studies to help elucidate the molecular mechanism of particulate Ni uptake. Originally the process of uptake observed was described as phagocytosis, however in the context of recent research we hypothesize that the process is macropinocytosis and/or clathrin mediated endocytosis. Primary considerations in determining the route of uptake here include calcium dependence, particle size, and inhibition through temperature and pharmacological approaches. Particle characteristics that influenced uptake include size, charge, surface characteristics, and structure. This discussion is relevant in the context of nanoparticle studies and the emerging interest in nano-nickel (nano-Ni), where toxicity assessments require a clear understanding of the parameters of particulate uptake and where establishment of such parameters is often obscured through inconsistencies across experimental systems. In this regard, this review aims to carefully document one system (particulate nickel compound uptake) and characterize its properties.

Plutonium uptake by marine phytoplankton in culture

International Nuclear Information System (INIS)

Fisher, N.S.; Olson, B.L.; Bowen, V.T.

1980-01-01

At environmentally realistic atom concentrations 237 Pu tracer was used to examine Pu uptake by unialgla cultures of Thalassiosira pseudonana (live and dead), Thalassiosira sp., and Platymonas sp., as well as by glass particles. Live or dead cells and glass particles accumulated Pu at similar rates, indicating that initial uptake was a passive phenomenon. Uptake was strongly affected by the nature of particle surfaces, but much less by composition of the media. Cells from rapidly growing cultures took up more Pu, than did those from late log or senescent cultures. Acid-washed glass took up more Pu, faster, than did unwashed glass. Cells accumulated more Pu from uv-treated seawater than from seawater untreated or enriched with f/50-level EDTA or f/50 vitamins; from complete f/50 medium uptake was even less, as with f/50 trace metals + EDTA. After a shot uptake Pu was 25% removable in tracer-free media, but after 3 days of uptake none was removable in seawater or exometabolite media, and only 15% in f/50-level EDTA. The data support the hypothesis that Pu in marine environments associates with suspended particles that could act as vertical vectors for this element

Further studies on the nature of postsynaptic dopamine uptake and metabolism in rat striatum: sodium dependency and investigation of a possible role for carrier-mediated uptake into serotonin neurons

Energy Technology Data Exchange (ETDEWEB)

Schoepp, D.D.; Azzaro, A.J.

1985-06-01

The nature of postsynaptic sites involved in the uptake and metabolism of striatal 3,4-dihydroxyphenylethylamine (dopamine, DA) was investigated. The accumulation of (/sup 3/H)DA (10(-7) M) into slices of rat striatum was found to be greatly dependent on the presence of sodium ion in the incubation medium. However, the formation of the (/sup 3/H)dihydroxyphenylacetic acid (DOPAC) and (/sup 3/H)homovanillic acid (HVA) was only partially reduced in the absence of sodium. Inhibition of carrier-mediated DA neuronal uptake with nomifensine significantly decreased DA accumulation (18% of control) and (/sup 3/H)DOPAC formation (62% of control), but enhanced (/sup 3/H)HVA production (143% of control). Inhibition of the 5-hydroxytryptamine (5-HT, serotonin) neuronal uptake system with fluoxetine (10(-6) M) or selective 5-HT neuronal lesions with 5,7-dihydroxytryptamine (5,7-DHT) had no effect on (/sup 3/H)DOPAC or (/sup 3/H)HVA formed from (/sup 3/H)DA in the presence or absence of nomifensine. These results demonstrate that the uptake and subsequent metabolism of striatal DA to DOPAC and HVA is only partially dependent on carrier-mediated uptake mechanism(s) requiring sodium ion. These data support our previous findings suggesting a significant role for synaptic glial cell deamination and O-methylation of striatal DA. Further, experiments with fluoxetine or 5,7-DHT suggest that 5-HT neurons do not significantly contribute in the synaptic uptake and metabolism of striatal DA.

Ocean uptake of carbon dioxide

International Nuclear Information System (INIS)

Peng, Tsung-Hung; Takahashi, Taro

1993-01-01

Factors controlling the capacity of the ocean for taking up anthropogenic C0 2 include carbon chemistry, distribution of alkalinity, pCO 2 and total concentration of dissolved C0 2 , sea-air pCO 2 difference, gas exchange rate across the sea-air interface, biological carbon pump, ocean water circulation and mixing, and dissolution of carbonate in deep sea sediments. A general review of these processes is given and models of ocean-atmosphere system based on our understanding of these regulating processes axe used to estimate the magnitude of C0 2 uptake by the ocean. We conclude that the ocean can absorb up to 35% of the fossil fuel emission. Direct measurements show that 55% Of C0 2 from fossil fuel burning remains in the atmosphere. The remaining 10% is not accounted for by atmospheric increases and ocean uptake. In addition, it is estimated that an amount equivalent to 30% of recent annual fossil fuel emissions is released into the atmosphere as a result of deforestation and farming. To balance global carbon budget, a sizable carbon sink besides the ocean is needed. Storage of carbon in terrestrial biosphere as a result of C0 2 fertilization is a potential candidate for such missing carbon sinks

Modulatory Role of Surface Coating of Superparamagnetic Iron Oxide Nanoworms in Complement Opsonization and Leukocyte Uptake

DEFF Research Database (Denmark)

Inturi, Swetha; Wang, Guankui; Chen, Fangfang

2015-01-01

demonstrated that neutrophils, monocytes, lymphocytes and eosinophils took up SPIO NWs, and the uptake was prevented by EDTA (a general complement inhibitor) and by antiproperdin antibody (an inhibitor of the alternative pathway of the complement system). Cross-linking and hydrogelation of SPIO NWs surface...... by epichlorohydrin decreased C3 opsonization in mouse serum, and consequently reduced the uptake by mouse leukocytes by more than 70% in vivo. Remarkably, the cross-linked particles did not show a decrease in C3 opsonization in human serum, but showed a significant decrease (over 60%) of the uptake by human...... leukocytes. The residual uptake of cross-linked nanoparticles was completely blocked by EDTA. These findings demonstrate species differences in complement-mediated nanoparticle recognition and uptake by leukocytes, and further show that human hemocompatibility could be improved by inhibitors of complement...

Electrochemical behaviour of silver complexes of dithia-alkanedicarboxylic acids

NARCIS (Netherlands)

Janssen, L.J.J.; Hoogland, J.G.

1972-01-01

The composition and electrochemical behaviour of the Ag-complexes of dithia-alkane-dicarboxylic acids, viz. 2,5-dithiahexane-1,6-dicarboxylic acid (I), 3,6-dithiaoctane-1,8-dicarboxylic acid(II), 4,7-dithiadecane-1,10-dicarboxylic acid (III) and 2,2,7,7,-tetramethyl-3,6-dithiaoctane-1,8-dicarboxylic

``Sheddable'' PEG-lipid to balance the contradiction of PEGylation between long circulation and poor uptake

Science.gov (United States)

Zhao, Caiyan; Deng, Hongzhang; Xu, Jing; Li, Shuyi; Zhong, Lin; Shao, Leihou; Wu, Yan; Liang, Xing-Jie

2016-05-01

PEGylated lipids confer longer systemic circulation and tumor accumulation via the enhanced permeability and retention (EPR) effect. However, PEGylation inhibits cellular uptake and subsequent endosomal escape. In order to balance the contradiction between the advantages of long circulation and the disadvantages of poor uptake of PEGylated lipids, we prepared a ``sheddable'' PEG-lipid micelle system based on the conjugation of PEG and phosphatidyl ethanolamine (DSPE) with a pH sensitive benzoic imine bond. In a physiological environment, the PEG-protected micelles were not readily taken up by the reticuloendothelial system (RES) and could be successfully delivered to tumor tissue by the EPR effect. In a tumor acidic microenvironment, the PEG chains detached from the surfaces of the micelles while the degree of linker cleavage could not cause a significant particle size change, which facilitated the carrier binding to tumor cells and improved the cellular uptake. Subsequently, the ``sheddable'' PEG-lipid micelles easily internalized into cells and the increased acidity in the lysosomes further promoted drug release. Thus, this ``sheddable'' PEG-lipid nanocarrier could be a good candidate for effective intracellular drug delivery in cancer chemotherapy.PEGylated lipids confer longer systemic circulation and tumor accumulation via the enhanced permeability and retention (EPR) effect. However, PEGylation inhibits cellular uptake and subsequent endosomal escape. In order to balance the contradiction between the advantages of long circulation and the disadvantages of poor uptake of PEGylated lipids, we prepared a ``sheddable'' PEG-lipid micelle system based on the conjugation of PEG and phosphatidyl ethanolamine (DSPE) with a pH sensitive benzoic imine bond. In a physiological environment, the PEG-protected micelles were not readily taken up by the reticuloendothelial system (RES) and could be successfully delivered to tumor tissue by the EPR effect. In a tumor acidic

Potassium uptake system Trk2 is crucial for yeast cell viability during anhydrobiosis

Czech Academy of Sciences Publication Activity Database

Borovikova, D.; Herynková, Pavla; Rapoport, A.; Sychrová, Hana

2014-01-01

Roč. 350, č. 1 (2014), s. 28-33 ISSN 0378-1097 R&D Projects: GA MŠk(CZ) LD13037; GA ČR(CZ) GAP503/10/0307 Institutional support: RVO:67985823 Keywords : desiccation * yeast * potassium uptake * stress survival Subject RIV: EE - Microbiology, Virology Impact factor: 2.121, year: 2014

Rolipram depresses [{sup 3}H]2-deoxyglucose uptake in mouse brain and heart in vivo

Energy Technology Data Exchange (ETDEWEB)

Ishikawa, Megumi; Hosoi, Rie; Kobayashi, Kaoru; Inoue, Osamu [Department of Medical Physics, School of Allied Health Sciences, Faculty of Medicine, Osaka University, 1-7 Yamadaoka, Suita-shi, Osaka (Japan); Nishimura, Tsunehiko [Department of Radiology, Kyoto Prefectural University of Medicine, Kyoto (Japan)

2002-09-01

The effects of systemic administration of rolipram, a selective phosphodiesterase type 4 inhibitor, on [{sup 3}H]2-deoxyglucose (DG) uptake in brain and peripheral tissues were examined. Rolipram significantly and dose-dependently decreased [{sup 3}H]DG uptake in brain, heart and skeletal muscle. In contrast, the radioactivity concentrations in the plasma of rolipram-treated mice were significantly higher than those of control mice at all times after injection of the tracer. In the kinetic study, the initial uptake of [{sup 3}H]DG in brain was decreased by rolipram, whereas no significant differences were observed in the uptake in heart and skeletal muscle. However, radioactivity concentrations in the brain, heart and skeletal muscle 30 min after the injection of [{sup 3}H]DG were significantly lowered by rolipram to about 60%, 10% and 10% of control values, respectively. The uptake of [{sup 13}N]ammonia in brain and heart of rolipram-treated mice was slightly decreased, which indicated that rolipram diminished both cerebral and cardiac blood flow. These results indicate that the phosphorylation process via hexokinase rather than the transport of [{sup 3}H]DG might be depressed by rolipram. Together with the previous observations that inhibition of protein kinase A (PKA) markedly enhanced [{sup 14}C]DG uptake in rat brain, these results indicate an important role of the cAMP/PKA systems in the regulation of glucose metabolism in the living brain as well as in peripheral tissues such as the heart and skeletal muscle. (orig.)

Factors influencing physiological FDG uptake in the intestine

International Nuclear Information System (INIS)

Yasuda, Seiei; Takahashi, Wakoh; Takagi, Shigeharu; Fujii, Hirofumi; Ide, Michiru; Shohtsu, Akira

1998-01-01

The intestine is a well-known site of physiological 18 F-fluorodeoxyglucose (FDG) accumulation in positron emission tomography (PET). To identify factors influencing physiological FDG uptake in the intestine, the intensity of FDG uptake was evaluated in a total of 1,068 healthy adults. Non-attenuation-corrected whole-body PET images were obtained for all subjects and visually evaluated. Subjects were then classified into two groups according to the intensity of intestinal FDG uptake. Sex, age, presence or absence of constipation, and serum glucose, hemoglobin A 1 c, and free fatty acid levels were compared between the two groups. High intestinal FDG uptake was observed at an overall rate of 11.0%. Sex (female), age, and bowel condition (constipation) were found to affect intestinal FDG uptake. The factors we identified lead to further questions the relationship between intestinal motility and glucose uptake that warrant further study. (author)

Population uptake of antiretroviral treatment through primary care in rural South Africa

Directory of Open Access Journals (Sweden)

Bärnighausen Till W

2010-09-01

Full Text Available Abstract Background KwaZulu-Natal is the South African province worst affected by HIV and the focus of early modeling studies investigating strategies of antiretroviral treatment (ART delivery. The reality of antiretroviral roll-out through primary care has differed from that anticipated and real world data are needed to inform the planning of further scaling up of services. We investigated the factors associated with uptake of antiretroviral treatment through a primary healthcare system in rural South Africa. Methods Detailed demographic, HIV surveillance and geographic information system (GIS data were used to estimate the proportion of HIV positive adults accessing antiretroviral treatment within northern KwaZulu-Natal, South Africa in the period from initiation of antiretroviral roll-out until the end of 2008. Demographic, spatial and socioeconomic factors influencing the likelihood of individuals accessing antiretroviral treatment were explored using multivariable analysis. Results Mean uptake of ART among HIV positive resident adults was 21.0% (95%CI 20.1-21.9. Uptake among HIV positive men (19.2% was slightly lower than women (21.8%, P = 0.011. An individual's likelihood of accessing ART was not associated with level of education, household assets or urban/rural locale. ART uptake was strongly negatively associated with distance from the nearest primary healthcare facility (aOR = 0.728 per square-root transformed km, 95%CI 0.658-0.963, P = 0.002. Conclusions Despite concerns about the equitable nature of antiretroviral treatment rollout, we find very few differences in ART uptake across a range of socio-demographic variables in a rural South African population. However, even when socio-demographic factors were taken into account, individuals living further away from primary healthcare clinics were still significantly less likely to be accessing ART

Homeostatic and toxic mechanisms regulating manganese uptake, retention, and elimination

Directory of Open Access Journals (Sweden)

JEROME A ROTH

2006-01-01

Full Text Available This review attempts to summarize and clarify our basic knowledge as to the various factors that potentially influence the risks imposed from chronic exposure to high atmospheric levels of manganese (Mn. The studies describe the interrelationship of the different systems in the body that regulate Mn homeostasis by characterizing specific, biological components involved in its systemic and cellular uptake and its elimination from the body. A syndrome known as manganism occurs when individuals are exposed chronically to high levels of Mn, consisting of reduced response speed, intellectual deficits, mood changes, and compulsive behaviors in the initial stages of the disorder to more prominent and irreversible extrapyramidal dysfunction resembling Parkinson's disease upon protracted exposure. Mn intoxication is most often associated with occupations in which abnormally high atmospheric concentrations prevail, such as in welding and mining. There are three potentially important routes by which Mn in inspired air can gain access the body to: 1 direct uptake into the CNS via uptake into the olfactory or trigeminal presynaptic nerve endings located in the nasal mucosa and the subsequent retrograde axonal transport directly into the CNS; 2 transport across the pulmonary epithelial lining and its subsequent deposition into lymph or blood; and/or 3 mucocilliary elevator clearance from the lung and the subsequent ingestion of the metal in the gastrointestinal tract. Each of these processes and their overall contribution to the uptake of Mn in the body is discussed in this review as well as a description of the various mechanisms that have been proposed for the transport of Mn across the blood-brain barrier which include both a transferrin-dependent and a transferrin-independent process that may involve store-operated Ca channels.

Do general practice characteristics influence uptake of an information technology (IT innovation in primary care?

Directory of Open Access Journals (Sweden)

Josie Evans

2008-05-01

Conclusions The analyses show that structural characteristics of a practice are not associated with uptake of a new IT facility, but that its use may be influenced by post-graduate education in the relevant clinical condition. For this diabetes system at least, practice nurse use was critical in spreading uptake beyond initial GP enthusiasts and for sustained and rising use in subsequent years.

Sugar uptake and starch biosynthesis by slices of developing maize endosperm

International Nuclear Information System (INIS)

Felker, F.C.; Liu, Kangchien; Shannon, J.C.

1990-01-01

14 C-Sugar uptake and incorporation into starch by slices of developing maize (Zea mays L.) endosperm were examined and compared with sugar uptake by maize endosperm-derived suspension cultures. Rates of sucrose, fructose, and D- and L-glucose uptake by slices were similar, whereas uptake rates for these sugars differed greatly in suspension cultures. Concentration dependence of sucrose, fructose, and D-glucose uptake was biphasic (consisting of linear plus saturable components) with suspension cultures but linear with slices. These and other differences suggest that endosperm slices are freely permeable to sugars. After diffusion into the slices, sugars were metabolized and incorporated into starch. Starch synthesis, but not sugar accumulation, was greatly reduced by 2.5 millimolar p-chloromercuribenzenesulfonic acid and 0.1 millimolar carbonyl cyanide m-chlorophenylhydrazone. Starch synthesis was dependent on kernel age and incubation temperature, but not on external pH (5 through 8). Competing sugars generally did not affect the distribution of 14 C among the soluble sugars extracted from endosperm slices incubated in 14 C-sugars. Competing hexoses reduced the incorporation of 14 C into starch, but competing sucrose did not, suggesting that sucrose is not a necessary intermediate in starch biosynthesis. The bidirectional permeability of endosperm slices to sugars makes the characterization of sugar transport into endosperm slices impossible, however the model system is useful for experiments dealing with starch biosynthesis which occurs in the metabolically active tissue

A Study of Iodine aerial deposition on crops, grass and soil and it's subsequent uptake and translocation

International Nuclear Information System (INIS)

Shang, Zhaorong

2008-01-01

Full text: In order to further the knowledge of radioiodine mobility in the Asian biosphere system, a closed experimental system was established to study gaseous iodine deposition and uptake in a simulated agricultural system using 125 I. Pot experiments were carried out to study airborne 125 I deposition on crops and soil, the results show that: 1) 125 I aerosol deposited on plants in a dry deposition mode; 2) 125 I aerial deposition on leaves can be transferred to other tissues through foliar absorption; and 3) Corn and navy bean have the largest observed translocation factor of the selected crops. The 125 I soil-to-crops uptake test shows that 125 I deposited in soil can be transferred to plants via root uptake, and that the transfer factors in millet and broomcorn are significantly higher than other crops. (author)

A study of iodine aerial deposition on crops, grass and soil and it's subsequent uptake and translocation

International Nuclear Information System (INIS)

Shang Zhaorong

2006-03-01

In order to further the knowledge of radioiodine mobility in the Asian biosphere system, a closed experimental system was established to study gaseous iodine deposition and uptake in a simulated agricultural system using 125 I. Pot experiments were carried out to study airborne 125 I deposition on crops and soil, the results show that (1) 125 I aerosol deposited on plants in a dry deposition mode; (2) 125 I aerial deposition on leaves can be transferred to other tissues through foliar absorption; (3) corn and navy bean have the largest observed translocation factor of the selected crops. The 125 I soil-to-crops uptake test shows that 125 I deposited in soil can be transfered to plants via root uptake, and that the transfer factors in millet and broomcorn are significantly higher than that in other crops. (authors)

Nitrate Uptake Capacity and Efficiency of Upper Mississippi River Flow-Regulated Backwaters

National Research Council Canada - National Science Library

James, William F; Richardson, William B; Soballe, David M

2007-01-01

In-stream uptake and processing of nitrate nitrite-N may be improved in large river systems by increasing hydrological connectivity between the main channel and adjoining backwaters, wetlands, and floodplain areas...

CONSEXPO 3.0, consumer exposure and uptake models

NARCIS (Netherlands)

Veen MP van; LBM

2001-01-01

The report provides a modelling approach to consumer exposure to chemicals, based on mathematical contact, exposure and uptake models. For each route of exposure, a number of exposure and uptake models are included. A general framework joins the exposure and uptake models selected by the user. By

Knudsen cell and smog chamber study of the heterogeneous uptake of sulfur dioxide on Chinese mineral dust.

Science.gov (United States)

Zhou, Li; Wang, Weigang; Gai, Yanbo; Ge, Maofa

2014-12-01

The heterogeneous uptake processes of sulfur dioxide on two types of Chinese mineral dust (Inner Mongolia desert dust and Xinjiang sierozem) were investigated using both Knudsen cell and smog chamber system. The temperature dependence of the uptake coefficients was studied over a range from 253 to 313 K using the Knudsen cell reactor, the initial uptake coefficients decreased with the increasing of temperature for these two mineral dust samples, whereas the steady state uptake coefficients of the Xinjiang sierozem increased with the temperature increasing, and these temperature dependence functions were obtained for the first time. In the smog chamber experiments at room temperature, the steady state uptake coefficients of SO2 decreased evidently with the increasing of sulfur dioxide initial concentration from 1.72 × 10¹² to 6.15 × 10¹² mol/cm³. Humid air had effect on the steady state uptake coefficients of SO₂onto Inner Mongolia desert dust. Consequences about the understanding of the uptake processes onto mineral dust samples and the environmental implication were also discussed. Copyright © 2014. Published by Elsevier B.V.

Dependence of FDG uptake on tumor microenvironment

International Nuclear Information System (INIS)

Pugachev, Andrei; Ruan, Shutian; Carlin, Sean; Larson, Steven M.; Campa, Jose; Ling, C. Clifton; Humm, John L.

2005-01-01

Purpose: To investigate the factors affecting the 18 F-fluorodeoxyglucose ( 18 F-FDG) uptake in tumors at a microscopic level, by correlating it with tumor hypoxia, cellular proliferation, and blood perfusion. Methods and Materials: Nude mice bearing Dunning prostate tumors (R3327-AT) were injected with 18 F-FDG and pimonidazole, bromodeoxyuridine, and, 1 min before sacrifice, with Hoechst 33342. Selected tumor sections were imaged by phosphor plate autoradiography, while adjacent sections were used to obtain the images of the spatial distribution of Hoechst 33342, pimonidazole, and bromodeoxyuridine. The images were co-registered and analyzed on a pixel-by-pixel basis. Results: Statistical analysis of the data obtained from these tumors demonstrated that 18 F-FDG uptake was positively correlated with pimonidazole staining intensity in each data set studied. Correlation of FDG uptake with bromodeoxyuridine staining intensity was always negative. In addition, FDG uptake was always negatively correlated with the staining intensity of Hoechst 33342. Conclusions: For the Dunning prostate tumors studied, FDG uptake was always positively correlated with hypoxia and negatively correlated with both cellular proliferation and blood flow. Therefore, for the tumor model studied, higher FDG uptake is indicative of tumor hypoxia, but neither blood flow nor cellular proliferation

Role of the reaction intermediates in determining PHIP (parahydrogen induced polarization) effect in the hydrogenation of acetylene dicarboxylic acid with the complex [Rh (dppb)]+ (dppb: 1,4-bis(diphenylphosphino)butane)

International Nuclear Information System (INIS)

Reineri, F.; Aime, S.; Gobetto, R.; Nervi, C.

2014-01-01

This study deals with the parahydrogenation of the symmetric substrate acetylene dicarboxylic acid catalyzed by a Rh(I) complex bearing the chelating diphosphine dppb (1,4-bis(diphenylphosphino)butane). The two magnetically equivalent protons of the product yield a hyperpolarized emission signal in the 1 H-NMR spectrum. Their polarization intensity varies upon changing the reaction solvent from methanol to acetone. A detailed analysis of the hydrogenation pathway is carried out by means of density functional theory calculations to assess the structure of hydrogenation intermediates and their stability in the two solvents. The observed polarization effects have been accounted on the basis of the obtained structures. Insights into the lifetime of a short-lived reaction intermediate are also obtained

Proximal Tubules Have the Capacity to Regulate Uptake of Albumin.

Science.gov (United States)

Wagner, Mark C; Campos-Bilderback, Silvia B; Chowdhury, Mahboob; Flores, Brittany; Lai, Xianyin; Myslinski, Jered; Pandit, Sweekar; Sandoval, Ruben M; Wean, Sarah E; Wei, Yuan; Satlin, Lisa M; Wiggins, Roger C; Witzmann, Frank A; Molitoris, Bruce A

2016-02-01

Evidence from multiple studies supports the concept that both glomerular filtration and proximal tubule (PT) reclamation affect urinary albumin excretion rate. To better understand these roles of glomerular filtration and PT uptake, we investigated these processes in two distinct animal models. In a rat model of acute exogenous albumin overload, we quantified glomerular sieving coefficients (GSC) and PT uptake of Texas Red-labeled rat serum albumin using two-photon intravital microscopy. No change in GSC was observed, but a significant decrease in PT albumin uptake was quantified. In a second model, loss of endogenous albumin was induced in rats by podocyte-specific transgenic expression of diphtheria toxin receptor. In these albumin-deficient rats, exposure to diphtheria toxin induced an increase in albumin GSC and albumin filtration, resulting in increased exposure of the PTs to endogenous albumin. In this case, PT albumin reabsorption was markedly increased. Analysis of known albumin receptors and assessment of cortical protein expression in the albumin overload model, conducted to identify potential proteins and pathways affected by acute protein overload, revealed changes in the expression levels of calreticulin, disabled homolog 2, NRF2, angiopoietin-2, and proteins involved in ATP synthesis. Taken together, these results suggest that a regulated PT cell albumin uptake system can respond rapidly to different physiologic conditions to minimize alterations in serum albumin level. Copyright © 2016 by the American Society of Nephrology.

Short-term uptake of heavy metals by periphyton algae

Energy Technology Data Exchange (ETDEWEB)

Vymazal, J.

1984-12-31

The utilization of periphyton for the removal of heavy metals from enriched small streams has been examined. By means of short-term batch laboratory experiments the courses of metal uptake have been studied. For uptake study naturally growing periphyton community and periphytic filamentous algae Cladophora glomerata and Oedogonium rivulare have been used. Uptakes of nine heavy metals (Pb, Cd, Cu, Co, Cr, Ni, Zn, Fe and Mn) have been determined during four hours exposure. In addition the influence of humic substances on heavy metals uptake has been determined. Uptake of all metals increased during four hours exposure but not in the same way. Some metals were removed continuously (Ni, Cr, Fe and Mn), other metals were removed more rapidly during the first hour or first two hours of exposure and then only slight removal continued (Cu, Pb, Cd, Co). Uptake of Zn was rather unambiguous. Results of these experiments suggest that the course of uptake for individual metals could be similar for most periphyton algae. It was established that humic substances significantly reduce heavy metals uptake. The highest decrease of uptake was observed in Cu, Cr, Co and Cd. The results of model experiments are being tested in a pilot scale with respect to the demands of engineering practice. (J.R.)

The role of ocean transport in the uptake of anthropogenic CO2

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I. Totterdell

2009-03-01

Full Text Available We compare modeled oceanic carbon uptake in response to pulse CO2 emissions using a suite of global ocean models and Earth system models. In response to a CO2 pulse emission of 590 Pg C (corresponding to an instantaneous doubling of atmospheric CO2 from 278 to 556 ppm, the fraction of CO2 emitted that is absorbed by the ocean is: 37±8%, 56±10%, and 81±4% (model mean ±2σ in year 30, 100, and 1000 after the emission pulse, respectively. Modeled oceanic uptake of pulse CO2 on timescales from decades to about a century is strongly correlated with simulated present-day uptake of chlorofluorocarbons (CFCs and CO2 across all models, while the amount of pulse CO2 absorbed by the ocean from a century to a millennium is strongly correlated with modeled radiocarbon in the deep Southern and Pacific Ocean. However, restricting the analysis to models that are capable of reproducing observations within uncertainty, the correlation is generally much weaker. The rates of surface-to-deep ocean transport are determined for individual models from the instantaneous doubling CO2 simulations, and they are used to calculate oceanic CO2 uptake in response to pulse CO2 emissions of different sizes pulses of 1000 and 5000 Pg C. These results are compared with simulated oceanic uptake of CO2 by a number of models simulations with the coupling of climate-ocean carbon cycle and without it. This comparison demonstrates that the impact of different ocean transport rates across models on oceanic uptake of anthropogenic CO2 is of similar magnitude as that of climate-carbon cycle feedbacks in a single model, emphasizing the important role of ocean transport in the uptake of anthropogenic CO2.

Phosphorus deficiency enhances molybdenum uptake by tomato plants

International Nuclear Information System (INIS)

Heuwinkel, H.; Kirkby, E.A.; Le Bot, J.; Marschner, H.

1992-01-01

Water culture experiments are described which provide conclusive evidence that Mo uptake by tomato plants is markedly enhanced by P deficiency. In a longterm experiment, which ran for 11 days, in marked contrast to the uptake of other nutrients, a three fold higher Mo uptake rate was observed after only four days of withdrawal of P from the nutrient medium. In contrast to the gradual increase in pH of the nutrient medium of the plants supplied with P, the pH in the medium of the -P plants fell. Throughout the growth of these plants net H+ efflux could be accounted for by excess cation over anion uptake, indicating that organic acid extrusion plays no major role in the observed fall in pH. Further evidence that Mo uptake is enhanced in P deficient tomato plants is provided in short-term nutrient solution experiments (1h and 4h) using radioactive molybdenum (99Mo). Compared with P sufficient plants, the uptake rates of 99Mo by P deficient plants were three to five times higher after 1h and nine to twelve times higher after 4h. Resupplying P during the uptake periods to deficient plants reduced the uptake rate of 99Mo to values similar to those of P sufficient plants. It is concluded that the uptake of molybdate occurs via phosphate binding/ transporting sites at the plasma membrane of root cells. Further support for this conclusion comes from exchange experiments with non-labelled molybdenum, which show a much larger amount of 99Mo exchangeable from the roots of P deficient plants

Skeletal muscle glucose uptake during dynamic exercise in humans

DEFF Research Database (Denmark)

Richter, Erik; Kiens, Bente; Saltin, Bengt

1988-01-01

uptake was not compensated for by increased uptake of free fatty acids but was accompanied by decreases in plasma insulin and increases in plasma epinephrine and norepinephrine. During work with large muscle masses, arterial lactate increased to approximately 6 mM, and net leg lactate release reverted......To study the role of muscle mass in glucoregulation, six subjects worked with the knee extensors of one leg on a specially constructed cycle ergometer. The knee extensors of one leg worked either alone or in combination with the knee extensors of the other leg and/or with the arms. Substrate usage...... to net lactate uptake. Decreased glucose uptake could not be explained by decreased perfusion. It is concluded that thigh muscle glucose uptake is affected by the size of the total muscle mass engaged in exercise. The decrease in thigh glucose uptake, when arm cranking was added and O2 uptake...

Evaluation of hilar 67Ga-citrate uptake in bronchogenic carcinoma

International Nuclear Information System (INIS)

Matsuno, Noriyo; Kuyama, Junpei; Uchida, Yoshitaka; Hatano, Osamu; Imai, Yasunori; Uno, Kimiichi; Minoshima, Satoshi.

1995-01-01

We evaluated hilar uptake on 67 Ga-citrate scintigraphy and correlated with hilar lymph node metastases in one-hundred seventeen cases (two-hundred thirty four hila) of bronchogenic carcinoma. Hilar uptake was classified into three grades independently on anterior and posterior chest views: no uptake (grade 0), uptake equal to that in the thoracic vertebrae (grade 1), and uptake higher than that in the thoracic vertebrae (grade 2). If a summed grade of anterior and posterior view was larger than 3, hilar uptake was considered as positive. In forty-four cases (forty-nine hila) with hilar lymph node metastases, positive hilar uptake was found in ten cases (eleven hila), resulting in sensitivity of 22% based on cases and 23% based on hila. In seventy-three cases (one-hundred forty-six hila) without hilar lymph node metastases, positive hilar uptake was found in six cases (ten hila), resulting in specificity of 91% based on cases and 93% based on hila. In comparison to scintigraphic findings of unilaterally positive hilar uptake, findings of bilaterally positive hilar uptake showed significantly lower accuracy in determining presence of hilar lymph node metastases. No definite correlation between hilar uptake and histopathology or 67 Ga-citrate uptake in a primary tumor was observed. The results indicate that usefulness of 67 Ga-citrate scintigraphy is limited when evaluating hilar lymph node metastases in bronchogenic carcinoma. (author)

Capturing Individual Uptake: Toward a Disruptive Research Methodology

Science.gov (United States)

Bastian, Heather

2015-01-01

This article presents and illustrates a qualitative research methodology for studies of uptake. It does so by articulating a theoretical framework for qualitative investigations of uptake and detailing a research study designed to invoke and capture students' uptakes in a first-year writing classroom. The research design sought to make uptake…

Concomitant uptake of antimicrobials and Salmonella in soil and into lettuce following wastewater irrigation

International Nuclear Information System (INIS)

Sallach, J. Brett; Zhang, Yuping; Hodges, Laurie; Snow, Daniel; Li, Xu; Bartelt-Hunt, Shannon

2015-01-01

The use of wastewater for irrigation may introduce antimicrobials and human pathogens into the food supply through vegetative uptake. The objective of this study was to investigate the uptake of three antimicrobials and Salmonella in two lettuce cultivars. After repeated subirrigation with synthetic wastewater, lettuce leaves and soil were collected at three sequential harvests. The internalization frequency of Salmonella in lettuce was low. A soil horizon-influenced Salmonella concentration gradient was determined with concentrations in bottom soil 2 log CFU/g higher than in top soil. Lincomycin and sulfamethoxazole were recovered from lettuce leaves at concentrations as high as 822 ng/g and 125 ng/g fresh weight, respectively. Antimicrobial concentrations in lettuce decreased from the first to the third harvest suggesting that the plant growth rate may exceed antimicrobial uptake rates. Accumulation of antimicrobials was significantly different between cultivars demonstrating a subspecies level variation in uptake of antibiotics in lettuce. - Highlights: • Antimicrobial uptake in lettuce is cultivar dependent. • Antimicrobial concentrations in lettuce decrease despite repeated exposure. • Lincomycin is better conserved in the soil-plant system than oxytetracycline or sulfamethoxazole. • Subirrigation resulted in more Salmonella in bottom soil than in top soil. • Internalization frequency of Salmonella in lettuce is low despite repeated exposure. - Cultivar-specific differences in lincomycin and sulfamethazine uptake were observed in lettuce, while uptake of Salmonella was low despite repeated exposure from wastewater

Effects of soil properties on the uptake of pharmaceuticals into earthworms

International Nuclear Information System (INIS)

Carter, Laura J.; Ryan, Jim J.; Boxall, Alistair B.A.

2016-01-01

Pharmaceuticals can enter the soil environment when animal slurries and sewage sludge are applied to land as a fertiliser or during irrigation with contaminated water. These pharmaceuticals may then be taken up by soil organisms possibly resulting in toxic effects and/or exposure of organisms higher up the food chain. This study investigated the influence of soil properties on the uptake and depuration of pharmaceuticals (carbamazepine, diclofenac, fluoxetine and orlistat) in the earthworm Eisenia fetida. The uptake and accumulation of pharmaceuticals into E. fetida changed depending on soil type. Orlistat exhibited the highest pore water based bioconcentration factors (BCFs) and displayed the largest differences between soil types with BCFs ranging between 30.5 and 115.9. For carbamazepine, diclofenac and fluoxetine BCFs ranged between 1.1 and 1.6, 7.0 and 69.6 and 14.1 and 20.4 respectively. Additional analysis demonstrated that in certain treatments the presence of these chemicals in the soil matrices changed the soil pH over time, with a statistically significant pH difference to control samples. The internal pH of E. fetida also changed as a result of incubation in pharmaceutically spiked soil, in comparison to the control earthworms. These results demonstrate that a combination of soil properties and pharmaceutical physico-chemical properties are important in terms of predicting pharmaceutical uptake in terrestrial systems and that pharmaceuticals can modify soil and internal earthworm chemistry which may hold wider implications for risk assessment. - Highlights: • Uptake of pharmaceuticals into earthworms is influenced by soil parameters. • Presence of pharmaceuticals in the terrestrial environment influences soil pH. • Uptake of pharmaceuticals by earthworms changes internal earthworm pH. - The uptake of pharmaceuticals into soil invertebrates is dependent on the complex interplay between pharmaceutical physico-chemical properties and soil

Validation of a spatial–temporal soil water movement and plant water uptake model

KAUST Repository

HEPPELL, J.

2014-06-01

© 2014, (publisher). All rights reserved. Management and irrigation of plants increasingly relies on accurate mathematical models for the movement of water within unsaturated soils. Current models often use values for water content and soil parameters that are averaged over the soil profile. However, many applications require models to more accurately represent the soil–plant–atmosphere continuum, in particular, water movement and saturation within specific parts of the soil profile. In this paper a mathematical model for water uptake by a plant root system from unsaturated soil is presented. The model provides an estimate of the water content level within the soil at different depths, and the uptake of water by the root system. The model was validated using field data, which include hourly water content values at five different soil depths under a grass/herb cover over 1 year, to obtain a fully calibrated system for plant water uptake with respect to climate conditions. When compared quantitatively to a simple water balance model, the proposed model achieves a better fit to the experimental data due to its ability to vary water content with depth. To accurately model the water content in the soil profile, the soil water retention curve and saturated hydraulic conductivity needed to vary with depth.

Water oxidation catalyzed by mononuclear ruthenium complexes with a 2,2'-bipyridine-6,6'-dicarboxylate (bda) ligand: how ligand environment influences the catalytic behavior.

Science.gov (United States)

Staehle, Robert; Tong, Lianpeng; Wang, Lei; Duan, Lele; Fischer, Andreas; Ahlquist, Mårten S G; Sun, Licheng; Rau, Sven

2014-02-03

A new water oxidation catalyst [Ru(III)(bda)(mmi)(OH2)](CF3SO3) (2, H2bda = 2,2'-bipyridine-6,6'-dicarboxylic acid; mmi = 1,3-dimethylimidazolium-2-ylidene) containing an axial N-heterocyclic carbene ligand and one aqua ligand was synthesized and fully characterized. The kinetics of catalytic water oxidation by 2 were measured using stopped-flow technique, and key intermediates in the catalytic cycle were probed by density functional theory calculations. While analogous Ru-bda water oxidation catalysts [Ru(bda)L2] (L = pyridyl ligands) are supposed to catalyze water oxidation through a bimolecular coupling pathway, our study points out that 2, surprisingly, undergoes a single-site water nucleophilic attack (acid-base) pathway. The diversion of catalytic mechanisms is mainly ascribed to the different ligand environments, from nonaqua ligands to an aqua ligand. Findings in this work provide some critical proof for our previous hypothesis about how alternation of ancillary ligands of water oxidation catalysts influences their catalytic efficiency.

Characterization of zinc uptake, binding, and translocation in intact seedlings of bread and durum wheat cultivars

International Nuclear Information System (INIS)

Hart, J.J.; Norvell, W.A.; Welch, R.M.; Sullivan, L.A.; Kochian, L.V.

1998-01-01

Durum wheat (Triticum turgidum L. var durum) cultivars exhibit lower Zn efficiency than comparable bread wheat (Triticum aestivum L.) cultivars. To understand the physiological mechanism(s) that confers Zn efficiency, this study used 65Zn to investigate ionic Zn2+ root uptake, binding, and translocation to shoots in seedlings of bread and durum wheat cultivars. Time-dependent Zn2+ accumulation during 90 min was greater in roots of the bread wheat cultivar. Zn2+ cell wall binding was not different in the two cultivars. In each cultivar, concentration-dependent Zn2+ influx was characterized by a smooth, saturating curve, suggesting a carrier-mediated uptake system. At very low solution Zn2+ activities, Zn2+ uptake rates were higher in the bread wheat cultivar. As a result, the Michaelis constant for Zn2+ uptake was lower in the bread wheat cultivar (2.3 micromolar) than in the durum wheat cultivar (3.9 micromolar). Low temperature decreased the rate of Zn2+ influx, suggesting that metabolism plays a role in Zn2+ uptake. Ca inhibited Zn2+ uptake equally in both cultivars. Translocation of Zn to shoots was greater in the bread wheat cultivar, reflecting the higher root uptake rates. The study suggests that lower root Zn2+ uptake rates may contribute to reduced Zn efficiency in durum wheat varieties under Zn-limiting conditions

Platinum uptake from chloride solutions using biosorbents

Directory of Open Access Journals (Sweden)

Mehmet Hakan Morcali

2013-04-01

Full Text Available Present work investigates platinum uptake from synthetically prepared, dilute platinum-bearing solutions using biomass residues, i.e. pistachio nut shell and rice husk, which are abundant in Turkey, and provides a comparison between these two biosorbents. Effects of the different uptake parameters, sorbent dosage, contact time, temperature and pH of solution on platinum uptake (% were studied in detail on a batch sorption. Before the pistachio nut shell was activated, platinum uptake (% was poor compared to the rice husk. However, after the pistachio nut shell was activated at 1000 °C under an argon atmosphere, the platinum uptake (% increased two-fold. The pistachio nut shell (original and activated and rice husk were shown to be better than commercially available activated carbon in terms of adsorption capacity. These two sorbents have also been characterized by FTIR and SEM. Adsorption equilibrium data best complied with the Langmuir isotherm model. Maximum adsorption capacities, Qmax, at 25 °C were found to be 38.31 and 42.02 mg.g- 1for the activated pistachio nut shell and rice husk, respectively. Thermodynamic calculations using the measured ∆H°, ∆S° and ∆G° values indicate that the uptake process was spontaneous and endothermic. The experimental data were shown to be fit the pseudo-second-order kinetic model.

Uptake of SPECT radiopharmaceuticals in neocortical brain cultures

Energy Technology Data Exchange (ETDEWEB)

Jong, B.M. de; Royen, E.A. van

1989-01-01

The uptake, retention and uptake antagonism of /sup 201/Tl-DDC, /sup 201/Tl-Cl, /sup 123/I-IMP, /sup 99m/Tc-HMPAO and /sup 99m/Tc-O4/sup -/ were compared in rat neocortex cultures. /sup 201/Tl-DDC and /sup 123/I-IP revealed the highest uptake of radioactivity in the cultures. /sup 99m/Tc-HMPAO and /sup 123/I-IMP showed the highest retention of radioactivity within the tissue in washout experiments. Blocking of bioelectric activity by tetrodotoxin did not significantly affect the uptake of the radiopharmaceuticals (RPHA). Inhibition of Na K ATPase by ouabain inhibited the uptake of /sup 201/Tl-Cl (77%) and /sup 201/Tl-DDC (27%). Imipramine showed a significantly stronger inhibitory effect on /sup 123/I-IMP uptake in comparison with the effect on other RPHA. /sup 99m/Tc-O4/sup -/ was not concentrated within the cultured tissue. Under the in vitro conditions used in this study, the various RPHA were characterised by distinct differences in their interaction with cortical brain tissue.

Systemic and lung protein changes in sarcoidosis. Lymphocyte counts, gallium uptake values, and serum angiotensin-converting enzyme levels may reflect different aspects of disease activity

International Nuclear Information System (INIS)

Check, I.J.; Kidd, M.R.; Staton, G.W. Jr.

1986-01-01

BAL lymphocyte percentages, quantitated gallium-67 lung uptake, and SACE levels have all been proposed as measures of disease activity in sarcoidosis. We analyzed 32 paired sera and BAL fluids from sarcoidosis patients by high-resolution agarose electrophoresis to look for protein changes characteristic of systemic or local inflammation and compared the results with those from the above tests. Nine patients (group 1) had serum inflammatory protein changes and increased total protein, albumin, beta 1-globulin (transferrin), and gamma-globulin levels in fluid recovered by BAL. Thirteen patients (group 2) had normal protein levels in sera but abnormal protein levels in BAL specimens. Ten patients (group 3) had normal protein levels in sera and in BAL specimens. Patients in groups 1 and 2 had a disproportionate increase in beta 1-globulin (transferrin) and gamma-globulin levels in their BAL specimens. The BAL lymphocyte percentage changes paralleled the BAL protein level changes, suggesting relationships among the immunoregulatory role of these cells, increased local immunoglobulin synthesis, and the pathogenesis of altered alveolar permeability. Gallium-67 uptake was highest in patients with serum inflammatory protein changes. Thus, systemic inflammation may facilitate pulmonary gallium-67 uptake, possibly by changes in BAL fluid or serum transferrin saturation and/or kinetics. SACE levels showed no relationship to changes in the levels of serum or BAL proteins. These data suggest that the various proposed measures of disease activity reflect different aspects of inflammation in sarcoidosis

Incidence and characteristics of uterine leiomyomas with FDG uptake

International Nuclear Information System (INIS)

Nishizawa, Sadahiko; Inubushi, Masayuki; Kido, Aki; Miyagawa, Masao; Inoue, Takeshi; Shinohara, Katsura; Kajihara, Makoto

2008-01-01

Uterine leiomyomas sometimes show focal 18 F-fluorodeoxyglucose (FDG) uptake on positron emission tomography (PET) images that may result in a false-positive diagnosis for malignant lesions. This study was conducted to investigate the incidence and characteristics of uterine leiomyomas that showed FDG uptake. We reviewed FDG-PET and pelvic magnetic resonance (MR) images of 477 pre-menopausal (pre-MP, age 42.1±7.3 years) and 880 post-MP (age 59.9±6.8 years) healthy women who underwent these tests as parts of cancer screening. Of 1357, 323 underwent annual cancer screening four times, 97 did three times, 191 did twice, and the rest were screened once. Focal FDG uptake (maximal standardized uptake value >3.0) in the pelvis was localized and characterized on co-registered PET/MR images. Uterine leiomyomas were found in 164 pre-MP and 338 post-MP women. FDG uptake was observed in 18 leiomyomas of 17 of the 164 (10.4%) pre-MP women and in 4 leiomyomas of 4 of the 338 (1.2%) post-MP women. The incidence was significantly higher in pre-MP women than in post-MP women (chi-square, P<0.001). Of the 22, 13 showed signal intensity equal to or higher than that of the myometrium on T2-weighted MR images, which suggested abundant cellularity, whereas the majority of leiomyomas without FDG uptake showed low signal intensity. Of the 13 women, 12 examined more than twice showed substantial changes in the level of FDG uptake in leiomyomas each year with FDG uptake disappearing or newly appearing. These changes were observed frequently in relation with menopause or menstrual phases. Leiomyomas with focal FDG uptake were seen in both pre- and post-MP women with a higher incidence in pre-MP women. Abundant cellularity and hormonal dependency may explain a part of the mechanisms of FDG uptake in leiomyomas. It is important to know that the level of FDG uptake in leiomyomas can change and newly appearing FDG uptake does not necessarily mean malignant transformation. (author)

Nitrite uptake by nitrogen-depleted wheat seedlings

Energy Technology Data Exchange (ETDEWEB)

Jackson, W A; Johnson, R E; Volk, R J

1974-01-01

Intact, 14-day-old nitrogen-depleted wheat (Triticum vulgare cv. Blueboy) seedlings were exposed to solutions of 0.5 mM KNO/sub 2/, 0.05 mM CaSO/sub 4/ and 1 mM sodium 2-(N-morpholino)-ethanesulfonate, pH 6.1. Nitrite uptake was determined from depletion of the ambient solution or from incorporation of /sup 15/N in the tissue. An initial nitrite uptake shoulder was followed by a relatively slow uptake rate which subsequently increased to a substantially greater rate. This accelerated phase was maintained through 24 h. Nitrite accumulated to a slight extent in the root tissues during the first few hours but declined to low values when the accelerated rate was fully developed, indicating an increase in nitrite reductase activity paralleling the increase in nitrite uptake capacity. About 50% of the nitrogen absorbed as nitrite was translocated to the shoots by 9 to 12 h. Development of the accelerated nitrite uptake rate was restricted in excised roots, in intact plants kept in darkness, by 400 ..mu..g puromycin ml/sup -1/ and by 1 mM L-ethionine. When puromycin and L-ethionine were added after the accelerated phase had been initiated, their effects were not as detrimental as when they were added at first exposure to KNO/sub 2/. The two inhibitors restricted translocation more than uptake. The data indicate an involvement of protein synthesis and a requirement for movement of a substance from shoots to roots for maximal development of the accelerated nitrite uptake phase. A requirement for protein synthesis in the transport of soluble organic nitrogen from roots to shoots is also suggested.

Striatal FP-CIT uptake differs in the subtypes of early Parkinson's disease

International Nuclear Information System (INIS)

Spiegel, J.; Fassbender, K.; Dillmann, U.; Hellwig, D.; Samnick, S.; Moellers, M.-O.; Kirsch, C.-M.; Jost, W.

2007-01-01

In idiopathic Parkinson's disease (PD), a tremor-dominant type (TDT), an akinetic-rigid type (ART), and a mixed type (MT) are distinguished. We compared cerebral [I- 123 ]FP-CIT SPECT in the PD subtypes (67 patients Hoehn and Yahr stage 1:26 with ART, 19 with MT, 22 with TDT). We measured the ratios putamen/occipital lobe binding and caudate nucleus/occipital lobe binding. Parkinsonian motor symptoms were quantified by UPDRS motor scale. In both putamen and caudate nucleus contralateral to the clinically affected body side TDT patients showed a significantly higher FP-CIT uptake than ART or MT patients (ANOVA; p 0.05). The missing correlation between striatal FP-CIT uptake and tremor suggests, that further systems besides the nigrostriatal dopaminergic system may contribute to generation of parkinsonian tremor. (author)

Propane-1,3-diaminium–2-carboxypyridine-6-carboxylate–pyridine-2,6-dicarboxylic acid–water (1/2/2/8

Directory of Open Access Journals (Sweden)

Hossein Aghabozorg

2008-01-01

Full Text Available The title proton-transfer compound, C3H12N22+·2C7H4NO4−·2C7H5NO4·8H2O or (pnH2(pydcH2.2(pydcH2·8H2O, was obtained by the reaction of pyridine-2,6-dicarboxylic acid (pydcH2 and propane-1,3-diamine (pn in aqueous solution. Both neutral and monoanionic forms of the diacid are observed in the crystal structure. The negative charge of two monoanions is balanced by the dicationic propane-1,3-diaminium species. In addition, considerable π–π stacking interactions between the aromatic rings of the (pydcH− and (pydcH2 fragments [with centroid–centroid distances of 3.5108 (11–3.5949 (11 Å] are observed. The most important feature of this crystal structure is the presence of a large number of O—H...O, O—H...N, N—H...O, N—H...N, C—H...O and C—H...N hydrogen bonds, with D...A ranging from 2.445 (2 to 3.485 (3 Å. These interactions as well as ion pairing and π–π stacking connect the various fragments into a supramolecular structure.

Binding proteins enhance specific uptake rate by increasing the substrate-transporter encounter rate.

Science.gov (United States)

Bosdriesz, Evert; Magnúsdóttir, Stefanía; Bruggeman, Frank J; Teusink, Bas; Molenaar, Douwe

2015-06-01

Microorganisms rely on binding-protein assisted, active transport systems to scavenge for scarce nutrients. Several advantages of using binding proteins in such uptake systems have been proposed. However, a systematic, rigorous and quantitative analysis of the function of binding proteins is lacking. By combining knowledge of selection pressure and physiochemical constraints, we derive kinetic, thermodynamic, and stoichiometric properties of binding-protein dependent transport systems that enable a maximal import activity per amount of transporter. Under the hypothesis that this maximal specific activity of the transport complex is the selection objective, binding protein concentrations should exceed the concentration of both the scarce nutrient and the transporter. This increases the encounter rate of transporter with loaded binding protein at low substrate concentrations, thereby enhancing the affinity and specific uptake rate. These predictions are experimentally testable, and a number of observations confirm them. © 2015 FEBS.

Facilitation of trace metal uptake in cells by inulin coating of metallic nanoparticles

Science.gov (United States)

Santillán-Urquiza, Esmeralda; Arteaga-Cardona, Fernando; Torres-Duarte, Cristina; Cole, Bryan; Wu, Bing; Méndez-Rojas, Miguel A.; Cherr, Gary N.

2017-09-01

Trace elements such as zinc and iron are essential for the proper function of biochemical processes, and their uptake and bioavailability are dependent on their chemical form. Supplementation of trace metals through nanostructured materials is a new field, but its application raises concerns regarding their toxicity. Here, we compared the intracellular zinc uptake of different sources of zinc: zinc sulfate, and ZnO and core-shell α-Fe2O3@ZnO nanoparticles, coated or uncoated with inulin, an edible and biocompatible polysaccharide. Using mussel haemocytes, a well-known model system to assess nanomaterial toxicity, we simultaneously assessed zinc accumulation and multiple cellular response endpoints. We found that intracellular zinc uptake was strongly enhanced by inulin coating, in comparison to the uncoated nanoparticles, while no significant effects on cell death, cell viability, mitochondrial membrane integrity, production of reactive oxygen species or lysosome abundance were observed at concentrations up to 20 ppm. Since no significant increments in toxicity were observed, the coated nanomaterials may be useful to increase in vivo zinc uptake for nutritional applications.

Nanoparticle synthesis and delivery by an aerosol route for watermelon plant foliar uptake

International Nuclear Information System (INIS)

Wang Weining; Tarafdar, Jagadish C.; Biswas, Pratim

2013-01-01

An aerosol process was developed for synthesis and delivery of nanoparticles for living watermelon plant foliar uptake. This is an efficient technique capable of generating nanoparticles with controllable particle sizes and number concentrations. Aerosolized nanoparticles were easily applied to leaf surfaces and enter the stomata via gas uptake, avoiding direct interaction with soil systems, eliminating potential ecological risks. The uptake and transport of nanoparticles inside the watermelon plants were investigated systematically by various techniques, such as elemental analysis by inductively coupled plasma mass spectrometry and plant anatomy by transmission electron microscopy. The results revealed that certain fractions of nanoparticles (d p < 100 nm) generated by the aerosol process could enter the leaf following the stomatal pathway, then pass through the stem, and reach the root of the watermelon plants. The particle size and number concentration played an important role in nanoparticle translocation inside the plants. In addition, the nanoparticle application method, working environment, and leaf structure are also important factors to be considered for successful plant foliar uptake.

Nanoparticle synthesis and delivery by an aerosol route for watermelon plant foliar uptake

Energy Technology Data Exchange (ETDEWEB)

Wang Weining [Washington University in St. Louis, Aerosol and Air Quality Research Laboratory, Department of Energy, Environmental and Chemical Engineering (United States); Tarafdar, Jagadish C. [Central Arid Zone Research Institute (India); Biswas, Pratim, E-mail: pbiswas@wustl.edu [Washington University in St. Louis, Aerosol and Air Quality Research Laboratory, Department of Energy, Environmental and Chemical Engineering (United States)

2013-01-15

An aerosol process was developed for synthesis and delivery of nanoparticles for living watermelon plant foliar uptake. This is an efficient technique capable of generating nanoparticles with controllable particle sizes and number concentrations. Aerosolized nanoparticles were easily applied to leaf surfaces and enter the stomata via gas uptake, avoiding direct interaction with soil systems, eliminating potential ecological risks. The uptake and transport of nanoparticles inside the watermelon plants were investigated systematically by various techniques, such as elemental analysis by inductively coupled plasma mass spectrometry and plant anatomy by transmission electron microscopy. The results revealed that certain fractions of nanoparticles (d{sub p} < 100 nm) generated by the aerosol process could enter the leaf following the stomatal pathway, then pass through the stem, and reach the root of the watermelon plants. The particle size and number concentration played an important role in nanoparticle translocation inside the plants. In addition, the nanoparticle application method, working environment, and leaf structure are also important factors to be considered for successful plant foliar uptake.

FDG uptake in the stomach

International Nuclear Information System (INIS)

Yun, M. J.; Cho, H. J.; Cho, E. H.; Kim, T. S.; Kang, W. J.; Lee, J. D.

2007-01-01

This study was performed to evaluate histopathologic features of advanced gastric cancer (AGC) to predict FDG uptake on PET. 153 patients(102 men; mean age, 55 y) were diagnosed with AGC by surgery were included in this study. PET images were evaluated by visual and semi-quantitative analysis of FDG uptake in primary tumors. Primary tumors size were measured and divided according to Borrmann classification. Tumor histology was classified under WHO classification, depth of invasion and Iymphovascular invasion. The tumors were also grouped by high cellular(cellularity = 50%) and low cellular group (<50%). Microscopic growth type was based on Lauren classification. Stromal fibrosis degree and inflammatory cell infiltration amount was graded as low(none∼mild), or high(moderate∼severe). Lymph node metastases was assessed in all patients. Statistical analyses were performed to evaluate differences in SUV as to histopathologic factors. Of the 153 patients, 21 patients(14%) had primary tumor invisible on initial whole body images. After water ingestion, the tumors became visible in 15 of the 21 patients due to disappearance of physiologic stomach uptake. Polypoid or ulcerofungating tumors, high cellularity, intestinal growth pattern, and larger tumors significantly predicted increased tumor SUVs. Well or moderately differentiated adenocarcinoma tended to show high cellularity and intestinal growth pattern. Poorly differentiated adenocarcinoma had diverse spectrum of histopathology. Signet ring cell carcinomas were mostly ulceroinfiltrative or diffusely infiltrative in macroscopic type and diffuse in microscopic tumor growth. Mucinous adenocarcinomas were mostly low in cellularity. FDG uptake patterns are useful in representing histopathologic characteristics of the entire tumor in gastric cancers. The degree of FDG uptake depends on tumor size, macroscopic type, cellularity, and microscopic growth pattern and it shows no association with well known important prognostic

Correlation of hepatic 18F-fluorodeoxyglucose uptake with fatty liver

International Nuclear Information System (INIS)

An, Young Sil; Yoon, Joon Kee; Hong, Seon Pyo; Joh, Chul Woo; Yoon, Seok Nam

2006-01-01

Liver demonstrates heterogeneous FDG uptake and sometimes it shows abnormally increased uptake even though there is no malignant tissue. However, there was no previous study to correlate these various pattern of hepatic FDG uptake with benign liver disease. Therefore, we evaluated the significance of hepatic FDG uptake associated with various clinical factors including fatty liver, liver function tests and lipid profiles. We reviewed a total of 188 patients (male/female: 120/68, mean age: 50 ± 9) who underwent PET/CT for screening of malignancy. Patients with DM, impaired glucose tolerance, previous severe hepatic disease or long-term medication history were excluded. The FDG uptake in liver was analyzed semi-quantitatively using ROI on transaxial images (segment 8) and we compared mean standardized uptake value (SUV) between fatty liver and non-fatty liver group. We also evaluated the correlation between hepatic FDG uptake and various clinical factors including serum liver function test (ALT, AST), γ -GT, total cholesterol and triglyceride concentration. The effect of alcoholic history and body mass index on hepatic FDG uptake was analyzed within the fatty liver patients. The hepatic FDG uptake of fatty liver group was significantly higher than that of non-fatty liver group. Serum total cholesterol and triglyceride concentration showed significant correlation with hepatic FDG uptake. However, there was no significant correlation between other factors (ALT, AST, and γ -GT) and FDG uptake. Also there was no difference of mean SUV between normal and abnormal groups on the basis of alcoholic history and body mass index within fatty liver patients. Fatty liver and high serum triglyceride concentration were the independent factors affecting hepatic FDG uptake according to multivariate analysis. In conclusion, hepatic FDG uptake was strongly correlated with fatty liver and serum triglyceride concentration

Fluorescent Nanoparticle Uptake for Brain Tumor Visualization

Directory of Open Access Journals (Sweden)

Rachel Tréhin

2006-04-01

Full Text Available Accurate delineation of tumor margins is vital to the successful surgical resection of brain tumors. We have previously developed a multimodal nanoparticle CLIO-Cy5.5, which is detectable by both magnetic resonance imaging and fluorescence, to assist in intraoperatively visualizing tumor boundaries. Here we examined the accuracy of tumor margin determination of orthotopic tumors implanted in hosts with differing immune responses to the tumor. Using a nonuser-based signal intensity method applied to fluorescent micrographs of 9L gliosarcoma green fluorescent protein (GFP tumors, mean overestimations of 2 and 24 µm were obtained using Cy5.5 fluorescence, compared to the true tumor margin determined by GFP fluorescence, in nude mice and rats, respectively. To resolve which cells internalized the nanoparticle and to quantitate degree of uptake, tumors were disaggregated and cells were analyzed by flow cytometry and fluorescence microscopy. Nanoparticle uptake was seen in both CD11b+ cells (representing activated microglia and macrophages and tumor cells in both animal models by both methods. CD11b+ cells were predominantly found at the tumor margin in both hosts, but were more pronounced at the margin in the rat model. Additional metastatic (CT26 colon and primary (Gli36 glioma brain tumor models likewise demonstrated that the nanoparticle was internalized both by tumor cells and by host cells. Together, these observations suggest that fluorescent nanoparticles provide an accurate method of tumor margin estimation based on a combination of tumor cell and host cell uptake for primary and metastatic tumors in animal model systems and offer potential for clinical translation.

Particle size and surface charge affect particle uptake by human dendritic cells in an in vitro model

DEFF Research Database (Denmark)

Foged, Camilla; Brodin, Birger; Frøkjær, Sven

2005-01-01

Current vaccine development includes optimization of antigen delivery to antigen presenting cells, such as dendritic cells (DC). Particulate systems have attracted increasing attention in the development of vaccine delivery systems. In the present study, we investigated DC uptake of model...... fluorescent polystyrene particles with a broad size range and variable surface properties. Localization of particles was investigated using confocal laser scanning microscopy and uptake was quantified by flow cytometry. Immature DC were generated from mononuclear cells isolated from human blood...

Uptake of organic nitrogen by plants

Science.gov (United States)

Torgny Nasholm; Knut Kielland; Ulrika. Ganeteg

2009-01-01

Languishing for many years in the shadow of plant inorganic nitrogen (N) nutrition research, studies of organic N uptake have attracted increased attention during the last decade. The capacity of plants to acquire organic N, demonstrated in laboratory and field settings, has thereby been well established. Even so, the ecological significance of organic N uptake for...

Gallium 67 uptake in thymic rebound

International Nuclear Information System (INIS)

Hurst, R.; Sabio, H.; Teates, C.D.

1988-01-01

We have reported a case of localized thymic enlargement and uptake of gallium 67 in a child who had received antineoplastic chemotherapy. The enlarged thymus showed normal histology, a picture consistent with thymic rebound after nonspecific stress. This case further demonstrates the need to consider thymic rebound as a cause of gallium 67 uptake in children with neoplastic diseases

Uptake of nourseothricin by the producing microorganism, Streptomyces noursei

International Nuclear Information System (INIS)

Roeder, B.; Graefe, U.

1985-01-01

The uptake of 14 C-(U)-nourseothricin by stationary phase mycelium of Streptomyces noursei JA 3890b-NG 13/14 was demonstrated. An energy-dependent transport system appears to be involved in the transport of the antibiotic. Relatively large quantities of the antibiotic were adsorbed to the surface of mycelium. Degradation of nourseothricin by the producing microorganism was not detectable. (author)

Intracellular uptake and distribution of radiolabeled iodovinly deoxy uridine (IVDU) for gene therapy monitoring

Energy Technology Data Exchange (ETDEWEB)

Choi, T. H.; Lee, T. S.; Lee, S. J.; Woo, K. S.; Jeon, W. S.; Choi, C. W.; Yim, S. M. [KCCH, Seoul (Korea, Republic of)

2001-05-01

We have evaluated a useful synthetic radiolabeled nucleoside substrate, (E)-5-2(2-[125I] idodovinyl) uracil deoxyuridine (IVDU), for herpes simplex virus type-1 thymidine kinase (HSV1-TK). Cellular uptake of these labeled compounds was observed in vitro. low uptake was showed in MCA cell line and high uptake was observed in Herpes simplex virus type-1 thymidine kinase(HSV1-tk) gene tranduced MCA(MCA-tk) cell line. Intracellular distribution of {sup 125}I-IVDU was differently occured in the MCA and MCA-TK cell line, respectively. Main distribution of MCA cells is in cytosol, and that of MCA-TK cells was in mitochondria and nuclei. For HSV1-tk system. We confirmed that IVDU was incorporated into DNA synthesis.

Clinical significance of abnormal nonosseous soft tissue uptake of bone tracer

International Nuclear Information System (INIS)

Zhu Bao; Shang Yukun; Li Jiannan; Bai Jing; Cai Liang

2006-01-01

Objective: To evaluate the clinical significance of abnormal soft tissue uptake of bone tracer. Methods: Thirty patients with abnormal soft tissue uptake of bone tracer on 99 Tc m -methylene diphosphonic acid (MDP) skeletal imaging were analyzed. Radioactivity of soft tissue accumulated equal to or greater than the ribs were considered as abnormal. The result was compared with pathology, MRI, CT, X-ray, ultrasound, findings for evaluating its clinical significance. Results: In 7 patients with diffuse liver uptake of 99 Tc m -MDP, 6 were massive and 1 nodular liver cancer. In 2 patients with local liver uptake, one was metastatic and the other primary liver cancer. In 5 local lung uptake cases 4 were primary lung cancer and one metastatic. In 5 cases with colonic uptake 1 was schistosomiasis while the other 4 unexplainable. Subcutaneous tissue uptake was observed in 4 patients, symmetrical uptake in 2 patients with metastatic calcification microfoci in multiple myeloma, unsymmetrical uptake in 2 patients with hemangioma and abscess. Pleural uptake in 3 patients all was metastatic cancer. Abdominal uptake in 3 patients was omentum, paravertebral soft tissue metastasis and unknown cause. Breast uptake in one patient was due to breast cancer. Conclusions: There are many causes resulting in abnormal nonosseous soft tissue uptake of 99 Tc m -MDP. The final diagnosis should correlate with clinical data and other examinations. (authors)

Effects of warming on uptake and translocation of cadmium (Cd) and copper (Cu) in a contaminated soil-rice system under Free Air Temperature Increase (FATI).

Science.gov (United States)

Ge, Li-Qiang; Cang, Long; Liu, Hui; Zhou, Dong-Mei

2016-07-01

Global warming has received growing attentions about its potential threats to human in recent, however little is known about its effects on transfer of heavy metals in agro-ecosystem, especially for Cd in rice. Pot experiments were conducted to evaluate Cd/Cu translocation in a contaminated soil-rice system under Free Air Temperature Increase (FATI). The results showed that warming gradually decreased soil porewater pH and increased water-soluble Cd/Cu concentration, reduced formation of iron plaque on root surface, and thus significantly increased total uptake of Cd/Cu by rice. Subsequently, warming significantly promoted Cd translocation from root to shoot, and increased Cd distribution percentage in shoot, while Cu was not significantly affected. Enhanced Cd uptake and translocation synergistically resulted in higher rice grain contamination with increasing concentration from 0.27 to 0.65 and 0.14-0.40 mg kg(-1) for Indica and Japonica rice, respectively. However increase of Cu in brown grain was only attributed to its uptake enhancement under warming. Our study provides a new understanding about the food production insecurity of heavy metal contaminated soil under the future global warming. Copyright © 2016. Published by Elsevier Ltd.

Pulmonary uptake of 198Au during liver scanning in two patients with amyloidosis

International Nuclear Information System (INIS)

Goebel, R.

1976-01-01

Lung uptake of 198 Au-colloid, injected for a liver scan, is demonstrated in two patients with systemic amyloidosis. The incidence, importance and mechanism of this phenomenon is discussed. (orig.) [de

Quantitative 99mTc diphosphonate uptake measurements

International Nuclear Information System (INIS)

Smith, M.L.

1987-01-01

There are several different techniques currently in use for quantifying diphosphonate uptake by the skeleton. These can be considered in two main categories: local bone or whole-body uptake measurements. The choice of technique depends on the clinical problem being investigated and also on available equipment an expertise. The wide variety of approaches to diphosphonate quantitation ensures that these measurements can be obtained in almost any nuclear medicine department. This chapter discusses the general factors which may influence diphosphonate uptake measurements and outlines the techniques most relevant to current clinical practice

Experimental increase in brain HIPDM uptake by hypercapnia

International Nuclear Information System (INIS)

Karatzas, N.D.; Sfakianakis, G.N.; Pappas, D.; Duncan, R.; Heal, A.; Serafini, A.; Kung, H.F.

1988-01-01

The 30-min brain uptake of [ 125 I]HIPDM was measured in conscious rats--normocapnic (n = 8), hypercapnic (n = 12), and hyperoxic (n = 6). A mean 41.2% higher uptake was found in the brains of hypercapnic animals (p less than 0.01). In the three groups of rats, brain HIPDM uptake had a negative correlation with body weight (p less than 0.001) and a positive correlation with arterial pCO 2 (p less than 0.01), when adjusted for body weight. These results indicate that HIPDM uptake with hypercapnia may be used as a provocative test to measure cerebral blood flow reserves

Metallic mercury uptake by catalase Part 1 In Vitro metallic mercury uptake by various kind of animals' erythrocytes and purified human erythrocyte catalase

OpenAIRE

劒持,堅志

1980-01-01

The uptake of metallic mercury was studied using erythrocytes with different catalase activities taken from various kind of animals. The results were: 1) The uptake of metallic mercury by erythrocytes paralleled the activity of catalase in the erythrocytes with and without hydrogen peroxide, suggesting that the erythrocyte catalase activity is related to the uptake of metallic mercury. 2) The uptake of metallic mercury occurred not only with purified human erythrocyte catalase but also with h...

Cadmium uptake by plants

Energy Technology Data Exchange (ETDEWEB)

Haghiri, F.

1973-01-01

Absorption of /sup 115m/Cd by soybean (Gylcine max l.) plants via foliar and root systems and translocation into the seed was determined. The uptake of /sup 115m/Cd by soybeans via the root system was more efficient than that of the foliar placement. Growth and Cd concentrations of soybean and wheat (Triticum aestivum l.) tops were influenced by soil-applied Cd. In both crops, the Cd concentration of plant tops increased while yield decreased with increasing levels of applied Cd. Cadmium toxicitiy began to occur in both crops at the lowest level of soil applied Cd (2.5 ppM). With soybean plants, Cd toxicity symptoms resembled fe chlorosis. For wheat plants there were no visual symptoms other than the studied growth. The relative concentration of Cd found in several vegetable crops varied depending on the plant species. The relative Cd concentration in descending order for various vegetables was lettuce (Lactuca sativa l.) > radish top (Raphanus sativus l.) > celery stalk (Apium graveolens l.) > celery leaves greater than or equal to green pepper (Capsicum frutescens l.) > radish roots.

Structural modulation and luminescent properties of four CdII coordination architectures based on 3-(pyridin-4-yl)-5-(pyrazin-2-yl)-1H-1,2,4-triazole and flexible/rigid dicarboxylate ligands

Science.gov (United States)

Xia, Liang; Dong, Wen-Wen; Ye, Xiao; Zhao, Jun; Li, Dong-Sheng

2016-10-01

To systematically investigate the influence of the flexible or rigid auxiliary ligands on the structures and properties of transition metal compounds, we synthesized four new d10 coordination polymers (CPs) from 3-(pyridin-4-yl)-5-(pyrazin-2-yl)-1H-1,2,4-triazole (4-Hpzpt) and flexible/rigid dicarboxylate ligands, [Cd(4-pzpt)2]n (1), [Cd3(4-pzpt)2(suc)2]n (2), [Cd2(4-Hpzpt)(nbc)2(H2O)]n (3) and {[Cd2(4-pzpt)2(tfbdc)(H2O)4]·H2O}n (4) (H2suc=1,2-ethanedicarboxylic acid, H2nbc=hthalene-1,4-dicarboxylic acid, H2tfbdc =2,3,5,6-tetrafluoroterephthalic acid). Single crystal X-ray analysis indicates that compound 1 shows a 44-sql layer, which is extended to a 3D network via nonclassical C-H…N hydrogen bonds. Compound 2 possesses a 6-connected pcu-4120.63 net composed of trinuclear CdII-clusters. Compound 3 represents a rare 3D (3,4,4,5)-connected topology with a Schläfli symbol of (4·6·7)(4·53·72)(53·6·7·9)(42·55·6·72). Compound 4 exhibits a 2D+2D→2D parallel interpenetrated 63-hcb network. The adjacent 2D networks are interdigitated with each other to form the resulting 3D supramolecular architecture through classical O-H…N and O-H…O hydrogen bonds. Structural diversities indicate that the nature of flexible/rigid-dicarboxlates plays crucial roles in modulating structures of these compounds. Moreover, the luminescent properties of them have been briefly investigated.

Interaction of photoactive cis(CO)-trans(I)-Ru-(4,4‧-dicarboxylate-2,2‧-bipyridine)(CO)2I2 with anatase (1 0 1) surface

Science.gov (United States)

Haukka, Matti; Hirva, Pipsa

2002-06-01

The coordination of cis(CO)-trans(I)-Ru(4,4‧-dicarboxylate-2,2‧-bipyridine)(CO)2I2 on an anatase (1 0 1) surface was investigated using a computational density functional method. The adsorbate is able to interact with the anatase surface by one or two carboxylate substituents of the bipyridine ligand. Three of the studied coordination modes involved a single carboxylate as the binding group, including monodentate (1M), bidentate chelating (1BC) and bidentate bridging (1BB) modes. The possibility of monodentate binding via both carboxylate groups in (2M) was also studied. The results showed that the multidentate binding is clearly preferred over monodentate coordination. The stability of the modes increased in the order 1M, 1BC, 1BB and 2M. The flexibility of the bipyridine ligand was found to be the key factor in the binding via two carboxylate groups.

Coupling nutrient uptake and energy flow in headwater streams

Energy Technology Data Exchange (ETDEWEB)

Mulholland, Patrick J [ORNL; Fellows, Christine [Griffith University, Nathan, Queensland, Australia; Valett, H. Maurice [Virginia Polytechnic Institute and State University (Virginia Tech); Dahm, Cliff [University of New Mexico, Albuquerque; Thomas, Steve [University of Nebraska

2006-08-01

Nutrient cycling and energy flow in ecosystems are tightly linked through the metabolic processes of organisms. Greater uptake of inorganic nutrients is expected to be associated with higher rates of metabolism [gross primary production (GPP) and respiration (R)], due to assimilatory demand of both autotrophs and heterotrophs. However, relationships between uptake and metabolism should vary with the relative contribution of autochthonous and allochthonous sources of organic matter. To investigate the relationship between metabolism and nutrient uptake, we used whole-stream and benthic chamber methods to measure rates of nitrate-nitrogen (NO{sub 3}-N) uptake and metabolism in four headwater streams chosen to span a range of light availability and therefore differing rates of GPP and contributions of autochthonous carbon. We coupled whole-stream metabolism with measures of NO{sub 3}-N uptake conducted repeatedly over the same stream reach during both day and night, as well as incubating benthic sediments under both light and dark conditions. NO{sub 3}-N uptake was generally greater in daylight compared to dark conditions, and although day-night differences in whole-stream uptake were not significant, light-dark differences in benthic chambers were significant at three of the four sites. Estimates of N demand indicated that assimilation by photoautotrophs could account for the majority of NO{sub 3}-N uptake at the two sites with relatively open canopies. Contrary to expectations, photoautotrophs contributed substantially to NO{sub 3}-N uptake even at the two closed-canopy sites, which had low values of GPP/R and relied heavily on allochthonous carbon to fuel R.

Differential expression of fatty acid uptake in 3T3-L1 cells

International Nuclear Information System (INIS)

Waggoner, D.; Bernlohr, D.A.

1987-01-01

Cultured 3T3-L1 cells have been used as a model system to investigate the mechanism of fatty acid uptake by adipose tissue. Using a 1:1 molar ratio of 14 C-oleate and defatted bovine serum albumin (BSA), fatty acid (FA) uptake was quantitated at 4 0 and 37 0 as cell associated radioactivity. The profile of FA uptake in preadipocytes and adipocytes was biphasic; an initial rapid phase (1-20s) followed by a second slower phase (60-480s). At 37 0 the initial rate of FA accumulation in preadipocytes was identical to that in adipocytes, whereas the rate of accumulation during the second phase increased 7-fold (100 μM total FA) as a consequence of adipose conversion. When uptake measurements were made at 4 0 in adipocytes, the initial rate was identical to that at 37 0 , however the rate of second phase decreased 5-fold. Incubation of 14 C-BSA and nonradiolabeled FA with adipocyte monolayers (100 μM total FA) resulted in the rapid association (t/sub 1/2/ = 20s) of the BSA-FA complex with the cell surface. Incubation of 100, 10, and 1 μM total FA with adipocytes resulted in a 50-fold change in FA accumulation during the second phase. These results suggest that (1) FA uptake is significantly increased after differentiation, suggesting the participation of specialized proteins, (2) the temperature-insensitive initial FA accumulation can be attributed to rapid association of the BSA-FA complex to the cell surface, (3) the second phase of FA accumulation represents uptake

Uptake of inorganic contaminants by pteridophytes

International Nuclear Information System (INIS)

Zheng Jiemin; Chen Ziyuan; Tang Shirong; Guangzhou Univ., Guangzhou; Ding Bingyang

2005-01-01

The review covers results at home and abroad in terms of uptake of inorganic contaminants by pteridophytes, and suggests pteridophytes' significance in phytoremediation; the mechanisms related to uptake of inorganic contaminants by pteridophytes and some methods and means used for research on the mechanism are also introduced; the authors' viewpoints on future development trends are presented in this paper. (authors)

Radio-active iodine uptake in vitiligo

Energy Technology Data Exchange (ETDEWEB)

Kumar, V.; Shankar, V.; Chaudhary, S.; Bhatia, K.K.; Mehta, L.K.; Arora, D.R. (Medical College and Hospital, Rohtak-124001 (India))

1990-01-01

Vitiligo and thyroid disease are commonly associated disorders. Twenty-two clinically euthyroid vitiligo patients were studied for functional assessment of thyroid by radioactive iodine uptake assay. Half of them showed abnormal uptake values at 24 hours. Of these patients, 90% had lower values indicating a tendency towards developing hypothyroid state. Subclinical thyroid dysfunction in vitiligo appears to be an adaptive change. (author).

Radio-active iodine uptake in vitiligo

International Nuclear Information System (INIS)

Kumar, V.; Shankar, V.; Chaudhary, S.; Bhatia, K.K.; Mehta, L.K.; Arora, D.R.

1990-01-01

Vitiligo and thyroid disease are commonly associated disorders. Twenty-two clinically euthyroid vitiligo patients were studied for functional assessment of thyroid by radioactive iodine uptake assay. Half of them showed abnormal uptake values at 24 hours. Of these patients, 90% had lower values indicating a tendency towards developing hypothyroid state. Subclinical thyroid dysfunction in vitiligo appears to be an adaptive change. (author)

Determinants in the uptake of the human papillomavirus vaccine

DEFF Research Database (Denmark)

de Casadevante, Victoria Fernández; Cuesta, Julita Gil; Cantarero Arevalo, Lourdes

2015-01-01

of HPVV uptake in Europe. Methods: We performed a systematic Pubmed, Scopus, and Science Direct search to find articles published from HPVV availability in European countries until April 2014. No age restriction was applied. We included all studies assessing factors associated with HPVV uptake. Uptake...

Methionine Uptake and Required Radiation Dose to Control Glioblastoma

Energy Technology Data Exchange (ETDEWEB)

Iuchi, Toshihiko, E-mail: tiuchi@chiba-cc.jp [Division of Neurological Surgery, Chiba Cancer Center, Chiba (Japan); Hatano, Kazuo [Division of Radiation Oncology, Tokyo Bay Advanced Imaging and Radiation Oncology Clinic, Makuhari, Chiba (Japan); Uchino, Yoshio [Division of Nuclear Medicine, Chiba Ryogo Center, Chiba (Japan); Itami, Makiko [Division of Surgical Pathology, Chiba Cancer Center, Chiba (Japan); Hasegawa, Yuzo; Kawasaki, Koichiro; Sakaida, Tsukasa [Division of Neurological Surgery, Chiba Cancer Center, Chiba (Japan); Hara, Ryusuke [Division of Radiation Oncology, Chiba Cancer Center, Chiba (Japan)

2015-09-01

Purpose: The purpose of this study was to retrospectively assess the feasibility of radiation therapy planning for glioblastoma multiforme (GBM) based on the use of methionine (MET) positron emission tomography (PET), and the correlation among MET uptake, radiation dose, and tumor control. Methods and Materials: Twenty-two patients with GBM who underwent MET-PET prior to radiation therapy were enrolled. MET uptake in 30 regions of interest (ROIs) from 22 GBMs, biologically effective doses (BEDs) for the ROIs and their ratios (MET uptake:BED) were compared in terms of whether the ROIs were controlled for >12 months. Results: MET uptake was significantly correlated with tumor control (odds ratio [OR], 10.0; P=.005); however, there was a higher level of correlation between MET uptake:BED ratio and tumor control (OR, 40.0; P<.0001). These data indicated that the required BEDs for controlling the ROIs could be predicted in terms of MET uptake; BED could be calculated as [34.0 × MET uptake] Gy from the optimal threshold of the MET uptake:BED ratio for tumor control. Conclusions: Target delineation based on MET-PET was demonstrated to be feasible for radiation therapy treatment planning. MET-PET could not only provide precise visualization of infiltrating tumor cells but also predict the required radiation doses to control target regions.

Effect of moisture content of concrete on water uptake

International Nuclear Information System (INIS)

Rucker-Gramm, P.; Beddoe, R.E.

2010-01-01

The penetration of water and non-polar hexane in Portland cement mortar prisms with different initial moisture contents was investigated using nuclear magnetic resonance ( 1 H NMR). The amount of water in gel pores strongly affects the penetration of water in much larger capillary pores. Water penetration is reduced by the self-sealing effect as characterized by non-√t dependence of capillary uptake and penetration depth. This is explained by the ongoing redistribution of water from capillaries into gel pores which results in internal swelling and loss of continuity of the capillary pore system; a correlation was observed between the amount of redistributed water and departure from √t behaviour. A descriptive model is used to explain the dependence of water uptake and penetration on moisture content. For increasing initial moisture contents up to a critical value equivalent to equilibrium with a relative humidity between 65 and 80%, less penetrating water is able to redistribute. Thus more penetrating water is in larger capillaries with less viscous resistance; uptake and penetration depth increase. Above the critical initial moisture content, uptake and penetration depth decrease towards zero. This is explained by (a) an overall reduction in capillary pressure because transport takes places in fewer and larger pores and (b) an increase in viscous resistance due to the connection of penetrating capillary water with pores already containing water. Less capillary pore space is available for transport. The surface region of concrete placed in contact with water is not instantaneously saturated. Water content increases with time depending on the degree of surface saturation. A new transition coefficient for capillary suction γ is defined for the calculation of surface flux.

Does Elevated CO2 Alter Silica Uptake in Trees?

Directory of Open Access Journals (Sweden)

Robinson W. Fulweiler

2015-01-01

Full Text Available Human activities have greatly altered global carbon (C and N (N cycling. In fact, atmospheric concentrations of carbon dioxide (CO2 have increased 40% over the last century and the amount of N cycling in the biosphere has more than doubled. In an effort to understand how plants will respond to continued global carbon dioxide fertilization, long-term free-air CO2 enrichment (FACE experiments have been conducted at sites around the globe. Here we examine how atmospheric CO2 enrichment and N fertilization affects the uptake of silicon (Si in the Duke Forest, North Carolina, a stand dominated by Pinus taeda (loblolly pine, and five hardwood species. Specifically, we measured foliar biogenic silica (BSi concentrations in five deciduous and one coniferous species across three treatments: CO2 enrichment, N enrichment, and N and CO2 enrichment. We found no consistent trends in foliar Si concentration under elevated CO2, N fertilization, or combined elevated CO2 and N fertilization. However, two-thirds of the tree species studied here have Si foliar concentrations greater than well-known Si accumulators, such as grasses. Based on net primary production values and aboveground Si concentrations in these trees, we calculated forest Si uptake rates under control and elevated CO2 concentrations. Due largely to increased primary production, elevated CO2 enhanced the magnitude of Si uptake between 20% and 26%, likely intensifying the terrestrial silica pump. This uptake of Si by forests has important implications for Si export from terrestrial systems, with the potential to impact C sequestration and higher trophic levels in downstream ecosystems.

Increased muscle glucose uptake after exercise

DEFF Research Database (Denmark)

Richter, Erik; Ploug, Thorkil; Galbo, Henrik

1985-01-01

responsiveness of glucose uptake was noted only in controls. Analysis of intracellular glucose-6-phosphate, glucose, glycogen synthesis, and glucose transport suggested that the exercise effect on responsiveness might be due to enhancement of glucose disposal. After electrical stimulation of diabetic...... of glucose. At maximal insulin concentrations, the enhancing effect of exercise on glucose uptake may involve enhancement of glucose disposal, an effect that is probably less in muscle from diabetic rats.(ABSTRACT TRUNCATED AT 250 WORDS)......It has recently been shown that insulin sensitivity of skeletal muscle glucose uptake and glycogen synthesis is increased after a single exercise session. The present study was designed to determine whether insulin is necessary during exercise for development of these changes found after exercise...

Identification of Diethyl 2,5-Dioxahexane Dicarboxylate and Polyethylene Carbonate as Decomposition Products of Ethylene Carbonate Based Electrolytes by Fourier Transform Infrared Spectroscopy

KAUST Repository

Shi, Feifei; Zhao, Hui; Liu, Gao; Ross, Philip N.; Somorjai, Gabor A.; Komvopoulos, Kyriakos

2014-01-01

The formation of passive films on electrodes due to electrolyte decomposition significantly affects the reversibility of Li-ion batteries (LIBs); however, understanding of the electrolyte decomposition process is still lacking. The decomposition products of ethylene carbonate (EC)-based electrolytes on Sn and Ni electrodes are investigated in this study by Fourier transform infrared (FTIR) spectroscopy. The reference compounds, diethyl 2,5-dioxahexane dicarboxylate (DEDOHC) and polyethylene carbonate (poly-EC), were synthesized, and their chemical structures were characterized by FTIR spectroscopy and nuclear magnetic resonance (NMR). Assignment of the vibration frequencies of these compounds was assisted by quantum chemical (Hartree-Fock) calculations. The effect of Li-ion solvation on the FTIR spectra was studied by introducing the synthesized reference compounds into the electrolyte. EC decomposition products formed on Sn and Ni electrodes were identified as DEDOHC and poly-EC by matching the features of surface species formed on the electrodes with reference spectra. The results of this study demonstrate the importance of accounting for the solvation effect in FTIR analysis of the decomposition products forming on LIB electrodes. © 2014 American Chemical Society.

Identification of Diethyl 2,5-Dioxahexane Dicarboxylate and Polyethylene Carbonate as Decomposition Products of Ethylene Carbonate Based Electrolytes by Fourier Transform Infrared Spectroscopy

KAUST Repository

Shi, Feifei

2014-07-10

The formation of passive films on electrodes due to electrolyte decomposition significantly affects the reversibility of Li-ion batteries (LIBs); however, understanding of the electrolyte decomposition process is still lacking. The decomposition products of ethylene carbonate (EC)-based electrolytes on Sn and Ni electrodes are investigated in this study by Fourier transform infrared (FTIR) spectroscopy. The reference compounds, diethyl 2,5-dioxahexane dicarboxylate (DEDOHC) and polyethylene carbonate (poly-EC), were synthesized, and their chemical structures were characterized by FTIR spectroscopy and nuclear magnetic resonance (NMR). Assignment of the vibration frequencies of these compounds was assisted by quantum chemical (Hartree-Fock) calculations. The effect of Li-ion solvation on the FTIR spectra was studied by introducing the synthesized reference compounds into the electrolyte. EC decomposition products formed on Sn and Ni electrodes were identified as DEDOHC and poly-EC by matching the features of surface species formed on the electrodes with reference spectra. The results of this study demonstrate the importance of accounting for the solvation effect in FTIR analysis of the decomposition products forming on LIB electrodes. © 2014 American Chemical Society.

Syntheses, structures and properties of three new two-dimensional Cu(I)-Ln(III) heterometallic coordination polymers based on 2,2'-dipyridyl-5,5'-dicarboxylate ligands.

Science.gov (United States)

Zhao, Junwei; Cheng, Yamin; Shang, Sensen; Zhang, Fang; Chen, Li; Chen, Lijuan

2013-12-01

Three new two-dimensional Cu(I)-Ln(III) heterometallic coordination polymers [Ln(III)Cu2(I)(Hbpdc)4] · Cl · xH2O [Ln(III) = La(III), x = 8 (1); Ln(III) = Pr(III), x=9 (2); Ln(III) = Eu(III), x = 8 (3)] (H2bpdc = 2,2'-bipyridyl-5,5'-dicarboxylic acid) have been prepared under hydrothermal conditions and structurally characterized by elemental analyses, inductively coupled plasma atomic emission spectrometry (ICP-AES) analyses, IR spectra, X-ray photoelectron spectroscopy (XPS) and single-crystal X-ray diffraction. X-ray diffraction indicates that the isomorphic 1-3 display the two-dimensional sheet structure constructed from [Cu(I)(Hbpdc)2](-) fragments through Ln(3+) connectors. Moreover, the solid-state photoluminescence measurements of 3 indicate that the Eu(III) ions, Hbpdc(-) ligands and Cu(I) cations make contributions to its luminescent properties simultaneously. Copyright © 2013 Elsevier B.V. All rights reserved.

Explaining variation in Down's syndrome screening uptake

DEFF Research Database (Denmark)

Crombag, Neeltje M T H; Vellinga, Ynke E; Kluijfhout, Sandra A

2014-01-01

), in an attempt to explain the observed variation in national uptake rates. METHODS: We used a mixed methods approach with an embedded design: a) documentary analysis and b) expert stakeholder analysis. National central statistical offices and legal documents were studied first to gain insight in demographic....... RESULTS: There were many similarities in the demographics, healthcare systems, government abortion legislation and Down's syndrome screening policy across the studied countries. However, the additional cost for Down's syndrome screening over and above standard antenatal care in the Netherlands...

Ganciclovir uptake in human mammary carcinoma cells expressing herpes simplex virus thymidine kinase

International Nuclear Information System (INIS)

Haberkorn, Uwe; Khazaie, Khashayarsha; Morr, Iris; Altmann, Annette; Mueller, Markus; Kaick, Gerhard van

1998-01-01

Assessment of suicide enzyme activity would have considerable impact on the planning and the individualization of suicide gene therapy of malignant tumors. This may be done by determining the pharmacokinetics of specific substrates. We generated ganciclovir (GCV)-sensitive human mammary carcinoma cell lines after transfection with a retroviral vector bearing the herpes simplex virus thymidine kinase (HSV-tk) gene. Thereafter, uptake measurements and HPLC analyses were performed up to 48 h in an HSV-tk-expressing cell line and in a wild-type cell line using tritiated GCV. HSV-tk-expressing cells showed higher GCV uptake and phosphorylation than control cells, whereas in wild-type MCF7 cells no phosphorylated GCV was detected. In bystander experiments the total GCV uptake was related to the amount of HSV-tk-expressing cells. Furthermore, the uptake of GCV correlated closely with the growth inhibition (r=0.92). Therefore, the accumulation of specific substrates may serve as an indicator of the HSV-tk activity and of therapy outcome. Inhibition and competition experiments demonstrated slow transport of GCV by the nucleoside carriers. The slow uptake and low affinity to HSV-tk indicate that GCV is not an ideal substrate for the nucleoside transport systems or for HSV-tk. This may be the limiting factor for therapy success, necessitating the search for better substrates of HSV-tk