bluuebunny/crossref_metadata_2025_split huggingface dataset:
Aliphatic and Aromatic Nitrogen Compounds
Authors: Jr. Kennedy Gerald L. 
Published: August 2012

AbstractThis chapter covers both aliphatic and aromatic compounds that contain one or more nitrogen atoms in their structures. Only a small number of the nitrogen‐containing compounds that could be considered will be reviewed here mainly based on their uses in industry. This is an update of a previous chapter and for each chemical, the first sentence will tell the reader whether there has been significant new information published in the literature and included or whether there has been little or no new information available for update and inclusion.Three‐membered rings discussed are ethyleneimine, propyleneimine, and, one polyfunctional derivative, triethylenemelamine. Toxicologists, chemists, and biologists have always been interested in ethyleneimine and its derivatives because they are reactive, are useful at relatively low doses, and are moderately to highly toxic. Ethyleneimines are classic alkylating agents and have toxicological effects similar to nitrogen mustards. Monofunctional derivatives of ethyleneimine are less potent in producing the characteristic toxicity of the group than the derivatives that have two or more ethyleneimine groups. Finally, polymers of ethyleneimine and its derivatives have shown a relatively low order of toxicity.Six simple nitrogen mustards (β‐chloroethylamines) are also covered in this chapter. They are all tertiary amines in which the halogen atom and the amine portion have reactivities similar to the alkyl halides and alkyl amines. They have no significant industrial uses in the United States, but they are used in medicine as “antineoplastic agents” and in treating some nonmalignant diseases.Representative nitrogen‐containing chemicals that have five‐membered rings (pyrrolidine,N‐methyl‐2‐pyrrolidinone) and six‐membered rings (piperidine, piperazine, morpholine, and hexamethylenetetramine) are also discussed in this chapter in some detail.Several representative aromatic nitrogen compounds are covered—pyrrole, aminotriazole,N‐sulfenyl phthalimide fungicides, benzimidazole fungicides, and 1‐H‐benzotriazole. The data presented for compounds of this class that are used in agriculture include toxicology studies that have been published in the open literature as well as those available through company files to support governmental registration.In some cases, the high toxicity of the agent has been considered and is the reason for its inclusion here, rather than usage volume or industrial importance. Further, very little pharmacological information is presented because this is adequately covered in the pharmacological literature. We have tried to minimize hypotheses regarding the mechanism of action not because it is unimportant, but because the biochemistries are often very detailed, are almost always fairly speculative, and are presented comprehensively in other texts. Likewise, we resisted the temptation to employ structure–activity relationships because, although the database is very thorough for some chemicals, it did not contain enough analogous chemicals with known, comparable toxicity profiles.
Ethers of Ethylene Glycol and Derivatives
Authors: Cragg Steven T. 
Published: August 2012

AbstractThere are seven U.S. manufacturers of ethers and other derivatives of ethylene glycol (EG), diethylene glycol (DEG), and higher glycols. Five of them are members of the American Chemistry Council (ACC) Glycol Ethers' Panel.The glycol ethers most commonly encountered industrially are colorless liquids that have mild ethereal odors. Alkyl glycol ethers are manufactured in a closed, continuous process by reacting ethylene oxide with an anhydrous alcohol in the presence of a suitable catalyst. Depending on the molar ratios of the reactants and other process parameters, the product mixtures obtained contain varying amounts of the monoethylene, diethylene, triethylene, and higher glycol ethers. Typically, the products in these mixtures are separated and purified by fractional distillation.The miscibility of most of these ethers with water and with a large number of organic solvents makes them especially useful as solvents in oil–water compositions. Their relatively slow rate of evaporation also makes them useful as solvents and coalescing agents in paints. Other uses include inks, cleaners, chemical intermediates, process solvents, brake fluids, and deicers. The ethers of the higher glycols are used as hydraulic fluids. An estimate of the U.S. production and use of representative ethylene glycol ethers is presented. Production of ethylene glycol ethers (total) in Western Europe amounted to 245 thousand metric tons in 1995.Occupational exposure to glycol ethers occurs dermally and by inhalation. Ingestion is not a concern in industrial exposure, although some cases of intentional ingestion of consumer products containing ethylene glycol ethers have been reported.A number of analytical methods have been published that are suitable for detecting glycol ethers in environmental air samples.Glycol ethers generally have low acute, single‐dose toxicity, and LD50values generally range from 1.0 to 4.0 g/kg of body weight. In animals and humans, high‐dose administrations (>350 mg/kg) result in central nervous system (CNS) depression, although the results from many studies show no specific damage to neural tissues. Other toxicological effects attributable to glycol ethers are associated with metabolism to the corresponding alkoxyacetic acids. In the case of EGME, EGEE, and certain other glycol ether derivatives, significant reproductive, developmental, hematologic, and immunologic effects have been associated with the formation of either methoxyacetic acid (MAA) or ethoxyacetic acids (EAA). For other glycol ether derivatives substituted with propyl, butyl, or higher homologues, both developmental effects secondary to maternal toxicity (without teratogenic effects) and hematologic effects are observed.Ethylene glycol ethers and acetates may enter the environment from manufacturing effluents and emissions and as a result of their use in commercial products.
Carbon Black
Authors: McCunney Robert J. , Muranko Henry J. , Long Chris M. , Hamade Ali K. , Valberg Peter A. , Morfeld Peter 
Published: August 2012

AbstractCarbon black is a powdered form of elemental carbon, obtained by partial combustion or thermal decomposition of hydrocarbons. It is a member of the class of substances known as industrial aciniform aggregates (IAA). Carbon black can be released to the ambient environment during the manufacturing process, and it thus can be a component of airborne particulate matter (PM) in the vicinity of carbon black manufacturing plants and user industries. Carbon black production in Asia has experienced substantial growth in the past decade. Today over 95% of carbon black worldwide is produced by the oil furnace process. The potential health implications of occupational exposure to carbon black have been addressed primarily in cohort mortality and cross‐sectional morbidity studies among workers who manufacture carbon black. Carbon black has gained usage as a model particle in particle toxicology investigations, with extensive study in bothin vivoandin vitrolaboratory experiment. The particle size characteristics of manufactured carbon blacks have been extensively studied and found that inhalable airborne carbon black particles are significantly larger in aerodynamic diameter than particles that occur in the early stages of carbon black formation. The scientific evidence of the potential carcinogenicity of carbon black are described extending the current evaluation given by IARC. A number of health‐based air quality standards have been developed for airborne PM and carbon black. Occupational exposure limits (OELs) for carbon black are presented and discussed.
Toxicology of Flavors in the Food Industry
Authors: Doepker Candace L. , Maier Andrew , Willis, B.S Alison , Hermansky Steven J. 
Published: August 2012

AbstractThe present chapter represents toxicological information on selected flavoring ingredients commonly found in the food and beverage workplace that have recently gathered attention regarding potential risks to the workers handling them. GRAS ingredients can present hazards in the occupational context, it is very important that workers review material safety data sheets (MSDS) and understand the verbiage on these MSDS as part of a comprehensive hazard communication program. FEMA and the Joint FAO/WHO Expert Committee on Food Additives (JECFA) have adopted modified Cramer approaches and the TTC concept to classify flavor ingredients by structure and, thus, according to risk. Today, new chemical entities are being designed and created to maximize and/or customize the interaction of the flavor ingredient with taste receptors. Several important flavor chemicals have been covered in this chapter with respect to their properties, exposure assessment, toxicity, and regulations of exposure.
A 4‐Amino‐1,8‐Naphthalimide Derivative for Selective Fluorescent Detection of Palladium(II) Ions
Authors: Wang Changcheng , Zheng Xiaolong , Huang Rong , Yan Shengyong , Xie Xia , Tian Tian , Huang Shiwen , Weng Xiaocheng , Zhou Xiang 
Published: August 2012

AbstractPalladium is a member of the platinum group of metals and can be used in the electronics industry for applications such as preparing precision resistors. It is also utilized for catalysis in organic chemistry to achieve faster reaction speeds and lower costs of production in industry. Overexposure to Pd is harmful to the environment and to human health because it can be conveyed quickly to the liver, kidney, spleen, adrenal glands, lungs, and bones. Herein, a fluorescent probe that contains an alkynyl group for specific reaction with PdII ions, and a naphthalimide group as a fluorophore was designed. This probe has high specificity and selectivity for PdII ions relative to many other metal ions. HPLC analysis was carried out to verify the mechanism of the detection. There is a distinct color change during the detection process. The influence of pH values shows that the probe is suitable to detect PdII ions in the range pH 6–9.
Determination of the critical concentration of partially hydrolyzed polyacrylamide by potentiometry in an acidic medium
Authors: Gomes Marcos P. S. , Costa Marta 
Published: August 2012

AbstractThe literature presents different methods for quantifying and characterizing partially hydrolyzed polyacrylamide (HPAM) in solution. However, only a few of these are suitable for determining the critical overlap concentration (C*). The evaluation of C* is important for describing the transition from the dilute to the semidilute regime, that is, when the solution depicts a characteristic viscosity at concentrations above C*. This article describes the determination of C* for HPAM in solution by potentiometry. The molecular weight, degree of hydrolysis, and polymerization degree are determined by mathematical manipulation of the constant of formation of aggregates, which is based on the law of mass action. The potentiometric curves were initially linear; asymptotic behavior followed. The inflection point was determined by the intersection, and the resulting equation of mathematical development statistically satisfied the experimental data and described the number of moles of monomers, the equilibrium constant for the formation of the aggregate, C*, and the acidity constant of the polymer. The results for C*, the degree of copolymerization, and the molecular weight proved that this method is a good alternative for the characterization of polymers with ionizable monomers and that are soluble in water. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Nanocomposites of ethylene vinyl alcohol copolymer with thermally resistant cellulose nanowhiskers by melt compounding (II): Water barrier and mechanical properties
Authors: Martínez‐Sanz Marta , Lopez‐Rubio Amparo , Lagaron Jose M. 
Published: August 2012

AbstractIn the present work, the crystallinity and crystalline morphology, thermal stability, water barrier, and mechanical properties of ethylene vinyl alcohol copolymer (EVOH) nanocomposites prepared by melt compounding and incorporating both plant (CNW) and bacterial cellulose nanowhiskers (BCNW) are reported. An improvement in the water barrier performance was observed, that is, 67% permeability drop, only for the microcomposite sample incorporating 2 wt % of bacterial cellulose fibrils. No significant differences in the water‐barrier properties of the nanocomposites generated through the two studied preincorporation methods were observed despite the fact that an excellent dispersion was observed in the previous study. On the other hand, direct melt‐mixing of the freeze‐dried nanofiller with EVOH resulted in increased water permeation. The aggregation of the filler in the latter nanocomposite was also ascribed to the detrimental effect on the mechanical properties. Interestingly, by using the precipitation method, an increase in the elastic modulus and tensile strength of ∼36 and 22%, respectively, was observed for a 3 wt % BCNW loading, which was thought to coincide with the percolation threshold. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Stable Sugar‐Chain‐Immobilized Fluorescent Nanoparticles for Probing Lectin and Cells
Authors: Shinchi Hiroyuki , Wakao Masahiro , Nakagawa Sho , Mochizuki Eiko , Kuwabata Susumu , Suda Yasuo 
Published: August 2012

AbstractSugar chains are important molecules in cellular recognition and signaling, and quantum dots (QDs) are a very powerful tool for in vitro and in vivo imaging. Herein, we report the preparation of stable sugar‐chain‐immobilized fluorescent nanoparticles (SFNPs) and their application to the analysis of sugar‐chain–protein interactions and cellular imaging. SFNPs were easily prepared by mixing CdTe/CdS core/shell QDs with our previously developed sugar‐chain–ligand conjugates. The obtained SFNPs were very stable and could be stored for several months. In the binding analysis, β‐galactose‐ and α‐glucose‐immobilized SFNPs were specifically interacted with Ricinus communis agglutinin I and concanavalin A, respectively, and made into aggregates. The binding interaction was detected visually, fluorescently, or both. In the experiment for cellular imaging, it was found that SFNPs were predominantly taken up by human hepatocyto carcinoma cells (HepG2), suggesting the possible usage of our designed SFNPs for various biochemical analyses of sugar chains.
Closing the Ring to Bring Up the Light: Synthesis of a Hexacyclic Acridinium Cyanine Dye
Authors: Mahmood Tariq , Wu Yilei , Loriot Domitille , Kuimova Marina , Ladame Sylvain 
Published: August 2012

AbstractThe synthesis of a geometrically constrained and near‐planar hexacyclic acridinium cyanine dye 9 is reported. When compared to its unlocked and non‐fluorescent monomethine cyanine dye analogue 3, this photostable dye emits in the green area of the spectrum with a remarkable quantum yield close to unity in organic solvents and above 0.5 in water. A detailed steady‐state and time‐resolved spectroscopic study revealed that dye 9 forms emissive aggregates in water, which are responsible for a red‐shifted and broadened emission band and longer emission lifetime, τ≈33 compared to 6.5–7.0 ns for the monomeric dye. Dye 9 also binds strongly to DNA (both duplex and quadruplex) in its monomeric form and is very efficiently taken up by cells, in which it accumulates primarily into the nucleus.
Formation of Metal Oxyfluorides from Specific Metal Reactions with Oxygen Difluoride: Infrared Spectroscopic and Theoretical Investigations of the OScF2 Radical and OScF with Terminal Single and Triple ScO Bonds
Authors: Gong Yu , Andrews Lester , Bauschlicher Charles W. 
Published: August 2012

AbstractThe scandium oxydifluoride free radical, OScF2, is produced by the spontaneous, specific reaction of laser ablated Sc atoms with OF2 in solid argon and characterized by using matrix infrared spectroscopy and theoretical calculations. The OScF2 molecule is predicted to have C2v symmetry and a 2B2 ground state with an unpaired electron located primarily on the terminal oxygen atom, which makes it a scandium difluoride molecule coordinated by a neutral oxygen atom radical in forming the ScO single bond. The closed shell singlet OScF molecule with an obtuse bent geometry has a much shorter ScO bond of 1.682 Å than that of the OScF2 radical (1.938 Å) on the basis of B3LYP calculations. The ScO bond in OScF consists of two covalent bonds and a dative bond in which the oxygen 2pπ lone pair donates electron density into an empty Sc 3d orbital thus forming a triple oxo bond. Density functional calculations suggest it is highly exothermic for fluorine transfer from OF2 to scandium, which favors the formation of the OScF2 radical species as well as the OScF molecule after fluorine loss.
Effect on Charge Transfer and Charge Recombination by Insertion of a Naphthalene‐Based Bridge in Molecular Dyads Based on Borondipyrromethene (Bodipy)
Authors: Benniston Andrew C. , Clift Sophie , Hagon Jerry , Lemmetyinen Helge , Tkachenko Nikolai V. , Clegg William , Harrington Ross W. 
Published: August 2012

AbstractThe photophysical properties of two related dyads based on a N,N‐dimethylaniline donor coupled to a fully‐alkylated boron dipyrromethene (Bodipy) acceptor are described. In one dyad, BD1, the donor unit is attached directly to the Bodipy group, whereas in the second dyad, BD2, a naphthalene spacer separates the two units. Cyclic voltammograms recorded for the two dyads in deoxygenated MeCN containing a background electrolyte are consistent with the reversible one‐electron oxidation of the N,N‐dimethylaniline group and the reversible one‐electron reduction of the Bodipy nucleus. There is a reasonable driving force (ΔGCT) for photoinduced charge transfer from the N,N‐dimethylaniline to the Bodipy segment in MeCN. The charge‐transfer state is formed for BD1 extremely fast (1.5 ps), but decays over 140 ps to partially restore the ground state. On the other hand, the charge‐transfer state for BD2 is formed more slowly, but it decays extremely rapidly. Charge recombination for both dyads leads to a partial triplet formation on the Bodipy group. The naphthalene spacer group is extremely efficient at promoting back electron transfer.
Synthesis and Electrocatalytic Properties of Palladium Network Nanostructures
Authors: Zhang Guojie , Zhang Lu , Shen Liping , Chen Yu , Zhou Yiming , Tang Yawen , Lu Tianhong 
Published: August 2012

AbstractAn inorganic polymeric hydrogel, which is formed irreversibly in water through interaction between K2PdIICl4 and K4FeII(CN)6, is synthesized. The palladium nanostructures take the form of three‐dimensional (3D) networks and are obtained in a facile manner by simple reduction of the hydrogel using NaBH4. The size, morphology, and surface composition of these 3D palladium networks are investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy‐dispersive spectroscopy (EDS), selected‐area electron diffraction (SAED), X‐ray diffraction (XRD), and X‐ray photoelectron spectroscopy (XPS). The electrochemical properties are investigated in detail by cyclic voltammetry, chronoamperometry, and CO stripping tests. Such 3D nanostructures exhibit a large electroactive surface area, excellent electrochemical stability, and high electrocatalytic activity toward electrooxidation of formic acid.
Laminin and integrin expression in the ventral ectodermal ridge of the mouse embryo: Implications for regulation of BMP signalling
Authors: Lopez‐Escobar Beatriz , De Felipe Beatriz , Sanchez‐Alcazar Jose Antonio , Sasaki Takako , Copp Andrew J. , Ybot‐Gonzalez Patricia 
Published: August 2012

AbstractBackground: The ventral ectodermal ridge (VER) is an important signalling centre in the mouse tail‐bud following completion of gastrulation. BMP regulation is essential for VER function, but how these signals are transmitted between adjacent tissues is unclear. Results: We investigated the idea that extracellular matrix components might be involved, using immunohistochemistry and in situ hybridisation to detect all known α, β, and γ laminin chains and their mRNAs in the early tail bud. We identified an apparently novel laminin variant, comprising α5, β3 and γ2 chains, as a major component of the VER basement membrane at E9.5. Strikingly, only the mRNAs for these chains were co‐expressed in VER cells, suggesting that lamin532 may be the sole basement membrane laminin at this stage. Since α6 integrin was also expressed in VER cells, this raises the possibility of cell‐matrix interactions regulating BMP signalling at this site of caudal morphogenesis. Conclusions: Laminin532 could interact with α6‐containing integrin to direct differentiation of the specialised VER cells from surface ectoderm. Developmental Dynamics 241:1808–1815, 2012. © 2012 Wiley Periodicals Inc.
Cdc42 GTPase and Rac1 GTPase act downstream of p120 catenin and require GTP exchange during gastrulation of zebrafish mesoderm
Authors: Hsu Cynthia L. , Muerdter Claire P. , Knickerbocker Abhay D. , Walsh Ryan M. , Zepeda‐Rivera Martha A. , Depner Kevin H. , Sangesland Maya , Cisneros Trinidad B. , Kim Ju Youn , Sanchez‐Vazquez Patricia , Cherezova Lidia , Regan Rainy D. , Bahrami Nadia M. , Gray Elizabeth A. , Chan Andrew Y. , Chen Terry , Rao Milly Y. , Hille Merrill B. 
Published: August 2012

AbstractBackground: We investigated the roles of p120 catenin, Cdc42, Rac1, and RhoA GTPases in regulating migration of presomitic mesoderm cells in zebrafish embryos. p120 catenin has dual roles: It binds the intracellular and juxtamembrane region of cadherins to stabilize cadherin‐mediated adhesion with the aid of RhoA GTPase, and it activates Cdc42 GTPase and Rac1 GTPase in the cytosol to initiate cell motility. Results: During gastrulation of zebrafish embryos, knockdown of the synthesis of zygotic p120 catenin δ1 mRNAs with a splice‐site morpholino caused lateral widening and anterior‐posterior shortening of the presomitic mesoderm and somites and a shortened anterior‐posterior axis. These phenotypes indicate a cell‐migration effect. Co‐injection of low amounts of wild‐type Cdc42 or wild‐type Rac1 or dominant‐negative RhoA mRNAs, but not constitutively‐active Cdc42 mRNA, rescued these p120 catenin δ1‐depleted embryos. Conclusions: These downstream small GTPases require appropriate spatiotemporal stimulation or cycling of GTP to guide mesodermal cell migration. A delicate balance of Rho GTPases and p120 catenin underlies normal development. Developmental Dynamics 241:1545–1561, 2012. © 2012 Wiley Periodicals Inc.
Node‐positive hypopharyngeal cancer treated by (chemo)radiotherapy: Impact of up‐front neck dissection on outcome, toxicity, and quality of life
Authors: Al‐Mamgani Abrahim , Meeuwis Cees A. , van Rooij Peter H. , Mehilal Robert , Basdew Harie , Sewnaik Aniel , Levendag Peter C. 
Published: August 2012

AbstractBackgroundTo investigate the impact of up‐front neck dissection on the outcome of patients with node‐positive hypopharyngeal cancer (HPC) treated with (chemo)radiation.MethodsOf 135 consecutive patients with node‐positive HPC, 32 patients underwent up‐front neck dissection followed by (chemo)radiation (group 1), and 103 patients received definitive (chemo)radiation (group 2).ResultsThe 3‐year regional, local and distant control for groups 1 and 2 were 92% versus 87% (p = .37), 84% versus 72% (p = .15), and 80% versus 62% (p = .08), respectively. High T classification was the only significant predictor for poor overall survival on multivariate analysis (OR = 3.0, p = .02). Acute and late toxicities and the prospectively assessed quality of life were comparable in both groups.ConclusionUpfront neck dissection followed by (chemo)radiation did not negatively impact on oncologic outcomes, toxicity, or quality of life and therefore is to be regarded as a safe and effective treatment option for small HPC with bulky nodal disease, especially in busy radiation departments with unacceptably long waiting time for definitive (chemo)radiation. © 2012 Wiley Periodicals, Inc. Head Neck, 2013