Silencing and heterologous expression of ppo-2 indicate a specific function of a single polyphenol oxidase isoform in resistance of dandelion (Taraxacum officinale) against Pseudomonas syringae pv. tomato.

PubMed

Richter, Carolin; Dirks, Mareike E; Gronover, Christian Schulze; Prüfer, Dirk; Moerschbacher, Bruno M

2012-02-01

Dandelion (Taraxacum officinale) possesses an unusually high degree of disease resistance. As this plant exhibits high polyphenol oxidase (PPO) activity and PPO have been implicated in resistance against pests and pathogens, we analyzed the potential involvement of five PPO isoenzymes in the resistance of dandelion against Botrytis cinerea and Pseudomonas syringae pv. tomato. Only one PPO (ppo-2) was induced during infection, and ppo-2 promoter and β-glucuronidase marker gene fusions revealed strong induction of the gene surrounding lesions induced by B. cinerea. Specific RNAi silencing reduced ppo-2 expression only, and concomitantly increased plant susceptibility to P. syringae pv. tomato. At 4 days postinoculation, P. syringae pv. tomato populations were strongly increased in the ppo-2 RNAi lines compared with wild-type plants. When the dandelion ppo-2 gene was expressed in Arabidopsis thaliana, a plant having no PPO gene, active protein was formed and protein extracts of the transgenic plants exhibited substrate-dependent antimicrobial activity against P. syringae pv. tomato. These results clearly indicate a strong contribution of a specific, single PPO isoform to disease resistance. Therefore, we propose that specific PPO isoenzymes be included in a new family of pathogenesis-related (PR) proteins.

Genetic Mapping of a new family of Seed-Expressed Polyphenol Oxidase genes in Wheat (Triticum aestivum L.)

USDA-ARS?s Scientific Manuscript database

Polyphenol oxidase (PPO) enzymatic activity is a major cause in time-dependent discoloration in wheat dough products. The PPO-A1 and PPO-D1 genes have been shown to contribute to wheat kernel PPO activity. However it has been shown that wheat contains multiple PPO genes. Recently a novel PPO gene...

Cloning and Expression Analysis of Litchi (Litchi Chinensis Sonn.) Polyphenol Oxidase Gene and Relationship with Postharvest Pericarp Browning

PubMed Central

Wang, Jiabao; Liu, Baohua; Xiao, Qian; Li, Huanling; Sun, Jinhua

2014-01-01

Polyphenol oxidase (PPO) plays a key role in the postharvest pericarp browning of litchi fruit, but its underlying mechanism remains unclear. In this study, we cloned the litchi PPO gene (LcPPO, JF926153), and described its expression patterns. The LcPPO cDNA sequence was 2120 bps in length with an open reading frame (ORF) of 1800 bps. The ORF encoded a polypeptide with 599 amino acid residues, sharing high similarities with other plant PPO. The DNA sequence of the ORF contained a 215-bp intron. After carrying out quantitative RT-PCR, we proved that the LcPPO expression was tissue-specific, exhibiting the highest level in the flower and leaf. In the pericarp of newly-harvested litchi fruits, the LcPPO expression level was relatively high compared with developing fruits. Regardless of the litchi cultivar and treatment conditions, the LcPPO expression level and the PPO activity in pericarp of postharvest fruits exhibited the similar variations. When the fruits were stored at room temperature without packaging, all the pericarp browning index, PPO activity and the LcPPO expression level of litchi pericarps were reaching the highest in Nandaowuhe (the most rapid browning cultivar), but the lowest in Ziniangxi (the slowest browning cultivar) within 2 d postharvest. Preserving the fruits of Feizixiao in 0.2-μm plastic bag at room temperature would decrease the rate of pericarp water loss, delay the pericarp browning, and also cause the reduction of the pericarp PPO activity and LcPPO expression level within 3 d postharvest. In addition, postharvest storage of Feizixiao fruit stored at 4°C delayed the pericarp browning while decreasing the pericarp PPO activity and LcPPO expression level within 2 d after harvest. Thus, we concluded that the up-regulation of LcPPO expression in pericarp at early stage of postharvest storage likely enhanced the PPO activity and further accelerated the postharvest pericarp browning of litchi fruit. PMID:24763257

WE-AB-BRA-06: 4DCT-Ventilation: A Novel Imaging Modality for Thoracic Surgical Evaluation

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

Vinogradskiy, Y; Jackson, M; Schubert, L

Purpose: The current standard-of-care imaging used to evaluate lung cancer patients for surgical resection is nuclear-medicine ventilation. Surgeons use nuclear-medicine images along with pulmonary function tests (PFT) to calculate percent predicted postoperative (%PPO) PFT values by estimating the amount of functioning lung that would be lost with surgery. 4DCT-ventilation is an emerging imaging modality developed in radiation oncology that uses 4DCT data to calculate lung ventilation maps. We perform the first retrospective study to assess the use of 4DCT-ventilation for pre-operative surgical evaluation. The purpose of this work was to compare %PPO-PFT values calculated with 4DCT-ventilation and nuclear-medicine imaging. Methods:more » 16 lung cancer patients retrospectively reviewed had undergone 4DCTs, nuclear-medicine imaging, and had Forced Expiratory Volume in 1 second (FEV1) acquired as part of a standard PFT. For each patient, 4DCT data sets, spatial registration, and a density-change based model were used to compute 4DCT-ventilation maps. Both 4DCT and nuclear-medicine images were used to calculate %PPO-FEV1 using %PPO-FEV1=pre-operative FEV1*(1-fraction of total ventilation of resected lung). Fraction of ventilation resected was calculated assuming lobectomy and pneumonectomy. The %PPO-FEV1 values were compared between the 4DCT-ventilation-based calculations and the nuclear-medicine-based calculations using correlation coefficients and average differences. Results: The correlation between %PPO-FEV1 values calculated with 4DCT-ventilation and nuclear-medicine were 0.81 (p<0.01) and 0.99 (p<0.01) for pneumonectomy and lobectomy respectively. The average difference between the 4DCT-ventilation based and the nuclear-medicine-based %PPO-FEV1 values were small, 4.1±8.5% and 2.9±3.0% for pneumonectomy and lobectomy respectively. Conclusion: The high correlation results provide a strong rationale for a clinical trial translating 4DCT-ventilation to the surgical domain. Compared to nuclear-medicine, 4DCT-ventilation is cheaper, does not require a radioactive contrast agent, provides a faster imaging procedure, and has improved spatial resolution. 4DCT-ventilation can reduce the cost and imaging time for patients while providing improved spatial accuracy and quantitative results for surgeons. YV discloses grant from State of Colorado.« less

Perennial peanut (Arachis glabrata Benth.) contains polyphenol oxidase (PPO) and PPO substrates that can reduce post-harvest proteolysis.

PubMed

Sullivan, Michael L; Foster, Jamie L

2013-08-15

Studies of perennial peanut (Arachis glabrata Benth.) suggest its hay and haylage have greater levels of rumen undegraded protein (RUP) than other legume forages such as alfalfa (Medicago sativa L.). Greater RUP can result in more efficient nitrogen utilization by ruminant animals with positive economic and environmental effects. We sought to determine whether, like red clover (Trifolium pretense L.), perennial peanut contains polyphenol oxidase (PPO) and PPO substrates that might be responsible for increased RUP. Perennial peanut extracts contain immunologically detectible PPO protein and high levels of PPO activity (>100 nkatal mg(-1) protein). Addition of caffeic acid (PPO substrate) to perennial peanut extracts depleted of endogenous substrates reduced proteolysis by 90%. Addition of phenolics prepared from perennial peanut leaves to extracts of either transgenic PPO-expressing or control (non-expressing) alfalfa showed peanut phenolics could reduce proteolysis >70% in a PPO-dependent manner. Two abundant likely PPO substrates are present in perennial peanut leaves including caftaric acid. Perennial peanut contains PPO and PPO substrates that together are capable of inhibiting post-harvest proteolysis, suggesting a possible mechanism for increased RUP in this forage. Research related to optimizing the PPO system in other forage crops will likely be applicable to perennial peanut. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

Mushroom (Agaricus bisporus) polyphenoloxidase inhibited by apigenin: Multi-spectroscopic analyses and computational docking simulation.

PubMed

Xiong, Zhiqiang; Liu, Wei; Zhou, Lei; Zou, Liqiang; Chen, Jun

2016-07-15

It has been revealed that some polyphenols can prevent enzymatic browning caused by polyphenoloxidase (PPO). Apigenin, widely distributed in many fruits and vegetables, is an important bioactive flavonoid compound. In this study, apigenin exhibited a strong inhibitory activity against PPO, and some reagents had synergistic effect with apigenin on inhibiting PPO. Apigenin inhibited PPO activity reversibly in a mixed-type manner. The fact that inactivation rate constant (k) of PPO increased while activation energy (Ea) and thermodynamic parameters (ΔG, ΔH and ΔS) decreased indicated that the thermosensitivity and stability of PPO decreased. The conformational changes of PPO were revealed by fluorescence emission spectra and circular dichroism. Atomic force microscopy observation suggested that the dimension of PPO molecules was larger after interacting with apigenin. Moreover, computational docking simulation indicated that apigenin bound to PPO and inserted into the hydrophobic cavity of PPO to interact with some amino acid residues. Copyright © 2016 Elsevier Ltd. All rights reserved.

Mental health and selection of preferred providers. Experience in three employee groups.

PubMed

Wells, K B; Marquis, M S; Hosek, S D

1991-09-01

While Preferred Provider Organizations (PPOs) are designed to contain the costs of health care, they may not be able to do so if sicker individuals opt not to use PPO providers. This study examined how level of mental health status and prior use of mental health services affected the decision to use or not use PPO providers for mental health care for employees enrolled in fee-for-service plans with a PPO option. Data were obtained from an employee survey and claims data on three large employee groups. It was not possible to examine effects of sickliness on the intent to select PPO providers for mental health care directly because about one half of employees could not identify who they would visit for mental health care or even how they would select a provider for such care. The intent to use PPO or non-PPO providers for general medical care, however, was not significantly associated with mental health status when other factors were controlled. Furthermore, among persons who used mental health services after implementation of the PPO option, those who had previously visited providers who were to become part of the PPO panel tended to stay with PPO providers, while those who previously visited providers who were not to enter the PPO panel subsequently selected away from PPO providers for mental health care. This pattern of results suggests that established individual patient-provider relationships, rather than sickliness, determined the selection of PPO versus non-PPO providers for mental health care for employees enrolled in these optional PPO fee-for-service plans.

A catechol oxidase AcPPO from cherimoya (Annona cherimola Mill.) is localized to the Golgi apparatus.

PubMed

Olmedo, Patricio; Moreno, Adrián A; Sanhueza, Dayan; Balic, Iván; Silva-Sanzana, Christian; Zepeda, Baltasar; Verdonk, Julian C; Arriagada, César; Meneses, Claudio; Campos-Vargas, Reinaldo

2018-01-01

Cherimoya (Annona cherimola) is an exotic fruit with attractive organoleptic characteristics. However, it is highly perishable and susceptible to postharvest browning. In fresh fruit, browning is primarily caused by the polyphenol oxidase (PPO) enzyme catalyzing the oxidation of o-diphenols to quinones, which polymerize to form brown melanin pigment. There is no consensus in the literature regarding a specific role of PPO, and its subcellular localization in different plant species is mainly described within plastids. The present work determined the subcellular localization of a PPO protein from cherimoya (AcPPO). The obtained results revealed that the AcPPO- green fluorescent protein co-localized with a Golgi apparatus marker, and AcPPO activity was present in Golgi apparatus-enriched fractions. Likewise, transient expression assays revealed that AcPPO remained active in Golgi apparatus-enriched fractions obtained from tobacco leaves. These results suggest a putative function of AcPPO in the Golgi apparatus of cherimoya, providing new perspectives on PPO functionality in the secretory pathway, its effects on cherimoya physiology, and the evolution of this enzyme. Copyright © 2017. Published by Elsevier B.V.

Reducing peanut allergens by high pressure combined with polyphenol oxidase

NASA Astrophysics Data System (ADS)

Chung, Si-Yin; Houska, Milan; Reed, Shawndrika

2013-12-01

Polyphenol oxidase (PPO) has been shown to reduce major peanut allergens. Since high pressure (HP) can increase enzyme activity, we postulated that further reduction of peanut allergens can be achieved through HP combined with PPO. Peanut extracts containing caffeic acid were treated with each of the following: (1) HP; (2) HP+PPO; (3) PPO; and (4) none. HP was conducted at 300 and 500 MPa, each for 3 and 10 min, 37 °C. After treatment, SDS-PAGE was performed and allergenic capacity (IgE binding) was determined colorimetrically in inhibition enzyme-linked immunosorbent assay and Western blots, using a pooled plasma from peanut-allergic patients. Data showed that HP alone had no effect on major peanut allergens. However, HP at 500 MPa combined with PPO (HP500/PPO) induced a higher (approximately twofold) reduction of major peanut allergens and IgE binding than PPO alone or HP300/PPO. There was no difference between treatment times. We concluded that HP500/PPO at 3-min enhanced a twofold reduction of the allergenic capacity of peanut extracts, as compared to PPO itself.

Interaction of Curcumin with PEO-PPO-PEO block copolymers: a molecular dynamics study.

PubMed

Samanta, Susruta; Roccatano, Danilo

2013-03-21

Curcumin, a naturally occurring drug molecule, has been extensively investigated for its various potential usages in medicine. Its water insolubility and high metabolism rate require the use of drug delivery systems to make it effective in the human body. Among various types of nanocarriers, block copolymer based ones are the most effective. These polymers are broadly used as drug-delivery systems, but the nature of this process is poorly understood. In this paper, we propose a molecular dynamics simulation study of the interaction of Curcumin with block copolymer based on polyethylene oxide (PEO) and polypropylene oxide (PPO). The study has been conducted considering the smallest PEO and PPO oligomers and multiple chains of the block copolymer Pluronic P85. Our study shows that the more hydrophobic 1,2-dimethoxypropane (DMP) molecules and PPO block preferentially coat the Curcumin molecule. In the case of the Pluronic P85, simulation shows formation of a drug-polymer aggregate within 50 ns. This process leaves exposed the PEO part of the polymers, resulting in better solvation and stability of the drug in water.

Purification and partial biochemical characterization of polyphenol oxidase from mango (Mangifera indica cv. Manila).

PubMed

Palma-Orozco, Gisela; Marrufo-Hernández, Norma A; Sampedro, José G; Nájera, Hugo

2014-10-08

Polyphenol oxidase (PPO) is an enzyme widely distributed in the plant kingdom that has been detected in most fruits and vegetables. PPO was extracted and purified from Manila mango (Mangifera indica), and its biochemical properties were studied. PPO was purified 216-fold by hydrophobic interaction and ion exchange chromatography. PPO was purified to homogeneity, and the estimated PPO molecular weight (MW) by SDS-PAGE was ≈31.5 kDa. However, a MW of 65 kDa was determined by gel filtration, indicating a dimeric structure for the native PPO. The isolated PPO showed the highest affinity to pyrogallol (Km = 2.77 mM) followed by 4-methylcatechol (Km = 3.14 mM) and catechol (Km = 15.14 mM). The optimum pH for activity was 6.0. PPO was stable in the temperature range of 20-70 °C. PPO activity was completely inhibited by tropolone, ascorbic acid, sodium metabisulfite, and kojic acid at 0.1 mM.

Purification and characterization of polyphenol oxidase from rape flower.

PubMed

Sun, Han-Ju; Wang, Jing; Tao, Xue-Ming; Shi, Juan; Huang, Mei-Ying; Chen, Zhe

2012-01-25

The purification and partial enzymology characteristics of polyphenol oxidase (PPO) from rape flower were studied. After preliminary treatments, the crude enzyme solution was in turn purified with ammonium sulfate, dialysis, and Sephadex G-75 gel chromatography. The optimal conditions and stability of PPO were examined at different pH values and temperatures. Subsequently, PPO was also characterized by substrate (catechol) concentrations, inhibitors, kinetic parameters, and molecular weight. Results showed that the optimal pH for PPO activity was 5.5 in the presence of catechol and that PPO was relatively stable at pH 3.5-5.5. PPO was moderately stable at temperatures from 60 to 70 °C, whereas it was easily denatured at 80-90 °C. Ethylenediaminetetraacetic acid, sodium chloride, and calcium chloride had little inhibitive effects on PPO, whereas citric acid, sodium sulfite, and ascorbic acid had strongly inhibitive effects. The Michaelis-Menten constant (K(m)) and maximal reaction velocity (V(max)) of PPO were 0.767 mol/L and 0.519 Ab/min/mL of the crude PPO solution, respectively. PPO was finally purified to homogeneity with a purification factor of 4.41-fold and a recovery of 12.41%. Its molecular weight was 60.4 kDa, indicating that the PPO is a dimer. The data obtained in this research may help to prevent the enzymatic browning of rape flower during its storage and processing.

Aggregation behaviors of PEO-PPO-ph-PPO-PEO and PPO-PEO-ph-PEO-PPO at an air/water interface: experimental study and molecular dynamics simulation.

PubMed

Gong, Houjian; Xu, Guiying; Liu, Teng; Xu, Long; Zhai, Xueru; Zhang, Jian; Lv, Xin

2012-09-25

The block polyethers PEO-PPO-ph-PPO-PEO (BPE) and PPO-PEO-ph-PEO-PPO (BEP) are synthesized by anionic polymerization using bisphenol A as initiator. Compared with Pluronic P123, the aggregation behaviors of BPE and BEP at an air/water interface are investigated by the surface tension and dilational viscoelasticity. The molecular construction can influence the efficiency and effectiveness of block polyethers in decreasing surface tension. BPE has the most efficient ability to decrease surface tension of water among the three block polyethers. The maximum surface excess concentration (Γ(max)) of BPE is larger than that of BEP or P123. Moreover, the dilational modulus of BPE is almost the same as that of P123, but much larger than that of BEP. The molecular dynamics simulation provides the conformational variations of block polyethers at the air/water interface.

Study on performance of blended fuel PPO - Diesel at generator

NASA Astrophysics Data System (ADS)

Prasetyo, Joni; Prasetyo, Dwi Husodo; Murti, S. D. Sumbogo; Adiarso, Priyanto, Unggul

2018-02-01

Bio-energy is renewable energy made from plant. Biomass-based energy sources are potentially CO2 neutral and recycle the same carbon atoms. In order to reduce pollution caused by fossil fuel combustion either for mechanical or electrical energy generation, the performance characteristic of purified palm oil blends are analyzed at various ratios. Bio-energy, Pure Plant Oil, represent a sustainable solution.A generator has been modified due to adapt the viscosity ofblended fuel, PPO - diesel, by pre-heating. Several PPO - diesel composition and injection timing were tested in order to investigate the characteristic of mixed fuel with and without pre-heating. The term biofuel refers to liquid or gaseous fuels for the internal combustion engines that are predominantly produced fro m biomass. Surprising result showed that BSFC of blended PPO - diesel was more efficient when injection timing set more than 15° BTDC. The mixed fuel produced power with less mixed fuel even though the calorie content of diesel is higher than PPO. The most efficient was 20% PPO in diesel with BSFC 296 gr fuel / kwh rather than 100% diesel with BSFC 309 gr fuel / kwh at the same injection timing 18° BTDC with pre-heating. The improvement of BSFC is caused by heating up of mixed fuel which it added calorie in the mixed fuel. Therefore, the heating up of blended PPO - diesel is not only to adapt the viscosity but also improving the efficiency of fuel usage representing by lower BSFC. In addition, torque of the 20% PPO was also as smooth as 100% diesel representing by almost the same torqueat injection timing 15° BTDC. The AIP Proceedings article template has many predefined paragraph styles for you to use/apply as you write your paper. To format your abstract, use the Microsoft Word template style: Abstract. Each paper must include an abstract. Begin the abstract with the word "Abstract" followed by a period in bold font, and then continue with a normal 9 point font.

Molecular Cloning and Characterization of Apricot Fruit Polyphenol Oxidase

PubMed Central

Chevalier, Tony; de Rigal, David; Mbéguié-A-Mbéguié, Didier; Gauillard, Frédéric; Richard-Forget, Florence; Fils-Lycaon, Bernard R.

1999-01-01

A reverse transcriptase-polymerase chain reaction experiment was done to synthesize a homologous polyphenol oxidase (PPO) probe from apricot (Prunus armeniaca var Bergeron) fruit. This probe was further used to isolate a full-length PPO cDNA, PA-PPO (accession no. AF020786), from an immature-green fruit cDNA library. PA-PPO is 2070 bp long and contains a single open reading frame encoding a PPO precursor peptide of 597 amino acids with a calculated molecular mass of 67.1 kD and an isoelectric point of 6.84. The mature protein has a predicted molecular mass of 56.2 kD and an isoelectric point of 5.84. PA-PPO belongs to a multigene family. The gene is highly expressed in young, immature-green fruit and is turned off early in the ripening process. The ratio of PPO protein to total proteins per fruit apparently remains stable regardless of the stage of development, whereas PPO specific activity peaks at the breaker stage. These results suggest that, in addition to a transcriptional control of PPO expression, other regulation factors such as translational and posttranslational controls also occur. PMID:10198084

Control of enzymatic browning in potato (Solanum tuberosum L.) by sense and antisense RNA from tomato polyphenol oxidase.

PubMed

Coetzer, C; Corsini, D; Love, S; Pavek, J; Tumer, N

2001-02-01

Polyphenol oxidase (PPO) activity of Russet Burbank potato was inhibited by sense and antisense PPO RNAs expressed from a tomato PPO cDNA under the control of the 35S promoter from the cauliflower mosaic virus. Transgenic Russet Burbank potato plants from 37 different lines were grown in the field. PPO activity and the level of enzymatic browning were measured in the tubers harvested from the field. Of the tubers from 28 transgenic lines that were sampled, tubers from 5 lines exhibited reduced browning. The level of PPO activity correlated with the reduction in enzymatic browning in these lines. These results indicate that expression of tomato PPO RNA in sense or antisense orientation inhibits PPO activity and enzymatic browning in the major commercial potato cultivar. Expression of tomato PPO RNA in sense orientation led to the greatest decrease in PPO activity and enzymatic browning, possibly due to cosuppression. These results suggest that expression of closely related heterologous genes can be used to prevent enzymatic browning in a wide variety of food crops without the application of various food additives.

Insect prophenoloxidase: the view beyond immunity

PubMed Central

Lu, Anrui; Zhang, Qiaoli; Zhang, Jie; Yang, Bing; Wu, Kai; Xie, Wei; Luan, Yun-Xia; Ling, Erjun

2014-01-01

Insect prophenoloxidase (PPO) is an important innate immunity protein due to its involvement in cellular and humoral defense. It belongs to a group of type-3 copper-containing proteins that occurs in almost all organisms. Insect PPO has been studied for over a century, and the PPO activation cascade is becoming clearer. The insect PPO activation pathway incorporates several important proteins, including pattern-recognition receptors (PGRP, β GRP, and C-type lectins), serine proteases, and serine protease inhibitors (serpins). Due to their complexity, PPO activation mechanisms vary among insect species. Activated phenoloxidase (PO) oxidizes phenolic molecules to produce melanin around invading pathogens and wounds. The crystal structure of Manduca sexta PPO shows that a conserved amino acid, phenylalanine (F), can block the active site pocket. During activation, this blocker must be dislodged or even cleaved at the N-terminal sequence to expose the active site pockets and allow substrates to enter. Thanks to the crystal structure of M. sexta PPO, some domains and specific amino acids that affect PPO activities have been identified. Further studies of the relationship between PPO structure and enzyme activities will provide an opportunity to examine other type-3 copper proteins, and trace when and why their various physiological functions evolved. Recent researches show that insect PPO has a relationship with neuron activity, longevity, feces melanization (phytophagous insects) and development, which suggests that it is time for us to look back on insect PPO beyond the view of immunity in this review. PMID:25071597

Planetary period oscillations in Saturn's magnetosphere: New results from the F-ring and proximal orbits

NASA Astrophysics Data System (ADS)

Provan, G.; Cowley, S. W. H.; Bunce, E. J.; Hunt, G. J.; Dougherty, M. K.

2017-12-01

We investigate planetary period oscillations (PPOs) in Saturn's magnetosphere using Cassini magnetic field data during the high cadence ( 7 days) F-ring and proximal orbits. Previous results have shown that there are two PPO systems, one in each hemisphere. Both PPO periods show seasonal dependence, and since mid-2014 the Northern PPO period has been 10.8 h and the Southern PPO period 10.7 h. The beat period of the two oscillations is 45 days. Previous results demonstrated that in the Northern (Southern) polar region only pure Northern (Southern) oscillations can be observed, whilst in the equatorial region both oscillations are present and constructively and destructively interfere over the beat-cycle of the two oscillations. The PPOs are believed to be driven by twin-cell convection patterns in the polar ionosphere/thermosphere regions, with two systems of field-aligned currents transmitting the PPO flows to the magnetospheric plasma.The F-ring and proximal orbits uniquely observe the PPOs over 6 orbits during each PPO beat cycle. This high-cadence data demonstrates that over a beat cycle both the periods and amplitudes of the PPO observed within the each polar region are modulated by the PPO system from the opposite hemisphere. When the two oscillations are in phase (anti-phase) the `drag' of one system on the other acts to decrease (increase) the amplitude of the oscillations and the two PPO periods diverge (converge). We present a theoretical model showing that this coupling is due to the PPO flows from one hemisphere not just being communicated to the magnetosphere as previously assumed, but also to the opposite hemisphere. The result is inter-hemispheric coupling of the PPO flow systems within the ionosphere/thermosphere system, so that the northern PPO system drives a northern twin-cell convection pattern in the southern hemisphere, and vice versa, thus leading to the observed polar modulations of the PPOs.We will also present PPO phase models determined throughout the entire Cassini mission. These models define the orientations of the two PPO current/field systems with respect to the Sun at any instant of time, thus allowing any Saturnian observations to be organized by PPO phase. The models are freely available to the community.

Expression analysis of polyphenol oxidase isozymes by active staining method and tissue browning of head lettuce (Lactuca sativa L.).

PubMed

Noda, Takahiro; Iimure, Kazuhiko; Okamoto, Shunsuke; Saito, Akira

2017-08-01

Browning of plant tissue is generally considered attributable to enzymatic oxidation by polyphenol oxidase (PPO). Electrophoresis followed by activity staining has been used as an effective procedure to visually detect and isolate isozymes; however, it has not been applied for examination of various PPO isozymes in lettuce. Our study demonstrated that different lettuce PPO isozymes could be detected at different pH in active staining, and multiple isozymes were detected only under alkaline conditions. As a result, we concluded that activity staining with approximately pH 8 enabled to detect various PPO isozymes in lettuce. By expression analysis of the PPO isozymes after wounding, PPO isozymes that correlated with time-course of tissue browning were detected. The wound-induced PPO may play a key role in enzymatic browning.

The Involvement of Hemocyte Prophenoloxidase in the Shell-Hardening Process of the Blue Crab, Callinectes sapidus

PubMed Central

Alvarez, Javier V.; Chung, J. Sook

2015-01-01

Cuticular structures of arthropods undergo dramatic molt-related changes from being soft to becoming hard. The shell-hardening process of decapod crustaceans includes sclerotization and mineralization. Hemocyte PPO plays a central role in melanization and sclerotization particularly in wound healing in crustaceans. However, little is known about its role in the crustacean initial shell-hardening process. The earlier findings of the aggregation of heavily granulated hemocytes beneath the hypodermis during ecdysis imply that the hemocytes may be involved in the shell-hardening process. In order to determine if hemocytes and hemocyte PPO have a role in the shell-hardening of crustaceans, a knockdown study using specific CasPPO-hemo-dsRNA was carried out with juvenile blue crabs, Callinectes sapidus. Multiple injections of CasPPO-hemo-dsRNA reduce specifically the levels of CasPPO-hemo expression by 57% and PO activity by 54% in hemocyte lysate at the postmolt, while they have no effect on the total hemocyte numbers. Immunocytochemistry and flow cytometry analysis using a specific antiserum generated against CasPPO show granulocytes, semigranulocytes and hyaline cells as the cellular sources for PPO at the postmolt. Interestingly, the type of hemocytes, as the cellular sources of PPO, varies by molt stage. The granulocytes always contain PPO throughout the molt cycle. However, semigranulocytes and hyaline cells become CasPPO immune-positive only at early premolt and postmolt, indicating that PPO expression in these cells may be involved in the shell-hardening process of C. sapidus. PMID:26393802

Different inhibition mechanisms of gentisic acid and cyaniding-3-O-glucoside on polyphenoloxidase.

PubMed

Zhou, Lei; Xiong, Zhiqiang; Liu, Wei; Zou, Liqiang

2017-11-01

Gentisic acid and cyanidin-3-O-glucoside are important bioactive polyphenols which are widely distributed in many fruits and cereals. In this work, kinetic study, spectral analysis and computational simulation were used to compare the inhibitory effects and inhibition mechanisms of gentisic acid and cyanidin-3-O-glucoside on mushroom polyphenoloxidase (PPO). The inhibitory effect of cyanidin-3-O-glucoside on PPO was much stronger than that of gentisic acid. Gentisic acid inhibited PPO in a reversible mixed-type manner while cyanidin-3-O-glucoside was an irreversible inhibitor. Gentisic acid and cyanidin-3-O-glucoside made the thermal inactivation of PPO easier, and induced apparent conformational changes of PPO. Compared with gentisic acid, cyanidin-3-O-glucoside had stronger effects on the thermal inactivation and conformation of PPO. Molecular docking results revealed gentisic acid bound to the active site of PPO by hydrogen bonding, π-π stacking and van der Waals forces. However, cyanidin-3-O-glucoside might irreversibly interact with the Met or Cys in PPO by covalent bonds. Copyright © 2017 Elsevier Ltd. All rights reserved.

Consistency of polyphenol oxidase (PPO) thermostability in ripening apricots (Prunus armeniaca L.): evidence for the presence of thermostable PPO forming and destabilizing mechanisms in apricots.

PubMed

Yemenicioğlu, Ahmet; Cemeroğlu, Bekir

2003-04-09

Destabilization of thermostable polyphenol oxidase (TS-PPO) during the ripening of peaches has been previously shown (Yemenicioğlu, A.; Cemeroğlu, B. Tr. J. Agric. For. 1998, 22, 261-265). This work studied the effect of ripening on thermal stability of apricot PPO for three different cultivars. Kabaaşi cultivar contained thermolabile PPO, whereas TS-PPO appeared in Hacihaliloğlu and Cataloğlu cultivars. The TS-PPO showed biphasic inactivation curves, and its D and z values between 60 and 90 degrees C varied in the ranges of 357-1.12 min and 11.9-12.7 degrees C, respectively. In Hacihaliloğlu cultivar the TS-PPO was very consistent and existed at all stages of ripening, whereas in Cataloğlu cultivar it appeared only at the half-ripe stage. The loss of consistent TS-PPO in Hacihaliloğlu apricots after partial purification by acetone precipitation and DEAE-cellulose chromatography suggested the non-covalent nature of its stabilization. The main purified fractions (F1 and F2) showed monophasic inactivation curves with similar thermal inactivation parameters (z(F1) = 10.4 degrees C, z(F2) = 10.1 degrees C). However, their kinetic properties against catechol (K(mF1) = 61 mM, K(mF2) = 122.7 mM) and substrate specificities were considerably different. The results of this study showed the presence of TS-PPO forming and destabilizing mechanisms in apricots. Further studies are needed for the solution of these mechanisms and to develop some new strategies that may be utilized by molecular techniques for a planned production of apricot cultivars provided with heat labile but normal PPO activity.

PPO-ethanol system as wavelength shifter for the Cherenkov counting technique using a liquid scintillation counter

NASA Astrophysics Data System (ADS)

Takiue, Makoto; Fujii, Haruo; Ishikawa, Hiroaki

1984-12-01

2, 5-diphenyloxazole (PPO) has been proposed as a wavelength shifter for Cherenkov counting. Since PPO is not incorporated with water, we have introduced the fluor into water in the form of micelle using a PPO-ethanol system. This technique makes it possible to obtain a high Cherenkov counting efficiency under stable sample conditions, attributed to the proper spectrometric features of the PPO. The 32P Cherenkov counting efficiency (68.4%) obtained from this technique is large as that measured with a conventional Cherenkov technique.

Role of ascorbic acid in the inhibition of polyphenol oxidase and the prevention of browning in different browning-sensitive Lactuca sativa var. capitata (L.) and Eruca sativa (Mill.) stored as fresh-cut produce.

PubMed

Landi, Marco; Degl'Innocenti, Elena; Guglielminetti, Lorenzo; Guidi, Lucia

2013-06-01

Polyphenol oxidase (PPO) and, to a minor extent, peroxidase (POD) represent the key enzymes involved in enzymatic browning, a negative process induced by cutting fresh-cut produce such as lettuce (Lactuca sativa) and rocket salad (Eruca sativa). Although ascorbic acid is frequently utilised as an anti-browning agent, its mechanism in the prevention of the browning phenomenon is not clearly understood. The activity of PPO and POD and their isoforms in lettuce (a high-browning and low-ascorbic acid species) and rocket salad (a low-browning and high-ascorbic species) was characterised. The kinetic parameters of PPO and in vitro ascorbic acid-PPO inhibition were also investigated. In rocket salad, PPO activity was much lower than that in lettuce and cutting induced an increase in PPO activity only in lettuce. Exogenous ascorbic acid (5 mmol L(-1)) reduced PPO activity by about 90% in lettuce. POD did not appear to be closely related to browning in lettuce. PPO is the main enzyme involved in the browning phenomenon; POD appears to play a minor role. The concentration of endogenous ascorbic acid in rocket salad was related to its low-browning sensitivity after cutting. In lettuce, the addition of ascorbic acid directly inhibited PPO activity. The results suggest that the high ascorbic acid content found in rocket salad plays an effective role in reducing PPO activity. © 2012 Society of Chemical Industry.

Polyphenol oxidase and peroxidase expression in four pineapple varieties (Ananas comosus L.) after a chilling injury.

PubMed

Raimbault, Astrid-Kim; Marie-Alphonsine, Paul-Alex; Horry, Jean-Pierre; Francois-Haugrin, Madlyn; Romuald, Karell; Soler, Alain

2011-01-12

Pineapple internal browning (IB) is a chilling injury that produces enzymatic browning associated with flesh translucency. Pineapple biodiversity allowed the investigation of how polyphenol oxidase (PPO) and peroxidase (POD) activities with their different isoforms are involved in the IB mechanism. Fruits of four varieties that expressed IB symptoms differently, Smooth Cayenne (SCay) and the hybrids MD2, Flhoran 41 (Flh 41), and Flhoran 53 (Flh 53), were stressed by cold. The susceptible varieties showed classical brown spots but different patterns of IB, whereas MD2 and controls showed no IB. Enzymatic activities were measured on fruit protein extracts and PPO and POD isoforms separated on mini-gels (PhastSystem). Only PPO activity was significantly enhanced in the presence of IB. Up to six PPO isoforms were identified in the susceptible varieties. PPO was barely detectable in the nonsusceptible variety MD2 and in controls. The number of PPO isoforms and the total PPO activity after chilling are varietal characteristics.

A structural model of PpoA derived from SAXS-analysis-implications for substrate conversion.

PubMed

Koch, Christian; Tria, Giancarlo; Fielding, Alistair J; Brodhun, Florian; Valerius, Oliver; Feussner, Kirstin; Braus, Gerhard H; Svergun, Dmitri I; Bennati, Marina; Feussner, Ivo

2013-09-01

In plants and mammals, oxylipins may be synthesized via multi step processes that consist of dioxygenation and isomerization of the intermediately formed hydroperoxy fatty acid. These processes are typically catalyzed by two distinct enzyme classes: dioxygenases and cytochrome P450 enzymes. In ascomycetes biosynthesis of oxylipins may proceed by a similar two-step pathway. An important difference, however, is that both enzymatic activities may be combined in a single bifunctional enzyme. These types of enzymes are named Psi-factor producing oxygenases (Ppo). Here, the spatial organization of the two domains of PpoA from Aspergillus nidulans was analyzed by small-angle X-ray scattering and the obtained data show that the enzyme exhibits a relatively flat trimeric shape. Atomic structures of the single domains were obtained by template-based structure prediction and docked into the enzyme envelope of the low resolution structure obtained by SAXS. EPR-based distance measurements between the tyrosyl radicals formed in the activated dioxygenase domain of the enzyme supported the trimeric structure obtained from SAXS and the previous assignment of Tyr374 as radical-site in PpoA. Furthermore, two phenylalanine residues in the cytochrome P450 domain were shown to modulate the specificity of hydroperoxy fatty acid rearrangement. Copyright © 2013 Elsevier B.V. All rights reserved.

Preferred Provider Organization (PPO) Plans

MedlinePlus

... Find & compare doctors, hospitals, & other providers Preferred Provider Organization (PPO) Plans How PPO Plans Work A Medicare ... extra for these benefits. Related Resources Health Maintenance Organization (HMO) Private Fee-for-Service (PFFS) Special Needs ...

Peak power, force, and velocity during jump squats in professional rugby players.

PubMed

Turner, Anthony P; Unholz, Cedric N; Potts, Neill; Coleman, Simon G S

2012-06-01

Training at the optimal load for peak power output (PPO) has been proposed as a method for enhancing power output, although others argue that the force, velocity, and PPO are of interest across the full range of loads. The aim of this study was to examine the influence of load on PPO, peak barbell velocity (BV), and peak vertical ground reaction force (VGRF) during the jump squat (JS) in a group of professional rugby players. Eleven male professional rugby players (age, 26 ± 3 years; height, 1.83 ± 6.12 m; mass, 97.3 ± 11.6 kg) performed loaded JS at loads of 20-100% of 1 repetition maximum (1RM) JS. A force plate and linear position transducer, with a mechanical braking unit, were used to measure PPO, VGRF, and BV. Load had very large significant effects on PPO (p < 0.001, partial η² = 0.915); peak VGRF (p < 0.001, partial η² = 0.854); and peak BV (p < 0.001, partial η² = 0.973). The PPO and peak BV were the highest at 20% 1RM, though PPO was not significantly greater than that at 30% 1RM. The peak VGRF was significantly greater at 1RM than all other loads, with no significant difference between 20 and 60% 1RM. In resistance trained professional rugby players, the optimal load for eliciting PPO during the loaded JS in the range measured occurs at 20% 1RM JS, with decreases in PPO and BV, and increases in VGRF, as the load is increased, although greater PPO likely occurs without any additional load.

Nanofiber Composite Membranes for Alkaline Fuel Cells: Generation of Compositional, Morphological, and Functional Property Relationships

DTIC Science & Technology

2015-12-01

and chemical stability. Also in Year 3, membranes were prepared by simultaneously electrospinning brominated poly(phenylene oxide) ( PPO ) and... PPO fibers (preventing water solubility when charged groups were added to the PPO ), as shown in Scheme 3. Subsequent mat processing included...brominated PPO fibers), and reaction of the resulting films with either trimethylamine or 1,2-dimethylimidazole to create cationic groups at those

Characterization of polyphenol oxidase from blueberry (Vaccinium corymbosum L.).

PubMed

Siddiq, M; Dolan, K D

2017-03-01

Polyphenol oxidase (PPO) was extracted and characterized from high-bush blueberries. PPO showed an optimum activity at pH 6.1-6.3 and 35°C, with the enzyme showing significant activity over a wide temperature range (25-60°C). Catechol was the most readily oxidized substrate followed by 4-methylcatechol, DL-DOPA, and dopamine. Blueberry PPO showed a K m of 15mM and V max of 2.57 ΔA 420 nm/min×10 -1 , determined with catechol. PPO was completely inactivated in 20min at 85°C, however, after 30minat 75°C it showed about 10% residual activity. Thermal treatment at 55 and 65°C for 30min resulted in the partial inactivation of PPO. Ascorbic acid, sodium diethyldithiocarbamic acid, L-cysteine, and sodium metabisulfite were effective inhibitors of PPO at 1.0mM. Benzoic acid and cinnamic acid series inhibitors showed relatively weak inhibition of PPO (21.8-27.6%), even at as high as 2.0mM concentration. Copyright © 2016 Elsevier Ltd. All rights reserved.

Direct fabrication of ordered mesoporous carbons with super-micropore/small mesopore using mixed triblock copolymers.

PubMed

Li, Peng; Song, Yan; Tang, Zhihong; Yang, Guangzhi; Yang, Junhe

2014-01-01

Ordered mesoporous carbons (OMCs) have been prepared by the strategy of evaporation-induced organic-organic self-assembly method by employing a mixture of amphiphilic triblock copolymers poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) (PEO-PPO-PEO) and reverse PPO-PEO-PPO as templates, with soluble in ethanol, low-molecular-weight phenolic resin as precursor, followed by carbonization. It has been found that the as prepared OMCs with porosity that combines super-micropore and small mesopore size distributed from 0.8 to 4 nm, which bridges the pore size from 2 to 3 nm and also for the diversification of the soft-templating synthesis of OMCs. Furthermore, the results showed that the OMCs obtained have mesophase transition from cylindrical p6 mm to centered rectangular c2 mm structure by simply tuning the ratio of PPO-PEO-PPO/PEO-PPO-PEO. Copyright © 2013 Elsevier Inc. All rights reserved.

Patient choice of providers in a preferred provider organization.

PubMed

Wouters, A V; Hester, J

1988-03-01

This article is an analysis of patient choice of providers by the employees of the Security Pacific Bank of California and their dependents who have access to the Med Network Preferred Provider Organization (PPO). The empirical results show that not only is the PPO used by individuals who require relatively little medical care (as measured by predicted office visit charges) but that the PPO is most intensively used for low-risk services such as treatment for minor illness and preventive care. Also, the most likely Security Pacific Health Care beneficiary to use a PPO provider is a recently hired employee who lives in the south urban region, has a relatively low income, does not have supplemental insurance coverage, and is without previous attachments to non-PPO primary care providers. In order to maximize their ability to reduce plan paid benefits, insurers who contract with PPOs should focus on increasing PPO utilization among poorer health risks.

A transgenic apple callus showing reduced polyphenol oxidase activity and lower browning potential.

PubMed

Murata, M; Nishimura, M; Murai, N; Haruta, M; Homma, S; Itoh, Y

2001-02-01

Polyphenol oxidase (PPO) is responsible for enzymatic browning of apples. Apples lacking PPO activity might be useful not only for the food industry but also for studies of the metabolism of polyphenols and the function of PPO. Transgenic apple calli were prepared by using Agrobacterium tumefaciens carrying the kanamycin (KM) resistant gene and antisense PPO gene. Four KM-resistant callus lines were obtained from 356 leaf explants. Among these transgenic calli, three calli grew on the medium containing KM at the same rate as non-transgenic callus on the medium without KM. One callus line had an antisense PPO gene, in which the amount and activity of PPO were reduced to half the amount and activity in non-transgenic callus. The browning potential of this line, which was estimated by adding chlorogenic acid, was also half the browning potential of non-transgenic callus.

Partial purification of coriolus versicolor's extracellular polyphenol oxidase (PPO)

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

Moore, N.L.; Dashek, W.V.

1993-05-01

Coriolus versicolor, a white-rot basidiomycete, secretes ligno-celluloytic enzymes. Because these are valuable to paper-pulp agricultural industries, trials are in progress to substrate induce these enzymes enhance their secretions. Reported are attempts to develop an extracellular PPO (o-diphenols to 0-diquinones) purification protocol applicable to [open quote]batch-cultured[close quote] C. versicolor. Whereas dialysis (MW [open quote]cut-off[close quote], 14,000) of 13 day growth medium (GM) resulted in 2.17 fold PPO spc. act. increase, dialysis plus a 0-30% (NH[sub 4])[sub 2]SO[sub 4] [open quote]cut[close quote] yielded a 3.27 fold enhancement. Subsequent GM chromatography on DEAE CM-Sephadexes revealed that PPO exchanged with DEAE's counterion without enhancingmore » spc. act. Gel filtration of GM commercial PPOs on G-150 resulted in similar elutions indicating a substitute for ion exchange chromatography. Time-dependent fungal growth in liquid medium followed by viscometry utilizing CMC revealed a GM endocellulase 2 days after inoculation an activity rise to day 12. Filteration of Onozuka cellulase on G-150 yielded an elution profile similar to those of GM authentic PPO's compounding C. versicolor's PPO purification. SDS-PAGE of dialyzed GM revealed 4 proteins, one of which was removed by the (NH[sub 4])[sub 2]SO[sub 4]. The m[sub TS] of commercial Sigma's PPO Onozuka cellulase were 0.76 0.59, respectively, for comparison to C. versicolor's PPO. Affinity, hydroxylapatite hydrophobic interaction chromatographies may yield a single SDS-PAGE PPO band.« less

Polyphenoloxidase Silencing Affects Latex Coagulation in Taraxacum Species1[W

PubMed Central

Wahler, Daniela; Gronover, Christian Schulze; Richter, Carolin; Foucu, Florence; Twyman, Richard M.; Moerschbacher, Bruno M.; Fischer, Rainer; Muth, Jost; Prüfer, Dirk

2009-01-01

Latex is the milky sap that is found in many different plants. It is produced by specialized cells known as laticifers and can comprise a mixture of proteins, carbohydrates, oils, secondary metabolites, and rubber that may help to prevent herbivory and protect wound sites against infection. The wound-induced browning of latex suggests that it contains one or more phenol-oxidizing enzymes. Here, we present a comprehensive analysis of the major latex proteins from two dandelion species, Taraxacum officinale and Taraxacum kok-saghyz, and enzymatic studies showing that polyphenoloxidase (PPO) is responsible for latex browning. Electrophoretic analysis and amino-terminal sequencing of the most abundant proteins in the aqueous latex fraction revealed the presence of three PPO-related proteins generated by the proteolytic cleavage of a single precursor (pre-PPO). The laticifer-specific pre-PPO protein contains a transit peptide that can target reporter proteins into chloroplasts when constitutively expressed in dandelion protoplasts, perhaps indicating the presence of structures similar to plastids in laticifers, which lack genuine chloroplasts. Silencing the PPO gene by constitutive RNA interference in transgenic plants reduced PPO activity compared with wild-type controls, allowing T. kok-saghyz RNA interference lines to expel four to five times more latex than controls. Latex fluidity analysis in silenced plants showed a strong correlation between residual PPO activity and the coagulation rate, indicating that laticifer-specific PPO plays a major role in latex coagulation and wound sealing in dandelions. In contrast, very little PPO activity is found in the latex of the rubber tree Hevea brasiliensis, suggesting functional divergence of latex proteins during plant evolution. PMID:19605551

The Effect of Surfactant and Compatibilizer on Inorganic Loading and Properties of PPO-based EPMM Membranes

NASA Astrophysics Data System (ADS)

Bissadi, Golnaz

Hybrid membranes represent a promising alternative to the limitations of organic and inorganic materials for high productivity and selectivity gas separation membranes. In this study, the previously developed concept of emulsion-polymerized mixed matrix (EPMM) membranes was further advanced by investigating the effects of surfactant and compatibilizer on inorganic loading in poly(2,6-dimethyl-1,4-phenylene oxide) (PPO)-based EPMM membranes, in which inorganic part of the membranes originated from tetraethylorthosilicate (TEOS). The polymerization of TEOS, which consists of hydrolysis of TEOS and condensation of the hydrolyzed TEOS, was carried out as (i) one- and (ii) two-step processes. In the one-step process, the hydrolysis and condensation take place in the same environment of a weak acid provided by the aqueous solution of aluminum hydroxonitrate and sodium carbonate. In the two-step process, the hydrolysis takes place in the environment of a strong acid (solution of hydrochloric acid), whereas the condensation takes place in weak base environment obtained by adding excess of the ammonium hydroxide solution to the acidic solution of the hydrolyzed TEOS. For both one- and two-step processes, the emulsion polymerization of TEOS was carried out in two types of emulsions made of (i) pure trichloroethylene (TCE) solvent, and (ii) 10 w/v% solution of PPO in TCE, using different combinations of the compatibilizer (ethanol) and the surfactant (n-octanol). The experiments with pure TCE, which are referred to as a gravimetric powder method (GPM) allowed assessing the effect of different experimental parameters on the conversion of TEOS. The GPM tests also provided a guide for the synthesis of casting emulsions containing PPO, from which the EPMM membranes were prepared using a spin coating technique. The synthesized EPMM membranes were characterized using 29Si nuclear magnetic resonance (29Si NMR), differential scanning calorimetry (DSC), inductively coupled plasma mass spectrometry (ICP-MS), and gas permeation measurements carried out in a constant pressure (CP) system. The 29Si NMR analysis verified polymerization of TEOS in the emulsions made of pure TCE, and the PPO solution in TCE. The conversions of TEOS in the two-step process in the two types of emulsions were very close to each other. In the case of the one-step process, the conversions in the TCE emulsion were significantly greater than those in the emulsion of the PPO solution in TCE. Consequently, the conversions of TEOS in the EPMM membranes made in the two-step process were greater than those in the EPMM membranes made in the one-step process. The latter ranged between 10 - 20%, while the highest conversion in the two-step process was 74% in the presence of pure compatibilizer with no surfactant. Despite greater conversions and hence the greater inorganic loadings, the EPMM membranes prepared in the two-step process had glass transition temperatures (Tg) only slightly greater than the reference PPO membranes. In contrast, despite relatively low inorganic loadings, the EPMM membranes prepared in the one-step process had Tgs markedly greater than PPO, and showed the expected trend of an increase in Tg with the inorganic loading. These results indicate that in the case of the one-step process the polymerized TEOS was well integrated with the PPO chains and the interactions between the two phases lead to high Tgs. On the other hand, this was not the case for the EPMM membranes prepared in the two-step process, suggesting possible phase separation between the polymerized TEOS and the organic phase. The latter was confirmed by detecting no selectivity in the EPMM membranes prepared by the two-step process. In contrast, the EPMM membranes prepared in the one-step process in the presence of the compatibilizer and no surfactant showed 50% greater O2 permeability coefficient and a slightly greater O2/N2 permeability ratio compared to the reference PPO membranes.

Diffusion of liquid polystyrene into glassy poly(phenylene oxide) characterized by DSC

NASA Astrophysics Data System (ADS)

Li, Linling; Wang, Xiaoliang; Zhou, Dongshan; Xue, Gi

2013-03-01

We report a diffusion study on the polystyrene/poly(phenylene oxide) (PS/PPO) mixture consisted by the PS and PPO nanoparticles. Diffusion of liquid PS into glassy PPO (l-PS/g-PPO) is promoted by annealing the PS/PPO mixture at several temperatures below Tg of the PPO. By tracing the Tgs of the PS-rich domain behind the diffusion front using DSC, we get the relationships of PS weight fractions and diffusion front advances with the elapsed diffusion times at different diffusion temperatures using the Gordon-Taylor equation and core-shell model. We find that the plots of weight fraction of PS vs. elapsed diffusion times at different temperatures can be converted to a master curve by Time-Temperature superposition, and the shift factors obey the Arrhenius equation. Besides, the diffusion front advances of l-PS into g-PPO show an excellent agreement with the t1/2 scaling law at the beginning of the diffusion process, and the diffusion coefficients of different diffusion temperatures also obey the Arrhenius equation. We believe the diffusion mechanism for l-PS/g-PPO should be the Fickean law rather than the Case II, though there are departures of original linearity at longer diffusion times due to the limited liquid supply system. Diffusion of liquid polystyrene into glassy poly(phenylene oxide) characterized by DSC

Promising perspectives for ruminal protection of polyunsaturated fatty acids through polyphenol-oxidase-mediated crosslinking of interfacial protein in emulsions.

PubMed

De Neve, N; Vlaeminck, B; Gadeyne, F; Claeys, E; Van der Meeren, P; Fievez, V

2018-03-16

Previously, polyunsaturated fatty acids (PUFA) from linseed oil were effectively protected (>80%) against biohydrogenation through polyphenol-oxidase-mediated protein crosslinking of an emulsion, prepared with polyphenol oxidase (PPO) extract from potato tuber peelings. However, until now, emulsions of only 2 wt% oil have been successfully protected, which implies serious limitations both from a research perspective (e.g. in vivo trials) as well as for further upscaling toward practical applications. Therefore, the aim of this study was to increase the oil/PPO ratio. In the original protocol, the PPO extract served both an emulsifying function as well as a crosslinking function. Here, it was first evaluated whether alternative protein sources could replace the emulsifying function of the PPO extract, with addition of PPO extract and 4-methylcatechol (4MC) to induce crosslinking after emulsion preparation. This approach was then further used to evaluate protection of emulsions with higher oil content. Five candidate emulsifiers (soy glycinin, gelatin, whey protein isolate (WPI), bovine serum albumin and sodium caseinate) were used to prepare 10 wt% oil emulsions, which were diluted five times (w/w) with PPO extract (experiment 1). As a positive control, 2 wt% oil emulsions were prepared directly with PPO extract according to the original protocol. Further, emulsions of 2, 4, 6, 8 and 10 wt% oil were prepared, with 80 wt% PPO extract (experiment 2), or with 90, 80, 70, 60 and 50 wt% PPO extract, respectively (experiment 3) starting from WPI-stabilized emulsions. Enzymatic crosslinking was induced by 24-h incubation with 4MC. Ruminal protection efficiency was evaluated by 24-h in vitro batch simulation of the rumen metabolism. In experiment 1, protection efficiencies were equal or higher than the control (85.5% to 92.5% v. 81.3%). In both experiments 2 and 3, high protection efficiencies (>80%) were achieved, except for emulsions containing 10 wt% oil emulsions (<50% protection), which showed oiling-off after enzymatic crosslinking. This study demonstrated that alternative emulsifier proteins can be used in combination with PPO extract to protect emulsified PUFA-rich oils against ruminal biohydrogenation. By applying the new protocol, 6.5 times less PPO extract was required.

In crystallo activity tests with latent apple tyrosinase and two mutants reveal the importance of the mutated sites for polyphenol oxidase activity.

PubMed

Kampatsikas, Ioannis; Bijelic, Aleksandar; Pretzler, Matthias; Rompel, Annette

2017-08-01

Tyrosinases are type 3 copper enzymes that belong to the polyphenol oxidase (PPO) family and are able to catalyze both the ortho-hydroxylation of monophenols and their subsequent oxidation to o-quinones, which are precursors for the biosynthesis of colouring substances such as melanin. The first plant pro-tyrosinase from Malus domestica (MdPPO1) was recombinantly expressed in its latent form (56.4 kDa) and mutated at four positions around the catalytic pocket which are believed to influence the activity of the enzyme. Mutating the amino acids, which are known as activity controllers, yielded the mutants MdPPO1-Ala239Thr and MdPPO1-Leu243Arg, whereas mutation of the so-called water-keeper and gatekeeper residues resulted in the mutants MdPPO1-Glu234Ala and MdPPO1-Phe259Ala, respectively. The wild-type enzyme and two of the mutants, MdPPO1-Ala239Thr and MdPPO1-Phe259Ala, were successfully crystallized, leading to single crystals that diffracted to 1.35, 1.55 and 1.70 Å resolution, respectively. All crystals belonged to space group P2 1 2 1 2 1 , exhibiting similar unit-cell parameters: a = 50.70, b = 80.15, c = 115.96 Å for the wild type, a = 50.58, b = 79.90, c = 115.76 Å for MdPPO1-Ala239Thr and a = 50.53, b = 79.76, c = 116.07 Å for MdPPO1-Phe259Ala. In crystallo activity tests with the crystals of the wild type and the two mutants were performed by adding the monophenolic substrate tyramine and the diphenolic substrate dopamine to crystal-containing drops. The effects of the mutation on the activity of the enzyme were observed by colour changes of the crystals owing to the conversion of the substrates to dark chromophore products.

PpoC from Aspergillus nidulans is a fusion protein with only one active haem.

PubMed

Brodhun, Florian; Schneider, Stefan; Göbel, Cornelia; Hornung, Ellen; Feussner, Ivo

2010-01-15

In Aspergillus nidulans Ppos [psi (precocious sexual inducer)-producing oxygenases] are required for the production of so-called psi factors, compounds that control the balance between the sexual and asexual life cycle of the fungus. The genome of A. nidulans harbours three different ppo genes: ppoA, ppoB and ppoC. For all three enzymes two different haem-containing domains are predicted: a fatty acid haem peroxidase/dioxygenase domain in the N-terminal region and a P450 haem-thiolate domain in the C-terminal region. Whereas PpoA was shown to use both haem domains for its bifunctional catalytic activity (linoleic acid 8-dioxygenation and 8-hydroperoxide isomerization), we found that PpoC apparently only harbours a functional haem peroxidase/dioxygenase domain. Consequently, we observed that PpoC catalyses mainly the dioxygenation of linoleic acid (18:2Delta9Z,12Z), yielding 10-HPODE (10-hydroperoxyoctadecadienoic acid). No isomerase activity was detected. Additionally, 10-HPODE was converted at lower rates into 10-KODE (10-keto-octadecadienoic acid) and 10-HODE (10-hydroxyoctadecadienoic acid). In parallel, decomposition of 10-HPODE into 10-ODA (10-octadecynoic acid) and volatile C-8 alcohols that are, among other things, responsible for the characteristic mushroom flavour. Besides these principle differences we also found that PpoA and PpoC can convert 8-HPODE and 10-HPODE into the respective epoxy alcohols: 12,13-epoxy-8-HOME (where HOME is hydroxyoctadecenoic acid) and 12,13-epoxy-10-HOME. By using site-directed mutagenesis we demonstrated that both enzymes share a similar mechanism for the oxidation of 18:2Delta9Z,12Z; they both use a conserved tyrosine residue for catalysis and the directed oxygenation at the C-8 and C-10 is most likely controlled by conserved valine/leucine residues in the dioxygenase domain.

In crystallo activity tests with latent apple tyrosinase and two mutants reveal the importance of the mutated sites for polyphenol oxidase activity

PubMed Central

Kampatsikas, Ioannis; Bijelic, Aleksandar; Pretzler, Matthias

2017-01-01

Tyrosinases are type 3 copper enzymes that belong to the polyphenol oxidase (PPO) family and are able to catalyze both the ortho-hydroxylation of monophenols and their subsequent oxidation to o-quinones, which are precursors for the biosynthesis of colouring substances such as melanin. The first plant pro-tyrosinase from Malus domestica (MdPPO1) was recombinantly expressed in its latent form (56.4 kDa) and mutated at four positions around the catalytic pocket which are believed to influence the activity of the enzyme. Mutating the amino acids, which are known as activity controllers, yielded the mutants MdPPO1-Ala239Thr and MdPPO1-Leu243Arg, whereas mutation of the so-called water-keeper and gatekeeper residues resulted in the mutants MdPPO1-Glu234Ala and MdPPO1-Phe259Ala, respectively. The wild-type enzyme and two of the mutants, MdPPO1-Ala239Thr and MdPPO1-Phe259Ala, were successfully crystallized, leading to single crystals that diffracted to 1.35, 1.55 and 1.70 Å resolution, respectively. All crystals belonged to space group P212121, exhibiting similar unit-cell parameters: a = 50.70, b = 80.15, c = 115.96 Å for the wild type, a = 50.58, b = 79.90, c = 115.76 Å for MdPPO1-Ala239Thr and a = 50.53, b = 79.76, c = 116.07 Å for MdPPO1-Phe259Ala. In crystallo activity tests with the crystals of the wild type and the two mutants were performed by adding the monophenolic substrate tyramine and the diphenolic substrate dopamine to crystal-containing drops. The effects of the mutation on the activity of the enzyme were observed by colour changes of the crystals owing to the conversion of the substrates to dark chromophore products. PMID:28777094

Triblock copolymer matrix-based capillary electrophoretic microdevice for high-resolution multiplex pathogen detection.

PubMed

Kim, Se Jin; Shin, Gi Won; Choi, Seok Jin; Hwang, Hee Sung; Jung, Gyoo Yeol; Seo, Tae Seok

2010-03-01

Rapid and simple analysis for the multiple target pathogens is critical for patient management. CE-SSCP analysis on a microchip provides high speed, high sensitivity, and a portable genetic analysis platform in molecular diagnostic fields. The capability of separating ssDNA molecules in a capillary electrophoretic microchannel with high resolution is a critical issue to perform the precise interpretation in the electropherogram. In this study, we explored the potential of poly(ethyleneoxide)-poly(propyleneoxide)-poly(ethyleneoxide) (PEO-PPO-PEO) triblock copolymer as a sieving matrix for CE-SSCP analysis on a microdevice. To demonstrate the superior resolving power of PEO-PPO-PEO copolymers, 255-bp PCR amplicons obtained from 16S ribosomal RNA genes of four bacterial species, namely Proteus mirabilis, Haemophilus ducreyi, Pseudomonas aeruginosa, and Neisseria meningitidis, were analyzed in the PEO-PPO-PEO matrix in comparison with 5% linear polyacrylamide and commercial GeneScan gel. Due to enhanced dynamic coating and sieving ability, PEO-PPO-PEO copolymer displayed fourfold enhancement of resolving power in the CE-SSCP to separate same-sized DNA molecules. Fivefold input of genomic DNA of P. aeruginosa and/or N. meningitidis produced proportionally increased corresponding amplicon peaks, enabling correct quantitative analysis in the pathogen detection. Besides the high-resolution sieving capability, a facile loading and replenishment of gel in the microchannel due to thermally reversible gelation property makes PEO-PPO-PEO triblock copolymer an excellent matrix in the CE-SSCP analysis on the microdevice.

Amphiphilic polymeric micelles originating from 1,4-β-D-glucan-g-polyphenylene oxide as the carriers for delivery of docetaxel and the corresponding release behaviors.

PubMed

Yang, Fang; Xiao, Dan; Han, Huaxin; Chen, Yuhuan; Li, Gang

2018-07-15

A novel amphiphilic polymeric drug carrier was synthesized through grafting polymerization of water-soluble 1,4-β-D-glucan from cotton cellulose tailored and polypropylene oxide (PPO), and then use thereof to synthesize graft copolymer 1,4-β-D-glucan-PPO-docetaxel (DTX). The products were characterized by FTIR, 1 H NMR, and 13 C NMR. The physicochemical characteristics of 1,4-β-D-glucan-PPO and 1,4-β-D-glucan-PPO-DTX such as molecular weight distribution (MWD), micro-morphology, size, critical micelle concentration (CMC), aggregation number of micelle (N), in vitro stability and drug pharmacokinetic study in vivo were investigated. The results reveal that the degree of polymerization (DP) of the water-soluble 1,4-β-D-glucan from cotton cellulose tailored is equal to 7; the 1,4-β-D-glucan-PPO surfactant possesses good surface activity while the adduct number of propylene oxide reaches appropriately to 20; the DTX is completely dispersed in water medium with 1,4-β-D-glucan-PPO-DTX micelle and the drug conjugated percent is up to 40.3%; In vitro study confirms that 1,4-β-D-glucan-PPO-DTX has the capacity for sustained drug release; In plasma, 1,4-β-D-glucan-PPO-DTX exhibits a significantly enhanced C max , AUC (0-t) and T 1/2 compared with DTX. These results demonstrate that 1,4-β-D-glucan-PPO has the potential to be used as a novel biocompatible biomaterial for drug delivery. Copyright © 2018 Elsevier B.V. All rights reserved.

Prediction of post-operative pulmonary function after lobectomy for primary lung cancer: A comparison among counting method, effective lobar volume, and lobar collapsibility using inspiratory/expiratory CT.

PubMed

Yabuuchi, Hidetake; Kawanami, Satoshi; Kamitani, Takeshi; Yonezawa, Masato; Yamasaki, Yuzo; Yamanouchi, Torahiko; Nagao, Michinobu; Okamoto, Tatsuro; Honda, Hiroshi

2016-11-01

To compare the predictabilities of postoperative pulmonary function after lobectomy for primary lung cancer among counting method, effective lobar volume, and lobar collapsibility. Forty-nine patients who underwent lobectomy for primary lung cancer were enrolled. All patients underwent inspiratory/expiratory CT and pulmonary function tests 2 weeks before surgery and postoperative pulmonary function tests 6-7 months after surgery. Pulmonary function losses (ΔFEV 1.0 and ΔVC) were calculated from the pulmonary function tests. Predictive postoperative pulmonary function losses (ppoΔFEV 1.0 and ppoΔVC) were calculated using counting method, effective volume, and lobar collapsibility. Correlations and agreements between ΔFEV 1.0 and ppoFEV 1.0 and those between ΔVC and ppoΔVC were tested among three methods using Spearman's correlation coefficient and Bland-Altman plots. ΔFEV 1.0 and ppoΔFEV 1.0insp-exp were strongly correlated (r=0.72), whereas ΔFEV 1.0 and ppoΔFEV 1.0count and ΔFEV 1.0 and Pred. ΔFEV 1.0eff.vol. were moderately correlated (r=0.50, 0.56). ΔVC and ppoΔVC eff.vol. (r=0.71) were strongly correlated, whereas ΔVC and ppoΔVC count , and ΔVC and ppoΔVC insp-exp were moderately correlated (r=0.55, 0.42). Volumetry from inspiratory/expiratory CT data could be useful to predict postoperative pulmonary function after lobectomy for primary lung cancer. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Comprehensive two-dimensional liquid chromatographic analysis of poloxamers.

PubMed

Malik, Muhammad Imran; Lee, Sanghoon; Chang, Taihyun

2016-04-15

Poloxamers are low molar mass triblock copolymers of poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO), having number of applications as non-ionic surfactants. Comprehensive one and two-dimensional liquid chromatographic (LC) analysis of these materials is proposed in this study. The separation of oligomers of both types (PEO and PPO) is demonstrated for several commercial poloxamers. This is accomplished at the critical conditions for one of the block while interaction for the other block. Reversed phase LC at CAP of PEO allowed for oligomeric separation of triblock copolymers with regard to PPO block whereas normal phase LC at CAP of PPO renders oligomeric separation with respect to PEO block. The oligomeric separation with regard to PEO and PPO are coupled online (comprehensive 2D-LC) to reveal two-dimensional contour plots by unconventional 2D IC×IC (interaction chromatography) coupling. The study provides chemical composition mapping of both PEO and PPO, equivalent to combined molar mass and chemical composition mapping for several commercial poloxamers. Copyright © 2016 Elsevier B.V. All rights reserved.

Recombinant expression, purification, and characterization of polyphenol oxidase 2 (VvPPO2) from "Shine Muscat" (Vitis labruscana Bailey × Vitis vinifera L.).

PubMed

Katayama-Ikegami, Ayako; Suehiro, Yuka; Katayama, Takane; Jindo, Kazushi; Itamura, Hiroyuki; Esumi, Tomoya

2017-12-01

Polyphenol oxidases (PPOs) catalyze browning reactions in various plant organs, therefore controlling the reactions is important for the food industry. PPOs have been assumed to be involved in skin browning of white grape cultivars; however, the molecular mechanism underlying PPO-mediated browning process remains elusive. We have recently identified a new PPO gene named VvPPO2 from "Shine Muscat" (Vitis labruscana Bailey × V. vinifera L.), and have shown that the gene is transcribed at a higher level than the previously identified VvPPO1 in browning, physiologically disordered berry skins at the maturation stage. In this study, we expressed VvPPO2 in Escherichia coli and, using the purified preparation, revealed unique physicochemical characteristics of the enzyme. Our study opens up a way to not only understand the berry skin browning process but also to elucidate the enzymatic maturation process of grape PPOs.

Over production of lignocellulosic enzymes of Coriolus versicolor by genetic engineering methodology. Final report

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

Williams, A.L.

1998-07-01

The project seeks to understand the biological and chemical processes involved in the secretion of the enzyme polyphenol oxidase (PPO) by the hyphae, the basic unit of the filamentous fungus Coriolus versicolor. These studies are made to determine rational strategies for enhanced secretion of PPO, both with the use of recombinant DNA techniques and without. This effort focuses on recombinant DNA techniques to enhance enzyme production. The major thrust of this project was two-fold: to mass produce C. versicolor tyrosinase (polyphenol oxidase) by genetic engineering as well as cultural manipulations; and to utilize PPO as a biocatalyst in the processingmore » of lignocellulose as a renewable energy resource. In this study, the assessment of genomic and cDNA recombinant clones with regards to the overproduction of PPO continued. Further, immunocytochemical techniques were employed to assess the mechanism(s) involved in the secretion of PPO by the hyphae. Also, factors influencing PPO secretion were examined.« less

[Validity of psychoprophylaxis in obstetrics. Authors' experience].

PubMed

D'Alfonso, A; Zaurito, V; Facchini, D; Di Stefano, L; Patacchiola, F; Cappa, F

1990-12-01

The Authors report the results based on 20 years of practice on obstetric psycho-prophylaxis (PPO). Data on presence at course, on frequency, on primipares/pluripares ratio, on labour, on timing and mode of delivery, are assembled. Moreover, neonatal status at birth and at 10th day of life, are investigated. The data obtained were compared with a control group, constituted by women without any treatment before delivery. The acquired experience confirm the utility of PPO in the ordinary clinical practice.

Phase behavior of binary mixture systems of saturated-unsaturated mixed-acid triacylglycerols: effects of glycerol structures and chain-chain interactions.

PubMed

Bayés-García, Laura; Calvet, Teresa; Cuevas-Diarte, Miquel Àngel; Ueno, Satoru; Sato, Kiyotaka

2015-03-26

We systematically examined the phase behavior of binary mixtures of mixed-acid triacylglycerols (TAGs) containing palmitic and oleic acid moieties 1,3-dioleoyl-2-palmitoyl-glycerol (OPO), 1,2-dipalmitoyl-3-oleoyl-rac-glycerol (PPO), and 1,2-dioleoyl-3-palmitoyl-rac-glycerol (OOP), which are widely present in natural fats and are employed in the food, pharmaceutical, and cosmetic industries. Differential scanning calorimetry and X-ray diffraction methods were applied to observe the mixing behavior of PPO/OPO, OOP/OPO, and PPO/OOP under metastable and stable conditions. The results led to three conclusions: (1) Eutectic behavior was observed in PPO/OPO. (2) Molecular compound (MC) crystals were formed in the mixtures of OOP/OPO and PPO/OOP. (3) However, the MC crystals occurred only under metastable conditions and tended to separate into component TAGs to form eutectic mixture systems after 17 months of incubation. These results were contrary to those of previous studies on 1,3-dipalmitoyl-2-oleoyl glycerol (POP)/OPO and POP/PPO in which the MC crystals were thermodynamically stable. We determined that specific molecular interactions may cause this different phase behavior (stability of POP/OPO and POP/PPO MC crystals and metastability of OOP/OPO and PPO/OOP MC crystals). All results confirm the significant effects of molecular structures of glycerol groups, interactions of fatty acid chains, and polymorphism of the component TAGs on the mixing behavior of mixed-acid TAGs.

Development and validation of MRM methods to quantify protein isoforms of polyphenol oxidase in loquat fruits.

PubMed

Martínez-Márquez, Ascensión; Morante-Carriel, Jaime; Sellés-Marchart, Susana; Martínez-Esteso, María José; Pineda-Lucas, José Luis; Luque, Ignacio; Bru-Martínez, Roque

2013-12-06

Multiple reaction monitoring (MRM) is emerging as a promising technique for the detection and quantification of protein biomarkers in complex biological samples. Compared to Western blotting or enzyme assays, its high sensitivity, specificity, accuracy, assay speed, and sample throughput represent a clear advantage for being the approach of choice for the analysis of proteins. MRM assays are capable of detecting and quantifying proteolytic peptides differing in mass unique to particular proteins, that is, proteotypic peptides, through which different protein isoforms can be distinguished. We have focused on polyphenol oxidase (PPO), a plant conspicuous enzyme encoded by a multigenic family in loquat (Eriobotrya japonica Lindl.) and other related species. PPO is responsible for both the protection of plants from biotic stress as a feeding deterrent for herbivore insects and the enzymatic browning of fruits and vegetables. The latter makes fruit more attractive to seed dispersal agents but is also a major cause of important economic losses in agriculture and food industry. An adequate management of PPO at plant breeding level would maximize the benefits and minimize the disadvantages of this enzyme, but it would require a precise knowledge of the biological role played by each isoform in the plant. Thus, for the functional study of the PPOs, we have cloned and overexpressed fragments of three PPO isoforms from loquat to develop MRM-based methods for the quantification of each isoform. The method was developed using an ion trap instrument and validated in a QQQ instrument. It resulted in the selection of at least two peptides for each isoform that can be monitored by at least three transitions. A combination of SDS-PAGE and MRM lead to detect two out of three monitored isoforms in different gel bands corresponding to different processing stages of PPO. The method was applied to determine the amount of the PPO2 isoform in protein extracts from fruit samples using external calibrants.

Drosophila innate immunity: regional and functional specialization of prophenoloxidases.

PubMed

Dudzic, Jan P; Kondo, Shu; Ueda, Ryu; Bergman, Casey M; Lemaitre, Bruno

2015-10-01

The diversification of immune systems during evolution involves the expansion of particular gene families in given phyla. A better understanding of the metazoan immune system requires an analysis of the logic underlying such immune gene amplification. This analysis is now within reach due to the ease with which we can generate multiple mutations in an organism. In this paper, we analyze the contribution of the three Drosophila prophenoloxidases (PPOs) to host defense by generating single, double and triple mutants. PPOs are enzymes that catalyze the production of melanin at the site of infection and around parasites. They are the rate-limiting enzymes that contribute to the melanization reaction, a major immune mechanism of arthropods. The number of PPO-encoding genes is variable among insects, ranging from one in the bee to ten in the mosquito. By analyzing mutations alone and in combination, we ascribe a specific function to each of the three PPOs of Drosophila. Our study confirms that two PPOs produced by crystal cells, PPO1 and PPO2, contribute to the bulk of melanization in the hemolymph, upon septic or clean injury. In contrast, PPO3, a PPO restricted to the D. melanogaster group, is expressed in lamellocytes and contributes to melanization during the encapsulation process. Interestingly, another overlapping set of PPOs, PPO2 and PPO3, achieve melanization of the capsule upon parasitoid wasp infection. The use of single or combined mutations allowed us to show that each PPO mutant has a specific phenotype, and that knocking out two of three genes is required to abolish fully a particular function. Thus, Drosophila PPOs have partially overlapping functions to optimize melanization in at least two conditions: following injury or during encapsulation. Since PPO3 is restricted to the D. melanogaster group, this suggests that production of PPO by lamellocytes emerged as a recent defense mechanism against parasitoid wasps. We conclude that differences in spatial localization, immediate or late availability, and mode of activation underlie the functional diversification of the three Drosophila PPOs, with each of them having non-redundant but overlapping functions.

Isolation of a latent polyphenol oxidase from loquat fruit (Eriobotrya japonica Lindl.): kinetic characterization and comparison with the active form.

PubMed

Sellés-Marchart, Susana; Casado-Vela, Juan; Bru-Martínez, Roque

2006-02-15

Polyphenol oxidase (PPO) has been extracted from both soluble and particulate fractions of loquat fruit (Eriobotrya japonica Lindl. cv. Algerie). The soluble PPO (20% of total activity) was partially purified 3.3-fold after ammonium sulfate fractionation being in its active state. The particulate PPO fraction (80% of total activity) was purified to homogeneity in a latent form being activable by sodium dodecyl sulfate (SDS). The enzyme was purified 40.0-fold with a total yield of 15.3% after extraction by phase partitioning in Triton X-114 followed by three chromatographic steps. The molecular weight was estimated to be about 59.2 and 61.2 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and gel filtration chromatography, respectively, indicating that latent PPO is a monomer. Latent PPO catalyzed the oxidation of chlorogenic acid (CA) at a rate 50-fold faster than that of 4-tert-butylcatechol (TBC) but the soluble active counterpart only twice. Both PPOs exhibited similar Km values for TBC but Km for CA was 5-fold higher for the latent than for the active soluble PPO. Other kinetic characteristics, including sensitivity to inhibitors, substrate specificity, thermal stability, temperature, and pH profiles, were quite different between both PPOs. These results provide strong evidences that the soluble active and the particulate latent are different forms of PPO in loquat fruit flesh. The results suggest that the major PPO form for the oxidation of CA, leading to enzymatic browning under physiological conditions, is the latent one.

Field-Aligned Currents in Saturn's Magnetosphere: Observations From the F-Ring Orbits

NASA Astrophysics Data System (ADS)

Hunt, G. J.; Provan, G.; Bunce, E. J.; Cowley, S. W. H.; Dougherty, M. K.; Southwood, D. J.

2018-05-01

We investigate the azimuthal magnetic field signatures associated with high-latitude field-aligned currents observed during Cassini's F-ring orbits (October 2016-April 2017). The overall ionospheric meridional current profiles in the northern and southern hemispheres, that is, the regions poleward and equatorward of the field-aligned currents, differ most from the 2008 observations. We discuss these differences in terms of the seasonal change between data sets and local time (LT) differences, as the 2008 data cover the nightside while the F-ring data cover the post-dawn and dusk sectors in the northern and southern hemispheres, respectively. The F-ring field-aligned currents typically have a similar four current sheet structure to those in 2008. We investigate the properties of the current sheets and show that the field-aligned currents in a hemisphere are modulated by that hemisphere's "planetary period oscillation" (PPO) systems. We separate the PPO-independent and PPO-related currents in both hemispheres using their opposite symmetry. The average PPO-independent currents peak at 1.5 MA/rad just equatorward of the open closed field line boundary, similar to the 2008 observations. However, the PPO-related currents in both hemispheres are reduced by 50% to 0.4 MA/rad. This may be evidence of reduced PPO amplitudes, similar to the previously observed weaker equatorial oscillations at similar dayside LTs. We do not detect the PPO current systems' interhemispheric component, likely a result of the weaker PPO-related currents and their closure within the magnetosphere. We also do not detect previously proposed lower latitude discrete field-aligned currents that act to "turn off" the PPOs.

Field-aligned currents in Saturn's northern nightside magnetosphere: Evidence for interhemispheric current flow associated with planetary period oscillations

NASA Astrophysics Data System (ADS)

Hunt, G. J.; Cowley, S. W. H.; Provan, G.; Bunce, E. J.; Alexeev, I. I.; Belenkaya, E. S.; Kalegaev, V. V.; Dougherty, M. K.; Coates, A. J.

2015-09-01

We investigate the magnetic perturbations associated with field-aligned currents observed on 34 Cassini passes over the premidnight northern auroral region during 2008. These are found to be significantly modulated not only by the northern planetary-period oscillation (PPO) system, similar to the southern currents by the southern PPO system found previously, but also by the southern PPO system as well, thus providing the first clear evidence of PPO-related interhemispheric current flow. The principal field-aligned currents of the two PPO systems are found to be co-located in northern ionospheric colatitude, together with the currents of the PPO-independent (subcorotation) system, located between the vicinity of the open-closed field boundary and field lines mapping to ~9 Saturn radius (Rs) in the equatorial plane. All three systems are of comparable magnitude, ~3 MA in each PPO half-cycle. Smaller PPO-related field-aligned currents of opposite polarity also flow in the interior region, mapping between ~6 and ~9 Rs in the equatorial plane, carrying a current of ~ ±2 MA per half-cycle, which significantly reduce the oscillation amplitudes in the interior region. Within this interior region the amplitudes of the northern and southern oscillations are found to fall continuously with distance along the field lines from the corresponding hemisphere, thus showing the presence of cross-field currents, with the southern oscillations being dominant in the south, and modestly lower in amplitude than the northern oscillations in the north. As in previous studies, no oscillations related to the opposite hemisphere are found on open field lines in either hemisphere.

Theoretical study of binding and permeation of ether-based polymers through interfaces.

PubMed

Samanta, Susruta; Hezaveh, Samira; Roccatano, Danilo

2013-11-27

We present a molecular dynamics simulation study on the interactions of poly(ethylene oxide) (PEO), poly(propylene oxide) (PPO), and their ABA-type block copolymer, poloxamers, at water/n-heptane and 1,2-dimyristoyl-sn-glycero-3-phospatidycholine (DMPC) lipid bilayer/water interfaces. The partition coefficients in water/1-octanol of the linear polyethers up to three monomers were calculated. The partition coefficients evidenced a higher hydrophobicity of the PPO in comparison to PEO. At the water/n-heptane interface, the polymers tend to adopt elongated conformations in agreement with similar experimental ellipsometry studies of different poloxamers. In the case of the poloxamers at the n-heptane/water interface, the stronger preference of the PPO block for the hydrophobic phase resulted in bottle-brush-type polymer conformations. At lipid bilayer/water interface, the PEO polymers, as expected from their hydrophilic nature, are weakly adsorbed on the surface of the lipid bilayer and locate in the water phase close to the headgroups. The free energy barriers of permeation calculated for short polymer chains suggest a thermodynamics propensity for the water phase that increase with the chain length. The lower affinity of PEO for the hydrophobic interior of the lipid bilayer resulted in the spontaneous expulsion within the simulation time. On the contrary, PPO chains and poloxamers have a longer residence time inside the bilayer, and they tend to concentrate in the tail region of the bilayer near the polar headgroups. In addition, polymers with PPO unit length comparable to the thickness of the hydrophobic region of the bilayer tend to span across the bilayer.

Browning in Annona cherimola fruit: role of polyphenol oxidase and characterization of a coding sequence of the enzyme.

PubMed

Prieto, Humberto; Utz, Daniella; Castro, Alvaro; Aguirre, Carlos; González-Agüero, Mauricio; Valdés, Héctor; Cifuentes, Nicolas; Defilippi, Bruno G; Zamora, Pablo; Zúñiga, Gustavo; Campos-Vargas, Reinaldo

2007-10-31

Cherimoya (Annona cherimola Mill.) fruit is an attractive candidate for food processing applications as fresh cut. However, along with its desirable delicate taste, cherimoya shows a marked susceptibility to browning. This condition is mainly attributed to polyphenol oxidase activity (PPO). A general lack of knowledge regarding PPO and its role in the oxidative loss of quality in processed cherimoya fruit requires a better understanding of the mechanisms involved. The work carried out included the cloning of a full-length cDNA, an analysis of its properties in the deduced amino sequence, and linkage of its mRNA levels with enzyme activity in mature and ripe fruits after wounding. The results showed one gene different at the nucleotide level when compared with previously reported genes, but a well-conserved protein, either in functional and in structural terms. Cherimoya PPO gene (Ac-ppo, GenBank DQ990911) showed to be present apparently in one copy of the genome, and its transcripts could be significantly detected in leaves and less abundantly in flowers and fruits. Analysis of wounded matured and ripened fruits revealed an inductive behavior for mRNA levels in the flesh of mature cherimoya after 16 h. Although the highest enzymatic activity was observed on rind, a consistent PPO activity was detected on flesh samples. A lack of correlation between PPO mRNA level and PPO activity was observed, especially in flesh tissue. This is probably due to the presence of monophenolic substrates inducing a lag period, enzyme inhibitors and/or diphenolic substrates causing suicide inactivation, and proenzyme or latent isoforms of PPO. To our knowledge this is the first report of a complete PPO sequence in cherimoya. Furthermore, the gene is highly divergent from known nucleotide sequences but shows a well conserved protein in terms of its function, deduced structure, and physiological role.

Inheritance of polyphenol oxidase activity in wheat breeding lines derived from matings of low polyphenol oxidase parents

USDA-ARS?s Scientific Manuscript database

Polyphenol oxidase (PPO) in grain plays a major role in time-dependent discoloration of wheat (Triticum aestivum L.) products, especially fresh noodles. Breeding wheat cultivars with low or nil PPO activity can reduce the undesirable product darkening. The low PPO line PI 117635 was crossed to two...

Multiple origins of the phenol reaction negative phenotype in foxtail millet, Setaria italica (L.) P. Beauv., were caused by independent loss-of-function mutations of the polyphenol oxidase (Si7PPO) gene during domestication.

PubMed

Inoue, Takahiko; Yuo, Takahisa; Ohta, Takeshi; Hitomi, Eriko; Ichitani, Katsuyuki; Kawase, Makoto; Taketa, Shin; Fukunaga, Kenji

2015-08-01

Foxtail millet shows variation in positive phenol color reaction (Phr) and negative Phr in grains, but predominant accessions of this crop are negative reaction type, and the molecular genetic basis of the Phr reaction remains unresolved. In this article, we isolated polyphenol oxidase (PPO) gene responsible for Phr using genome sequence information and investigated molecular genetic basis of negative Phr and crop evolution of foxtail millet. First of all, we searched for PPO gene homologs in a foxtail millet genome database using a rice PPO gene as a query and successfully found three copies of the PPO gene. One of the PPO gene homologs on chromosome 7 showed the highest similarity with PPO genes expressed in hulls (grains) of other cereal species including rice, wheat, and barley and was designated as Si7PPO. Phr phenotypes and Si7PPO genotypes completely co-segregated in a segregating population. We also analyzed the genetic variation conferring negative Phr reaction. Of 480 accessions of the landraces investigated, 87 (18.1 %) showed positive Phr and 393 (81.9 %) showed negative Phr. In the 393 Phr negative accessions, three types of loss-of-function Si7PPO gene were predominant and independently found in various locations. One of them has an SNP in exon 1 resulting in a premature stop codon and was designated as stop codon type, another has an insertion of a transposon (Si7PPO-TE1) in intron 2 and was designated as TE1-insertion type, and the other has a 6-bp duplication in exon 3 resulting in the duplication of 2 amino acids and was designated as 6-bp duplication type. As a rare variant of the stop codon type, one accession additionally has an insertion of a transposon, Si7PPO-TE2, in intron 2 and was designated as "stop codon +TE2 insertion type". The geographical distribution of accessions with positive Phr and those with three major types of negative Phr was also investigated. Accessions with positive Phr were found in subtropical and tropical regions at frequencies of ca. 25-67 % and those with negative Phr were broadly found in Europe and Asia. The stop codon type was found in 285 accessions and was broadly distributed in Europe and Asia, whereas the TE-1 insertion type was found in 99 accessions from Europe and Asia but was not found in India. The 6-bp duplication type was found in only 8 accessions from Nansei Islands (Okinawa Prefecture) of Japan. We also analyzed Phr in the wild ancestor and concluded that the negative Phr type was likely to have originated after domestication of foxtail millet. It was also implied that negative Phr of foxtail millet arose by multiple independent loss of function of PPO gene through dispersal because of some advantages under some environmental conditions and human selection as in rice and barley.

Real-time evaluation of polyphenol oxidase (PPO) activity in lychee pericarp based on weighted combination of spectral data and image features as determined by fuzzy neural network.

PubMed

Yang, Yi-Chao; Sun, Da-Wen; Wang, Nan-Nan; Xie, Anguo

2015-07-01

A novel method of using hyperspectral imaging technique with the weighted combination of spectral data and image features by fuzzy neural network (FNN) was proposed for real-time prediction of polyphenol oxidase (PPO) activity in lychee pericarp. Lychee images were obtained by a hyperspectral reflectance imaging system operating in the range of 400-1000nm. A support vector machine-recursive feature elimination (SVM-RFE) algorithm was applied to eliminating variables with no or little information for the prediction from all bands, resulting in a reduced set of optimal wavelengths. Spectral information at the optimal wavelengths and image color features were then used respectively to develop calibration models for the prediction of PPO in pericarp during storage, and the results of two models were compared. In order to improve the prediction accuracy, a decision strategy was developed based on weighted combination of spectral data and image features, in which the weights were determined by FNN for a better estimation of PPO activity. The results showed that the combined decision model was the best among all of the calibration models, with high R(2) values of 0.9117 and 0.9072 and low RMSEs of 0.45% and 0.459% for calibration and prediction, respectively. These results demonstrate that the proposed weighted combined decision method has great potential for improving model performance. The proposed technique could be used for a better prediction of other internal and external quality attributes of fruits. Copyright © 2015 Elsevier B.V. All rights reserved.

Structure of the physical therapy benefit in a typical Blue Cross Blue Shield preferred provider organization plan available in the individual insurance market in 2011.

PubMed

Sandstrom, Robert W; Lehman, Jedd; Hahn, Lee; Ballard, Andrew

2013-10-01

The Affordable Care Act of 2010 establishes American Health Benefit Exchanges. The benefit design of insurance plans in state health insurance exchanges will be based on the structure of existing small-employer-sponsored plans. The purpose of this study was to describe the structure of the physical therapy benefit in a typical Blue Cross Blue Shield (BCBS) preferred provider organization (PPO) health insurance plan available in the individual insurance market in 2011. A cross-sectional survey design was used. The physical therapy benefit within 39 BCBS PPO plans in 2011 was studied for a standard consumer with a standard budget. First, whether physical therapy was a benefit in the plan was determined. If so, then the structure of the benefit was described in terms of whether the physical therapy benefit was a stand-alone benefit or part of a combined-discipline benefit and whether a visit or financial limit was placed on the physical therapy benefit. Physical therapy was included in all BCBS plans that were studied. Ninety-three percent of plans combined physical therapy with other disciplines. Two thirds of plans placed a limit on the number of visits covered. The results of the study are limited to 1 standard consumer, 1 association of insurance companies, 1 form of insurance (a PPO), and 1 PPO plan in each of the 39 states that were studied. Physical therapy is a covered benefit in a typical BCBS PPO health insurance plan. Physical therapy most often is combined with other therapy disciplines, and the number of covered visits is limited in two thirds of plans.

Effects of peach palm oil on performance, serum lipoproteins and haemostasis in broilers.

PubMed

Baldizán, G; Oviedo, M; Michelangeli, C; Vargas, R E

2010-12-01

1. An experiment was conducted to study the comparative effects of peach palm oil (PPO, Bactris gasipaes H.B.K), crude palm oil (CPO, Elaeis guinenesis), maize oil (MO) and beef tallow (BT) on serum total and lipoprotein cholesterol levels and haemostatic factors in broiler chickens. 2. Four experimental diets were formulated to be isocaloric (14·2 MJ AME(N)/kg) and isonitrogenous (230 g CP/kg). PPO was extracted from the whole dry fruit with hexane. Each fat was added to the diet in an amount equivalent to 25% of total dietary calories. Six replicate groups of eight male broiler chicks were assigned randomly to each dietary treatment. Diets were fed on ad libitum basis. The experiment lasted 42 d. 3. At 42 d, birds were fasted overnight and three chickens/dietary treatment were utilised to draw blood for lipoprotein separation. Various haemostatic factors were determined in thrombocyte-poor plasma. Thrombocyte aggregation was assayed in whole blood. 4. No significant differences were detected in body-weight gain or feed efficiency between the chickens fed on the PPO diet and those receiving the CPO, MO or BT diets. Total serum cholesterol (TC), very low density lipoprotein cholesterol and low density lipoprotein cholesterol (LDL(C)) were not significantly affected after consuming the PPO, CPO and MO diets. Serum high density lipoprotein cholesterol (HDL(C)) was reduced only by the MO diet. Birds fed on the PPO diet had a significantly lower [corrected] LDLC/HDLC ratio compared with other dietary treatments 5. Thrombocyte count and thrombin time were not significantly affected by the experimental diets. Dietary oils significantly affected prothrombin time, fibrinogen concentration and thrombocyte aggregation. PPO and MO diets elicited the lowest fibrinogen levels compared to the CPO and BT diets. Thrombocyte aggregation in broilers fed on the PPO diet was similar to that of the CPO, MO and BT diets. 6. The results suggest that PPO might efficiently provide up to 25% of dietary energy in broiler diets. Additionally, PPO elicited a more favourable LDL(C)/HDL(C) ratio and haemostatic pattern in broiler chickens. These findings may be of general interest to the food industry.

Physico-chemical and antioxidant properties of four mango (Mangifera indica L.) cultivars in China.

PubMed

Liu, Feng-Xia; Fu, Shu-Fang; Bi, Xiu-Fang; Chen, Fang; Liao, Xiao-Jun; Hu, Xiao-Song; Wu, Ji-Hong

2013-05-01

Four principal mango cultivars (Tainong No.1, Irwin, JinHwang and Keitt) grown in southern China were selected, and their physico-chemical and antioxidant properties were characterized and compared. Of all the four cultivars, Tainong No.1 had highest content of total phenols, ρ-coumaric acid, sinapic acid, quercetin, titratable acidity, citric acid, malic acid, fructose, higher antioxidant activities (DPPH, FRAP) and L(*), lower pH, PPO activity and individual weight. Keitt mangoes showed significantly (p<0.05) higher contents of β-carotene, ρ-hydroxybenzoic acid, sucrose, total sugar, total soluble solid, catechin, succinic acid and higher PPO activity. JinHwang mangoes exhibited significantly (p<0.05) higher individual weight and PPO activity, but had lower content of total phenols, β-carotene and lower antioxidant activity. Principal component analysis (PCA) allowed the four mango cultivars to be differentiated clearly based on all these physico-chemical and antioxidant properties determined in the study. Copyright © 2012 Elsevier Ltd. All rights reserved.

Healthcare and Social Services Providers Who Serve Sexual and Gender Minorities in a U.S.-Mexico Border City.

PubMed

Loza, Oralia; Alvarez, Carlos R; Peralta-Torres, David

2018-01-15

Sexual and gender minorities, including lesbian, gay, bisexual, transgender, and queer (LGBTQ) individuals, experience barriers to healthcare as a result of stigma, discrimination, and poor cultural competence by healthcare and social services providers (HCSSP). The purpose of the study is to increase access to care and services for the LGBTQ community in a U.S.-Mexico border city by identifying LGBTQ-friendly HCSSP. A survey, developed based on concerns voiced in a predominantly Hispanic LGBTQ community, was administered to HCSSP and used to create a referral list, "The Purple Pages of El Paso" (PPoEP). Overall, 77 HCSSP have responded and 43 are included in the most recent version of the PPoEP. This model for developing a referral list of providers can be adapted in areas where LGBTQ communities face similar barriers to care and services. To be effective in reducing barriers to care, PPoEP must be updatable and sustainable.

Effect of catechin and its derivatives on inhibition of polyphenoloxidase and melanosis of Pacific white shrimp.

PubMed

Sae-Leaw, Thanasak; Benjakul, Soottawat; Simpson, Benjamin K

2017-04-01

This study aimed to investigate the effect of tea catechin (C) and 4 of its derivatives on the Pacific white shrimp PPO inhibition and melanosis during refrigerated storage. Epigallocatechin gallate (EGCG) exhibited the highest inhibition towards PPO, followed by C. Inhibitory activity of all compounds tested was in a dose dependent manner (0.1-2.0 mM). Based on activity staining, EGCG most effectively inhibited PPO. For inhibition kinetic studies, C and epicatechin (EC) showed uncompetitive type, whereas epicatechin gallate (ECG), epigallocatechin (EGC) and EGCG exhibited mixed type inhibition. When whole shrimps were treated with EGCG solution at various concentrations (0.25-0.75%), those treated with 0.5 or 0.75% EGCG had lower melanosis scores throughout storage for 10 days at 4 °C, compared with the control and the 1.25% sodium metabisulfite treated samples ( P  < 0.05). Therefore, EGCG could be used as a potential inhibitor for melanosis in raw Pacific white shrimp during refrigerated storage.

Full inhibition of enzymatic browning in the presence of thiol-functionalised silica nanomaterial.

PubMed

Muñoz-Pina, Sara; Ros-Lis, José V; Argüelles, Ángel; Coll, Carmen; Martínez-Máñez, Ramón; Andrés, Ana

2018-02-15

Darkening processed fruits and vegetables is caused mainly by enzymatic browning through polyphenol oxidase (PPO) action. Accordingly, we explored the potential of four silica-based materials (MCM-41 nanometric size, MCM-41 micrometric size, UVM-7 and aerosil), non-functionalised and functionalised with thiol groups, to inhibit PPO activity in the model system and apple juice. All materials showed relevant performance when immobilising and inhibiting PPO in model systems, and support topology is a main factor for enzyme immobilisation and inhibition. Thiol-containing silica UVM7-SH showed the greatest inactivation, and similar browning values to those obtained by acidification. The enzyme's kinetic parameters in the presence of UVM-7-SH suggested non-competitive inhibition, which indicated that the material interacted with the enzyme, but beyond the active centre. In real systems, UVM-7-SH completely inhibited enzymatic browning in apple juice (cv. Granny Smith and cv. Golden Delicious) up to 9days after 5min of contact. Copyright © 2017 Elsevier Ltd. All rights reserved.

Characterization and electrochemical application of carbon materials based on poly(phenylene oxide)

NASA Astrophysics Data System (ADS)

Gray, Hunter

Carbon materials possess excellent electrical and surface properties for the next generation of energy storage devices. Polymers provide a carbon rich and tailorable precursor for the production of carbon materials. Therefore, activated carbons were prepared from poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) via a three step process: thermal oxidation, carbonization, and activation with KOH. The activated carbons are predominately microporous with BET specific surface areas up to 2638 m2/g. Impedance spectroscopy revealed these carbons possess electrical conductivities comparable to commercial carbon blacks and consequently were employed in thin-film composite electrodes in electrochemical double-layer capacitors. Cyclic voltammetry confirmed maximum specific capacitances of 13.23 F/g and 2.848 F/g for aqueous and organic electrolyte systems, respectively. Additionally, carbon nanotubes were synthesized from PPO and other polymers with a nickel catalyst via chemical vapor deposition as revealed by transmission electron microscopy. This is the first report of carbon nanotubes produced from PPO.

Novel "anchor modification" of polymeric biomaterial surfaces by the utilization of cyclodextrin inclusion complex supramolecules.

PubMed

Zhao, Xiaobin; Courtney, James M

2009-07-01

In this article, a novel approach for the surface modification of polymeric biomaterials by the utilization of supramolecules was studied. The supramolecules selected were cyclodextrin inclusion complexes (CICs). The biomaterial selected for surface modification was plasticized poly (vinyl chloride) (PVC-P). Results indicate that when the CICs were blended into PVC-P, they tend to migrate and "anchor" on the surface to achieve a remarkable protein-resistant surface, with improved blood compatibility. In comparison with a physical mixture of cyclodextrins and a "guest" molecule, such as poly(ethylene oxide) (PEO)-poly(propylene oxide) (PPO)-PEO and PPO-PEO-PPO for PVC-P modification, CICs modified PVC-P are more consistent in processing and achieve reproducible surface characteristics. Based on this study, a novel "anchor modification" was proposed regarding CICs modified surface. This "anchor modification" is likely to reduce plasticizer extraction from PVC-P and also can be utilized for the modification of polymers other than PVC-P.

Methacrylate based cross-linkers for improved thermomechanical properties and retention of radiation detection response in plastic scintillators

NASA Astrophysics Data System (ADS)

Mahl, Adam; Lim, Allison; Latta, Joseph; Yemam, Henok A.; Greife, Uwe; Sellinger, Alan

2018-03-01

Pulse shape discrimination (PSD) is an important method that can efficiently sort and separate neutron and gamma radiation signals. PSD is currently achieved in plastic scintillators by over-doping poly(vinyl toluene) (PVT) matrices with fluorescent molecules. Meaningful separation of the signals requires addition of >20 wt% 2,5-diphenyloxazole (PPO) fluor in PVT. At these concentrations PPO acts as a plasticizer, negatively affecting the physical properties of the final plastic such as hardness, machinability, and thermomechanical stability. This work addresses these issues by implementing a cost-effective solution using cross-linking chemistry via commercially available bisphenol A dimethacrylate (BPA-DM), and a synthesized fluorinated analogue. Both improve the physical properties of over-doped PPO based plastic scintillators without degrading the measured light yield or PSD and Figure of Merit (FoM). In addition, the fluorinated analogue appears to enhance the hydrophobicity of the surface of the plastic scintillators, which may improve the scintillators' resistance to water diffusion and subsequent radiation response degradation. The new formulations improve the feasibility of widely deploying long lifetime PSD capable plastic scintillators in large area coverage assemblies.

Extraction and quantitation of coumarin from cinnamon and its effect on enzymatic browning in fresh apple juice: a bioinformatics approach to illuminate its antibrowning activity.

PubMed

Thada, Rajarajeshwari; Chockalingam, Shivashri; Dhandapani, Ramesh Kumar; Panchamoorthy, Rajasekar

2013-06-05

Enzymatic browning by polyphenoloxidase (PPO) affects food quality and taste in fruits and vegetables. Thus, the study was designed to reduce browning in apple juice by coumarin. The ethanolic extract of cinnamon was prepared and its coumarin content was quantitated by HPLC, using authentic coumarin (AC) as standard. The effect of cinnamon extract (CE) and AC on enzymatic browning, its time dependent effects, and the specific activity of PPO and peroxidase (POD) were studied in apple juice. The docking of coumarin with PPO and POD was also performed to elucidate its antibrowning mechanism. The CE (73%) and AC (82%) showed better reduction in browning, maintained its antibrowning effect at all time points, and significantly (p < 0.05) reduced the specific activity of PPO and POD when compared with controls. Coumarin showed strong interaction with binding pockets of PPO and POD, suggesting its potential use as inhibitor to enzyme mediated browning in apple juice.

Dielectric Properties of Generation 3 Pamam Dendrimer Nanocomposites

NASA Astrophysics Data System (ADS)

Ristić, Sanja; Mijović, Jovan

2008-08-01

Broadband dielectric relaxation spectroscopy (DRS) was employed to study molecular dynamics of blends composed of generation 3 poly(amidoamine) (PAMAM) dendrimers with ethylenediamine core and amino surface groups and four linear polymers: poly(propylene oxide)—PPO, two block copolymers, poly(propylene oxide)/poly(ethylene oxide)—PPO/PEO with different mol ratios (29/6 and 10/31) and poly(ethylene oxide)—PEO. The results were generated over a broad range of frequency. Dielectric spectra of dendrimers in PPO matrix reveal slight shift of normal and segmental processes to higher frequency with increasing concentration of dendrimers. In the 29PPO/6PEO matrix, no effect of concentration on the average relaxation time for normal and segmental processes was observed. In the 10PPO/31PEO matrix the relaxation time of the segmental process increases with increasing dendrimer concentration, while in the PEO matrix, local processes in dendrimers slow down. A detailed analysis of the effect of concentration of dendrimers and morphology of polymer matrix on the dielectric properties of dendrimer nanocomposites will be presented.

Thin Robust Anion Exchange Membranes for Fuel Cell Applications

DTIC Science & Technology

2014-01-01

water diffsuion. Here we use a Polyphenylene Oxide dibock polymer co-polymerized with polyvinyl benzyl trimethyl ammonium blocks ( PPO -b-PVBTMA[F...in PPO -b-PVBTMA[F-] AEM under saturated humidity environment ECS Transactions, 64 (3) 1185-1194 (2014) 1191 Conductivity of this membrane was...makes it a promising material for applications in anion exchange membrane fuel cells. Figure 5: Conductivity of PPO -b-PVBTMA[F-] under 95% Relative

A systematic study on hemocyte identification and plasma prophenoloxidase from Culex pipiens quinquefasciatus at different developmental stages.

PubMed

Wang, Zhixiang; Lu, Anrui; Li, Xuquan; Shao, Qimiao; Beerntsen, Brenda T; Liu, Chaoliang; Ma, Yajun; Huang, Yamin; Zhu, Huaimin; Ling, Erjun

2011-01-01

Culexpipiens quinquefasciatus (C. quinquefasciatus) is an important vector that can transmit human diseases such as West Nile virus, lymphatic filariasis, Japanese encephalitis and St. Louis encephalitis. However, very limited research concerning the humoral and cellular immune defenses of C. quinquefasciatus has been done. Here we present the research on hemocyte identification and plasma including hemocyte prophenoloxidase from C. quinquefasciatus at all developmental stages in order to obtain a complete picture of C. quinquefasciatus innate immunity. We identified hemocytes into four types: prohemocytes, oenocytoids, plasmatocytes and granulocytes. Prophenoloxidase (PPO) is an essential enzyme to induce melanization after encapsulation. PPO-positive hemocytes and plasma PPO were observed at all developmental stages. As for specific hemocyte types, prophenoloxidase was found in the plasmatocytes at larval stage alone and in the smallest prohemocytes during almost all developmental stages. Moreover, the granulocytes were PPO-positive from blood-fed female mosquitoes and oenocytoids were observed PPO-positive in pupae and in adult females after blood-feeding. As for plasma, there were different patterns of PPO in C. quinquefasciatus at different developmental stages. These results are forming a basis for further studies on the function of C. quinquefasciatus hemocytes and prophenoloxidase as well as their involvement in fighting against mosquito-borne pathogens. Copyright © 2010 Elsevier Inc. All rights reserved.

Browning inhibition mechanisms by cysteine, ascorbic acid and citric acid, and identifying PPO-catechol-cysteine reaction products.

PubMed

Ali, Hussein M; El-Gizawy, Ahmed M; El-Bassiouny, Rawia E I; Saleh, Mahmoud A

2015-06-01

The titled compounds were examined as PPO inhibitors and antibrowning agents; their various mechanisms were investigated and discussed. All compounds reduced significantly both the browning process and PPO activity. Browning index gave strong correlation with PPO activity (r(2) = 0.96, n = 19) indicating that the browning process is mainly enzymatic. Ascorbic acid could reduce the formed quinone instantly to the original substrate (catechol) at high concentration (>1.5 %) while at lower concentrations acted as competitive inhibitor (KI = 0.256 ± 0.067 mM). Cysteine, at higher concentrations (≥1.0 %), reacted with the resulted quinone to give a colorless products while at the low concentrations, cysteine worked as competitive inhibitor (KI = 1.113 ± 0.176 mM). Citric acid acted only as PPO non-competitive inhibitor with KI = 2.074 ± 0.363 mM. The products of PPO-catechole-cysteine reaction could be separation and identification by LC-ESI-MS. Results indicated that the product of the enzymatic oxidation of catechol, quinone, undergoes two successive nucleophilic attacks by cysteine thiol group. Cysteine was condensed with the resulted mono and dithiocatechols to form peptide side chains.

Gd2O3:Eu3+/PPO/POPOP/PS composites for digital imaging radiation detectors

NASA Astrophysics Data System (ADS)

Oliveira, J.; Martins, P. M.; Martins, P.; Correia, V.; Rocha, J. G.; Lanceros-Mendez, S.

2015-11-01

Polymer-based scintillator composites have been produced by combining polystyrene (PS) and Gd2O3:Eu3+ scintillator nanoparticles. Polystyrene has been used since it is a flexible and stable binder matrix, resistant to thermal and light deterioration and with suitable optical properties. Gd2O3:Eu3+ has been selected as scintillator material due to its wide band gap, high density and visible light yield. The optical, thermal and electrical characteristics of the composites were studied as a function of filler content, together with their performance as scintillator material. Additionally 1 wt.% of 2,5-diphenyloxazole (PPO) and 0.01 wt.% of 1,4 di[2-(5phenyloxazolyl)]benzene (POPOP) were introduced in the polymer matrix in order to strongly improve light yield, i.e., the measured intensity of the output visible radiation, under X-ray irradiation. Increasing scintillator filler concentration (from 0.25 to 7.5 wt.%) increases scintillator light yield and decreases the optical transparency of the composite. The addition of PPO and POPOP strongly increased the overall transduction performance of the composite due to specific absorption and re-emission processes. It is thus shown that Gd2O3:Eu3+/PPO/POPOP/PS composites with 0.25 wt.% of scintillator content with fluorescence molecules are suitable for the development of innovative large-area X-ray radiation detectors with huge demand from the industries.

Two endogenous substrates for polyphenoloxidase in pericarp tissues of postharvest rambutan fruit.

PubMed

Sun, Jian; Su, Weiqiang; Peng, Hongxiang; Zhu, Jianhua; Xu, Liangxiong; Bruñá, Nuria Martí

2010-08-01

The catalytic oxidation of phenolic substrates by polyphenoloxidase (PPO) causes pericarp browning of postharvest rambutan fruit. In the present study, PPO and its endogenous substrates were extracted from rambutan pericarp tissues (RPT). The substrate extracts were sequentially partitioned with ethyl acetate and n-butanol. The analysis of total phenolic content showed that the most phenolic compounds were distributed in ethyl acetate fraction. By high-performance liquid chromatography (HPLC), (-)-epicatechin (EC) and proanthocyanidin A2 (PA2) were identified from this fraction. After reacting with rambutan PPO, EC turned brown rapidly within 10 min, indicating that it was a significant endogenous substrate. Although PA2 could also be oxidized by the PPO, it turned brown very slowly. In addition, because EC and PA2 were continually catalyzed into browning products by PPO during storage of the fruit at 4 and 25 degrees C, their contents in RPT gradually declined with the extended storage time. It was further observed that both substrate contents in rambutan fruit storing at 25 degrees C decreased more rapidly than that storing at 4 degrees C, suggesting that low temperature inhibited the catalytic oxidation of substrates so as to slow down pericarp browning. Practical Application: Pericarp browning is a serious problem to storage and transport of harvested rambutan fruit. A generally accepted opinion on the browning mechanism is the oxidation of phenolic substrates by PPO. Ascertaining PPO substrates will effectively help us to control enzymatic reaction by chemical methods so as to delay or even prevent pericarp browning of harvested rambutan fruit.

Evidence of formation of site-selective inclusion complexation between beta-cyclodextrin and poly(ethylene oxide)-block-poly(propylene oxide)- block-poly(ethylene oxide) copolymers.

PubMed

Tsai, Chi-Chun; Zhang, Wen-Bin; Wang, Chien-Lung; Van Horn, Ryan M; Graham, Matthew J; Huang, Jing; Chen, Yongming; Guo, Mingming; Cheng, Stephen Z D

2010-05-28

A series of inclusion complexes of poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) (PEO-b-PPO-b-PEO) with beta-cyclodextrin (beta-CD) was prepared. Their formation, structure, and dynamics were investigated by solution two-dimensional rotating-frame Overhauser effect spectroscopy (2D ROESY) and one-dimensional (1D) and 2D solid-state (13)C NMR. The inclusion complexes between the PEO-b-PPO-b-PEO copolymers and the beta-CDs were formed in aqueous solution and detected by 2D ROESY. The high efficiency of cross polarization and spin diffusion experiments in (13)C solid-state NMR showed that the mobility of the PPO blocks dramatically decreases after beta-CD complexation, indicating that they are selectively incorporated onto the PPO blocks. The hydrophobic cavities of beta-CD restrict the PPO block mobility, which is evidence of the formation of inclusion complexes in the solid state. The 2D wide-line separation NMR experiments suggested that beta-CDs only thread onto the PPO blocks while forming the inclusion complexes. The stoichiometry of inclusion complexes was studied using (1)H NMR, and a 3:1 (PO unit to beta-CD) was found for all inclusion complexes, which indicated that the number of threaded beta-CDs was only dependent on the molecular weight of the PPO blocks. 1D wide angle x-ray diffraction studies demonstrated that the beta-CD in the inclusion complex formed a channel-like structure that is different from the pure beta-CD crystal structure.

Evidence of formation of site-selective inclusion complexation between β-cyclodextrin and poly(ethylene oxide)-block-poly(propylene oxide)- block-poly(ethylene oxide) copolymers

NASA Astrophysics Data System (ADS)

Tsai, Chi-Chun; Zhang, Wen-Bin; Wang, Chien-Lung; Van Horn, Ryan M.; Graham, Matthew J.; Huang, Jing; Chen, Yongming; Guo, Mingming; Cheng, Stephen Z. D.

2010-05-01

A series of inclusion complexes of poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) (PEO-b-PPO-b-PEO) with β-cyclodextrin (β-CD) was prepared. Their formation, structure, and dynamics were investigated by solution two-dimensional rotating-frame Overhauser effect spectroscopy (2D ROESY) and one-dimensional (1D) and 2D solid-state C13 NMR. The inclusion complexes between the PEO-b-PPO-b-PEO copolymers and the β-CDs were formed in aqueous solution and detected by 2D ROESY. The high efficiency of cross polarization and spin diffusion experiments in C13 solid-state NMR showed that the mobility of the PPO blocks dramatically decreases after β-CD complexation, indicating that they are selectively incorporated onto the PPO blocks. The hydrophobic cavities of β-CD restrict the PPO block mobility, which is evidence of the formation of inclusion complexes in the solid state. The 2D wide-line separation NMR experiments suggested that β-CDs only thread onto the PPO blocks while forming the inclusion complexes. The stoichiometry of inclusion complexes was studied using H1 NMR, and a 3:1 (PO unit to β-CD) was found for all inclusion complexes, which indicated that the number of threaded β-CDs was only dependent on the molecular weight of the PPO blocks. 1D wide angle x-ray diffraction studies demonstrated that the β-CD in the inclusion complex formed a channel-like structure that is different from the pure β-CD crystal structure.

Molecular cloning and characterisation of banana fruit polyphenol oxidase.

PubMed

Gooding, P S; Bird, C; Robinson, S P

2001-09-01

Polyphenol oxidase (PPO; EC 1.10.3.2) is the enzyme thought to be responsible for browning in banana [Musa cavendishii (AAA group, Cavendish subgroup) cv. Williams] fruit. Banana flesh was high in PPO activity throughout growth and ripening. Peel showed high levels of activity early in development but activity declined until ripening started and then remained constant. PPO activity in fruit was not substantially induced after wounding or treatment with 5-methyl jasmonate. Banana flowers and unexpanded leaf roll had high PPO activities with lower activities observed in mature leaves, roots and stem. Four different PPO cDNA clones were amplified from banana fruit (BPO1, BPO11, BPO34 and BPO35). Full-length cDNA and genomic clones were isolated for the most abundant sequence (BPO1) and the genomic clone was found to contain an 85-bp intron. Introns have not been previously found in PPO genes. Northern analysis revealed the presence of BPO1 mRNA in banana flesh early in development but little BPO1 mRNA was detected at the same stage in banana peel. BPO11 transcript was only detected in very young flesh and there was no detectable expression of BPO34 or BPO35 in developing fruit samples. PPO transcripts were also low throughout ripening in both flesh and peel. BPO1 transcripts were readily detected in flowers, stem, roots and leaf roll samples but were not detected in mature leaves. BPO11 showed a similar pattern of expression to BPO1 in these tissues but transcript levels were much lower. BPO34 and BPO35 mRNAs were only detected at a low level in flowers and roots and BPO34 transcript was detected in mature leaves, the only clone to do so. The results suggest that browning of banana fruit during ripening results from release of pre-existing PPO enzyme, which is synthesised very early in fruit development.

A Practical Application of Value of Information and Prospective Payback of Research to Prioritize Evaluative Research.

PubMed

Andronis, Lazaros; Billingham, Lucinda J; Bryan, Stirling; James, Nicholas D; Barton, Pelham M

2016-04-01

Efforts to ensure that funded research represents "value for money" have led to increasing calls for the use of analytic methods in research prioritization. A number of analytic approaches have been proposed to assist research funding decisions, the most prominent of which are value of information (VOI) and prospective payback of research (PPoR). Despite the increasing interest in the topic, there are insufficient VOI and PPoR applications on the same case study to contrast their methods and compare their outcomes. We undertook VOI and PPoR analyses to determine the value of conducting 2 proposed research programs. The application served as a vehicle for identifying differences and similarities between the methods, provided insight into the assumptions and practical requirements of undertaking prospective analyses for research prioritization, and highlighted areas for future research. VOI and PPoR were applied to case studies representing proposals for clinical trials in advanced non-small-cell lung cancer and prostate cancer. Decision models were built to synthesize the evidence available prior to the funding decision. VOI (expected value of perfect and sample information) and PPoR (PATHS model) analyses were undertaken using the developed models. VOI and PPoR results agreed in direction, suggesting that the proposed trials would be cost-effective investments. However, results differed in magnitude, largely due to the way each method conceptualizes the possible outcomes of further research and the implementation of research results in practice. Compared with VOI, PPoR is less complex but requires more assumptions. Although the approaches are not free from limitations, they can provide useful input for research funding decisions. © The Author(s) 2015.

Influence of ballistic bench press on upper body power output in professional rugby players.

PubMed

West, Daniel J; Cunningham, Daniel J; Crewther, Blair T; Cook, Christian J; Kilduff, Liam P

2013-08-01

The use of heavy resistance exercise provides an effective preload stimulus for inducing postactivation potentiation (PAP) and increasing peak power output (PPO). However, this approach has limited application in many sporting situations (e.g., incorporation in a precompetition warm-up); and therefore, more practical strategies for inducing PAP need to be investigated. The aim of the present study was to compare the PPO changes after performing a preload stimulus of either a ballistic exercise or a traditional heavy resistance exercise. Twenty professional rugby union players completed 3 testing sessions, each separated by 48 hours. On the first occasion, subjects underwent a 3 repetition maximum (3RM)-bench press testing session. On the next 2 occasions, subjects performed a ballistic bench throw at baseline (30% of 1RM), followed by a preload stimulus of either heavy resistance training (HRT) (heavy bench press: 3 sets of 3 repetitions at 87% 1RM) or BBP (3 sets of 3 repetitions at 30% on 1RM) followed by ballistic bench throw after 8 minutes recovery. The trials were randomized and counterbalanced. Both preload stimuli protocols increased PPO compared with baseline (BBP baseline 892 ± 108 vs. 8 minutes 924 ± 119 W, p < 0.001; HRT baseline 893 ± 104 vs. 8 minutes 931 ± 116 W; p < 0.001). There were no conditional differences between PPO at 8 minutes (p = 0.141); moreover, the change in PPO from baseline was also similar between conditions (BBP Δ + 33 ± 18; HRT Δ + 38 ± 21 W; p = 0.112). In conclusion, a ballistic exercise provided an effective method of inducing PAP and increasing upper-body PPO; moreover, this elicited similar increases in PPO as a traditional heavy resistance exercise preloading stimulus.

HIIT produces increases in muscle power and free testosterone in male masters athletes

PubMed

Herbert, P; Hayes, L D; Sculthorpe, N F; Grace, F M

2017-10-01

High-intensity interval training (HIIT) improves peak power output (PPO) in sedentary aging men but has not been examined in masters endurance athletes. Therefore, we investigated whether a six-week program of low-volume HIIT would (i) improve PPO in masters athletes and (ii) whether any change in PPO would be associated with steroid hormone perturbations. Seventeen male masters athletes (60 ± 5 years) completed the intervention, which comprised nine HIIT sessions over six weeks. HIIT sessions involved six 30-s sprints at 40% PPO, interspersed with 3 min active recovery. Absolute PPO (799 ± 205 W and 865 ± 211 W) and relative PPO (10.2 ± 2.0 W/kg and 11.0 ± 2.2 W/kg) increased from pre- to post-HIIT respectively (P < 0.001, Cohen’s d = 0.32−0.38). No significant change was observed for total testosterone (15.2 ± 4.2 nmol/L to 16.4 ± 3.3 nmol/L (P = 0.061, Cohen’s d = 0.32)), while a small increase in free testosterone occurred following HIIT (7.0 ± 1.2 ng/dL to 7.5 ± 1.1 ng/dL pre- to post-HIIT (P = 0.050, Cohen’s d = 0.40)). Six weeks’ HIIT improves PPO in masters athletes and increases free testosterone. Taken together, these data indicate there is a place for carefully timed HIIT epochs in regimes of masters athletes.

HIIT produces increases in muscle power and free testosterone in male masters athletes

PubMed Central

Herbert, P; Sculthorpe, NF; Grace, FM

2017-01-01

High-intensity interval training (HIIT) improves peak power output (PPO) in sedentary aging men but has not been examined in masters endurance athletes. Therefore, we investigated whether a six-week program of low-volume HIIT would (i) improve PPO in masters athletes and (ii) whether any change in PPO would be associated with steroid hormone perturbations. Seventeen male masters athletes (60 ± 5 years) completed the intervention, which comprised nine HIIT sessions over six weeks. HIIT sessions involved six 30-s sprints at 40% PPO, interspersed with 3 min active recovery. Absolute PPO (799 ± 205 W and 865 ± 211 W) and relative PPO (10.2 ± 2.0 W/kg and 11.0 ± 2.2 W/kg) increased from pre- to post-HIIT respectively (P < 0.001, Cohen’s d = 0.32−0.38). No significant change was observed for total testosterone (15.2 ± 4.2 nmol/L to 16.4 ± 3.3 nmol/L (P = 0.061, Cohen’s d = 0.32)), while a small increase in free testosterone occurred following HIIT (7.0 ± 1.2 ng/dL to 7.5 ± 1.1 ng/dL pre- to post-HIIT (P = 0.050, Cohen’s d = 0.40)). Six weeks’ HIIT improves PPO in masters athletes and increases free testosterone. Taken together, these data indicate there is a place for carefully timed HIIT epochs in regimes of masters athletes. PMID:28794164

HIIT produces increases in muscle power and free testosterone in male masters athletes.

PubMed

Herbert, P; Hayes, L D; Sculthorpe, N F; Grace, F M

2017-10-01

High-intensity interval training (HIIT) improves peak power output (PPO) in sedentary aging men but has not been examined in masters endurance athletes. Therefore, we investigated whether a six-week program of low-volume HIIT would (i) improve PPO in masters athletes and (ii) whether any change in PPO would be associated with steroid hormone perturbations. Seventeen male masters athletes (60 ± 5 years) completed the intervention, which comprised nine HIIT sessions over six weeks. HIIT sessions involved six 30-s sprints at 40% PPO, interspersed with 3 min active recovery. Absolute PPO (799 ± 205 W and 865 ± 211 W) and relative PPO (10.2 ± 2.0 W/kg and 11.0 ± 2.2 W/kg) increased from pre- to post-HIIT respectively ( P  < 0.001, Cohen's d  = 0.32-0.38). No significant change was observed for total testosterone (15.2 ± 4.2 nmol/L to 16.4 ± 3.3 nmol/L ( P  = 0.061, Cohen's d  = 0.32)), while a small increase in free testosterone occurred following HIIT (7.0 ± 1.2 ng/dL to 7.5 ± 1.1 ng/dL pre- to post-HIIT ( P  = 0.050, Cohen's d  = 0.40)). Six weeks' HIIT improves PPO in masters athletes and increases free testosterone. Taken together, these data indicate there is a place for carefully timed HIIT epochs in regimes of masters athletes. © 2017 The authors.

A chlorhexidine-loaded biodegradable cellulosic device for periodontal pockets treatment.

PubMed

Tabary, Nicolas; Chai, Feng; Blanchemain, Nicolas; Neut, Christel; Pauchet, Lucile; Bertini, Sabrina; Delcourt-Debruyne, Elisabeth; Hildebrand, Hartmut Frederic; Martel, Bernard

2014-01-01

Absorbent points widely used in endodontic therapy were transformed into bioresorbable chlorhexidine delivery systems for the treatment of the periodontal pocket by preventing its recolonization by the subgingival microflora. These paper points (PPs) were first oxidized to promote their resorption, then grafted with β-cyclodextrin (CD) or maltodextrin (MD) in order to achieve sustained delivery of chlorhexidine. We investigated the oxidation step parameters through the time of reaction and the nitric and phosphoric acid ratios in the oxidizing mixture, and then the dextrin grafting step parameters through the time and temperature of reaction. A first selection of the appropriate functionalization parameters was undertaken in relation to the degradation profile kinetics of the oxidized (PPO) and oxidized-grafted samples (PPO-CD and PPO-MD). Samples were then loaded with chlorhexidine digluconate (digCHX), a widely used antiseptic agent in periodontal therapy. The release kinetics of digCHX from PPO-CD and PPO-MD samples were compared to PP, PPO and to PerioChip(®) (a commercial digCHX containing gelatine chip) in phosphate buffered saline (pH 7.4) by ultraviolet spectrophotometry. The cytocompatibility of the oxidized-grafted PP was demonstrated by cell proliferation assays. Finally, the disc diffusion test from digCHX loaded PPO-MD samples immersed in human plasma was developed on pre-inoculated agar plates with four common periodontal pathogenic strains: Fusobacterium nucleatum, Prevotella melaninogenica, Aggregatibacter actinomycetem comitans and Porphyromonas gingivalis. To conclude, the optimized oxidized-dextrin-grafted PPs responded to our initial specifications in terms of resorption and digCHX release rates and therefore could be adopted as a reliable complementary periodontal therapy. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Synthesis and energy applications of oriented metal oxide nanoporous films

NASA Astrophysics Data System (ADS)

Wu, Qingliu

This dissertation mainly addresses the synthesis of well-ordered mesoporous titania thin films by dip coating with PEO-PPO-PEO triblock copolymer surfactant template P123. Because P123 is composed of poly(ethylene oxide) [PEO] and poly(propylene oxide) [PPO] blocks, concentrations of ingredients are adjusted to tune the films' wall thickness, pore size and mesophase. Structural changes are consistent with partitioning of species among PEO blocks, PPO blocks, and the PEO/PPO interface. Titanates localize near PEO and increase wall thickness (by 5 nm to 7 nm). Depending on aging temperature, PPG either swells the PPO cores (when it is hydrophobic) or introduces large (>200 nm) voids (when it is hydrophilic but phase separates during heating). 1-butanol localizes at the PEO/PPO interface to favor a 3D hexagonal mesostructure. In another approach, anodizing Ti foils yields vertically aligned titania nanotubes arrays with exceptional stabilities as anodes in lithium ion batteries; they maintain capacities of 130-230 mAhg-1 over 200 cycles. No microstructural changes are induced by battery cycling and good electrical contact is maintained. A diffusion induced stress model suggests that thin-walled nanotubes arrays should be stable under testing conditions, and that ordered hexagonal columnar pore arrays should have both high charge/discharge rates and low stress development. KEY WORDS: materials synthesis, porous, thin film, alternative energy, self-assembly

Modelling the interactions between free phenols, L-ascorbic acid, apple polyphenoloxidase and oxygen during a thermal treatment.

PubMed

Aka, Jean-Pierre; Courtois, Francis; Louarme, Loïc; Nicolas, Jacques; Billaud, Catherine

2013-06-01

The kinetics of degradation of chlorogenic acid (CG), (-) epicatechin (EPI), L-ascorbic acid (AA) and polyphenoloxidase (PPO) activity from Marie-Ménard apple in pH 3.8 solutions at 20 and 50°C were investigated to provide information on the impact of the presence of CG, EPI and/or AA on PPO thermostability. The effect of the heat treatment on their degradation by enzymatic and/or nonenzymatic ways was also studied. Stoechiokinetic reactions on the basis of experimental data and literature and determination of the kinetic constants (k) at 20 and 50°C were elaborated before modelling the interaction among reactants, by fitting the reaction curves to predictive model. Apple PPO was thermolabile, denaturing after 10min at 70°C. Losses of PPO activity were favoured by the presence of EPI in model solutions, compared with CG, due to the formation of o-quinones of EPI (QEPI) lowering PPO stability. Temperature quickened both enzymatic phenol oxidations before PPO deteriorated and the whole set of the chemical reactions, including the production of secondary oxidation products and CG or EPI regeneration. Results also confirmed that AA in excess induced a fast regeneration of CG and EPI from the corresponding o-quinones formed enzymatically via redox chemical reactions. Copyright © 2012 Elsevier Ltd. All rights reserved.

Knockdown of Polyphenol Oxidase Gene Expression in Potato (Solanum tuberosum L.) with Artificial MicroRNAs.

PubMed

Chi, Ming; Bhagwat, Basdeo; Tang, Guiliang; Xiang, Yu

2016-01-01

It is of great importance and interest to develop crop varieties with low polyphenol oxidase (PPO) activity for the food industry because PPO-mediated oxidative browning is a main cause of post-harvest deterioration and quality loss of fresh produce and processed foods. We recently demonstrated that potato tubers with reduced browning phenotypes can be produced by inhibition of the expression of several PPO gene isoforms using artificial microRNA (amiRNA) technology. The approach introduces a single type of 21-nucleotide RNA population to guide silencing of the PPO gene transcripts in potato tissues. Some advantages of the technology are: small RNA molecules are genetically transformed, off-target gene silencing can be avoided or minimized at the stage of amiRNA designs, and accuracy and efficiency of the processes can be detected at every step using molecular biological techniques. Here we describe the methods for transformation and regeneration of potatoes with amiRNA vectors, detection of the expression of amiRNAs, identification of the cleaved product of the target gene transcripts, and assay of the expression level of PPO gene isoforms in potatoes.

Hydrogen Bonding-Mediated Microphase Separation during the Formation of Mesoporous Novolac-Type Phenolic Resin Templated by the Triblock Copolymer, PEO-b-PPO-b-PEO

PubMed Central

Chu, Wei-Cheng; Chiang, Shih-Fan; Li, Jheng-Guang; Kuo, Shiao-Wei

2013-01-01

After blending the triblock copolymer, poly(ethylene oxide-b-propylene oxide-b-ethylene oxide) (PEO-b-PPO-b-PEO) with novolac-type phenolic resin, Fourier transform infrared spectroscopy revealed that the ether groups of the PEO block were stronger hydrogen bond acceptors for the OH groups of phenolic resin than were the ether groups of the PPO block. Thermal curing with hexamethylenetetramine as the curing agent resulted in the triblock copolymer being incorporated into the phenolic resin, forming a nanostructure through a mechanism involving reaction-induced microphase separation. Mild pyrolysis conditions led to the removal of the PEO-b-PPO-b-PEO triblock copolymer and formation of mesoporous phenolic resin. This approach provided a variety of composition-dependent nanostructures, including disordered wormlike, body-centered-cubic spherical and disorder micelles. The regular mesoporous novolac-type phenolic resin was formed only at a phenolic content of 40–60 wt %, the result of an intriguing balance of hydrogen bonding interactions among the phenolic resin and the PEO and PPO segments of the triblock copolymer. PMID:28788378

Highly Soluble p-Terphenyl and Fluorene Derivatives as Efficient Dopants in Plastic Scintillators for Sensitive Nuclear Material Detection.

PubMed

Yemam, Henok A; Mahl, Adam; Tinkham, Jonathan S; Koubek, Joshua T; Greife, Uwe; Sellinger, Alan

2017-07-03

Plastic scintillators are commonly used as first-line detectors for special nuclear materials. Current state-of-the-art plastic scintillators based on poly(vinyltoluene) (PVT) matrices containing high loadings (>15.0 wt %) of 2,5-diphenyloxazole (PPO) offer neutron signal discrimination in gamma radiation background (termed pulse shape discrimination, PSD), however, they suffer from poor mechanical properties. In this work, a series of p-terphenyl and fluorene derivatives were synthesized and tested as dopants in PVT based plastic scintillators as possible alternatives to PPO to address the mechanical property issue and to study the PSD mechanism. The derivatives were synthesized from low cost starting materials in high yields using simple chemistry. The photophysical and thermal properties were investigated for their influence on radiation sensitivity/detection performance, and mechanical stability. A direct correlation was found between the melting point of the dopants and the subsequent mechanical properties of the PVT based plastic scintillators. For example, select fluorene derivatives used as dopants produced scintillator samples with mechanical properties exceeding those of the commercial PPO-based scintillators while producing acceptable PSD capabilities. The physical properties of the synthesized dopants were also investigated to examine their effect on the final scintillator samples. Planar derivatives of fluorene were found to be highly soluble in PVT matrices with little to no aggregation induced effects. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Sustaining the Single Naval Battle: Enhancing USMC Expeditionary Logistics with the Addition of the Maritime Prepositioning Force (MPF) Auxiliary Dry Cargo / Ammunition Ships (T-AKES)

DTIC Science & Technology

2012-04-18

of Employment. Official Message. (CMC WASHINGTON DC PPO POE), DTG: 291447Z Mar 2010. 28 Military Sealift Command, Combat Logistics Force Webpage...Ammunition Ship (F-AKE) Concept of Employment. Official Message. (CMC WASHINGTON DC PPO POE), DTG: 291447Z Mar 2010. 28 30 Headquarters u.s. Marine Corps...Maritime Prepositioning Force (MPF) Auxiliary Dry Cargo/Ammunition Ship (I’-AKE) Concept of Employment. Official Message. (CMC WASHINGTON DC PPO POE

Nonhydrolytic sol-gel approach to facile creation of surface-bonded zirconia organic-inorganic hybrid coatings for sample preparation. Ι. Capillary microextraction of catecholamine neurotransmitters.

PubMed

Alhendal, Abdullah; Mengis, Stephanie; Matthews, Jacob; Malik, Abdul

2016-10-14

Nonhydrolytic sol-gel (NHSG) route was used for the creation of novel zirconia-polypropylene oxide (ZrO 2 -PPO) sol-gel hybrid sorbents in the form of surface coatings for the extraction and preconcentration of catecholamine neurotransmitters and molecules structurally related to their deaminated metabolites. In comparison to other sorbents made of inorganic transition metal oxides, the presented hybrid organic-inorganic sorbents facilitated reversible sorption properties that allowed for efficient desorption of the extracted analytes by LC-MS compatible mobile phases. The presented sol-gel hybrid sorbents effectively overcame the major drawbacks of traditional silica- or polymer-based sorbents by providing superior pH stability (pH range: 0-14), and a variety of intermolecular interactions. Nonaqueous sol-gel treatment of PPO with ZrCl 4 was employed for the derivatization of the terminal hydroxyl groups on PPO, providing zirconium trichloride-containing end groups characterized by enhanced sol-gel reactivity. NHSG ZrO 2 -PPO sorbent provided excellent microextraction performance for catecholamines, low detection limits (5.6-9.6pM), high run-to-run reproducibility (RSD 0.6-5.1%), high desorption efficiency (95.0-99.5%) and high enrichment factors (∼1480-2650) for dopamine and epinephrine, respectively, extracted from synthetic urine samples. The presented sol-gel sorbents provided effective alternative to conventional extraction media providing unique physicochemical characteristics and excellent extraction capability. Copyright © 2016 Elsevier B.V. All rights reserved.

A preferred provider organization (PPO) case study for mental health and substance abuse.

PubMed

Gomillion, I; Self, D R

1988-01-01

The Preferred Provider Organization concept is quickly becoming more popular because of its relative cost-effectiveness and recent successes. Managed care through means of this mental health and substance abuse PPO may well serve as the prototype for the general health care cost containment efforts of the future for the self-insured insurance plans for Alabama state employees and teachers. The first year also revealed several problems in the original proposal especially with respect to the unintended attractiveness of inpatient/residential care. Consequently, copayment plans were added to dissuade unnecessary lengthy stays (see Table 2). Second, a new quality assurance mechanism has been added to further evaluate the need for admissions to facilities, as well as for the need for continued inpatient treatment. The Alabama Quality Assurance Foundation (AQAF) began on January 1, 1988, conducting the preadmission certification on all admissions based upon criteria established jointly by AQAF and the PPO providers. In addition, AQAF will conduct continuing stay reviews at predetermined time periods to ensure that continued treatment in an inpatient setting is indeed necessary.

Bis(pinacolato)diboron as an additive for the detection of thermal neutrons in plastic scintillators

NASA Astrophysics Data System (ADS)

Mahl, Adam; Yemam, Henok A.; Stuntz, John; Remedes, Tyler; Sellinger, Alan; Greife, Uwe

2016-04-01

A readily available and inexpensive boron compound was tested as an additive for the detection of thermal neutrons in plastic scintillators. Bis(pinacolato)diboron (B2Pin2) was determined to be a compatible boron source (8.51 wt% boron, 1.70 wt% 10B) in poly(vinyltoluene) based matrices. Plastic scintillator blends of 1-20 wt% 2,5-diphenyloxazole (PPO), 0.1 wt% 1,4-bis(5-phenyloxazol-2-yl) benzene (POPOP) and 1-15 wt% B2Pin2 were prepared that provided optical clarity, good mechanical properties, and the capability of thermal neutron detection. Independent of B2Pin2 concentration, strong 10B neutron capture signals around 90 keVee were observed at essentially constant light output. Increasing PPO concentration allowed for the use of pulse shape discrimination (PSD) in both fast and thermal neutron detection. High PPO concentrations appear to cause additional alpha quenching that affected the 10B neutron capture signal. Aging effects after storage in air for several months were observed, which led to degradation of performance and in some samples of mechanical stability.

Medicare Special Needs Plan (SNP)

MedlinePlus

... of Medicare Advantage Plan (like an HMO or PPO). Medicare SNPs limit membership to people with specific ... work Health Maintenance Organization (HMO) Preferred Provider Organization (PPO) Private Fee-for-Service (PFFS) Find someone to ...

Health Insurance: Understanding Your Health Plan's Rules

MedlinePlus

... Point of service (POS) plan Preferred provider organization (PPO) Rules for selecting doctors and hospitals Managed care ... If you have a POS plan or a PPO, the insurance company will probably pay for you ...

PEO-PPO-PEO Tri-Block Copolymers for Gene Delivery Applications in Human Regenerative Medicine—An Overview

PubMed Central

Cucchiarini, Magali

2018-01-01

Lineal (poloxamers or Pluronic®) or X-shaped (poloxamines or Tetronic®) amphiphilic tri-block copolymers of poly(ethylene oxide) and poly(propylene oxide) (PEO-PPO-PEO) have been broadly explored for controlled drug delivery in different regenerative medicine approaches. The ability of these copolymers to self-assemble as micelles and to undergo sol-to-gel transitions upon heating has endowed the denomination of “smart” or “intelligent” systems. The use of PEO-PPO-PEO copolymers as gene delivery systems is a powerful emerging strategy to improve the performance of classical gene transfer vectors. This review summarizes the state of art of the application of PEO-PPO-PEO copolymers in both nonviral and viral gene transfer approaches and their potential as gene delivery systems in different regenerative medicine approaches. PMID:29518011

Salicylic acid inhibits enzymatic browning of fresh-cut Chinese chestnut (Castanea mollissima) by competitively inhibiting polyphenol oxidase.

PubMed

Zhou, Dan; Li, Lin; Wu, Yanwen; Fan, Junfeng; Ouyang, Jie

2015-03-15

The inhibitory effect and associated mechanisms of salicylic acid (SA) on the browning of fresh-cut Chinese chestnut were investigated. Shelled and sliced chestnuts were immersed in different concentrations of an SA solution, and the browning of the chestnut surface and interior were inhibited. The activities of polyphenol oxidase (PPO) and peroxidase (POD) extracted from chestnuts were measured in the presence and absence of SA. SA at concentrations higher than 0.3g/L delayed chestnut browning by significantly inhibiting the PPO activity (P<0.01), and the POD activity was not significantly affected (P>0.05). The binding and inhibition modes of SA with PPO and POD, determined by AUTODOCK 4.2 and Lineweaver-Burk plots, respectively, established SA as a competitive inhibitor of PPO. Copyright © 2014 Elsevier Ltd. All rights reserved.

Molecular characterization of prophenoloxidase-1 (PPO1) and the inhibitory effect of kojic acid on phenoloxidase (PO) activity and on the development of Zeugodacus tau (Walker) (Diptera: Tephritidae).

PubMed

Zhang, H-H; Luo, M-J; Zhang, Q-W; Cai, P-M; Idrees, A; Ji, Q-E; Yang, J-Q; Chen, J-H

2018-06-22

Phenoloxidase (PO) plays a key role in melanin biosynthesis during insect development. Here, we isolated the 2310-bp full-length cDNA of PPO1 from Zeugodacus tau, a destructive horticultural pest. qRT-polymerase chain reaction showed that the ZtPPO1 transcripts were highly expressed during larval-prepupal transition and in the haemolymph. When the larvae were fed a 1.66% kojic acid (KA)-containing diet, the levels of the ZtPPO1 transcripts significantly increased by 2.79- and 3.39-fold in the whole larvae and cuticles, respectively, while the corresponding PO activity was significantly reduced; in addition, the larval and pupal durations were significantly prolonged; pupal weights were lowered; and abnormal phenotypes were observed. An in vitro inhibition experiment indicated that KA was an effective competitive inhibitor of PO in Z. tau. Additionally, the functional analysis showed that 20E could significantly up-regulate the expression of ZtPPO1, induce lower pupal weight, and advance pupation. Knockdown of the ZtPPO1 gene by RNAi significantly decreased mRNA levels after 24 h and led to low pupation rates and incomplete pupae with abnormal phenotypes during the larval-pupal interim period. These results proved that PO is important for the normal growth of Z. tau and that KA can disrupt the development of this pest insect.

Developing a PPO: challenges and benefits.

PubMed

Range, R P

1984-12-01

When deciding upon which kind of alternative delivery system to develop, Saint Vincent Charity Hospital and Health Center, Cleveland, selected the preferred provider organization (PPO) mode because of four basic advantages: (1) the health care consumer's freedom to choose providers; (2) effective cost containment; (3) coordination of services among allied providers; and (4) health promotion programs. More specifically, the Ohio Health Choice Plan (OHCP) benefits hospitals by assisting to maintain or increase market share, facilitating prompt claims payments, and improving financial mix. Physicians benefit not only because they receive prompt payment and are not a risk but also because the fee-for-service system is retained and their market shares can also be preserved or enhanced. Employers' advantages include savings through controlled utilization, positive employee relations, and improved management information. Employees' benefits include lower out-of-pocket costs and freedom of choice. As a full-service PPO, the organization provides benefits plans designed to meet each employer's needs as well as actuary services, claims screening and processing, benefits coordination, utilization control, management reporting, health promotion activities, and networking capabilities. Four major challenges do confront PPOs: 1. Start-up and operating costs can be significant; 2. The administrative skills required are different from those used in traditional health care systems; 3. The commitment in implementing and operating a PPO; and 4. All participating providers must genuinely accept the PPO. A PPO's success also can be measured in three ways: the development of a strong network; size of enrollment; and effectiveness in utilization control.(ABSTRACT TRUNCATED AT 250 WORDS)

Cost Benefit Analysis of Expeditionary Warfare Training Group Atlantic Forward Air Controller / Joint Terminal Attack Controller Training Options

DTIC Science & Technology

2013-03-13

Previous versions were signed in 2004, 2007, and 2010. The most recent version was signed 1 January 2012 by HQMC PPO and includes 17 United States DoD and...Amos) to Cdr USJFCOM - 21 Mar 2008 From CMC PPO POG: Ground Board discussion Collateral Duties of JTAC not compatible with primary duties MSG dtd...EWTGLANT Trng Cmd PPO APP MCSCG MARFORCOM USFFC CNAL CSFWL SFWSL CVW-X CVW-X OPNAV N-98 II MEF 2D MARDIV 2D MAW OPNAV N-95 NAWCTSD

Toxicological characterization of diesel engine emissions using biodiesel and a closed soot filter

NASA Astrophysics Data System (ADS)

Kooter, Ingeborg M.; van Vugt, Marcel A. T. M.; Jedynska, Aleksandra D.; Tromp, Peter C.; Houtzager, Marc M. G.; Verbeek, Ruud P.; Kadijk, Gerrit; Mulderij, Mariska; Krul, Cyrille A. M.

2011-03-01

This study was designed to determine the toxicity (oxidative stress, cytotoxicity, genotoxicity) in extracts of combustion aerosols. A typical Euro III heavy truck engine was tested over the European Transient Cycle with three different fuels: conventional diesel EN590, biodiesel EN14214 as B100 and blends with conventional diesel (B5, B10, and B20) and pure plant oil DIN51605 (PPO). In addition application of a (wall flow) diesel particulate filter (DPF) with conventional diesel EN590 was tested. The use of B100 or PPO as a fuel or the DPF reduced particulate matter (PM) mass and numbers over 80%. Similarly, significant reduction in the emission of chemical constituents (EC 90%, (oxy)-PAH 70%) were achieved. No significant changes in nitro-PAH were observed. The use of B100 or PPO led to a NOx increase of about 30%, and no increase for DPF application. The effects of B100, PPO and the DPF on the biological test results vary strongly from positive to negative depending on the biological end point. The oxidative potential, measured via the DTT assay, of the B100 and PPO or DPF emissions is reduced by 95%. The cytotoxicity is increased for B100 by 200%. The measured mutagenicity, using the Ames assay test with TA98 and YG1024 strains of Salmonella typhimurium indicate a dose response for the nitroarene sensitive YG1024 strain for B100 and PPO (fold induction: 1.6). In summary B100 and PPO have good potential for the use as a second generation biofuel resulting in lower PM mass, similar to application of a DPF, but caution should be made due to potential increased toxicity. Besides regulation via mass, the biological reactivity of exhaust emissions of new (bio)fuels and application of new technologies, needs attention. The different responses of different biological tests as well as differences in results between test laboratories underline the need for harmonization of test methods and international cooperation.

[Postoperative implant-associated osteomyelitis of the shoulder: Hardware-retaining revision concept using temporary drainage].

PubMed

Schnetzke, M; Aytac, S; Herrmann, P; Wölfl, C; Grützner, P A; Heppert, V; Guehring, T

2015-06-01

Posttraumatic and postoperative osteomyelitis (PPO) is a subgroup of bone infections with increasing importance. However, to date no standardized reoperation concept exists particularly for patients with PPO of the shoulder region. Therefore the purpose of this study was to evaluate a revision concept including débridement, irrigation, and insertion of temporary drainage with hardware retention until healing. A total of 31 patients with PPO were included with a proximal humerus fracture (n = 14), clavicle fracture (n = 10), or AC-joint separation (n = 7). In all, 27 of these patients could be followed for > 1 year. Hardware retention until fracture or ligament healing could be achieved in > 83%. Six patients required follow-up débridement due to recurrent infections, but then were unremarkable. Clinical outcome showed excellent Constant scores (91.6 ± 2.8). A cost-efficient, simple, and successful revision concept for patients with PPO of the shoulder region is described.

Characterisation of phenol oxidase and peroxidase from maize silk.

PubMed

Sukalović, V Hadzi-Tasković; Veljović-Jovanović, S; Maksimović, J Dragisić; Maksimović, V; Pajić, Z

2010-05-01

Silk of some maize genotypes contains a high level of phenolics that undergo enzymatic oxidation to form quinones, which condense among themselves or with proteins to form brown pigments. Two phenolic oxidizing enzymes, peroxidase (POD; EC 1.11.1.7) and polyphenol oxidase (PPO; EC 1.10.3.1), from maize (Zea mays L.) silk were characterised with respect to their preferred substrate, different isoforms and specific effectors. One browning silk sample with high, and two non-browning samples with low phenolic content were investigated. Although POD oxidizes a wide range of phenolic substrates in vitro, its activity rate was independent of silk phenolic content. PPO activity, detected with o-diphenolic substrates, was abundant only in browning silk, and low or absent in non-browning silk. Pollination increased POD but not PPO activity. Isoelectric-focusing (IEF) and specific staining for POD and PPO showed a high degree of polymorphism that varied with silk origin. The IEF pattern of POD revealed a number of anionic and several cationic isoenzymes, with the most pronounced having neutral pI 7 and a basic isoform with pI 10. Detected isoforms of PPO were anionic, except for one neutral form found only in browning silk, and occupied positions different from those of POD. Different inhibitory effects of NaN(3), EDTA, KCN, and L-cysteine, as well as different impacts of a variety of cations on the oxidation of chlorogenic acid, mediated by PPO or POD, were detected. The findings are discussed in terms of a possible roles of these enzymes in defence and pollination.

Effect of ionic detergents, nonionic detergents, and chaotropic agents on polyphenol oxidase activity from dormant saffron (Crocus sativus L.) corms.

PubMed

Saeidian, Shahriar; Keyhani, Ezzatollah; Keyhani, Jacqueline

2007-05-02

Polyphenol oxidase (PPO; EC 1.14.18.1) catalyzes the hydroxylation of monophenols to o-diphenols (cresolase activity) and the oxidation of o-diphenols to o-quinones (catecholase activity), leading to browning in plants and produce. Further interest in the enzyme has been triggered by the active role that it plays in plant defense systems. PPO can be found in latent forms and is activated in vitro by various agents including urea, detergents, and proteases. The activation of PPO from several sources by sodium dodecyl sulfate (SDS) has been extensively investigated, but reports on the effect of other detergents or on the differential effect of detergents on each of PPO's activities are scarce. In addition, investigations on the enzyme in other plant parts besides fruits and vegetables are also scarce. Here, the effect of various detergents and chaotropic agents on PPO from dormant saffron (Crocus sativus L.) corm extract was investigated. SDS and sarkosyl activated the cresolase activity, while only SDS activated the catecholase activity. All other detergents tested, in milli- or micromolar concentrations, inhibited the cresolase activity but barely affected the catecholase activity. In contrast, urea and guanidine-HCl drastically inhibited the catecholase activity but moderately inhibited the cresolase activity. The same effects were obtained on the partially purified enzyme. Results identified a PPO, present in dormant corms, which was activated only by anionic detergents and was inhibited by other reputed activating agents such as urea. Results also emphasized the differences in structure and accessibility of the active sites for cresolase and catecholase activities.

Quantifying Residues from Postharvest Propylene Oxide Fumigation of Almonds and Walnuts.

PubMed

Jimenez, Leonel R; Hall, Wiley A; Rodriquez, Matthew S; Cooper, William J; Muhareb, Jeanette; Jones, Tom; Walse, Spencer S

2015-01-01

A novel analytical approach involving solvent extraction with methyl tert-butyl ether (MTBE) followed by GC was developed to quantify residues that result from the postharvest fumigation of almonds and walnuts with propylene oxide (PPO). Verification and quantification of PPO, propylene chlorohydrin (PCH) [1-chloropropan-2-ol (PCH-1) and 2-chloropropan-1-ol (PCH-2)], and propylene bromohydrin (PBH) [1-bromopropan-2-ol (PBH-1) and 2-bromopropan-1-ol (PBH-2)] was accomplished with a combination of electron impact ionization MS (EIMS), negative ion chemical ionization MS (NCIMS), and electron capture detection (ECD). Respective GC/EIMS LOQs for PPO, PCH-1, PCH-2, PBH-1, and PBH-2 in MTBE extracts were [ppm (μg/g nut)] 0.9, 2.1, 2.5, 30.3, and 50.0 for almonds and 0.8, 2.2, 2.02, 41.6, and 45.7 for walnuts. Relative to GC/EIMS, GC-ECD analyses resulted in no detection of PPO, similar detector responses for PCH isomers, and >100-fold more sensitive detection of PBH isomers. NCIMS did not enhance detection of PBH isomers relative to EIMS and was, respectively, approximately 20-, 5-, and 10-fold less sensitive to PPO, PCH-1, and PCH-2. MTBE extraction efficiencies were >90% for all analytes. The 10-fold concentration of MTBE extracts yielded recoveries of 85-105% for the PBH isomers and a concomitant decrease in LODs and LOQs across detector types. The recoveries of PCH isomers and PPO in the MTBE concentrate were relatively low (approximately 50 to 75%), which confound improvements in LODs and LOQs regardless of detector type.

Structure-activity relationships of diphenyl-ether as protoporphyrinogen oxidase inhibitors: insights from computational simulations

NASA Astrophysics Data System (ADS)

Hao, Ge-Fei; Tan, Ying; Yu, Ning-Xi; Yang, Guang-Fu

2011-03-01

Protoporphyrinogen oxidase (PPO, EC 1.3.3.4), which has been identified as a significant target for a great family of herbicides with diverse chemical structures, is the last common enzyme responsible for the seventh step in the biosynthetic pathway to heme and chlorophyll. Among the existing PPO inhibitors, diphenyl-ether is the first commercial family of PPO inhibitors and used as agriculture herbicides for decades. Most importantly, diphenyl-ether inhibitors have been found recently to possess the potential in Photodynamic therapy (PDT) to treat cancer. Herein, molecular dynamics simulations, approximate free energy calculations and hydrogen bond energy calculations were integrated together to uncover the structure-activity relationships of this type of PPO inhibitors. The calculated binding free energies are correlated very well with the values derived from the experimental k i data. According to the established computational models and the results of approximate free energy calculation, the substitution effects at different position were rationalized from the view of binding free energy. Some outlier ( e.g. LS) in traditional QSAR study can also be explained reasonably. In addition, the hydrogen bond energy calculation and interaction analysis results indicated that the carbonyl oxygen on position-9 and the NO2 group at position-8 are both vital for the electrostatic interaction with Arg98, which made a great contribution to the binding free energy. These insights from computational simulations are not only helpful for understanding the molecular mechanism of PPO-inhibitor interactions, but also beneficial to the future rational design of novel promising PPO inhibitors.

Development of biosensor for phenolic compounds containing PPO in β-cyclodextrin modified support and iridium nanoparticles.

PubMed

da Silva, Cristiano P; Franzoi, Ana C; Fernandes, Suellen C; Dupont, Jairton; Vieira, Iolanda C

2013-04-10

A biosensor based on the iridium nanoparticles dispersed in ionic liquid (IL) 1-butyl-3-methylimidazolium hexafluorophosphate (Ir-BMI·PF6) and a celery (Apium graveolens) extract as a source of polyphenol oxidase (PPO) was constructed. A modified support based on β-cyclodextrin (β-CDEP) was used for enzyme immobilization. The behavior of phenolic compounds was investigated by square-wave voltammetry and rutin was selected by presenting the greatest signal. The best performance was obtained with a composition of 70:10:10:10% (w/w/w/w) of the graphite powder:β-CDEP:Nujol:Ir-BMI·PF6 composition, a PPO concentration of 500unitsmL(-1), in 0.1M phosphate buffer solution (pH 6.0) with frequency, pulse amplitude and scan increment at 100Hz, 60mV, and 3.0mV, respectively. Under optimized conditions, the cathodic currents increased linearly for the rutin concentration range of 1.3×10(-7)-2.0×10(-6)M with a detection limit of 7.9×10(-8)M. This sensor demonstrated acceptable repeatability and reproducibility and the results for the rutin recovery ranged from 92.8 to 103.4%. A relative error of 0.7% was obtained in the rutin determination in simulated samples. Copyright © 2013 Elsevier Inc. All rights reserved.

Isolation of a polyphenol oxidase (PPO) cDNA from artichoke and expression analysis in wounded artichoke heads.

PubMed

Quarta, Angela; Mita, Giovanni; Durante, Miriana; Arlorio, Marco; De Paolis, Angelo

2013-07-01

The polyphenol oxidase (PPO) enzyme, which can catalyze the oxidation of phenolics to quinones, has been reported to be involved in undesirable browning in many plant foods. This phenomenon is particularly severe in artichoke heads wounded during the manufacturing process. A full-length cDNA encoding for a putative polyphenol oxidase (designated as CsPPO) along with a 1432 bp sequence upstream of the starting ATG codon was characterized for the first time from [Cynara cardunculus var. scolymus (L.) Fiori]. The 1764 bp CsPPO sequence encodes a putative protein of 587 amino acids with a calculated molecular mass of 65,327 Da and an isoelectric point of 5.50. Analysis of the promoter region revealed the presence of cis-acting elements, some of which are putatively involved in the response to light and wounds. Expression analysis of the gene in wounded capitula indicated that CsPPO was significantly induced after 48 h, even though the browning process had started earlier. This suggests that the early browning event observed in artichoke heads was not directly related to de novo mRNA synthesis. Finally, we provide the complete gene sequence encoding for polyphenol oxidase and the upstream regulative region in artichoke. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Inhibition of enzymatic browning in actual food systems by the Maillard reaction products.

PubMed

Mogol, Burçe Ataç; Yildirim, Asli; Gökmen, Vural

2010-12-01

The Maillard reaction occurring between amino acids and sugars produces neo-formed compounds having certain levels of antioxidant activity depending on the reaction conditions and the type of reactants. The objective of this study was to investigate enzymatic browning inhibition capacity of Maillard reaction products (MRPs) formed from different amino acids including arginine (Arg), histidine (His), lysine (Lys) and proline (Pro). The inhibitory effects of the MRPs on polyphenol oxidase (PPO) were determined. The total antioxidant capacity (TAC) of MRPs derived from different amino acids were in the order Arg > His > Lys > Pro. The TAC and PPO inhibition of MRPs were evaluated as a function of temperature (80-120 °C), time (1-6 h) and pH (2-12). Arg-Glc and His-Glc MRPs exhibited strong TAC and PPO inhibition. Increasing temperature (up to 100 °C) and time also increased TAC and PPO inhibition. Kinetics analysis indicated a mixed type inhibition of PPO by MRPs. The results indicate that the MRPs derived from Arg and His under certain reaction conditions significantly prevent enzymatic browning in actual food systems. The intermediate compounds capable of preventing enzymatic browning are reductones and dehydroreductones, as confirmed by liquid chromatographic-mass spectrometric analyses. Copyright © 2010 Society of Chemical Industry.

Planetary period modulations of Saturn's magnetotail current sheet: A simple illustrative mathematical model

NASA Astrophysics Data System (ADS)

Cowley, S. W. H.; Provan, G.; Hunt, G. J.; Jackman, C. M.

2017-01-01

We mathematically model the modulation effects on Saturn's equatorial magnetotail and magnetodisk current sheet produced by the combined magnetic field perturbations of the northern and southern planetary period oscillation (PPO) systems, specifically north-south displacements associated with the radial perturbation field and thickness modulations associated with the colatitudinal perturbation field. Since the phasing of the two PPO systems is taken to be related to the radial field perturbations, while the relative phasing of the colatitudinal perturbations is opposite for the two systems, the north-south oscillations reinforce when the two PPO systems are in phase, while the thickening-thinning effects reinforce when they are in antiphase. For intermediate relative phases we show that when the northern PPO system leads the southern the sheet is thicker when moving south to north than when moving north to south, while when the northern PPO system lags the southern the sheet is thicker when moving north to south than when moving south to north, thus leading to sawtooth profiles in the radial field for near-equatorial observers, of opposite senses in the two cases. Given empirically determined modulation amplitudes, the maximum sawtooth effect is found to be small when one system dominates the other, but becomes clear when the amplitude of one system lies within a factor of 2 of the other.

Relation between Peak Power Output in Sprint Cycling and Maximum Voluntary Isometric Torque Production.

PubMed

Kordi, Mehdi; Goodall, Stuart; Barratt, Paul; Rowley, Nicola; Leeder, Jonathan; Howatson, Glyn

2017-08-01

From a cycling paradigm, little has been done to understand the relationships between maximal isometric strength of different single joint lower body muscle groups and their relation with, and ability to predict PPO and how they compare to an isometric cycling specific task. The aim of this study was to establish relationships between maximal voluntary torque production from isometric single-joint and cycling specific tasks and assess their ability to predict PPO. Twenty male trained cyclists participated in this study. Peak torque was measured by performing maximum voluntary contractions (MVC) of knee extensors, knee flexors, dorsi flexors and hip extensors whilst instrumented cranks measured isometric peak torque from MVC when participants were in their cycling specific position (ISOCYC). A stepwise regression showed that peak torque of the knee extensors was the only significant predictor of PPO when using SJD and accounted for 47% of the variance. However, when compared to ISOCYC, the only significant predictor of PPO was ISOCYC, which accounted for 77% of the variance. This suggests that peak torque of the knee extensors was the best single-joint predictor of PPO in sprint cycling. Furthermore, a stronger prediction can be made from a task specific isometric task. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comparative study of the banana pulp browning process of 'Giant Dwarf' and FHIA-23 during fruit ripening based on image analysis and the polyphenol oxidase and peroxidase biochemical properties.

PubMed

Escalante-Minakata, Pilar; Ibarra-Junquera, Vrani; Ornelas-Paz, José de Jesús; García-Ibáñez, Victoria; Virgen-Ortíz, José J; González-Potes, Apolinar; Pérez-Martínez, Jaime D; Orozco-Santos, Mario

2018-01-01

This work presents a novel method to associate the polyphenol oxidase (PPO) and the peroxidase (POD) activities with the ripening-mediated color changes in banana peel and pulp by computational image analysis. The method was used to follow up the de-greening of peel and browning of homogenized pulp from 'Giant Dwarf' (GD: Musa AAA, subgroup Cavendish) and FHIA-23 (tetraploid hybrid, AAAA) banana cultivars. In both cultivars, the color changes of peel during the ripening process clearly showed four stages, which were used to group the fruit into ripening stages. The PPO and POD were extracted from pulp of fruit at these ripening stages, precipitated, and partially purified by gel filtration chromatography. Moreover, the pulp browning was digitally monitored after homogenization for a span time of up to 120 min. The browning level was higher for GD than FHIA-23 tissues. This fact correlated with an 11.7-fold higher PPO activity in the GD cultivar, as compared with that of FHIA-23. POD activity was 8.1 times higher for GD as compared that that of FHIA-23.

The use of cross-linked chitosan beads for nutrients (nitrate and orthophosphate) removal from a mixture of P-PO4, N-NO2 and N-NO3.

PubMed

Jóźwiak, Tomasz; Filipkowska, Urszula; Szymczyk, Paula; Kuczajowska-Zadrożna, Małgorzata; Mielcarek, Artur

2017-11-01

A hydrogel chitosan sorbent ionically cross-linked with sodium citrate and covalently cross-linked with epichlorohydrin was used to remove nutrients from an equimolar mixture of P-PO 4 , N-NO 2 and N-NO 3 . The scope of the study included, among other things, determination of the influence of pH on nutrient sorption effectiveness, nutrient sorption kinetics as well as determination of the maximum sorption capacity of cross-linked chitosan sorbents regarding P-PO 4 (H 2 PO 4 - , HPO 4 2- ), N-NO 2 (HNO 2 , NO 2 - ), and N-NO 3 (NO 3 - ). The effect of the type of the cross-linking agent on the affinity of the modified chitosan to each nutrient was studied as well. The kinetics of nutrient sorption on the tested chitosan sorbents was best described with the pseudo-second order model. The model of intramolecular diffusion showed that P-PO 4 , N-NO 2 and N-NO3 sorption on cross-linked hydrogel chitosan beads proceeded in two phases. The best sorbent of nutrients turned out to be chitosan cross-linked covalently with epichlorohydrin; with P-PO 4 , N-NO 2 and N-NO 3 sorption capacity reaching: 1.23, 0.94 and 0.76mmol/g, respectively (total of 2.92mmol/g). For comparison, the sorption capacity of chitosan cross-linked ionically with sodium citrate was: 0.43, 0.39 and 0.39mmol/g for P-PO 4 , N-NO 2 and N-NO 3 , respectively (total of 1.21mmol/g). Copyright © 2017 Elsevier B.V. All rights reserved.

Ultrasound-assisted three-phase partitioning of polyphenol oxidase from potato peel (Solanum tuberosum).

PubMed

Niphadkar, Sonali S; Rathod, Virendra K

2015-01-01

Conventional three phase partitioning (TPP) and ultrasound assisted three phase partitioning (UATPP) were optimized for achieving the maximum extraction and purification of polyphenol oxidase (PPO) from waste potato peels. Different process parameters such as ammonium sulfate (NH4)2SO4 concentration, crude extract to t-butanol ratio, time, temperature and pH were studied for conventional TPP. Except agitation speed, the similar parameters were also optimized for UATPP. Further additional parameters were also studied for UATPP viz. irradiation time at different frequencies, duty cycle and, rated power in order to obtain the maximum purification factor and recovery of PPO. The optimized conditions for conventional TPP were (NH4)2SO4 0-40% (w/v), extract to t-butanol ratio 1:1 (v/v), time 40 min and pH 7 at 30°C. These conditions provided 6.3 purification factor and 70% recovery of PPO from bottom phase. On the other hand, UATPP gives maximum purification fold of 19.7 with 98.3% recovery under optimized parameters which includes (NH4)2SO4 0-40% (w/v), crude extract to t-butanol ratio 1: 1 (v/v) pH 7, irradiation time 5 min with 25 kHz, duty cycle 40% and rated power 150W at 30°C. UATPP delivers higher purification factor and % recovery of PPO along with reduced operation time from 40 min to 5 min when compared with TPP. SDS PAGE showed partial purification of PPO enzyme with UATPP with molecular weight in the range of 26-36 kDa. Results reveal that UATPP would be an attractive option for the isolation and purification of PPO without need of multiple steps. © 2015 American Institute of Chemical Engineers.

High isostatic pressure and thermal processing of açaí fruit (Euterpe oleracea Martius): Effect on pulp color and inactivation of peroxidase and polyphenol oxidase.

PubMed

Jesus, Ana Laura Tibério de; Leite, Thiago Soares; Cristianini, Marcelo

2018-03-01

The present study evaluated the effect of high isostatic pressure (HIP) on the activity of peroxidase (POD) and polyphenol oxidase (PPO) from açaí. Açaí pulp was submitted to several combinations of pressure (400, 500, 600MPa), temperature (25 and 65°C) for 5 and 15min. The combined effect of HIP technology and high temperatures (690MPa by 2 and 5min at 80°C) was also investigated and compared to the conventional thermal treatment (85°C/1min). POD and PPO enzyme activity and instrumental color were examined after processing and after 24h of refrigerated storage. Results showed stability of POD for all pressures at 25°C, which proved to be heat-resistant and baro-resistant at 65°C. For PPO, the inactivation at 65°C was 71.7% for 600MPa after 15min. In general, the increase in temperature from 25°C to 65°C reduced the PPO relative activity with no changes in color. Although the thermal treatment and the HIP (690MPa) along with high temperature (80°C) reduced the PPO relative activity, and relevant darkening was observed in the processed samples. Thus, it can be concluded that POD is more baro-resistant than PPO in açaí pulp subjected to the same HIP processing conditions and processing at 600MPa/65°C for 5min may be an effective alternative for thermal pasteurization treatments. Copyright © 2017 Elsevier Ltd. All rights reserved.

Determinants of wheat noodle color.

PubMed

Morris, Craig F

2018-05-16

Noodles are a leading food in the world, and color is a key determinant of consumer acceptance. In this review the two prominent forms of wheat noodles are considered, white salted and alkaline. Many of the preparation and evaluation strategies are the same for both, with prominence placed on 'brightness' (L*) or a lack of discoloration (ΔL*), and the absence of 'specks'. All raw noodles darken over time. Increasing protein content of flours almost always translates into darker noodles. Greater discoloration is also associated with higher flour extraction rates, higher ash contents and higher starch damage. Increasing storage time, dough water absorption, and temperature all often lead to greater discoloration. There is a large range in noodle color variation, and much of this variation is associated with genetics. Consequently, much research has been devoted to methods of screening germplasm, either as whole seeds, meals, flours or noodle sheets. Polyphenol oxidase (PPO) is a primary culprit in noodle discoloration and has guided much of the research on noodle color. It is now possible to select germplasm with very low levels of PPO through the use of efficacious phenotype screens and the use of molecular markers. Lastly, the success of this research has provided the opportunity to select wheat breeding lines with nil PPO activity, and to combine favorable alleles at multiple PPO loci. Yet, when noodles are prepared, we continue to observe discoloration. As our ability to minimize PPO activity increases, this 'non-PPO' discoloration has become more important. Perhaps the 'holy grail' is a noodle that never discolors, and has the 'perfect' level of a* (redness, zero?) and b* (yellowness/creaminess). This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Optimizing elderly pharmacotherapy: polypharmacy vs. undertreatment. Are these two concepts related?

PubMed

Blanco-Reina, Encarnación; Ariza-Zafra, Gabriel; Ocaña-Riola, Ricardo; León-Ortíz, Matilde; Bellido-Estévez, Inmaculada

2015-02-01

This study aimed to estimate the prevalence of polypharmacy and potential prescribing omissions (PPO) and their related factors in community-dwelling elderly patients and to examine any possible relationship between these two concepts. A cross-sectional study was carried out including patients 65 years of age or over living on the island of Lanzarote (Spain). Sociodemographic, clinical and functional variables were collected, together with full data on drug therapy. The percentage of patients receiving ≥5 medications (polypharmacy) and the percentage of patients receiving at least one PPO according to Screening Tool to Alert doctors to Right Treatment (START) criteria (underprescription) were the two primary endpoints. A total of 1844 medications were prescribed to the 407 patients included in our study. The overall prevalence of polypharmacy was 45 %. The risk factors associated with polypharmacy were comorbidity (OR 1.98, 95 % CI 1.63-2.44), limitations in activities of daily living (ADL; OR 3.0, 95 % CI 1.51-6.11), and being prescribed a drug in the Anatomical Therapeutic Chemical classification (ATC) C group (OR 7.92, 95 % CI 4.10-16.25) or in the N group (OR 3.80, 95 % CI 2.25-6.55). START criteria identified a total of 303 PPO in 170 (41.8 %) subjects. The risk of PPO increased by 60 % for every additional point in the Charlson Comorbidity Index (OR 1.60, 95 % CI 1.35-1.91). Polypharmacy also independently predicted the odds of at least one PPO according to START criteria (OR 2.19, 95 % CI 1.36-3.55). Our findings show high rates of polypharmacy and PPO, as well as a clear relationship between these two concepts.

Cost and Schedule Analytical Techniques Development: Option 1

NASA Technical Reports Server (NTRS)

1996-01-01

This Final Report summarizes the activities performed by Science Applications International Corporation (SAIC) for the base contract year from December 1, 1995 through November 30, 1996. The Final Report is in compliance with Paragraph 5 of Section F of the contract. This CSATD contract provides technical services and products to the NASA Marshall Space Flight Center's (MSFC) Engineering Cost Office (PPO3) and the Program Plans and Requirements Officer (PPO2). Detailed Monthly Progress Reports were submitted to MSFC in accordance with the contract's Statement of Work Section IV "Reporting and Documentation". These reports spelled out each month's specific work accomplishments, deliverables submitted, major meetings held, and other pertinent information. This Final Report will summarize these activities at a higher level.

Development of a Polarizable Force Field for Molecular Dynamics Simulations of Poly (Ethylene Oxide) in Aqueous Solution.

PubMed

Starovoytov, Oleg N; Borodin, Oleg; Bedrov, Dmitry; Smith, Grant D

2011-06-14

We have developed a quantum chemistry-based polarizable potential for poly(ethylene oxide) (PEO) in aqueous solution based on the APPLE&P polarizable ether and the SWM4-DP polarizable water models. Ether-water interactions were parametrized to reproduce the binding energy of water with 1,2-dimethoxyethane (DME) determined from high-level quantum chemistry calculations. Simulations of DME-water and PEO-water solutions at room temperature using the new polarizable potentials yielded thermodynamic properties in good agreement with experimental results. The predicted miscibility of PEO and water as a function of the temperature was found to be strongly correlated with the predicted free energy of solvation of DME. The developed nonbonded force field parameters were found to be transferrable to poly(propylene oxide) (PPO), as confirmed by capturing, at least qualitatively, the miscibility of PPO in water as a function of the molecular weight.

The Plant Phenology Ontology: A New Informatics Resource for Large-Scale Integration of Plant Phenology Data.

PubMed

Stucky, Brian J; Guralnick, Rob; Deck, John; Denny, Ellen G; Bolmgren, Kjell; Walls, Ramona

2018-01-01

Plant phenology - the timing of plant life-cycle events, such as flowering or leafing out - plays a fundamental role in the functioning of terrestrial ecosystems, including human agricultural systems. Because plant phenology is often linked with climatic variables, there is widespread interest in developing a deeper understanding of global plant phenology patterns and trends. Although phenology data from around the world are currently available, truly global analyses of plant phenology have so far been difficult because the organizations producing large-scale phenology data are using non-standardized terminologies and metrics during data collection and data processing. To address this problem, we have developed the Plant Phenology Ontology (PPO). The PPO provides the standardized vocabulary and semantic framework that is needed for large-scale integration of heterogeneous plant phenology data. Here, we describe the PPO, and we also report preliminary results of using the PPO and a new data processing pipeline to build a large dataset of phenology information from North America and Europe.

Development of Protoporphyrinogen Oxidase as an Efficient Selection Marker for Agrobacterium tumefaciens-Mediated Transformation of Maize

PubMed Central

Li, Xianggan; Volrath, Sandy L.; Nicholl, David B.G.; Chilcott, Charles E.; Johnson, Marie A.; Ward, Eric R.; Law, Marcus D.

2003-01-01

In this article, we report the isolation of plant protoporphyrinogen oxidase (PPO) genes and the isolation of herbicide-tolerant mutants. Subsequently, an Arabidopsis double mutant (Y426M + S305L) was used to develop a selectable marker system for Agrobacterium tumefaciens-mediated transformation of maize (Zea mays) and to obtain multiple events tolerant to the PPO family of herbicides. Maize transformants were produced via butafenacil selection using a flexible light regime to increase selection pressure. Butafenacil selection per se did not change transgene copy number distribution relative to other selectable marker systems, but the most tolerant events identified in the greenhouse were more likely to contain multiple copies of the introduced mutant PPO gene. To date, more than 2,500 independent transgenic maize events have been produced using butafenacil selection. The high frequency of A. tumefaciens-mediated transformation via PPO selection enabled us to obtain single-copy transgenic maize lines tolerant to field levels of butafenacil. PMID:12972658

Comparison of content in phenolic compounds, polyphenol oxidase, and peroxidase in grains of fifty sorghum varieties from burkina faso.

PubMed

Dicko, Mamoudou H; Hilhorst, Riet; Gruppen, Harry; Traore, Alfred S; Laane, Colja; van Berkel, Willem J H; Voragen, Alphons G J

2002-06-19

Analysis of fifty sorghum [Sorghum bicolor (L.) Moench] varieties used in Burkina Faso showed that they have different contents of phenolic compounds, peroxidase (POX), and polyphenol oxidase (PPO). Most of the varieties (82%) had a tannin content less than 0.25% (w/w). POX specific activity was higher than the monophenolase and o-diphenolase specific activities of PPO. For POX, there was a diversity of isoforms among varieties. No clear correlation could be made between the quantitative composition of the grain in phenolics, PPO, and POX, and resistance of plant to pathogens. In general, varieties good for a thick porridge preparation ("tô") had low phenolic compounds content and a medium POX activity. From the red varieties, those used for local beer ("dolo") had a high content in phenolic compounds and PPO, and a low POX activity. The variety considered good for couscous had a low POX content. The characteristics might be useful as selection markers for breeding for specific applications.

A Preliminary study of deoxygenation of Calophyllum inophyllum L. oil for green diesel production

NASA Astrophysics Data System (ADS)

Prasetyo, J.; Adiarso; Murti, S. D. S.; Senda, S. P.; Rfdh, S. M.; Prada, Y. E.; Oktariani, E.

2018-03-01

Biofuel is a solution to reduce the dependence of fossil fuels. Pure Plant Oil (PPO) of Calophyllum inophyllum L. is a potential raw material for green diesel through the processes of deoxygenation, hydrotreating, and isomerization. Deoxygenation of the PPO with NiMo / Al2O3 catalyst was carried out in a stirred autoclave reactor at a temperature of 300 - 400°C for 3 hours, and the water/PPO ratio was 1:2 and 1:4. The result showed that deoxygenation would work more effective at high temperature as indicated by higher CO and CO2 resulting from carboxylation and carbonylation. In addition, raising the reaction temperature from 300 to 400°C succeeded in increasing the diesel fraction of C16 - C20 by 33.01% and decreased the fraction of C21-C25 by 2.41%. Increasing water/ppo ratio did not give any significant improvement on green diesel products.

Interaction of polyphenol oxidase of Solanum tuberosum with β-cyclodextrin: Process details and applications.

PubMed

Singh, Virendra; Jadhav, Swati B; Singhal, Rekha S

2015-09-01

Polysaccharides differing in structure and chemical nature were screened for their ability to bind non-covalently with polyphenol oxidase (PPO) from potato (as a model) and their effect on enzyme activity. All the polysaccharides selected inhibited the PPO but β-cyclodextrin showed maximum inhibition under optimum conditions. Process details for the inhibition of PPO were studied with respect to concentration of β-cyclodextrin, temperature, pH, and time. Higher inhibition constant and lower half life was obtained at 40 °C than at 30 °C in the presence of inhibitor. β-Cyclodextrin showed mixed type of inhibition of PPO. β-Cyclodextrin was further exploited as anti-browning agent in selected fruit juices. It not only showed a significant anti-browning effect on freshly prepared potato juice but was also effective in other fruit juices. Better effect was seen in pineapple, apple and pear as compared to banana, sugarcane and guava fruit juices. Copyright © 2015 Elsevier B.V. All rights reserved.

Fermentation characteristics of some assamica clones and process optimization of black tea manufacturing.

PubMed

Baruah, Ananta Madhab; Mahanta, Pradip Kumar

2003-10-22

Changes in the specific activities of polyphenol oxidase (PPO), peroxidase (POD), and protease and in the relative amounts of flavan-3-ols for eight genetically derived cultivated teas at various stages of leaf maturity and in four succescive seasons were examined. A series of investigations were carried out to study the cross-reactivity of complex polyphenols and PPO-generated orange-yellow theaflavins, as well as of POD oxidized substrates, producing brown so-called thearubigins during fermented tea processing. From the estimation of five major catechins, PPO activities in young shoots, and theaflavin and thearubigin contents of crushed, torn, and curled (CTC) black teas, the superior variety and flavorful flush characteristics were refined. Notable protein hydrolysis by endogenous protease as measured from free amino acids and formation of tannin-protein complex (browning products) was obtained for cultivar character and product quality. Results showed that process optimization with respect to time, temperature, moisture, and pH maximizes PPO-catalyzed desirable theaflavin pigments, whereas POD-mediated chemical reaction produces dull color.

The role of polyphenol oxidase and peroxidase in the browning of water caltrop pericarp during heat treatment.

PubMed

Ciou, Jhih-Ying; Lin, Hsin-Hung; Chiang, Po-Yuan; Wang, Chiun-C; Charles, Albert Linton

2011-07-15

The mechanism of browning involving enzymatic browning was investigated in the pericarp of water caltrop, an Asian vegetable popular for its taste and medicinal properties. Polyphenol oxidase (PPO) and peroxidase (POD) activities were determined in pericarp at various times and temperatures. Water caltrop consisted of 44.22% moisture content, 37.23% crude fibre, and 2.63% crude protein. PPO and POD activities dropped from 62 and 38units/g sample, respectively, as water temperature was increased from 30 to 80°C. Optimum pH and temperature for PPO activity was at pH 5.0, 25-45°C, and POD activity peaked at 60°C. High PPO and POD activities at 40-50°C resulted in degradation of phenolic compounds, which led to increased aggregation of browning pigments and discolouration (lower L-values) of the pericarp. Enzymatic browning was determined as the major factor in the browning discolouration of heat-treated water caltrop pericarp. Copyright © 2011 Elsevier Ltd. All rights reserved.

Training Prescription Guided by Heart Rate Variability in Cycling.

PubMed

Javaloyes, Alejandro; Sarabia, Jose Manuel; Lamberts, Robert Patrick; Moya-Ramon, Manuel

2018-05-29

Road cycling is a sport with extreme physiological demands. Therefore, there is a need to find new strategies to improve performance. Heart rate variability (HRV) has been suggested as an effective alternative for prescribing training load against predefined training programs. The purpose of this study is to examine the effect of training prescription based on HRV in road cycling performance. Seventeen well-trained cyclists participated in this study. After an initial evaluation week (EW), cyclists performed 4 baseline weeks (BW) of standardized training to establish their resting HRV. Then, cyclists were divided into two groups, a HRV-guided group (HRV-G) and a traditional periodization group (TRAD) and they carried out 8 training weeks (TW). Cyclists performed two EW, after and before TW. During the EW, cyclists performed: (1) a graded exercise test to assess VO2max, peak power output (PPO) and ventilatory thresholds with their corresponding power output (VT1, VT2, WVT1, and WVT2, respectively) and (2) a 40-min simulated time-trial. HRV-G improved PPO (5.1 ± 4.5 %; p = 0.024), WVT2 (13.9 ± 8.8 %; p = 0.004) and 40TT (7.3 ± 4.5 %; p = 0.005). VO2max and WVT1 remained similar. TRAD did not improve significantly after TW. There were no differences between groups. However, magnitude-based inference analysis showed likely beneficial and possibly beneficial effects for HRV-G instead of TRAD in 40TT and PPO, respectively. Daily training prescription based on HRV could result in a better performance enhancement than a traditional periodization in well-trained cyclists.

A Venom Serpin Splicing Isoform of the Endoparasitoid Wasp Pteromalus puparum Suppresses Host Prophenoloxidase Cascade by Forming Complexes with Host Hemolymph Proteinases*

PubMed Central

Yan, Zhichao; Fang, Qi; Liu, Yang; Xiao, Shan; Yang, Lei; Wang, Fei; An, Chunju; Werren, John H.; Ye, Gongyin

2017-01-01

To ensure successful parasitism, parasitoid wasps inject venom along with their eggs into their hosts. The venom serves to suppress host immune responses, including melanization. Venom from Pteromalus puparum, a pupal endoparasitoid, inhibits melanization of host hemolymph in vitro in a dose-dependent manner. Using assay-guided fractionation, a serpin splicing isoform with phenoloxidase inhibitory activity was identified as P. puparum serpin-1, venom isoform (PpS1V). This serpin gene has 16 predicted splicing isoforms that differ only in the C-terminal region. RT-PCR results show that the specific serpin isoform is differentially expressed in the venom gland. Recombinant PpS1V (rPpS1V) suppresses host prophenoloxidase (PPO) activation rather than inhibiting the phenoloxidase directly. Pulldown assays show that PpS1V forms complexes with two host hemolymph proteins, here named Pieris rapae hemolymph proteinase 8 (PrHP8) and P. rapae prophenoloxidase-activating proteinase 1 (PrPAP1), based on gene sequence blasting and phylogenetic analysis. The role of rPrPAP1 in the PPO activation cascade and its interaction with rPpS1V were confirmed. The stoichiometry of inhibition of PrPAP1 by PpS1V is 2.3. PpS1V also inhibits PPO activation in a non-natural host, Ostrinia furnacalis, through forming a complex with O. furnacalis serine protease 13 (OfSP13), an ortholog to PrPAP1. Our results identify a venom-enriched serpin isoform in P. puparum that inhibits host PPO activation, probably by forming a complex with host hemolymph proteinase PrPAP1. PMID:27913622

Quantifying residues from postharvest fumigation of almonds and walnuts with propylene oxide

USDA-ARS?s Scientific Manuscript database

A novel analytical approach, involving solvent extraction with methyl tert-butyl ether (MTBE) followed by gas chromatography (GC), was developed to quantify residues that result from the postharvest fumigation of almonds and walnuts with propylene oxide (PPO). Verification and quantification of PPO,...

Ottawa County Writing Process Model for PPO Assessments.

ERIC Educational Resources Information Center

Ottawa County Office of Education, OH.

This guide outlines the writing procedures for English Composition Pupil Performance Objective (PPO) assessments and tests. Procedures for both students and teachers are included for the prewriting, first draft writing, and revising/rewriting sessions. A brief guide to evaluation procedures and intervention strategies is also provided. (MM)

The use of reactive material for limiting P-leaching from green roof substrate.

PubMed

Bus, Agnieszka; Karczmarczyk, Agnieszka; Baryła, Anna

2016-01-01

The aim of the study is to assess the influence of drainage layer made of reactive material Polonite(®) on the water retention and P-PO(4) concentration in runoff. A column experiment was performed for extensive substrate underlined by 2 cm of Polonite(®) layer (SP) and the same substrate without supporting layer as a reference (S). The leakage phosphorus concentration ranged from 0.001 to 0.082 mg P-PO(4)·L(-1), with average value 0.025 P-PO(4)·L(-1) of S experiment and 0.000-0.004 P-PO(4)·L(-1) and 0.001 P-PO(4)·L(-1) of SP experiment, respectively. The 2 cm layer of Polonite(®) was efficient in reducing P outflow from green roof substrate by 96%. The average effluent volumes from S and SP experiments amounted 61.1 mL (5.8-543.3 mL) and 46.4 mL (3.3-473.3 mL) with the average irrigation rate of 175.5 mL (6.3-758.0 mL). The substrate retention ability of S and SP experiments was 65% and 74%, respectively. Provided with reactive materials, green roof layers implemented in urban areas for rain water retention and delaying runoff also work for protection of water quality.

A study of over production and enhanced secretion of enzymes. Quarterly report 1

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

Dashek, W.V.

1992-12-28

The current project is concerned with the over-production and enhanced secretion of PPO, cellulase and lignin peroxidase. The project is divided into two segments: over-production of lignocellulolytic enzymes by genetic engineering methodologies and hyper-production and enhanced secretion of these enzymes by biochemical/electron microscopical techniques. The former approach employs recombinant DNA procedures, ligation of appropriate nuclease generated DNA fragments into a vector and the subsequent transformation of Escherichia coli to yield E. coli harboring a C. versicolor DNA insert. The biochemistry/electron microscopical method involves substrate induction and the time-dependent addition of respiration and PPO inhibitors to elevate C.versicolor`s ability to synthesizemore » and secrete lignocellulosic enzymes. In this connection, cell fractionation/kinetic analysis, TEM immunoelectron microscopic localization and TEM substrate localization of PPO are being employed to assess the route of secretion. Both approaches will culminate in the batch culture of either E. coli or C. versicolor, in a fermentor with the subsequent development of rapid isolation and purification procedures to yield elevated quantities of pure lignocellulosic enzymes. During the past year, research effort were directed toward determining the route of polyphenol oxidase (PPO) secretion by the wood-decay fungus, Coriolus versicolor. In addition, research activities were continued to over-produce and to purify PPO as well as define the time-dependent intra- and extra-cellular appearances of C. versicolor ligninases and cellulases.« less

Ellipsometric measurements of the refractive indices of linear alkylbenzene and EJ-301 scintillators from 210 to 1000 nm

NASA Astrophysics Data System (ADS)

Tseung, H. Wan Chan; Tolich, N.

2011-09-01

We report on ellipsometric measurements of the refractive indices of linear alkylbenzene-2,5-diphenyloxazole (LAB-PPO), Nd-doped LAB-PPO and EJ-301 scintillators to the nearest ± 0.005, in the wavelength range 210-1000 nm.

The Command & Control of Aggregated Marine Expeditionary Units. Is Anyone Available Today?

DTIC Science & Technology

2013-04-11

Operations. 24 April 2012. https://ehqmc.usmc.mil/org/ ppo /pl/pln. 2. Personal correspondence or phone interviews with each command listed...and Operations. 24 April 2012. https://ehqmc.usmc.mil/org/ ppo /pl/pln. Stover 53 Congressional Budget Office. A CBO Study: An Analysis of the

Toward Strong Thermoplastic Elastomers with Asymmetric Miktoarm Block Copolymer Architectures

DTIC Science & Technology

2014-03-05

temperature [such as poly(phenylene oxide), PPO ].7,8 Yet, this method does not lift the volume fraction limitation, and the total hard phase fraction f...PS + f PPO must still remain below approximately 0.3. Being able to significantly displace the classical phase diagram and stabilize morphologies

Transportation Challenges in the Hampton Roads, VA, Region

DTIC Science & Technology

2012-06-01

ORDERS ( PPO ) ...........................................................11 J. HIGHWAYS FOR NATIONAL DEFENSE (HND) ...................................12 K... PPO Port Planning Orders RND Railroads for National Defense SDDCTEA Surface Deployment and Distribution Command Transportation Engineering...important Continental United States (CONUS) port infrastructure in both peacetime and wartime. Strategic Seaports and Port Planning Orders ( PPOs ) were

Optimization of synthesis of the nickel-cobalt oxide based anode electrocatalyst and of the related membrane-electrode assembly for alkaline water electrolysis

NASA Astrophysics Data System (ADS)

Chanda, Debabrata; Hnát, Jaromir; Bystron, Tomas; Paidar, Martin; Bouzek, Karel

2017-04-01

In this work, the Ni-Co spinel oxides are synthesized via different methods and using different calcination temperatures. Properties of the prepared materials are compared. The best route is selected and used to prepare a Ni1+xCo2-xO4 (-1 ≤ x ≤ 1) series of materials in order to investigate their catalytic activity towards the oxygen evolution reaction (OER). The results show that hydroxide preparation yields NiCo2O4 oxide with the highest activity. 325 °C is identified as the optimum calcination temperature. Subsequently, the catalysts are tested in an electrolysis cell. To prepare an anode catalyst layer based on NiCo2O4 catalyst on top of a nickel foam substrate for membrane electrode assembly (MEA) construction, following polymer binders are used: anion-selective quaternized polyphenylene oxide (qPPO), inert polytetrafluoroethylene (PTFE®), and cation-selective Nafion®. qPPO ionomer containing MEA exhibited highest OER activity. The current density obtained using a MEA containing qPPO binder attains a value of 135 mA cm-2 at a cell voltage of 1.85 V. After 7 h chronopotentiometric experiment at a constant current density of 225 mA cm-2, the MEA employing PTFE® binder shows higher stability than the other binders in alkaline water electrolysis at 50 °C. Under similar conditions, stability of the PTFE®-binding MEA is examined for 135 h.

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

Cherepy, Nerine J.; Sanner, Robert D.; Beck, Patrick R.

In this paper, transparent plastic scintillators based on polyvinyltoluene (PVT) have been fabricated with high loading of bismuth carboxylates for gamma spectroscopy, and with lithium carboxylates for neutron detection. When activated with a combination of standard fluors, 2,5-diphenyloxazole (PPO) and tetraphenylbutadiene (TPB), gamma light yields with 15 wt% bismuth tripivalate of 5000 Ph/MeV are measured. A PVT plastic formulation including 30 wt% lithium pivalate and 30 wt% PPO offers both pulse shape discrimination, and a neutron capture peak at ~400 keVee. Finally, in another configuration, a bismuth-loaded PVT plastic is coated with ZnS( 6Li) paint, permitting simultaneous gamma and neutronmore » detection via pulse shape discrimination with a figure-of-merit of 3.8, while offering gamma spectroscopy with energy resolution of R(662 keV)=15%.« less

Bismuth- and lithium-loaded plastic scintillators for gamma and neutron detection

NASA Astrophysics Data System (ADS)

Cherepy, Nerine J.; Sanner, Robert D.; Beck, Patrick R.; Swanberg, Erik L.; Tillotson, Thomas M.; Payne, Stephen A.; Hurlbut, Charles R.

2015-04-01

Transparent plastic scintillators based on polyvinyltoluene (PVT) have been fabricated with high loading of bismuth carboxylates for gamma spectroscopy, and with lithium carboxylates for neutron detection. When activated with a combination of standard fluors, 2,5-diphenyloxazole (PPO) and tetraphenylbutadiene (TPB), gamma light yields with 15 wt% bismuth tripivalate of 5000 Ph/MeV are measured. A PVT plastic formulation including 30 wt% lithium pivalate and 30 wt% PPO offers both pulse shape discrimination, and a neutron capture peak at 400 keVee. In another configuration, a bismuth-loaded PVT plastic is coated with ZnS(6Li) paint, permitting simultaneous gamma and neutron detection via pulse shape discrimination with a figure-of-merit of 3.8, while offering gamma spectroscopy with energy resolution of R(662 keV)=15%.

Reducing peanut allergens by high pressure combined with polyphenol oxidase

USDA-ARS?s Scientific Manuscript database

Polyphenol oxidase (PPO) has been shown to reduce major peanut allergens (Ara h 1 and Ara h 2). Because high pressure (HP) can increase enzyme activity, we postulated that further reduction of peanut allergens can be achieved through HP combined with PPO. Peanut extracts were treated with each of th...

Perennial peanut (Arachis glabrata Benth.) leaves contain hydroxycinnamoyl-CoA:tartaric acid hydroxycinnamoyl transferase activity and accumulate hydroxycinnamoyl-tartaric acid esters

USDA-ARS?s Scientific Manuscript database

Many plants accumulate hydroxycinnamoyl esters to protect against abiotic and biotic stresses. Caffeoyl esters, in particular, can be substrates for endogenous polyphenol oxidases (PPOs). Recently, we showed that perennial peanut (Arachis glabrata Benth.) leaves contain PPO and identified one PPO su...

Perennial peanut (Arachis glabrata Benth.) contains polyphenol oxidase (PPO) and PPO substrates that can reduce post-harvest proteolysis

USDA-ARS?s Scientific Manuscript database

Studies of perennial peanut (Arachis glaburata Benth.) suggest its hay and haylage have higher levels of rumen undegraded protein (RUP) than other legume forages such as alfalfa. Higher RUP can result in more efficient utilization of nitrogen by ruminant animals with positive economic and environmen...

Heterologous expression of Gaeumannomyces graminis lipoxygenase in Aspergillus nidulans.

PubMed

Heshof, Ruud; van Schayck, J Paul; Tamayo-Ramos, Juan Antonio; de Graaff, Leo H

2014-01-01

Aspergillus sp. contain ppo genes coding for Ppo enzymes that produce oxylipins from polyunsaturated fatty acids. These oxylipins function as signal molecules in sporulation and influence the asexual to sexual ratio of Aspergillus sp. Fungi like Aspergillus nidulans and Aspergillus niger contain just ppo genes where the human pathogenic Aspergillus flavus and Aspergillus fumigatus contain ppo genes as well as lipoxygenases. Lipoxygenases catalyze the synthesis of oxylipins and are hypothesized to be involved in quorum-sensing abilities and invading plant tissue. In this study we used A. nidulans WG505 as an expression host to heterologously express Gaeumannomyces graminis lipoxygenase. The presence of the recombinant LOX induced phenotypic changes in A. nidulans transformants. Also, a proteomic analysis of an A. nidulans LOX producing strain indicated that the heterologous protein was degraded before its glycosylation in the secretory pathway. We observed that the presence of LOX induced the specific production of aminopeptidase Y that possibly degrades the G. graminis lipoxygenase intercellularly. Also the presence of the protein thioredoxin reductase suggests that the G. graminis lipoxygenase is actively repressed in A. nidulans.

Spatial distribution of total phenolic content, enzymatic activities and browning in white yam (Dioscorea rotundata) tubers.

PubMed

Graham-Acquaah, Seth; Ayernor, George Sodah; Bediako-Amoa, Betty; Saalia, Firibu Kwesi; Afoakwa, Emmanuel Ohene

2014-10-01

Browning in raw and processed yams resulting from enzymes, polyphenol oxidase (PPO) and peroxidase (POD), activities is a major limitation to the industrial utilization of Dioscorea varieties of yams. Two elite cultivars of D. rotundata species were selected to study the spatial distribution of total phenols and enzymes (PPO and POD) activities. The intensities of tissue darkening in fresh yam chips prepared from the tuber sections of cultivars during frozen storage were also studied. Total phenolic content was observed to be highest in the head and mid sections of the cultivars than at the tail end. PPO activity did not have any specific distribution pattern whereas POD activity was found to be more concentrated in the head than in the middle and tail regions. Browning was found to be most intense in the head regions of the two cultivars studied; and was observed to correlate with total phenol and dry matter contents of tubers. Between the two enzymes, POD activity appeared to be more related to browning than PPO.

Heterologous expression of Gaeumannomyces graminis lipoxygenase in Aspergillus nidulans

PubMed Central

2014-01-01

Aspergillus sp. contain ppo genes coding for Ppo enzymes that produce oxylipins from polyunsaturated fatty acids. These oxylipins function as signal molecules in sporulation and influence the asexual to sexual ratio of Aspergillus sp. Fungi like Aspergillus nidulans and Aspergillus niger contain just ppo genes where the human pathogenic Aspergillus flavus and Aspergillus fumigatus contain ppo genes as well as lipoxygenases. Lipoxygenases catalyze the synthesis of oxylipins and are hypothesized to be involved in quorum-sensing abilities and invading plant tissue. In this study we used A. nidulans WG505 as an expression host to heterologously express Gaeumannomyces graminis lipoxygenase. The presence of the recombinant LOX induced phenotypic changes in A. nidulans transformants. Also, a proteomic analysis of an A. nidulans LOX producing strain indicated that the heterologous protein was degraded before its glycosylation in the secretory pathway. We observed that the presence of LOX induced the specific production of aminopeptidase Y that possibly degrades the G. graminis lipoxygenase intercellularly. Also the presence of the protein thioredoxin reductase suggests that the G. graminis lipoxygenase is actively repressed in A. nidulans. PMID:25401068

A multidisciplinary approach providing new insight into fruit flesh browning physiology in apple (Malus x domestica Borkh.).

PubMed

Di Guardo, Mario; Tadiello, Alice; Farneti, Brian; Lorenz, Giorgia; Masuero, Domenico; Vrhovsek, Urska; Costa, Guglielmo; Velasco, Riccardo; Costa, Fabrizio

2013-01-01

In terms of the quality of minimally processed fruit, flesh browning is fundamentally important in the development of an aesthetically unpleasant appearance, with consequent off-flavours. The development of browning depends on the enzymatic action of the polyphenol oxidase (PPO). In the 'Golden Delicious' apple genome ten PPO genes were initially identified and located on three main chromosomes (2, 5 and 10). Of these genes, one element in particular, here called Md-PPO, located on chromosome 10, was further investigated and genetically mapped in two apple progenies ('Fuji x Pink Lady' and 'Golden Delicious x Braeburn'). Both linkage maps, made up of 481 and 608 markers respectively, were then employed to find QTL regions associated with fruit flesh browning, allowing the detection of 25 QTLs related to several browning parameters. These were distributed over six linkage groups with LOD values spanning from 3.08 to 4.99 and showed a rate of phenotypic variance from 26.1 to 38.6%. Anchoring of these intervals to the apple genome led to the identification of several genes involved in polyphenol synthesis and cell wall metabolism. Finally, the expression profile of two specific candidate genes, up and downstream of the polyphenolic pathway, namely phenylalanine ammonia lyase (PAL) and polyphenol oxidase (PPO), provided insight into flesh browning physiology. Md-PPO was further analyzed and two haplotypes were characterised and associated with fruit flesh browning in apple.

Effects of different warm-up modalities on power output during the high pull.

PubMed

Barnes, Matthew John; Petterson, Ashley; Cochrane, Darryl J

2017-05-01

This study compared the effects of six warm-up modalities on peak power output (PPO) during the high-pull exercise. Nine resistance-trained males completed six trials using different warm-ups: high-pull specific (HPS), cycle, whole body vibration (WBV), cycle+HPS, WBV+HPS and a control. Intramuscular temperature (T m ) was increased by 2°C using WBV or cycling. PPO, T m and electromyography (EMG) were recorded during each trial. Two high-pulls were performed prior to and 3 min after participants completed the warm-up. The greatest increase in PPO occurred with HPS (232.8 ± 89.7 W, P < 0.001); however, this was not different to combined warm-ups (cycle+HPS 158.6 ± 121.1 W; WBV+HPS 177.3 ± 93.3 W, P = 1.00). These modalities increased PPO to a greater extent than those that did not involve HPS (all P < 0.05). HPS took the shortest time to complete, compared to the other conditions (P < 0.05). EMG did not differ from pre to post warm-up or between modalities in any of the muscles investigated. No change in T m occurred in warm-ups that did not include cycling or WBV. These results suggest that a movement-specific warm-up improves performance more than temperature-related warm-ups. Therefore, mechanisms other than increased muscle temperature and activation may be important for improving short-term PPO.

Green tea extract as an anti-browning agent for cloudy apple juice.

PubMed

Klimczak, Inga; Gliszczyńska-Świgło, Anna

2017-03-01

Enzymatic browning of fruits and vegetables and their products is an important factor worsening their quality. The influence of five green tea extracts at the concentrations of 1 g L -1 , 2 g L -1 and 3 g L -1 on polyphenol oxidase (PPO) activity in fresh cloudy apple juice was investigated. Moreover, PPO inhibition by tea extract and colour stability of juice during short-time refrigerated storage was studied. The changes of juice colour during storage was expressed as the total colour differences (ΔE*), browning index (BI), yellowness index (YI), and the absorbance at 420 nm (A 420 ). All extracts inhibited PPO activity in fresh apple juice in concentration-dependent manner. PPO activity in pure apple juice decreased by 7% after 48 h, whereas PPO activity in samples with 1 g L -1 , 2 g L -1 and 3 g L -1 tea extract decreased by 53%, 74%, and 96%, respectively. Browning of apple juice during storage decreased with increased concentration of green tea extract. After 48 h, extract at 1 g L -1 , 2 g L -1 and 3 g L -1 inhibited browning of juice expressed as BI by 48%, 60%, and 86%, respectively, comparing to pure apple juice. Green tea extract may be an effective anti-browning agent for short-time stored cloudy apple juices. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

A Multidisciplinary Approach Providing New Insight into Fruit Flesh Browning Physiology in Apple (Malus x domestica Borkh.)

PubMed Central

Farneti, Brian; Lorenz, Giorgia; Masuero, Domenico; Vrhovsek, Urska; Costa, Guglielmo; Velasco, Riccardo; Costa, Fabrizio

2013-01-01

In terms of the quality of minimally processed fruit, flesh browning is fundamentally important in the development of an aesthetically unpleasant appearance, with consequent off-flavours. The development of browning depends on the enzymatic action of the polyphenol oxidase (PPO). In the ‘Golden Delicious’ apple genome ten PPO genes were initially identified and located on three main chromosomes (2, 5 and 10). Of these genes, one element in particular, here called Md-PPO, located on chromosome 10, was further investigated and genetically mapped in two apple progenies (‘Fuji x Pink Lady’ and ‘Golden Delicious x Braeburn’). Both linkage maps, made up of 481 and 608 markers respectively, were then employed to find QTL regions associated with fruit flesh browning, allowing the detection of 25 QTLs related to several browning parameters. These were distributed over six linkage groups with LOD values spanning from 3.08 to 4.99 and showed a rate of phenotypic variance from 26.1 to 38.6%. Anchoring of these intervals to the apple genome led to the identification of several genes involved in polyphenol synthesis and cell wall metabolism. Finally, the expression profile of two specific candidate genes, up and downstream of the polyphenolic pathway, namely phenylalanine ammonia lyase (PAL) and polyphenol oxidase (PPO), provided insight into flesh browning physiology. Md-PPO was further analyzed and two haplotypes were characterised and associated with fruit flesh browning in apple. PMID:24205065

Investigation of performance and durability of polymer electrolytes for electrochemical energy storage and conversion technologies

NASA Astrophysics Data System (ADS)

Jung, Min-Suk

Polymeric ion exchange membranes are integral components of electrochemical conversion/storage devices such as fuel cells, water electrolyzers, and redox flow batteries. There has been dramatic progress in the research and development of cation exchange membranes (CEM). NafionRTM (perfluorosulfonic acid membranes) is one example of a state-of-the-art CEM and has been successfully demonstrated in various electrochemical energy devices. Unlike CEMs, anion exchange membranes (AEMs) have been of limited utility to date due to their drawbacks, including poor chemical/mechanical stability and low ionic conductivity. However, alkaline environments result in better activity for electrochemical reactions and afford the possibility of using non-platinum group metal (PGM) electrocatalysts. AEMs, therefore, are still being studied in order to resolve existing challenges in terms of conductivity and stability in alkaline media and in strongly oxidizing solutions. In this work, AEMs derived from different types of polymer backbones were prepared, and their chemical stability and electrochemical property were investigated. Polysulfone (PSF) AEMs were prepared by first chloromethylating polysulfone, then by functionalizing chloromethylated polysulfone (CMPSF) with different base reagents. PSF-trimethylamine (TMA) AEMs showed a 40-fold reduction in vanadium (IV) ion (VO2+) permeability when compared to a NafionRTM membrane and exceptional oxidative stability after exposure to a 1.5 M vanadium (V) ion (VO2+) solution for 90 days. PSF-TMA AEMs were successfully demonstrated in the all-vanadium redox flow battery. Excellent energy efficiencies (>75 %) were attained and sustained over 75 charge-discharge cycles for a vanadium redox flow battery prepared using the PSF-TMA separator. Crosslinking of poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) AEMs using diamine was tried with intentions to improve the mechanical stability and electrochemical property of PPO AEM. Crosslinked PPO AEMs (30 +/- 4 % at 25 °C) showed less liquid water uptake than non-crosslinked PPO AEMs (46 +/- 5% at 25 °C) while maintaining comparable ionic conductivities (hydroxide ion conductivity of 45 mS/cm at 60 °C). Crosslinked PPO AEMs maintained mechanical integrity and still showed some mechanical stability (ultimate tensile strength of 3˜4 MPa and elongation at break of 13˜17 %) after exposure to 1 M KOH at 60 °C for 14 days, while non-crosslinked PPO AEMs completely lost their mechanical durability. Finally, this dissertation presents research related to perfluorinated AEMs prepared using a Grignard reagent. These membranes exhibited 0.7 mmol/g of Cl- ion exchange capacity (IEC), 20 mS/cm of hydroxide ion conductivity at 20 °C, and 10 % of water uptake at room temperature. The membranes also maintained 90 % of their initial conductivity after an exposure to 1.5 M VO2+ in 3 M H2SO4 solution for seven days.

Characterization and purification of polyphenol oxidase from artichoke (Cynara scolymus L.).

PubMed

Dogan, Serap; Turan, Yusuf; Ertürk, Hatibe; Arslan, Oktay

2005-02-09

In this study, the polyphenol oxidase (PPO) of artichoke (Cynara scolymus L.) was first purified by a combination of (NH(4))(2)SO(4) precipitation, dialysis, and a Sepharose 4B-L-tyrosine-p-aminobenzoic acid affinity column. At the end of purification, 43-fold purification was achieved. The purified enzyme migrated as a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Polyacrylamide gel electrophoresis indicated that PPO had a 57 kDa molecular mass. Second, the contents of total phenolic and protein of artichoke head extracts were determined. The total phenolic content of artichoke head was determined spectrophotometrically according to the Folin-Ciocalteu procedure and was found to be 425 mg 100 g(-1) on a fresh weight basis. Protein content was determined according to Bradford method. Third, the effects of substrate specificity, pH, temperature, and heat inactivation were investigated on the activity of PPO purified from artichoke. The enzyme showed activity to 4-methylcatechol, pyrogallol, catechol, and L-dopa. No activity was detected toward L-tyrosine, resorsinol, and p-cresol. According to V(max)/K(m) values, 4-methylcatechol (1393 EU min(-1) mM(-1)) was the best substrate, followed by pyrogallol (1220 EU min(-1) mM(-1)), catechol (697 EU min(-1) mM(-1)), and L-dopa (102 EU min(-1) mM(-1)). The optimum pH values for PPO were 5.0, 8.0, and 7.0 using 4-methylcatechol, pyrogallol, and catechol as substrate, respectively. It was found that optimum temperatures were dependent on the substrates studied. The enzyme activity decreased due to heat denaturation of the enzyme with increasing temperature and inactivation time for 4-methylcatechol and pyrogallol substrates. However, all inactivation experiments for catechol showed that the activity of artichoke PPO increased with mild heating, reached a maximum, and then decreased with time. Finally, inhibition of artichoke PPO was investigated with inhibitors such as L-cysteine, EDTA, ascorbic acid, gallic acid, d,L-dithiothreitol, tropolone, glutathione, sodium azide, benzoic acid, salicylic acid, and 4-aminobenzoic acid using 4-methylcatechol, pyrogallol, and catechol as substrate. The presence of EDTA, 4-aminobenzoic acid, salicylic acid, gallic acid, and benzoic acid did not cause the inhibition of artichoke PPO. A competitive-type inhibition was obtained with sodium azide, L-cysteine, and d,L-dithiothreitol inhibitors using 4-methylcatechol as substrate; with L-cysteine, tropolone, d,L-dithiothreitol, ascorbic acid, and sodium azide inhibitors using pyrogallol as substrate; and with L-cysteine, tropolone, d,L-dithiotreitol, and ascorbic acid inhibitors using catechol as a substrate. A mixed-type inhibition was obtained with glutathione inhibitor using 4-methylcatechol as a substrate. A noncompetitive inhibition was obtained with tropolone and ascorbic acid inhibitors using 4-methylcatechol as substrate, with glutathione inhibitor using pyrogallol as substrate, and with glutathione and sodium azide inhibitors using catechol as substrate. From these results, it can be said that the most effective inhibitor for artichoke PPO is tropolone. Furthermore, it was found that the type of inhibition depended on the origin of the PPO studied and also on the substrate used.

Ground-based observations of Saturn's auroral ionosphere over three days: Trends in H3+ temperature, density and emission with Saturn local time and planetary period oscillation

NASA Astrophysics Data System (ADS)

O'Donoghue, James; Melin, Henrik; Stallard, Tom S.; Provan, G.; Moore, Luke; Badman, Sarah V.; Cowley, Stan W. H.; Baines, Kevin H.; Miller, Steve; Blake, James S. D.

2016-01-01

On 19-21 April 2013, the ground-based 10-m W.M. Keck II telescope was used to simultaneously measure H3+ emissions from four regions of Saturn's auroral ionosphere: (1) the northern noon region of the main auroral oval; (2) the northern midnight main oval; (3) the northern polar cap and (4) the southern noon main oval. The H3+ emission from these regions was captured in the form of high resolution spectral images as the planet rotated. The results herein contain twenty-three H3+ temperatures, column densities and total emissions located in the aforementioned regions - ninety-two data points in total, spread over timescales of both hours and days. Thermospheric temperatures in the spring-time northern main oval are found to be cooler than their autumn-time southern counterparts by tens of K, consistent with the hypothesis that the total thermospheric heating rate is inversely proportional to magnetic field strength. The main oval H3+ density and emission is lower at northern midnight than it is at noon, in agreement with a nearby peak in the electron influx in the post-dawn sector and a minimum flux at midnight. Finally, when arranging the northern main oval H3+ parameters as a function of the oscillation period seen in Saturn's magnetic field - the planetary period oscillation (PPO) phase - we see a large peak in H3+ density and emission at ∼115° northern phase, with a full-width at half-maximum (FWHM) of ∼44°. This seems to indicate that the influx of electrons associated with the PPO phase at 90° is responsible at least in part for the behavior of all H3+ parameters. A combination of the H3+ production and loss timescales and the ±10° uncertainty in the location of a given PPO phase are likely, at least in part, to be responsible for the observed peaks in H3+ density and emission occurring at a later time than the peak precipitation expected at 90° PPO phase.

Phenolic profiles and polyphenol oxidase (PPO) gene expression of red clover (Trifolium pratense) selected for decreased postharvest browning

USDA-ARS?s Scientific Manuscript database

Red clover (Trifolium pratense L.) is a legume forage abundant in phenolic compounds. It tends to brown when cut for hay, due to oxidation of phenolic compounds catalyzed by polyphenol oxidase (PPO), and subsequent binding to proteins. Selecting for a greener hay may provide information about the re...

Effect of high pressure on peanut allergens in the presence of polyphenol oxidase and caffeic acid

USDA-ARS?s Scientific Manuscript database

High pressure (HP) enhances enzymatic reactions. Because polyphenol oxidase (PPO) is an enzyme, and reduces IgE binding of peanut allergens in presence of caffeic acid (CA), we postulated that a further reduction in IgE binding can be achieved, using HP together with PPO and CA. Peanut extracts cont...

Biochemical characteristics and thermal inhibition kinetics of polyphenol oxidase extracted from Thompson seedless grape

USDA-ARS?s Scientific Manuscript database

Polyphenol oxidase (PPO) was isolated from Thompson seedless grape (Vitis vinifera 'Thompson Seedless') and its biochemical characteristics were studied. Optimum pH and temperature for grape PPO activity were pH 6.0 and 25 degrees C with 10 mM catechol as substrate. The enzyme was heat-stable betwee...

Two-photon excitation of 2,5-diphenyloxazole using a low power green solid state laser

NASA Astrophysics Data System (ADS)

Luchowski, Rafal

2011-01-01

This Letter concerns two-photon excitation of 2,5-diphenyloxazole (PPO) upon illumination from a pulsed 532 nm solid state laser, with an average power of 30 mW, and a repetition rate of 20 MHz. A very agreeable emission spectrum position and shape has been achieved for PPO receiving one- and two-photon excitation, which suggests that the same excited state is involved for both excitation modes. Also, a perfect quadratic dependence of laser power in the emission intensity function has been recorded. We tested the application of a small solid state green laser to two-photon induced time-resolved fluorescence, revealing the emission anisotropy of PPO to be considerably higher for two-photon than for one-photon excitation.

High-Temperature and High-Energy-Density Dipolar Glass Polymers Based on Sulfonylated Poly(2,6-dimethyl-1,4-phenylene oxide).

PubMed

Zhang, Zhongbo; Wang, David H; Litt, Morton H; Tan, Loon-Seng; Zhu, Lei

2018-02-05

A new class of high-temperature dipolar polymers based on sulfonylated poly(2,6-dimethyl-1,4-phenylene oxide) (SO 2 -PPO) was synthesized by post-polymer functionalization. Owing to the efficient rotation of highly polar methylsulfonyl side groups below the glass transition temperature (T g ≈220 °C), the dipolar polarization of these SO 2 -PPOs was enhanced, and thus the dielectric constant was high. Consequently, the discharge energy density reached up to 22 J cm -3 . Owing to its high T g  , the SO 2 -PPO 25 sample also exhibited a low dielectric loss. For example, the dissipation factor (tan δ) was 0.003, and the discharge efficiency at 800 MV m -1 was 92 %. Therefore, these dipolar glass polymers are promising for high-temperature, high-energy-density, and low-loss electrical energy storage applications. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Controlled synthesis of multi-arm star polyether-polycarbonate polyols based on propylene oxide and CO2.

PubMed

Hilf, Jeannette; Schulze, Patricia; Seiwert, Jan; Frey, Holger

2014-01-01

Multi-arm star copolymers based on a hyperbranched poly(propylene oxide) polyether-polyol (hbPPO) as a core and poly(propylene carbonate) (PPC) arms are synthesized in two steps from propylene oxide (PO), a small amount of glycidol and CO2 . The PPC arms are prepared via carbon dioxide (CO2 )/PO copolymerization, using hbPPO as a multifunctional macroinitiator and the (R,R)-(salcy)CoOBzF5 catalyst. Star copolymers with 14 and 28 PPC arms, respectively, and controlled molecular weights in the range of 2700-8800 g mol(-1) are prepared (Mw /Mn = 1.23-1.61). Thermal analysis reveals lowered glass transition temperatures in the range of -8 to 10 °C for the PPC star polymers compared with linear PPC, which is due to the influence of the flexible polyether core. Successful conversion of the terminal hydroxyl groups with phenylisocyanate demonstrates the potential of the polycarbonate polyols for polyurethane synthesis. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Bismuth- and lithium-loaded plastic scintillators for gamma and neutron detection

DOE PAGES

Cherepy, Nerine J.; Sanner, Robert D.; Beck, Patrick R.; ...

2015-01-09

In this paper, transparent plastic scintillators based on polyvinyltoluene (PVT) have been fabricated with high loading of bismuth carboxylates for gamma spectroscopy, and with lithium carboxylates for neutron detection. When activated with a combination of standard fluors, 2,5-diphenyloxazole (PPO) and tetraphenylbutadiene (TPB), gamma light yields with 15 wt% bismuth tripivalate of 5000 Ph/MeV are measured. A PVT plastic formulation including 30 wt% lithium pivalate and 30 wt% PPO offers both pulse shape discrimination, and a neutron capture peak at ~400 keVee. Finally, in another configuration, a bismuth-loaded PVT plastic is coated with ZnS( 6Li) paint, permitting simultaneous gamma and neutronmore » detection via pulse shape discrimination with a figure-of-merit of 3.8, while offering gamma spectroscopy with energy resolution of R(662 keV)=15%.« less

A scintillator purification plant and fluid handling system for SNO+

NASA Astrophysics Data System (ADS)

Ford, Richard J.

2015-08-01

A large capacity purification plant and fluid handling system has been constructed for the SNO+ neutrino and double-beta decay experiment, located 6800 feet underground at SNOLAB, Canada. SNO+ is a refurbishment of the SNO detector to fill the acrylic vessel with liquid scintillator based on Linear Alkylbenzene (LAB) and 2 g/L PPO, and also has a phase to load natural tellurium into the scintillator for a double-beta decay experiment with 130Te. The plant includes processes multi-stage dual-stream distillation, column water extraction, steam stripping, and functionalized silica gel adsorption columns. The plant also includes systems for preparing the scintillator with PPO and metal-loading the scintillator for double-beta decay exposure. We review the basis of design, the purification principles, specifications for the plant, and the construction and installations. The construction and commissioning status is updated.

Auroral field-aligned current observations during the Cassini F-ring and Proximal orbits

NASA Astrophysics Data System (ADS)

Hunt, G. J.; Bunce, E. J.; Cao, H.; Cowley, S.; Dougherty, M. K.; Khurana, K. K.; Provan, G.; Southwood, D. J.

2017-12-01

Cassini's F-ring and Proximal orbits have provided a fantastic opportunity to examine Saturn's magnetic field closer to the planet than ever before. It is critical to understand external contributions to the azimuthal field component, as it can provide information on any asymmetry of the internal field. However, signatures of the auroral field-aligned currents are also present in this field component. Here we will identify and discuss these current signatures in the dawn and dusk sections in the northern and southern hemispheres, respectively. Previous results from observations during 2008 showed that in southern hemisphere these currents were strongly modulated by the southern planetary period oscillation (PPO) system. While the northern hemisphere data was modulated by both northern and southern PPOs, thus giving the first direct evidence of inter-hemispheric PPO currents. In both hemispheres, the PPO currents that give rise to the 10.7 h magnetic field oscillations observed throughout Saturn's magnetosphere, were separated from the PPO-independent (e.g. subcorotation) currents. These results provide a framework to which the Grand Finale orbits can be examined within. Here, we will assess how the field-aligned currents have evolved in comparison to the 2008 dataset. We will show that for the most part the observed field-aligned currents agree with the theoretical expectations. However, we will discuss the differences in terms of the PPO modulation, seasonal, and local time changes between the two datasets. Finally, we will discuss the implications of the azimuthal magnetic field contributions of these field-aligned currents on the data from the Proximal orbits.

Residual oxygen time model for oxygen partial pressure near 130 kPa (1.3 atm).

PubMed

Shykoff, Barbara E

2015-01-01

A two-part residual oxygen time model predicts the probability of detectible pulmonary oxygen toxicity P(P[O2tox]) after dives with oxygen partial pressure (PO2) approximately 130 kPa, and provides a tool to plan dive series with selected risk of P[O2tox]. Data suggest that pulmonary oxygen injury at this PO2 is additive between dives. Recovery begins after a delay and continues during any following dive. A logistic relation expresses P(P[O2tox]) as a function of dive duration (T(dur)) [hours]: P(P[O2tox]) = 100/[1+exp (3.586-0.49 x T(dur))] This expression maps T(dur) to P(P[O2tox]) or, in the linear mid-portion of the curve, P(P[O2tox]) usefully to T(dur). For multiple dives or during recovery, it maps to an equivalent dive duration, T(eq). T(eq) was found after second dives of duration T(dur 2). Residual time from the first dive t(r) = T(eq) - T(dur2). With known t(r), t and T(dur) a recovery model was fitted. t(r) = T(dur) x exp [-k x((t-5)/T(dur)2], where t = t - 5 hours, k = 0.149 for resting, and 0.047 for exercising divers, and t represents time after surfacing. The fits were assessed for 1,352 man-dives. Standard deviations of the residuals were 8.5% and 18.3% probability for resting or exercise dives, respectively.

Understanding the interaction of block copolymers with DMPC lipid bilayer using coarse-grained molecular dynamics simulations.

PubMed

Hezaveh, Samira; Samanta, Susruta; De Nicola, Antonio; Milano, Giuseppe; Roccatano, Danilo

2012-12-13

In this paper, we present a computational model of the adsorption and percolation mechanism of poloxamers (poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO) triblock copolymers) across a 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) lipid bilayer. A coarse-grained model was used to cope with the long time scale of the percolation process. The simulations have provided details of the interaction mechanism of Pluronics with lipid bilayer. In particular, the results have shown that polymer chains containing a PPO block with a length comparable to the DMPC bilayer thickness, such as P85, tends to percolate across the lipid bilayer. On the contrary, Pluronics with a shorter PPO chain, such as L64 and F38, insert partially into the membrane with the PPO block part while the PEO blocks remain in water on one side of the lipid bilayer. The percolation of the polymers into the lipid tail groups reduces the membrane thickness and increases the area per lipid. These effects are more evident for P85 than L64 or F38. Our findings are qualitatively in good agreement with published small-angle X-ray scattering experiments that have evidenced a thinning effect of Pluronics on the lipid bilayer as well as the role of the length of the PPO block on the permeation process of the polymer through the lipid bilayer. Our theoretical results complement the experimental data with a detailed structural and dynamic model of poloxamers at the interface and inside the lipid bilayer.

Particle Disease: A Current Review of the Biological Mechanisms in Periprosthetic Osteolysis After Hip Arthroplasty

PubMed Central

Sukur, Erhan; Akman, Yunus Emre; Ozturkmen, Yusuf; Kucukdurmaz, Fatih

2016-01-01

Background: Inflammatory responses to wear debris cause osteolysis that leads to aseptic prosthesis loosening and hip arthroplasty failure. Although osteolysis is usually associated with aseptic loosening, it is rarely seen around stable implants. Aseptic implant loosening is a simple radiologic phenomenon, but a complex immunological process. Particulate debris produced by implants most commonly causes osteolysis, and this is called particle-associated periprosthetic osteolysis (PPO). Objective: The objective of this review is to outline the features of particle-associated periprosthetic osteolysis to allow the physician to recognise this condition and commence early treatment, thereby optimizing patient outcome. Methods: A thorough literature search was performed using available databases, including Pubmed, to cover important research published covering particle-associated PPO. Results: Although osteolysis causes bone resorption, clinical, animal, and in vitro studies of particle bioreactivity suggest that particle-associated PPO represents the culmination of several biological reactions of many cell types, rather than being caused solely by the osteoclasts. The biological activity is highly dependent on the characteristics and quantity of the wear particles. Conclusion: Despite advances in total hip arthroplasty (THA), particle-associated PPO and aseptic loosening continue to be major factors that affect prosthetic joint longevity. Biomarkers could be exploited as easy and objective diagnostic and prognostic targets that would enable testing for osteolysis after THA. Further research is needed to identify new biomarkers in PPO. A comprehensive understanding of the underlying biological mechanisms is crucial for developing new therapeutic interventions to reverse or suppress biological responses to wear particles. PMID:27499822

Blueberry polyphenol oxidase: Characterization and the kinetics of thermal and high pressure activation and inactivation.

PubMed

Terefe, Netsanet Shiferaw; Delon, Antoine; Buckow, Roman; Versteeg, Cornelis

2015-12-01

Partially purified blueberry polyphenol oxidase (PPO) in Mcllvaine buffer (pH=3.6, typical pH of blueberry juice) was subjected to processing at isothermal-isobaric conditions at temperatures from 30 to 80 °C and pressure from 0.1 to 700 MPa. High pressure processing at 30-50 °C at all pressures studied caused irreversible PPO activity increase with a maximum of 6.1 fold increase at 500 MPa and 30 °C. Treatments at mild pressure-mild temperature conditions (0.1-400 MPa, 60 °C) also caused up to 3 fold PPO activity increase. Initial activity increase followed by a decrease occurred at relatively high pressure-mild temperature (400-600 MPa, 60 °C) and mild pressure-high temperature (0.1-400 MPa, 70-80 °C) combinations. At temperatures higher than 76 °C, monotonic decrease in PPO activity occurred at 0.1 MPa and pressures higher than 500 MPa. The activation/inactivation kinetics of the enzyme was successfully modelled assuming consecutive reactions in series with activation followed by inactivation. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

Synthesis and Herbicidal Activity of Pyrido[2,3-d]pyrimidine-2,4-dione-Benzoxazinone Hybrids as Protoporphyrinogen Oxidase Inhibitors.

PubMed

Wang, Da-Wei; Li, Qian; Wen, Kai; Ismail, Ismail; Liu, Dan-Dan; Niu, Cong-Wei; Wen, Xin; Yang, Guang-Fu; Xi, Zhen

2017-07-05

To search for new protoporphyrinogen oxidase (PPO, EC 1.3.3.4) inhibitors with improved bioactivity, a series of novel pyrido[2,3-d]pyrimidine-2,4-dione-benzoxazinone hybrids, 9-13, were designed and synthesized. Several compounds with improved tobacco PPO (mtPPO)-inhibiting and promising herbicidal activities were found. Among them, the most potent compound, 3-(7-fluoro-3-oxo-4-(prop-2-yn-1-yl)-3,4-dihydro-2H-benzo[b][1,4] oxazin-6-yl)-1-methylpyrido[2,3-d]pyrimidine-2,4(1H,3H)-dione, 11q, with a K i value of 0.0074 μM, showed six times more activity than flumioxazin (K i = 0.046 μM) against mtPPO. Compound 11q displayed a strong and broad spectrum of weed control at 37.5-150 g of active ingredient (ai)/ha by both post- and pre-emergence application, which was comparable to that of flumioxazin. 11q was safe to maize, soybean, peanut, and cotton at 150 g ai/ha, and selective to rice and wheat at 75 g ai/ha by pre-emergence application, indicating potential applicability in these fields.

Thermoresponsive complex amphiphilic block copolymer micelles investigated by laser light scattering.

PubMed

Zhao, Fang; Xie, Dinghai; Zhang, Guangzhao; Pispas, Stergios

2008-05-22

Poly(isoprene)-block-poly(ethylene oxide) (PI-b-PEO) diblock copolymers form micelles in water. The introduction of poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) (PEO-b-PPO-b-PEO) triblock copolymer leads to the formation of mixed micelles through hydrophobic interaction. The dimension of the mixed micelles varies with the weight ratio (r) of PEO-b-PPO-b-PEO to PI-b-PEO. By use of laser light scattering, we have investigated the temperature dependence of the structural evolution of the micelles at different r. At r<10, the size of the mixed micelles decreases with temperature. At r>10, due to the excessive PEO-b-PPO-b-PEO chains in solution, as temperature increases, the mixed micelles aggregate into larger micelle clusters.

Inhibition of polyphenol oxidases activity by various dipeptides.

PubMed

Girelli, Anna M; Mattei, Enrico; Messina, Antonella; Tarola, Anna M

2004-05-19

In an effort to develop natural and nontoxic inhibitors on the activity of mushroom polyphenol oxidase (PPO) the effect of various glycyl-dipeptides (GlyAsp, GlyGly, GlyHis, GlyLeu, GlyLys, GlyPhe, GlyPro, GlyTyr) was investigated. The inhibition study with dihydroxyphenylalanine (DOPA) as substrate is based on separation of the enzymatic reaction components by reversed phase HPLC and the UV detection of the dopachrome formed. The results have evidenced that several of tested dipeptides inhibited PPO activity in the range of 20-40% while GlyPro and GlyLeu had no effect. The study has also permitted the characterization of the following kinetic pattern: a linear-mixed-type mechanism for GlyAsp, GlyGly, GlyLys, and GlyPhe and a hyperbolic-mixed-type for GlyTyr. It was not possible to identify the inhibition mechanism for GlyHis, although it affects PPO activity. In addition the effects of GlyAsp, GlyLys and GlyHis were evaluated for lessening the browning of fresh Golden Delicious apple and Irish White Skinned potato. The effectiveness of such inhibitors was determined by the difference between the colors observed in the dipeptide-treated sample and the controls using the color space CIE-Lab system. The % browning inhibition on potato (20-50%) was greater than of apple (20-30%) by the all tested dipeptides. Only GlyLys presented the significant value of 50%.

Effect of poly(ethylene oxide) homopolymer and two different poly(ethylene oxide-b-poly(propylene oxide)-b-poly(ethylene oxide) triblock copolymers on morphological, optical, and mechanical properties of nanostructured unsaturated polyester.

PubMed

Builes, Daniel H; Hernández-Ortiz, Juan P; Corcuera, Ma Angeles; Mondragon, Iñaki; Tercjak, Agnieszka

2014-01-22

Novel nanostructured unsaturated polyester resin-based thermosets, modified with poly(ethylene oxide) (PEO), poly(propylene oxide) (PPO), and two poly(ethylene oxide-b-propylene oxide-b-ethylene oxide) block copolymers (BCP), were developed and analyzed. The effects of molecular weights, blocks ratio, and curing temperatures on the final morphological, optical, and mechanical properties were reported. The block influence on the BCP miscibility was studied through uncured and cured mixtures of unsaturated polyester (UP) resins with PEO and PPO homopolymers having molecular weights similar to molecular weights of the blocks of BCP. The final morphology of the nanostructured thermosetting systems, containing BCP or homopolymers, was investigated, and multiple mechanisms of nanostructuration were listed and explained. By considering the miscibility of each block before and after curing, it was determined that the formation of the nanostructured matrices followed a self-assembly mechanism or a polymerization-induced phase separation mechanism. The miscibility between PEO or PPO blocks with one of two phases of UP matrix was highlighted due to its importance in the final thermoset properties. Relationships between the final morphology and thermoset optical and mechanical properties were examined. The mechanisms and physics behind the morphologies lead toward the design of highly transparent, nanostructured, and toughened thermosetting UP systems.

Isolation and characterization of spinach photosystem II membrane-associated catalase and polyphenol oxidase.

PubMed

Sheptovitsky, Y G; Brudvig, G W

1996-12-17

Photosystem II (PSII) membranes exhibit catalase and polyphenol oxidase (PPO) activities. Mild heat treatment of PSII membranes for 90 min at 30 degrees C releases most of these enzyme activities into the supernatant, accompanied by a 7-fold activation of PPO. In contrast, mild heat treatment of thylakoid membranes does not release significant amounts of either activity, indicating that both enzymes are bound to the luminal surface of the thylakoid membrane. The heat-released PSII membrane-associated catalase and PPO have been purified and characterized. Catalase activity was correlated with a 63 kDa polypeptide which was purified by batch adsorption to anion-exchange beads followed by gel filtration. The PSII membrane-associated catalase is unstable in solution, probably due to irreversible aggregation. The enzyme was characterized in terms of molecular and subunit size, amino-acid composition, UV-visible absorption, heme content, pH optimum, inhibitor sensitivity, and K(m) value for H2O2. Its properties indicate that the PSII membrane-associated catalase is a luminal thylakoid membrane-bound heme enzyme that has not been identified previously. The residual catalase activity of PSII membranes after mild heat treatment is irreversibly inhibited with 3-amino-1,2,4-triazole, a specific inhibitor of heme catalases, without inhibition of O2-evolution activity. This result indicates that little, if any, of the catalase activity from PSII membranes in the dark is catalyzed by the O2-evolving center of PSII. PPO activity was correlated with a 48 kDa polypeptide. However, the 48 kDa polypeptide and another heat-released polypeptide of 72 kDa have the same N-terminal sequence, which is also identical to that of a known 64 kDa protein [Hind, G., Marshak, D. R., & Coughlan, S. J. (1995) Biochemistry 34, 8157-8164]. During heat treatment of PSII membranes and further manipulations it was found that the 72 kDa polypeptide was largely converted into the 48 kDa polypeptide. Thus, the 72 kDa polypeptide appears to be a latent precursor of the active 48 kDa PPO. The PSII membrane-associated PPO was purified by anion-exchange chromatography and was characterized in terms of substrate specificity, pH optimum, inhibitor sensitivity and native molecular weight. The heat-released PPO appears to be identical to the enzyme previously isolated from spinach thylakoid membranes [Golbeck, J. H., & Cammarata, K. V. (1981) Plant Physiol. 67, 977-984].

Solution rheology of polyelectrolytes and polyelectrolyte-surfactant systems

NASA Astrophysics Data System (ADS)

Plucktaveesak, Nopparat

The fundamental understanding of polyelectrolytes in aqueous solutions is an important branch of polymer research. In this work, the rheological properties of polyelectrolytes and polyelectrolyte/surfactant systems are studied. Various synthetic poly electrolytes are chosen with varied hydrophobicity. We discuss the effects of adding various surfactants to aqueous solutions of poly(ethylene oxide)-b-poly(propylene oxide)- b-polyethylene oxide)-g-poly(acrylic acid) (PEO-PPO-PAA) in the first chapter. Thermogelation in aqueous solutions of PEO-PPO-PAA is due to micellization caused by aggregation of poly(propylene oxide) (PPO) blocks resulting from temperature-induced dehydration of PPO. When nonionic surfactants with hydrophilic-lipophilic balance (HLB) parameter exceeding 11 or Cn alkylsulfates; n-octyl (C8), n-decyl (C 10) and n-dodecyl (C12) sulfates are added, the gelation threshold temperature (Tgel) of 1.0wt% PEO-PPO-PAA in aqueous solutions increases. In contrast, when nonionic surfactants with HLB below 11 are added, the gelation temperature decreases. On the other hand, alkylsulfates with n = 16 or 18 and poly(ethylene oxide) (PEO) do not affect the Tgel. The results imply that both hydrophobicity and tail length of the added surfactant play important roles in the interaction of PEO-PPO-PAA micelles and the surfactant. In the second chapter, the solution behavior of alternating copolymers of maleic acid and hydrophobic monomer is studied. The alternating structure of monomers with two-carboxylic groups and hydrophobic monomers make these copolymers unique. Under appropriate conditions, these carboxylic groups dissociate leaving charges on the chain. The potentiometric titrations of copolymer solutions with added CaCl2 reveal two distinct dissociation processes corresponding to the dissociation of the two adjacent carboxylic acids. The viscosity data as a function of polymer concentration of poly(isobutylene-alt-sodium maleate), poly(styrene-alt-sodium maleate) and poly(diisobutylene- alt-sodium maleate) show the polyelectrolyte behavior as predicted. However, the viscosity as a function of concentration of sodium maleate based copolymers with 1-alkenes; 1-octene (C8), 1-decene (C10), 1-dodecene (C12) and 1-hexene (C14) exhibit an abnormal scaling power, which might be caused by aggregation of the alkene tails to form micelles. In the last chapter, we report the rheological properties of aqueous solutions of poly(acrylic acid) and oppositely charged surfactant, dodecyl trimethylammonium bromide (C12TAB). The solution viscosity decreases as surfactant is added, partly because the polyelectrolyte wraps around the surface of the spherical surfactant micelles, shortening the effective chain length. The effects of polymer molecular weight, polymer concentration, and polymer charge have been studied with no added salt. The results are compared with the predictions of a simple model based on the scaling theory for the viscosity of dilute and unentangled semidilute polyelectrolyte solutions in good solvent. This model takes into account two effects of added surfactant. The effective chain length of the polyelectrolyte is shortened when a significant fraction of the chain wraps around micelles. Another effect is the change of solution ionic strength resulting from surfactant addition that further lowers the viscosity. The parameters used in this model are independently determined, allowing the model to make a quantitative prediction of solution viscosity with no adjustable parameters. The model is also applied to predict the decrease in viscosity of various polyelectrolyte/oppositely charged surfactant systems reported in literature. The results are in good agreement with experimental data, proving that our model applies to all polyelectrolytes mixed with oppositely charged surfactants that form spherical micelles.

Evaluation of three pumpkin species: correlation with physicochemical, antioxidant properties and classification using SPME-GC-MS and E-nose methods.

PubMed

Zhou, Chun-Li; Mi, Li; Hu, Xue-Yan; Zhu, Bi-Hua

2017-09-01

To ascertain the most discriminant variables for three pumpkin species principal component analysis (PCA) was performed. Twenty-four parameters (pH, conductivity, sucrose, glucose, total soluble solids, L* , a* , b* , individual weight, edible rate, firmness, citric acid, fumaric acid, l-ascorbic acid, malic acid, PPO activity, POD activity, total flavonoids, vitamin E, total phenolics, DPPH, FRAP, β-carotene, and aroma) were considered. The studied pumpkin species were Cucurbita maxima , Cucurbita moschata , and Cucurbita pepo . Three pumpkin species were classified by PCA based on aroma, physicochemical and antioxidant properties because the sum of PC1 and PC2 were both greater than 85% (85.06 and 93.64% respectively). Results were validated by the PCA and showed that PPO activity, total flavonoid, sucrose, glucose, TSS, a* , pH, malic acid, vitamin E, DPPH, FRAP and β-carotene, and aroma are highly useful parameters to classify pumpkin species.

Micellization and phase transitions in a triblock copolymer-D2O system

NASA Astrophysics Data System (ADS)

Odhner, Hosanna; Huff, Alison; Patton, Kelly; Jacobs, D. T.; Clover, Bryna; Greer, Sandra

2011-03-01

The triblock copolymer (``unimer'') of PPO-PEO-PPO (commercially known as 17R4) has hydrophobic ends and a hydrophilic center. When placed in D2 O at lower concentrations and temperatures, only a network of unimers exists. However, at higher concentrations or temperatures, micelles of different geometries can form. We have measured the micellization line marking the transition from only unimers to some micelles, as well as a one- to two-phase transition at higher temperatures. This second transition is an Ising-like, LCST critical point, based on the shape of the coexistence curve. We find the LCST to not correspond to the minimum of the cloud point curve, which indicates polydispersity as described by Sollich. We acknowledge the support from Research Corporation, NSF-REU grant DMR 0649112, The College of Wooster, and (for BC and SG) to the donors of the Petroleum Research Fund, administered by the American Chemical Society.

Herbivore Oral Secreted Bacteria Trigger Distinct Defense Responses in Preferred and Non-Preferred Host Plants.

PubMed

Wang, Jie; Chung, Seung Ho; Peiffer, Michelle; Rosa, Cristina; Hoover, Kelli; Zeng, Rensen; Felton, Gary W

2016-06-01

Insect symbiotic bacteria affect host physiology and mediate plant-insect interactions, yet there are few clear examples of symbiotic bacteria regulating defense responses in different host plants. We hypothesized that plants would induce distinct defense responses to herbivore- associated bacteria. We evaluated whether preferred hosts (horsenettle) or non-preferred hosts (tomato) respond similarly to oral secretions (OS) from the false potato beetle (FPB, Leptinotarsa juncta), and whether the induced defense triggered by OS was due to the presence of symbiotic bacteria in OS. Both horsenettle and tomato damaged by antibiotic (AB) treated larvae showed higher polyphenol oxidase (PPO) activity than those damaged by non-AB treated larvae. In addition, application of OS from AB treated larvae induced higher PPO activity compared with OS from non-AB treated larvae or water treatment. False potato beetles harbor bacteria that may provide abundant cues that can be recognized by plants and thus mediate corresponding defense responses. Among all tested bacterial isolates, the genera Pantoea, Acinetobacter, Enterobacter, and Serratia were found to suppress PPO activity in tomato, while only Pantoea sp. among these four isolates was observed to suppress PPO activity in horsenettle. The distinct PPO suppression caused by symbiotic bacteria in different plants was similar to the pattern of induced defense-related gene expression. Pantoea inoculated FPB suppressed JA-responsive genes and triggered a SA-responsive gene in both tomato and horsenettle. However, Enterobacter inoculated FPB eliminated JA-regulated gene expression and elevated SA-regulated gene expression in tomato, but did not show evident effects on the expression levels of horsenettle defense-related genes. These results indicate that suppression of plant defenses by the bacteria found in the oral secretions of herbivores may be a more widespread phenomenon than previously indicated.

Histochemical and immunohistochemical analysis of enzymes involved in phenolic metabolism during berry development in Vitis vinifera L.

PubMed

Molero de Ávila, María Eugenia; Alarcón, María Victoria; Uriarte, David; Mancha, Luis Alberto; Moreno, Daniel; Francisco-Morcillo, Javier

2018-06-20

Phenolics are involved in many of plants' biological functions. In particular, they play important roles in determining the quality of grape berries and the wine made from them, and can also act as antioxidants with beneficial effects for human health. Several enzymes are involved in the synthesis of phenolic compounds. Among them, stilbene synthase (STS) is a key to the biosynthesis of stilbenes, which are considered to be important secondary metabolites in plants. Other enzymes, such as polyphenol oxidase (PPO) and peroxidase (POD), are involved in the degradation of phenolics, and become activated during late stages of berry ripening. In the present study, Vitis vinifera L. berries were sampled at eight stages of development, from 10 days after anthesis to late harvest. The PPO and POD enzymatic activities were determined at each stage. The presence of STS, PPO, and POD proteins in the grape exocarp and mesocarp was detected immunohistochemically and histochemically. The amount and intensity of the immunohistochemical and histochemical signals correlate with the variations in enzyme activities throughout fruit development. Strong STS immunoreactivity was detected until the onset of ripening. Labeled tissue increased gradually from mesocarp to exocarp, showing an intense signal in epidermis. At subcellular level, STS was mainly detected in cytoplasm grains and cell walls. The amount of PPO immunoreactivity increased progressively until the end of ripening. The PPO signal was detected in hypodermal layers and, to a lesser extent, in mesocarp parenchyma cells, especially in cytoplasm grains and cell walls. Finally, POD activity was stronger at the onset of ripening, and the POD histochemical signal was mainly detected in the cell walls of both exocarp and mesocarp tissue.

Combination Phenyl Propionate/Pheromone Traps for Monitoring Navel Orangeworm (Lepidoptera: Pyralidae) in Almonds in the Vicinity of Mating Disruption.

PubMed

Burks, Charles S

2017-04-01

Aerosol mating disruption is used for management of navel orangeworm, Amyelois transitella (Walker) (Lepidoptera: Pyralidae), in an increasing portion of California almonds and pistachios. This formulation suppresses pheromone monitoring traps far beyond the treatment block, potentially complicating monitoring and management of this key pest. Phenyl propionate is an attractant used to capture adults in the presence of mating disruption, completely suppressing pheromone traps, and lures combining phenyl propionate with a pheromone lure (PPO-combo lure) synergize trap capture in the presence of mating disruption. In this study, laboratory and field trials of different phenyl propionate dispensers indicate a useful life of six weeks. Controlled experiments found similar numbers of adults captured in phenyl propionate and PPO-combo lures in the presence of varying levels of mating disruption intensity. A subsequent trial compared monitoring of field plots at various distances from fields under commercial mating disruption for much of the growing season with pheromone and PPO-combo lures. Although there was some evidence of partial suppression of capture in PPO-combo traps closer to mating disruption compared with lures farther away, there was no failure of detection as occurred with pheromone lures. The ratio of adults in pheromone and PPO-combo traps varied with proximity from treated fields. These results indicate that, in addition to monitoring in mating disruption plots, phenyl propionate lures can be useful for insuring against failure of detection of navel orangeworm pressure in areas where mating disruption is widely used. Published by Oxford University Press on behalf of Entomological Society of America 2017. This work is written by a US Government employee and is in the public domain in the US.

Effects of argon enriched low-oxygen atmospheres and of high-oxygen atmospheres on the kinetics of polyphenoloxidase (PPO).

PubMed

O'Beirne, David; Murphy, Eileen; Ni Eidhin, Deirdre

2011-01-01

The reported benefits of enrichment of air atmospheres with argon or oxygen for control of enzymatic browning were investigated by determining the effects of these atmospheres on PPO kinetics. Kinetics of purified apple PPO and a commercially available mushroom PPO were studied in an in vitro model system. Enrichment with argon produced greater inhibitory effects than the current industry practice of enrichment with nitrogen. Km(app) values (mM) for apple PPO in 3%O(2)/97%Ar, 3%O(2)/97%N(2), and air, were 133, 87, and 48, respectively. The data indicate that inhibition by both gases is competitive, and also support the hypothesis that the greater inhibitory effect of argon was proportional to the size of the Van der Waals radius of argon against nitrogen (1.91 Å against 1.54 Å). Much smaller inhibitory effects were observed in the presence of 80% O(2) (Km(app) 57 mM), and the nature of this inhibition was less clear. The results suggest that the benefits of argon enrichment may be relatively small, and may require critical enzyme, substrate, and gas levels to be successful. However, these benefits may be exploitable commercially in some fresh-cut products, and may allow less anoxic atmospheres to be used. Practical Application: Control of enzymatic browning without sulfites continues to be a challenge in some fresh-cut products. While sporadic benefits of these atmospheres in control of enzymatic browning have been reported, results have been inconsistent in commercial practice. The results suggest that the benefits of argon enrichment may be relatively small, and may require critical enzyme, substrate, and gas levels to be successful. However, these benefits may be exploitable commercially in some fresh-cut products, and allow less anoxic atmospheres to be used.

Adsorption and association of a symmetric PEO-PPO-PEO triblock copolymer on polypropylene, polyethylene, and cellulose surfaces.

PubMed

Li, Yan; Liu, Hongyi; Song, Junlong; Rojas, Orlando J; Hinestroza, Juan P

2011-07-01

The association of a symmetric polyoxyethylene-polyoxypropylene-polyoxyethylene (PEO(19)-PPO(29)-PEO(19)) triblock copolymer adsorbed from aqueous solutions onto polypropylene (PP), polyethylene (PE), and cellulose surfaces was probed using Atomic Force Microscopy (AFM). Significant morphological differences between the polyolefin substrates (PP and PE) and the cellulose surfaces were observed after immersion of the films in the PEO(19)-PPO(29)-PEO(19) solutions. When the samples were scanned, while immersed in solutions of the triblock copolymer, it was revealed that the structures adsorbed on the polyolefin surfaces were smoothed by the adsorbed PEO(19)-PPO(29)-PEO(19). In contrast, those structures on the hydrophilic cellulose surfaces were sharpened. These observations were related to the roughness of the substrate and the energy of interaction between the surfaces and the PEO and PPO polymer segments. The interaction energy between each of the blocks and the surface was calculated using molecular dynamics simulations. It is speculated that the associative structures amply reported in aqueous solution at concentrations above the critical micelle concentration, CMC, are not necessarily preserved upon adsorption; instead, it appears that molecular arrangements of the anchor-buoy type and hemimicelles prevail. The reported data suggests that the roughness of the surface, as well as its degree of hydrophobicity, have a large influence on the nature of the resulting adsorbed layer. The reported observations are valuable in explaining the behavior of finishing additives and lubricants commonly used in textile and fiber processing, as well as the effect of the morphology of the boundary layers on friction and wear, especially in the case of symmetric triblock copolymers, which are commonly used as antifriction, antiwear additives.

Optimal load for the peak power and maximal strength of the upper body in Brazilian Jiu-Jitsu athletes.

PubMed

da Silva, Bruno Victor C; Simim, Mário A de Moura; Marocolo, Moacir; Franchini, Emerson; da Mota, Gustavo R

2015-06-01

We determined the optimal load for the peak power output (PPO) during the bench press throw (BPT) in Brazilian Jiu-Jitsu (BJJ) athletes and compared the PPO and maximal strength between advanced (AD) and nonadvanced (NA) athletes. Twenty-eight BJJ athletes (24.8 ± 5.7 years) performed the BPT at loads of 30, 40, 50, and 60% of their 1 repetition maximum (RM) in a randomized order (5-minute rest between BPTs). The PPO was determined by measuring the barbell displacement by an accelerometer (Myotest). The absolute (F = 7.25; p < 0.001; effect size [ES] = 0.21) and relative intensities were different (F = 7.11; p < 0.001; ES = 0.21) between the AD and NA. There was also a group and intensity interaction effect (F = 2.79; p = 0.046; ES = 0.10), but the differences were centered around the AD group, which achieved higher values using 40% (p = 0.001) and 50% of the 1RM (p < 0.001) than the PPO with 60% of 1RM. The AD athletes presented with higher 1RM than NA (p ≤ 0.05; ES = 1.0), but there was no difference (p > 0.05) in the PPO (30-60% 1RM). A polynomial adjustment indicated that the optimal load was ∼42% of 1RM for all groups and subgroups (R from 0.82 to 0.99). Our results suggest that there can be (1RM) differences between AD and NA BJJ athletes; however, there is no difference in the muscle power between the AD and NA groups. Additionally, ∼42% of 1RM seems to be the optimal load for developing maximal power using the BPT for the BJJ athletes.

Characteristics of a nationwide cohort of patients presenting with isolated hypogonadotropic hypogonadism (IHH).

PubMed

Bonomi, Marco; Vezzoli, Valeria; Krausz, Csilla; Guizzardi, Fabiana; Vezzani, Silvia; Simoni, Manuela; Bassi, Ivan; Duminuco, Paolo; Di Iorgi, Natascia; Giavoli, Claudia; Pizzocaro, Alessandro; Russo, Gianni; Moro, Mirella; Fatti, Letizia; Ferlin, Alberto; Mazzanti, Laura; Zatelli, Maria Chiara; Cannavò, Salvo; Isidori, Andrea M; Pincelli, Angela Ida; Prodam, Flavia; Mancini, Antonio; Limone, Paolo; Tanda, Maria Laura; Gaudino, Rossella; Salerno, Mariacarolina; Francesca, Pregnolato; Maghnie, Mohamad; Maggi, Mario; Persani, Luca

2018-01-01

Isolated hypogonadotropic hypogonadism (IHH) is a rare disorder with pubertal delay, normal (normoosmic-IHH, nIHH) or defective sense of smell (Kallmann syndrome, KS). Other reproductive and non-reproductive anomalies might be present although information on their frequency are scanty, particularly according to the age of presentation. Observational cohort study carried out between January 2008 and June 2016 within a national network of academic or general hospitals. We performed a detailed phenotyping of 503 IHH patients with: (1) manifestations of hypogonadism with low sex steroid hormone and low/normal gonadotropins; (2) absence of expansive hypothalamic/pituitary lesions or multiple pituitary hormone defects. Cohort was divided on IHH onset (PPO, pre-pubertal onset or AO, adult onset) and olfactory function: PPO-nIHH ( n  = 275), KS ( n  = 184), AO-nIHH ( n  = 36) and AO-doIHH (AO-IHH with defective olfaction, n  = 8). 90% of patients were classified as PPO and 10% as AO. Typical midline and olfactory defects, bimanual synkinesis and familiarity for pubertal delay were also found among the AO-IHH. Mean age at diagnosis was significantly earlier and more frequently associated with congenital hypogonadism stigmata in patients with Kallmann's syndrome (KS). Synkinesis, renal and male genital tract anomalies were enriched in KS. Overweight/obesity are significantly associated with AO-IHH rather than PPO-IHH. Patients with KS are more prone to develop a severe and complex phenotype than nIHH. The presence of typical extra-gonadal defects and familiarity for PPO-IHH among the AO-IHH patients indicates a common predisposition with variable clinical expression. Overall, these findings improve the understanding of IHH and may have a positive impact on the management of patients and their families. © 2018 European Society of Endocrinology.

Analysis of the blackening of green pepper (Piper nigrum Linnaeus) berries.

PubMed

Gu, Fenglin; Tan, Lehe; Wu, Huasong; Fang, Yiming; Wang, Qinghuang

2013-06-01

This paper investigates polyphenol oxidase (PPO) activity, reduced weight percentage after sun drying, and the changes in colour and appearance of green pepper (Piper nigrum Linnaeus) berries after blanching and sun drying. The results show that the degree of reduced weight percentage and browning in green pepper berries after blanching for 10 min is greater at 100°C than at 90 and 80°C. Moreover, the samples blanched at 100°C for 10 min had the fastest water loss, but the lowest PPO activity. Thus, the PPO enzymatic oxidation of polyphenols might not be the only reason for the browning of green pepper berries. This result is significantly different from that of Variyar, Pendharkar, Banerjeea, and Bandyopadhyay (1988) and therefore deserves further study. Copyright © 2012 Elsevier Ltd. All rights reserved.

Efficient reductive amination process for enantioselective synthesis of L-phosphinothricin applying engineered glutamate dehydrogenase.

PubMed

Yin, Xinjian; Wu, Jianping; Yang, Lirong

2018-05-01

The objective of this study was to identify and exploit a robust biocatalyst that can be applied in reductive amination for enantioselective synthesis of the competitive herbicide L-phosphinothricin. Applying a genome mining-based library construction strategy, eight NADPH-specific glutamate dehydrogenases (GluDHs) were identified for reductively aminating 2-oxo-4-[(hydroxy)(methyl)phosphinoyl]butyric acid (PPO) to L-phosphinothricin. Among them, the glutamate dehydrogenase cloned from Pseudomonas putida (PpGluDH) exhibited relatively high catalytic activity and favorable soluble expression. This enzyme was purified to homogeneity for further characterization. The specific activity of PpGluDH was 296.1 U/g-protein, which is significantly higher than the reported value for a GluDH. To the best of our knowledge, there has not been any report on protein engineering of GluDH for PPO-oriented activity. Taking full advantage of the available information and the diverse characteristics of the enzymes in the enzyme library, PpGluDH was engineered by site-directed mutation based on multiple sequence alignment. The mutant I170M, which had 2.1-fold enhanced activity, was successfully produced. When the I170M mutant was applied in the batch production of L-phosphinothricin, it showed markedly improved catalytic efficiency compared with the wild type enzyme. The conversion reached 99% (0.1 M PPO) with an L-phosphinothricin productivity of 1.35 g/h·L, which far surpassed the previously reported level. These results show that PpGluDH I170M is a promising biocatalyst for highly enantioselective synthesis of L-phosphinothricin by reductive amination.

EFFECTS OF 2,4-DICHLOROPHENOL, A METABOLITE OF A GENETICALLY ENGINEERED BACTERIUM, AND 2,4-DICHLOROPHENOXYACETATE ON SOME MICROORGANISM-MEDIATED ECOLOGICAL PROCESSES IN SOIL

EPA Science Inventory

A genetically engineered microorganism, Pseudomonas putida PPO301 (pRO103), and the plasmidless parent strain, PPO301, were added at approximately 10 7 CFU/g of soil amended with 500 ppm of 2,4-dichlorophenoxyacete (2,4-D)(500 ug/g). he degradation of 2,4-D and the accumulation o...

The effect of ultrasound on particle size, color, viscosity and polyphenol oxidase activity of diluted avocado puree.

PubMed

Bi, Xiufang; Hemar, Yacine; Balaban, Murat O; Liao, Xiaojun

2015-11-01

The effect of ultrasound treatment on particle size, color, viscosity, polyphenol oxidase (PPO) activity and microstructure in diluted avocado puree was investigated. The treatments were carried out at 20 kHz (375 W/cm(2)) for 0-10 min. The surface mean diameter (D[3,2]) was reduced to 13.44 μm from an original value of 52.31 μm by ultrasound after 1 min. A higher L(∗) value, ΔE value and lower a(∗) value was observed in ultrasound treated samples. The avocado puree dilution followed pseudoplastic flow behavior, and the viscosity of diluted avocado puree (at 100 s(-1)) after ultrasound treatment for 1 min was 6.0 and 74.4 times higher than the control samples for dilution levels of 1:2 and 1:9, respectively. PPO activity greatly increased under all treatment conditions. A maximum increase of 25.1%, 36.9% and 187.8% in PPO activity was found in samples with dilution ratios of 1:2, 1:5 and 1:9, respectively. The increase in viscosity and measured PPO activity might be related to the decrease in particle size. The microscopy images further confirmed that ultrasound treatment induced disruption of avocado puree structure. Copyright © 2015 Elsevier B.V. All rights reserved.

Characteristics of a gelled liquid hyprogen polyphenylene oxide (PPO) foam open-cell insulation system, phase 1

NASA Technical Reports Server (NTRS)

1973-01-01

A large scale gel production and storage facility and a small scale facility, the latter used for detailed visual examination of the gel/PPO foam interface, were developed. A subcontract was given to investigate techniques for the production of gelled liquid hydrogen, develop a process design for scale-up to a 1.89 cu m (500 gallon) gel production and storage facility, determine gel transfer characteristics, determine the solubility rate of gaseous helium in the gel, and investigate the gross gel/PPO foam interfacial phenomena. An inside-tank process for scaled-up production of gelled liquid hydrogen was selected. No detectable gel structure degradation occurred during repeated shearing. The viscosity of gelled liquid hydrogen at shear rates of 300/sec and higher is 2 to 5-fold greater than that of neat liquid hydrogen. No clogging problems were encountered during the transfer of gelled liquid hydrogen through warmed transfer lines. The solubility rate of helium in liquid hydrogen was significantly reduced by the presence of gel structure. The boil-off rates from gelled liquid hydrogen were reduced from 25 to 50 percent compared to those observed for the neat liquid hydrogen under compatible conditions. The polyphenylene oxide (PPO) foam insulation was found to be compatible with liquid ethane.

Hofmeister effect on thermo-responsive poly(propylene oxide): Role of polymer molecular weight and concentration.

PubMed

Moghaddam, Saeed Zajforoushan; Thormann, Esben

2016-03-01

Although a vast amount of research has been dedicated to investigate the Hofmeister effect on the stability of polymer solutions, a clear understanding of the role of polymer properties in this phenomenon is still missing. Here, the Hofmeister effect of NaCl (destabilizing) and NaSCN (stabilizing) salts on aqueous solutions of poly(propylene oxide) (PPO) is studied. Four different molecular weights of PPO were investigated, to determine how the variation in the polymer coil size affects the Hofmeister effect. The investigation was further conducted for different PPO concentrations, in order to understand the effect of inter-chain interactions on the response to addition of salt. The temperature-driven phase separation of the solutions was monitored by differential scanning calorimetry, which provides the precise value of the phase separation temperature, as well as the enthalpy change accompanied with the transition. It was observed that increasing the molecular weight weakens the effect of the both salts, which is interpreted in terms of a scaling law between the molecular weight and the accessible surface area of the polymers. Increasing the PPO concentration further diminished the NaCl effect, but amplified the NaSCN effect. This difference is attributed to an electrostatic stabilization mechanism in the case of NaSCN. Copyright © 2015 Elsevier Inc. All rights reserved.

Elucidation of the mechanism of enzymatic browning inhibition by sodium chlorite.

PubMed

He, Qiang; Luo, Yaguang; Chen, Pei

2008-10-15

Sodium chlorite (SC) is a well known anti-microbial agent and its strong inhibitory effect on enzymatic browning of fresh-cut produce has recently been identified. We investigated the effect of SC on polyphenol oxidase (PPO) and its substrate, chlorogenic acid (CA), as it relates to the mechanisms of browning inhibition by SC. Results indicate that the browning reaction of CA (1.0mM) catalyzed by PPO (33U/mL) was significantly inhibited by 1.0mM SC at pH 4.6. Two PPO isoforms were identified by native polyacrylamide gel electrophoresis, and both were inactivated by SC (3.0mM). This suggests that SC serves as a PPO inhibitor to prevent enzymatic browning. Furthermore, the effect of SC on the stability of CA in both acidic (pH 4.5) and basic conditions (pH 8.3) was studied by UV-Vis scan and LC-MS analysis. The results showed that at the presence of SC (3.0mM), CA (0.1mM) degraded to quinic acid and caffeic acid as well as other intermediates. Hence, the anti-browning property of SC can be attributed to the two modes of action: the inactivation of polyphenol oxidase directly and the oxidative degradation of phenolic substrates. Published by Elsevier Ltd.

Effects of hydrogen rich water on prolonged intermittent exercise.

PubMed

Da Ponte, Alessandro; Giovanelli, Nicola; Nigris, Daniele; Lazzer, Stefano

2018-05-01

Recent studies showed a positive effect of hydrogen rich water (HRW) intake on acid-base homeostasis at rest. We investigated 2-weeks of HRW intake on repeated sprint performance and acid-base status during prolonged intermittent cycling exercise. In a cross over single-blind protocol, 8 trained male cyclists (age [mean±SD] 41±7 years, body mass 72.3±4.4 kg, height 1.77±0.04 m, maximal oxygen uptake [V̇O2max] 52.6±4.4 mL·kg-1·min-1) were provided daily with 2 liters of placebo normal water (PLA, pH 7.6, oxidation/reduction potential [ORP] +230 mV, free hydrogen content 0 ppb) or HRW (pH 9.8, ORP -180 mV, free Hydrogen 450 ppb). Tests were performed at baseline and after each period of 2 weeks of treatment. The treatments were counter-balanced and the sequence randomized. The 30-minute intermittent cycling trial consisted in 10 3-minute blocks, each one composed by 90 seconds at 40% V̇O2max, 60 seconds at 60% V̇O2max, 16 seconds all out sprint, and 14 seconds active recovery. Oxygen uptake (V̇O2), heart rate and power output were measured during the whole test, while mean and peak power output (PPO), time to peak power and Fatigue Index (FI) were determined during all the 16 seconds sprints. Lactate, pH and bicarbonate (HCO3-) concentrations were determined at rest and after each sprint on blood obtained by an antecubital vein indwelling catheter. In the PLA group, PPO in absolute values decreased significantly at the 8th and 9th of 10 sprints and in relative values, ΔPPO, decreased significantly at 6th, 8th and 9th of 10 sprints (by mean: -12±5%, P<0.006), while it remained unchanged in HRW group. Mean power, FI, time to peak power and total work showed no differences between groups. In both conditions lactate levels increased while pH and HCO3- decreased progressively as a function of the number of sprints. Two weeks of HRW intake may help to maintain PPO in repetitive sprints to exhaustion over 30 minutes.

The Federal Employees Health Benefits Program: A Model for Competition in Rural America?

ERIC Educational Resources Information Center

Mueller, Keith J.; McBride, Timothy D.; Andrews, Courtney; Fraser, Roslyn; Xu, Liyan

2005-01-01

The Medicare Prescription Drug, Improvement, and Modernization Act of 2003 (MMA) created the Medicare Advantage (MA) program, which promotes the entry of private Preferred Provider Organization (PPO) plans into regions that have not previously had Medicare managed care plans. The assumption that a competitive environment will develop is based on…

Thermally Stable White Emitting Eu3+ Complex@Nanozeolite@Luminescent Glass Composite with High CRI for Organic-Resin-Free Warm White LEDs.

PubMed

Zhang, Jinhui; Gong, Shuming; Yu, Jinbo; Li, Peng; Zhang, Xuejie; He, Yuwei; Zhou, Jianbang; Shi, Rui; Li, Huanrong; Peng, Aiyun; Wang, Jing

2017-03-01

Nowadays, it is still a great challenge for lanthanide complexes to be applied in solid state lighting, especially for high-power LEDs because they will suffer severe thermal-induced luminescence quenching and transmittance loss when LEDs are operated at high current. In this paper, we have not only obtained high efficient and thermally chemical stable red emitting hybrid material by introducing europium complex into nanozeolite (NZ) functionalized with the imidazolium-based stopper but also abated its thermal-induced transmittance loss and luminescence quenching behavior via coating it onto a heat-resistant luminescent glass (LG) with high thermal conductivity (1.07 W/mK). The results show that the intensity at 400 K for Eu(PPO) n -C 4 Si@NZ@LG remains 21.48% of the initial intensity at 300 K, which is virtually 153 and 13 times the intensity of Eu(PPO) 3 ·2H 2 O and Eu(PPO) n -C 4 Si@NZ, respectively. Moreover, an organic-resin-free warm white LEDs device with a low CCT of 3994K, a high Ra of 90.2 and R9 of 57.9 was successfully fabricated simply by combining NUV-Chip-On-Board with a warm white emitting glass-film composite (i.e., yellowish-green emitting luminescent glass coated with red emitting hybrid film). Our method and results provide a feasible and promising way for lanthanide complexes to be used for general illumination in the future.

Early response of wheat antioxidant system with special reference to Fusarium head blight stress.

PubMed

Spanic, Valentina; Viljevac Vuletic, Marija; Abicic, Ivan; Marcek, Tihana

2017-06-01

Fusarium head blight (FHB) is a destructive fungal disease of wheat (Triticum aestivum L.) that causes significant grain yield losses and end-use quality reduction associated with contamination by the mycotoxin deoxynivalenol (DON). Three winter wheat varieties ('Vulkan', 'Kraljica' and 'Golubica') were screened for FHB resistance using artificial inoculation technique under field conditions. The aim of this study was to examine a relationship between FHB resistance and the effectiveness of enzyme antioxidant system of wheat varieties under different sampling times (3, 15, 24, 48, 96, 120 and 336 hai). In the time-course experiments FHB-resistant variety 'Vulkan' showed rapid induction of ascorbate peroxidase (APX) and polyphenol oxidase (PPO) activity in the early stages after infection (3 hai) and it seems that in 'Vulkan' FHB-resistance is associated with antioxidative enzymes activity. Moderately FHB resistant variety 'Kraljica' showed the higher guaiacol peroxidase (POD) activity and higher H 2 O 2 content after 24 hai, increased malondialdehyde (MDA) content at the beginning of infection (3, 15 hai) while induction of catalase (CAT), APX and PPO was delayed. FHB-susceptible variety 'Golubica' involved antioxidant enzymes in defense response much later. Based on our results the activity of antioxidant enzymes (APX and PPO) was more pronounced in 'Vulkan' than in FHB-medium resistant variety 'Kraljica' and FHB-susceptible 'Golubica'. The differences in antioxidant response of wheat varieties under Fusarium infestation could be the result of genetic properties. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

A study of overproduction and enhanced secretion of enzymes. Quarterly report

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

Dashek, W.V.

1993-09-01

Wood decay within forests, a significant renewable photosynthetic energy resource, is caused primarily by Basidiomycetous fungi, e.g., white rot fungi. These organisms possess the ability to degrade lignin, cellulose and hemicellulose, the main organic polymers of wood. In the case of the white rot fungi, e.g., Coriolus versicolor, the capacity results from the fungus` ability to elaborate extracellular cellulolytic and ligninolytic enzymes. With regard to the latter, at least one of the enzymes, polyphenol oxidase (PPO) appears within a defined growth medium. This proposal focuses on the over-production and enhanced secretion of PPO, cellulase and lignin peroxidase. There are twomore » major sections to the proposal: (1) overproduction of lignocellulolytic enzymes by genetic engineering methodologies and hyper-production and enhanced secretion of these enzymes by biochemical/electro microscopical techniques and (2) the biochemical/electron microscopical method involves substrate induction and the time-dependent addition of respiration and PPO enzymes.« less

Phenol metabolism in the leaves of the olive tree (Olea europaea L.) cv. Picual, Verdial, Arbequina, and Frantoio during ripening.

PubMed

Ortega-García, Francisca; Peragón, Juan

2010-12-08

The kinetic behavior and protein-expression level of phenylalanine ammonia-lyase (PAL) and polyphenol oxidase (PPO) have been determined in the leaves of the olive tree (Olea europaea L.) of cv. Picual, Verdial, Arbequina, and Frantoio during fruit ripening. Moreover, the concentration of total phenolic compounds, oleuropein, hydroxytyrosol, and tyrosol has been also determined. This study was carried out in 20-year-old olive trees grown in Jaén (Spain). The concentration of total and specific phenols showed a specific pattern in each cultivar. Frantoio showed the highest phenol concentration followed by Arbequina, Picual, and Verdial. A coordinated response between PAL, PPO, and the concentration of total phenols in the four cultivars was found. Also, specific changes were shown over the course of ripening, indicating a regulation of PAL, PPO, and phenol concentration in the olive-tree leaves during fruit ripening.

Effects of PEO-PPO-PEO Triblock Copolymers on Phospholipid Membrane Integrity under Osmotic Stress

PubMed Central

Wang, Jia-Yu; Chin, Jaemin; Marks, Jeremy D.; Lee, Ka Yee C.

2010-01-01

The effects of PEO-PPO-PEO triblock copolymers, mainly Poloxamer 188, on phospholipid membrane integrity under osmotic gradients were explored using giant unilamellar vesicles (GUVs). Fluorescence leakage assays showed two opposing effects of P188 on the structural integrity of GUVs depending on the duration of their incubation time. A two-state transition mechanism of interaction between the triblock copolymers and the phospholipid membrane is proposed: an adsorption (I) and an insertion (II) state. While the triblock copolymer in state I acts to moderately retard the leakage, their insertion in state II perturbs the lipid packing, thus increasing the membrane permeability. Our results suggest that the biomedical application of PEO-PPO-PEO triblock copolymers, either as cell membrane resealing agents or as accelerators for drug delivery, is directed by the delicate balance between these two states. PMID:20666423

Measurement of light yield dependence on electron energy for SNO+ scintillator

NASA Astrophysics Data System (ADS)

Wan Chan Tseung, Hok

2011-10-01

SNO+ is a multi-purpose neutrino experiment whose reach extends to the following areas of neutrino physics: neutrinoless double beta decay (with Nd-loaded scintillator), geo-neutrinos, reactor and low-energy solar neutrinos, as well as supernova neutrinos. It is a ~780-tonne liquid scintillator detector currently under construction at the SNOLAB facility in Sudbury, Ontario,Canada. The scintillator to be used in SNO+ is linear alkylbenzene (LAB) with ~2 g/L of PPO (2,5-diphenyloxazole). In this talk, we describe an experiment to test the linearity of the response of LAB-PPO with respect to electrons. We find that below ~0.4 MeV, the energy scale of LAB-PPO becomes non-linear. An explanation is given in terms of Cherenkov light absorption and re-emission by the scintillator. This research has been supported under DOE Grant No. DE-FG02-97ER41020.

Effects of Peach Cultivar on Enzymatic Browning Following Cell Damage from High-Pressure Processing.

PubMed

Techakanon, Chukwan; Gradziel, Thomas M; Barrett, Diane M

2016-10-12

Peach cultivars contribute to unique product characteristics and may affect the degree of browning after high-pressure processing (HPP). Nine peach cultivars were subjected to HPP at 0, 100, and 400 MPa for 10 min. Proton nuclear magnetic resonance ( 1 H NMR) relaxometry, light microscopy, color, polyphenol oxidase (PPO) activity, and total phenols were evaluated. The development of enzymatic browning during refrigerated storage occurred because of damage during HPP that triggered loss of cell integrity, allowing substrates to interact with enzymes. Increasing pressure levels resulted in greater damage, as determined by shifts in transverse relaxation time (T 2 ) and by light micrographs. Discoloration was triggered by membrane decompartmentalization but limited by PPO activity, which was found to correlate to cultivar harvest time (early, mid, and late season). Outcomes from the microstructure, 1 H NMR ,and PPO activity evaluation were an effective means of determining membrane decompartmentalization and allowed for prediction of browning scenarios.

Tracing the sources and cycling of phosphorus in river sediments using oxygen isotopes: Methodological adaptations and first results from a case study in France.

PubMed

Pistocchi, Chiara; Tamburini, Federica; Gruau, Gerard; Ferhi, André; Trevisan, Dominique; Dorioz, Jean-Marcel

2017-03-15

An essential aspect of eutrophication studies is to trace the ultimate origin of phosphate ions (P-PO 4 ) associated with the solid phase of river sediments, as certain processes can make these ions available for algae. However, this is not a straightforward task because of the diversity of allochthonous and autochthonous sources that can supply P-PO 4 to river sediments as well as the existence of in-stream processes that can change the speciation of these inputs and obscure the original sources. Here, we present the results of a study designed to explore the potentials, limitations and conditions for the use of the oxygen isotope composition of phosphate (δ 18 Op) extracted from river sediments for this type of tracing. We first tested if the method commonly applied to soils to purify P-PO 4 and to measure their δ 18 Op concentrations could be adapted to sediments. We then applied this method to a set of sediments collected in a river along a gradient of anthropogenic pressure and compared their isotopic signatures with those from samples that are representative of the potential P-PO 4 inputs to the river system (soils and riverbank material). The results showed that following some adaptations, the purification method could be successfully transposed to river sediments with a high level of P-PO 4 purification (>97%) and high δ 18 Op measurement repeatability and accuracy (<0.4‰). The values for the potential allochthonous sources varied from 11.8 to 18.3‰, while the δ 18 Op value for the river sediments ranged from 12.2 to 15.8‰. Moreover, a sharp increase (>3‰) in the sediment δ 18 Op value immediately downstream from the discharge point revealed the strong impact of municipal wastewater. The calculation of the theoretical equilibrium δ 18 O p values using the river water temperature and δ 18 O w showed that the downstream sediments were in equilibrium, which was not the case for the upstream sediments. This difference could be related to the contrast between the short residence time of the transfer system in the catchment head, which can preserve the isotopic variability of the source materials, and the longer residence times and higher P bioavailability in the lower catchment, possibly fostering the recycling of P-PO 4 by the biota and the equilibration of the oxygen isotope signature in P-PO 4 . These results demonstrate the potential of the isotopic approach to assess the sources and in-stream turnover of sedimentary P in river systems. Copyright © 2016 Elsevier Ltd. All rights reserved.

Validity of a Jump Mat for assessing Countermovement Jump Performance in Elite Rugby Players.

PubMed

Dobbin, Nick; Hunwicks, Richard; Highton, Jamie; Twist, Craig

2017-02-01

This study determined the validity of the Just Jump System ® (JJS) for measuring flight time, jump height and peak power output (PPO) in elite rugby league players. 37 elite rugby league players performed 6 countermovement jumps (CMJ; 3 with and 3 without arms) on a jump mat and force platform. A sub-sample (n=28) was used to cross-validate the equations for flight time, jump height and PPO. The JJS systematically overestimated flight time and jump height compared to the force platform (P<0.05), but demonstrated strong associations for flight time ( with R 2 =0.938; without R 2 =0.972) and jump height ( with R 2 =0.945; without R 2 =0.987). Our equations revealed no systematic difference between corrected and force platform scores and an improved the agreement for flight time (Ratio limits of agreement: with 1.00 vs. 1.36; without 1.00 vs. 1.16) and jump height ( with 1.01 vs. 1.34; without 1.01 vs. 1.15), meaning that our equations can be used to correct JJS scores for elite rugby players. While our equation improved the estimation of PPO ( with 1.02; without 1.01) compared to existing equations (Harman: 1.20; Sayers: 1.04), this only accounted for 64 and 69% of PPO. © Georg Thieme Verlag KG Stuttgart · New York.

Phosphoniums as catalysts for metal-free polymerization: Synthesis of well-defined poly(propylene oxide)

NASA Astrophysics Data System (ADS)

Zhang, Jie; Liu, Quan; Ren, Haojun; Zhang, Nanjie; Li, Pengfei; Yang, Kang

2017-11-01

The anionic ring-opening polymerization of propylene oxide (PO) was initiated with glycerol and catalyzed by three new synthetic phosphonium salts, tetrakis (pyrrolidino) phosphonium (Py4P1+), tetrakis (piperidino) phosphonium (Pi4P1+), tetrakis (morpholino) phosphonium (Mo4P1+), and the known tetrakis [cyclohexyl (methyl) amino] phosphonium (Cy4P1+) and tetrakis [tris (dimethylamino) phosphonoamino] phosphazene (P5+). The effects of substituents on the polymerization behavior, especially the molecular weight and its distribution, degree of unsaturation, and the sequential structures of poly (propylene oxide) (PPO) were investigated. The structures of these catalysts and PPOs were characterized by FT-IR, 1H and 13C NMR, and GPC. The results indicate that Cy4P1+, Py4P1+, and Pi4P1+ have lower optimum reaction temperatures at 90, 70, and 70 °C, respectively, and are better than traditional catalysts KOH and double metal cyanide. PPO samples with high molecular weight, narrow polydispersity, and high functionality were accessible when catalyzed with Cy4P1+, Pi4P1+, and P5+ at the optimum temperature. Notably, Pi4P1+ formed unimodal distribution PPO with 9000 g/mol, 2.93 of functionality, and 0.008 mmol/g degree of unsaturation. Majority segments of PPO from five catalysts adopted the stereoregular head-to-tail structure, exhibiting excellent regularity.

[Postoperative peritonitis. The criteria for a reintervention].

PubMed

Amorotti, C; Mosca, D; Palladino, L; Spallanzani, A; Rossi, A

1999-09-01

Postoperative peritonitis is a pathologic condition with a sometime nuclear clinical occurrence and therefore with an uncertain timing for reoperation. Aim of this paper is to identify the type and frequency of the digestive and systemic symptoms in relation to the anatomo-pathologic peroperative picture. Between 1980 and 1996, 119 patients were reoperated for a postoperative peritonitis (PPO) in the Surgical Department of Modena University. PPO was due to a lesion situated above the mesocolon in 33 patients, from the small bowel in 18, postappendicectomy in 25 and from the colon in 40. The first operation (for benign disease in 66.4%, for malignancy in 33.6%) was performed in emergency in 47 cases (39.5%) and as elective surgery in 72 (60.5%). The global mortality was of 33.6% (40 patients). An attempt is made to identify, the earlier and the most important bioclinical parameters for a correct indication to surgery. Twenty symptoms have been identified that, with different frequency, are strictly related with the onset of a PPO (in average 5 symptoms were positive). A research of these parameters, each 4-6 hours, allow to identify a subclinical PPO. During the decisional timing, it is important to check these general and digestive symptoms, apparently not serious, in order to avoid the onset appearance of an abdominal tenderness or a multiorgan failure that make the prognosis more severe.

Membranes of Polymers of Intrinsic Microporosity (PIM-1) Modified by Poly(ethylene glycol).

PubMed

Bengtson, Gisela; Neumann, Silvio; Filiz, Volkan

2017-06-05

Until now, the leading polymer of intrinsic microporosity PIM-1 has become quite famous for its high membrane permeability for many gases in gas separation, linked, however, to a rather moderate selectivity. The combination with the hydrophilic and low permeable poly(ethylene glycol) (PEG) and poly(ethylene oxides) (PEO) should on the one hand reduce permeability, while on the other hand enhance selectivity, especially for the polar gas CO₂ by improving the hydrophilicity of the membranes. Four different paths to combine PIM-1 with PEG or poly(ethylene oxide) and poly(propylene oxide) (PPO) were studied: physically blending, quenching of polycondensation, synthesis of multiblock copolymers and synthesis of copolymers with PEO/PPO side chain. Blends and new, chemically linked polymers were successfully formed into free standing dense membranes and measured in single gas permeation of N₂, O₂, CO₂ and CH₄ by time lag method. As expected, permeability was lowered by any substantial addition of PEG/PEO/PPO regardless the manufacturing process and proportionally to the added amount. About 6 to 7 wt % of PEG/PEO/PPO added to PIM-1 halved permeability compared to PIM-1 membrane prepared under similar conditions. Consequently, selectivity from single gas measurements increased up to values of about 30 for CO₂/N₂ gas pair, a maximum of 18 for CO₂/CH₄ and 3.5 for O₂/N₂.

Effects of four weeks of high-intensity interval training and creatine supplementation on critical power and anaerobic working capacity in college-aged men.

PubMed

Kendall, Kristina L; Smith, Abbie E; Graef, Jennifer L; Fukuda, David H; Moon, Jordan R; Beck, Travis W; Cramer, Joel T; Stout, Jeffrey R

2009-09-01

The critical power test provides 2 measures, critical power (CP) and anaerobic working capacity (AWC). In theory, the CP measurement represents the maximal power output that can be maintained without fatigue, and AWC is an estimate of work capacity associated with muscle energy reserves. High-intensity interval training (HIIT) has been shown to be an effective training method for improving endurance performance, including VO2PEAK. In addition, creatine (Cr) supplementation has been reported to improve AWC without training; however, it has shown no effect on CP. The purpose of this study was to examine the effects of 4 weeks of HIIT with Cr supplementation on CP and AWC. Forty-two recreationally active men volunteered to participate in this study. Participants were randomly assigned to 1 of 3 groups: Cr (n = 16), 10 g Cr + 10 g dextrose; placebo (PL, n = 16), 20 g dextrose; control (CON, n = 10), no treatment. Before and after supplementation, each participant performed a maximal oxygen consumption test VO2PEAK on a cycle ergometer to establish peak power output (PPO). Participants then completed a CP test involving 3 exercise bouts with the workloads set as a percentage of their PPO to determine CP and AWC. After a 2-week familiarization period of training and supplementing, PPO, CP, and AWC were remeasured before an additional 4 weeks of HIIT and supplementation were completed. Training consisted of 5 sets of 2-minute exercise bouts with 1 minute rest in between performed on the cycle ergometer, with intensities based on PPO. A significant improvement in CP was observed in the Cr group (6.72% +/- 2.54%), whereas PL showed no significant change (3.87% +/- 2.30%), and CON significantly decreased (6.27% +/- 2.38%). Furthermore, no changes in AWC were observed in any of the groups after treatment. The current findings suggest that Cr supplementation may enhance the effects of intense interval endurance training on endurance performance changes.

Control of Wilt and Rot Pathogens of Tomato by Antagonistic Pink Pigmented Facultative Methylotrophic Delftia lacustris and Bacillus spp.

PubMed

Janahiraman, Veeranan; Anandham, Rangasamy; Kwon, Soon W; Sundaram, Subbiah; Karthik Pandi, Veeranan; Krishnamoorthy, Ramasamy; Kim, Kiyoon; Samaddar, Sandipan; Sa, Tongmin

2016-01-01

The studies on the biocontrol potential of pink pigmented facultative methylotrophic (PPFM) bacteria other than the genus Methylobacterium are scarce. In the present study, we report three facultative methylotrophic isolates; PPO-1, PPT-1, and PPB-1, respectively, identified as Delftia lacustris, Bacillus subtilis , and Bacillus cereus by 16S rRNA gene sequence analysis. Hemolytic activity was tested to investigate the potential pathogenicity of isolates to plants and humans, the results indicates that the isolates PPO-1, PPT-1, and PPB-1 are not pathogenic strains. Under in vitro conditions, D. lacustris PPO-1, B . subtilis PPT-1, and B . cereus PPB-1 showed direct antagonistic effect by inhibiting the mycelial growth of fungal pathogens; Fusarium oxysporum f. sp. lycopersici (2.15, 2.05, and 1.95 cm), Sclerotium rolfsii (2.14, 2.04, and 1.94 cm), Pythium ultimum (2.12, 2.02, and 1.92 cm), and Rhizoctonia solani (2.18, 2.08, and 1.98 cm) and also produced volatile inhibitory compounds. Under plant growth chamber condition methylotrophic bacterial isolates; D . lacustris PPO-1, B . subtilis PPT-1, and B. cereus PPB-1 significantly reduced the disease incidence of tomato. Under greenhouse condition, D . lacustris PPO-1, B . subtilis PPT-1, and B . cereus PPB-1 inoculated tomato plants, when challenged with F . oxysporum f. sp. lycopersici, S . rolfsii, P . ultimum , and R . solani , increased the pathogenesis related proteins (β-1,3-glucanase and chitinase) and defense enzymes (phenylalanine ammonia lyase, peroxidase, polyphenol oxidase, and catalase) on day 5 after inoculation. In the current study, we first report the facultative methylotrophy in pink pigmented D. lacustris, B . subtilis , and B . cereus and their antagonistic potential against fungal pathogens. Direct antagonistic and ISR effects of these isolates against fungal pathogens of tomato evidenced their possible use as a biocontrol agent.

Control of Wilt and Rot Pathogens of Tomato by Antagonistic Pink Pigmented Facultative Methylotrophic Delftia lacustris and Bacillus spp.

PubMed Central

Janahiraman, Veeranan; Anandham, Rangasamy; Kwon, Soon W.; Sundaram, Subbiah; Karthik Pandi, Veeranan; Krishnamoorthy, Ramasamy; Kim, Kiyoon; Samaddar, Sandipan; Sa, Tongmin

2016-01-01

The studies on the biocontrol potential of pink pigmented facultative methylotrophic (PPFM) bacteria other than the genus Methylobacterium are scarce. In the present study, we report three facultative methylotrophic isolates; PPO-1, PPT-1, and PPB-1, respectively, identified as Delftia lacustris, Bacillus subtilis, and Bacillus cereus by 16S rRNA gene sequence analysis. Hemolytic activity was tested to investigate the potential pathogenicity of isolates to plants and humans, the results indicates that the isolates PPO-1, PPT-1, and PPB-1 are not pathogenic strains. Under in vitro conditions, D. lacustris PPO-1, B. subtilis PPT-1, and B. cereus PPB-1 showed direct antagonistic effect by inhibiting the mycelial growth of fungal pathogens; Fusarium oxysporum f. sp. lycopersici (2.15, 2.05, and 1.95 cm), Sclerotium rolfsii (2.14, 2.04, and 1.94 cm), Pythium ultimum (2.12, 2.02, and 1.92 cm), and Rhizoctonia solani (2.18, 2.08, and 1.98 cm) and also produced volatile inhibitory compounds. Under plant growth chamber condition methylotrophic bacterial isolates; D. lacustris PPO-1, B. subtilis PPT-1, and B. cereus PPB-1 significantly reduced the disease incidence of tomato. Under greenhouse condition, D. lacustris PPO-1, B. subtilis PPT-1, and B. cereus PPB-1 inoculated tomato plants, when challenged with F. oxysporum f. sp. lycopersici, S. rolfsii, P. ultimum, and R. solani, increased the pathogenesis related proteins (β-1,3-glucanase and chitinase) and defense enzymes (phenylalanine ammonia lyase, peroxidase, polyphenol oxidase, and catalase) on day 5 after inoculation. In the current study, we first report the facultative methylotrophy in pink pigmented D. lacustris, B. subtilis, and B. cereus and their antagonistic potential against fungal pathogens. Direct antagonistic and ISR effects of these isolates against fungal pathogens of tomato evidenced their possible use as a biocontrol agent. PMID:27872630

Silent PPOs: the stealth discounting of provider reimbursement.

PubMed

Marks, James W

2005-01-01

Physicians are losing millions of dollars per year from payers engaging in abusive discounting practices. One of the worst of these practices is the silent PPO. This article explains what a silent PPO is and how it unlawfully reduces a provider's reimbursement. The article discusses how providers can recognize silent PPOs and how to protect their practices from this discounting. The article also reviews statutes that prohibit or regulate silent PPOs and recent court decisions finding in favor of providers and against silent PPOs.

Effect of Structure on Physical Properties of Polymers.

DTIC Science & Technology

1979-12-31

PORT NUMBE . J ! 2. GOVT ACCESSION NO. 3. RECIPIENT’S CATALOG NUMBER OSRT R’.-8 00 7 5 0 4_7_5_ Effecc of Structure on Physical Properties of -Final...Compatibility of Fluorosubstituted Styrene Polymers with PPO and PS. R. Vukovic , F.E. Karasz, W.J. MacKnight, (in press). (6) Compatibility of Ortho- and Para...fluorostyrene Copolymers with PPO and PS. R. Vukovic , F.E. Karasz, W.J. MacKnight, (in press). (7) Partial Miscibility in the System Poly (para

Defense Logistics: The Department of Defense’s Report on Strategic Seaports Addressed All Congressionally Directed Elements

DTIC Science & Technology

2013-05-13

executes the strategic seaport program for DOD. • MARAD and DOD use Port Planning Orders ( PPOs ) to identify and coordinate DOD’s needs in advance...outline each port’s ability to meet the PPO requirements. • The National Port Readiness Network, chaired by MARAD, provides for the establishment of...However, a key assumption of the report was that the PPO facilities at the strategic seaports provide sufficient capacity to meet the DOD cargo

Nature of Interactions between PEO-PPO-PEO Triblock Copolymers and Lipid Membranes: (I) The Effect of Polymer Hydrophobicity on Its Ability to Protect Liposomes from Peroxidation

PubMed Central

Wang, Jia-Yu; Marks, Jeremy; Lee, Ka Yee C.

2013-01-01

PEO-PPO-PEO triblock copolymers have opposing effects on lipid membrane integrity- they can behave either as membrane sealants or as membrane permeabilizers. To gain insights into their biomembrane activities, the fundamental interactions between a series of PEO-based polymers and phospholipid vesicles were investigated. Specifically, the effect of copolymer hydrophobicity on its ability to prevent liposomes from peroxidation was evaluated, and partitioning free energy and coefficient involved in the interactions were derived. Our results show that the high degree of hydrophilicity is a key feature of the copolymers that can effectively protect liposomes from peroxidation and the protective effect of the copolymers stems from their adsorption at the membrane surface without penetrating into the bilayer core. The origin of this protective effect induced by polymer absorption is attributed to the retardation of membrane hydration dynamics, which is further illustrated in the accompany study on dynamic nuclear polarization (DNP)-derived hydration dynamics1. PMID:22808900

HIIT enhances endurance performance and aerobic characteristics more than high-volume training in trained rowers.

PubMed

Ní Chéilleachair, Niamh J; Harrison, Andrew J; Warrington, Giles D

2017-06-01

This study compared the effects of long slow distance training (LSD) with high-intensity interval training (HIIT) in rowers. Nineteen well-trained rowers performed three tests before and after an 8-week training intervention: (1) 2000 m time trial; (2) seven-stage incremental step test to determine maximum oxygen uptake ([Formula: see text]O 2max ), power output at [Formula: see text]O 2max (W[Formula: see text]O 2max ), peak power output (PPO), rowing economy and blood lactate indices and (3) seven-stroke power-output test to determine maximal power output (W max ) and force (F max ). After baseline testing, participants were randomly assigned either to a HIIT or LSD group. The LSD comprised 10 weekly aerobic sessions. The HIIT also comprised 10 weekly sessions: 8 aerobic and 2 HIIT. The HIIT sessions comprised 6-8 × 2.5 min intervals at 100% PPO with recovery time based on heart rate (HR) returning to 70% HR max . Results demonstrated that the HIIT produced greater improvement in 2000 m time trial performance than the LSD (effect size (ES) = 0.25). Moreover, the HIIT produced greater improvements in [Formula: see text]O 2max (ES = 0.95, P = 0.035) and power output at lactate threshold (W LT ) (ES = 1.15, P = 0.008). Eight weeks of HIIT performed at 100% PPO is more effective than LSD in improving performance and aerobic characteristics in well-trained rowers.

A highly sensitive electrochemical biosensor for catechol using conducting polymer reduced graphene oxide-metal oxide enzyme modified electrode.

PubMed

Sethuraman, V; Muthuraja, P; Anandha Raj, J; Manisankar, P

2016-10-15

The fabrication, characterization and analytical performances were investigated for a catechol biosensor, based on the PEDOT-rGO-Fe2O3-PPO composite modified glassy carbon (GC) electrode. The graphene oxide (GO) doped conducting polymer poly (3,4-ethylenedioxythiophene) (PEDOT) was prepared through electrochemical polymerization by potential cycling. Reduction of PEDOT-GO was carried out by amperometric method. Fe2O3 nanoparticles were synthesized in ethanol by hydrothermal method. The mixture of Fe2O3, PPO and glutaraldehyde was casted on the PEDOT-rGO electrode. The surface morphology of the modified electrodes was studied by FE-SEM and AFM. Cyclic voltammetric studies of catechol on the enzyme modified electrode revealed higher reduction peak current. Determination of catechol was carried out successfully by Differential Pulse Voltammetry (DPV) technique. The fabricated biosensor investigated shows a maximum current response at pH 6.5. The catechol biosensor exhibited wide sensing linear range from 4×10(-8) to 6.20×10(-5)M, lower detection limit of 7×10(-9)M, current maxima (Imax) of 92.55µA and Michaelis-Menten (Km) constant of 30.48µM. The activation energy (Ea) of enzyme electrode is 35.93KJmol(-1) at 50°C. There is no interference from d-glucose and l-glutamic acid, ascorbic acid and o-nitrophenol. The PEDOT-rGO-Fe2O3-PPO biosensor was stable for at least 75 days when stored in a buffer at about 4°C. Copyright © 2015 Elsevier B.V. All rights reserved.

Discoloration of Indigo Carmine Using Aqueous Extracts from Vegetables and Vegetable Residues as Enzyme Sources

PubMed Central

Solís, A.; Perea, F.; Solís, M.; Manjarrez, N.; Pérez, H. I.; Cassani, J.

2013-01-01

Several vegetables and vegetable residues were used as sources of enzymes capable to discolor indigo carmine (IC), completely or partially. Complete discoloration was achieved with aqueous extracts of green pea seeds and peels of green pea, cucumber, and kohlrabi, as well as spring onion leaves. The source of polyphenol oxidase (PPO), pH, time, and aeration is fundamental for the discoloration process catalyzed by PPO. The PPO present in the aqueous extract of green pea seeds was able to degrade 3,000 ppm of IC at a pH of 7.6 and magnetic stirring at 1,800 rpm in about 36 h. In addition, at 1,800 rpm and a pH of 7.6, this extract discolored 300 ppm of IC in 1:40 h; in the presence of 10% NaCl, the discoloration was complete in 5:50 h, whereas it was completed in 4:30 h with 5% NaCl and 2% laundry soap. PMID:24151588

Inhibitory effect of rice bran extracts and its phenolic compounds on polyphenol oxidase activity and browning in potato and apple puree.

PubMed

Sukhonthara, Sukhontha; Kaewka, Kunwadee; Theerakulkait, Chockchai

2016-01-01

Full-fatted and commercially defatted rice bran extracts (RBE and CDRBE) were evaluated for their ability to inhibit enzymatic browning in potato and apple. RBE showed more effective inhibition of polyphenol oxidase (PPO) activity and browning in potato and apple as compared to CDRBE. Five phenolic compounds in RBE and CDRBE (protocatechuic acid, vanillic acid, p-coumaric acid, ferulic acid and sinapic acid) were identified by HPLC. They were then evaluated for their important role in the inhibition using a model system which found that ferulic acid in RBE and p-coumaric acid in CDRBE were active in enzymatic browning inhibition of potato and apple. p-Coumaric acid exhibited the highest inhibitory effect on potato and apple PPO (p ⩽ 0.05). Almost all phenolic compounds showed higher inhibitory effect on potato and apple PPO than 100 ppm citric acid. Copyright © 2015 Elsevier Ltd. All rights reserved.

Identification and functional characterization of the soybean GmaPPO12 promoter conferring Phytophthora sojae induced expression.

PubMed

Chai, Chunyue; Lin, Yanling; Shen, Danyu; Wu, Yuren; Li, Hongjuan; Dou, Daolong

2013-01-01

Identification of pathogen-inducible promoters largely lags behind cloning of the genes for disease resistance. Here, we cloned the soybean GmaPPO12 gene and found that it was rapidly and strongly induced by Phytophthorasojae infection. Computational analysis revealed that its promoter contained many known cis-elements, including several defense related transcriptional factor-binding boxes. We showed that the promoter could mediate induction of GUS expression upon infection in both transient expression assays in Nicotianabenthamiana and stable transgenic soybean hairy roots. Importantly, we demonstrated that pathogen-induced expression of the GmaPPO12 promoter was higher than that of the soybean GmaPR1a promoter. A progressive 5' and 3' deletion analysis revealed two fragments that were essential for promoter activity. Thus, the cloned promoter could be used in transgenic plants to enhance resistance to phytophthora pathogens, and the identified fragment could serve as a candidate to produce synthetic pathogen-induced promoters.

The effect of ultraviolet treatment on enzymatic activity and total phenolic content of minimally processed potato slices.

PubMed

Teoh, Li Shing; Lasekan, Ola; Adzahan, Noranizan Mohd; Hashim, Norhashila

2016-07-01

In this work, potato slices were exposed to different doses of UV-C irradiation (i.e. 2.28, 6.84, 11.41, and 13.68 kJ m -2 ) with or without pretreatment [i.e. ascorbic acid and calcium chloride (AACCl) dip] and stored at 4 ± 1 °C. Changes in enzymatic activities of polyphenol oxidase (PPO), peroxidase (POD) and phenylalanine ammonia lyase (PAL), as well as total phenolic content (TPC) were investigated after 0, 3, 7 and 10 days of storage. Results showed that untreated and UV-C treated potato slices at 13.68 kJ m -2 dosage level showed significantly higher PPO, POD and PAL activities. Conversely, untreated potato slices showed the lowest TPC during storage period. Potato slices subjected to AACCl dip plus UV-C at 6.84 kJ m -2 produced lower PPO, POD and PAL activities, as well as maintained a high TPC during storage.

Microwave-assisted extraction and pharmacological evaluation of polysaccharides from Posidonia oceanica.

PubMed

Ben Salem, Yosra; Abdelhamid, Amal; Mkadmini Hammi, Khaoula; Le Cerf, Didier; Bouraoui, Abderrahman; Majdoub, Hatem

2017-10-01

Microwave-assisted extraction was employed for the isolation of polysaccharides from Posidonia oceanica (PPO). The extracting parameters were optimized adopting response surface methodology. The highest polysaccharide yield (2.55 ± 0.09%), which is in concordance with the predicted value (2.76%), was obtained under the following conditions: extraction time 60 s, liquid-solid ratio of 50:1 (mL/g) and power of 800 W. This polysaccharide, with molecular weight of 524 KDa, characterized by gas chromatography-mass spectrometry showed that PPO was mainly composed of galactose, glucose, and arabinose with molar percentages 25.38, 24.37, and 21.64%, respectively. The pharmacological evaluation of PPO using animal models at the dose of 100 mg/kg indicated a significant anti-inflammatory activity with a percentage of inhibition of edema of 54.65% and a significant antinociceptive activity with 78.91% inhibition of writhing for peripheral analgesic activity and an increase in the hot plate reaction time for central analgesic activity.

Simplified recovery of enzymes and nutrients in sweet potato wastewater and preparing health black tea and theaflavins with scrap tea.

PubMed

Li, Qing-Rong; Luo, Jia-Ling; Zhou, Zhong-Hua; Wang, Guang-Ying; Chen, Rui; Cheng, Shi; Wu, Min; Li, Hui; Ni, He; Li, Hai-Hang

2018-04-15

The industry discards generous organic wastewater in sweet potato starch factory and scrap tea in tea production. A simplified procedure to recover all biochemicals from the wastewater of sweet potato starch factory and use them to make health black tea and theaflavins from scrap green tea was developed. The sweet potato wastewater was sequentially treated by isoelectric precipitation, ultrafiltration and nanofiltration to recover polyphenol oxidase (PPO), β-amylase, and small molecular fractions, respectively. The PPO fraction can effectively transform green tea extracts into black tea with high content of theaflavins through the optimized fed-batch feeding fermentation. The PPO transformed black tea with sporamins can be used to make health black tea, or make theaflavins by fractionation with ethyl acetate. This work provides a resource- and environment-friendly approach for economically utilizing the sweet potato wastewater and the scrap tea, and making biochemical, nutrient and health products. Copyright © 2017 Elsevier Ltd. All rights reserved.

Indirect determination of sulfite using a polyphenol oxidase biosensor based on a glassy carbon electrode modified with multi-walled carbon nanotubes and gold nanoparticles within a poly(allylamine hydrochloride) film.

PubMed

Sartori, Elen Romão; Vicentini, Fernando Campanhã; Fatibello-Filho, Orlando

2011-12-15

The modification of a glassy carbon electrode with multi-walled carbon nanotubes and gold nanoparticles within a poly(allylamine hydrochloride) film for the development of a biosensor is proposed. This approach provides an efficient method used to immobilize polyphenol oxidase (PPO) obtained from the crude extract of sweet potato (Ipomoea batatas (L.) Lam.). The principle of the analytical method is based on the inhibitory effect of sulfite on the activity of PPO, in the reduction reaction of o-quinone to catechol and/or the reaction of o-quinone with sulfite. Under the optimum experimental conditions using the differential pulse voltammetry technique, the analytical curve obtained was linear in the concentration of sulfite in the range from 0.5 to 22 μmol L(-1) with a detection limit of 0.4 μmol L(-1). The biosensor was applied for the determination of sulfite in white and red wine samples with results in close agreement with those results obtained using a reference iodometric method (at a 95% confidence level). Copyright © 2011 Elsevier B.V. All rights reserved.

Photoluminescence properties of polystyrene-hosted fluorophore thin films

NASA Astrophysics Data System (ADS)

Chakraborty, Subha; Harris, Katherine; Huang, Mengbing

2016-12-01

We report on a photo-luminescence study of four different fluorophores: Coumarin 6, 2,5-Diphenyloxazole (PPO), 1,4-Bis(5-phenyl-2-oxazolyl)benzene (POPOP) and Para-terpehnyl (PTP), doped in a polystyrene-based thin film. All of the samples are prepared by spin coating from a non-polar polymer solution at various concentrations. Their emission spectra and transient properties are characterized by photoluminescence measurements. Red-shifts in the emission spectra are observed for all four types of fluorophores as their concentration increases. We explain this phenomenon based on concentration dependence of solvatochromic effects and the results show good agreement with existing literature. We also show that the singlet-singlet annihilation processes are possibly a prevalent mechanism in the high concentration regime that affects the steady state and transient emission characteristics of the fluors. With the exception of PTP, photoluminescence quenching occurs as the fluorophore concentration in the polymer is increased. Rate equations for excited state decay mechanisms are analysed by considering different radiative and non-radiative energy transfer mechanisms. The results show consistency with our experimental observations. PTP shows the best photoluminescence results as an efficient fluor in the thin film, whereas PPO shows the strongest concentration dependent quenching and an anomalous lifetime distribution.

The conformational state of polyphenol oxidase from field bean (Dolichos lablab) upon SDS and acid-pH activation

PubMed Central

Kanade, Santosh R.; Paul, Beena; Rao, A. G. Appu; Gowda, Lalitha R.

2006-01-01

Field bean (Dolichos lablab) contains a single isoform of PPO (polyphenol oxidase) – a type III copper protein that catalyses the o-hydroxylation of monophenols and oxidation of o-diphenols using molecular oxygen – and is a homotetramer with a molecular mass of 120 kDa. The enzyme is activated manyfold either in the presence of the anionic detergent SDS below its critical micellar concentration or on exposure to acid-pH. The enhancement of kcat upon activation is accompanied by a marked shift in the pH optimum for the oxidation of t-butyl catechol from 4.5 to 6.0, an increased sensitivity to tropolone, altered susceptibility to proteolytic degradation and decreased thermostability. The Stokes radius of the native enzyme is found to increase from 49.1±2 to 75.9±0.6 Å (1 Å=0.1 nm). The activation by SDS and acid-pH results in a localized conformational change that is anchored around the catalytic site of PPO that alters the microenvironment of an essential glutamic residue. Chemical modification of field bean and sweet potato PPO with 1-ethyl-3-(3-dimethylaminopropyl)carbodi-imide followed by kinetic analysis leads to the conclusion that both the enzymes possess a core carboxylate essential to activity. This enhanced catalytic efficiency of PPO, considered as an inducible defence oxidative enzyme, is vital to the physiological defence strategy adapted by plants to insect herbivory and pathogen attack. PMID:16393141

Polyphenol oxidase inhibitor from blue mussel (Mytilus edulis) extract.

PubMed

Schulbach, Kurt F; Johnson, Jodie V; Simonne, Amarat H; Kim, Jeong-Mok; Jeong, Yoonhwa; Yagiz, Yavuz; Marshall, Maurice R

2013-03-01

Enzymatic browning remains a problem for the fruit and vegetable industry, especially new emerging markets like pre-cuts. A crude inhibitor from blue mussel (Mytilus edulis) showed broad inhibition for apple (58%), mushroom (32%), and potato (44%) polyphenol oxidase (PPO) and was further characterized. Inhibition increased as the concentration of inhibitor increased in the reaction mixture eventually leveling off at a maximum inhibition of 92% for apple PPO. The inhibitor was capable of bleaching the brown color formed in the reaction mixture with apple PPO. Identification of the inhibitor by mass spectrometry and high-performance liquid chromatography revealed it to be hypotaurine (C2 H7 NO2 S). Hypotaurine and other sulfinic acid analogs (methane and benzene sulfinic acids) showed very good inhibition for apple PPO at various concentrations with the highest inhibition occurring at 500 μM for hypotaurine (89%), methane sulfinic acid (100%), and benzene sulfinic acid (100%). An inhibitor found in the expressed liquid from blue mussel shows very good inhibition on enzymatic browning. Since this enzyme is responsible for losses to the fruit and vegetable industry, natural inhibitors that prevent browning would be valuable. Finding alternative chemistries that inhibit browning and understanding their mode of action would be beneficial to the fruit and vegetable industries and their segments such as pre-cuts, juices, and so on. Inhibitors from products ingested by consumers are more acceptable as natural ingredients. © 2013 Institute of Food Technologists®

Ground-based observations of Saturn's H3+ aurora and ring rain from Keck in 2013

NASA Astrophysics Data System (ADS)

O'Donoghue, J.; Melin, H.; Stallard, T.; Provan, G.; Moore, L.; Badman, S. V.; Baines, K. H.; Miller, S.; Cowley, S. W. H.

2014-12-01

The ground-based 10-metre Keck telescope was used to probe Saturn's H3+ ionosphere in 2013. The slit on the high resolution near infrared spectrometer (NIRSPEC; (R~25,000) was aligned pole-to-pole along Saturn's rotational axis at local noon. This is also aligned (within uncertainties) to the effectively dipolar magnetic field. Four polar/auroral regions of Saturn's ionosphere were measured simultaneously as the planet rotated: 1) the northern noon main auroral oval; 2) the northern midnight main oval; 3) the northern polar cap and 4) the southern main oval at noon. The results here contain twenty-three H3+ temperatures, column densities and total emissions located at the above regions spread over timescales of both hours and days. The main findings of this study are that ionospheric temperatures in the northern main oval are cooler than their southern counterparts by tens of K; supportive of the hypothesis that the total thermospheric heating rate (Joule heating and ion drag) is inversely proportional to magnetic field strength. The main oval H3+ density and emission is lower at northern midnight than at noon, and this is in agreement with an electron influx peaking at 08:00 Saturn local time and having a minimum at midnight. When ordering the northern main oval parameters of H3+ as a function of the oscillation period seen in Saturn's magnetic field - the planetary period oscillation (PPO) phase - we see a large peak in H3+ density and emission at ˜110° phase, with a full-width at half-maximum (FWHM) of ˜40°. This seems to indicate that the influx of electrons associated with the PPO phase at 90° is responsible at least in part for the behavior of all H3+ parameters. In addition to the auroral/polar data we also present the latest results from observations of Saturn's mid-to-low latitude H3+ emission. This emission is thought to be modulated by charged water product influx which flows into the planet along magnetic field lines from Saturn's rings, i.e. ring rain. Figure: H3+ Q(1,0) parameters as a functon of northern PPO phase. The x- and y-axes show the PPO phase angle versus the H3+ parameters in each of the four panels: a) Q(1,0) line intensity, b) temperature, c) column density and d) total emission. The blue, green and red correspond to the 19th, 20th and 21st of April, respectively.

Effect of chain length on binding of fatty acids to Pluronics in microemulsions.

PubMed

James-Smith, Monica A; Shekhawat, Dushyant; Cheung, Sally; Moudgil, Brij M; Shah, Dinesh O

2008-03-15

We investigated the effect of fatty acid chain length on the binding capacity of drug and fatty acid to Pluronic F127-based microemulsions. This was accomplished by using turbidity experiments. Pluronic-based oil-in-water microemulsions of various compositions were synthesized and titrated to turbidity with concentrated Amitriptyline, an antidepressant drug. Sodium salts of C(8), C(10), or C(12) fatty acid were used in preparation of the microemulsion and the corresponding binding capacities were observed. It has been previously determined that, for microemulsions prepared with sodium caprylate (C(8) fatty acid soap), a maximum of 11 fatty acid molecules bind to the microemulsion per 1 molecule of Pluronic F127 and a maximum of 12 molecules of Amitriptyline bind per molecule of F127. We have found that with increasing the chain length of the fatty acid salt component of the microemulsion, the binding capacity of both the fatty acid and the Amitriptyline to the microemulsion decreases. For sodium salts of C(8), C(10) and C(12) fatty acids, respectively, a maximum of approximately 11, 8.4 and 8.3 molecules of fatty acid molecules bind to 1 Pluronic F127 molecule. We propose that this is due to the decreasing number of free monomers with increasing chain length. As chain length increases, the critical micelle concentration (cmc) decreases, thus leading to fewer monomers. Pluronics are symmetric tri-block copolymers consisting of propylene oxide (PO) and ethylene oxide (EO). The polypropylene oxide block, PPO is sandwiched between two polyethylene oxide (PEO) blocks. The PEO blocks are hydrophilic while PPO is hydrophobic portion in the Pluronic molecule. Due to this structure, we propose that the fatty acid molecules that are in monomeric form most effectively diffuse between the PEO "tails" and bind to the hydrophobic PPO groups.

Design and development of polyphenylene oxide foam as a reusable internal insulation for LH2 tanks, phase 2

NASA Technical Reports Server (NTRS)

1972-01-01

PPO form was tested for mechanical strength, for the effects of 100 thermal cycles from 450 K (359 F) to 21 K (-423 F) and for gas flow resistance characteristics. PPO foam panels were investigated for density variations, methods for joining panels were studied and panel joint thermal test specimens were fabricated. The range of foam panel thickness under investigation was extended to include 7 mm (0.3 in) and 70 mm (2.8 in) panels which also were tested for thermal performance.

Chcanges in Germinability and Activities of Polyphenol Oxidase and Peroxidase in Seeds of Pentaclethramacrophylla During Lowtemperature Treatment

NASA Astrophysics Data System (ADS)

Udosen, I. R.; Nkang, A. E.; Sam, S. M.

2012-07-01

Activities of peroxidase (POD) and polyphenol Oxidase (PPO) were investigated in seeds of Pentaclethramacrophylla during low temperature treatment. The seeds from the small-sized fruits (variety A) and those of the big-sized fruits (variety B) showed high germination, with maximum germination values ranging between 60 ñ 90%. Low temperature treatment did not significantly (P< 0.5) affect maximum germination values. Activities of POD and PPO increased initially (2-4 days) but declined with prolonged (6ñ8 days) low temperature treatment.

Low Permeable Hydrocarbon Polymer Electrolyte Membrane for Vanadium Redox Flow Battery.

PubMed

Jung, Ho-Young; Moon, Geon-O; Jung, Seunghun; Kim, Hee Tak; Kim, Sang-Chai; Roh, Sung-Hee

2017-04-01

Polymer electrolyte membrane (PEM) confirms the life span of vanadium redox flow battery (VRFB). Products from Dupont, Nafion membrane, is mainly used for PEM in VRFB. However, permeation of vanadium ion occurs because of Nafion’s high permeability. Therefore, the efficiency of VRFB decreases and the prices becomes higher, which hinders VRFB’s commercialization. In order to solve this problem, poly(phenylene oxide) (PPO) is sulfonated for the preparation of low-priced hydrocarbon polymer electrolyte membrane. sPPO membrane is characterized by fundamental properties and VRFB cell test.

Immunological and molecular comparison of polyphenol oxidase in Rosaceae fruit trees.

PubMed

Haruta, M; Murata, M; Kadokura, H; Homma, S

1999-03-01

An antibody raised against apple polyphenol oxidase (PPO) cross-reacted with PPOs from Japanese pear (Pyrus pyrifolia), pear (Pyrus communis), peach (Prunus persica), Chinese quince (Pseudocydonia sinensis) and Japanese loquat (Eriobotrya japonica). Core fragments (681 bp) of the corresponding PPO genes were amplified and characterized. The deduced protein sequences showed identities of 85.3 to 97.5%. Chlorogenic acid oxidase activity of these PPOs showed higher activities when assayed at pH 4 than at pH 6. These results indicate that PPOs in Rosaceae plants are structurally and enzymatically similar.

Polymer-grafted gold nanorods in polymer thin films: Dispersion and plasmonic coupling

NASA Astrophysics Data System (ADS)

Hore, Michael-Jon Ainsley

This dissertation describes complementary experimental and theoretical studies to deter- mine the thermodynamic factors that affect the dispersion of polymer-grafted Au nanorods within polymer thin films. Au nanorods exhibit a uniform dispersion with a regular spacing for favorable brush / matrix interactions, such as poly(ethylene glycol) (PEG)-Au / poly(methyl methacrylate) (PMMA) and polystyrene (PS)-Au / poly(2,6-dimethyl-p-phenylene oxide) (PPO). For PEG-Au / PMMA, the nanorods are locally oriented and their dispersion is independent of the ratio of the degree of polymerization of the matrix (P) to that of the brush (N), α = P/N, whereas for chemically similar brush / matrix combinations, such as PS-Au / PS and PEG-Au / poly(ethylene oxide) (PEO), nanorods are randomly dispersed for α 2. For aggregated systems (α > 2), nanorods are found primarily within aggregates containing side-by-side aligned nanorods with a spacing that scales with N. UV-visible spectroscopy and discrete dipole approximation (DDA) calculations demonstrate that coupling between surface plasmons within the aggregates leads to a blue shift in the optical absorption as α increases, indicating the sensitivity of spectroscopy for determining nanorod dispersion in polymer nanocomposite films. Self-consistent field theory (SCFT) calculations and Monte Carlo (MC) simulations show that the aggregation of nanorods for α > 2 can be attributed to depletion-attraction forces caused by autophobic dewetting of the brush and matrix. Finally, miscible blends of PS and PPO are investigated as a route to control depletion-attraction interactions between PS-Au nanorods. Initially, nanorods aggregate in matrices having 50 vol. % PPO and then gradually disperse as PPO becomes the majority component. The brush and matrix density profiles, determined by SCFT, show that PPO segregates into the PS brush, and acts as a compatibilizer, which improves dispersion. As dispersion improves, coupling between surface plasmons is reduced, leading to a red shift in the optical absorption. The outcome of these systematic structure-property-modeling studies is the ability to control nanorod dispersion, orientation, and optical absorption by manipulating brush/matrix interactions and entropic depletion-attraction forces.

Design and synthesis of 1-(benzothiazol-5-yl)-1H-1,2,4-triazol-5-ones as protoporphyrinogen oxidase inhibitors.

PubMed

Zuo, Yang; Yang, Sheng-Gang; Luo, Yan-Ping; Tan, Ying; Hao, Ge-Fei; Wu, Qiong-You; Xi, Zhen; Yang, Guang-Fu

2013-06-01

Protoporphyrinogen oxidase (PPO, E.C. 1.3.3.4) is the action target for several structurally diverse herbicides. A series of novel 4-(difluoromethyl)-1-(6-halo-2-substituted-benzothiazol-5-yl)-3-methyl-1H-1,2,4-triazol-5(4H)-ones 2a-z were designed and synthesized via the ring-closure of two ortho-substituents. The in vitro bioassay results indicated that the 26 newly synthesized compounds exhibited good PPO inhibition effects with K(i) values ranging from 0.06 to 17.79 μM. Compound 2e, ethyl 2-{[5-(4-(difluoromethyl)-3-methyl-5-oxo-4,5-dihydro-1H-1,2,4-triazol-1-yl)-6-fluorobenzo-thiazol-2-yl]thio}acetate, was the most potent inhibitor with K(i) value of 0.06 μM against mtPPO, comparable to (K(i)=0.03 μM) sulfentrazone. Further green house assays showed that compound 2f (K(i)=0.24 μM, mtPPO), ethyl 2-{[5-(4-(difluoromethyl)-3-methyl-5-oxo-4,5-dihydro-1H-1,2,4-triazol-1-yl)-6-fluorobenzothiazol-2-yl]thio}propanoate, showed the most promising post-emergence herbicidal activity with broad spectrum even at concentrations as low as 37.5 gai/ha. Soybean exhibited tolerance to compound 2f at the dosages of 150 gai/ha, whereas they are susceptible to sulfentrazone even at 75 gai/ha. Thus, compound 2f might be a potential candidate as a new herbicide for soybean fields. Copyright © 2013 Elsevier Ltd. All rights reserved.

Precooling leg muscle improves intermittent sprint exercise performance in hot, humid conditions.

PubMed

Castle, Paul C; Macdonald, Adam L; Philp, Andrew; Webborn, Anthony; Watt, Peter W; Maxwell, Neil S

2006-04-01

We used three techniques of precooling to test the hypothesis that heat strain would be alleviated, muscle temperature (Tmu) would be reduced, and as a result there would be delayed decrements in peak power output (PPO) during exercise in hot, humid conditions. Twelve male team-sport players completed four cycling intermittent sprint protocols (CISP). Each CISP consisted of twenty 2-min periods, each including 10 s of passive rest, 5 s of maximal sprint against a resistance of 7.5% body mass, and 105 s of active recovery. The CISP, preceded by 20 min of no cooling (Control), precooling via an ice vest (Vest), cold water immersion (Water), and ice packs covering the upper legs (Packs), was performed in hot, humid conditions (mean +/- SE; 33.7 +/- 0.3 degrees C, 51.6 +/- 2.2% relative humidity) in a randomized order. The rate of heat strain increase during the CISP was faster in Control than Water and Packs (P < 0.01), but it was similar to Vest. Packs and Water blunted the rise of Tmu until minute 16 and for the duration of the CISP (40 min), respectively (P < 0.01). Reductions in PPO occurred from minute 32 onward in Control, and an increase in PPO by approximately 4% due to Packs was observed (main effect; P < 0.05). The method of precooling determined the extent to which heat strain was reduced during intermittent sprint cycling, with leg precooling offering the greater ergogenic effect on PPO than either upper body or whole body cooling.

Gene expression of antioxidant enzymes and coffee seed quality during pre- and post-physiological maturity.

PubMed

Santos, F C; Caixeta, F; Clemente, A C S; Pinho, E V; Rosa, S D V F

2014-12-19

Seeds collected at different maturation stages vary in physiological quality and patterns of protective antioxidant systems against deterioration. In this study we investigated the expression of genes that codify catalase (CAT), dismutase superoxide (SOD), and polyphenol oxidase (PPO) during the pre- and post-physiological maturation phases in whole seeds and in endosperms and embryos extracted from the seeds. Coffea arabica L. berries were collected at the green, yellowish-green, cherry, over-ripe, and dry stages, and the seeds were examined physiologically. The transcription levels of the genes were quantified by quantitative real-time polymerase chain reaction using coffee-specific primers. The highest level of SOD expression was observed in the endosperm at the cherry and over-ripe stages; in addition, these seeds presented the greatest physiological quality (assessed via germination test). The highest CAT3 transcript expression was observed at the green stage in whole seeds, and at the green and over-ripe stages in the embryos and endosperms. High expression of the PPO transcript was observed at the green and yellowish-green stages in whole seeds. In embryos and endosperms, peak expression of the PPO transcript was observed at the green stage; subsequently, peaks at the cherry and over-ripe stages were observed. We concluded that the expression patterns of the SOD and CAT3 transcripts were similar at the more advanced maturation stages, which corresponded to enhanced physiological seed quality. High expression of the PPO transcript at the over-ripe stage, also observed in the embryos and endosperms at the cherry stage, coincided with the highest physiological seed quality.

Planetary period modulations of Saturn's magnetotail current sheet during northern spring: Observations and modeling

NASA Astrophysics Data System (ADS)

Cowley, S. W. H.; Provan, G.

2017-06-01

We study Cassini magnetic field observations at Saturn on a sequence of passes through the near-equatorial magnetotail during 2015, focusing on dual modulation of the plasma/current sheet associated with northern and southern planetary period oscillations (PPOs). Previous study of inner magnetosphere PPOs during this northern spring interval showed that the southern system amplitude was generally half that of the northern during the first part of the year to late August, after which the southern amplitude weakened to less than one-fifth that of the northern. We examine four sequential tail passes in the earlier interval, during which prominent PPO-related tail field modulations were observed, with relative (beat) phases of the two PPO systems being near in phase, antiphase, and two opposite near-quadrature conditions. We find that the radial field displayed opposite "sawtooth" asymmetry modulations under opposite near-quadrature conditions, related to previous findings under equinoctial conditions with near-equal northern and southern PPO amplitudes, while modulations were near symmetric for in-phase and antiphase conditions, but with larger radial field modulations for in-phase and larger colatitudinal field modulations for antiphase. A simple physical mathematical model of dual modulation is developed, which provides reasonable correspondence with these data using one set of current sheet parameters while varying only the relative PPO phases, thus demonstrating that dual modulation can be discerned and modeled even when the northern and southern amplitudes differ by a factor of 2. No such effects were consistently discerned during the later interval when the amplitude ratio was >5.

Evaluation of three herbicide resistance genes for use in genetic transformations and for potential crop protection in algae production.

PubMed

Brueggeman, Andrew J; Kuehler, Daniel; Weeks, Donald P

2014-09-01

Genes conferring resistance to the herbicides glyphosate, oxyfluorfen and norflurazon were developed and tested for use as dominant selectable markers in genetic transformation of Chlamydomonas reinhardtii and as potential tools for the protection of commercial-scale algal production facilities against contamination by organisms sensitive to these broad-spectrum herbicides. A synthetic glyphosate acetyltransferase (GAT) gene, when fitted with a strong Chlamydomonas promoter, conferred a 2.7×-fold increase in tolerance to the EPSPS inhibitor, glyphosate, in transgenic cells compared with progenitor WT cells. A mutant Chlamydomonas protoporphyrinogen oxidase (protox, PPO) gene previously shown to produce an enzyme insensitive to PPO-inhibiting herbicides, when genetically engineered, generated transgenic cells able to tolerate up to 136× higher levels of the PPO inhibitor, oxyfluorfen, than nontransformed cells. Genetic modification of the Chlamydomonas phytoene desaturase (PDS) gene-based gene sequences found in various norflurazon-resistant organisms allowed production of transgenic cells tolerant to 40× higher levels of norflurazon than nontransgenic cells. The high efficiency of all three herbicide resistance genes in producing transgenic cells demonstrated their suitability as dominant selectable markers for genetic transformation of Chlamydomonas and, potentially, other eukaryotic algae. However, the requirement for high concentrations of glyphosate and its associated negative effects on cell growth rates preclude its consideration for use in large-scale production facilities. In contrast, only low doses of norflurazon and oxyfluorfen (~1.5 μm and ~0.1 μm, respectively) are required for inhibition of cell growth, suggesting that these two herbicides may prove effective in large-scale algal production facilities in suppressing growth of organisms sensitive to these herbicides. © 2014 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

Is the Functional Threshold Power (FTP) a Valid Surrogate of the Lactate Threshold?

PubMed

Valenzuela, Pedro L; Morales, Javier S; Foster, Carl; Lucia, Alejandro; de la Villa, Pedro

2018-05-10

This study aimed to analyze the relationship between the Functional Threshold Power (FTP) and the Lactate Threshold (LT). 20 male cyclists performed an incremental test in which the LT was determined. At least 48 h later, they performed a 20-minute time trial and 95% of the mean power output (P20) was defined as FTP. Participants were divided into recreational (Peak Power Output [PPO] < 4.5 W∙kg -1 , n=11) or trained cyclists (PPO > 4.5 W∙kg -1 , n=9) according to their fitness status. The FTP (240 ± 35 W) was overall not significantly different (effect size[ES]=0.20, limits of agreement [LoA]=-2.4 ± 11.5%) from the LT (246 ± 24 W), and both markers were strongly correlated (r=0.95, p<0.0001). Accounting for the participants' fitness status, no significant differences were found between FTP and LT ([ES]=0.22; LoA=2.1 ± 7.8%) in TC, but FTP was significantly lower than the LT (p=0.0004, ES=0.81; LoA=-6.5 ± 8.3%) in RC. A significant relationship was found between relative PPO and the bias between FTP and the LT markers (r=0.77, p<0.0001). The FTP is a valid field test-based marker for the assessment of endurance fitness. However, caution should be taken when using the FTP interchangeably with the LT as the bias between markers seems to depend on the athletes' fitness status. Whereas the FTP provides a good estimate of the LT in trained cyclists, in recreational cyclists FTP may underestimate LT.

Impact of high pressure processing on color, bioactive compounds, polyphenol oxidase activity, and microbiological attributes of pumpkin purée.

PubMed

González-Cebrino, Francisco; Durán, Rocío; Delgado-Adámez, Jonathan; Contador, Rebeca; Bernabé, Rosario Ramírez

2016-04-01

Physicochemical parameters, bioactive compounds' content (carotenoids and total phenols), total antioxidant activity, and enzymatic activity of polyphenol oxidase (PPO) were evaluated after high pressure processing (HPP) on a pumpkin purée (cv. 'Butternut'). Three pressure levels (400, 500, and 600 MPa) were combined with three holding times (200, 400, and 600 s). The applied treatments reduced the levels of total aerobic mesophilic (TAM), total psychrophilic and psychrotrophic bacteria (TPP), and molds and yeasts (M&Y). All applied treatments did not affect enzymatic activity of PPO. Pressure level increased CIE L* values, which could enhance the lightness perception of high pressure (HP)-treated purées. No differences were found between the untreated and HP-treated purées regarding total phenols and carotenoids content (lutein, α-carotene, and β-carotene) and total antioxidant activity. HPP did not affect most quality parameters and maintained the levels of bioactive compounds. However, it did not achieve the complete inhibition of PPO, which could reduce the shelf-life of the pumpkin purée. © The Author(s) 2015.

Effect of high hydrostatic pressure on the microbiological, biochemical characteristics of white shrimp Litopenaeus vannamei.

PubMed

Li, Xiu-Xia; Tian, Xin; Li, Jian-Rong

2016-06-01

Using thermal processing (TP) treatment (100 ℃, 1-8 min) as a control, the effects of high hydrostatic pressure (HHP, 200-500 MPa, 2.5-20 min) on the microbiological and biochemical characteristics of white shrimp Litopenaeus vannamei were investigated. The results showed that the efficiency of polyphenol oxidase (PPO) inactivation and log reduction of total plate count (TPC) by HHP treatment were all significantly lower than by TP treatment (p < 0.05). The rate of inactivation for TPC and PPO all increased with the increase of HHP pressure and holding time (p < 0.05). The inactivation of PPO was in accordance with a first-order kinetics with the HHP treating time. Hardness of HHP-treated samples at the pressure of 300-500 MPa was higher than TP-treated samples, while the yield loss of HHP treatment was significantly lower than with TP treatment (p < 0.05), long time and high pressure of HHP treatment turned the appearance of shrimps slightly pink. © The Author(s) 2015.

Anomalous Diffusion of Water in Lamellar Membranes Formed by Pluronic Polymers

NASA Astrophysics Data System (ADS)

Zhang, Zhe; Ohl, Michael; Han, Youngkyu; Smith, Gregory; Do, Changwoo; Biology; Soft-Matter Division, Oak Ridge National Laboratory Team; Julich CenterNeutron Science Team

Water diffusion is playing an important role in polymer systems. We calculated the water diffusion coefficient at different layers along z-direction which is perpendicular to the lamellar membrane formed by Pluronic block copolymers (L62: (EO6-PO34-EO6)) with the molecular dynamics simulation trajectories. Water molecules at bulk layers are following the normal diffusion, while that at hydration layers formed by polyethylene oxide (PEO) and hydrophobic layers formed by polypropylene oxide (PPO) are following anomalous diffusion. We find that although the subdiffusive regimes at PEO layers and PPO layers are the same, which is the fractional Brownian motion, however, the dynamics are different, i.e. diffusion at the PEO layers is much faster than that at the PPO layers, and meanwhile it exhibits a normal diffusive approximation within a short time period which is governed by the localized free self-diffusion, but becomes subdiffusive after t >8 ps, which is governed by the viscoelastic medium. The Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy; and Zhe Zhang gratefully acknowledges financial support from Julich Center for Neutron Science.

Ascorbic Acid Enhances the Accumulation of Polycyclic Aromatic Hydrocarbons (PAHs) in Roots of Tall Fescue (Festuca arundinacea Schreb.)

PubMed Central

Gao, Yanzheng; Li, Hui; Gong, Shuaishuai

2012-01-01

Plant contamination by polycyclic aromatic hydrocarbons (PAHs) is crucial to food safety and human health. Enzyme inhibitors are commonly utilized in agriculture to control plant metabolism of organic components. This study revealed that the enzyme inhibitor ascorbic acid (AA) significantly reduced the activities of peroxidase (POD) and polyphenol oxidase (PPO), thus enhancing the potential risks of PAH contamination in tall fescue (Festuca arundinacea Schreb.). POD and PPO enzymes in vitro effectively decomposed naphthalene (NAP), phenanthrene (PHE) and anthracene (ANT). The presence of AA reduced POD and PPO activities in plants, and thus was likely responsible for enhanced PAH accumulation in tall fescue. This conclusion is supported by the significantly enhanced uptake of PHE in plants in the presence of AA, and the positive correlation between enzyme inhibition efficiencies and the rates of metabolism of PHE in tall fescue roots. This study provides a new perspective, that the common application of enzyme inhibitors in agricultural production could increase the accumulation of organic contaminants in plants, hence enhancing risks to food safety and quality. PMID:23185628

Varroa destructor parasitism reduces hemocyte concentrations and prophenol oxidase gene expression in bees from two populations.

PubMed

Koleoglu, Gun; Goodwin, Paul H; Reyes-Quintana, Mariana; Hamiduzzaman, Mollah Md; Guzman-Novoa, Ernesto

2018-04-01

Circulating hemocytes are responsible for defensive and healing mechanisms in the honey bee, Apis mellifera. Parasitism by the mite Varroa destructor and injection of V. destructor homogenate in buffer, but not buffer injection, showed similar reductions in total hemocyte concentrations in both Africanized and European adult honey bees. This indicated that compounds in V. destructor homogenate can have similar effects as V. destructor parasitism and that the response is not solely due to wounding. Samples from honey bees with different hemocyte concentrations were compared for the expression patterns of hemolectin (AmHml), prophenol oxidase (AmPpo), and class C scavenger receptor (AmSRC-C). Of the genes tested, only the expression of AmPpo correlated well with hemocyte counts for all the treatments, indicating that melanization is associated with those responses. Thus, the expression of AmPpo might be a suitable biomarker for hemocyte counts as part of cellular defenses against injection of buffer or mite compounds and V. destructor parasitism and perhaps other conditions involving healing and immunity.

Effects of clove essential oil and eugenol on quality and browning control of fresh-cut lettuce.

PubMed

Chen, Xiangning; Ren, Lupei; Li, Menglin; Qian, Jia; Fan, Junfeng; Du, Bin

2017-01-01

This study confirmed the inhibitory effects of clove essential oil (CEO) and eugenol (EUG) on the browning and relevant enzymes of fresh-cut lettuce, and examined associated mechanisms by inhibition kinetics and computational docking analysis. Fresh-cut lettuce was treated with 0.05% CEO and 0.05% EUG solutions, resulting in inhibition of the deterioration of texture quality and browning of the lettuce surface and interior. Compared with the controls, CEO and EUG significantly inhibited the activities of phenylalanine ammonia lyase (PAL), polyphenol oxidase (PPO), and peroxidase (POD, all p<0.05). EUG suppressed PAL, PPO, and POD in vitro in a dose-dependent manner, with IC50 values of 5.4±0.9, 29.5±3.5, and 61.9±6.7mM, respectively. The binding and inhibition effects of EUG on PAL, PPO, and POD, determined by inhibition kinetics and computational docking analysis, established EUG as a competitive inhibitor of these browning-relevant enzymes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Unraveling the inhibition mechanism of cyanidin-3-sophoroside on polyphenol oxidase and its effect on enzymatic browning of apples.

PubMed

Hemachandran, Hridya; Anantharaman, Amrita; Mohan, Sankari; Mohan, Gopalakrishnan; Kumar, D Thirumal; Dey, Diksha; Kumar, Drishty; Dey, Priyanka; Choudhury, Amrita; George Priya Doss, C; Ramamoorthy, Siva

2017-07-15

The hunt for anti-browning agents in the food and agricultural industries aims to minimize nutritional loss and prolong post harvest storage. In the present study, the effect of cyanidin-3-sophoroside (CS) from Garcinia mangostana rind, on polyphenol oxidase (PPO) activity was investigated. The non-competitive inhibition mode of CS was determined by Lineweaver Burk plot. CS forms a ground-state complex by quenching the intrinsic fluorescence of PPO. The static quenching was temperature-dependent with an activation energy of 4.654±0.1091kJmol -1 to withstand the disruption of amino acid residues of the enzyme binding site. The enzyme conformational change was validated by 3D fluorescence and CD spectrum. Docking (binding energy -8.124kcal/mol) and simulation studies confirmed the binding pattern and stability. CS decreased PPO activity and browning index of fresh cut apples and prolonged the shelf life. Thus, CS appears to be a promising anti-browning agent to control enzymatic browning. Copyright © 2017 Elsevier Ltd. All rights reserved.

Purification and characterization of polyphenol oxidase from jackfruit ( Artocarpus heterophyllus ) bulbs.

PubMed

Tao, Yi-Ming; Yao, Le-Yi; Qin, Qiu-Yan; Shen, Wang

2013-12-26

Polyphenol oxidase (PPO) from jackfruit bulb was purified through acetone precipitation, ion-exchange column, and gel filtration column. PPO was a dimer with the molecular weight of 130 kDa determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and gel filtration. The Km was 8.3 and 18.2 mM using catechol and 4-methylcatechol as substrates, respectively. The optimum pH was 7.0 (catechol as the substrate) or 6.5 (4-methylcatechol as the substrate). The optimum temperature was 8 °C. The enzyme was stable below 40 °C. The activation energy (Ea) of heat inactivation was estimated to be 103.30 kJ/mol. The PPO activity was activated by Mn(2+), SDS, Tween-20, Triton X-100, citric acid, and malic acid but inhibited by K(+), Zn(2+), Mg(2+), Ca(2+), Ba(2+), cetyl trimethyl ammonium bromide (CTAB), kojic acid, tropolone, glutathione (GSH), cysteine (Cys), and ascorbic acid (AA). Cys and AA were effective to reduce browning of jackfruit bulbs during the storage at 8 °C for 15 days.

Analysis of efficiency of phosphates sorption by different granulation of selected reactive material

NASA Astrophysics Data System (ADS)

Kasprzyk, Magda; Węgler, Jarosław; Gajewska, Magdalena

2018-01-01

In the light of the need to find an effective way to remove phosphorus from wastewater, studies on the suitability of sorption materials in this process should be conducted. The aim of the study was to examine the potential benefits of using selected adsorbents to reduce orthophosphates from the model solution under steady conditions. The study was conducted on a laboratory scale using synthetic wastewater with concentration of P-PO4 in the range of 5-100 mg/dm3. Experiment has shown that fine-grained material M1 (0-2 mm) is highly effective at removal of phosphorus compounds at the level of 97.8% at the highest concentration of P-PO4. The sorption capacity achieved during the investigation was 9.6 mg/g, while the maximum sorption capacity from the Langmuir model could reach up to 256 mg/g. Material M2 (2-8 mm) did not show satisfactory sorption capacity (maximum calculated sorption capacity: 0.36 mg/g) and the effectiveness of phosphate reduction did not exceeded 6% at the lowest concentration of P-PO4.

Nanoscale Structure of Urethane/Urea Elastomeric Films

NASA Astrophysics Data System (ADS)

Reis, Dennys; Trindade, Ana C.; Godinho, Maria Helena; Silva, Laura C.; do Carmo Gonçalves, Maria; Neto, Antônio M. Figueiredo

2017-02-01

The nanostructure of urethane/urea elastomeric membranes was investigated by small-angle X-ray scattering (SAXS) in order to establish relationships between their structure and mechanical properties. The networks were made up of polypropylene oxide (PPO) and polybutadiene (PB) segments. The structural differences were investigated in two types of membranes with the same composition but with different thermal treatment after casting. Type I was cured at 70-80 °C and type II at 20 °C. Both membranes showed similar phase separation by TEM, with nanodomains rich in PB or PPO and 25 nm dimensions. The main difference between type I and type II membranes was found by SAXS. The type I membrane spectra showed, besides a broad band at a 27-nm q value (modulus of the scattering vector), an extra band at 6 nm, which was not observed in the type II membrane. The SAXS spectra were interpreted in terms of PPO, PB soft segments, and urethane/urea links, as well as hard moiety segregation in the reaction medium. This additional segregation ( q = 7 nm), although subtle, results in diverse mechanical behavior of in both membranes.

Characterization of polyphenol oxidase from Cape gooseberry (Physalis peruviana L.) fruit.

PubMed

Bravo, Karent; Osorio, Edison

2016-04-15

Cape gooseberry (Physalis peruviana) is an exotic fruit highly valued, however it is a very rich source of polyphenol oxidase (PPO). In this study, Cape gooseberry PPO was isolated and biochemically characterized. The enzyme was extracted and purified using acetone and aqueous two-phase systems. The data indicated that PPO had the highest substrate affinity for chlorogenic acid, 4-methylcatechol and catechol. Chlorogenic acid was the most suitable substrate (Km=0.56±0.07 mM and Vmax=53.15±2.03 UPPO mL(-1) min(-1)). The optimal pH values were 5.5 for catechol and 4-methylcatechol and 5.0 for chlorogenic acid. Optimal temperatures were 40°C for catechol, 25°C for 4-methylcatechol and 20°C for chlorogenic acid. In inhibition tests, the most potent inhibitor was found to be ascorbic acid followed by L-cysteine and quercetin. This study shows possible treatments that can be implemented during the processing of Cape gooseberry fruits to prevent browning. Copyright © 2015 Elsevier Ltd. All rights reserved.

Opportunities and Challenges for Payment Reform: Observations from Massachusetts.

PubMed

Mechanic, Robert E

2016-08-01

Policy makers and private health plans are expanding their efforts to implement new payment models that will encourage providers to improve quality and deliver health care more efficiently. Over the past five years, payment reforms have progressed faster in Massachusetts than in any other state. The reasons include a major effort by Blue Cross Blue Shield of Massachusetts to implement global payment, the presence of large integrated systems willing to take on financial risk, and a supportive state policy environment. By 2014, thirty-seven percent of Massachusetts's residents enrolled in health plans were covered under risk-based payment models tied to global budgets. But the expansion of payment reform in Massachusetts slowed between 2012 and 2015 because some commercial enrollment shifted from risk-based health maintenance organization products to fee-for-service preferred provider organization (PPO) plans, and the state Medicaid program fell short of its payment reform goals. Provider groups will not fully commit to population-based clinical models if they believe it will result in large reductions in fee-for-service revenue. The use of alternative payment models will accelerate in 2016 when Blue Cross begins implementing PPO payment reforms, but it is unknown how quickly other payers will follow. Massachusetts's experience illustrates the complexity of payment reform in pluralistic health care markets and the need for complementary efforts by public and private stakeholders. Copyright © 2016 by Duke University Press.

Role of chlorogenic acid quinone and interaction of chlorogenic acid quinone and catechins in the enzymatic browning of apple.

PubMed

Amaki, Kanako; Saito, Eri; Taniguchi, Kumiko; Joshita, Keiko; Murata, Masatsune

2011-01-01

Chlorogenic acid (CQA) is one of the major polyphenols in apple and a good substrate for the polyphenol oxidase (PPO) in apple. Apple contains catechins as well as CQA, and the role of CQA quinone and its interaction with catechins in the enzymatic browning of apple were examined. Browning was repressed and 2-cysteinyl-CQA was formed when cysteine was added to apple juice. CQA quinone was essential for browning to occur. Although catechins and CQA were oxidized by PPO, some catechins seemed to be non-enzymatically oxidized by CQA quinone.

Effect of pigment concentration on fastness and color values of thermal and UV curable pigment printing

NASA Astrophysics Data System (ADS)

Baysal, Gulcin; Kalav, Berdan; Karagüzel Kayaoğlu, Burçak

2017-10-01

In the current study, it is aimed to determine the effect of pigment concentration on fastness and colour values of thermal and ultraviolet (UV) curable pigment printing on synthetic leather. For this purpose, thermal curable solvent-based and UV curable water-based formulations were prepared with different pigment concentrations (3, 5 and 7%) separately and applied by screen printing technique using a screen printing machine. Samples printed with solvent-based formulations were thermally cured and samples printed with water-based formulations were cured using a UV curing machine equipped with gallium and mercury (Ga/Hg) lamps at room temperature. The crock fastness values of samples printed with solvent-based formulations showed that increase in pigment concentration was not effective on both dry and wet crock fastness values. On the other hand, in samples printed with UV curable water-based formulations, dry crock fastness was improved and evaluated as very good for all pigment concentrations. However, increasing the pigment concentration affected the wet crock fastness values adversely and lower values were observed. As the energy level increased for each irradiation source, the fastness values were improved. In comparison with samples printed with solvent-based formulations, samples printed with UV curable water-based formulations yielded higher K/S values at all pigment concentrations. The results suggested that, higher K/S values can be obtained in samples printed with UV curable water-based formulations at a lower pigment concentration compared to samples printed with solvent-based formulations.

Effects of Exercise Training under Hyperbaric Oxygen on Oxidative Stress Markers and Endurance Performance in Young Soccer Players: A Pilot Study.

PubMed

Burgos, Carlos; Henríquez-Olguín, Carlos; Andrade, David Cristóbal; Ramírez-Campillo, Rodrigo; Araneda, Oscar F; White, Allan; Cerda-Kohler, Hugo

2016-01-01

The aim of the present study was to determine the effects of three weeks of hyperbaric oxygen (HBO 2 ) training on oxidative stress markers and endurance performance in young soccer players. Participants (18.6 ± 1.6 years) were randomized into hyperbaric-hyperoxic (HH) training ( n = 6) and normobaric normoxic (NN) training ( n = 6) groups. Immediately before and after the 5th, 10th, and 15th training sessions, plasma oxidative stress markers (lipid hydroperoxides and uric acid), plasma antioxidant capacity (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid [TROLOX]), arterial blood gases, acid-base balance, bases excess (BE), and blood lactate analyses were performed. Before and after intervention, maximal oxygen uptake (VO 2 max) and peak power output (PPO) were determined. Neither HH nor NN experienced significant changes on oxidative stress markers or antioxidant capacity during intervention. VO 2 max and PPO were improved (moderate effect size) after HH training. The results suggest that HBO 2 endurance training does not increase oxidative stress markers and improves endurance performance in young soccer players. Our findings warrant future investigation to corroborate that HBO 2 endurance training could be a potential training approach for highly competitive young soccer players.

Effects of Exercise Training under Hyperbaric Oxygen on Oxidative Stress Markers and Endurance Performance in Young Soccer Players: A Pilot Study

PubMed Central

Henríquez-Olguín, Carlos; Andrade, David Cristóbal; Ramírez-Campillo, Rodrigo; White, Allan; Cerda-Kohler, Hugo

2016-01-01

The aim of the present study was to determine the effects of three weeks of hyperbaric oxygen (HBO2) training on oxidative stress markers and endurance performance in young soccer players. Participants (18.6 ± 1.6 years) were randomized into hyperbaric-hyperoxic (HH) training (n = 6) and normobaric normoxic (NN) training (n = 6) groups. Immediately before and after the 5th, 10th, and 15th training sessions, plasma oxidative stress markers (lipid hydroperoxides and uric acid), plasma antioxidant capacity (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid [TROLOX]), arterial blood gases, acid-base balance, bases excess (BE), and blood lactate analyses were performed. Before and after intervention, maximal oxygen uptake (VO2max) and peak power output (PPO) were determined. Neither HH nor NN experienced significant changes on oxidative stress markers or antioxidant capacity during intervention. VO2max and PPO were improved (moderate effect size) after HH training. The results suggest that HBO2 endurance training does not increase oxidative stress markers and improves endurance performance in young soccer players. Our findings warrant future investigation to corroborate that HBO2 endurance training could be a potential training approach for highly competitive young soccer players. PMID:28083148

Preferable removal of phosphate from water using hydrous zirconium oxide-based nanocomposite of high stability.

PubMed

Chen, Liang; Zhao, Xin; Pan, Bingcai; Zhang, Weixian; Hua, Ming; Lv, Lu; Zhang, Weiming

2015-03-02

In this study, we employed a new nanocomposite adsorbent HZO-201, which featured high stability under varying solution chemistry, for preferable removal of phosphate from synthetic solution and a real effluent. An anion exchange resin (D-201) was employed as the host of HZO-201, where nano-hydrous zirconium oxide (HZO) was encapsulated as the active species. D-201 binds phosphate through nonspecific electrostatic affinity, whereas the loaded HZO nanoparticles capture phosphate through formation of the inner-sphere complexes. Quantitative contribution of both species to phosphate adsorption was predicted based on the double-Langmuir model. Preferable removal of phosphate by HZO-201 was observed in the presence of the competing anions at higher levels (Cl(-), NO3(-), SO4(2-), HCO3(-)). Fixed-bed adsorption indicated that the effective volume capacity of a synthetic water (2.0 mg P-PO4(3-)/L) by using HZO-201 was ∼1600 BV in the first run (<0.5mg P-PO4(3-)/L), comparable to Fe(III)-based nanocomposite HFO-201 (∼1500 BV) and much larger than D-201 (<250 BV). The exhausted HZO-201 can be in situ regenerated by using a binary NaOH-NaCl solution for cyclic runs, whether fed with the synthetic solution or real effluent. In general, HZO-201 is a promising alternative to Fe(III)-based adsorbents for trace phosphate removal from effluent particularly at acidic pH. Copyright © 2014 Elsevier B.V. All rights reserved.

A brief review of extrusion-based tissue scaffold bio-printing.

PubMed

Ning, Liqun; Chen, Xiongbiao

2017-08-01

Extrusion-based bio-printing has great potential as a technique for manipulating biomaterials and living cells to create three-dimensional (3D) scaffolds for damaged tissue repair and function restoration. Over the last two decades, advances in both engineering techniques and life sciences have evolved extrusion-based bio-printing from a simple technique to one able to create diverse tissue scaffolds from a wide range of biomaterials and cell types. However, the complexities associated with synthesis of materials for bio-printing and manipulation of multiple materials and cells in bio-printing pose many challenges for scaffold fabrication. This paper presents an overview of extrusion-based bio-printing for scaffold fabrication, focusing on the prior-printing considerations (such as scaffold design and materials/cell synthesis), working principles, comparison to other techniques, and to-date achievements. This paper also briefly reviews the recent development of strategies with regard to hydrogel synthesis, multi-materials/cells manipulation, and process-induced cell damage in extrusion-based bio-printing. The key issue and challenges for extrusion-based bio-printing are also identified and discussed along with recommendations for future, aimed at developing novel biomaterials and bio-printing systems, creating patterned vascular networks within scaffolds, and preserving the cell viability and functions in scaffold bio-printing. The address of these challenges will significantly enhance the capability of extrusion-based bio-printing. Copyright © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

N+ ion-target interactions in PPO polymer: A structural characterization

NASA Astrophysics Data System (ADS)

Das, A.; Dhara, S.; Patnaik, A.

1999-01-01

N + ion beam induced effects on the spin coated amorphous poly(2,6-dimethyl phenylene oxide) (PPO) films in terms of chemical structure and electronic and vibrational properties were investigated using Fourier Transform Infrared spectroscopy (FTIR) and Ultraviolet-Visible (UV-VIS) spectroscopy. Both techniques revealed that the stability of PPO was very weak towards 100 keV N + ions revealing the threshold fluence to be 10 14 ions/cm 2 for fragmentation of the polymer. FTIR analysis showed disappearance of all characteristic IR bands at a total fluence of 10 14 ions/cm 2 except for the band CC at 1608 cm -1 which was found to shift to a lower wave number along with an enhancement in the full width half maximum (FWHM) value with increasing fluence. A new bond appeared due to oxidation as a shoulder at 1680 cm -1 in FTIR spectra indicating the presence of CO type bond as a result of N + implantation on PPO films. The optical band gap ( Eg) deduced from absorption spectra, was observed to decrease from 4.4 to 0.5 eV with fluence. The implantation induced carbonaceous clusters, determined using Robertson's formula for the optical band gap, were found to consist of ˜160 fused hexagonal aromatic rings at the maximum energy fluence. An enhanced absorption coefficient as a function of fluence indicated incorporation of either much larger concentration of charge carriers or their mobility than that of the pristine sample. Calculated band tail width from Urbach band tail region for the implanted samples pointed the band edge sharpness to be strongly dependent on fluence indicating an increased disorder with increasing fluence.

Cloning, sequencing, purification, and crystal structure of Grenache (Vitis vinifera) polyphenol oxidase.

PubMed

Virador, Victoria M; Reyes Grajeda, Juan P; Blanco-Labra, Alejandro; Mendiola-Olaya, Elizabeth; Smith, Gary M; Moreno, Abel; Whitaker, John R

2010-01-27

The full-length cDNA sequence (P93622_VITVI) of polyphenol oxidase (PPO) cDNA from grape Vitis vinifera L., cv Grenache, was found to encode a translated protein of 607 amino acids with an expected molecular weight of ca. 67 kDa and a predicted pI of 6.83. The translated amino acid sequence was 99%, identical to that of a white grape berry PPO (1) (5 out of 607 amino acid potential sequence differences). The protein was purified from Grenache grape berries by using traditional methods, and it was crystallized with ammonium acetate by the hanging-drop vapor diffusion method. The crystals were orthorhombic, space group C222(1). The structure was obtained at 2.2 A resolution using synchrotron radiation using the 39 kDa isozyme of sweet potato PPO (PDB code: 1BT1 ) as a phase donor. The basic symmetry of the cell parameters (a, b, and c and alpha, beta, and gamma) as well as in the number of asymmetric units in the unit cell of the crystals of PPO, differed between the two proteins. The structures of the two enzymes are quite similar in overall fold, the location of the helix bundles at the core, and the active site in which three histidines bind each of the two catalytic copper ions, and one of the histidines is engaged in a thioether linkage with a cysteine residue. The possibility that the formation of the Cys-His thioether linkage constitutes the activation step is proposed. No evidence of phosphorylation or glycoslyation was found in the electron density map. The mass of the crystallized protein appears to be only 38.4 kDa, and the processing that occurs in the grape berry that leads to this smaller size is discussed.

Effects of a high O2 dynamic-controlled atmosphere technology on the browning of postharvest white mushroom ( Agaricus bisporus) in relation to energy metabolism.

PubMed

Li, Ling; Sun, Han; Kitazawa, Hiroaki; Wang, Xiangyou

2017-07-01

Browning is one of the main problems in senescence of mushrooms, and it is also one of the most important attributes accounting for the loss of the quality and reduction in market value. In order to study the relationship between the energy metabolism and the browning of white mushroom under high O 2 dynamic-controlled atmosphere (HO-DCA), mushrooms were stored in 100% O 2 (SCA1), 80% O 2  + 20% CO 2 (SCA2), 100% O 2 for three days and then transferred into the treatment of 80% O 2  + 20% CO 2 (HO-DCA) at 2 ± 1 ℃ and air as control. In this study, adenosine triphosphate (ATP) content, energy charge level, sensory evaluation, browning of surface and flesh, cell membrane integrity, exogenous ATP, polyphenol oxidase (PPO) and peroxidase (POD) activity and genes encoding PPO of the white mushroom were investigated. These were all closely related to the browning of products. The optimal storage condition of the HO-DCA treatment could delay the browning of pericarp and flesh tissues of the mushrooms, inhibit PPO activity and reduce the relative expression levels of the three genes encoding PPO. Meanwhile, it maintained moderate POD activity, good sensory properties and cell membrane integrity in a certain extent and thus slowed down the senescence of mushrooms. Results indicated that there was a positive correlation between the ATP content and whitening index ( r = 0.901). In addition, HO-DCA maintained a higher ATP level, prolonged the storage time to 28 days and it might be an ideal strategy for preserving the quality of mushroom during storage.

Control of rotting and browning of Longan fruit cv. Biew Kiew after harvested by sulphur dioxide treatment under various storage temperatures.

PubMed

Chitbanchong, W; Sardsud, V; Whangchai, K; Koslanund, R; Thobunluepop, P

2009-11-15

The experiment of Longan fruit cv. Biew Kiew, untreated (control) and treated with SO2 treatment were stored under 2 +/- 2 and 7 +/- 2 degrees C for 0, 2, 4, 6 and 8 weeks were studied. The treatment of fresh longan fruit with SO2 fumigation combined with the suitable storage condition improved the overall longan fruit quality, especially on inner and outer peel tissue and aril color than no SO2 treatment. Treatment stabilizes peel color with no subsequent loss of color during storage (fruit color were bright-yellowish color). When the fruit showed during SO2 treatment, increasing of storage duration and temperatures, the dark color of inner and outer peel of longan fruit was appeared, this was correlated with the increasing of PPO activity. The activity of PPO enzyme in control fruit (no SO2 treatment) gradually lower than SO2 treatments. Fruit exposed to cool storage temperature (2 degrees C) exhibited a lower PPO enzymatic activity compared to those kept in high storage temperature (7 degrees C). Moreover, PPO enzymatic activity significantly increased over the storage durations The additional SO2 treatment no subsequent loss of weight of longan fruit during storage. However, the sulphite residues could detect immediately after SO2 treatment in all part of longan fruit, especially on aril tissue. The SEM evaluation found that the surface cracking was also impair the physiological function of the cuticle and increasing water permeability, which may cause water soaking at the inner side of the peel. The injured cell would accelerate the oxidation of phenolic substances and the oxidative products resulted in dark color of inner and outer peel.

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

Virador, V.; Reyes Grajeda, J; Blanco-Labra, A

The full-length cDNA sequence (P93622{_}VITVI) of polyphenol oxidase (PPO) cDNA from grape Vitis vinifera L., cv Grenache, was found to encode a translated protein of 607 amino acids with an expected molecular weight of ca. 67 kDa and a predicted pI of 6.83. The translated amino acid sequence was 99%, identical to that of a white grape berry PPO (1) (5 out of 607 amino acid potential sequence differences). The protein was purified from Grenache grape berries by using traditional methods, and it was crystallized with ammonium acetate by the hanging-drop vapor diffusion method. The crystals were orthorhombic, space groupmore » C2221. The structure was obtained at 2.2 {angstrom} resolution using synchrotron radiation using the 39 kDa isozyme of sweet potato PPO (PDB code: 1BT1) as a phase donor. The basic symmetry of the cell parameters (a, b, and c and {alpha}, {beta}, and {gamma}) as well as in the number of asymmetric units in the unit cell of the crystals of PPO, differed between the two proteins. The structures of the two enzymes are quite similar in overall fold, the location of the helix bundles at the core, and the active site in which three histidines bind each of the two catalytic copper ions, and one of the histidines is engaged in a thioether linkage with a cysteine residue. The possibility that the formation of the Cys-His thioether linkage constitutes the activation step is proposed. No evidence of phosphorylation or glycoslyation was found in the electron density map. The mass of the crystallized protein appears to be only 38.4 kDa, and the processing that occurs in the grape berry that leads to this smaller size is discussed.« less

Effects of triacylglycerol structure and solid fat content on fasting responses of mice.

PubMed

Wang, Xiaosan; Wang, Tong; Spurlock, Michael E; Wang, Xingguo

2016-06-01

Fat randomization and interesterification change triacylglycerol (TAG) structure and its solid fat content profile. It has not been thoroughly investigated whether these changes affect lipid metabolism. Two experiments were conducted to investigate the effects of TAG structure and solid fat content on feed intake, body weight change, and serum metabolite concentrations in mice. An experiment used two fats rich in 1,2-dipalmitoyl-3-oleoylglycerol (PPO) and 1,3-dipalmitoyl-2-oleoylglycerol (POP) as comparative pair of fats to assess the effect of TAG structure since PPO and POP have the same fatty acid composition and solid fat content at 37 °C. Another experiment used a fat rich in 1-palmitoyl-2,3-dioleoylglycerol (POO) with solid fat content of zero at 37 °C and a mixture of fats that had the same general fatty acid composition and palmitic acid positional distribution, but with solid fat content of 22 % at 37 °C. This pair of fats was used to examine the effect of solid fat content on blood lipid profile. After 6-week feeding, the pair of fats with different solid fat contents did not significantly affect the concentrations of total serum cholesterol, HDL cholesterol, TAG, non-esterified fatty acid (NEFA), or blood glucose. However, the PPO fat significantly reduced feed intake, body weight, and serum glucose concentration as compared to POP. These results suggest that the presence of solid fat at the level examined does not affect lipid metabolism and lipemia, but PPO diet significantly affects NEFA and glucose concentrations. Palmitic acid at the sn-2 position of the TAG may have significant effect on appetite, which may be mediated via the gut receptors.

Green Printing: Colorimetric and Densitometric Analysis of Solvent-Based and Vegetable Oil-Based Inks of Multicolor Offset Printing

ERIC Educational Resources Information Center

Dharavath, H. Naik; Hahn, Kim

2009-01-01

The purpose of this study was to determine the differences in the measurable print attributes (Print Contrast and Dot Gain) and color gamut of solvent-based (SB) inks vs. vegetable oil-based (VO) inks of multicolor offset printing. The literature review revealed a lack of published research on this subject. VO inks tend to perform (color…

Effect of Processing Parameters on 3D Printing of Cement - based Materials

NASA Astrophysics Data System (ADS)

Lin, Jia Chao; Wang, Jun; Wu, Xiong; Yang, Wen; Zhao, Ri Xu; Bao, Ming

2018-06-01

3D printing is a new study direction of building method in recent years. The applicability of 3D printing equipment and cement based materials is analyzed, and the influence of 3D printing operation parameters on the printing effect is explored in this paper. Results showed that the appropriate range of 3D printing operation parameters: print height/nozzle diameter is between 0.4 to 0.6, the printing speed 4-8 cm/s with pumpage 9 * 10-2 m 3/ h.

Learning-Based Cell Injection Control for Precise Drop-on-Demand Cell Printing.

PubMed

Shi, Jia; Wu, Bin; Song, Bin; Song, Jinchun; Li, Shihao; Trau, Dieter; Lu, Wen F

2018-06-05

Drop-on-demand (DOD) printing is widely used in bioprinting for tissue engineering because of little damage to cell viability and cost-effectiveness. However, satellite droplets may be generated during printing, deviating cells from the desired position and affecting printing position accuracy. Current control on cell injection in DOD printing is primarily based on trial-and-error process, which is time-consuming and inflexible. In this paper, a novel machine learning technology based on Learning-based Cell Injection Control (LCIC) approach is demonstrated for effective DOD printing control while eliminating satellite droplets automatically. The LCIC approach includes a specific computational fluid dynamics (CFD) simulation model of piezoelectric DOD print-head considering inverse piezoelectric effect, which is used instead of repetitive experiments to collect data, and a multilayer perceptron (MLP) network trained by simulation data based on artificial neural network algorithm, using the well-known classification performance of MLP to optimize DOD printing parameters automatically. The test accuracy of the LCIC method was 90%. With the validation of LCIC method by experiments, satellite droplets from piezoelectric DOD printing are reduced significantly, improving the printing efficiency drastically to satisfy requirements of manufacturing precision for printing complex artificial tissues. The LCIC method can be further used to optimize the structure of DOD print-head and cell behaviors.

Maillard reaction products as "natural antibrowning" agents in fruit and vegetable technology.

PubMed

Billaud, Catherine; Maraschin, Christelle; Chow, Yin-Naï; Chériot, Sophie; Peyrat-Maillard, Marie-Nöelle; Nicolas, Jacques

2005-07-01

The effects of Maillard reaction products (MRPs), synthesized from a sugar (pentose, hexose, or disaccharide) and either a cysteine-related compound, an amino acid, or a sulfur compound, were investigated on polyphenoloxidase (PPO) activity from apple, mushroom, and eggplant. The optimal conditions for the production of inhibitory MRPs were performed using two-factor and five-level central experimental designs. It resulted that thiol-derived MRPs were highly prone to give rise to inhibitory compounds of PPO activity. Technological assays were also performed to test the efficiency of selected MRPs in the prevention of enzymatic browning in raw and minimally processed fruits and vegetables.

Enzymatic browning in avocado (Persea americana) revisited: History, advances, and future perspectives.

PubMed

Toledo, Lea; Aguirre, Carolina

2017-12-12

Considering nearly 80 years of research regarding one of the enzymes responsible for catalyzing the formation of pigments in higher animals, plants, fungi and bacteria, this review will focus on collecting and categorizing the existing information about polyphenol oxidase (PPO) in fruits, with particular emphasis on the information in relation to avocado, which is one of the hardiest species in terms of inactivation, has documented dual activity (EC 1.14.18.1/EC 1.10.3.1), and represents one of the oldest challenges for food science research and fruit processors. It is expected that this review will contribute to the further development of the field by highlighting the questions that have arisen during the characterization of PPO, the progress that has been made and the questions that remain today, in addition to new methodologies that are being applied to study this system. Holistic methodologies offer unexplored potential for advancing our understanding of the complex phenomena that govern PPO activity in fruits, because these methodologies will enable the characterization of this family of enzymes in all of its complexity. Subsequently, it will be possible to develop better techniques for controlling enzymatic browning in this valuable fruit.

Application of poly (p-phenylene oxide) as blocking layer to reduce self-discharge in supercapacitors

NASA Astrophysics Data System (ADS)

Tevi, Tete; Yaghoubi, Houman; Wang, Jing; Takshi, Arash

2013-11-01

Supercapacitors are electrochemical energy storage devices with high power density. However, application of supercapacitors is limited mainly due to their high leakage current. In this work, application of an ultra-thin layer of electrodeposited poly (p-phenylene oxide) (PPO) has been investigated as a blocking layer to reduce the leakage current. The polymer was first deposited on a glassy carbon electrode. The morphology of the film was studied by atomic force microscopy (AFM), and the film thickness was estimated to be ˜1.5 nm by using the electrochemical impedance spectroscopy (EIS) technique. The same deposition method was applied to coat the surface of the activated carbon electrodes of a supercapacitor with PPO. The specific capacitance, the leakage current, and the series resistance were measured in two devices with and without the blocking layer. The results demonstrate that the application of the PPO layer reduced the leakage current by ˜78%. However, the specific capacitance was decreased by ˜56%, when the blocking layer was applied. Due to the lower rate of self-discharge, the suggested approach can be applied to fabricate devices with longer charge storage time.

Nucleolar Reorganization Upon Site-Specific Double-Strand Break Induction.

PubMed

Franek, Michal; Kovaříková, Alena; Bártová, Eva; Kozubek, Stanislav

2016-11-01

DNA damage response (DDR) in ribosomal genes and mechanisms of DNA repair in embryonic stem cells (ESCs) are less explored nuclear events. DDR in ESCs should be unique due to their high proliferation rate, expression of pluripotency factors, and specific chromatin signature. Given short population doubling time and fast progress through G1 phase, ESCs require a sustained production of rRNA, which leads to the formation of large and prominent nucleoli. Although transcription of rRNA in the nucleolus is relatively well understood, little is known about DDR in this nuclear compartment. Here, we directed formation of double-strand breaks in rRNA genes with I- PpoI endonuclease, and we studied nucleolar morphology, DDR, and chromatin modifications. We observed a pronounced formation of I- PpoI-induced nucleolar caps, positive on BRCA1, NBS1, MDC1, γH2AX, and UBF1 proteins. We showed interaction of nucleolar protein TCOF1 with HDAC1 and TCOF1 with CARM1 after DNA injury. Moreover, H3R17me2a modification mediated by CARM1 was found in I- PpoI-induced nucleolar caps. Finally, we report that heterochromatin protein 1 is not involved in DNA repair of nucleolar caps.

Changes in microbial populations and enzyme activities during the bioremediation of oil-contaminated soil.

PubMed

Lin, Xin; Li, Xiaojun; Sun, Tieheng; Li, Peijun; Zhou, Qixing; Sun, Lina; Hu, Xiaojun

2009-10-01

In the process of bioremediation in the soil contaminated by different oil concentrations, the changes in the microbial numbers (bacteria and fungi) and the enzyme (catalase (CAT), polyphenol oxidase (PPO) and lipase) activities were evaluated over a 2-year period. The results showed that the microbial numbers after 2-year bioremediation were one to ten times higher than those in the initial. The changes in the bacterial and the fungal populations were different during the bioremediation, and the highest microbial numbers for bacteria and fungi were 5.51 x 10(9) CFU g(-1) dry soil in treatment 3 (10,000 mg kg(-1)) in the initial and 5.54 x 10(5) CFU g(-1) dry soil in treatment 5 (50,000 mg kg(-1)) after the 2-year bioremediation period, respectively. The CAT and PPO activities in the contaminated soil decreased with increasing oil concentration, while the lipase activity increased. The activities of CAT and PPO improved after the bioremediation, but lipase activity was on the contrary. The CAT activity was more sensible to the oil than others, and could be alternative to monitor the bioremediation process.

Selective pressure against horizontally acquired prokaryotic genes as a driving force of plastid evolution.

PubMed

Llorente, Briardo; de Souza, Flavio S J; Soto, Gabriela; Meyer, Cristian; Alonso, Guillermo D; Flawiá, Mirtha M; Bravo-Almonacid, Fernando; Ayub, Nicolás D; Rodríguez-Concepción, Manuel

2016-01-11

The plastid organelle comprises a high proportion of nucleus-encoded proteins that were acquired from different prokaryotic donors via independent horizontal gene transfers following its primary endosymbiotic origin. What forces drove the targeting of these alien proteins to the plastid remains an unresolved evolutionary question. To better understand this process we screened for suitable candidate proteins to recapitulate their prokaryote-to-eukaryote transition. Here we identify the ancient horizontal transfer of a bacterial polyphenol oxidase (PPO) gene to the nuclear genome of an early land plant ancestor and infer the possible mechanism behind the plastidial localization of the encoded enzyme. Arabidopsis plants expressing PPO versions either lacking or harbouring a plastid-targeting signal allowed examining fitness consequences associated with its subcellular localization. Markedly, a deleterious effect on plant growth was highly correlated with PPO activity only when producing the non-targeted enzyme, suggesting that selection favoured the fixation of plastid-targeted protein versions. Our results reveal a possible evolutionary mechanism of how selection against heterologous genes encoding cytosolic proteins contributed in incrementing plastid proteome complexity from non-endosymbiotic gene sources, a process that may also impact mitochondrial evolution.

Response Surface Optimization of Process Parameters and Fuzzy Analysis of Sensory Data of High Pressure-Temperature Treated Pineapple Puree.

PubMed

Chakraborty, Snehasis; Rao, Pavuluri Srinivasa; Mishra, Hari Niwas

2015-08-01

The high-pressure processing conditions were optimized for pineapple puree within the domain of 400-600 MPa, 40-60 °C, and 10-20 min using the response surface methodology (RSM). The target was to maximize the inactivation of polyphenoloxidase (PPO) along with a minimal loss in beneficial bromelain (BRM) activity, ascorbic acid (AA) content, antioxidant capacity, and color in the sample. The optimum condition was 600 MPa, 50 °C, and 13 min, having the highest desirability of 0.604, which resulted in 44% PPO and 47% BRM activities. However, 93% antioxidant activity and 85% AA were retained in optimized sample with a total color change (∆E*) value less than 2.5. A 10-fold reduction in PPO activity was obtained at 600 MPa/70 °C/20 min; however, the thermal degradation of nutrients was severe at this condition. Fuzzy mathematical approach confirmed that sensory acceptance of the optimized sample was close to the fresh sample; whereas, the thermally pasteurized sample (treated at 0.1 MPa, 95 °C for 12 min) had the least sensory score as compared to others. © 2015 Institute of Food Technologists®

Influence of pH, benzoic acid, glutathione, EDTA, 4-hexylresorcinol, and sodium chloride on the pressure inactivation kinetics of mushroom polyphenol oxidase.

PubMed

Weemaes, C A; Ludikhuyze, L R; Van den Broeck, I; Hendrickx, M E

1999-09-01

Pressure inactivation of mushroom PPO was studied for pH values ranging from 4 to 8, and the effect of some antibrowning agents on the pressure stability of mushroom PPO at pH 6.5 was evaluated. pH reduction below 6.5 resulted in a lowered inactivation threshold pressure and an increase of the absolute value of the activation volume (or a decrease of the z(p) value), the latter two parameters reflecting the pressure dependency of the inactivation rate constant. An increase in pH from 6.5 to 8, on the other hand, did only marginally affect the pressure stability of the enzyme. Mushroom PPO at pH 6.5 was markedly sensitized toward pressure by the presence of 2.5 mM 4-hexylresorcinol and slightly stabilized by the presence of 5 mM EDTA. The presence of 5 mM glutathione, sodium chloride, or benzoic acid caused no significant alteration of the enzyme pressure stability. Only in the presence of 4-hexylresorcinol, significant changes of the activation volume and z(p) value were noticed.

Mesoscopic Simulations of Adsorption and Association of PEO-PPO-PEO Triblock Copolymers on a Hydrophobic Surface: From Mushroom Hemisphere to Rectangle Brush.

PubMed

Song, Xianyu; Zhao, Shuangliang; Fang, Shenwen; Ma, Yongzhang; Duan, Ming

2016-11-08

The dissipative particle dynamics (DPD) method is used to investigate the adsorption behavior of PEO-PPO-PEO triblock copolymers at the liquid/solid interface. The effect of molecular architecture on the self-assembled monolayer adsorption of PEO-PPO-PEO triblock copolymers on hydrophobic surfaces is elucidated by the adsorption process, film properties, and adsorption morphologies. The adsorption thicknesses on hydrophobic surfaces and the diffusion coefficient as well as the aggregation number of Pluronic copolymers in aqueous solution observed in our simulations agree well with previous experimental and numerical observations. The radial distribution function revealed that the ability of self-assembly on hydrophobic surfaces is P123 > P84 > L64 > P105 > F127, which increased with the EO ratio of the Pluronic copolymers. Moreover, the shape parameter and the degree of anisotropy increase with increasing molecular weight and mole ratio of PO of the Pluronic copolymers. Depending on the conformation of different Pluronic copolymers, the morphology transition of three regimes on hydrophobic surfaces is present: mushroom or hemisphere, progressively semiellipsoid, and rectangle brush regimes induced by decreasing molecular weight and mole ratio of EO of Pluronic copolymers.

Gas sorption in poly-(2,6-dimethyl-1,4-phenylene)oxide containing nanoporous crystalline phases

NASA Astrophysics Data System (ADS)

Galizia, M.; Daniel, C.; Fasano, G.; Guerra, G.; Mensitieri, G.

2012-07-01

In this contribution is presented an analysis of mass transport properties of low molecular weight compounds in amorphous PPO and in semi-crystalline PPO obtained by treating with benzene and carbon tetrachloride the amorphous sample. It is found that semi-crystalline samples are endowed with larger gas sorption capacity and diffusivity as compared to the amorphous ones: this behaviour has been attributed to the nanoporous nature of the crystalline phases induced by treatment with solvents. In particular, sorption experiments, carried out at 30°C with methane, carbon dioxide, propane and propylene, have shown that both semi-crystalline PPOs display rather interesting features which make them suitable for use as membrane materials in gas separation processes, in view of the relatively high values of solubility and diffusivity. Moreover, these peculiar sorption and mass transport properties have been found to be virtually unaffected by thermal ageing: in fact, sorption experiments conducted on amorphous and semi-crystalline PPO after treatment at 65°C for three months showed that sorption properties of aged samples are the same as for the untreated samples. This is an important feature to assure the stability of performances in membrane applications.

Partial purification and characterization of polyphenol oxidase from banana (Musa sapientum L.) peel.

PubMed

Yang, C P; Fujita, S; Kohno, K; Kusubayashi, A; Ashrafuzzaman, M; Hayashi, N

2001-03-01

Polyphenol oxidase (EC 1.10.3.1, o-diphenol: oxygen oxidoreductase, PPO) of banana (Musa sapientum L.) peel was partially purified about 460-fold with a recovery of 2.2% using dopamine as substrate. The enzyme showed a single peak on Toyopearl HW55-S chromatography. However, two bands were detected by staining with Coomassie brilliant blue on PAGE: one was very clear, and the other was faint. Molecular weight for purified PPO was estimated to be about 41 000 by gel filtration. The enzyme quickly oxidized dopamine, and its Km value (Michaelis constant) for dopamine was 3.9 mM. Optimum pH was 6.5 and the PPO activity was quite stable in the range of pH 5-11 for 48 h. The enzyme had an optimum temperature at 30 degrees C and was stable up to 60 degrees C after heat treatment for 30 min. The enzyme activity was strongly inhibited by sodium diethyldithiocarbamate, potassium cyanide, L-ascorbic acid, and cysteine at 1 mM. Under a low buffer capacity, the enzyme was also strongly inhibited by citric acid and acetic acid at 10 mM.

Homochiral Asymmetric Triacylglycerol Isomers in Egg Yolk.

PubMed

Nagai, Toshiharu; Ishikawa, Keiko; Yoshinaga, Kazuaki; Yoshida, Akihiko; Beppu, Fumiaki; Gotoh, Naohiro

2017-12-01

The composition of triacylglycerol (TAG) positional isomer (-PI) and enantiomer (-E) in immature chicken egg yolk, mature chicken yolk, and chicken meat was examined. POO (consisting of one palmitic acid (P) and two oleic acids (Os)), PPO (consisting of two Ps and one O), and PPL (consisting of two Ps and one linoleic acid (L)) were treated as representative TAG molecular species in all the analytical samples because P, O, and L were the major fatty acids comprising egg and chicken meat. sn-POO (binding P at sn-1 position) was predominant in egg yolks, while sn-OOP and sn-OPO were present in chicken meat. This difference was ascribed to the different roles of these isomers as nutrients, because TAG in egg yolk is important for new born organisms and TAG in chicken meat is used for fat accumulation. The compositions of the TAG isomers in PPO and PPL in egg yolk were similar, and O and L did not bind at the sn-1 position. In contrast, all the isomers of PPO and PPL were found in chicken meat. These results imply that the TAG structure could be modified so that the nutrient requirement is fulfilled in egg yolk and chicken meat.

Effect of Ternary Solutes on the Evolution of Structure and Gel Formation in Amphiphilic Copolymer Solutions

NASA Astrophysics Data System (ADS)

Meznarich, Norman Anthony Kang

Aqueous solutions of polyoxyethylene-polyoxypropylene-polyoxyethylene (PEO-PPO-PEO) amphiphilic triblock copolymers (commercially known as Pluronic surfactants) undergo reversible and temperature-dependent micellization and arrangement into cubic ordered lattices known as "micelle gels". The macroscopic behavior of the ordering is a transition from a liquid to a gel. While the phase behavior and gel structure of pure Pluronic surfactant solutions have been well studied, less is known about the effects of added ternary solutes. In this dissertation, a comprehensive investigation into the effects of the added pharmaceutical methylparaben on solutions of F127 ranging from 10 to 30 wt% was conducted in order to better understand the behavior of F127 in multicomponent pharmaceutical formulations. The viscoelastic properties of F127 gel formation were studied using rheometry, where heating rates of 0.1, 1, and 10 degrees C/min were also used to probe the kinetics of the gel transition. In solutions containing methylparaben, F127 gelation occurred at up to 15 degrees C lower temperatures and was accelerated by a factor of three to four. Small angle x-ray scattering (SAXS) was used to characterize the structure of the ordered domains, and how they were affected by the presence of dissolved pharmaceuticals. It was found that ordered domain formation changed from heterogeneous nucleation and growth to possible homogeneous nucleation and growth. A roughly 2% reduction in the cubic lattice parameter was also observed for solutions containing methylparaben. Differential scanning calorimetry (DSC) experiments were performed on a series of different Pluronic surfactants in order to characterize the micellization behavior as a function of PPO center block length and PEO/PPO ratio. Added methylparaben suppressed the micellization endotherm, the degree of suppression depending linearly on the amount of added methylparaben, as well as the length of the PPO center block and PEO/PPO ratio. This dissertation yielded a thorough characterization of the changes in micellization and gelation behavior in F127 gels as a result of added pharmaceuticals. Previously unobserved behavior such as the onset of ordered domain formation in F127 gels was observed, and a greater understanding of the interactions between amphiphilic copolymer solutions and dissolved solutes was achieved.

Embedding objects during 3D printing to add new functionalities.

PubMed

Yuen, Po Ki

2016-07-01

A novel method for integrating and embedding objects to add new functionalities during 3D printing based on fused deposition modeling (FDM) (also known as fused filament fabrication or molten polymer deposition) is presented. Unlike typical 3D printing, FDM-based 3D printing could allow objects to be integrated and embedded during 3D printing and the FDM-based 3D printed devices do not typically require any post-processing and finishing. Thus, various fluidic devices with integrated glass cover slips or polystyrene films with and without an embedded porous membrane, and optical devices with embedded Corning(®) Fibrance™ Light-Diffusing Fiber were 3D printed to demonstrate the versatility of the FDM-based 3D printing and embedding method. Fluid perfusion flow experiments with a blue colored food dye solution were used to visually confirm fluid flow and/or fluid perfusion through the embedded porous membrane in the 3D printed fluidic devices. Similar to typical 3D printed devices, FDM-based 3D printed devices are translucent at best unless post-polishing is performed and optical transparency is highly desirable in any fluidic devices; integrated glass cover slips or polystyrene films would provide a perfect optical transparent window for observation and visualization. In addition, they also provide a compatible flat smooth surface for biological or biomolecular applications. The 3D printed fluidic devices with an embedded porous membrane are applicable to biological or chemical applications such as continuous perfusion cell culture or biocatalytic synthesis but without the need for any post-device assembly and finishing. The 3D printed devices with embedded Corning(®) Fibrance™ Light-Diffusing Fiber would have applications in display, illumination, or optical applications. Furthermore, the FDM-based 3D printing and embedding method could also be utilized to print casting molds with an integrated glass bottom for polydimethylsiloxane (PDMS) device replication. These 3D printed glass bottom casting molds would result in PDMS replicas with a flat smooth bottom surface for better bonding and adhesion.

Multivariate modelling and personality organization: a comparative study of the Defense Mechanism Test and linguistic expressions.

PubMed

Sundbom, E; Jeanneau, M

1996-03-01

The main aim of the study is to establish an empirical connection between perceptual defences as measured by the Defense Mechanism Test (DMT)--a projective percept-genetic method--and manifest linguistic expressions based on word pattern analyses. The subjects were 25 psychiatric patients with the diagnoses neurotic personality organization (NPO), borderline personality organization (BPO) and psychotic personality organization (PPO) in accordance with Kernberg's theory. A set of 130 DMT variables and 40 linguistic variables were analyzed by means of partial least squares (PLS) discriminant analysis separately and then pooled together. The overall hypothesis was that it would be possible to define the personality organization of the patients in terms of an amalgam of perceptual defences and word patterns, and that these two kinds of data would confirm each other. The result of the combined PLS analysis revealed a very good separation between the diagnostic groups as measured by the pooled variable sets. Among other things, it was shown that NPO patients are principally characterized by linguistic variables, whereas BPO and PPO patients are better defined by perceptual defences as measured by the DMT method.

Tunable Encapsulation Structure of Block Copolymer Coated Single-Walled Carbon Nanotubes in Aqueous Solution

DOE PAGES

Han, Youngkyu; Ahn, Suk-Kyun; Zhang, Zhe; ...

2015-05-15

The nano-sized and shape-tunable molecular building blocks can provide great opportunities for the fabrication of precisely controlled nanostructures. In this work, we have fabricated a molecular building block of single-walled carbon nanotubes (SWNTs) coated by PPO-PEO-PPO block copolymers whose encapsulation structure can be controlled via temperature or addition of small molecules. The structure and optical properties of SWNT-block copolymers have been investigated by small angle neutron scattering (SANS), ultraviolet-visible (UV-vis) spectroscopy, atomic force microscopy (AFM), and molecular dynamics (MD) simulation. The structure of the hydrated block copolymer layer surrounding SWNT can be controlled reversibly by varying temperature as well asmore » by irreversibly adding 5-methylsalicylic acid (5MS). Increasing hydrophobicity of the polymers with temperature and strong tendency of 5MS to interact with both block copolymers and orbitals of the SWNTs are likely to be responsible for the significant structural change of the block copolymer encapsulation layer, from loose corona shell to tightly encapsulating compact shell. These result shows an efficient and simple way to fabricate and manipulate carbon-based nano building blocks in aqueous systems with tunable structure.« less

CdS/ZnS core-shell nanocrystal photosensitizers for visible to UV upconversion.

PubMed

Gray, Victor; Xia, Pan; Huang, Zhiyuan; Moses, Emily; Fast, Alexander; Fishman, Dmitry A; Vullev, Valentine I; Abrahamsson, Maria; Moth-Poulsen, Kasper; Lee Tang, Ming

2017-08-01

Herein we report the first example of nanocrystal (NC) sensitized triplet-triplet annihilation based photon upconversion from the visible to ultraviolet (vis-to-UV). Many photocatalyzed reactions, such as water splitting, require UV photons in order to function efficiently. Upconversion is one possible means of extending the usable range of photons into the visible. Vis-to-UV upconversion is achieved with CdS/ZnS core-shell NCs as the sensitizer and 2,5-diphenyloxazole (PPO) as annihilator and emitter. The ZnS shell was crucial in order to achieve any appreciable upconversion. From time resolved photoluminescence and transient absorption measurements we conclude that the ZnS shell affects the NC and triplet energy transfer (TET) from NC to PPO in two distinct ways. Upon ZnS growth the surface traps are passivated thus increasing the TET. The shell, however, also acts as a tunneling barrier for TET, reducing the efficiency. This leads to an optimal shell thickness where the upconversion quantum yield ( Φ ' UC ) is maximized. Here the maximum Φ ' UC was determined to be 5.2 ± 0.5% for 4 monolayers of ZnS shell on CdS NCs.

Effect of Organic Blocking Layer on the Energy Storage Characteristics of High-Permittivity Sol-Gel Thin Film Based on Neat 2-Cyanoethyltrimethoxysilane

NASA Astrophysics Data System (ADS)

Kim, Yunsang; Kathaperumal, Mohanalingam; Pan, Ming-Jen; Perry, Joseph

2014-03-01

Organic-inorganic hybrid sol-gel materials with polar groups that can undergo reorientational polarization provide a potential route to dielectric materials for energy storage. We have investigated the influence of nanoscale polymeric layer on dielectric and energy storage properties of 2-cyanoethyltrimethoxysilane (CNETMS) films. Two polymeric materials, fluoropolymer (CYTOP) and poly(p-phenylene oxide, PPO), are examined as potential materials to control charge injection from electrical contacts into CNETMS films by means of a potential barrier, whose width and height are defined by thickness and permittivity. Blocking layers ranging from 20 nm to 200 nm were deposited on CNETMS films by spin casting and subjected to thermal treatment. Polarization-electric field measurements show 30% increase in extractable energy density with PPO/CNETMS bilayers, relative to CNETMS alone, due to improved breakdown strength. Conduction current of the bilayers indicate that onset of charge conduction at high field is much delayed, which can be translated into effective suppression of charge injection and probability of breakdown events. The results will be discussed in regards to film morphology, field partitioning, width and height of potential barrier, charge trapping and loss of bilayers.

Exploring backbone-cation alkyl spacers for multi-cation side chain anion exchange membranes

NASA Astrophysics Data System (ADS)

Zhu, Liang; Yu, Xuedi; Hickner, Michael A.

2018-01-01

In order to systematically study how the arrangement of cations on the side chain and length of alkyl spacers between cations impact the performance of multi-cation AEMs for alkaline fuel cells, a series of polyphenylene oxide (PPO)-based AEMs with different cationic side chains were synthesized. This work resulted in samples with two or three cations in a side chain pendant to the PPO backbone. More importantly, the length of the spacer between cations varied from 3 methylene (-CH2-) (C3) groups to 8 methylene (C8) groups. The highest conductivity, up to 99 mS/cm in liquid water at room temperature, was observed for the triple-cation side chain AEM with pentyl (C5) or hexyl (C6) spacers. The multi-cation AEMs were found to have decreased water uptake and ionic conductivity when the spacer chains between cations were lengthened from pentyl (C5) or hexyl (C6) to octyl (C8) linking groups. The triple-cation membranes with pentyl (C5) or hexyl (C6) groups between cations showed greatest stability after immersion in 1 M NaOH at 80 °C for 500 h.

Ion pair reinforced semi-interpenetrating polymer network for direct methanol fuel cell applications.

PubMed

Fang, Chunliu; Julius, David; Tay, Siok Wei; Hong, Liang; Lee, Jim Yang

2012-06-07

This paper describes the synthesis of ion-pair-reinforced semi-interpenetrating polymer networks (SIPNs) as proton exchange membranes (PEMs) for the direct methanol fuel cells (DMFCs). Specifically, sulfonated poly(2,6-dimethyl-1,4-phenylene oxide) (SPPO), a linear polymer proton source, was immobilized in a brominated PPO (BPPO) network covalently cross-linked by ethylenediamine (EDA). The immobilization of SPPO in the SIPN network was accomplished not only by the usual means of mechanical interlocking but also by ion pair formation between the sulfonic acid groups of SPPO and the amine moieties formed during the cross-linking reaction of BPPO with EDA. Through the ion pair interactions, the immobilization of SPPO polymer in the BPPO network was made more effective, resulting in a greater uniformity of sulfonic acid cluster distribution in the membrane. The hydrophilic amine-containing cross-links also compensated for some of the decrease in proton conductivity caused by ion pair formation. The SIPN membranes prepared as such showed good proton conductivity, low methanol permeability, good mechanical properties, and dimensional stability. Consequently, the PPO based SIPN membranes were able to deliver a higher maximum power density than Nafion, demonstrating the potential of the SIPN structure for PEM designs.

Recent Advances in Extrusion-Based 3D Printing for Biomedical Applications.

PubMed

Placone, Jesse K; Engler, Adam J

2018-04-01

Additive manufacturing, or 3D printing, has become significantly more commonplace in tissue engineering over the past decade, as a variety of new printing materials have been developed. In extrusion-based printing, materials are used for applications that range from cell free printing to cell-laden bioinks that mimic natural tissues. Beyond single tissue applications, multi-material extrusion based printing has recently been developed to manufacture scaffolds that mimic tissue interfaces. Despite these advances, some material limitations prevent wider adoption of the extrusion-based 3D printers currently available. This progress report provides an overview of this commonly used printing strategy, as well as insight into how this technique can be improved. As such, it is hoped that the prospective report guides the inclusion of more rigorous material characterization prior to printing, thereby facilitating cross-platform utilization and reproducibility. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ultrafast fluorescence spectroscopy of biologically relevant chromophores using type II difference frequency generation

NASA Astrophysics Data System (ADS)

Léonard, J.; Gelot, T.; Torgasin, K.; Haacke, S.

2011-01-01

A novel femtosecond fluorescence experiment based on type II difference frequency mixing is demonstrated. This approach is particularly interesting for near-UV emitting biological chromophores like amino acids and nucleotides, as the fluorescence is converted into the spectral range where CCD have their highest quantum efficiencies. The method is implemented with a 5-kHz amplified Ti:Sapphire laser system and first results obtained with 2,5-diphenyloxazole (PPO) in ethanol are reported.

MARY spectroscopy in the presence of coordination compound Zn(hfac) 2(PPO) 2

NASA Astrophysics Data System (ADS)

Sergey, N. V.; Burdukov, A. B.; Pervukhina, N. V.; Kuibida, L. V.; Pozdnyakov, I. P.; Stass, D. V.

2011-02-01

MARY spectroscopy is finding increasing use in the studies of transient organic radical ions and their reactions. Extending this technique to organometallic species will broaden the class of potential target compounds and can help answer important mechanistic questions in organometallic and spin chemistry. We probed this approach using a tailored Zn(hfac)2(PPO)2 complex. The synthesized complex has quantum yield and fluorescence lifetime (n-decane solution) φ ∼0.8 and τ ∼1.3 ns, respectively. For this type of complex it is the first observation of MARY spectra different from those of free ligand, thus implying participation of the complex in the development of the observed signal.

Two-photon absorption in oxazole derivatives: An experimental and quantum chemical study

NASA Astrophysics Data System (ADS)

Silva, D. L.; De Boni, L.; Correa, D. S.; Costa, S. C. S.; Hidalgo, A. A.; Zilio, S. C.; Canuto, S.; Mendonca, C. R.

2012-05-01

Experimental and theoretical studies on the two-photon absorption properties of two oxazole derivatives: 2,5-diphenyloxazole (PPO) and 2-(4-biphenylyl)-5-phenyl-1,3,4-oxadiazole (PBD) are presented. The two-photon absorption cross-section spectra were determined by means of the Z-scan technique, from 460 up to 650 nm, and reached peak values of 84 GM for PBD and 27 GM for PPO. Density Functional Theory and response function formalism are used to determine the molecular structures and the one- and two-photon absorption properties and to assist in the interpretation of the experimental results. The Polarizable Continuum Model in one-photon absorption calculations is used to estimate solvent effects.

Study of absorption and re-emission processes in a ternary liquid scintillation system

NASA Astrophysics Data System (ADS)

Xiao, Hua-Lin; Li, Xiao-Bo; Zheng, Dong; Cao, Jun; Wen, Liang-Jian; Wang, Nai-Yan

2010-11-01

Liquid scintillators are widely used as the neutrino target in neutrino experiments. The absorption and emission of different components of a ternary liquid scintillator (Linear Alkyl Benzene (LAB) as the solvent, 2,5-diphenyloxazole (PPO) as the fluor and p-bis-(o-methylstyryl)-benzene (bis-MSB) as wavelength shifter) are studied. It is shown that the absorption of this liquid scintillator is dominant by LAB and PPO at wavelengths less than 349 nm, and the absorption by bis-MSB becomes prevalent at the wavelength larger than 349 nm. The fluorescence quantum yields, which are the key parameters to model the absorption and re-emission processes in large liquid scintillation detectors, are measured.

Research on torsional vibration modelling and control of printing cylinder based on particle swarm optimization

NASA Astrophysics Data System (ADS)

Wang, Y. M.; Xu, W. C.; Wu, S. Q.; Chai, C. W.; Liu, X.; Wang, S. H.

2018-03-01

The torsional oscillation is the dominant vibration form for the impression cylinder of printing machine (printing cylinder for short), directly restricting the printing speed up and reducing the quality of the prints. In order to reduce torsional vibration, the active control method for the printing cylinder is obtained. Taking the excitation force and moment from the cylinder gap and gripper teeth open & closing cam mechanism as variable parameters, authors establish the dynamic mathematical model of torsional vibration for the printing cylinder. The torsional active control method is based on Particle Swarm Optimization(PSO) algorithm to optimize input parameters for the serve motor. Furthermore, the input torque of the printing cylinder is optimized, and then compared with the numerical simulation results. The conclusions are that torsional vibration active control based on PSO is an availability method to the torsional vibration of printing cylinder.

High-Content Screening in Zebrafish Embryos Identifies Butafenacil as a Potent Inducer of Anemia

PubMed Central

Leet, Jessica K.; Lindberg, Casey D.; Bassett, Luke A.; Isales, Gregory M.; Yozzo, Krystle L.; Raftery, Tara D.; Volz, David C.

2014-01-01

Using transgenic zebrafish (fli1:egfp) that stably express enhanced green fluorescent protein (eGFP) within vascular endothelial cells, we recently developed and optimized a 384-well high-content screening (HCS) assay that enables us to screen and identify chemicals affecting cardiovascular development and function at non-teratogenic concentrations. Within this assay, automated image acquisition procedures and custom image analysis protocols are used to quantify body length, heart rate, circulation, pericardial area, and intersegmental vessel area within individual live embryos exposed from 5 to 72 hours post-fertilization. After ranking developmental toxicity data generated from the U.S. Environmental Protection Agency's (EPA's) zebrafish teratogenesis assay, we screened 26 of the most acutely toxic chemicals within EPA's ToxCast Phase-I library in concentration-response format (0.05–50 µM) using this HCS assay. Based on this screen, we identified butafenacil as a potent inducer of anemia, as exposure from 0.39 to 3.125 µM butafenacil completely abolished arterial circulation in the absence of effects on all other endpoints evaluated. Butafenacil is an herbicide that inhibits protoporphyrinogen oxidase (PPO) – an enzyme necessary for heme production in vertebrates. Using o-dianisidine staining, we then revealed that severe butafenacil-induced anemia in zebrafish was due to a complete loss of hemoglobin following exposure during early development. Therefore, six additional PPO inhibitors within the ToxCast Phase-I library were screened to determine whether anemia represents a common adverse outcome for these herbicides. Embryonic exposure to only one of these PPO inhibitors – flumioxazin – resulted in a similar phenotype as butafenacil, albeit not as severe as butafenacil. Overall, this study highlights the potential utility of this assay for (1) screening chemicals for cardiovascular toxicity and (2) prioritizing chemicals for future hypothesis-driven and mechanism-focused investigations within zebrafish and mammalian models. PMID:25090246

Embedding objects during 3D printing to add new functionalities

PubMed Central

2016-01-01

A novel method for integrating and embedding objects to add new functionalities during 3D printing based on fused deposition modeling (FDM) (also known as fused filament fabrication or molten polymer deposition) is presented. Unlike typical 3D printing, FDM-based 3D printing could allow objects to be integrated and embedded during 3D printing and the FDM-based 3D printed devices do not typically require any post-processing and finishing. Thus, various fluidic devices with integrated glass cover slips or polystyrene films with and without an embedded porous membrane, and optical devices with embedded Corning® Fibrance™ Light-Diffusing Fiber were 3D printed to demonstrate the versatility of the FDM-based 3D printing and embedding method. Fluid perfusion flow experiments with a blue colored food dye solution were used to visually confirm fluid flow and/or fluid perfusion through the embedded porous membrane in the 3D printed fluidic devices. Similar to typical 3D printed devices, FDM-based 3D printed devices are translucent at best unless post-polishing is performed and optical transparency is highly desirable in any fluidic devices; integrated glass cover slips or polystyrene films would provide a perfect optical transparent window for observation and visualization. In addition, they also provide a compatible flat smooth surface for biological or biomolecular applications. The 3D printed fluidic devices with an embedded porous membrane are applicable to biological or chemical applications such as continuous perfusion cell culture or biocatalytic synthesis but without the need for any post-device assembly and finishing. The 3D printed devices with embedded Corning® Fibrance™ Light-Diffusing Fiber would have applications in display, illumination, or optical applications. Furthermore, the FDM-based 3D printing and embedding method could also be utilized to print casting molds with an integrated glass bottom for polydimethylsiloxane (PDMS) device replication. These 3D printed glass bottom casting molds would result in PDMS replicas with a flat smooth bottom surface for better bonding and adhesion. PMID:27478528

Influence of Laccase and Tyrosinase on the Antioxidant Capacity of Selected Phenolic Compounds on Human Cell Lines.

PubMed

Riebel, Matthias; Sabel, Andrea; Claus, Harald; Fronk, Petra; Xia, Ning; Li, Huige; König, Helmut; Decker, Heinz

2015-09-18

Polyphenolic compounds affect the color, odor and taste of numerous food products of plant origin. In addition to the visual and gustatory properties, they serve as radical scavengers and have antioxidant effects. Polyphenols, especially resveratrol in red wine, have gained increasing scientific and public interest due to their presumptive beneficial impact on human health. Enzymatic oxidation of phenolic compounds takes place under the influence of polyphenol oxidases (PPO), including tyrosinase and laccase. Several studies have demonstrated the radical scavenger effect of plants, food products and individual polyphenols in vitro, but, apart from resveratrol, such impact has not been proved in physiological test systems. Furthermore, only a few data exist on the antioxidant capacities of the enzymatic oxidation products of phenolic compounds generated by PPO. We report here first results about the antioxidant effects of phenolic substances, before and after oxidation by fungal model tyrosinase and laccase. In general, the common chemical 2,2-diphenyl-1-picrylhydrazyl assay and the biological tests using two different types of cell cultures (monocytes and endothelial cells) delivered similar results. The phenols tested showed significant differences with respect to their antioxidant activity in all test systems. Their antioxidant capacities after enzymatic conversion decreased or increased depending on the individual PPO used.

Nucleolar Reorganization Upon Site-Specific Double-Strand Break Induction

PubMed Central

Franek, Michal; Kovaříková, Alena; Bártová, Eva; Kozubek, Stanislav

2016-01-01

DNA damage response (DDR) in ribosomal genes and mechanisms of DNA repair in embryonic stem cells (ESCs) are less explored nuclear events. DDR in ESCs should be unique due to their high proliferation rate, expression of pluripotency factors, and specific chromatin signature. Given short population doubling time and fast progress through G1 phase, ESCs require a sustained production of rRNA, which leads to the formation of large and prominent nucleoli. Although transcription of rRNA in the nucleolus is relatively well understood, little is known about DDR in this nuclear compartment. Here, we directed formation of double-strand breaks in rRNA genes with I-PpoI endonuclease, and we studied nucleolar morphology, DDR, and chromatin modifications. We observed a pronounced formation of I-PpoI-induced nucleolar caps, positive on BRCA1, NBS1, MDC1, γH2AX, and UBF1 proteins. We showed interaction of nucleolar protein TCOF1 with HDAC1 and TCOF1 with CARM1 after DNA injury. Moreover, H3R17me2a modification mediated by CARM1 was found in I-PpoI-induced nucleolar caps. Finally, we report that heterochromatin protein 1 is not involved in DNA repair of nucleolar caps. PMID:27680669

Season-controlled changes in biochemical constituents and oxidase enzyme activities in tomato (Lycopersicon esculentum Mill.).

PubMed

Sen, Supatra; Mukherji, S

2009-07-01

Season-controlled changes in biochemical constituents viz. carotenoids (carotene and xanthophyll) and pectic substances along with IAA-oxidase and polyphenol oxidase (PPO) enzyme activities were estimated/assayed in leaves of Lycopersicon esculentum Mill. (tomato) in two developmental stages--pre-flowering (35 days after sowing) and post-flowering (75 days after sowing) in three different seasons--summer rainy and winter Carotenoid content along with pectic substances were highest in winter and declined significantly in summer followed by rainy i.e. winter > summer > rainy. Carotenoid content was significantly higher in the pre-flowering as compared to post-flowering in all three seasons while pectic substances increased in the post-flowering as compared to pre-flowering throughout the annual cycle. IAA oxidase and PPO enzyme activities were enhanced in rainy and decreased sharply in summer and winter i.e. rainy > summer > winter. Both the enzymes exhibited higher activity in the post-flowering stage as compared to pre-flowering in all three seasons. These results indicate winter to be the most favourable season for tomato plants while rainy season environmental conditions prove to be unfavourable (stressful) with diminished content of carotenoid and pectic substances and low activities of IAA oxidase and PPO, ultimately leading to poor growth and productivity.

Phase behavior and dynamics of a micelle-forming triblock copolymer system

NASA Astrophysics Data System (ADS)

Mohan, P. Harsha; Bandyopadhyay, Ranjini

2008-04-01

Synperonic F-108 (generic name, “pluronic”) is a micelle forming triblock copolymer of type ABA , where A is polyethylene oxide (PEO) and B is polypropylene oxide (PPO). At high temperatures, the hydrophobicity of the PPO chains increase, and the pluronic molecules, when dissolved in an aqueous medium, self-associate into spherical micelles with dense PPO cores and hydrated PEO coronas. At appropriately high concentrations, these micelles arrange in a face centered cubic lattice to show inverse crystallization, with the samples exhibiting high-temperature crystalline and low-temperature fluidlike phases. By studying the evolution of the elastic and viscous moduli as temperature is increased at a fixed rate, we construct the concentration-temperature phase diagram of Synperonic F-108. For a certain range of temperatures and at appropriate sample concentrations, we observe a predominantly elastic response. Oscillatory strain amplitude sweep measurements on these samples show pronounced peaks in the loss moduli, a typical feature of soft solids. The soft solidlike nature of these materials is further demonstrated by measuring their frequency-dependent mechanical moduli. The storage moduli are significantly larger than the loss moduli and are almost independent of the applied angular frequency. Finally, we perform strain rate frequency superposition experiments to measure the slow relaxation dynamics of this soft solid.

Phenol contents, oxidase activities, and the resistance of coffee to the leaf miner Leucoptera coffeella.

PubMed

Ramiro, Daniel Alves; Guerreiro-Filho, Oliveiro; Mazzafera, Paulo

2006-09-01

We examined the role of phenolic compounds, and the enzymes peroxidase and polyphenol oxidase, in the expression of resistance of coffee plants to Leucoptera coffeella (Lepidoptera: Lyonetiidae). The concentrations of total soluble phenols and chlorogenic acid (5-caffeoylquinic acid), and the activities of the oxidative enzymes peroxidase (POD) and polyphenol oxidase (PPO), were estimated in leaves of Coffea arabica, C. racemosa, and progenies of crosses between these species, which have different levels of resistance, before and after attack by this insect. The results indicate that phenols do not play a central role in resistance to the coffee leaf miner. Differences were detected between the parental species in terms of total soluble phenol concentrations and activities of the oxidative enzymes. However, resistant and susceptible hybrid plants did not differ in any of these characteristics. Significant induction of chlorogenic acid and PPO was only found in C. racemosa, the parental donator of the resistance genes against L. coffeella. High-performance liquid chromatography (HPLC) analysis also showed qualitative similarity between hybrids and the susceptible C. arabica. These results suggest that the phenolic content and activities of POD and PPO in response to the attack by the leaf miner may not be a strong evidence of their participation in direct defensive mechanisms.

Removal of bisphenol derivatives through quinone oxidation by polyphenol oxidase and subsequent quinone adsorption on chitosan in the heterogeneous system.

PubMed

Kimura, Yuji; Takahashi, Ayumi; Kashiwada, Ayumi; Yamada, Kazunori

2015-01-01

In this study, the combined use of a biopolymer chitosan and an oxidoreductase polyphenol oxidase (PPO) was systematically investigated for the removal of bisphenol derivatives from aqueous medium. The process parameters, such as the pH value, temperature, and PPO concentration, were estimated to conduct the enzymatic quinone oxidation of bisphenol derivatives by as little enzyme as possible. Bisphenol derivatives effectively underwent PPO-catalysed quinone oxidation without H2O2 unlike other oxidoreductases, such as peroxidase and tyrosinase, and the optimum conditions were determined to be pH 7.0 and 40°C for bisphenol B, bisphenol E, bisphenol O, and bisphenol Z; pH 7.0 and 30°C for bisphenol C and bisphenol F; and pH 8.0 and 40°C for bisphenol T. They were completely removed through adsorption of enzymatically generated quinone derivatives on chitosan beads or chitosan powders. Quinone adsorption on chitosan beads or chitosan powders in the heterogeneous system was found to be a more effective procedure than generation of aggregates in the homogeneous system with chitosan solution. The removal time was shortened by increasing the amount of chitosan beads or decreasing the size of the chitosan powders.

Characterization and Comparative Overview of Complete Sequences of the First Plasmids of Pandoraea across Clinical and Non-clinical Strains

PubMed Central

Yong, Delicia; Tee, Kok Keng; Yin, Wai-Fong; Chan, Kok-Gan

2016-01-01

To date, information on plasmid analysis in Pandoraea spp. is scarce. To address the gap of knowledge on this, the complete sequences of eight plasmids from Pandoraea spp. namely Pandoraea faecigallinarum DSM 23572T (pPF72-1, pPF72-2), Pandoraea oxalativorans DSM 23570T (pPO70-1, pPO70-2, pPO70-3, pPO70-4), Pandoraea vervacti NS15 (pPV15) and Pandoraea apista DSM 16535T (pPA35) were studied for the first time in this study. The information on plasmid sequences in Pandoraea spp. is useful as the sequences did not match any known plasmid sequence deposited in public databases. Replication genes were not identified in some plasmids, a situation that has led to the possibility of host interaction involvement. Some plasmids were also void of par genes and intriguingly, repA gene was also not discovered in these plasmids. This further leads to the hypothesis of host-plasmid interaction. Plasmid stabilization/stability protein-encoding genes were observed in some plasmids but were not established for participating in plasmid segregation. Toxin-antitoxin systems MazEF, VapBC, RelBE, YgiT-MqsR, HigBA, and ParDE were identified across the plasmids and their presence would improve plasmid maintenance. Conjugation genes were identified portraying the conjugation ability amongst Pandoraea plasmids. Additionally, we found a shared region amongst some of the plasmids that consists of conjugation genes. The identification of genes involved in replication, segregation, toxin-antitoxin systems and conjugation, would aid the design of drugs to prevent the survival or transmission of plasmids carrying pathogenic properties. Additionally, genes conferring virulence and antibiotic resistance were identified amongst the plasmids. The observed features in the plasmids shed light on the Pandoraea spp. as opportunistic pathogens. PMID:27790203

Donor predicted post-operative forced expiratory volume in one second predicts recipients' best forced expiratory volume in one second following size-reduced lung transplantation.

PubMed

Inci, Ilhan; Irani, Sarosh; Kestenholz, Peter; Benden, Christian; Boehler, Annette; Weder, Walter

2011-01-01

The limited number of available grafts is one of the major obstacles of lung transplantation. Size-reduced lung transplantation allows the use of oversized grafts for small recipients. Optimal lung size matching is vital to achieve best functional outcome and avoid potential problems when using oversized grafts. We hypothesise that donor-predicted postoperative forced expiratory volume in 1s (ppoFEV1) correlates with the recipient best FEV1 after size-reduced lung transplant, being useful for the estimation of function outcome. All patients undergoing size-reduced or standard bilateral lung transplantation were included (1992-2007). Donor ppoFEV1 was calculated and corrected with respect to size reduction and correlated with recipient measured best FEV1 post-transplant. In addition, pre- and postoperative clinical data including surgical complications and outcome of all size-reduced lung transplant recipients were compared with standard lung transplant recipients. A total of 61 size-reduced lung transplant recipients (lobar transplants, n=20; anatomic or non-anatomic resection, n=41) were included and compared to 145 standard transplants. The mean donor-recipient height difference was statistically significant between the two groups (p=0.0001). The mean donor ppoFEV1 was comparable with recipient best FEV1 (2.7±0.6 vs 2.6±0.7 l). There was a statistically significant correlation between donor ppoFEV1 and recipient best FEV1 (p=0.01, r=0.688). The 30-day mortality rate and 3-month, 1- and 5-year survival rates were comparable between the two groups. In size-reduced lung transplantation, postoperative recipient best FEV1 could be predicted from donor-calculated and corrected FEV1 with respect to its size reduction. Compared to standard lung transplantation, equivalent morbidity, mortality and functional results could be obtained after size-reduced lung transplantation. Copyright © 2010 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.

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

Panchalingam, V.

The polymerization of propylene oxide (PO) was studied with an initiator prepared by the reaction of R(-)-3,3-dimethyl-1,2-butanediol amount of zinc chloride, the initiator was found to be highly reactive and also stereoselective in the polymerization of PO, preferentially incorporating R-(+)-PO into the polymer chain. Analysis of the polymer structure by {sup 13}C-NMR spectroscopy showed that chlorine, hydroxy, and one type of alkoxy end groups derived from the initiator were present in the polymer prepared in the polymer prepared at room temperature. Fractionation of poly(propylene oxide) (PPO) in acetone at -30{degrees}C gave about 10% insoluble PPO shown to be isotatic bymore » {sup 13}C-NMR. The soluble, largely atactic fraction contained irregular head-to-head (h,h) and tail-to-tail (t,t) structures. In the absence of coinitiator zinc chloride the PPO product was completely soluble at -30{degrees}C and contained a greater proportion of irregular h,h and t,t structures. The {sup 13}C-NMR peak assignments were made for the methine and methylene carbon sin the irregular h,h and t,t linkages in PPO by the use of DEPT (Distortionless Enhancement by Polarization Transfer) experiment. An attempt was made to fit the stereoselective behavior of this initator systems to a kinetic scheme. It was found that the system follows a second order monomer consumption. An initiator prepared by the reaction of aluminum hydride and N-methyl-1-ephedrine in a 1:3 molar ratio as also used for the polymerization of PO to check its stereoselective potential. This initiator system was found to be poor and its efficiency was not improved very much even by the use of zinch chloride as a coiniator. However, this initator preferentially elected the S-enantiomer from the racemic PO as opposed to the preferential electron of R-enantiomer by the initiator derived from DMBD.« less

The effects of training with loads that maximise power output and individualised repetitions vs. traditional power training

PubMed Central

Moya-Ramón, M.; Hernández-Davó, J. L.; Fernandez-Fernandez, J.; Sabido, R.

2017-01-01

Background It has been suggested that strength training effects (i.e. neural or structural) vary, depending on the total repetitions performed and velocity loss in each training set. Purpose The aim of this study is to compare the effects of two training programmes (i.e. one with loads that maximise power output and individualised repetitions, and the other following traditional power training). Methods Twenty-five males were divided into three groups (optimum power [OP = 10], traditional training [TT = 9] and control group [CG = 6]). The training load used for OP was individualised using loads that maximised power output (41.7% ± 5.8 of one repetition maximum [1RM]) and repetitions at maximum power (4 to 9 repetitions, or ‘reps’). Volume (sets x repetitions) was the same for both experimental groups, while intensity for TT was that needed to perform only 50% of the maximum number of possible repetitions (i.e. 61.1%–66.6% of 1RM). The training programme ran over 11 weeks (2 sessions per week; 4–5 sets per session; 3-minute rests between sets), with pre-, intermediate and post-tests which included: anthropometry, 1RM, peak power output (PPO) with 30%, 40% and 50% of 1RM in the bench press throw, and salivary testosterone (ST) and cortisol (SC) concentrations. Rate of perceived exertion (RPE) and power output were recorded in all sessions. Results Following the intermediate test, PPO was increased in the OP group for each load (10.9%–13.2%). Following the post-test, both experimental groups had increased 1RM (11.8%–13.8%) and PPO for each load (14.1%–19.6%). Significant decreases in PPO were found for the TT group during all sets (4.9%–15.4%), along with significantly higher RPE (37%). Conclusion OP appears to be a more efficient method of training, with less neuromuscular fatigue and lower RPE. PMID:29053725

Combined effect of ultrasound, heat, and pressure on Escherichia coli O157:H7, polyphenol oxidase activity, and anthocyanins in blueberry (Vaccinium corymbosum) juice.

PubMed

Zhu, Jinyan; Wang, Yuehua; Li, Xinghe; Li, Bin; Liu, Suwen; Chang, Nan; Jie, Ding; Ning, Chong; Gao, Haiyan; Meng, Xianjun

2017-07-01

The objective of this study was to evaluate the effect of different treatments-heat treatment (HT), sonication (SC), thermosonication (TS), manosonication (MS), manothermal (MT), and manothermosonication (MTS) on Escherichia coli O157:H7, polyphenol oxidase (PPO), and anthocyanin content in blueberry juice. First, samples were treated at different temperatures (30, 40, 50, 60, 70, and 80°C) and power intensities (280, 420, 560, and 700W) for 10min. Subsequently, samples were treated using combinations of power intensity and mild temperature for 10min. For further study, samples were treated using HT (80°C), TS (40°C, 560W), MT (350MPa, 40°C), MS (560W, 5min/350MPa), or MTS (560W, 5min, 40°C/350MPa, 40°C) for 5, 10, 15, 20min for each treatment, and the results compared between treatments. HT significantly reduced PPO activation (2.05% residual activity after only 5min), and resulted in a 2.00-log reduction in E. coli O157:H7 and an 85.25% retention of anthocyanin. Escherichia coli O157:H7 was slightly inactivated by TS after 5min (0.17-log reduction), while residual PPO activity was 23.36% and anthocyanin retention was 98.48%. However, Escherichia coli O157:H7 was rapidly inactivated by MTS (5.85-log reduction) after 5min, while anthocyanin retention was 97.49% and residual PPO activity dropped to 10.91%. The destruction of E. coli cells as a result of these treatments were confirmed using SEM and TEM. Therefore, a combination of sonication, high pressure, and mild heat allows the safety of blueberry juice to be maintained without compromising the retention of desirable antioxidant compounds. Copyright © 2017 Elsevier B.V. All rights reserved.

Adsorption isotope effects of water on mesoporous silica and alumina with implications for the land-vegetation-atmosphere system

NASA Astrophysics Data System (ADS)

Lin, Ying; Horita, Juske; Abe, Osamu

2018-02-01

Soil water dynamics within a vadose (unsaturated) zone is a key component in the hydrologic cycle, especially in arid regions. In applying the Craig-Gordon evaporation model to obtain isotopic compositions of soil water and the evaporated vapor in land-surface models (LSMs), it has been assumed that the equilibrium isotope fractionation factors between soil water and water vapor, α(2H) and α(18O), are identical to those between liquid and vapor of bulk water. Isotope effects in water condensation arise from intermolecular hydrogen bonding in the condensed phase and the appearance of hindered rotation/translation. Hydrogen bonding between water molecules and pore surface hydroxyl groups influences adsorption isotope effects. To test whether equilibrium fractionation factors between soil water and water vapor are identical to those between liquid and vapor of bulk water and to evaluate the influence of pore size and chemical composition upon adsorption isotope effects, we extended our previous experiments of a mesoporous silica (15 nm) to two other mesoporous materials, a silica (6 nm) and an alumina (5.8 nm). Our results demonstrated that α(2H) and α(18O) between adsorbed water and water vapor are 1.057 and 1.0086 for silica (6 nm) and 1.041 and 1.0063 for alumina (5.8 nm), respectively, at saturation pressure (po), which are smaller than 1.075 and 1.0089, respectively, between liquid and vapor phases of free water at 30 °C and that the differences exaggerate at low water contents. However, the profiles of α values with relative pressures (p/po) for these three materials differ due to the differences in chemical compositions and pore sizes. Empirical formula relating α(2H) and α(18O) values to the proportions of filled pores (f) are developed for potential applications to natural soils. Our results from triple oxygen isotope analyses demonstrated that the isotope fractionation does not follow a canonical law. For the silica (15 nm), fractionation exponents (17θ) are 0.5361 ± 0.0018 and 0.5389 ± 0.0016 at p/po = 0.72 and 0.77, respectively. For the silica (6 nm), 17θ values are 0.5330 ± 0.0011 at p/po = 0.65 and 0.5278 ± 0.0010 at p/po = 0.81. For the alumina (5.8 nm), 17θ value is 0.5316 ± 0.0015 at p/po = 0.78. These values are greater than or equal to that of liquid-vapor equilibrium of bulk water (0.529 ± 0.001).

The Differentiated Effectiveness of a Printed versus a Web-Based Tailored Physical Activity Intervention among Adults Aged over 50

ERIC Educational Resources Information Center

Peels, D. A.; van Stralen, M. M.; Bolman, C.; Golsteijn, R. H. J.; de Vries, H.; Mudde, A. N.; Lechner, L.

2014-01-01

This study provides insight in the effectiveness of a print-delivered and a Web-based physical activity (PA) intervention (with or without additional environmental information on local PA possibilities) among people aged over 50. Intervention groups (print-delivered basic [PB; n = 439], print-delivered environmental [PE; n = 435], Web-based basic…

Luminescent and scintillation properties of composites based on sol-gel SiO2 matrices and organic scintillators

NASA Astrophysics Data System (ADS)

Vyagin, O. G.; Bespalova, I. I.; Masalov, A. A.; Zelenskaya, O. V.; Tarasov, V. A.; Malyukin, Yu. V.

2014-11-01

Luminescent composites based on SiO2 matrices synthesized using the sol-gel method and organic scintillators PPO and o-POPOP are produced, and their optical, luminescent, and scintillation characteristics are studied. It is shown that these composites generate an intense photoluminescence signal, possess a nanosecond decay time, and have a transparency in the range of 400-700 nm of no less than 70%. The absolute light output during excitation by α radiation with an energy of 5.46 MeV is 4400-5100 photon/MeV, and the amplitude resolution is 27-32%.

A comparison of web-based versus print-based decision AIDS for prostate cancer screening: participants' evaluation and utilization.

PubMed

Tomko, Catherine; Davis, Kimberly M; Luta, George; Krist, Alexander H; Woolf, Steven H; Taylor, Kathryn L

2015-01-01

Patient decision aids facilitate informed decision making for medical tests and procedures that have uncertain benefits. To describe participants' evaluation and utilization of print-based and web-based prostate cancer screening decision aids that were found to improve decisional outcomes in a prior randomized controlled trial. Men completed brief telephone interviews at baseline, one month, and 13 months post-randomization. Participants were primary care patients, 45-70 years old, who received the print-based (N = 628) or web-based decision aid (N = 625) and completed the follow-up assessments. We assessed men's baseline preference for web-based or print-based materials, time spent using the decision aids, comprehension of the overall message, and ratings of the content. Decision aid use was self-reported by 64.3 % (web) and 81.8 % (print) of participants. Significant predictors of decision aid use were race (white vs. non-white, OR = 2.43, 95 % CI: 1.77, 3.35), higher education (OR = 1.68, 95 % CI: 1.06, 2.70) and trial arm (print vs. web, OR = 2.78, 95 % CI: 2.03, 3.83). Multivariable analyses indicated that web-arm participants were more likely to use the website when they preferred web-based materials (OR: 1.91, CI: 1.17, 3.12), whereas use of the print materials was not significantly impacted by a preference for print-based materials (OR: 0.69, CI: 0.38, 1.25). Comprehension of the decision aid message (i.e., screening is an individual decision) did not significantly differ between arms in adjusted analyses (print: 61.9 % and web: 68.2 %, p = 0.42). Decision aid use was independently influenced by race, education, and the decision aid medium, findings consistent with the 'digital divide.' These results suggest that when it is not possible to provide this age cohort with their preferred decision aid medium, print materials will be more highly used than web-based materials. Although there are many advantages to web-based decision aids, providing an option for print-based decision aids should be considered.

3D Printing of Carbon Nanotubes-Based Microsupercapacitors.

PubMed

Yu, Wei; Zhou, Han; Li, Ben Q; Ding, Shujiang

2017-02-08

A novel 3D printing procedure is presented for fabricating carbon-nanotubes (CNTs)-based microsupercapacitors. The 3D printer uses a CNTs ink slurry with a moderate solid content and prints a stream of continuous droplets. Appropriate control of a heated base is applied to facilitate the solvent removal and adhesion between printed layers and to improve the structure integrity without structure delamination or distortion upon drying. The 3D-printed electrodes for microsupercapacitors are characterized by SEM, laser scanning confocal microscope, and step profiler. Effect of process parameters on 3D printing is also studied. The final solid-state microsupercapacitors are assembled with the printed multilayer CNTs structures and poly(vinyl alcohol)-H 3 PO 4 gel as the interdigitated microelectrodes and electrolyte. The electrochemical performance of 3D printed microsupercapacitors is also tested, showing a significant areal capacitance and excellent cycle stability.

Photocopy of print (original sepia print is backward and in ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Photocopy of print (original sepia print is backward and in possession of MacDill Air Force Base, Civil Engineering, Tampa, Florida; 1953 architectural drawings by Horowick & Lee, Architects, Jacksonville, Florida) EXTERIOR ELEVATIONS - MacDill Air Force Base, Photography Laboratory, 2617 Florida Keys Avenue, Tampa, Hillsborough County, FL

Photocopy of print (original sepia print is backward and in ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Photocopy of print (original sepia print is backward and in possession of MacDill Air Force Base, Civil Engineering, Tampa, Florida; 1953 architectural drawings by Horowick & Lee, Architects, Jacksonville, Florida) FLOOR PLAN AND SCHEDULES - MacDill Air Force Base, Photography Laboratory, 2617 Florida Keys Avenue, Tampa, Hillsborough County, FL

A Web-Based and Print-Based Computer-Tailored Physical Activity Intervention for Prostate and Colorectal Cancer Survivors: A Comparison of User Characteristics and Intervention Use

PubMed Central

Bolman, Catherine; Peels, Denise Astrid; Volders, Esmee; de Vries, Hein; Lechner, Lilian

2017-01-01

Background Physical activity (PA) is beneficial in improving negative physical and psychological effects of cancer. The rapidly increasing number of cancer survivors, resulting from aging and improved cancer care, emphasizes the importance to develop and provide low cost, easy accessible PA programs. Such programs could be provided through the Internet, but that could result in the exclusion of cancer survivors not familiar with the Internet. Therefore, we developed a computer-tailored PA intervention for prostate and colorectal cancer survivors in which both Web-based and print materials are provided, and participants can choose their own preferred delivery mode. Objective The aim of this study was to assess participants’ characteristics related to delivery mode and use of intervention materials. Methods We studied characteristics of participants using Web-based and printed intervention materials in a randomized controlled trial (RCT). Prostate and colorectal cancer survivors recruited from hospitals were randomized to OncoActive (computer-tailored PA intervention) or a usual-care control group. OncoActive participants received both Web-based and printed materials. Participants were classified into initial print- or Web-based participants based on their preferred mode of completion of the first questionnaire, which was needed for the computer-tailored PA advice. Intervention material use during the remainder of the intervention was compared for initial print- or Web-based participants. Additionally, participants were classified into those using only print materials and those using Web-based materials. Differences in participant characteristics and intervention material use were studied through analysis of variance (ANOVAs), chi-square tests, and logistic regressions. Results The majority of the participants in the intervention group were classified as initial Web-based participants (170/249, 68.3%), and 84.9% (191/249) used Web-based intervention materials. Dropout was low (15/249, 6.0%) and differed between initial Web-based (4/170, 2.4%) and print-based (11/79, 14%) participants. Participants were less likely to start Web-based with higher age (odds ratio [OR]=0.93), longer time since last treatment (OR=0.87), and higher fatigue (OR=0.96), and more likely with higher education (OR=4.08) and having completed treatments (OR=5.58). Those who were older (OR=0.93) and post treatment for a longer time (OR=0.86) were less likely to use Web-based intervention materials. Initial print-based participants predominantly used print-based materials, whereas initial Web-based participants used both print- and Web-based materials. Conclusions To our knowledge, this is one of the first studies that assessed participant characteristics related to delivery mode in an intervention in which participants had a free choice of delivery modes. Use of print-based materials among the initial Web-based participants was substantial, indicating the importance of print-based materials. According to our findings, it may be important to offer Web- and print-based materials alongside each other. Providing Web-based materials only may exclude older, less educated, more fatigued, or currently treated participants; these groups are especially more vulnerable and could benefit most from PA interventions. PMID:28835353

Service quality assessment of workers compensation health care delivery programs in New York using SERVQUAL.

PubMed

Arunasalam, Mark; Paulson, Albert; Wallace, William

2003-01-01

Preferred provider organizations (PPOs) provide healthcare services to an expanding proportion of the U.S. population. This paper presents a programmatic assessment of service quality in the workers' compensation environment using two different models: the PPO program model and the fee-for-service (FFS) payor model. The methodology used here will augment currently available research in workers' compensation, which has been lacking in measuring service quality determinants and assessing programmatic success/failure of managed care type programs. Results indicated that the SERVQUAL tool provided a reliable and valid clinical quality assessment tool that ascertained that PPO marketers should focus on promoting physician outreach (to show empathy) and accessibility (to show reliability) for injured workers.

Printed organo-functionalized graphene for biosensing applications.

PubMed

Wisitsoraat, A; Mensing, J Ph; Karuwan, C; Sriprachuabwong, C; Jaruwongrungsee, K; Phokharatkul, D; Daniels, T M; Liewhiran, C; Tuantranont, A

2017-01-15

Graphene is a highly promising material for biosensors due to its excellent physical and chemical properties which facilitate electron transfer between the active locales of enzymes or other biomaterials and a transducer surface. Printing technology has recently emerged as a low-cost and practical method for fabrication of flexible and disposable electronics devices. The combination of these technologies is promising for the production and commercialization of low cost sensors. In this review, recent developments in organo-functionalized graphene and printed biosensor technologies are comprehensively covered. Firstly, various methods for printing graphene-based fluids on different substrates are discussed. Secondly, different graphene-based ink materials and preparation methods are described. Lastly, biosensing performances of printed or printable graphene-based electrochemical and field effect transistor sensors for some important analytes are elaborated. The reported printed graphene based sensors exhibit promising properties with good reliability suitable for commercial applications. Among most reports, only a few printed graphene-based biosensors including screen-printed oxidase-functionalized graphene biosensor have been demonstrated. The technology is still at early stage but rapidly growing and will earn great attention in the near future due to increasing demand of low-cost and disposable biosensors. Copyright © 2016 Elsevier B.V. All rights reserved.

Accelerating preschoolers' early literacy development through classroom-based teacher-child storybook reading and explicit print referencing.

PubMed

Justice, Laura M; Kaderavek, Joan N; Fan, Xitao; Sofka, Amy; Hunt, Aileen

2009-01-01

This study examined the impact of teacher use of a print referencing style during classroom-based storybook reading sessions conducted over an academic year. Impacts on preschoolers' early literacy development were examined, focusing specifically on the domain of print knowledge. This randomized, controlled trial examined the effects of a print referencing style on 106 preschool children attending 23 classrooms serving disadvantaged preschoolers. Following random assignment, teachers in 14 classrooms used a print referencing style during 120 large-group storybook reading sessions during a 30-week period. Teachers in 9 comparison classrooms read at the same frequency and with the same storybooks but used their normal style of reading. Children whose teachers used a print referencing style showed larger gains on 3 standardized measures of print knowledge: print concept knowledge, alphabet knowledge, and name writing, with medium-sized effects. The convergence of the present findings with those of previous efficacy studies indicates that print referencing intervention can be used confidently as an approach for facilitating print knowledge in preschool-age children. Speech-language pathologists can serve an important role in supporting preschool educators as they use this evidence-based technique with pupils in their classrooms.

A Web-Based and Print-Based Computer-Tailored Physical Activity Intervention for Prostate and Colorectal Cancer Survivors: A Comparison of User Characteristics and Intervention Use.

PubMed

Golsteijn, Rianne Henrica Johanna; Bolman, Catherine; Peels, Denise Astrid; Volders, Esmee; de Vries, Hein; Lechner, Lilian

2017-08-23

Physical activity (PA) is beneficial in improving negative physical and psychological effects of cancer. The rapidly increasing number of cancer survivors, resulting from aging and improved cancer care, emphasizes the importance to develop and provide low cost, easy accessible PA programs. Such programs could be provided through the Internet, but that could result in the exclusion of cancer survivors not familiar with the Internet. Therefore, we developed a computer-tailored PA intervention for prostate and colorectal cancer survivors in which both Web-based and print materials are provided, and participants can choose their own preferred delivery mode. The aim of this study was to assess participants' characteristics related to delivery mode and use of intervention materials. We studied characteristics of participants using Web-based and printed intervention materials in a randomized controlled trial (RCT). Prostate and colorectal cancer survivors recruited from hospitals were randomized to OncoActive (computer-tailored PA intervention) or a usual-care control group. OncoActive participants received both Web-based and printed materials. Participants were classified into initial print- or Web-based participants based on their preferred mode of completion of the first questionnaire, which was needed for the computer-tailored PA advice. Intervention material use during the remainder of the intervention was compared for initial print- or Web-based participants. Additionally, participants were classified into those using only print materials and those using Web-based materials. Differences in participant characteristics and intervention material use were studied through analysis of variance (ANOVAs), chi-square tests, and logistic regressions. The majority of the participants in the intervention group were classified as initial Web-based participants (170/249, 68.3%), and 84.9% (191/249) used Web-based intervention materials. Dropout was low (15/249, 6.0%) and differed between initial Web-based (4/170, 2.4%) and print-based (11/79, 14%) participants. Participants were less likely to start Web-based with higher age (odds ratio [OR]=0.93), longer time since last treatment (OR=0.87), and higher fatigue (OR=0.96), and more likely with higher education (OR=4.08) and having completed treatments (OR=5.58). Those who were older (OR=0.93) and post treatment for a longer time (OR=0.86) were less likely to use Web-based intervention materials. Initial print-based participants predominantly used print-based materials, whereas initial Web-based participants used both print- and Web-based materials. To our knowledge, this is one of the first studies that assessed participant characteristics related to delivery mode in an intervention in which participants had a free choice of delivery modes. Use of print-based materials among the initial Web-based participants was substantial, indicating the importance of print-based materials. According to our findings, it may be important to offer Web- and print-based materials alongside each other. Providing Web-based materials only may exclude older, less educated, more fatigued, or currently treated participants; these groups are especially more vulnerable and could benefit most from PA interventions. ©Rianne Henrica Johanna Golsteijn, Catherine Bolman, Denise Astrid Peels, Esmee Volders, Hein de Vries, Lilian Lechner. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 23.08.2017.

Study on the Characteristics of a Scintillator for Beta-ray Detection using Epoxy Resin

NASA Astrophysics Data System (ADS)

Nam, Jong Soo; Choi, Yong Seok; Hong, Sang Bum; Seo, Bum Kyung; Moon, Jei Kwon; Choi, Jong Won

2017-09-01

A thin plate of a plastic scintillator for detecting a beta-ray was developed. The plastic scintillator was made using epoxy resin and organic scintillators such as 2.5-diphenyloxazole (PPO) and 1,4-bis [5-phenyl-2-oxazole] benzene (POPOP). The mixture ratio of epoxy resin and the organic scintillators was determined using their absorbance, transmittance, emission spectra, and transparency. Their optimal weight percentage of PPO and POPOP in the organic scintillators was adjusted to 0.2 wt%:0.01 wt%. The prepared plastic scintillator was used to measure the standard source of Sr-90. The pulse height spectra and total counts of the prepared plastic scintillator were similar to a commercial plastic scintillator. Based on the above results, a large-area plastic scintillator was prepared for rapid investigation of a site contaminated with Sr-90. The prepared large-area plastic scintillator was evaluated for the characteristics in the laboratory. The evaluation results are expected to be usefully utilized in the development of a large-area plastic scintillation detector. The large-area plastic scintillation detector developed on the basis of the evaluation results is expected to be utilized to quickly measure the contamination of Sr-90 in the grounds used as a nuclear power facility.

Stress responses of duckweed (Lemna minor L.) and water velvet (Azolla filiculoides Lam.) to anionic surfactant sodium-dodecyl-sulphate (SDS).

PubMed

Forni, C; Braglia, R; Harren, F J M; Cristescu, S M

2012-04-01

Surfactants are used for several purposes and recently they have attracted the attention for their ability to modify the behavior of other preexistent or co-disposed contaminants, although their use or discharge in wastewaters can represent a real or potential risk for the environment. Lemna minor L. and Azolla filiculoides Lam. are floating aquatic macrophytes, very effective in accumulating several pollutants including sodium dodecyl sulphate (SDS). In this work we evaluated the effects of SDS on these species by determining the stress ethylene production via laser-based trace gas detection, and the activities of enzymes involved in stress response, such as guaiacol peroxidase (G-POD), phenylalanine ammonia-lyase (PAL) and polyphenol-oxidase (PPO). Phenolics content was also determined. The macrophytes were treated with different concentrations of SDS for one week. SDS affected duckweed enzymatic activities and phenol content. While in the fern phenolics amount, PAL, G-POD and PPO activities were not affected by SDS except for 100 ppm SDS, the only concentration that was taken up and not completely degraded. Stress ethylene production was induced only in the fern treated with 50 and 100 ppm SDS. Copyright © 2011 Elsevier B.V. All rights reserved.

Comparative evaluation of oxidative enzyme activities during adventitious rooting in the cuttings of grapevine rootstocks.

PubMed

Kose, Cafer; Erdal, Serkan; Kaya, Ozkan; Atici, Okkeş

2011-03-15

This study investigated changes in peroxidase (POX) and polyphenol oxidase (PPO) activities through adventitious rooting in hardwood cuttings of grapevine rootstocks. Three grapevine rootstocks with different propensity to produce adventitious roots were selected: recalcitrant (Ramsey), non-recalcitrant (Rupestris du Lot) and intermediate (99R) cultivars. The averages of root number at 65 days were 96 in Lot, 76 in 99R and 30 in Ramsey. Both enzyme activities characteristically increased before adventitious rooting, regardless of rooting ability of the rootstocks, and then decreased. POX activity increased in Ramsey cuttings at 22 days, in Lot and 99R cuttings at 14 days after planting, and then decreased gradually until 51 days. The highest POX activity was determined in Ramsey rootstock with the highest rooting ability and the lowest activity was determined in the rootstocks with the lowest rooting ability. PPO activity gradually increased in Ramsey rootstock cuttings from 10 days to 22 days, in Lot and 99R cuttings at 14 days, and then decreased until 51 days. A significant correlation was identified between high POX activity and adventitious rooting capability in rootstocks, but the same result was not determined with PPO activity. A recalcitrant rooting variety cannot increase POX activity sufficiently before rooting. Therefore applications that could increase POX activity in stem cuttings during rooting may facilitate increased rooting in such rootstocks. Copyright © 2011 Society of Chemical Industry.

Spirometry: predicting risk and outcome.

PubMed

Brunelli, Alessandro; Rocco, Gaetano

2008-02-01

Predicted postoperative FEV1 is certainly the most widely used parameter in preoperative risk stratification [54] and the measure recommend by BTS and ACCP functional guidelines as a first step in the screening of patients for lung resection surgery. Nevertheless, recent evidences have demonstrated that ppoFEV1 is not a reliable predictor of postoperative cardiopulmonary complications in patients with preoperative impaired pulmonary function. This may be because of the fact that the resection of a portion of lung in patients with obstructive disease determines only a minimal loss, or even an improvement, in overall respiratory function and exercise tolerance. This lung volume reduction effect takes place very early, since the first postoperative days, balancing what ever negative physiologic effects a thoracotomy and lung resection may entail. In addition to its poor predictive role in COPD patients, ppoFEV1 largely underestimate the actual loss in the very first days after operation, when most of the complications develop. The rationale to use a parameter which is poorly correlated with the pulmonary function at the moment the complications occur seems unwarranted. At the very best, ppoFEV1 appears a weak surrogate of the immediate postoperative FEV1. The FEV1 measured on the first postoperative day may be 30% less than predicted. Corrective equations have been published to correct this discrepancy with the aim to improve risk stratification.

Self-assembly behavior of pH- and thermosensitive amphiphilic triblock copolymers in solution: experimental studies and self-consistent field theory simulations.

PubMed

Cai, Chunhua; Zhang, Liangshun; Lin, Jiaping; Wang, Liquan

2008-10-09

We investigated, both experimentally and theoretically, the self-assembly behaviors of pH- and thermosensitive poly(L-glutamic acid)- b-poly(propylene oxide)-b-poly(L-glutamic acid) (PLGA-b-PPO-b-PLGA) triblock copolymers in aqueous solution by means of transmission electron microscopy (TEM), scanning electron microscopy (SEM), dynamic light scattering (DLS), circular dichroism (CD), and self-consistent field theory (SCFT) simulations. Vesicles were observed when the hydrophilic PLGA block length is shorter or the pH value of solution is lower. The vesicles were found to transform to spherical micelles when the PLGA block length increases or its conformation changes from helix to coil with increasing the pH value. In addition, increasing temperature gives rise to a decrease in the size of aggregates, which is related to the dehydration of the PPO segments at higher temperatures. The SCFT simulation results show that the vesicles transform to the spherical micelles with increasing the fraction or statistical length of A block in model ABA triblock copolymer, which corresponds to the increase in the PLGA length or its conformation change from helix to coil in experiments, respectively. The SCFT calculations also provide chain distribution information in the aggregates. On the basis of both experimental and SCFT results, the mechanism of the structure change of the PLGA- b-PPO- b-PLGA aggregates was proposed.

Cascade synthesis of a gold nanoparticle-network polymer composite

DOE PAGES

Grubjesic, Simonida; Ringstrand, Bryan Scott; Jungjohann, Katherine L.; ...

2015-11-02

In this paper, the multi-step, cascade synthesis of a self-supporting, hierarchically-structured gold nanoparticle hydrogel composite is described. The composite is spontaneously prepared from a non-covalent, lamellar lyotropic mesophase composed of amphiphiles that support the reactive constituents, a mixture of hydroxyl- and acrylate-end-derivatized PEO 117-PPO 47-PEO 117 and [AuCl 4] -. The reaction sequence begins with the auto-reduction of aqueous [AuCl 4] - by PEO 117-PPO 47-PEO 117 which leads to both the production of Au NPs and the free radical initiated polymerization and crosslinking of the acrylate endderivatized PEO 117-PPO 47-PEO 117 to yield a network polymer. Optical spectroscopy andmore » TEM monitored the reduction of [AuCl 4] -, formation of large aggregated Au NPs and oxidative etching into a final state of dispersed, spherical Au NPs. ATR/FT-IR spectroscopy and thermal analysis confirms acrylate crosslinking to yield the polymer network. X-ray scattering (SAXS and WAXS) monitored the evolution of the multilamellar structured mesophase and revealed the presence of semi-crystalline PEO confined within the water layers. The hydrogel could be reversibly swollen without loss of the well-entrained Au NPs with full recovery of composite structure. Finally, optical spectroscopy shows a notable red shift (Δλ~ 45 nm) in the surface plasmon resonance between swollen and contracted states, demonstrating solvent-mediated modulation of the internal NP packing arrangement.« less

Does competition by health maintenance organizations affect the adoption of cost-containment measures by fee-for-service plans?

PubMed

Joesch, J M; Wickizer, T M; Feldstein, P J

1998-06-01

How groups insured by fee-for-service health plans react to increased competition from health maintenance organizations (HMOs) is an unresolved question. We investigated whether groups insured by indemnity plans respond to HMO market competition by changing selected health insurance features, such as deductible amounts, stop loss levels, and coinsurance rates, or by adopting utilization management or preferred provider organization (PPO) benefit options. We collected benefit design data for the years 1985 through 1992 from 95 insured groups in 62 US metropolitan statistical areas. Multivariate hazard analysis showed that groups located in markets with higher rates of change in HMO enrollment were less likely to increase deductibles or stop loss levels. Groups located in markets with higher HMO enrollment were more likely to adopt utilization management or PPO benefit options. A group located in a market with an HMO penetration rate of 20% was 65% more likely to have included a PPO option as part of its insurance benefit plan than a group located in a market with an HMO penetration rate of 15% (p < 0.05). Concern about possible adverse selection effects may deter some fee-for-service groups from changing their health insurance coverage. Under some conditions, however, groups insured under fee-for-service plans do respond to managed care competition by changing their insurance benefits to achieve greater cost containment.

Resistance to PPO‐inhibiting herbicide in Palmer amaranth from Arkansas

PubMed Central

Salas, Reiofeli A; Tranel, Patrick J; Singh, Shilpa; Glasgow, Les; Scott, Robert C; Nichols, Robert L

2016-01-01

Abstract BACKGROUND The widespread occurrence of ALS inhibitor‐ and glyphosate‐resistant Amaranthus palmeri has led to increasing use of protoporphyrinogen oxidase (PPO)‐inhibiting herbicides in cotton and soybean. Studies were conducted to confirm resistance to fomesafen (a PPO inhibitor), determine the resistance frequency, examine the resistance profile to other foliar‐applied herbicides and investigate the resistance mechanism of resistant plants in a population collected in 2011 (AR11‐LAW B) and its progenies from two cycles of fomesafen selection (C1 and C2). RESULTS The frequency of fomesafen‐resistant plants increased from 5% in the original AR11‐LAW‐B to 17% in the C2 population. The amounts of fomesafen that caused 50% growth reduction were 6‐, 13‐ and 21‐fold greater in AR11‐LAW‐B, C1 and C2 populations, respectively, than in the sensitive ecotype. The AR11‐LAW‐B population was sensitive to atrazine, dicamba, glufosinate, glyphosate and mesotrione but resistant to ALS‐inhibiting herbicides pyrithiobac and trifloxysulfuron. Fomesafen survivors from C1 and C2 populations tested positive for the PPO glycine 210 deletion previously reported in waterhemp (Amaranthus tuberculatus). CONCLUSION These studies confirmed that Palmer amaranth in Arkansas has evolved resistance to foliar‐applied PPO‐inhibiting herbicide. © 2016 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. PMID:26817647

Characterization of oxylipins and dioxygenase genes in the asexual fungus Aspergillus niger

PubMed Central

2009-01-01

Background Aspergillus niger is an ascomycetous fungus that is known to reproduce through asexual spores, only. Interestingly, recent genome analysis of A. niger has revealed the presence of a full complement of functional genes related to sexual reproduction [1]. An example of such genes are the dioxygenase genes which in Aspergillus nidulans, have been shown to be connected to oxylipin production and regulation of both sexual and asexual sporulation [2-4]. Nevertheless, the presence of sex related genes alone does not confirm sexual sporulation in A. niger. Results The current study shows experimentally that A. niger produces the oxylipins 8,11-dihydroxy octadecadienoic acid (8,11-diHOD), 5,8-dihydroxy octadecadienoic acid (5,8-diHOD), lactonized 5,8-diHOD, 8-hydroxy octadecadienoic acid (8-HOD), 10-hydroxy octadecadienoic acid (10-HOD), small amounts of 8-hydroxy octadecamonoenoic acid (8-HOM), 9-hydroxy octadecadienoic acid (9-HOD) and 13-hydroxy octadecadienoic acid (13-HOD). Importantly, this study shows that the A. niger genome contains three putative dioxygenase genes, ppoA, ppoC and ppoD. Expression analysis confirmed that all three genes are indeed expressed under the conditions tested. Conclusion A. niger produces the same oxylipins and has similar dioxygenase genes as A. nidulans. Their presence could point towards the existence of sexual reproduction in A. niger or a broader role for the gene products in physiology, than just sexual development. PMID:19309517

Effect of halide salts on development of surface browning on fresh-cut 'Granny Smith' (Malus × domestica Borkh) apple slices during storage at low temperature.

PubMed

Li, Yongxin; Wills, Ron B H; Golding, John B; Huque, Roksana

2015-03-30

The postharvest life of fresh-cut apple slices is limited by browning on cut surfaces. Dipping in halide salt solutions was examined for their inhibition of surface browning on 'Granny Smith' apple slices and the effects on biochemical factors associated with browning. Delay in browning by salts was greatest with chloride = phosphate > sulfate > nitrate with no difference between sodium, potassium and calcium ions. The effectiveness of sodium halides on browning was fluoride > chloride = bromide > iodide = control. Polyphenol oxidase (PPO) activity of tissue extracted from chloride- and fluoride-treated slices was not different to control but when added into the assay solution, NaF > NaCl both showed lower PPO activity at pH 3-5 compared to control buffer. The level of polyphenols in treated slices was NaF > NaCl > control. Addition of chlorogenic acid to slices enhanced browning but NaCl and NaF counteracted this effect. There was no effect of either halide salt on respiration, ethylene production, ion leakage, and antioxidant activity. Dipping apple slices in NaCl is a low cost treatment with few impediments to commercial use and could be a replacement for other anti-browning additives. The mode of action of NaCl and NaF is through decreasing PPO activity resulting in reduced oxidation of polyphenols. © 2014 Society of Chemical Industry.

Endurance Exercise in Hypoxia, Hyperoxia and Normoxia: Mitochondrial and Global Adaptations.

PubMed

Przyklenk, Axel; Gutmann, Boris; Schiffer, Thorsten; Hollmann, Wildor; Strueder, Heiko K; Bloch, Wilhelm; Mierau, Andreas; Gehlert, Sebastian

2017-07-01

We hypothesized short-term endurance exercise (EN) in hypoxia (HY) to exert decreased mitochondrial adaptation, peak oxygen consumption (VO 2peak ) and peak power output (PPO) compared to EN in normoxia (NOR) and hyperoxia (PER). 11 male subjects performed repeated unipedal cycling EN in HY, PER, and NOR over 4 weeks in a cross-over design. VO 2peak , PPO, rate of perceived exertion (RPE) and blood lactate (Bla) were determined pre- and post-intervention to assess physiological demands and adaptation. Skeletal muscle biopsies were collected to determine molecular mitochondrial signaling and adaptation. Despite reduced exercise intensity (P<0.05), increased Bla and RPE levels in HY revealed higher metabolic load compared to PER (P<0.05) and NOR (n.s.). PPO increased in all groups (P<0.05) while VO 2peak and mitochondrial signaling were unchanged (P>0.05). Electron transport chain complexes tended to increase in all groups with the highest increase in HY (n.s.). EN-induced mitochondrial adaptability and exercise capacity neither decreased significantly in HY nor increased in PER compared to NOR. Despite decreased exercise intensity, short term EN under HY may not necessarily impair mitochondrial adaptation and exercise capacity while PER does not augment adaptation. HY might strengthen adaptive responses under circumstances when absolute training intensity has to be reduced. © Georg Thieme Verlag KG Stuttgart · New York.

Characterization of the polyphenol oxidase gene family reveals a novel microRNA involved in posttranscriptional regulation of PPOs in Salvia miltiorrhiza

PubMed Central

Li, Caili; Li, Dongqiao; Li, Jiang; Shao, Fenjuan; Lu, Shanfa

2017-01-01

Salvia miltiorrhiza is a well-known material of traditional Chinese medicine. Understanding the regulatory mechanisms of phenolic acid biosynthesis and metabolism are important for S. miltiorrhiza quality improvement. We report here that S. miltiorrhiza contains 19 polyphenol oxidases (PPOs), forming the largest PPO gene family in plant species to our knowledge. Analysis of gene structures and sequence features revealed the conservation and divergence of SmPPOs. SmPPOs were differentially expressed in plant tissues and eight of them were predominantly expressed in phloem and xylem, indicating that some SmPPOs are functionally redundant, whereas the others are associated with different physiological processes. Expression patterns of eighteen SmPPOs were significantly altered under MeJA treatment, and twelve were yeast extract and Ag+-responsive, suggesting the majority of SmPPOs are stress-responsive. Analysis of high-throughput small RNA sequences and degradome data showed that miR1444-mediated regulation of PPOs existing in P. trichocarpa is absent from S. miltiorrhiza. Instead, a subset of SmPPOs was posttranscriptionally regulated by a novel miRNA, termed Smi-miR12112. It indicates the specificity and significance of miRNA-mediated regulation of PPOs. The results shed light on the regulation of SmPPO expression and suggest the complexity of SmPPO-associated phenolic acid biosynthesis and metabolism. PMID:28304398

Characterization of the polyphenol oxidase gene family reveals a novel microRNA involved in posttranscriptional regulation of PPOs in Salvia miltiorrhiza.

PubMed

Li, Caili; Li, Dongqiao; Li, Jiang; Shao, Fenjuan; Lu, Shanfa

2017-03-17

Salvia miltiorrhiza is a well-known material of traditional Chinese medicine. Understanding the regulatory mechanisms of phenolic acid biosynthesis and metabolism are important for S. miltiorrhiza quality improvement. We report here that S. miltiorrhiza contains 19 polyphenol oxidases (PPOs), forming the largest PPO gene family in plant species to our knowledge. Analysis of gene structures and sequence features revealed the conservation and divergence of SmPPOs. SmPPOs were differentially expressed in plant tissues and eight of them were predominantly expressed in phloem and xylem, indicating that some SmPPOs are functionally redundant, whereas the others are associated with different physiological processes. Expression patterns of eighteen SmPPOs were significantly altered under MeJA treatment, and twelve were yeast extract and Ag + -responsive, suggesting the majority of SmPPOs are stress-responsive. Analysis of high-throughput small RNA sequences and degradome data showed that miR1444-mediated regulation of PPOs existing in P. trichocarpa is absent from S. miltiorrhiza. Instead, a subset of SmPPOs was posttranscriptionally regulated by a novel miRNA, termed Smi-miR12112. It indicates the specificity and significance of miRNA-mediated regulation of PPOs. The results shed light on the regulation of SmPPO expression and suggest the complexity of SmPPO-associated phenolic acid biosynthesis and metabolism.

Electrohydrodynamic printing of silver nanowires for flexible and stretchable electronics.

PubMed

Cui, Zheng; Han, Yiwei; Huang, Qijin; Dong, Jingyan; Zhu, Yong

2018-04-19

A silver nanowire (AgNW) based conductor is a promising component for flexible and stretchable electronics. A wide range of flexible/stretchable devices using AgNW conductors has been demonstrated recently. High-resolution, high-throughput printing of AgNWs remains a critical challenge. Electrohydrodynamic (EHD) printing has been developed as a promising technique to print different materials on a variety of substrates with high resolution. Here, AgNW ink was developed for EHD printing. The printed features can be controlled by several parameters including AgNW concentration, ink viscosity, printing speed, stand-off distance, etc. With this method, AgNW patterns can be printed on a range of substrates, e.g. paper, polyethylene terephthalate (PET), glass, polydimethylsiloxane (PDMS), etc. First, AgNW samples on PDMS were characterized under bending and stretching. Then AgNW heaters and electrocardiogram (ECG) electrodes were fabricated to demonstrate the potential of this printing technique for AgNW-based flexible and stretchable devices.

Managed Care

MedlinePlus

... three types of managed care plans: Health Maintenance Organizations (HMO) usually only pay for care within the ... who coordinates most of your care. Preferred Provider Organizations (PPO) usually pay more if you get care ...

Adsorption in single-walled carbon nanotubes by experiments and molecular simulation II: Effect of morphology and temperature on organic adsorption

USGS Publications Warehouse

Agnihotri, S.; Rostam-Abadi, M.; Mota, J.P.B.; Rood, M.J.

2005-01-01

Hexane adsorption on single-walled carbon nanotube (SWNT) bundles was studied. Hexane adsorption capacities of two purified SWNT samples was gravimetrically determined at isothermal conditions of 25??, 37??, and 50??C for 10-4 < p/po < 0.9, where p/po is hexane vapor pressure relative to its saturation pressure. Simulation of hexane adsorption under similar temperature and pressure conditions were performed on the external and internal sites of nanotube bundles of diameters same as those in experimental samples. The simulations could predict isotherms for a hypothetical scenario where all nanotubes in a sample would be open. This is an abstract of a paper presented at the AIChE Annual Meeting and Fall Showcase (Cincinnati, OH 10/30/2005-11/4/2005).

Modified release from lipid bilayer coated mesoporous silica nanoparticles using PEO–PPO–PEO triblock copolymers [Modified release from lipid bilayer coated mesoporous silica nanoparticles using PEO PPO PEO triblock copolymers

DOE PAGES

Rahman, Masoud; Yu, Erick; Forman, Evan; ...

2014-08-20

Triblock copolymers comprised of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO, or trade name Pluronic) interact with lipid bilayers to increase their permeability. Here we demonstrate a novel application of Pluronic L61 and L64 as modification agents in tailoring the release rate of a molecular indicator species from 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) bilayer-coated superparamagnetic Fe 3O 4/mesoporous silica coreshell nanoparticles. Lastly, we show there is a direct relationship between Pluronic concentration and the indicator molecule release, suggesting Pluronic may be useful for the controlled release of drugs from lipid bilayer-coated carriers.

Polyphenol oxidase activity from three sicilian artichoke [ Cynara cardunculus L. Var. scolymus L. (Fiori)] cultivars: studies and technological application on minimally processed production.

PubMed

Todaro, Aldo; Peluso, Orazio; Catalano, Anna Eghle; Mauromicale, Giovanni; Spagna, Giovanni

2010-02-10

Several papers helped with the development of more methods to control browning, or study thermal polyphenol oxidase (PPO) inactivation, but did not provide any solutions to technological process problems and food process improvement. Artichokes [ Cynara cardunculus L. var. scolymus L. (Fiori)] are susceptible to browning; this alteration could affect and reduce the suitability for its use, fresh or processed. Within this study, the catecholase and cresolase activities of PPO from three different Sicilian artichokes cultivar were characterized with regard to substrate specificity and enzyme kinetics, optimum pH and temperature, temperature and pH stability, and inhibitor test; all of the results were used for technological purposes, particularly to optimize minimally processed productions (ready-to-eat and cook-chilled artichokes).

An alternative method to remove PEO-PPO-PEO template in organic-inorganic mesoporous nanocomposites by sulfuric acid extraction

NASA Astrophysics Data System (ADS)

Zhuang, Xin; Qian, Xufang; Lv, Jiahui; Wan, Ying

2010-06-01

Sulfuric acid is used as an extraction agent to remove PEO-PPO-PEO templates in the organic-inorganic mesoporous nanocomposites from the triconstituent co-assembly which includes the low-polymerized phenolic resins, TEOS and triblock copolymer F127. The XRD and TEM results show well ordered mesostructure after extraction with sulfuric acid. As followed from the N 2 sorption isotherms the extracted composites possess high surface areas (332-367 m 2/g), large pore volumes (0.66-0.78 cm 3/g), and large pore sizes (about 10.7 nm). The FT-IR analysis reveals almost complete elimination of triblock copolymer F127, and the maintenance of organic groups. This method shows potentials in removing templates from nanocomposites containing functional moieties.

Direct-write fabrication of 4D active shape-changing behavior based on a shape memory polymer and its nanocomposite (Conference Presentation)

NASA Astrophysics Data System (ADS)

Wei, Hongqiu; Zhang, Qiwei; Yao, Yongtao; Liu, Liwu; Liu, Yanju; Leng, Jinsong

2017-04-01

Shape memory polymers (SMPs), a typical class of smart materials, have been witnessed significant advances in the past decades. Based on the unique performance to recover the initial shape after going through a shape deformation, the applications of SMPs have aroused growing interests. However, most of the researches are hindered by traditional processing technologies which limit the design space of SMPs-based structures. Three-dimension (3D) printing as an emerging technology endows design freedom to manufacture materials with complex structures. In present article, we show that by employing direct-write printing method; one can realize the printing of SMPs to achieve 4D active shape-changing structures. We first fabricated a kind of 3D printable polylactide (PLA)-based SMPs and characterized the overall properties of such materials. Results demonstrated the prepared PLA-based SMPs presenting excellent shape memory effect. In what follows, the rheological properties of such PLA-based SMP ink during printing process were discussed in detail. Finally, we designed and printed several 3D configurations for investigation. By combining 3D printing with shape memory behavior, these printed structures achieve 4D active shape-changing performance under heat stimuli. This research presents a high flexible method to realize the fabrication of SMP-based 4D active shape-changing structures, which opens the way for further developments and improvements of high-tech fields like 4D printing, soft robotics, micro-systems and biomedical devices.

Oxygen quenching in a LAB based liquid scintillator and the nitrogen bubbling model

NASA Astrophysics Data System (ADS)

Xiao, Hua-Lin; Deng, Jing-Shan; Wang, Nai-Yan

2010-05-01

The oxygen quenching effect in a Linear Alkl Benzene (LAB) based liquid scintillator (LAB as the solvent, 3 g/L 2, 5 diphe-nyloxazole (PPO) as the fluor and 15 mg/L p-bis-(o-methylstyryl)-benzene (bis-MSB) as the λ-shifter) is studied by measuring the light yield as a function of the nitrogen bubbling time. It is shown that the light yield of the fully purged liquid scintillator is increased by 11% at room temperature and the room atmospheric pressure. A simple nitrogen bubbling model is proposed to describe the relationship between the relative light yield (oxygen quenching factor) and the bubbling time.

Effect of Layer Thickness and Printing Orientation on Mechanical Properties and Dimensional Accuracy of 3D Printed Porous Samples for Bone Tissue Engineering

PubMed Central

Farzadi, Arghavan; Solati-Hashjin, Mehran; Asadi-Eydivand, Mitra; Abu Osman, Noor Azuan

2014-01-01

Powder-based inkjet 3D printing method is one of the most attractive solid free form techniques. It involves a sequential layering process through which 3D porous scaffolds can be directly produced from computer-generated models. 3D printed products' quality are controlled by the optimal build parameters. In this study, Calcium Sulfate based powders were used for porous scaffolds fabrication. The printed scaffolds of 0.8 mm pore size, with different layer thickness and printing orientation, were subjected to the depowdering step. The effects of four layer thicknesses and printing orientations, (parallel to X, Y and Z), on the physical and mechanical properties of printed scaffolds were investigated. It was observed that the compressive strength, toughness and Young's modulus of samples with 0.1125 and 0.125 mm layer thickness were more than others. Furthermore, the results of SEM and μCT analyses showed that samples with 0.1125 mm layer thickness printed in X direction have more dimensional accuracy and significantly close to CAD software based designs with predefined pore size, porosity and pore interconnectivity. PMID:25233468

Plastic scintillators with efficient neutron/gamma pulse shape discrimination

NASA Astrophysics Data System (ADS)

Zaitseva, Natalia; Rupert, Benjamin L.; PaweŁczak, Iwona; Glenn, Andrew; Martinez, H. Paul; Carman, Leslie; Faust, Michelle; Cherepy, Nerine; Payne, Stephen

2012-03-01

A possibility of manufacturing plastic scintillators with efficient neutron/gamma pulse shape discrimination (PSD) is demonstrated using a system of a polyvinyltoluene (PVT) polymer matrix loaded with a scintillating dye, 2,5-diphenyloxazole (PPO). Similarities and differences of conditions leading to the rise of PSD in liquid and solid organic scintillators are discussed based on the classical model of excited state interaction and delayed light formation. First characterization results are presented to show that PSD in plastic scintillators can be of the similar magnitude or even higher than in standard commercial liquid scintillators.

Structural and congenital heart disease interventions: the role of three-dimensional printing.

PubMed

Meier, L M; Meineri, M; Qua Hiansen, J; Horlick, E M

2017-02-01

Advances in catheter-based interventions in structural and congenital heart disease have mandated an increased demand for three-dimensional (3D) visualisation of complex cardiac anatomy. Despite progress in 3D imaging modalities, the pre- and periprocedural visualisation of spatial anatomy is relegated to two-dimensional flat screen representations. 3D printing is an evolving technology based on the concept of additive manufacturing, where computerised digital surface renders are converted into physical models. Printed models replicate complex structures in tangible forms that cardiovascular physicians and surgeons can use for education, preprocedural planning and device testing. In this review we discuss the different steps of the 3D printing process, which include image acquisition, segmentation, printing methods and materials. We also examine the expanded applications of 3D printing in the catheter-based treatment of adult patients with structural and congenital heart disease while highlighting the current limitations of this technology in terms of segmentation, model accuracy and dynamic capabilities. Furthermore, we provide information on the resources needed to establish a hospital-based 3D printing laboratory.

Impact of Increasing Age on Cause-Specific Mortality and Morbidity in Patients With Stage I Non-Small-Cell Lung Cancer: A Competing Risks Analysis.

PubMed

Eguchi, Takashi; Bains, Sarina; Lee, Ming-Ching; Tan, Kay See; Hristov, Boris; Buitrago, Daniel H; Bains, Manjit S; Downey, Robert J; Huang, James; Isbell, James M; Park, Bernard J; Rusch, Valerie W; Jones, David R; Adusumilli, Prasad S

2017-01-20

Purpose To perform competing risks analysis and determine short- and long-term cancer- and noncancer-specific mortality and morbidity in patients who had undergone resection for stage I non-small-cell lung cancer (NSCLC). Patients and Methods Of 5,371 consecutive patients who had undergone curative-intent resection of primary lung cancer at our institution (2000 to 2011), 2,186 with pathologic stage I NSCLC were included in the analysis. All preoperative clinical variables known to affect outcomes were included in the analysis, specifically, Charlson comorbidity index, predicted postoperative (ppo) diffusing capacity of the lung for carbon monoxide, and ppo forced expiratory volume in 1 second. Cause-specific mortality analysis was performed with competing risks analysis. Results Of 2,186 patients, 1,532 (70.1%) were ≥ 65 years of age, including 638 (29.2%) ≥ 75 years of age. In patients < 65, 65 to 74, and ≥ 75 years of age, 5-year lung cancer-specific cumulative incidence of death (CID) was 7.5%, 10.7%, and 13.2%, respectively (overall, 10.4%); noncancer-specific CID was 1.8%, 4.9%, and 9.0%, respectively (overall, 5.3%). In patients ≥ 65 years of age, for up to 2.5 years after resection, noncancer-specific CID was higher than lung cancer-specific CID; the higher noncancer-specific, early-phase mortality was enhanced in patients ≥ 75 years of age than in those 65 to 74 years of age. Multivariable analysis showed that low ppo diffusing capacity of lung for carbon monoxide was an independent predictor of severe morbidity ( P < .001), 1-year mortality ( P < .001), and noncancer-specific mortality ( P < .001), whereas low ppo forced expiratory volume in 1 second was an independent predictor of lung cancer-specific mortality ( P = .002). Conclusion In patients who undergo curative-intent resection of stage I NSCLC, noncancer-specific mortality is a significant competing event, with an increasing impact as patient age increases.

A passive heat maintenance strategy implemented during a simulated half-time improves lower body power output and repeated sprint ability in professional Rugby Union players.

PubMed

Russell, Mark; West, Daniel J; Briggs, Marc A; Bracken, Richard M; Cook, Christian J; Giroud, Thibault; Gill, Nicholas; Kilduff, Liam P

2015-01-01

Reduced physical performance has been observed following the half-time period in team sports players, likely due to a decrease in muscle temperature during this period. We examined the effects of a passive heat maintenance strategy employed between successive exercise bouts on core temperature (Tcore) and subsequent exercise performance. Eighteen professional Rugby Union players completed this randomised and counter-balanced study. After a standardised warm-up (WU) and 15 min of rest, players completed a repeated sprint test (RSSA 1) and countermovement jumps (CMJ). Thereafter, in normal training attire (Control) or a survival jacket (Passive), players rested for a further 15 min (simulating a typical half-time) before performing a second RSSA (RSSA 2) and CMJ's. Measurements of Tcore were taken at baseline, post-WU, pre-RSSA 1, post-RSSA 1 and pre-RSSA 2. Peak power output (PPO) and repeated sprint ability was assessed before and after the simulated half-time. Similar Tcore responses were observed between conditions at baseline (Control: 37.06±0.05°C; Passive: 37.03±0.05°C) and for all other Tcore measurements taken before half-time. After the simulated half-time, the decline in Tcore was lower (-0.74±0.08% vs. -1.54±0.06%, p<0.001) and PPO was higher (5610±105 W vs. 5440±105 W, p<0.001) in the Passive versus Control condition. The decline in PPO over half-time was related to the decline in Tcore (r = 0.632, p = 0.005). In RSSA 2, best, mean and total sprint times were 1.39±0.17% (p<0.001), 0.55±0.06% (p<0.001) and 0.55±0.06% (p<0.001) faster for Passive versus Control. Passive heat maintenance reduced declines in Tcore that were observed during a simulated half-time period and improved subsequent PPO and repeated sprint ability in professional Rugby Union players.

A Water-Based Silver-Nanowire Screen-Print Ink for the Fabrication of Stretchable Conductors and Wearable Thin-Film Transistors.

PubMed

Liang, Jiajie; Tong, Kwing; Pei, Qibing

2016-07-01

A water-based silver-nanowire (AgNW) ink is formulated for screen printing. Screen-printed AgNW patterns have uniform sharp edges, ≈50 μm resolution, and electrical conductivity as high as 4.67 × 10(4) S cm(-1) . The screen-printed AgNW patterns are used to fabricate a stretchable composite conductor, and a fully printed and intrinsically stretchable thin-film transistor array is also realized. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

3D Printing Factors Important for the Fabrication of Polyvinylalcohol Filament-Based Tablets.

PubMed

Tagami, Tatsuaki; Fukushige, Kaori; Ogawa, Emi; Hayashi, Naomi; Ozeki, Tetsuya

2017-01-01

Three-dimensional (3D) printers have been applied in many fields, including engineering and the medical sciences. In the pharmaceutical field, approval of the first 3D-printed tablet by the U.S. Food and Drug Administration in 2015 has attracted interest in the manufacture of tablets and drugs by 3D printing techniques as a means of delivering tailor-made drugs in the future. In current study, polyvinylalcohol (PVA)-based tablets were prepared using a fused-deposition-modeling-type 3D printer and the effect of 3D printing conditions on tablet production was investigated. Curcumin, a model drug/fluorescent marker, was loaded into PVA-filament. We found that several printing parameters, such as the rate of extruding PVA (flow rate), can affect the formability of the resulting PVA-tablets. The 3D-printing temperature is controlled by heating the print nozzle and was shown to affect the color of the tablets and their curcumin content. PVA-based infilled tablets with different densities were prepared by changing the fill density as a printing parameter. Tablets with lower fill density floated in an aqueous solution and their curcumin content tended to dissolve faster. These findings will be useful in developing drug-loaded PVA-based 3D objects and other polymer-based articles prepared using fused-deposition-modeling-type 3D printers.

Highly Stretchable Fully-Printed CNT-Based Electrochemical Sensors and Biofuel Cells: Combining Intrinsic and Design-Induced Stretchability.

PubMed

Bandodkar, Amay J; Jeerapan, Itthipon; You, Jung-Min; Nuñez-Flores, Rogelio; Wang, Joseph

2016-01-13

We present the first example of an all-printed, inexpensive, highly stretchable CNT-based electrochemical sensor and biofuel cell array. The synergistic effect of utilizing specially tailored screen printable stretchable inks that combine the attractive electrical and mechanical properties of CNTs with the elastomeric properties of polyurethane as a binder along with a judiciously designed free-standing serpentine pattern enables the printed device to possess two degrees of stretchability. Owing to these synergistic design and nanomaterial-based ink effects, the device withstands extremely large levels of strains (up to 500% strain) with negligible effect on its structural integrity and performance. This represents the highest stretchability offered by a printed device reported to date. Extensive electrochemical characterization of the printed device reveal that repeated stretching, torsional twisting, and indenting stress has negligible impact on its electrochemical properties. The wide-range applicability of this platform to realize highly stretchable CNT-based electrochemical sensors and biofuel cells has been demonstrated by fabricating and characterizing potentiometric ammonium sensor, amperometric enzyme-based glucose sensor, enzymatic glucose biofuel cell, and self-powered biosensor. Highly stretchable printable multianalyte sensor, multifuel biofuel cell, or any combination thereof can thus be realized using the printed CNT array. Such combination of intrinsically stretchable printed nanomaterial-based electrodes and strain-enduring design patterns holds considerable promise for creating an attractive class of inexpensive multifunctional, highly stretchable printed devices that satisfy the requirements of diverse healthcare and energy fields wherein resilience toward extreme mechanical deformations is mandatory.

3D printing of optical materials: an investigation of the microscopic properties

NASA Astrophysics Data System (ADS)

Persano, Luana; Cardarelli, Francesco; Arinstein, Arkadii; Uttiya, Sureeporn; Zussman, Eyal; Pisignano, Dario; Camposeo, Andrea

2018-02-01

3D printing technologies are currently enabling the fabrication of objects with complex architectures and tailored properties. In such framework, the production of 3D optical structures, which are typically based on optical transparent matrices, optionally doped with active molecular compounds and nanoparticles, is still limited by the poor uniformity of the printed structures. Both bulk inhomogeneities and surface roughness of the printed structures can negatively affect the propagation of light in 3D printed optical components. Here we investigate photopolymerization-based printing processes by laser confocal microscopy. The experimental method we developed allows the printing process to be investigated in-situ, with microscale spatial resolution, and in real-time. The modelling of the photo-polymerization kinetics allows the different polymerization regimes to be investigated and the influence of process variables to be rationalized. In addition, the origin of the factors limiting light propagation in printed materials are rationalized, with the aim of envisaging effective experimental strategies to improve optical properties of printed materials.

Using Print in the Environment to Promote Early Writing

ERIC Educational Resources Information Center

Gerde, Hope K.; Goetsch, Megan E.; Bingham, Gary E.

2016-01-01

Print in the environment is typically posted in early childhood classrooms. However, the print that exists is often not meaningful to children, and teachers rarely engage children in using the print. This is a missed opportunity to support children's writing. This article presents research-based ideas for engaging children with meaningful print in…

Synthesis of plastic scintillation microspheres: Evaluation of scintillators

NASA Astrophysics Data System (ADS)

Santiago, L. M.; Bagán, H.; Tarancón, A.; Garcia, J. F.

2013-01-01

The use of plastic scintillation microspheres (PSm) appear to be an alternative to liquid scintillation for the quantification of alpha and beta emitters because it does not generate mixed wastes after the measurement (organic and radioactive). In addition to routine radionuclide determinations, PSm can be used for further applications, e.g. for usage in a continuous monitoring equipment, for measurements of samples with a high salt concentration and for an extractive scintillation support which permits the separation, pre-concentration and measurement of the radionuclides without additional steps of elution and sample preparation. However, only a few manufacturers provide PSm, and the low number of regular suppliers reduces its availability and restricts the compositions and sizes available. In this article, a synthesis method based on the extraction/evaporation methodology has been developed and successfully used for the synthesis of plastic scintillation microspheres. Seven different compositions of plastic scintillation microspheres have been synthesised; PSm1 with polystyrene, PSm2 with 2,5-Diphenyloxazol(PPO), PSm3 with p-terphenyl (pT), PSm4 with PPO and 1,4-bis(5-phenyloxazol-2-yl) (POPOP), PSm5 pT and (1,4-bis [2-methylstyryl] benzene) (Bis-MSB), PSm6 with PPO, POPOP and naphthalene and PSm7 with pT, Bis-MSB and naphthalene. The synthesised plastic scintillation microspheres have been characterised in terms of their morphology, detection capabilities and alpha/beta separation capacity. The microspheres had a median diameter of approximately 130 μm. Maximum detection efficiency values were obtained for the PSm4 composition as follows 1.18% for 3H, 51.2% for 14C, 180.6% for 90Sr/90Y and 76.7% for 241Am. Values of the SQP(E) parameter were approximately 790 for PSm4 and PSm5. These values show that the synthesised PSm exhibit good scintillation properties and that the spectra are at channel numbers higher than in commercial PSm. Finally, the addition of naphthalene modifies the shape of the pulses produced by alpha and beta particles leading to better alpha/beta separation.

Health Maintenance Organization (HMO) Plan

MedlinePlus

... Find & compare doctors, hospitals, & other providers Health Maintenance Organization (HMO) Plan In most HMO Plans, you generally ... certain service when needed. Related Resources Preferred Provider Organization (PPO) Private Fee-for-Service (PFFS) Special Needs ...

Printability of papers recycled from toner and inkjet-printed papers after deinking and recycling processes.

PubMed

Karademir, Arif; Aydemir, Cem; Tutak, Dogan; Aravamuthan, Raja

2018-04-01

In our contemporary world, while part of the fibers used in the paper industry is obtained from primary fibers such as wood and agricultural plants, the rest is obtained from secondary fibers from waste papers. To manufacture paper with high optical quality from fibers of recycled waste papers, these papers require deinking and bleaching of fibers at desired levels. High efficiency in removal of ink from paper mass during recycling, and hence deinkability, are especially crucial for the optical and printability quality of the ultimate manufactured paper. In the present study, deinkability and printability performance of digitally printed paper with toner or inkjet ink were compared for the postrecycling product. To that end, opaque 80 g/m 2 office paper was digitally printed under standard printing conditions with laser toner or inkjet ink; then these sheets of paper were deinked by a deinking process based on the INGEDE method 11 p. After the deinking operation, the optical properties of the obtained recycled handsheets were compared with unprinted (reference) paper. Then the recycled paper was printed on once again under the same conditions as before with inkjet and laser printers, to monitor and measure printing color change before and after recycling, and differences in color universe. Recycling and printing performances of water-based inkjet and toner-based laser printed paper were obtained. The outcomes for laser-printed recycled paper were better than those for inkjet-printed recycled paper. Compared for luminosity Y, brightness, CIE a* and CIE b* values, paper recycled from laser-printed paper exhibited higher value than paper recycled from inkjet-printed paper.

Progress in 3D Printing of Carbon Materials for Energy-Related Applications.

PubMed

Fu, Kun; Yao, Yonggang; Dai, Jiaqi; Hu, Liangbing

2017-03-01

The additive-manufacturing (AM) technique, known as three-dimensional (3D) printing, has attracted much attention in industry and academia in recent years. 3D printing has been developed for a variety of applications. Printable inks are the most important component for 3D printing, and are related to the materials, the printing method, and the structures of the final 3D-printed products. Carbon materials, due to their good chemical stability and versatile nanostructure, have been widely used in 3D printing for different applications. Good inks are mainly based on volatile solutions having carbon materials as fillers such as graphene oxide (GO), carbon nanotubes (CNT), carbon blacks, and solvent, as well as polymers and other additives. Studies of carbon materials in 3D printing, especially GO-based materials, have been extensively reported for energy-related applications. In these circumstances, understanding the very recent developments of 3D-printed carbon materials and their extended applications to address energy-related challenges and bring new concepts for material designs are becoming urgent and important. Here, recent developments in 3D printing of emerging devices for energy-related applications are reviewed, including energy-storage applications, electronic circuits, and thermal-energy applications at high temperature. To close, a conclusion and outlook are provided, pointing out future designs and developments of 3D-printing technology based on carbon materials for energy-related applications and beyond. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Taiwanese College Students' Reading Practices and Profiles in Both Print- and Internet-Based Formats

ERIC Educational Resources Information Center

Chen, Su-Yen; Fang, Sheng-Ping

2014-01-01

This study expanded the definition of reading practices to include both print- and Internet-based reading, and examined the relationship of reading profiles to Taiwanese college students' performance on various practices. The results showed that more time was spent on Internet-than print-based extracurricular reading, and that the three…

Powder-based 3D printing application for geomechanical testing

NASA Astrophysics Data System (ADS)

Williams, M.; Yoon, H.; Choens, R. C., II; Martinez, M. J.; Dewers, T. A.; Lee, M.

2017-12-01

3D printing of fractured and porous analog geomaterials has the potential to enhance hydrogeological and mechanical interpretations by generating engineered samples in testable configurations with reproducible microstructures and tunable surface and mechanical properties. For geoscience applications, 3D printing technology can be co-opted to print reproducible structures derived from CT-imaging of actual rocks and theoretical algorithms. In particular, the use of 3D printed samples allows us to overcome sample-to-sample heterogeneity that plague rock physics testing and to test material response independent from material variability. In this work, gypsum powder-based 3D printing was used to print cylindrical core samples and block samples with a pre-existing flaw geometry. All samples are printed in three different directions to evaluate the impact of printing direction on mechanical properties. For the cylindrical samples, unconfined compression testing has been performed. For compressive strength, the samples printed perpendicular to the loading direction show stronger than those printed parallel to the loading and at 45 degree. Micro-CT images of the printed samples reveal the uneven spreading of binder, resulting in soft inner core surrounded by stronger outer shell. In particular, the layered feature with binder causes the strong anisotropic properties. This was also confirmed by the wave velocity. For the small block samples ( 6.1cm wide, 10cm high, and 1.25cm thick) with an inclined flaw, uniaxial tests coupled with an array of acoustic emission sensors and digital image correlation revealed that cracks were developed at/near the tip of flaw as expected. Although acoustic events were detected, localization was not detectable mainly due to strong attenuation. Advantage and disadvantage of power-based 3D printing for mechanical testing will be discussed and a few attempts will be presented to improve the applicability of powder-based printing technique. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA0003525.

3D Printing of Biosamples: A Concise Review

NASA Astrophysics Data System (ADS)

Zhao, Victoria Xin Ting; Wong, Ten It; Zhou, Xiaodong

This paper reviews the recent development of 3D printing of biosamples, in terms of the 3D structure design, suitable printing technology, and available materials. Successfully printed 3D biosamples should possess the properties of high cell viability, vascularization and good biocompatibility. These goals are attained by printing the materials of hydrogels, polymers and cells, with a carefully selected 3D printer from the categories of inkjet printing, extrusion printing and laser printing, based on the uniqueness, advantages and disadvantages of these technologies. For recent developments, we introduce the 3D applications of creating scaffolds, printing cells for self-assembly and testing platforms. We foresee more bio-applications of 3D printing will be developed, with the advancements on materials and 3D printing machines.

77 FR 29341 - Protection of Stratospheric Ozone: Request for Methyl Bromide Critical Use Exemption Applications...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-17

...: Sulfuryl fluoride, propylene oxide (PPO), phosphine, and/or controlled atmosphere/temperature treatment... alternatives. Alternatives for which such information is needed include: Sulfuryl fluoride, micro-sanitation...

[Mechanism of effects of soil microbes on cuttings rooting of Huperzia serrata].

PubMed

Li, Na; Chen, Jun; Zhu, Da-Yuan

2007-12-01

To study the effects of soil microbes of habitats on the cuttings rooting of Huperzia serrata and its mechanism. The cuttings of H. serrata were planted on the primary habitat soil and on the soil autoclaved, rooting rates were examined respectively. Changes of contents of phenolic compounds (catechin, quercetin, chlorogenic acid, ferulic acid) and indoleacetic acid (IAA) , and changes of activities of polyphenoloxidase (PPO) and peroxydase (POD) during the cuttings rooting were determined. Soil microbes of primary habitat could increase the rooting rate and the number of roots, could increase contents of catechin, chlorogenic acid, ferulic acid and IAA during rooting, and could affect activities of PPO and POD. During the rooting higher contents of catechin, chlorogenic, ferulic acid and IAA caused by soil microbes of primary habitat are important factor for rooting rate.

One session of high-intensity interval training (HIIT) every 5 days, improves muscle power but not static balance in lifelong sedentary ageing men

PubMed Central

Sculthorpe, Nicholas F.; Herbert, Peter; Grace, Fergal

2017-01-01

Abstract Background: Declining muscle power during advancing age predicts falls and loss of independence. High-intensity interval training (HIIT) may improve muscle power, but remains largely unstudied in ageing participants. Methods: This randomized controlled trial (RCT) investigated the efficacy of a low-frequency HIIT (LfHIIT) intervention on peak muscle power (peak power output [PPO]), body composition, and balance in lifelong sedentary but otherwise healthy males. Methods: Thirty-three lifelong sedentary ageing men were randomly assigned to either intervention (INT; n = 22, age 62.3 ± 4.1 years) or control (n = 11, age 61.6 ± 5.0 years) who were both assessed at 3 distinct measurement points (phase A), after 6 weeks of conditioning exercise (phase B), and after 6 weeks of HIIT once every 5 days in INT (phase C), where control remained inactive throughout the study. Results: Static balance remained unaffected, and both absolute and relative PPO were not different between groups at phases A or B, but increased significantly in INT after LfHIIT (P < 0.01). Lean body mass displayed a significant interaction (P < 0.01) due to an increase in INT between phases B and C (P < 0.05). Conclusions: 6 weeks of LfHIIT exercise feasible and effective method to induce clinically relevant improvements in absolute and relative PPO, but does not improve static balance in sedentary ageing men. PMID:28178145

Induced resistance by oxidative shifts in pigeonpea (Cajanus cajan L.) following Helicoverpa armigera (Hübner) herbivory.

PubMed

Kaur, Rimaljeet; Gupta, Anil K; Taggar, Gaurav K

2015-05-01

Oxidative responses in leaves, developing seeds and the pod wall of nine pigeonpea genotypes were investigated against Helicoverpa armigera feeding. Out of nine genotypes, four were moderately resistant, three were intermediate and two were moderately susceptible genotypes. A significant shift in the oxidative status of pigeonpea following herbivory was depicted by the upregulation of diamine oxidase (DAO), polyamine oxidase (PAO) and lipoxygenase 2 (LOX 2) activities. Polyphenol oxidase (PPO) activity was significantly higher in the infested pod wall and leaves of moderately resistant genotypes than in those of moderately susceptible genotypes. H. armigera infestation markedly enhanced phenylalanine ammonia lyase (PAL) and tyrosine ammonia lyase (TAL) activities in wounded tissues. The decline in ascorbate peroxidase (APX) activity and ascorbate content was lower in moderately resistant genotypes than in moderately susceptible genotypes. A significant decrease in LOX 3 activity was also observed in the infested pod wall of moderately resistant and intermediate genotypes. A lower malondialdehyde (MDA) content and higher proline content of the infested pod wall and developing seeds was observed. Higher activities of PPO, PAL and proline content in leaves of uninfested moderately resistant genotypes could either be an unrelated observation or alternatively could help in identifying H. armigera-resistant genotypes. The increase in activities of PPO, DAO, PAO, PAL and TAL and higher proline and lower MDA content upon herbivory suggested their integrated contribution in providing resistance to pigeonpea against H. armigera. © 2014 Society of Chemical Industry.

Phenolics content, fruit flesh colour and browning in cultivated eggplant, wild relatives and interspecific hybrids and implications for fruit quality breeding.

PubMed

Kaushik, Prashant; Gramazio, Pietro; Vilanova, Santiago; Raigón, María D; Prohens, Jaime; Plazas, Mariola

2017-12-01

Increasing the content in bioactive phenolics in the eggplant (Solanum melongena) fruit is of interest, but may result in enhanced browning. We evaluated six varieties of S. melongena, 22 accessions of wild related species and 42 interspecific hybrids between cultivated eggplant and wild relatives for phenolics content, fruit flesh colour, polyphenol oxidase (PPO) activity, and fruit flesh browning. Wild relatives generally had a higher content in phenolics and a broader range of variation than cultivated eggplant. Chlorogenic acid was the predominant (>65.0%) phenolic acid in cultivated eggplant and its primary genepool wild ancestor S. insanum, while for the other wild species on average represented <50% of the chromatogram peak area. Fruit flesh colour was lighter in S. melongena than in the wild species, while PPO activity and browning was much higher in wild species of the secondary and tertiary genepools. Interspecific hybrids between S. melongena and S. insanum were intermediate in their characteristics, while those with secondary and tertiary genepool species were more similar to the wild species. No significant correlations were found between total phenolics or chlorogenic acid contents and fruit flesh browning, but PPO activity was correlated to both the degree of browning (r=0.404) and colour difference (r=0.458). The results indicate that wild species can contribute to improving the bioactive properties of eggplant without affecting negatively fruit flesh colour and browning. Copyright © 2017 Elsevier Ltd. All rights reserved.

A colored avocado seed extract as a potential natural colorant.

PubMed

Dabas, Deepti; Elias, Ryan J; Lambert, Joshua D; Ziegler, Gregory R

2011-01-01

There is an increasing consumer demand for and scientific interest in new natural colorants. Avocado (Persea americana) seed when crushed with water develops an orange color (= 480 nm) in a time-dependent manner. Heat treatment of the seed prevented color development, whereas the addition of exogenous polyphenol oxidase (PPO), but not peroxidase restored color development. Color development was also inhibited by the addition of tropolone, an inhibitor of PPO. Color formation resulted in a decrease in the concentration of polyphenols indicating utilization for color formation. The orange color intensified as the pH was adjusted from 2.0 to 11.0, and these changes were only partially reversible when pH was adjusted from 7.5 to 11.0 in the presence of oxygen, but completely reversible when the pH was changed in the absence of oxygen. The color was found to be stable in solution at -18 °C for 2 mo. These results suggest that the avocado seed may be a potential source of natural colorant, and that color development is PPO-dependent. There is growing public and scientific interest in the development of natural alternatives to synthetic colorants in foods. Extracts of turmeric, paprika, and beets are examples of food-derived natural colorants. Avocado seeds, which represent an under-utilized waste stream, form a stable orange color when crushed in the presence of air. Our data indicate that avocado seed represents a potential source of new natural colorants for use in foods. © 2011 Institute of Food Technologists®

One session of high-intensity interval training (HIIT) every 5 days, improves muscle power but not static balance in lifelong sedentary ageing men: A randomized controlled trial.

PubMed

Sculthorpe, Nicholas F; Herbert, Peter; Grace, Fergal

2017-02-01

Declining muscle power during advancing age predicts falls and loss of independence. High-intensity interval training (HIIT) may improve muscle power, but remains largely unstudied in ageing participants. This randomized controlled trial (RCT) investigated the efficacy of a low-frequency HIIT (LfHIIT) intervention on peak muscle power (peak power output [PPO]), body composition, and balance in lifelong sedentary but otherwise healthy males. Thirty-three lifelong sedentary ageing men were randomly assigned to either intervention (INT; n = 22, age 62.3 ± 4.1 years) or control (n = 11, age 61.6 ± 5.0 years) who were both assessed at 3 distinct measurement points (phase A), after 6 weeks of conditioning exercise (phase B), and after 6 weeks of HIIT once every 5 days in INT (phase C), where control remained inactive throughout the study. Static balance remained unaffected, and both absolute and relative PPO were not different between groups at phases A or B, but increased significantly in INT after LfHIIT (P < 0.01). Lean body mass displayed a significant interaction (P < 0.01) due to an increase in INT between phases B and C (P < 0.05). 6 weeks of LfHIIT exercise feasible and effective method to induce clinically relevant improvements in absolute and relative PPO, but does not improve static balance in sedentary ageing men.

Reducing inpatient heritable thrombophilia testing using a clinical decision-making tool.

PubMed

Smith, Tyler W; Pi, David; Hudoba, Monika; Lee, Agnes Y Y

2014-04-01

To evaluate the impact of a clinical decision-making tool, designed to educate physicians regarding heritable thrombophilia (HT) testing, on the volume of testing in hospitalised patients in the tertiary care setting. We performed a retrospective cohort study over a 6-year period (2007-2012) at a single tertiary care centre intervention site and two regional control sites. In January 2010, the intervention site instituted a policy change whereby physicians ordering HT testing on inpatients needed to complete a pre-preprinted order (PPO) form that outlined the limitations of HT testing in the hospitalised setting. Failure to complete the PPO within 24 h resulted in test cancellation. Our main outcome measure was the volume of HT testing performed at the three study sites. Introduction of the PPO resulted in a 79.4% (95% CI 71.2% to 87.6%) reduction in factor V Leiden (FVL) testing at the intervention site. This decrease was significantly greater compared with those in the two control teaching hospitals over the same time periods (33.7% and 43.6%; both p<0.001). Reductions in FVL testing postintervention were observed among all ordering specialists. Similar postintervention reductions in testing volumes were observed for antithrombin (57.4%), protein C (61.9%) and protein S (62.2%) activity assays. In a large tertiary care hospital, the introduction of a clinical decision-making tool significantly reduced HT testing in inpatients across clinical specialties. The impact on patient outcome should be assessed in further studies.

Automated Interior Lighting Design Software for Base Civil Engineers.

DTIC Science & Technology

1987-09-01

1085 OPEN "I". #1, "A:MAINTCAT.INF" 1090 FOR ^=I TO 6 1i95 FOR B=l TO ? 1100 INPUT#I, MCAT $,A,B) 1105 NEXT B 1110 NEXT A 1115 CLOSE #1 112: REM 125...34 5415(1 PRINT 54155 FOR A=I TO 6 541,0 PRINT TAB󈧏 A; TAB(27) ’,A+61; TAB(45) ICAT$(A,I); TABt63) MCAT $(A,2, 54165 NEXT A 54170 PRINT :PRINT :PRINT...54305 54195 REM 542ry’) CLS 54205 PRINT :FRINT 54210 PRINT TAB(28) "MAINTENANCE CATEGORY EXAMPLE" 54215 PRINT 54:26 PRINT TAB(35i *CATEGORY " MCAT $(B

Indirect X-ray Detectors Based on Inkjet-Printed Photodetectors with a Screen-Printed Scintillator Layer.

PubMed

Oliveira, Juliana; Correia, Vitor; Sowade, Enrico; Etxebarria, Ikerne; Rodriguez, Raul D; Mitra, Kalyan Y; Baumann, Reinhard R; Lanceros-Mendez, Senentxu

2018-04-18

Organic photodetectors (PDs) based on printing technologies will allow to expand the current field of PD applications toward large-area and flexible applications in areas such as medical imaging, security, and quality control, among others. Inkjet printing is a powerful digital tool for the deposition of smart and functional materials on various substrates, allowing the development of electronic devices such as PDs on various substrates. In this work, inkjet-printed PD arrays, based on the organic thin-film transistor architecture, have been developed and applied for the indirect detection of X-ray radiation using a scintillator ink as an X-ray absorber. The >90% increase of the photocurrent of the PDs under X-ray radiation, from about 53 nA without the scintillator film to about 102 nA with the scintillator located on top of the PD, proves the suitability of the developed printed device for X-ray detection applications.

High ink absorption performance of inkjet printing based on SiO2@Al13 core-shell composites

NASA Astrophysics Data System (ADS)

Chen, YiFan; Jiang, Bo; Liu, Li; Du, Yunzhe; Zhang, Tong; Zhao, LiWei; Huang, YuDong

2018-04-01

The increasing growth of the inkjet market makes the inkjet printing more necessary. A composite material based on core-shell structure has been developed and applied to prepare inkjet printing layer. In this contribution, the ink printing record layers based on SiO2@Al13 core-shell composite was elaborated. The prepared core-shell composite materials were characterized by X-ray photoelectron spectroscopy (XPS), zeta potential, X-ray diffraction (XRD), scanning electron microscopy (SEM). The results proved the presence of electrostatic adsorption between SiO2 molecules and Al13 molecules with the formation of the well-dispersed system. In addition, based on the adsorption and the liquid permeability analysis, SiO2@Al13 ink printing record layer achieved a relatively high ink uptake (2.5 gmm-1) and permeability (87%), respectively. The smoothness and glossiness of SiO2@Al13 record layers were higher than SiO2 record layers. The core-shell structure facilitated the dispersion of the silica, thereby improved its ink absorption performance and made the clear printed image. Thus, the proposed procedure based on SiO2@Al13 core-shell structure of dye particles could be applied as a promising strategy for inkjet printing.

Recent advances in bioprinting techniques: approaches, applications and future prospects.

PubMed

Li, Jipeng; Chen, Mingjiao; Fan, Xianqun; Zhou, Huifang

2016-09-20

Bioprinting technology shows potential in tissue engineering for the fabrication of scaffolds, cells, tissues and organs reproducibly and with high accuracy. Bioprinting technologies are mainly divided into three categories, inkjet-based bioprinting, pressure-assisted bioprinting and laser-assisted bioprinting, based on their underlying printing principles. These various printing technologies have their advantages and limitations. Bioprinting utilizes biomaterials, cells or cell factors as a "bioink" to fabricate prospective tissue structures. Biomaterial parameters such as biocompatibility, cell viability and the cellular microenvironment strongly influence the printed product. Various printing technologies have been investigated, and great progress has been made in printing various types of tissue, including vasculature, heart, bone, cartilage, skin and liver. This review introduces basic principles and key aspects of some frequently used printing technologies. We focus on recent advances in three-dimensional printing applications, current challenges and future directions.

Inkjet-Printed Organic Transistors Based on Organic Semiconductor/Insulating Polymer Blends.

PubMed

Kwon, Yoon-Jung; Park, Yeong Don; Lee, Wi Hyoung

2016-08-02

Recent advances in inkjet-printed organic field-effect transistors (OFETs) based on organic semiconductor/insulating polymer blends are reviewed in this article. Organic semiconductor/insulating polymer blends are attractive ink candidates for enhancing the jetting properties, inducing uniform film morphologies, and/or controlling crystallization behaviors of organic semiconductors. Representative studies using soluble acene/insulating polymer blends as an inkjet-printed active layer in OFETs are introduced with special attention paid to the phase separation characteristics of such blended films. In addition, inkjet-printed semiconducting/insulating polymer blends for fabricating high performance printed OFETs are reviewed.

Inkjet-Printed Organic Transistors Based on Organic Semiconductor/Insulating Polymer Blends

PubMed Central

Kwon, Yoon-Jung; Park, Yeong Don; Lee, Wi Hyoung

2016-01-01

Recent advances in inkjet-printed organic field-effect transistors (OFETs) based on organic semiconductor/insulating polymer blends are reviewed in this article. Organic semiconductor/insulating polymer blends are attractive ink candidates for enhancing the jetting properties, inducing uniform film morphologies, and/or controlling crystallization behaviors of organic semiconductors. Representative studies using soluble acene/insulating polymer blends as an inkjet-printed active layer in OFETs are introduced with special attention paid to the phase separation characteristics of such blended films. In addition, inkjet-printed semiconducting/insulating polymer blends for fabricating high performance printed OFETs are reviewed. PMID:28773772

Personalised 3D Printed Medicines: Which Techniques and Polymers Are More Successful?

PubMed

Konta, Andrea Alice; García-Piña, Marta; Serrano, Dolores R

2017-09-22

The interindividual variability is an increasingly global problem when treating patients from different backgrounds with diverse customs, metabolism, and necessities. Dose adjustment is frequently based on empirical methods, and therefore, the chance of undesirable side effects to occur is high. Three-dimensional (3D) Printed medicines are revolutionsing the pharmaceutical market as potential tools to achieve personalised treatments adapted to the specific requirements of each patient, taking into account their age, weight, comorbidities, pharmacogenetic, and pharmacokinetic characteristics. Additive manufacturing or 3D printing consists of a wide range of techniques classified in many categories but only three of them are mostly used in the 3D printing of medicines: printing-based inkjet systems, nozzle-based deposition systems, and laser-based writing systems. There are several drawbacks when using each technique and also the type of polymers readily available do not always possess the optimal properties for every drug. The aim of this review is to give an overview about the current techniques employed in 3D printing medicines, highlighting their advantages, disadvantages, along with the polymer and drug requirements for a successful printing. The major application of these techniques will be also discussed.

Personalised 3D Printed Medicines: Which Techniques and Polymers Are More Successful?

PubMed Central

Konta, Andrea Alice; García-Piña, Marta

2017-01-01

The interindividual variability is an increasingly global problem when treating patients from different backgrounds with diverse customs, metabolism, and necessities. Dose adjustment is frequently based on empirical methods, and therefore, the chance of undesirable side effects to occur is high. Three-dimensional (3D) Printed medicines are revolutionsing the pharmaceutical market as potential tools to achieve personalised treatments adapted to the specific requirements of each patient, taking into account their age, weight, comorbidities, pharmacogenetic, and pharmacokinetic characteristics. Additive manufacturing or 3D printing consists of a wide range of techniques classified in many categories but only three of them are mostly used in the 3D printing of medicines: printing-based inkjet systems, nozzle-based deposition systems, and laser-based writing systems. There are several drawbacks when using each technique and also the type of polymers readily available do not always possess the optimal properties for every drug. The aim of this review is to give an overview about the current techniques employed in 3D printing medicines, highlighting their advantages, disadvantages, along with the polymer and drug requirements for a successful printing. The major application of these techniques will be also discussed. PMID:28952558

A model-based approach for the scattering-bar printing avoidance

NASA Astrophysics Data System (ADS)

Du, Yaojun; Li, Liang; Zhang, Jingjing; Shao, Feng; Zuniga, Christian; Deng, Yunfei

2018-03-01

As the technology node for the semiconductor manufacturing approaches advanced nodes, the scattering-bars (SBs) are more crucial than ever to ensure a good on-wafer printability of the line space pattern and hole pattern. The main pattern with small pitches requires a very narrow PV (process variation) band. A delicate SB addition scheme is thus needed to maintain a sufficient PW (process window) for the semi-iso- and iso-patterns. In general, the wider, longer, and closer to main feature SBs will be more effective in enhancing the printability; on the other hand, they are also more likely to be printed on the wafer; resulting in undesired defects transferable to subsequent processes. In this work, we have developed a model based approach for the scattering-bar printing avoidance (SPA). A specially designed optical model was tuned based on a broad range of test patterns which contain a variation of CDs and SB placements showing printing and non-printing scattering bars. A printing threshold is then obtained to check the extra-printings of SBs. The accuracy of this threshold is verified by pre-designed test patterns. The printing threshold associated with our novel SPA model allows us to set up a proper SB rule.

Continuous Inkjet Printing of Enalapril Maleate onto Orodispersible Film Formulations.

PubMed

Thabet, Yasmin; Lunter, Dominique; Breitkreutz, Joerg

2018-05-10

Piezoelectric inkjet printing onto orodispersible films (ODFs) was proven to be a successful technique applying flexible doses of active pharmaceutical ingredients (APIs) onto edible substrates. The reported API printing and ODF production was conducted in a non-continuous production approach. Within this study, drug-free and hydrochlorothiazide (HCT) containing ODFs should be imprinted in-line with enalapril maleate (EM) ink during continuous ODF production. Macrogol inks based on various solvents and solvent-water mixtures were developed providing dynamic viscosities from 7 to 17 mPa∗s. Water based inks contained 1.25%, methanol based inks up to 10% EM. Both inks could be printed (500-1000 Hz) during continuous ODF production. No EM recrystallization was observed for water-based inks. Mechanical properties were not affected by drug printing using various firing frequencies. ODF imprinted with water-based EM inks contained 0.04 mg EM / 6cm 2 . EM amount can be increased to a paediatric therapeutic dose of 0.5 mg EM utilizing methanol-based inks. These inks were successfully printed onto HCT ODFs resulting in a therapeutically relevant fixed-dose combination. No EM migration into the HCT layer could be observed. In conclusion, it was feasible to print EM doses onto drug-free and HCT ODFs during an in-line continuous manufacturing process. Copyright © 2018 Elsevier B.V. All rights reserved.

Rapid Laser Printing of Paper-Based Multilayer Circuits.

PubMed

Huang, Gui-Wen; Feng, Qing-Ping; Xiao, Hong-Mei; Li, Na; Fu, Shao-Yun

2016-09-27

Laser printing has been widely used in daily life, and the fabricating process is highly efficient and mask-free. Here we propose a laser printing process for the rapid fabrication of paper-based multilayer circuits. It does not require wetting of the paper, which is more competitive in manufacturing paper-based circuits compared to conventional liquid printing process. In the laser printed circuits, silver nanowires (Ag-NWs) are used as conducting material for their excellent electrical and mechanical properties. By repeating the printing process, multilayer three-dimensional (3D) structured circuits can be obtained, which is quite significant for complex circuit applications. In particular, the performance of the printed circuits can be exactly controlled by varying the process parameters including Ag-NW content and laminating temperature, which offers a great opportunity for rapid prototyping of customized products with designed properties. A paper-based high-frequency radio frequency identification (RFID) label with optimized performance is successfully demonstrated. By adjusting the laminating temperature to 180 °C and the top-layer Ag-NW areal density to 0.3 mg cm(-2), the printed RFID antenna can be conjugately matched with the chip, and a big reading range of ∼12.3 cm with about 2.0 cm over that of the commercial etched Al antenna is achieved. This work provides a promising approach for fast and quality-controlled fabrication of multilayer circuits on common paper and may be enlightening for development of paper-based devices.

High-Speed Printing Process Characterization using the Lissajous Trajectory Method

NASA Astrophysics Data System (ADS)

Lee, Sangwon; Kim, Daekeun

2018-04-01

We present a novel stereolithographic three-dimensional (3D) printing process that uses Lissajous trajectories. By using Lissajous trajectories, this 3D printing process allows two laser-scanning mirrors to operate at similar high-speed frequencies simultaneously, and the printing speed can be faster than that of raster scanning used in conventional stereolithography. In this paper, we first propose the basic theoretical background for this printing process based on Lissajous trajectories. We also characterize its printing conditions, such as printing size, laser spot size, and minimum printing resolution, with respect to the operating frequencies of the scanning mirrors and the capability of the laser modulation. Finally, we demonstrate simulation results for printing basic 2D shapes by using a noble printing process algorithm.

Recent Advances in Biomaterials for 3D Printing and Tissue Engineering

PubMed Central

Jammalamadaka, Udayabhanu

2018-01-01

Three-dimensional printing has significant potential as a fabrication method in creating scaffolds for tissue engineering. The applications of 3D printing in the field of regenerative medicine and tissue engineering are limited by the variety of biomaterials that can be used in this technology. Many researchers have developed novel biomaterials and compositions to enable their use in 3D printing methods. The advantages of fabricating scaffolds using 3D printing are numerous, including the ability to create complex geometries, porosities, co-culture of multiple cells, and incorporate growth factors. In this review, recently-developed biomaterials for different tissues are discussed. Biomaterials used in 3D printing are categorized into ceramics, polymers, and composites. Due to the nature of 3D printing methods, most of the ceramics are combined with polymers to enhance their printability. Polymer-based biomaterials are 3D printed mostly using extrusion-based printing and have a broader range of applications in regenerative medicine. The goal of tissue engineering is to fabricate functional and viable organs and, to achieve this, multiple biomaterials and fabrication methods need to be researched. PMID:29494503

Recent Advances in Biomaterials for 3D Printing and Tissue Engineering.

PubMed

Jammalamadaka, Udayabhanu; Tappa, Karthik

2018-03-01

Three-dimensional printing has significant potential as a fabrication method in creating scaffolds for tissue engineering. The applications of 3D printing in the field of regenerative medicine and tissue engineering are limited by the variety of biomaterials that can be used in this technology. Many researchers have developed novel biomaterials and compositions to enable their use in 3D printing methods. The advantages of fabricating scaffolds using 3D printing are numerous, including the ability to create complex geometries, porosities, co-culture of multiple cells, and incorporate growth factors. In this review, recently-developed biomaterials for different tissues are discussed. Biomaterials used in 3D printing are categorized into ceramics, polymers, and composites. Due to the nature of 3D printing methods, most of the ceramics are combined with polymers to enhance their printability. Polymer-based biomaterials are 3D printed mostly using extrusion-based printing and have a broader range of applications in regenerative medicine. The goal of tissue engineering is to fabricate functional and viable organs and, to achieve this, multiple biomaterials and fabrication methods need to be researched.

Commercial printing and electronic color printing

NASA Astrophysics Data System (ADS)

Webb, Joseph W.

1995-04-01

Technologies such as Xeikon, Indigo, and the Heidelberg/Presstek GTO-DI can change both the way print buyers may purchase printed material and the way printers and trade services respond to changing demands. Our recent study surveys the graphic arts industry for their current views of these new products and provides forecasts of installations and usage with breakdowns by market segment and size of firm. The acceptance of desktop publishing and electronic prepress have not only paved the way for a totally electronic printing process, but it has broadened the base of people who develop color originals for reproduction. Electronic printing adds the ability to customize jobs on the fly. How print providers will respond to the impact of electronic color printing depends on how each firm perceives the 'threat.' Most printing companies are run by entrepreneurial individuals who have, as their highest priority, their own economic survival. Service bureaus are already looking at electronic color printing as yet another way to differentiate their businesses. The study was based on a mail survey with 682 responses from graphic arts firms, interviews with printers, suppliers, associations and industry executives, and detailed secondary research. Results of a new survey in progress in January 1995 is also presented.

3D nanostructured inkjet printed graphene via UV-pulsed laser irradiation enables paper-based electronics and electrochemical devices.

PubMed

Das, Suprem R; Nian, Qiong; Cargill, Allison A; Hondred, John A; Ding, Shaowei; Saei, Mojib; Cheng, Gary J; Claussen, Jonathan C

2016-09-21

Emerging research on printed and flexible graphene-based electronics is beginning to show tremendous promise for a wide variety of fields including wearable sensors and thin film transistors. However, post-print annealing/reduction processes that are necessary to increase the electrical conductivity of the printed graphene degrade sensitive substrates (e.g., paper) and are whole substrate processes that are unable to selectively anneal/reduce only the printed graphene-leaving sensitive device components exposed to damaging heat or chemicals. Herein a pulsed laser process is introduced that can selectively irradiate inkjet printed reduced graphene oxide (RGO) and subsequently improve the electrical conductivity (Rsheet∼0.7 kΩ□(-1)) of printed graphene above previously published reports. Furthermore, the laser process is capable of developing 3D petal-like graphene nanostructures from 2D planar printed graphene. These visible morphological changes display favorable electrochemical sensing characteristics-ferricyanide cyclic voltammetry with a redox peak separation (ΔEp) ≈ 0.7 V as well as hydrogen peroxide (H2O2) amperometry with a sensitivity of 3.32 μA mM(-1) and a response time of <5 s. Thus this work paves the way for not only paper-based electronics with graphene circuits, it enables the creation of low-cost and disposable graphene-based electrochemical electrodes for myriad applications including sensors, biosensors, fuel cells, and theranostic devices.

Effect of cinnamaldehyde on melanosis and spoilage of Pacific white shrimp (Litopenaeus vannamei) during storage.

PubMed

Mu, Honglei; Chen, Hangjun; Fang, Xiangjun; Mao, Jinlin; Gao, Haiyan

2012-08-15

Shrimp is a very perishable product and postmortem changes occur rapidly. Sulfiting agents were once and are still widely used as a preservative in the shrimp industry. However, the application of sulfite in shrimp may pose a risk to human health. Thus development of a natural preservative as a sulfite alternative to extend the shelf life of Pacific white shrimp is urgently needed. The effects of cinnamaldehyde essential oil (1 and 5 g kg(-1) ) on the shelf life of Pacific white shrimp stored at 4 °C were investigated. As the concentration of cinnamaldehyde increased, residual polyphenoloxidase (PPO) enzyme activity decreased. Kinetic analysis showed that cinnamaldehyde was a noncompetitive inhibitor for the oxidation of L-DOPA (L-3,4-dihydroxyphenylalanine) by PPO of Pacific white shrimp. Based on this study, shrimp treated with 5 g kg(-1) cinnamaldehyde possessed the lowest aerobic plate count, total volatile basic nitrogen, and pH values in all treatments after 10 days of storage. According to the results of L*, cinnamaldehyde showed inhibitory activity toward the formation of melanosis. Treatment with cinnamaldehyde could improve the sensory properties and extend the shelf life of Pacific white shrimp to 8 days. Therefore, cinnamaldehyde could be used as a promising natural preservative for inhibiting melanosis and preventing the growth of microbes during the chilled storage of Pacific white shrimp. Copyright © 2012 Society of Chemical Industry.

Fully Packaged Carbon Nanotube Supercapacitors by Direct Ink Writing on Flexible Substrates.

PubMed

Chen, Bolin; Jiang, Yizhou; Tang, Xiaohui; Pan, Yayue; Hu, Shan

2017-08-30

The ability to print fully packaged integrated energy storage components (e.g., supercapacitors) is of critical importance for practical applications of printed electronics. Due to the limited variety of printable materials, most studies on printed supercapacitors focus on printing the electrode materials but rarely the full-packaged cell. This work presents for the first time the printing of a fully packaged single-wall carbon nanotube-based supercapacitor with direct ink writing (DIW) technology. Enabled by the developed ink formula, DIW setup, and cell architecture, the whole printing process is mask free, transfer free, and alignment free with precise and repeatable control on the spatial distribution of all constituent materials. Studies on cell design show that a wider electrode pattern and narrower gap distance between electrodes lead to higher specific capacitance. The as-printed fully packaged supercapacitors have energy and power performances that are among the best in recently reported planar carbon-based supercapacitors that are only partially printed or nonprinted.

Tensile and fatigue behaviors of printed Ag thin films on flexible substrates

NASA Astrophysics Data System (ADS)

Sim, Gi-Dong; Won, Sejeong; Lee, Soon-Bok

2012-11-01

Flexible electronics using nanoparticle (NP) printing has been highlighted as a key technology enabling eco-friendly, low-cost, and large-area fabrication. For NP-based printing to be used as a successive alternative to photolithography and vacuum deposition, stretchability and long term reliability must be considered. This paper reports the stretchability and fatigue behavior of 100 nm thick NP-based silver thin films printed on polyethylene-terephthalate substrate and compares it to films deposited by electron-beam evaporation. NP-based films show stretchability and fatigue life comparable to evaporated films with intergranular fracture as the dominant failure mechanism.

Optical and Scintillation Properties of Polydimethyl-Diphenylsiloxane Based Organic Scintillators

NASA Astrophysics Data System (ADS)

Quaranta, Alberto; Carturan, Sara Maria; Marchi, Tommaso; Kravchuk, Vladimir L.; Gramegna, Fabiana; Maggioni, Gianluigi; Degerlier, Meltem

2010-04-01

Polysiloxane based scintillators with high light yield have been synthesized. The polymer consists in cross-linked polydimethyl-co-diphenylsiloxane with different molar percentages of phenyl units. 2,5-diphenyl oxazole (PPO) and 2,5-bis(5-ter-butyl-2-benzoxazolyl)thiophene (BBOT) have been dispersed in the polymer as dopants. The energy transfer and scintillation capabilities have been investigated, for two different amounts of phenyl groups in the polymer network and for different concentrations of dye molecules, by means of fluorescence spectroscopy, ion beam induced luminescence (IBIL) and scintillation yield measurements with ¿ particles from an 241Am source. The luminescence features and the scintillation yields have been correlated to the composition of the scintillators.

Media and memory: the efficacy of video and print materials for promoting patient education about asthma.

PubMed

Wilson, Elizabeth A H; Park, Denise C; Curtis, Laura M; Cameron, Kenzie A; Clayman, Marla L; Makoul, Gregory; Vom Eigen, Keith; Wolf, Michael S

2010-09-01

We examined the effects of presentation medium on immediate and delayed recall of information and assessed the effect of giving patients take-home materials after initial presentations. Primary-care patients received video-based, print-based or no asthma education about asthma symptoms and triggers and then answered knowledge-based questions. Print participants and half the video participants received take-home print materials. A week later, available participants completed the knowledge assessment again. Participants receiving either intervention outperformed controls on immediate and delayed assessments (p<0.001). For symptom-related information, immediate performance did not significantly differ between print and video participants. A week later, receiving take-home print predicted better performance (p<0.05), as did self-reported review among recipients of take-home print (p<0.01). For content about inhaler usage, although video watchers outperformed print participants immediately after seeing the materials (p<0.001), a week later these two groups' performance did not significantly differ. Among participants given take-home materials, review predicted marginally better recall (p=0.06). Video and print interventions can promote recall of health-related information. Additionally, reviewable materials, if they are utilized, may improve retention. When creating educational tools, providers should consider how long information must be retained, its content, and the feasibility of providing tangible supporting materials. Copyright (c) 2010. Published by Elsevier Ireland Ltd.

Review: Polymeric-Based 3D Printing for Tissue Engineering.

PubMed

Wu, Geng-Hsi; Hsu, Shan-Hui

Three-dimensional (3D) printing, also referred to as additive manufacturing, is a technology that allows for customized fabrication through computer-aided design. 3D printing has many advantages in the fabrication of tissue engineering scaffolds, including fast fabrication, high precision, and customized production. Suitable scaffolds can be designed and custom-made based on medical images such as those obtained from computed tomography. Many 3D printing methods have been employed for tissue engineering. There are advantages and limitations for each method. Future areas of interest and progress are the development of new 3D printing platforms, scaffold design software, and materials for tissue engineering applications.

A combined system for 3D printing cybersecurity

NASA Astrophysics Data System (ADS)

Straub, Jeremy

2017-06-01

Previous work has discussed the impact of cybersecurity breaches on 3D printed objects. Multiple attack types that could weaken objects, make them unsuitable for certain applications and even create safety hazards have been presented. This paper considers a visible light sensing-based verification system's efficacy as a means of thwarting cybersecurity threats to 3D printing. This system detects discrepancies between expected and actual printed objects (based on an independent pristine CAD model). Whether reliance on an independent CAD model is appropriate is also considered. The future of 3D printing is projected and the importance of cybersecurity in this future is discussed.

Office-Based Three-Dimensional Printing Workflow for Craniomaxillofacial Fracture Repair.

PubMed

Elegbede, Adekunle; Diaconu, Silviu C; McNichols, Colton H L; Seu, Michelle; Rasko, Yvonne M; Grant, Michael P; Nam, Arthur J

2018-03-08

Three-dimensional printing of patient-specific models is being used in various aspects of craniomaxillofacial reconstruction. Printing is typically outsourced to off-site vendors, with the main disadvantages being increased costs and time for production. Office-based 3-dimensional printing has been proposed as a means to reduce costs and delays, but remains largely underused because of the perception among surgeons that it is futuristic, highly technical, and prohibitively expensive. The goal of this report is to demonstrate the feasibility and ease of incorporating in-office 3-dimensional printing into the standard workflow for facial fracture repair.Patients with complex mandible fractures requiring open repair were identified. Open-source software was used to create virtual 3-dimensional skeletal models of the, initial injury pattern, and then the ideally reduced fractures based on preoperative computed tomography (CT) scan images. The virtual 3-dimensional skeletal models were then printed in our office using a commercially available 3-dimensional printer and bioplastic filament. The 3-dimensional skeletal models were used as templates to bend and shape titanium plates that were subsequently used for intraoperative fixation.Average print time was 6 hours. Excluding the 1-time cost of the 3-dimensional printer of $2500, roughly the cost of a single commercially produced model, the average material cost to print 1 model mandible was $4.30. Postoperative CT imaging demonstrated precise, predicted reduction in all patients.Office-based 3-dimensional printing of skeletal models can be routinely used in repair of facial fractures in an efficient and cost-effective manner.

[The design and implementation of DICOM self-help film printing system].

PubMed

Wang, Xiaodong; Jiang, Mowen

2013-09-01

This article focuses on the design and implementation of self-help film printing system which based on DICOM standard. According to DICOM standard and the working process of the radiology department, the system realizes self-help printing film as well as monitoring and managing the film printing business.

Surgeon-Based 3D Printing for Microvascular Bone Flaps.

PubMed

Taylor, Erin M; Iorio, Matthew L

2017-07-01

Background  Three-dimensional (3D) printing has developed as a revolutionary technology with the capacity to design accurate physical models in preoperative planning. We present our experience in surgeon-based design of 3D models, using home 3D software and printing technology for use as an adjunct in vascularized bone transfer. Methods  Home 3D printing techniques were used in the design and execution of vascularized bone flap transfers to the upper extremity. Open source imaging software was used to convert preoperative computed tomography scans and create 3D models. These were printed in the surgeon's office as 3D models for the planned reconstruction. Vascularized bone flaps were designed intraoperatively based on the 3D printed models. Results  Three-dimensional models were created for intraoperative use in vascularized bone flaps, including (1) medial femoral trochlea (MFT) flap for scaphoid avascular necrosis and nonunion, (2) MFT flap for lunate avascular necrosis and nonunion, (3) medial femoral condyle (MFC) flap for wrist arthrodesis, and (4) free fibula osteocutaneous flap for distal radius septic nonunion. Templates based on the 3D models allowed for the precise and rapid contouring of well-vascularized bone flaps in situ, prior to ligating the donor pedicle. Conclusions  Surgeon-based 3D printing is a feasible, innovative technology that allows for the precise and rapid contouring of models that can be created in various configurations for pre- and intraoperative planning. The technology is easy to use, convenient, and highly economical as compared with traditional send-out manufacturing. Surgeon-based 3D printing is a useful adjunct in vascularized bone transfer. Level of Evidence  Level IV. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Surface topography study of prepared 3D printed moulds via 3D printer for silicone elastomer based nasal prosthesis

NASA Astrophysics Data System (ADS)

Abdullah, Abdul Manaf; Din, Tengku Noor Daimah Tengku; Mohamad, Dasmawati; Rahim, Tuan Noraihan Azila Tuan; Akil, Hazizan Md; Rajion, Zainul Ahmad

2016-12-01

Conventional prosthesis fabrication is highly depends on the hand creativity of laboratory technologist. The development in 3D printing technology offers a great help in fabricating affordable and fast yet esthetically acceptable prostheses. This study was conducted to discover the potential of 3D printed moulds for indirect silicone elastomer based nasal prosthesis fabrication. Moulds were designed using computer aided design (CAD) software (Solidworks, USA) and converted into the standard tessellation language (STL) file. Three moulds with layer thickness of 0.1, 0.2 and 0.3mm were printed utilizing polymer filament based 3D printer (Makerbot Replicator 2X, Makerbot, USA). Another one mould was printed utilizing liquid resin based 3D printer (Objet 30 Scholar, Stratasys, USA) as control. The printed moulds were then used to fabricate maxillofacial silicone specimens (n=10)/mould. Surface profilometer (Surfcom Flex, Accretech, Japan), digital microscope (KH77000, Hirox, USA) and scanning electron microscope (Quanta FEG 450, Fei, USA) were used to measure the surface roughness as well as the topological properties of fabricated silicone. Statistical analysis of One-Way ANOVA was employed to compare the surface roughness of the fabricated silicone elastomer. Result obtained demonstrated significant differences in surface roughness of the fabricated silicone (p<0.01). Further post hoc analysis also revealed significant differences in silicone fabricated using different 3D printed moulds (p<0.01). A 3D printed mould was successfully prepared and characterized. With surface topography that could be enhanced, inexpensive and rapid mould fabrication techniques, polymer filament based 3D printer is potential for indirect silicone elastomer based nasal prosthesis fabrication.

The influence of printing parameters on cell survival rate and printability in microextrusion-based 3D cell printing technology.

PubMed

Zhao, Yu; Li, Yang; Mao, Shuangshuang; Sun, Wei; Yao, Rui

2015-11-02

Three-dimensional (3D) cell printing technology has provided a versatile methodology to fabricate cell-laden tissue-like constructs and in vitro tissue/pathological models for tissue engineering, drug testing and screening applications. However, it still remains a challenge to print bioinks with high viscoelasticity to achieve long-term stable structure and maintain high cell survival rate after printing at the same time. In this study, we systematically investigated the influence of 3D cell printing parameters, i.e. composition and concentration of bioink, holding temperature and holding time, on the printability and cell survival rate in microextrusion-based 3D cell printing technology. Rheological measurements were utilized to characterize the viscoelasticity of gelatin-based bioinks. Results demonstrated that the bioink viscoelasticity was increased when increasing the bioink concentration, increasing holding time and decreasing holding temperature below gelation temperature. The decline of cell survival rate after 3D cell printing process was observed when increasing the viscoelasticity of the gelatin-based bioinks. However, different process parameter combinations would result in the similar rheological characteristics and thus showed similar cell survival rate after 3D bioprinting process. On the other hand, bioink viscoelasticity should also reach a certain point to ensure good printability and shape fidelity. At last, we proposed a protocol for 3D bioprinting of temperature-sensitive gelatin-based hydrogel bioinks with both high cell survival rate and good printability. This research would be useful for biofabrication researchers to adjust the 3D bioprinting process parameters quickly and as a referable template for designing new bioinks.

75 FR 74863 - Health Insurance Issuers Implementing Medical Loss Ratio (MLR) Requirements Under the Patient...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-01

... regarding that topic, rather than here. For example, ``aggregation'' is addressed in Sec. 158.120... would disaggregate products by type of coverage--for example, HMO, PPO, and high-deductible coverage...

Plan choice, health insurance cost and premium sharing.

PubMed

Kosteas, Vasilios D; Renna, Francesco

2014-05-01

We develop a model of premium sharing for firms that offer multiple insurance plans. We assume that firms offer one low quality plan and one high quality plan. Under the assumption of wage rigidities we found that the employee's contribution to each plan is an increasing function of that plan's premium. The effect of the other plan's premium is ambiguous. We test our hypothesis using data from the Employer Health Benefit Survey. Restricting the analysis to firms that offer both HMO and PPO plans, we measure the amount of the premium passed on to employees in response to a change in both premiums. We find evidence of large and positive effects of the increase in the plan's premium on the amount of the premium passed on to employees. The effect of the alternative plan's premium is negative but statistically significant only for the PPO plans. Copyright © 2014 Elsevier B.V. All rights reserved.

Activation energy-activation volume master plots for ion transport behavior in polymer electrolytes and supercooled molten salts.

PubMed

Ingram, Malcolm D; Imrie, Corrie T; Stoeva, Zlatka; Pas, Steven J; Funke, Klaus; Chandler, Howard W

2005-09-08

We demonstrate the use of activation energy versus activation volume "master plots" to explore ion transport in typical fragile glass forming systems exhibiting non-Arrhenius behavior. These systems include solvent-free salt complexes in poly(ethylene oxide) (PEO) and low molecular weight poly(propylene oxide) (PPO) and molten 2Ca(NO3)2.3KNO3 (CKN). Plots showing variations in apparent activation energy EA versus apparent activation volume VA are straight lines with slopes given by M = DeltaEA/DeltaVA. A simple ion transport mechanism is described where the rate determining step involves a dilatation (expressed as VA) around microscopic cavities and a corresponding work of expansion (EA). The slopes of the master plots M are equated to internal elastic moduli, which vary from 1.1 GPa for liquid PPO to 5.0 GPa for molten CKN on account of differing intermolecular forces in these materials.

Toward better understanding of postharvest deterioration: biochemical changes in stored cassava (Manihot esculenta Crantz) roots.

PubMed

Uarrota, Virgílio Gavicho; Nunes, Eduardo da Costa; Peruch, Luiz Augusto Martins; Neubert, Enilto de Oliveira; Coelho, Bianca; Moresco, Rodolfo; Domínguez, Moralba Garcia; Sánchez, Teresa; Meléndez, Jorge Luis Luna; Dufour, Dominique; Ceballos, Hernan; Becerra Lopez-Lavalle, Luis Augusto; Hershey, Clair; Rocha, Miguel; Maraschin, Marcelo

2016-05-01

Food losses can occur during production, postharvest, and processing stages in the supply chain. With the onset of worldwide food shortages, interest in reducing postharvest losses in cassava has been increasing. In this research, the main goal was to evaluate biochemical changes and identify the metabolites involved in the deterioration of cassava roots. We found that high levels of ascorbic acid (AsA), polyphenol oxidase (PPO), dry matter, and proteins are correlated with overall lower rates of deterioration. On the other hand, soluble sugars such as glucose and fructose, as well as organic acids, mainly, succinic acid, seem to be upregulated during storage and may play a role in the deterioration of cassava roots. Cultivar Branco (BRA) was most resilient to postharvest physiological deterioration (PPD), while Oriental (ORI) was the most susceptible. Our findings suggest that PPO, AsA, and proteins may play a distinct role in PPD delay.

Effect of Hyaluronic Acid on the Self Assembling Behaviour of PEO-PPO Copolymers in Aqueous Solution

NASA Astrophysics Data System (ADS)

Mayol, L.; Borzacchiello, A.; Quaglia, F.; La Rotonda, M. I.; Ambrosio, L.

2008-07-01

The influence of hyaluronic acid (HA) on the self assembling properties of pluronic (PEO-PPO-PEO block copolymers) blends has been studied with the aim of engineering thermosensitive and mucoadhesive polymeric platforms for drug delivery. The gelation temperature (Tgel), viscoelastic properties and mucoadhesive force of the systems were investigated and optimised by means of rheological analyses. Pluronic micellar radius was evaluated by Photon Correlation Spectroscopy (PCS). The addition of Low Molecular Weight HA did not hamper the self assembling process of pluronics just delaying the gelation temperature of few Celsius degrees. Furthermore, HA presence led to a strong increase of the pluronics gel rheological properties. PCS results show, in formulations containing HA, aggregates with hydrodynamic diameters values much higher than those of pluronic micelles. Mucoadhesive experiments indicate the possibility of interactions between the pluronic/HA gel and mucus glycoproteins.

How arbuscular mycorrhizal fungi influence the defense system of sunflower during different abiotic stresses.

PubMed

Mayer, Zoltán; Duc, Nguyen Hong; Sasvári, Zita; Posta, Katalin

2017-12-01

The association between terrestrial plants and arbuscular mycorrhizal (AM) fungi is one of the most common and widespread mutualistic plant-fungi interaction. AM fungi are of beneficial effects on the water and nutrient uptake of plants and increase plant defense mechanisms to alleviate different stresses. The aim of this study was to determine the level of polyphenol oxidase (PPO), guaiacol peroxidase (POX) and glutathione S-transferase (GST) enzyme activities and to track the expression of glutathione S-transferase (GST) gene in plant-arbuscular mycorrhizal system under temperature- and mechanical stress conditions. Our results suggest that induced tolerance of mycorrhizal sunflower to high temperature may be attributed to the induction of GST, POX and PPO enzyme activities as well as to the elevated expression of GST. However, the degree of tolerance of the plant is significantly influenced by the age which is probably justified by the energy considerations.

The research and preparation of a novel nano biodegradable polymer external reinforcement

NASA Astrophysics Data System (ADS)

Zhang, Xiangman; Chen, Bin; Fu, Weiguo; Fang, Zhengdong; Liu, Zhenjie; Lu, Weifeng; Shi, Zhengyu; Chen, Lili; Chen, Tao

2011-10-01

The use of current drug-loaded vascular scaffolds is limited in sustained drug release and stability studies in clinical and preclinical trials. We found that poly( L-glutamic acid)-b-poly(propylene oxide)-b-poly( L-glutamic acid) (PLGA-b-PPO-b-PLGA) triblock copolymers can deliver multiple poorly water-soluble drugs (e.g., Paclitaxel) at clinically relevant doses. In this study, we synthesized a new drug-loaded vascular external graft with electrospun nanofibrous scaffolds [poly( L-lactide-co-ɛ-caprolactone) (PLCL):fibrinogen; 2:1 (w/w)] and drug-loaded PLGA-b-PPO-b-PLGA micelles. Cell proliferation and viability assay results showed that beagle smooth muscle cells grew well on the surface of vascular graft-coated micelles at a percentages of 10% (w/w) GPG:PLCL-fibrinogen. This study demonstrates that micelle-coated electrospun PLCL-fibrinogen vascular scaffolds have potential applications in vascular tissue engineering.

Synthesis of plastic scintillation microspheres: alpha/beta discrimination.

PubMed

Santiago, L M; Bagán, H; Tarancón, A; Garcia, J F

2014-11-01

Plastic scintillation microspheres (PSm) have been developed as an alternative for liquid scintillation cocktails due to their ability to avoid the mixed waste, besides other strengths in which the possibility for alpha/beta discrimination is included. The aim of this work was to evaluate the capability of PSm containing two combinations of fluorescence solutes (PPO/POPOP and pT/Bis-MSB) and variable amounts of a second organic solvent (naphthalene) to enhance the alpha/beta discrimination. Two commercial detectors with different Pulse Shape Discrimination performances (Quantulus and Triathler) were used to evaluate the alpha/beta discrimination. An optimal discrimination of alpha/beta particles was reached, with very low misclassification values (2% for beta particles and 0.5% for alpha particles), when PSm containing PPO/POPOP and between 0.6 and 2.0 g of naphthalene were evaluated using Triathler and the appropriate programme for data processing. Copyright © 2014 Elsevier Ltd. All rights reserved.

Honeys from different floral sources as inhibitors of enzymatic browning in fruit and vegetable homogenates.

PubMed

Chen, L; Mehta, A; Berenbaum, M; Zangerl, A R; Engeseth, N J

2000-10-01

Honeys from different floral sources were evaluated for their antioxidant content and for their ability to inhibit enzymatic browning in fruits and vegetables. Antioxidant contents of honeys vary widely from different floral sources, as do their abilities to protect against enzymatic browning. Polyphenol oxidase (PPO) activity was reduced over a range of approximately 2-45% in fruit and vegetable homogenates, corresponding to a reduction in browning index by 2.5-12 units. Soy honey was particularly effective when compared to clover honey, which had a similar antioxidant content. When compared to commercial inhibitors of browning, honeys were less effective; however, in combination they added to the effectiveness of metabisulfite and ascorbic acid. Honey has great potential to be used as a natural source of antioxidants to reduce the negative effects of PPO browning in fruit and vegetable processing.

Pineapple juice and its fractions in enzymatic browning inhibition of banana [Musa (AAA group) Gros Michel].

PubMed

Chaisakdanugull, Chitsuda; Theerakulkait, Chockchai; Wrolstad, Ronald E

2007-05-16

The effectiveness of pineapple juice in enzymatic browning inhibition was evaluated on the cut surface of banana slices. After storage of banana slices at 15 degrees C for 3 days, pineapple juice showed browning inhibition to a similar extent as 8 mM ascorbic acid but less than 4 mM sodium metabisulfite. Fractionation of pineapple juice by a solid-phase C18 cartridge revealed that the directly eluted fraction (DE fraction) inhibited banana polyphenol oxidase (PPO) about 100% when compared to the control. The DE fraction also showed more inhibitory effect than 8 mM ascorbic acid in enzymatic browning inhibition of banana puree during storage at 5 degrees C for 24 h. Further identification of the DE fraction by fractionation with ion exchange chromatography and confirmation using model systems indicated that malic acid and citric acid play an important role in the enzymatic browning inhibition of banana PPO.

Synthesis and 3D printing of biodegradable polyurethane elastomer by a water-based process for cartilage tissue engineering applications.

PubMed

Hung, Kun-Che; Tseng, Ching-Shiow; Hsu, Shan-Hui

2014-10-01

Biodegradable materials that can undergo degradation in vivo are commonly employed to manufacture tissue engineering scaffolds, by techniques including the customized 3D printing. Traditional 3D printing methods involve the use of heat, toxic organic solvents, or toxic photoinitiators for fabrication of synthetic scaffolds. So far, there is no investigation on water-based 3D printing for synthetic materials. In this study, the water dispersion of elastic and biodegradable polyurethane (PU) nanoparticles is synthesized, which is further employed to fabricate scaffolds by 3D printing using polyethylene oxide (PEO) as a viscosity enhancer. The surface morphology, degradation rate, and mechanical properties of the water-based 3D-printed PU scaffolds are evaluated and compared with those of polylactic-co-glycolic acid (PLGA) scaffolds made from the solution in organic solvent. These scaffolds are seeded with chondrocytes for evaluation of their potential as cartilage scaffolds. Chondrocytes in 3D-printed PU scaffolds have excellent seeding efficiency, proliferation, and matrix production. Since PU is a category of versatile materials, the aqueous 3D printing process developed in this study is a platform technology that can be used to fabricate devices for biomedical applications. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Investigation of polymer membranes modified by fullerenol for dehydration of organic mixtures

NASA Astrophysics Data System (ADS)

Dmitrenko, Mariia E.; Penkova, Anastasia V.; Kuzminova, Anna I.; Ermakov, Sergey S.; Roizard, Denis

2017-07-01

This study focuses on the development of novel dense and supported mixed-matrix membranes based on chitosan and poly(2,6-dimethyl-1,4-phenylenoxide) (PPO) with low-hydroxylated fullerenol C60(OH)12. These novel membranes containing nano-carbon particles were prepared to reach high membrane performances for further integration in a dehydration process like distillation coupled with pervaporation. SEM microscopy was used to visualize the internal morphology of the membrane. It was found that all membranes were well stable and highly water-selective in spite of the different nature of polymers.

Structural color printing based on plasmonic metasurfaces of perfect light absorption

PubMed Central

Cheng, Fei; Gao, Jie; Luk, Ting S.; Yang, Xiaodong

2015-01-01

Subwavelength structural color filtering and printing technologies employing plasmonic nanostructures have recently been recognized as an important and beneficial complement to the traditional colorant-based pigmentation. However, the color saturation, brightness and incident angle tolerance of structural color printing need to be improved to meet the application requirement. Here we demonstrate a structural color printing method based on plasmonic metasurfaces of perfect light absorption to improve color performances such as saturation and brightness. Thin-layer perfect absorbers with periodic hole arrays are designed at visible frequencies and the absorption peaks are tuned by simply adjusting the hole size and periodicity. Near perfect light absorption with high quality factors are obtained to realize high-resolution, angle-insensitive plasmonic color printing with high color saturation and brightness. Moreover, the fabricated metasurfaces can be protected with a protective coating for ambient use without degrading performances. The demonstrated structural color printing platform offers great potential for applications ranging from security marking to information storage. PMID:26047486

Structural color printing based on plasmonic metasurfaces of perfect light absorption

DOE PAGES

Cheng, Fei; Gao, Jie; Luk, Ting S.; ...

2015-06-05

Subwavelength structural color filtering and printing technologies employing plasmonic nanostructures have recently been recognized as an important and beneficial complement to the traditional colorant-based pigmentation. However, the color saturation, brightness and incident angle tolerance of structural color printing need to be improved to meet the application requirement. Here we demonstrate a structural color printing method based on plasmonic metasurfaces of perfect light absorption to improve color performances such as saturation and brightness. Thin-layer perfect absorbers with periodic hole arrays are designed at visible frequencies and the absorption peaks are tuned by simply adjusting the hole size and periodicity. Near perfectmore » light absorption with high quality factors are obtained to realize high-resolution, angle-insensitive plasmonic color printing with high color saturation and brightness. Moreover, the fabricated metasurfaces can be protected with a protective coating for ambient use without degrading performances. The demonstrated structural color printing platform offers great potential for applications ranging from security marking to information storage.« less

A Pilot Study to Investigate the Effectiveness of Multimedia CD-ROM vis-a-vis Traditional Print-Based Technology in Teaching Fourth-Grade Children

ERIC Educational Resources Information Center

Shana, Zuhrieh A.

2009-01-01

The purpose of this study was to examine the degree of effectiveness of multimedia technology in teaching in comparison to the traditional print-based teaching methods. Multimedia CD was designed to teach the second semester unit of science and Islamic studies for the fourth graders. The unit's content was the same in the print-based teaching…

Mechanical, thermal, morphological, and rheological characteristics of high performance 3D-printing lignin-based composites for additive manufacturing applications

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

Nguyen, Ngoc A.; Bowland, Christopher C.; Naskar, Amit K.

Here, the article presents different mechanical, thermal and rheological data corresponding to the morphological formation within various renewable lignin-based composites containing acrylonitrile butadiene styrene (ABS), acrylonitrile butadiene rubber (NBR41, 41 mol% nitrile content), and carbon fibers (CFs). The data of 3D-printing properties and morphology of 3D-printed layers of selected lignin-based composites are revealed.

Mechanical, thermal, morphological, and rheological characteristics of high performance 3D-printing lignin-based composites for additive manufacturing applications

DOE PAGES

Nguyen, Ngoc A.; Bowland, Christopher C.; Naskar, Amit K.

2018-05-29

Here, the article presents different mechanical, thermal and rheological data corresponding to the morphological formation within various renewable lignin-based composites containing acrylonitrile butadiene styrene (ABS), acrylonitrile butadiene rubber (NBR41, 41 mol% nitrile content), and carbon fibers (CFs). The data of 3D-printing properties and morphology of 3D-printed layers of selected lignin-based composites are revealed.

Printing Electronic Components from Copper-Infused Ink and Thermoplastic Mediums

NASA Astrophysics Data System (ADS)

Flowers, Patrick F.

The demand for printable electronics has sharply increased in recent years and is projected to continue to rise. Unfortunately, electronic materials which are suitable for desired applications while being compatible with available printing techniques are still often lacking. This thesis addresses two such challenging areas. In the realm of two-dimensional ink-based printing of electronics, a major barrier to the realization of printable computers that can run programs is the lack of a solution-coatable non-volatile memory with performance metrics comparable to silicon-based devices. To address this deficiency, I developed a nonvolatile memory based on Cu-SiO2 core-shell nanowires that can be printed from solution and exhibits on-off ratios of 106, switching speeds of 50 ns, a low operating voltage of 2 V, and operates for at least 104 cycles without failure. Each of these metrics is similar to or better than Flash memory (the write speed is 20 times faster than Flash). Memory architectures based on the individual memory cells demonstrated here could enable the printing of the more complex, embedded computing devices that are expected to make up an internet of things. Recently, the exploration of three-dimensional printing techniques to fabricate electronic materials began. A suitable general-purpose conductive thermoplastic filament was not available, however. In this work I examine the current state of conductive thermoplastic filaments, including a newly-released highly conductive filament that my lab has produced which we call Electrifi. I focus on the use of dual-material fused filament fabrication (FFF) to 3D print electronic components (conductive traces, resistors, capacitors, inductors) and circuits (a fully-printed high-pass filter). The resistivity of traces printed from conductive thermoplastic filaments made with carbon-black, graphene, and copper as conductive fillers was found to be 12, 0.78, and 0.014 ohm cm, respectively, enabling the creation of resistors with resistances spanning 3 orders of magnitude. The carbon black and graphene filaments were brittle and fractured easily, but the copper-based filament could be bent at least 500 times with little change in its resistance. Impedance measurements made on the thermoplastic filaments demonstrate that the copper-based filament had an impedance similar to a conductive PCB trace at 1 MHz. Dual material 3D printing was used to fabricate a variety of inductors and capacitors with properties that could be predictably tuned by modifying either the geometry of the components, or the materials used to fabricate the components. These resistors, capacitors, and inductors were combined to create a fully 3D printed high-pass filter with properties comparable to its conventional counterparts. The relatively low impedance of the copper-based filament enable its use to 3D print a receiver coil for wireless power transfer. We also demonstrate the ability to embed and connect surface mounted components in 3D printed objects with a low-cost ($1,000 in parts), open source dual-material 3D printer. This work thus demonstrates the potential for FFF 3D printing to create complex, three-dimensional circuits composed of either embedded or fully-printed electronic components.

Cost of unreliability method to estimate loss of revenue based on unreliability data: Case study of Printing Company

NASA Astrophysics Data System (ADS)

alhilman, Judi

2017-12-01

In the production line process of the printing office, the reliability of the printing machine plays a very important role, if the machine fail it can disrupt production target so that the company will suffer huge financial loss. One method to calculate the financial loss cause by machine failure is use the Cost of Unreliability(COUR) method. COUR method works based on down time machine and costs associated with unreliability data. Based on the calculation of COUR method, so the sum of cost due to unreliability printing machine during active repair time and downtime is 1003,747.00.

Stable aqueous based Cu nanoparticle ink for printing well-defined highly conductive features on a plastic substrate.

PubMed

Jeong, Sunho; Song, Hae Chun; Lee, Won Woo; Lee, Sun Sook; Choi, Youngmin; Son, Wonil; Kim, Eui Duk; Paik, Choon Hoon; Oh, Seok Heon; Ryu, Beyong-Hwan

2011-03-15

With the aim of inkjet printing highly conductive and well-defined Cu features on plastic substrates, aqueous based Cu ink is prepared for the first time using water-soluble Cu nanoparticles with a very thin surface oxide layer. Owing to the specific properties, high surface tension and low boiling point, of water, the aqueous based Cu ink endows a variety of advantages over conventional Cu inks based on organic solvents in printing narrow conductive patterns without irregular morphologies. It is demonstrated how the design of aqueous based ink affects the basic properties of printed conductive features such as surface morphology, microstructure, conductivity, and line width. The long-term stability of aqueous based Cu ink against oxidation is analyzed through an X-ray photoelectron spectroscopy (XPS) based investigation on the evolution of the surface oxide layer in the aqueous based ink.

Accelerating Preschoolers' Early Literacy Development through Classroom-Based Teacher-Child Storybook Reading and Explicit Print Referencing

ERIC Educational Resources Information Center

Justice, Laura M.; Kaderavek, Joan N.; Fan, Xitao; Sofka, Amy; Hunt, Aileen

2009-01-01

Purpose: This study examined the impact of teacher use of a print referencing style during classroom-based storybook reading sessions conducted over an academic year. Impacts on preschoolers' early literacy development were examined, focusing specifically on the domain of print knowledge. Method: This randomized, controlled trial examined the…

Effect of dose rate of gamma irradiation on biochemical quality and browning of mushrooms Agaricus bisporus

NASA Astrophysics Data System (ADS)

Beaulieu, M.; D'Aprano, G.; Lacroix, M.

2002-03-01

In order to enhance the shelf-life of edible mature mushrooms Agaricus bisporus, 2 kGy ionising treatments were applied at two different dose rates: 4.5 kGy/h ( I-) and 32 kGy/h ( I+). Both I+ and I- showed 2 and 4 days shelf-life enhancement compared to the control ( C). Before day 9, no significant difference ( p>0.05) in L* value was detected in irradiated mushrooms. However, after day 9, the highest observed L* value (whiteness) was obtained for the mushrooms irradiated in I-. Analyses of phenolic compounds revealed that mushrooms in I- contained more phenols than I+ and C, the latter containing the lower level of phenols. The polyphenol oxidase (PPO) activities of irradiated mushrooms, analysed via catechol oxidase and dopa oxidase substrates, resulted in being significantly lowered ( p⩽0.05) compared to C, with a further decrease in I+. Analyses of the enzymes indicated that PPO activity was lower in I+, contrasting with its lower phenol concentration. Ionising treatments also increased significantly ( p⩽0.05) the phenylalanine ammonia-lyase (PAL) activity. The observation of mushrooms cellular membranes, by electronic microscopy, revealed a better preserved integrity in I- than in I+. It is thus assumed that the browning effect observed in I+ was caused by both the decompartimentation of vacuolar phenol and by the entry of molecular oxygen into the cell cytoplasm. The synergetic effect of the residual active PPO and the molecular oxygen, in contact with the phenols, allowed an increased oxidation rate and, therefore, a more pronounced browning in I+ than in I-.

The effect of rapid response teams on end-of-life care: A retrospective chart review

PubMed Central

Tam, Benjamin; Salib, Mary; Fox-Robichaud, Alison

2014-01-01

BACKGROUND: A subset of critically ill patients have end-of-life (EOL) goals that are unclear. Rapid response teams (RRTs) may aid in the identification of these patients and the delivery of their EOL care. OBJECTIVES: To characterize the impact of RRT discussion on EOL care, and to examine how a preprinted order (PPO) set for EOL care influenced EOL discussions and outcomes. METHODS: A single-centre retrospective chart review of all RRT calls (January 2009 to December 2010) was performed. The effect of RRT EOL discussions and the effect of a hospital-wide PPO set on EOL care was examined. Charts were from the Ontario Ministry of Health and Long-Term Care Critical Care Information Systemic database, and were interrogated by two reviewers. RESULTS: In patients whose EOL status changed following RRT EOL discussion, there were fewer intensive care unit (ICU) transfers (8.4% versus 17%; P<0.001), decreased ICU length of stay (5.8 days versus 20 days; P=0.08), increased palliative care consultations (34% versus 5.3%; P<0.001) and an increased proportion who died within 24 h of consultation (25% versus 8.3%; P<0.001). More patients experienced a change in EOL status following the introduction of an EOL PPO, from 20% (before) to 31% (after) (P<0.05). CONCLUSIONS: A change in EOL status following RRT-led EOL discussion was associated with reduced ICU transfers and enhanced access to palliative care services. Further study is required to identify and deconstruct barriers impairing timely and appropriate EOL discussions. PMID:25299222

Measuring recovery: An adapted Brief Assessment of Mood (BAM+) compared to biochemical and power output alterations.

PubMed

Shearer, David A; Sparkes, William; Northeast, Jonny; Cunningham, Daniel J; Cook, Christian J; Kilduff, Liam P

2017-05-01

Biochemical (e.g. creatine kinase (CK)) and neuromuscular (e.g. peak power output (PPO)) markers of recovery are expensive and require specialist equipment. Perceptual measures are an effective alternative, yet most validated scales are too long for daily use. This study utilises a longitudinal multi-level design to test an adapted Brief Assessment of Mood (BAM+), with four extra items and a 100mm visual analogue scale to measure recovery. Elite under-21 academy soccer players (N=11) were monitored across five games with data (BAM+, CK and PPO) collected for each game at 24h pre, 24h and 48h post-match. Match activity data for each participant was also collected using GPS monitors on players. BAM+, CK and PPO had significant (p<.05) linear and quadratic growth curves across time and games that matched the known time reports of fatigue and recovery. Multi-level linear modelling (MLM) with random intercepts for 'participant' and 'game' indicated only CK significantly contributed to the variance of BAM+ scores (p<.05). Significant correlations (p<.01) were found between changes in BAM+ scores from baseline at 24 and 48h post-match for total distance covered per minute, high intensity distance covered per minute, and total number of sprints per minute. Visual and inferential results indicate that the BAM+ appears effective for monitoring longitudinal recovery cycles in elite level athletes. Future research is needed to confirm both the scales reliability and validity. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Application of Fused Deposition Modelling (FDM) Method of 3D Printing in Drug Delivery.

PubMed

Long, Jingjunjiao; Gholizadeh, Hamideh; Lu, Jun; Bunt, Craig; Seyfoddin, Ali

2017-01-01

Three-dimensional (3D) printing is an emerging manufacturing technology for biomedical and pharmaceutical applications. Fused deposition modelling (FDM) is a low cost extrusion-based 3D printing technique that can deposit materials layer-by-layer to create solid geometries. This review article aims to provide an overview of FDM based 3D printing application in developing new drug delivery systems. The principle methodology, suitable polymers and important parameters in FDM technology and its applications in fabrication of personalised tablets and drug delivery devices are discussed in this review. FDM based 3D printing is a novel and versatile manufacturing technique for creating customised drug delivery devices that contain accurate dose of medicine( s) and provide controlled drug released profiles. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Screen printed, transparent, and flexible electrodes based on graphene nanoplatelet pastes

NASA Astrophysics Data System (ADS)

Wróblewski, Grzegorz; Janczak, Daniel

Transparent, flexible and conducting graphene films were produced by screen printing method using printing pastes based on graphene nanoplatelets in polymer matrix. The transparency of received layers and the mechanical resistivity in several bending cycles were measured. Subsequently percolation threshold was investigated. Graphene layers were printed on diverse substrates (glass, Al2O3, PET) and afterwards for samples printed on glass different firing atmospheres (N2, H2, air) were studied. Best firing results (resistance decrease) were obtained for treatment in 250 °C in atmosphere of air. Finally investigation results were used to produce a transparent and elastic electrode for an electroluminescent display, showing the application potential of our graphene nanocomposite pastes.

3D printed graphene-based electrodes with high electrochemical performance

NASA Astrophysics Data System (ADS)

Vernardou, D.; Vasilopoulos, K. C.; Kenanakis, G.

2017-10-01

Three-dimensional (3D) printed graphene pyramids were fabricated through a dual-extrusion FDM-type 3D printer using a commercially available PLA-based conductive graphene. Compared with flat printed graphene, a substantial enhancement in the electrochemical performance was clearly observed for the case of 3D printed graphene pyramids with 5.0 mm height. Additionally, the charge transfer of Li+ across the graphene pyramids/electrolyte interface was easier enhancing its performance presenting a specific discharge capacity of 265 mAh g-1 with retention of 93% after 1000 cycles. The importance of thickness control towards the printing of an electrode with good stability and effective electrochemical behavior is highlighted.

Utility of a Web-based intervention for individuals with type 2 diabetes: the impact on physical activity levels and glycemic control.

PubMed

Kim, Chun-Ja; Kang, Duck-Hee

2006-01-01

Despite the numerous benefits of physical activity for patients with diabetes, most healthcare providers in busy clinical settings rarely find time to counsel their patients about it. A Web-based program for healthcare providers can be used as an effective counseling tool, when strategies are outlined for specific stages of readiness for physical activity. Seventy-three adults with type 2 diabetes were randomly assigned to Web-based intervention, printed-material intervention, or usual care. After 12 weeks, the effects of the interventions on physical activity, fasting blood sugar, and glycosylated hemoglobin were evaluated. Both Web-based and printed material intervention, compared with usual care, were effective in increasing physical activity (P < .001) and decreasing fasting blood sugar (P<.01) and glycosylated hemoglobin (P < .01). Post hoc analysis for change scores indicated significant differences between Web-based intervention and usual care and between printed material intervention and usual care, but not between web-based and printed material intervention. The findings of this study support the value of Web-based and printed material interventions in healthcare counseling. With increasing Web access, the effectiveness of Web-based programs offered directly to patients needs to be tested.

One night of partial sleep deprivation impairs recovery from a single exercise training session.

PubMed

Rae, Dale E; Chin, Tayla; Dikgomo, Kagiso; Hill, Lee; McKune, Andrew J; Kohn, Tertius A; Roden, Laura C

2017-04-01

The effects of sleep deprivation on physical performance are well documented, but data on the consequence of sleep deprivation on recovery from exercise are limited. The aim was to compare cyclists' recovery from a single bout of high-intensity interval training (HIIT) after which they were given either a normal night of sleep (CON, 7.56 ± 0.63 h) or half of their usual time in bed (DEP, 3.83 ± 0.33 h). In this randomized cross-over intervention study, 16 trained male cyclists (age 32 ± 7 years), relative peak power output (PPO 4.6 ± 0.7 W kg -1 ) performed a HIIT session at ±18:00 followed by either the CON or DEP sleep condition. Recovery from the HIIT session was assessed the following day by comparing pre-HIIT variables to those measured 12 and 24 h after the session. Following a 2-week washout, cyclists repeated the trial, but under the alternate sleep condition. PPO was reduced more 24 h after the HIIT session in the DEP (ΔPPO -0.22 ± 0.22 W kg -1 ; range -0.75 to 0.1 W kg -1 ) compared to the CON condition (ΔPPO -0.05 ± 0.09 W kg -1 , range -0.19 to 0.17 W kg -1 , p = 0.008, d = -2.16). Cyclists were sleepier (12 h: p = 0.002, d = 1.90; 24 h: p = 0.001, d = 1.41) and felt less motivated to train (12 h, p = 0.012, d = -0.89) during the 24 h recovery phase when the HIIT session was followed by the DEP condition. The exercise-induced 24 h reduction in systolic blood pressure observed in the CON condition was absent in the DEP condition (p = 0.039, d = 0.75). One night of partial sleep deprivation impairs recovery from a single HIIT session in cyclists. Further research is needed to understand the mechanisms behind this observation.

Surface processing and ageing behavior of silk fabrics treated with atmospheric-pressure plasma for pigment-based ink-jet printing

NASA Astrophysics Data System (ADS)

Zhang, Chunming; Wang, Libing; Yu, Miao; Qu, Lijun; Men, Yajing; Zhang, Xiangwu

2018-03-01

Pigment inkjet printing has highlighted the advantages of cost-effective, short production cycle and environment-friendly. However, patterns directly printed with pigment inks usually have low color yields and blurry images which are caused by bleeding phenomenon. This work presents an atmospheric-pressure plasma method for improving the pigment-based ink-jet printing performance of silk fabrics. The effects of surface changes induced are discussed, with data derived from morphological study by atomic force microscopy (AFM), chemical analysis using X-ray photoelectron spectroscopy (XPS) and contact angle measurement. Ink-jet printing experiments were conducted to study the influence of measured changes on anti-bleeding property and color strength of treated and original samples. The ageing experiment indicates that the modified silk fabrics should be printed within 24 h after plasma processing for maximum color yields. This study explores an effective approach for the atmospheric-pressure plasma, which can provide its significant use in improving the surface properties and ink-jet printing performance of fabrics.

Inkjet printing of metal-oxide-based transparent thin-film capacitors

NASA Astrophysics Data System (ADS)

Matavž, A.; Malič, B.; Bobnar, V.

2017-12-01

We report on the inkjet printing of transparent, thin-film capacitors (TTFCs) composed of indium-zinc-oxide electrodes and a tantalum-oxide-based dielectric on glass substrates. The printing parameters were adapted for the sequential deposition of functional layers, resulting in approximately 100-nm-thick transparent capacitors with a uniform thickness. The relatively high electrical resistivity of the electrodes is reflected in the frequency dispersive dielectric behaviour, which is explained in terms of an equivalent circuit. The resistivity of the electrode strongly decreases with the number of printing passes; consequently, any misalignment of the printed layers is detected in the measured response. At low frequency, the TTFCs show a stable intrinsic dielectric response and a high capacitance density of ˜280 nF/cm2. The good dielectric performance as well as the low leakage-current density (8 × 10-7 A/cm2 at 1 MV cm-1) of our capacitors indicates that inkjet printing can be used to produce all-printed, high-quality electrical devices.

Understanding wax screen-printing: a novel patterning process for microfluidic cloth-based analytical devices.

PubMed

Liu, Min; Zhang, Chunsun; Liu, Feifei

2015-09-03

In this work, we first introduce the fabrication of microfluidic cloth-based analytical devices (μCADs) using a wax screen-printing approach that is suitable for simple, inexpensive, rapid, low-energy-consumption and high-throughput preparation of cloth-based analytical devices. We have carried out a detailed study on the wax screen-printing of μCADs and have obtained some interesting results. Firstly, an analytical model is established for the spreading of molten wax in cloth. Secondly, a new wax screen-printing process has been proposed for fabricating μCADs, where the melting of wax into the cloth is much faster (∼5 s) and the heating temperature is much lower (75 °C). Thirdly, the experimental results show that the patterning effects of the proposed wax screen-printing method depend to a certain extent on types of screens, wax melting temperatures and melting time. Under optimized conditions, the minimum printing width of hydrophobic wax barrier and hydrophilic channel is 100 μm and 1.9 mm, respectively. Importantly, the developed analytical model is also well validated by these experiments. Fourthly, the μCADs fabricated by the presented wax screen-printing method are used to perform a proof-of-concept assay of glucose or protein in artificial urine with rapid high-throughput detection taking place on a 48-chamber cloth-based device and being performed by a visual readout. Overall, the developed cloth-based wax screen-printing and arrayed μCADs should provide a new research direction in the development of advanced sensor arrays for detection of a series of analytes relevant to many diverse applications. Copyright © 2015 Elsevier B.V. All rights reserved.

Job-based health benefits in 2002: some important trends.

PubMed

Gabel, Jon; Levitt, Larry; Holve, Erin; Pickreign, Jeremy; Whitmore, Heidi; Dhont, Kelley; Hawkins, Samantha; Rowland, Diane

2002-01-01

Based on a national survey of 2,014 randomly selected public and private firms with three or more workers, this paper reports changes in employer-based health insurance from spring 2001 to spring 2002. The cost of health insurance rose 12.7 percent, the highest rate of growth since 1990. Employee contributions for health insurance rose in 2002, from $30 to $38 for single coverage and from $150 to $174 for family coverage. Deductibles and copayments rose also, and employers adopted formularies and three-tier cost-sharing formulas to control prescription drug expenses. PPO and HMO enrollment rose, while the percentage of small employers offering health benefits fell. Because increasing claims expenses rather than the underwriting cycle are the major driver of rising premiums, double-digit growth appears likely to continue.

Clear as Glass: A Combined List of Print and Electronic Journals in the Knowledge Base

ERIC Educational Resources Information Center

Lowe, M. Sara

2008-01-01

The non-standard practice at Cowles Library at Drake University has been to display electronic journals and some print journals in the Knowledge Base while simultaneously listing print journals and some electronic journals in the online public access catalog (OPAC). The result was a system that made it difficult for patrons to determine our…

Color analysis and image rendering of woodblock prints with oil-based ink

NASA Astrophysics Data System (ADS)

Horiuchi, Takahiko; Tanimoto, Tetsushi; Tominaga, Shoji

2012-01-01

This paper proposes a method for analyzing the color characteristics of woodblock prints having oil-based ink and rendering realistic images based on camera data. The analysis results of woodblock prints show some characteristic features in comparison with oil paintings: 1) A woodblock print can be divided into several cluster areas, each with similar surface spectral reflectance; and 2) strong specular reflection from the influence of overlapping paints arises only in specific cluster areas. By considering these properties, we develop an effective rendering algorithm by modifying our previous algorithm for oil paintings. A set of surface spectral reflectances of a woodblock print is represented by using only a small number of average surface spectral reflectances and the registered scaling coefficients, whereas the previous algorithm for oil paintings required surface spectral reflectances of high dimension at all pixels. In the rendering process, in order to reproduce the strong specular reflection in specific cluster areas, we use two sets of parameters in the Torrance-Sparrow model for cluster areas with or without strong specular reflection. An experiment on a woodblock printing with oil-based ink was performed to demonstrate the feasibility of the proposed method.

Comparative Study on Cushion Performance Between 3D Printed Kelvin Structure and 3D Printed Lattice Structure

NASA Astrophysics Data System (ADS)

Priyadarshini, Lakshmi

Frequently transported packaging goods are more prone to damage due to impact, jolting or vibration in transit. Fragile goods, for example, glass, ceramics, porcelain are susceptible to mechanical stresses. Hence ancillary materials like cushions play an important role when utilized within package. In this work, an analytical model of a 3D cellular structure is established based on Kelvin model and lattice structure. The research will provide a comparative study between the 3D printed Kelvin unit structure and 3D printed lattice structure. The comparative investigation is based on parameters defining cushion performance such as cushion creep, indentation, and cushion curve analysis. The applications of 3D printing is in rapid prototyping where the study will provide information of which model delivers better form of energy absorption. 3D printed foam will be shown as a cost-effective approach as prototype. The research also investigates about the selection of material for 3D printing process. As cushion development demands flexible material, three-dimensional printing with material having elastomeric properties is required. Further, the concept of cushion design is based on Kelvin model structure and lattice structure. The analytical solution provides the cushion curve analysis with respect to the results observed when load is applied over the cushion. The results are reported on basis of attenuation and amplification curves.

A fully roll-to-roll gravure-printed carbon nanotube-based active matrix for multi-touch sensors

PubMed Central

Lee, Wookyu; Koo, Hyunmo; Sun, Junfeng; Noh, Jinsoo; Kwon, Kye-Si; Yeom, Chiseon; Choi, Younchang; Chen, Kevin; Javey, Ali; Cho, Gyoujin

2015-01-01

Roll-to-roll (R2R) printing has been pursued as a commercially viable high-throughput technology to manufacture flexible, disposable, and inexpensive printed electronic devices. However, in recent years, pessimism has prevailed because of the barriers faced when attempting to fabricate and integrate thin film transistors (TFTs) using an R2R printing method. In this paper, we report 20 × 20 active matrices (AMs) based on single-walled carbon nanotubes (SWCNTs) with a resolution of 9.3 points per inch (ppi) resolution, obtained using a fully R2R gravure printing process. By using SWCNTs as the semiconducting layer and poly(ethylene terephthalate) (PET) as the substrate, we have obtained a device yield above 98%, and extracted the key scalability factors required for a feasible R2R gravure manufacturing process. Multi-touch sensor arrays were achieved by laminating a pressure sensitive rubber onto the SWCNT-TFT AM. This R2R gravure printing system overcomes the barriers associated with the registration accuracy of printing each layer and the variation of the threshold voltage (Vth). By overcoming these barriers, the R2R gravure printing method can be viable as an advanced manufacturing technology, thus enabling the high-throughput production of flexible, disposable, and human-interactive cutting-edge electronic devices based on SWCNT-TFT AMs. PMID:26635237

Scalability of carbon-nanotube-based thin film transistors for flexible electronic devices manufactured using an all roll-to-roll gravure printing system

PubMed Central

Koo, Hyunmo; Lee, Wookyu; Choi, Younchang; Sun, Junfeng; Bak, Jina; Noh, Jinsoo; Subramanian, Vivek; Azuma, Yasuo; Majima, Yutaka; Cho, Gyoujin

2015-01-01

To demonstrate that roll-to-roll (R2R) gravure printing is a suitable advanced manufacturing method for flexible thin film transistor (TFT)-based electronic circuits, three different nanomaterial-based inks (silver nanoparticles, BaTiO3 nanoparticles and single-walled carbon nanotubes (SWNTs)) were selected and optimized to enable the realization of fully printed SWNT-based TFTs (SWNT-TFTs) on 150-m-long rolls of 0.25-m-wide poly(ethylene terephthalate) (PET). SWNT-TFTs with 5 different channel lengths, namely, 30, 80, 130, 180, and 230 μm, were fabricated using a printing speed of 8 m/min. These SWNT-TFTs were characterized, and the obtained electrical parameters were related to major mechanical factors such as web tension, registration accuracy, impression roll pressure and printing speed to determine whether these mechanical factors were the sources of the observed device-to-device variations. By utilizing the electrical parameters from the SWNT-TFTs, a Monte Carlo simulation for a 1-bit adder circuit, as a reference, was conducted to demonstrate that functional circuits with reasonable complexity can indeed be manufactured using R2R gravure printing. The simulation results suggest that circuits with complexity, similar to the full adder circuit, can be printed with a 76% circuit yield if threshold voltage (Vth) variations of less than 30% can be maintained. PMID:26411839

Fabrication and evaluation of a protruding Si-based printhead for electrohydrodynamic jet printing

NASA Astrophysics Data System (ADS)

Pan, Yanqiao; Chen, Xinyuan; Zeng, Liangcai; Huang, YongAn; Yin, Zhouping

2017-12-01

A printhead that is compatible with Si-based processes and able to generate homogeneous micro- and nano-scale droplets plays an important role in electrohydrodynamic jet printing (E-jet printing) for the large-scale manufacturing. This paper proposes the design, fabrication and evaluation of a novel protruding Si-based printhead for E-jet printing. The protruding nozzle can concentrate the electrical field and restrain the lateral wetting so as to improve the jetting stability. However, it is a challenge to have both the protruding structure and a stable solution/voltage supply. Accordingly, a set of micro-manufacturing processes, as well as methods of adopting hydrophobic and insulation treatments, are also presented to stabilize the solution/voltage supply. The diameter and height of the protruding nozzle are 50 µm and 60 µm, respectively. Printing tests are performed using both quantum dots solution (CdSe/CdS/ZnS) and a mixed solution of glycerol, ethylene glycol and water. Feasibility of the protruding nozzle is proved by experiments that a stable meniscus with Taylor cone could form on the nozzle orifice, and fine dots (⩽30 µm) could be printed successfully and continuously. The protruding design and micro-fabrication processes of the protruding Si-based printhead pave the way for the multi-nozzle E-jet printing with high efficiency and resolution.

Printing of polymer microcapsules for enzyme immobilization on paper substrate.

PubMed

Savolainen, Anne; Zhang, Yufen; Rochefort, Dominic; Holopainen, Ulla; Erho, Tomi; Virtanen, Jouko; Smolander, Maria

2011-06-13

Poly(ethyleneimine) (PEI) microcapsules containing laccase from Trametes hirsuta (ThL) and Trametes versicolor (TvL) were printed onto paper substrate by three different methods: screen printing, rod coating, and flexo printing. Microcapsules were fabricated via interfacial polycondensation of PEI with the cross-linker sebacoyl chloride, incorporated into an ink, and printed or coated on the paper substrate. The same ink components were used for three printing methods, and it was found that laccase microcapsules were compatible with the ink. Enzymatic activity of microencapsulated TvL was maintained constant in polymer-based ink for at least eight weeks. Thick layers with high enzymatic activity were obtained when laccase-containing microcapsules were screen printed on paper substrate. Flexo printed bioactive paper showed very low activity, since by using this printing method the paper surface was not fully covered by enzyme microcapsules. Finally, screen printing provided a bioactive paper with high water-resistance and the highest enzyme lifetime.

Interactive Print: The Design of Cognitive Tasks in Blended Augmented Reality and Print Documents

ERIC Educational Resources Information Center

Nadolny, Larysa

2017-01-01

The combination of print materials and augmented reality in education is increasingly accessible due to advances in mobile technologies. Using familiar paper-based activities overlaid with digital items, also known as interactive print, educators can create a custom learning experience for students. There is very little guidance on the design of…

Future of printing: changes and challenges, technologies and markets

NASA Astrophysics Data System (ADS)

Kipphan, Helmut

1998-01-01

Digitalization within the graphic arts industry is described and it is explained how it is improving and changing the print production strategies and which new kinds of print production systems are developed or can be expected. The relationship of printed media and electronic media is analyzed and a positioning for the next century is given. The state of the art of conventional printing technologies, especially using direct imagine techniques, and their position within the digital workflow are shortly described. Non-impact printing multicolor printing systems are explained, based on general design criteria and linked to existing and newly announced equipment. The use of high-tech components for building up successful systems with high reliability, high quality and low production costs is included with some examples. Digital printing systems open many opportunities in print production: distributed printing, personalization, print and book on demand are explained as examples. The overview of the several printing technologies and their positioning regarding quality and productivity leads to the scenario about the important position of printed media, also in the distant future.

Phase-field modeling of liquids splitting between separating surfaces and its application to high-resolution roll-based printing technologies

NASA Astrophysics Data System (ADS)

Hizir, F. E.; Hardt, D. E.

2017-05-01

An in-depth understanding of the liquid transport in roll-based printing systems is essential for advancing the roll-based printing technology and enhancing the performance of the printed products. In this study, phase-field simulations are performed to characterize the liquid transport in roll-based printing systems, and the phase-field method is shown to be an effective tool to simulate the liquid transport. In the phase-field simulations, the liquid transport through the ink transfer rollers is approximated as the stretching and splitting of liquid bridges with pinned or moving contact lines between vertically separating surfaces. First, the effect of the phase-field parameters and the mesh characteristics on the simulation results is examined. The simulation results show that a sharp interface limit is approached as the capillary width decreases while keeping the mobility proportional to the capillary width squared. Close to the sharp interface limit, the mobility changes over a specified range are observed to have no significant influence on the simulation results. Next, the ink transfer from the cells on the surface of an ink-metering roller to the surface of stamp features is simulated. Under negligible inertial effects and in the absence of gravity, the amount of liquid ink transferred from an axisymmetric cell with low surface wettability to a stamp with high surface wettability is found to increase as the cell sidewall steepness and the cell surface wettability decrease and the stamp surface wettability and the capillary number increase. Strategies for improving the resolution and quality of roll-based printing are derived based on an analysis of the simulation results. The application of novel materials that contain cells with irregular surface topography to stamp inking in high-resolution roll-based printing is assessed.

Incorporating sprint training with endurance training improves anaerobic capacity and 2,000-m Erg performance in trained oarsmen.

PubMed

Stevens, Alexander W J; Olver, Terry T; Lemon, Peter W R

2015-01-01

A 2,000-m time-trial performance, aerobic capacity, and anaerobic capacity were assessed in 16 trained oarsmen after sprint interval training (SIT) replaced a portion of an endurance-based training program (EBTSIT) vs. an endurance-based program alone (EBTAlone). The EBTSIT involved 10 SIT sessions over 4 weeks, in addition to 12 continuous exercise sessions, 2 anaerobic threshold exercise sessions, and 4 strength training sessions. The EBTAlone consisted of 20 continuous, 6 anaerobic threshold, 2 interval exercise sessions, and 8 strength training sessions. Time-trial performance (2,000-m erg performance) improved with EBTSIT (baseline = 414.6 ± 18.5, post = 410.6 ± 17.5 seconds; p < 0.001) but only approached significance in EBTAlone (baseline = 413.0 ± 27.7, post = 411.4 ± 27.9 seconds; p = 0.06). In a 60-second "all-out" anaerobic capacity test, peak power output (PPO) increased significantly with EBTSIT (PPO: EBTSIT: baseline = 566 ± 82, post = 623 ± 60 W; p = 0.02) but not with EBTAlone (EBTAlone: baseline = 603 ± 81, post = 591 ± 123 W; p = 0.59). Changes in average power output (APO) also approached significance (p = 0.07) (APO: EBTSIT: baseline = 508 ± 48, post = 530 ± 52 W; EBTAlone: baseline = 532 ± 55, post = 533 ± 68 W). Neither group experienced any change in aerobic capacity ((Equation is included in full-text article.)or ventilatory threshold; p ≥ 0.16). We conclude that replacing a portion of EBT with SIT can improve both 2,000-m erg performance and anaerobic capacity, while maintaining aerobic fitness in trained oarsmen. Incorporating SIT within endurance training programs may be useful during periods of low-volume training, to improve performance without sacrificing aerobic capacity.

Fabrication of tough epoxy with shape memory effects by UV-assisted direct-ink write printing.

PubMed

Chen, Kaijuan; Kuang, Xiao; Li, Vincent; Kang, Guozheng; Qi, H Jerry

2018-03-07

3D printing of epoxy-based shape memory polymers with high mechanical strength, excellent thermal stability and chemical resistance is highly desirable for practical applications. However, thermally cured epoxy in general is difficult to print directly. There have been limited numbers of successes in printing epoxy but they suffer from relatively poor mechanical properties. Here, we present an ultraviolet (UV)-assisted 3D printing of thermally cured epoxy composites with high tensile toughness via a two-stage curing approach. The ink containing UV curable resin and epoxy oligomer is used for UV-assisted direct-ink write (DIW)-based 3D printing followed by thermal curing of the part containing the epoxy oligomer. The UV curable resin forms a network by photo polymerization after the 1st stage of UV curing, which can maintain the printed architecture at an elevated temperature. The 2nd stage thermal curing of the epoxy oligomer yields an interpenetrating polymer network (IPN) composite with highly enhanced mechanical properties. It is found that the printed IPN epoxy composites enabled by the two-stage curing show isotropic mechanical properties and high tensile toughness. We demonstrated that the 3D-printed high-toughness epoxy composites show good shape memory properties. This UV-assisted DIW 3D printing via a two-stage curing method can broaden the application of 3D printing to fabricate thermoset materials with enhanced tensile toughness and tunable properties for high-performance and functional applications.

Direct selective growth of ZnO nanowire arrays from inkjet-printed zinc acetate precursor on a heated substrate

PubMed Central

2013-01-01

Inkjet printing of functional materials has drawn tremendous interest as an alternative to the conventional photolithography-based microelectronics fabrication process development. We introduce direct selective nanowire array growth by inkjet printing of Zn acetate precursor ink patterning and subsequent hydrothermal ZnO local growth without nozzle clogging problem which frequently happens in nanoparticle inkjet printing. The proposed process can directly grow ZnO nanowires in any arbitrary patterned shape, and it is basically very fast, low cost, environmentally benign, and low temperature. Therefore, Zn acetate precursor inkjet printing-based direct nanowire local growth is expected to give extremely high flexibility in nanomaterial patterning for high-performance electronics fabrication especially at the development stage. As a proof of concept of the proposed method, ZnO nanowire network-based field effect transistors and ultraviolet photo-detectors were demonstrated by direct patterned grown ZnO nanowires as active layer. PMID:24252130

Inkjet printing-based volumetric display projecting multiple full-colour 2D patterns

NASA Astrophysics Data System (ADS)

Hirayama, Ryuji; Suzuki, Tomotaka; Shimobaba, Tomoyoshi; Shiraki, Atsushi; Naruse, Makoto; Nakayama, Hirotaka; Kakue, Takashi; Ito, Tomoyoshi

2017-04-01

In this study, a method to construct a full-colour volumetric display is presented using a commercially available inkjet printer. Photoreactive luminescence materials are minutely and automatically printed as the volume elements, and volumetric displays are constructed with high resolution using easy-to-fabricate means that exploit inkjet printing technologies. The results experimentally demonstrate the first prototype of an inkjet printing-based volumetric display composed of multiple layers of transparent films that yield a full-colour three-dimensional (3D) image. Moreover, we propose a design algorithm with 3D structures that provide multiple different 2D full-colour patterns when viewed from different directions and experimentally demonstrate prototypes. It is considered that these types of 3D volumetric structures and their fabrication methods based on widely deployed existing printing technologies can be utilised as novel information display devices and systems, including digital signage, media art, entertainment and security.

Style Guide for AFIT Dissertations, Theses, and Graduate Research Papers

DTIC Science & Technology

2007-05-01

1989 Changeover in Assembly Plants .” Report to Directors of GMC automotive divisions. Fisher Body Division, General Motors Corporation, Warren...to fit on an 8 ½ x 11 inch page, consider having the base printing plant or photo lab reduce it, or consider designing it across several pages with...printing plant is 11 x 17 inches. Any larger foldouts will be sent to off-base printers; orders for such foldouts must be placed with the base printing

Characterization of 3D printing techniques: Toward patient specific quality assurance spine-shaped phantom for stereotactic body radiation therapy.

PubMed

Kim, Min-Joo; Lee, Seu-Ran; Lee, Min-Young; Sohn, Jason W; Yun, Hyong Geon; Choi, Joon Yong; Jeon, Sang Won; Suh, Tae Suk

2017-01-01

Development and comparison of spine-shaped phantoms generated by two different 3D-printing technologies, digital light processing (DLP) and Polyjet has been purposed to utilize in patient-specific quality assurance (QA) of stereotactic body radiation treatment. The developed 3D-printed spine QA phantom consisted of an acrylic body phantom and a 3D-printed spine shaped object. DLP and Polyjet 3D printers using a high-density acrylic polymer were employed to produce spine-shaped phantoms based on CT images. Image fusion was performed to evaluate the reproducibility of our phantom, and the Hounsfield units (HUs) were measured based on each CT image. Two different intensity-modulated radiotherapy plans based on both CT phantom image sets from the two printed spine-shaped phantoms with acrylic body phantoms were designed to deliver 16 Gy dose to the planning target volume (PTV) and were compared for target coverage and normal organ-sparing. Image fusion demonstrated good reproducibility of the developed phantom. The HU values of the DLP- and Polyjet-printed spine vertebrae differed by 54.3 on average. The PTV Dmax dose for the DLP-generated phantom was about 1.488 Gy higher than that for the Polyjet-generated phantom. The organs at risk received a lower dose for the 3D printed spine-shaped phantom image using the DLP technique than for the phantom image using the Polyjet technique. Despite using the same material for printing the spine-shaped phantom, these phantoms generated by different 3D printing techniques, DLP and Polyjet, showed different HU values and these differently appearing HU values according to the printing technique could be an extra consideration for developing the 3D printed spine-shaped phantom depending on the patient's age and the density of the spinal bone. Therefore, the 3D printing technique and materials should be carefully chosen by taking into account the condition of the patient in order to accurately produce 3D printed patient-specific QA phantom.

Characterization of 3D printing techniques: Toward patient specific quality assurance spine-shaped phantom for stereotactic body radiation therapy

PubMed Central

Lee, Min-Young; Sohn, Jason W.; Yun, Hyong Geon; Choi, Joon Yong; Jeon, Sang Won

2017-01-01

Development and comparison of spine-shaped phantoms generated by two different 3D-printing technologies, digital light processing (DLP) and Polyjet has been purposed to utilize in patient-specific quality assurance (QA) of stereotactic body radiation treatment. The developed 3D-printed spine QA phantom consisted of an acrylic body phantom and a 3D-printed spine shaped object. DLP and Polyjet 3D printers using a high-density acrylic polymer were employed to produce spine-shaped phantoms based on CT images. Image fusion was performed to evaluate the reproducibility of our phantom, and the Hounsfield units (HUs) were measured based on each CT image. Two different intensity-modulated radiotherapy plans based on both CT phantom image sets from the two printed spine-shaped phantoms with acrylic body phantoms were designed to deliver 16 Gy dose to the planning target volume (PTV) and were compared for target coverage and normal organ-sparing. Image fusion demonstrated good reproducibility of the developed phantom. The HU values of the DLP- and Polyjet-printed spine vertebrae differed by 54.3 on average. The PTV Dmax dose for the DLP-generated phantom was about 1.488 Gy higher than that for the Polyjet-generated phantom. The organs at risk received a lower dose for the 3D printed spine-shaped phantom image using the DLP technique than for the phantom image using the Polyjet technique. Despite using the same material for printing the spine-shaped phantom, these phantoms generated by different 3D printing techniques, DLP and Polyjet, showed different HU values and these differently appearing HU values according to the printing technique could be an extra consideration for developing the 3D printed spine-shaped phantom depending on the patient’s age and the density of the spinal bone. Therefore, the 3D printing technique and materials should be carefully chosen by taking into account the condition of the patient in order to accurately produce 3D printed patient-specific QA phantom. PMID:28472175

SU-G-BRB-01: A Novel 3D Printed Patient-Specific Phantom for Spine SBRT Quality Assurance: Comparison of 3D Printing Techniques

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

Lee, S; Kim, M; Lee, M

Purpose: The novel 3 dimensional (3D)-printed spine quality assurance (QA) phantoms generated by two different 3D-printing technologies, digital light processing (DLP) and Polyjet, were developed and evaluated for spine stereotactic body radiation treatment (SBRT). Methods: The developed 3D-printed spine QA phantom consisted of an acrylic body and a 3D-printed spine phantom. DLP and Polyjet 3D printers using the high-density acrylic polymer were employed to produce spine-shaped phantoms based on CT images. To verify dosimetric effects, the novel phantom was made it enable to insert films between each slabs of acrylic body phantom. Also, for measuring internal dose of spine, 3D-printedmore » spine phantom was designed as divided laterally exactly in half. Image fusion was performed to evaluate the reproducibility of our phantom, and the Hounsfield unit (HU) was measured based on each CT image. Intensity-modulated radiotherapy plans to deliver a fraction of a 16 Gy dose to a planning target volume (PTV) based on the two 3D-printing techniques were compared for target coverage and normal organ-sparing. Results: Image fusion demonstrated good reproducibility of the fabricated spine QA phantom. The HU values of the DLP- and Polyjet-printed spine vertebrae differed by 54.3 on average. The PTV Dmax dose for the DLP-generated phantom was about 1.488 Gy higher than for the Polyjet-generated phantom. The organs at risk received a lower dose when the DLP technique was used than when the Polyjet technique was used. Conclusion: This study confirmed that a novel 3D-printed phantom mimicking a high-density organ can be created based on CT images, and that a developed 3D-printed spine phantom could be utilized in patient-specific QA for SBRT. Despite using the same main material, DLP and Polyjet yielded different HU values. Therefore, the printing technique and materials must be carefully chosen in order to accurately produce a patient-specific QA phantom.« less

Hierarchical Co-Assembly Enhanced Direct Ink Writing.

PubMed

Li, Longyu; Zhang, Pengfei; Zhang, Zhiyun; Lin, Qianming; Wu, Yuyang; Cheng, Alexander; Lin, Yunxiao; Thompson, Christina M; Smaldone, Ronald A; Ke, Chenfeng

2018-04-23

Integrating intelligent molecular systems into 3D printing materials and transforming their molecular functions to the macroscale with controlled superstructures will unleash great potential for the development of smart materials. Compared to macromolecular 3D printing materials, self-assembled small-molecule-based 3D printing materials are very rare owing to the difficulties of facilitating 3D printability as well as preserving their molecular functions macroscopically. Herein, we report a general approach for the integration of functional small molecules into 3D printing materials for direct ink writing through the introduction of a supramolecular template. A variety of inorganic and organic small-molecule-based inks were 3D-printed, and their superstructures were refined by post-printing hierarchical co-assembly. Through spatial and temporal control of individual molecular events from the nano- to the macroscale, fine-tuned macroscale features were successfully installed in the monoliths. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Nanoparticle chemisorption printing technique for conductive silver patterning with submicron resolution

PubMed Central

Yamada, Toshikazu; Fukuhara, Katsuo; Matsuoka, Ken; Minemawari, Hiromi; Tsutsumi, Jun'ya; Fukuda, Nobuko; Aoshima, Keisuke; Arai, Shunto; Makita, Yuichi; Kubo, Hitoshi; Enomoto, Takao; Togashi, Takanari; Kurihara, Masato; Hasegawa, Tatsuo

2016-01-01

Silver nanocolloid, a dense suspension of ligand-encapsulated silver nanoparticles, is an important material for printing-based device production technologies. However, printed conductive patterns of sufficiently high quality and resolution for industrial products have not yet been achieved, as the use of conventional printing techniques is severely limiting. Here we report a printing technique to manufacture ultrafine conductive patterns utilizing the exclusive chemisorption phenomenon of weakly encapsulated silver nanoparticles on a photoactivated surface. The process includes masked irradiation of vacuum ultraviolet light on an amorphous perfluorinated polymer layer to photoactivate the surface with pendant carboxylate groups, and subsequent coating of alkylamine-encapsulated silver nanocolloids, which causes amine–carboxylate conversion to trigger the spontaneous formation of a self-fused solid silver layer. The technique can produce silver patterns of submicron fineness adhered strongly to substrates, thus enabling manufacture of flexible transparent conductive sheets. This printing technique could replace conventional vacuum- and photolithography-based device processing. PMID:27091238

Development of a Hydrogen Peroxide Sensor Based on Screen-Printed Electrodes Modified with Inkjet-Printed Prussian Blue Nanoparticles

PubMed Central

Cinti, Stefano; Arduini, Fabiana; Moscone, Danila; Palleschi, Giuseppe; Killard, Anthony J.

2014-01-01

A sensor for the simple and sensitive measurement of hydrogen peroxide has been developed which is based on screen printed electrodes (SPEs) modified with Prussian blue nanoparticles (PBNPs) deposited using piezoelectric inkjet printing. PBNP-modified SPEs were characterized using physical and electrochemical techniques to optimize the PBNP layer thickness and electroanalytical conditions for optimum measurement of hydrogen peroxide. Sensor optimization resulted in a limit of detection of 2 × 10−7 M, a linear range from 0 to 4.5 mM and a sensitivity of 762 μA·mM−1·cm−2 which was achieved using 20 layers of printed PBNPs. Sensors also demonstrated excellent reproducibility (<5% rsd). PMID:25093348

Anatomic modeling using 3D printing: quality assurance and optimization.

PubMed

Leng, Shuai; McGee, Kiaran; Morris, Jonathan; Alexander, Amy; Kuhlmann, Joel; Vrieze, Thomas; McCollough, Cynthia H; Matsumoto, Jane

2017-01-01

The purpose of this study is to provide a framework for the development of a quality assurance (QA) program for use in medical 3D printing applications. An interdisciplinary QA team was built with expertise from all aspects of 3D printing. A systematic QA approach was established to assess the accuracy and precision of each step during the 3D printing process, including: image data acquisition, segmentation and processing, and 3D printing and cleaning. Validation of printed models was performed by qualitative inspection and quantitative measurement. The latter was achieved by scanning the printed model with a high resolution CT scanner to obtain images of the printed model, which were registered to the original patient images and the distance between them was calculated on a point-by-point basis. A phantom-based QA process, with two QA phantoms, was also developed. The phantoms went through the same 3D printing process as that of the patient models to generate printed QA models. Physical measurement, fit tests, and image based measurements were performed to compare the printed 3D model to the original QA phantom, with its known size and shape, providing an end-to-end assessment of errors involved in the complete 3D printing process. Measured differences between the printed model and the original QA phantom ranged from -0.32 mm to 0.13 mm for the line pair pattern. For a radial-ulna patient model, the mean distance between the original data set and the scanned printed model was -0.12 mm (ranging from -0.57 to 0.34 mm), with a standard deviation of 0.17 mm. A comprehensive QA process from image acquisition to completed model has been developed. Such a program is essential to ensure the required accuracy of 3D printed models for medical applications.

Prekindergarten teachers' verbal references to print during classroom-based, large-group shared reading.

PubMed

Zucker, Tricia A; Justice, Laura M; Piasta, Shayne B

2009-10-01

The frequency with which adults reference print when reading with preschool-age children is associated with growth in children's print knowledge (e.g., L.M. Justice & H.K. Ezell, 2000, 2002). This study examined whether prekindergarten (pre-K) teachers naturally reference print during classroom shared reading and if verbal print references occur at similar rates across different types of books. The relation between frequency of print referencing and quality of teachers' language instruction was also studied. Seventeen pre-K teachers were randomly assigned to a regular reading condition as part of a larger study, and 92 videos of their large-group, shared-reading sessions were analyzed for print-referencing utterances and quality of language instruction. Teachers' verbal print references were compared across texts that were purposefully sampled to include different levels of print salience. Teachers discussed all domains of print studied; however, their rate of print referencing was relatively low. More verbal print references were observed when the teachers read books exhibiting higher amounts of print-salient features. When reading books, there was no apparent relation between teachers' use of print referencing and their quality of language instruction. It is unclear whether this low rate of explicit, verbal print referencing would impact children's print knowledge. Nonetheless, print-salient books appear to offer a natural context for discussions about print. Implications for educational practice are considered.

A new chapter in pharmaceutical manufacturing: 3D-printed drug products.

PubMed

Norman, James; Madurawe, Rapti D; Moore, Christine M V; Khan, Mansoor A; Khairuzzaman, Akm

2017-01-01

FDA recently approved a 3D-printed drug product in August 2015, which is indicative of a new chapter for pharmaceutical manufacturing. This review article summarizes progress with 3D printed drug products and discusses process development for solid oral dosage forms. 3D printing is a layer-by-layer process capable of producing 3D drug products from digital designs. Traditional pharmaceutical processes, such as tablet compression, have been used for decades with established regulatory pathways. These processes are well understood, but antiquated in terms of process capability and manufacturing flexibility. 3D printing, as a platform technology, has competitive advantages for complex products, personalized products, and products made on-demand. These advantages create opportunities for improving the safety, efficacy, and accessibility of medicines. Although 3D printing differs from traditional manufacturing processes for solid oral dosage forms, risk-based process development is feasible. This review highlights how product and process understanding can facilitate the development of a control strategy for different 3D printing methods. Overall, the authors believe that the recent approval of a 3D printed drug product will stimulate continual innovation in pharmaceutical manufacturing technology. FDA encourages the development of advanced manufacturing technologies, including 3D-printing, using science- and risk-based approaches. Published by Elsevier B.V.

A Bioactive Carbon Nanotube-Based Ink for Printing 2D and 3D Flexible Electronics.

PubMed

Shin, Su Ryon; Farzad, Raziyeh; Tamayol, Ali; Manoharan, Vijayan; Mostafalu, Pooria; Zhang, Yu Shrike; Akbari, Mohsen; Jung, Sung Mi; Kim, Duckjin; Comotto, Mattia; Annabi, Nasim; Al-Hazmi, Faten Ebrahim; Dokmeci, Mehmet R; Khademhosseini, Ali

2016-05-01

The development of electrically conductive carbon nanotube-based inks is reported. Using these inks, 2D and 3D structures are printed on various flexible substrates such as paper, hydrogels, and elastomers. The printed patterns have mechanical and electrical properties that make them beneficial for various biological applications. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Digital multicolor printing: state of the art and future challenges

NASA Astrophysics Data System (ADS)

Kipphan, Helmut

1995-04-01

During the last 5 years, digital techniques have become extremely important in the graphic arts industry. All sections in the production flow for producing multicolor printed products - prepress, printing and postpress - are influenced by digitalization, in an evolutionary and revolutionary way. New equipment and network techniques bring all the sections closer together. The focus is put on high-quality multicolor printing, together with high productivity. Conventional offset printing technology is compared with the leading nonimpact printing technologies. Computer to press is contrasted with computer to print techniques. The newest available digital multicolor presses are described - the direct imaging offset printing press from HEIDELBERG with new laser imaging technique as well as the INDIGO and XEIKON presses based on electrophotography. Regarding technical specifications, economic calculations and print quality, it is worked out that each technique has its own market segments. An outlook is given for future computer to press techniques and the potential of nonimpact printing technologies for advanced high-speed multicolor computer to print equipment. Synergy effects from the NIP-technologies to the conventional printing technologies and vice versa are possible for building up innovative new products, for example hybrid printing systems. It is also shown that there is potential for improving the print quality, based on special screening algorithms, and a higher number of grey levels per pixel by using NIP-technologies. As an intermediate step in digitalization of the production flow, but also as an economical solution computer to plate equipment is described. By producing printed products totally in a digital way, digital color proofing as well as color management systems are needed. The newest high-tech equipment using NIP-technologies for producing proofs is explained. All in all it is shown that the state of the art in digital multicolor printing has reached a very high level in technology, productivity and quality, but that there is still space for improvements and innovations. Manufacturers of equipment and producers of printed products can take part in a successful evolution-changes, chances and challenges must be recognized and considered for future orientated activities and investments.

Advances in Additive Manufacturing

DTIC Science & Technology

2016-07-14

of 3D - printed structures. Analysis examples will include quantification of tolerance differences between the designed and manufactured parts, void...15. SUBJECT TERMS 3-D printing , validation and verification, nondestructive inspection, print -on-the-move, prototyping 16. SECURITY CLASSIFICATION...researching the formation of AM-grade metal powder from battlefield scrap and operating base waste, 2) potential of 3-D printing with sand to make

Freeform inkjet printing of cellular structures with bifurcations.

PubMed

Christensen, Kyle; Xu, Changxue; Chai, Wenxuan; Zhang, Zhengyi; Fu, Jianzhong; Huang, Yong

2015-05-01

Organ printing offers a great potential for the freeform layer-by-layer fabrication of three-dimensional (3D) living organs using cellular spheroids or bioinks as building blocks. Vascularization is often identified as a main technological barrier for building 3D organs. As such, the fabrication of 3D biological vascular trees is of great importance for the overall feasibility of the envisioned organ printing approach. In this study, vascular-like cellular structures are fabricated using a liquid support-based inkjet printing approach, which utilizes a calcium chloride solution as both a cross-linking agent and support material. This solution enables the freeform printing of spanning and overhang features by providing a buoyant force. A heuristic approach is implemented to compensate for the axially-varying deformation of horizontal tubular structures to achieve a uniform diameter along their axial directions. Vascular-like structures with both horizontal and vertical bifurcations have been successfully printed from sodium alginate only as well as mouse fibroblast-based alginate bioinks. The post-printing fibroblast cell viability of printed cellular tubes was found to be above 90% even after a 24 h incubation, considering the control effect. © 2014 Wiley Periodicals, Inc.

Pharmaceutical-grade oral films as substrates for printed medicine.

PubMed

Wimmer-Teubenbacher, M; Planchette, C; Pichler, H; Markl, D; Hsiao, W K; Paudel, A; Stegemann, S

2018-05-18

In contact-less printing, such as piezo-electric drop on demand printing used in the study, the drop formation process is independent of the substrate. This means that having developed a printable formulation, printed pharmaceutical dosage forms can be obtained on any pharmaceutical grade substrate, such as polymer-based films. In this work we evaluated eight different oral films based on their suitability as printing substrates for sodium picosulfate. The different polymer films were compared regarding printed spot morphology, chemical stability and dissolution profile. The morphology of printed sodium picosulfate was investigated with scanning electron microscopy and optical coherence tomography. The spreading of the deposited drops was found to be governed by the contact angle of the ink with the substrate. The form of the sodium picosulfate drops changed on microcrystalline cellulose films at ambient conditions over 8 weeks and stayed unchanged on other tested substrates. Sodium picosulfate remained amorphous on all substrates according to small and wide angle X-ray scattering, differential scanning calorimetry and polarized light microscopy measurements. The absence of chemical interactions between the drug and substrates, as indicated by infrared spectroscopy, makes all tested substrates suitable for printing sodium picosulfate onto them. Copyright © 2018 Elsevier B.V. All rights reserved.

Differences in reach and attrition between Web-based and print-delivered tailored interventions among adults over 50 years of age: clustered randomized trial.

PubMed

Peels, Denise Astrid; Bolman, Catherine; Golsteijn, Rianne Henrica Johanna; De Vries, Hein; Mudde, Aart Nicolaas; van Stralen, Maartje Marieke; Lechner, Lilian

2012-12-17

The Internet has the potential to provide large populations with individual health promotion advice at a relatively low cost. Despite the high rates of Internet access, actual reach by Web-based interventions is often disappointingly low, and differences in use between demographic subgroups are present. Furthermore, Web-based interventions often have to deal with high rates of attrition. This study aims to assess user characteristics related to participation and attrition when comparing Web-based and print-delivered tailored interventions containing similar content and thereby to provide recommendations in choosing the appropriate delivery mode for a particular target audience. We studied the distribution of a Web-based and a print-delivered version of the Active Plus intervention in a clustered randomized controlled trial (RCT). Participants were recruited via direct mailing within the participating Municipal Health Council regions and randomized to the printed or Web-based intervention by their region. Based on the answers given in a prior assessment, participants received tailored advice on 3 occasions: (1) within 2 weeks after the baseline, (2) 2 months after the baseline, and (3) within 4 months after the baseline (based on a second assessment at 3 months). The baseline (printed or Web-based) results were analyzed using ANOVA and chi-square tests to establish the differences in user characteristics between both intervention groups. We used logistic regression analyses to study the interaction between the user characteristics and the delivery mode in the prediction of dropout rate within the intervention period. The printed intervention resulted in a higher participation rate (19%) than the Web-based intervention (12%). Participants of the Web-based intervention were significantly younger (P<.001), more often men (P=.01), had a higher body mass index (BMI) (P=.001) and a lower intention to be physically active (P=.03) than participants of the printed intervention. The dropout rate was significantly higher in the Web-based intervention group (53%) compared to the print-delivered intervention (39%, P<.001). A low intention to be physically active was a strong predictor for dropout within both delivery modes (P<.001). The difference in dropout rate between the Web-based and the printed intervention was not explained by user characteristics. The reach of the same tailored physical activity (PA) intervention in a printed or Web-based delivery mode differed between sociodemographic subgroups of participants over 50 years of age. Although the reach of the Web-based intervention is lower, Web-based interventions can be a good channel to reach high-risk populations (lower PA intention and higher BMI). While the dropout rate was significantly higher in the Web-based intervention group, no specific user characteristics explained the difference in dropout rates between the delivery modes. More research is needed to determine what caused the high rate of dropout in the Web-based intervention. Dutch Trial Register (NTR): 2297: http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=2297 (Archived by WebCite at http://www.webcitation.org/65TkwoESp).

Differences in Reach and Attrition Between Web-Based and Print-Delivered Tailored Interventions Among Adults over 50 Years of Age: Clustered Randomized Trial

PubMed Central

Bolman, Catherine; Golsteijn, Rianne Henrica Johanna; De Vries, Hein; Mudde, Aart Nicolaas; van Stralen, Maartje Marieke; Lechner, Lilian

2012-01-01

Background The Internet has the potential to provide large populations with individual health promotion advice at a relatively low cost. Despite the high rates of Internet access, actual reach by Web-based interventions is often disappointingly low, and differences in use between demographic subgroups are present. Furthermore, Web-based interventions often have to deal with high rates of attrition. Objective This study aims to assess user characteristics related to participation and attrition when comparing Web-based and print-delivered tailored interventions containing similar content and thereby to provide recommendations in choosing the appropriate delivery mode for a particular target audience. Methods We studied the distribution of a Web-based and a print-delivered version of the Active Plus intervention in a clustered randomized controlled trial (RCT). Participants were recruited via direct mailing within the participating Municipal Health Council regions and randomized to the printed or Web-based intervention by their region. Based on the answers given in a prior assessment, participants received tailored advice on 3 occasions: (1) within 2 weeks after the baseline, (2) 2 months after the baseline, and (3) within 4 months after the baseline (based on a second assessment at 3 months). The baseline (printed or Web-based) results were analyzed using ANOVA and chi-square tests to establish the differences in user characteristics between both intervention groups. We used logistic regression analyses to study the interaction between the user characteristics and the delivery mode in the prediction of dropout rate within the intervention period. Results The printed intervention resulted in a higher participation rate (19%) than the Web-based intervention (12%). Participants of the Web-based intervention were significantly younger (P<.001), more often men (P=.01), had a higher body mass index (BMI) (P=.001) and a lower intention to be physically active (P=.03) than participants of the printed intervention. The dropout rate was significantly higher in the Web-based intervention group (53%) compared to the print-delivered intervention (39%, P<.001). A low intention to be physically active was a strong predictor for dropout within both delivery modes (P<.001). The difference in dropout rate between the Web-based and the printed intervention was not explained by user characteristics. Conclusions The reach of the same tailored physical activity (PA) intervention in a printed or Web-based delivery mode differed between sociodemographic subgroups of participants over 50 years of age. Although the reach of the Web-based intervention is lower, Web-based interventions can be a good channel to reach high-risk populations (lower PA intention and higher BMI). While the dropout rate was significantly higher in the Web-based intervention group, no specific user characteristics explained the difference in dropout rates between the delivery modes. More research is needed to determine what caused the high rate of dropout in the Web-based intervention. Trial Registration Dutch Trial Register (NTR): 2297: http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=2297 (Archived by WebCite at http://www.webcitation.org/65TkwoESp). PMID:23246790

Implementation of Non-Destructive Evaluation and Process Monitoring in DLP-based Additive Manufacturing

NASA Astrophysics Data System (ADS)

Kovalenko, Iaroslav; Verron, Sylvain; Garan, Maryna; Šafka, Jiří; Moučka, Michal

2017-04-01

This article describes a method of in-situ process monitoring in the digital light processing (DLP) 3D printer. It is based on the continuous measurement of the adhesion force between printing surface and bottom of a liquid resin bath. This method is suitable only for the bottom-up DPL printers. Control system compares the force at the moment of unsticking of printed layer from the bottom of the tank, when it has the largest value in printing cycle, with theoretical value. Implementation of suggested algorithm can make detection of faults during the printing process possible.

Printed energy storage devices by integration of electrodes and separators into single sheets of paper

NASA Astrophysics Data System (ADS)

Hu, Liangbing; Wu, Hui; Cui, Yi

2010-05-01

We report carbon nanotube thin film-based supercapacitors fabricated with printing methods, where electrodes and separators are integrated into single sheets of commercial paper. Carbon nanotube films are easily printed with Meyer rod coating or ink-jet printing onto a paper substrate due to the excellent ink absorption of paper. A specific capacity of 33 F/g at a high specific power of 250 000 W/kg is achieved with an organic electrolyte. Such a lightweight paper-based supercapacitor could be used to power paper electronics such as transistors or displays.

Paper-Based Textbooks with Audio Support for Print-Disabled Students.

PubMed

Fujiyoshi, Akio; Ohsawa, Akiko; Takaira, Takuya; Tani, Yoshiaki; Fujiyoshi, Mamoru; Ota, Yuko

2015-01-01

Utilizing invisible 2-dimensional codes and digital audio players with a 2-dimensional code scanner, we developed paper-based textbooks with audio support for students with print disabilities, called "multimodal textbooks." Multimodal textbooks can be read with the combination of the two modes: "reading printed text" and "listening to the speech of the text from a digital audio player with a 2-dimensional code scanner." Since multimodal textbooks look the same as regular textbooks and the price of a digital audio player is reasonable (about 30 euro), we think multimodal textbooks are suitable for students with print disabilities in ordinary classrooms.

Overlay accuracy on a flexible web with a roll printing process based on a roll-to-roll system.

PubMed

Chang, Jaehyuk; Lee, Sunggun; Lee, Ki Beom; Lee, Seungjun; Cho, Young Tae; Seo, Jungwoo; Lee, Sukwon; Jo, Gugrae; Lee, Ki-yong; Kong, Hyang-Shik; Kwon, Sin

2015-05-01

For high-quality flexible devices from printing processes based on Roll-to-Roll (R2R) systems, overlay alignment during the patterning of each functional layer poses a major challenge. The reason is because flexible substrates have a relatively low stiffness compared with rigid substrates, and they are easily deformed during web handling in the R2R system. To achieve a high overlay accuracy for a flexible substrate, it is important not only to develop web handling modules (such as web guiding, tension control, winding, and unwinding) and a precise printing tool but also to control the synchronization of each unit in the total system. A R2R web handling system and reverse offset printing process were developed in this work, and an overlay between the 1st and 2nd layers of ±5μm on a 500 mm-wide film was achieved at a σ level of 2.4 and 2.8 (x and y directions, respectively) in a continuous R2R printing process. This paper presents the components and mechanisms used in reverse offset printing based on a R2R system and the printing results including positioning accuracy and overlay alignment accuracy.

Engraving Print Classification

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

Hoelck, Daniel; Barbe, Joaquim

2008-04-15

A print is a mark, or drawing, made in or upon a plate, stone, woodblock or other material which is cover with ink and then is press usually into a paper reproducing the image on the paper. Engraving prints usually are image composed of a group of binary lines, specially those are made with relief and intaglio techniques. Varying the number and the orientation of lines, the drawing of the engraving print is conformed. For this reason we propose an application based on image processing methods to classify engraving prints.

Development of a Recombination System for the Generation of Occlusion Positive Genetically Modified Anticarsia Gemmatalis Multiple Nucleopolyhedrovirus

PubMed Central

Haase, Santiago; McCarthy, Christina B.; Ferrelli, M. Leticia; Pidre, Matias L.; Sciocco-Cap, Alicia; Romanowski, Victor

2015-01-01

Anticarsia gemmatalis is an important pest in legume crops in South America and it has been successfully controlled using Anticarsia gemmatalis Multiple Nucleopolyhedrovirus (AgMNPV) in subtropical climate zones. Nevertheless, in temperate climates its speed of kill is too slow. Taking this into account, genetic modification of AgMNPV could lead to improvements of its biopesticidal properties. Here we report the generation of a two-component system that allows the production of recombinant AgMNPV. This system is based on a parental AgMNPV in which the polyhedrin gene (polh) was replaced by a bacterial β-galactosidase (lacZ) gene flanked by two target sites for the homing endonuclease I-PpoI. Co-transfection of insect cells with linearized (I-PpoI-digested) parental genome and a transfer vector allowed the restitution of polh and the expression of a heterologous gene upon homologous recombination, with a low background of non-recombinant AgMNPV. The system was validated by constructing a recombinant occlusion-positive (polh+) AgMNPV expressing the green fluorescent protein gene (gfp). This recombinant virus infected larvae normally per os and led to the expression of GFP in cell culture as well as in A. gemmatalis larvae. These results demonstrate that the system is an efficient method for the generation of recombinant AgMNPV expressing heterologous genes, which can be used for manifold purposes, including biotechnological and pharmaceutical applications and the production of orally infectious recombinants with improved biopesticidal properties. PMID:25835531

Employee choice of consumer-driven health insurance in a multiplan, multiproduct setting.

PubMed

Parente, Stephen T; Feldman, Roger; Christianson, Jon B

2004-08-01

To determine who chooses a Consumer-Driven Health Plan (CDHP) in a multiplan, multiproduct setting, and, specifically, whether the CDHP attracts the sicker employees in a company's risk pool. We estimated a health plan choice equation for employees of the University of Minnesota, who had a choice in 2002 of a CDHP and three other health plans--a traditional health maintenance organization (HMO), a preferred provider organization (PPO), and a tiered network product based on care systems. Data from an employee survey were matched to information from the university's payroll system. Chronic illness of the employee or family members had no effect on choice of the CDHP, but such employees tended to choose the PPO. The employee's age was not related to CDHP choice. Higher-income employees chose the CDHP, as well as those who preferred health plans with a national provider panel that includes their physician in the panel. Employees tended to choose plans with lower out-of-pocket premiums, and surprisingly, employees with a chronic health condition themselves or in their family were more price-sensitive. This study provides the first evidence on who chooses a CDHP in a multiplan, multiproduct setting. The CDHP was not chosen disproportionately by the young and healthy, but it did attract the wealthy and those who found the availability of providers more appealing. Low out-of-pocket premiums are important features of health plans and in this setting, low premiums appeal to those who are less healthy.

Impact of nano-CaCO3 -LDPE packaging on quality of fresh-cut sugarcane.

PubMed

Luo, Zisheng; Wang, Yansheng; Wang, Haohui; Feng, Simin

2014-12-01

In order to evaluate the effects of nano-CaCO3 -based low density polyethylene (nano-CaCO3 -LDPE) packaging on the quality of fresh-cut sugarcane, concentrations of O2 and CO2 within the packages, overall visual quality (OVQ), total bacterial count (TBC), yeast and mould count (YMC), reducing sugar content and total phenolic content, respiration, ethylene production, and the activities of phenylalanine ammonia-lyase (PAL), polyphenol oxidase (PPO), peroxidase (POD), acid invertase (AI) and neutral invertase (NI) were examined during storage at 10 °C for 5 days. The transmission rate of O2 and CO2 of the nano-CaCO3 -LDPE material was lower than that of LDPE, which lead to the more rapid formation of gas environment with low O2 and high CO2 concentration in the package. TBC and YMC counts of fresh-cut sugarcane were significantly retarded by nano-CaCO3 -LDPE packaging. Nano-CaCO3 -LDPE packaging fresh-cut sugarcane exhibited significantly lower activities of PAL, PPO, POD AI and NI than LDPE packaging fresh-cut sugarcanes during the storage. Meanwhile, nano-CaCO3 -LDPE packaging significantly inhibited the increase of browning index and total phenolic content, while improving OVQ. Our results indicated that nano-CaCO3 -LDPE packaging together with the cold storage is a promising approach in inhibiting browning and maintaining quality of fresh-cut sugarcane. © 2014 Society of Chemical Industry.

Morbidity, mortality, and categorization of the risk of perioperative complications in lung cancer patients*

PubMed Central

Stanzani, Fabiana; Paisani, Denise de Moraes; de Oliveira, Anderson; de Souza, Rodrigo Caetano; Perfeito, João Aléssio Juliano; Faresin, Sonia Maria

2014-01-01

OBJECTIVE: To determine morbidity and mortality rates by risk category in accordance with the American College of Chest Physicians guidelines, to determine what role pulmonary function tests play in this categorization process, and to identify risk factors for perioperative complications (PCs). METHODS: This was a historical cohort study based on preoperative and postoperative data collected for cases of lung cancer diagnosed or suspected between 2001 and 2010. RESULTS: Of the 239 patients evaluated, only 13 (5.4%) were classified as being at high risk of PCs. Predicted postoperative FEV1 (FEV1ppo) was sufficient to define the risk level in 156 patients (65.3%); however, cardiopulmonary exercise testing (CPET) was necessary for identifying those at high risk. Lung resection was performed in 145 patients. Overall morbidity and mortality rates were similar to those reported in other studies. However, morbidity and mortality rates for patients at an acceptable risk of PCs were 31.6% and 4.3%, respectively, whereas those for patients at high risk were 83.3% and 33.3%. Advanced age, COPD, lobe resection, and lower FEV1ppo were correlated with PCs. CONCLUSIONS: Although spirometry was sufficient for risk assessment in the majority of the population studied, CPET played a key role in the identification of high-risk patients, among whom the mortality rate was seven times higher than was that observed for those at an acceptable risk of PCs. The risk factors related to PCs coincided with those reported in previous studies. PMID:24626266

Fatty acid composition of ruminal digesta and longissimus muscle from lambs fed silage mixtures including red clover, sainfoin, and timothy.

PubMed

Campidonico, L; Toral, P G; Priolo, A; Luciano, G; Valenti, B; Hervás, G; Frutos, P; Copani, G; Ginane, C; Niderkorn, V

2016-04-01

This work investigated the effects of feeding silage mixtures of a plant containing polyphenol oxidase (PPO; red clover [; RC]), a plant containing tannins (sainfoin [; SF]), and a grass species not containing these compounds (timothy [; T]) on ruminal and intramuscular (i.m.) fatty acids of lambs. Forty 4-mo-old castrated male Romane lambs, divided into 5 groups, received 1 of the following silages: 1) T (100%), 2) a binary mixture of timothy and tannin-containing sainfoin ( cv. Perly; 50:50 [T-SF]), 3) a binary mixture of timothy and PPO-containing red clover ( cv. Mervius; 50:50 [T-RC]), 4) a ternary mixture of timothy, sainfoin, and red clover containing both tannins and PPO (50:25:25, respectively [T-SF-RC]), and 5) a binary mixture of tannin-containing sainfoin and PPO-containing red clover (50:50 [SF-RC]). In the rumen digesta, the partial or total replacement of T with forage legumes was associated with greater concentrations of PUFA ( < 0.001) and 1esser concentrations of MUFA ( < 0.001). The inclusion of forage legumes in the silage favored the accumulation of 18:3 -3 ( < 0.001), with the greatest concentrations being observed in SF-RC. This latter diet also led to the greatest percentage of 18:2 -6 ( < 0.001). Forage legumes decreased the -11 18:1 to 30% of T in rumen digesta ( < 0.001). Forage legumes decreased the total concentration of branched-chain fatty acids in the rumen digesta (on average, -28%; < 0.001), this effect being less marked (-17%; = 0.014) in T-RC in comparison with T. The dietary treatment tended to affect the proportion of MUFA ( = 0.081) and of PUFA ( = 0.079) in the i.m. fat of the LM, respectively, at the highest and lowest numerical value in the T group. The sum of -3 fatty acids was less in the T and T-SF groups compared with the mixture of legumes without T (SF-RC; < 0.001 and < 0.008, respectively). The latter group had also a lesser -6-to--3 ratio than the T-SF group ( = 0.01). -11 18:1 was greater ( < 0.03) in lambs given T as the sole silage in comparison with lambs given T-RC, T-SF-RC, and SF-RC. Rumenic acid (-9 -11 CLA) was detected at a greater percentage in the LM from the animals fed the T silage compared with animals fed the T-SF-RC treatment ( = 0.004). Contrarily, -9 -12 -15 18:3 was found at a greater concentration in the muscle from lambs in the SF-RC treatment compared with lambs in the other treatments ( < 0.001). Furthermore, the T-RC group showed a greater proportion of α-linolenic acid than the T group ( = 0.03). In conclusion, the effects of the 2 active compounds (PPO and tannins) appear to be similar and additive. Moreover, a silage composed of a mixture of RC and SF is an excellent forage for growing lambs in terms of i.m. fatty acid composition.

Factors associated with choice of web or print intervention materials in the healthy directions 2 study.

PubMed

Greaney, Mary L; Puleo, Elaine; Bennett, Gary G; Haines, Jess; Viswanath, K; Gillman, Matthew W; Sprunck-Harrild, Kim; Coeling, Molly; Rusinak, Donna; Emmons, Karen M

2014-02-01

Many U.S. adults have multiple behavioral risk factors, and effective, scalable interventions are needed to promote population-level health. In the health care setting, interventions are often provided in print, although accessible to nearly everyone, are brief (e.g., pamphlets), are not interactive, and can require some logistics around distribution. Web-based interventions offer more interactivity but may not be accessible to all. Healthy Directions 2 was a primary care-based cluster randomized controlled trial designed to improve five behavioral cancer risk factors among a diverse sample of adults (n = 2,440) in metropolitan Boston. Intervention materials were available via print or the web. Purpose. To (a) describe the Healthy Directions 2 study design and (b) identify baseline factors associated with whether participants opted for print or web-based materials. Hierarchical regression models corrected for clustering by physician were built to examine factors associated with choice of intervention modality. At baseline, just 4.0% of participants met all behavioral recommendations. Nearly equivalent numbers of intervention participants opted for print and web-based materials (44.6% vs. 55.4%). Participants choosing web-based materials were younger, and reported having a better financial status, better perceived health, greater computer comfort, and more frequent Internet use (p < .05) than those opting for print. In addition, Whites were more likely to pick web-based material than Black participants. Interventions addressing multiple behaviors are needed in the primary care setting, but they should be available in web and print formats as nearly equal number of participants chose each option, and there are significant differences in the population groups using each modality.

Biosynthesis of hydroxycinnamoyl esters and amides in legume species

USDA-ARS?s Scientific Manuscript database

In forage crops, protein that is degraded following harvest is poorly utilized by ruminant animals, resulting in both economic and environmental consequences. In red clover, secondary reactions of quinones resulting from polyphenol oxidase (PPO)-mediated oxidation of the caffeic acid derivatives pha...

Possibility of reconstruction of dental plaster cast from 3D digital study models

PubMed Central

2013-01-01

Objectives To compare traditional plaster casts, digital models and 3D printed copies of dental plaster casts based on various criteria. To determine whether 3D printed copies obtained using open source system RepRap can replace traditional plaster casts in dental practice. To compare and contrast the qualities of two possible 3D printing options – open source system RepRap and commercially available 3D printing. Design and settings A method comparison study on 10 dental plaster casts from the Orthodontic department, Department of Stomatology, 2nd medical Faulty, Charles University Prague, Czech Republic. Material and methods Each of 10 plaster casts were scanned by inEos Blue scanner and the printed on 3D printer RepRap [10 models] and ProJet HD3000 3D printer [1 model]. Linear measurements between selected points on the dental arches of upper and lower jaws on plaster casts and its 3D copy were recorded and statistically analyzed. Results 3D printed copies have many advantages over traditional plaster casts. The precision and accuracy of the RepRap 3D printed copies of plaster casts were confirmed based on the statistical analysis. Although the commercially available 3D printing enables to print more details than the RepRap system, it is expensive and for the purpose of clinical use can be replaced by the cheaper prints obtained from RepRap printed copies. Conclusions Scanning of the traditional plaster casts to obtain a digital model offers a pragmatic approach. The scans can subsequently be used as a template to print the plaster casts as required. Using 3D printers can replace traditional plaster casts primarily due to their accuracy and price. PMID:23721330

All Inkjet-Printed Amperometric Multiplexed Biosensors Based on Nanostructured Conductive Hydrogel Electrodes.

PubMed

Li, Lanlan; Pan, Lijia; Ma, Zhong; Yan, Ke; Cheng, Wen; Shi, Yi; Yu, Guihua

2018-06-13

Multiplexing, one of the main trends in biosensors, aims to detect several analytes simultaneously by integrating miniature sensors on a chip. However, precisely depositing electrode materials and selective enzymes on distinct microelectrode arrays remains an obstacle to massively produced multiplexed sensors. Here, we report on a "drop-on-demand" inkjet printing process to fabricate multiplexed biosensors based on nanostructured conductive hydrogels in which the electrode material and several kinds of enzymes were printed on the electrode arrays one by one by employing a multinozzle inkjet system. The whole inkjet printing process can be finished within three rounds of printing and only one round of alignment. For a page of sensor arrays containing 96 working electrodes, the printing process took merely ∼5 min. The multiplexed assays can detect glucose, lactate, and triglycerides in real time with good selectivity and high sensitivity, and the results in phosphate buffer solutions and calibration serum samples are comparable. The inkjet printing process exhibited advantages of high efficiency and accuracy, which opens substantial possibilities for massive fabrication of integrated multiplexed biosensors for human health monitoring.

Water-based polyurethane 3D printed scaffolds with controlled release function for customized cartilage tissue engineering.

PubMed

Hung, Kun-Che; Tseng, Ching-Shiow; Dai, Lien-Guo; Hsu, Shan-hui

2016-03-01

Conventional 3D printing may not readily incorporate bioactive ingredients for controlled release because the process often involves the use of heat, organic solvent, or crosslinkers that reduce the bioactivity of the ingredients. Water-based 3D printing materials with controlled bioactivity for customized cartilage tissue engineering is developed in this study. The printing ink contains the water dispersion of synthetic biodegradable polyurethane (PU) elastic nanoparticles, hyaluronan, and bioactive ingredients TGFβ3 or a small molecule drug Y27632 to replace TGFβ3. Compliant scaffolds are printed from the ink at low temperature. These scaffolds promote the self-aggregation of mesenchymal stem cells (MSCs) and, with timely release of the bioactive ingredients, induce the chondrogenic differentiation of MSCs and produce matrix for cartilage repair. Moreover, the growth factor-free controlled release design may prevent cartilage hypertrophy. Rabbit knee implantation supports the potential of the novel 3D printing scaffolds in cartilage regeneration. We consider that the 3D printing composite scaffolds with controlled release bioactivity may have potential in customized tissue engineering. Copyright © 2016 Elsevier Ltd. All rights reserved.

Study of thermo-fluidic behavior of micro-droplet in inkjet-based micro manufacturing processes

NASA Astrophysics Data System (ADS)

Das, Raju; Mahapatra, Abhijit; Ball, Amit Kumar; Roy, Shibendu Shekhar; Murmu, Naresh Chandra

2017-06-01

Inkjet printing technology, a maskless, non-contact patterning operation, which has been a revelation in the field of micro and nano manufacturing for its use in the selective deposition of desired materials. It is becoming an exciting alternative technology such as lithography to print functional material on to a substrate. Selective deposition of functional materials on desired substrates is a basic requirement in many of the printing based micro and nano manufacturing operations like the fabrication of microelectronic devices, solar cell, Light-emitting Diode (LED) research fields like pharmaceutical industries for drug discovery purposes and in biotechnology to make DNA microarrays. In this paper, an attempt has been made to design and develop an indigenous Electrohydrodynamic Inkjet printing system for micro fabrication and to study the interrelationships between various thermos-fluidic parameters of the ink material in the printing process. The effect of printing process parameters on printing performance characteristics has also been studied. And the applicability of the process has also been experimentally demonstrated. The experimentally found results were quite satisfactory and accordance to its applicability.

Benford's Law based detection of latent fingerprint forgeries on the example of artificial sweat printed fingerprints captured by confocal laser scanning microscopes

NASA Astrophysics Data System (ADS)

Hildebrandt, Mario; Dittmann, Jana

2015-03-01

The possibility of forging latent fingerprints at crime scenes is known for a long time. Ever since it has been stated that an expert is capable of recognizing the presence of multiple identical latent prints as an indicator towards forgeries. With the possibility of printing fingerprint patterns to arbitrary surfaces using affordable ink- jet printers equipped with artificial sweat, it is rather simple to create a multitude of fingerprints with slight variations to avoid raising any suspicion. Such artificially printed fingerprints are often hard to detect during the analysis procedure. Moreover, the visibility of particular detection properties might be decreased depending on the utilized enhancement and acquisition technique. In previous work primarily such detection properties are used in combination with non-destructive high resolution sensory and pattern recognition techniques to detect fingerprint forgeries. In this paper we apply Benford's Law in the spatial domain to differentiate between real latent fingerprints and printed fingerprints. This technique has been successfully applied in media forensics to detect image manipulations. We use the differences between Benford's Law and the distribution of the most significant digit of the intensity and topography data from a confocal laser scanning microscope as features for a pattern recognition based detection of printed fingerprints. Our evaluation based on 3000 printed and 3000 latent print samples shows a very good detection performance of up to 98.85% using WEKA's Bagging classifier in a 10-fold stratified cross-validation.

3D Printed Graphene Based Energy Storage Devices

NASA Astrophysics Data System (ADS)

Foster, Christopher W.; Down, Michael P.; Zhang, Yan; Ji, Xiaobo; Rowley-Neale, Samuel J.; Smith, Graham C.; Kelly, Peter J.; Banks, Craig E.

2017-03-01

3D printing technology provides a unique platform for rapid prototyping of numerous applications due to its ability to produce low cost 3D printed platforms. Herein, a graphene-based polylactic acid filament (graphene/PLA) has been 3D printed to fabricate a range of 3D disc electrode (3DE) configurations using a conventional RepRap fused deposition moulding (FDM) 3D printer, which requires no further modification/ex-situ curing step. To provide proof-of-concept, these 3D printed electrode architectures are characterised both electrochemically and physicochemically and are advantageously applied as freestanding anodes within Li-ion batteries and as solid-state supercapacitors. These freestanding anodes neglect the requirement for a current collector, thus offering a simplistic and cheaper alternative to traditional Li-ion based setups. Additionally, the ability of these devices’ to electrochemically produce hydrogen via the hydrogen evolution reaction (HER) as an alternative to currently utilised platinum based electrodes (with in electrolysers) is also performed. The 3DE demonstrates an unexpectedly high catalytic activity towards the HER (-0.46 V vs. SCE) upon the 1000th cycle, such potential is the closest observed to the desired value of platinum at (-0.25 V vs. SCE). We subsequently suggest that 3D printing of graphene-based conductive filaments allows for the simple fabrication of energy storage devices with bespoke and conceptual designs to be realised.

3D Printed Graphene Based Energy Storage Devices

PubMed Central

Foster, Christopher W.; Down, Michael P.; Zhang, Yan; Ji, Xiaobo; Rowley-Neale, Samuel J.; Smith, Graham C.; Kelly, Peter J.; Banks, Craig E.

2017-01-01

3D printing technology provides a unique platform for rapid prototyping of numerous applications due to its ability to produce low cost 3D printed platforms. Herein, a graphene-based polylactic acid filament (graphene/PLA) has been 3D printed to fabricate a range of 3D disc electrode (3DE) configurations using a conventional RepRap fused deposition moulding (FDM) 3D printer, which requires no further modification/ex-situ curing step. To provide proof-of-concept, these 3D printed electrode architectures are characterised both electrochemically and physicochemically and are advantageously applied as freestanding anodes within Li-ion batteries and as solid-state supercapacitors. These freestanding anodes neglect the requirement for a current collector, thus offering a simplistic and cheaper alternative to traditional Li-ion based setups. Additionally, the ability of these devices’ to electrochemically produce hydrogen via the hydrogen evolution reaction (HER) as an alternative to currently utilised platinum based electrodes (with in electrolysers) is also performed. The 3DE demonstrates an unexpectedly high catalytic activity towards the HER (−0.46 V vs. SCE) upon the 1000th cycle, such potential is the closest observed to the desired value of platinum at (−0.25 V vs. SCE). We subsequently suggest that 3D printing of graphene-based conductive filaments allows for the simple fabrication of energy storage devices with bespoke and conceptual designs to be realised. PMID:28256602

Highly Stretchable and UV Curable Elastomers for Digital Light Processing Based 3D Printing.

PubMed

Patel, Dinesh K; Sakhaei, Amir Hosein; Layani, Michael; Zhang, Biao; Ge, Qi; Magdassi, Shlomo

2017-04-01

Stretchable UV-curable (SUV) elastomers can be stretched by up to 1100% and are suitable for digital-light-processing (DLP)-based 3D-printing technology. DLP printing of these SUV elastomers enables the direct creation of highly deformable complex 3D hollow structures such as balloons, soft actuators, grippers, and buckyball electronical switches. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

3D direct writing fabrication of electrodes for electrochemical storage devices

NASA Astrophysics Data System (ADS)

Wei, Min; Zhang, Feng; Wang, Wei; Alexandridis, Paschalis; Zhou, Chi; Wu, Gang

2017-06-01

Among different printing techniques, direct ink writing is commonly used to fabricate 3D battery and supercapacitor electrodes. The major advantages of using the direct ink writing include effectively building 3D structure for energy storage devices and providing higher power density and higher energy density than traditional techniques due to the increased surface area of electrode. Nevertheless, direct ink writing has high standards for the printing inks, which requires high viscosity, high yield stress under shear and compression, and well-controlled viscoelasticity. Recently, a number of 3D-printed energy storage devices have been reported, and it is very important to understand the printing process and the ink preparation process for further material design and technology development. We discussed current progress of direct ink writing technologies by using various electrode materials including carbon nanotube-based material, graphene-based material, LTO (Li4Ti5O12), LFP (LiFePO4), LiMn1-xFexPO4, and Zn-based metallic oxide. Based on achieve electrochemical performance, these 3D-printed devices deliver performance comparable to the energy storage device fabricated using traditional methods still leaving large room for further improvement. Finally, perspectives are provided on the potential future direction of 3D printing for all solid-state electrochemical energy storage devices.

Consumer cost sharing and use of biopharmaceuticals for rheumatoid arthritis.

PubMed

Robinson, James C

2013-06-01

To evaluate the effect of consumer cost sharing on use of physician-administered and patient self-administered specialty drugs for rheumatoid arthritis. Multivariate statistical analysis of probability and use of physician-administered specialty drugs, patient self-injected specialty drugs, non-biologic disease-modifying anti-rheumatic drugs, and symptom relief drugs. Analyses were conducted for patients enrolling in preferred provider organization (PPO) plans and health maintenance organization (HMO) plans with different cost-sharing requirements, adjusted for patient demographics, health status, and geographical location. Professional, facility, and pharmaceutical claims for beneficiaries of CalPERS, the public employee insurance purchasing alliance in California, for 2008-2009. Consumer cost-sharing requirements were obtained for each type of drug and service for each type of insurance plan. PPO insurance enrollees face substantially higher cost sharing for physician-administered specialty drugs, compared with HMO enrollees in CalPERS. PPO patients with rheumatoid arthritis are only half as likely as HMO enrollees to choose a physician-administered specialty drug (4.2% vs 9.3%) (P ≤.05), and use 25% less of the drugs if they use any ($10,356 vs $13,678) (P ≤.05). They are 30% more likely to use a self-administered specialty drug than are HMO enrollees (29.3% vs 22.1%) (P ≤.05), and use 35% more of the drugs if any ($16,015 vs $12,378) (P ≤.05). Consumer cost sharing reduces the use of physician-administered specialty drugs for rheumatoid arthritis. The higher use of patient self-administered specialty drugs suggests that the disincentives for use of physician-administered drugs were offset by an increased incentive to use self-administered drugs.

Effect of Seed Treatment by Cold Plasma on the Resistance of Tomato to Ralstonia solanacearum (Bacterial Wilt)

PubMed Central

Jiang, Jiafeng; Lu, Yufang; Li, Jiangang; Li, Ling; He, Xin; Shao, Hanliang; Dong, Yuanhua

2014-01-01

This study investigated the effect of cold plasma seed treatment on tomato bacterial wilt, caused by Ralstonia solanacearum (R. solanacearum), and the regulation of resistance mechanisms. The effect of cold plasma of 80W on seed germination, plant growth, nutrient uptake, disease severity, hydrogen peroxide (H2O2) concentration and activities of peroxidase (POD; EC 1.11.1.7), polyphenol oxidase (PPO; EC 1.10.3.2) and phenylalanine ammonia lyase (PAL; EC 4.3.1.5) were examined in tomato plants. Plasma treatment increased tomato resistance to R. solanacearum with an efficacy of 25.0%. Plasma treatment significantly increased both germination and plant growth in comparison with the control treatment, and plasma-treated plants absorbed more calcium and boron than the controls. In addition, H2O2 levels in treated plants rose faster and reached a higher peak, at 2.579 µM gFW−1, 140% greater than that of the control. Activities of POD (421.3 U gFW−1), PPO (508.8 U gFW−1) and PAL (707.3 U gFW−1) were also greater in the treated plants than in the controls (103.0 U gFW−1, 166.0 U gFW−1 and 309.4 U gFW−1, respectively). These results suggest that plasma treatment affects the regulation of plant growth, H2O2 concentration, and POD, PPO and PAL activity in tomato, resulting in an improved resistance to R. solanacearum. Consequently, cold plasma seed treatment has the potential to control tomato bacterial wilt caused by R. solanacearum. PMID:24840508

Design and syntheses of novel N-(benzothiazol-5-yl)-4,5,6,7-tetrahydro-1H-isoindole-1,3(2H)-dione and N-(benzothiazol-5-yl)isoindoline-1,3-dione as potent protoporphyrinogen oxidase inhibitors.

PubMed

Jiang, Li-Li; Zuo, Yang; Wang, Zhi-Fang; Tan, Yin; Wu, Qiong-You; Xi, Zhen; Yang, Guang-Fu

2011-06-08

Discovery of protoporphyrinogen oxidase (PPO, EC 1.3.3.4) inhibitors has been one of the hottest research areas in the field of herbicide development for many years. As a continuation of our research work on the development of new PPO-inhibiting herbicides, a series of novel N-(benzothiazol-5-yl)-4,5,6,7-tetrahydro-1H-isoindole-1,3(2H)-diones (1a-p) and N-(benzothiazol-5-yl)isoindoline-1,3-diones (2a-h) were designed and synthesized according to the ring-closing strategy of two ortho-substituents. The bioassay results indicated that some newly synthesized compounds exhibited higher PPO inhibition activity than the control of sulfentrazone. Compound 1a, S-(5-(1,3-dioxo-4,5,6,7-tetrahydro-1H-isoindol-2(3H)-yl)-6-fluorobenzothiazol-2-yl) O-methyl carbonothioate, was identified as the most potent inhibitor with k(i) value of 0.08 μM, about 9 times higher than that of sulfentrazone (k(i) = 0.72 μM). Further green house assay showed that compound 1b, methyl 2-((5-(1,3-dioxo-4,5,6,7-tetrahydro-1H-isoindol-2(3H)-yl)-6-fluorobenzothiazol-2-yl)thio)acetate, exhibited herbicidal activity comparable to that of sulfentrazone even at a concentration of 37.5 g ai/ha. In addition, among six tested crops, wheat exhibited high tolerance to compound 1b even at a dosage of 300 g ai/ha. These results indicated that compound 1b might have the potential to be developed as a new herbicide for weed control of wheat field.

Evaluation of accuracy of portable fingertip pulse oximeter, as compared to that of a hospital oximeter with digital sensor.

PubMed

Pupim, Denise; Iwaki Filho, Liogi; Takeshita, Wilton Mitsunari; Iwaki, Lilian Cristina Vessoni

2013-01-01

The pulse oximeter is a device that noninvasively provides continuous information about the peripheral oxygen saturation (SpO2) rate. This device is utilized in the detection of hypoxemia, due to its able to sense changes in hemoglobin oxygen saturation. The objective of this study was to verify the accuracy of the Choice® Medical MD300C3 Fingertip Pulse Oximeter, as compared to that of a hospital oximeter coupled with a Drager® Infinity Delta monitor, with the purpose of using this first methodology in dental procedures to monitor the peripheral oxygen saturation (SpO2) of patients submitted to dental treatments. Fifty-five adult patients, both genders, were selected in the Santa Casa Hospital of Maringa, Brazil. The volunteers did not present cardiac problems, prosthetic cardiac valves, pacemakers, or pulmonary diseases, and were not pregnant or children. Each patient received a portable fingertip pulse oximeter (PPO) on the middle finger of the left hand and the hospital oximeter (control device) on the forefinger of the same hand. A total of six measurements were developed. The Pearson correlation coefficient and the Bland and Altman method was used to calculate the statistical analysis. No statistically significant difference was found between the measurements taken by the utilized devices. The average of comparative analysis presented by the devices was 0.2337 ± 0.4355 (mean ± SD), suggesting a strong correlation between the obtained results. According to the methodology of the research, the PPO has similar accuracy to the conventional hospital oximeter with digital sensor. The PPO can be used in dental treatments.

Micro and Macroscale Drivers of Nutrient Concentrations in Urban Streams in South, Central and North America.

PubMed

Loiselle, Steven A; Gasparini Fernandes Cunha, Davi; Shupe, Scott; Valiente, Elsa; Rocha, Luciana; Heasley, Eleanore; Belmont, Patricia Pérez; Baruch, Avinoam

Global metrics of land cover and land use provide a fundamental basis to examine the spatial variability of human-induced impacts on freshwater ecosystems. However, microscale processes and site specific conditions related to bank vegetation, pollution sources, adjacent land use and water uses can have important influences on ecosystem conditions, in particular in smaller tributary rivers. Compared to larger order rivers, these low-order streams and rivers are more numerous, yet often under-monitored. The present study explored the relationship of nutrient concentrations in 150 streams in 57 hydrological basins in South, Central and North America (Buenos Aires, Curitiba, São Paulo, Rio de Janeiro, Mexico City and Vancouver) with macroscale information available from global datasets and microscale data acquired by trained citizen scientists. Average sub-basin phosphate (P-PO4) concentrations were found to be well correlated with sub-basin attributes on both macro and microscales, while the relationships between sub-basin attributes and nitrate (N-NO3) concentrations were limited. A phosphate threshold for eutrophic conditions (>0.1 mg L-1 P-PO4) was exceeded in basins where microscale point source discharge points (eg. residential, industrial, urban/road) were identified in more than 86% of stream reaches monitored by citizen scientists. The presence of bankside vegetation covaried (rho = -0.53) with lower phosphate concentrations in the ecosystems studied. Macroscale information on nutrient loading allowed for a strong separation between basins with and without eutrophic conditions. Most importantly, the combination of macroscale and microscale information acquired increased our ability to explain sub-basin variability of P-PO4 concentrations. The identification of microscale point sources and bank vegetation conditions by citizen scientists provided important information that local authorities could use to improve their management of lower order river ecosystems.

Effect of electrostatic interaction on the location of molecular probe in polymer-surfactant supramolecular assembly: a solvent relaxation study.

PubMed

Singh, Prabhat K; Kumbhakar, Manoj; Pal, Haridas; Nath, Sukhendu

2008-07-03

Effect of electrostatic interaction on the location of a solubilized molecular probe with ionic character in a supramolecular assembly composed of a triblock copolymer, P123 ((ethylene oxide) 20-(propylene oxide) 70-(ethylene oxide) 20) and a cosurfactant cetyltrimethylammonium chloride (CTAC) in aqueous medium has been studied using steady-state and time-resolved fluorescence measurements. Coumarin-343 dye in its anionic form has been used as the molecular probe. In the absence of the surfactant, CTAC, the probe C343 prefers to reside at the surface region of the P123 micelle, showing a relatively less dynamic Stokes' shift, as a large part of the Stokes' shift is missed in the present measurements due to faster solvent relaxation at micellar surface region. As the concentration of CTAC is increased in the solution, the percentage of the total dynamic Stokes' shift observed from time-resolved measurements gradually increases until it reaches a saturation value. Observed results have been rationalized on the basis of the mixed micellar structure of the supramolecular assembly, where the hydrocarbon chain of the CTAC surfactant dissolves into the nonpolar poly(propylene oxide) (PPO) core of the P123 micelle and the positively charged headgroup of CTAC resides at the interfacial region between the central PPO core and the surrounding hydrated poly(ethylene oxide) (PEO) shell or the corona region. The electrostatic attraction between the anionic probe molecule and the positively charged surface of the PPO core developed by the presence of CTAC results in a gradual shift of the probe in the deeper region of the micellar corona region with an increase in the CTAC concentration, as clearly manifested from the solvation dynamics results.

Molecular dynamics simulation study of solvent effects on conformation and dynamics of polyethylene oxide and polypropylene oxide chains in water and in common organic solvents.

PubMed

Hezaveh, Samira; Samanta, Susruta; Milano, Giuseppe; Roccatano, Danilo

2012-03-28

In this paper, the conformation and dynamics properties of polyethylene oxide (PEO) and polypropylene oxide (PPO) polymer chains at 298 K have been studied in the melt and at infinite dilution condition in water, methanol, chloroform, carbon tetrachloride, and n-heptane using molecular dynamics simulations. The calculated density of PEO melt with chain lengths of n = 2, 3, 4, 5 and, for PPO, n = 7 are in good agreement with the available experimental data. The conformational properties of PEO and PPO show an increasing gauche preference for the O-C-C-O dihedral in the following order water>methanol>chloroform>carbon tetrachloride = n-heptane. On the contrary, the preference for trans conformation has a maximum in carbon tetrachloride and n-heptane followed in the order by chloroform, methanol, and water. The PEO conformational preferences are in qualitative agreement with results of NMR studies. PEO chains formed different types of hydrogen bonds with polar solvent molecules. In particular, the occurrence of bifurcated hydrogen bonding in chloroform was also observed. Radii of gyration of PEO chains of length larger than n = 9 monomers showed a good agreement with light scattering data in water and in methanol. For the shorter chains the observed deviations are probably due to the enhanced hydrophobic effects caused by the terminal methyl groups. For PEO the fitting of end-to-end distance distributions with the semi-flexible chain model at 298 K provided persistence lengths of 0.375 and 0.387 nm in water and methanol, respectively. Finally, the radius of gyration of Pluronic P85 turned out to be 2.25 ± 0.4 nm at 293 K in water in agreement with experimental data.

Gas Transport Properties of Polybenzimidazole and Poly(Phenylene Oxide) Mixed Matrix Membranes Incorporated with PDA-Functionalised Titanate Nanotubes

NASA Astrophysics Data System (ADS)

Giel, V.; Perchacz, M.; Kredatusová, J.; Pientka, Z.

2017-01-01

Functionalised titanate nanotubes (TiNTs) were incorporated to poly(5,5-bisbenzimidazole-2,2-diyl-1,3-phenylene) (PBI) or poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) for improving the interfacial compatibility between the polymer matrix and inorganic material and for altering the gas separation performance of the neat polymer membranes. Functionalisation consisted in oxidative polymerisation of dopamine-hydrochloride on the surface of non-functionalised TiNTs. Transmission electron microscopy (TEM) confirmed that a thin polydopamine (PDA) layer was created on the surface of TiNTs. 1.5, 3, 6, and 9 wt.% of PDA-functionalised TiNTs (PDA-TiNTs) were dispersed to each type of polymer matrix to create so-called mixed matrix membranes (MMMs). Infrared spectroscopy confirmed that -OH and -NH groups exist on the surface of PDA-TiNTs and that the nanotubes interact via H-bonding with PBI but not with PPO. The distribution of PDA-TiNTs in the MMMs was to some extent uniform as scanning electron microscope (SEM) studies showed. Beyond, PDA-TiNTs exhibit positive effect on gas transport properties, resulting in increased selectivities of MMMs. The addition of nanotubes caused a decrease in permeabilities but an increase in selectivities. It is shown that 9 wt.% of PDA-TiNTs in PBI gave a rise to CO2/N2 and CO2/CH4 selectivities of 112 and 63 %, respectively. In case of PPO-PDA-TiNT MMMs, CO2/N2 and CO2/CH4 selectivity increased about 25 and 17 %, respectively. Sorption measurement showed that the presence of PDA-TiNTs in PBI caused an increase in CO2 sorption, whereas the influence on other gases is less noticeable.

Heat capacity anomaly in a self-aggregating system: Triblock copolymer 17R4 in water

NASA Astrophysics Data System (ADS)

Dumancas, Lorenzo V.; Simpson, David E.; Jacobs, D. T.

2015-05-01

The reverse Pluronic, triblock copolymer 17R4 is formed from poly(propylene oxide) (PPO) and poly(ethylene oxide) (PEO): PPO14 - PEO24 - PPO14, where the number of monomers in each block is denoted by the subscripts. In water, 17R4 has a micellization line marking the transition from a unimer network to self-aggregated spherical micelles which is quite near a cloud point curve above which the system separates into copolymer-rich and copolymer-poor liquid phases. The phase separation has an Ising-like, lower consolute critical point with a well-determined critical temperature and composition. We have measured the heat capacity as a function of temperature using an adiabatic calorimeter for three compositions: (1) the critical composition where the anomaly at the critical point is analyzed, (2) a composition much less than the critical composition with a much smaller spike when the cloud point curve is crossed, and (3) a composition near where the micellization line intersects the cloud point curve that only shows micellization. For the critical composition, the heat capacity anomaly very near the critical point is observed for the first time in a Pluronic/water system and is described well as a second-order phase transition resulting from the copolymer-water interaction. For all compositions, the onset of micellization is clear, but the formation of micelles occurs over a broad range of temperatures and never becomes complete because micelles form differently in each phase above the cloud point curve. The integrated heat capacity gives an enthalpy that is smaller than the standard state enthalpy of micellization given by a van't Hoff plot, a typical result for Pluronic systems.

Molecular dynamics simulation study of solvent effects on conformation and dynamics of polyethylene oxide and polypropylene oxide chains in water and in common organic solvents

NASA Astrophysics Data System (ADS)

Hezaveh, Samira; Samanta, Susruta; Milano, Giuseppe; Roccatano, Danilo

2012-03-01

In this paper, the conformation and dynamics properties of polyethylene oxide (PEO) and polypropylene oxide (PPO) polymer chains at 298 K have been studied in the melt and at infinite dilution condition in water, methanol, chloroform, carbon tetrachloride, and n-heptane using molecular dynamics simulations. The calculated density of PEO melt with chain lengths of n = 2, 3, 4, 5 and, for PPO, n = 7 are in good agreement with the available experimental data. The conformational properties of PEO and PPO show an increasing gauche preference for the O-C-C-O dihedral in the following order water>methanol>chloroform>carbon tetrachloride = n-heptane. On the contrary, the preference for trans conformation has a maximum in carbon tetrachloride and n-heptane followed in the order by chloroform, methanol, and water. The PEO conformational preferences are in qualitative agreement with results of NMR studies. PEO chains formed different types of hydrogen bonds with polar solvent molecules. In particular, the occurrence of bifurcated hydrogen bonding in chloroform was also observed. Radii of gyration of PEO chains of length larger than n = 9 monomers showed a good agreement with light scattering data in water and in methanol. For the shorter chains the observed deviations are probably due to the enhanced hydrophobic effects caused by the terminal methyl groups. For PEO the fitting of end-to-end distance distributions with the semi-flexible chain model at 298 K provided persistence lengths of 0.375 and 0.387 nm in water and methanol, respectively. Finally, the radius of gyration of Pluronic P85 turned out to be 2.25 ± 0.4 nm at 293 K in water in agreement with experimental data.