Monolithic Pellets, Composites and Thick Films of Hydroxyapatite: Correlation of Mechanical Properties with Microstructure.

NASA Astrophysics Data System (ADS)

Wang, Pauchiu Either

Hydroxyapatite Ca_{10}(PO _4)_6(OH)_2 (abbreviated as HA) has great biocompatibility. Poor mechanical properties of HA implants and decomposition of HA during processing are the major obstacles for widespread uses of HA. In the present thesis we have attempted to understand the sintering behavior of monolithic HA and metal-reinforced HA-matrix composites, and the mechanism of formation of HA coating in the solutions at the normal temperature. The powders of two calcium phosphates, namely hydroxyapatite and dicalcium phosphate (DCP: chemical formula Ca_2P_2O_7), were sintered at various temperatures and in various environments. The density, flexural strength and knoop hardness of both phosphates sintered in air for 4 h initially increased with the sintering temperature, reaching maxima at around 1000-1150 ^circC, and then decreased due to decomposition. To reduce dehydroxylation, HA powder was sintered in moisture at various temperatures up to 1350^circ C and X-ray diffraction study did not indicate any decomposition at the highest sintering temperature. It is seen that dehydroxylation did not hinder sintering, but decomposition obstructed sintering of both HA and DCP. Ductile-phase reinforcement of hydroxyapatite was achieved by addition of silver particulates (5-30 vol.%) in HA powder compacts. A composite made by sintering 10 vol.% Ag and balance HA at 1200^circ C for 1 h in air had flexural strength of 75 +/- 7 MPa, which was almost double that of pure HA sintered under an identical condition. Silver in the composite melted during sintering, but due to poor wetting, did not spread in between HA particles. The increase in the flexural strength of the composites was thought to be due to crack-bridging and crack-arrest by silver inclusions. Thick films (several μm) of hydroxyapatite were deposited on silicon single crystal placed in close proximity to a plate of apatite- and wollastonite -containing glass and dipped into a simulated body fluid (SBF) at 36^circC. Amorphous calcium phosphate phase present in the glass leached into the SBF, causing supersaturation of Ca^ {2+} and (PO_4)^ {3-} ions. HA films grown on Si(111) showed strong (102) texture. As a contrast hardly any HA film could be grown on Si(100) surface. Our results suggest that the driving force for formation of apatite films arises from lowering of free energy of the supersatured solution by deposition of ions in certain crystallographic arrangements on suitable substrates with low interface energies.

Phosphorus retention mechanisms of a water treatment residual.

PubMed

Ippolito, J A; Barbarick, K A; Heil, D M; Chandler, J P; Redente, E F

2003-01-01

Water treatment residuals (WTRs) are a by-product of municipal drinking water treatment plants and can have the capacity to adsorb tremendous amounts of P. Understanding the WTR phosphorus adsorption process is important for discerning the mechanism and tenacity of P retention. We studied P adsorbing mechanism(s) of an aluminum-based [Al2(SO4)3 x 14H2O] WTR from Englewood, CO. In a laboratory study, we shook mixtures of P-loaded WTR for 1 to 211 d followed by solution pH analysis, and solution Ca, Al, and P analysis via inductively coupled plasma atomic emission spectroscopy. After shaking periods, we also examined the solids fraction by X-ray diffraction (XRD) and electron microprobe analysis using wavelength dispersive spectroscopy (EMPA-WDS). The shaking results indicated an increase in pH from 7.2 to 8.2, an increase in desorbed Ca and Al concentrations, and a decrease in desorbed P concentration. The pH and desorbed Ca concentration increases suggested that CaCO3 controlled Ca solubility. Increased desorbed Al concentration may have been due to Al(OH)4 formation. Decreased P content, in conjunction with the pH increase, was consistent with calcium phosphate formation or precipitation. The system appeared to be undersaturated with respect to dicalcium phosphate (DCP; CaHPO4) and supersaturated with respect to octacalcium phosphate [OCP; Ca4H(PO4)3 x 2.5H2O]. The Ca and Al increases, as well as OCP formation, were supported by MINTEQA2 modeling. The XRD and EMPA-WDS results for all shaking times, however, suggested surface P chemisorption as an amorphous Al-P mineral phase.

Ability of a beta-casein phosphopeptide to modulate the precipitation of calcium phosphate by forming amorphous dicalcium phosphate nanoclusters.

PubMed Central

Holt, C; Wahlgren, N M; Drakenberg, T

1996-01-01

The ability of casein in the form of colloidal-sized casein micelles to modulate the phase separation of calcium phosphate during milk secretion is adapted to produce nanometre-sized particles of calcium phosphate stabilized by a casein phosphopeptide (nanoclusters). The nanoclusters were prepared from an undersaturated solution of salts and the peptide by raising the pH homogeneously from about 5.5 to 6.7 with urea plus urease. Chemical analysis and IR spectroscopy showed that they comprise an amorphous dicalcium phosophate bound to the phosphopeptide. Multinuclear NMR spectroscopy of the cluster solutions showed that the small ions and free peptide in the solution were in a state of dynamic exchange with the nanoclusters. The peptide is linked to the calcium phosphate through its sequence of phosphorylated residues, but, in a proportion of adsorbed conformational states, the termini retain the conformational freedom of the unbound peptide. The ability of casein to form nanoclusters in milk suggests a more general mechanism for avoiding pathological calcification and regulating calcium flow in tissues and biological fluids exposed to or containing high concentrations of calcium. PMID:8615755

Influence of shot peening on corrosion properties of biocompatible magnesium alloy AZ31 coated by dicalcium phosphate dihydrate (DCPD).

PubMed

Mhaede, Mansour; Pastorek, Filip; Hadzima, Branislav

2014-06-01

Magnesium alloys are promising materials for biomedical applications because of many outstanding properties like biodegradation, bioactivity and their specific density and Young's modulus are closer to bone than the commonly used metallic implant materials. Unfortunately their fatigue properties and low corrosion resistance negatively influenced their application possibilities in the field of biomedicine. These problems could be diminished through appropriate surface treatments. This study evaluates the influence of a surface pre-treatment by shot peening and shot peening+coating on the corrosion properties of magnesium alloy AZ31. The dicalcium phosphate dihydrate coating (DCPD) was electrochemically deposited in a solution containing 0.1M Ca(NO3)2, 0.06M NH4H2PO4 and 10mL/L of H2O2. The effect of shot peening on the surface properties of magnesium alloy was evaluated by microhardness and surface roughness measurements. The influence of the shot peening and dicalcium phosphate dihydrate layer on the electrochemical characteristics of AZ31 magnesium alloy was evaluated by potentiodynamic measurements and electrochemical impedance spectroscopy in 0.9% NaCl solution at a temperature of 22±1°C. The obtained results were analyzed by the Tafel-extrapolation method and equivalent circuit method. The results showed that the application of shot peening process followed by DCPD coating improves the properties of the AZ31 surface from corrosion and mechanical point of view. Copyright © 2014 Elsevier B.V. All rights reserved.

Heterogeneous Nucleation of Dicalcium Phosphate Dihydrate on Modified Silica Surfaces

PubMed Central

Miller, Carrie; Komunjer, Ljepša; Hlady, Vladimir

2012-01-01

Heterogeneous nucleation of dicalcium phosphate dihydrate, CaHPO4•2H2O (DCPD) was studied on untreated planar fused silica and on three modified silica surfaces: octadecylsilyl (OTS) modified silica, human serum albumin treated OTS silica, and UV-oxidized 3-mercaptopropyltriethoxysilyl (MTS) modified silica. The supersaturation ratio of calcium and phosphate solution with respect to DCPD was kept below ~10. The nucleated crystals were observed 24 hours and one week after initial contact between supersaturated solutions and substrate surfaces using bright field and reflectance interference contrast microscopy. No DCPD crystals nucleated on albumin-treated OTS-silica. Majority of the DCDP crystals formed on the other modified silica surfaces appeared to be morphologically similar irrespective of the nature of nucleating substrate. Reflectance interference contrast microscopy provided a proof that the majority of the crystals on these substrates do not develop an extended contact with the substrate surface. The images showed that the most extended contact planes were between the DCPD crystals and MTS modified silica surface. The crystals nucleated on OTS-treated and untreated silica surfaces showed only few or none well-developed contact planes. PMID:25264399

Phosphorus forms and extractability in dairy manure: a case study for Wisconsin on-farm anaerobic digesters.

PubMed

Güngör, Kerem; Karthikeyan, K G

2008-01-01

The effect of anaerobic digestion on phosphorus (P) forms and water P extractability was investigated using dairy manure samples from six full-scale on-farm anaerobic digesters in Wisconsin, USA. On an average, total dissolved P (TDP) constituted 12 +/- 4% of total P (TP) in the influent to the anaerobic digesters. Only 7 +/- 2% of the effluent was in a dissolved form. Dissolved unreactive P (DUP), comprising polyphosphates and organic P, dominated the dissolved P component in both the influent and effluent. In most cases, it appeared that the fraction of DUP mineralized during anaerobic digestion became subsequently associated with particulate-bound solids. Geochemical equilibrium modeling with Mineql+ indicated that dicalcium phosphate dihydrate, dicalcium phosphate anhydrous, octacalcium phosphate, newberyite, and struvite were the probable solid phases in both the digester influent and effluent samples. The water-extractable P (WEP) fraction in undigested manure ranged from 45% to 70% of TP, which reduced substantially after anaerobic digestion to 25% to 45% of TP. Anaerobic digestion of dairy manure appears capable of reducing the fraction of P that is immediately available by increasing the stability of the solid phases controlling P solubility.

Topography, wetting, and corrosion responses of electrodeposited hydroxyapatite and fluoridated hydroxyapatite on magnesium.

PubMed

Assadian, Mahtab; Jafari, Hassan; Ghaffari Shahri, Seyed Morteza; Idris, Mohd Hasbullah; Almasi, Davood

2016-08-12

In this study, different types of calcium-phosphate phases were coated on NaOH pre-treated pure magnesium. The coating was applied by electrodeposition method in order to provide higher corrosion resistance and improve biocompatibility for magnesium. Thickness, surface morphology and topography of the coatings were analyzed using optical, scanning electron and atomic-force microscopies, respectively. Composition and chemical bonding, crystalline structures and wettability of the coatings were characterized using energy-dispersive and attenuated total reflectance-Fourier transform infrared spectroscopies, grazing incidence X-ray diffraction and contact angle measurement, respectively. Degradation behavior of the coated specimens was also investigated by potentiodynamic polarization and immersion tests. The experiments proved the presence of a porous coating dominated by dicalcium-phosphate dehydrate on the specimens. It was also verified that the developed hydroxyapatite was crystallized by alkali post-treatment. Addition of supplemental fluoride to the coating electrolyte resulted in stable and highly crystallized structures of fluoridated hydroxyapatite. The coatings were found effective to improve biocompatibility combined with corrosion resistance of the specimens. Noticeably, the fluoride supplemented layer was efficient in lowering corrosion rate and increasing surface roughness of the specimens compared to hydroxyapatite and dicalcium-phosphate dehydrates layers.

Calcium-deficient apatite synthesized by ammonia hydrolysis of dicalcium phosphate dihydrate: influence of temperature, time, and pressure.

PubMed

Obadia, Laetitia; Rouillon, Thierry; Bujoli, Bruno; Daculsi, Guy; Bouler, Jean Michel

2007-01-01

In this work, calcium-deficient apatites (CDA) were synthesized by ammonia hydrolysis reaction of dicalcium phosphate dihydrate (DCPD; CaHPO4 x 2 H2O) to obtain biphasic calcium phosphates (BCP) without any extraionic substitution. The influence of three parameters was studied: temperature of the reaction (70 and 100 degrees C), time of the reaction (4 and 18 h), and the pressure (open and closed system). Experiments were made according to a factorial design method (FDM) allowing optimization of the number of samples as well as statistical analysis of results. Moreover, the influence of temperature (until 200 degrees C) was investigated. The crystal size of CDA was determined according to the Scherrer's formula and from Rietveld refinements taking the CDA anisotropy into account. The last method seems to be a reliable method to determine crystallite sizes of CDA, since crystallite sizes of CDA along <00l> and directions were accessible. The results describe the hydroxyapatite % (HA%) in BCP by a first-order polynomial equation in the experimental area studied and the HA content was found to increase by raising time and temperature of the reaction. Moreover, the type of reaction system (open/closed vessel) appeared to have little influence on HA%. 2006 Wiley Periodicals, Inc.

Fabrication of carbonate apatite block based on internal dissolution-precipitation reaction of dicalcium phosphate and calcium carbonate.

PubMed

Daitou, Fumikazu; Maruta, Michito; Kawachi, Giichiro; Tsuru, Kanji; Matsuya, Shigeki; Terada, Yoshihiro; Ishikawa, Kunio

2010-05-01

In this study, we investigated a novel method for fabrication of carbonate apatite block without ionic movement between precursor and solution by using precursor that includes all constituent ions of carbonate apatite. A powder mixture prepared from dicalcium phosphate anhydrous and calcite at appropriate Ca/P ratios (1.5, 1.67, and 1.8) was used as starting material. For preparation of specimens, the slurry made from the powder mixture and distilled water was packed in a split stainless steel mold and heat - treated, ranging from 60 degrees C to 100 degrees C up to 48 hours at 100% humidity. It appeared that carbonate apatite could be obtained above 70 degrees C and monophasic carbonate apatite could be obtained from the powder mixture at Ca/P ratio of 1.67. Carbonate content of the specimen was about 5-7%. Diametral tensile strength of the carbonate apatite blocks slightly decreased with increasing treatment temperature. The decrease in diametral tensile strength is thought to be related to the crystal size of the carbonate apatite formed.

[Modern hygiene products impact on oral microbial, pH and mineral balance].

PubMed

Gromova, S N; Rumiantsev, V A

2012-01-01

Several toothpastes are compared in the study: "Zhemchuzhnaya-complex protection" containing as abrasive substance finely dispersed dicalcium phosphate phosphathydrate, "Noviy zhemchug ftor" and "Zhemchug svezhaya myata" with calcium carbonate. "Zhemchuzhnaya-complex protection" and "Noviy zhemchug ftor" both contain sodium monophosphate as active substance. Impact of these toothpastes on oral microbial, pH and mineral balance was assessed in the study.

The influence of product brand-to-brand variability on superdisintegrant Performance. A case study with croscarmellose sodium.

PubMed

Zhao, Na; Augsburger, L L

2006-01-01

The purpose of this study is to investigate factors influencing croscarmellose sodium functionality with special emphasis on developing a discriminating model tablet formulation to evaluate product brand-to-brand variability. The particle size distribution, water uptake, and swelling properties of five brands of croscarmellose sodium in either neutral water or 0.1 N HCl were studied. Differences were observed in all properties between brands. Media with acidic pH had a negative impact, but to different extents, on both the water uptake and swelling of all croscarmellose sodium brands due to the presence of carboxymethyl sodium substituents. A tablet matrix composed of lactose (75% w/w) and dicalcium phosphate (25% wt/wt) was used to compare the functional equivalency of the five brands of croscarmellose sodium. The tablet disintegration times were inversely proportional to the swelling ability of superdisintegrant in the testing medium regardless of medium temperature and disintegrant concentration. In conclusion; the particle size, total degree of substitution, and the ratio of basic to acidic substituents are important factors that should be considered during product optimization. The tablet matrix composed of lactose and dicalcium phosphate at a weight ratio of 3:1 can be used as a model formulation for product lot-to-lot consistency and product brand-to-brand comparison purposes.

Grazing incidence synchrotron X-ray diffraction of marbles consolidated with diammonium hydrogen phosphate treatments: non-destructive probing of buried minerals

NASA Astrophysics Data System (ADS)

Possenti, Elena; Colombo, Chiara; Conti, Claudia; Gigli, Lara; Merlini, Marco; Plaisier, Jasper Rikkert; Realini, Marco; Gatta, G. Diego

2018-05-01

Diammonium hydrogen phosphate (DAP)-based consolidating treatments react with carbonatic stones and form calcium phosphates phases, whose composition depends on the availability of free calcium ions. In this work, an innovative non-destructive approach based on grazing incidence X-ray diffraction (GIXRD) with synchrotron radiation (SR) is used to investigate DAP-treated Carrara marble specimens and to study the influence of the substrate composition on the crystallization of calcium phosphate phases. The outcomes indicate that the presence of compositional micro-heterogeneity of Carrara marble favours the formation of specific phases. Dicalcium phosphate dihydrate, a calcium phosphate with a low Ca/P molar ratio, is formed on carbonatic phases with a low Ca amount, such as dolomite grains and Mg-containing veins. Furthermore, this study highlights the potentialities of SR-GIXRD as a powerful non-destructive tool for the diagnostic of Cultural Heritage objects since it allows investigating the conservation history of stone materials and their interaction with the environment.

Effect of Mg2+ on acidic calcium phosphate phases grown by electrodeposition

NASA Astrophysics Data System (ADS)

Correia, Matheus Bento; Júnior, José Pedro Gualberto; Macedo, Michelle Cardinale S. S.; Resende, Cristiane Xavier; dos Santos, Euler Araujo

2017-10-01

In this work, the effect of Mg2+ ions on the electrodeposition of dicalcium phosphate dihydrate (DCPD), octacalcium phosphate (OCP) and calcium-deficient hydroxyapatite (CDHA) crystals on a commercially pure titanium (cp-Ti) substrate was evaluated. We demonstrated that Mg2+ ions could change the morphology of the coatings by inhibiting the growth rate of the OCP and CDHA crystals and diminishing the crystallite size of DCPD. The inhibition effect on OCP and CDHA was most likely due to a surface adsorption mechanism since no evidence of a doping process was observed using Rietveld refinement and electron diffraction analyses. Conversely, the presence of Mg2+ ions generated a favorable condition for the nucleation of a new Mg2+-rich DCPD crystal population, presenting smaller crystallite sizes.

Dioxins, furans, biphenyls, arsenic, thorium and uranium in natural and anthropogenic sources of phosphorus and calcium used in agriculture.

PubMed

Avelar, A C; Ferreira, W M; Pemberthy, D; Abad, E; Amaral, M A

2016-05-01

The aim of this study was to assess the presence of dioxins, furans and biphenyls, and the inorganic contaminants such as arsenic (As), thorium (Th) and uranium (U) in three main products used in Agriculture in Brazil: feed grade dicalcium phosphate, calcined bovine bone meal and calcitic limestone. The first two are anthropogenic sources of phosphorus and calcium, while calcitic limestone is a natural unprocessed mineral. Regarding to dioxin-like substances, all samples analyzed exhibited dioxins (PCDD) and furans (PCDF) and dioxin-like polychlorinated biphenyls (dl-PCBs) concentrations below limit of detection (LOD). In general, achieved is in accordance with regulation in Brazil where is established a maximum limit in limestone used in the citric pulp production (0.50pg WHO-TEQ g(-1)). In addition, reported data revealed very low levels for limestone in comparison with similar materials reported by European legislation. As result for toxic metals, achieved data were obtained using Instrumental Neutron Activation Analysis (INAA). On one hand, limestone sample exhibits the largest arsenic concentration. On another hand, dicalcium phosphate exhibited the largest uranium concentration, which represents a standard in animal nutrition. Therefore, it is phosphorus source in the animal feed industry can be a goal of concern in the feed field. Copyright © 2016 Elsevier B.V. All rights reserved.

The theoretical and experimental study on dicalcium phosphate dehydrate loading with protocatechuic aldehyde.

PubMed

Guo, Yuehua; Qu, Shuxin; Lu, Xiong; Xie, Haodong; Zhang, Hongping; Weng, Jie

2010-07-01

The aim of this study is to investigate the interaction between dicalcium phosphate dihydrate (CaHPO(4) x 2H(2)O, DCPD) and Protocatechuic aldehyde (C(7)H(6)O(3), Pca), which is the water-soluble constituents of Chinese Medicine, Salvia Miltiorrhiza Bunge (SMB), by calculating the absorption energy through molecular dynamics simulation. Furthermore, the effects of functional groups of Pca and temperature on Pca adsorbed by DCPD are calculated respectively. DCPD/Pca and DCPD were analyzed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TG). The simulation results showed that Pca mostly absorbed on the (0 2 0) surface of DCPD. The aldehyde group of Pca played a moren important role on the adsorption of Pca on DCPD than hydroxyl did, while temperature had no distinct effects on the adsorption. XRD results indicated that Pca induced the preferential growth of (0 2 0) crystal surface in DCPC/Pca whereas it had no influence on the crystal structure, the crystallinity and grain size of DCPD. FTIR and TG results showed that the characteristic peak of Pca was at 1295 cm(-1) and the content of Pca in DCPD was 16%, respectively. The present results show that molecular dynamics simulation is a very effective and complementary method to study the interaction between materials and medicine.

Three-Dimensional Analysis of the Contact Pattern between the Cortical Bone and Femoral Prosthesis after Cementless Total Hip Arthroplasty

PubMed Central

Mishima, Hajime; Sugaya, Hisashi; Nishino, Tomofumi; Yamazaki, Masashi

2016-01-01

The cementless stem Excia (B. Braun, Melsungen, Germany) implant has a rectangular cross-sectional shape with back-and-forth flanges and a plasma-sprayed, dicalcium phosphate dihydrate coating from the middle to proximal portion to increase initial fixation and early bone formation. Here, the conformity of the Excia stem to the femoral canal morphology was three-dimensionally assessed using computed tomography. Forty-three patients (45 hips) were examined after primary total hip arthroplasty with a mean follow-up of 27 ± 3 months (range: 24–36 months). Spot welds occurred at zone 2 in 16 hips and at zone 6 in 24 hips, with 83% (20/24 hips) of those occurring within 3 months after surgery. First- (n = 12 hips), second- (n = 32), and third- (n = 1) degree stress shielding were observed. The stem was typically in contact with the cortical bone in the anterolateral mid-portion (100%) and posteromedial distal portions (85%). Stress shielding did not progress, even in cases where the stems were in contact with the distal portions. The anterior flange was in contact with the bone in all cases. The stability of the mid-lateral portion with the dicalcium phosphate dihydrate coating and the anterior flange may have inhibited the progression of stress shielding beyond the second degree. PMID:26881087

Identification of critical formulation and processing variables for metoprolol tartrate extended-release (ER) matrix tablets.

PubMed

Rekhi, G S; Nellore, R V; Hussain, A S; Tillman, L G; Malinowski, H J; Augsburger, L L

1999-06-02

The objective of this study, was to examine the influence of critical formulation and processing variables as described in the AAPS/FDA Workshop II report on scale-up of oral extended-release dosage forms, using a hydrophilic polymer hydroxypropyl methylcellulose (Methocel K100LV). A face-centered central composite design (26 runs+3 center points) was selected and the variables studied were: filler ratio (lactose:dicalcium phosphate (50:50)), polymer level (15/32.5/50%), magnesium stearate level (1/1.5/2%), lubricant blend time (2/6/10 min) and compression force (400/600/800 kg). Granulations (1.5 kg, 3000 units) were manufactured using a fluid-bed process, lubricated and tablets (100 mg metoprolol tartrate) were compressed on an instrumented Manesty D3B rotary tablet press. Dissolution tests were performed using USP apparatus 2, at 50 rpm in 900 ml phosphate buffer (pH 6.8). Responses studied included percent drug released at Q1 (1 h), Q4, Q6, Q12. Analysis of variance indicated that change in polymer level was the most significant factor affecting drug release. Increase in dicalcium phosphate level and compression force were found to affect the percent released at the later dissolution time points. Some interaction effects between the variables studied were also found to be statistically significant. The drug release mechanism was predominantly found to be Fickian diffusion controlled (n=0.46-0.59). Response surface plots and regression models were developed which adequately described the experimental space. Three formulations having slow-, medium- and fast-releasing dissolution profiles were identified for a future bioavailability/bioequivalency study. The results of this study provided the framework for further work involving both in vivo studies and scale-up.

Tailoring the structure of biphasic calcium phosphate via synthesis procedure

NASA Astrophysics Data System (ADS)

Mansour, S. F.; El-dek, S. I.; Ahmed, M. K.

2017-12-01

Nano calcium phosphate ceramics (CaPC) were synthesized using simple co-precipitation method at different preparation conditions. The selected Ca/P ratio with a variation of pH value lead to formation of dicalcium phosphate dihydrate (DCPD) at pH 5 and 6 while, hydroxyapatite (HAP) nano particles were formed at pH 9 and 12 at room temperature. The crystallite size was in the range of 15-55 nm depending on the obtained crystalline phase. The study displayed variation of decomposition depending on the annealing temperature. The significant note is the different transformation trend of each phase depending on the starting pH value. The HRTEM illustrated that the DCPD phase was formed as fibers with diameter around 4-6 nm, while HAP was formed in rod shape. The aspect ratio decreased from 6.6 at pH 9 to 4 at pH 12 which refer to the great influence of pH value on the morphology of calcium phosphates.

Improving the de-agglomeration and dissolution of a poorly water soluble drug by decreasing the agglomerate strength of the cohesive powder.

PubMed

Allahham, Ayman; Stewart, Peter J; Das, Shyamal C

2013-11-30

Influence of ternary, poorly water-soluble components on the agglomerate strength of cohesive indomethacin mixtures during dissolution was studied to explore the relationship between agglomerate strength and extent of de-agglomeration and dissolution of indomethacin (Ind). Dissolution profiles of Ind from 20% Ind-lactose binary mixtures, and ternary mixtures containing additional dibasic calcium phosphate (1% or 10%; DCP), calcium sulphate (10%) and talc (10%) were determined. Agglomerate strength distributions were estimated by Monte Carlo simulation of particle size, work of cohesion and packing fraction distributions. The agglomerate strength of Ind decreased from 1.19 MPa for the binary Ind mixture to 0.84 MPa for 1DCP:20Ind mixture and to 0.42 MPa for 1DCP:2Ind mixture. Both extent of de-agglomeration, demonstrated by the concentration of the dispersed indomethacin distribution, and extent of dispersion, demonstrated by the particle size of the dispersed indomethacin, were in descending order of 1DCP:2Ind>1DCP:20Ind>binary Ind. The addition of calcium sulphate dihydrate and talc also reduced the agglomerate strength and improved de-agglomeration and dispersion of indomethacin. While not definitively causal, the improved de-agglomeration and dispersion of a poorly water soluble drug by poorly water soluble components was related to the agglomerate strength of the cohesive matrix during dissolution. Copyright © 2013 Elsevier B.V. All rights reserved.

Concise and Efficient Fluorescent Probe via an Intromolecular Charge Transfer for the Chemical Warfare Agent Mimic Diethylchlorophosphate Vapor Detection.

PubMed

Yao, Junjun; Fu, Yanyan; Xu, Wei; Fan, Tianchi; Gao, Yixun; He, Qingguo; Zhu, Defeng; Cao, Huimin; Cheng, Jiangong

2016-02-16

Sarin, used as chemical warfare agents (CWAs) for terrorist attacks, can induce a number of virulent effects. Therefore, countermeasures which could realize robust and convenient detection of sarin are in exigent need. A concise charge-transfer colorimetric and fluorescent probe (4-(6-(tert-butyl)pyridine-2-yl)-N,N-diphenylaniline, TBPY-TPA) that could be capable of real-time and on-site monitoring of DCP vapor was reported in this contribution. Upon contact with DCP, the emission band red-shifted from 410 to 522 nm upon exposure to DCP vapor. And the quenching rate of TBPY-TPA reached up to 98% within 25 s. Chemical substances such as acetic acid (HAc), dimethyl methylphosphonate (DMMP), pinacolyl methylphosphonate (PAMP), and triethyl phosphate (TEP) do not interfere with the detection. A detection limit for DCP down to 2.6 ppb level is remarkably achieved which is below the Immediately Dangerous to Life or Health concentration. NMR data suggested that a transformation of the pyridine group into pyridinium salt via a cascade reaction is responsible for the sensing process which induced the dramatic fluorescent red shift. All of these data suggest TBPY-TPA is a promising fluorescent sensor for a rapid, simple, and low-cost method for DCP detection, which could be easy to prepare as a portable chemosensor kit for its practical application in real-time and on-site monitoring.

Fabrication of mineralized electrospun PLGA and PLGA/gelatin nanofibers and their potential in bone tissue engineering.

PubMed

Meng, Z X; Li, H F; Sun, Z Z; Zheng, W; Zheng, Y F

2013-03-01

Surface mineralization is an effective method to produce calcium phosphate apatite coating on the surface of bone tissue scaffold which could create an osteophilic environment similar to the natural extracellular matrix for bone cells. In this study, we prepared mineralized poly(D,L-lactide-co-glycolide) (PLGA) and PLGA/gelatin electrospun nanofibers via depositing calcium phosphate apatite coating on the surface of these nanofibers to fabricate bone tissue engineering scaffolds by concentrated simulated body fluid method, supersaturated calcification solution method and alternate soaking method. The apatite products were characterized by the scanning electron microscopy (SEM), Fourier transform-infrared spectroscopy (FT-IR), and X-ray diffractometry (XRD) methods. A large amount of calcium phosphate apatite composed of dicalcium phosphate dihydrate (DCPD), hydroxyapatite (HA) and octacalcium phosphate (OCP) was deposited on the surface of resulting nanofibers in short times via three mineralizing methods. A larger amount of calcium phosphate was deposited on the surface of PLGA/gelatin nanofibers rather than PLGA nanofibers because gelatin acted as nucleation center for the formation of calcium phosphate. The cell culture experiments revealed that the difference of morphology and components of calcium phosphate apatite did not show much influence on the cell adhesion, proliferation and activity. Copyright © 2012 Elsevier B.V. All rights reserved.

Effect of preparation conditions on the nanostructure of hydroxyapatite and brushite phases

NASA Astrophysics Data System (ADS)

Mansour, S. F.; El-dek, S. I.; Ahmed, M. A.; Abd-Elwahab, S. M.; Ahmed, M. K.

2016-10-01

Hydroxyapatite (HAP) and dicalcium phosphate dihydrate (brushite) nanoparticles were prepared by co-precipitation method. The obtained products were characterized by X-ray powder diffraction (XRD), Fourier transformation infra-red spectroscopy (FTIR) and thermo-gravimetric analysis (TGA). Scanning electron microscopy (SEM) and transmission electron microscope (TEM) were used to investigate the morphology of the powdered samples as well as their microstructure, respectively. Brushite samples were obtained in a spherical shape, while hydroxyapatite was formed in a needle and rice shape depending on the pH value.

Calcium phosphates deposited on titanium electrode surface--part 1: Effect of the electrode polarity and oxide film on the deposited materials.

PubMed

Okawa, Seigo; Watanabe, Kouichi; Kanatani, Mitsugu

2013-01-01

We report experimental results about the effect of polarity of electrode and anodized titanium oxide film on the deposited materials by electrolysis of an acidic calcium phosphate solution. Mirror-polished titanium and anodized titanium were used as anode or cathode, and a Pt plate was used as a counter electrode. The load voltage was held constant at 20 VDC. No deposited materials were found on the anode surface. On the other hand, dicalcium phosphate dihydrate (DCPD) was deposited on the cathode surface at the beginning of the electrolysis. After the electrolysis time 600 s, the non-stoichiometric hydroxyapatite (HAp) with several hundred nanometers was formed on the specimen surface. Based on X-ray photoelectron spectroscopy data, the anodized oxide film contained both P(5+) and P(3+) ions. This characteristic of the oxide film and the electrolysis conditions were related to the behavior of the deposition of ultra fine HAp with high crystallinity.

Electrochemical characteristics of calcium-phosphatized AZ31 magnesium alloy in 0.9 % NaCl solution.

PubMed

Hadzima, Branislav; Mhaede, Mansour; Pastorek, Filip

2014-05-01

Magnesium alloys suffer from their high reactivity in common environments. Protective layers are widely created on the surface of magnesium alloys to improve their corrosion resistance. This article evaluates the influence of a calcium-phosphate layer on the electrochemical characteristics of AZ31 magnesium alloy in 0.9 % NaCl solution. The calcium phosphate (CaP) layer was electrochemically deposited in a solution containing 0.1 M Ca(NO3)2, 0.06 M NH4H2PO4 and 10 ml l(-1) of H2O2. The formed surface layer was composed mainly of brushite [(dicalcium phosphate dihidrate (DCPD)] as proved by energy-dispersive X-ray analysis. The surface morphology was observed by scanning electron microscopy. Immersion test was performed in order to observe degradation of the calcium phosphatized surfaces. The influence of the phosphate layer on the electrochemical characteristics of AZ31, in 0.9 % NaCl solution, was evaluated by potentiodynamic measurements and electrochemical impedance spectroscopy. The obtained results were analysed by the Tafel-extrapolation method and equivalent circuits method. The results showed that the polarization resistance of the DCPD-coated surface is about 25 times higher than that of non-coated surface. The CaP electro-deposition process increased the activation energy of corrosion process.

Brittle and ductile adjustable cement derived from calcium phosphate cement/polyacrylic acid composites.

PubMed

Chen, Wen-Cheng; Ju, Chien-Ping; Wang, Jen-Chyan; Hung, Chun-Cheng; Chern Lin, Jiin-Huey

2008-12-01

Bone filler has been used over the years in dental and biomedical applications. The present work is to characterize a non-dispersive, fast setting, modulus adjustable, high bioresorbable composite bone cement derived from calcium phosphate-based cement combined with polymer and binding agents. This cement, we hope, will not swell in simulated body fluid and keep the osteogenetic properties of the dry bone and avoid its disadvantages of being brittle. We developed a calcium phosphate cement (CPC) of tetracalcium phosphate/dicalcium phosphate anhydrous (TTCP/DCPA)-polyacrylic acid with tartaric acid, calcium fluoride additives and phosphate hardening solution. The results show that while composite, the hard-brittle properties of 25wt% polyacrylic acid are proportional to CPC and mixing with additives is the same as those of the CPC without polyacrylic acid added. With an increase of polyacrylic acid/CPC ratio, the 67wt% samples revealed ductile-tough properties and 100wt% samples kept ductile or elastic properties after 24h of immersion. The modulus range of this development was from 200 to 2600MPa after getting immersed in simulated body fluid for 24h. The TTCP/DCPA-polyacrylic acid based CPC demonstrates adjustable brittle/ductile strength during setting and after immersion, and the final reaction products consist of high bioresorbable monetite/brushite/calcium fluoride composite with polyacrylic acid.

Optimization of orodispersible and conventional tablets using simplex lattice design: Relationship among excipients and banana extract.

PubMed

Duangjit, Sureewan; Kraisit, Pakorn

2018-08-01

The objective of this study was focused on the optimization of the pharmaceutical excipients and banana extract in the preparation of orally disintegrating banana extract tablets (OD-BET) and conventional banana extract tablets (CO-BET) using a simplex lattice design. Various ratios of banana extract (BE), dibasic calcium phosphate (DCP) and microcrystalline cellulose (MCC) were used to prepare banana extract tablets (BET). The results indicated that the optimal OD-BET and CO-BET consisted of BE: DCP: MCC at 10.0, 88.8, 1.2, 10.0, 83.8: and 6.2, respectively. AFM demonstrated that the surface of BET with BE + MCC was smooth and compacted when compared to BET with BE + DCP + MCC and BE + DCP. FTIR and XRD showed a correlation in the results and indicated that no interaction of each ingredient occurred in the process of BET formulation. Therefore, the experimental design is potentially useful in formulated OD-BET and CO-BET by using only one design simultaneously. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effect of citric acid on setting reaction and tissue response to β-TCP granular cement.

PubMed

Fukuda, Naoyuki; Tsuru, Kanji; Mori, Yoshihide; Ishikawa, Kunio

2017-02-24

We recently reported that when an acidic calcium phosphate solution is mixed with β-tricalcium phosphate (β-TCP) granules, the resulting dicalcium phosphate dihydrate (DCPD) crystals form bridges between the β-TCP granules, creating a set interconnected porous structure in approximately 1 min. Although this self-setting β-TCP granular cement (β-TCPGC) is useful for clinical applications, the short setting time is a key drawback for handling. In this study, the setting time of β-TCPGC was adjusted with the addition of citric acid, which is a known inhibiter of DCPD crystal growth. As the concentration of citric acid in the acidic calcium phosphate solution increased, the amount of DCPD formation in the set β-TCPGC decreased, and the crystal morphology of DCPD became elongated. β-TCPGC prepared with various citric acid concentrations were used as grafting material in rat calvarial bone defects to evaluate bone regeneration in vivo. Four weeks after implantation, no inflammatory reaction and approximately 20% new bone formation were observed, regardless of the presence or absence of citric acid in the liquid phase of β-TCPGC. We concluded, therefore, that citric acid might be a useful retarder of β-TCPGC setting times.

Dicalcium phosphate (CaHPO4·2H2O) precipitation through ortho- or meta-phosphoric acid-etching: effects on the durability and nanoleakage/ultra-morphology of resin-dentine interfaces.

PubMed

Feitosa, Victor Pinheiro; Bazzocchi, Maria Giulia; Putignano, Angelo; Orsini, Giovanna; Luzi, Arlinda Luzi; Sinhoreti, Mário Alexandre Coelho; Watson, Timothy F; Sauro, Salvatore

2013-11-01

To compare the effects of two etching procedures using meta-phosphoric (MPA) or ortho-phosphoric acid (OPA) on dentine demineralisation, resin-dentine bonds durability and interface nanoleakage/ultra-morphology. Middle-dentine specimens were etched using 37% OPA (15s) or 40% MPA (60s) and submitted to infrared spectroscopy (FTIR) or ultra-morphology dye-assisted (calcium-staining) confocal microscopy (Ca-CLSM). A three-step etch-and-rinse adhesive was formulated, applied onto dentine and light-cured for 30s before composite build-up. After 24h, the dentine-bonded specimens were cut into 1mm(2) beams; half were immediately submitted to microtensile bond strength (μTBS) and half stored in DW for six months. The μTBS results were analysed with repeated-measures ANOVA and Tukey's test (p<0.05). Further teeth were bonded and prepared for interface nanoleakage/ultra-morphology confocal evaluation. FTIR and Ca-CLSM analyses showed dicalcium phosphate dihydrate (Brushite) precipitation in MPA-etched dentine and on the bottom (front of demineralisation) of the OPA-etched dentine. Statistical analysis showed similar μTBS for both etching procedures after 24h. The μTBS of specimens in OPA-group dropped significantly (p<0.05) after six month; the specimens in the MPA group showed no statistically difference (p>0.05). CLSM depicted no evident sign of nanoleakage within the resin-dentine interface of the MPA-treated specimens, while the specimens in OPA-group presented intense nanoleakage and interface degradation. The use of MPA (60s) as an alternative dentine conditioning agent in etch-and-rinse bonding procedures may be a suitable strategy to create more durable resin-dentine bonds. Copyright © 2013 Elsevier Ltd. All rights reserved.

Coating electrospun poly(epsilon-caprolactone) fibers with gelatin and calcium phosphate and their use as biomimetic scaffolds for bone tissue engineering.

PubMed

Li, Xiaoran; Xie, Jingwei; Yuan, Xiaoyan; Xia, Younan

2008-12-16

Electrospinning was employed to fabricate fibrous scaffolds of poly(epsilon-caprolactone) in the form of nonwoven mats. The surfaces of the fibers were then coated with gelatin through layer-by-layer self-assembly, followed by functionalization with a uniform coating of bonelike calcium phosphate by mineralization in the 10 times concentrated simulated body fluid for 2 h. Transmission electron microscopy, water contact angle, and scanning electron microscopy measurements confirmed the presence of gelatin and calcium phosphate coating layers, and X-ray diffraction results suggested that the deposited mineral phase was a mixture of dicalcium phosphate dehydrate (a precursor to apatite) and apatite. It was also demonstrated that the incorporation of gelatin promoted nucleation and growth of calcium phosphate. The porous scaffolds could mimic the structure, composition, and biological function of bone extracellular matrix. It was found that the preosteoblastic MC3T3-E1 cells attached, spread, and proliferated well with a flat morphology on the mineralized scaffolds. The proliferation rate of the cells on the mineralized scaffolds was significantly higher (by 1.9-fold) than that on the pristine fibrous scaffolds after culture for 7 days. These results indicated that the hybrid system containing poly(epsilon-caprolactone), gelatin, and calcium phosphate could serve as a new class of biomimetic scaffolds for bone tissue engineering.

Fabrication of hydroxyapatite block from gypsum block based on (NH4)2HPO4 treatment.

PubMed

Suzuki, Yumiko; Matsuya, Shigeki; Udoh, Koh-ichi; Nakagawa, Masaharu; Tsukiyama, Yoshihiro; Koyano, Kiyoshi; Ishikawa, Kunio

2005-12-01

The aim of this study was to evaluate the feasibility of fabricating low-crystalline, porous apatite block using set gypsum as a precursor based on the fact that apatite is thermodynamically more stable than gypsum. When the set gypsum was immersed in 1 mol/L diammonium hydrogen phosphate aqueous solution at 100 degrees C, it transformed to low-crystalline porous apatite retaining its original shape. The transformation reaction caused a release of sulfate ions due to an ion exchange with phosphate ions, thus leading to a decrease in the pH of the solution. Then, due to decreased pH, dicalcium phosphate anhydrous--which has similar thermodynamic stability at lower pH--was also produced as a by-product. Apatite formed in the present method was low-crystalline, porous B-type carbonate apatite that contained approximately 0.5 wt% CO3, even though no carbonate sources--except carbon dioxide from air--were added to the reaction system. We concluded therefore that this is a useful bone filler fabrication method since B-type carbonate apatite is the biological apatite contained in bone.

Comparative study on in vitro biocompatibility of synthetic octacalcium phosphate and calcium phosphate ceramics used clinically.

PubMed

Morimoto, Shinji; Anada, Takahisa; Honda, Yoshitomo; Suzuki, Osamu

2012-08-01

The present study was designed to investigate the extent to which calcium phosphate bone substitute materials, including osteoconductive octacalcium phosphate (OCP), display cytotoxic and inflammatory responses based on their dissolution in vitro. Hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) ceramics, which are clinically used, as well as dicalcium phosphate dihydrate (DCPD) and synthesized OCP were compared. The materials were well characterized by chemical analysis, x-ray diffraction and Fourier transform infrared spectroscopy. Calcium and phosphate ion concentrations and the pH of culture media after immersion of the materials were determined. The colony forming rate of Chinese hamster lung fibroblasts was estimated with extraction of the materials. Proliferation of bone marrow stromal ST-2 cells and inflammatory cytokine TNF-α production by THP-1 cells grown on the material-coated plates were examined. The materials had characteristics that corresponded to those reported. DCPD was shown to dissolve the most in the culture media, with a marked increase in phosphate ion concentration and a reduction in pH. ST-2 cells proliferated well on the materials, with the exception of DCPD, which markedly inhibited cellular growth. The colony forming capacity was the lowest on DCPD, while that of the other calcium phosphates was not altered. In contrast, TNF-α was not detected even in cells grown on DCPD, suggesting that calcium phosphate materials are essentially non-inflammatory, while the solubility of the materials can affect osteoblastic and fibroblastic cellular attachment. These results indicate that OCP is biocompatible, which is similar to the materials used clinically, such as HA. Therefore, OCP could be clinically used as a biocompatible bone substitute material.

Adsorption behavior of methacryloyloxydecyl dihydrogen phosphate on an apatite surface at neutral pH.

PubMed

Bista, Baba; Nakashima, Syozi; Nikaido, Toru; Sadr, Alireza; Takagaki, Tomohiro; Romero, Maria J R H; Sato, Takaaki; Tagami, Junji

2016-04-01

This study aimed to quantify the adsorption affinity of neutralized 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP-N) toward hydroxyapatite (HA) and dicalcium phosphate dihydrate (DCPD) at pH 7.0 by employing the Langmuir isotherm model. Furthermore, the effects of inorganic phosphate (Pi) and fluoride (F(-) ) ions on the adsorption of 10-MDP-N onto HA and DCPD were examined. Fixed amounts of HA and DCPD powders were suspended in different concentrations of 10-MDP-N solutions and were incubated for 18 h. Equilibrated concentrations of 10-MDP-N were measured by spectrophotometry and the adsorption affinity was estimated using the Langmuir model. Moreover, the adsorption was examined by zeta-potential analysis. The results indicated that significant Langmuir correlation was noted in both substrates, along with an increasing negative zeta-potential; however, in DCPD the correlation was less strong. The addition of 1.0 mM Pi slightly delayed the adsorption of 10-MDP-N onto both substrates, whereas 3.0 mM Pi drastically delayed adsorption onto HA but completely inhibited adsorption onto DCPD. Up to 50 ppm, F(-) enhanced the adsorption onto HA, and the adsorption plateaued at higher concentrations of F(-) , whereas no obvious influence of F(-) on the adsorption onto DCPD was noted. © 2016 Eur J Oral Sci.

Characterization of the calcification of cardiac valve bioprostheses by environmental scanning electron microscopy and vibrational spectroscopy.

PubMed

Delogne, Christophe; Lawford, Patricia V; Habesch, Steven M; Carolan, Vikki A

2007-10-01

Bioprosthetic heart valve tissue and associated calcification were studied in their natural state, using environmental scanning electron microscopy (ESEM). Energy dispersive X-ray micro-analysis, X-ray diffraction, Fourier-transform infrared and Raman spectroscopy were used to characterize the various calcific deposits observed with ESEM. The major elements present in calcified valves were also analyzed by inductively coupled plasma-optical emission spectroscopy. To better understand the precursor formation of the calcific deposits, results from the elemental analyses were statistically correlated. ESEM revealed the presence of four broad types of calcium phosphate crystal morphology. In addition, two main patterns of organization of calcific deposits were observed associated with the collagen fibres. Energy dispersive X-ray micro-analysis identified the crystals observed by ESEM as salts containing mainly calcium and phosphate with ratios from 1.340 (possibly octacalcium phosphate, which has a Ca/P ratio of 1.336) to 2.045 (possibly hydroxyapatite with incorporation of carbonate and metal ion contaminants, such as silicon and magnesium, in the crystal lattice). Raman and fourier-transform infrared spectroscopy also identified the presence of carbonate and the analyses showed spectral features very similar to a crystalline hydroxyapatite spectrum, also refuting the presence of precursor phases such as beta-tricalcium phosphate, octacalcium phosphate and dicalcium phosphate dihydrate. The results of this study raised the possibility of the presence of precursor phases associated with the early stages of calcification.

Fabrication of calcium phosphate–calcium sulfate injectable bone substitute using hydroxy-propyl-methyl-cellulose and citric acid

PubMed Central

Thai, Van Viet

2010-01-01

In this study, an injectable bone substitute (IBS) consisting of citric acid, chitosan, and hydroxyl propyl methyl cellulose (HPMC) as the liquid phase and tetra calcium phosphate (TTCP), dicalcium phosphate dihydrate (DCPD) and calcium sulfate dehydrate (CSD, CaSO4·2H2O) powders as the solid phase, were fabricated. Two groups were classified based on the percent of citric acid in the liquid phase (20, 40 wt%). In each groups, the HPMC percentage was 0, 2, and 4 wt%. An increase in compressive strength due to changes in morphology was confirmed by scanning electron microscopy images. A good conversion rate of HAp at 20% citric acid was observed in the XRD profiles. In addition, HPMC was not obviously affected by apatite formation. However, both HPMC and citric acid increased the compressive strength of IBS. The maximum compressive strength for IBS was with 40% citric acid and 4% HPMC after 14 days of incubation in 100% humidity at 37°C. PMID:20333539

Impact of Increasing Dietary Calcium Levels on Calcium Excretion and Vitamin D Metabolites in the Blood of Healthy Adult Cats.

PubMed

Paßlack, Nadine; Schmiedchen, Bettina; Raila, Jens; Schweigert, Florian J; Stumpff, Friederike; Kohn, Barbara; Neumann, Konrad; Zentek, Jürgen

2016-01-01

Dietary calcium (Ca) concentrations might affect regulatory pathways within the Ca and vitamin D metabolism and consequently excretory mechanisms. Considering large variations in Ca concentrations of feline diets, the physiological impact on Ca homeostasis has not been evaluated to date. In the present study, diets with increasing concentrations of dicalcium phosphate were offered to ten healthy adult cats (Ca/phosphorus (P): 6.23/6.02, 7.77/7.56, 15.0/12.7, 19.0/17.3, 22.2/19.9, 24.3/21.6 g/kg dry matter). Each feeding period was divided into a 10-day adaptation and an 8-day sampling period in order to collect urine and faeces. On the last day of each feeding period, blood samples were taken. Urinary Ca concentrations remained unaffected, but faecal Ca concentrations increased (P < 0.001) with increasing dietary Ca levels. No effect on whole and intact parathyroid hormone levels, fibroblast growth factor 23 and calcitriol concentrations in the blood of the cats were observed. However, the calcitriol precursors 25(OH)D2 and 25(OH)D3, which are considered the most useful indicators for the vitamin D status, decreased with higher dietary Ca levels (P = 0.013 and P = 0.033). Increasing dietary levels of dicalcium phosphate revealed an acidifying effect on urinary fasting pH (6.02) and postprandial pH (6.01) (P < 0.001), possibly mediated by an increase of urinary phosphorus (P) concentrations (P < 0.001). In conclusion, calcitriol precursors were linearly affected by increasing dietary Ca concentrations. The increase in faecal Ca excretion indicates that Ca homeostasis of cats is mainly regulated in the intestine and not by the kidneys. Long-term studies should investigate the physiological relevance of the acidifying effect observed when feeding diets high in Ca and P.

Calcium phosphates recovery from digester supernatant by fast precipitation and recrystallization

NASA Astrophysics Data System (ADS)

Vasenko, Liubov; Qu, Haiyan

2018-01-01

Conditional solubility of dicalcium phosphate dihydrate (DCPD) and hydroxyapatite (HAp) in digester supernatant was determined as a function of pH and was compared to its conditional solubility in distilled water. Conditional solubility of both substances in digester supernatant at pH >5-6 was higher than their conditional solubility in pure water due to the presence of impurities, and this influence is more significant for HAp. Amorphous CaP was precipitated through a fast precipitation process from digester supernatant with initial total phosphate concentration 0.008 mol/L and 0.015 mol/L and Ca/P ratios 2 and 5. The amorphous CaP can be subsequently recrystallized into crystalline CaP. Obtained amorphous products have Ca/P ratio > 1, which allow performing the recrystallization process without further Ca dosing into the system. Batch recrystallization of the amorphous products resulted in crystallization of HAp, DCPD or their mixture depending on the conditions of the process. Maximum achieved P-recovery was 69.5%. The increase of phosphate concentration and the addition of seeding decreased the yield of the process but promoted crystallization of DCPD. The increase of Ca/P ratio had a positive effect on the total P-recovery. Compared with the direct batch crystallization of CaP from digester supernatant, the two-step process with fast precipitation and recrystallization significantly improved the color of the obtained products.

Preparation of micro/nano-fibrous brushite coating on titanium via chemical conversion for biomedical applications

NASA Astrophysics Data System (ADS)

Liu, Bing; Guo, Yong-yuan; Xiao, Gui-yong; Lu, Yu-peng

2017-03-01

Calcium phosphate coatings have been applied on the surface of Ti implants to realize better osseointegration. The formation of dicalcium phosphate dihydrate (CaHPO4·2H2O), mineralogically named brushite on pure Ti substrate has been investigated via chemical conversion method. Coating composition and microstructure have been investigated by X-ray diffractometer, Fourier transform infrared spectrometer and field emission scanning electron microscope. The results reveal that the coatings are composed of high crystalline brushite with minor scholzite (CaZn2(PO4)2·2H2O). A micro/nano-scaled fibrous morphology can be produced in the acidic chemical conversion bath with pH 5.00. The surface of the fibrous brushite coating exhibits high hydrophilicity and corrosion resistance in the simulated body fluid. The osteoblast cells grow and spread actively on the coated samples and the proliferation numbers and alkaline phosphate activities of the cells improve significantly compared to the uncoated Ti. It is suggested that the micro/nano-fibrous brushite coating can be a potential approach to improve the osteoinductivity and osteoconductivity of Ti implant, due to its similarity in morphology and dimension to inorganic components of biological hard tissues, and favorable responses to the osteoblasts.

Rheological and Mechanical Properties of Thermoresponsive Methylcellulose/Calcium Phosphate-Based Injectable Bone Substitutes.

PubMed

Demir Oğuz, Öznur; Ege, Duygu

2018-04-14

In this study, a novel injectable bone substitute (IBS) was prepared by incorporating a bioceramic powder in a polymeric solution comprising of methylcellulose (MC), gelatin and citric acid. Methylcellulose was utilized as the polymeric matrix due to its thermoresponsive properties and biocompatibility. 2.5 wt % gelatin and 3 wt % citric acid were added to the MC to adjust the rheological properties of the prepared IBS. Then, 0, 20, 30 and 50 wt % of the bioceramic component comprising tetracalcium phosphate/hydroxyapatite (TTCP/HA), dicalcium phosphate dehydrate (DCPD) and calcium sulfate dehydrate (CSD) were added into the prepared polymeric component. The prepared IBS samples had a chewing gum-like consistency. IBS samples were investigated in terms of their chemical structure, rheological characteristics, and mechanical properties. After that, in vitro degradation studies were carried out by measurement of pH and % remaining weight. Viscoelastic characteristics of the samples indicated that all of the prepared IBS were injectable and they hardened at approximately 37 °C. Moreover, with increasing wt % of the bioceramic component, the degradation rate of the samples significantly reduced and the mechanical properties were improved. Therefore, the experimental results indicated that the P50 mix may be a promising candidates to fill bone defects and assist bone recovery for non-load bearing applications.

Rheological and Mechanical Properties of Thermoresponsive Methylcellulose/Calcium Phosphate-Based Injectable Bone Substitutes

PubMed Central

2018-01-01

In this study, a novel injectable bone substitute (IBS) was prepared by incorporating a bioceramic powder in a polymeric solution comprising of methylcellulose (MC), gelatin and citric acid. Methylcellulose was utilized as the polymeric matrix due to its thermoresponsive properties and biocompatibility. 2.5 wt % gelatin and 3 wt % citric acid were added to the MC to adjust the rheological properties of the prepared IBS. Then, 0, 20, 30 and 50 wt % of the bioceramic component comprising tetracalcium phosphate/hydroxyapatite (TTCP/HA), dicalcium phosphate dehydrate (DCPD) and calcium sulfate dehydrate (CSD) were added into the prepared polymeric component. The prepared IBS samples had a chewing gum-like consistency. IBS samples were investigated in terms of their chemical structure, rheological characteristics, and mechanical properties. After that, in vitro degradation studies were carried out by measurement of pH and % remaining weight. Viscoelastic characteristics of the samples indicated that all of the prepared IBS were injectable and they hardened at approximately 37 °C. Moreover, with increasing wt % of the bioceramic component, the degradation rate of the samples significantly reduced and the mechanical properties were improved. Therefore, the experimental results indicated that the P50 mix may be a promising candidates to fill bone defects and assist bone recovery for non-load bearing applications. PMID:29662018

Reinforcing of a calcium phosphate cement with hydroxyapatite crystals of various morphologies.

PubMed

Neira, Inés S; Kolen'ko, Yury V; Kommareddy, Krishna P; Manjubala, Inderchand; Yoshimura, Masahiro; Guitián, Francisco

2010-11-01

A series of biocomposite materials was successfully prepared by reinforcing advanced calcium phosphate cement with hydroxyapatite fibrous and elongated plate-like particles. Powder X-ray diffraction showed that ball-milled biocomposite precursors (dicalcium and tetracalcium phosphates) entirely transform to a single phase hydroxyapatite end product within 7 h at 37 °C. Electron microscopy showed that the resultant biocomposites are constituted of nanoscaled cement particles intimately associated with the reinforcement crystals. The influence of shape, size, and concentration of the hydroxyapatite filler on the compression strength of reinforced cements is discussed. The best compression strength of 37 ± 3 MPa (enhancement of ∼50% compared to pure cement) was achieved using submicrometer-sized hydroxyapatite crystals with complementary shapes. Nanoindentation revealed that averaged elastic modulus and hardness values of the cements are consistent with those reported for trabecular and cortical human bones, indicating a good match of the micromechanical properties for their potential use for bone repair. The stiffness of the biocomposites was confirmed to gradate-compliant cement matrix, cement-filler interface, and stiff filler-as a result of the structuring at the nanometer-micrometer level. This architecture is critical in conditioning the final mechanical properties of the functional composite biomaterial. In vitro cell culture experiments showed that the developed biomaterial system is noncytotoxic.

Fabrication of interconnected porous β-tricalcium phosphate (β-TCP) based on a setting reaction of β-TCP granules with HNO3 followed by heat treatment.

PubMed

Ishikawa, Kunio; Putri, Tansza Setiana; Tsuchiya, Akira; Tanaka, Keisuke; Tsuru, Kanji

2018-03-01

β-Tricalcium phosphate [β-TCP] is the typical bone substitute due to its excellent osteoconductivity and bioresorbability. One of the keys to improve its potential as bone substitute is to introduce porous structure and its regulation. In this study, interconnected porous β-TCP blocks were fabricated through a setting reaction of β-TCP granules and subsequent heat treatment. First, β-TCP granules were mixed with HNO 3 . Upon mixing, β-TCP granules were bridged with dicalcium phosphate dihydrate [DCPD: CaHPO 4 ·2H 2 O] containing Ca(NO 3 ) 2 . Then, the DCPD-bridged β-TCP was heated at 1100°C. During the heating process, DCPD containing Ca(NO 3 ) 2 transformed into β-TCP and bonded with β-TCP granules. As a result, an interconnected porous β-TCP block formed. The diametral tensile strength and porosity of the interconnected porous β-TCP block fabricated from 200-300-μm β-TCP granules and 5 N HNO 3 and then heated at 1,100°C were 1.4 ± 0.2 MPa and 57% ± 2%, respectively. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 797-804, 2018. © 2017 Wiley Periodicals, Inc.

Phase Transformations in a Human Tooth Tissue at the Initial Stage of Caries

PubMed Central

Prutskij, Tatiana; Ippolitov, Yury

2015-01-01

The aim of the paper is to study phase transformations in solid tissues of the human teeth during the development of fissure caries by Raman and fluorescence microspectroscopy. The study of the areas with fissure caries confirmed the assumption of the formation of a weak interaction between phosphate apatite enamel and organic acids (products of microorganisms). The experimental results obtained with by Raman microspectroscopy showed the formation of dicalcium phosphate dihydrate - CaHPO4-2H2O in the area of mural demineralization of carious fissure. A comparative analysis of structural and spectroscopic data for the intact and carious enamel shows that emergence of a more soluble phase - carbonate-substituted hydroxyapatite - is typical for the initial stage of caries. It is shown that microareas of dental hard tissues in the carious fissure due to an emerging misorientation of apatite crystals have a higher fluorescence yield than the area of the intact enamel. These areas can be easily detected even prior to a deep demineralization (white spot stage) for the case of irreversibly changed organomineral complex and intensive removal of the mineral component. PMID:25901743

Study of a hydraulic dicalcium phosphate dihydrate/calcium oxide-based cement for dental applications.

PubMed

el-Briak, Hasna; Durand, Denis; Nurit, Josiane; Munier, Sylvie; Pauvert, Bernard; Boudeville, Phillipe

2002-01-01

By mixing CaHPO(4) x 2H(2)O (DCPD) and CaO with water or sodium phosphate buffers as liquid phase, a calcium phosphate cement was obtained. Its physical and mechanical properties, such as compressive strength, initial and final setting times, cohesion time, dough time, swelling time, dimensional and thermal behavior, and injectability were investigated by varying different parameters such as liquid to powder (L/P) ratio (0.35-0.7 ml g(-1)), molar calcium to phosphate (Ca/P) ratio (1.67-2.5) and the pH (4, 7, and 9) and the concentration (0-1 M) of the sodium phosphate buffer. The best results were obtained with the pH 7 sodium phosphate buffer at the concentration of 0.75 M. With this liquid phase, physical and mechanical properties depended on the Ca/P and L/P ratios, varying from 3 to 11 MPa (compressive strength), 6 to 10 min (initial setting time), 11 to 15 min (final setting time), 15 to 30 min (swelling time), 7 to 20 min (time of 100% injectability). The dough or working time was over 16 min. This cement expanded during its setting (1.2-5 % according to Ca/P and L/P ratios); this would allow a tight filling. Given the mechanical and rheological properties of this new DCPD/CaO-based cement, its use as root canal sealing material can be considered as classical calcium hydroxide or ZnO/eugenol-based pastes, without or with a gutta-percha point. Copyright 2002 Wiley Periodicals, Inc. J Biomed Mater Res (Appl Biomater) 63: 447-453, 2002

Short-term implantation effects of a DCPD-based calcium phosphate cement.

PubMed

Frayssinet, P; Gineste, L; Conte, P; Fages, J; Rouquet, N

1998-06-01

Calcium phosphate cements can be handled in paste form and set in a wet medium after precipitation of calcium phosphate crystals in the implantation site. Depending on the products entering into the chemical reaction leading to the precipitation of calcium phosphates, different phases can be obtained with different mechanical properties, setting times and injectability. We tested a cement composed of a powder, containing beta-tricalcium phosphate (beta-TCP) and sodium pyrophosphate mixed with a solution of phosphoric and sulphuric acids. The cement set under a dicalcium phosphate dihydrate (DCPD)-based matrix containing beta-TCP particles. This was injected with a syringe into a defect drilled in rabbit condyles, the control being an identical defect left empty in the opposite condyle. The condyles were analysed histologically 2, 6 and 18 weeks after implantation. After injection into the bone defect the cement set and formed a porous calcium phosphate structure. Two different calcium phosphate phases with different solubility rates could be identified by scanning electron microscopy (SEM) observation. The less-soluble fragments could be degraded by cell phagocytosis in cell compartments of low pH or integrated in the newly formed bone matrix. The degradation rate of the material was relatively high but compatible with the ingrowth of bone trabeculae within the resorbing material. The ossification process was different from the creeping substitution occurring at the ceramic contact. Bone did not form directly at the cement surface following the differentiation of osteoblasts at the material surface. The trabeculae came to the material surface from the edges of the implantation site. Bone formation in the implantation site was significantly higher than in the control region during the first week of implantation. In conclusion, this material set in situ was well tolerated, inducing a mild foreign-body reaction, which did not impair its replacement by newly formed bone within a few weeks.

A compressibility based model for predicting the tensile strength of directly compressed pharmaceutical powder mixtures.

PubMed

Reynolds, Gavin K; Campbell, Jacqueline I; Roberts, Ron J

2017-10-05

A new model to predict the compressibility and compactability of mixtures of pharmaceutical powders has been developed. The key aspect of the model is consideration of the volumetric occupancy of each powder under an applied compaction pressure and the respective contribution it then makes to the mixture properties. The compressibility and compactability of three pharmaceutical powders: microcrystalline cellulose, mannitol and anhydrous dicalcium phosphate have been characterised. Binary and ternary mixtures of these excipients have been tested and used to demonstrate the predictive capability of the model. Furthermore, the model is shown to be uniquely able to capture a broad range of mixture behaviours, including neutral, negative and positive deviations, illustrating its utility for formulation design. Copyright © 2017 Elsevier B.V. All rights reserved.

Circulating dendritic cell precursors in chronic kidney disease: a cross-sectional study.

PubMed

Paul, Katharina; Kretzschmar, Daniel; Yilmaz, Atilla; Bärthlein, Barbara; Titze, Stephanie; Wolf, Gunter; Busch, Martin

2013-12-10

Dendritic cells (DC) are professional antigen-presenting cells in the immune system. They patrol the blood as circulating dendritic cell precursors (DCP). Decreased blood DCP count has been shown to be related to atherosclerotic plaque burden. Since chronic kidney disease (CKD) is associated with chronic inflammation and increased cardiovascular risk, the aim of our study was to investigate a potential effect of CKD on circulating DCP numbers especially in patients with a history of cardiovascular disease. The number of circulating myeloid (mDCP), plasmacytoid (pDCP), and total DCP (tDCP) was analysed by flow cytometry in 245 patients with CKD stage 3 (with and without known cardiovascular events) and 85 coronary healthy controls. In addition, data were compared with a historical group of 130 patients with known coronary artery disease (CAD). Compared to controls, patients with CKD 3 revealed a significant decrease in circulating mDCP (-29%), pDCP (-43%), and tDCP (-38%) (P < 0.001, respectively). Compared with CAD-patients, the decrease in circulating DCP in CKD was comparable or even more pronounced indicating a potential role for DCP in cardiovascular risk potentiation due to CKD. Based on previous findings in CAD, the marked decrease of DCP in CKD implicates a potential role for DCP as a mediator of cardiovascular disease. Whether DCP in CKD may act as new cardiovascular biomarkers needs to be established in future prospective trials.

Blooming gelatin: an individual additive for enhancing nanoapatite precipitation, physical properties, and osteoblastic responses of nanostructured macroporous calcium phosphate bone cements

PubMed Central

Orshesh, Ziba; Hesaraki, Saeed; Khanlarkhani, Ali

2017-01-01

In recent years, there has been a great interest in using natural polymers in the composition of calcium phosphate bone cements to enhance their physical, mechanical, and biological performance. Gelatin is a partially hydrolyzed form of collagen, a natural component of bone matrix. In this study, the effect of blooming gelatin on the nanohydroxyapatite precipitation, physical and mechanical properties, and cellular responses of a calcium phosphate bone cement (CPC) was investigated. Various concentrations of blooming gelatin (2, 5, and 8 wt.%) were used as the cement liquid and an equimolar mixture of tetracalcium phosphate and dicalcium phosphate was used as solid phase. The CPC without any gelatin additive was also evaluated as a control group. The results showed that gelatin accelerated hydraulic reactions of the cement paste, in which the reactants were immediately converted into nanostructured apatite precipitates after hardening. Gelatin molecules induced 4%–10% macropores (10–300 μm) into the cement structure, decreased initial setting time by ~190%, and improved mechanical strength of the as-set cement. Variation in the above-mentioned properties was influenced by the gelatin concentration and progressed with increasing the gelatin content. The numbers of the G-292 osteoblastic cells on gelatin-containing CPCs were higher than the control group at entire culture times (1–14 days), meanwhile better alkaline phosphatase (ALP) activity was determined using blooming gelatin additive. The observation of cell morphologies on the cement surfaces revealed an appropriate cell attachment with extended cell membranes on the cements. Overall, adding gelatin to the composition of CPC improved the handling characteristics such as setting time and mechanical properties, enhanced nanoapatite precipitation, and augmented the early cell proliferation rate and ALP activity. PMID:28176961

Blooming gelatin: an individual additive for enhancing nanoapatite precipitation, physical properties, and osteoblastic responses of nanostructured macroporous calcium phosphate bone cements.

PubMed

Orshesh, Ziba; Hesaraki, Saeed; Khanlarkhani, Ali

2017-01-01

In recent years, there has been a great interest in using natural polymers in the composition of calcium phosphate bone cements to enhance their physical, mechanical, and biological performance. Gelatin is a partially hydrolyzed form of collagen, a natural component of bone matrix. In this study, the effect of blooming gelatin on the nanohydroxyapatite precipitation, physical and mechanical properties, and cellular responses of a calcium phosphate bone cement (CPC) was investigated. Various concentrations of blooming gelatin (2, 5, and 8 wt.%) were used as the cement liquid and an equimolar mixture of tetracalcium phosphate and dicalcium phosphate was used as solid phase. The CPC without any gelatin additive was also evaluated as a control group. The results showed that gelatin accelerated hydraulic reactions of the cement paste, in which the reactants were immediately converted into nanostructured apatite precipitates after hardening. Gelatin molecules induced 4%-10% macropores (10-300 μm) into the cement structure, decreased initial setting time by ~190%, and improved mechanical strength of the as-set cement. Variation in the above-mentioned properties was influenced by the gelatin concentration and progressed with increasing the gelatin content. The numbers of the G-292 osteoblastic cells on gelatin-containing CPCs were higher than the control group at entire culture times (1-14 days), meanwhile better alkaline phosphatase (ALP) activity was determined using blooming gelatin additive. The observation of cell morphologies on the cement surfaces revealed an appropriate cell attachment with extended cell membranes on the cements. Overall, adding gelatin to the composition of CPC improved the handling characteristics such as setting time and mechanical properties, enhanced nanoapatite precipitation, and augmented the early cell proliferation rate and ALP activity.

Reduction of orthophosphates loss in agricultural soil by nano calcium sulfate.

PubMed

Chen, Dong; Szostak, Paul; Wei, Zongsu; Xiao, Ruiyang

2016-01-01

Nutrient loss from soil, especially phosphorous (P) from farmlands to natural water bodies via surface runoff or infiltration, have caused significant eutrophication problems. This is because dissolved orthophosphates are usually the limiting nutrient for algal blooms. Currently, available techniques to control eutrophication are surprisingly scarce. Calcium sulfate or gypsum is a common soil amendment and has a strong complexation to orthophosphates. The results showed that calcium sulfate reduced the amount of water extractable P (WEP) through soil incubation tests, suggesting less P loss from farmlands. A greater decrease in WEP occurred with a greater dosage of calcium sulfate. Compared to conventional coarse calcium sulfate, nano calcium sulfate further reduced WEP by providing a much greater specific surface area, higher solubility, better contact with the fertilizer and the soil particles, and superior dispersibility. The enhancement of the nano calcium sulfate for WEP reduction is more apparent for a pellet- than a powdered- fertilizer. At the dosage of Ca/P weight ratio of 2.8, the WEP decreased by 31±5% with the nano calcium sulfate compared to 20±5% decrease with the coarse calcium sulfate when the pellet fertilizer was used. Computation of the chemical equilibrium speciation shows that calcium hydroxyapatite has the lowest solubility. However, other mineral phases such as hydroxydicalcium phosphate, dicalcium phosphate dihydrate, octacalcium phosphate, and tricalcium phosphate might form preceding to calcium hydroxyapatite. Since calcium sulfate is the major product of the flue gas desulfurization (FGD) process, this study demonstrates a potential beneficial reuse and reduction of the solid FGD waste. Copyright © 2015 Elsevier B.V. All rights reserved.

Investigation of drug-excipient compatibility using rheological and thermal tools

NASA Astrophysics Data System (ADS)

Trivedi, Maitri R.

HYPOTHESIS: We plan to investigate a different approach to evaluate drug-excipient physical compatibility using rheological and thermal tools as opposed to commonly used chemical techniques in pharmaceutical industry. This approach offers practical solutions to routinely associated problems arising with API's and commonly used hydrates forms of excipients. ABSTRACT: Drug-Excipient compatibility studies are an important aspect of pre-formulation and formulation development in pharmaceutical research and development. Various approaches have been used in pharmaceutical industry including use of thermal analysis and quantitative assessment of drug-excipient mixtures after keeping the samples under stress environment depending upon the type of formulation. In an attempt to provide better understanding of such compatibility aspect of excipients with different properties of API, various rheological and thermal studies were conducted on binary mixtures of excipients which exist in different hydrates. Dibasic Calcium Phosphate (DCP, anhydrous and dihydrate forms) and Lactose (Lac, anhydrous and monohydrate) were selected with cohesive API's (Acetaminophen and Aspirin). Binary mixtures of DCP and Lac were prepared by addition of 0% w/w to 50% w/w of the API into each powder blend. Rheological and thermal aspects were considered using different approaches such as powder rheometer, rotational shear cell and traditional rheometery approaches like angle of repose (AOR), hausner's ratio (HR) and cares index (CI). Thermal analysis was conducted using modulated differential scanning calorimetry (MDSC) and thermal effusivity. The data suggested that the powder rheometer showed distinctive understanding in the flowability behavior of binary mixtures with addition of increasing proportion of API's than traditional approaches. Thermal approaches revealed the potential interaction of water of crystallization DCP-D with the API (APAP) while such interactions were absent in DCP-A, while in case of Lac-M and Lac-A, interaction with water of crystallization were not present. Binary mixtures prepared with DCP-D were better flowable while blends with DCP-A were better in stability (physical), compressibility and permeability. Similarly binary mixtures prepared with Lac-M were better flowable and stable in physical compatibility as compared to Lac-A. Lac-A were better in compressibility and permeability. Second part of these research included understanding the powder behavior from wet granulation point of view. Wet granulation includes the formation of agglomerates with powders to form granules in order to have better flowability, content uniformity and compressibility of granular mass. End point determination of powders involving change in powder energies and compressibility, permeability along with thermal analyses were conducted. The effects of water of crystallization on end point determination was studied and based on which overall effects on drug-excipient compatibility using different hydrate forms of excipients were evaluated.

MicroRNA-141-3p/200a-3p target and may be involved in post-transcriptional repression of RNA decapping enzyme Dcp2 during renal development.

PubMed

Zhang, Ming-Nan; Tang, Qun-Ye; Li, Rui-Min; Song, Man-Gen

2018-06-18

The RNA decapping enzyme Dcp2 is a crucial enzyme involved in the process of RNA turnover, which can post-transcriptionally regulate gene expression. Dcp2 has been found to be highly expressed in embryonic, but not adult, kidneys. Here we showed that Dcp2 mRNA was expressed, but Dcp2 proteins were absent, in mouse kidneys after postnatal day 10 (P10). In kidneys of adult Dcp2-IRES-EGFP knock-in mice, Dcp2 was undetectable but EGFP was expressed, indicating that Dcp2 mRNA was not completely silenced in adult kidneys. Using luciferase reporter assays, we found that miR-141-3p/200a-3p directly targeted the 3' UTR of Dcp2 mRNA. Overexpression of miR-141-3p and miR-200a-3p downregulated endogenous Dcp2 protein expression. Furthermore, miR-141-3p and miR-200a-3p expression was low in embryonic kidneys but increased dramatically after P10 and was negatively correlated with Dcp2 protein expression during renal development. These results suggest miR-141-3p/200a-3p may be involved in post-transcriptional repression of Dcp2 expression during renal development. IRES: internal ribosome entry site; EGFP: enhanced green fluorescent protein; UTR: untranslated region.

Simple and Rapid Synthesis of Magnetite/Hydroxyapatite Composites for Hyperthermia Treatments via a Mechanochemical Route

PubMed Central

Iwasaki, Tomohiro; Nakatsuka, Ryo; Murase, Kenya; Takata, Hiroshige; Nakamura, Hideya; Watano, Satoru

2013-01-01

This paper presents a simple method for the rapid synthesis of magnetite/hydroxyapatite composite particles. In this method, superparamagnetic magnetite nanoparticles are first synthesized by coprecipitation using ferrous chloride and ferric chloride. Immediately following the synthesis, carbonate-substituted (B-type) hydroxyapatite particles are mechanochemically synthesized by wet milling dicalcium phosphate dihydrate and calcium carbonate in a dispersed suspension of magnetite nanoparticles, during which the magnetite nanoparticles are incorporated into the hydroxyapatite matrix. We observed that the resultant magnetite/hydroxyapatite composites possessed a homogeneous dispersion of magnetite nanoparticles, characterized by an absence of large aggregates. When this material was subjected to an alternating magnetic field, the heat generated increased with increasing magnetite concentration. For a magnetite concentration of 30 mass%, a temperature increase greater than 20 K was achieved in less than 50 s. These results suggest that our composites exhibit good hyperthermia properties and are promising candidates for hyperthermia treatments. PMID:23629669

Effect of Chicken Bone Meal as Phosphorus Supplement on Blood Metabolites in Fattening Lambs

NASA Astrophysics Data System (ADS)

Pujiastuti, A.; Muktiani, A.

2018-02-01

The aim of this study was to evaluate the effect of chicken bone meal (CBM) as phosphorus supplementon blood metabolites in fattening lambs. The experiment used 16 of 12 months old local male lambs with initial body weight 27.01 ± 1.51 kg. The experiment used a complete randomized design with 4 treatments and 4 replications. The treatments were T0 (basal ration = native grass + soybean curd waste), T1 (basal ration + 0.49% P Dicalcium phosphate), T2 (basal ration + 0.70% P CBM), T3 (basal ration + 1.39 % P CBM). The results indicated that CBM as phosphorus supplement was significantly different (P<0,05) on P intake, phosphorus and glucose serum and did not different significantly on dry matter intake and alkaline phosphatase activity. In conclusion, CBM is one of requirement organic phosphorus supplement which can be applied on ruminants.

Bovine spongiform encephalopathy and spatial analysis of the feed industry.

PubMed

Paul, Mathilde; Abrial, David; Jarrige, Nathalie; Rican, Stéphane; Garrido, Myriam; Calavas, Didier; Ducrot, Christian

2007-06-01

In France, despite the ban of meat-and-bone meal (MBM) in cattle feed, bovine spongiform encephalopathy (BSE) was detected in hundreds of cattle born after the ban. To study the role of MBM, animal fat, and dicalcium phosphate on the risk for BSE after the feed ban, we conducted a spatial analysis of the feed industry. We used data from 629 BSE cases as well as data on use of each byproduct and market area of the feed factories. We mapped risk for BSE in 951 areas supplied by the same factories and connection with use of byproducts. A disease map of BSE with covariates was built with the hierarchical Bayesian modeling methods, based on Poisson distribution with spatial smoothing. Only use of MBM was spatially linked to risk for BSE, which highlights cross-contamination as the most probable source of infection after the feed ban.

Experiments on the heat-induced salt balance changes in cow's milk.

PubMed

Pouliot, Y; Boulet, M; Paquin, P

1989-01-01

The heat-induced changes in salt balance between the colloidal phase of milk and its serum were studied using an ultrafiltration technique. Milk permeate was isolated at the heating temperature by means of a hollow fibre ultrafiltration cartridge coupled with a stainless steel heat exchanger unit. The milk samples initially at 4 degrees C were heated to 20, 40, 60, 80 or 90 degrees C. Ca, P, Mg and citrate contents of the permeates were determined. The decreases in Ca and P were proportional to the increase in temperature. Smaller losses in Mg and citrate were observed. An initial sharp decrease in concentration occurred within the first seconds of holding time and was followed by a slower and smaller decrease. The possible occurrence of a two-stage mechanism for the heat-induced salt precipitation is discussed. The precipitation of dicalcium phosphate is believed to occur together with some tricalcium citrate precipitation.

Urinary metabolites of organophosphate esters in children in South China: Concentrations, profiles and estimated daily intake.

PubMed

Chen, Yi; Fang, Jianzhang; Ren, Lu; Fan, Ruifang; Zhang, Jianqing; Liu, Guihua; Zhou, Li; Chen, Dingyan; Yu, Yingxin; Lu, Shaoyou

2018-04-01

Organophosphate esters (OPEs) are widely used in household products as flame retardants or plasticizers and have become ubiquitous pollutants in environmental media. However, little is known about OPE metabolites in humans, especially in children. In this study, eight OPE metabolites were measured in 411 urine samples collected from 6 to 14-year-old children in South China. Bis(2-chloroethyl) phosphate (BCEP), bis(1-chloro-2-propyl) phosphate (BCIPP) and diphenyl phosphate (DPHP) were the dominant OPE metabolites, and their median concentrations were 1.04, 0.15 and 0.28 μg/L, respectively. The levels of urinary OPE metabolites in the present study were much lower than those in participants from other countries, with the exception of BCEP, suggesting widespread exposure to tris(2-chlorethyl) phosphate (TCEP, the parent chemical of BCEP) in South China. No significant difference in the concentrations of any of the OPE metabolites was observed between males and females (p > .05). Significant negative correlations were observed between age and BCEP, BCIPP, bis(1,3-dichloro-2-propyl) phosphate (BDCIPP), di-o-cresyl phosphate (DoCP) and di-p-cresyl phosphate (DpCP) (DCP), or DPHP (p < .05). Pearson correlation coefficients between urinary OPE metabolites indicated multiple sources and OPE exposure pathways in children. The estimated daily intake suggested that children in South China have a relatively high exposure level to TCEP. To the best of our knowledge, this is the first study to report the urinary levels of OPE metabolites in Chinese children. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effects of DCPD Cement Chemistry on Degradation Properties and Cytocompatibility: Comparison of MCPM/β-TCP and MCPM/HA Formulations

PubMed Central

Alge, Daniel L.; Goebel, W. Scott; Chu, Tien-Min Gabriel

2013-01-01

Dicalcium phosphate dihydrate (DCPD) cements are attractive biomaterials for bone repair, and a number of different DCPD cement formulations have been proposed in the literature. In this study we have specifically compared monocalcium phosphate monohydrate (MCPM)/hydroxyapatite (HA) and MCPM/β-tricalcium phosphate (β-TCP) formulations to test the hypothesis that DCPD cement chemistry affects the degradation properties and cytocompatibility of the cement. Using simple in vitro models we found that MCPM/β-TCP formulations degraded primarily by DCPD dissolution, which was associated with a slight pH drop and relatively low mass loss. Cytocompatibility testing of cement conditioned culture media revealed no significant change in cell viability relative to the negative control for all of the MCPM/β-TCP formulations. In contrast, the MCPM/HA formulations were prone to undergo rapid conversion of DCPD to HA, resulting in a sharp pH drop and extensive mass loss. A stoichiometric excess of HA in the cement was found to accelerate the conversion process, and significant cytotoxicity was observed for the MCPM/HA formulations containing excess HA. Collectively, these results show that, although the product of the setting reaction is the same, DCPD cements produced with MCPM/HA and MCPM/β-TCP formulations differ significantly in their degradation properties and cytocompatibility. These differences may have important implications for the selection of a DCPD cement formulation for clinical application. PMID:23428798

αTCP ceramic doped with dicalcium silicate for bone regeneration applications prepared by powder metallurgy method: in vitro and in vivo studies.

PubMed

Velasquez, Pablo; Luklinska, Zofia B; Meseguer-Olmo, Luis; Mate-Sanchez de Val, Jose E; Delgado-Ruiz, Rafael A; Calvo-Guirado, Jose L; Ramirez-Fernandez, Ma P; de Aza, Piedad N

2013-07-01

This study reports on the in vitro and in vivo behavior of α-tricalcium phosphate (αTCP) and also αTCP doped with either 1.5 or 3.0 wt % of dicalcium silicate (C2 S). The ceramics were successfully prepared by powder metallurgy method combined with homogenization and heat treatment procedures. All materials were composed of a single-phase, αTCP in the case of a pure material, or solid solution of C2 S in αTCP for the doped αTCP, which were stable at room temperature. The ceramics were tested for bioactivity in simulated body fluid, cell culture medium containing adult mesenchymal stem cells of human origin, and in animals. Analytical scanning electron microscopy combined with chemical elemental analysis was used and Fourier transform infrared and conventional histology methods. The in vivo behavior of the ceramics matched the in vitro results, independently of the C2 S content in αTCP. Carbonated hydroxyapatite (CHA) layer was formed on the surface and within the inner parts of the specimens in all cases. A fully mineralized new bone growing in direct contact with the implants was found under the in vivo conditions. The bioactivity and biocompatibility of the implants increased with the C2 S content in αTCP. The C2 S doped ceramics also favoured a phase transformation of αTCP into CHA, important for full implant integration during the natural bone healing processes. αTCP ceramic doped with 3.0 wt % C2 S showed the best bioactive in vitro and in vivo properties of all the compositions and hence could be of interest in specific applications for bone restorative purposes. Copyright © 2012 Wiley Periodicals, Inc.

DcpS is a transcript-specific modulator of RNA in mammalian cells

PubMed Central

Zhou, Mi; Bail, Sophie; Plasterer, Heather L.; Rusche, James

2015-01-01

The scavenger decapping enzyme DcpS is a multifunctional protein initially identified by its property to hydrolyze the resulting cap structure following 3′ end mRNA decay. In Saccharomyces cerevisiae, the DcpS homolog Dcs1 is an obligate cofactor for the 5′-3′ exoribonuclease Xrn1 while the Caenorhabditis elegans homolog Dcs-1, facilitates Xrn1 mediated microRNA turnover. In both cases, this function is independent of the decapping activity. Whether DcpS and its decapping activity can affect mRNA steady state or stability in mammalian cells remains unknown. We sought to determine DcpS target genes in mammalian cells using a cell-permeable DcpS inhibitor compound, RG3039 initially developed for therapeutic treatment of spinal muscular atrophy. Global mRNA levels were examined following DcpS decapping inhibition with RG3039. The steady-state levels of 222 RNAs were altered upon RG3039 treatment. Of a subset selected for validation, two transcripts that appear to be long noncoding RNAs HS370762 and BC011766, were dependent on DcpS and its scavenger decapping catalytic activity and referred to as DcpS-responsive noncoding transcripts (DRNT) 1 and 2, respectively. Interestingly, only the increase in DRNT1 transcript was accompanied with an increase of its RNA stability and this increase was dependent on both DcpS and Xrn1. Importantly, unlike in yeast where the DcpS homolog is an obligate cofactor for Xrn1, stability of additional Xrn1 dependent RNAs were not altered by a reduction in DcpS levels. Collectively, our data demonstrate that DcpS in conjunction with Xrn1 has the potential to regulate RNA stability in a transcript-selective manner in mammalian cells. PMID:26001796

Silver-Doped Calcium Phosphate Bone Cements with Antibacterial Properties

PubMed Central

Rau, J. V.; Fosca, M.; Graziani, V.; Egorov, A. A.; Zobkov, Yu. V.; Fedotov, A. Yu.; Ortenzi, M.; Caminiti, R.; Baranchikov, A. E.; Komlev, V. S.

2016-01-01

Calcium phosphate bone cements (CPCs) with antibacterial properties are demanded for clinical applications. In this study, we demonstrated the use of a relatively simple processing route based on preparation of silver-doped CPCs (CPCs-Ag) through the preparation of solid dispersed active powder phase. Real-time monitoring of structural transformations and kinetics of several CPCs-Ag formulations (Ag = 0 wt %, 0.6 wt % and 1.0 wt %) was performed by the Energy Dispersive X-ray Diffraction technique. The partial conversion of β-tricalcium phosphate (TCP) phase into the dicalcium phosphate dihydrate (DCPD) took place in all the investigated cement systems. In the pristine cement powders, Ag in its metallic form was found, whereas for CPC-Ag 0.6 wt % and CPC-Ag 1.0 wt % cements, CaAg(PO3)3 was detected and Ag (met.) was no longer present. The CPC-Ag 0 wt % cement exhibited a compressive strength of 6.5 ± 1.0 MPa, whereas for the doped cements (CPC-Ag 0.6 wt % and CPC-Ag 1.0 wt %) the reduced values of the compressive strength 4.0 ± 1.0 and 1.5 ± 1.0 MPa, respectively, were detected. Silver-ion release from CPC-Ag 0.6 wt % and CPC-Ag 1.0 wt % cements, measured by the Atomic Emission Spectroscopy, corresponds to the average values of 25 µg/L and 43 µg/L, respectively, rising a plateau after 15 days. The results of the antibacterial test proved the inhibitory effect towards pathogenic Escherichia coli for both CPC-Ag 0.6 wt % and CPC-Ag 1.0 wt % cements, better performances being observed for the cement with a higher Ag-content. PMID:27096874

Metabolism of 2,4-dichlorophenol in tobacco engineered with bacterial degradative genes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Perkins, E.J.; Sekine, M.; Gordon, M.P.

1990-05-01

The potential use of plants in toxic waste remediation has been overlooked. While chlorophenols are relatively slowly metabolized in Nicotiana tabacum var. Xanthi leaf extracts, chlorocatechols are rapidly metabolized, presumably by polyphenol oxidases. Our initial focus has been the fate of 2,4-dichlorophenol (2,4DCP) in var. Xanthi plants which express a bacterial 2,4DCP hydroxylase, which converts 2,4DCP to 3,5-dichlorocatechol. The roots of wild type and 2,4DCP hydroxylase transgenic plants growing in hydroponics were exposed to {sup 14}C-2,4DCP. Approximately 95% of {sup 14}C-2,4DCP metabolites remained in the roots when exposed to 2,4DCP. Upon extraction of root tissue, three major metabolites were foundmore » in untransformed plants and four major metabolites in transformed plants. Upon digestion with beta-D-glucosidase, these metabolites disappeared concomitant with the appearance of free 2,4DCP in wild type plants and 2,4DCP and 3,5-dichlorocatechol in transgenic plants. It is apparent that the chlorophenols are not readily available substrates for polyphenol oxidases in whole plants.« less

Characterization of dipeptidylcarboxypeptidase of Leishmania donovani: a molecular model for structure based design of antileishmanials

NASA Astrophysics Data System (ADS)

Baig, Mirza Saqib; Kumar, Ashutosh; Siddiqi, Mohammad Imran; Goyal, Neena

2010-01-01

Leishmania donovani dipeptidylcarboxypeptidsae (LdDCP), an angiotensin converting enzyme (ACE) related metallopeptidase has been identified and characterized as a putative drug target for antileishmanial chemotherapy. The kinetic parameters for LdDCP with substrate, Hip-His-Leu were determined as, Km, 4 mM and Vmax, 1.173 μmole/ml/min. Inhibition studies revealed that known ACE inhibitors (captopril and bradykinin potentiating peptide; BPP1) were weak inhibitors for LdDCP as compared to human testicular ACE (htACE) with Ki values of 35.8 nM and 3.9 μM, respectively. Three dimensional model of LdDCP was generated based on crystal structure of Escherichia coli DCP (EcDCP) by means of comparative modeling and assessed using PROSAII, PROCHECK and WHATIF. Captopril docking with htACE, LdDCP and EcDCP and analysis of molecular electrostatic potentials (MEP) suggested that the active site domain of three enzymes has several minor but potentially important structural differences. These differences could be exploited for designing selective inhibitor of LdDCP thereby antileishmanial compounds either by denovo drug design or virtual screening of small molecule databases.

Maternally Recruited DCP1A and DCP2 Contribute to Messenger RNA Degradation During Oocyte Maturation and Genome Activation in Mouse1

PubMed Central

Ma, Jun; Flemr, Matyas; Strnad, Hynek; Svoboda, Petr; Schultz, Richard M.

2012-01-01

ABSTRACT The oocyte-to-zygote transition entails transforming a highly differentiated oocyte into totipotent blastomeres and represents one of the earliest obstacles that must be successfully hurdled for continued development. Degradation of maternal mRNAs, which likely lies at the heart of this transition, is characterized by a transition from mRNA stability to instability during oocyte maturation. Although phosphorylation of the oocyte-specific RNA-binding protein MSY2 during maturation is implicated in making maternal mRNAs more susceptible to degradation, mechanisms underlying mRNA degradation during oocyte maturation remain poorly understood. We report that DCP1A and DCP2, proteins responsible for decapping mRNA, are encoded by maternal mRNAs recruited for translation during maturation via cytoplasmic polyadenylation elements located in their 3′ untranslated regions. Both DCP1A and DCP2 are phosphorylated during maturation, with CDC2A being the kinase likely responsible for both, although MAPK may be involved in DCP1A phosphorylation. Inhibiting accumulation of DCP1A and DCP2 by RNA interference or morpholinos decreases not only degradation of mRNAs during meiotic maturation but also transcription of the zygotic genome. The results indicate that maternally recruited DCP1A and DCP2 are critical players in the transition from mRNA stability to instability during meiotic maturation and that proper maternal mRNA degradation must be successful to execute the oocyte-to-zygote transition. PMID:23136299

Regiospecific dechlorination of pentachlorophenol by dichlorophenol-adapted microorganisms in freshwater, anaerobic sediment slurries.

PubMed Central

Bryant, F O; Hale, D D; Rogers, J E

1991-01-01

The reductive dechlorination of pentachlorophenol (PCP) was investigated in anaerobic sediments that contained nonadapted or 2,4- or 3,4-dichlorophenol (DCP)-adapted microbial communities. Adaptation of sediment communities increased the rate of conversion of 2,4- or 3,4-DCP to monochlorophenols (CPs) and eliminated the lag phase before dechlorination was observed. Both 2,4- and 3,4-DCP-adapted sediment communities dechlorinated the six DCP isomers to CPs. The specificity of chlorine removal from the DCP isomers indicated a preference for ortho-chlorine removal by 2,4-DCP-adapted sediment communities and for para-chlorine removal by 3,4-DCP-adapted sediment communities. Sediment slurries containing nonadapted microbial communities either did not dechlorinate PCP or did so following a lag phase of at least 40 days. Sediment communities adapted to dechlorinate 2,4- or 3,4-DCP dechlorinated PCP without an initial lag phase. The 2,4-DCP-adapted communities initially removed the ortho-chlorine from PCP, whereas the 3,4-DCP-adapted communities initially removed the para-chlorine from PCP. A 1:1 mixture of the adapted sediment communities also dechlorinated PCP without a lag phase. Dechlorination by the mixture was regiospecific, following a para greater than ortho greater than meta order of chlorine removal. Intermediate products of degradation, 2,3,5,6-tetrachlorophenol, 2,3,5-trichlorophenol, 3,5-DCP, 3-CP, and phenol, were identified by a combination of cochromatography (high-pressure liquid chromatography) with standards and gas chromatography-mass spectrometry. PMID:1768102

7-methylguanosine diphosphate (m(7)GDP) is not hydrolyzed but strongly bound by decapping scavenger (DcpS) enzymes and potently inhibits their activity.

PubMed

Wypijewska, Anna; Bojarska, Elzbieta; Lukaszewicz, Maciej; Stepinski, Janusz; Jemielity, Jacek; Davis, Richard E; Darzynkiewicz, Edward

2012-10-09

Decapping scavenger (DcpS) enzymes catalyze the cleavage of a residual cap structure following 3' → 5' mRNA decay. Some previous studies suggested that both m(7)GpppG and m(7)GDP were substrates for DcpS hydrolysis. Herein, we show that mononucleoside diphosphates, m(7)GDP (7-methylguanosine diphosphate) and m(3)(2,2,7)GDP (2,2,7-trimethylguanosine diphosphate), resulting from mRNA decapping by the Dcp1/2 complex in the 5' → 3' mRNA decay, are not degraded by recombinant DcpS proteins (human, nematode, and yeast). Furthermore, whereas mononucleoside diphosphates (m(7)GDP and m(3)(2,2,7)GDP) are not hydrolyzed by DcpS, mononucleoside triphosphates (m(7)GTP and m(3)(2,2,7)GTP) are, demonstrating the importance of a triphosphate chain for DcpS hydrolytic activity. m(7)GTP and m(3)(2,2,7)GTP are cleaved at a slower rate than their corresponding dinucleotides (m(7)GpppG and m(3)(2,2,7)GpppG, respectively), indicating an involvement of the second nucleoside for efficient DcpS-mediated digestion. Although DcpS enzymes cannot hydrolyze m(7)GDP, they have a high binding affinity for m(7)GDP and m(7)GDP potently inhibits DcpS hydrolysis of m(7)GpppG, suggesting that m(7)GDP may function as an efficient DcpS inhibitor. Our data have important implications for the regulatory role of m(7)GDP in mRNA metabolic pathways due to its possible interactions with different cap-binding proteins, such as DcpS or eIF4E.

Development of fluorapatite cement for dental enamel defects repair.

PubMed

Wei, Jie; Wang, Jiecheng; Shan, Wenpeng; Liu, Xiaochen; Ma, Jian; Liu, Changsheng; Fang, Jing; Wei, Shicheng

2011-06-01

In order to restore the badly carious lesion of human dental enamel, a crystalline paste of fluoride substituted apatite cement was synthesized by using the mixture of tetracalcium phosphate (TTCP), dicalcium phosphate anhydrous (DCPA) and ammonium fluoride. The apatite cement paste could be directly filled into the enamel defects (cavities) to repair damaged dental enamel. The results indicated that the hardened cement was fluorapatite [Ca(10)(PO(4))(6)F(2), FA] with calcium to phosphorus atom molar ratio (Ca/P) of 1.67 and Ca/F ratio of 5. The solubility of FA cement in Tris-HCl solution (pH = 5) was slightly lower than the natural enamel, indicating the FA cement was much insensitive to the weakly acidic solutions. The FA cement was tightly combined with the enamel surface, and there was no obvious difference of the hardness between the FA cement and natural enamel. The extracts of FA cement caused no cytotoxicity on L929 cells, which satisfied the relevant criterion on dental biomaterials, revealing good cytocompatibility. In addition, the results showed that the FA cement had good mechanical strength, hydrophilicity, and anti-bacterial adhesion properties. The study suggested that using FA cement was simple and promising approach to effectively and conveniently restore enamel defects.

Preparation of reactive beta-dicalcium silicate

DOEpatents

Shen, M.S.; Chen, J.M.; Yang, R.T.

1980-02-28

This invention relates to the preparation of fine particles of reactive beta-dicalcium silicate by means of a solid state process which comprises firing a mixture of calcium sulfate, silica, and a reducing additive selected from the group consisting of calcium sulfide, carbon, carbon monoxide, methane, and hydrogen, at a temperature of about 850 to 1000/sup 0/C. A carrier gas such as nitrogen or carbon dioxide may also be added, if desired. A high concentration of sulfur dioxide is a by-product of this process.

Preparation of reactive beta-dicalcium silicate

DOEpatents

Shen, Ming-Shing; Chen, James M.; Yang, Ralph T.

1982-01-01

This invention relates to the preparation of fine particles of reactive beta-dicalcium silicate by means of a solid state process which comprises firing a mixture of calcium sulfate, silica and a reducing additive selected from the group consisting of calcium sulfide, carbon, carbon monoxide, methane and hydrogen, at a temperature of about 850.degree.-1000.degree. C. A carrier gas such as nitrogen or carbon dioxide may also be added, if desired. A high concentration of sulfur dioxide is a by-product of this process.

[Degradation of 2, 4-dichlorophenol in aqueous solution by ZVI/EDDS/air system].

PubMed

Sun, Qian; Zhou, Hai-Yan; Cao, Meng-Hua; Wu, Lin-Na; Wang, Lin-Ling; Chen, Jing; Lu, Xiao-Hua

2012-11-01

A new oxidation system of Fenton-like system (ZVI/EDDS/Air) has been developed to degrade 2,4-chlorophenols (2,4-DCP) in aqueous solution. The influences of initial conditions, i. e., EDDS concentration, iron dosage, aeration rate, 2,4-DCP concentration and pH as well as reaction temperature on the degradation of 2,4-DCP were studied. The results demonstrated that this ZVI/EDDS/Air system was able to effectively degrade 2,4-DCP in aqueous solution, and the degradation of 2,4-DCP conforms to the pseudo-first-order reaction kinetics equation. Removal of above 99% 2,4-DCP was achieved in ZVI/EDDS/Air system at room temperature and pressure after 1 h reaction when the initial conditions were 2,4-DCP 100 mg x L(-1), EDDS 0.80 mmo x L(-1), ZVI 20 g x L(-1), aeration rate 2 L x (min x L)(-1). Compared with ZVI/EDTA/Air system, ZVI/EDDS/Air system showed higher efficiency in the degradation of 2,4-DCP at ambient circumstance and was more environmentally benign.

Fate and origin of 1,2-dichloropropane in an unconfined shallow aquifer

USGS Publications Warehouse

Tesoriero, A.J.; Loffler, F.E.; Liebscher, H.

2001-01-01

A shallow aquifer with different redox zones overlain by intensive agricultural activity was monitored for the occurrence of 1,2-dichloropropane (DCP) to assess the fate and origin of this pollutant. DCP was detected more frequently in groundwater samples collected in aerobic and nitrate-reducing zones than those collected from iron-reducing zones. Simulated DCP concentrations for groundwater entering an iron-reducing zone were calculated from a fate and transport model that included dispersion, sorption, and hydrolysis but not degradation. Simulated concentrations were well in excess of measured values, suggesting that microbial degradation occurred in the iron-reducing zone. Microcosm experiments were conducted using aquifer samples collected from iron-reducing and aerobic zones to evaluate the potential for microbial degradation of DCP and to explain field observations. Hydrogenolysis of DCP and production of monochlorinated propanes in microcosm experiments occurred only with aquifer materials collected from the iron-reducing zone, and no dechlorination was observed in microcosms established with aquifer materials collected from the aerobic zones. Careful analyses of the DCP/1,2,2-trichloropropane ratios in groundwater indicated that older fumigant formulations were responsible for the high levels of DCP present in this aquifer.A shallow aquifer with different redox zones overlain by intensive agricultural activity was monitored for the occurrence of 1,2-dichloropropane (DCP) to assess the fate and origin of this pollutant. DCP was detected more frequently in groundwater samples collected in aerobic and nitrate-reducing zones than those collected from iron-reducing zones. Simulated DCP concentrations for groundwater entering an iron-reducing zone were calculated from a fate and transport model that included dispersion, sorption, and hydrolysis but not degradation. Simulated concentrations were well in excess of measured values, suggesting that microbial degradation occurred in the iron-reducing zone. Microcosm experiments were conducted using aquifer samples collected from iron-reducing and aerobic zones to evaluate the potential for microbial degradation of DCP and to explain field observations. Hydrogenolysis of DCP and production of monochlorinated propanes in microcosm experiments occurred only with aquifer materials collected from the iron-reducing zone, and no dechlorination was observed in microcosms established with aquifer materials collected from the aerobic zones. Careful analyses of the DCP/1,2,2-trichloropropane ratios in groundwater indicated that older fumigant formulations were responsible for the high levels of DCP present in this aquifer.

The calcium phosphate coating of soy lecithin nanoemulsion with performance in stability and as an oxygen carrier

NASA Astrophysics Data System (ADS)

Han, Kyu B.

This work studied the relationship between surfactant, oil, and water, by building ternary phase diagrams, the goal of which was to identify the oil-in-water phase composition. The resulting nano-sized emulsion was coated with dicalcium phosphate by utilizing the ionic affinity between calcium ions and the emulsion surface. Since the desired function of the particle is as an oxygen carrier, the particle stability, oxygen capacity, and oxygen release rate were investigated. The first step in the process was to construct ternary phase diagrams with 1,2-dioleoyl-sn-glycero-3-phosphate (DOPA) and soy derived lecithin. The results showed that the lecithin surfactant formed an oil-in-water phase region that was 36 times greater than that of DOPA. With the desired phase composition set, the lecithin emulsion was extruded, resulting in a well-dispersed nanosized particle. A pH titration study of the emulsion found an optimized calcium phosphate coating condition at pH 8.8, at which, the calcium ion had a greater affinity for the emulsion surface than phosphate. A Hill plot was used to show calcium cooperativeness on the emulsion surface which suggested one calcium ion binds to one lecithin molecule. The lecithin emulsion particles were then coated with calcium phosphate using a layering technique that allowed for careful control of the coating thickness. The overall particle hydrodynamic radius was consistent with the growth of the calcium phosphate coating, from 8 nm to 28 nm. This observation was further supported with cryo-TEM measurements. The stability of the coated emulsion was tested in conditions that simulate practical thermal, physical, and time-dependent conditions. Throughout the tests, the coated emulsion exhibited a constant mono-dispersed particle size, while the uncoated emulsion size fluctuated greatly and exhibited increased polydispersion. The fast mixing method with the stopped-flow apparatus was employed to test the product as an oxygen carrier, and it was shown that particles with thicker calcium phosphate coatings released smaller amounts of oxygen in a given timeframe. This study proved the hypothesis by showing a fundamental understanding of emulsion science, coating the flexible emulsion surface with a biocompatible material, and a strong particle performance with regard to stability and as an oxygen carrier.

Effect of a bonding agent on in vitro biochemical activities of remineralizing resin-based calcium phosphate cements.

PubMed

Dickens, Sabine H; Flaim, Glenn M

2008-09-01

To test whether fluoride in a resin-based Ca-PO4 ion releasing cement or coating with an acidic bonding agent for improved adhesion compromised the cement remineralization potential. Cements were formulated without fluoride (Cement A) or with fluoride (Cement B). The treatment groups were A=Cement A; A2=Cement A+bonding agent; B=Cement B; B2=Cement B+bonding agent. The calcium, phosphate, and fluoride ion release in saliva-like solution (SLS) was determined from hardened cement disks without or with a coating of bonding agent. For the remineralization, two cavities were prepared in dentin of extracted human molars and demineralized. One cavity received composite resin (control); the other received treatment A, A2, B or B2. After 6 week incubation in SLS, 180 microm cross-sections were cut. The percentage remineralization was determined by transverse microradiography comparing the dentin mineral density under the cement to that under the control. The percentage of remineralization (mean+/-S.D.) was A (39+/-14)=B (37+/-18), A2 (23+/-13), B2 (14+/-7). Two-way analysis of variance (ANOVA) and Holm-Sidak test showed a significant effect from the presence of bonding agent (p<0.05), but not from fluoride (p>0.05). The ion solution concentrations of all groups showed undersaturation with respect to dicalcium phosphate dihydrate and calcium fluoride and supersaturation for fluorapatite and hydroxyapatite suggesting a positive remineralization potential. Compared to the control all treatments resulted in mineral increase. The remineralization was negatively affected by the presence of the bonding agent.

Response of human bone marrow-derived MSCs on triphasic Ca-P substrate with various HA/TCP ratio.

PubMed

Bajpai, Indu; Kim, Duk Yeon; Kyong-Jin, Jung; Song, In-Hwan; Kim, Sukyoung

2017-01-01

Calcium phosphates (Ca-P) are used commonly as artificial bone substitutes to control the biodegradation rate of an implant in the body fluid. This study examined the in vitro proliferation of human bone marrow-derived mesenchymal stem cells (hBMSCs) on triphasic Ca-P samples. For this aspect, hydroxyapatite (HA), dicalcium phosphate dehydrate (DCPD), and calcium hydroxide (Ca(OH) 2 ) were mixed at various ratios, cold compacted, and sintered at 1250°C in air. X-ray diffraction showed that the β-tricalcium phosphate (TCP) to α-TCP phase transformation increased with increasing DCPD/HA ratio. The micro-hardness deceased with increasing TCP content, whereas the mean grain size and porosity increased with increasing TCP concentration. To evaluate the in vitro degree of adhesion and proliferation on the HA/TCP samples, human BMSCs were incubated on the HA/TCP samples and analyzed by a cells proliferation assay, expression of the extracellular matrix (ECM) genes, such as α-smooth muscle actin (α-SMA) and fibronectin (FN), and FITC-phalloidin fluorescent staining. In terms of the interactions of human BMSCs with the triphasic Ca-P samples, H50T50 (Ca/P = 1.59) markedly enhanced cell spreading, proliferation, FN, and α-SMA compared with H100T0 (Ca/P = 1.67). Interestingly, these results show that among the five HA/TCP samples, H50T50 is the optimal Ca-P composition for in vitro cell proliferation. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 72-80, 2017. © 2015 Wiley Periodicals, Inc.

Fenton-like oxidation of 2,4-DCP in aqueous solution using iron-based nanoparticles as the heterogeneous catalyst.

PubMed

Li, Renchao; Gao, Ying; Jin, Xiaoying; Chen, Zuliang; Megharaj, Mallavarapu; Naidu, Ravendra

2015-01-15

In this report, various iron-based nanoparticles (nZVI, n-Ni/Fe, n-Pd/Fe) were used for both heterogeneous Fenton oxidation of 2,4-dichlorophenol (2,4-DCP) and reductive dechlorination of 2,4-DCP in order to understand their roles in the Fenton oxidation and the reductive degradation of 2,4-DCP. The dechlorination efficiency of 2,4-DCP using nZVI, n-Ni/Fe, n-Fe/Pd and Fe(2)(+) was 6.48%, 6.80%, 15.95%, 5.02%, while Fenton oxidation efficiency of 2,4-DCP was 57.87%, 34.23%, 27.94%, 19.61% after 180 min, respectively. The new findings included a higher dechlorination using n-Fe/Pd due to Pd effective catalysis and the effective heterogeneous Fenton oxidation using nZVI depending on reductive dechlorination and heterogeneous Fenton oxidation occurs simultaneously. However, nZVI as the potential catalyst for heterogeneous Fenton was observed, and SEM, EDS and XRD demonstrate that change on the nZVI surface occurred due to the Fe(2+) leaching, and Total Organic Carbon (TOC) (30.71%) shows that 2,4-DCP was degraded. Furthermore, the experiment indicates that the pH values and concentration of 2,4-DCP significantly impacted on the heterogeneous Fenton oxidation of 2,4-DCP and the data fits well with the pseudo first-order kinetic model, which was a diffusion-controlled reaction. Finally, a possible mechanism for degradation of 2,4-DCP was proposed. Copyright © 2014 Elsevier Inc. All rights reserved.

Birnessite-induced mechanochemical degradation of 2,4-dichlorophenol.

PubMed

Nasser, A; Mingelgrin, U

2014-07-01

DCP (2,4-dichlorophenol) is the key-intermediate in the synthesis of some widely used pesticides and is an EPA priority pollutant. The mechanochemical breakdown of DCP loaded on birnessite (δ-MnO2), montmorillonite saturated with Na(+) or Cu(2+) and hematite was investigated. Mechanical force was applied by grinding of mixtures of DCP and the minerals, using mortar and pestle. Grinding of DCP for 5 min with the montmorillonites or with hematite resulted in negligible degradation during grinding, while grinding with birnessite induced the immediate degradation of 90% of the loaded DCP. Incubation for 24h after grinding did result in up to 30% degradation of the DCP loaded on the other minerals tested. HPLC and LC-MS analysis revealed that the transformation of DCP yielded oligomerization products as well as partial dechlorination. DCP degradation on birnessite was accompanied with a substantial increase in the extractability of manganese from the mineral into an acidic aqueous solution, indicating that Mn(IV) in the mineral transformed into Mn(II) and that birnessite served as an electron acceptor in the transformation. The oligomerization and partial dechlorination brought about by grinding, suggest a reduction in bioavailability and toxicity. Copyright © 2013 Elsevier Ltd. All rights reserved.

In vitro and in vivo effects of 2,4 diaminoquinazoline inhibitors of the decapping scavenger enzyme DcpS: Context-specific modulation of SMN transcript levels

PubMed Central

Androphy, Elliot J.; Calo, Alessandro; Potter, Kyle; Custer, Sara K.; Du, Sarah; Foley, Timothy L.; Gopalsamy, Ariamala; Reedich, Emily J.; Gordo, Susana M.; Gordon, William; Hosea, Natalie; Jones, Lyn H.; Krizay, Daniel K.; LaRosa, Gregory; Li, Hongxia; Mathur, Sachin; Menard, Carol A.; Patel, Paraj; Ramos-Zayas, Rebeca; Rietz, Anne; Rong, Haojing; Zhang, Baohong; Tones, Michael A.

2017-01-01

C5-substituted 2,4-diaminoquinazoline inhibitors of the decapping scavenger enzyme DcpS (DAQ-DcpSi) have been developed for the treatment of spinal muscular atrophy (SMA), which is caused by genetic deficiency in the Survival Motor Neuron (SMN) protein. These compounds are claimed to act as SMN2 transcriptional activators but data underlying that claim are equivocal. In addition it is unclear whether the claimed effects on SMN2 are a direct consequence of DcpS inhibitor or might be a consequence of lysosomotropism, which is known to be neuroprotective. DAQ-DcpSi effects were characterized in cells in vitro utilizing DcpS knockdown and 7-methyl analogues as probes for DcpS vs non-DcpS-mediated effects. We also performed analysis of Smn transcript levels, RNA-Seq analysis of the transcriptome and SMN protein in order to identify affected pathways underlying the therapeutic effect, and studied lysosomotropic and non-lysosomotropic DAQ-DCpSi effects in 2B/- SMA mice. Treatment of cells caused modest and transient SMN2 mRNA increases with either no change or a decrease in SMNΔ7 and no change in SMN1 transcripts or SMN protein. RNA-Seq analysis of DAQ-DcpSi-treated N2a cells revealed significant changes in expression (both up and down) of approximately 2,000 genes across a broad range of pathways. Treatment of 2B/- SMA mice with both lysomotropic and non-lysosomotropic DAQ-DcpSi compounds had similar effects on disease phenotype indicating that the therapeutic mechanism of action is not a consequence of lysosomotropism. In striking contrast to the findings in vitro, Smn transcripts were robustly changed in tissues but there was no increase in SMN protein levels in spinal cord. We conclude that DAQ-DcpSi have reproducible benefit in SMA mice and a broad spectrum of biological effects in vitro and in vivo, but these are complex, context specific, and not the result of simple SMN2 transcriptional activation. PMID:28945765

“Rational” Management of Dichlorophenols Biodegradation by the Microalga Scenedesmus obliquus

PubMed Central

Papazi, Aikaterini; Kotzabasis, Kiriakos

2013-01-01

The microalga Scenedesmus obliquus exhibited the ability to biodegrade dichlorophenols (dcps) under specific autotrophic and mixotrophic conditions. According to their biodegradability, the dichlorophenols used can be separated into three distinct groups. Group I (2,4-dcp and 2,6 dcp – no meta-substitution) consisted of quite easily degraded dichlorophenols, since both chloride substituents are in less energetically demanding positions. Group II (2,3-dcp, 2,5-dcp and 3,4-dcp – one meta-chloride) was less susceptible to biodegradation, since one of the two substituents, the meta one, required higher energy for C-Cl-bond cleavage. Group III (3,5-dcp – two meta-chlorides) could not be biodegraded, since both chlorides possessed the most energy demanding positions. In general, when the dcp-toxicity exceeded a certain threshold, the microalga increased the energy offered for biodegradation and decreased the energy invested for biomass production. As a result, the biodegradation per cell volume of group II (higher toxicity) was higher, than group I (lower toxicity) and the biodegradation of dichlorophenols (higher toxicity) was higher than the corresponding monochlorophenols (lower toxicity). The participation of the photosynthetic apparatus and the respiratory mechanism of microalga to biodegrade the group I and the group II, highlighted different bioenergetic strategies for optimal management of the balance between dcp-toxicity, dcp-biodegradability and culture growth. Additionally, we took into consideration the possibility that the intermediates of each dcp-biodegradation pathway could influence differently the whole biodegradation procedures. For this reason, we tested all possible combinations of phenolic intermediates to check cometabolic interactions. The present contribution bring out the possibility of microalgae to operate as “smart” bioenergetic “machines”, that have the ability to continuously “calculate” the energy reserves and “use” the most energetically advantageous dcp-biodegradation strategy. We tried to manipulate the above fact, changing the energy reserves and as a result the chosen strategy, in order to take advantage of their abilities in detoxifying the environment. PMID:23613903

A genetic screen for modifiers of Drosophila caspase Dcp-1 reveals caspase involvement in autophagy and novel caspase-related genes.

PubMed

Kim, Young-Il; Ryu, Taewoo; Lee, Judong; Heo, Young-Shin; Ahnn, Joohong; Lee, Seung-Jae; Yoo, OokJoon

2010-01-25

Caspases are cysteine proteases with essential functions in the apoptotic pathway; their proteolytic activity toward various substrates is associated with the morphological changes of cells. Recent reports have described non-apoptotic functions of caspases, including autophagy. In this report, we searched for novel modifiers of the phenotype of Dcp-1 gain-of-function (GF) animals by screening promoter element- inserted Drosophila melanogaster lines (EP lines). We screened approximately 15,000 EP lines and identified 72 Dcp-1-interacting genes that were classified into 10 groups based on their functions and pathways: 4 apoptosis signaling genes, 10 autophagy genes, 5 insulin/IGF and TOR signaling pathway genes, 6 MAP kinase and JNK signaling pathway genes, 4 ecdysone signaling genes, 6 ubiquitination genes, 11 various developmental signaling genes, 12 transcription factors, 3 translation factors, and 11 other unclassified genes including 5 functionally undefined genes. Among them, insulin/IGF and TOR signaling pathway, MAP kinase and JNK signaling pathway, and ecdysone signaling are known to be involved in autophagy. Together with the identification of autophagy genes, the results of our screen suggest that autophagy counteracts Dcp-1-induced apoptosis. Consistent with this idea, we show that expression of eGFP-Atg5 rescued the eye phenotype caused by Dcp-1 GF. Paradoxically, we found that over-expression of full-length Dcp-1 induced autophagy, as Atg8b-GFP, an indicator of autophagy, was increased in the eye imaginal discs and in the S2 cell line. Taken together, these data suggest that autophagy suppresses Dcp-1-mediated apoptotic cell death, whereas Dcp-1 positively regulates autophagy, possibly through feedback regulation. We identified a number of Dcp-1 modifiers that genetically interact with Dcp-1-induced cell death. Our results showing that Dcp-1 and autophagy-related genes influence each other will aid future investigations of the complicated relationships between apoptosis and autophagy.

"Rational" management of dichlorophenols biodegradation by the microalga Scenedesmus obliquus.

PubMed

Papazi, Aikaterini; Kotzabasis, Kiriakos

2013-01-01

The microalga Scenedesmus obliquus exhibited the ability to biodegrade dichlorophenols (dcps) under specific autotrophic and mixotrophic conditions. According to their biodegradability, the dichlorophenols used can be separated into three distinct groups. Group I (2,4-dcp and 2,6 dcp - no meta-substitution) consisted of quite easily degraded dichlorophenols, since both chloride substituents are in less energetically demanding positions. Group II (2,3-dcp, 2,5-dcp and 3,4-dcp - one meta-chloride) was less susceptible to biodegradation, since one of the two substituents, the meta one, required higher energy for C-Cl-bond cleavage. Group III (3,5-dcp - two meta-chlorides) could not be biodegraded, since both chlorides possessed the most energy demanding positions. In general, when the dcp-toxicity exceeded a certain threshold, the microalga increased the energy offered for biodegradation and decreased the energy invested for biomass production. As a result, the biodegradation per cell volume of group II (higher toxicity) was higher, than group I (lower toxicity) and the biodegradation of dichlorophenols (higher toxicity) was higher than the corresponding monochlorophenols (lower toxicity). The participation of the photosynthetic apparatus and the respiratory mechanism of microalga to biodegrade the group I and the group II, highlighted different bioenergetic strategies for optimal management of the balance between dcp-toxicity, dcp-biodegradability and culture growth. Additionally, we took into consideration the possibility that the intermediates of each dcp-biodegradation pathway could influence differently the whole biodegradation procedures. For this reason, we tested all possible combinations of phenolic intermediates to check cometabolic interactions. The present contribution bring out the possibility of microalgae to operate as "smart" bioenergetic "machines", that have the ability to continuously "calculate" the energy reserves and "use" the most energetically advantageous dcp-biodegradation strategy. We tried to manipulate the above fact, changing the energy reserves and as a result the chosen strategy, in order to take advantage of their abilities in detoxifying the environment.

Hydration of dicalcium silicate and diffusion through neo-formed calcium-silicate-hydrates at weathered surfaces control the long-term leaching behaviour of basic oxygen furnace (BOF) steelmaking slag.

PubMed

Stewart, Douglas I; Bray, Andrew W; Udoma, Gideon; Hobson, Andrew J; Mayes, William M; Rogerson, Mike; Burke, Ian T

2018-04-01

Alkalinity generation and toxic trace metal (such as vanadium) leaching from basic oxygen furnace (BOF) steel slag particles must be properly understood and managed by pre-conditioning if beneficial reuse of slag is to be maximised. Water leaching under aerated conditions was investigated using fresh BOF slag at three different particle sizes (0.5-1.0, 2-5 and 10 × 10 × 20 mm blocks) and a 6-month pre-weathered block. There were several distinct leaching stages observed over time associated with different phases controlling the solution chemistry: (1) free-lime (CaO) dissolution (days 0-2); (2) dicalcium silicate (Ca 2 SiO 4 ) dissolution (days 2-14) and (3) Ca-Si-H and CaCO 3 formation and subsequent dissolution (days 14-73). Experiments with the smallest size fraction resulted in the highest Ca, Si and V concentrations, highlighting the role of surface area in controlling initial leaching. After ~2 weeks, the solution Ca/Si ratio (0.7-0.9) evolved to equal those found within a Ca-Si-H phase that replaced dicalcium silicate and free-lime phases in a 30- to 150-μm altered surface region. V release was a two-stage process; initially, V was released by dicalcium silicate dissolution, but V also isomorphically substituted for Si into the neo-formed Ca-Si-H in the alteration zone. Therefore, on longer timescales, the release of V to solution was primarily controlled by considerably slower Ca-Si-H dissolution rates, which decreased the rate of V release by an order of magnitude. Overall, the results indicate that the BOF slag leaching mechanism evolves from a situation initially dominated by rapid hydration and dissolution of primary dicalcium silicate/free-lime phases, to a slow diffusion limited process controlled by the solubility of secondary Ca-Si-H and CaCO 3 phases that replace and cover more reactive primary slag phases at particle surfaces.

[Impact of disabling chronic pain: results of a cross-sectional population study with face-to-face interview].

PubMed

Cabrera-Leon, Andrés; Cantero-Braojos, Miguel Ángel

2017-11-16

To assess the impact of disabling chronic pain (DCP) on quality of life, work, consumption of medication and usage of health services. Cross-sectional population study with face-to-face interview. Andalusian Health Survey (2011 edition). 6,507 people over the age of 16 (p=q=0.5; confidence level=95%; sampling error=1.49, design effect=1.52). Not applicable. Dependent variable: DCP: population limited in their activity by any of the CP specified in the survey. quality of life, absence from work, consumption of medication and utilization of health services. Compared to a population without CP, DCP impact is 6 points less on the mental quality of life and 12 points on the physical one, medication consumption is triple, health services utilization is almost double, and long absence from work is triple. On the other hand, a population with nondisabling chronic pain (nDCP) presents similar results to a population without CP. We have considered DCP as another CP category because of its huge impact, as is shown in our study, on the study variables. On the contrary, the population with nDCP does not obtain significant impact differences when compared to the population without CP. Therefore, we believe that Primary Care and Public Health should lead different prevention strategies for DCP as well as for the identification of the nDCP population to decrease its possible deterioration towards DCP. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

The effect of a microscale fracture on dynamic capillary pressure of two-phase flow in porous media

NASA Astrophysics Data System (ADS)

Tang, Mingming; Lu, Shuangfang; Zhan, Hongbin; Wenqjie, Guo; Ma, Huifang

2018-03-01

Dynamic capillary pressure (DCP) effects, which is vital for predicting multiphase flow behavior in porous media, refers to the injection rate dependence capillary pressure observed during non-equilibrium displacement experiments. However, a clear picture of the effects of microscale fractures on DCP remains elusive. This study quantified the effects of microscale fractures on DCP and simulated pore-scale force and saturation change in fractured porous media using the multiphase lattice Boltzmann method (LBM). Eighteen simulation cases were carried out to calculate DCP as a function of wetting phase saturation. The effects of viscosity ratio and fracture orientation, aperture and length on DCP and DCP coefficient τ were investigated, where τ refers to the ratio of the difference of DCP and static capillary pressure (SCP) over the rate of wetting-phase saturation change versus time. Significant differences in τ values were observed between unfractured and fractured porous media. The τ values of fractured porous media were 1.1  × 104 Pa ms to 5.68 × 105 Pa ms, which were one or two orders of magnitude lower than those of unfractured porous media with a value of 4 × 106 Pa. ms. A horizontal fracture had greater effects on DCP and τ than a vertical fracture, given the same fracture aperture and length. This study suggested that a microscale fracture might result in large magnitude changes in DCP for two-phase flow.

An in vitro biomechanical comparison of hydroxyapatite coated and uncoated ao cortical bone screws for a limited contact: dynamic compression plate fixation of osteotomized equine 3rd metacarpal bones.

PubMed

Durham, Myra E; Sod, Gary A; Riggs, Laura M; Mitchell, Colin F

2015-02-01

To compare the monotonic biomechanical properties of a broad 4.5 mm limited contact-dynamic compression plate (LC-DCP) fixation secured with hydroxyapatite (HA) coated cortical bone screws (HA-LC-DCP) versus uncoated cortical bone screws (AO-LC-DCP) to repair osteotomized equine 3rd metacarpal (MC3) bones. Experimental. Adult equine cadaveric MC3 bones (n = 12 pair). Twelve pairs of equine MC3 were divided into 3 test groups (4 pairs each) for: (1) 4 point bending single cycle to failure testing; (2) 4 point bending cyclic fatigue testing; and (3) torsional single cycle to failure testing. For the HA-LC-DCP-MC3 construct, an 8-hole broad LC-DCP (Synthes Ltd, Paoli, PA) was secured on the dorsal surface of each randomly selected MC3 bone with a combination of four 5.5 mm and four 4.5 mm HA-coated cortical screws. For the AO-LC-DCP-MC3 construct, an 8-hole 4.5 mm broad LC-DCP was secured on the dorsal surface of the contralateral MC3 bone with a combination of four 5.5 mm and four 4.5 mm uncoated cortical screws. All MC3 bones had mid-diaphyseal osteotomies. Mean test variable values for each method were compared using a paired t-test within each group. Significance was set at P < .05. Mean yield load, yield bending moment, composite rigidity, failure load, and failure bending moment, under 4 point bending, single cycle to failure, of the HA-LC-DCP fixation were significantly greater than those of the AO-LC-DCP fixation. Mean ± SD values for the HA-LC-DCP and the AO-LC-DCP fixation techniques, respectively, in single cycle to failure under 4 point bending were: yield load, 26.7 ± 2.15 and 16.3 ± 1.38 kN; yield bending moment, 527.4 ± 42.4 and 322.9 ± 27.2 N-m; composite rigidity, 5306 ± 399 and 3003 ± 300 N-m/rad; failure load, 40.6 ± 3.94 and 26.5 ± 2.52 kN; and failure bending moment, 801.9 ± 77.9 and 522.9 ± 52.2 N-m. Mean cycles to failure in 4 point bending of the HA-LC-DCP fixation (116,274 ± 13,211) was significantly greater than that of the AO-LC-DCP fixation 47,619 ± 6580. Mean yield load, mean composite rigidity, and mean failure load under torsional testing, single cycle to failure was significantly greater for the broad HA-LC-DCP fixation compared with the AO-LC-DCP fixation. In single cycle to failure under torsion, mean ± SD values for the HA-LC-DCP and the AO-LC-DCP fixation techniques, respectively, were: yield load, 101.3 ± 14.68 and 70.54 ± 10.20 N-m; composite rigidity, 437.9 ± 32.9 and 220.7 ± 17.6 N-m/rad; and failure load: 105.7 ± 15.5 and 75.28 ± 10.1 N-m. HA-LC-DCP was superior to AO-LC-DCP in resisting the static overload forces (palmarodorsal 4 point bending and torsional) and in resisting cyclic fatigue under palmarodorsal 4 point bending. © Copyright 2014 by The American College of Veterinary Surgeons.

Evaluation of carbonate apatite blocks fabricated from dicalcium phosphate dihydrate blocks for reconstruction of rabbit femoral and tibial defects.

PubMed

Kanazawa, Masayuki; Tsuru, Kanji; Fukuda, Naoyuki; Sakemi, Yuta; Nakashima, Yasuharu; Ishikawa, Kunio

2017-06-01

This study aimed to evaluate in vivo behavior of a carbonate apatite (CO 3 Ap) block fabricated by compositional transformation via a dissolution-precipitation reaction using a calcium hydrogen phosphate dihydrate [DCPD: CaHPO 4 ·2H 2 O] block as a precursor. These blocks were used to reconstruct defects in the femur and tibia of rabbits, using sintered dense hydroxyapatite (HAp) blocks as the control. Both the CO 3 Ap and HAp blocks showed excellent tissue response and good osteoconductivity. HAp block maintained its structure even after 24 weeks of implantation, so no bone replacement of the implant was observed throughout the post-implantation period in either femoral or tibial bone defects. In contrast, CO 3 Ap was resorbed with increasing time after implantation and replaced with new bone. The CO 3 Ap block was resorbed approximately twice as fast at the metaphysis of the proximal tibia than at the epiphysis of the distal femur. The CO 3 Ap block was resorbed at an approximately linear change over time, with complete resorption was estimated by extrapolation of data at approximately 1-1.5 years. Hence, the CO 3 Ap block fabricated in this study has potential value as an ideal artificial bone substitute because of its resorption and subsequent replacement by bone.

About DCP | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) is the division of the National Cancer Institute (NCI) devoted to cancer prevention research. DCP provides funding and administrative support to clinical and laboratory researchers, community and multidisciplinary teams, and collaborative scientific networks. |

Effects of increasing concentrations of an Escherichia coli phytase on the apparent ileal digestibility of amino acids and the apparent total tract digestibility of energy and nutrients in corn-soybean meal diets fed to growing pigs.

PubMed

She, Y; Sparks, J C; Stein, H H

2018-04-24

An experiment was conducted to test the hypothesis that inclusion of increasing concentrations of an Escherichia coli (E. coli) phytase to a corn-soybean meal (SBM) diet results in improved digestibility of DM, GE, CP, NDF, ADF, macro minerals, micro minerals, and AA. Twenty four growing barrows (initial BW: 37.0 ± 1.4 kg) were equipped with a T-cannula in the distal ileum and placed individually in metabolism crates, and allotted to a 2-period switch-back design with 6 diets and 4 replicate pigs per diet in each period. The positive control diet was a corn-SBM diet that contained limestone and dicalcium phosphate to meet the requirement for standardized total tract digestible (STTD) P and Ca (0.31% STTD P and 0.70% Ca). A negative control diet that was similar to the positive control diet with the exception that no dicalcium phosphate was used and formulated to contain 0.16% STTD P and 0.43% Ca. Four additional diets were formulated by adding 500, 1,000, 2,000, or 4,000 units of microbial phytase (FTU) to the negative control diet. Each period lasted 14 d. Fecal and urine samples were collected from the feed provided from d 6 to 11 of each period following 5 d of adaptation to the diets. Ileal digesta were collected for 8 h on d 13 and 14. Results indicated that addition of the E. coli phytase to the negative control diet tended to quadratically improve the apparent ileal digestibility (AID) of Phe (P = 0.086) and Asp (P = 0.054), and linearly increased (P < 0.05) the apparent total tract digestibility (ATTD) of ADF, K, and Fe. Microbial phytase also quadratically increased (P < 0.05) the ATTD of NDF and Mg, and linearly and quadratically increased (P < 0.05) the ATTD and retention of Ca and P. However, no effects of the phytase on ATTD of GE or the concentration of DE were observed. In conclusion, the increased absorption of several minerals including Ca, P, K, Mg, and Fe that was observed as increasing concentrations of an E. coli phytase were added to a corn-SBM meal diet indicates that the dietary provision of these minerals may be reduced if phytase is fed.

Diagnostic accuracy of des-gamma-carboxy prothrombin for hepatocellular carcinoma in a French cohort using the Lumipulse® G600 analyzer.

PubMed

Sultanik, P; Ginguay, A; Vandame, J; Popovici, T; Meritet, J-F; Cynober, L; Pol, S; Bories, P-N

2017-01-01

The increasing incidence of hepatocellular carcinoma (HCC) in Western countries requests reliable tumour markers for preclinical diagnosis. We evaluated the diagnostic accuracy of des-gamma-carboxy prothrombin (DCP), in comparison with alpha-fetoprotein (AFP) in a French cohort using a new analyser. One hundred and sixty-two patients with virus-related cirrhosis (46 HCC patients and 116 controls) were recruited in this retrospective proof-of-concept study. DCP was measured on new Lumipulse ® G600 analyzer and AFP on usual Cobas e602 analyzer in serum samples that were collected at the time of HCC diagnosis for HCC patients or during follow-up for controls. DCP and AFP levels were higher in HCC patients. The area under receiver operating characteristic curve was larger for DCP than for AFP (0.89 vs 0.77, P=.03). At the cut-off value of 128 mAU/mL, sensitivity and specificity for DCP were 74% and 92%. At the cut-off value of 20 μg/L, sensitivity and specificity for AFP were 63% and 82%. NRI >0 for the association of "AFP+DCP" were 101%, P<.0001, and 23%, P=.03, compared to "AFP" or "DCP" alone, respectively. We conclude that DCP outperformed AFP for the detection of HCC. © 2016 John Wiley & Sons Ltd.

Chemical interaction of glycero-phosphate dimethacrylate (GPDM) with hydroxyapatite and dentin.

PubMed

Yoshihara, Kumiko; Nagaoka, Noriyuki; Hayakawa, Satoshi; Okihara, Takumi; Yoshida, Yasuhiro; Van Meerbeek, Bart

2018-04-28

Although the functional monomer glycero-phosphate dimethacrylate (GPDM) has since long been used in several dental adhesives and more recently in self-adhesive composite cements and restoratives, its mechanism of chemical adhesion to hydroxyapatite (HAp) is still unknown. We therefore investigated the chemical interaction of GPDM with HAp using diverse chemical analyzers and ultra-structurally characterized the interface of a GPDM-based primer formulation with dentin. HAp particles were added to a GPDM solution for various periods, upon which they were thoroughly washed with ethanol and water prior to being air-dried. As control, 10-methacryloyloxydecyl dihydrogen phosphate (MDP) was used. The molecular interaction of GPDM with HAp was analyzed using X-ray diffraction (XRD) and solid-state nuclear magnetic resonance (NMR) spectroscopy. Crystal formation upon application of GPDM onto dentin was analyzed using thin-film XRD (TF-XRD). Its hydrophobicity was measured using contact-angle measurement. The interaction of GPDM with dentin was characterized using transmission electron microscopy (TEM). XRD revealed the deposition of dicalcium phosphate dihydrate (DCPD: CaHPO 4 ·2H 2 O) on HAp after 24h. NMR confirmed the adsorption of GPDM onto HAp. However, GPDM was easily removed after washing with water, unlike MDP that remained adhered to HAp. Dentin treated with GPDM appeared more hydrophilic compared to dentin treated with MDP. TEM disclosed exposed collagen in the hybrid layer produced by the GPDM-based primer formulation. Although GPDM adsorbed to HAp, it did not form a stable calcium salt. The bond between GPDM and HAp was weak, unlike the strong bond formed by MDP to HAp. Due to its high hydrophilicity, GPDM might be an adequate monomer for an etch-and-rinse adhesive, but appears less appropriate for a 'mild' self-etch adhesive that besides micro-retention ionically interacts with HAp, or for a self-adhesive restorative material. Copyright © 2018 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.

Disposition and metabolism of 2,3-( UC)dichloropropene in rats after inhalation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bond, J.A.; Medinsky, M.A.; Dutcher, J.S.

1985-01-01

2,3-Dichloropropene (2,3-DCP) is a constituent of some commercially available preplant soil fumigants for the control of plant parasitic nematodes. The purpose of this investigation was to determine the disposition and metabolism of 2,3-( UC)DCP in rats after inhalation. Male Fischer-344 rats were exposed nose-only to a vapor concentration of 250 nmol 2,3-( UC)DCP/liter air (7.5 ppm; 25C, 620 Torr) for 6 hr. Blood samples were taken during exposure, and urine, feces, expired air, and tissues were collected for up to 65 hr after exposure. Urinary excretion was the major route of elimination of UC (55% of estimated absorbed 2,3-DCP). Half-timemore » for elimination of UC in urine was 9.8 +/- 0.05 hr (anti x +/- SE). Half-time for elimination of UC feces (17% of absorbed 2,3-DCP) was 12.9 +/- 0.14 hr (anti x +/- SE). Approximately 1 and 3% of the estimated absorbed 2,3-( UC)DCP were exhaled as either 2,3-( UC)DCP or UCO2, respectively. Concentrations of UC in blood increased during 240 min of exposure, after which no further increases in blood concentration of UC were seen. UC was widely distributed in tissues analyzed after a 6-hr exposure of rats to 2,3-( UC)DCP. Urinary bladder (150 nmol/g), nasal turbinates (125 nmol/g), kidneys (84 nmol/g), small intestine (61 nmol/g), and liver (35 nmol/g) were tissues with the highest concentrations of UC immediately after exposure. Over 90% of the UC in tissues analyzed was 2,3-DCP metabolites. Half-times for elimination of UC from tissues examined ranged from 3 to 11 hr. The data from this study indicate that after inhalation 2,3-DCP is metabolized in tissues and readily excreted. 21 references. 2 figures, 4 tables.« less

Mechanical properties and ion release from bioactive restorative composites containing glass fillers and calcium phosphate nano-structured particles.

PubMed

Chiari, Marina D S; Rodrigues, Marcela C; Xavier, Tathy A; de Souza, Eugen M N; Arana-Chavez, Victor E; Braga, Roberto R

2015-06-01

To evaluate the effect of the replacement of barium glass by dicalcium phosphate dihydrate (DCPD) particles on the mechanical properties and degree of conversion (DC) of composites. Additionally, calcium and hydrogen phosphate (HPO4(2-)) release were followed for 28 days. Nine composites containing equal parts (in mols) of BisGMA and TEGDMA and 40, 50 or 60 vol% of total filler were manipulated. Filler phase was constituted by silanated barium glass and 0%, 10% or 20% of DCPD particles. DC was determined by near-FTIR. Biaxial flexural strength (BFS) and modulus (E) were tested using the "piston on three balls" method, while fracture toughness (KIc) used the "single edge notched beam" method. Specimens were tested after 24h and 28 days in water. Ion release was determined using inductively coupled plasma optical emission spectrometry (ICP-OES). Data were analyzed by ANOVA/Tukey (DC and ion release) or Kruskal-Wallis/Mann-Whitney (mechanical properties; alpha: 5%). DC was not affected by DCPD. The presence of DCPD reduced BFS for both storage times, while differences in E became evident after 28 days. After 24h, KIc increased with the addition of DCPD; after 28 days, however, KIc decreased only for DCPD-containing composites. Calcium release was similar for both DCPD contents and remained fairly constant during the 28-day period. Overall, HPO4(2-) release was higher at 7 days and did not decrease after 14 days. The composite with the highest filler level and 10% DCPD represented the best compromise between mechanical properties after aging in water and ion release. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Effects of Silicon on Osteoclast Cell Mediated Degradation, In Vivo Osteogenesis and Vasculogenesis of Brushite Cement.

PubMed

Vahabzadeh, Sahar; Roy, Mangal; Bose, Susmita

2015-12-14

Calcium phosphate cements (CPCs) are being widely used for treating small scale bone defects. Among the various CPCs, brushite (dicalcium phosphate dihydrate, DCPD) cement is widely used due to its superior solubility and ability to form new bone. In the present study, we have studied the physical, mechanical, osteoclast-like-cells differentiation and in vivo osteogenic and vasculogenic properties of silicon (Si) doped brushite cements. Addition of Si did not alter the phase composition of final product and regardless of Si level, all samples included β-tricalcium phosphate (β-TCP) and DCPD. 1.1 wt. % Si addition increased the compressive strength of undoped brushite cement from 4.78±0.21 MPa to 5.53±0.53 MPa, significantly. Cellular activity was studied using receptor activator of nuclear factor κβ ligand (RANKL) supplemented osteoclast-like-cells precursor RAW 264.7 cell. Phenotypic expressions of the cells confirmed successful differentiation of RAW264.7 monocytes to osteoclast-like-cells on undoped and doped brushite cements. An increased activity of osteoclast-like cells was noticed due to Si doping in the brushite cement. An excellent new bone formation was found in all cement compositions, with significant increase in Si doped brushite samples as early as 4 weeks post implantation in rat femoral model. After 4 weeks of implantation, no significant difference was found in blood vessel formation between the undoped and doped cements, however, a significant increase in vasculgenesis was found in 0.8 and 1.1 wt. % Si doped brushite cements after 8 weeks. These results show the influence of Si dopant on physical, mechanical, in vitro osteoclastogenesis and in vivo osteogenic and vasculogenic properties of brushite cements.

Fate and origin of 1,2 - dichloropropane in an unconfined shallow aquifer

USGS Publications Warehouse

Tesoriero, Anthony J.; Loffler, F.E.; Liebscher, Hugh

2001-01-01

A shallow aquifer with different redox zones overlain by intensive agricultural activity was monitored for the occurrence of 1,2-dichloropropane (DCP) to assess the fate and origin of this pollutant. DCP was detected more frequently in groundwater samples collected in aerobic and nitrate-reducing zones than those collected from iron-reducing zones. Simulated DCP concentrations for groundwater entering an iron-reducing zone were calculated from a fate and transport model that included dispersion, sorption, and hydrolysis but not degradation. Simulated concentrations were well in excess of measured values, suggesting that microbial degradation occurred in the iron-reducing zone. Microcosm experiments were conducted using aquifer samples collected from iron-reducing and aerobic zones to evaluate the potential for microbial degradation of DCP and to explain field observations. Hydrogenolysis of DCP and production of monochlorinated propanes in microcosm experiments occurred only with aquifer materials collected from the iron-reducing zone, and no dechlorination was observed in microcosms established with aquifer materials collected from the aerobic zones. Careful analyses of the DCP/1,2,2-trichloropropane ratios in groundwater indicated that older fumigant formulations were responsible for the high levels of DCP present in this aquifer.

Differential utilization of decapping enzymes in mammalian mRNA decay pathways

PubMed Central

Li, You; Song, Mangen; Kiledjian, Megerditch

2011-01-01

mRNA decapping is a crucial step in the regulation of mRNA stability and gene expression. Dcp2 is an mRNA decapping enzyme that has been widely studied. We recently reported the presence of a second mammalian cytoplasmic decapping enzyme, Nudt16. Here we address the differential utilization of the two decapping enzymes in specified mRNA decay processes. Using mouse embryonic fibroblast (MEF) cell lines derived from a hypomorphic knockout of the Dcp2 gene with undetectable levels of Dcp2 or MEF cell lines harboring a Nudt16-directed shRNA to generate reduced levels of Nudt16, we demonstrate the distinct roles for Dcp2 and Nudt16 in nonsense-mediated mRNA decay (NMD), decay of ARE-containing mRNA and miRNA-mediated silencing. Our results indicated that NMD preferentially utilizes Dcp2 rather than Nudt16; Dcp2 and Nudt16 are redundant in miRNA-mediated silencing; and Dcp2 and Nudt16 are differentially utilized for ARE-mRNA decay. These data demonstrate that the two distinct decapping enzymes can uniquely function in specific mRNA decay processes in mammalian cells. PMID:21224379

Stalagmite carbon isotopes and dead carbon proportion (DCP) in a near-closed-system situation: An interplay between sulphuric and carbonic acid dissolution

NASA Astrophysics Data System (ADS)

Bajo, Petra; Borsato, Andrea; Drysdale, Russell; Hua, Quan; Frisia, Silvia; Zanchetta, Giovanni; Hellstrom, John; Woodhead, Jon

2017-08-01

In this study, the 'dead carbon proportion' (DCP) calculated from combined U-Th and radiocarbon analyses was used to explore the carbon isotope systematics in Corchia Cave (Italy) speleothems, using the example of stalagmite CC26 which grew during the last ∼12 ka. The DCP values in CC26 are among the highest ever recorded in a stalagmite, spanning the range 44.8-68.8%. A combination of almost closed-system conditions and sulphuric acid dissolution (SAD) are proposed as major drivers in producing such a high DCP with minor contribution from old organic matter from the deep vadose zone. The long-term decrease in both DCP and δ13C most likely reflects post-glacial soil recovery above the cave, with a progressive increase of soil CO2 contribution to the total dissolved inorganic carbon (DIC). Pronounced millennial-scale shifts in DCP and relatively small coeval but antipathetic changes in δ13C are modulated by the effects of hydrological variability on open and closed-system dissolution, SAD and prior calcite precipitation. Hence, the DCP in Corchia Cave speleothems represents an additional proxy for rainfall amount.

Rapid and early α-fetoprotein and des-γ-carboxy prothrombin responses to initial arterial infusion chemotherapy predict treatment outcomes of advanced hepatocellular carcinoma

PubMed Central

OYAMA, KENJI; KODA, MASAHIKO; SUGIHARA, TAKAAKI; KISHINA, MANABU; MIYOSHI, KENICHI; OKAMOTO, TOSHIAKI; HODOTSUKA, MASANORI; FUJISE, YUKI; MATONO, TOMOMITSU; TOKUNAGA, SHIHO; OKAMOTO, KINYA; HOSHO, KEIKO; OKANO, JUNICHI; MURAWAKI, YOSHIKAZU

2015-01-01

The aim of the present study was to predict the effects of transarterial infusion (TAI) chemotherapy based on early changes in α-fetoprotein (AFP) and des-γ-carboxy prothrombin (DCP) in patients with advanced hepatocellular carcinoma (HCC). Seventy-four patients who underwent TAI with cisplatin, 5-fluorouracil, mitomycin C and epirubicin for advanced HCC were enrolled. Antitumor responses were evaluated 6 months after TAI. Rapid and early responses were defined as the ratio of AFP or DCP after 1 week and 1 month compared to baseline. A total of 5, 10, 17 and 42 patients had complete response (CR), partial response (PR), stable disease (SD) or progressive disease (PD), respectively. Early AFP response was significantly lower in the CR+PR compared to the SD+PD groups (P<0.01). The early DCP response was significantly lower in the CR+PR compared to the SD+PD. The sensitivity and specificity of rapid and early AFP responses in the CR+PR were 0.78 and 0.72, and 0.80 and 0.73, respectively, and those of rapid and early DCP responses were 0.67 and 0.65, and 0.77 and 0.71, respectively. The combination of AFP and DCP responses had higher specificity compared to AFP or DCP alone responses. Patients were divided into responder and non-responder groups to evaluate the prediction of survival outcome. Early responders of AFP, DCP and AFP+DCP, who were divided based on the cut-off values of CR+PR survived significantly longer than the non-responders (P<0.05). In conclusion, rapid or early responses of AFP and/or DCP levels 1 and 4 weeks after TAI chemotherapy helped to predict the treatment effects. PMID:26137283

Effect of wheat bran and dried carrot pomace addition on quality characteristics of chicken sausage

PubMed Central

2018-01-01

Objective Effect of addition of wheat bran (WB) and dried carrot pomace (DCP) on sensory, textural, colour, physico-chemical and nutritional characteristics of chicken sausage were evaluated. Methods WB and DCP were used as a source of dietary fibre at 3%, 6%, and 9% level individually. Different quality attributes of sausages were estimated. One product from each source with very good sensory acceptability was selected to analyze dietary fibre content and shelf life under refrigerated storage. Results Sensory acceptability of 3% fibre enriched sausage was comparable with control and a further increase in fibre level resulted in a decrease in sensory acceptability. Fibre enriched sausages were significantly harder and less cohesive than control sausage. Significant increase in gumminess and chewiness was observed at 6% level in WB treated sausages and 9% level in DCP treated sausages. Moisture content decreased significantly in all treated sausages, protein content decreased significantly in DCP-2 and DCP-3 sausages while fat content decreased in all WB and DCP-3 treated sausages in comparison to control. The fibre enriched sausage had significantly higher dietary fibre and lower cholesterol content. Cooking yield and emulsion stability increased in treated sausages and a significant difference was noticed at 6% level in both types of sausages. pH of WB treated sausages was significantly higher and DCP treated sausage significantly lower in comparison to control. Conclusion The results of present study indicate that fibre enriched chicken sausage with moderate acceptability can be developed by incorporating WB and DCP each up to 9% level. Chicken sausage with very good acceptability, higher dietary fibre content and storability up to 15 days at refrigerated temperature can be developed by incorporating WB and DCP at 6% level each. PMID:28823131

[Experimental study on Dendrobium candidum polysaccharides on promotion of hair growth].

PubMed

Chen, Jian; Qi, Hui; Li, Jin-Biao; Yi, Yan-Qun; Chen, Dan; Hu, Xiao-Hong; Wang, Mei-Ling; Sun, Xing-Li; Wei, Xiao-Yong

2014-01-01

To observe the effect and mechanism of Dendrobium candidum polysaccharides (DCP) in promoting hair growth, in order to lay a foundation for the development and utilization of D. candidum. The water-extraction and alcohol-precipitation method was adopted to extract DCP, and the phenol-sulphuric acid method was used to determine its content. Thirty C57BL6J mice were collected to establish the hair loss model with hair removal cream. They were randomly divided into the control group, the positive control group and the DCP group, and given 0.2 mL of ultra-pure water, minoxidil tincture and DCP (5.0 g x L(-1)) 21 days. The mice hair growth scoring standard was adopted to evaluate the hair growth of C57BL/6J mice at 7, 14 d. The hairs in unit hair-losing areas of treated C57BL/6J mice at 21 d were weighed to evaluate the effect of DCP on the promotion of hair growth. MTT assay and RT-PCR method were used to evaluate the effect of DCP on the proliferatin of HaCaT cells and the mRNA expression of VEGF in HaCaT cells. The extraction percent of DCP was 29.87%, and its content was 79.65%. The average scores for the hair growth and weight of C57BL/6J mice of DCP group were much higher than the control group. The survival rate and mRNA expression of VEGF of HaCaT cells were much higher than the control group. DCP has the effect in promoting hair growth. Its mechanism may be related to the up-regulation of the mRNA expression of VEGF.

Identification of functional domains in Arabidopsis thaliana mRNA decapping enzyme (AtDcp2)

PubMed Central

Gunawardana, Dilantha; Cheng, Heung-Chin; Gayler, Kenwyn R.

2008-01-01

The Arabidopsis thaliana decapping enzyme (AtDcp2) was characterized by bioinformatics analysis and by biochemical studies of the enzyme and mutants produced by recombinant expression. Three functionally significant regions were detected: (i) a highly disordered C-terminal region with a putative PSD-95, Discs-large, ZO-1 (PDZ) domain-binding motif, (ii) a conserved Nudix box constituting the putative active site and (iii) a putative RNA binding domain consisting of the conserved Box B and a preceding loop region. Mutation of the putative PDZ domain-binding motif improved the stability of recombinant AtDcp2 and secondary mutants expressed in Escherichia coli. Such recombinant AtDcp2 specifically hydrolysed capped mRNA to produce 7-methyl GDP and decapped RNA. AtDcp2 activity was Mn2+- or Mg2+-dependent and was inhibited by the product 7-methyl GDP. Mutation of the conserved glutamate-154 and glutamate-158 in the Nudix box reduced AtDcp2 activity up to 400-fold and showed that AtDcp2 employs the catalytic mechanism conserved amongst Nudix hydrolases. Unlike many Nudix hydrolases, AtDcp2 is refractory to inhibition by fluoride ions. Decapping was dependent on binding to the mRNA moiety rather than to the 7-methyl diguanosine triphosphate cap of the substrate. Mutational analysis of the putative RNA-binding domain confirmed the functional significance of an 11-residue loop region and the conserved Box B. PMID:18025047

Analysis of 3-MCPD and 1,3-DCP in Various Foodstuffs Using GC-MS

PubMed Central

Kim, Wooseok; Jeong, Yun A; On, Jiwon; Choi, Ari; Lee, Jee-yeon; Lee, Joon Goo; Lee, Kwang-Geun

2015-01-01

3-Monochloro-1,2-propanediol (3-MCPD) and 1,3-dichloro-2-propanol (1,3-DCP) are not only produced in the manufacturing process of foodstuffs such as hydrolyzed vegetable proteins and soy sauce but are also formed by heat processing in the presence of fat and low water activity. 3-MCPD exists both in free and ester forms, and the ester form has been also detected in various foods. Free 3-MCPD and 1,3-DCP are classified as Group 2B by the International Agency for Research on Cancer. Although there is no data confirming the toxicity of either compound in humans, their toxicity was evidenced in animal experimentation or in vitro. Although few studies have been conducted, free 3-MCPD has been shown to have neurotoxicity, reproductive toxicity, and carcinogenicity. In contrast, 1,3-DCP only has mutagenic activity. The purpose of this study was to analyze 3-MCPD and 1,3-DCP in various foods using gas chromatography -mass spectrometry. 3-MCPD and 1,3-DCP were analyzed using phenyl boronic acid derivatization and the liquid–liquid extraction method, respectively. The analytical method for 3-MCPD and 1,3-DCP was validated in terms of linearity, limit of detection (LOD), limit of quantitation, accuracy and precision. Consequently, the LODs of 3-MCPD and 1,3-DCP in various matrices were identified to be in the ranges of 4.18~10.56 ng/g and 1.06~3.15 ng/g, respectively. PMID:26483891

75 FR 38802 - DCP Raptor Pipeline, LLC; Notice of Baseline Filing

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-06

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. PR10-42-000] DCP Raptor Pipeline, LLC; Notice of Baseline Filing June 28, 2010. Take notice that on June 22, 2010, DCP Raptor Pipeline, LLC submitted a baseline filing of its Statement of Operating Conditions for services provided...

76 FR 47576 - DCP Intrastate Network, LLC; Notice of Filing

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-05

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. PR11-120-000] DCP Intrastate Network, LLC; Notice of Filing Take notice that on July 26, 2011, DCP Intrastate Network, LLC filed to provide notice of its cancellation of its Statement of Operating Conditions for Interstate Gas...

76 FR 9012 - DCP Intrastate Network, LLC; Notice of Filing

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-16

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. PR11-85-000] DCP Intrastate Network, LLC; Notice of Filing Take notice that on February 1, 2011, DCP Intrastate Network, LLC (DCPIN) filed to provide notice of its withdrawal of rates for transportation service under Section 311 of the...

75 FR 37786 - DCP Guadalupe Pipeline, LLC; Notice of Baseline Filing

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-30

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. PR10-31-000] DCP Guadalupe Pipeline, LLC; Notice of Baseline Filing June 23, 2010. Take notice that on June 10, 2010, DCP Guadalupe Pipeline, LLC submitted a baseline filing of its Storage Statement of Operating Conditions for services...

76 FR 7552 - DCP Guadalupe Pipeline, LLC; Notice of Baseline Filing

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-10

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [ Docket No. PR10-31-001] DCP Guadalupe Pipeline, LLC; Notice of Baseline Filing Take notice that on February 3, 2011, DCP Guadalupe Pipeline, LLC submitted a revised baseline filing of their Statement of Operating Conditions for services provided under...

The Diaper Change Play: Validation of a New Observational Assessment Tool for Early Triadic Family Interactions in the First Month Postpartum.

PubMed

Rime, Jérôme; Tissot, Hervé; Favez, Nicolas; Watson, Michael; Stadlmayr, Werner

2018-01-01

The quality of family relations, observed during mother-father-infant triadic interactions, has been shown to be an important contributor to child social and affective development, beyond the quality of dyadic mother-child, father-child, and marital relationships. Triadic interactions have been well described in families with 3 month olds and older children using the Lausanne Trilogue Play (LTP). Little is known about the development of mother-father-baby interactions in the very 1st weeks postpartum, mostly because no specific observational setting or particular instrument had been designed to cover this age yet. To fill this gap, we adapted the LTP to create a new observational setting, namely the Diaper Change Play (DCP). Interactions are assessed using the Family Alliance Assessment Scales for DCP (FAAS-DCP). We present the validation of the DCP and its coding system, the FAAS-DCP. The three validation studies presented here (44 mother-father-child-triads) involve a sample of parents with 3-week-old infants recruited in two maternity wards ( n = 32 and n = 12) in Switzerland. Infants from both sites were all healthy according to their APGAR scores, weight at birth, and scores on the NICU Network Neurobehavioral Scale (NNNS), which was additionally conducted on the twelve infants recruited in one of the maternity ward. Results showed that the "FAAS - DCP" coding system has good psychometric properties, with a good internal consistency and a satisfying reliability among the three independent raters. Finally, the "FAAS-DCP" scores on the interactive dimensions are comparable to the similar dimensions in the FAAS-LTP. The results showed that there is no statistically significant difference on scores between the "FAAS-DCP" and the "FAAS," which is consistent with previous studies underlying stability in triadic interaction patterns from pregnancy to 18 months. These first results indicated that the DCP is a promising observational setting, able to assess the development of the early family triadic functioning. The DCP and the FAAS-DCP offer to both clinicians and researchers a way to improve the understanding of the establishment of early family functioning as well as to study the young infant's triangular capacity. Perspectives for future research will be discussed.

Feasibility of in vivo three-dimensional T 2* mapping using dicarboxy-PROXYL and CW-EPR-based single-point imaging.

PubMed

Kubota, Harue; Komarov, Denis A; Yasui, Hironobu; Matsumoto, Shingo; Inanami, Osamu; Kirilyuk, Igor A; Khramtsov, Valery V; Hirata, Hiroshi

2017-06-01

The aim of this study was to demonstrate the feasibility of in vivo three-dimensional (3D) relaxation time T 2 * mapping of a dicarboxy-PROXYL radical using continuous-wave electron paramagnetic resonance (CW-EPR) imaging. Isotopically substituted dicarboxy-PROXYL radicals, 3,4-dicarboxy-2,2,5,5-tetra( 2 H 3 )methylpyrrolidin-(3,4- 2 H 2 )-(1- 15 N)-1-oxyl ( 2 H, 15 N-DCP) and 3,4-dicarboxy-2,2,5,5-tetra( 2 H 3 )methylpyrrolidin-(3,4- 2 H 2 )-1-oxyl ( 2 H-DCP), were used in the study. A clonogenic cell survival assay was performed with the 2 H-DCP radical using squamous cell carcinoma (SCC VII) cells. The time course of EPR signal intensities of intravenously injected 2 H, 15 N-DCP and 2 H-DCP radicals were determined in tumor-bearing hind legs of mice (C3H/HeJ, male, n = 5). CW-EPR-based single-point imaging (SPI) was performed for 3D T 2 * mapping. 2 H-DCP radical did not exhibit cytotoxicity at concentrations below 10 mM. The in vivo half-life of 2 H, 15 N-DCP in tumor tissues was 24.7 ± 2.9 min (mean ± standard deviation [SD], n = 5). The in vivo time course of the EPR signal intensity of the 2 H, 15 N-DCP radical showed a plateau of 10.2 ± 1.2 min (mean ± SD) where the EPR signal intensity remained at more than 90% of the maximum intensity. During the plateau, in vivo 3D T 2 * maps with 2 H, 15 N-DCP were obtained from tumor-bearing hind legs, with a total acquisition time of 7.5 min. EPR signals of 2 H, 15 N-DCP persisted long enough after bolus intravenous injection to conduct in vivo 3D T 2 * mapping with CW-EPR-based SPI.

PKCε Increases Extracellular Elastin and Fibulin-5/DANCE in Dermal Fibroblasts.

PubMed

Nishizaki, Tomoyuki

2018-01-01

In the earlier study, the selective PKCε activator DCP-LA increased elastic fibres in the dermis of HR-1 hairless mice. As a process of elastic fibre formation, tropoelastin, an elastin monomer, is secreted into the extracellular space. Secreted tropoelastin is delivered to the microfibrils by fibulin-5/developmental arteries and neural crest epidermal growth factor-like (DANCE) and undergoes self-association. Then, tropoelastin assembles around the microfibrils, growing into elastin and elastic fibres by lysyl oxidase (LOX)- or LOX-like (LOXL)-mediated cross-linking. The present study was conducted to understand the mechanism underlying DCP-LA-induced increase in elastin/elastic fibre. Western blotting, immunocytochemistory, and real-time reverse transcription-polymerase chain reaction (RT-PCR) were carried out in cultured human dermal fibroblasts. PKCε, mammalian target of rapamycin complex (mTOR), and p70 S6 kinase (S6K) were knocked-down by transfecting each siRNA. DCP-LA increased elastin and fibulin-5/DANCE in a treatment time (6-24 h)- and a bell-shaped concentration (1 nM-1 µM)-dependent manner in the culture medium of human dermal fibroblasts. DCP-LA markedly increased elastic fibres in the extracellular space of cultured fibroblasts. DCP-LA-induced increase in extracellular elastin and fibulin-5/DANCE was abolished by a PKC inhibitor or knocking-down PKCε. DCP-LA did not affect expression of mRNAs for tropoelastin and fiblin-5/DANCE in cultured fibroblasts. DCP-LA-induced increase in extracellular elastin and fibulin-5/DANCE was not inhibited by the protein synthesis inhibitor cycloheximide or by knocking-down mTOR and S6K. DCP-LA never increased extracellular elastin in the presence of elastase, that breaks down elastin. An inhibitor of matrix metalloproteinase 9, that degrades multiple extracellular matrix components including elastin, had no effect on the basal levels and the DCP-LA-induced increase levels of extracellular elastin. The results of the present study indicate that PKCε, activated by DCP-LA, increases elastin and fibulin-5/DANCE in the extracellular space of cultured fibroblasts by the mechanism independent of transcriptional and translational modulation or inhibition of elastolysis. © 2018 The Author(s). Published by S. Karger AG, Basel.

Down-regulation of Decapping Protein 2 mediates chronic nicotine exposure-induced locomotor hyperactivity in Drosophila.

PubMed

Ren, Jing; Sun, Jinghan; Zhang, Yunpeng; Liu, Tong; Ren, Qingzhong; Li, Yan; Guo, Aike

2012-01-01

Long-term tobacco use causes nicotine dependence via the regulation of a wide range of genes and is accompanied by various health problems. Studies in mammalian systems have revealed some key factors involved in the effects of nicotine, including nicotinic acetylcholine receptors (nAChRs), dopamine and other neurotransmitters. Nevertheless, the signaling pathways that link nicotine-induced molecular and behavioral modifications remain elusive. Utilizing a chronic nicotine administration paradigm, we found that adult male fruit flies exhibited locomotor hyperactivity after three consecutive days of nicotine exposure, while nicotine-naive flies did not. Strikingly, this chronic nicotine-induced locomotor hyperactivity (cNILH) was abolished in Decapping Protein 2 or 1 (Dcp2 or Dcp1) -deficient flies, while only Dcp2-deficient flies exhibited higher basal levels of locomotor activity than controls. These results indicate that Dcp2 plays a critical role in the response to chronic nicotine exposure. Moreover, the messenger RNA (mRNA) level of Dcp2 in the fly head was suppressed by chronic nicotine treatment, and up-regulation of Dcp2 expression in the nervous system blocked cNILH. These results indicate that down-regulation of Dcp2 mediates chronic nicotine-exposure-induced locomotor hyperactivity in Drosophila. The decapping proteins play a major role in mRNA degradation; however, their function in the nervous system has rarely been investigated. Our findings reveal a significant role for the mRNA decapping pathway in developing locomotor hyperactivity in response to chronic nicotine exposure and identify Dcp2 as a potential candidate for future research on nicotine dependence.

Solar photocatalytic degradation of chlorophenols mixture (4-CP and 2,4-DCP): Mechanism and kinetic modelling.

PubMed

Abeish, Abdulbasit M; Ang, Ha Ming; Znad, Hussein

2015-01-01

The solar-photocatalytic degradation mechanisms and kinetics of 4-chlorophenol (4-CP) and 2,4-dichlorophenol (2,4-DCP) using TiO2 have been investigated both individually and combined. The individual solar-photocatalytic degradation of both phenolic compounds showed that the reaction rates follow pseudo-first-order reaction. During the individual photocatalytic degradation of both 4-CP and 2,4-DCP under the same condition of TiO2 (0.5 g L(-1)) and light intensities (1000 mW cm(-2)) different intermediates were detected, three compounds associated with 4-CP (hydroquinone (HQ), phenol (Ph) and 4-chlorocatechol (4-cCat)) and two compounds associated with 2,4-DCP (4-CP and Ph). The photocatalytic degradation of the combined mixture (4-CP and 2,4-DCP) was also investigated at the same conditions and different 2,4-DCP initial concentrations. The results showed that the degradation rate of 4-CP decreases when the 2,4-DCP concentration increases. Furthermore, the intermediates detected were similar to that found in the individual degradation but with high Ph concentration. Therefore, a possible reaction mechanism for degradation of this combined mixture was proposed. Moreover, a modified Langmuir-Hinshelwood (L-H) kinetic model considering all detected intermediates was developed. A good agreement between experimental and estimated results was achieved. This model can be useful for scaling-up purposes more accurately as its considering the intermediates formed, which has a significant effect on degrading the main pollutants (4-CP and 2,4-DCP).

Down-Regulation of Decapping Protein 2 Mediates Chronic Nicotine Exposure-Induced Locomotor Hyperactivity in Drosophila

PubMed Central

Ren, Jing; Sun, Jinghan; Zhang, Yunpeng; Liu, Tong; Ren, Qingzhong; Li, Yan; Guo, Aike

2012-01-01

Long-term tobacco use causes nicotine dependence via the regulation of a wide range of genes and is accompanied by various health problems. Studies in mammalian systems have revealed some key factors involved in the effects of nicotine, including nicotinic acetylcholine receptors (nAChRs), dopamine and other neurotransmitters. Nevertheless, the signaling pathways that link nicotine-induced molecular and behavioral modifications remain elusive. Utilizing a chronic nicotine administration paradigm, we found that adult male fruit flies exhibited locomotor hyperactivity after three consecutive days of nicotine exposure, while nicotine-naive flies did not. Strikingly, this chronic nicotine-induced locomotor hyperactivity (cNILH) was abolished in Decapping Protein 2 or 1 (Dcp2 or Dcp1) -deficient flies, while only Dcp2-deficient flies exhibited higher basal levels of locomotor activity than controls. These results indicate that Dcp2 plays a critical role in the response to chronic nicotine exposure. Moreover, the messenger RNA (mRNA) level of Dcp2 in the fly head was suppressed by chronic nicotine treatment, and up-regulation of Dcp2 expression in the nervous system blocked cNILH. These results indicate that down-regulation of Dcp2 mediates chronic nicotine-exposure-induced locomotor hyperactivity in Drosophila. The decapping proteins play a major role in mRNA degradation; however, their function in the nervous system has rarely been investigated. Our findings reveal a significant role for the mRNA decapping pathway in developing locomotor hyperactivity in response to chronic nicotine exposure and identify Dcp2 as a potential candidate for future research on nicotine dependence. PMID:23300696

76 FR 79675 - DCP Raptor Pipeline, LLC; Notice of Extension of Time

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-22

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. PR09-32-003] DCP Raptor Pipeline, LLC; Notice of Extension of Time On November 30, 2011, DCP Raptor Pipeline, LLC (Raptor) filed a... ] 61,150 (May 20, 2010). Upon consideration, notice is hereby given that an extension of time for...

[Characteristic of the removal of 2,4-dichlorophenol by biological activated carbon].

PubMed

Liu, Hong; Li, An-jie; Quan, Xiang-chun; Kong, Xiang-hui; Yun, Ying

2004-11-01

The adsorption characteristics and kinetics of 2,4-Dichlorophenol (2,4-DCP) by biological activated carbon (BAC) was studied through contrast experiments with conventional activated sludge alone or quartz as the carrier. The advantage and disadvantage of removing 2,4-DCP using BAC and the mechanism of this process were investigated. The results show that the method of removing 2,4-DCP by BAC is applicable in practices, and the process of BAC demonstrates high removal rate than the process of suspended activated sludge and biofilm with quartz as the carrier. In addition, the BAC process showed high resistance to shock loadings, therefore, it is suitable to be utilized at high organic loading and under long-term operation. In BAC-system, activated carbon could not only adsorb 2,4-DCP but also oxidized 2,4-DCP.

Electrochemical properties of the erbium-chitosan-fluorine-modified PbO2 electrode for the degradation of 2,4-dichlorophenol in aqueous solution.

PubMed

Wang, Ying; Shen, Zhenyao; Li, Yang; Niu, Junfeng

2010-05-01

The erbium (Er)-chitosan-fluorine (F) modified PbO(2) electrode was prepared by electrodeposition method, and its use for adsorption and electrochemical degradation of 2,4-dichlorophenol (2,4-DCP) in aqueous solution was compared with F-PbO(2) and Er-F-PbO(2) electrodes in a batch experiment. The electrodes were characterized by scanning electron microscopy, X-ray diffraction and cyclic voltammetry. Degradation of 2,4-DCP depending on Er and chitosan contents was discussed. The results showed that Er(2)O(3) and chitosan were scattered between the prevailing crystal structure of beta-PbO(2) and thus decreased the internal stress of PbO(2) film. Prior to each electrolysis, the modified PbO(2) anode was first pre-saturated with 2,4-DCP solution for 360 min to preclude the 2,4-DCP decrease due to adsorption. Among the electrodes examined in our study, the highest adsorption and electrochemical degradation for 2,4-DCP and TOC removals that are due to oxidation and adsorption of the organic products onto the chitosan was observed on Er-chitosan-F-PbO(2) electrode. At an applied current density of 5 mAcm(-2), the removal percentages of 2,4-DCP and TOC (solution volume: 180 mL, initial 2,4-DCP concentration: 90 mgL(-1)) were 95% after 120 min and 53% after 360 min, respectively. At Er amount of 10mM in the precursor coating solution, the degradation and mineralization removal for 2,4-DCP on the Er-F-PbO(2) electrode reached a maximum. At chitosan amount of 5 gL(-1), the highest TOC removal on the Er-chitosan-F-PbO(2) electrode was observed. Intermediates mainly including aliphatic carboxylic acids were examined and a possible degradation pathway for 2,4-DCP in aqueous solution involving dechlorination and hydroxylation reactions was proposed. Copyright 2010 Elsevier Ltd. All rights reserved.

Enhanced tolerance and remediation to mixed contaminates of PCBs and 2,4-DCP by transgenic alfalfa plants expressing the 2,3-dihydroxybiphenyl-1,2-dioxygenase.

PubMed

Wang, Yan; Ren, Hejun; Pan, Hongyu; Liu, Jinliang; Zhang, Lanying

2015-04-09

Polychlorinated biphenyls (PCBs) and 2,4-dichlorophenol (2,4-DCP) generally led to mixed contamination of soils as a result of commercial and agricultural activities. Their accumulation in the environment poses great risks to human and animal health. Therefore, the effective strategies for disposal of these pollutants are urgently needed. In this study, genetic engineering to enhance PCBs/2,4-DCP phytoremediation is a focus. We cloned the 2,3-dihydroxybiphenyl-1,2-dioxygenase (BphC.B) from a soil metagenomic library, which is the key enzyme of aerobic catabolism of a variety of aromatic compounds, and then it was expressed in alfalfa driven by CaMV 35S promoter using Agrobacterium-mediated transformation. Transgenic line BB11 was selected out through PCR, Western blot analysis and enzyme activity assays. Its disposal and tolerance to both PCBs and 2,4-DCP were examined. The tolerance capability of transgenic line BB11 towards complex contaminants of PCBs/2,4-DCP significantly increased compared with non-transgenic plants. Strong dissipation of PCBs and high removal efficiency of 2,4-DCP were exhibited in a short time. It was confirmed expressing BphC.B would be a feasible strategy to help achieving phytoremediation in mixed contaminated soils with PCBs and 2,4-DCP. Copyright © 2014 Elsevier B.V. All rights reserved.

Synthesis and characterization of eggshell-derived hydroxyapatite via mechanochemical method: A comparative study

NASA Astrophysics Data System (ADS)

Hamidi, A. A.; Salimi, M. N.; Yusoff, A. H. M.

2017-04-01

The focus of bone graft properties has developed through generations, from the ability to withstand mechanical stress to the ability to integrate with the biological structure. In recent years, the use of hydroxyapatite (HA) as bone graft material in orthopedic and dental applications has been increasing. HA is a natural occuring mineral with excellent bioactivity but relatively poor mechanical properties. It constitutes 96% portion of enamel in teeth and 67% portion of bone. HA can be extracted from animal bones or fabricated from synthetic or biologic sources. In this study, eggshells were used as raw material to synthesize eggshell-derived HA (EHA) via mechanochemical method. The synthesis of EHA involved CaO, which was obtained from the calcination of eggshells, and reaction with dicalcium hydrogen phosphate dihydrous (DCPD) or phosphoric acid (H3PO4). The effects of rotational speed and heat treatment temperature on EHA's characteristics were investigated. The characterization studies were carried out by using the Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD) analysis and Scanning Electron Microscopy (SEM). HA powder was successfully synthesized with crystallite and particle sizes in the range of 8-47 nm and 250-550 nm respectively. It was observed from this study that the increase of milling rotational speed had increased the phase purity of EHA samples. Furthermore, the higher heating temperature of HA samples resulted in higher degree of crystallinity of HA and the appearance of β-tricalcium phosphate (β-TCP) as secondary phase.

Effect of NH4-N/P and Ca/P molar ratios on the reactive crystallization of calcium phosphates for phosphorus recovery from wastewater

NASA Astrophysics Data System (ADS)

Vasenko, Liubov; Qu, Haiyan

2017-02-01

In this work, the effects of operational parameters, initial phosphorus concentration and molar ratios of Ca/P and NH4-N/P (further in the text N/P), on the nature and purity of precipitated phosphorus products have been investigated in an artificial system that mimics the supernatant in wastewater treatment plants. Metastable zone width was determined for two target phosphorus products: DCPD (dicalcium phosphate dihydrate) and HAp (hydroxyapatite) in the range of pH 4.5 - 7. HAp crystallizes at final pH higher than 6.3 while DCPD crystallizes at the final pH in between 4.7 and 5.7. At the final pH 5.7 - 6.3 and at pH lower than 4.7 the mixtures of DCPD and HAp were obtained. It was observed that N/P ratio affects not only the metastable zone width but also the kinetics of crystal growth for both DCPD and HAp: the higher the N/P ratio, the lower is the growth rate for both P-products. Investigation of the effect of Ca/P and N/P ratios on the nucleation and crystal growth of DCPD in batch crystallization experiment was performed. It showed that at high supersaturation level, crystals with larger median size can be obtained at higher N/P ratio despite the negative effects of N/P ratio on the growth rate of the crystals.

76 FR 76711 - DCP Raptor Pipeline, LLC; Notice of Motion for Extension of Rate Case Filing Deadline

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-08

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. PR09-32-003] DCP Raptor..., 2011, DCP Raptor Pipeline, LLC (Raptor) filed a request for an extension consistent with the Commission... pipelines to extend the cycle for such reviews from three to five years.\\1\\ Therefore, Raptor requests that...

Evaluation of a Diabetes Coach Program Aimed to Improve the Care of Children and Youth With Type 1 Diabetes and With Compromised Control.

PubMed

Luca, Paola; Haugrud, Bodiel; Husband, Allison; Dawrant, Jonathan; Pacaud, Danièle

2018-01-31

To evaluate the impact of the Diabetes Coach Program (DCP) on glycated hemoglobin (A1C) levels in youth with type 1 diabetes. The youth were referred to and participated in the DCP between October 2011 and May 2016. The Diabetes Coach visited families in their homes every 1 to 2 weeks and updated patients' diabetes teams regularly. A1C levels before the DCP were compared with A1C levels during and after discharge from the DCP. Six participating families completed satisfaction surveys via telephone. The DCP included 23 participants (43% male; median age, 11 years; range, 8.8 to 14.5 years); median duration of type 1 diabetes, 1.7 years (range, 0.1 to 6.3 years); median time in the DCP, 1.5 years (range, 0.2 to 2.5 years). During involvement in the program, median A1C levels decreased from baselines of 11.1% (range, 8.9% to 15.3%) to 10.2% (range, 7.6% to 12.4%) (p=0.0028). For 11 of 13 patients discharged from the DCP, the most recent median A1C levels, 11.2% (range, 9.1% to 13.6%), an average of 2.4 years later, were not different from the initial A1C levels (p=0.85). Family feedback was overwhelmingly positive. Participation in the DCP decreased A1C values in pediatric patients; however, the levels were not sustained after visits stopped. Pediatric health coaches may play an important role in the management of type 1 diabetes, but further research is needed to explore their benefits and how positive effects can be sustained. Copyright © 2018 Diabetes Canada. Published by Elsevier Inc. All rights reserved.

Digestibility, productive performance, and egg quality of laying hens as affected by dried cassava pulp replacement with corn and enzyme supplementation.

PubMed

Khempaka, Sutisa; Maliwan, Prapot; Okrathok, Supattra; Molee, Wittawat

2018-02-24

Two experiments were conducted to investigate the potential use of dried cassava pulp (DCP) supplemented with enzymes as an alternative feed ingredient in laying hen diets. In experiment 1, 45 laying hens (Isa Brown) aged 45 weeks were placed in individual cages to measure nutrient digestibility for 10 days. Nine dietary treatments were control and DCP as a replacement for corn at 20, 25, 30, and 35% supplemented with mixed enzymes (cellulase, glucanase, and xylanase) at 0.10 and 0.15%. Results showed that the use of DCP at 20-35% added with mixed enzymes had no negative effects on dry matter digestibility, while organic matter digestibility and nitrogen retention decreased with increased DCP up to 30-35% in diets. Both enzyme levels (0.10 and 0.15%) showed similar results on nutrient digestibility and retention. In experiment 2, a total of 336 laying hens aged 32 weeks were randomly allocated to seven dietary treatments (control and DCP-substituted diets at 20, 25, and 30%) supplemented with mixed enzymes (0.10 and 0.15%). Diets incorporated with 20-30% of DCP and supplemented with mixed enzymes at both levels had no significant effects on egg production, egg weight, feed intake, egg mass, feed conversion ratio, protein efficiency ratio, or egg quality, except for egg yolk color being decreased with an increase of DCP in diets (P < 0.05). In conclusion, it is suggested that DCP supplemented with enzymes can be used as an energy source in laying hen diets up to 30% without showing negative effects on nutrient digestibility, productive performance, or egg quality.

Experimental determination of solubilities of di-calcium ethylenediaminetetraacetic acid hydrate [Ca2C10H12N2O8·7H2O(s)] in NaCl and MgCl2 solutions to high ionic strengths and its Pitzer model: Applications to geological disposal of nuclear waste and other low temperature environments

DOE PAGES

Xiong, Yongliang; Kirkes, Leslie; Westfall, Terry

2017-04-01

In this study, solubility measurements on di-calcium ethylenediaminetetraacetic acid [Ca 2C 10H 12N 2O 8(s), abbreviated as Ca 2EDTA(s)] as a function of ionic strength are conducted in NaCl solutions up to I = 5.0 mol•kg –1 and in MgCl 2 solutions up to I = 7.5 mol•kg –1, at room temperature (22.5 ± 0.5oC).

Evaluation of four biodegradable, injectable bone cements in an experimental drill hole model in sheep.

PubMed

von Rechenberg, Brigitte; Génot, Oliver R; Nuss, Katja; Galuppo, Larry; Fulmer, Mark; Jacobson, Evan; Kronen, Peter; Zlinszky, Kati; Auer, Jörg A

2013-09-01

Four cement applications were tested in this investigation. Two dicalcium phosphate dihydrate (DCPD-brushite) hydraulic cements, an apatite hydraulic fiber loaded cement, and a calcium sulfate cement (Plaster of Paris) were implanted in epiphyseal and metaphyseal cylindrical bone defects in sheep. The in vivo study was performed to assess the biocompatibility and bone remodeling of four cement formulations. After time periods of 2, 4, and 6 months, the cement samples were clinically and histologically evaluated. Histomorphometrically, the amount of new bone formation, fibrous tissue, and bone marrow and the area of remaining cement were measured. In all specimens, no signs of inflammation were detectable either macroscopically or microscopically. Cements differed mainly in their resorption time. Calcium sulfate was already completely resorbed at 2 months and showed a variable amount of new bone formation and/or fibrous tissue in the original drill hole over all time periods. The two DCPD cements in contrast were degraded to a large amount at 6 months, whereas the apatite was almost unchanged over all time periods. Copyright © 2013. Published by Elsevier B.V.

78 FR 47313 - DCP Midstream, LP; Notice of Intent To Prepare an Environmental Assessment for the Proposed...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-05

... Commission (FERC or Commission) will prepare an environmental assessment (EA) that will discuss the... by DCP Midstream, LP (DCP) in Weld County, Colorado. The Commission will use this EA in its decision... to evaluate in the EA. Please note that the scoping period will close on August 28, 2013. This notice...

GENOTOXICITY OF 1,3-DICHLOROPROPANE, 2,2-DICHLOROPROPANE, AND L,1-DICHLOROPROPENE IN SALMONELLA AND E. COLI PROPHAGE-INDUCTION ASSAYS

EPA Science Inventory

Genotoxicity of 1,3-Dichloropropane, 2,2-Dichloropropane, and 1,1-Dichloropropene in
Salmonella and E. coli Prophage-Induction Assays

1,3-Dichloropropane (1,3-DCP), 2,2-dichloropropane (2,2-DCP), and 1,1- dichloropropene (I,I-DCP) have been detected in ground water i...

Identification and environmental distribution of dcpA encoding the 1,2-dichloropropane-to-propene reductive dehalogenase in organohalide-respiring Chloroflexi

DOE Office of Scientific and Technical Information (OSTI.GOV)

Padilla-Crespo, Elizabeth; Yan, Jun; Swift, Cynthia M

2014-01-01

Dehalococcoides mccartyi (Dhc) strains KS and RC grow with 1,2-dichloropropane (1,2-D) as an electron acceptor in enrichment cultures derived from hydrocarbon-contaminated and pristine river sediments, respectively. Transcription, expression, enzymatic and PCR analyses implicated the reductive dehalogenase gene dcpA in 1,2-D dichloroelimination to propene and inorganic chloride. Quantitative real-time PCR (qPCR) analyses demonstrated Dhc cell increase during growth with 1,2-D and suggested that both Dhc strains carried a single dcpA gene copy per genome. Dhc strain RC and strain KS produced 1.8 0.1 x 107 and 1.4 0.5 x 107 cells per mole of propene formed, respectively. The dcpA gene wasmore » identified in 1,2-D-to-propene-dechlorinating microcosms established with sediment samples collected from different geographical locations in Europe and North and South America. Clone library analysis revealed two distinct dcpA phylogenetic clusters, both of which the dcpA gene-targeted qPCR assay captured, suggesting the qPCR assay is useful for site assessment and bioremediation monitoring at 1,2-D-contaminated sites.« less

The use of used automobile tyres in a partitioning bioreactor for the biodegradation of xenobiotic mixtures.

PubMed

Tomeia, M Concetta; Angeluccia, Domenica Mosca; Daugulis, Andrew J

2014-01-01

Waste tyres were utilized as the sorption phase in a two-phase partitioning bioreactor (TPPB) for the biodegradation of a binary mixture of 2,4-dichlorophenol (DCP) and 4-nitrophenol (4NP). These compounds are extensively used in the chemical industry and are found in many industrial effluents. Although both compounds are toxic and are on the EPA list of priority pollutants, a higher inhibitory effect on microorganisms is exerted by DCP, and our experimental tests were focused on strategies to reduce its negative impact on microbial activity. Sorption/desorption tests for the DCP-4NP mixture were first performed to verify the related uptake/release rates by the tyres, which showed that the tyres had a higher capacity for DCP uptake and practically no affinity for 4NP. An acclimatized mixed culture was then utilized in a sequencing batch reactor (SBR) operated in conventional and two-phase mode. For the binary DCP-4NP mixture a significant reduction in DCP toxicity, and a concomitant enhancement in substrate removal efficiency (up to 83%for DCP and approximate 100% for 4NP) were clearly seen for the TPPB operated with 10% and 15% v/v tyres, for influent concentrations up to 180 mg/L, with practically negligible biodegradation in the conventional single phase reactor. The long-term utilization of tyres was confirmed at an influent loading of 180 mg/L with a test performed over 20 work cycles showing an improvement of the removal performance for both compounds.

GENOTOXICITY OF 1,3-DICHLOROPROPANE, 2,2-DICHLOROPROPANE, AND 1,1-DICHLOROPROPENE IN SALMONELLA, THE E. COLI PROPHAGE-INDUCTION ASSAY, AND HUMAN HEPH2 CELLS

EPA Science Inventory

Genotoxicity of 1,3-Dichloropropane, 2,2-Dichloropropane, and 1,1-Dichloropropene in Salmonella, the E. coli Prophage-Induction Assay and Human HepG2 Cells

1,3-Dichloropropane (1,3-DCP), 2,2-dichloropropane (2,2-DCP), and 1,1- dichloropropene ( 1,1- DCP) have been detecte...

Reducing mineral usage in feedlot diets for Nellore cattle: II. Impacts of calcium, phosphorus, copper, manganese, and zinc contents on intake, performance, and liver and bone status.

PubMed

Prados, L F; Sathler, D F T; Silva, B C; Zanetti, D; Valadares Filho, S C; Alhadas, H M; Detmann, E; Santos, S A; Mariz, L D S; Chizzotti, M L

2017-04-01

Weaned Nellore bulls ( = 36; 274 ± 34 kg) were used in a randomized block design with a 2 × 2 factorial arrangement of treatments to evaluate intake, fecal excretion, and performance with different concentrations of minerals. Experimental diets were formulated with 2 concentrations of Ca and P (macromineral factor; diet supplying 100% of Ca and P according to BR-CORTE () [CaP+] or diet without limestone and dicalcium phosphate [CaP-]) and 2 concentrations of microminerals (micromineral factor; diet with supplementation of microminerals [Zn, Mn, and Cu; CuMnZn+] or diet without supplementation of microminerals [Zn, Mn, and Cu; CuMnZn-]). The factor CaP- was formulated without the addition of limestone and dicalcium phosphate, and the factor CuMnZn- was formulated without inorganic supplementation of microminerals (premix). The diets were isonitrogenous (13.3% CP). Intake was individually monitored every day. Indigestible NDF was used as an internal marker for digestibility estimates. The bulls were slaughtered (84 or 147 d on feed), and then carcass characteristics were measured and liver and rib samples were collected. Feed, feces, rib bones, and liver samples were analyzed for DM, ash, CP, ether extract (EE), Ca, P, Zn, Mn, and Cu. There were no significant interactions ( ≥ 0.06) between macro- and micromineral supplementation for any variables in the study. Calcium, P, and micromineral concentrations did not affect ( ≥ 0.20) intake of DM, OM, NDF, EE, CP, TDN, and nonfiber carbohydrates (NFC). Calcium and P intake were affected ( < 0.01) by macromineral factor. Animals fed without Ca and P supplementation consumed less of these minerals. Dry matter and nutrient fecal excretion (OM, NDF, EE, CP, and NFC) were similar ( ≥ 0.23) among all factors. Performance and carcass characteristics were similar ( ≥ 0.09) among diets. The content of ash in rib bones was not affected by diets ( ≥ 0.06). Plasma P and phosphatase alkaline concentrations were similar ( ≥ 0.52) among diets. Supplementation of microminerals decreased ( < 0.01) plasma Ca concentration; nevertheless, all analyzed blood metabolites were within the reference values. Supplementation of Ca and P increased ( < 0.01) fecal excretion of these minerals. These results indicate that mineral supplementation (Ca, P, Zn, Mn, and Cu) of conventional feedlot diets for Nellore bulls may be not necessary. Dietary reductions in these minerals would represent a decrease in the cost of feedlot diets. Dietary reduction in Ca and P content cause a decrease in fecal excretion of these minerals, which, in turn, represents an opportunity to reduce the environmental impact of feedlot operations.

1,3-Dichloro-2-propanol inhibits progesterone production through the expression of steroidogenic enzymes and cAMP concentration in Leydig cells.

PubMed

Sun, Jianxia; Bai, Shun; Bai, Weibin; Zou, Feiyan; Zhang, Lei; Li, Guoqiang; Hu, Yunfeng; Li, Mingwei; Yan, Rian; Su, Zhijian; Huang, Yadong

2014-07-01

1,3-Dichloro-2-propanol (1,3-DCP) is a well-known food processing contaminant that has been shown to impede male reproductive function. However, its mechanism of action remains elusive. In this study, the effects of 1,3-DCP on progesterone production were investigated using the R2C Leydig cell model. 1,3-DCP significantly reduced cell viability from 7.48% to 97.4% at doses comprised between 0.5 and 6mM. Single cell gel/comet assays and atomic force microscopy assays showed that 1,3-DCP induced early phase cell apoptosis. In addition, 1,3-DCP significantly reduced progesterone production detected by radioimmunoassay (RIA). The results from quantitative polymerase chain reaction and western blotting demonstrated that the mRNA expression levels of steroidogenic acute regulatory protein (StAR), cytochrome P450 side-chain cleavage enzyme and 3β-hydroxysteroid dehydrogenase were significantly down-regulated in R2C cells. Particularly, the change rhythm of Star expression was highly consistent with progesterone production. Furthermore, the cyclic adenosine monophosphate (cAMP) and the mitochondrial membrane potential mediated by ROS, which are involved in regulating progesterone synthesis were also decreased in response to the 1,3-DCP treatment. Overall, the data presented here suggested that 1,3-DCP interferes with the male steroidogenic capacity mainly by down-regulating the level of cAMP and the key enzymes involved in the androgen synthesis pathway. Copyright © 2014 Elsevier Ltd. All rights reserved.

Urinary concentrations of dichlorophenol pesticides and obesity among adult participants in the U.S. National Health and Nutrition Examination Survey (NHANES) 2005-2008.

PubMed

Wei, Yudan; Zhu, Jianmin; Nguyen, An

2014-03-01

Accumulating evidence from recent studies has suggested a possible link between exposure to environmental pesticides and obesity. In this study, we assessed the potential associations between exposure to dichlorophenol pesticides and obesity in adults. Study participants aged 20-85 years were selected from the 2005 to 2006 and 2007 to 2008 U.S. National Health and Nutrition Examination Survey, and were categorized as obese and non-obese based on body mass index. Creatinine-corrected urinary concentrations of dichlorophenols were determined to assess level of exposure to environmental pesticides. Multivariate logistic regression was performed using SAS 9.3 to assess the association between 2,4-dichlorophenol (2,4-DCP) and 2,5-dichlorophenol (2,5-DCP) levels in urine and obesity with adjustment for potential confounders. Significantly higher geometric means of urinary concentrations of both 2,5-DCP (p<0.0001) and 2,4-DCP (p=0.0170) were seen in obese adults, compared to that in non-obese adults. A dose-dependent increase in the prevalence of obesity was observed in the study participants across increasing levels of urinary 2,5-DCP (p-trend<0.0001). Urinary concentrations of 2,5-DCP were significantly associated with obesity among the second (AOR: 1.47, 95% CI: 1.12, 1.93), third (AOR: 1.41, 95% CI: 1.07, 1.87), and fourth (AOR: 1.62, 95% CI: 1.21, 2.17) inter-quartiles after adjustment for age, gender, race, education, total fat intake, and physical activity. A statistically significant association was not seen between urinary 2,4-DCP and obesity. Our findings suggest a potential relationship between exposure to the fumigant insecticide paradichlorobenzene, measured as urinary concentrations of 2,5-DCP, and obesity in adults. Because we cannot rule out the possibility of reverse causality in our study, prospective studies measuring exposure during etiologically relevant periods are warranted. Copyright © 2013 Elsevier GmbH. All rights reserved.

Formation of Epichlorohydrin, a Known Rodent Carcinogen, Following Oral Administration of 1,3-Dichloro-2-propanol in Rats

PubMed Central

2015-01-01

The observed toxicity and carcinogenicity of 1,3-dichloro-2-propanol (DCP) in rodents is thought to be due to the formation of reactive metabolites, epichlorohydrin (ECH) and dichloroacetone (DCA). However, there is no direct evidence for the formation of these metabolites from exposure to DCP in rodents due to the challenges of measuring these reactive intermediates directly in vivo. The objective of this work was to investigate the metabolism of DCP to ECH and DCA in vivo by first developing a sensitive analytical method in a suitable biological matrix and analyzing samples from rats administered DCP. DCA reacted rapidly in vitro in rat blood, plasma, and liver homogenate, precluding its detection. Because ECH rapidly disappeared in liver homogenate, but was relatively long-lived in plasma and blood in vitro, blood was selected for analysis of this metabolite. Following a single oral dose of 50 mg/kg DCP in male or female Harlan Sprague–Dawley rats, ECH was detected in blood with a maximum concentration reached at ≤13.7 min. ECH was cleared rapidly with a half-life of ca. 33 and 48 min in males and females, respectively. Following a single oral dose of 25 mg/kg ECH in male and female rats, the elimination half-life of ECH was ca. 34 and 20 min, respectively; the oral bioavailability of ECH was low (males, 5.2%; females, 2.1%), suggesting extensive first pass metabolism of ECH following oral administration. The area under the concentration vs time curve for ECH following oral administration of DCP and intravenous administration of ECH was used to estimate the percent of the DCP dose converted to ECH in rats. On the basis of this analysis, we concluded that in male and female rats following oral administration of 50 mg/kg DCP, ≥1.26% or ≥1.78% of the administered dose was metabolized to ECH, respectively. PMID:25254956

Effects of neutral sodium hydrogen phosphate on setting reaction and mechanical strength of hydroxyapatite putty.

PubMed

Ishikawa, K; Miyamoto, Y; Takechi, M; Ueyama, Y; Suzuki, K; Nagayama, M; Matsumura, T

1999-03-05

The setting reaction and mechanical strength in terms of diametral tensile strength (DTS) of hydroxyapatite (HAP) putty made of tetracalcium phosphate, dicalcium phosphate anhydrous, and neutral sodium hydrogen phosphate (Na1.8H1.2PO4) solution containing 8 wt % sodium alginate were evaluated as a function of the Na1.8H1.2PO4 concentration. In one condition, HAP putty was placed in an incubator kept at 37 degrees C and 100% relative humidity. In the other condition, immediately after mixing HAP putty was immersed in serum kept at 37 degrees C. Longer setting times and lower DTS values were observed when HAP putty was immersed in serum regardless of the Na1.8H1.2PO4 concentration. The setting times of the HAP putty in both conditions became shorter with an increase in the Na1. 8H1.2PO4 concentration, reaching approximately 7-13 min when the Na1. 8H1.2PO4 concentration was 0.6 mol/L or higher. The DTS value of HAP putty was relatively constant (10 MPa) regardless of the Na1.8H1. 2PO4 concentration (0.2-1.0 mol/L) when HAP putty was kept in an incubator. In contrast, when HAP putty was immersed in serum, the DTS value was dependent on the Na1.8H1.2PO4 concentration. It increased with the Na1.8H1.2PO4 concentration and reached approximately 5 MPa when the Na1.8H1.2PO4 concentration was 0.6 mol/L, after which it showed a relatively constant DTS value. We therefore would recommend a HAP putty that uses 0.6 mol/L Na1.8H1. 2PO4 since at that concentration the putty's setting time (approximately 10 min) is proper for clinical use and it shows good DTS value (approximately 5 MPa) even when it is immersed in serum immediately after mixing. Copyright 1999 John Wiley & Sons, Inc.

Calcium phosphate deposition rate, structure and osteoconductivity on electrospun poly(l-lactic acid) matrix using electrodeposition or simulated body fluid incubation

PubMed Central

He, Chuanglong; Jin, Xiaobing; Ma, Peter X.

2013-01-01

Mineralized nanofibrous scaffolds have been proposed as promising scaffolds for bone regeneration due to their ability to mimic both nanoscale architecture and chemical composition of natural bone extracellular matrix (ECM). In this study, a novel electrodeposition method was compared with an extensively explored simulated body fluid (SBF) incubation method in terms of the deposition rate, chemical composition, and morphology of calcium phosphate formed on electrospun fibrous thin matrices with a fiber diameter in the range from about 200 nm to about 1400 nm prepared using 6, 8, 10 and 12 wt% poly(l-lactic acid) (PLLA) solutions in a mixture of dichloromethane and acetone (2:1 in volume). The effects of the surface modification using the two mineralization techniques on osteoblastic cell (MC3T3-E1) proliferation and differentiation were also examined. It was found that electrodeposition was two to three orders of magnitude faster than the SBF method in mineralizing the fibrous matrices, reducing the mineralization time from about two weeks to an hour to achieve the same amounts of mineralization. The mineralization rate also varied with the fiber diameter but in opposite directions between the two mineralization methods. As a general trend, the increase of fiber diameter resulted in a faster mineralization rate for the electrodeposition method but a slower mineralization rate for the SBF incubation method. Using the electrodeposition method, one can control the chemical composition and morphology of the calcium phosphate by varying the electric deposition potential and electrolyte temperature to tune the mixture of dicalcium phosphate dihydrate (DCPD) and hydroxy apatite (HAp). Using the SBF method, one can only obtain a low crystallinity HAp. The mineralized electrospun PLLA fibrous matrices from either method similarly facilitate the proliferation and osteogenic differentiation of preosteoblastic MC3T3-E1 cells as compared to neat PLLA matrices. Therefore, the electrodeposition method can be utilized as a fast and versatile technique to fabricate mineralized nanofibrous scaffolds for bone tissue engineering. PMID:24012605

A Degradome-Based Polymerase Chain Reaction to Resolve the Potential of Environmental Samples for 2,4-Dichlorophenol Biodegradation.

PubMed

Ibrahim, Eslam S; Kashef, Mona T; Essam, Tamer M; Ramadan, Mohammed A

2017-12-01

A clean way to overcome environmental pollution is biodegradation. In this perspective, at the intersection of biodegradation and metagenomics, the degradome is defined as the totality of genes related to the biodegradation of a certain compound. It includes the genetic elements from both culturable and uncultured microorganisms. The possibility of assessing the biodegradation potential of an environmental samples, using a degradome-based polymerase chain reaction, was explored. 2,4-Dichlorophenol (2,4-DCP) was chosen as a model and the use of tfdB gene as a biodegradation marker was confirmed by bioinformatics study of TfdB protein. Five primer pairs were designed for the detection of different tfdB gene families. A total of 16 environmental samples were collected from Egyptian agricultural soils and wastewaters and tested for the presence of 2,4-DCP. The biodegradation capacity of 2,4-DCP was determined, for all isolated consortia, to reach up to 350 mg/l. Metagenomic DNA was extracted directly from the soil samples while successive 2,4-DCP-degrading microbial communities were enriched, with increasing concentrations of 2,4-DCP, then their DNA was extracted. The extracted DNA was tested for the distribution of the tfdB gene using a degradome-based polymerase chain reaction. tfdB-1 and tfdB-2 were detected in 5 and 9 samples, respectively. However, the co-existence of both genes was detected only in five samples. All tfdB positive samples were capable of 2,4-DCP degradation. The developed approach of assessing the potential of different environments for degrading 2,4-DCP was successfully measured in terms of accuracy (81.25%) and specificity (100%).

Acylhydrazone bond dynamic covalent polymer gel monolithic column online coupling to high-performance liquid chromatography for analysis of sulfonamides and fluorescent whitening agents in food.

PubMed

Zhang, Chengjiang; Luo, Xialin; Wei, Tianfu; Hu, Yufei; Li, Gongke; Zhang, Zhuomin

2017-10-13

A new dynamic covalent polymer (DCP) gel was well designed and constructed based on imine chemistry. Polycondensation of 4,4'-biphenyldicarboxaldehyde and 1,3,5-benzenetricarbohydrazide via Schiff-base reaction resulted in an acylhydrazone bond gel (AB-gel) DCP. AB-gel DCP had three-dimensional network of interconnected nanoparticles with hierarchically porous structure. AB-gel DCP was successfully fabricated as a monolithic column by an in-situ chemical bonding method for online enrichment and separation purpose with excellent permeability. AB-gel DCP based monolithic column showed remarkable adsorption affinity towards target analytes including sulfonamides (SAs) and fluorescent whitening agents (FWAs) due to its strong π-π affinity, hydrophobic effect and hydrogen bonding interaction. Then, AB-gel DCP based monolithic column was applied for online separation and analysis of trace SAs and FWAs in food samples coupled with high-performance liquid chromatography (HPLC). Sulfathiazole (ST) and sulfadimidine (SM2) in one positive weever sample were actually found and determined with concentrations of 273.8 and 286.3μg/kg, respectively. 2,5-Bis(5-tert-butyl-2-benzoxazolyl) thiophene (FWA184) was actually quantified in one tea infusion sample with the concentration of 268.5ng/L. The spiked experiments suggested the good recoveries in range of 74.5-110% for SAs in weever and shrimp samples with relative standard deviations (RSDs) less than 9.7% and in range of 74.0-113% for FWAs in milk and tea infusion samples with RSDs less than 9.0%. AB-gel DCP monolithic column was proved to be a promising sample preparation medium for online separation and analysis of trace analytes in food samples with complex matrices. Copyright © 2017 Elsevier B.V. All rights reserved.

Deep Retinal Capillary Nonperfusion Is Associated With Photoreceptor Disruption in Diabetic Macular Ischemia.

PubMed

Scarinci, Fabio; Nesper, Peter L; Fawzi, Amani A

2016-08-01

To report outer retinal structural changes associated with macular capillary nonperfusion at the level of deep capillary plexus (DCP) in diabetic patients. Prospective observational cross-sectional study. The study included 14 eyes of 10 patients who were diagnosed as having diabetic retinopathy. To study the outer retina and localize areas of capillary nonperfusion at the superficial (SCP) or DCP, we used the spectral-domain optical coherence tomography (SDOCT) device (RTVue-XR Avanti; Optovue Inc, Fremont, California, USA) with split-spectrum amplitude-decorrelation angiography (SSADA) software for optical coherence tomography angiography (OCTA). Two independent masked graders (F.S. and A.A.F.) qualitatively evaluated SDOCT scans as either normal or having outer retina disruption. The angiographic images were examined to define the presence and location of capillary nonperfusion. Eight eyes showed outer retinal disruption on SDOCT that co-localized to areas of enlarged foveal avascular zone, areas of no flow between capillaries, and capillary nonperfusion of the DCP. Six eyes without outer retinal changes on SDOCT showed robust perfusion of the DCP. Using OCTA, this study shows that macular photoreceptor disruption on SDOCT in patients with diabetic retinopathy corresponds to areas of capillary nonperfusion at the level of the DCP. This is important in highlighting the contribution of the DCP to the oxygen requirements of the photoreceptors as well as the outer retina in diabetic macular ischemia. Copyright © 2016 Elsevier Inc. All rights reserved.

Dry mechanochemical synthesis of hydroxyapatites from DCPD and CaO: influence of instrumental parameters on the reaction kinetics.

PubMed

Mochales, Carolina; El Briak-BenAbdeslam, Hassane; Ginebra, Maria Pau; Terol, Alain; Planell, Josep A; Boudeville, Philippe

2004-01-01

Mechanochemistry is a possible route to synthesize calcium deficient hydroxyapatite (CDHA) with an expected molar calcium-to-phosphate (Ca/P) ratio +/-0.01. To optimize the experimental conditions of CDHA preparation from dicalcium phosphate dihydrate (DCPD) and calcium oxide by dry mechanosynthesis reaction, we performed the kinetic study varying some experimental parameters. This kinetic study was carried out with two different planetary ball mills (Retsch or Fritsch Instuments). Results obtained with the two mills led to the same conclusions although the values of the rate constants of DCPD disappearance and times for complete reaction were very different. Certainly, the origin of these differences was from the mills used, thus we investigated the influence of instrumental parameters such as the mass and the surface area of the balls or the rotation velocity on the mechanochemical reaction kinetics of DCPD with CaO. Results show that the DCPD reaction rate constant and the inverse of the time for complete disappearance of CaO both vary linearly with (i) the square of the rotation velocity, (ii) the square of eccentricity of the vial on the rotating disc and (iii) the product of the mass by the surface area of the balls. These observations comply with theoretical models developed for mechanical alloying. The consideration of these four parameters allows the transposition of experimental conditions from one mill to another or the comparison between results obtained with different planetary ball mills. These instrumental parameters have to be well described in papers concerning mechanochemistry or when grinding is an important stage in a process.

Segmental Bone Regeneration Using a Load Bearing Biodegradable Carrier of Bone Morphogenetic Protein-2

PubMed Central

Chu, Tien-Min G.; Warden, Stuart J.; Turner, Charles H.; Stewart, Rena L.

2006-01-01

Segmental defect regeneration has been a clinical challenge. Current tissue engineering approach using porous biodegradable scaffolds to delivery osteogenic cells and growth factors demonstrated success in facilitating bone regeneration in these cases. However, due to the lack of mechanical property, the porous scaffolds were evaluated in non-load bearing area or were stabilized with stress-shielding devices (bone plate or external fixation). In this paper, we tested a scaffold that does not require a bone plate because it has sufficient biomechanical strength. The tube-shaped scaffolds were manufactured from poly(propylene) fumarate/tricalcium phosphate (PPF/TCP) composites. Dicalcium phosphate dehydrate (DCPD) were used as bone morphogenetic protein -2 (BMP-2) carrier. Twenty two scaffolds were implanted in 5 mm segmental defects in rat femurs stabilized with k-wire for 6 and 15 weeks with and without 10 μg of rhBMP-2. Bridging of the segmental defect was evaluated first radiographically and was confirmed by histology and micro- computer tomography (μ-CT) imaging. The scaffolds in the BMP group maintained the bone length throughout the duration of the study and allow for bridging. The scaffolds in the control group failed to induce bridging and collapsed at 15 weeks. Peripheral computed tomography (pQCT) showed that BMP-2 does not increase the bone mineral density in the callus. Finally, the scaffold in BMP group was found to restore the mechanical property of the rat femur after 15 weeks. Our results demonstrated that the load-bearing BMP-2 scaffold can maintain bone length and allow successfully regeneration in segmental defects. PMID:16996588

In vitro study of root fracture treated by CO2 laser and DP-bioactive glass paste.

PubMed

Wang, Yin-Lin; Lee, Bor-Shiunn; Tseng, Ching-Li; Lin, Feng-Huei; Lin, Chun-Pin

2008-01-01

An ideal material has yet to be discovered that can successfully treat vertical root fracture. Therefore, the purpose of this study was to use a continuous-wave CO2 laser of medium-energy density to fuse DP-bioactive glass paste (DPGP) to vertical root fracture. The DP-bioglass powder was based on a Na2O-CaO-SiO2-P2O5 system and it was mixed with phosphoric acid (65% concentration) with a powder/liquid ratio of 2 g/4 mL to form DPGP. The interaction of DPGP and dentin was analyzed by means of X-ray diffractometer (XRD) and differential thermal analysis/thermogravimetric analysis (DTA/TGA). Root fracture line was filled with DPGP followed by CO2 laser irradiation and the result was examined by scanning electron microscopy (SEM). The main crystal phase of DPGP was monocalcium phosphate monohydrate (Ca(H2PO4)2.H2O) and the phase transformed to dicalcium phosphate dihydrate (CaHPO4.2H2O) after mixing DPGP with dentin powder (DPG-D). Additionally, gamma-Ca2P2O7 and beta-Ca2P2O7 were identified when DPG-D was lased by CO2 laser. The reaction temperature was between 500 degrees C and 1100 degrees C. SEM results demonstrated that the fracture line was effectively sealed by DPGP. The chemical reaction of DPGP and dentin indicated that DPGP combined with CO2 laser is a potential regimen for the treatment of vertical root fracture.

Molecular Imprinted Polymer of Methacrylic Acid Functionalised β-Cyclodextrin for Selective Removal of 2,4-Dichlorophenol

PubMed Central

Surikumaran, Hemavathy; Mohamad, Sharifah; Sarih, Norazilawati Muhamad

2014-01-01

This work describes methacrylic acid functionalized β-cyclodextrin (MAA-βCD) as a novel functional monomer in the preparation of molecular imprinted polymer (MIP MAA-βCD) for the selective removal of 2,4-dichlorophenol (2,4-DCP). The polymer was characterized using Fourier Transform Infrared (FTIR) spectroscopy, Brunauer-Emmett-Teller (BET) and Field Emission Scanning Electron Microscopy (FESEM) techniques. The influence of parameters such as solution pH, contact time, temperature and initial concentrations towards removal of 2,4-DCP using MIP MAA-βCD have been evaluated. The imprinted material shows fast kinetics and the optimum pH for removal of 2,4-DCP is pH 7. Compared with the corresponding non-imprinted polymer (NIP MAA-βCD), the MIP MAA-βCD exhibited higher adsorption capacity and outstanding selectivity towards 2,4-DCP. Freundlich isotherm best fitted the adsorption equilibrium data of MIP MAA-βCD and the kinetics followed a pseudo-second-order model. The calculated thermodynamic parameters showed that adsorption of 2,4-DCP was spontaneous and exothermic under the examined conditions. PMID:24727378

Evaluation of automated serum des-gamma-carboxyprothrombin (DCP) assays for detecting hepatocellular carcinoma.

PubMed

Choi, Jonghyeon; Park, Yongjung; Kim, Jeong-Ho; Kim, Hyon-Suk

2011-12-01

We evaluated two new autoanalyzers, μTAS and Lumipulse for des-γ-carboxyprothrombin (DCP) assay. Analytical performance was evaluated, and the upper reference limit of the 97.5th percentile for DCP was re-established using sera from 140 healthy individuals. DCP levels were determined by the two autoanalyzers and EIA in a total of 239 sera from HCC patients (n=120) and those without HCC (n=119). Total imprecision of the two automated assays was <5% CV. Analytical measurement ranges (AMRs) were verified to be linear. The new reference limits were 29.5 mAU/mL for μTAS and 35.0 mAU/mL for Lumipulse. There were proportional and constant biases between the results from the autoanalyzers and those from EIA. The two newly developed DCP assays showed high analytical performance, but re-establishment of reference limits would be necessary. The new analyzers could be useful for clinical laboratories because of convenience of operation and wide AMRs. Copyright © 2011 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

The C-terminal region of Ge-1 presents conserved structural features required for P-body localization.

PubMed

Jinek, Martin; Eulalio, Ana; Lingel, Andreas; Helms, Sigrun; Conti, Elena; Izaurralde, Elisa

2008-10-01

The removal of the 5' cap structure by the DCP1-DCP2 decapping complex irreversibly commits eukaryotic mRNAs to degradation. In human cells, the interaction between DCP1 and DCP2 is bridged by the Ge-1 protein. Ge-1 contains an N-terminal WD40-repeat domain connected by a low-complexity region to a conserved C-terminal domain. It was reported that the C-terminal domain interacts with DCP2 and mediates Ge-1 oligomerization and P-body localization. To understand the molecular basis for these functions, we determined the three-dimensional crystal structure of the most conserved region of the Drosophila melanogaster Ge-1 C-terminal domain. The region adopts an all alpha-helical fold related to ARM- and HEAT-repeat proteins. Using structure-based mutants we identified an invariant surface residue affecting P-body localization. The conservation of critical surface and structural residues suggests that the C-terminal region adopts a similar fold with conserved functions in all members of the Ge-1 protein family.

The simultaneous separation and determination of chloropropanols in soy sauce and other flavoring with gas chromatography-mass spectrometry in negative chemical and electron impact ionization modes.

PubMed

Xu, Xiaomin; Ren, Yiping; Wu, Pinggu; Han, Jianlong; Shen, Xianghong

2006-02-01

Both gas chromatography-mass spectrometry in electron ionization (GC-MS-EI) and negative chemical ionization (GC-MS-NCI) modes are reported in this paper for the simultaneous determination of 1,3-dichloropropan-2-ol (1,3-DCP), 2,3-dichloropropan-1-ol (2,3-DCP), 3-chloropropane-1,2-diol (3-MCPD) and 2-chloropropane-1,3-diol (2-MCPD) in soy sauce and other flavoring. D(5)-3-MCPD (for 3-MCPD and 2-MCPD) and d(5)-1,3-DCP (for 1,3-DCP and 2,3-DCP) were used as the deuterium isotopic labelled internal standards. The feasibility of using heptafluorobutyric anhydride modified with triethylamine (HFBA-Et(3)N) as a new derivatization reagent to replace heptafluorobutyrylimidazole (HFBI) is proposed. Liquid/liquid extraction with hexane was introduced for high lipid content samples. A small survey was carried out of soy sauces (103 samples) and instant noodles (45 samples) and the applicability of GC-MS-NCI and GC-MS-EI was assessed in these different matrices.

Water survey of Canada: Application for use of ERTS-A for retransmission of water resources data

NASA Technical Reports Server (NTRS)

Halliday, R. A. (Principal Investigator); Reid, I. A.

1974-01-01

The author has identified the following significant results. Water resources data were retransmitted from nine data collection platforms (DCP) located in remote regions of Canada. The DCPs located in the Arctic operated in temperatures lower than -40 C and the DCP antennas have survived wind speeds of greater than 80 kph and snow loads of a depth of one metre. Ice-out indicators were installed at a few DCP sites. The purpose of these indicators was to enable the detection of the movement of ice out of river channel during spring break-up. The suitability of satellite retransmission as a means of obtaining data from remote areas of Canada continues to be demonstrated. A modest expansion of the DCP network is planned.

Permeable reactive barrier of coarse sand-supported zero valent iron for the removal of 2,4-dichlorophenol in groundwater.

PubMed

Gao, Weichun; Zhang, Yongxiang; Zhang, Xiaoye; Duan, Zhilong; Wang, Youhao; Qin, Can; Hu, Xiao; Wang, Hao; Chang, Shan

2015-11-01

In this study, coarse sand-supported zero valent iron (ZVI) composite was synthesized by adding sodium alginate to immobilize. Composite was detected by scanning electron microscope (SEM), X-ray diffraction (XRD), and X-ray fluorescence (XRF). SEM results showed that composite had core-shell structure and a wide porous distribution pattern. The synthesized composite was used for degradation of 2,4-dichlorophenol (2,4-DCP) contamination in groundwater. Experimental results demonstrated that degradation mechanism of 2,4-DCP using coarse sand-supported ZVI included adsorption, desorption, and dechlorination. 2,4-DCP adsorption was described as pseudo-second-order kinetic model. It was concluded that dechlorination was the key reaction pathway, ZVI and hydrogen are prime reductants in dechlorination of 2,4-DCP using ZVI.

Kinetic of carbonaceous substrate in an upflow anaerobic sludge sludge blanket (UASB) reactor treating 2,4 dichlorophenol (2,4 DCP).

PubMed

Sponza, Delia Teresa; Uluköy, Ayşen

2008-01-01

The performance of an upflow anaerobic sludge blanket (UASB) reactor treating 2,4 dichlorophenol (2,4 DCP) was evaluated at different hydraulic retention times (HRTs) using synthetic wastewater in order to obtain the growth substrate (glucose-COD) and 2,4 DCP removal kinetics. Treatment efficiencies of the UASB reactor were investigated at different hydraulic retention times (2-20 h) corresponding to a food to mass (F/M) ratio of 1.2-1.92 g-COD g(-1) VSS day(-1). A total of 65-83% COD removal efficiencies were obtained at HRTs of 2-20 h. In all, 83% and 99% 2,4 DCP removals were achieved at the same HRTs in the UASB reactor. Conventional Monod, Grau Second-order and Modified Stover-Kincannon models were applied to determine the substrate removal kinetics of the UASB reactor. The experimental data obtained from the kinetic models showed that the Monod kinetic model is more appropriate for correlating the substrate removals compared to the other models for the UASB reactor. The maximum specific substrate utilization rate (k) (mg-COD mg(-1) SS day(-1)), half-velocity concentration (K(s)) (mg COD l(-1)), growth yield coefficient (Y) (mg mg(-1)) and bacterial decay coefficient (b) (day(-1)) were 0.954 mg-COD mg(-1) SS day(-1), 560.29 mg-COD l(-1), 0.78 mg-SS g(-1)-COD, 0.093 day(-1) in the Conventional Monod kinetic model. The second-order kinetic coefficient (k(2)) was calculated as 0.26 day(-1) in the Grau reaction kinetic model. The maximum COD removal rate constant (U(max)) and saturation value (K(B)) were calculated as 7.502 mg CODl(-1)day(-1) and 34.56 mg l(-1)day(-1) in the Modified Stover-Kincannon Model. The (k)(mg-2,4 DCP mg(-1) SS day(-1)), (K(s)) (mg 2,4 DCPl(-1)), (Y) (mg SS mg(-1) 2,4 DCP) and (k(d)) (day(-1)) were 0.0041 mg-2,4 DCP mg(-1) SS day(-1), 2.06 mg-COD l(-1), 0.0017 mg-SS mg(-1) 2,4 DCP and 3.1 x 10(-5) day(-1) in the Conventional Monod kinetic model for 2,4 DCP degradation. The second-order kinetic coefficient (k(2)) was calculated as 0.30 day(-1) in the Grau reaction kinetic model. The maximum 2,4 DCP removal rate constant (U(max)) and saturation value (K(B)) were calculated as 0.01 mg COD l(-1) day(-1) and 9.8 x 10(-3) mg l(-1) day(-1) in the Modified Stover-Kincannon model.

Flexible DCP interface. [signal conditioning system for use with Kansas environmental sensors

NASA Technical Reports Server (NTRS)

Kanemasu, E. T. (Principal Investigator); Schimmelpfenning, H.

1974-01-01

The author has identified the following significant results. A user of an ERTS data collection system must supply the sensors and signal conditioning interface. The electronic interface must be compatible with the NASA-furnished data collection platform (DCP). A universal signal conditioning system for use with a wide range of environmental sensors is described. The interface is environmentally and electronically compatible with the DCP and has operated satisfactorily for a complete winter wheat growing season in Kansas.

Diagnostic utility of alpha-fetoprotein and des-gamma-carboxyprothrombin in nigerians with hepatocellular carcinoma.

PubMed

Ette, Akpakip Ikpong; Ndububa, D A; Adekanle, O; Ekrikpo, U

2017-10-01

Alpha-fetoprotein (AFP) and Des-gamma-carboxyprothrombin (DCP) have been extensively studied as biomarkers for the diagnosis of and prognostication in hepatocellular carcinoma (HCC). However there are only few reports on the clinical characteristics of hepatocellular carcinoma in relation to the combination of the two tumor markers in hepatitis B virus-related HCC. The aim of this study was to investigate the clinical characteristics of HBV-related HCC in relation to different sets of AFP and DCP values. Sixty-two patients with untreated HCC were studied. The positive value of AFP was set at 20 1U/L while DCP positive value was set at 150 mAU/ml. Patients were divided into three groups: Group 1(n=36) with AFP ≥ 20 IU/L and DCP ≥ 150 mAU/ml. Group 2(n=24) with AFP <20 1U/L and DCP ≥ 150 mAU/ml. Group 3 (n=2) with AFP < 20 1U/L and DCP < 150 mAU/ml. There were no patients in group 4 meant for those with AFP ≥ 20 1U/L and DCP < 150 mAU/ml. Clinical and laboratory variables were compared among the groups. Clinical and laboratory variables were comparable among the groups with the exception of gender and values of serum alanine aminotransferase (ALT). Males were significantly more than females among the groups (p<0.03). ALT values were significantly different among the groups (p<0.006). Paired comparisons between the groups showed the mean values of serum ALT were significantly higher in group 2 than in group 1(p<0.003). The mean serum ALT values were also higher in group 2 than in group 3 (p <0.014). There was no significant difference between group 1 and group 3 (P = 0.124). HCC patients who are sero-positive for DCP and sero-negative for AFP have significantly higher levels of serum ALT; serum ALT levels may be of diagnostic importance in AFP-negative, HBV-related HCC patients.

Reduction of tablet weight variability by optimizing paddle speed in the forced feeder of a high-speed rotary tablet press.

PubMed

Peeters, Elisabeth; De Beer, Thomas; Vervaet, Chris; Remon, Jean-Paul

2015-04-01

Tableting is a complex process due to the large number of process parameters that can be varied. Knowledge and understanding of the influence of these parameters on the final product quality is of great importance for the industry, allowing economic efficiency and parametric release. The aim of this study was to investigate the influence of paddle speeds and fill depth at different tableting speeds on the weight and weight variability of tablets. Two excipients possessing different flow behavior, microcrystalline cellulose (MCC) and dibasic calcium phosphate dihydrate (DCP), were selected as model powders. Tablets were manufactured via a high-speed rotary tablet press using design of experiments (DoE). During each experiment also the volume of powder in the forced feeder was measured. Analysis of the DoE revealed that paddle speeds are of minor importance for tablet weight but significantly affect volume of powder inside the feeder in case of powders with excellent flowability (DCP). The opposite effect of paddle speed was observed for fairly flowing powders (MCC). Tableting speed played a role in weight and weight variability, whereas changing fill depth exclusively influenced tablet weight. The DoE approach allowed predicting the optimum combination of process parameters leading to minimum tablet weight variability. Monte Carlo simulations allowed assessing the probability to exceed the acceptable response limits if factor settings were varied around their optimum. This multi-dimensional combination and interaction of input variables leading to response criteria with acceptable probability reflected the design space.

Importance of Considering the Middle Capillary Plexus on OCT Angiography in Diabetic Retinopathy.

PubMed

Onishi, Alex C; Nesper, Peter L; Roberts, Philipp K; Moharram, Ganna A; Chai, Haitao; Liu, Lei; Jampol, Lee M; Fawzi, Amani A

2018-04-01

To quantify microvasculature changes in the superficial (SCP), middle (MCP), and deep capillary plexuses (DCP) in diabetic retinopathy (DR). Retrospective cross-sectional study at a tertiary academic referral center, in which 26 controls (44 eyes), 27 diabetic subjects without retinopathy (44 eyes), 32 subjects with nonproliferative retinopathy (52 eyes), and 27 subjects with proliferative retinopathy (40 eyes) were imaged with optical coherence tomography angiography (OCTA). Outcome measures included parafoveal vessel density (VD), percentage area of nonperfusion (PAN), and adjusted flow index (AFI) at the different plexuses. MCP VD and MCP AFI decreased with worsening DR, while PAN increased, mirroring changes within the DCP. The fitted regression line for MCP and DCP AFI were significantly different than the SCP, while DCP PAN differed from SCP PAN with disease progression. Higher SCP AFI and PAN were different in eyes with diabetes without retinopathy compared with controls. Unexpectedly, sex was found to independently influence MCP VD and AFI with worsening disease. OCTA parameters in the MCP and DCP displayed parallel changes with DR progression, different from the SCP, emphasizing the importance of physiologic considerations in the retinal capillaries. Thus, segmentation protocols that include the MCP within the SCP may be confounded. A difference in DCP PAN with worsening DR was unmasked relative to a prior study that included the MCP with SCP. We confirm that SCP AFI and PAN may serve as early indicators of microvascular changes in DR and identify an interaction between sex and the MCP deserving further study.

Theoretical comparative studies on transport properties of pentacene, pentathienoacene, and 6,13-dichloropentacene.

PubMed

Zhang, Xu; Yang, Xiaodi; Geng, Hua; Nan, Guangjun; Sun, Xingwen; Xi, Jinyang; Xu, Xin

2015-05-05

Pentacene derivative 6,13-dichloropentacene (DCP) is one of the latest additions to the family of organic semiconductors with a great potential for use in transistors. We carry out a detailed theoretical calculation for DCP, with systematical comparison to pentacene, pentathienoacene (PTA, the thiophene equivalent of pentacene), to gain insights in the theoretical design of organic transport materials. The charge transport parameters and carrier mobilities are investigated from the first-principles calculations, based on the widely used Marcus electron transfer theory and quantum nuclear tunneling model, coupled with random walk simulation. Molecular structure and the crystal packing type are essential to understand the differences in their transport behaviors. With the effect of molecule modification, significant one-dimensional π-stacks are found within the molecular layer in PTA and DCP crystals. The charge transport along the a-axis plays a dominant role for the carrier mobilities in the DCP crystal due to the strong transfer integrals within the a-axis. Pentacene shows a relatively large 3D mobility. This is attributed to the relatively uniform electronic couplings, which thus provides more transport pathways. PTA has a much smaller 3D mobility than pentacene and DCP for the obvious increase of the reorganization energy with the introduction of thiophene. It is found that PTA and DCP exhibit lower HOMO (highest occupied molecular orbital) levels and better environmental stability, indicating the potential applications in organic electronics. © 2015 Wiley Periodicals, Inc.

Responses of soluble microbial products and extracellular polymeric substances to the presence of toxic 2,6-dichlorophenol in aerobic granular sludge system.

PubMed

Li, Kai; Wei, Dong; Yan, Tao; Du, Bin; Wei, Qin

2016-12-01

The objective of this study was to evaluate the responses of soluble microbial products (SMP) and extracellular polymeric substances (EPS) to the presence of toxic 2,6-dichlorophenol (2,6-DCP) in aerobic granular sludge (AGS) system. Batch experiment showed that NH 4 + -N removal efficiency significantly decreased from 99.6% to 47.2% in the toxic 2,6-DCP of 20 mg/L. Moreover, the inhibition degrees of 2,6-DCP on (SOUR) H , [Formula: see text] and [Formula: see text] were 7.8%, 32.1% and 9.5%, respectively. The main components of SMP, including protein (PN) and polysaccharide (PS) increased from 2.3 ± 0.74 and 16.8 ± 0.12 mg/L to 66.4 ± 0.56 and 18.0 ± 0.19 mg/L in the presence of 2,6-DCP. Three-dimensional excitation-emission matrix (3D-EEM) spectroscopy identified tryptophan PN-like, humic acid-like and fulvic acid-like substances in the control SMP, and their fluorescence intensities increased after exposure to 2,6-DCP. Synchronous fluorescence spectra suggested that the fluorescence quenching between EPS and 2,6-DCP was a static quenching process. The obtained results could provide insightful information on the responses of microbial products to AGS in the presence of toxic chlorophenols. Copyright © 2016 Elsevier Ltd. All rights reserved.

Development of modified release diltiazem HCl tablets using composite index to identify optimal formulation.

PubMed

Gohel, M C; Patel, M M; Amin, A F

2003-05-01

This article reports the preparation of tartaric acid treated ispaghula husk powder for the development of modified release tablets of diltiazem HCl by adopting direct compression technique and a 32 full factorial design. The modified ispaghula husk powder showed superior swelling and gelling as compared to untreated powder. Addition of compaction augmenting agent such as dicalcium phosphate was found to be essential for obtaining tablets with adequate crushing strength. In order to improve the crushing strength of diltiazem HCl tablets, to modulate drug release pattern, and to obtain similarity of dissolution profiles in distilled water and simulated gastric fluid (pH 1.2), modified guar gum was used along with modified ispaghula husk powder and tartaric acid. A novel composite index, which considers a positive or a negative deviation from an ideal value, was calculated considering percentage drug release in 60, 300, and 540 min as dependent variables for the selection of a most appropriate batch. Polynomial equation and contour plots are presented. The concept of similarity factor (f2) was used to prove similarity of dissolution in water and simulated gastric fluid (pH 1.2).

Triple shape memory effects of cross-linked polyethylene/polypropylene blends with cocontinuous architecture.

PubMed

Zhao, Jun; Chen, Min; Wang, Xiaoyan; Zhao, Xiaodong; Wang, Zhenwen; Dang, Zhi-Min; Ma, Lan; Hu, Guo-Hua; Chen, Fenghua

2013-06-26

In this paper, the triple shape memory effects (SMEs) observed in chemically cross-linked polyethylene (PE)/polypropylene (PP) blends with cocontinuous architecture are systematically investigated. The cocontinuous window of typical immiscible PE/PP blends is the volume fraction of PE (v(PE)) of ca. 30-70 vol %. This architecture can be stabilized by chemical cross-linking. Different initiators, 2,5-dimethyl-2,5-di(tert-butylperoxy)-hexane (DHBP), dicumylperoxide (DCP) coupled with divinylbenzene (DVB) (DCP-DVB), and their mixture (DHBP/DCP-DVB), are used for the cross-linking. According to the differential scanning calorimetry (DSC) measurements and gel fraction calculations, DHBP produces the best cross-linking and DCP-DVB the worst, and the mixture, DHBP/DCP-DVB, is in between. The chemical cross-linking causes lower melting temperature (Tm) and smaller melting enthalpy (ΔHm). The prepared triple shape memory polymers (SMPs) by cocontinuous immiscible PE/PP blends with v(PE) of 50 vol % show pronounced triple SMEs in the dynamic mechanical thermal analysis (DMTA) and visual observation. This new strategy of chemically cross-linked immiscible blends with cocontinuous architecture can be used to design and prepare new SMPs with triple SMEs.

Long term measurement network for FIFE

NASA Technical Reports Server (NTRS)

Blad, Blaine L.; Walter-Shea, Elizabeth A.; Hays, Cynthia J.

1988-01-01

The objectives were: to obtain selected instruments which were not standard equipment on the Portable Automated Mesometeorological (PAM) and Data Control Platform (DCP) stations; to assist in incorporation of these instruments onto the PAM and DCP stations; to help provide routine maintenance of the instruments; to conduct periodic instrument calibrations; and to repair or replace malfunctioning instruments when possible. All of the objectives were or will be met soon. All instruments and the necessary instrument stands were purchased or made and were available for inclusion on the PAM and DCP stations before the beginning of the IFC-1. Due to problems beyond control, the DCP stations experienced considerable difficulty in becoming operational. To fill some of the gaps caused by the DCP problems, Campbell CR21-X data loggers were installed and the data collected on cassette tapes. Periodic checks of all instruments were made, to maintain data quality, to make necessary adjustments in certain instruments, to replace malfunctioning instruments, and to provide instrument calibration. All instruments will be calibrated before the beginning of the 1988 growing season as soon as the weather permits access to all stations and provides conditions that are not too harsh to work in for extended periods of time.

Degradation of 2,4-dichlorophenol with a novel TiO2/Ti-Fe-graphite felt photoelectrocatalytic oxidation process.

PubMed

Zhao, Bao-xiu; Li, Xiang-zhong; Wang, Peng

2007-01-01

Degradation of 2,4-dichlorophenol (2,4-DCP) was studied in a novel three-electrode photoelectrocatalytic (PEC) integrative oxidation process, and the factors influencing the degradation rate, such as applied current, flow speed of O2, pH, adscititious voltage and initial 2,4-DCP concentration were investigated and optimized. H2O2 was produced nearby cathode and Fe2+ continuously generated from Fe anode in solution when current and O2 were applied, so, main reactions, H2O2-assisted TiO2 PEC oxidation and E-Fenton reaction, occurred during degradation of 2,4-DCP in this integrative system. The degradation ratio of 2,4-DCP was 93% in this integrative oxidation process, while it was only 31% in E-Fenton process and 46% in H2O2-assisted TiO2 PEC process. So, it revealed that the degradation of 2,4-DCP was improved greatly by photoelectrical cooperation effect. By the investigation of pH, it showed that this integrative process could work well in a wide pH range from pH 3 to pH 9.

Evaluation of the Dignity Care Pathway for community nurses caring for people at the end of life.

PubMed

Johnston, Bridget; Östlund, Ulrika; Brown, Hilary

2012-10-01

People nearing the end of life fear loss of dignity, and a central tenet of palliative care is to help people die with dignity. The Dignity Care Pathway (DCP) is an intervention based on the Chochinov theoretical model of dignity care. It has four sections: a manual, a Patient Dignity Inventory, reflective questions, and care actions. The feasibility and acceptability of the DCP were evaluated using a qualitative design with a purposive sample of community nurses. Data was collected from April to October 2010 using in-depth interviews, reflective diaries, and case studies and then analysed using framework analysis. The DCP was acceptable to the community nurses, helped them identify when patients were at the end of life, identified patients' key concerns, and aided nurses in providing holistic end-of-life care. It requires the nurse to have excellent communication skills. Some of the nurses found it hard to initiate a conversation on dignity-conserving care. The DCP helps nurses to deliver individualised care and psychological care, which has previously been identified as a difficult area for community nurses. All of the nurses wished to continue to use the DCP and would recommend it to others.

Diagnostic Evaluation of Des-Gamma-Carboxy Prothrombin versus α-Fetoprotein for Hepatitis B Virus-Related Hepatocellular Carcinoma in China: A Large-Scale, Multicentre Study

PubMed Central

Zheng, Lei; Yin, Yuepeng; Zou, Zhenzhen; Zhou, Feiguo; Zhou, Weiping; Shen, Feng; Gao, Chunfang

2016-01-01

An efficient serum marker for hepatocellular carcinoma (HCC) is currently lacking and requires intensive exploration. We aimed to evaluate the performance of des-gamma-carboxy prothrombin (DCP) for identifying hepatitis B virus-related HCC in a large, multicentre study in China. A total of 1034 subjects in three cohorts (A, B, and C) including HCC and various non-HCC controls were enrolled from 4 academic medical centers in China from January 2011 to February 2014. Blind parallel detections were conducted for DCP and AFP. The area under the receiver operating characteristic curve (AUC) was used to evaluate the diagnostic efficacies. In cohort A, which comprised 521 subjects, including patients with HCC, liver metastasis, liver cirrhosis (LC), and liver hemangiomas as well as healthy controls (HCs), the accuracy of DCP for distinguishing HCC from various controls was 6.2–9.7% higher than that of AFP. In cohort B, which comprised 447 subjects, including patients with HCC, LC, and chronic hepatitis B as well as HC, the accuracy of DCP was further elevated (12.3–20.67% higher than that of AFP). The superiority of DCP to AFP was more profound in the surveillance of early HCC [AUC 0.837 (95% CI: 0.771–0.903) vs. 0.650 (0.555–0.745)] and AFP-negative HCC [AUC: 0.856 (0.798–0.914)] and in discriminating HCC from LC (accuracy: 92.9% vs.64.71%). Higher DCP levels were associated with worse clinical behaviors and shorter disease-free survival. DCP not only is complementary to AFP in identifying AFP-negative HCC and in excluding AFP-positive non-HCC (liver cirrhosis), but also demonstrates improved performance in HCC surveillance, early diagnosis, treatment response and recurrence monitoring in the HBV-related population. PMID:27070780

A study of universal modulation techniques applied to satellite data collection

NASA Technical Reports Server (NTRS)

1980-01-01

A universal modulation and frequency control system for use with data collection platform (DCP) transmitters is examined. The final design discussed can, under software/firmwave control, generate all of the specific digital data modulation formats currently used in the NASA satellite data collection service and can simultaneously synthesize the proper RF carrier frequencies employed. A novel technique for DCP time and frequency control is presented. The emissions of NBS radio station WWV/WWVH are received, detected, and finally decoded in microcomputer software to generate a highly accurate time base for the platform; with the assistance of external hardware, the microcomputer also directs the recalibration of all DCP oscillators to achieve very high frequency accuracies and low drift rates versus temperature, supply voltage, and time. The final programmable DCP design also employs direct microcomputer control of data reduction, formatting, transmitter switching, and system power management.

The relationship of photoreceptor degeneration to retinal vascular development and loss in mutant rhodopsin transgenic and RCS rats.

PubMed

Pennesi, Mark E; Nishikawa, Shimpei; Matthes, Michael T; Yasumura, Douglas; LaVail, Matthew M

2008-12-01

The early loss of photoreceptors in some retinal degenerations in mice has been shown to have a profound effect on vascular development of the retina. To better characterize this relationship, we have examined the formation of retinal blood vessels during the first month of life in 8 lines of transgenic rats with different ages of onset and rates of photoreceptor cell loss mediated by the expression of mutant rhodopsin (P23H and S334ter). The number of capillary profiles in the superficial plexus (SP) and deep capillary plexus (DCP) of the retina were quantified in retinal sections taken at postnatal day (P) 8, 10, 12, 15 and 30. In normal wild-type rats, the SP and DCP had mostly established mature, adult patterns by P15, as previously shown. In the transgenic rats, the loss of photoreceptors had relatively little effect on the SP. By contrast, the loss of photoreceptors during vascular development had a major impact on the DCP. In the two lines with early and most rapid photoreceptor loss, S334ter-7 and S334ter-3, where about 90% and 65%, respectively, of the photoreceptors were already lost by P15, the DCP either failed to form (S334ter-7) or the number of capillary profiles was less than 7% of controls (S334ter-3). In lines where almost all photoreceptors were still present at P15 (S334ter-4, S334ter-9, P23H-2 and P23H-3), the number of profiles in the DCP were the same as in wild-type controls at P30. In two lines with an intermediate rate of degeneration (S334ter-5 and P23H-1), where only about 25% of the photoreceptors were lost by P15, there was an intermediate number of vascular profiles in the DCP at P30. Thus, a very close relationship between the number of photoreceptors and vessel profiles in the DCP during its development exists in the transgenic rats, and the loss of photoreceptors results in the failure or inhibition of the DCP to develop. Several mechanisms may explain this relationship including changes in the level of physiological oxygen tension or alteration in the release of angiogenic factors that normally drive vessel development. Analysis of older transgenic retinas up to 1 year of age revealed that (1) vascular profiles are lost from the DCP in essentially all lines once fewer than about 30-33% of photoreceptors remain; (2) in those lines where the DCP essentially did not develop (S334ter-7 and S334ter-3), the effect of photoreceptor absence was permanent, and there was no late vascularization of the DCP; (3) the number of capillary profiles in the SP remained no different from controls in any of the lines, despite long-standing loss of photoreceptors; and (4) neovascularization of the RPE by retinal capillaries occurred with a latency of 60-180 days after the loss of photoreceptors, except in S334ter-7 rats, where neovascularization essentially did not occur. Analysis of RCS rats was carried out for comparison.

Ultraviolet A photosensitivity profile of dexchlorpheniramine maleate and promethazine-based creams: Anti-inflammatory, antihistaminic, and skin barrier protection properties.

PubMed

Facchini, Gustavo; Eberlin, Samara; Clerici, Stefano Piatto; Alves Pinheiro, Ana Lucia Tabarini; Costa, Adilson

2017-12-01

Unwanted side effects such as dryness, hypersensitivity, and cutaneous photosensitivity are challenge for adherence and therapeutical success for patients using treatments for inflammatory and allergic skin response. In this study, we compared the effects of two dermatological formulations, which are used in inflammatory and/or allergic skin conditions: dexchlorpheniramine maleate (DCP; 10 mg/g) and promethazine (PTZ; 20 mg/g). We evaluated both formulations for phototoxicity potential, skin irritation, anti-inflammatory and antihistaminic abilities, and skin barrier repair in vitro and ex vivo using the standard OECD test guideline n° 432, the ECVAM protocol n° 78, and cultured skin explants from a healthy patient. Ultraviolet A was chosen as exogenous agent to induce allergic and inflammatory response. Both PTZ and DCP promoted increases in interleukin-1 (IL-1) synthesis in response to ultraviolet A (UVA) radiation compared to control. However, the increase observed with PTZ was significantly greater than the DCP, indicating that the latter has a lower irritant potential. DCP also demonstrated a protective effect on UVA-induced leukotriene B4 and nuclear factor kappa B (NF-κB) synthesis. Conversely, PTZ demonstrates more robust UVA antihistaminic activity. Likewise, PTZ promoted a significantly greater increase in the production of involucrin and keratin 14, both associated with protective skin barrier property. In conclusion, these data suggest possible diverging UVA response mechanisms of DCP and PTZ, which gives greater insight into the contrasting photosensitizing potential between DCP and PTZ observed in the patients. © 2017 Wiley Periodicals, Inc.

Reinforcement effect of poly(butylene succinate) (PBS)-grafted cellulose nanocrystal on toughened PBS/polylactic acid blends.

PubMed

Zhang, Xuzhen; Zhang, Yong

2016-04-20

Poly(butylene succinate) (PBS)/polylactic acid (PLA) blends modified with dicumyl peroxide (DCP) were reinforced by PBS-g-cellulose nanocrystal (CNC) through melt mixing. PBS-g-CNC was prepared through in situ polymerization and its structure was confirmed by FTIR, (13)C NMR, XPS and GPC analysis after saponification. The morphological analysis of PBS/PLA/PBS-g-CNC composites before and after etched by CH2Cl2 shows that the addition of DCP and PBS-g-CNC could decrease the size of PBS as a dispersed phase in PLA matrix and improve the dispersion of PBS-g-CNC in both PBS and PLA phases, which could affect the crystallization and mechanical properties of composites. The crystallinity of PLA α'-phase crystal in PBS/PLA/PBS-g-CNC composites is increased obviously by the addition of PBS-g-CNC, leading to an increase of the crystallinity of the composites. PBS/PLA blends modified by DCP have high Notched Izod impact strength and moduli, and the values are increased by the addition of PBS-g-CNC. Both storage modulus and glass translation temperature of PBS/PLA blend are increased by DCP and PBS-g-CNC, which is proved by DMA results, showing a weak molecular segment mobility of PBS/PLA matrix. The addition of DCP decreases the crystallization temperature and crystallinity of PBS/PLA composite, but increases the thermal stability of composites, mostly because of the crosslink effect of DCP on PBS/PLA matrix. Copyright © 2015 Elsevier Ltd. All rights reserved.

Retrospective review of diphencyprone in the treatment of alopecia areata.

PubMed

Lamb, R C; Young, D; Holmes, S

2016-06-01

Contact immunotherapy with diphencyprone (DCP) is used to treat alopecia areata (AA). Its reported efficacy is variable, and individual response cannot be predicted. To identify patient and treatment course variables that may affect treatment outcome, and to review DCP service to identify potential areas for development and improvement. This was a retrospective review of a DCP service over a 20-year period (1991-2010). Complete data was available for 205 treatment courses, and 162 (79%) treatment courses were completed for 133 patients. Overall, 72.2% (96/133) of patients had some hair regrowth (any grade). In 15.8% of cases (21/133), response was > 90% regrowth. However, 27.1% (36/133) had no response. We found that extent of alopecia at baseline and duration of disease were statistically significant when comparing patients with an optimal outcome to those without (P < 0.05). In contrast to other reports, atopy, age at onset and nail dystrophy were not statistically significant. For patients receiving more than one course, response to DCP treatment was broadly consistent. Extent of alopecia at baseline and duration of disease are important factors in predicting response. Our results suggest that atopy should not be considered a predictor of poor outcome with respect to DCP treatment. A need for improved data collection, particularly regarding longer-term outcomes, was identified. The role of maintenance therapy requires objective assessment. Opportunities for DCP self-administration by patients should be explored. Limitations of this study include the retrospective nature of the review and lack of long-term follow-up data. © 2015 British Association of Dermatologists.

The Diaper Change Play: Validation of a New Observational Assessment Tool for Early Triadic Family Interactions in the First Month Postpartum

PubMed Central

Rime, Jérôme; Tissot, Hervé; Favez, Nicolas; Watson, Michael; Stadlmayr, Werner

2018-01-01

The quality of family relations, observed during mother–father–infant triadic interactions, has been shown to be an important contributor to child social and affective development, beyond the quality of dyadic mother–child, father–child, and marital relationships. Triadic interactions have been well described in families with 3 month olds and older children using the Lausanne Trilogue Play (LTP). Little is known about the development of mother–father–baby interactions in the very 1st weeks postpartum, mostly because no specific observational setting or particular instrument had been designed to cover this age yet. To fill this gap, we adapted the LTP to create a new observational setting, namely the Diaper Change Play (DCP). Interactions are assessed using the Family Alliance Assessment Scales for DCP (FAAS-DCP). We present the validation of the DCP and its coding system, the FAAS-DCP. The three validation studies presented here (44 mother–father–child–triads) involve a sample of parents with 3-week-old infants recruited in two maternity wards (n = 32 and n = 12) in Switzerland. Infants from both sites were all healthy according to their APGAR scores, weight at birth, and scores on the NICU Network Neurobehavioral Scale (NNNS), which was additionally conducted on the twelve infants recruited in one of the maternity ward. Results showed that the “FAAS – DCP” coding system has good psychometric properties, with a good internal consistency and a satisfying reliability among the three independent raters. Finally, the “FAAS-DCP” scores on the interactive dimensions are comparable to the similar dimensions in the FAAS-LTP. The results showed that there is no statistically significant difference on scores between the “FAAS-DCP” and the “FAAS,” which is consistent with previous studies underlying stability in triadic interaction patterns from pregnancy to 18 months. These first results indicated that the DCP is a promising observational setting, able to assess the development of the early family triadic functioning. The DCP and the FAAS-DCP offer to both clinicians and researchers a way to improve the understanding of the establishment of early family functioning as well as to study the young infant’s triangular capacity. Perspectives for future research will be discussed. PMID:29706912

Peroxidase-catalyzed stabilization of 2,4-dichlorophenol in alkali-extracted soils.

PubMed

Palomo, Mónica; Bhandari, Alok

2011-01-01

Horseradish peroxidase- (HRP) mediated stabilization of phenolic contaminants is a topic of interest due to its potential for remediation of contaminated soils. This study evaluated the sorption of 2,4-dichlorophenol (DCP) and its HRP-mediated stabilization in two alkali-extracted soils. Alkali extraction reduced the soil organic matter (SOM) contents of the geomaterials and enriched the residual SOM with humin C. Sorption of DCP on these sorbents was complete within 1 d. However, most of the sorbed DCP was removed from the geomaterials by water and methanol, suggesting weak solute-sorbent interactions. The addition of HRP resulted in the generation of DCP polymerization products (DPP), which partitioned between the aqueous and solid phases. The DPP phase distribution was rapid and complete within 24 h. Between 70 and 90% of the added DCP was converted to DPP and up to 43% of the initial aqueous phase contaminant was transformed into a residue that was resistant to extraction with methanol. Bound residues of DPP increased with initial aqueous phase solute concentration and remained fairly constant after 7 d of contact. Contaminant stabilization was noted to be high in the humin-mineral geomaterial. Results illustrate that HRP may be effective in stabilizing phenolic contaminants in subsoils that are likely to contain SOM enriched in humin C.

Development of metoprolol tartrate extended-release matrix tablet formulations for regulatory policy consideration.

PubMed

Nellore, R V; Rekhi, G S; Hussain, A S; Tillman, L G; Augsburger, L L

1998-01-02

This research study was designed to develop model extended-release (ER) matrix tablet formulations for metoprolol tartrate (100 mg) sufficiently sensitive to manufacturing variable and to serve as the scientific basis for regulatory policy development on scale-up and post approval changes for modified-release dosage forms (SUPAC-MR). Several grades and levels of hydroxypropyl methylcellulose (Methocel K4M, K15M, K100M and K100LV), fillers and binders and studied. Three granulation processes were evaluated; direct compression, fluid-bed or high-shear granulation. Lubrication was performed in a V-blender and tablets were compressed on an instrumented rotary tablet press. Direct compression formulations exhibited poor flow, picking and sticking problems during tableting. High-shear granulation resulted in the formation of hard granules that were difficult to mill but yielded good tablets. Fluid-bed granulations were made using various binders and appeared to be satisfactory in terms of flow and tableting performance. In vitro drug release testing was performed in pH 6.8 phosphate buffer using USP apparatus 2 (paddle) at 50 rpm. At a fixed polymer level, drug release from the higher viscosity grades (K100M) was slower as compared to the lower viscosity grades (K100LV). In addition, release from K100LV was found to be more sensitive to polymer level changes. Increased in polymer level from 10 to 40% and/or filler change from lactose to dicalcium phosphate resulted in about 25-30% decrease in the amount of metoprolol release after 12 h. The results of this study led to the choice of Methocel K100LV as the hydrophilic matrix polymer and fluid-bed granulation as the process of choice for further evaluation of critical and non-critical formulation and processing variables.

Site Targeted Press Coated Delivery of Methylprednisolone Using Eudragit RS 100 and Chitosan for Treatment of Colitis.

PubMed

Jagdale, Swati; Chandekar, Apoorva

2016-01-01

Inflammatory bowel disease (IBD) is one of the five most prevalent gastrointestinal disease burdens which commonly require lifetime care. Worldwide incidence rate of ulcerative colitis and Crohn's disease is about 16.8% and 13.4% respectively. Colitis is an inflammation of the colon. Colon targeted drug delivery will direct the drug to the colon. The drug will reach at the site of action and hence its side effects as well as dose can be reduced. Recent patent describes treatment of ulcerative colitis using anti CD3 antibodies, with nicotine and anti-depressant drugs, budesonide foam etc. Present study deals with optimization of site targeted methylprednisolone delivery for treatment of colitis. Chitosan and Eudragit RS 100 were used as coating polymers. Tablets were prepared by press coated technology. The core tablets contain drug, avicel as binder, croscarmellose sodium as super disintegrant and dicalcium phosphate as diluent. Drug excipient compatibility was carried out using FTIR, UV and DSC. Design of experiment was used to optimize the formulation. Tablets were evaluated for thickness, weight variation, hardness, swelling index, in-vitro drug release and release of drug in simulated media. Optimized batch (B2) contained chitosan 40% and eudragit RS 100 17.5%. B2 showed in-vitro drug release 85.65 ± 7.6% in 6.8 pH phosphate buffer and 96.7 ±9.1% in simulated media after 7.5 hours. In-vivo x-ray placebo study for formulation B2 had shown that the tablet reached to the ascending colon after 5 hours. This indicated a potential site targeted delivery of optimized batch B2.

Quantitative Evaluation of MDP-Ca Salt and DCPD after Application of an MDP-based One-step Self-etching Adhesive on Enamel and Dentin.

PubMed

Yokota, Yoko; Fujita, Kou Nakajima; Uchida, Ryoichiro; Aida, Etsuko; Aoki, Naoko Tabei; Aida, Masahiro; Nishiyama, Norihiro

To investigate the effects of an experimental 10-methacryloyloxydecyl dihydrogen phosphate (MDP)-based one-step self-etching adhesive (EX adhesive) applied to enamel and dentin on the production of calcium salt of MDP (MDP-Ca salt) and dicalcium phosphate dehydrate (DCPD) at various periods. The EX adhesive was prepared. Bovine enamel and dentin reactants were prepared by varying the application period of the EX adhesive: 0.5, 1, 5, 30, 60 and 1440 min. Enamel and dentin reactants were analyzed using x-ray diffraction and solid-state phosphorus-31 nuclear magnetic resonance (31P NMR). Curvefitting analyses of corresponding 31P NMR spectra were performed. Enamel and dentin developed several types of MDP-Ca salts and DCPDs with amorphous and crystalline phases throughout the application period. The predominant molecular species of MDP-Ca salt was determined as the monocalcium salt of the MDP monomer. Dentin showed a faster production rate and greater produced amounts of MDP-Ca salt than did enamel, since enamel showed a knee-point in the production rate of the MDP-Ca salt at the application period of 5 min. In contrast, enamel developed greater amounts of DCPD than did dentin and two types of DCPDs with different crystalline phases at application periods > 30 min. The amounts of MDP-Ca salt developed during the 30-s application of the EX adhesive on enamel and dentin were 7.3 times and 21.2 times greater than DCPD, respectively. The MDP-based one-step adhesive yielded several types of MDP-Ca salts and DCPD with an amorphous phase during the 30-s application period on enamel and dentin.

Hydrothermal Synthesis of Dicalcium Silicate Based Cement

NASA Astrophysics Data System (ADS)

Dutta, N.; Chatterjee, A.

2017-06-01

It is imperative to develop low energy alternative binders considering the large amounts of energy consumed as well as carbon dioxide emissions involved in the manufacturing of ordinary Portland cement. This study is on the synthesis of a dicalcium silicate based binder using a low temperature hydrothermal route.The process consists of synthesizing an intermediate product consisting of a calcium silicate hydrate phase with a Ca:Si ratio of 2:1 and further thermal treatment to produce the β-Ca2SiO4 (C2S) phase.Effect of various synthesis parameters like water to solid ratio, dwell time and temperature on the formation of the desired calcium silicate hydrate phase is reported along with effect of heating conditions for formation of the β-C2S phase. Around 77.45% of β-C2S phase was synthesized by thermal treatment of the intermediate phase at 820°C.

On the use and potential use of seasonal to decadal climate predictions for decision-making in Europe

NASA Astrophysics Data System (ADS)

Soares, Marta Bruno; Dessai, Suraje

2014-05-01

The need for climate information to help inform decision-making in sectors susceptible to climate events and impacts is widely recognised. In Europe, developments in the science and models underpinning the study of climate variability and change have led to an increased interest in seasonal to decadal climate predictions (S2DCP). While seasonal climate forecasts are now routinely produced operationally by a number of centres around the world, decadal climate predictions are still in its infancy restricted to the realm of research. Contrary to other regions of the world, where the use of these types of forecasts, particularly at seasonal timescales, has been pursued in recent years due to higher levels of predictability, little is known about the uptake and climate information needs of end-users regarding S2DCP in Europe. To fill this gap we conducted in-depth interviews with experts and decision-makers across a range of European sectors, a workshop with European climate services providers, and a systematic literature review on the use of S2DCP in Europe. This study is part of the EUropean Provision Of Regional Impact Assessment on a Seasonal-to-decadal timescale (EUPORIAS) project which aims to develop semi-operational prototypes of impact prediction systems in Europe on seasonal to decadal timescales. We found that the emerging landscape of users and potential users of S2DCP in Europe is complex and heterogeneous. Differences in S2DCP information needs across and within organisations and sectors are largely underpinned by factors such as the institutional and regulatory context of the organisations, the plethora of activities and decision-making processes involved, the level of expertise and capacity of the users, and the availability of resources within the organisations. In addition, although the use of S2DCP across Europe is still fairly limited, particular sectors such as agriculture, health, energy, water, (re)insurance, and transport are taking the lead on the use of seasonal forecasts. The potential to use decadal predictions across European sectors was also noted although these are currently not used due to the limitations of the science and the experimental nature of existing predictions. Despite the limited use of these types of climate predictions there is a general understanding that information on the uncertainty of such predictions is a fundamental component of S2DCP although approaches for dealing with such uncertainty also tend to differ across organisations. Perceived barriers to the uptake of these types of climate predictions are mainly associated with low skill and reliability of the models but also with other factors such as relevance, usability, and accessibility of S2DCP by end-users. Potential solutions to overcome such barriers include the potential to explore existing 'windows of opportunity' in Europe, improve current understanding of users' needs, and increase accessibility and awareness of users to available S2DCP in Europe. This paper will present findings from our analysis and consider some of the broader issues raised by the emergence of S2DCP for climate services in Europe.

Biosynthesis of Lipoteichoic Acid in Lactobacillus rhamnosus: Role of DltD in d-Alanylation

PubMed Central

Debabov, Dmitri V.; Kiriukhin, Michael Y.; Neuhaus, Francis C.

2000-01-01

The dlt operon (dltA to dltD) of Lactobacillus rhamnosus 7469 encodes four proteins responsible for the esterification of lipoteichoic acid (LTA) by d-alanine. These esters play an important role in controlling the net anionic charge of the poly (GroP) moiety of LTA. dltA and dltC encode the d-alanine–d-alanyl carrier protein ligase (Dcl) and d-alanyl carrier protein (Dcp), respectively. Whereas the functions of DltA and DltC are defined, the functions of DltB and DltD are unknown. To define the role of DltD, the gene was cloned and sequenced and a mutant was constructed by insertional mutagenesis of dltD from Lactobacillus casei 102S. Permeabilized cells of a dltD::erm mutant lacked the ability to incorporate d-alanine into LTA. This defect was complemented by the expression of DltD from pNZ123/dlt. In in vitro assays, DltD bound Dcp for ligation with d-alanine by Dcl in the presence of ATP. In contrast, the homologue of Dcp, the Escherichia coli acyl carrier protein (ACP), involved in fatty acid biosynthesis, was not bound to DltD and thus was not ligated with d-alanine. DltD also catalyzed the hydrolysis of the mischarged d-alanyl–ACP. The hydrophobic N-terminal sequence of DltD was required for anchoring the protein in the membrane. It is hypothesized that this membrane-associated DltD facilitates the binding of Dcp and Dcl for ligation of Dcp with d-alanine and that the resulting d-alanyl–Dcp is translocated to the primary site of d-alanylation. PMID:10781555

Mobilization of phenol and dichlorophenol in unsaturated soils by non-uniform electrokinetics.

PubMed

Luo, Qishi; Zhang, Xihui; Wang, Hui; Qian, Yi

2005-06-01

The poor mobility of organic pollutants in contaminated sites frequently results in slow remediation processes. Organics, especially hydrophobic compounds, are generally retained strongly in soil matrix as a result of sorption, sequestration, or even formation into non-aqueous-phase liquids and their mobility is thus greatly reduced. The objective of this study was to evaluate the feasibility of using non-uniform electrokinetic transport processes to enhance the mobility of organic pollutants in unsaturated soils with no injection reagents. Phenol and 2,4-dichlorophenol (2,4-DCP), and kaolin and a natural sandy loam soil were selected as model organics and soils, respectively. The results showed that non-uniform electrokinetics can accelerate the desorption and movement of phenol and 2,4-DCP in unsaturated soils. Electromigration and electroosmotic flow were the main driving forces, and their role in the mobilization of phenol and 2,4-DCP varied with soil pH. The movement of 2,4-DCP in the sandy loam towards the anode (about 1.0 cmd(-1)V(-1)) was 1.0-1.5 cmd(-1)V(-1) slower than that in the kaolin soil, but about 0.5 cmd(-1)V(-1) greater than that of phenol in the sandy loam. When the sandy loam was adjusted to pH 9.3, the movement of phenol and 2,4-DCP towards the anode was about twice and five times faster than that at pH 7.7, respectively. The results also demonstrated that the movement of phenol and 2,4-DCP in soils can be easily controlled by regulating the operational mode of electric field. It is believed that non-uniform electrokinetics has the potential for practical application to in situ remediation of organics-contaminated sites.

Optical coherence tomography angiography discerns preclinical diabetic retinopathy in eyes of patients with type 2 diabetes without clinical diabetic retinopathy.

PubMed

Cao, Dan; Yang, Dawei; Huang, Zhongning; Zeng, Yunkao; Wang, Jun; Hu, Yunyan; Zhang, Liang

2018-05-01

To investigate changes in retinal vascular plexuses and choriocapillaris in patients with type 2 diabetes mellitus (DM2) without diabetic retinopathy (DR) and healthy controls using optical coherence tomography angiography (OCTA). A total of 71 DM2 and 67 healthy control subjects were included. All subjects underwent OCTA examination (RTVue-XR Avanti; Optovue, Fremont, CA, USA). Average vessel density in superficial capillary plexus (SCP), deep capillary plexus (DCP) and choriocapillaris, parafoveal vessel density in SCP and DCP, FAZ area (mm 2 ) in SCP, microaneurysms and capillary nonperfusion were taken into analysis. Parafoveal vessel density in both SCP and DCP decreased in the eyes without clinical DR compared to normal controls (p < 0.001). Diabetic patients with no signs of DR also had a significant reduction in average vessel density of SCP, DCP and choriocapillaris (p < 0.001, p < 0.001 and p = 0.006, respectively). No significant difference was found in FAZ area of SCP between DM2 eyes and healthy controls (p = 0.253). The average vessel density of SCP and DCP is not correlated with HbA1c or serum creatinine in DM2 patients. Microaneurysms seen in OCTA but not in fundus examination were found in 8 out of the 71 (11.3%) diabetic eyes, and capillary nonperfusion was noted in 18 of 71 diabetic eyes. We demonstrated that OCTA can identify preclinical DR before the manifestation of clinically apparent retinopathy in diabetic eyes. DM2 patients without DR have SCP, DCP and choriocapillaris impairment. Our results suggested that OCTA might be a promising tool for regular screening of diabetic eyes for DR.

An analysis of marketing authorisation applications via the mutual recognition and decentralised procedures in Europe.

PubMed

Ebbers, Hans C; Langedijk, Joris; Bouvy, Jacoline C; Hoekman, Jarno; Boon, Wouter P C; de Jong, Jean Philippe; De Bruin, Marie L

2015-10-01

The aim of this study is to provide a comprehensive overview of the outcomes of marketing authorisation applications via the mutual recognition and decentralised procedures (MRP/DCP) and assess determinants of licensing failure during CMDh referral procedures. All MRP/DCP procedures to the Co-ordination group for Mutual recognition and Decentralised procedures-human (CMDh) during the period from January 2006 to December 2013 were analysed. Reasons for starting referral procedures were scored. In addition, a survey under pharmaceutical companies was performed to estimate the frequency of licensing failure prior to CMDh referrals. During the study period, 10392 MRP/DCP procedures were finalized. Three hundred seventy-seven (3.6%) resulted in a referral procedure, of which 70 (19%) resulted in licensing failure, defined as refusal or withdrawal of the application. The frequency of CMDh referrals decreased from 14.5% in 2006 to 1.6% in 2013. Of all referrals, 272 (72%) were resolved through consensus within the CMDh, the remaining 105 (28%) were resolved at the level of the CHMP. Most referrals were started because of objections raised about the clinical development program. Study design issues and objections about the demonstration of equivalence were most likely to result in licensing failure. An estimated 11% of all MRP/DCP procedures resulted in licensing failure prior to CMDh referral. Whereas the absolute number of MRP/DCP procedures resulting in a referral has reduced substantially over the past years, no specific time trend could be observed regarding the frequency of referrals resulting in licensing failure. Increased knowledge at the level of companies and regulators has reduced the frequency of late-stage failure of marketing applications via the MRP/DCP.

A Resilience Intervention in African American Adults with Type 2 Diabetes: A Pilot Study of Efficacy

PubMed Central

Steinhardt, Mary A.; Mamerow, Madonna M.; Brown, Sharon A.; Jolly, Christopher A.

2010-01-01

Purpose The purpose of this pilot study was to determine the feasibility of offering our Diabetes Coaching Program (DCP), adapted for African Americans, in a sample of African American adults with type 2 diabetes. Methods The study utilized a one-group, pretest-posttest design to test the acceptance and potential effectiveness of the DCP. Subjects were a convenience sample of 16 African Americans (8 females; 8 males) with type 2 diabetes; twelve subjects (6 females; 6 males) completed the program. The DCP included four weekly class sessions devoted to resilience education and diabetes self-management, followed by eight biweekly support group meetings. Psychosocial process variables (resilience, coping strategies, diabetes empowerment), and proximal (perceived stress, depressive symptoms, diabetes self-management) and distal outcomes (BMI, fasting blood glucose, HbA1c, lipidemia, blood pressure) were assessed at baseline and six-months post study entry. Qualitative data were collected at eight-months via a focus group conducted to examine the acceptability of the DCP. Results Preliminary paired t-tests indicated statistically significant improvements in diabetes empowerment, diabetes self-management, BMI, HbA1c, total cholesterol, LDL-cholesterol, and systolic and diastolic blood pressure. Medium to large effect sizes were reported. Resilience, perceived stress, fasting blood glucose, and HDL-cholesterol improved, but changes were not statistically significant. Focus group data confirmed that participants held positive opinions regarding the DCP and follow-up support group sessions, although they suggested an increase in program length from 4 to 8 weeks. Conclusions The pilot study documented the feasibility and potential effectiveness of the DCP to enhance diabetes empowerment, diabetes self-management, and reductions in the progression of obesity, type 2 diabetes, and CVD in the African American community. Randomized experimental designs are needed to confirm these findings. PMID:19204102

Implant failure in lower limb long bone diaphyseal fractures at a tertiary hospital in Ile- Ife. Nigeria.

PubMed

Esan, O; Ikem, I C; Orimolade, E A; Esan, O T

2014-06-01

This included determining aetiology of failure and comparing the failure rate in implant fixations using solid intramedullary nail and DCP. A retrospective study conducted at the Orthopaedic Department, Obafemi Awolowo University Teaching Hospital, Ile-Ife,Nigeria. Records of all operated cases of lower limb long bone diaphyseal fractures including those with failed fixations from August 2006-July 2011 were reviewed. Data retrieved included type of implant used, aetiology and characteristics of Implant failure. Data were analysed using SPSS version 16. Frequency distribution of the variables of interest was done. Difference in failure rate of intramedullary nail versus DCP was tested using chi-square. Statistical significance was inferred at p<0.05. A total of 280 patients were studied out of which two hundred and twenty-one patients had long bone diaphyseal fractures and met inclusion criteria, of which 135 had intramedullary nail fixation and 86 had DCP. The rate of implant failure in intramedullary nail was 1.5% while it was 5.8% in patients with DCP (p=0.113; 0R=4.10; 95% CI=0.65- 43.77). Implant fracture was the commonest type of failure seen (100% versus 60%) and non union was the commonest cause of failure seen (50% versus 40%) in the intramedullary nailing and DCP groups respectively. The likelihood of a failed implant is higher in fixations done with DCP compared with intramedullary nail though the difference was not statistically significant. Commonest reason for failure in both groups was non-union. Findings from this study may guide surgeons in choice of implant in the management of long bone fractures.

Comparative evaluation of subgrade resilient modulus from non-destructive, in-situ, and laboratory methods.

DOT National Transportation Integrated Search

2007-08-01

Field and laboratory testing programs were conducted to develop models that predict the resilient modulus of subgrade soils from : the test results of DCP, CIMCPT, FWD, Dynaflect, and soil properties. The field testing program included DCP, CIMCPT, F...

Liver Full Reference Set Application: Hiro Yamada - Wako (2011) — EDRN Public Portal

Cancer.gov

Wako has received new 510(k) clearance for Lens culinaris agglutinin-reactive fraction of alpha-fetoprotein (AFP-L3) and Des-gamma-carboxy prothrombin (DCP) tests on an innovative μTASWako i30 analyzer from FDA. The AFP-L3 and DCP assayed on an older platform LiBASys have been cleared with indication of use for risk assessment of hepatocellular carcinoma (HCC) in patient at risk for the liver malignancy. Wako believes that early detection of HCC is critical for improving HCC patient outcome. Therefore, Wako is currently seeking collaborative opportunities to retrospectively measure clinical samples using the AFP-L3 and DCP for further determining of effectiveness of the HCC biomarkers in early detection which are collected prospectively during HCC surveillance. The Reference Sample Set in the EDRN biorepository are well characterized and studied. Access to these samples would allow Wako to quickly determine the clinical effectiveness of AFP-L3 and DCP in detecting early HCC

Endocrine actions of pesticides measured in the Flemish environment and health studies (FLEHS I and II).

PubMed

Croes, K; Den Hond, E; Bruckers, L; Govarts, E; Schoeters, G; Covaci, A; Loots, I; Morrens, B; Nelen, V; Sioen, I; Van Larebeke, N; Baeyens, W

2015-10-01

Within the Flemish Environment and Health studies (FLEHS I, 2002-2006, and FLEHS II, 2007-2012), pesticide exposure, hormone levels and degree of sexual maturation were measured in 14-15-year-old adolescents residing in Flanders (Belgium). In FLEHS II, geometric mean concentrations (with 95 % confidence interval (CI)) of 307 (277-341) and 36.5 ng L(-1) (34.0-39.2) were found for p,p'-dichlorophenyldichloroethylene (p,p'-DDE) and hexachlorobenzene (HCB). These values were respectively 26 and 60 % lower than levels in FLEHS I, 5 years earlier. Metabolites of organophosphorus pesticides (OPPs) and of para-dichlorobenzene were measured for the first time in FLEHS II, yielding concentrations of 11.4, 3.27 and 1.57 μg L(-1) for the sum of dimethyl- and diethyl phosphate metabolites and 2,5-dichlorophenol (2,5-DCP), respectively. Data on internal exposure of HCB showed a positive correlation with sexual maturation, testosterone and the aromatase index for boys and with free thyroxine (fT4) and thyroid stimulating hormone (TSH) (both boys and girls). For both p,p'-DDE and HCB, a negative association with sexual development in girls was found. The OPP metabolites were negatively associated with sex hormone levels in the blood of boys and with sexual maturation (both boys and girls). The pesticide metabolite 2,5-DCP was negatively correlated with free T4, while a positive association with TSH was reported (boys and girls). These results show that even exposure to relatively low concentrations of pesticides can have significant influences on hormone levels and the degree of sexual maturation in 14-15-year-old adolescents.

Stabilization of enzymatically polymerized phenolic chemicals in a model soil organic matter-free geomaterial.

PubMed

Palomo, Mónica; Bhandari, Alok

2012-01-01

A variety of remediation methods, including contaminant transformation by peroxidase-mediated oxidative polymerization, have been proposed to manage soils and groundwater contaminated with chlorinated phenols. Phenol stabilization has been successfully observed during cross polymerization between phenolic polymers and soil organic matter (SOM) for soils with SOM >3%. This study evaluates peroxidase-mediated transformation and removal of 2,4-dichlorophenol (DCP) from an aqueous phase in contact with a natural geomaterial modified to contain negligible (<0.3%) SOM. The results are compared with those for soils with higher SOM. The SOM-free sorbent was generated by removing SOM using a NaOCl oxidation. When horseradish peroxidase (HRP) was used to induce polymerization of DCP, the soil-water phase distribution relationship (PDR) of DCP polymerization products (DPP) was complete within 1 d and PDRs did not significantly change over the 28 d of study. The conversion of DCP to DPP was close to 95% efficient. Extractable solute consisted entirely of DPP with 5% or less of unreacted DCP. The aqueous extractability of DPP from SOM-free geomaterial decreased at longer contact times and at smaller residual aqueous concentrations of DPP. DCP stabilization appeared to have resulted from a combination of sorption, precipitation, and ligand exchange between oligomeric products and the exposed mineral surfaces. Modification of the mineral surface through coverage with DPP enhanced the time-dependent retention of the oligomers. DPP stabilization in SOM-free geomaterial was comparable with that reported in the literature with soil containing SOM contents >1%. Results from this study suggest that the effectiveness of HRP-mediated stabilization of phenolic compounds not only depends on the cross-coupling with SOM, but also on the modification of the surface of the sorbent that can augment affinity with oligomers and enhance stabilization. Coverage of the mineral surface by phenolic oligomers may be analogous to SOM that can potentially sorb other xenobiotics. HRP- mediated reactions can be used to stabilize DCP associated with low SOM mineral soils or aquifer media, thereby restricting the transport of phenolic contaminants in the soil environment. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Effects of dietary inclusion of citrus pulp and rockrose soft stems and leaves on lamb meat quality and fatty acid composition.

PubMed

Francisco, A; Alves, S P; Portugal, P V; Dentinho, M T; Jerónimo, E; Sengo, S; Almeida, J; Bressan, M C; Pires, V M R; Alfaia, C M; Prates, J A M; Bessa, R J B; Santos-Silva, J

2018-04-01

Meat from lambs finished with high-starch diets often contains low concentration of vaccenic (t11-18:1) and rumenic (c9,t11-18:2) acids and high concentration of t10-18:1. We hypothesized that replacing cereals by dehydrated citrus pulp (DCP) and the inclusion of tanniferous feed sources in oil supplemented diets might reduce the accumulation of t10-18:1 and increase the t11-18:1 and c9,t11-18:2 in lamb meat, without affecting the productive performance. In total, 32 lambs were assigned to four diets which combine two factors: basal diet (BD) (cereals v. DCP) and Cistus ladanifer (CL) (0 v. 150 g/kg dry matter). Feed intake, average daily weight gain and carcass traits were not affected by treatments, except for dressing percentage that was reduced with DCP (P=0.046). Both DCP and C. ladanifer reduced tenderness and juiciness of meat, and C. ladanifer also reduced (P0.05) by diets. However, DCP increased the proportions of odd-chain FA (P=0.005) and several minor biohydrogenation (BH) intermediates in meat lipids. C. ladanifer had few effects on meat FA profile. The proportions of t11-18:1 and c9,t11-18:2 were high in all diets (5.4% and 1.5% of total FA, respectively) and were not influenced by the treatments. Basal diet and CL showed some significant interactions concerning FA composition of intramuscular fat. In diets without C. ladanifer, replacement of cereals by DCP increased the 18:0 (P<0.05) and decreased t10,c12-18:2 (P<0.05), t10-18:1 (P<0.10) and t10-/t11-18:1 ratio (P<0.10) with a large reduction of the individual variation for t10-18:1 and of t10-/t11-18:1 ratio. Combined with cereals, C. ladanifer increased 18:0 and reduced the BH intermediates in meat. Replacement of cereals by DCP seems to promote a more predictable FA profile in lamb meat, reducing the risk of t10-shifted BH pathways in the rumen.

Comparative studies on crosslinked and uncrosslinked natural rubber biodegradation by Pseudomonas sp.

PubMed

Roy, Ram Vinod; Das, Mithu; Banerjee, Rintu; Bhowmick, Anil K

2006-12-01

A comparative study on biodegradation of di-cumyl peroxide (DCP) crosslinked and uncrosslinked natural rubber by Pseudomonas sp. was carried out. Decrease in organic carbon content along with the changes in tensile strength of the treated rubber, both DCP crosslinked and uncrosslinked natural rubber, indicated rubber hydrocarbon utilization by the Pseudomonas sp. A decrease in 60.88% MPa and 41.66% MPa was observed after five month's old treated uncrosslinked natural rubber and DCP crosslinked rubber, respectively. Biodegradation was more pronounced in natural uncrosslinked rubber, which was further confirmed by the formation of aldehydic compounds with decrease in CH2 stretching frequencies.

Toxicant inhibition in activated sludge: fractionation of the physiological status of bacteria.

PubMed

Foladori, P; Bruni, L; Tamburini, S

2014-09-15

In wastewater treatment plants the sensitivity of activated sludge to a toxicant depends on the toxicity test chosen, and thus the use of more than one test is suggested. The physiological status of bacteria in response to toxicants was analysed by flow cytometry to distinguish intact, permeabilised, active cells and cells disrupted. Results were compared with respirometry and bioluminescence bioassay (Vibrio fischeri). 3,5-Dichlorophenol (DCP) was used as reference xenobiotic. DCP has a strong effect on cellular integrity, causing an increase in permeabilised and disrupted cells. A reduction of 44-80% of intact cells with 6-30 mgDCP/L for 5h was found. Inhibition of active cells was 25-49%, at 6-30 mgDCP/L for 5h. The bioluminescence bioassay resulted oversensitive to DCP compared to tests based on activated sludge, while oxygen uptake rate was affected similarly to intact cells measured by flow cytometry. Landfill leachate was tested: a detrimental impact on both cellular integrity and enzymatic activity was observed. Reduction of intact cells and active cells was by 32% and 61% respectively after addition of 50% (v/v) of leachate for 5h. The flow cytometry analysis proposed here might be widely applicable in the monitoring of various toxicants and in other aquatic biosystems. Copyright © 2014 Elsevier B.V. All rights reserved.

Cyanidin-3-O-Glucoside Protects against 1,3-Dichloro-2-Propanol-Induced Reduction of Progesterone by Up-regulation of Steroidogenic Enzymes and cAMP Level in Leydig Cells

PubMed Central

Sun, Jianxia; Xu, Wei; Zhu, Cuijuan; Hu, Yunfeng; Jiang, Xinwei; Ou, Shiyi; Su, Zhijian; Huang, Yadong; Jiao, Rui; Bai, Weibin

2016-01-01

1,3-Dichloro-2-propanol (1,3-DCP) is a food processing contaminant and has been shown to perturb male reproductive function. Cyanidin-3-O-glucoside (C3G), an anthocyanin antioxidant, is reported to have protective effects on many organs. However, it remains unclear whether C3G protects against chemical-induced reproductive toxicity. The present study was therefore to investigate the intervention of C3G on 1,3-DCP-induced reproductive toxicity in R2C Leydig cells. Results demonstrated that C3G inhibited the 1,3-DCP-induced cytotoxicity and cell shape damage with the effective doses being ranging from 10 to 40 μmol/L. In addition, 1,3-DCP (2 mmol/L) exposure significantly increased the ROS level and mitochondrial membrane potential damage ratio, leading to a decrease in progesterone production, while C3G intervention reduced the ROS level, and increased the progesterone production after 24 h treatment. Most importantly, C3G intervention could up-regulate the cyclic adenosine monophosphate (cAMP) level and protein expression of steroidogenic acute regulatory protein and 3β-hydroxysteroid dehydrogenase. It was concluded that C3G is effective in reducing 1,3-DCP-induced reproductive toxicity via activating steroidogenic enzymes and cAMP level. PMID:27867356

Electronic thermal sensor and Data Collection Platform technology: Part 5 in Thermal surveillance of active volcanoes using the Landsat-1 Data Collection System

USGS Publications Warehouse

Preble, Duane M.; Friedman, Jules D.; Frank, David

1976-01-01

Five Data Collection Platforms (DCP) were integrated electronically with thermall sensing systems, emplaced and operated in an analog mode at selected thermally significant volcanic and geothermal sites. The DCP's transmitted 3260 messages comprising 26,080 ambient, surface, and near-surface temperature records at an accuracy of ±1.15 °C for 1121 instrument days between November 14, 1972 and April 17, 1974. In harsh, windy, high-altitude volcanic environments the DCP functioned best with a small dipole antenna. Sixteen kg of alkaline batteries provided a viable power supply for the DCP systems, operated at a low-duty cycle, for 5 to 8 months. A proposed solar power supply system would lengthen the period of unattended operation of the system considerably. Special methods of data handling such as data storage via a proposed memory system would increase the significance of the twice-daily data reception enabling the DCP's to record full diurnal-temperature cycles at volcanic or geothermal sites. Refinements in the temperature-monitoring system designed and operated in experiment SR 251 included a backup system consisting of a multipoint temperature scanner, a servo mechanism and an analog-to-digital recorder. Improvements were made in temperature-probe design and in construction of corrosion-resistant seals by use of a hydrofluoric-acid-etching technique.

Bioelectrochemical biosensor for water toxicity detection: generation of dual signals for electrochemical assay confirmation.

PubMed

Yang, Yuan; Wang, Yan-Zhai; Fang, Zhen; Yu, Yang-Yang; Yong, Yang-Chun

2018-02-01

Toxicity assessment of water is of great important to the safety of human health and to social security because of more and more toxic compounds that are spilled into the aquatic environment. Therefore, the development of fast and reliable toxicity assessment methods is of great interest and attracts much attention. In this study, by using the electrochemical activity of Shewanella oneidensis MR-1 cells as the toxicity indicator, 3,5-dichlorophenol (DCP) as the model toxic compound, a new biosensor for water toxicity assessment was developed. Strikingly, the presence of DCP in the water significantly inhibited the maximum current output of the S. oneidensis MR-1 in a three-electrode system and also retarded the current evolution by the cells. Under the optimized conditions, the maximum current output of the biosensor was proportional to the concentration of DCP up to 30 mg/L. The half maximal inhibitory concentration of DCP determined by this biosensor is about 14.5 mg/L. Furthermore, simultaneous monitoring of the retarded time (Δt) for current generation allowed the identification of another biosensor signal in response to DCP which could be employed to verify the electrochemical result by dual confirmation. Thus, the present study has provided a reliable and promising approach for water quality assessment and risk warning of water toxicity.

Cyanidin-3-O-Glucoside Protects against 1,3-Dichloro-2-Propanol-Induced Reduction of Progesterone by Up-regulation of Steroidogenic Enzymes and cAMP Level in Leydig Cells.

PubMed

Sun, Jianxia; Xu, Wei; Zhu, Cuijuan; Hu, Yunfeng; Jiang, Xinwei; Ou, Shiyi; Su, Zhijian; Huang, Yadong; Jiao, Rui; Bai, Weibin

2016-01-01

1,3-Dichloro-2-propanol (1,3-DCP) is a food processing contaminant and has been shown to perturb male reproductive function. Cyanidin-3- O -glucoside (C3G), an anthocyanin antioxidant, is reported to have protective effects on many organs. However, it remains unclear whether C3G protects against chemical-induced reproductive toxicity. The present study was therefore to investigate the intervention of C3G on 1,3-DCP-induced reproductive toxicity in R2C Leydig cells. Results demonstrated that C3G inhibited the 1,3-DCP-induced cytotoxicity and cell shape damage with the effective doses being ranging from 10 to 40 μmol/L. In addition, 1,3-DCP (2 mmol/L) exposure significantly increased the ROS level and mitochondrial membrane potential damage ratio, leading to a decrease in progesterone production, while C3G intervention reduced the ROS level, and increased the progesterone production after 24 h treatment. Most importantly, C3G intervention could up-regulate the cyclic adenosine monophosphate (cAMP) level and protein expression of steroidogenic acute regulatory protein and 3β-hydroxysteroid dehydrogenase. It was concluded that C3G is effective in reducing 1,3-DCP-induced reproductive toxicity via activating steroidogenic enzymes and cAMP level.

Reactive processing of biodegradable polyesters with dicumyl peroxide: A structural, rheological and property study

NASA Astrophysics Data System (ADS)

Canale, Philip Louis

Studies were undertaken to gain an understanding as to the mechanistic, rheological, thermal, and mechanical property effects that can be expected by reactively extruding biodegradable polyesters with dicumyl peroxide (DCP). The two main polymers used were poly(epsilon-caprolactone), (PCL), and proprietary copolyester, Eastar 14766. The reactive extrusions were carried out at 160°C at various DCP levels. The percent branching and type of branching, (tetraor tri-functional), were determined by SEC and by the comparison of branched distributions to statistical models. It was found that PCL quantitatively formed tetra-functional branches while the Eastar 14766 formed a combination of tri- and tetra-functional branch points. The Eastar 14766 was also shown to be more reactive than the PCL, with half as much DCP being required to achieve equivalent amounts of branching. Thermal properties were studied by differential scanning calorimetry. In a multi-phase, upper critical solution temperature (UCST) system, such as Eastar 14766, the branches resulted in a compatiblization effect. This was shown as an increase in the glass transition temperature rising with the DCP level used in the reactive extrusion. The crystallization temperature decreased, and the heat of melting increased as the amount of branching/DCP level increased. The latter was attributed to the lower stereo regularity and/or the lower crystallization rate. The crystallization temperature increase is attributed to increased kinetics required, due to slower phase separation or increased viscosity. Branching/DCP level was shown to have a smaller effect on PCL, with the largest effect being an 11% relative decrease in heat of melting at the highest DCP level. Rheology studies showed that both Eastar 14766 and PCL displayed typical branching behavior with increases in melt elasticity and zero shear viscosity. An estimate of the plateau modulus revealed the entanglement molecular weight for Eastar 14766 to be approximately three times lower than that of PCL. This explained why Eastar 14766 had a larger enhancement in zero shear viscosity and elasticity than PCL. It was also noted, qualitatively, that branching in both materials produced a broadened elastic modulus curve. This was attributed to the difference in the molecular weight/relaxation time relationship between linear and branched materials. Tensile modulus and elongation studies showed PCL to be insensitive to branching. However, studies with Eastar 14766 showed tensile strength and elongation at break to be increased 30 and 10% respectively with branching. Tensile modulus on the other hand, remained relatively unchanged. These effects were attributed to phase changes due to increased compatibilization of the copolymer. A brief study of a 50/50 blend of Eastar 14766 and Poly(lactic acid) with and without DCP showed that the blend with DCP had a similar tensile strength. However, the ultimate elongation increased by 150% and the modulus decreased of 26%. This shows the possible utility of reactive blending with peroxides in order to achieve a higher degree of compatibilization in a blend.

76 FR 63915 - DCP Midstream, LP; Notice of Application

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-14

... application pursuant to Section 7(c) of the Natural Gas Act and Part 157 of the Commission's Regulations, for... diameter pipeline (the LaSalle Residue Line) connecting DCP's new non-jurisdictional natural gas processing... non-jurisdictional gas gathering company having facilities in Texas, Oklahoma, New Mexico, Louisiana...

76 FR 8725 - Notice of Baseline Filings

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-15

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Notice of Baseline Filings Enstor Grama Ridge Storage and Docket No. PR10-97-002. Transportation, L.L.C.. EasTrans, LLC Docket No. PR10-30-001. DCP Guadalupe Pipeline, LLC...... Docket No. PR10-31-002. DCP Raptor Pipeline, LLC......... Docket No...

78 FR 43190 - DCP Midstream, LP; Notice of Application

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-19

... capacity of 230 MMcf/day and will be used for transportation of natural gas solely on behalf of DCP without... will either: complete its environmental assessment (EA) and place it into the Commission's public... anticipated date for the Commission staff's issuance of the final environmental impact statement (FEIS) or EA...

Elevated alpha-fetoprotein: differential diagnosis - hepatocellular carcinoma and other disorders.

PubMed

Wong, Robert J; Ahmed, Aijaz; Gish, Robert G

2015-05-01

The incidence of cirrhosis-related hepatocellular carcinoma (HCC) is rising. Curative surgical options are available; outcomes are acceptable with early diagnosis. Lens culinaris agglutinin-reactive fraction of alpha-fetoprotein (AFP-L3) and des-gamma-carboxy prothrombin (DCP) are HCC risk markers. A high or increasing serum biomarker level can be predictive of the eventual development of HCC, large tumor size, advanced stage, extrahepatic metastases, portal vein thrombosis, and postoperative HCC recurrence. Based on FDA guidelines for HCC risk assessment, clinicians can consider using either the combination of AFP-L3 with DCP, or the combination of AFP-L3 with AFP and DCP. Copyright © 2015 Elsevier Inc. All rights reserved.

75 FR 9201 - DCP Raptor Pipeline, LLC; Notice of Compliance Filing

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-01

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. PR09-32-002] DCP Raptor... Raptor Pipeline, LLC (Raptor) filed its Statement of Operating Conditions in compliance with the January 27, 2010 Letter Order (January 27th Letter Order) in Docket Nos. PR09-32-000 and PR09-32-001. Raptor...

The Problem with the Delta Cost Project Database

ERIC Educational Resources Information Center

Jaquette, Ozan; Parra, Edna

2016-01-01

The Integrated Postsecondary Education System (IPEDS) collects data on Title IV institutions. The Delta Cost Project (DCP) integrated data from multiple IPEDS survey components into a public-use longitudinal dataset. The DCP Database was the basis for dozens of journal articles and a series of influential policy reports. Unfortunately, a flaw in…

Ultrasonometry evaluation of axial compression osteosinthesis. An experimental study

PubMed Central

Bezuti, Márcio Takey; Mandarano, Luiz Garcia; Barbieri, Giuliano; Mazzer, Nilton; Barbieri, Cláudio Henrique

2013-01-01

OBJECTIVE: To measure the ultrasound propagation velocity (UV) through a tibial transverse osteotomy in sheep, before and after the fixation with a DCP plate. MATERIAL AND METHODS: Ten assemblies of a DCP plate with the diaphyseal segment of tibiae, in which a transverse osteotomy was made, were used. Both coronal and sagittal transverse and the axial UV were measured, first with the intact bone assembled with the plate and then with the uncompressed and compressed osteotomy; statistical comparisons were made at the 1% (p<0.01) level of significance. RESULTS: Compared with the intact bone assembly, axial UV significantly decreased with the addition of the osteotomy and significantly increased with compression, presenting the same behavior for the other modalities, although not significantly. DISCUSSION AND CONCLUSION: In accordance with the literature data on the ultrasonometric evaluation of fracture healing, underwater UV measurement was able to demonstrate the efficiency of DCP plate fixation. The authors conclude that the method has a potential for clinical application in the postoperative follow-up of DCP plate osteosinthesis, with a capability to demonstrate when it becomes ineffective. Laboratory investigation. PMID:24453644

Sharp organic interface of molecular C60 chains and a pentacene derivative SAM on Au(788): A combined STM & DFT study

NASA Astrophysics Data System (ADS)

Wang, Jun; Tang, Jian-Ming; Larson, Amanda M.; Miller, Glen P.; Pohl, Karsten

2013-12-01

Controlling the molecular structure of the donor-acceptor interface is essential to overcoming the efficiency bottleneck in organic photovoltaics. We present a study of self-assembled fullerene (C60) molecular chains on perfectly ordered 6,13-dichloropentacene (DCP) monolayers forming on a vicinal Au(788) surface using scanning tunneling microscopy in conjunction with density functional theory calculations. DCP is a novel pentacene derivative optimized for photovoltaic applications. The molecules form a brick-wall patterned centered rectangular lattice with the long axis parallel to the monatomic steps that separate the 3.9 nm wide Au(111) terraces. The strong interaction between the C60 molecules and the gold substrate is well screened by the DCP monolayer. At submonolayer C60 coverage, the fullerene molecules form long parallel chains, 1.1 nm apart, with a rectangular arrangement instead of the expected close-packed configuration along the upper step edges. The perfectly ordered DCP structure is unaffected by the C60 chain formation. The controlled sharp highly-ordered organic interface has the potential to improve the conversion efficiency in organic photovoltaics.

Decapping activators in Saccharomyces cerevisiae act by multiple mechanisms.

PubMed

Nissan, Tracy; Rajyaguru, Purusharth; She, Meipei; Song, Haiwei; Parker, Roy

2010-09-10

Eukaryotic mRNA degradation often occurs in a process whereby translation initiation is inhibited and the mRNA is targeted for decapping. In yeast cells, Pat1, Scd6, Edc3, and Dhh1 all function to promote decapping by an unknown mechanism(s). We demonstrate that purified Scd6 and a region of Pat1 directly repress translation in vitro by limiting the formation of a stable 48S preinitiation complex. Moreover, while Pat1, Edc3, Dhh1, and Scd6 all bind the decapping enzyme, only Pat1 and Edc3 enhance its activity. We also identify numerous direct interactions between Pat1, Dcp1, Dcp2, Dhh1, Scd6, Edc3, Xrn1, and the Lsm1-7 complex. These observations identify three classes of decapping activators that function to directly repress translation initiation and/or stimulate Dcp1/2. Moreover, Pat1 is identified as critical in mRNA decay by first inhibiting translation initiation, then serving as a scaffold to recruit components of the decapping complex, and finally activating Dcp2. Copyright © 2010 Elsevier Inc. All rights reserved.

Novel Dehalogenase Mechanism for 2,3-Dichloro-1-Propanol Utilization in Pseudomonas putida Strain MC4

PubMed Central

Arif, Muhammad Irfan; Samin, Ghufrana; van Leeuwen, Jan G. E.; Oppentocht, Jantien

2012-01-01

A Pseudomonas putida strain (MC4) that can utilize 2,3-dichloro-1-propanol (DCP) and several aliphatic haloacids and haloalcohols as sole carbon and energy source for growth was isolated from contaminated soil. Degradation of DCP was found to start with oxidation and concomitant dehalogenation catalyzed by a 72-kDa monomeric protein (DppA) that was isolated from cell lysate. The dppA gene was cloned from a cosmid library and appeared to encode a protein equipped with a signal peptide and that possessed high similarity to quinohemoprotein alcohol dehydrogenases (ADHs), particularly ADH IIB and ADH IIG from Pseudomonas putida HK. This novel dehalogenating dehydrogenase has a broad substrate range, encompassing a number of nonhalogenated alcohols and haloalcohols. With DCP, DppA exhibited a kcat of 17 s−1. 1H nuclear magnetic resonance experiments indicated that DCP oxidation by DppA in the presence of 2,6-dichlorophenolindophenol (DCPIP) and potassium ferricyanide [K3Fe(CN)6] yielded 2-chloroacrolein, which was oxidized to 2-chloroacrylic acid. PMID:22752160

Color tuning in neodymium doped dicalcium silicate nanostructures prepared via ultrasound method

NASA Astrophysics Data System (ADS)

Venkataravanappa, M.; Nagabhushana, H.; Basavaraj, R. B.; Venkatachalaiah, K. N.; Prasad, B. Daruka

2017-05-01

Blue light emitting neodymium (Nd) doped dicalcium (Ca2SiO4) silicate nanostructures were prepared for the first time via ultrasound assisted sonochemical synthesis route using cetyltrimethylammonium bromide (CTAB) surfactant. The obtained final product was well characterized. The powder X-ray diffraction (PXRD) profiles confirmed that product was highly crystalline in nature with monoclinic phase. Influence of various reaction parameters such as, the effect of sonication time, concentration of the surfactant and pH of the precursor solution on the morphology was studied in detail. Diffuse reflectance spectroscopy (DRS) was studied to evaluate the band gap energy of the products and the values were found in the range of 5.78 - 6.17 eV. The particle size was estimated by transmission electron microscope (TEM) and it was found in the range of 20-30 nm. Photoluminescence (PL) properties were studied in detail by recording emission spectra of all the Nd doped dicalcium silicate nanostructures at an excitation wavelength of 380 nm. The emission peaks were observed at 469, 520, 545 and 627 nm which corresponds to Nd3+ ion transitions. The 7 mol% Nd3+ doped Ca2SiO4 nanostructures showed maximum intensity. Further photometric measurements were done by evaluating, Commission International De I-Eclairage (CIE) and correlated color temperature (CCT). From CIE it was observed that the color coordinates lies in blue-green region, which slightly shifts to green as the Nd3+ concentration increases. The color purity and quantum efficiency were also estimated and the results indicate that the nanophosphor obtained in this route can be used in preparing light emitting diodes with a blue-green emission as prominent color.

Toxicity and metabolism of 2,4-dichlorophenol by the aquatic angiosperm Lemna gibba

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ensley, H.E.; Barber, J.T.; Polito, M.A.

1994-02-01

The toxicity and metabolism of 2,4-dichlorophenol with regard to the aquatic macrophyte Lemna gibba (duckweed), have been studied. Toxicity is described in terms of the effect of 2,4-dichlorophenol (2,4-DCP) on the vegetative reproduction of duckweed over a 10-d growth period; the EC10 and EC50 were 2.5 and 9.2 [mu]M, respectively. Metabolism of 2,4-dichlorophenol was monitored by incubation of the plants with radiolabeled substrate, and periodic sampling and analysis by reversed-phase HPLC of the plant growth medium. Depending on the growth conditions, up to 95% of the 2,4-DCP was metabolized over a 6-d growth period. To analyze the metabolites, the plantsmore » were grown in the presence of sublethal concentrations of [U-[sup 14]C]-2,4-DCP. The growth medium was lyophilized and then mixed with the plants, extracted, and analyzed using reversed-phase HPLC, followed by scintillation counting of the fractions. The major metabolite was isolated and identified as 2,4-dichlorophenol-[beta]-D-glucopyranoside by high-field NMR and MS. The structure of the metabolite was confirmed by synthesis and by enzymatic cleavage of the [beta]-glucosidic linkage to afford 2,4-DCP. An important consequence of conjugate formation is the masking of the presence of 2,4-DCP to the usual analytical techniques used for its detection and quantitation. This finding is probably applicable to other contaminants and organisms.« less

Synthesis and characterization of Ag₃PO₄ immobilized with graphene oxide (GO) for enhanced photocatalytic activity and stability over 2,4-dichlorophenol under visible light irradiation.

PubMed

Chen, Xiao-juan; Dai, You-zhi; Wang, Xing-yan; Guo, Jing; Liu, Tan-hua; Li, Fen-fang

2015-07-15

A series of visible-light responsive photocatalysts prepared using Ag3PO4 immobilized with graphene oxide (GO) with varying GO content were obtained by an electrostatically driven method, and 2,4-dichlorophenol (2,4-DCP) was used to evaluate the performance of the photocatalysts. The composites exhibited superior photocatalytic activity and stability compared with pure Ag3PO4. When the content of GO was 5%, the degradation efficiency of 2,4-DCP could reach 98.95%, and 55.91% of the total organic (TOC) content was removed within 60 min irradiation. Meanwhile, the efficiency of 91.77% was achieved for 2,4-DCP degradation even after four times of recycling in the photocatalysis/Ag3PO4-GO (5%) system. Reactive species of O2(˙-), OH˙ and h(+) were considered as the main participants for oxidizing 2,4-DCP, as confirmed by the free radical capture experiments. And some organic intermediates including 4-chlorophenol (4-CP), hydroquinone (HQ), benzoquinone (BZQ), 2-chlorohydroquinone and hydroxyhydroquinone (HHQ) were detected by comparison with the standard retention times from the high performance liquid chromatography (HPLC). In short, the enhanced photocatalytic property of Ag3PO4-GO was closely related to the strong absorption ability of GO relative to 2,4-DCP, the effective separation of photogenerated electron-hole pairs, and the excellent electron capture capability of GO. Copyright © 2015. Published by Elsevier B.V.

Efficient peroxydisulfate activation process not relying on sulfate radical generation for water pollutant degradation.

PubMed

Zhang, Tao; Chen, Yin; Wang, Yuru; Le Roux, Julien; Yang, Yang; Croué, Jean-Philippe

2014-05-20

Peroxydisulfate (PDS) is an appealing oxidant for contaminated groundwater and toxic industrial wastewaters. Activation of PDS is necessary for application because of its low reactivity. Present activation processes always generate sulfate radicals as actual oxidants which unselectively oxidize organics and halide anions reducing oxidation capacity of PDS and producing toxic halogenated products. Here we report that copper oxide (CuO) can efficiently activate PDS under mild conditions without producing sulfate radicals. The PDS/CuO coupled process is most efficient at neutral pH for decomposing a model compound, 2,4-dichlorophenol (2,4-DCP). In a continuous-flow reaction with an empty-bed contact time of 0.55 min, over 90% of 2,4-DCP (initially 20 μM) and 90% of adsorbable organic chlorine (AOCl) can be removed at the PDS/2,4-DCP molar ratio of 1 and 4, respectively. Based on kinetic study and surface characterization, PDS is proposed to be first activated by CuO through outer-sphere interaction, the rate-limiting step, followed by a rapid reaction with 2,4-DCP present in the solution. In the presence of ubiquitous chloride ions in groundwater/industrial wastewater, the PDS/CuO oxidation shows significant advantages over sulfate radical oxidation by achieving much higher 2,4-DCP degradation capacity and avoiding the formation of highly chlorinated degradation products. This work provides a new way of PDS activation for contaminant removal.

Simultaneous identification and quantification of 4-cumylphenol, 2,4-bis-(dimethylbenzyl)phenol and bisphenol A in prawn Macrobrachium rosenbergii.

PubMed

Zuo, Yuegang; Zhu, Zhuo

2014-07-01

Bisphenol A (BPA), 4-cumylphenol (4-CP) and 2,4-bis-(dimethylbenzyl)phenol (2,4-DCP) are all high production volume chemicals and widely used in plastic and other consumer products. During the past two decades, BPA has attracted a great deal of scientific and public attention due to its presence in the environment and estrogenic property. Although 4-CP and 2,4-DCP are much more estrogenic and toxic than BPA, little information is available about their occurrence and fate in the environment. In this study, a rapid, selective, accurate and reliable analytical method was developed for the simultaneous determination of 4-CP, 2,4-DCP and BPA in prawn Macrobrachium rosenbergii. The method comprises an ultrasound-accelerated extraction followed by capillary gas chromatographic (GC) separation. The detection limits range from 1.50 to 36.4 ng kg(-1) for the three alkylphenols. The calibration curves are linear over the concentration range tested with the coefficients of determination, R(2), greater than 0.994. The developed method was successfully applied to the simultaneous determination of 4-CP, 2,4-DCP and BPA in prawn samples. The peak identification was confirmed using GC-MS. Bisphenol A, 2,4-bis-(dimethylbenzyl)phenol and 4-cumylphenol were found in prawn samples in the concentration ranges of 0.67-5.51, 0.36-1.61, and 0.00-1.96 ng g(-1) (wet weight), respectively. All relative standard deviations are less than 4.8%. At these environmentally relevant concentration levels, 4-CP, 2,4-DCP and BPA may affect the reproduction and development of aquatic organisms, including negative influence on crustaceans' larval survival, molting, metamorphosis and shell hardening. This is the first study reported on the occurrence of 4-CP, 2,4-DCP and BPA in prawn M. rosenbergii. Copyright © 2014 Elsevier Ltd. All rights reserved.

Energy efficiency of digestible protein, fat and carbohydrate utilisation for growth in rainbow trout and Nile tilapia.

PubMed

Schrama, Johan W; Haidar, Mahmoud N; Geurden, Inge; Heinsbroek, Leon T N; Kaushik, Sachi J

2018-04-01

Currently, energy evaluation of fish feeds is performed on a digestible energy basis. In contrast to net energy (NE) evaluation systems, digestible energy evaluation systems do not differentiate between the different types of digested nutrients regarding their potential for growth. The aim was to develop an NE evaluation for fish by estimating the energy efficiency of digestible nutrients (protein, fat and carbohydrates) and to assess whether these efficiencies differed between Nile tilapia and rainbow trout. Two data sets were constructed. The tilapia and rainbow data set contained, respectively, eight and nine experiments in which the digestibility of protein, fat and energy and the complete energy balances for twenty-three and forty-five diets was measured. The digestible protein (dCP), digestible fat (dFat) and digestible carbohydrate intakes (dCarb) were calculated. By multiple regression analysis, retained energy (RE) was related to dCP, dFat and dCarb. In tilapia, all digestible nutrients were linearly related to RE (P<0·001). In trout, RE was quadratically related to dCarb (P<0·01) and linearly to dCP and dFat (P<0·001). The NE formula was NE=11·5×dCP+35·8×dFAT+11·3×dCarb for tilapia and NE=13·5×dCP+33·0×dFAT+34·0×dCarb-3·64×(dCarb)2 for trout (NE in kJ/(kg0·8×d); dCP, dFat and dCarb in g/(kg0·8×d)). In tilapia, the energetic efficiency of dCP, dFat and dCarb was 49, 91 and 66 %, respectively, showing large similarity with pigs. Tilapia and trout had similar energy efficiencies of dCP (49 v. 57 %) and dFat (91 v. 84 %), but differed regarding dCarb.

5'-Phosphorothiolate Dinucleotide Cap Analogues: Reagents for Messenger RNA Modification and Potent Small-Molecular Inhibitors of Decapping Enzymes.

PubMed

Wojtczak, Blazej A; Sikorski, Pawel J; Fac-Dabrowska, Kaja; Nowicka, Anna; Warminski, Marcin; Kubacka, Dorota; Nowak, Elzbieta; Nowotny, Marcin; Kowalska, Joanna; Jemielity, Jacek

2018-05-09

The 5' cap consists of 7-methylguanosine (m 7 G) linked by a 5'-5'-triphosphate bridge to messenger RNA (mRNA) and acts as the master regulator of mRNA turnover and translation initiation in eukaryotes. Cap analogues that influence mRNA translation and turnover (either as small molecules or as part of an RNA transcript) are valuable tools for studying gene expression, which is often also of therapeutic relevance. Here, we synthesized a series of 15 dinucleotide cap (m 7 GpppG) analogues containing a 5'-phosphorothiolate (5'-PSL) moiety (i.e., an O-to-S substitution within the 5'-phosphoester) and studied their biological properties in the context of three major cap-binding proteins: translation initiation factor 4E (eIF4E) and two decapping enzymes, DcpS and Dcp2. While the 5'-PSL moiety was neutral or slightly stabilizing for cap interactions with eIF4E, it significantly influenced susceptibility to decapping. Replacing the γ-phosphoester with the 5'-PSL moiety (γ-PSL) prevented β-γ-pyrophosphate bond cleavage by DcpS and conferred strong inhibitory properties. Combining the γ-PSL moiety with α-PSL and β-phosphorothioate (PS) moiety afforded first cap-derived hDcpS inhibitor with low nanomolar potency. Susceptibility to Dcp2 and translational properties were studied after incorporation of the new analogues into mRNA transcripts by RNA polymerase. Transcripts containing the γ-PSL moiety were resistant to cleavage by Dcp2. Surprisingly, superior translational properties were observed for mRNAs containing the α-PSL moiety, which were Dcp2-susceptible. The overall protein expression measured in HeLa cells for this mRNA was comparable to mRNA capped with the translation augmenting β-PS analogue reported previously. Overall, our study highlights 5'-PSL as a synthetically accessible cap modification, which, depending on the substitution site, can either reduce susceptibility to decapping or confer superior translational properties on the mRNA. The 5'-PSL-analogues may find application as reagents for the preparation of efficiently expressed mRNA or for investigation of the role of decapping enzymes in mRNA processing or neuromuscular disorders associated with decapping.

Estimation of leaf area index and foliage clumping in deciduous forests using digital photography

NASA Astrophysics Data System (ADS)

Chianucci, Francesco; Cutini, Andrea

2013-04-01

Rapid, reliable and meaningful estimates of leaf area index (LAI) are essential to the characterization of forest ecosystems. In this contribution the accuracy of both fisheye and non-fisheye digital photography for the estimation of forest leaf area in deciduous stands was evaluated. We compared digital hemispherical photography (DHP), the most widely used technique that measures the gap fraction at multiple zenith angles, with methods that measure the gap fraction at a single zenith angle, namely 57.5 degree photography and cover photography (DCP). Comparison with other different gap fraction methods used to calculate LAI such as canopy transmittance measurements from AccuPAR ceptometer and LAI- 2000 Plant Canopy Analyzer (PCA) were also performed. LAI estimated from all these indirect methods were compared with direct measurements obtained by litter traps (LAILT). We applied these methods in 10 deciduous stands of Quercus cerris, Castanea sativa and Fagus sylvatica, the most common deciduous species in Italy, where LAILT ranged from 3.9 to 7.3. DHP and DCP provided good indirect estimates of LAILT, and outperformed the other indirect methods. The DCP method provided estimates of crown porosity, crown cover, foliage cover and the clumping index at the zenith, but required assumptions about the light extinction coefficient at the zenith (k), to accurately estimate LAI. Cover photography provided good indirect estimates of LAI assuming a spherical leaf angle distribution, even though k appeared to decrease as LAI increased, thus affecting the accuracy of LAI estimates in DCP. In contrast, the accuracy of LAI estimates in DHP appeared insensitive to LAILT values, but the method was sensitive to photographic exposure, gamma-correction and was more time-consuming than DCP. Foliage clumping was estimated from all the photographic methods by analyzing either gap size distribution (DCP) or gap fraction distribution (DHP). Foliage clumping was also calculated from PCA and compared with DHP. The studied stands were characterized by fairly homogeneous canopies with higher within-crown clumping than between-crowns clumping; only the segmented analysis of gap fraction for each ring of the fisheye images was found to provide useful clumping index in such homogeneous canopies. By contrast, the 1-azimuth segment method employed in PCA poorly detected clumping in dense canopies. We conclude both fisheye and non-fisheye photographic methods are suitable for dense deciduous forests. Cover photography holds great promise as a means to quickly obtain inexpensive estimates of LAI over large areas. However, in situations where no direct reference measurements of k are available, we recommend using both DHP and DCP, in order to cross-calibrate the two methods; DCP could then be used for more routinely indirect measurement and monitoring of LAI. Keywords: digital hemispherical photography, cover photography, litter trap, AccuPAR ceptometer, LAI-2000.

A comparison of simultaneous plasma, atomic absorption, and iron colorimetric determinations of major and trace constituents in acid mine waters

USGS Publications Warehouse

Ball, J.W.; Nordstrom, D. Kirk

1994-01-01

Sixty-three water samples collected during June to October 1982 from the Leviathan/Bryant Creek drainage basin were originally analyzed by simultaneous multielement direct-current plasma (DCP) atomic-emission spectrometry, flame atomic-absorption spectrometry, graphite-furnace atomic-absorption spectrometry (GFAAS) (thallium only), ultraviolet-visible spectrometry, and hydride-generation atomic-absorption spectrometry.Determinations were made for the following metallic and semi-metallic constituents: AI, As, B, Ba, Be, Bi, Cd, Ca, Cr, Co, Cu, Fe(11), Fe(total), Li, Pb, Mg, Mn, Mo, Ni, K, Sb, Se, Si, Na, Sr, TI, V, and Zn. These samples were re-analyzed later by simultaneous multielement inductively coupled plasma (ICP) atomic-emission spectrometry and Zeeman-corrected GFAAS to determine the concentrations of many of the same constituents with improved accuracy, precision, and sensitivity. The result of this analysis has been the generation of comparative concentration values for a significant subset of the solute constituents. Many of the more recently determined values replace less-than-detection values for the trace metals; others constitute duplicate analyses for the major constituents. The multiple determinations have yielded a more complete, accurate, and precise set of analytical data. They also have resulted in an opportunity to compare the performance of the plasma-emission instruments operated in their respective simultaneous multielement modes. Flame atomic-absorption spectrometry was judged best for Na and K and hydride-generation atomic-absorption spectrometry was judged best for As because of their lower detection limit and relative freedom from interelement spectral effects. Colorimetric determination using ferrozine as the color agent was judged most accurate, precise, and sensitive for Fe. Cadmium, lead, and vanadium concentrations were too low in this set of samples to enable a determination of whether ICP or DCP is a more suitable technique. Of the remaining elements, Ba, Be, Ca, Cr, Mg, Mn, Sr, and Zn have roughly equivalent accuracy, precision, and detection limit by ICP and DCP. Cobalt and Ni were determined to be better analyzed by ICP, because of lower detection limits; B, Cu, Mo, and Si were determined to be better analyzed by DCP, because of relative freedom from interferences. The determination oral by DCP was far more sensitive, owing to the use of a more sensitive wavelength, compared with the ICP. However, there is a very serious potential interference from a strong Ca emission line near the 396.15 nanometer DCP wavelength. Thus, there is no clear choice between the plasma techniques tested, for the determination oral. The ICP and DCP detection limits are typically between 0.001 and 0.5 milligrams per liter in acid mine waters. For those metals best analyzed by ICP and/or DCP, but below these limits, GFAAS is the method of choice because of its relatively greater sensitivity and specificity. Six of the elements were not determined by DCP, ICP or Zeeman-corrected GFAAS, and are not discussed in this report. These elements are: Bi, Fe(11), Li, Sb, Se, and TI.

Using H. Stephen Glenn's Developing Capable People Program with Adults in Montana: How Effective Is the Curriculum?

ERIC Educational Resources Information Center

Astroth, Kirk A.; Lorbeer, Scott

1998-01-01

Pre/posttest scores of 30 participants in H. Stephen Glenn's Developing Capable People (DCP) program offered by Montana Extension showed that DCP effectively increased the use of positive behaviors and decreased negative behaviors in adults interacting with youth. These changes were sustained over 18 months after program completion. (SK)

Grafting of Bacterial Polyhydroxybutyrate (PHB) onto Cellulose via In Situ Reactive Extrusion with Dicumyl Peroxide

Treesearch

Liqing Wei; Armando G. McDonald; Nicole M. Stark

2015-01-01

Polyhydroxybutyrate (PHB) was grafted onto cellulose fiber by dicumyl peroxide (DCP) radical initiation via in situ reactive extrusion. The yield of the grafted (cellulose-g-PHB) copolymer was recorded and grafting efficiency was found to be dependent on the reaction time and DCP concentration. The grafting mechanism was investigated by electron spin...

ORAL TOXICITY OF 1,3-DICHLOROPROPANE: ACUTE, SHORT-TERM, AND LONG-TERM STUDIES IN RATS

EPA Science Inventory

The objective of this investigation was to characterize the acute and short- and long-term toxic potency of orally administered 1,2-dichloropropane (DCP). In the acute and short-term studies, male rats of 250-300 g were gavaged with 0, 100, 250, 500, or 1000 mg DCP/kg in corn oil...

Similar Modes of Interaction Enable Trailer Hitch and EDC3 To Associate with DCP1 and Me31B in Distinct Protein Complexes▿ †

PubMed Central

Tritschler, Felix; Eulalio, Ana; Helms, Sigrun; Schmidt, Steffen; Coles, Murray; Weichenrieder, Oliver; Izaurralde, Elisa; Truffault, Vincent

2008-01-01

Trailer Hitch (Tral or LSm15) and enhancer of decapping-3 (EDC3 or LSm16) are conserved eukaryotic members of the (L)Sm (Sm and Like-Sm) protein family. They have a similar domain organization, characterized by an N-terminal LSm domain and a central FDF motif; however, in Tral, the FDF motif is flanked by regions rich in charged residues, whereas in EDC3 the FDF motif is followed by a YjeF_N domain. We show that in Drosophila cells, Tral and EDC3 specifically interact with the decapping activator DCP1 and the DEAD-box helicase Me31B. Nevertheless, only Tral associates with the translational repressor CUP, whereas EDC3 associates with the decapping enzyme DCP2. Like EDC3, Tral interacts with DCP1 and localizes to mRNA processing bodies (P bodies) via the LSm domain. This domain remains monomeric in solution and adopts a divergent Sm fold that lacks the characteristic N-terminal α-helix, as determined by nuclear magnetic resonance analyses. Mutational analysis revealed that the structural integrity of the LSm domain is required for Tral both to interact with DCP1 and CUP and to localize to P-bodies. Furthermore, both Tral and EDC3 interact with the C-terminal RecA-like domain of Me31B through their FDF motifs. Together with previous studies, our results show that Tral and EDC3 are structurally related and use a similar mode to associate with common partners in distinct protein complexes. PMID:18765641

Similar modes of interaction enable Trailer Hitch and EDC3 to associate with DCP1 and Me31B in distinct protein complexes.

PubMed

Tritschler, Felix; Eulalio, Ana; Helms, Sigrun; Schmidt, Steffen; Coles, Murray; Weichenrieder, Oliver; Izaurralde, Elisa; Truffault, Vincent

2008-11-01

Trailer Hitch (Tral or LSm15) and enhancer of decapping-3 (EDC3 or LSm16) are conserved eukaryotic members of the (L)Sm (Sm and Like-Sm) protein family. They have a similar domain organization, characterized by an N-terminal LSm domain and a central FDF motif; however, in Tral, the FDF motif is flanked by regions rich in charged residues, whereas in EDC3 the FDF motif is followed by a YjeF_N domain. We show that in Drosophila cells, Tral and EDC3 specifically interact with the decapping activator DCP1 and the DEAD-box helicase Me31B. Nevertheless, only Tral associates with the translational repressor CUP, whereas EDC3 associates with the decapping enzyme DCP2. Like EDC3, Tral interacts with DCP1 and localizes to mRNA processing bodies (P bodies) via the LSm domain. This domain remains monomeric in solution and adopts a divergent Sm fold that lacks the characteristic N-terminal alpha-helix, as determined by nuclear magnetic resonance analyses. Mutational analysis revealed that the structural integrity of the LSm domain is required for Tral both to interact with DCP1 and CUP and to localize to P-bodies. Furthermore, both Tral and EDC3 interact with the C-terminal RecA-like domain of Me31B through their FDF motifs. Together with previous studies, our results show that Tral and EDC3 are structurally related and use a similar mode to associate with common partners in distinct protein complexes.

Structures and Nuclear Quadrupole Coupling Tensors of a Series of Chlorine-Containing Hydrocarbons

NASA Astrophysics Data System (ADS)

Dikkumbura, Asela S.; Webster, Erica R.; Dorris, Rachel E.; Peebles, Rebecca A.; Peebles, Sean A.; Seifert, Nathan A.; Pate, Brooks

2016-06-01

Rotational spectra for gauche-1,2-dichloroethane (12DCE), gauche-1-chloro-2-fluoroethane (1C2FE) and both anti- and gauche-2,3-dichloropropene (23DCP) have been observed using chirped-pulse Fourier-transform microwave (FTMW) spectroscopy in the 6-18 GHz region. Although the anti conformers for all three species are predicted to be more stable than the gauche forms, they are nonpolar (12DCE) or nearly nonpolar (predicted dipole components for anti-1C2FE: μ_a = 0.11 D, μ_b = 0.02 D and for anti-23DCP: μ_a = 0.25 D, μ_b = 0.02 D); nevertheless, it was also possible to observe and assign the spectrum of anti-23DCP. Assignments of parent spectra and 37Cl and 13C substituted isotopologues utilized predictions at the MP2/6-311++G(2d,2p) level and Pickett's SPCAT/SPFIT programs. For the weak anti-23DCP spectra, additional measurements also utilized a resonant-cavity FTMW spectrometer. Full chlorine nuclear quadrupole coupling tensors for gauche-12DCE and both anti- and gauche-23DCP have been diagonalized to allow comparison of coupling constants. Kraitchman's equations were used to determine r_s coordinates of isotopically substituted atoms and r_0 structures were also deduced for gauche conformers of 12DCE and 1C2FE. Structural details and chlorine nuclear quadrupole coupling constants of all three molecules will be compared, and effects of differing halogen substitution and carbon chain length on molecular properties will be evaluated.

Guide to DCP Study Close-Out: Milestones and Tasks | Division of Cancer Prevention

Cancer.gov

This guide assists Consortium Lead Organization (CLO) planning for DCP study close-out. Study close-out tasks are organized under milestones, which help mark progress toward completion of the close-out process. Once tasks associated with a milestone are underway, planning for the next milestone may begin. Click on a milestone to view the associated close-out tasks. |

External Link Policy | Division of Cancer Prevention

Cancer.gov

The following graphic notice means that you are leaving the DCP Web site: (link is external)This external link provides additional information that is consistent with the intended purpose of DCP.The National Cancer Institute (NCI) cannot attest to the accuracy of a non-federal site.Linking to a non-federal site does not constitute an endorsement by HHS or any of its employees

76 FR 70717 - DCP Midstream, LP; Notice of Intent To Prepare an Environmental Assessment for the Proposed...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-15

... (FERC or Commission) will prepare an environmental assessment (EA) that will discuss the environmental... Midstream, LP (DCP) in Weld County, Colorado. This EA will be used by the Commission in its decision-making... be evaluated in the EA. Please note that the scoping period will close on December 8, 2011. Comments...

Effects of process variables and kinetics on the degradation of 2,4-dichlorophenol using advanced reduction processes (ARP).

PubMed

Yu, Xingyue; Cabooter, Deirdre; Dewil, Raf

2018-05-24

This study aims at investigating the efficiency and kinetics of 2,4-DCP degradation via advanced reduction processes (ARP). Using UV light as activation method, the highest degradation efficiency of 2,4-DCP was obtained when using sulphite as a reducing agent. The highest degradation efficiency was observed under alkaline conditions (pH = 10.0), for high sulphite dosage and UV intensity, and low 2,4-DCP concentration. For all process conditions, first-order reaction rate kinetics were applicable. A quadratic polynomial equation fitted by a Box-Behnken Design was used as a statistical model and proved to be precise and reliable in describing the significance of the different process variables. The analysis of variance demonstrated that the experimental results were in good agreement with the predicted model (R 2  = 0.9343), and solution pH, sulphite dose and UV intensity were found to be key process variables in the sulphite/UV ARP. Consequently, the present study provides a promising approach for the efficient degradation of 2,4-DCP with fast degradation kinetics. Copyright © 2018 Elsevier B.V. All rights reserved.

ERTS-1 DCS technical support provided by Wallops Station. [ground truth stations and DCP repair depot

NASA Technical Reports Server (NTRS)

Smith, R.

1975-01-01

Wallops Station accepted the tasks of providing ground truth to several ERTS investigators, operating a DCP repair depot, designing and building an airborne DCP Data Acquisition System, and providing aircraft underflight support for several other investigators. Additionally, the data bank is generally available for use by ERTS and other investigators that have a scientific interest in data pertaining to the Chesapeake Bay area. Working with DCS has provided a means of evaluating the system as a data collection device possibly applicable to ongoing Earth Resources Program activities in the Chesapeake Bay area as well as providing useful data and services to other ERTS investigators. The two areas of technical support provided by Wallops, ground truth stations and repair for DCPs, are briefly discussed.

In vitro biomechanical comparison of equine proximal interphalangeal joint arthrodesis techniques: prototype equine spoon plate versus axially positioned dynamic compression plate and two abaxial transarticular cortical screws inserted in lag fashion.

PubMed

Sod, Gary A; Mitchell, Colin F; Hubert, Jeremy D; Martin, George S; Gill, Marjorie S

2007-12-01

To compare in vitro monotonic biomechanical properties of an equine spoon plate (ESP) with an axial 3-hole, 4.5 mm narrow dynamic compression plate (DCP) using 5.5 mm cortical screws in conjunction with 2 abaxial transarticular 5.5 mm cortical screws (DCP-TLS) inserted in lag fashion for equine proximal interphalangeal (PIP) joint arthrodesis. Paired in vitro biomechanical testing of 2 methods of stabilizing cadaveric adult equine forelimb PIP joints. Cadaveric adult equine forelimbs (n=18 pairs). For each forelimb pair, 1 PIP joint was stabilized with an ESP (8 hole, 4.5 mm) and 1 with an axial 3-hole narrow DCP (4.5 mm) using 5.5 mm cortical screws in conjunction with 2 abaxial transarticular 5.5 mm cortical screws inserted in lag fashion. Six matching pairs of constructs were tested in single cycle to failure under axial compression with load applied under displacement control at a constant rate of 5 cm/s. Six construct pairs were tested for cyclic fatigue under axial compression with cyclic load (0-7.5 kN) applied at 6 Hz; cycles to failure were recorded. Six construct pairs were tested in single cycle to failure under torsional loading applied at a constant displacement rate (0.17 radians/s) until rotation of 0.87 radians occurred. Mean values for each fixation method were compared using a paired t-test within each group with statistical significance set at P<.05. Mean yield load, yield stiffness, and failure load for ESP fixation were significantly greater (for axial compression and torsion) than for DCP-TLS fixation. Mean (+/- SD) values for the ESP and DCP-TLS fixation techniques, respectively, in single cycle to failure under axial compression were: yield load 123.9 +/- 8.96 and 28.5 +/- 3.32 kN; stiffness, 13.11 +/- 0.242 and 2.60 +/- 0.17 kN/cm; and failure load, 144.4 +/- 13.6 and 31.4 +/- 3.8 kN. In single cycle to failure under torsion, mean (+/- SD) values for ESP and DCP-TLS, respectively, were: stiffness 2,022 +/- 26.2 and 107.9 +/- 11.1 N m/rad; and failure load: 256.4 +/- 39.2 and 87.1 +/- 11.5 N m. Mean cycles to failure in axial compression of ESP fixation (622,529 +/- 65,468) was significantly greater than DCP-TLS (95,418 +/- 11,037). ESP was superior to an axial 3-hole narrow DCP with 2 abaxial transarticular screws inserted in lag fashion in resisting static overload forces and cyclic fatigue. In vitro results support further evaluation of ESP for PIP joint arthrodesis in horses. Its specific design may provide increased stability without need for external coaptation support.

Mechanical characterization and ion release of bioactive dental composites containing calcium phosphate particles.

PubMed

Natale, Livia C; Rodrigues, Marcela C; Alania, Yvette; Chiari, Marina D S; Boaro, Leticia C C; Cotrim, Marycel; Vega, Oscar; Braga, Roberto R

2018-08-01

to verify the effect of the addition of dicalcium phosphate dihydrate (DCPD) particles functionalized with di- or triethylene glycol dimethacrylate (DEGDMA or TEGDMA) on the degree of conversion (DC), post-gel shrinkage (PS), mechanical properties, and ion release of experimental composites. Four composites were prepared containing a BisGMA/TEGDMA matrix and 60 vol% of fillers. The positive control contained only barium glass fillers, while in the other composites 15 vol% of the barium was replaced by DCPD. Besides the functionalized particles, non-functionalized DCPD was also tested. DC after 24 h (n = 3) was determined by FTIR spectroscopy. The strain gage method was used to obtain PS 5 min after photoactivation (n = 5). Flexural strength and modulus (n = 10) were calculated based on the biaxial flexural test results, after specimen storage for 24 h or 60 days in water. The same storage times were used for fracture toughness testing (FT, n = 10). Calcium and phosphate release up to 60 days was quantified by ICP-OES (n = 3). Data were analyzed by ANOVA/Tukey test (alpha: 5%). Composites containing functionalized DCPD presented higher DC than the control (p < 0.001). The material containing DEGDMA-functionalized particles showed higher PS than the other composites (p < 0.001). After 60 days, only the composite with DEGDMA-functionalized DCPD presented fracture strength similar to the control, while for flexural modulus only the composite with TEGDMA-functionalized particles was lower than the control (p < 0.001). FT of all composites containing DCPD was higher than the control after 60 days (p < 0.005). Calcium release was higher for the composite with non-functionalized DCPD at 15 days and no significant reductions were observed for composites with functionalized DCPD during the observation period (p < 0.001). For all the tested composites, phosphate release was higher at 15 days than in the subsequent periods, and no difference among them was recorded at 45 and 60 days (p < 0.001). DCPD functionalization affected all the studied variables. The composite with DEGDMA-functionalized particles was the only material with strength similar to the control after 60 days in water; however, it also presented the highest shrinkage. The presence of DCPD improved FT, regardless of functionalization. DCPD functionalization reduced ion release only during the first 15 days. Copyright © 2018 Elsevier Ltd. All rights reserved.

Biomechanical assessment and 3D finite element analysis of the treatment of tibial fractures using minimally invasive percutaneous plates

PubMed Central

Hu, Xin-Jia; Wang, Hua

2017-01-01

The aim of the present study was to investigate the biomechanical effects of varying the length of a limited contact-dynamic compression plate (LC-DCP) and the number and position of screws on middle tibial fractures, and to provide biomechanical evidence regarding minimally invasive plate osteosynthesis (MIPO). For biomechanical testing, 60 tibias from cadavers (age at mortality, 20–40 years) were used to create middle and diagonal fracture models without defects. Tibias were randomly grouped and analyzed by biomechanic and three-dimensional (3D) finite element analysis. The differences among LC-DCPs of different lengths (6-, 10- and 14-hole) with 6 screws, 14-hole LC-DCPs with different numbers of screws (6, 10 and 14), and 14-hole LC-DCPs with 6 screws at different positions with regard to mechanical characteristics, including compressing, torsion and bending, were examined. The 6-hole LC-DCP had greater vertical compression strain compared with the 10- and 14-hole LC-DCPs (P<0.01), and the 14-hole LC-DCP had greater lateral strain than the 6- and 10-hole LC-DCPs (P<0.01). Furthermore, significant differences in torque were observed among the LC-DPs of different lengths (P<0.01). For 14-hole LC-DCPs with different numbers of screws, no significant differences in vertical strain, lateral strain or torque were detected (P>0.05). However, plates with 14 screws had greater vertical strain compared with those fixed with 6 or 10 screws (P<0.01). For 4-hole LC-DCPs with screws at different positions, vertical compression strain values were lowest for plates with screws at positions 1, 4, 7, 8, 11 and 14 (P<0.01). The lateral strain values and vertical strain values for plates with screws at positions 1, 3, 6, 9, 12 and 14 were significantly lower compared with those at the other positions (P<0.01), and torque values were also low. Thus, the 14-hole LC-DCP was the most stable against vertical compression, torsion and bending, and the 6-hole LC-DCP was the least stable. However, the use of 14 screws with a 14-hole LC-DCP provided less stability against bending than did 6 or 10 screws. Furthermore, fixation with distributed screws, in which some screws were close to the fracture line, provided good stability against compression and torsion, while fixation with screws at the ends of the LC-DCP provided poor stability against bending, compressing and torsion. PMID:28781632

IN VITRO DETERMINATION OF KINETIC CONSTANTS FOR 1,3-DICHLOROPROPANE, 2,2-DICHLOROPROPANE, AND 1,1-DICHLOROPROPENE IN RAT LIVER MICROSOMES AND CYTOSOL

EPA Science Inventory

The Safe Drinking Water Act requires the U.S. EPA to establish a list of contaminants to aid in priority setting for the Agency's drinking water program. The 1998 Contaminant Candidate List (CCL) designated 1,3-Dichloropropane (1,3-DCP), 2,2-dichloropropane (2,2-DCP), and 1,1-...

District-Charter Partnerships: Collaboration to Advance Teaching and Learning in New York City. Year 1 Evaluation Results (2016-17)

ERIC Educational Resources Information Center

Litt, J.; Fishel, G.

2017-01-01

The Office of School Design and Charter Partnerships (OSDCP) at the New York City Department of Education (DOE) developed and executed a plan for district-charter collaboration, which they called the District-Charter Partnerships (DCP) initiative. This document describes the results of a mixed-method study of DCP conducted during the 2016-17…

A simultaneous derivatization of 3-monochloropropanediol and 1,3-dichloropropane with hexamethyldisilazane-trimethylsilyl trifluoromethanesulfonate at room temperature for efficient analysis of food sample analysis.

PubMed

Lee, Bai Qin; Wan Mohamed Radzi, Che Wan Jasimah Bt; Khor, Sook Mei

2016-02-05

This paper reports the application of hexamethyldisilazane-trimethylsilyl trifluoromethanesulfonate (HMDS-TMSOTf) for the simultaneous silylation of 3-monochloro-1,2-propanediol (3-MCPD) and 1,3-dicholoropropanol (1,3-DCP) in solid and liquid food samples. 3-MCPD and 1,3-DCP are chloropropanols that have been established as Group 2B carcinogens in clinical testing. They can be found in heat-processed food, especially when an extended high-temperature treatment is required. However, the current AOAC detection method is time-consuming and expensive. Thus, HMDS-TMSOTf was used in this study to provide a safer, and cost-effective alternative to the HFBI method. Three important steps are involved in the quantification of 3-MCPD and 1,3-DCP: extraction, derivatization and quantification. The optimization of the derivatization process, which involved focusing on the catalyst volume, derivatization temperature, and derivatization time was performed based on the findings obtained from both the Box-Behnken modeling and a real experimental set up. With the optimized conditions, the newly developed method was used for actual food sample quantification and the results were compared with those obtained via the standard AOAC method. The developed method required less samples and reagents but it could be used to achieve lower limits of quantification (0.0043mgL(-1) for 1,3-DCP and 0.0011mgL(-1) for 3-MCPD) and detection (0.0028mgL(-1) for 1,3-DCP and 0.0008mgL(-1) for 3-MCPD). All the detected concentrations are below the maximum tolerable limit of 0.02mgL(-1). The percentage of recovery obtained from food sample analysis was between 83% and 96%. The new procedure was validated with the AOAC method and showed a comparable performance. The HMDS-TMSOTf derivatization strategy is capable of simultaneously derivatizing 1,3-DCP and 3-MCPD at room temperature, and it also serves as a rapid, sensitive, and accurate analytical method for food samples analysis. Copyright © 2015 Elsevier B.V. All rights reserved.

An in vitro biomechanical comparison of equine proximal interphalangeal joint arthrodesis techniques: an axial positioned dynamic compression plate and two abaxial transarticular cortical screws inserted in lag fashion versus three parallel transarticular cortical screws inserted in lag fashion.

PubMed

Sod, Gary A; Riggs, Laura M; Mitchell, Colin F; Hubert, Jeremy D; Martin, George S

2010-01-01

To compare in vitro monotonic biomechanical properties of an axial 3-hole, 4.5 mm narrow dynamic compression plate (DCP) using 5.5 mm cortical screws in conjunction with 2 abaxial transarticular 5.5 mm cortical screws inserted in lag fashion (DCP-TLS) with 3 parallel transarticular 5.5 mm cortical screws inserted in lag fashion (3-TLS) for the equine proximal interphalangeal (PIP) joint arthrodesis. Paired in vitro biomechanical testing of 2 methods of stabilizing cadaveric adult equine forelimb PIP joints. Cadaveric adult equine forelimbs (n=15 pairs). For each forelimb pair, 1 PIP joint was stabilized with an axial 3-hole narrow DCP (4.5 mm) using 5.5 mm cortical screws in conjunction with 2 abaxial transarticular 5.5 mm cortical screws inserted in lag fashion and 1 with 3 parallel transarticular 5.5 mm cortical screws inserted in lag fashion. Five matching pairs of constructs were tested in single cycle to failure under axial compression, 5 construct pairs were tested for cyclic fatigue under axial compression, and 5 construct pairs were tested in single cycle to failure under torsional loading. Mean values for each fixation method were compared using a paired t-test within each group with statistical significance set at P<.05. Mean yield load, yield stiffness, and failure load under axial compression and torsion, single cycle to failure, of the DCP-TLS fixation were significantly greater than those of the 3-TLS fixation. Mean cycles to failure in axial compression of the DCP-TLS fixation was significantly greater than that of the 3-TLS fixation. The DCP-TLS was superior to the 3-TLS in resisting the static overload forces and in resisting cyclic fatigue. The results of this in vitro study may provide information to aid in the selection of a treatment modality for arthrodesis of the equine PIP joint.

Risk of bile duct cancer among printing workers exposed to 1,2-dichloropropane and/or dichloromethane.

PubMed

Sobue, Tomotaka; Utada, Mai; Makiuchi, Takeshi; Ohno, Yuko; Uehara, Shinichiro; Hayashi, Tomoshige; Sato, Kyoko Kogawa; Endo, Ginji

2015-01-01

We conducted a retrospective cohort study to examine the risk of bile duct cancer among current and former workers in the offset color proof printing department at a printing company in Osaka, Japan. Standardized incidence ratios (SIRs) between January 1, 1985, and December 31, 2012, were estimated for the cumulative years of exposure to two chemicals, dichloromethane (DCM) and 1,2-dichloropropane (1,2-DCP), using the national incidence level as a reference. In addition, we examined risk patterns by the calendar year in which observation started. Among 106 workers with a total of 1,452.4 person-years of exposure, 17 bile duct cancer cases were observed, resulting in an estimated overall SIR of 1,132.5 (95% confidence interval (CI): 659.7-1,813.2). The SIR was 1,319.9 (95% CI: 658.9-2,361.7) for those who were exposed to both DCM and 1,2-DCP, and it was 1,002.8 (95% CI: 368.0-2,182.8) for those exposed to 1,2-DCP only. SIRs tended to increase according to years of exposure to 1,2-DCP but not DCM when a 5-year lag time was assumed. The SIRs were higher for the cohorts in which observation started in 1993-2000, particularly in cohorts in which it started in 1996-1999, compared with those in which it started before or after 1993-2000. We observed an extraordinarily high risk of bile duct cancer among the offset color proof printing workers. Elevated risk may be related to cumulative exposure to 1,2-DCP, but there remains some possibility that a portion of the risk is due to other unidentified substances.

Genetic variants in the PIWI-piRNA pathway gene DCP1A predict melanoma disease-specific survival.

PubMed

Zhang, Weikang; Liu, Hongliang; Yin, Jieyun; Wu, Wenting; Zhu, Dakai; Amos, Christopher I; Fang, Shenying; Lee, Jeffrey E; Li, Yi; Han, Jiali; Wei, Qingyi

2016-12-15

The Piwi-piRNA pathway is important for germ cell maintenance, genome integrity, DNA methylation and retrotransposon control and thus may be involved in cancer development. In this study, we comprehensively analyzed prognostic roles of 3,116 common SNPs in PIWI-piRNA pathway genes in melanoma disease-specific survival. A published genome-wide association study (GWAS) by The University of Texas M.D. Anderson Cancer Center was used to identify associated SNPs, which were later validated by another GWAS from the Harvard Nurses' Health Study and Health Professionals Follow-up Study. After multiple testing correction, we found that there were 27 common SNPs in two genes (PIWIL4 and DCP1A) with false discovery rate < 0.2 in the discovery dataset. Three tagSNPs (i.e., rs7933369 and rs508485 in PIWIL4; rs11551405 in DCP1A) were replicated. The rs11551405 A allele, located at the 3' UTR microRNA binding site of DCP1A, was associated with an increased risk of melanoma disease-specific death in both discovery dataset [adjusted Hazards ratio (HR) = 1.66, 95% confidence interval (CI) = 1.21-2.27, p =1.50 × 10 -3 ] and validation dataset (HR = 1.55, 95% CI = 1.03-2.34, p = 0.038), compared with the C allele, and their meta-analysis showed an HR of 1.62 (95% CI, 1.26-2.08, p =1.55 × 10 -4 ). Using RNA-seq data from the 1000 Genomes Project, we found that DCP1A mRNA expression levels increased significantly with the A allele number of rs11551405. Additional large, prospective studies are needed to validate these findings. © 2016 UICC.

Failure mode and bending moment of canine pancarpal arthrodesis constructs stabilized with two different implant systems.

PubMed

Wininger, Fred A; Kapatkin, Amy S; Radin, Alex; Shofer, Frances S; Smith, Gail K

2007-12-01

To compare failure mode and bending moment of a canine pancarpal arthrodesis construct using either a 2.7 mm/3.5 mm hybrid dynamic compression plate (HDCP) or a 3.5 mm dynamic compression plate (DCP). Paired in vitro biomechanical testing of canine pancarpal arthrodesis constructs stabilized with either a 2.7/3.5 HDCP or 3.5 DCP. Paired cadaveric canine antebrachii (n=5). Pancarpal arthrodesis constructs were loaded to failure (point of maximum load) in 4-point bending using a materials-testing machine. Using this point of failure, bending moments were calculated from system variables for each construct and the 2 plating systems compared using a paired t-test. To examine the relationship between metacarpal diameter and screw diameter failure loads, linear regression was used and Pearson' correlation coefficient was calculated. Significance was set at P<.05. HDCP failed at higher loads than DCP for 9 of 10 constructs. The absolute difference in failure rates between the 2 plates was 0.552+/-0.182 N m, P=.0144 (95% confidence interval: -0.58 to 1.68). This is an 8.1% mean difference in bending strength. There was a significant linear correlation r=0.74 (P-slope=.014) and 0.8 (P-slope=.006) between metacarpal diameter and failure loads for the HDCP and 3.5 DCP, respectively. There was a small but significant difference between bending moment at failure between 2.7/3.5 HDCP and 3.5 DCP constructs; however, the difference may not be clinically evident in all patients. The 2.7/3.5 HDCP has physical and mechanical properties making it a more desirable plate for pancarpal arthrodesis.

Changes in highly sensitive alpha-fetoprotein for the prediction of the outcome in patients with hepatocellular carcinoma after hepatectomy.

PubMed

Toyoda, Hidenori; Kumada, Takashi; Tada, Toshifumi; Ito, Takanori; Maeda, Atsuyuki; Kaneoka, Yuji; Kagebayashi, Chiaki; Satomura, Shinji

2014-06-01

We investigated changes in highly sensitive lens culinaris agglutinin A-reactive fraction of alpha-fetoprotein (hsAFP-L3) measured using a novel method and its predictive ability for prognosis in patients with hepatocellular carcinoma (HCC) who underwent curative hepatectomy, comparing to other HCC tumor markers, that is, AFP, des-gamma-carboxy prothrombin (DCP), and AFP-L3 measured with conventional method (cAFP-L3). AFP, DCP, and AFP-L3 including both cAFP-L3 and hsAFP-L3 were measured before and after curative hepatectomy in 187 patients. The percentage of patients with elevated tumor marker levels pre- and postoperatively was compared, and recurrence-free and overall survival rates were analyzed based on changes in tumor markers. The percentages of patients with elevated AFP, DCP, and cAFP-L3 decreased postoperatively. In contrast, the percentage of patients with elevated hsAFP-L3 did not decrease postoperatively. Both recurrence-free and overall survival rates were significantly lower in patients whose tumor marker levels remained elevated postoperatively than patients without tumor marker elevation postoperatively. Recurrence-free and overall survival rates of patients in whom hsAFP-L3 became elevated postoperatively despite normal preoperative hsAFP-L3 levels were significantly lower than those of patients with normal hsAFP-L3 postoperatively, and were similar to those of patients with persistent elevation. Preoperative elevations of AFP, DCP, and cAFP normalized in many patients postoperatively, but not for hsAFP-L3. The elevation of hsAFP-L3 identifies patients with poor prognosis despite the normalization of AFP and DCP. © 2014 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

Heterogeneous electro-Fenton using modified iron-carbon as catalyst for 2,4-dichlorophenol degradation: influence factors, mechanism and degradation pathway.

PubMed

Zhang, Chao; Zhou, Minghua; Ren, Gengbo; Yu, Xinmin; Ma, Liang; Yang, Jie; Yu, Fangke

2015-03-01

Modified iron-carbon with polytetrafluoroethylene (PTFE) was firstly investigated as heterogeneous electro-Fenton (EF) catalyst for 2,4-dichlorophenol (2,4-DCP) degradation in near neutral pH condition. The catalyst was characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD), and the effects of some important operating parameters such as current intensity and pH on the 2,4-DCP degradation were investigated. After the catalyst modification with 20% PTFE, the degradation performance maintained well with much lower iron leaching, and at current intensity 100 mA, initial pH 6.7, catalyst loading 6 g/L, the degradation efficiency of 2,4-DCP could exceed 95% within 120 min treatment. Two-stage pseudo first-order kinetics of 2,4-DCP degradation was observed, including a slow anodic oxidation stage (first-stage) and much faster heterogeneous EF oxidation (second-stage), in which the automatic drop of pH in the first-stage initiated the Fe(2+) release from micro-electrolysis and thus benefited to the subsequent EF reaction. Aromatic intermediates such as 3,5-dichlorocatechol, 4,6-dichlororesorcinol and 2-chlorohydroquinone were detected by GC-MS. Oxalic acid, acetic acid, formic acid and Cl(-) were quantified by ion chromatograph. Based on these analysis as well as the detection of H₂O₂ and OH, a possible mechanism and degradation pathway for 2,4-DCP were proposed. This work demonstrated that such a heterogeneous EF using cheap modified Fe-C catalyst was promising for organic wastewater treatment in initial neutral pH condition. Copyright © 2014 Elsevier Ltd. All rights reserved.

Process Parameters on the Crystallization and Morphology of Hydroxyapatite Powders Prepared by a Hydrolysis Method

NASA Astrophysics Data System (ADS)

Wang, Moo-Chin; Hon, Min-Hsiung; Chen, Hui-Ting; Yen, Feng-Lin; Hung, I.-Ming; Ko, Horng-Huey; Shih, Wei-Jen

2013-07-01

The effects of process parameters on the crystallization and morphology of hydroxyapatite (Ca10(PO4)6(OH)2, HA) powders synthesized from dicalcium phosphate dihydrate (CaHPO4·2H2O, DCPD) using a hydrolysis method have been investigated. X-ray diffraction (XRD), Fourier-transform infrared (FT-IR) spectra, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and selected area electron diffraction (SAED) were used to characterize the synthesized powders. When DCPD underwent hydrolysis in 2.5 NaOH solution (Na(aq)) at 303 K to 348 K (30 °C to 75 °C) for 1 hour, the XRD results revealed that HA was obtained for all the as-dried samples. The SEM morphology of the HA powders for DCPD hydrolysis produced at 348 K (75 °C) shows regular alignment and a short rod shape with a size of 200 nm in length and 50 nm in width. With DCPD hydrolysis in 2.5 M NaOH(aq) holding at 348 K (75 °C) for 1 to 24 hours, XRD results demonstrated that all samples were HA and no other phases could be detected. Moreover, the XRD results also show that all the as-dried powders still maintained the HA structure when DCPD underwent hydrolysis in 0.1 to 5 M NaOH(aq) at 348 K (75 °C) for 1 hour. Otherwise, the full transformation from HA to octa-calcium phosphate (OCP, Ca8H2(PO4)6·5H2O) occurred when hydrolysis happened in 10 M NaOH(aq). FT-IR spectra analysis revealed that some carbonated HA (Ca10(PO4)6(CO3), CHA) had formed. The SEM morphology results show that the 60 to 65 nm width of the uniformly long rods with regular alignment formed in the HA powder aggregates when DCPD underwent hydrolysis in 2.5 M NaOH(aq) at 348 K (75 °C) for 1 hour.

In vitro evaluation of different heat-treated radio frequency magnetron sputtered calcium phosphate coatings.

PubMed

Yonggang, Yan; Wolke, Joop G C; Yubao, Li; Jansen, John A

2007-06-01

Surface chemical compositions, such as calcium/phosphorus ratio and phase content, have a strong influence on the bioactivity and biocompatibility of calcium phosphate (CaP) coatings as applied on orthopedic and dental implants. Hydroxylapatite (HA) and dicalcium pyrophosphate (DCPP) coatings were prepared on titanium substrates by RF magnetron sputter deposition. The surfaces were left as-prepared (amorphous HA coating; A-HA, amorphous DCPP coating; A-DCPP) or heat treated with: infrared (IR) at 550 degrees C (I-HA) or at 650 degrees C (I-DCPP), and a water steam at 140 degrees C (S-HA and S-DCPP). The surface changes of these coatings were determined after incubation in simulated body fluid (SBF). Also, the growth of rat bone marrow cells (RBM) was studied with scanning electron microscopy (SEM). Both IR and water steam heat treatment changed the sputter-deposited coatings from the amorphous into the crystalline phase. As-prepared amorphous coatings dissolved partially in SBF within 4 weeks of incubation, while heat-treated coatings supported the deposition of a precipitate, i.e., carbonated apatite on both I-HA and S-HA specimens, and tricalciumphosphate on the I-DCPP and S-DCPP specimens. The Ca/P ratio of the A-HA, I-HA, S-HA, A-DCPP, I-DCPP and S-DCPP coatings changed, respectively, from 1.98 to 1.12, 2.01 to 1.76, 1.91 to 1.68, 0.76 to 1.23, 0.76 to 1.26 and 1.62 to 1.55 after 4 weeks of incubation in SBF. Finally, the RBM cells grew well on all heat-treated coatings, but showed different mineralization morphology during cell culturing. The different heat-treatment procedures for the sputtered HA and DCPP coatings influenced the surface characteristics of these coatings, whereby a combination of crystallinity and specific phase composition (Ca/P ratio) strongly affected their in vitro bioactivity.

Liver Rapid Reference Set Application: Hiro Yamada - Wako (2011) — EDRN Public Portal

Cancer.gov

Measure clinical effectiveness of AFP-L3 and DCP for early detection of HCC in patient samples collected prospectively during surveillance. However since such samples are not readily available in the USA the reference set samples are well characterized and studied, gaining access to these samples will allow Wako to quickly measure clinical effectiveness of AFP-L3 and DCP in detecting early HCC.

Efficient Wideband Numerical Simulations for Nanostructures Employing a Drude-Critical Points (DCP) Dispersive Model.

PubMed

Ren, Qiang; Nagar, Jogender; Kang, Lei; Bian, Yusheng; Werner, Ping; Werner, Douglas H

2017-05-18

A highly efficient numerical approach for simulating the wideband optical response of nano-architectures comprised of Drude-Critical Points (DCP) media (e.g., gold and silver) is proposed and validated through comparing with commercial computational software. The kernel of this algorithm is the subdomain level discontinuous Galerkin time domain (DGTD) method, which can be viewed as a hybrid of the spectral-element time-domain method (SETD) and the finite-element time-domain (FETD) method. An hp-refinement technique is applied to decrease the Degrees-of-Freedom (DoFs) and computational requirements. The collocated E-J scheme facilitates solving the auxiliary equations by converting the inversions of matrices to simpler vector manipulations. A new hybrid time stepping approach, which couples the Runge-Kutta and Newmark methods, is proposed to solve the temporal auxiliary differential equations (ADEs) with a high degree of efficiency. The advantages of this new approach, in terms of computational resource overhead and accuracy, are validated through comparison with well-known commercial software for three diverse cases, which cover both near-field and far-field properties with plane wave and lumped port sources. The presented work provides the missing link between DCP dispersive models and FETD and/or SETD based algorithms. It is a competitive candidate for numerically studying the wideband plasmonic properties of DCP media.

Biomechanical comparison of straight DCP and helical plates for fixation of transverse and oblique bone fractures.

PubMed

Aksakal, Bunyamin; Gurger, Murat; Say, Yakup; Yilmaz, Erhan

2014-01-01

Biomechanical comparison of straight DCP and helical plates for fixation of transversal and oblique tibial bone fractures were analyzed and compared to each other by axial compression, bending and torsion tests. An in vitro osteosynthesis of transverse (TF) and oblique bone fracture (OF) fixations have been analysed on fresh sheep tibias by using the DCP and helical compression plates (HP). Statistically significant differences were found for both DCP and helical plate fixations under axial compression, bending and torsional loads. The strength of fixation systems was in favor of DC plating with exception of the TF-HP fixation group under compression loads and torsional moments. The transvers fracture (TF) stability was found to be higher than that found in oblique fracture (OF) fixed by helical plates (HP). However, under torsional testing, compared to conventional plating, the helical plate fixations provided a higher torsional resistance and strength. The maximum stiffness at axial compression loading and maximum torsional strength was achieved in torsional testing for the TF-HP fixations. From in vitro biomechanical analysis, fracture type and plate fixation system groups showed different responses under different loadings. Consequently, current biomechanical analyses may encourage the usage of helical HP fixations in near future during clinical practice for transverse bone fractures.

USDI DCS technical support: Mississippi Test Facility

NASA Technical Reports Server (NTRS)

Preble, D. M.

1975-01-01

The objective of the technical support effort is to provide hardware and data processing support to DCS users so that application of the system may be simply and effectively implemented. Technical support at Mississippi Test Facility (MTF) is concerned primarily with on-site hardware. The first objective of the DCP hardware support was to assure that standard measuring apparatus and techniques used by the USGS could be adapted to the DCS. The second objective was to try to standardize the miscellaneous variety of parameters into a standard instrument set. The third objective was to provide the necessary accessories to simplify the use and complement the capabilities of the DCP. The standard USGS sites have been interfaced and are presently operating. These sites are stream gauge, ground water level and line operated quality of water. Evapotranspiration, meteorological and battery operated quality of water sites are planned for near future DCP operation. Three accessories which are under test or development are the Chu antenna, solar power supply and add-on memory. The DCP has proven to be relatively easy to interface with many monitors. The large antenna is awkward to install and transport. The DCS has met the original requirements well; it has and is proving that an operation, satellite-based data collection system is feasible.

Removal of 2,4-dichlorophenol and pentachlorophenol from waters by sorption using coal fly ash from a Portuguese thermal power plant.

PubMed

Estevinho, Berta N; Martins, Isabel; Ratola, Nuno; Alves, Arminda; Santos, Lúcia

2007-05-08

Chlorophenols are one of the most important groups of priority pollutants, due to their high toxicity, mutagenicity and carcinogenicity. Although activated carbon has been the preferred choice for the removal of such pollutants from wastewaters, the search for cheaper alternative sorbents became common in the last years. Fly ash, a by-product from coal burning power plants, has a surface composition that may enable the sorption of specific organic compounds. Therefore, this feasibility study presents the optimization of the operating parameters of a fixed-bed column containing fly ash particles, percolated by aqueous solutions of 2,4-dichlorophenol (2,4-DCP) and pentachlorophenol (PCP) with concentrations of 1 and 100 microg/ml. Both chlorophenols were analysed by gas chromatography with electron capture detection (GC-ECD), after solid-phase microextraction (SPME), with limits of detection (LODs) of 7.28 microg/l for 2,4-DCP and 1.76 microg/l for PCP. Removal efficiencies above 99% were obtained for an initial concentration of 10 microg/ml of chlorophenols. Column saturation was achieved after 7h of continuous operation for 2,4-DCP and 10h for the PCP for feed levels of 10 microg/ml. Fly ash exhibited more affinity towards the sorption of PCP, in comparison to 2,4-DCP.

Relationship between compatibilizer and yield strength of PLA/PP Blend

NASA Astrophysics Data System (ADS)

Jariyakulsith, Pattanun; Puajindanetr, Somchai

2018-01-01

The aim of this research is to study the relationship between compatibilizer and yield strength of polylactic acid (PLA) and polypropylene (PP) blend. The PLA is blended with PP (PLA/PP) at the ratios of 70/30, 50/50 and 30/70. In addition, (1) polypropylene grafted maleic anhydride (PP-g-MAH) as a compatibilizer at 0.3 and 0.7 part per hundred of PLA/PP resin (phr) and (2) dicumyl peroxide (DCP) being an initiator at 0.03 and 0.07 phr are added in each composition. Yield strength is characterized to study the interaction between compatibilizer, initiator and yield strength by using experimental design of multilevel full factorial. The results show that (1) the yield strength of PLA/PP blend are increased after addition of compatibilizer. Because the adding of PP-g-MAH and DCP resulted in improving compatibility between PLA and PP. (2) there are interaction between PP-g-MAH and DCP that have affected the final properties of PLA/PP blend. The highest yield strength of 27.68 MPa is provided at the ratio of 70/30 blend by using the 0.3 phr of PP-g-MAH and 0.03 phr of DCP. Linear regression model is fitted and follow the assumptions of normal distribution.

Application of response surface methodology (RSM) for optimisation of COD, NH3-N and 2,4-DCP removal from recycled paper wastewater in a pilot-scale granular activated carbon sequencing batch biofilm reactor (GAC-SBBR).

PubMed

Muhamad, Mohd Hafizuddin; Sheikh Abdullah, Siti Rozaimah; Mohamad, Abu Bakar; Abdul Rahman, Rakmi; Hasan Kadhum, Abdul Amir

2013-05-30

In this study, the potential of a pilot-scale granular activated carbon sequencing batch biofilm reactor (GAC-SBBR) for removing chemical oxygen demand (COD), ammoniacal nitrogen (NH3-N) and 2,4-dichlorophenol (2,4-DCP) from recycled paper wastewater was assessed. For this purpose, the response surface methodology (RSM) was employed, using a central composite face-centred design (CCFD), to optimise three of the most important operating variables, i.e., hydraulic retention time (HRT), aeration rate (AR) and influent feed concentration (IFC), in the pilot-scale GAC-SBBR process for recycled paper wastewater treatment. Quadratic models were developed for the response variables, i.e., COD, NH3-N and 2,4-DCP removal, based on the high value (>0.9) of the coefficient of determination (R(2)) obtained from the analysis of variance (ANOVA). The optimal conditions were established at 750 mg COD/L IFC, 3.2 m(3)/min AR and 1 day HRT, corresponding to predicted COD, NH3-N and 2,4-DCP removal percentages of 94.8, 100 and 80.9%, respectively. Copyright © 2013 Elsevier Ltd. All rights reserved.

The important role of polyvinylpyrrolidone and Cu on enhancing dechlorination of 2,4-dichlorophenol by Cu/Fe nanoparticles: Performance and mechanism study

NASA Astrophysics Data System (ADS)

Fang, Liping; Xu, Cuihong; Zhang, Wenbin; Huang, Li-Zhi

2018-03-01

The important role of polyvinylpyrrolidone (PVP) and Cu on the reductive dechlorination of 2,4-dichlorophenol (2,4-DCP) by Cu/Fe bimetal nanoparticles has been investigated. The synthesized PVP coated Cu/Fe bimetal nanoparticles with different Cu/Fe ratios were systematically characterized by FTIR, XRD, TEM and magnetic hysteresis loops. The Cu/Fe ratio and the PVP loading were optimized for dechlorination performance, and the optimum ratio of PVP to Cu/Fe was found to be 0.35 and the content of Cu in Cu/Fe nanoparticles was 41%. The presence of PVP as a dispersant/stabilizer results in a highly-dispersed Cu/Fe NPs and increase the reactivity of Cu/Fe NPs for 2,4-DCP removal. The dechlorination rate was enhanced at lower pH and higher temperature conditions. The presence of humic acid, PO43-, NO3-, SO42- leads to a slightly decreased removal efficiency of 2,4-DCP. The magnetic property of PVP-Cu/Fe nanoparticles allows rapid magnetic separation of the catalysts after reaction. A galvanic corrosion model was proposed where iron corrodes and transfers electrons to Cu-rich catalytic regions of the nanoparticles, and finally accelerating the reduction efficiency of 2,4-DCP.

Interaction of Endomycorrhizal Fungi, Superphosphate, and Meloidogyne incognita on Cotton in Microplot and Field Studies.

PubMed

Smith, G S; Roncadori, R W; Hussey, R S

1986-04-01

Microplot and field experiments were conducted to determine the effects of two vesicular-arbuscular mycorrhizal (VAM) fungi, Glomus intraradices (Gi) and Gigaspora margarita (Gm), and dicalcium phosphate (P) on Meloidogyne incognita (Mi) reproduction and seed cotton yield of the Mi-susceptible cotton cultivar, Stoneville 213. In 1983 population densities of Mi juveniles were significantly lower 60 and 90 days after planting in microplots receiving Gi. Mycorrhizal fungi reduced the severity of yield losses to Mi, whereas P fertilization increased yield losses to Mi. In 1984 microplot yields were reduced linearly as nematode inoculum densities increased in treatments of Mi alone, Gm, or P, but the response was curvilinear with Gi. Yield suppressions in the 1984 field experiment occurred only in plots infested with Mi alone. In the 1984 microplots, numbers of Mi juveniles penetrating seedling roots increased Iinearly with increasing nematode inoculum densities and was favored when mycorrhizal fungi or superphosphate were added. Juvenile penetration of roots was negatively correlated with yields in all treatments (r = -0.54 to -0.81) except Gm and with number of bolls in Mi alone (r = -0.85) and P (r = -0.81) treatments. Mycorrhizal fungi can increase host tolerance to M. incognita in field conditions and may function as important biological control agents in soils infested with high population densities of efficient VAM species.

Potential of carrageenans to protect drugs from polymorphic transformation.

PubMed

Schmidt, Andrea G; Wartewig, Siegfried; Picker, Katharina M

2003-07-01

Carrageenans were analysed in mixture with polymorphic drugs to test their potential for minimising polymorphic or pseudopolymorphic transitions, which are induced by the tableting process. The kappa-carrageenans Gelcarin GP-812 NF and Gelcarin GP-911 NF and the iota-carrageenan Gelcarin GP-379 NF were tested in comparison to the well-known tableting excipients microcrystalline cellulose (MCC), hydroxypropyl methylcellulose (HPMC), and dicalcium phosphate dihydrate (DCPD). Amorphous indomethacin was chosen as model drug since its well-known recrystallisation behaviour can be mechanically stimulated. Further on, theophylline monohydrate was used. Its dehydration is induced by tableting. Pure materials and mixtures containing 20% (w/w) drug were compressed up to different maximum relative densities. The data obtained during tableting were analysed by three-dimensional (3D) modelling. Afterwards tablets were broken and examined by Fourier transform Raman spectroscopy in order to determine the degree of transformation inside the tablet. For quantitative interpretation, the intensities of representative bands were used. Thermal analysis was used additionally. Using 3D modelling a decrease of plastic deformation can be noticed in the order HPMC>MCC>carrageenans, whereas DCPD represents an exception because of brittle fracture. Best hindrance of polymorphic transformation showed the carrageenans, the hindrance was slightly worse for HPMC. MCC and DCPD could not hinder transformation. A complete protection of the amorphous form could not be achieved. For theophylline monohydrate, the results were similar.

The influence of granulation on super disintegrant performance.

PubMed

Zhao, Na; Augsburger, Larry L

2006-02-01

The purpose of this study is to identify the causes of efficiency loss of super disintegrants following granulation or reworking. Two processes, precompression and prewetting, were proposed to simulate the processes during dry and wet granulation, respectively. The disintegration efficiency of the resulting disintegrant granules was tested in model formulations composed of dicalcium phosphate and lactose with the unprocessed disintegrants as controls. No significant difference was shown in the intrinsic swelling and the water uptake abilities of all super disintegrants following dry granulation. However, a significant decrease was observed for both Primojel and Polyplasdone XL10 in the rate of water being absorbed into the tablet matrix following wet granulation, but not for Ac-Di-Sol. United States Pharmacopeia (USP) disintegration testing without disc revealed a significant increase in disintegration time for tablets formulated with dry granulated Primojel and Polyplasdone XL10 and all wet granulated disintegrants. The increase in particle size following granulation appears to be the cause of the loss in disintegration efficiency. In conclusion, Ac-Di-Sol is less affected by both precompression and prewetting. The efficiency of Primojel and Polyplasdone XL10 is highly dependent on their particle size. Descreasing the particle size tends to increase their efficiency. Due to the size increase following granulation, a higher addition level of super disintegrant is required to ensure fast and uniform disintegration of tablets prepared by granulation.

Phase Equilibria in the System "FeO"-CaO-SiO2-Al2O3-MgO at Different CaO/SiO2 Ratios

NASA Astrophysics Data System (ADS)

Jang, Kyoung-oh; Ma, Xiaodong; Zhu, Jinming; Xu, Haifa; Wang, Geoff; Zhao, Baojun

2017-06-01

The "FeO"-containing slags play an important role in the operation of an ironmaking blast furnace (BF), in particular the primary slags such as the system "FeO"-CaO-SiO2-Al2O3-2 mass pct MgO with CaO/SiO2 weight ratios of 1.3, 1.5, and 1.8 saturated with metallic iron. To investigate the characteristics of such a slag system and its behavior in BF, the phase equilibria and liquidus temperatures in the slag system have been experimentally determined using the high-temperature equilibration and quenching technique followed by an electron probe X-ray microanalysis (EPMA). Isotherms between 1553 K and 1603 K (1280 °C and 1330 °C) were determined in the primary phase fields of dicalcium silicate, melilite, spinel, and monoxide [(Mg,Fe2+)O]. Pseudo-ternary phase diagrams of (CaO + SiO2)-Al2O3-"FeO" with a fixed MgO concentration at 2 mass pct and at CaO/SiO2 ratios of 1.3, 1.5, and 1.8 have been discussed, respectively, simplifying the complexity of the slag system for easy understanding and applying in BF operation. It was found that the liquidus temperatures increase in melilite and spinel primary phase fields, but decrease in dicalcium silicate and monoxide primary phase fields with increasing Al2O3/(CaO + SiO2) ratio. In addition, the liquidus temperatures decrease with increasing "FeO" concentration in dicalcium silicate and melilite primary phase fields, while showing an increasing trend in the spinel and monoxide primary phase fields. The data resulted from this study can be used to improve and optimize currently available database of thermodynamic models used in FactSage.

DCP-collected absolute target reflectance signatures assist accurate interpretation of ERTS-1 imagery

NASA Technical Reports Server (NTRS)

Weber, F. P.

1973-01-01

Data collection platforms (DCP's) are being used at a Black Hills, South Dakota, test site (MMC 226A) to record radiometric measurements needed to determine solar and atmospheric parameters that affect ERTS-1 multispectral scanner radiance measurements. A total of 72 channels of analog data transmitted from an unattended ground truth site via three DCP's at least six times a day. The system has operated with only minor problems since September, sending forth daily measurements of biophysical responses and atmospheric conditions. Comparisons of scene radiance data calculated from ERTS images with that measured on the ground show the image-measured values to be 35 percent higher for the green channel and 20 percent higher for the red channel for the same scene targets. Radiance values for channels 6 and 7 are nearly the same from the ground data and from the imagery.

Sensitive fluorescence on-off probes for the fast detection of a chemical warfare agent mimic.

PubMed

Khan, Muhammad Shar Jhahan; Wang, Ya-Wen; Senge, Mathias O; Peng, Yu

2018-01-15

Two highly sensitive probes bearing a nucleophilic imine moiety have been utilized for the selective detection of chemical warfare agent (CWA) mimics. Diethyl chlorophosphate (DCP) was used as mimic CWAs. Both iminocoumarin-benzothiazole-based probes not only demonstrated a remarkable fluorescence ON-OFF response and good recognition, but also exhibited fast response times (10s) along with color changes upon addition of DCP. Limits of detection for the two sensors 1 and 2 were calculated as 0.065μM and 0.21μM, respectively, which are much lower than most other reported probes. These two probes not only show high sensitivity and selectivity in solution, but can also be applied for the recognition of DCP in the gas state, with significant color changes easily observed by the naked eye. Copyright © 2017 Elsevier B.V. All rights reserved.

Identification of pneumonia and influenza deaths using the death certificate pipeline

PubMed Central

2012-01-01

Background Death records are a rich source of data, which can be used to assist with public surveillance and/or decision support. However, to use this type of data for such purposes it has to be transformed into a coded format to make it computable. Because the cause of death in the certificates is reported as free text, encoding the data is currently the single largest barrier of using death certificates for surveillance. Therefore, the purpose of this study was to demonstrate the feasibility of using a pipeline, composed of a detection rule and a natural language processor, for the real time encoding of death certificates using the identification of pneumonia and influenza cases as an example and demonstrating that its accuracy is comparable to existing methods. Results A Death Certificates Pipeline (DCP) was developed to automatically code death certificates and identify pneumonia and influenza cases. The pipeline used MetaMap to code death certificates from the Utah Department of Health for the year 2008. The output of MetaMap was then accessed by detection rules which flagged pneumonia and influenza cases based on the Centers of Disease and Control and Prevention (CDC) case definition. The output from the DCP was compared with the current method used by the CDC and with a keyword search. Recall, precision, positive predictive value and F-measure with respect to the CDC method were calculated for the two other methods considered here. The two different techniques compared here with the CDC method showed the following recall/ precision results: DCP: 0.998/0.98 and keyword searching: 0.96/0.96. The F-measure were 0.99 and 0.96 respectively (DCP and keyword searching). Both the keyword and the DCP can run in interactive form with modest computer resources, but DCP showed superior performance. Conclusion The pipeline proposed here for coding death certificates and the detection of cases is feasible and can be extended to other conditions. This method provides an alternative that allows for coding free-text death certificates in real time that may increase its utilization not only in the public health domain but also for biomedical researchers and developers. Trial Registration This study did not involved any clinical trials. PMID:22569097

Annual Report 1984.

DTIC Science & Technology

1985-01-01

equipped with data collection platforms (DCP) by the end of FY 1985. (b) Communication. The DCP’s transmit the remote gaging station data over the...activated 78 platforms in FY 84 bringing the total number of operating stations to 85. Plans are to activate seven more platforms in FY 85. c. Acoustic... Platforms . The total program cost for FY 1984 is shown in Table VI-3. The total program cost for FY 1985 will be $172,720. (2) National Weather Service

GOES data-collection system instrumentation, installation, and maintenance manual

USGS Publications Warehouse

Blee, J.W.; Herlong, H.E.; Kaufmann, C.D.; Hardee, J.H.; Field, M.L.; Middelburg, R.F.

1986-01-01

The purpose of the manual is to describe the installation, operation, and maintenance of Geostationary Operational Environmental Satellite (GOES) data collection platforms (DCP's) and associated equipment. This manual is not a substitute for DCP manufacturers ' manuals but is additional material that describes the application of data-collection platforms in the Water Resources Division. Power supplies, encoders, antennas, Mini Monitors, voltage analog devices, and the installation of these at streamflow-gaging stations are discussed in detail. (USGS)

Quantitative determination and toxicity evaluation of 2,4-dichlorophenol using poly(eosin Y)/hydroxylated multi-walled carbon nanotubes modified electrode

PubMed Central

Zhu, Xiaolin; Zhang, Kexin; Wang, Chengzhi; Guan, Jiunian; Yuan, Xing; Li, Baikun

2016-01-01

This study aimed at developing simple, sensitive and rapid electrochemical approach to quantitatively determine and assess the toxicity of 2,4-dichlorophenol (2,4-DCP), a priority pollutant and has potential risk to public health through a novel poly(eosin Y, EY)/hydroxylated multi-walled carbon nanotubes composite modified electrode (PEY/MWNTs-OH/GCE). The distinct feature of this easy-fabricated electrode was the synergistic coupling effect between EY and MWNTs-OH that enabled a high electrocatalytic activity to 2,4-DCP. Under optimum conditions, the oxidation peak current enhanced linearly with concentration increasing from 0.005 to 0.1 μM and 0.2 to 40.0 μM, and revealed the detection limit of 1.5 nM. Moreover, the PEY/MWNTs-OH/GCE exhibited excellent electrocatalytic activity toward intracellular electroactive species. Two sensitive electrochemical signals ascribed to guanine/xanthine and adenine/hypoxanthine in human hepatoma (HepG2) cells were detected simultaneously. The sensor was successfully applied to evaluate the toxicity of 2,4-DCP to HepG2 cells. The IC50 values based on the two electrochemical signals are 201.07 and 252.83 μM, respectively. This study established a sensitive platform for the comprehensive evaluation of 2,4-DCP and posed a great potential to simplify environmental toxicity monitoring. PMID:27941912

Polarization Characteristics of Zebra Patterns in Type IV Solar Radio Bursts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaneda, K.; Misawa, H.; Tsuchiya, F.

The polarization characteristics of zebra patterns (ZPs) in type IV solar bursts were studied. We analyzed 21 ZP events observed by the Assembly of Metric-band Aperture Telescope and Real-time Analysis System between 2010 and 2015 and identified the following characteristics: a degree of circular polarization (DCP) in the range of 0%–70%, a temporal delay of 0–70 ms between the two circularly polarized components (i.e., the right- and left-handed components), and dominant ordinary-mode emission in about 81% of the events. For most events, the relation between the dominant and delayed components could be interpreted in the framework of fundamental plasma emissionmore » and depolarization during propagation, though the values of DCP and delay were distributed across wide ranges. Furthermore, it was found that the DCP and delay were positively correlated (rank correlation coefficient R = 0.62). As a possible interpretation of this relationship, we considered a model based on depolarization due to reflections at sharp density boundaries assuming fundamental plasma emission. The model calculations of depolarization including multiple reflections and group delay during propagation in the inhomogeneous corona showed that the DCP and delay decreased as the number of reflections increased, which is consistent with the observational results. The dispersive polarization characteristics could be explained by the different numbers of reflections causing depolarization.« less

Detection of ovomucoid-specific low-affinity IgE in infants and its relationship to eczema.

PubMed

Kawamoto, Norio; Kamemura, Norio; Kido, Hiroshi; Fukao, Toshiyuki

2017-06-01

Allergen-specific low-affinity IgE was previously detected in cord blood by a highly sensitive densely carboxylated protein (DCP) chip, but not by ImmunoCAP. Here, we investigated the presence of low-affinity IgE during the early life of infants and observed its relationship with eczema. We conducted a birth cohort study, collecting sera at birth and 6 and 14 months of age (n = 110). We monitored the ovomucoid (OM)- and egg white (EW)-specific IgE (sIgE) by ImmunoCAP or DCP chip and analyzed the antigen affinity of sIgE by binding inhibition assays in the presence or absence of a mild chaotropic agent, diethyl amine (DEA). The low- and high-affinity OM-sIgEs and sensitization risk factors were analyzed by a multivariate logistic analysis. The OM-sIgE measured by DCP chip significantly correlated with that measured by ImmunoCAP, but some samples assessed as OM-sIgE positive by DCP chip were considered OM-sIgE negative by ImmunoCAP. Binding inhibition analysis after DEA treatment was performed for participants judged as OM-sIgE positive by DCP chip at 14 M. The group assessed as negative for OM- and EW-sIgE by ImmunoCAP at 6 and 14 months showed a larger binding inhibition curve shift after DEA treatment than did the group assessed as positive at these times, indicating the presence of low-affinity sIgE antibodies at 14 months. The logistic regression analysis found that persistent eczema from 6 to 14 months is a significant risk factor for developing high-affinity, but not low-affinity, sIgE. Human infant peripheral blood contains allergen-specific low-affinity sIgE. Persistent eczema is related to the development of high-affinity, but not low-affinity, IgE. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Exploring the use of social network analysis to measure communication between disease programme and district managers at sub-national level in South Africa.

PubMed

Kawonga, Mary; Blaauw, Duane; Fonn, Sharon

2015-06-01

With increasing interest in maximising synergies between disease control programmes (DCP) and general health services (GHS), methods are needed to measure interactions between DCP and GHS actors. In South Africa, administrative integration reforms make GHS managers at decentralised level (district managers) responsible for the oversight of DCP operations within districts, with DCP managers (programme managers) providing specialist support. The reforms necessitate interdependence, but these actors work together ineffectively. Communication is crucial for joint working, but no research to assess communication between these actors has been done. This study explores the use of social network analysis (SNA) to measure the extent to which programme and district managers in South Africa communicate, using HIV monitoring and evaluation (M&E) as an exemplar. Data were collected from fifty one managers in two provinces during 2010-2011, to measure: a) one-on-one task-related communication - talking about the collation (verification, reporting) and use of HIV data for monitoring HIV interventions; and b) group communication through co-participating in management committees where HIV data are used for monitoring HIV interventions in districts. SNA measures were computed to describe actor centrality, network density (cohesion), and communication within and between respective manager groups. Block modelling was applied to identify management committees that connect respective manager groups. Results show HIV programme managers located at higher level communicated largely amongst themselves as a group (homophily), seldom talked to the district managers to whom they are supposed to provide specialist HIV M&E support, and rarely participated with them in management committees. This research demonstrates the utility of SNA as a tool for measuring the extent of communication between DCP and GHS actors at sub-national level. Actions are needed to bridge observed communication gaps in order to promote collaborative monitoring of HIV programme interventions within districts. Copyright © 2015 Elsevier Ltd. All rights reserved.

Performance evaluation of a granular activated carbon-sequencing batch biofilm reactor pilot plant system used in treating real wastewater from recycled paper industry.

PubMed

Muhamad, Mohd Hafizuddin; Sheikh Abdullah, Siti Rozaimah; Mohamad, Abu Bakar; Rahman, Rakmi Abdul; Kadhum, Abdul Amir Hasan

2012-01-01

A pilot scale granular activated carbon-sequencing batch biofilm reactor with a capacity of 2.2 m3 was operated for over three months to evaluate its performance treating real recycled paper industry wastewater under different operational conditions. In this study, dissolved air floatation (DAF) and clarifier effluents were used as influent sources of the pilot plant. During the course of the study, the reactor was able to biodegrade the contaminants in the incoming recycled paper mill wastewater in terms of chemical oxygen demand (COD), adsorbable organic halides (AOX; specifically 2,4-dichlorophenol (2,4-DCP)) and ammoniacal nitrogen (NH3-N) removal efficiencies at varying hydraulic retention times (HRTs) of 1-3 days, aeration rates (ARs) of 2.1-3.4 m3/min and influent feed concentration of 40-950 mg COD/l. Percentages of COD, 2,4-DCP and NH3-N removals increased with increasing HRT, resulting in more than 90% COD, 2,4-DCP and NH3-N removals at HRT values above two days. Degradation of COD, 2,4-DCP and NH3-N were seriously affected by variation of ARs, which resulted in significant decrease of COD, 2,4-DCP and NH3-N removals by decreasing ARs from 3.4 m3/min to 2.1 m3/min, varying in the ranges of 24-80%, 6-96% and 5-42%, respectively. In comparison to the clarifier effluent, the treatment performance of DAF effluent, containing high COD concentration, resulted in a higher COD removal of 82%. The use of diluted DAF effluent did not improve significantly the COD removal. Higher NH3-N removal efficiency of almost 100% was observed during operation after maintenance shutdown compared to normal operation, even at the same HRT of one day due to the higher dissolved oxygen concentrations (1-7 mg/l), while no significant difference in COD removal efficiency was observed.

Balancing Materiel Readiness Risks and Concurrency in Weapon System Acquisition: A Handbook for Program Managers

DTIC Science & Technology

1984-07-15

ftViCCii UWNC COMMAND MIX CM AFT DCP OUTUNC moo ffEOUCST FOR PROGRAM DECISION DRAFT DCP AFSC REVIEW RECOWMEM CATIONS OHI*OC Arse wioc...CS.P3 F16. El*. P» MCA Exhibit 4-6b. EMBEDDED COMPUTER HARDWARE vs. SOFTWARE Exhibit 4-6c. DoD EMBEDDED COMPUTER MARKET 31.J1...the mix of stores carried by that vehicle 6. Anticipated combat tactics employed by the carrying or launching vehicle and its maneuvering

Gene-Environment Interaction and Breast Cancer on Long Island, NY

DTIC Science & Technology

2008-05-01

Report on Human Exposure to Environmental Chemicals, 2005; 6–11-year age group, 2001–2002 survey years; 1999–2000 survey years used for 2,4-DCP and 2,5-DCP...Examination Survey (NHANES) conducted between 1999 and 2002 (Centers for Disease Control and Prevention, 2005). NHANES is designed to collect data on the...The CDC has previ- ously reported concentrations in child partici- pants in the National Health and Nutrition Examination Survey (NHANES) for some

Evaluation of an ERTS-1 data collection platform installed in the Alpine Tundra, Colorado. [for meteorological measurements

NASA Technical Reports Server (NTRS)

Barry, R. G.; Clark, J. M.

1975-01-01

The communication of data in real-time to users from ground stations in remote areas is a major objective of recent space technology. The data collection system considered uses small battery-operated ground-based transmitters called data collection platforms (DCP). The feasibility of collecting environmental data in extreme cold and windy environments using the ERTS DCP, has been investigated. A summary of the results of an evaluation of the system used is presented.

Advanced data mining approaches in the assessment of urinary concentrations of bisphenols, chlorophenols, parabens and benzophenones in Brazilian children and their association to DNA damage.

PubMed

Rocha, Bruno A; Asimakopoulos, Alexandros G; Honda, Masato; da Costa, Nattane L; Barbosa, Rommel M; Barbosa, Fernando; Kannan, Kurunthachalam

2018-07-01

Human exposure to endocrine disrupting chemicals (EDCs) has received considerable attention over the last three decades. However, little is known about the influence of co-exposure to multiple EDCs on effect-biomarkers such as oxidative stress in Brazilian children. In this study, concentrations of 40 EDCs were determined in urine samples collected from 300 Brazilian children of ages 6-14 years and data were analyzed by advanced data mining techniques. Oxidative DNA damage was evaluated from the urinary concentrations of 8-hydroxy-2'-deoxyguanosine (8OHDG). Fourteen EDCs, including bisphenol A (BPA), methyl paraben (MeP), ethyl paraben (EtP), propyl paraben (PrP), 3,4-dihydroxy benzoic acid (3,4-DHB), methyl-protocatechuic acid (OH-MeP), ethyl-protocatechuic acid (OH-EtP), triclosan (TCS), triclocarban (TCC), 2-hydroxy-4-methoxybenzophenone (BP3), 2,4-dihydroxybenzophenone (BP1), bisphenol A bis(2,3-dihydroxypropyl) glycidyl ether (BADGE·2H 2 O), 2,4-dichlorophenol (2,4-DCP), and 2,5-dichlorophenol (2,5-DCP) were found in >50% of the urine samples analyzed. The highest geometric mean concentrations were found for MeP (43.1 ng/mL), PrP (3.12 ng/mL), 3,4-DHB (42.2 ng/mL), TCS (8.26 ng/mL), BP3 (3.71 ng/mL), and BP1 (4.85 ng/mL), and exposures to most of which were associated with personal care product (PCP) use. Statistically significant associations were found between urinary concentrations of 8OHDG and BPA, MeP, 3,4-DHB, OH-MeP, OH-EtP, TCS, BP3, 2,4-DCP, and 2,5-DCP. After clustering the data on the basis of i) 14 EDCs (exposure levels), ii) demography (age, gender and geographic location), and iii) 8OHDG (effect), two distinct clusters of samples were identified. 8OHDG concentration was the most critical parameter that differentiated the two clusters, followed by OH-EtP. When 8OHDG was removed from the dataset, predictability of exposure variables increased in the order of: OH-EtP > OH-MeP > 3,4-DHB > BPA > 2,4-DCP > MeP > TCS > EtP > BP1 > 2,5-DCP. Our results showed that co-exposure to OH-EtP, OH-MeP, 3,4-DHB, BPA, 2,4-DCP, MeP, TCS, EtP, BP1, and 2,5-DCP was associated with DNA damage in children. This is the first study to report exposure of Brazilian children to a wide range of EDCs and the data mining approach further strengthened our findings of chemical co-exposures and biomarkers of effect. Copyright © 2018 Elsevier Ltd. All rights reserved.

Phase modification and dielectric properties of a cullet-paper ash-kaolin clay-based ceramic

NASA Astrophysics Data System (ADS)

Samah, K. A.; Sahar, M. R.; Yusop, M.; Omar, M. F.

2018-03-01

Novel ceramics from waste material made of ( x) paper ash-(80 - x) cullet-20 kaolin clay (10wt% ≤ x ≤ 30wt%) were successfully synthesized using a conventional solid-state reaction technique. Energy-dispersive X-ray analysis confirmed the presence of Si, Ca, Al, and Fe in the waste material for preparing these ceramics. The influence of the cullet content on the phase structures and the dielectric properties of these ceramics were systematically investigated. The impedance spectra were verified in the range from 1 Hz to 10 MHz at room temperature. The phase of the ceramics was found to primarily consist of wollastonite (CaSiO3), along with minor phases of γ-dicalcium silicate (Ca2SiO4) and quartz (SiO2). The sample with a cullet content of 55wt% possessed the optimum wollastonite structure and exhibited good dielectric properties. An increase of the cullet content beyond 55wt% resulted in a structural change from wollastonite to dicalcium silicate, a decrease in dielectric constant, and an increase in dielectric loss. All experimental results suggested that these novel ceramics from waste are applicable for electronic devices.

β-Dicalcium silicate-based cement: synthesis, characterization and in vitro bioactivity and biocompatibility studies.

PubMed

Correa, Daniel; Almirall, Amisel; García-Carrodeguas, Raúl; dos Santos, Luis Alberto; De Aza, Antonio H; Parra, Juan; Delgado, José Ángel

2014-10-01

β-dicalcium silicate (β-Ca₂ SiO₄, β-C₂ S) is one of the main constituents in Portland cement clinker and many refractory materials, itself is a hydraulic cement that reacts with water or aqueous solution at room/body temperature to form a hydrated phase (C-S-H), which provides mechanical strength to the end product. In the present investigation, β-C₂ S was synthesized by sol-gel process and it was used as powder to cement preparation, named CSiC. In vitro bioactivity and biocompatibility studies were assessed by soaking the cement samples in simulated body fluid solutions and human osteoblast cell cultures for various time periods, respectively. The results showed that the sol-gel process is an available synthesis method in order to obtain a pure powder of β-C₂ S at relatively low temperatures without chemical stabilizers. A bone-like apatite layer covered the material surface after soaking in SBF and its compressive strength (CSiC cement) was comparable with that of the human trabecular bone. The extracts of this cement were not cytotoxic and the cell growth and relative cell viability were comparable to negative control. © 2013 Wiley Periodicals, Inc.

Sonochemical synthesis of fructose 1,6-bisphosphate dicalcium porous microspheres and their application in promotion of osteogenic differentiation.

PubMed

Qi, Chao; Zhou, Ding; Zhu, Ying-Jie; Sun, Tuan-Wei; Chen, Feng; Zhang, Chang-Qing

2017-08-01

Human bone mesenchymal stem cells (hBMSCs) have the ability to differentiate into bone and cartilage for clinical bone regeneration. Biomaterials with an innate ability to stimulate osteogenic differentiation of hBMSCs into bone and cartilage are considered attractive candidates for the applications in bone tissue engineering and regeneration. In this paper, we synthesized fructose 1,6-bisphosphate dicalcium (Ca 2 FBP) porous microspheres by the sonochemical method, and investigated the ability of Ca 2 FBP for the promotion of the osteogenic differentiation of hBMSCs. After the hBMSCs were co-cultured with the sterilized powder of Ca 2 FBP porous microspheres for different times, the cell proliferation assay, alkaline phosphatase activity assay, quantitative real-time polymerase chain reaction and western blotting were performed to investigate the bioactivity and osteogenic differentiation performance of the as-prepared product. Compared with hydroxyapatite nanorods, Ca 2 FBP porous microspheres show a superior bioactivity and osteoinductive potential, and can promote the cell differentiation of hBMSCs in vitro, thus, they are promising for applications in the tissue engineering field such as dental and bone defect repair. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of relaxation on the delayed-type hypersensitivity (DTH) reaction to diphenylcyclopropenone (DCP).

PubMed

Zachariae, R; Jørgensen, M M; Christensen, S; Bjerring, P

1997-07-01

Delayed-type hypersensitivity (DTH) reactions to the experimental allergen diphenylcyclopropenone (DCP) were measured in four groups, which either trained (+) or did not train in relaxation (-) during the sensitization and/or the challenge phase. All groups consisted of high and low hypnotic susceptible subjects. While there were no differences in erythema, the mean induration of the group which trained in relaxation in both the sensitization and the challenge phase (+/+) was significantly greater than that of the group which trained in relaxation in the challenge phase only (-/+). Significant correlations were found between induration and hypnotic susceptibility scores, and between induration and degree of perceived relaxation during challenge. High hypnotic susceptible subjects experienced a higher degree of perceived relaxation and exhibited greater indurative and erythematous DTH reactions to DCP than low hypnotic susceptible subjects in all four experimental conditions. Though the mediating mechanisms remain unclear, our results suggest that relaxation may affect the DTH reaction, and support previous findings of higher psychophysiologic reactivity of high hypnotic susceptible subjects.

Hsp83 loss suppresses proteasomal activity resulting in an upregulation of caspase-dependent compensatory autophagy.

PubMed

Choutka, Courtney; DeVorkin, Lindsay; Go, Nancy Erro; Hou, Ying-Chen Claire; Moradian, Annie; Morin, Gregg B; Gorski, Sharon M

2017-09-02

The 2 main degradative pathways that contribute to proteostasis are the ubiquitin-proteasome system and autophagy but how they are molecularly coordinated is not well understood. Here, we demonstrate an essential role for an effector caspase in the activation of compensatory autophagy when proteasomal activity is compromised. Functional loss of Hsp83, the Drosophila ortholog of human HSP90 (heat shock protein 90), resulted in reduced proteasomal activity and elevated levels of the effector caspase Dcp-1. Surprisingly, genetic analyses showed that the caspase was not required for cell death in this context, but instead was essential for the ensuing compensatory autophagy, female fertility, and organism viability. The zymogen pro-Dcp-1 was found to interact with Hsp83 and undergo proteasomal regulation in an Hsp83-dependent manner. Our work not only reveals unappreciated roles for Hsp83 in proteasomal activity and regulation of Dcp-1, but identifies an effector caspase as a key regulatory factor for sustaining adaptation to cell stress in vivo.

ERTS-1 data collection systems used to predict wheat disease severities. [Riley County, Kansas

NASA Technical Reports Server (NTRS)

Kanemasu, E. T.; Schimmelpfenning, H.; Choy, E. C.; Eversmeyer, M. G.; Lenhert, D.

1974-01-01

The author has identified the following significant results. The feasibility of using the data collection system on ERTS-1 to predict wheat leaf rust severity and resulting yield loss was tested. Ground-based data collection platforms (DCP'S), placed in two commercial wheat fields in Riley County, Kansas, transmitted to the satellite such meteorological information as maximum and minimum temperature, relative humidity, and hours of free moisture. Meteorological data received from the two DCP'S from April 23 to 29 were used to estimate the disease progress curve. Values from the curve were used to predict the percentage decrease in wheat yields resulting from leaf rust. Actual decrease in yield was obtained by applying a zinc and maneb spray (5.6 kg/ha) to control leaf rust, then comparing yields of the controlled (healthy) and the noncontrolled (rusted) areas. In each field a 9% decrease in yield was predicted by the DCP-derived data; actual decreases were 12% and 9%.

Enzymatic coupling of 2,4-dichlorophenol to stream fulvic acid in the presence of oxidoreductases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sarkar, J.M.; Malcolm, R.L.; Bollag, J.M.

The coupling {sup 14}C-ring-labelled 2,4-dichlorophenol (2,4-DCP) to stream fulvic acid was investigated in the presence of several oxidoreductases including tyrosinase, peroxidase, and laccases of Rhizoctonia praticola and Trametes vesicolor. During 12-h incubation of the oxidoreductases with {sup 14}C-2, 4-DCP and stream fulvic acid, a substantial amount of the radioactivity was incorporated into fulvic acid. Chromatographic analysis indicated that although a large portion of the radioactivity remained in solution, no unbound {sup 14}C-2,4-DCP was present in the supernatant. The effects of pH, temperature, concentration of fulvic acid, and concentration of enzyme on the coupling processes were studied. The results of thismore » research provide evidence that the enzymatic coupling of certain xenobiotic pollutants to humic substances is an important natural process which must be considered in studies of the fate, reactivity, and persistence of these organic compounds in soils and stream waters.« less

Dietary exposure to chloropropanols of secondary school students in Hong Kong.

PubMed

Yau, J C W; Kwong, K P; Chung, S W C; Ho, Y Y; Xiao, Y

2008-01-01

This paper reports levels of 3-monochloropropan-1,2-diol (3-MCPD) and 1,3-dichloro-2-propanol (1,3-DCP) in a wide range of food items and estimates their dietary exposure for secondary school students in Hong Kong. Dietary exposure to chloropropanols was estimated using local food consumption data obtained from secondary school students in 2000 and the concentrations of 3-MCPD and 1,3-DCP in food samples taken from the local market. The dietary exposure to 3-MCPD for an average secondary school student consumer was estimated to be 0.063-0.150 µg kg(-1) body weight (bw) day(-1), whilst that for the high consumer was 0.152-0.300 µg kg(-1) bw day(-1). Both estimates fell below the provisional maximum tolerable daily intake of 2 µg kg(-1) bw established by the Joint Expert Committee on Food Additives (JECFA) and amounted to less than 20% of this safety reference value. The dietary exposure to 1,3-DCP for an average secondary school student consumer was estimated to be 0.003-0.019 µg kg(-1) bw day(-1), whilst that for the high consumer was 0.009-0.040 µg kg(-1) bw day(-1). The resulting margins of exposures were of low concern for human health. It could be concluded that both the average and high secondary school student consumers were unlikely to experience major toxicological effects of 3-MCPD and 1,3-DCP.

The reduction of starch in finishing diets supplemented with oil does not prevent the accumulation of trans-10 18:1 in lamb meat.

PubMed

Costa, M; Alves, S P; Francisco, A; Almeida, J; Alfaia, C M; Martins, S V; Prates, J A M; Santos-Silva, J; Doran, O; Bessa, R J B

2017-08-01

The experiment was conducted to test the hypothesis that the replacement of cereal with low-starch feed ingredients in lambs' finishing diets supplemented with oils could prevent the accumulation of -10-18:1 in meat. Forty lambs were fed 1 of 4 diets supplemented with soybean oil (5.9%) and fish oil (1%) for 6 wk before slaughter. The control (CON) diet contained 43% barley, and in the other diets, barley was completely replaced by dehydrated citrus pulp (DCP), dehydrated sugar beet pulp (DBP), or soybean hulls (SH). Growth performance, feed intake, and carcass and meat quality traits were analyzed. At slaughter, LM samples were collected for gene expression evaluation, and 3 d after slaughter, LM and subcutaneous (s.c.) fat samples were collected for fatty acid analysis. None of the diets affected meat quality, but the DCP diet reduced ADG ( < 0.05) and the DCP and SH diets decreased the feed-to-gain ratio ( < 0.01). The DCP diet increased ( < 0.05) the risk of parakeratosis and the severity of the lesions. Moreover, the DBP treatment led to increased a* (redness) and b* (yellowness) in s.c. fat compared with the CON treatment ( < 0.05). The lipid content of LM did not differ ( > 0.05) with treatment and averaged 34.4 g/kg of meat. Diets had no effect ( > 0.05) on SFA, PUFA, and -MUFA sums and on the -6:-3 ratio in both LM and s.c. fat. A lower expression of fatty acid synthase (FASN) was found with the DCP treatment than with the other treatments ( < 0.001). All treatments showed a high accumulation of -10-18:1, averaging 91 mg/g fatty acid in LM and 147 mg/g fatty acid in s.c. fat. The concentration of -11-18:1 in the tissues was considerably lower than that of -10-18:1, and thus the -10-18:1:-11-18:1 ratio was above 3 with all treatments. Despite this, the SH diet clearly promoted a larger deposition of -11-18:1 and -9,-11-18:2 in tissues compared with the other treatments. () gene expression and SCD activity index in LM were reduced with the SH diet compared with the CON and DCP diets. Overall, these results clearly showed, for the first time, that low-starch/high-NDF diets are not able to prevent the establishment of -10 shifted rumen biohydrogenation pathways, evaluated by the deposition of biohydrogenation intermediates in lamb meat and fat.

Double- and multi-carbapenemase-producers: the excessively armored bacilli of the current decade.

PubMed

Meletis, G; Chatzidimitriou, D; Malisiovas, N

2015-08-01

Multidrug-resistant (MDR) and extensively drug-resistant (XDR) Gram-negative nosocomial pathogens commonly carry one carbapenemase gene conferring resistance to carbapenems and other beta-lactam antibiotics. However, increasing reports show that double-carbapenemase-producing (DCP) and even multi-carbapenemase-producing (MCP) bacteria are emerging in some parts of the world, diminishing further, in some cases, the already limited treatment options. In the present review, the up-to-date reports of DCP and MCP isolates are summarized and concerns regarding their emergence are discussed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xiong, Yongliang; Kirkes, Leslie; Westfall, Terry

In this study, solubility measurements on di-calcium ethylenediaminetetraacetic acid [Ca 2C 10H 12N 2O 8(s), abbreviated as Ca 2EDTA(s)] as a function of ionic strength are conducted in NaCl solutions up to I = 5.0 mol•kg –1 and in MgCl 2 solutions up to I = 7.5 mol•kg –1, at room temperature (22.5 ± 0.5oC).

Simultaneous Analysis of 3-MCPD and 1,3-DCP in Asian Style Sauces Using QuEChERS Extraction and Gas Chromatography-Triple Quadrupole Mass Spectrometry.

PubMed

Genualdi, Susan; Nyman, Patricia; DeJager, Lowri

2017-02-01

Acid hydrolyzed vegetable protein (aHVP) is used for flavoring a wide variety of foods and also in the production of nonfermented soy sauce. During the production of aHVP, chloropropanols including 3-monochloropropane-1,2-diol (3-MCPD) and 1,3 dichloropropane-2-ol (1,3-DCP) can be formed through the reaction of the hydrochloric acid catalyst and residual fat and the reaction of 3-MCPD with acetic acid, respectively. 3-MCPD is a carcinogen, and 1,3-DCP has been classified as a genotoxic carcinogen. The European Union (EU) has set a maximum concentration of 0.02 mg/kg of 3-MCPD in aHVP, and the Food and Drug Administration (FDA) set a guidance limit of 1 mg/kg of 3-MCPD in aHVP. 1,3-DCP is not an approved food additive, and the Joint FAO/WHO Expert Committee on Food Additives (JEFCA) has set a limit at 0.005 mg/kg, which is close to the estimated method detection limit. Currently there are few analytical methods for the simultaneous determination of 3-MCPD and 1,3-DCP without derivatization due to differences in their physical chemical properties and reactivity. A new method was developed using QuEChERS (quick, easy, cheap, effective, rugged, and safe) with direct analysis of the extract without derivatization using gas chromatography-triple quadrupole mass spectrometry (GC-QQQ). Additionally, a market sampling of 60 soy sauce samples was performed in 2015 to determine if concentrations have changed since the FDA limit was set in 2008. The sampling results were compared between the new QuEChERS method and a method using phenylboronic acid (PBA) as a derivatizing agent for 3-MCPD analysis. The concentrations of 3-MCPD detected in soy sauce samples collected in 2015 (

Simultaneous Analysis of 3-MCPD and 1,3-DCP in Asian Style Sauces Using QuEChERS Extraction and Gas Chromatography–Triple Quadrupole Mass Spectrometry

PubMed Central

Genualdi, Susan; Nyman, Patricia; DeJager, Lowri

2017-01-01

Acid hydrolyzed vegetable protein (aHVP) is used for flavoring a wide variety of foods and also in the production of nonfermented soy sauce. During the production of aHVP, chloropropanols including 3-monochloropropane-1,2-diol (3-MCPD) and 1,3 dichloropropane-2-ol (1,3-DCP) can be formed through the reaction of the hydrochloric acid catalyst and residual fat and the reaction of 3-MCPD with acetic acid, respectively. 3-MCPD is a carcinogen, and 1,3-DCP has been classified as a genotoxic carcinogen. The European Union (EU) has set a maximum concentration of 0.02 mg/kg of 3-MCPD in aHVP, and the Food and Drug Administration (FDA) set a guidance limit of 1 mg/kg of 3-MCPD in aHVP. 1,3-DCP is not an approved food additive, and the Joint FAO/WHO Expert Committee on Food Additives (JEFCA) has set a limit at 0.005 mg/kg, which is close to the estimated method detection limit. Currently there are few analytical methods for the simultaneous determination of 3-MCPD and 1,3-DCP without derivatization due to differences in their physical chemical properties and reactivity. A new method was developed using QuEChERS (quick, easy, cheap, effective, rugged, and safe) with direct analysis of the extract without derivatization using gas chromatography–triple quadrupole mass spectrometry (GC-QQQ). Additionally, a market sampling of 60 soy sauce samples was performed in 2015 to determine if concentrations have changed since the FDA limit was set in 2008. The sampling results were compared between the new QuEChERS method and a method using phenylboronic acid (PBA) as a derivatizing agent for 3-MCPD analysis. The concentrations of 3-MCPD detected in soy sauce samples collected in 2015 (

Error quantification of osteometric data in forensic anthropology.

PubMed

Langley, Natalie R; Meadows Jantz, Lee; McNulty, Shauna; Maijanen, Heli; Ousley, Stephen D; Jantz, Richard L

2018-06-01

This study evaluates the reliability of osteometric data commonly used in forensic case analyses, with specific reference to the measurements in Data Collection Procedures 2.0 (DCP 2.0). Four observers took a set of 99 measurements four times on a sample of 50 skeletons (each measurement was taken 200 times by each observer). Two-way mixed ANOVAs and repeated measures ANOVAs with pairwise comparisons were used to examine interobserver (between-subjects) and intraobserver (within-subjects) variability. Relative technical error of measurement (TEM) was calculated for measurements with significant ANOVA results to examine the error among a single observer repeating a measurement multiple times (e.g. repeatability or intraobserver error), as well as the variability between multiple observers (interobserver error). Two general trends emerged from these analyses: (1) maximum lengths and breadths have the lowest error across the board (TEM<0.5), and (2) maximum and minimum diameters at midshaft are more reliable than their positionally-dependent counterparts (i.e. sagittal, vertical, transverse, dorso-volar). Therefore, maxima and minima are specified for all midshaft measurements in DCP 2.0. Twenty-two measurements were flagged for excessive variability (either interobserver, intraobserver, or both); 15 of these measurements were part of the standard set of measurements in Data Collection Procedures for Forensic Skeletal Material, 3rd edition. Each measurement was examined carefully to determine the likely source of the error (e.g. data input, instrumentation, observer's method, or measurement definition). For several measurements (e.g. anterior sacral breadth, distal epiphyseal breadth of the tibia) only one observer differed significantly from the remaining observers, indicating a likely problem with the measurement definition as interpreted by that observer; these definitions were clarified in DCP 2.0 to eliminate this confusion. Other measurements were taken from landmarks that are difficult to locate consistently (e.g. pubis length, ischium length); these measurements were omitted from DCP 2.0. This manual is available for free download online (https://fac.utk.edu/wp-content/uploads/2016/03/DCP20_webversion.pdf), along with an accompanying instructional video (https://www.youtube.com/watch?v=BtkLFl3vim4). Copyright © 2018 Elsevier B.V. All rights reserved.

Development of form stable Poly(methyl methacrylate) (PMMA) coated thermal phase change material for solar water heater applications

NASA Astrophysics Data System (ADS)

Munusamy, Y.; Shanmugam, S.; Shi-Ying, Kee

2018-04-01

Phase change material (PCM) is one of the most popular and widely used thermal energy storage material in solar water heater because it able to absorb and release a large amount of latent heat during a phase change process over a narrow temperature range. However the practical application of PCM is limited by two major issues; 1) leakage which leads to material loss and corrosion of tank and 2) large volume change during phase change process which cause pressure build up in the tank. In this work, form-stable PCM was prepared by coating myristic acid with Poly(methyl methacrylate) (PMMA) to prevent leakage of PCM. PMMA was mixed with different weight percentage (0.1, 0.2, 0.3, 0.4 and 0.5 wt%) of dicumyl peroxide (DCP). The purpose of adding DCP to PMMA is to crosslink the polymer and to increase the mechanical strength of PMMA to hold the myristic acid content inside the coating during the phase change process. Leakage test results showed that PMMA mixed with 0.1% DCP exhibit 0% leakage. This result is further supported by Field Emission Scanning Electron Microscopy (FESEM) images and Fourier transform infrared spectroscopy (FTIR) analysis results, where a compact and uniform coating without cracks were formed for PCM coated with PMMA with 0.1% DCP. Differential scanning calorimetry (DSC) results shows that the melting point of form-stable PCM is 55°C, freezing point is 50°C, the latent heat of melting and freezing is 67.59 J/g.

Drosophila caspases involved in developmentally regulated programmed cell death of peptidergic neurons during early metamorphosis.

PubMed

Lee, Gyunghee; Wang, Zixing; Sehgal, Ritika; Chen, Chun-Hong; Kikuno, Keiko; Hay, Bruce; Park, Jae H

2011-01-01

A great number of obsolete larval neurons in the Drosophila central nervous system are eliminated by developmentally programmed cell death (PCD) during early metamorphosis. To elucidate the mechanisms of neuronal PCD occurring during this period, we undertook genetic dissection of seven currently known Drosophila caspases in the PCD of a group of interneurons (vCrz) that produce corazonin (Crz) neuropeptide in the ventral nerve cord. The molecular death program in the vCrz neurons initiates within 1 hour after pupariation, as demonstrated by the cytological signs of cell death and caspase activation. PCD was significantly suppressed in dronc-null mutants, but not in null mutants of either dredd or strica. A double mutation lacking both dronc and strica impaired PCD phenotype more severely than did a dronc mutation alone, but comparably to a triple dredd/strica/dronc mutation, indicating that dronc is a main initiator caspase, while strica plays a minor role that overlaps with dronc's. As for effector caspases, vCrz PCD requires both ice and dcp-1 functions, as they work cooperatively for a timely removal of the vCrz neurons. Interestingly, the activation of the Ice and Dcp-1 is not solely dependent on Dronc and Strica, implying an alternative pathway to activate the effectors. Two remaining effector caspase genes, decay and damm, found no apparent functions in the neuronal PCD, at least during early metamorphosis. Overall, our work revealed that vCrz PCD utilizes dronc, strica, dcp-1, and ice wherein the activation of Ice and Dcp-1 requires a novel pathway in addition to the initiator caspases.

Novel rubbers from cationic copolymerization of soybean oils and dicyclopentadiene. 1. Synthesis and characterization.

PubMed

Andjelkovic, Dejan D; Larock, Richard C

2006-03-01

Novel thermosetting copolymers, ranging from tough and ductile to very soft rubbers, have been prepared by the cationic copolymerization of regular (SOY) and 100% conjugated soybean oils (C(100)SOY) with dicyclopentadiene (DCP) catalyzed by Norway fish oil (NFO)-modified and SOY- and C(100)SOY-diluted boron trifluoride diethyl etherate (BFE). The gelation time of the reactions varies from 4 to 991 min at 110 degrees C. The yields of the bulk copolymers are essentially quantitative, while the yields of the cross-linked copolymers remaining after Soxhlet extraction with methylene chloride range from 69% to 88%, depending on the monomer stoichiometry and the catalyst used. (1)H NMR spectroscopy and Soxhlet extraction data indicate that these copolymers consist of a cross-linked soybean oil-DCP network plasticized by certain amounts of methylene chloride-soluble linear or less cross-linked soybean oil-DCP copolymers, unreacted oil, and some low molecular weight hydrolyzed oil. The molecular weights of these soluble fractions are in the range from 400 to 10,000 g/mol based on polystyrene standards. The bulk copolymers have glass transition temperatures ranging from -22.6 to 56.6 degrees C, while their tan delta peak values range from 0.7 to 1.2. Thermogravimetric analysis (TGA) indicates that these soybean oil-DCP copolymers are thermally stable below 200 degrees C, with 10% and 50% weight loss temperatures ranging from 280 to 372 degrees C and 470-554 degrees C, respectively. These properties suggest that these biobased thermosets may prove useful alternatives to current petroleum-based plastics and find widespread utility.

Resolution and some properties of enzymes involved in enantioselective transformation of 1,3-dichloro-2-propanol to (R)-3-chloro-1,2-propanediol by Corynebacterium sp. strain N-1074.

PubMed Central

Nakamura, T; Nagasawa, T; Yu, F; Watanabe, I; Yamada, H

1992-01-01

During the course of the transformation of 1,3-dichloro-2-propanol (DCP) into (R)-3-chloro-1,2-propanediol [(R)-MCP] with the cell extract of Corynebacterium sp. strain N-1074, epichlorohydrin (ECH) was transiently formed. The cell extract was fractionated into two DCP-dechlorinating activities (fractions Ia and Ib) and two ECH-hydrolyzing activities (fractions IIa and IIb) by TSKgel DEAE-5PW column chromatography. Fractions Ia and Ib catalyzed the interconversion of DCP to ECH, and fractions IIa and IIb catalyzed the transformation of ECH into MCP. Fractions Ia and IIa showed only low enantioselectivity for each reaction, whereas fractions Ib and IIb exhibited considerable enantioselectivity, yielding R-rich ECH and MCP, respectively. Enzymes Ia and Ib were isolated from fractions Ia and Ib, respectively. Enzyme Ia had a molecular mass of about 108 kDa and consisted of four subunits identical in molecular mass (about 28 kDa). Enzyme Ib was a protein of 115 kDa, composed of two different polypeptides (about 35 and 32 kDa). The specific activity of enzyme Ib for DCP was about 30-fold higher than that of enzyme Ia. Both enzymes catalyzed the transformation of several halohydrins into the corresponding epoxides with liberation of halides and its reverse reaction. Their substrate specificities and immunological properties differed from each other. Enzyme Ia seemed to be halohydrin hydrogen-halide-lyase which was already purified from Escherichia coli carrying a gene from Corynebacterium sp. strain N-1074. Images PMID:1447132

Acinus integrates AKT1 and subapoptotic caspase activities to regulate basal autophagy.

PubMed

Nandi, Nilay; Tyra, Lauren K; Stenesen, Drew; Krämer, Helmut

2014-10-27

How cellular stresses up-regulate autophagy is not fully understood. One potential regulator is the Drosophila melanogaster protein Acinus (Acn), which is necessary for autophagy induction and triggers excess autophagy when overexpressed. We show that cell type-specific regulation of Acn depends on proteolysis by the caspase Dcp-1. Basal Dcp-1 activity in developing photoreceptors is sufficient for this cleavage without a need for apoptosis to elevate caspase activity. On the other hand, Acn was stabilized by loss of Dcp-1 function or by the presence of a mutation in Acn that eliminates its conserved caspase cleavage site. Acn stability also was regulated by AKT1-mediated phosphorylation. Flies that expressed stabilized forms of Acn, either the phosphomimetic Acn(S641,731D) or the caspase-resistant Acn(D527A), exhibited enhanced basal autophagy. Physiologically, these flies showed improvements in processes known to be autophagy dependent, including increased starvation resistance, reduced Huntingtin-induced neurodegeneration, and prolonged life span. These data indicate that AKT1 and caspase-dependent regulation of Acn stability adjusts basal autophagy levels. © 2014 Nandi et al.

Near real time water resources data for river basin management

NASA Technical Reports Server (NTRS)

Paulson, R. W. (Principal Investigator)

1973-01-01

The author has identified the following significant results. Twenty Data Collection Platforms (DCP) are being field installed on USGS water resources stations in the Delaware River Basin. DCP's have been successfully installed and are operating well on five stream gaging stations, three observation wells, and one water quality monitor in the basin. DCP's have been installed at nine additional water quality monitors, and work is progressing on interfacing the platforms to the monitors. ERTS-related water resources data from the platforms are being provided in near real time, by the Goddard Space Flight Center to the Pennsylvania district, Water Resources Division, U.S. Geological Survey. On a daily basis, the data are computer processed by the Survey and provided to the Delaware River Basin Commission. Each daily summary contains data that were relayed during 4 or 5 of the 15 orbits made by ERTS-1 during the previous day. Water resources parameters relays by the platforms include dissolved oxygen concentrations, temperature, pH, specific conductance, well level, and stream gage height, which is used to compute stream flow for the daily summary.

The influence of heavy metals on the polymorphs of dicalcium silicate in the belite-rich clinkers produced from electroplating sludge.

PubMed

Chen, Ying-Liang; Shih, Pai-Haung; Chiang, Li-Choung; Chang, Yi-Kuo; Lu, Hsing-Cheng; Chang, Juu-En

2009-10-15

The purpose of this study is to utilize an electroplating sludge for belite-rich clinker production and to observe the influence of heavy metals on the polymorphs of dicalcium silicate (C(2)S). Belite-rich clinkers prepared with 0.5-2% of NiO, ZnO, CuO, and Cr(2)O(3) were used to investigate the individual effects of the heavy metals in question. The Reference Intensity Ratio (RIR) method was employed to determine the weight fractions of gamma-C(2)S and beta-C(2)S in the clinkers, and their microstructures were examined by the transmission electron microscopy (TEM). The results showed that nickel, zinc, and chromium have positive effects on beta-C(2)S stabilization (Cr(3+)>Ni(2+)>Zn(2+)), whereas copper has a negative effect. The addition of up to 10% electroplating sludge did not have any negative influence on the formation of C(2)S. It was observed that gamma-C(2)S decreased while beta-C(2)S increased with a rise in the addition of the electroplating sludge. Moreover, nickel and chromium mainly contributed to stabilizing beta-C(2)S in the belite-rich clinkers produced from the electroplating sludge.

A New Biphasic Dicalcium Silicate Bone Cement Implant.

PubMed

Zuleta, Fausto; Murciano, Angel; Gehrke, Sergio A; Maté-Sánchez de Val, José E; Calvo-Guirado, José L; De Aza, Piedad N

2017-07-06

This study aimed to investigate the processing parameters and biocompatibility of a novel biphasic dicalcium silicate (C₂S) cement. Biphasic α´ L + β-C₂S ss was synthesized by solid-state processing, and was used as a raw material to prepare the cement. In vitro bioactivity and biocompatibility studies were assessed by soaking the cement samples in simulated body fluid (SBF) and human adipose stem cell cultures. Two critical-sized defects of 6 mm Ø were created in 15 NZ tibias. A porous cement made of the high temperature forms of C₂S, with a low phosphorous substitution level, was produced. An apatite-like layer covered the cement's surface after soaking in SBF. The cell attachment test showed that α´ L + β-C₂S ss supported cells sticking and spreading after 24 h of culture. The cement paste (55.86 ± 0.23) obtained higher bone-to-implant contact (BIC) percentage values (better quality, closer contact) in the histomorphometric analysis, and defect closure was significant compared to the control group (plastic). The residual material volume of the porous cement was 35.42 ± 2.08% of the initial value. The highest BIC and bone formation percentages were obtained on day 60. These results suggest that the cement paste is advantageous for initial bone regeneration.

A New Biphasic Dicalcium Silicate Bone Cement Implant

PubMed Central

Murciano, Angel; Maté-Sánchez de Val, José E.

2017-01-01

This study aimed to investigate the processing parameters and biocompatibility of a novel biphasic dicalcium silicate (C2S) cement. Biphasic α´L + β-C2Sss was synthesized by solid-state processing, and was used as a raw material to prepare the cement. In vitro bioactivity and biocompatibility studies were assessed by soaking the cement samples in simulated body fluid (SBF) and human adipose stem cell cultures. Two critical-sized defects of 6 mm Ø were created in 15 NZ tibias. A porous cement made of the high temperature forms of C2S, with a low phosphorous substitution level, was produced. An apatite-like layer covered the cement’s surface after soaking in SBF. The cell attachment test showed that α´L + β-C2Sss supported cells sticking and spreading after 24 h of culture. The cement paste (55.86 ± 0.23) obtained higher bone-to-implant contact (BIC) percentage values (better quality, closer contact) in the histomorphometric analysis, and defect closure was significant compared to the control group (plastic). The residual material volume of the porous cement was 35.42 ± 2.08% of the initial value. The highest BIC and bone formation percentages were obtained on day 60. These results suggest that the cement paste is advantageous for initial bone regeneration. PMID:28773119

Phosphorus bioavailability and digestibility of normal and genetically modified low-phytate corn for pigs.

PubMed

Spencer, J D; Allee, G L; Sauber, T E

2000-03-01

We conducted two studies to determine the bioavailability and apparent digestibility of P in a low-phytate corn hybrid (.28% total P, .10% phytate P) genetically modified to be homozygous for the 1pa1-1 allele and a nearly isogenic corn hybrid (normal) (.25% total P, .20% phytate P). Additionally, we conducted an in vitro assay involving a peptic and pancreatin digestion to estimate P availability. The first study used 50 individually penned pigs (initial body weight 9 kg) and 10 treatments in a randomized complete block design. A cornstarch-soybean meal basal diet (.6% Ca, .2% P) was used. Treatments consisted of the basal diet and the basal diet plus .05, .10, or .15% P from monosodium phosphate (MSP), low-phytate corn, or normal corn. After a 35-d feeding period, pigs were killed to collect the fourth metacarpal for measurements of ash and breaking load. Breaking load was regressed on added P intake, and the bioavailability of P was determined by the slope ratio method. The bioavailabilities of P (relative to MSP) for low-phytate and normal corn were 62 and 9%, respectively. These were similar to the determined in vitro values of 57 and 11% for low-phytate and normal corn, respectively. In the second study, 20 pigs (initial BW 20 kg) were used in a randomized complete block design with a 2 x 2 factorial arrangement of treatments. Two corn lines (low-phytate and normal) and two levels of supplemental P (0 and .2%) from dicalcium phosphate were used. Diets with no added P were formulated to contain .9% lysine, .6% Ca, and .34% P. Apparent nutrient digestibilities were calculated from total collection of urine and feces for 5 d. There were no differences among treatments for energy and nitrogen digestibility. Pigs fed low-phytate corn with no added P had increased digestibility and retention of P and reduced total P excretion (P < .05). We conclude that low-phytate corn contains at least five times as much available P as normal corn. The use oflow-phytate corn greatly reduced the amount of P excreted by the pig and increased the N:P ratio in the manure.

[Marketing of medicinal products in the European Community. The Mutual Recognition and Decentralised Procedures].

PubMed

Bachmann, Peter

2008-07-01

The Mutual Recognition Procedure (MRP) and the Decentralised Procedure (DCP), which were first established in late 2005, can be regarded as the backbone for marketing authorisation of medicinal products in the European Community (EC) and the European Economic Area (EEA). Both procedures are compared and advantages and disadvantages are discussed. However, the focus is more related to current developments than the detailed comparison of both procedures. The role of the Coordination Group for Mutual Recognition and Decentralised Procedures-Human (CMD(h)) and the decision making process in relation to the MRP and DCP is also discussed.

Prognostic roles of preoperative α-fetoprotein and des-γ-carboxy prothrombin in hepatocellular carcinoma patients

PubMed Central

Meguro, Makoto; Mizuguchi, Toru; Nishidate, Toshihiko; Okita, Kenji; Ishii, Masayuki; Ota, Shigenori; Ueki, Tomomi; Akizuki, Emi; Hirata, Koichi

2015-01-01

AIM: To clarify the utility of using des-γ-carboxy prothrombin (DCP) and α-fetoprotein (AFP) levels to predict the prognosis of hepatocellular carcinoma (HCC) in patients with hepatitis B virus (HBV) and the hepatitis C virus (HCV) infections. METHODS: A total of 205 patients with HCC (105 patients with HBV infection 100 patients with HCV infection) who underwent primary hepatectomy between January 2004 and May 2012 were enrolled retrospectively. Preoperative AFP and DCP levels were used to create interactive dot diagrams to predict recurrence within 2 years after hepatectomy, and cutoff levels were calculated. Patients in the HBV and HCV groups were classified into three groups: a group with low AFP and DCP levels (LL group), a group in which one of the two parameters was high and the other was low (HL group), and a group with high AFP and DCP levels (HH group). Liver function parameters, the postoperative recurrence-free survival rate, and postoperative overall survival were compared between groups. The survival curves were compared by log-rank test using the Kaplan-Meier method. Multivariate analysis using a Cox forward stepwise logistic regression model was conducted for a prognosis. RESULTS: The preoperative AFP cutoff levels for recurrence within 2 years after hepatectomy in the HBV and HCV groups were 529.8 ng/mL and 60 mAU/mL, respectively; for preoperative DCP levels, the cutoff levels were 21.0 ng/mL in the HBV group and 67 mAU/mL in the HCV group. The HBV group was significantly different from the other groups in terms of vascular invasion, major hepatectomy, volume of intraoperative blood loss, and surgical duration. Significant differences were found between the LL group, the HL group, and the HH group in terms of both mean disease-free survival time (MDFST) and mean overall survival time (MOST): 64.81 ± 7.47 vs 36.63 ± 7.62 vs 18.98 ± 6.17 mo (P = 0.001) and 85.30 ± 6.55 vs 59.44 ± 7.87 vs 46.57 ± 11.20 mo (P = 0.018). In contrast, the HCV group exhibited a significant difference in tumor size, vascular invasion, volume of intraoperative blood loss, and surgical duration; however, no significant difference was observed between the three groups in liver function parameters except for albumin levels. In the LL group, the HL group, and the HH group, the MDFST was 50.09 ± 5.90, 31.01 ± 7.21, and 14.81 ± 3.08 mo (log-rank test, P < 0.001), respectively, and the MOST was 79.45 ± 8.30, 58.82 ± 7.56, and 32.87 ± 6.31 mo (log-rank test, P < 0.001), respectively. CONCLUSION: In the HBV group, the prognosis was poor when either AFP or DCP levels were high. In the HCV group, the prognosis was good when either or both levels were low; however, the prognosis was poor when both levels were high. High levels of both AFP and DCP were an independent risk factor associated with tumor recurrence in the HBV and HCV groups. The relationship between tumor marker levels and prognosis was characteristic to the type of viral hepatitis. PMID:25945007

PDZ Binding Domains, Structural Disorder and Phosphorylation: A Menage-a-trois Tailing Dcp2 mRNA Decapping Enzymes.

PubMed

Gunawardana, Dilantha

2016-01-01

Diverse cellular activities are mediated through the interaction of protein domains and their binding partners. One such protein domain widely distributed in the higher metazoan world is the PDZ domain, which facilitates abundant protein-protein interactions. The PDZ domain-PDZ binding domain interaction has been implicated in several pathologies including Alzheimer's disease, Parkinson's disease and Down syndrome. PDZ domains bind to C-terminal peptides/proteins which have either of the following combinations: S/T-X-hydrophobic-COOH for type I, hydrophobic-Xhydrophobic- COOH for type II, and D/E-X-hydrophobic-COOH for type III, although hydrophobicity in the termini form the key characteristic of the PDZ-binding domains. We identified and characterized a Dcp2 type mRNA decapping enzyme from Arabidopsis thaliana, a protein containing a putative PDZ-binding domain using mutagenesis and protein biochemistry. Now we are using bioinformatics to study the Cterminal end of mRNA decapping enzymes from complex metazoans with the aim of (1) identifying putative PDZ-binding domains (2) Correlating structural disorder with PDZ binding domains and (3) Demonstrating the presence of phosphorylation sites in C-terminal extremities of Dcp2 type mRNA decapping enzymes. It is proposed here that the trinity of PDZbinding domains, structural disorder and phosphorylation-susceptible sites are a feature of the Dcp2 family of decapping enzymes and perhaps is a wider trick in protein evolution where scaffolding/tethering is a requirement for localization and function. It is critical though laboratory-based supporting evidence is sought to back-up this bioinformatics exploration into tail regions of mRNA decapping enzymes.

Characterization of a Highly Enriched Microbial Consortium Reductively Dechlorinating 2,3-Dichlorophenol and 2,4,6-Trichlorophenol and the Corresponding cprA Genes from River Sediment.

PubMed

El-Sayed, Wael S

2016-08-26

Anaerobic reductive dechlorination of 2,3-dichlorophenol (2,3DCP) and 2,4,6-trichlorophenol (2,4,6TCP) was investigated in microcosms from River Nile sediment. A stable sediment-free anaerobic microbial consortium reductively dechlorinating 2,3DCP and 2,4,6TCP was established. Defined sediment-free cultures showing stable dechlorination were restricted to ortho chlorine when enriched with hydrogen as the electron donor, acetate as the carbon source, and either 2,3-DCP or 2,4,6-TCP as electron acceptors. When acetate, formate, or pyruvate were used as electron donors, dechlorination activity was lost. Only lactate can replace dihydrogen as an electron donor. However, the dechlorination potential was decreased after successive transfers. To reveal chlororespiring species, the microbial community structure of chlorophenol-reductive dechlorinating enrichment cultures was analyzed by PCR-denaturing gradient gel electrophoresis (DGGE) of 16S rRNA gene fragments. Eight dominant bacteria were detected in the dechlorinating microcosms including members of the genera Citrobacter, Geobacter, Pseudomonas, Desulfitobacterium, Desulfovibrio and Clostridium. Highly enriched dechlorinating cultures were dominated by four bacterial species belonging to the genera Pseudomonas, Desulfitobacterium, and Clostridium. Desulfitobacterium represented the major fraction in DGGE profiles indicating its importance in dechlorination activity, which was further confirmed by its absence resulting in complete loss of dechlorination. Reductive dechlorination was confirmed by the stoichiometric dechlorination of 2,3DCP and 2,4,6TCP to metabolites with less chloride groups and by the detection of chlorophenol RD cprA gene fragments in dechlorinating cultures. PCR amplified cprA gene fragments were cloned and sequenced and found to cluster with the cprA/pceA type genes of Dehalobacter restrictus.

Electrochemical treatment of 2, 4-dichlorophenol using a nanostructured 3D-porous Ti/Sb-SnO2-Gr anode: Reaction kinetics, mechanism, and continuous operation.

PubMed

Asim, Sumreen; Zhu, Yunqing; Batool, Aisha; Hailili, Reshalaiti; Luo, Jianmin; Wang, Yuanhao; Wang, Chuanyi

2017-10-01

2, 4-dichlorophenol (2, 4-DCP) is considered to be a highly toxic, mutagenic, and possibly carcinogenic pollutant. This study is focused on the electrochemical oxidation of 2, 4-DCP on nanostructured 3D-porous Ti/Sb-SnO 2 -Gr anodes, with the aim of presenting a comprehensive elucidation of mineralization process through the investigation of influential kinetics, the reactivity of hydroxyl radical's and analysis of intermediates. High efficiency was achieved at pH of 3 using Na 2 SO 4 electrolytes at a current density of 30 mA cm -2 . Under the optimized conditions, a maximum removal of 2, 4-DCP of up to 99.9% was reached, whereas a TOC removal of 81% was recorded with the lowest EC TOC (0.49 kW h g -1 ) within 40 min of electrolysis. To explore the stability of the 3D-Ti/Sb-SnO 2 -Gr electrodes, a continuous electrochemical operation was established, and the consistent mineralization results indicated the effectiveness of the 3D-Ti/Sb-SnO 2 -Gr system concerning its durability and practical utilization. EPR studies demonstrated the abundant generation of OH radicals on 3D-Ti/Sb-SnO 2 -Gr, resulting in fast recalcitrant pollutant incineration. From dechlorination and the reactivity of the OH radicals, several intermediates including six cyclic byproducts and three aliphatic carboxylic acids were detected, and two possible degradation pathways were proposed that justify the complete mineralization of 2, 4-DCP. Copyright © 2017 Elsevier Ltd. All rights reserved.

Chlorinated phenol removal from aqueous media by tea (Camellia sinensis) leaf waste tailored activated carbon

NASA Astrophysics Data System (ADS)

Joseph, C. G.; Anisuzzaman, S. M.; Daud, W. M. A. W.; Krishnaiah, D.; Ng, K. A.

2017-06-01

In this study, activated carbons (ACs) wereprepared from tea leaves by using a two-stage self-generated atmosphere method. The process was done by semi-carbonizing the precursor at 300 °C for 1 h, followed by the impregnation of the resulting char at 85 °C for 4 h and finally activation at 500 °C for 2 h. The semi-carbonised samples were impregnated with different ratios of zinc chloride (ZnCl2) and their physicochemical effect was studied. The prepared ACs underwent several aspects of both, chemical and physical characterizations, such as the percentage of yield, moisture content, ash content, pH, porosity, adsorption capacity of 2,4-dichlorophenol (2,4-DCP), surface area, porosity, morphology and surface chemistry studies. It was found that sample AC2, with an impregnation ratio of 2:1 was the best AC produced in this study. The maximum Brunauer, Emmett and Teller surface area of AC2 was found to be 695 m2/g. Langmuir, Freundlich and Temkin isotherm models were used to examine the experimental isotherms while the kinetic data was analyzed using the pseudo-first-order, pseudo-second-order and intraparticle diffusion kinetic models. The 2,4-DCP adsorption isotherm results complied well to the Langmuir isotherm for the equilibrium data while the adsorption kinetic data fitted well to the pseudo-second order model, indicating that chemisorption by valency forces via the sharing (covalent bond) or exchanging of electrons between the AC and the 2,4-DCP molecules were mainly responsible for the adsorption process. From these findings, it is concluded that tea leaves can be used as a low cost precursor for the removal of 2,4-DCP in aqueous medium.

Biomechanical investigation of an alternative concept to angular stable plating using conventional fixation hardware.

PubMed

Windolf, Markus; Klos, Kajetan; Wähnert, Dirk; van der Pol, Bas; Radtke, Roman; Schwieger, Karsten; Jakob, Roland P

2010-05-21

Angle-stable locking plates have improved the surgical management of fractures. However, locking implants are costly and removal can be difficult. The aim of this in vitro study was to evaluate the biomechanical performance of a newly proposed crossed-screw concept ("Fence") utilizing conventional (non-locked) implants in comparison to conventional LC-DCP (limited contact dynamic compression plate) and LCP (locking compression plate) stabilization, in a human cadaveric diaphyseal gap model. In eight pairs of human cadaveric femora, one femur per pair was randomly assigned to receive a Fence construct with either elevated or non-elevated plate, while the contralateral femur received either an LCP or LC-DCP instrumentation. Fracture gap motion and fatigue performance under cyclic loading was evaluated successively in axial compression and in torsion. Results were statistically compared in a pairwise setting. The elevated Fence constructs allowed significantly higher gap motion compared to the LCP instrumentations (axial compression: p

Changes in Retinal Microvasculature and Visual Acuity After Antivascular Endothelial Growth Factor Therapy in Retinal Vein Occlusion.

PubMed

Winegarner, Andrew; Wakabayashi, Taku; Fukushima, Yoko; Sato, Tatsuhiko; Hara-Ueno, Chikako; Busch, Caleb; Nishiyama, Issei; Shiraki, Nobuhiko; Sayanagi, Kaori; Nishida, Kentaro; Sakaguchi, Hirokazu; Nishida, Kohji

2018-06-01

To investigate the changes in the retinal microvasculature during the course of anti-VEGF therapy in eyes with macular edema due to retinal vein occlusion (RVO) and their association with visual outcomes. The vessel density (VD) and foveal avascular zone (FAZ) area in the superficial capillary plexus (SCP) and deep capillary plexus (DCP) were quantitatively measured by optical coherence tomography angiography (OCTA) in 48 consecutive eyes with RVO before and 1, 3, 6, 9, and 12 months after anti-VEGF therapy. Anti-VEGF therapy was performed either with ranibizumab or aflibercept following a pro re nata (PRN) regimen. The correlation between post-treatment best-corrected visual acuity (BCVA) and changes in the retinal microvasculature evaluated by OCTA were assessed. The BCVA improved significantly at 12 months (P < 0.001). Better BCVA at 12 months was significantly associated with a better VD in the SCP and DCP both at baseline (R2 = 0.524, P < 0.001 and R2 = 0.457, P < 0.001, respectively) and at 12 months (R2 = 0.521, P < 0.001 and R2 = 0.662, P < 0.001, respectively). Overall, both VD and FAZ did not change significantly during the 12 months. However, the progression of nonperfusion was observed in the SCP in 6 (13%) eyes and in the DCP in 10 (21%) eyes. The number of macular edema recurrence was significantly associated with a decrease in the VD (P = 0.006 [SCP] and P < 0.001 [DCP]) and less visual gain (P = 0.02) after treatment. Anti-VEGF therapy maintains retinal perfusion in most patients with RVO. Preserving retinal perfusion is crucial for better visual outcomes.

Screw Loosening and Pelvic Canal Narrowing After Lateral Plating of Feline Ilial Fractures With Locking and Nonlocking Plates.

PubMed

Schmierer, Philipp A; Kircher, Patrick R; Hartnack, Sonja; Knell, Sebastian C

2015-10-01

To compare the frequency of complications, including screw loosening and pelvic canal narrowing, associated with dynamic compression plating, locking plating, and double locking plating of ilial fractures in cats. Historical cohort study. The radiographs and medical records of cats with pelvic fractures that were presented between 2004 and 2013 were reviewed. The cases were categorized based on the plate type and number as dynamic compression plate (DCP), single locking plate (LPS) and double locking plates (dLPS). The frequency of screw loosening was compared across categories using a Fisher's exact test. The change in pelvic alignment, described by the change in sacral index (postoperative sacral index-followup sacral index), was compared across plate categories using ANOVA. The frequency of screw loosening for DCP (5/10) was significantly higher than LPS (1/13) and dLPS (0/11) (P = .05, P = .012, respectively). There was no significant difference in the SI change across plate categories. The mean change in sacral index for DCP was -0.11 (95%CI -0.25 to 0.03), for LPS was 0.0007 (95%CI -0.07 to 0.08), and for dLPS was -0.01 (95%CI -0.04 to 0.02). None of the cats showed constipation postoperatively. Screw loosening occurred less often but the change in pelvic canal alignment was not significantly different in ilial fractures repaired with LPS or dLPS compared to ilial fractures repaired with DCP. Locking plating of ilial fractures in cats may offer advantages compared to nonlocking plating. © Copyright 2015 by The American College of Veterinary Surgeons.

The GDP-switched GAF domain of DcpA modulates the concerted synthesis/hydrolysis of c-di-GMP in Mycobacterium smegmatis.

PubMed

Chen, Hui-Jie; Li, Na; Luo, Ye; Jiang, Yong-Liang; Zhou, Cong-Zhao; Chen, Yuxing; Li, Qiong

2018-04-09

The second messenger c-di-GMP [bis-(3'-5')-cyclic dimeric guanosine monophosphate] plays a key role in bacterial growth, survival and pathogenesis, and thus its intracellular homeostasis should be finely maintained. Mycobacterium smegmatis encodes a GAF (mammalian c G MP-regulated phosphodiesterases, Anabaena a denylyl cyclases and Escherichia coli transcription activator F hlA) domain containing bifunctional enzyme DcpA ( d iguanylate c yclase and p hosphodiesterase A ) that catalyzes the synthesis and hydrolysis of c-di-GMP . Here, we found that M. smegmatis DcpA catalyzes the hydrolysis of c-di-GMP at a higher velocity, compared with synthetic activity, resulting in a sum reaction from the ultimate substrate GTP to the final product pGpG [5'-phosphoguanylyl-(3'-5')-guanosine]. Fusion with the N-terminal GAF domain enables the GGDEF (Gly-Gly-Asp-Glu-Phe) domain of DcpA to dimerize and accordingly gain synthetic activity. Screening of putative metabolites revealed that GDP is the ligand of the GAF domain. Binding of GDP to the GAF domain down-regulates synthetic activity, but up-regulates hydrolytic activity, which, in consequence, might enable a timely response to the transient accumulation of c-di-GMP at the stationary phase or under stresses. Combined with the crystal structure of the EAL (Glu-Ala-Leu) domain and the small-angle X-ray scattering data, we propose a putative regulatory model of the GAF domain finely tuned by the intracellular GTP/GDP ratio. These findings help us to better understand the concerted control of the synthesis and hydrolysis of c-di-GMP in M. smegmatis in various microenvironments. © 2018 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

A new P. putida instrumental toxicity bioassay.

PubMed

Figueredo, Federico; Abrevaya, Ximena C; Cortón, Eduardo

2015-05-01

Here, we present a new toxicity bioassay (CO2-TOX), able to detect toxic or inhibitory compounds in water samples, based on the quantification of Pseudomonas putida KT2440 CO2 production. The metabolically produced CO2 was measured continuously and directly in the liquid assay media, with a potentiometric gas electrode. The optimization studies were performed using as a model toxicant 3,5-DCP (3,5-dichlorophenol); later, heavy metals (Pb(2+), Cu(2+), or Zn(2+)) and a metalloid (As(5+)) were assayed. The response to toxics was evident after 15 min of incubation and at relatively low concentrations (e.g., 1.1 mg/L of 3,5-DCP), showing that the CO2-TOX bioassay is fast and sensitive. The EC50 values obtained were 4.93, 0.12, 6.05, 32.17, and 37.81 mg/L for 3,5-DCP, Cu(2+), Zn(2+), As(5+), and Pb(2+), respectively, at neutral pH. Additionally, the effect of the pH of the sample and the use of lyophilized bacteria were also analyzed showing that the bioassay can be implemented in different conditions. Moreover, highly turbid samples and samples with very low oxygen levels were measured successfully with the new instrumental bioassay described here. Finally, simulated samples containing 3,5-DCP or a heavy metal mixture were tested using the proposed bioassay and a standard ISO bioassay, showing that our test is more sensible to the phenol but less sensible to the metal mixtures. Therefore, we propose CO2-TOX as a rapid, sensitive, low-cost, and robust instrumental bioassay that could perform as an industrial wastewater-process monitor among other applications.

Outcome of Repair of Distal Radial and Ulnar Fractures in Dogs Weighing 4 kg or Less Using a 1.5-mm Locking Adaption Plate or 2.0-mm Limited Contact Dynamic Compression Plate.

PubMed

Nelson, Thomas A; Strom, Adam

2017-11-01

Objectives  Retrospective evaluation of repairing distal radial and ulnar fractures in small breed dogs with the Synthes 1.5-mm locking Adaption plate system and compare results in a similar group of patients repaired with the Synthes 2.0-mm limited contact-dynamic compression plate (LC-DCP). Methods  Electronic medical records from one specialty referral centre were reviewed from March 21, 2010, to October 9, 2015, for patients weighing less than or equal to 4 kg that had a distal one-third radial and ulnar fracture repaired with a Synthes 1.5-mm locking adaption plate or Synthes 2.0-mm LC-DCP. Further inclusion criteria included application of the plate to the cranial surface of the radius via open reduction and internal fixation. Results  Six 1.5-mm Adaption plates and 7 2.0-mm LC-DCPs were used to repair 13 distal radial and ulnar fractures in 12 dogs. There were three major complications in the 1.5-mm adaption plate group (one plate fracture, one screw pull-out and one fracture through a distal screw hole) and one major complication in the 2.0-mm LC-DCP group due to a re-fracture. All patients without a complication had good or excellent functional outcome. Clinical Significance  The authors recommend that the 1.5-mm Adaption plate be used only when a 2.0-mm LC-DCP would not allow for a minimum of two screws in the distal segment and at the discretion of the surgeon. Schattauer GmbH Stuttgart.

Influence of cement compressive strength and porosity on augmentation performance in a model of orthopedic screw pull-out.

PubMed

Pujari-Palmer, Michael; Robo, Celine; Persson, Cecilia; Procter, Philip; Engqvist, Håkan

2018-01-01

Disease and injuries that affect the skeletal system may require surgical intervention and internal fixation, i.e. orthopedic plate and screw insertion, to stabilize the injury and facilitate tissue repair. If the surrounding bone quality is poor the screws may migrate, or the bone may fail, resulting in fixation failure. While numerous studies have shown that cement augmentation of the interface between bone and implant can increase screw pull-out force, the physical properties of cement that influence pull-out force have not been investigated. The present study sought to determine how the physical properties of high strength calcium phosphate cements (hsCPCs, specifically dicalcium phosphate) affected the corresponding orthopedic screw pull-out force in urethane foam models of "healthy" and "osteoporotic" synthetic bone (Sawbones). In the simplest model, where only the bond strength between screw thread and cement (without Sawbone) was tested, the correlation between pull-out force and cement compressive strength (R 2 = 0.79) was weaker than correlation with total cement porosity (R 2 = 0.89). In open pore Sawbone that mimics "healthy" cancellous bone density the stronger cements produced higher pull-out force (50-60% increase). High strength, low porosity cements also produced higher pull-out forces (50-190% increase) in "healthy" Sawbones with cortical fixation if the failure strength of the cortical material was similar to, or greater than (a metal shell), actual cortical bone. This result is of particular clinical relevance where fixation with a metal plate implant is indicated, as the nearby metal can simulate a thicker cortical shell, thereby increasing the pull-out force of screws augmented with stronger cements. The improvement in pull-out force was apparent even at low augmentation volumes of 0.5mL (50% increase), which suggest that in clinical situations where augmentation volume is limited the stronger, lower porosity calcium phosphate cement (CPC) may still produce a significant improvement in screw pull-out force. When the correlation strength of all the tested models were compared both cement porosity and compressive strength accurately predicted pull-out force (R 2 =1.00, R 2 =0.808), though prediction accuracy depended upon the strength of the material surrounding the Sawbone. The correlations strength was low for bone with no, or weak, cortical fixation (R 2 =0.56, 0.36). Higher strength and lower porosity CPCs also produced greater pull-out force (1-1.5kN) than commercial CPC (0.2-0.5kN), but lower pull-out force than PMMA (2-3kN). The results of this study suggest that the likelihood of screw fixation failure may be reduced by selecting calcium phosphate cements with lower porosity and higher compressive strength, in patients with healthy bone mineral density and/or sufficient cortical thickness. This is of particular clinical relevance when fixation with metal plates is indicated, or where the augmentation volume is limited. Copyright © 2017 Elsevier Ltd. All rights reserved.

Supertoughened Biobased Poly(lactic acid)-Epoxidized Natural Rubber Thermoplastic Vulcanizates: Fabrication, Co-continuous Phase Structure, Interfacial in Situ Compatibilization, and Toughening Mechanism.

PubMed

Wang, Youhong; Chen, Kunling; Xu, Chuanhui; Chen, Yukun

2015-09-10

In the presence of dicumyl peroxide (DCP), biobased thermoplastic vulcanizates (TPVs) composed of poly(lactic acid) (PLA) and epoxidized natural rubber (ENR) were prepared through dynamic vulcanization. Interfacial in situ compatibilization between PLA and ENR phases was confirmed by Fourier transform infrared spectroscopy (FT-IR). A novel "sea-sea" co-continuous phase in the PLA/ENR TPVs was observed through scanning electron microscopy (SEM) and differed from the typical "sea-island" morphology that cross-linked rubber particles dispersed in plastic matrix. A sharp, brittle-ductile transition occurred with 40 wt % of ENR, showing a significantly improved impact strength of 47 kJ/m(2), nearly 15 times that of the neat PLA and 2.6 times that of the simple blend with the same PLA/ENR ratio. Gel permeation chromatography (GPC) and dynamic mechanical analysis (DMA) results suggested that a certain amount of DCP was consumed in the PLA phase, causing a slight cross-linking or branching of PLA molecules. the effects of various DCP contents on the impact property were investigated. The toughening mechanism under impact testing was researched, and the influence factors for toughening were discussed.

Substrate interactions in dehalogenation of 1,2-dichloroethane, 1,2-dichloropropane, and 1,1,2-trichloroethane mixtures by Dehalogenimonas spp.

PubMed

Dillehay, Jacob L; Bowman, Kimberly S; Yan, Jun; Rainey, Fred A; Moe, William M

2014-04-01

When chlorinated alkanes are present as soil or groundwater pollutants, they often occur in mixtures. This study evaluated substrate interactions during the anaerobic reductive dehalogenation of chlorinated alkanes by the type strains of two Dehalogenimonas species, D. lykanthroporepellens and D. alkenigignens. Four contaminant mixtures comprised of combinations of the chlorinated solvents 1,2-dichloroethane (1,2-DCA), 1,2-dichloropropane (1,2-DCP), and 1,1,2-trichloroethane (1,1,2-TCA) were assessed for each species. Chlorinated solvent depletion and daughter product formation determined as a function of time following inoculation into anaerobic media revealed preferential dechlorination of 1,1,2-TCA over both 1,2-DCA and 1,2-DCP for both species. 1,2-DCA in particular was not dechlorinated until 1,1,2-TCA reached low concentrations. In contrast, both species concurrently dechlorinated 1,2-DCA and 1,2-DCP over a comparably large concentration range. This is the first report of substrate interactions during chlorinated alkane dehalogenation by pure cultures, and the results provide insights into the chlorinated alkane transformation processes that may be expected for contaminant mixtures in environments where Dehalogenimonas spp. are present.

Effector caspase Dcp-1 and IAP protein Bruce regulate starvation-induced autophagy during Drosophila melanogaster oogenesis.

PubMed

Hou, Ying-Chen Claire; Chittaranjan, Suganthi; Barbosa, Sharon González; McCall, Kimberly; Gorski, Sharon M

2008-09-22

A complex relationship exists between autophagy and apoptosis, but the regulatory mechanisms underlying their interactions are largely unknown. We conducted a systematic study of Drosophila melanogaster cell death-related genes to determine their requirement in the regulation of starvation-induced autophagy. We discovered that six cell death genes--death caspase-1 (Dcp-1), hid, Bruce, Buffy, debcl, and p53-as well as Ras-Raf-mitogen activated protein kinase signaling pathway components had a role in autophagy regulation in D. melanogaster cultured cells. During D. melanogaster oogenesis, we found that autophagy is induced at two nutrient status checkpoints: germarium and mid-oogenesis. At these two stages, the effector caspase Dcp-1 and the inhibitor of apoptosis protein Bruce function to regulate both autophagy and starvation-induced cell death. Mutations in Atg1 and Atg7 resulted in reduced DNA fragmentation in degenerating midstage egg chambers but did not appear to affect nuclear condensation, which indicates that autophagy contributes in part to cell death in the ovary. Our study provides new insights into the molecular mechanisms that coordinately regulate autophagic and apoptotic events in vivo.

Degradation of various chlorophenols under alkaline conditions by gram-negative bacteria closely related to Ochrobactrum anthropi.

PubMed

Müller, R H; Jorks, S; Kleinsteuber, S; Babel, W

1998-01-01

From concrete debris of a demolished herbicide production plant several Gram-negative bacterial strains were isolated, which exhibit metabolic capabilities for the degradation of 2,4-dichlorophenol (DCP)l), 4-chloro-2-methylphenol (MCP) and 4-chlorophenol (4-CP), while 2-chlorophenol (2-CP) was degraded at a slower rate. Degradative activity was inducible and was impeded by adding of 100 mg/l of chloramphenicol to growing cultures. The strains displayed alkaliphilic properties with optimum DCP/MCP degradation at pH values around 8.5-9.5; activity was observed up to pH values of 11. Degradation was most likely complete according to chlorine balances; formation of intermediary products was observed with MCP some time. Specific activity of up to 380 mumol/h.g dry mass was found within the concentration range of 10-20 mg/l DCP; higher concentrations retarded the activity with complete inhibition at 200-400 mg/l. Some of the strains carry plasmids whose presence was not unambiguously correlated to the degradative properties. Ribotyping revealed a high degree of relationship between the strains. Preliminary taxonomic investigations showed close relationship to Ochrobactrum anthropi.

Evaluation of the physicochemical properties and compaction behavior of melt granules produced in microwave-induced and conventional melt granulation in a single pot high shear processor.

PubMed

Loh, Z H; Sia, B Y; Heng, Paul W S; Lee, C C; Liew, Celine V

2011-12-01

Recently, microwave-induced melt granulation was shown to be a promising alternative to conventional melt granulation with improved process monitoring capabilities. This study aimed to compare the physicochemical and compaction properties of granules produced from microwave-induced and conventional melt granulation. Powder admixtures comprising equivalent proportions by weight of lactose 200 M and anhydrous dicalcium phosphate were granulated with polyethylene glycol 3350 under the influence of microwave-induced and conventional heating in a 10-L single pot high shear processor. The properties of the granules and compacts produced from the two processes were compared. Relative to conventional melt granulation, the rates at which the irradiated powders heated up in microwave-induced melt granulation were lower. Agglomerate growth proceeded at a slower rate, and this necessitated longer massing durations for growth induction. These factors prompted greater evaporative moisture losses from the melt granules. Additionally, nonuniform heating of the powders under the influence of microwaves led to increased inter-batch variations in the binder contents of resultant melt granules and a reliance of content homogeneity on massing duration. Agglomerate growth proceeded more rapidly under the influence of conventional heating due to the enhanced heating capabilities of the powders. Melt granules produced using the conventional method possessed higher moisture contents and improved content homogeneity. The compaction behavior of melt granules were affected by their mean sizes, porosities, flow properties, binder, and moisture contents. The last two factors were responsible for the disparities in compaction behavior of melt granules produced from microwave-induced and conventional melt granulation.

Use of first derivative of displacement vs. force profiles to determine deformation behavior of compressed powders.

PubMed

Gharaibeh, Shadi F; Aburub, Aktham

2013-03-01

Displacement (D) vs. force (F) profiles obtained during compaction of powders have been reported by several researchers. These profiles are usually used to obtain mechanical energies associated with the compaction of powders. In this work, we obtained displacement-force data associated with the compression of six powders; Avicel PH101, Avicel PH301, pregelatinized corn starch, anhydrous lactose, dicalcium phosphate, and mannitol. The first three powders are known to deform predominantly by plastic behavior while the later ones are known to deform predominantly by brittle fracture. Displacement-force data was utilized to perform in-die Heckel analysis and to calculate the first derivative (dD/dF) of displacement-force plots. First derivative results were then plotted against mean force (F') at each point and against 1/F' at compression forces between 1 and 20 kN. Results of the in-die Heckle analysis are in very good agreement with the known deformation behavior of the compressed materials. First derivative plots show that materials that deform predominantly by plastic behavior have first derivative values (0.0006-0.0016 mm/ N) larger than those of brittle materials (0.0004 mm/N). Moreover, when dD/dF is plotted against 1/F' for each powder, a linear correlation can be obtained (R2=>0.98). The slopes of the dD/dF vs. 1/F' plots for plastically deforming materials are relatively larger than those for materials that deform by brittle behavior. It is concluded that first derivative plots of displacement-force profiles can be used to determine deformation behavior of powders.

Thermal cycling effects on adhesion of resin-bovine enamel junction among different composite resins.

PubMed

Chen, Wen-Cheng; Ko, Chia-Ling; Wu, Hui-Yu; Lai, Pei-Ling; Shih, Chi-Jen

2014-10-01

Thermal cycling is used to mimic the changes in oral cavity temperature experienced by composite resins when used clinically. The purpose of this study is to assess the thermal cycling effects of in-house produced composite resin on bonding strength. The dicalcium phosphate anhydrous filler surfaces are modified using nanocrystals and silanization (w/NP/Si). The resin is compared with commercially available composite resins Filtek Z250, Z350, and glass ionomer restorative material GIC Fuji-II LC (control). Different composite resins were filled into the dental enamel of bovine teeth. The bond force and resin-enamel junction graphical structures of the samples were determined after thermal cycling between 5 and 55°C in deionized water for 600 cycles. After thermal cycling, the w/NP/Si 30wt%, 50wt% and Filtek Z250, Z350 groups showed higher shear forces than glass ionomer GIC, and w/NP/Si 50wt% had the highest shear force. Through SEM observations, more of the fillings with w/NP/Si 30wt% and w/NP/Si 50wt% groups flowed into the enamel tubule, forming closed tubules with the composite resins. The push-out force is proportional to the resin flow depth and uniformity. The push-out tubule pore and resin shear pattern is the most uniform and consistent in the w/NP/Si 50wt% group. Accordingly, this developed composite resin maintains great mechanical properties after thermal cycling. Thus, it has the potential to be used in a clinical setting when restoring non-carious cervical lesions. Copyright © 2014 Elsevier Ltd. All rights reserved.

An evaluation of three-dimensional modeling of compaction cycles by analyzing the densification behavior of binary and ternary mixtures.

PubMed

Picker, K M; Bikane, F

2001-08-01

The aim of the study is to use the 3D modeling technique of compaction cycles for analysis of binary and ternary mixtures. Three materials with very different deformation and densification characteristics [cellulose acetate (CAC), dicalcium phosphate dihydrate (EM) and theophylline monohydrate (TM)] have been tableted at graded maximum relative densities (rhorel, max) on an eccentric tableting machine. Following that, graded binary mixtures from CAC and EM have been compacted. Finally, the same ratios of CAC and EM have been tableted in a ternary mixture with 20 vol% TM. All compaction cycles have been analyzed by using different data analysis methods. Three-dimensional modeling, conventional determination of the slope of the Heckel function, determination of the elastic recovery during decompression, and calculations according to the pressure-time function were the methods of choice. The results show that the 3D model technique is able to gain the information in one step instead of three different approaches, which is an advantage for formulation development. The results show that this model enables one to better distinguish the compaction properties of mixtures and the interaction of the components in the tablet than 2D models. Furthermore, the information by 3D modeling is more precise since in the slope K of the Heckel-plot (in die) elasticity is included, and in the parameters of the pressure-time function beta and gamma plastic deformation due to pressure is included. The influence of time and pressure on the displacement can now be differentiated.

A novel solid dosage form of rifampicin and isoniazid with improved functionality.

PubMed

Gohel, Mukesh C; Sarvaiya, Krishnakant G

2007-08-24

The aim of the present investigation was to develop a novel dosage form of rifampicin and isoniazid to minimize degradation of rifampicin in acidic medium and to modulate the release of rifampicin in the stomach and isoniazid in the intestine. Gastroretentive tablets of rifampicin (150 mg) were prepared by the wet granulation method using hydroxypropyl methylcellulose, calcium carbonate, and polyethylene glycol 4000. The granules and tablets of rifampicin were characterized. Hard gelatin capsules (size 4) containing a compacted mass of isoniazid (150 mg) and dicalcium phosphate (75 mg) were enteric coated. Two tablets of rifampicin and 1 capsule (size 4) of isoniazid were put into a hard gelatin capsule (size 00). The in vitro drug release and in vitro drug degradation studies were performed. Rifampicin was released over 4 hours by zero-order kinetics from the novel dosage form. More than 90% of isoniazid was released in alkaline medium in 30 minutes. The results of dissolution studies with the US Pharmacopeia XXIII method revealed that a substantial amount of rifampicin was degraded from the immediate release capsule containing rifampicin and isoniazid powder owing to drug accumulation in the dissolution vessel and also to the presence of isoniazid. The degradation of rifampicin to 3-formyl rifampicin SV (3FRSV) was arrested (3.6%-4.8% degradation of rifampicin at 4 hours) because of the minimization of physical contact between the 2 drugs and controlled release of rifampicin in acidic medium in the modified Rossett-Rice apparatus. This study concludes that the problem of rifampicin degradation can be alleviated to a certain extent by this novel dosage form.

Universal health coverage and intersectoral action for health: key messages from Disease Control Priorities, 3rd edition

PubMed Central

Jamison, Dean T; Adeyi, Olusoji; Anand, Shuchi; Atun, Rifat; Bertozzi, Stefano; Bhutta, Zulfiqar; Binagwaho, Agnes; Black, Robert; Blecher, Mark; Bloom, Barry R; Brouwer, Elizabeth; Bundy, Donald A P; Chisholm, Dan; Cieza, Alarcos; Cullen, Mark; Danforth, Kristen; de Silva, Nilanthi; Debas, Haile T; Donkor, Peter; Dua, Tarun; Fleming, Kenneth A; Gallivan, Mark; Garcia, Patricia J; Gawande, Atul; Gaziano, Thomas; Gelband, Hellen; Glass, Roger; Glassman, Amanda; Gray, Glenda; Habte, Demissie; Holmes, King K; Horton, Susan; Hutton, Guy; Jha, Prabhat; Knaul, Felicia M; Kobusingye, Olive; Krakauer, Eric L; Kruk, Margaret E; Lachmann, Peter; Laxminarayan, Ramanan; Levin, Carol; Looi, Lai Meng; Madhav, Nita; Mahmoud, Adel; Mbanya, Jean Claude; Measham, Anthony; Medina-Mora, María Elena; Medlin, Carol; Mills, Anne; Mills, Jody-Anne; Montoya, Jaime; Norheim, Ole; Olson, Zachary; Omokhodion, Folashade; Oppenheim, Ben; Ord, Toby; Patel, Vikram; Patton, George C; Peabody, John; Prabhakaran, Dorairaj; Qi, Jinyuan; Reynolds, Teri; Ruacan, Sevket; Sankaranarayanan, Rengaswamy; Sepúlveda, Jaime; Skolnik, Richard; Smith, Kirk R; Temmerman, Marleen; Tollman, Stephen; Verguet, Stéphane; Walker, Damian G; Walker, Neff; Wu, Yangfeng; Zhao, Kun

2018-01-01

The World Bank is publishing nine volumes of Disease Control Priorities, 3rd edition (DCP3) between 2015 and 2018. Volume 9, Improving Health and Reducing Poverty, summarises the main messages from all the volumes and contains cross-cutting analyses. This Review draws on all nine volumes to convey conclusions. The analysis in DCP3 is built around 21 essential packages that were developed in the nine volumes. Each essential package addresses the concerns of a major professional community (eg, child health or surgery) and contains a mix of intersectoral policies and health-sector interventions. 71 intersectoral prevention policies were identified in total, 29 of which are priorities for early introduction. Interventions within the health sector were grouped onto five platforms (population based, community level, health centre, first-level hospital, and referral hospital). DCP3 defines a model concept of essential universal health coverage (EUHC) with 218 interventions that provides a starting point for country-specific analysis of priorities. Assuming steady-state implementation by 2030, EUHC in lower-middle-income countries would reduce premature deaths by an estimated 4·2 million per year. Estimated total costs prove substantial: about 9·1% of (current) gross national income (GNI) in low-income countries and 5·2% of GNI in lower-middle-income countries. Financing provision of continuing intervention against chronic conditions accounts for about half of estimated incremental costs. For lower-middle-income countries, the mortality reduction from implementing the EUHC can only reach about half the mortality reduction in non-communicable diseases called for by the Sustainable Development Goals. Full achievement will require increased investment or sustained intersectoral action, and actions by finance ministries to tax smoking and polluting emissions and to reduce or eliminate (often large) subsidies on fossil fuels appear of central importance. DCP3 is intended to be a model starting point for analyses at the country level, but country-specific cost structures, epidemiological needs, and national priorities will generally lead to definitions of EUHC that differ from country to country and from the model in this Review. DCP3 is particularly relevant as achievement of EUHC relies increasingly on greater domestic finance, with global developmental assistance in health focusing more on global public goods. In addition to assessing effects on mortality, DCP3 looked at outcomes of EUHC not encompassed by the disability-adjusted life-year metric and related cost-effectiveness analyses. The other objectives included financial protection (potentially better provided upstream by keeping people out of the hospital rather than downstream by paying their hospital bills for them), stillbirths averted, palliative care, contraception, and child physical and intellectual growth. The first 1000 days after conception are highly important for child development, but the next 7000 days are likewise important and often neglected. PMID:29179954

Universal health coverage and intersectoral action for health: key messages from Disease Control Priorities, 3rd edition.

PubMed

Jamison, Dean T; Alwan, Ala; Mock, Charles N; Nugent, Rachel; Watkins, David; Adeyi, Olusoji; Anand, Shuchi; Atun, Rifat; Bertozzi, Stefano; Bhutta, Zulfiqar; Binagwaho, Agnes; Black, Robert; Blecher, Mark; Bloom, Barry R; Brouwer, Elizabeth; Bundy, Donald A P; Chisholm, Dan; Cieza, Alarcos; Cullen, Mark; Danforth, Kristen; de Silva, Nilanthi; Debas, Haile T; Donkor, Peter; Dua, Tarun; Fleming, Kenneth A; Gallivan, Mark; Garcia, Patricia J; Gawande, Atul; Gaziano, Thomas; Gelband, Hellen; Glass, Roger; Glassman, Amanda; Gray, Glenda; Habte, Demissie; Holmes, King K; Horton, Susan; Hutton, Guy; Jha, Prabhat; Knaul, Felicia M; Kobusingye, Olive; Krakauer, Eric L; Kruk, Margaret E; Lachmann, Peter; Laxminarayan, Ramanan; Levin, Carol; Looi, Lai Meng; Madhav, Nita; Mahmoud, Adel; Mbanya, Jean Claude; Measham, Anthony; Medina-Mora, María Elena; Medlin, Carol; Mills, Anne; Mills, Jody-Anne; Montoya, Jaime; Norheim, Ole; Olson, Zachary; Omokhodion, Folashade; Oppenheim, Ben; Ord, Toby; Patel, Vikram; Patton, George C; Peabody, John; Prabhakaran, Dorairaj; Qi, Jinyuan; Reynolds, Teri; Ruacan, Sevket; Sankaranarayanan, Rengaswamy; Sepúlveda, Jaime; Skolnik, Richard; Smith, Kirk R; Temmerman, Marleen; Tollman, Stephen; Verguet, Stéphane; Walker, Damian G; Walker, Neff; Wu, Yangfeng; Zhao, Kun

2018-03-17

The World Bank is publishing nine volumes of Disease Control Priorities, 3rd edition (DCP3) between 2015 and 2018. Volume 9, Improving Health and Reducing Poverty, summarises the main messages from all the volumes and contains cross-cutting analyses. This Review draws on all nine volumes to convey conclusions. The analysis in DCP3 is built around 21 essential packages that were developed in the nine volumes. Each essential package addresses the concerns of a major professional community (eg, child health or surgery) and contains a mix of intersectoral policies and health-sector interventions. 71 intersectoral prevention policies were identified in total, 29 of which are priorities for early introduction. Interventions within the health sector were grouped onto five platforms (population based, community level, health centre, first-level hospital, and referral hospital). DCP3 defines a model concept of essential universal health coverage (EUHC) with 218 interventions that provides a starting point for country-specific analysis of priorities. Assuming steady-state implementation by 2030, EUHC in lower-middle-income countries would reduce premature deaths by an estimated 4·2 million per year. Estimated total costs prove substantial: about 9·1% of (current) gross national income (GNI) in low-income countries and 5·2% of GNI in lower-middle-income countries. Financing provision of continuing intervention against chronic conditions accounts for about half of estimated incremental costs. For lower-middle-income countries, the mortality reduction from implementing the EUHC can only reach about half the mortality reduction in non-communicable diseases called for by the Sustainable Development Goals. Full achievement will require increased investment or sustained intersectoral action, and actions by finance ministries to tax smoking and polluting emissions and to reduce or eliminate (often large) subsidies on fossil fuels appear of central importance. DCP3 is intended to be a model starting point for analyses at the country level, but country-specific cost structures, epidemiological needs, and national priorities will generally lead to definitions of EUHC that differ from country to country and from the model in this Review. DCP3 is particularly relevant as achievement of EUHC relies increasingly on greater domestic finance, with global developmental assistance in health focusing more on global public goods. In addition to assessing effects on mortality, DCP3 looked at outcomes of EUHC not encompassed by the disability-adjusted life-year metric and related cost-effectiveness analyses. The other objectives included financial protection (potentially better provided upstream by keeping people out of the hospital rather than downstream by paying their hospital bills for them), stillbirths averted, palliative care, contraception, and child physical and intellectual growth. The first 1000 days after conception are highly important for child development, but the next 7000 days are likewise important and often neglected. Copyright © 2018 Elsevier Ltd. All rights reserved.

Grafting of bacterial polyhydroxybutyrate (PHB) onto cellulose via in situ reactive extrusion with dicumyl peroxide.

PubMed

Wei, Liqing; McDonald, Armando G; Stark, Nicole M

2015-03-09

Polyhydroxybutyrate (PHB) was grafted onto cellulose fiber by dicumyl peroxide (DCP) radical initiation via in situ reactive extrusion. The yield of the grafted (cellulose-g-PHB) copolymer was recorded and grafting efficiency was found to be dependent on the reaction time and DCP concentration. The grafting mechanism was investigated by electron spin resonance (ESR) analysis and showed the presence of radicals produced by DCP radical initiation. The grafted copolymer structure was determined by nuclear magnetic resonance (NMR) spectroscopy. Scanning electronic microscopy (SEM) showed that the cellulose-g-PHB copolymer formed a continuous phase between the surfaces of cellulose and PHB as compared to cellulose-PHB blends. The relative crystallinity of cellulose and PHB were quantified from Fourier transform infrared (FTIR) spectra and X-ray diffraction (XRD) results, while the absolute degree of crystallinity was evaluated by differential scanning calorimetry (DSC). The reduction of crystallinity indicated the grafting reaction occurred not just in the amorphous region but also slightly in crystalline regions of both cellulose and PHB. The smaller crystal sizes suggested the brittleness of PHB was decreased. Thermogravimetric analysis (TGA) showed that the grafted copolymer was stabilized relative to PHB. By varying the reaction parameters the compositions (%PHB and %cellulose) of resultant cellulose-g-PHB copolymer are expected to be manipulated to obtain tunable properties.

Non-photochemical production of singlet oxygen via activation of persulfate by carbon nanotubes.

PubMed

Cheng, Xin; Guo, Hongguang; Zhang, Yongli; Wu, Xiao; Liu, Yang

2017-04-15

The reaction between persulfate (PS) and carbon nanotubes (CNTs) for the degradation of 2,4-dichlorophenol (2,4-DCP) was investigated. It was demonstrated that CNTs could efficiently activate PS for the degradation of 2,4-DCP. Results suggested that the neither hydroxyl radical (OH) nor sulfate radical (SO 4 - ) was produced therein. For the first time, the generation of singlet oxygen ( 1 O 2 ) was proved by several methods including electron paramagnetic resonance spectrometry (EPR) and liquid chromatography mass spectrometry measurements. Moreover, the generation of the superoxide radical as a precursor of the singlet oxygen was also confirmed by using certain scavengers and EPR measurement, in which the presence of molecular oxygen was not required as a precursor of 1 O 2 . The efficient generation of 1 O 2 using the PS/CNTs system without any light irradiation can be employed for the selective oxidation of aqueous organic compounds under neutral conditions with the mineralization and toxicity evaluated. A kinetic model was developed to theoretically evaluate the adsorption and oxidation of 2,4-DCP on the CNTs. Accordingly, a catalytic mechanism was proposed involving the formation of a dioxirane intermediate between PS and CNTs, and the subsequent decomposition of this intermediate into 1 O 2 . Copyright © 2017 Elsevier Ltd. All rights reserved.

Silver ion-enhanced particle-specific cytotoxicity of silver nanoparticles and effect on the production of extracellular secretions of Phanerochaete chrysosporium.

PubMed

Huang, Zhenzhen; Xu, Piao; Chen, Guiqiu; Zeng, Guangming; Chen, Anwei; Song, Zhongxian; He, Kai; Yuan, Lei; Li, Hui; Hu, Liang

2018-04-01

This study investigated the influence of silver ions (Ag + ) on the cytotoxicity of silver nanoparticles (AgNPs) in Phanerochaete chrysosporium and noted the degree of extracellular secretions in response to the toxicant's stress. Oxalate production was elicited with moderate concentrations of 2,4-dichlorophenol (2,4-DCP) and AgNPs reaching a plateau at 10 mg/L and 10 μM, respectively. Increased oxalate accumulation was accompanied by higher activities of manganese peroxidase (MnP) and lignin peroxidase (LiP). However, the secretion of oxalate, MnP and LiP was significantly inhibited owing to Ag + incorporation into AgNP solution. Production of extracellular polymeric substances (EPS) significantly elevated with an increase in 2,4-DCP concentrations; however, after 24 h of exposure to 100 mg/L 2,4-DCP, an obvious decrease in EPS occurred, indicating that part of EPS could be consumed as carbon and energy sources to ameliorate biological tolerance to toxic stress. Furthermore, AgNP-induced "particle-specific" cytotoxicity was substantially enhanced with additional Ag + as evidenced by its significant negative impact on cellular growth, plasma membrane integrity, and morphological preservation compared with AgNPs at equal Ag concentration. Copyright © 2017 Elsevier Ltd. All rights reserved.

Biomechanical analysis of posteromedial tibial plateau split fracture fixation.

PubMed

Zeng, Zhi-Min; Luo, Cong-Feng; Putnis, Sven; Zeng, Bing-Fang

2011-01-01

The purpose of this study was to compare the biomechanical strength of four different fixation methods for a posteromedial tibial plateau split fracture. Twenty-eight tibial plateau fractures were simulated using right-sided synthetic tibiae models. Each fracture model was randomly instrumented with one of the four following constructs, anteroposterior lag-screws, an anteromedial limited contact dynamic compression plate (LC-DCP), a lateral locking plate, or a posterior T-shaped buttress plate. Vertical subsidence of the posteromedial fragment was measured from 500 N to 1500 N during biomechanical testing, the maximum load to failure was also determined. It was found that the posterior T-shaped buttress plate allowed the least subsidence of the posteromedial fragment and produced the highest mean failure load than each of the other three constructs (P=0.00). There was no statistical significant difference between using lag screws or an anteromedial LC-DCP construct for the vertical subsidence at a 1500 N load and the load to failure (P>0.05). This study showed that a posterior-based buttress technique is biomechanically the most stable in-vitro fixation method for posteromedial split tibial plateau fractures, with AP screws and anteromedial-based LC-DCP are not as stable for this type of fracture. Copyright © 2010 Elsevier B.V. All rights reserved.

Expression of TGF-β in Fractures Fixed by Nitinol Swan-like Memory Compressive Connectors

NASA Astrophysics Data System (ADS)

Li, M.; Zhang, C. C.; Xu, S. G.; Fu, Q. G.

2011-07-01

In this article, the effect of internal fixation of a Nitinol swan-like memory compressive connector (SMC) on the temporal expression of transforming growth factor-β (TGF-β) at fracture sites is evaluated. Specimens were collected from 35 New Zealand rabbits modeled for bilateral humeral fracture fixed with either SMC or stainless dynamic compression plate (DCP). Five rabbits each were killed at day 1, 3, 7, 14, 21, 28, and 56. The local positive staining potency, positive area ratio, and positive index of TGF-β were measured using an immunohistochemistry approach (EnVision) in combination with a computerized image analysis system. TGF-β staining was seen in mesenchymal cells, osteoblasts, chondrocytes, and in the extracellular matrix of fractures fixed in both the SMC and the DCP samples without a significant difference in staining at both the early stages (days 1 and 3) and day 56. A higher TGF-β content was observed in the fractures fixed with SMC when compared to that of DCP from day 7 to 28. As a conclusion, TGF-β is highly expressed in fractures fixed with SMC during chondrogenesis stage and entochondrostosis stage. Finally, the mechanism of how SMC promoting synthesis and secretion of TGF-β in the process of fracture healing has been discussed.

Multi-Directional Multi-Level Dual-Cross Patterns for Robust Face Recognition.

PubMed

Ding, Changxing; Choi, Jonghyun; Tao, Dacheng; Davis, Larry S

2016-03-01

To perform unconstrained face recognition robust to variations in illumination, pose and expression, this paper presents a new scheme to extract "Multi-Directional Multi-Level Dual-Cross Patterns" (MDML-DCPs) from face images. Specifically, the MDML-DCPs scheme exploits the first derivative of Gaussian operator to reduce the impact of differences in illumination and then computes the DCP feature at both the holistic and component levels. DCP is a novel face image descriptor inspired by the unique textural structure of human faces. It is computationally efficient and only doubles the cost of computing local binary patterns, yet is extremely robust to pose and expression variations. MDML-DCPs comprehensively yet efficiently encodes the invariant characteristics of a face image from multiple levels into patterns that are highly discriminative of inter-personal differences but robust to intra-personal variations. Experimental results on the FERET, CAS-PERL-R1, FRGC 2.0, and LFW databases indicate that DCP outperforms the state-of-the-art local descriptors (e.g., LBP, LTP, LPQ, POEM, tLBP, and LGXP) for both face identification and face verification tasks. More impressively, the best performance is achieved on the challenging LFW and FRGC 2.0 databases by deploying MDML-DCPs in a simple recognition scheme.

Photo-Fenton degradation of phenol, 2,4-dichlorophenoxyacetic acid and 2,4-dichlorophenol mixture in saline solution using a falling-film solar reactor.

PubMed

Luna, Airton J; Nascimento, Cláudio A O; Foletto, Edson Luiz; Moraes, José E F; Chiavone-Filhoe, Osvaldo

2014-01-01

In this work, a saline aqueous solution of phenol, 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4-dichlorophenol (2,4-DCP) was treated by the photo-Fenton process in a falling-film solar reactor. The influence of the parameters such as initial pH (5-7), initial concentration of Fe2+ (1-2.5mM) and rate of H202 addition (1.87-3.74mmol min-1) was investigated. The efficiency of photodegradation was determined from the removal of dissolved organic carbon (DOC), described by the species degradation of phenol, 2,4-D and 2,4-DCP. Response surface methodology was employed to assess the effects of the variables investigated, i.e. [Fe2+], [H202] and pH, in the photo-Fenton process with solar irradiation. The results reveal that the variables' initial concentration of Fe2+ and H202 presents predominant effect on pollutants' degradation in terms of DOC removal, while pH showed no influence. Under the most adequate experimental conditions, about 85% DOC removal was obtained in 180 min by using a reaction system employed here, and total removal of phenol, 2,4- and 2,4-DCP mixture in about 30min.

Characterisation of chlorophyll oxidation mediated by peroxidative activity in olives (Olea europaea L.) cv. Hojiblanca.

PubMed

Vergara-Domínguez, Honorio; Roca, María; Gandul-Rojas, Beatriz

2013-08-15

The oxidation of chlorophyll a (chl a) catalysed by peroxidase (POD) from mesocarp of the olive fruit (Olea europaea L., cv Hojiblanca) in the presence of H2O2 and 2,4-dichlorophenol (2,4-DCP), is characterised via the individualised quantification of the products of the enzymatic reaction using a new methodology of HPLC-UV spectrometry. This innovation has allowed the discovery that, in addition to 13(2) OH chl a and 15(1) OH lactone chl a, which are the first products of POD on chl a, the reaction process sequentially creates another series of oxidised chlorophyll derivatives which have not been previously described. Their origins have been linked to POD activity in the presence of 2,4-DCP. Likewise, a study of the effect of the concentration of the various cosubstrates on the POD reaction rate demonstrated that the correct establishment of the relative concentrations of the same ([H2O2]/[2,4-DCP]/[Chl]=1:3:0.02) is crucial to explaining inhibition effects by substrates and carrying out optimum measurements. Therefore, new essential parameters for the determination of POD activity on a chlorophyll substrate are established. Copyright © 2013 Elsevier Ltd. All rights reserved.

The DcpS inhibitor RG3039 improves motor function in SMA mice

PubMed Central

Van Meerbeke, James P.; Gibbs, Rebecca M.; Plasterer, Heather L.; Miao, Wenyan; Feng, Zhihua; Lin, Ming-Yi; Rucki, Agnieszka A.; Wee, Claribel D.; Xia, Bing; Sharma, Shefali; Jacques, Vincent; Li, Darrick K.; Pellizzoni, Livio; Rusche, James R.; Ko, Chien-Ping; Sumner, Charlotte J.

2013-01-01

Spinal muscular atrophy (SMA) is caused by mutations of the survival motor neuron 1 (SMN1) gene, retention of the survival motor neuron 2 (SMN2) gene and insufficient expression of full-length survival motor neuron (SMN) protein. Quinazolines increase SMN2 promoter activity and inhibit the ribonucleic acid scavenger enzyme DcpS. The quinazoline derivative RG3039 has advanced to early phase clinical trials. In preparation for efficacy studies in SMA patients, we investigated the effects of RG3039 in severe SMA mice. Here, we show that RG3039 distributed to central nervous system tissues where it robustly inhibited DcpS enzyme activity, but minimally activated SMN expression or the assembly of small nuclear ribonucleoproteins. Nonetheless, treated SMA mice showed a dose-dependent increase in survival, weight and motor function. This was associated with improved motor neuron somal and neuromuscular junction synaptic innervation and function and increased muscle size. RG3039 also enhanced survival of conditional SMA mice in which SMN had been genetically restored to motor neurons. As this systemically delivered drug may have therapeutic benefits that extend beyond motor neurons, it could act additively with SMN-restoring therapies delivered directly to the central nervous system such as antisense oligonucleotides or gene therapy. PMID:23727836

¹H-MAS-NMR chemical shifts in hydrogen-bonded complexes of chlorophenols (pentachlorophenol, 2,4,6-trichlorophenol, 2,6-dichlorophenol, 3,5-dichlorophenol, and p-chlorophenol) and amine, and H/D isotope effects on ¹H-MAS-NMR spectra.

PubMed

Honda, Hisashi

2013-04-22

Chemical shifts (CS) of the ¹H nucleus in N···H···O type hydrogen bonds (H-bond) were observed in some complexes between chlorophenols [pentachlorophenol (PCP), 2,4,6-tricholorophenol (TCP), 2,6-dichlorophenol (26DCP), 3,5-dichlorophenol (35DCP), and p-chlorophenol (pCP)] and nitrogen-base (N-Base) by solid-state high-resolution ¹H-NMR with the magic-angle-spinning (MAS) method. Employing N-Bases with a wide range of pKa values (0.65-10.75), ¹H-MAS-NMR CS values of bridging H atoms in H-bonds were obtained as a function of the N-Base's pKa. The result showed that the CS values were increased with increasing pKa values in a range of DpKa < 0 [DpKa = pKa(N-Base)-pKa(chlorophenols)] and decreased when DpKa > 2: The maximum CS values was recorded in the PCP (pKa = 5.26)-4-methylpyridine (6.03), TCP (6.59)-imidazole (6.99), 26DCP (7.02)-2-amino-4-methylpyridine (7.38), 35DCP (8.04)-4-dimethylaminopyridine (9.61), and pCP (9.47)-4-dimethylaminopyridine (9.61) complexes. The largest CS value of 18.6 ppm was recorded in TCP-imidazole crystals. In addition, H/D isotope effects on ¹H-MAS-NMR spectra were observed in PCP-2-amino-3-methylpyridine. Based on the results of CS simulation using a B3LYP/6-311+G** function, it can be explained that a little changes of the N-H length in H-bond contribute to the H/D isotope shift of the ¹H-MAS-NMR peaks.

Quantification of superoxide radical production in thylakoid membrane using cyclic hydroxylamines.

PubMed

Kozuleva, Marina; Klenina, Irina; Mysin, Ivan; Kirilyuk, Igor; Opanasenko, Vera; Proskuryakov, Ivan; Ivanov, Boris

2015-12-01

Applicability of two lipophilic cyclic hydroxylamines (CHAs), CM-H and TMT-H, and two hydrophilic CHAs, CAT1-H and DCP-H, for detection of superoxide anion radical (O2(∙-)) produced by the thylakoid photosynthetic electron transfer chain (PETC) of higher plants under illumination has been studied. ESR spectrometry was applied for detection of the nitroxide radical originating due to CHAs oxidation by O2(∙-). CHAs and corresponding nitroxide radicals were shown to be involved in side reactions with PETC which could cause miscalculation of O2(∙-) production rate. Lipophilic CM-H was oxidized by PETC components, reducing the oxidized donor of Photosystem I, P700(+), while at the same concentration another lipophilic CHA, TMT-H, did not reduce P700(+). The nitroxide radical was able to accept electrons from components of the photosynthetic chain. Electrostatic interaction of stable cation CAT1-H with the membrane surface was suggested. Water-soluble superoxide dismutase (SOD) was added in order to suppress the reaction of CHA with O2(∙-) outside the membrane. SOD almost completely inhibited light-induced accumulation of DCP(∙), nitroxide radical derivative of hydrophilic DCP-H, in contrast to TMT(∙) accumulation. Based on the results showing that change in the thylakoid lumen pH and volume had minor effect on TMT(∙) accumulation, the reaction of TMT-H with O2(∙-) in the lumen was excluded. Addition of TMT-H to thylakoid suspension in the presence of SOD resulted in the increase in light-induced O2 uptake rate, that argued in favor of TMT-H ability to detect O2(∙-) produced within the membrane core. Thus, hydrophilic DCP-H and lipophilic TMT-H were shown to be usable for detection of O2(∙-) produced outside and within thylakoid membranes. Copyright © 2015 Elsevier Inc. All rights reserved.

Quantitation of a PEGylated protein in monkey serum by UHPLC-HRMS using a surrogate disulfide-containing peptide: A new approach to bioanalysis and in vivo stability evaluation of disulfide-rich protein therapeutics.

PubMed

Zheng, Naiyu; Zeng, Jianing; Manney, Amy; Williams, Lakenya; Aubry, Anne-Françoise; Voronin, Kimberly; Buzescu, Adela; Zhang, Yan J; Allentoff, Alban; Xu, Carrie; Shen, Hongwu; Warner, William; Arnold, Mark E

2016-04-15

To quantify a therapeutic PEGylated protein in monkey serum as well as to monitor its potential in vivo instability and methionine oxidation, a novel ultra high performance liquid chromatography-high resolution mass spectrometric (UHPLC-HRMS) assay was developed using a surrogate disulfide-containing peptide, DCP(SS), and a confirmatory peptide, CP, a disulfide-free peptide. DCP(SS) was obtained by eliminating the step of reduction/alkylation before trypsin digestion. It contains an intact disulfide linkage between two peptide sequences that are essential for drug function but susceptible to potential in vivo cleavages. HRMS-based single ion monitoring (SIM) on a Q Exactive™ mass spectrometer was employed to improve assay specificity and sensitivity for DCP(SS) due to its poor fragmentation and low sensitivity with SRM detection. The assay has been validated for the protein drug in monkey serum using both surrogate peptides with excellent accuracy (within ±4.4%Dev) and precision (within 7.5%CV) with a lower limit of quantitation (LLOQ) at 10 ng mL(-1). The protein concentrations in monkey serum obtained from the DCP(SS)-based assay not only provided important pharmacokinetic parameters, but also confirmed in vivo stability of the peptide regions of interest by comparing drug concentrations with those obtained from the CP-based assay or from a ligand-binding assay (LBA). Furthermore, UHPLC-HRMS allowed simultaneous monitoring of the oxidized forms of both surrogate peptides to evaluate potential ex vivo/in vivo oxidation of one methionine present in each of both surrogate peptides. To the best of our knowledge, this is the first report of using a surrogate disulfide-containing peptide for LC-MS bioanalysis of a therapeutic protein. Copyright © 2016 Elsevier B.V. All rights reserved.

Hazardous Waste Water Remediation by Ecoresin-Dry Cow Dung Powder

NASA Astrophysics Data System (ADS)

Bagla, Hemlata; Barot, Nisha

2013-04-01

Water, the matter, matrix, medium and the mother of our life, is indeed one of the drivers of Nature. Through water cycle only the intra and inter equilibrium is maintained constantly between entire 'green' and 'blue'. Unfortunately, with each successive epoch of industrialization and urbanization, human societies have produced non-biodegradable waste hulk with far beyond handling capacities of mankind. At this juncture the very need is to appreciate and move towards the cost as well as time effective scientific alternatives for the removal of aqueous heavy metal pollutants. Green chemistry advocates the utilization of naturally available bio-resins which are environmentally benign alternative to current synthetic materials and technologies employed for waste water treatment. This explicit investigation aims to explore Dry Cow dung powder, DCP, a natural biosorbent as a green and clean alternative for the aqueous waste water treatment. It is naturally available bio-organic, complex, polymorphic humified fecal matter of cow and is enriched with minerals, carbohydrates, fats, proteins, bile pigments, aliphatic - aromatic species such as 'Humic acid'(HA). The HA has been successfully extracted by authors from DCP and this piece of work has been published in the International Journal [1]. We have developed simple, efficient and eco-friendly method for the removal of aqueous heavy metal pollutant such as Cr(VI) [2], Cd(II), Cr(III) [3] and Hg(II) as well radiotoxic 90Sr(II) [4], employing DCP. DCP is employed without any pre or post treatment. Being freely and easily available DCP has an edge over processed natural adsorbent considering their cost, time and energy efficiency. In nutshell we have to remember that prevention is better than the cure. If we fail to meet this, the situation will surely augment which will drain our water, our life, to slaughters knife..! Reference: 1. H.K.Bagla, N.S.Barot, Soil Amendement by Green Supplement: Dry Cowdung powder, EGUGA - 11, 515B, (2009). 2. H.K.Bagla, N.S.Barot, Adsorption studies of Cr(VI) by a Green resin : Dry Cow Dung Powder employing Tracer Technique, Radiochemica Acta, 100, pp. 1- 10, (2012). 3. H.K.Bagla,N.S.Barot, Eco-friendly waste water treatment by cow-dung powder (Adsorption studies of Cr(III), Cr (VI) & Cd(II) using Tracer Technique), Desalination & Water Treatment, 38(1-3), pp.104-113, (2012). 4. H.K.Bagla, N.S.Barot, Biosorption of Radiotoxic 90Sr by Green adsorbent: Dry Cow Dung Powder, Journal of Radioanalytical and Nuclear Chemistry, 294, pp. 81-86, (2012) .

Nutritional evaluation of low-phytate peas (Pisum sativum L.) for young broiler chicks.

PubMed

Thacker, Philip; Deep, Aman; Petri, Daniel; Warkentin, Thomas

2013-02-01

This experiment determined the effects of including normal and low-phytate peas in diets fed to young broiler chickens on performance, phosphorus availability and bone strength. A total of 180, day-old, male broilers (Ross-308 line) were assigned to six treatments. The control was based on corn and soybean meal while two additional corn-based diets were formulated containing 30% of either normal or low-phytate pea providing 0.45% available phosphorus. For each of these three diets, a similar diet was formulated by reducing the amount of dicalcium phosphate to produce a diet with 0.3% available phosphorus. The total tract apparent availability (TTAA) of phosphorus was higher (p = 0.02) for broilers fed the low-phytate pea than for birds fed the normal pea diets. Birds fed diets containing the lower level of phosphorus had a higher TTAA of phosphorus (50.64 vs. 46.68%) than broilers fed diets adequate in phosphorus. Protein source had no effect on weight gain, feed intake or feed conversion. Broilers fed the low phosphorus diets had lower weight gain (p = 0.04) and feed intake (p < 0.01) than broilers fed the higher phosphorus level. Bone strength was higher (p < 0.01) for broilers fed diets based on low-phytate pea than for those fed diets based on normal pea or soybean meal. Increasing the availability of the phosphorus in peas could mean that less inorganic phosphorus would be required in order to meet the nutritional requirements of broilers. Since inorganic phosphorus sources tend to be expensive, a reduction in their use would lower ration costs. In addition, increased availability of phosphorus would reduce the amount of phosphorus excreted thus reducing the amount of phosphorus that can potentially pollute the environment.

Development of sustained release capsules containing "coated matrix granules of metoprolol tartrate".

PubMed

Siddique, Sabahuddin; Khanam, Jasmina; Bigoniya, Papiya

2010-09-01

The objective of this investigation was to prepare sustained release capsule containing coated matrix granules of metoprolol tartrate and to study its in vitro release and in vivo absorption. The design of dosage form was performed by choosing hydrophilic hydroxypropyl methyl cellulose (HPMC K100M) and hydrophobic ethyl cellulose (EC) polymers as matrix builders and Eudragit® RL/RS as coating polymers. Granules were prepared by composing drug with HPMC K100M, EC, dicalcium phosphate by wet granulation method with subsequent coating. Optimized formulation of metoprolol tartrate was formed by using 30% HPMC K100M, 20% EC, and ratio of Eudragit® RS/RL as 97.5:2.5 at 25% coating level. Capsules were filled with free flowing optimized granules of uniform drug content. This extended the release period upto 12 h in vitro study. Similarity factor and mean dissolution time were also reported to compare various dissolution profiles. The network formed by HPMC and EC had been coupled satisfactorily with the controlled resistance offered by Eudragit® RS. The release mechanism of capsules followed Korsemeyer-Peppas model that indicated significant contribution of erosion effect of hydrophilic polymer. Biopharmaceutical study of this optimized dosage form in rabbit model showed 10 h prolonged drug release in vivo. A close correlation (R(2) = 0.9434) was established between the in vitro release and the in vivo absorption of drug. The results suggested that wet granulation with subsequent coating by fluidized bed technique, is a suitable method to formulate sustained release capsules of metoprolol tartrate and it can perform therapeutically better than conventional immediate release dosage form.

Optimization of Chitosan and Cellulose Acetate Phthalate Controlled Delivery of Methylprednisolone for Treatment of Inflammatory Bowel Disease.

PubMed

Jagdale, Swati; Chandekar, Apoorva

2017-06-01

Purpose: Inflammatory bowel disease (IBD) is a chronic, relapsing and often life-long disorder. The best way to tackle IBD is to develop a site targeted drug delivery. Methylprednisolone is a potent anti-inflammatory steroid. The relative potency of methylprednisolone to hydrocortisone is at least four is to one. The aim of the present research was to develop a colon targeted drug delivery for treatment of IBD. Methods: Compression coated drug delivery system was designed and optimised. Core tablet contained drug, croscarmellose sodium (CCS-superdisintegrant), avicel (binder) and dicalcium phosphate (diluent). Design of experiment with 3 2 factorial design was applied for optimization of compression coated delivery. Chitosan and cellulose acetate phthalate were chosen as independent variables. Swelling index, hardness and % drug release were dependant variables. Results: Core tablet (C5 batch) containing 2.15% CCS showed disintegration in less than 10sec. FTIR, UV and DSC study had shown absence of any significant physical and chemical interaction between drug and polymers. F8 was found to be optimised formulation. F8 contained 35% chitosan and 17.5% cellulose acetate phthalate. It showed drug release of 86.3% ± 6.1%, hardness 6.5 ± 1.5 and lag time 7 hrs. Simulated media drug release was 97.51 ± 8.6% with 7.5 hrs lag time. The results confirmed that the lag time was highly affected by the coating of the polymers as well as the concentration of the superdisintegrant used in core tablet. Conclusion: In-vitro and in-vivo results confirmed a potential colon targeted drug therapy for treatment of IBD.

Evaluation of a rotary tablet press simulator as a tool for the characterization of compaction properties of pharmaceutical products.

PubMed

Michaut, F; Busignies, V; Fouquereau, C; de Barochez, B Huet; Leclerc, B; Tchoreloff, P

2010-06-01

The Stylcam 100R, a rotary press simulator, was designed to simulate speed profiles of rotary tablet presses. Such a simulator was qualified by numerous laboratories and, actually, its ability to be used for studying the behaviour of powders under pressure should be examined. Then, the purpose of this work was to investigate the performances of the Stylcam 100R for characterizing the compaction behaviour and the tabletting properties of pharmaceutical powders. The compressibility of three pharmaceutical excipients (microcrystalline cellulose, dicalcium phosphate dihydrate and alpha-lactose monohydrate) was studied. Four compression speeds were used on the compaction simulator. Force-displacement cycles were associated with two energy parameters, the specific total energy (Es(tot)) and the specific expansion energy (Es(exp)). The mean yield pressure was calculated from Heckel's plots obtained with the in-die method. The diametral tensile strength of compacts was measured in order to evaluate mechanical properties. To evaluate the accuracy of all these parameters, a comparative study was carried out on an eccentric instrumented press. The values of energy parameters and tensile strengths of tablets are close between the eccentric press and the compaction simulator, whatever the compression speed on the latter. The mean yield pressure values obtained using the two presses are different. Finally, the Stylcam 100R seems to be a good tool for characterising tabletting properties of powders, except for the Heckel's model probably due to an unadapted equation of deformation and a lack of accuracy of the displacement transducers. Future improvements should allow correcting these two points. (c) 2009 Wiley-Liss, Inc. and the American Pharmacists Association

Optimization of Chitosan and Cellulose Acetate Phthalate Controlled Delivery of Methylprednisolone for Treatment of Inflammatory Bowel Disease

PubMed Central

Jagdale, Swati; Chandekar, Apoorva

2017-01-01

Purpose: Inflammatory bowel disease (IBD) is a chronic, relapsing and often life-long disorder. The best way to tackle IBD is to develop a site targeted drug delivery. Methylprednisolone is a potent anti-inflammatory steroid. The relative potency of methylprednisolone to hydrocortisone is at least four is to one. The aim of the present research was to develop a colon targeted drug delivery for treatment of IBD. Methods: Compression coated drug delivery system was designed and optimised. Core tablet contained drug, croscarmellose sodium (CCS-superdisintegrant), avicel (binder) and dicalcium phosphate (diluent). Design of experiment with 32 factorial design was applied for optimization of compression coated delivery. Chitosan and cellulose acetate phthalate were chosen as independent variables. Swelling index, hardness and % drug release were dependant variables. Results: Core tablet (C5 batch) containing 2.15% CCS showed disintegration in less than 10sec. FTIR, UV and DSC study had shown absence of any significant physical and chemical interaction between drug and polymers. F8 was found to be optimised formulation. F8 contained 35% chitosan and 17.5% cellulose acetate phthalate. It showed drug release of 86.3% ± 6.1%, hardness 6.5 ± 1.5 and lag time 7 hrs. Simulated media drug release was 97.51 ± 8.6% with 7.5 hrs lag time. The results confirmed that the lag time was highly affected by the coating of the polymers as well as the concentration of the superdisintegrant used in core tablet. Conclusion: In-vitro and in-vivo results confirmed a potential colon targeted drug therapy for treatment of IBD. PMID:28761822

Development of Tablet Formulation of Amorphous Solid Dispersions Prepared by Hot Melt Extrusion Using Quality by Design Approach.

PubMed

Agrawal, Anjali; Dudhedia, Mayur; Deng, Weibin; Shepard, Kevin; Zhong, Li; Povilaitis, Edward; Zimny, Ewa

2016-02-01

The objective of the study was to identify the extragranular component requirements (level and type of excipients) to develop an immediate release tablet of solid dispersions prepared by hot melt extrusion (HME) process using commonly used HME polymers. Solid dispersions of compound X were prepared using polyvinyl pyrrolidone co-vinyl acetate 64 (PVP VA64), Soluplus, and hypromellose acetate succinate (HPMCAS-LF) polymers in 1:2 ratio by HME through 18 mm extruder. A mixture design was employed to study effect of type of polymer, filler (microcrystalline cellulose (MCC), lactose, and dicalcium phosphate anhydrous (DCPA)), and disintegrant (Crospovidone, croscarmellose sodium, and sodium starch glycolate (SSG)) as well as level of extrudates, filler, and disintegrant on tablet properties such as disintegration time (DT), tensile strength (TS), compactibility, and dissolution. Higher extrudate level resulted in longer DT and lower TS so 60-70% was the maximum amount of acceptable extrudate level in tablets. Fast disintegration was achieved with HPMCAS-containing tablets, whereas Soluplus- and PVP VA64-containing tablets had higher TS. Crospovidone and croscarmellose sodium were more suitable disintegrant than SSG to achieve short DT, and MCC was a suitable filler to prepare tablets with acceptable TS for each studied HME polymer. The influence of extragranular components on dissolution from tablets should be carefully evaluated while finalizing tablet composition, as it varies for each HME polymer. The developed statistical models identified suitable level of fillers and disintegrants for each studied HME polymer to achieve tablets with rapid DT (<15 min) and acceptable TS (≥1 MPa at 10-15% tablet porosity), and their predictivity was confirmed by conducting internal and external validation studies.

Apatite formation on bioactive calcium-silicate cements for dentistry affects surface topography and human marrow stromal cells proliferation.

PubMed

Gandolfi, Maria Giovanna; Ciapetti, Gabriela; Taddei, Paola; Perut, Francesca; Tinti, Anna; Cardoso, Marcio Vivan; Van Meerbeek, Bart; Prati, Carlo

2010-10-01

The effect of ageing in phosphate-containing solution of bioactive calcium-silicate cements on the chemistry, morphology and topography of the surface, as well as on in vitro human marrow stromal cells viability and proliferation was investigated. A calcium-silicate cement (wTC) mainly based on dicalcium-silicate and tricalcium-silicate was prepared. Alpha-TCP was added to wTC to obtain wTC-TCP. Bismuth oxide was inserted in wTC to prepare a radiopaque cement (wTC-Bi). A commercial calcium-silicate cement (ProRoot MTA) was tested as control. Cement disks were aged in DPBS for 5 h ('fresh samples'), 14 and 28 days, and analyzed by ESEM/EDX, SEM/EDX, ATR-FTIR, micro-Raman techniques and scanning white-light interferometry. Proliferation, LDH release, ALP activity and collagen production of human marrow stromal cells (MSC) seeded for 1-28 days on the cements were evaluated. Fresh samples exposed a surface mainly composed of calcium-silicate hydrates CSH (from the hydration of belite and alite), calcium hydroxide, calcium carbonate, and ettringite. Apatite nano-spherulites rapidly precipitated on cement surfaces within 5 h. On wTC-TCP the Ca-P deposits appeared thicker than on the other cements. Aged cements showed an irregular porous calcium-phosphate (Ca-P) coating, formed by aggregated apatite spherulites with interspersed calcite crystals. All the experimental cements exerted no acute toxicity in the cell assay system and allowed cell growth. Using biochemical results, the scores were: fresh cements>aged cements for cell proliferation and ALP activity (except for wTC-Bi), whereas fresh cements

2,4-D abatement from groundwater samples by photo-Fenton processes at circumneutral pH using naturally iron present. Effect of inorganic ions.

PubMed

Gutiérrez-Zapata, Héctor M; Rojas, Karen L; Sanabria, Janeth; Rengifo-Herrera, Julián Andrés

2017-03-01

This study evaluated, at laboratory scale, if the using iron naturally present (0.3 mg L -1 ) and adding 10 mg L -1 of hydrogen peroxide was effective to remove 24.3 mgL -1 of 2,4-dichlorophenoxyacetic acid (2,4-D) from groundwater samples by simulated solar irradiation (global intensity = 300 W m -2 ). Under these conditions, the degradation of 2,4-D reached 75.2 % and the apparition of its main oxidation byproduct 2,4-dichlorophenol (DCP) was observed. On the other hand, pH exhibited an increasing from 7.0 to 8.3 during the experiment. Experiments using Milli-Q water at pH 7.0, iron, and H 2 O 2 concentrations of 0.3 and 10 mg L -1 , respectively, were carried out in order to study the effect of ions such as carbonate species, phosphate, and fluoride in typical concentrations often found in groundwater. Ion concentrations were combined by using a factorial experimental design 2 3 . Results showed that carbonates and fluoride did not produce a detrimental effect on the 2,4-D degradation, while phosphate inhibited the process. In this case, the pH increased also from 7.0 to 7.95 and 8.99. Effect of parameters such as pH, iron concentration, and hydrogen peroxide concentration on the 2,4-D degradation by the photo-Fenton process in groundwater was evaluated by using a factorial experimental design 2 3 . Results showed that the pH was the main parameter affecting the process. This study shows for the first time that using the photo-Fenton process at circumneutral pH and iron naturally present seems to be a promising process to remove pesticides from groundwater.

Microbial degradation of 2,4-dichlorophenoxyacetic acid: Insight into the enzymes and catabolic genes involved, their regulation and biotechnological implications.

PubMed

Kumar, Ajit; Trefault, Nicole; Olaniran, Ademola Olufolahan

2016-01-01

A considerable progress has been made to understand the mechanisms of biodegradation of 2,4-dichlorophenoxyacetic acid (2,4-D). 2,4-D biodegradation pathway has been elucidated in many microorganisms including Cupriavidus necator JMP134 (previously known as Wautersia eutropha, Ralstonia eutropha and Alcaligenes eutrophus) and Pseudomonas strains. It generally involves the side chain removal of 2,4-D by α-ketoglutarate-dependent 2,4-D dioxygenase (tfdA) to form 2,4-dichlorophenol (2,4-DCP); hydroxylation of 2,4-DCP by 2,4-DCP hydroxylase (tfdB) to form dichlorocatechol; ortho or meta cleavage of dichlorocatechol by chlorocatechol 1,2-dioxygenase (tfdC) to form 2,4-dichloro-cis,cis-muconate; conversion of 2,4-dichloro-cis,cis-muconate to 2-chlorodienelactone by chloromuconate cycloisomerase (tfdD); conversion of 2-chlorodienelactone to 2-chloromaleylacetate by chlorodienelactone hydrolase (tfdE) and, finally, conversion of 2-chloromaleylacetate to 3-oxoadepate via maleylacetate by chloromaleylacetate reductase and maleylacetate reductase (tfdF), respectively, which is funnelled to the tricarboxylic acid cycle. The latest review on microbial breakdown of 2,4-D, other halogenated aromatic pesticides, and related compounds was compiled by Haggblom, however, a considerable progress has been made in this area of research since then. Thus, this review focuses on the recent advancement on 2,4-D biodegradation, the enzymes, and genes involved and their biotechlogical implications.

The Synergy of Double Cross-linking Agents on the Properties of Styrene Butadiene Rubber Foams

PubMed Central

Shao, Liang; Ji, Zhan-You; Ma, Jian-Zhong; Xue, Chao-Hua; Ma, Zhong-Lei; Zhang, Jing

2016-01-01

Sulfur (S) cross-linking styrene butadiene rubber (SBR) foams show high shrinkage due to the cure reversion, leading to reduced yield and increased processing cost. In this paper, double cross-linking system by S and dicumyl peroxide (DCP) was used to decrease the shrinkage of SBR foams. Most importantly, the synergy of double cross-linking agents was reported for the first time to our knowledge. The cell size and its distribution of SBR foams were investigated by FESEM images, which show the effect of DCP content on the cell structure of the SBR foams. The relationships between shrinkage and crystalline of SBR foams were analyzed by the synergy of double cross-linking agents, which were demonstrated by FTIR, Raman spectra, XRD, DSC and TGA. When the DCP content was 0.6 phr, the SBR foams exhibit excellent physical and mechanical properties such as low density (0.223 g/cm3), reduced shrinkage (2.25%) and compression set (10.96%), as well as elevated elongation at break (1.78 × 103%) and tear strength (54.63 N/mm). The results show that these properties are related to the double cross-linking system of SBR foams. Moreover, the double cross-linking SBR foams present high electromagnetic interference (EMI) shielding properties compared with the S cross-linking SBR foams. PMID:27841307

The Synergy of Double Cross-linking Agents on the Properties of Styrene Butadiene Rubber Foams

NASA Astrophysics Data System (ADS)

Shao, Liang; Ji, Zhan-You; Ma, Jian-Zhong; Xue, Chao-Hua; Ma, Zhong-Lei; Zhang, Jing

2016-11-01

Sulfur (S) cross-linking styrene butadiene rubber (SBR) foams show high shrinkage due to the cure reversion, leading to reduced yield and increased processing cost. In this paper, double cross-linking system by S and dicumyl peroxide (DCP) was used to decrease the shrinkage of SBR foams. Most importantly, the synergy of double cross-linking agents was reported for the first time to our knowledge. The cell size and its distribution of SBR foams were investigated by FESEM images, which show the effect of DCP content on the cell structure of the SBR foams. The relationships between shrinkage and crystalline of SBR foams were analyzed by the synergy of double cross-linking agents, which were demonstrated by FTIR, Raman spectra, XRD, DSC and TGA. When the DCP content was 0.6 phr, the SBR foams exhibit excellent physical and mechanical properties such as low density (0.223 g/cm3), reduced shrinkage (2.25%) and compression set (10.96%), as well as elevated elongation at break (1.78 × 103%) and tear strength (54.63 N/mm). The results show that these properties are related to the double cross-linking system of SBR foams. Moreover, the double cross-linking SBR foams present high electromagnetic interference (EMI) shielding properties compared with the S cross-linking SBR foams.

Metabolism and Residues of 2,4-Dichlorophenoxyacetic Acid in DAS-40278-9 Maize (Zea mays) Transformed with Aryloxyalkanoate Dioxygenase-1 Gene.

PubMed

Zhou, Xiao; Rotondaro, Sandra L; Ma, Mingming; Rosser, Steve W; Olberding, Ed L; Wendelburg, Brian M; Adelfinskaya, Yelena A; Balcer, Jesse L; Blewett, T Craig; Clements, Bruce

2016-10-12

DAS-40278-9 maize, which is developed by Dow AgroSciences, has been genetically modified to express the aryloxyalkanoate dioxygenase-1 (AAD-1) protein and is tolerant to phenoxy auxin herbicides, such as 2,4-dichlorophenoxyacetic acid (2,4-D). To understand the metabolic route and residue distribution of 2,4-D in DAS-40278-9 maize, a metabolism study was conducted with 14 C-radiolabeled 2,4-D applied at the maximum seasonal rate. Plants were grown in boxes outdoors. Forage and mature grain, cobs, and stover were collected for analysis. The metabolism study showed that 2,4-D was metabolized to 2,4-dichlorophenol (2,4-DCP), which was then rapidly conjugated with glucose. Field-scale residue studies with 2,4-D applied at the maximum seasonal rate were conducted at 25 sites in the U.S. and Canada to measure the residues of 2,4-D and free and conjugated 2,4-DCP in mature forage, grain, and stover. Residues of 2,4-D were not detectable in the majority of the grain samples and averaged <1.0 and <1.5 μg/g in forage and stover, respectively. Free plus conjugated 2,4-DCP was not observed in grain and averaged <1.0 μg/g in forage and stover.

Prediction of Liquefaction Potential of Dredge Fill Sand by DCP and Dynamic Probing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alam, Md. Jahangir; Azad, Abul Kalam; Rahman, Ziaur

2008-07-08

From many research it is proved that liquefaction potential of sand is function of mainly relative density and confining pressure. During routine site investigations, high-quality sampling and laboratory testing of sands are not feasible because of inevitable sample disturbance effects and budgetary constraints. On the other hand quality control of sand fill can be done by determining in situ density of sand in layer by layer which is expensive and time consuming. In this paper TRL DCP (Transportation Research Laboratory Dynamic Cone Penetration) and DPL (Dynamic Probing Light) are calibrated to predict the relative density of sand deposit. For thismore » purpose sand of known relative density is prepared in a calibration chamber which is a mild steel cylinder with diameter 0.5 m and height 1.0 m. Relative density of sand is varied by controlling height of fall and diameter of hole of sand discharge bowl. After filling, every time DPL and DCP tests are performed and for every blow the penetration of cone is recorded. N10 is then calculated from penetration records. Thus a database is compiled where N10 and relative densities are known. A correlation is made between N{sub 10} and relative density for two types of sand. A good correlation of N{sub 10} and relative density is found.« less

In vivo assessment of macula in eyes of healthy children 8 to 16 years old using optical coherence tomography angiography.

PubMed

Zhang, Zhengwei; Huang, Xiaoli; Meng, Xiaomei; Chen, Tiantian; Gu, Yan; Wu, Yan; Wu, Zhifeng

2017-08-21

The purpose of the present study was to investigate the vascular flow density (VD) of macular superficial (SCP), deep capillary plexus (DCP), and choriocapillaris and the size of the foveal avascular zone (FAZ) area in healthy children using optical coherence tomography angiography (OCTA). The potential associations of age, sex, intraocular pressure, body mass index, spherical equivalent, and axial length with OCTA parameters were also investigated. A total of 75 eyes from 75 healthy children were included for analysis, with the mean age 11.51 ± 1.91 years (range, 8-16 years). At the level of the SCP, mean VD and mean FAZ area were, respectively, 54.29 ± 2.25% and 0.290 ± 0.109 mm 2 . At the level of the DCP and choriocapillaris, mean VD were 60.19 ± 1.76% and 66.58 ± 1.33%, respectively. After adjustment on the signal strength index, there was no significant correlation between age and all OCTA parameters. Intra-observer repeatability was 0.91, 0.82, and 0.88 in the SCP, DCP and choriocapillaris, respectively. In healthy eyes of children, only sex has a significant influence on the FAZ area. OCTA may provide a noninvasive and reliable approach for evaluating macular perfusion in children, although sex-related variations should be considered.

Satellite Relaying of Geophysical Data

NASA Technical Reports Server (NTRS)

Allenby, R. J.

1977-01-01

Data Collection Platforms (DCPs) for transmitting surface data to an orbiting satellite for relaying to a central data distribution center are being used in a number of geophysical applications. "Off-the-shelf" DCP's, transmitting through Landsat or GOES satellites, are fully capable of relaying data from low-data-rate instruments, such as tiltmeters or tide gauges. In cooperation with the Lamont-Doherty Geological Observatory, Goddard has successfully installed DCP systems on a tide gauge and tiltmeter array on Anegada, British Virgin Islands. Because of the high-data-rate requirements, a practical relay system capable of handling seismic information is not yet available. Such a system could become the basis of an operational hazard prediction system for reducing losses due to major natural catastrophies such as earthquakes, volcanic eruptions, landslides or tsunamis.

Estimation of transport parameters of phenolic compounds and inorganic contaminants through composite landfill liners using one-dimensional mass transport model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Varank, Gamze, E-mail: gvarank@yildiz.edu.tr; Demir, Ahmet, E-mail: ahmetd@yildiz.edu.tr; Yetilmezsoy, Kaan, E-mail: yetilmez@yildiz.edu.tr

2011-11-15

Highlights: > We conduct 1D advection-dispersion modeling to estimate transport parameters. > We examine fourteen phenolic compounds and three inorganic contaminants. > 2-MP, 2,4-DCP, 2,6-DCP, 2,4,5-TCP, 2,3,4,6-TeCP have the highest coefficients. > Dispersion coefficients of Cu are determined to be higher than Zn and Fe. > Transport of phenolics can be prevented by zeolite and bentonite in landfill liners. - Abstract: One-dimensional (1D) advection-dispersion transport modeling was conducted as a conceptual approach for the estimation of the transport parameters of fourteen different phenolic compounds (phenol, 2-CP, 2-MP, 3-MP, 4-MP, 2-NP, 4-NP, 2,4-DNP, 2,4-DCP, 2,6-DCP, 2,4,5-TCP, 2,4,6-TCP, 2,3,4,6-TeCP, PCP) and threemore » different inorganic contaminants (Cu, Zn, Fe) migrating downward through the several liner systems. Four identical pilot-scale landfill reactors (0.25 m{sup 3}) with different composite liners (R1: 0.10 + 0.10 m of compacted clay liner (CCL), L{sub e} = 0.20 m, k{sub e} = 1 x 10{sup -8} m/s, R2: 0.002-m-thick damaged high-density polyethylene (HDPE) geomembrane overlying 0.10 + 0.10 m of CCL, L{sub e} = 0.20 m, k{sub e} = 1 x 10{sup -8} m/s, R3: 0.002-m-thick damaged HDPE geomembrane overlying a 0.02-m-thick bentonite layer encapsulated between 0.10 + 0.10 m CCL, L{sub e} = 0.22 m, k{sub e} = 1 x 10{sup -8} m/s, R4: 0.002-m-thick damaged HDPE geomembrane overlying a 0.02-m-thick zeolite layer encapsulated between 0.10 + 0.10 m CCL, L{sub e} = 0.22 m, k{sub e} = 4.24 x 10{sup -7} m/s) were simultaneously run for a period of about 540 days to investigate the nature of diffusive and advective transport of the selected organic and inorganic contaminants. The results of 1D transport model showed that the highest molecular diffusion coefficients, ranging from 4.77 x 10{sup -10} to 10.67 x 10{sup -10} m{sup 2}/s, were estimated for phenol (R4), 2-MP (R1), 2,4-DNP (R2), 2,4-DCP (R1), 2,6-DCP (R2), 2,4,5-TCP (R2) and 2,3,4,6-TeCP (R1). For all reactors, dispersion coefficients of Cu, ranging from 3.47 x 10{sup -6} m{sup 2}/s to 5.37 x 10{sup -2} m{sup 2}/s, was determined to be higher than others obtained for Zn and Fe. Average molecular diffusion coefficients of phenolic compounds were estimated to be about 5.64 x 10{sup -10} m{sup 2}/s, 5.37 x 10{sup -10} m{sup 2}/s, 2.69 x 10{sup -10} m{sup 2}/s and 3.29 x 10{sup -10} m{sup 2}/s for R1, R2, R3 and R4 systems, respectively. The findings of this study clearly indicated that about 35-50% of transport of phenolic compounds to the groundwater is believed to be prevented with the use of zeolite and bentonite materials in landfill liner systems.« less

[Development of gas chromatography-mass spectrometry for determination of fatty acid esters of chloropropanols in milk powder and the pollution level of infant formula].

PubMed

Li, Shan; Miao, Hong; Cui, Xia; Zhao, Yunfeng; Wu, Yongning

2015-06-01

To establish a method for determination of fatty acid esters of chloropropanols (chloropropanols esters) in milk powder by isotope dilution-gas chromatography-mass spectrometry (GC-MS), and to acquire the pollution level of chloropropanols esters in infant formula and evaluate the dietary exposure risk of chloropropanols esters in infant formula for infants. A total of 111 infant formula samples were collected from supermarkets in Beijing, and the infant formula with no chloropropanols esters detected was served as the blank sample. The samples were ultrasonically extracted with hexane, followed by ester-bond cleavage reaction with sodium methylate-methanol and purification by matrix solid-supported liquid-liquid extraction, then being derivatived with heptafluoro butyrylimidazol. After extracted by sodium chloride solution, the derivatives were determined by GC-MS. The concentration of chloropropanols esters were quantified using the deuterium chloropropanols esters as the internal standards. The accuracy of the method was assessed by the recoveries of the blank spiked samples, and the relative standard deviations (RSD) of the recoveries represent the precision of the method. The contamination level of chloropropanols esters and the intake amount of the infant formula of the 6-month infant were used to estimate the dietary exposure assessment, and x (95% CI) and P97.5 of the contamination level of chloropropanols esters were used to represent the average dietary exposure and the high-end dietary exposure. The satisfied linear correlations in the range of 0.010-0.800 mg/L was acquired for 3-MCPD esters, 2-MCPD esters, 1,3-DCP esters and 2,3-DCP esters with coefficient correlations of 0.999 9, 0.999 8, 0.999 5 and 0.999 6, respectively. The limits of detection (LOD) and the limits of quantitation (LOQ) for 3-MCPD esters, 2-MCPD esters, 1,3-DCP esters and 2,3-DCP esters were 0.005, 0.005, 0.015, 0.015 mg/kg, and 0.015, 0.015, 0.045, 0.045 mg/kg. The average recoveries of the four chloropropanols esters spiked at 0.025, 0.050 and 0.100 mg/kg in blank matrix were in a range from 80.3% to 111.9%, with relative standard deviations (RSD) less than 11.4%. Of the 111 infant formula samples, the detection rates and the contamination levels of 3-MCPD esters and 2-MCPD esters were 77.5% (86/111), 11.7% (13/111) with the contamination levels in the range of ND-0.230 mg/kg and ND-0.039 mg/kg, respectively, and χ (95% CI) and P97.5 of 3-MCPD esters and 2-MCPD esters were 0.020 (0.003-0.113) and 0.006 (0.005-0.025) mg/kg, 0.113 and 0.025 mg/kg, respectively. 1,3-DCP esters and 2,3-DCP esters were not detected in the 111 samples. x (95% CI) and P75 of the six-month old infants to 3-MCPD esters were 0.304 (0.038-1.735) and 1.735 µg · kg⁻¹ · d⁻¹, respectively, which accounted for 15.2% and 86.7% of the PMTDI (2 µg · kg⁻¹ · d⁻¹) of 3-MCPD. This GC-MS method was accurate and rugged for the determination of chloropropanols esters in milk powder. Based on the exposure assessment results, the health risk of chloropropanols esters for infants caused by the intake of infant formula was acceptable.

Implications of the Patient Protection and Affordable Care Act on Insurance Coverage and Rehabilitation Use Among Young Adult Trauma Patients.

PubMed

Zogg, Cheryl K; Payró Chew, Fernando; Scott, John W; Wolf, Lindsey L; Tsai, Thomas C; Najjar, Peter; Olufajo, Olubode A; Schneider, Eric B; Haut, Elliott R; Haider, Adil H; Canner, Joseph K

2016-12-21

Trauma is the leading cause of death and disability among young adults, who are also among the most likely to be uninsured. Efforts to increase insurance coverage, including passage of the Patient Protection and Affordable Care Act (ACA), were intended to improve access to care and promote improvements in outcomes. However, despite reported gains in coverage, the ACA's success in promoting use of high-quality care and enacting changes in clinical end points remains unclear. To assess for observed changes in insurance coverage and rehabilitation use among young adult trauma patients associated with the ACA, including the Dependent Coverage Provision (DCP) and Medicaid expansion/open enrollment, and to consider possible insurance and rehabilitation differences between DCP-eligible vs -ineligible patients and among stratified demographic and community subgroups. A longitudinal assessment of DCP implementation and Medicaid expansion/open enrollment using risk-adjusted before-and-after, difference-in-difference, and interrupted time-series analyses was conducted. Eleven years (January 1, 2005, to September 31, 2015) of Maryland Health Services Cost Review Commission data, representing complete patient records from all payers within the state, were used to identify all hospitalized young adult (aged 18-34 years) trauma patients in Maryland during the study period. Of the 69 507 hospitalized patients included, 50 548 (72.7%) were male, and the mean (SD) age was 25 (5) years. Before implementation of the DCP, 1 of 4 patients was uninsured. After ACA implementation, the number fell to less than 1 of 10, with similar patterns emerging in emergency department and outpatient settings. The change was primarily driven by Medicaid expansion/open enrollment, which corresponded to a 20.1 percentage-point increase in Medicaid (95% CI, 18.9-21.3) and an 18.2 percentage-point decrease in uninsured (95% CI, -19.3 to -17.2). No changes were detected among privately insured patients. Rehabilitation use increased by 5.4 percentage points (95% CI, 4.5-6.2)-a 60% relative increase from a baseline of 9%. Mortality (-0.5; 95% CI, -0.9 to -0.1) and failure-to-rescue rates (-4.5; 95% CI, -7.4 to -1.6) also significantly declined. Stratified changes point to significant differences in the percentage of uninsured patients and rehabilitation access across the board, mitigating or even eradicating disparities in certain cases. For patients who are injured, young, and uninsured, Medicaid expansion/open enrollment in Maryland changed insurance coverage and altered patient outcomes in ways that the DCP alone was never intended to do. Implementation of Medicaid expansion/open enrollment transformed the landscape of trauma coverage, directly affecting the health of one of the country's most vulnerable at-risk groups.

Destructive versus non-destructive methods for geochemical analyses of ceramic artifacts: comparison of portable XRF and ICP-MS data on Bronze Age ceramics from Failaka Island (Kuwait) and Bahrain

NASA Astrophysics Data System (ADS)

Stremtan, Ciprian; Ashkanani, Hasan; Tykot, Robert H.

2013-04-01

The study of bi-phase (i.e. matrix and clasts) geochemical composition of ceramic artifacts is a very powerful tool in fingerprinting the raw materials used by ancient manufacturers (clay sources, tempering materials, coloring agents, etc.), as well as in understanding the physical parameters of the manufacturing techniques. Reliable datasets often require the deployment of destructive techniques that will irremediably damage the artifact. Recent advances in portable X-ray fluorescence instrumentation (pXRF) allow for quick measurements of a range of chemical elements that not too long ago were available only through complicated and often destructive means of analytical chemistry (instrumental neutron activation analysis - INAA, inductively coupled plasma mass spectrometry - ICP-MS, direct coupled plasma-optical emission spectroscopy - DCP-OES etc.). In this contribution we present a comparison of datasets acquired by means of pXRF, DCP-OES, and ICP-MS on Bronze Age ceramics from Failaka Island (Kuwait) and Bahrain. The samples chosen for this study are fine grained, with very well sorted mineral components, and lack any visible organic material fragments. The sample preparation for ICP-MS and DCP-OES analyses was carried out on powdered samples, by using LiBO2 flux fusion and Ge (for the DCP-OES) and In (for ICP-MS) were used as internal standards. The measurements were calibrated against certified reference materials ranging from shales to rhyolites (SGR-1, SDo-1, JA-2, and JR-1) and performed at Univerity of South Florida's Center for Geochemical Analyses. The analytical errors for major elements was smaller than 5 %, while for selected trace elements the error was usually smaller than 3 %. The same set of elements was measured on the same samples at University of South Florida's Anthropology Department using a pXRF device equipped with obsidian filter. Each sample was measured three times and the values were averaged. Two certified reference materials (NIST-612 glass and MACS-3 pressed powder) were also measured to check for accuracy and precision. Our preliminary data shows that most of the major and trace elemental data acquired by both methods are consistent. Some transition metals (e.g. Y, Fe, and Mn) yielded overall lower values when measured with pXRF device (ranging from 27 to 60 % difference), while Ni and Ba showed systematically higher values (20 to 53 %). If samples are chosen properly for pXRF measurements (i.e. thoroughly cleaned, fine grained, well sorted) and the device is properly calibrated, the results are comparable with DCP-OES and ICP-MS data, thus being suitable to use for geochemical fingerprinting

Influence of bedrock on river hydrodynamics and channel geometry

NASA Astrophysics Data System (ADS)

Rennie, C. D.; Church, M. A.; Venditti, J. G.; Bomhof, J.; Adderley, C.

2013-12-01

We present an acoustic Doppler current profiler (aDcp) survey of a 524 km long reach of Fraser River, British Columbia, Canada, as it passes through the Fraser Canyons. The channel alternates between gravel-bedded reaches that are incised into semi-consolidated glacial deposits and bedrock-bound reaches (7.7% of the reach between the towns of Quesnel and Hope). A continuous centreline aDcp survey was employed to measure longitudinal variation in slope, depth, depth-averaged velocity, and shear velocity. A total of 71 aDcp sectional surveys throughout the reach provided section widths (w), section-averaged depths (d), velocity distributions, and discharge (Q). Finally, air photo analysis using Google imagery provided channel widths at 0.5 km spacing. The survey reach was subdivided into 10 morphological sub-reaches, which ranged from alluvial gravel-bed reaches with relatively moderate slope to steep non-alluvial rock-walled canyons. The resulting data provide a unique opportunity to evaluate the influence of bedrock confinement on river hydrodynamics and channel geometry. Continuous centreline longitudinal aDcp data and the widths from air photo analysis were grouped within each sub-reach based on presence of bedrock confinement on both banks, either bank, or neither bank. The results demonstrate that river widths decreased and water depths, flow velocities, and shear velocities increased from the alluvial sub-reaches to the semi-alluvial reaches to the canyon reaches. Within each sub-reach, locations with bedrock encroachment on both banks were also narrower and deeper, but had lower depth-averaged velocity and shear velocity. Sectional geometry data were homogenized along the river (to compensate increasing flows at tributary junctions) by computing w/Q^{1/2} and d/Q^{1/3}, following commonly observed scaling relations. Alluvial reaches are 2.3x wider than rock-bound reaches (from the more abundant imagery data) and 0.60x as deep (from aDcp sections), implying that mean velocity is accelerated in rock reaches by 38%. There is also variation from reach to reach along the river controlled by variation in rock lithologies, with the narrowest canyons occurring in Fraser Canyon proper (w/Q^{1/2} = 0.083 compared with 1.4 elsewhere). The uppermost (';Marguerite') and lowermost (';Agassiz') alluvial reaches are considerably wider (w/Q^{1/2}= 3.9 and 7.1 respectively) than intervening ones ( 2.35). These reaches have lower gradients and exhibit wandering channels. Because of lithological control, the downstream hydraulic geometry of the river does not, in fact, conform with the common pattern, even when sections are analyzed according to boundary material. However, river gradient is well correlated with scaled width; inversely for gravel reaches and directly, but with little sensitivity, for rock-bound reaches.

7 CFR 1412.61 - Contract violations.

Code of Federal Regulations, 2010 CFR

2010-01-01

... payments for each such acre. (2) Producers must protect land enrolled in DCP from weeds, including noxious weeds, and erosion, including providing sufficient cover if determined necessary by the county committee...

Characterization and modification of selected bioplastics

NASA Astrophysics Data System (ADS)

Wei, Liqing

Bioplastics are becoming increasingly prominent mainly due to the growing environmental pollutions caused by non-biodegradable plastics. Polyhydroxybutyrate-co-hydroxyvalerate (PHBV), the major copolymer of polyhydroxyalkanoates (PHAs) family, was biosynthesized (by mixed microbial culture fed with fermented diary manure) and characterized. The monomeric composition (HV% ~ 40%) was determined by GC-MS and NMR. ESI-MSn and NMR analyses showed these PHBVs had random co-monomeric sequence distribution; meantime, they showed characteristic properties (crystallinity, single melting, and tensile properties) as studied by DSC and DMA. The homopolymer poly(3-hydroxybutyrate) (PHB), usually shows interesting properties such as high crystallinity and multiple melting behaviors. The effect of thermal history, such as crystallization (isothermal (temepratures = 80 to 140 °C) and nonisothermal (cooling rates = 2 to 50 °C/min)) and melting (heating rates = 5 to 50 °C/min), on the multiple melting behavior of PHB has been studied using conventional and temperature modulated DSC (TMDSC) techniques. Results showed PHB multiple melting was ascribed to the melting-recrystallization-remelting mechanism and its crystallization kinetics varied with crystallization temperatures and cooling rates. The brittleness and poor melt strength properties of the bioplastics PHB and poly L-lactic acid (PLLA) were imporved by two strategies: (i) to modify polymer structures by cross-linking, (ii) to introduce an external component by grafting, which were initiated by dicumyl peroxide (DCP) via reactive extrusion, have been developed. In method (i), rheological measurements showed cross-linked PHB and PLLA (0.25 to 1 wt% DCP) separately had higher melting strength than their linear polymers due to the formation of long chain branching. Their brittleness was reduced because smaller crystal sizes were observed by hot-stage polarized microscope (HS-POM), meanwhile the reduction of crystallinity was positively correlated to DCP levels. For case (ii), cellulose (another abundant renewable material) was grafted onto PHB backbone induced by DCP (2 to 5 wt%). The chemical structures of grafted copolymer and grafting mechanism were studied by ESR, NMR, XRD and FTIR. Results suggested both amorphous and crystalline regions of cellulose were involved in the reaction. The characterization and modification approaches discussed in this dissertation would provide technical guidance to either researches or industrial processing of these bioplastics.

Degradation of 2,4-dichlorophenol using combined approach based on ultrasound, ozone and catalyst.

PubMed

Barik, Arati J; Gogate, Parag R

2017-05-01

The present work investigates the application of ultrasound and ozone operated individually and in combination with catalyst (ZnO and CuO) for establishing the possible synergistic effects for the degradation of 2,4-dichlorophenol. The dependency of extent of degradation on the operating parameters like temperature (over the range of 30-36°C), initial pH (3-9), catalyst as ZnO (loading of 0.025-0.15g/L) and CuO (loading of 0.02-0.1g/L) and initial concentration of 2,4-DCP (20-50ppm) has been established to maximize the efficacy of ultrasound (US) induced degradation. Using only US, the maximum degradation of 2,4-DCP obtained was 28.85% under optimized conditions of initial concentration as 20ppm, pH of 5 and temperature of 34°C. Study of effect of ozone flow rate for approach of only ozone revealed that maximum degradation was obtained at 400mg/h ozone flow rate. The combined approaches such as US+O 3 , US+ZnO, US+CuO, O 3 +ZnO, O 3 +CuO, US+O 3 +ZnO and US+O 3 +CuO have been subsequently investigated under optimized conditions and observed to be more efficient as compared to individual approaches. The maximum extent of degradation for the combined operation of US+O 3 (400mg/h)+ZnO (0.1g/L) and US+O 3 (400mg/h)+CuO (0.08g/L) has been obtained as 95.66% and 97.03% respectively. The degradation products of 2,4-DCP have been identified using GC-MS analysis and the toxicity analysis has also been performed based on the anti-microbial activity test (agar-well diffusion method) for the different treatment strategies. The present work has conclusively established that the combined approach of US+O 3 +CuO was the most efficient treatment scheme resulting in near complete degradation of 2,4-DCP with production of less toxic intermediates. Copyright © 2016 Elsevier B.V. All rights reserved.

The effects of gamma irradiation on diclofenac sodium, liposome and niosome ingredients for rheumatoid arthritis

PubMed Central

Turker, Selcan; Çolak, Seyda; Korkmaz, Mustafa; Kiliç, Ekrem; Özalp, Meral

2013-01-01

The use of gamma rays for the sterilization of pharmaceutical raw materials and dosage forms is an alternative method for sterilization. However, one of the major problems of the radiosterilization is the production of new radiolytic products during the irradiation process. Therefore, the principal problem in radiosterilization is to determine and to characterize these physical and chemical changes originating from high-energy radiation. Parenteral drug delivery systems were prepared and in vitro characterization, biodistribution and treatment studies were done in our previous studies. Drug delivery systems (liposomes, niosomes, lipogelosomes and niogelosomes) encapsulating diclofenac sodium (DFNa) were prepared for the treatment of rheumatoid arthritis (RA). This work complies information about the studies developed in order to find out if gamma radiation could be applied as a sterilization method to DFNa, and the raw materials as dimyristoyl phosphatidylcholine (DMPC), surfactant I [polyglyceryl-3-cethyl ether (SUR I)], dicethyl phosphate (DCP) and cholesterol (CHOL) that are used to prepare those systems. The raw materials were irradiated with different radiation doses (5, 10, 25 and 50 kGy) and physicochemical changes (organoleptic properties pH, UV and melting point), microbiological evaluation [sterility assurance level (SAL), sterility and pyrogen test] and electron spin resonance (ESR) characteristics were studied at normal (25 °C, 60% relative humidity) and accelerated (40 °C, 75% relative humidity) stability test conditions. PMID:24265902

Microstructure and Properties of DCP-Derived W-ZrC Composite Using Nontoxic Sodium Alginate to Fabricate WC Preform

NASA Astrophysics Data System (ADS)

Najafzadeh Khoee, Ali Asghar; Habibolahzadeh, Ali; Qods, Fathallah; Baharvandi, Hamidreza

2015-04-01

In the present work, tungsten carbide (WC) preforms were fabricated by gel-casting process, using different nontoxic Na-alginate to tertiary calcium phosphate ratios and different loadings of WC powder in the initial slurries. The gel-cast green bodies were dried and pre-sintered at 1723 K for 4 h and then reactively infiltrated by molten Zr2Cu at 1623 K for 0.5 h, to produce W-ZrC composite via displacive compensation of porosity process. The phases, microstructures, and mechanical properties of the preforms and the W-ZrC composites were investigated by Fourier transform infrared spectroscope, x-ray diffractometer (XRD), scanning electron microscope (SEM), image analyzer, and universal mechanical testing machine. XRD results, SEM micrographs, and elemental maps indicated uniform distribution of phases (W and ZrC) and elements (W, Zr, and C). Flexural strengths and hardness of the fabricated composites were in the ranges of 429-460 MPa and 7.5-9.5 GPa, respectively. Fractography studies revealed two types of dimple rupture and cleavage fracture modes in different composite samples. The W-ZrC composite was ablated by an oxyacetylene flame for 60 s. The mean value of mass and linear ablation rates of the composite were 2.1 ± 0.1 mg/s and 3.6 ± 0.5 µm/s, respectively.

Predicting Soil Strength with Remote Sensing Data

DTIC Science & Technology

2010-09-01

292/DCP1.12).....................................................................................................14 Figure 7. Left ( LWD )/Right ( LWD ...Printout) (From LWD Users Guide, 2005) ............15 Figure 8. White Calibration Panel (Pagan...18 Table 4. Trafficability Conditions..................................................................................32 Table 5. Pagan LWD

CA 19-9 (Cancer Antigen 19-9)

MedlinePlus

... Cytomegalovirus (CMV) Tests D-dimer Dengue Fever Testing Des-gamma-carboxy prothrombin (DCP) DHEAS Diabetes-related Autoantibodies ... article.cfm?id=296. Accessed June 28, 2016. De Paula JMP, Toranzo EM, Borge LG, Hidalgo SF. ...

Publication Search | Division of Cancer Prevention

Cancer.gov

Search this comprehensive bibliography of DCP publications. If available, links to PubMed will be provided in the search results. A report of the search results may be generated on the Publications Search Results page.

Validation of Serum Markers for the Early Detection of Hepatocellular Carcinoma — EDRN Public Portal

Cancer.gov

Using the guidelines for cancer biomarker validation suggested by Pepe et al. (23), we propose to perform a Phase 2 study of DCP for the detection of early stage HCC. In this proposal, we plan to perform a larger case-control study to compare the sensitivity and specificity of DCP and AFP alone and in combination in differentiating patients with all stages of HCC and more importantly those with early HCC from patients with cirrhosis. We plan to enroll consecutive patients with HCC seen at 7 centers in the United States. Controls are frequency matched to cases (all center combined) using the following criteria: age (±10 years), gender (+10%) and etiology of liver disease (viral vs non-viral (+5%). Within each participating institution, there will be an equal number (+20%) of cases and controls.

Use of additives to enhance the removal of phenols from water treated with horseradish and hydrogen peroxide.

PubMed

Tonegawa, Masami; Dec, Jerzy; Bollag, Jean-Marc

2003-01-01

Use of additives, such as polyethylene glycol (PEG), selected surfactants, chitosan gel, or activated carbon, has been shown to enhance enzymatic treatment of water polluted with organic compounds. In this study, additives were used to facilitate the removal of 2,4-dichlorophenol (2,4-DCP) from water using minced horseradish (Armoracia rusticana P. Gaertn. et al.) as a carrier of peroxidase activity. The specific objectives of the study were to (i) enhance the pollutant removal activity of minced horseradish by the addition of PEG and other additives (e.g., Tween 20, Triton X-100, and rhamnolipid); (ii) eliminate colored reaction products by the addition of chitosan; and (iii) eliminate color by amending treated water with activated carbon. The disappearance of 2,4-DCP in horseradish-treated water samples amended with PEG or various surfactants (75-90%) was greatly increased over that observed in nonamended samples (29%). The effect of PEG depended on its average molecular weight. As indicated by visible spectrophotometry, enclosing horseradish pieces between two sealed chitosan films completely eliminated colored reaction products; however, the decolorization was accompanied by a reduction in 2,4-DCP removal (from 95 to 60%). On the other hand, commercially available activated carbon completely removed colored reaction products from the treated water without reducing the removal efficiency. Based on the results obtained, it can be concluded that the use of additives may considerably improve the quality of wastewater treated by plant materials.

Role of Alicyclobacillus acidoterrestris in the development of a disinfectant taint in shelf-stable fruit juice.

PubMed

Jensen, N; Whitfield, F B

2003-01-01

This study was undertaken to identify the bacterium and metabolic products contributing to a disinfectant taint in shelf-stable fruit juice and to determine some of the growth conditions for the organism. Microbiological examination of tainted and untainted fruit juice drinks detected low numbers of acid-dependent, thermotolerant, spore-forming bacteria in the tainted juices only. The presence of omega-cyclohexyl fatty acids was confirmed in two of the isolates by cell membrane fatty acid analysis. The isolates were subsequently identified as Alicyclobacillus acidoterrestris by partial 16S rDNA sequencing. Studies on the isolates showed growth at pH 2.5-6.0 and 19.5-58 degrees C. Gas chromatography/mass spectrometry (GC/MS) was used to identify and quantify 2,6-dibromophenol (2,6-DBP) and 2,6-dichlorophenol (2,6-DCP) in the tainted juice. Challenge studies in a mixed fruit drink inoculated with the two isolates and the type strain of A. acidoterrestris, incubated at 44-46 degrees C for 4 d, showed the production of both metabolites, which were confirmed and quantified by GC/MS. The results show that A. acidoterrestris can produce 2,6-DBP and 2,6-DCP in shelf-stable juices. This is the first report detailing experimental methodology showing that A. acidoterrestris can produce 2,6-DCP in foods. Control of storage temperatures (to < 20 degrees C) immediately after processing may provide an effective control measure for the fruit juice industry to prevent spoilage by A. acidoterrestris.

GROWTH INHIBITORY ACTIONS OF PROTHROMBIN ON NORMAL HEPATOCYTES

PubMed Central

Carr, Brian I.; Kar, Siddhartha; Wang, Meifang; Wang, Ziqiu

2007-01-01

Most hepatomas have a defect in prothrombin carboxylation, and can secrete under-carboxylated prothrombin or des-γ-carboxy-prothrombin (DCP), the function of which is unknown. We considered that prothrombin-DCP axis might also be involved in growth control. Hepatocytes and hepatoma cells were treated with prothrombin, and DNA synthesis and cytoskeleton were studied. Prothrombin inhibited DNA synthesis in hepatocytes on fibronectin, but not collagen matrix. Hepatoma cell lines were not inhibited. We found that hepatoma cell matrix conferred resistance to hepatocytes. Prothrombin decreased fibronectin but not collagen amounts, but only in the presence of hepatocytes and not hepatoma cells, indicating that it has a differential action on matrix proteins. It also caused changes in cell shape and actin depolymerization. In vivo, there was a decrease in plasma prothrombin activity after a partial hepatectomy (PH) concomitant with a peak of DNA synthesis by the hepatocyte at 24 h after PH. Injection of warfarin at the time of PH, further inhibited PT activity and enhanced this 24 h peak of DNA synthesis. Furthermore, repeated injection of prothrombin lowered the peak DNA synthesis after PH. The data support the hypothesis that prothrombin can act as a hepatocyte growth inhibitor, likely at the level of fibronectin loss and result in cytoskeletal changes. Hepatomas resist this action, possibly due to their different matrix proteins. This represents a novel mechanism for growth regulation and provides a possible biological significance for the tumor marker DCP. PMID:17490900

Development and validation of an improved method for the determination of chloropropanols in paperboard food packaging by GC-MS.

PubMed

Mezouari, S; Liu, W Yun; Pace, G; Hartman, T G

2015-01-01

The objective of this study was to develop an improved analytical method for the determination of 3-chloro-1,2-propanediol (3-MCPD) and 1,3-dichloropropanol (1,3-DCP) in paper-type food packaging. The established method includes aqueous extraction, matrix spiking of a deuterated surrogate internal standard (3-MCPD-d₅), clean-up using Extrelut solid-phase extraction, derivatisation using a silylation reagent, and GC-MS analysis of the chloropropanols as their corresponding trimethyl silyl ethers. The new method is applicable to food-grade packaging samples using European Commission standard aqueous extraction and aqueous food stimulant migration tests. In this improved method, the derivatisation procedure was optimised; the cost and time of the analysis were reduced by using 10 times less sample, solvents and reagents than in previously described methods. Overall the validation data demonstrate that the method is precise and reliable. The limit of detection (LOD) of the aqueous extract was 0.010 mg kg(-1) (w/w) for both 3-MCPD and 1,3-DCP. Analytical precision had a relative standard deviation (RSD) of 3.36% for 3-MCPD and an RSD of 7.65% for 1,3-DCP. The new method was satisfactorily applied to the analysis of over 100 commercial paperboard packaging samples. The data are being used to guide the product development of a next generation of wet-strength resins with reduced chloropropanol content, and also for risk assessments to calculate the virtual safe dose (VSD).

On the accurate estimation of gap fraction during daytime with digital cover photography

NASA Astrophysics Data System (ADS)

Hwang, Y. R.; Ryu, Y.; Kimm, H.; Macfarlane, C.; Lang, M.; Sonnentag, O.

2015-12-01

Digital cover photography (DCP) has emerged as an indirect method to obtain gap fraction accurately. Thus far, however, the intervention of subjectivity, such as determining the camera relative exposure value (REV) and threshold in the histogram, hindered computing accurate gap fraction. Here we propose a novel method that enables us to measure gap fraction accurately during daytime under various sky conditions by DCP. The novel method computes gap fraction using a single DCP unsaturated raw image which is corrected for scattering effects by canopies and a reconstructed sky image from the raw format image. To test the sensitivity of the novel method derived gap fraction to diverse REVs, solar zenith angles and canopy structures, we took photos in one hour interval between sunrise to midday under dense and sparse canopies with REV 0 to -5. The novel method showed little variation of gap fraction across different REVs in both dense and spares canopies across diverse range of solar zenith angles. The perforated panel experiment, which was used to test the accuracy of the estimated gap fraction, confirmed that the novel method resulted in the accurate and consistent gap fractions across different hole sizes, gap fractions and solar zenith angles. These findings highlight that the novel method opens new opportunities to estimate gap fraction accurately during daytime from sparse to dense canopies, which will be useful in monitoring LAI precisely and validating satellite remote sensing LAI products efficiently.

DCP's Early Detection Research Guides Future Science | Division of Cancer Prevention

Cancer.gov

Early detection research funded by the NCI's Division of Cancer Prevention has positively steered both public health and clinical outcomes, and set the stage for findings in the next generation of research. |

Role of HSAB concept in understanding biosorptive behaviour of various metal ions employing green biosorbent - Dry Cow Dung Powder

NASA Astrophysics Data System (ADS)

Bagla, Hemlata; Khilnani, Roshan

2016-04-01

Hard & Soft Acid Base concept, HSAB theory given by Pearson, elucidates the crucial role of HSAB characteristics of both pollutants as well as the aqueous milieu. This theory can also explain the biosorptive behaviour of Dry Cow dung Powder, which helps in governing the success of process. The various metal ionic species exhibit a preference for the ligand binding on the biomass based on its chemical coordination characteristics. A comparative batch equilibration biosorptive assay has been carried out employing radiotracer technique for uptake of Cr(III), Cr(VI), Cd(II), Hg(II), Sr(II), Cs(I) and Co(II) at optimum biosorption parameters. To study the effect of interference of different salts on the percentage biosorption of metal ions on DCP, different organic as well as inorganic salts with varying proportion of 10 mg, 25 mg, 50 mg and 100 mg have been studied. The dynamics of the biosorption in terms of the order of the rate constant was studied applying different kinetic models. The best fitting model was Lagergren pseudo second order model. DCP, an eco-friendly humiresin, enriched with minerals, carbohydrates, fats, proteins, bile pigments, aliphatic - aromatic species such as 'Humic acid', Fulvic acid and many naturally present functional group such as carboxyl, phenols, quinols, amide etc. of both hard and soft nature, making it 'combo' in nature sorbs both concerned metal ions as well as ligands present in the system. Thus the ligands which were masking the biosorption process of heavy metal ions in this study were treated by mere increase in the dose of DCP, which successfully solves the problem without affecting efficiency of the process. This is exemplified by three very basic interactions happening in multicomponent system i.e. Synergism: Mutual enhancement; Antagonism: Mutual decrement; Non-interaction: Neutral effect. Thus DCP has a great potential in the field of water decontamination, industrial water treatment and in abatement of water pollution. So as to get optimum biosorption with in-situ conditions, it is very important to know the nature of ligands and their concentration present in the effluent. The selection of any process should be considered in the terms of its feasibility and it should also contest, the 3A's concept of affordability, acceptability and adaptability. On this background, our research with DCP proves its affordability by being free and naturally available, its acceptability by HSAB concept and its adaptability by its Combo nature. References 1. N. S. Barot, R. P. Khilnani, and H. K. Bagla, "Biosorptive profile of synthetic and natural humiresin for the remediation of metallic water pollutants," J. Radioanal. Nucl. Chem., vol. 302, no. 2, pp. 951-959, Nov. 2014. 2. R. G. Pearson, "Hard and Soft Acids and Bases," J. Am. Chem. Soc., vol. 85, no. 22, pp. 3533-3539, Nov. 1963.

Dual activity of certain HIT-proteins: A. thaliana Hint4 and C. elegans DcpS act on adenosine 5'-phosphosulfate as hydrolases (forming AMP) and as phosphorylases (forming ADP).

PubMed

Guranowski, Andrzej; Wojdyła, Anna Maria; Zimny, Jarosław; Wypijewska, Anna; Kowalska, Joanna; Jemielity, Jacek; Davis, Richard E; Bieganowski, Paweł

2010-01-04

Histidine triad (HIT)-family proteins interact with different mono- and dinucleotides and catalyze their hydrolysis. During a study of the substrate specificity of seven HIT-family proteins, we have shown that each can act as a sulfohydrolase, catalyzing the liberation of AMP from adenosine 5'-phosphosulfate (APS or SO(4)-pA). However, in the presence of orthophosphate, Arabidopsis thaliana Hint4 and Caenorhabditis elegans DcpS also behaved as APS phosphorylases, forming ADP. Low pH promoted the phosphorolytic and high pH the hydrolytic activities. These proteins, and in particular Hint4, also catalyzed hydrolysis or phosphorolysis of some other adenylyl-derivatives but at lower rates than those for APS cleavage. A mechanism for these activities is proposed and the possible role of some HIT-proteins in APS metabolism is discussed.

Crosslinked bicontinuous biobased PLA/NR blends via dynamic vulcanization using different curing systems.

PubMed

Yuan, Daosheng; Chen, Kunling; Xu, Chuanhui; Chen, Zhonghua; Chen, Yukun

2014-11-26

In this study, blends of entirely biosourced polymers, namely polylactide (PLA) and natural rubber (NR), were prepared through dynamic vulcanization using dicumyl peroxide (DCP), sulphur (S) and phenolic resin (2402) as curing agents, respectively. The crosslinked NR phase was found to be a continuous structure in all the prepared blends. The molecular weight changes of PLA were studied by gel permeation chromatography. Interfacial compatibilization between PLA and NR was investigated using Fourier transform infrared spectroscopy and scanning electron microscopy. The thermal properties of blends were evaluated by differential scanning calorimetry and thermogravimetric analysis instrument. It was found that the molecular weight of PLA and interfacial compatibilizaion between PLA and NR showed a significant influence on the mechanical and thermal properties of blends. The PLA/NR blend (60/40 w/w) by DCP-induced dynamic vulcanization owned the finest mechanical properties and thermal stability. Copyright © 2014 Elsevier Ltd. All rights reserved.

D-amino acid substitution enhances the stability of antimicrobial peptide polybia-CP.

PubMed

Jia, Fengjing; Wang, Jiayi; Peng, Jinxiu; Zhao, Ping; Kong, Ziqing; Wang, Kairong; Yan, Wenjin; Wang, Rui

2017-10-01

With the increasing emergence of resistant microbes toward conventional antimicrobial agents, there is an urgent need for the development of antimicrobial agents with novel action mode. Antimicrobial peptides (AMPs) are believed to be one kind of ideal alternatives. However, AMPs can be easily degraded by protease, which limited their therapeutic use. In the present study, D-amino acid substitution strategy was employed to enhance the stability of polybia-CP. We investigated the stability of peptides against the degradation of trypsin and chymotrypsin by determining the antimicrobial activity or determining the HPLC profile of peptides after incubation with proteases. Our results showed that both the all D-amino acid derivative (D-CP) and partial D-lysine substitution derivative (D-lys-CP) have an improved stability against trypsin and chymotrypsin. Although D-CP takes left-hand α-helical conformation and D-lys-CP loses some α-helical content, both of the D-amino acid-substituted derivatives maintain their parental peptides' membrane active action mode. In addition, D-lys-CP showed a slight weaker antimicrobial activity than polybia-CP, but the hemolytic activity decreased greatly. These results suggest that D-CP and D-lys-CP can offer strategy to improve the property of AMPs and may be leading compounds for the development of novel antimicrobial agents. © The Author 2017. Published by Oxford University Press on behalf of the Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Co(II), Ni(II), Cu(II) and Zn(II) complexes of tridentate ONO donor Schiff base ligand: Synthesis, characterization, thermal, non-isothermal kinetics and DFT calculations

NASA Astrophysics Data System (ADS)

Kusmariya, Brajendra S.; Mishra, A. P.

2017-02-01

We report here four mononuclear Co(II), Ni(II), Cu(II) and Zn(II) coordination compounds of general formula [M(L)2] {L = dcp; M = CoII, CuII & ZnII} and [M(L)(H2O)]·H2O {L = dcp; M = NiII} derived from tridentate 2,4-dichloro-6-{[(3-chloro-2-hydroxy-5-nitrophenyl)imino]methyl}phenol (dcp) ligand. These compounds were synthesized and characterized by elemental analysis, FT-IR, uv-vis, 1H NMR, molar conductance, magnetic moment, thermal, PXRD and SEM-EDX. The Powder X-ray Diffraction patterns and SEM analyses showed the crystalline nature of synthesized compounds. The peak broadening was explained in terms of crystallite size and the lattice strain using Scherrer and Williamson-Hall method. Thermogravimetric analysis was performed to determine the thermal stability of synthesized compounds under nitrogen atmosphere up to 820 K at 10 Kmin-1 heating rate. The kinetic and thermodynamic parameters of thermal decomposition were calculated using Coats-Redfern (C-R), Piloyan-Novikova (P-N) and Horowitz-Metzger (H-M) methods assuming first order degradation. The calculated optical band gap values of complexes were found to be in semiconducting range. To support the experimental findings, and derive some fruitful information viz. frequency calculations, HOMO-LUMO, energy gap (ΔE), molecular electrostatic potential (MEP), spin density, absorption spectra etc.; theoretical calculations by means of DFT and TD-DFT at B3LYP level were incorporated.

Selective removal of 2,4-dichlorophenoxyacetic acid from water by molecularly-imprinted amino-functionalized silica gel sorbent.

PubMed

Han, Deman; Jia, Wenping; Liang, Huading

2010-01-01

A molecularly-imprinted amino-functionalized sorbent for selective removal of 2,4-dichlorophenoxyacetic acid (2,4-D) was prepared by a surface imprinting technique in combination with a sol-gel process. The 2,4-D-imprinted amino-functionalized silica sorbent was characterized by FT-IR, nitrogen adsorption and static adsorption experiments. The selectivity of the sorbent was investigated by a batch competitive binding experiment using an aqueous 2,4-D and 2,4-dichlorophenol (2,4-DCP) mixture or using an aqueous 2,4-D and 2,4-dichlorophenylacetic acid (DPAC) mixture. The largest selectivity coefficient for 2,4-D in the presence of 2,4-DCP was found to be over 18, the largest relative selectivity coefficient between 2,4-D and 2,4-DCP over 9. The static uptake capacity and selectivity coefficient of the 2,4-D-imprinted functionalized sorbent are higher than those of the non-imprinted sorbent. The imprinted functionalized silica gel sorbent offered a fast kinetics for the extraction/stripping of 2,4-D, 73% of binding capacity (200 mg/L 2,4-D onto 20 mg of imprinted sorbent) was obtained within 5 min and the adsorbed 2,4-D can be easily stripped by the mixture solution of ethanol and 6 mol/L HCl (V:V = 1:1). In a test of five extraction/stripping cycles, the adsorption capacity of the sorbent was all above 93% of that of the fresh sorbent. Experimental result showed the potential of molecularly-imprinted amino-functionalized sorbent for selective removal of 2,4-D.

Analyses of GPR signals for characterization of ground conditions in urban areas

NASA Astrophysics Data System (ADS)

Hong, Won-Taek; Kang, Seonghun; Lee, Sung Jin; Lee, Jong-Sub

2018-05-01

Ground penetrating radar (GPR) is applied for the characterization of the ground conditions in urban areas. In addition, time domain reflectometry (TDR) and dynamic cone penetrometer (DCP) tests are conducted for the accurate analyses of the GPR images. The GPR images are acquired near a ground excavation site, where a ground subsidence occurred and was repaired. Moreover, the relative permittivity and dynamic cone penetration index (DCPI) are profiled through the TDR and DCP tests, respectively. As the ground in the urban area is kept under a low-moisture condition, the relative permittivity, which is inversely related to the electromagnetic impedance, is mainly affected by the dry density and is inversely proportional to the DCPI value. Because the first strong signal in the GPR image is shifted 180° from the emitted signal, the polarity of the electromagnetic wave reflected at the dense layer, where the reflection coefficient is negative, is identical to that of the first strong signal. The temporal-scaled GPR images can be accurately converted into the spatial-scaled GPR images using the relative permittivity determined by the TDR test. The distribution of the loose layer can be accurately estimated by using the spatial-scaled GPR images and reflection characteristics of the electromagnetic wave. Note that the loose layer distribution estimated in this study matches well with the DCPI profile and is visually verified from the endoscopic images. This study demonstrates that the GPR survey complemented by the TDR and DCP tests, may be an effective method for the characterization of ground conditions in an urban area.

Multicenter Guidelines | Division of Cancer Prevention

Cancer.gov

A Lead Organization conducting multi-institutional studies in the consortium has specific responsibilities in order to comply with the DCP Multicenter Guidelines. The Lead Organization is responsible for the following at all Participating Organizations as well as the Lead Organization: |

Replacing cereals with dehydrated citrus pulp in a soybean oil supplemented diet increases vaccenic and rumenic acids in ewe milk.

PubMed

Santos-Silva, José; Dentinho, Maria T; Francisco, Alexandra; Portugal, Ana P; Belo, Ana T; Martins, António P L; Alves, Susana P; Bessa, Rui J B

2016-02-01

This study evaluates the effect of the replacement of cereals by dried citrus pulp (DCP) in diets supplemented with 5% of soybean oil, on ewe milk yield and composition, including milk fatty acid (FA). Four Serra da Estrela multiparous ewes in the second month of lactation were used in a double 2×2 Latin square design. Ewes were individually penned and milked twice a day with an 8-h interval. Each experimental period included 14 d of diet adaptation followed by 5d of measurements and sampling. The 2 diets included on dry matter basis 450 g/kg of corn silage and 550 g/kg of either a soybean oil-supplemented concentrate meal containing barley and maize (cereal) or dried citrus pulp (DCP; citrus). Feed was offered ad libitum, considering 10% of orts, and intake was measured daily. Milk yield was higher and dry matter intake tended to be higher with the citrus diet. Milk composition and technological properties for cheese production were not affected by treatments, except for lactose, which was lower with the citrus diet. Replacement of cereals by DCP resulted in a 3-percentage-point decrease of both 18:0 and cis-9-18:1 that were mostly compensated by the 4.19- and 1.68-percentage-point increases of trans-11-18:1 and cis-9,trans-11-18:2, respectively. The intake of C18 FA tended to increase with the citrus diet compared with the cereal diet, but the apparent transfer of 18:2n-6 and of 18:3n-3 did not differ between diets. The milk output of C18 FA increased with the citrus compared with the cereal diet, mostly due to the increase of trans-11-18:1 and cis-9,trans-11-18:2 because the daily milk output of 18:0, trans-10-18:1, cis-9-18:1, 18:2n-6 and 18:3n-3 did not differ between diets. Replacing cereals with DCP in an oil-supplemented diet resulted in a selective increase of trans-11-18:1 and cis-9,trans-11-18:2 in milk, with no major effect on other biohydrogenation intermediates. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Green ambrosia for Soil- Dry Cow Dung Powder: Rhexistasy to Biostasy

NASA Astrophysics Data System (ADS)

Bagla, Hemlata; Barot, Nisha

2013-04-01

"Greener ambrosia for Soil - Dry cow dung powder: Rhexistasy to Biostasy" Pedosphere, the soil with its biotic and abiotic component, is produced by lithosphere`s interactions with atmosphere, hydrosphere and biosphere. The theory of Biorhexistasy proposed by pedologist H. Erhart [1], describes two crucial climatic phases of soil i.e. Biostasy, period of soil formation and Rhexistasy, periods of soil erosion. Humus, the organic matter in soil, permits better aeration, enhances the absorption and releases nutrients, and makes the soil less susceptible to leaching and erosion [2], thus the agent of soil`s vitality. Mismanagement of soil, leads to the degradation of millions of acres of land through erosion, compaction, salinization and acidification. Among these threats salinity is a major abiotic stress reducing the yield of wide variety of crops all over the world [3]. It is been proved that Humic Acid (HA) treatment can ameliorate the deleterious effects of salt stress by increasing root growth, altering mineral uptake, and decreasing membrane damage, thus inducing salt tolerance in plants [4]. HA can be inexpensively incorporated into soils via different biowastes. Dry cow dung powder (DCP), is naturally available bio-organic, complex, polymorphic humified fecal matter, enriched with minerals, carbohydrates, fats, proteins, bile pigments, aliphatic - aromatic species such as HA, Fulvic Acid (FA) etc [5]. The microbial consortium enables DCP with considerable potentials for biodegradation and biotransformation of even saline soil and further contributes to many biogeochemical processes, boosting humus content of soil. Due to unambiguous biological, microbiological as well as chemical inert properties of DCP, it has been successfully utilized as a fertilizer and soil conditioner since ages in India, one of the leading agrarian countries of the world. Thus we summarize that DCP is one of the best contenders for the biostasy and desaliner of soil, aptly, soil`s Greener ambrosia. Reference: 1. C. Feller, E. Blanchart, A. Herbillon, SSSAJ: 72(5), (2008). 2. N.Fedoroff, M.Courty, Z.Guo, Interpretation of Micromorphological Features of Soils and Regoliths. Elsevier B.V., (2010). 3. Mackowiak et al, SSSAJ: 65, (2001). 4. K.Cimrin, O.Turkmen, M.Turan, B.Tuncer, African Journal of Biotechnology, 9(36), (2010). 5. H.Bagla, N.Barot, EGUGA - 11, 515B, (2009).

Federal Register: Toxic Substances; 1,2- Dichloropropane; Testing Requirements

EPA Pesticide Factsheets

The EPA (also Agency) is issuing a final test rule under section 4(a) of the Toxic Substances (TSCA) that requires manufacturers and processors of 1,2-dichloropropane (DCP CAS Number 78-87—5) to test this chemical.

Potential applications of dynamic and static cone penetrometers in MDOT pavement design and construction.

DOT National Transportation Integrated Search

2003-09-01

This report discusses the current applications of the dynamic and static cone penetrometers in pavement design and construction. : The dynamic cone penetrometer (DCP) is the most versatile rapid, in situ evaluation device currently available. Correla...

DECHLORINATION ACTIVITY (CROSS-ACCLIMATION) OF FRESHWATER SEDIMENTS ADAPTED TO MONO- AND DI-CHLOROPHENOLS

EPA Science Inventory

The reductive dechlorination of chlorophenols (CPs) in sediment slurries (10% solids) adapted to dechlorinate mono- and di-CPs (DCP) was investigated to define the regiospecificity of the dechlorination reaction. nadapted sediment slurries amended with various ortho-substituted C...

Federal Register notice: Testing Requirement; Final Test Standards and Reporting Requirements; 1,2-Dichloropropane

EPA Pesticide Factsheets

EPA is issuing a final rule under section 4(a) of the Toxic Substances Control Act (TSCA) that requires manufacturers and processors of 1,2-dichioropropane (DCP: CAS Number 78—87—5) to conduct tests.

Cost-effectiveness analysis of the introduction of a quadrivalent human papillomavirus vaccine in France.

PubMed

Bergeron, Christine; Largeron, Nathalie; McAllister, Ruth; Mathevet, Patrice; Remy, Vanessa

2008-01-01

A vaccine to prevent diseases due to human papillomavirus (HPV) types 6, 11, 16, and 18 is now available in France. The objective of this study was to assess the health and economic impact in France of implementing a quadrivalent HPV vaccine alongside existing screening practices versus screening alone. A Markov model of the natural history of HPV infection incorporating screening and vaccination, was adapted to the French context. A vaccine that would prevent 100 percent of HPV 6, 11, 16, and 18-associated diseases, with lifetime duration and 80 percent coverage, given to girls at age 14 in conjunction with current screening was compared with screening alone. Results were analyzed from both a direct healthcare cost perspective (DCP) and a third-party payer perspective (TPP). Indirect costs such as productivity loss were not taken into account in this analysis. The incremental cost per life-year gained from vaccination was euro12,429 (TPP) and euro20,455 (DCP). The incremental cost per quality-adjusted life-year (QALY) for the introduction of HPV vaccination alongside the French cervical cancer screening program was euro8,408 (TPP) and euro13,809 (DCP). Sensitivity analyses demonstrated that cost-effectiveness was stable, but was most sensitive to the discount rate used for costs and benefits. Considering the commonly accepted threshold of euro50,000 per QALY, these analyses support the fact that adding a quadrivalent HPV vaccine to the current screening program in France is a cost-effective strategy for reducing the burden of cervical cancer, precancerous lesions, and genital warts caused by HPV types 6, 11, 16, and 18.

Visible-light-driven photocatalytic activation of peroxymonosulfate by Cu2(OH)PO4 for effective decontamination.

PubMed

Liu, Guoshuai; Zhou, Yanan; Teng, Jie; Zhang, Jinna; You, Shijie

2018-06-01

The advanced oxidation process (AOP) based on SO 4 - radicals draws an increasing interest in water and wastewater treatment. Producing SO 4 - radicals from the activation of peroxymonosulfate (PMS) by transition metal ions or oxides may be problematic due to high operational cost and potential secondary pollution caused by metal leaching. To address this challenge, the present study reports the efficient production of SO 4 - radicals through visible-light-driven photocatalytic activation (VL-PCA) of PMS by using Cu 2 (OH)PO 4 single crystal for enhanced degradation of a typical recalcitrant organic pollutant, i.e., 2,4-dichlorophenol (2,4-DCP). It took only 7 min to achieve almost 100% removal of 2,4-DCP in the Cu 2 (OH)PO 4 /PMS system under visible-light irradiation and pH-neutral condition. The 2,4-DCP degradation was positively correlated to the amount of Cu 2 (OH)PO 4 and PMS. Both OH and SO 4 - radicals were responsible for enhanced degradation performance, indicated by radical scavenger experiments and electron spin resonance (ESR) measurements. The Cu 2 (OH)PO 4 single crystal exhibited good cyclic stability and negligible metal leaching. According to density functional theory (DFT) calculations, the visible-light-driven transformation of two copper states between trigonal bipyramidal sites and octahedral sites in the crystal structure of Cu 2 (OH)PO 4 facilitates the generation of OH and SO 4 - radicals from the activation of PMS and cleavage of O-O bonds. This study provides the proof-in-concept demonstration of activation of PMS driven by visible light, making the SO 4 - radicals-based AOPs much easier, more economical and more sustainable in engineering applications for water and wastewater treatment. Copyright © 2018 Elsevier Ltd. All rights reserved.

Late deterioration of left ventricular function after right ventricular pacemaker implantation.

PubMed

Bellmann, Barbara; Muntean, Bogdan G; Lin, Tina; Gemein, Christopher; Schmitz, Kathrin; Schauerte, Patrick

2016-09-01

Right ventricular (RV) pacing induces a left bundle branch block pattern on ECG and may promote heart failure. Patients with dual chamber pacemakers (DCPs) who present with progressive reduction in left ventricular ejection fraction (LVEF) secondary to RV pacing are candidates for cardiac resynchronization therapy (CRT). This study analyzes whether upgrading DCP to CRT with the additional implantation of a left ventricular (LV) lead improves LV function in patients with reduced LVEF following DCP implantation. Twenty-two patients (13 males) implanted with DCPs and a high RV pacing percentage (>90%) were evaluated in term of new-onset heart failure symptoms. The patients were enrolled in this retrospective single-center study after obvious causes for a reduced LVEF were excluded with echocardiography and coronary angiography. In all patients, DCPs were then upgraded to biventricular devices. LVEF was analyzed with a two-sided t-test. QRS duration and brain natriuretic peptide (BNP) levels were analyzed with the unpaired t-test. LVEF declined after DCP implantation from 54±10% to 31±7%, and the mean QRS duration was 161±20 ms during RV pacing. NT-pro BNP levels were elevated (3365±11436 pmol/L). After upgrading to a biventricular device, a biventricular pacing percentage of 98.1±2% was achieved. QRS duration decreased to 108±16 ms and 106±20 ms after 1 and 6 months, respectively. There was a significant increase in LVEF to 38±8% and 41±11% and a decrease in NT-pro BNP levels to 3088±2326 pmol/L and 1860±1838 pmol/L at 1 and 6 months, respectively. Upgrading to CRT may be beneficial in patients with DCPs and heart failure induced by a high RV pacing percentage.

The DcpS inhibitor RG3039 improves survival, function and motor unit pathologies in two SMA mouse models

PubMed Central

Gogliotti, Rocky G.; Cardona, Herminio; Singh, Jasbir; Bail, Sophie; Emery, Carina; Kuntz, Nancy; Jorgensen, Michael; Durens, Madel; Xia, Bing; Barlow, Courtenay; Heier, Christopher R.; Plasterer, Heather L.; Jacques, Vincent; Kiledjian, Megerditch; Jarecki, Jill; Rusche, James; DiDonato, Christine J.

2013-01-01

Spinal muscular atrophy (SMA) is caused by insufficient levels of the survival motor neuron (SMN) protein due to the functional loss of the SMN1 gene and the inability of its paralog, SMN2, to fully compensate due to reduced exon 7 splicing efficiency. Since SMA patients have at least one copy of SMN2, drug discovery campaigns have sought to identify SMN2 inducers. C5-substituted quinazolines increase SMN2 promoter activity in cell-based assays and a derivative, RG3039, has progressed to clinical testing. It is orally bioavailable, brain-penetrant and has been shown to be an inhibitor of the mRNA decapping enzyme, DcpS. Our pharmacological characterization of RG3039, reported here, demonstrates that RG3039 can extend survival and improve function in two SMA mouse models of varying disease severity (Taiwanese 5058 Hemi and 2B/− SMA mice), and positively impacts neuromuscular pathologies. In 2B/− SMA mice, RG3039 provided a >600% survival benefit (median 18 days to >112 days) when dosing began at P4, highlighting the importance of early intervention. We determined the minimum effective dose and the associated pharmacokinetic (PK) and exposure relationship of RG3039 and DcpS inhibition ex vivo. These data support the long PK half-life with extended pharmacodynamic outcome of RG3039 in 2B/− SMA mice. In motor neurons, RG3039 significantly increased both the average number of cells with gems and average number of gems per cell, which is used as an indirect measure of SMN levels. These studies contribute to dose selection and exposure estimates for the first studies with RG3039 in human subjects. PMID:23736298

Determination of 2,4-dichlorophenoxyacetic acid and its major transformation product in soil samples by liquid chromatographic analysis.

PubMed

de Amarante, O P; Brito, N M; Dos Santos, T C R; Nunes, G S; Ribeiro, M L

2003-05-28

The 2,4-dichlorophenoxyacetic acid (2,4-D) is one of the most applied herbicides around the world to control broad leave herbs in many crops. In this study, a method was developed for simultaneous extraction and determination of 2,4-D and its major transformation product, i.e., the 2,4-dichlorophenol (2,4-DCP), in soil samples. The herbicide and its degradation product were extracted twice from soil samples, after acidification, by dichloromethane on ultrasound system for 1 h. Both extracts were combined and filtrated in qualitative filter paper and Celite((R)). The total extract was concentrated in rotatory evaporator, dried under N(2) and finally dissolved in 1 ml of methanol. High Performance Liquid Chromatography with UV detection at 230 nm was used for analysis. Recoveries were obtained from soil samples fortified at 0.1, 1.0, 2.0, 3.0 and 4.0 mgkg(-1) levels and the results varied from 85 to 111% (for 2,4-D) and from 95 to 98% (for 2,4-DCP). For both compounds, the limits of quantification were 0.1 mgkg(-1), which were the loss level at which the accuracy and the precision were studied. Nevertheless, the limits of detection, calculated by considering the blank standard deviation and the minimum concentration level, were 0.03 and 0.02 mgkg(-1), for 2,4-D and 2,4-DCP, respectively. This proposed method was applied to soil samples of eucalyptus crops, which was previously treated with the herbicide. Despite that, neither 2,4-D nor its degradation product were detected 30 days after the herbicide application.

Synthesis, properties, and biological activity of boranophosphate analogs of the mRNA cap: versatile tools for manipulation of therapeutically relevant cap-dependent processes

PubMed Central

Kowalska, Joanna; Wypijewska del Nogal, Anna; Darzynkiewicz, Zbigniew M.; Buck, Janina; Nicola, Corina; Kuhn, Andreas N.; Lukaszewicz, Maciej; Zuberek, Joanna; Strenkowska, Malwina; Ziemniak, Marcin; Maciejczyk, Maciej; Bojarska, Elzbieta; Rhoads, Robert E.; Darzynkiewicz, Edward; Sahin, Ugur; Jemielity, Jacek

2014-01-01

Modified mRNA cap analogs aid in the study of mRNA-related processes and may enable creation of novel therapeutic interventions. We report the synthesis and properties of 11 dinucleotide cap analogs bearing a single boranophosphate modification at either the α-, β- or γ-position of the 5′,5′-triphosphate chain. The compounds can potentially serve either as inhibitors of translation in cancer cells or reagents for increasing expression of therapeutic proteins in vivo from exogenous mRNAs. The BH3-analogs were tested as substrates and binding partners for two major cytoplasmic cap-binding proteins, DcpS, a decapping pyrophosphatase, and eIF4E, a translation initiation factor. The susceptibility to DcpS was different between BH3-analogs and the corresponding analogs containing S instead of BH3 (S-analogs). Depending on its placement, the boranophosphate group weakened the interaction with DcpS but stabilized the interaction with eIF4E. The first of the properties makes the BH3-analogs more stable and the second, more potent as inhibitors of protein biosynthesis. Protein expression in dendritic cells was 2.2- and 1.7-fold higher for mRNAs capped with m27,2′-OGppBH3pG D1 and m27,2′-OGppBH3pG D2, respectively, than for in vitro transcribed mRNA capped with m27,3′-OGpppG. Higher expression of cancer antigens would make mRNAs containing m27,2′-OGppBH3pG D1 and m27,2′-OGppBH3pG D2 favorable for anticancer immunization. PMID:25150148

Metabolism-Induced CaCO 3 Biomineralization During Reactive Transport in a Micromodel: Implications for Porosity Alteration

DOE PAGES

Singh, Rajveer; Yoon, Hongkyu; Sanford, Robert A.; ...

2015-09-08

We investigated the ability of Pseudomonas stutzeri strain DCP-Ps1 to drive CaCO 3 biomineralization in a microfluidic flowcell (i.e., micromodel) that simulates subsurface porous media. Results indicate that CaCO 3 precipitation occurs during NO 3 – reduction with a maximum saturation index (SI calcite) of ~1.56, but not when NO 3 – was removed, inactive biomass remained, and pH and alkalinity were adjusted to SI calcite ~ 1.56. CaCO 3 precipitation was promoted by metabolically active cultures of strain DCP-Ps1, which at similar values of SIcalcite, have a more negative surface charge than inactive strain DCP-Ps1. A two-stage NO 3more » – reduction (NO 3 – → NO 2 – → N 2) pore-scale reactive transport model was used to evaluate denitrification kinetics, which was observed in the micromodel as upper (NO 3 – reduction) and lower (NO 2 – reduction) horizontal zones of biomass growth with CaCO 3 precipitation exclusively in the lower zone. Our model results are consistent with two biomass growth regions and indicate that precipitation occurred in the lower zone because the largest increase in pH and alkalinity is associated with NO 2 – reduction. CaCO 3 precipitates typically occupied the entire vertical depth of pores and impacted porosity, permeability, and flow. This study provides a framework for incorporating microbial activity in biogeochemistry models, which often base biomineralization only on SI (caused by biotic or abiotic reactions) and, thereby, underpredict the extent of this complex process. Furthermore, these results have wide-ranging implications for understanding reactive transport in relevance to groundwater remediation, CO 2 sequestration, and enhanced oil recovery.« less

Preparation and Physicochemical Evaluation of Controlled-release Carbon Source Tablet for Groundwater in situ Denitrification

NASA Astrophysics Data System (ADS)

Kim, Y.; Kang, J. H.; Yeum, Y.; Han, K. J.; Kim, D. W.; Park, C. W.

2015-12-01

Nitric nitrogen could be the one of typical pollution source such asNO3-through domestic sewage, livestock and agricultural wastewater. Resident microflorain aquifer has known to remove the nitric nitrogen spontaneously following the denitration process with the carbon source (CS) as reactant. However, it could be reacted very slowly with the rack of CS and there have been some studies for controlled addition of CS (Ref #1-3). The aim of this study was to prepare the controlled-release carbon source (CR-CS) tablet and to evaluate in vitro release profile for groundwater in situ denitrification. CR-CS tablet could be manufactured by direct compression method using hydraulic laboratory press (Caver® 3850) with 8 mm rounded concave punch/ die.Seven kinds of CR-CS tablet were prepared to determine the nature of the additives and their ratio such as sodium silicate, dicalcium phosphate, bentonite and sand#8.For each formulation, the LOD% and flowability of pre-mixed powders and the hardness of compressed tablets were analyzed. In vitro release study was performed to confirm the dissolution profiles following the USP Apparatus 2 method with Distilled water of 900mL, 20 °C. As a result, for each lubricated powders, they were compared in terms of ability to give an acceptable dry pre-mixed powder for tableting process. The hardness of the compressed tablets is acceptable whatever the formulations tested. After in vitro release study, it could confirm that the different formulations of CR-CS tablet have a various release rate patterns, which could release 100% at 3 hrs, 6 hrs and 12 hrs. The in vitro dissolution profiles were in good correlation of Higuchi release kinetic model. In conclusion, this study could be used as a background for development and evaluation of the controlled-release carbon source (CR-CS) tablet for the purification of groundwater following the in situ denitrification.

The fate of calcium carbonate nanoparticles administered by oral route: absorption and their interaction with biological matrices

PubMed Central

Lee, Jeong-A; Kim, Mi-Kyung; Kim, Hyoung-Mi; Lee, Jong Kwon; Jeong, Jayoung; Kim, Young-Rok; Oh, Jae-Min; Choi, Soo-Jin

2015-01-01

Background Orally administered particles rapidly interact with biological fluids containing proteins, enzymes, electrolytes, and other biomolecules to eventually form particles covered by a corona, and this corona potentially affects particle uptake, fate, absorption, distribution, and elimination in vivo. This study explored relationships between the biological interactions of calcium carbonate particles and their biokinetics. Methods We examined the effects of food grade calcium carbonates of different particle size (nano [N-Cal] and bulk [B-Cal]: specific surface areas of 15.8 and 0.83 m2/g, respectively) on biological interactions in in vitro simulated physiological fluids, ex vivo biofluids, and in vivo in gastrointestinal fluid. Moreover, absorption and tissue distribution of calcium carbonates were evaluated following a single dose oral administration to rats. Results N-Cal interacted more with biomatrices than bulk materials in vitro and ex vivo, as evidenced by high fluorescence quenching ratios, but it did not interact more actively with biomatrices in vivo. Analysis of coronas revealed that immunoglobulin, apolipoprotein, thrombin, and fibrinogen, were the major corona proteins, regardless of particle size. A biokinetic study revealed that orally delivered N-Cal was more rapidly absorbed into the blood stream than B-Cal, but no significant differences were observed between the two in terms of absorption efficiencies or tissue distributions. Both calcium carbonates were primarily present as particulate forms in gastrointestinal fluids but enter the circulatory system in dissolved Ca2+, although both types showed partial phase transformation to dicalcium phosphate dihydrate. Relatively low dissolution (about 4%), no remarkable protein–particle interaction, and the major particulate fate of calcium carbonate in vivo gastrointestinal fluids can explain its low oral absorption (about 4%) regardless of particle size. Conclusion We conclude that calcium carbonate nanoparticles can act more actively with biological matrices in vitro and ex vivo, but that in vivo, their biological interactions and biokinetics are not affected by particle size. PMID:25848250

The fate of calcium carbonate nanoparticles administered by oral route: absorption and their interaction with biological matrices.

PubMed

Lee, Jeong-A; Kim, Mi-Kyung; Kim, Hyoung-Mi; Lee, Jong Kwon; Jeong, Jayoung; Kim, Young-Rok; Oh, Jae-Min; Choi, Soo-Jin

2015-01-01

Orally administered particles rapidly interact with biological fluids containing proteins, enzymes, electrolytes, and other biomolecules to eventually form particles covered by a corona, and this corona potentially affects particle uptake, fate, absorption, distribution, and elimination in vivo. This study explored relationships between the biological interactions of calcium carbonate particles and their biokinetics. We examined the effects of food grade calcium carbonates of different particle size (nano [N-Cal] and bulk [B-Cal]: specific surface areas of 15.8 and 0.83 m(2)/g, respectively) on biological interactions in in vitro simulated physiological fluids, ex vivo biofluids, and in vivo in gastrointestinal fluid. Moreover, absorption and tissue distribution of calcium carbonates were evaluated following a single dose oral administration to rats. N-Cal interacted more with biomatrices than bulk materials in vitro and ex vivo, as evidenced by high fluorescence quenching ratios, but it did not interact more actively with biomatrices in vivo. Analysis of coronas revealed that immunoglobulin, apolipoprotein, thrombin, and fibrinogen, were the major corona proteins, regardless of particle size. A biokinetic study revealed that orally delivered N-Cal was more rapidly absorbed into the blood stream than B-Cal, but no significant differences were observed between the two in terms of absorption efficiencies or tissue distributions. Both calcium carbonates were primarily present as particulate forms in gastrointestinal fluids but enter the circulatory system in dissolved Ca(2+), although both types showed partial phase transformation to dicalcium phosphate dihydrate. Relatively low dissolution (about 4%), no remarkable protein-particle interaction, and the major particulate fate of calcium carbonate in vivo gastrointestinal fluids can explain its low oral absorption (about 4%) regardless of particle size. We conclude that calcium carbonate nanoparticles can act more actively with biological matrices in vitro and ex vivo, but that in vivo, their biological interactions and biokinetics are not affected by particle size.

A comparative study of roll compaction of free-flowing and cohesive pharmaceutical powders.

PubMed

Yu, Shen; Gururajan, Bindhu; Reynolds, Gavin; Roberts, Ron; Adams, Michael J; Wu, Chuan-Yu

2012-05-30

Roll compaction is widely adopted as a dry granulation method in the pharmaceutical industry. The roll compaction behaviour of feed powders is primarily governed by two parameters: the maximum pressure and the nip angle. Although the maximum pressure can be measured directly using pressure sensors fitted in the rolls, it is not a trivial task to determine the nip angle, which is a measure of the size of the compaction zone and hence the degree of compression. Thus a robust approach based upon the calculation of the pressure gradient, which can be obtained directly from experiments using an instrumented roll compactor, was developed. It has been shown that the resulting nip angles are comparable to those obtained using the methods reported in literature. Nevertheless, the proposed approach has distinctive advantages including (1) it is based on the intrinsic features of slip and no-slip interactions between the powder and roll surface and (2) it is not necessary to carry out wall friction measurements that involve plates that may not be representative of the roll compactor in terms of the surface topography and surface energy. The method was evaluated by investigating the effect of roll speed for two pharmaceutical excipients with distinctive material properties: microcrystalline cellulose (MCC) and di-calcium phosphate dihydrate (DCPD). It was found that the maximum pressure and nip angle for DCPD, which is a cohesive powder, decrease sharply with increasing roll speed whereas they are essentially independent of roll speed for MCC, which is an easy flowing powder. The roll compaction behaviour of MCC-DCPD mixtures with various compositions was also investigated in order to evaluate the effect of flowability. It was found that the nip angle and maximum pressure generally increased with improved flowability of the feed powders. Copyright © 2012 Elsevier B.V. All rights reserved.

Improved Bone Micro Architecture Healing Time after Implant Surgery in an Ovariectomized Rat.

PubMed

Takahashi, Takahiro; Watanabe, Takehiro; Nakada, Hiroshi; Sato, Hiroki; Tanimoto, Yasuhiro; Sakae, Toshiro; Kimoto, Suguru; Mijares, Dindo; Zhang, Yu; Kawai, Yasuhiko

2016-01-01

The present animal study investigated whether oral intake of synthetic bone mineral (SBM) improves peri-implant bone formation and bone micro architecture (BMA). SBM was used as an intervention experimental diet and AIN-93M was used as a control. The SBM was prepared by mixing dicalcium phosphate dihydrate (CaHPO 4 ·2H 2 O) and magnesium and zinc chlorides (MgCl 2 and ZnCl 2 , respectively), and hydrolyzed in double-distilled water containing dissolved potassium carbonate and sodium fluoride. All rats were randomly allocated into one of two groups: a control group was fed without SBM (n = 18) or an experimental group was fed with SBM (n = 18), at seven weeks old. At 9 weeks old, all rats underwent implant surgery on their femurs under general anesthesia. The implant was inserted into the insertion socket prepared at rats' femur to a depth of 2.5 mm by using a drill at 500 rpm. Nine rats in each group were randomly selected and euthanized at 2 weeks after implantation. The remaining nine rats in each group continued their diets, and were euthanized in the same manner at 4 weeks after implantation. The femur, including the implant, was removed from the body and implant was pulled out by an Instron universal testing machine. After the implant removal, BMA was evaluated by bone surface ratio (BS/BV), bone volume fraction (BV/TV), trabecular thickness (TbTh), trabecular number (TbN), trabecular star volume (Vtr), and micro-CT images. BS/BV, BV/TV, TbTh and Vtr were significantly greater in the rats were fed with SBM than those were fed without SBM at 2 and 4 weeks after implantation (P < 0.05). The present results revealed that SBM improves the peri-implant formation and BMA, prominent with trabecular bone structure. The effect of SBM to improve secondary stability of the implant, and shortening the treatment period should be investigated in the future study.

What aspect of dietary modification in broilers controls litter water-soluble phosphorus: dietary phosphorus, phytase, or calcium?

PubMed

Leytem, A B; Plumstead, P W; Maguire, R O; Kwanyuen, P; Brake, J

2007-01-01

Environmental concerns about phosphorus (P) losses from animal agriculture have led to interest in dietary strategies to reduce the concentration and solubility of P in manures and litters. To address the effects of dietary available phosphorus (AvP), calcium (Ca), and phytase on P excretion in broilers, 18 dietary treatments were applied in a randomized complete block design to each of four replicate pens of 28 broilers from 18 to 42 d of age. Treatments consisted of three levels of AvP (3.5, 3.0, and 2.5 g kg(-1)) combined with three levels of Ca (8.0, 6.9, and 5.7 g kg(-1)) and two levels of phytase (0 and 600 phytase units [FTU]). Phytase was added at the expense of 1.0 g kg(-1) P from dicalcium phosphate. Fresh litter was collected from pens when the broilers were 41 d of age and analyzed for total P, soluble P, and phytate P as well as P composition by (31)P nuclear magnetic resonance (NMR) spectroscopy. Results indicated that the inclusion of phytase at the expense of inorganic P or reductions in AvP decreased litter total P by 28 to 43%. Litter water-soluble P (WSP) decreased by up to 73% with an increasing dietary Ca/AvP ratio, irrespective of phytase addition. The ratio of WSP/total P in litter decreased as the dietary Ca/AvP ratio increased and was greater in the phytase-amended diets. This study indicated that while feeding reduced AvP diets with phytase decreased litter total P, the ratio of Ca/AvP in the diet was primarily responsible for effects on WSP. This is important from an environmental perspective as the amount of WSP in litter could be related to potential for off-site P losses following land application of litter.

Identification of formulation and manufacturing variables that influence in vitro dissolution and in vivo bioavailability of propranolol hydrochloride tablets.

PubMed

Eddington, N D; Ashraf, M; Augsburger, L L; Leslie, J L; Fossler, M J; Lesko, L J; Shah, V P; Rekhi, G S

1998-11-01

The purpose of this study was to evaluate the effect of formulation and processing changes on the dissolution and bioavailability of propranolol hydrochloride tablets. Directly compressed blends of 6 kg (20,000 units) were prepared by mixing in a 16-qt V blender and tablets were compressed on an instrumented Manesty D3B tablet press. A half-factorial (2(5-1), Resolution V) design was used to study the following variables: filler ratio (lactose/dicalcium phosphate), sodium starch glycolate level, magnesium stearate level, lubricant blend time, and compression force. The levels and ranges of the excipients and processing changes studied represented level 2 or greater changes as indicated by the Scale-up and Post Approval Changes (SUPAC-IR) Guidance. Changes in filler ratio, disintegrant level, and compression force were significant in affecting percent drug released (Q) in 5 min (Q5) and Q10. However, changes in magnesium stearate level and lubricant blend time did not influence Q5 and Q10. Hardness was found to be affected by changes in all of the variables studied. Some interaction effects between the variables studied were also found to be significant. To examine the impact of formulation and processing variables on in vivo absorption, three batches were selected for a bioavailability study based on their dissolution profiles. Thirteen subjects received four propranolol treatments (slow-, medium-, and fast-dissolving formulations and Inderal 80 mg) separated by 1 week washout according to a randomized crossover design. The formulations were found to be bioequivalent with respect to the log Cmax and log AUC0-infinity. The results of this study suggest that (i) bioavailability/bioequivalency studies may not be necessary for propranolol and perhaps other class 1 drugs after level 2 type changes, and (ii) in vitro dissolution tests may be used to show bioequivalence of propranolol formulations with processing or formulation changes within the specified level 2 ranges examined.

Risk practices for animal and human anthrax in Bangladesh: an exploratory study

PubMed Central

Islam, Md. Saiful; Hossain, M. Jahangir; Mikolon, Andrea; Parveen, Shahana; Khan, M. Salah Uddin; Haider, Najmul; Chakraborty, Apurba; Titu, Abu Mohammad Naser; Rahman, M. Waliur; Sazzad, Hossain M. S.; Rahman, Mahmudur; Gurley, Emily S.; Luby, Stephen P.

2013-01-01

Introduction From August 2009 to October 2010, International Centre for Diarrheal Disease Research, Bangladesh and the Institute of Epidemiology, Disease Control and Research together investigated 14 outbreaks of anthrax which included 140 animal and 273 human cases in 14 anthrax-affected villages. Our investigation objectives were to explore the context in which these outbreaks occurred, including livestock rearing practices, human handling of sick and dead animals, and the anthrax vaccination program. Methods Field anthropologists used qualitative data-collection tools, including 15 hours of unstructured observations, 11 key informant interviews, 32 open-ended interviews, and 6 group discussions in 5 anthrax-affected villages. Results Each cattle owner in the affected communities raised a median of six ruminants on their household premises. The ruminants were often grazed in pastures and fed supplementary rice straw, green grass, water hyacinth, rice husk, wheat bran, and oil cake; lactating cows were given dicalcium phosphate. Cattle represented a major financial investment. Since Islamic law forbids eating animals that die from natural causes, when anthrax-infected cattle were moribund, farmers often slaughtered them on the household premises while they were still alive so that the meat could be eaten. Farmers ate the meat and sold it to neighbors. Skinners removed and sold the hides from discarded carcasses. Farmers discarded the carcasses and slaughtering waste into ditches, bodies of water, or open fields. Cattle in the affected communities did not receive routine anthrax vaccine due to low production, poor distribution, and limited staffing for vaccination. Conclusion Slaughtering anthrax-infected animals and disposing of butchering waste and carcasses in environments where ruminants live and graze, combined with limited vaccination, provided a context that permitted repeated anthrax outbreaks in animals and humans. Because of strong financial incentives, slaughtering moribund animals and discarding carcasses and waste products will likely continue. Long-term vaccination coverage for at-risk animal populations may reduce anthrax infection. PMID:24298326

AM2 Brickwork Pattern Evaluation with Refurbished Matting

DTIC Science & Technology

2015-08-01

13 2.3.1 Subgrade construction and posttest forensics...19 Figure 18. Posttest DCP data for the F...51 Figure 51. V2W, V2E (a) pretest and (b) posttest and V1-C (c) pretest and (d) posttest . ................... 51 Figure 52

WHEN IS THERE ENOUGH EVIDENCE TO PERFORM A NONLINEAR CANCER ASSESSMENT?

EPA Science Inventory

Under U.S. EPA's Proposed Guidelines for Carcinogen Risk Assessment (FR 61:179670-18011, 199996), departure from the default linear cancer assessment may be made for carcinogens for which there is sufficient evidence of a nonlinear mechanism. DCP, and agricultural fumigant that ...

Research on the electro-optical assistant landing system based on the dual camera photogrammetry algorithm

NASA Astrophysics Data System (ADS)

Mi, Yuhe; Huang, Yifan; Li, Lin

2015-08-01

Based on the location technique of beacon photogrammetry, Dual Camera Photogrammetry (DCP) algorithm was used to assist helicopters landing on the ship. In this paper, ZEMAX was used to simulate the two Charge Coupled Device (CCD) cameras imaging four beacons on both sides of the helicopter and output the image to MATLAB. Target coordinate systems, image pixel coordinate systems, world coordinate systems and camera coordinate systems were established respectively. According to the ideal pin-hole imaging model, the rotation matrix and translation vector of the target coordinate systems and the camera coordinate systems could be obtained by using MATLAB to process the image information and calculate the linear equations. On the basis mentioned above, ambient temperature and the positions of the beacons and cameras were changed in ZEMAX to test the accuracy of the DCP algorithm in complex sea status. The numerical simulation shows that in complex sea status, the position measurement accuracy can meet the requirements of the project.

Determination of epichlorohydrin and 1,3-dichloro-2-propanol in synthesis of cationic etherifying reagent by headspace gas chromatography.

PubMed

Tao, Zheng-Yi; Chai, Xin-Sheng; Wu, Shu-Bin

2011-09-16

This study demonstrates a headspace gas chromatographic(HS-GC) technique for the determination of residual epichlorohydrin (ECH) and generated 1,3-dichloro-2-propanol (DCP) in synthesis process of 3-chloro-2-hydroxypropyltrimethylammonium chloride (CHTAC). By a weight-based sampling method, coupled with significant dilution in 15.8% sodium sulfate and 0.1% silver nitrate mixed solution rapidly, the sample for HS-GC analysis is prepared. Based on the reaction stoichiometry, the conversion (R) of CHTAC during the synthesis process can be calculated from sampling weight and GC peak area. The results showed that the method has a good measurement precision (RSD<2.5%) and accuracy (recovery=101-104%) for the quantification of both ECH and DCP in the process samples. The present method is simple and accurate, which can be used for the efficient determination of the CHTAC conversion in the synthesis research. Copyright © 2011 Elsevier B.V. All rights reserved.

Determination of chlorinated volatile organic compounds in polyamine epichlorohydrin solution by headspace gas chromatography.

PubMed

Yan, Ning; Wan, Xiao-Fang; Chai, Xin-Sheng; Chen, Run-Quan

2017-05-05

This study demonstrated a headspace gas chromatographic (HS-GC) method for the determination of residual epichlorohydrin (ECH) and the by-product 1,3-dichloro-2-propanol (DCP) in polyamine epichlorohydrin (PAE) solution. It was based on the vapor-liquid phase equilibrium of these analytes at 60°C for 30min in a closed headspace sample vial before GC measurement. It was found that matrix of the PAE solution had the effect on the headspace equilibrium of these species and therefore a standard addition must be applied in the method validation. The results showed that the present method has a good measurement precision (RSD <2.90%) and accuracy (recoveries from 93.6 to 105%), and the limit of quantitation (LOQ) is 3.75mg/L for ECH and 0.8g/L for DCP. The present method is suitable to be used for analyzing the chlorinated volatile organic compounds in the commercial PAE resin solutions. Copyright © 2017 Elsevier B.V. All rights reserved.

[Review of assessment methods used to evaluate feeding for children with pervasive developmental disorder].

PubMed

Nadon, G; Ehrmann Feldman, D; Gisel, E

2008-08-01

Current evaluations used by occupational therapists to assess and treat feeding problems derive mainly from the domain of dysphagia. The purpose of this article is to familiarize the reader with tools used, in research, for children with pervasive developmental disorders (PDD) and to determine if any of these meet the needs of occupational therapists. The following data bases were searched: Medline, CINAHL, HAPI and PsyINFO, using the terms pervasive developmental disorder, autism, Asperger syndrome, pervasive developmental disorder not otherwise specified, eating behavior, eating disorder, food preference, food selectivity, feeding disorders, picky eater and child. All articles published between 1980 and 2006 (n=27) were reviewed. A total of 20 studies met our selection criteria. Assessment methods are compared using the Disability Creation Model (DCP). The DCP is the Quebec alternative to the International Classification of Functioning, Disability and Health (ICF). None of the evaluation tools reviewed met all factors that may influence eating in children with PDD. Implications for research and practice in occupational therapy are discussed.

Retransmission of water resources data using the ERTS-1 data collection system

NASA Technical Reports Server (NTRS)

Halliday, R. A.; Reid, I. A.; Chapman, E. F.

1974-01-01

The Water Survey of Canada operates a network of approximately 2400 gauging stations at which water level data are collected. Nine DCPs were installed in isolated areas of northern and western Canada. It was felt that DCPs in these locations would be exposed to climatic conditions severe enough to provide a check on system reliability. Water level data are transmitted from all sites and, also, some of the DCPs are used to transmit ice break-up, water velocity, precipitation, air temperature, water stage recorder clock operation or DCP battery voltage. Consideration is being given to transmitting other parameters that would be of value in flood or flow forecasting. Results of the project have been excellent. There has been no data loss that can be attributed to failure of a DCP although data were lost because of sensor malfunctions. The quality of data collected compares favourably with that of the hard record obtained at the remote sites. Costs of using the ERTS Data Collection System are reasonable.

New Cancer Prevention and Control Central Institutional Review Board Established | Division of Cancer Prevention

Cancer.gov

The NCI Central Institutional Review Board (CIRB) Initiative announced the establishment of the Cancer Prevention and Control (CPC) CIRB January 14, extending the benefits of centralized review to investigators participating in clinical trials sponsored by the Division of Cancer Prevention (DCP). |

ANAEROBIC BIODEGRADATION OF 2,4-DICHLOROPHENOL IN FRESHWATER LAKE SEDIMENTS AT DIFFERENT TEMPERATURES

EPA Science Inventory

Anaerobic degradation of 2,4-dichlorophenol (2,4-DCP) between 5 and 72C was investigated. naerobic sediment slurries prepared from local freshwater sediments were partitioned into anaerobic tubes or serum vials, which then were incubated separately at the various temperatures. ed...

7 CFR 1412.47 - Planting flexibility.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Administrator, is prohibited on base acreage of a farm enrolled in a DCP or ACRE program contract. Harvesting... payments will not be reduced for the planting or harvesting of the fruit, vegetable, or wild rice; (2) The... root, lychee (litchi), mandarins, mangos, marionberries, mar bub, melongene, mesple, mizuna, mongosteen...

7 CFR 1412.47 - Planting flexibility.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Administrator, is prohibited on base acreage of a farm enrolled in a DCP or ACRE program contract. Harvesting... payments will not be reduced for the planting or harvesting of the fruit, vegetable, or wild rice; (2) The... root, lychee (litchi), mandarins, mangos, marionberries, mar bub, melongene, mesple, mizuna, mongosteen...

7 CFR 1412.47 - Planting flexibility.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Administrator, is prohibited on base acreage of a farm enrolled in a DCP or ACRE program contract. Harvesting... payments will not be reduced for the planting or harvesting of the fruit, vegetable, or wild rice; (2) The... root, lychee (litchi), mandarins, mangos, marionberries, mar bub, melongene, mesple, mizuna, mongosteen...

7 CFR 1412.47 - Planting flexibility.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Administrator, is prohibited on base acreage of a farm enrolled in a DCP or ACRE program contract. Harvesting... payments will not be reduced for the planting or harvesting of the fruit, vegetable, or wild rice; (2) The... root, lychee (litchi), mandarins, mangos, marionberries, mar bub, melongene, mesple, mizuna, mongosteen...

Trial NCT00690924 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT02581137 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

CASE STUDY DEMONSTRATING THE STRESSOR IDENTIFICATION PROCESS THAT IDENTIFIES CAUSES OF BIOLOGICAL IMPAIRMENT IN THE NATION'S WATER BODIES

EPA Science Inventory

The stressor identification program developed guidance for identifying the causes of biological impairments in the nation's waters:

U.S. EPA. 2000. Stressor identification guidance document. EPA/822/B-00/025. U.S. Environmental Protection Agency, Washington, DC.

The ...

Trial NCT01382082 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Leslie Ford, MD | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Home | Division of Cancer Prevention

Cancer.gov

Our Research The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into cancer. |

Trial NCT01391689 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Administrative Resource Center | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT02052908 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT02116530 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT01503632 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT01793233 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT01406769 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

2016 News Articles | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

2017 News Articles | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

2015 News Articles | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

2014 News Articles | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

2013 News Articles | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

About the Cancer Biomarkers Research Group | Division of Cancer Prevention

Cancer.gov

The Cancer Biomarkers Research Group promotes research to identify, develop, and validate biological markers for early cancer detection and cancer risk assessment. Activities include development and validation of promising cancer biomarkers, collaborative databases and informatics systems, and new technologies or the refinement of existing technologies. NCI DCP News Note

Trial NCT01728571 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

2018 News Articles | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Howard Parnes, MD | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

major_program | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT02782949 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT02095145 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT02326805 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT01594502 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT01238172 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT02933489 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT00153816 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT00983580 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT02743364 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT01606124 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT00392561 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT01968798 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Early Detection Staff | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT00641147 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Cancer Biomarkers Staff | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Staff Directory | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Biometry Staff | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Nutritional Science Staff | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT00917735 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT02063698 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT01950403 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

clinical_trial | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT01781468 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT02134925 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT02568566 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT02382419 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT02273362 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT02314156 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT02155777 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT02636582 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT02780401 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT01550783 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT01935960 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT02028221 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Meetings and Events | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

The use of LANDSAT DCS and imagery in reservoir management and operation. [New England

NASA Technical Reports Server (NTRS)

Cooper, S. (Principal Investigator)

1976-01-01

The author has identified the following significant results. A tally of DCP messages received shows that the number of messages increased markedly at the beginning of the year as the downlink went into operation, but dropped off in May due to computer troubles.

Trial NCT02521285 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT01169259 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

| Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Clinical Trials | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Active Grants | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT01346267 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT01141231 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT02112188 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Eva Szabo, MD | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT02002533 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT02772003 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT02598557 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT02965703 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT02917629 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT01849250 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Sarah Temkin, MD | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Shizuko Sei, MD | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

news_and_event | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

research_group | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

newsletter | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Trial NCT03063619 | Division of Cancer Prevention

Cancer.gov

The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

Assessment of in situ test technology for construction control of base courses and embankments.

DOT National Transportation Integrated Search

2008-04-01

The main objective of this research is to assess the use of three nondestructive testing devices, the GeoGauge, the LFWD, and the DCP, in order to evaluate the in situ elastic modulus of highway materials for application in the quality assurance/qual...

7 CFR 1412.64 - Inaccurate representation, misrepresentation, and scheme or device.

Code of Federal Regulations, 2011 CFR

2011-01-01

... scheme or device. 1412.64 Section 1412.64 Agriculture Regulations of the Department of Agriculture..., misrepresentation, and scheme or device. (a) Producers must report and certify program matters accurately. Errors in... a misrepresentation or scheme or device, such person will be ineligible to receive DCP or ACRE...

7 CFR 1412.64 - Inaccurate representation, misrepresentation, and scheme or device.

Code of Federal Regulations, 2014 CFR

2014-01-01

... scheme or device. 1412.64 Section 1412.64 Agriculture Regulations of the Department of Agriculture..., misrepresentation, and scheme or device. (a) Producers must report and certify program matters accurately. Errors in... a misrepresentation or scheme or device, such person will be ineligible to receive DCP or ACRE...

7 CFR 1412.64 - Inaccurate representation, misrepresentation, and scheme or device.

Code of Federal Regulations, 2012 CFR

2012-01-01

... scheme or device. 1412.64 Section 1412.64 Agriculture Regulations of the Department of Agriculture..., misrepresentation, and scheme or device. (a) Producers must report and certify program matters accurately. Errors in... a misrepresentation or scheme or device, such person will be ineligible to receive DCP or ACRE...

7 CFR 1412.64 - Inaccurate representation, misrepresentation, and scheme or device.

Code of Federal Regulations, 2013 CFR

2013-01-01

... scheme or device. 1412.64 Section 1412.64 Agriculture Regulations of the Department of Agriculture..., misrepresentation, and scheme or device. (a) Producers must report and certify program matters accurately. Errors in... a misrepresentation or scheme or device, such person will be ineligible to receive DCP or ACRE...