bluuebunny/crossref_metadata_2025 huggingface dataset:
ChemInform Abstract: Catalytic Enantioselective C—H Functionalization of Alcohols by Redox‐Triggered Carbonyl Addition: Borrowing Hydrogen, Returning Carbon
Authors: Ketcham John M. , Shin Inji , Montgomery T. Patrick , Krische Michael J.
Published: November 2014

Review: [74 refs.
ChemInform Abstract: Solid‐Phase Peptide Synthesis: An Overview Focused on the Preparation of Biologically Relevant Peptides
Authors: Palomo Jose M.
Published: November 2014

Review: [74 refs.
ChemInform Abstract: Sulfur(VI) Fluoride Exchange (SuFEx): Another Good Reaction for Click Chemistry
Authors: Dong Jiajia , Krasnova Larissa , Finn M. G. , Sharpless K. Barry
Published: November 2014

Review: [147 refs.
ChemInform Abstract: Wittig‐ and Horner—Wadsworth—Emmons‐Olefination Reactions with Stabilized and Semi‐Stabilized Phosphoranes and Phosphonates under Non‐classical Conditions
Authors: Al Jasem Yosef , El‐Esawi Randa , Thiemann Thies
Published: November 2014

Review: 152 refs.
ChemInform Abstract: Phosphonium Salts and P‐Ylides
Authors: Selva Maurizio , Perosa Alvise , Noe Marco
Published: November 2014

Review: [state‐of‐the‐art for the period Jan.
ChemInform Abstract: Recent Progress in the Chemistry of Dihydropyrimidinones
Authors: Shah Hirenkumar D. , Sen Dhrubo Jyoti
Published: November 2014

Review: 24 refs.
ChemInform Abstract: Natural and Engineered Biosynthesis of Fluorinated Natural Products
Authors: Walker Mark C. , Chang Michelle C. Y.
Published: November 2014

Review: 61 refs.
ChemInform Abstract: A New C—C Bond Formation Model Based on the Quantum Chemical Topology of Electron Density
Authors: Domingo Luis R.
Published: November 2014

Review: 108 refs.
Synthesis of Cellulose Methylcarbonate in Ionic Liquids using Dimethylcarbonate
Authors: Labafzadeh Sara R. , Helminen K. Juhani , Kilpeläinen Ilkka , King Alistair W. T.
Published: November 2014

Dialkylcarbonates are viewed as low‐cost, low‐toxicity reagents, finding application in many areas of green chemistry. Homogeneous alkoxycarbonylation of cellulose was accomplished by applying dialkycarbonates (dimethyl and diethyl carbonate) in the ionic liquid‐electrolyte trioctylphosphonium acetate ([P8881][OAc])/DMSO or 1‐ethyl‐3‐methylimidazolium acetate ([emim][OAc]). Cellulose dialkylcarbonates with a moderate degree of substitution (DS∼1) are accessible via this procedure and cellulose methylcarbonate was thoroughly characterized for its chemical and physical properties after regeneration. This included HSQC & HMBC NMR, ATR‐IR, molecular weight distribution, morphology, thermal properties, and barrier properties after film formation.
Hydrolytic Stability and Hydrogen Peroxide Activation of Zirconium‐Based Oxoclusters
Authors: Faccioli Francesco , Bauer Matthias , Pedron Danilo , Sorarù Antonio , Carraro Mauro , Gross Silvia
Published: November 2014

The hydrolytic stability of [Zr6(OH)4O4{O(O)CC(CH3)=CH2}12] (Zr6), and [Zr6O4(OH)4{O(O)CCH2CH=CH2}12]2·6[CH2=CHCH2C(O)OH] (Zr12) oxoclusters in different environments was thoroughly investigated by FTIR, Raman, and X‐ray photoelectron spectroscopy (XPS). Specific information about the local structures around the Zr centers during the stability tests was achieved by in situ extended X‐ray absorption fine structure (EXAFS) measurements, and the exact compositions were determined by inductively coupled plasma MS (ICP‐MS) and elemental analysis. By this multidimensional spectroscopic approach, an overview on the structures formed after different treatments could be gained. The stability of the oxoclusters was then investigated in the presence of hydrogen peroxide, and the formation of peroxo–metal complexes was detected. Thus, a kinetic study was performed in acetonitrile to evaluate the performances of the oxoclusters as oxygen transfer catalysts. The oxidation of methyl p‐tolyl sulfide to the corresponding sulfoxide and sulfone was chosen as a model reaction; in some cases, an interesting selectivity towards the formation of the sulfone was found over more than 4700 catalytic cycles.
Tris(borane) Adducts of Diphosphanylmethanides: The [H3BCH(PPh2BH3)2]– Anion and Its Alkali Metal Complexes
Authors: Langer Jens , Geitner Robert , Görls Helmar
Published: November 2014

The reactivity of lithium complexes that contain the borane‐modified diphoshanylmethanide ligand [CH(PPh2BH3)2]– towards different Lewis base adducts of BH3 was studied to gain further insight into the mechanism of the isomerization of this derivative, which formally proceeds through a shift of one BH3 group from the phosphorus atom to the carbon atom. Whereas the use of BH3·THF in THF only resulted in the thf adduct of the starting material, [Li{CH(PPh2BH3)2}(thf)2] (1), the application of BH3·SMe2 in toluene resulted in the formation of the novel compound [(Li{H3BCH(PPh2BH3)2})∞] (2). The subsequent addition of ethereal ligands led to the isolation of [Li{H3BCH(PPh2BH3)2}(Me4thf)] (3) and [Li{H3BCH(PPh2BH3)2}(thf)3] (4). Treatment of these complexes with stronger Lewis bases such as N,N,N′,N′‐tetramethylethane‐1,2‐diamine (tmeda) results in the removal of one phosphorus‐bound BH3 molecule and the formation of the [Ph2PCH(BH3)PPh2BH3]– anion. These results indicate that the isomerization of [CH(PPh2BH3)2]– requires an additional BH3 source and a rather strong Lewis base. Complexes 1–4 and the related derivatives [Li{CH(PPh2BH3)2}(Me4THF)] (5) and [K{H3BCH(PPh2BH3)2}(dme)2] (6; dme = 1,2‐dimethoxyethane) were characterized by multinuclear NMR spectroscopy and by single‐crystal X‐ray diffraction analysis.
Room‐Temperature Direct Alkenylation of 3‐Arylsydnones
Authors: Yang Yiwen , Kuang Chunxiang
Published: November 2014

A new efficient method for the direct alkenylation of 3‐arylsydnones by palladium‐catalyzed C–H functionalization was developed. The reaction proceeded smoothly at room temperature and delivered the product in yields up to 83 %.
Iron(II)‐Catalyzed Asymmetric Epoxidation of Trisubstituted α,β‐Unsaturated Esters
Authors: Luo Lan , Yamamoto Hisashi
Published: November 2014

The asymmetric epoxidation of trisubstituted α,β‐unsaturated esters was developed. The oxidation utilizes a pseudo‐C2‐symmetric iron(II) catalyst [Fe(L*)2(CH3CN)(OTf)](OTf) (Tf = trifluoromethylsulfonyl) and peracetic acid as oxidant and yields α,β‐epoxy esters with high enantiomeric purity (up to 99 % ee).
Transition‐Metal‐Free Oxidative Iodination of 1,3,4‐Oxadiazoles
Authors: Dannenberg Carl Albrecht , Bizet Vincent , Zou Liang‐Hua , Bolm Carsten
Published: November 2014

Transition‐metal‐free oxidative iodination of 2‐substituted 1,3,4‐oxadiazoles was achieved by using sodium iodide as the halide source and Selectfluor as the oxidant. Variously substituted products were obtained in moderate to good yields under operationally straightforward conditions. Compared to existing methods for analogous conversions, the newly developed protocol appears synthetically attractive.
Fate and effects of clothianidin in fields using conservation practices
Authors: de Perre Chloé , Murphy Tracye M. , Lydy Michael J.
Published: November 2014

Despite the extensive use of the neonicotinoid insecticide clothianidin, and its known toxicity to beneficial insects such as pollinators, little attention has been given to its fate under agricultural field conditions. The present study investigated the fate and toxicity of clothianidin applied every other year as a corn seed-coating at 2 different rates, 0.25 mg/seed and 0.50 mg/seed, in an agricultural field undergoing a corn–soybean annual rotation, and conservation tillage. Concentrations were measured in soil, surface runoff, infiltration, and groundwater from 2011 to 2013. Clothianidin was detected at low concentrations in soil and water throughout the 2-yr corn and soybean rotation. Low and no-tillage had little or no effect on clothianidin concentrations. Laboratory toxicity bioassays were performed on nontarget species, including Daphnia magna, Hyalella azteca, Chironomus dilutus, Pimephales promelas and Eisenia fetida. Risk quotients were calculated from clothianidin concentrations measured in the field and compared with the laboratory toxicity bioassay results to assess the environmental risk of the insecticide. The risk quotient was found to be lower than the level of concern for C. dilutus, which was the most sensitive species tested; therefore, no short-term environmental risk was expected for the species investigated in the present study. Environ Toxicol Chem 2014;9999:1–8. © 2014 SETAC
Multimodal neuroimaging evidence of alterations in cortical structure and function in HIV‐infected older adults
Authors: Wilson Tony W. , Heinrichs‐Graham Elizabeth , Becker Katherine M. , Aloi Joseph , Robertson Kevin R. , Sandkovsky Uriel , White Matthew L. , O'Neill Jennifer , Knott Nichole L. , Fox Howard S. , Swindells Susan
Published: November 2014

Combination antiretroviral therapy transformed human immunodefiency virus (HIV)‐infection from a terminal illness to a manageable condition, but these patients remain at a significantly elevated risk of developing cognitive impairments and the mechanisms are not understood. Some previous neuroimaging studies have found hyperactivation in frontoparietal networks of HIV‐infected patients, whereas others reported aberrations restricted to sensory cortices. In this study, we utilize high‐resolution structural and neurophysiological imaging to determine whether alterations in brain structure, function, or both contribute to HIV‐related cognitive impairments. HIV‐infected adults and individually matched controls completed 3‐Tesla structural magnetic resonance imaging (sMRI) and a mechanoreception task during magnetoencephalography (MEG). MEG data were examined using advanced beamforming methods, and sMRI data were analyzed using the latest voxel‐based morphometry methods with DARTEL. We found significantly reduced theta responses in the postcentral gyrus and increased alpha activity in the prefrontal cortices of HIV‐infected patients compared with controls. Patients also had reduced gray matter volume in the postcentral gyrus, parahippocampal gyrus, and other regions. Importantly, reduced gray matter volume in the left postcentral gyrus was spatially coincident with abnormal MEG responses in HIV‐infected patients. Finally, left prefrontal and postcentral gyrus activity was correlated with neuropsychological performance and, when used in conjunction, these two MEG findings had a sensitivity and specificity of over 87.5% for HIV‐associated cognitive impairment. This study is the first to demonstrate abnormally increased activity in association cortices with simultaneously decreased activity in sensory areas. These MEG findings had excellent sensitivity and specificity for HIV‐associated cognitive impairment, and may hold promise as a potential disease marker. Hum Brain Mapp 36:897–910, 2015. © 2014 Wiley Periodicals, Inc.
Evaluating the effects of massed and distributed practice on acquisition and maintenance of tacts and textual behavior with typically developing children
Authors: Haq Shaji S. , Kodak Tiffany
Published: November 2014

This study evaluated the effects of massed and distributed practice on the acquisition of tacts and textual behavior in typically developing children. We compared the effects of massed practice (i.e., consolidating all practice opportunities during the week into a single session) and distributed practice (i.e., distributing all practice opportunities across 4 sessions during the week) on the acquisition of textual behavior in English, tacting pictures of common nouns in Spanish, and textual behavior in Spanish using an adapted alternating treatments design embedded within a multiple probe design. We also examined correct responding during probes that (a) excluded prompts and reinforcement and (b) occurred 48 hr after training each week. The results indicated that distributed practice was the more efficient training format. Maintenance data collected up to 4 weeks after training also indicated that the participants consistently displayed higher levels of correct responding to targets that had been trained in distributed format. We discuss implications for practice and potential areas for future research.
Light‐emitting diode therapy in exercise‐trained mice increases muscle performance, cytochrome c oxidase activity, ATP and cell proliferation
Authors: Ferraresi Cleber , Parizotto Nivaldo Antonio , Pires de Sousa Marcelo Victor , Kaippert Beatriz , Huang Ying‐Ying , Koiso Tomoharu , Bagnato Vanderlei Salvador , Hamblin Michael R.
Published: November 2014

Light‐emitting diode therapy (LEDT) applied over the leg, gluteus and lower‐back muscles of mice using a LED cluster (630 nm and 850 nm, 80 mW/cm2, 7.2 J/cm2) increased muscle performance (repetitive climbing of a ladder carrying a water‐filled tube attached to the tail), ATP and mitochondrial metabolism; oxidative stress and proliferative myocyte markers in mice subjected to acute and progressive strength training. Six bi‐daily training sessions LEDT‐After and LEDT‐Before‐After regimens more than doubled muscle performance and increased ATP more than tenfold. The effectiveness of LEDT on improving muscle performance and recovery suggest applicability for high performance sports and in training programs.

Positioning of the mice and light‐emitting diode therapy (LEDT) applied on mouse legs, gluteus and lower‐back muscles without contact.

magnified image

Positioning of the mice and light‐emitting diode therapy (LEDT) applied on mouse legs, gluteus and lower‐back muscles without contact.
Fortification of instant coffee beverages – influence of functional ingredients, packaging material and storage time on physical properties of newly formulated, enriched instant coffee powders
Authors: Benković Maja , Srečec Siniša , Špoljarić Igor , Mršić Gordan , Bauman Ingrid
Published: November 2014

BACKGROUND

Consumer demands for healthy, functional foods are growing rapidly nowadays. Coffee, as one of the most widespread commodities, represents an interesting aspect for enrichment, since it is consumed by millions of people on a daily basis. The aim of this study was to formulate enriched instant coffee powders with the purpose of estimating the influence of storage time, functional ingredients and packaging material on physical and sensory properties of the mixtures.

RESULTS

Storage time of 6 months significantly (P <0.05) influenced moisture content of the mixtures, which rose linearly with an increase in storage time. Packaging material proved to be an important variable affecting moisture content, particle size, colour and cohesion index. Functional ingredients (vitamins A and C, iron, inulin and oligofructose) influenced particle size, dispersibility, wettability and, in terms of sensory analysis, grades for aftertaste, chemical taste and overall acceptability.

CONCLUSION

Addition of functional ingredients significantly influenced some particle size distribution parameters and reconstitution properties, causing an increase in wettability and dispersibility times. Furthermore, in sensory terms, it influenced aftertaste and chemical taste grades. Packaging material significantly influenced moisture content, some particle size distribution parameters, colour and cohesion index. © 2014 Society of Chemical Industry
Different fingerprinting strategies to differentiate Porana sinensis and plants of Erycibe by high‐performance liquid chromatography with diode array detection, ultra high performance liquid chromatography with tandem quadrupole mass spectrometry, and chemometrics
Authors: Chen Zhiyong , Liao Liping , Yang Yuanyuan , Zhang Zijia , Wang Zhengtao
Published: November 2014

Plants of Erycibe are widely used in traditional Chinese medicine for the treatment of joint pain and rheumatoid arthritis. With the reduction of Erycibe resources in the wild, Porana sinensis has been widely used as a substitute. However, it is important to understand the chemical distinctions between the two kinds of plants and identify their individual chemical markers. In this study, multiwavelength chromatographic fingerprint and precursor ion fingerprint techniques were used in conjunction with chemometric tools to fingerprint and thus differentiate between plant samples. The similar results obtained from different fingerprints prove the reliability of the two fingerprints. Results obtained from principal component analysis and orthogonal projection to latent structures discriminant analysis identified similarities between the chemical components of P. sinensis and plants of Erycibe. However, concentrations of 4‐caffeoylquinic acid, 3,5‐dicaffeoylquinic acid, 3,4‐dicaffeoylquinic acid, and 4,5‐dicaffeoylquinic acid were higher in P. sinensis than in plants of Erycibe, suggesting that P. sinensis may be more effective in medical treatments of some diseases than Erycibe.
Pediatric tracheal tumor masked by a history of travel: Case report and literature review
Authors: Pugnale Marci J. , Maresh Alison , Sinha Pranava , Rossi Christopher , Murnick Jonathan , Reilly Brian K.
Published: November 2014

A previously healthy 10‐year‐old female reported a 1‐month history of wheezing and hemoptysis. Initial evaluation and treatment were focused on refractory reactive airway disease and infectious etiologies prompted by her recent travels in Africa. Worsening respiratory distress prompted emergent evaluation with imaging and endoscopy. Bronchoscopy diagnosed a distal tracheal tumor; pathology of this tumor was benign fibrous histiocytoma. Successful management of this condition included imaging, rigid bronchoscopy with biopsy, and tracheal resection to surgically excise the lesion. Although rare, tracheal tumors should be considered when presentation of asthma is atypical and nonresponsive to medical interventions. Laryngoscope, 125:1004–1007, 2015
National survey of adult transplant hepatologists on the pediatric‐to‐adult care transition after liver transplantation
Authors: Heldman Madeleine R. , Sohn Min‐Woong , Gordon Elisa J. , Butt Zeeshan , Mohammed Saeed , Alonso Estella M. , Levitsky Josh
Published: November 2014

Adult transplant hepatologists face challenges in providing care to young adults who received liver transplants during childhood. Because prior studies have focused mainly on pediatric providers, understanding these issues from the perspective of the adult hepatologist may provide novel insights and identify key barriers to care in this population. We conducted a national survey of adult transplant hepatologists to assess factors that may affect the transition of recipients from pediatric care to adult care. More than half of transplant hepatologists from all United Network for Organ Sharing regions (236/408 or 57.8%) completed the survey, and they reported that only 46.1% of patients arrived at their first adult clinic with both adequate knowledge of their condition and a parent/guardian. Moreover, 32.4% reported having no transition strategy, and only 15.5% reported having a formal transition program. The respondents reported that the greatest barriers to optimal care were patients' poor adherence and their limited knowledge and management of their condition. Those who reported participating in a formal transition program were less likely to report an inability of patients to discuss the impact of their condition on their overall daily life, fitness, and sexuality as a barrier to transition (odds ratio = 0.40, 95% confidence interval = 0.16‐1.00). Our survey suggests that a formalized transition process is uncommon in adult transplant hepatology clinics and that improving patient knowledge, understanding specific components of effective transition programs, and incorporating input from adult providers in designing such programs may improve this process. Liver Transpl 21:213‐223, 2015. © 2014 AASLD.
Solving the biharmonic Dirichlet problem on domains with corners
Authors: De Coster Colette , Nicaise Serge , Sweers Guido
Published: November 2014

The biharmonic Dirichlet boundary value problem on a bounded domain is the focus of the present paper. By Riesz' representation theorem the existence and uniqueness of a weak solution is quite direct. The problem that we are interested in appears when one is looking for constructive approximations of a solution. Numerical methods using for example finite elements, prefer systems of second equations to fourth order problems. Ciarlet and Raviart in and Monk in consider approaches through second order problems assuming that the domain is smooth. We will discuss what happens when the domain has corners. Moreover, we will suggest a setting, which is in some sense between Ciarlet‐Raviart and Monk, that inherits the benefits of both settings and that will give the weak solution through a system type approach.
Novel nanocomposites obtained by dispersion of LDH modified with N‐tetrabromophthaloyl‐glutamic in poly(amide‐imide) having N‐trimellitylimido‐l‐leucine and 4,4′‐diaminodiphenylether units
Authors: Mallakpour Shadpour , Dinari Mohammad , Talebi Meysam
Published: November 2014

Layered double hydroxides (LDHs) have attracted much attention as nanofillers in polymer nanocomposites (NCs) due to their particular surface structural, positively charged layer and so on. In this study, a chiral diacid was synthesized by the reaction of tetrabromophthalic anhydride and glutamic acid. LDH was modified by co‐precipitation of aluminum nitrate, magnesium nitrate, and glutamic acid containing diacid. Chiral poly(amide‐imide) (PAI) was synthesized by direct polycondensation reaction of N‐trimellitylimido‐l‐leucine and 4,4′‐diaminodiphenylether. Different NCs of the obtained modified LDHs and the chiral PAI were prepared in a short time using ultrasonic technique. The morphology and the structure of the obtained samples were characterized by Fourier transform infrared, thermogravimetric analysis (TGA), field emission scanning electron microscopy, transmission electron microscopy, and X‐ray diffraction analysis. TGA of the NCs showed a special order in thermal stability in compression with the neat PAI owing to the uniform distribution of the nanofillers. POLYM. COMPOS., 37:1323–1329, 2016. © 2014 Society of Plastics Engineers
High efficiency photovoltaic module based on mesoscopic organometal halide perovskite
Authors: Matteocci Fabio , Cinà Lucio , Di Giacomo Francesco , Razza Stefano , Palma Alessandro L. , Guidobaldi Andrea , D'Epifanio Alessandra , Licoccia Silvia , Brown Thomas M. , Reale Andrea , Di Carlo Aldo
Published: November 2014

We fabricated monolithic solid state modules based on organometal CH3NH3PbI3 and CH3NH3PbI3 − xClx perovskites using poly‐(3‐hexylthiophene) and Spiro‐OMeTAD as hole transport materials (HTMs). In particular, we developed innovative and scalable patterning procedures to minimize the series resistance at the integrated series‐interconnections. By using these optimization steps, we reached a maximum conversion efficiency of 8.2% under AM1.5G at 1 Sun illumination conditions using the CH3NH3PbI3 − xClx perovskite and the poly‐(3‐hexylthiophene) as HTM. Finally, we investigated the double‐step deposition of CH3NH3PbI3 using the Spiro‐OMeTAD, reaching a maximum conversion efficiency on active area (10.08 cm2) equal to 13.0% (9.1% on aperture area) under AM1.5G at 1 Sun illumination conditions. This remarkable result represents the highest PCE value reached for the perovskite solar modules. Copyright © 2014 John Wiley & Sons, Ltd.
Kinetics of the inhibition of styrene polymerization by nitro compounds
Authors: Tüdös F. , Kende I. , Azori M.
Published: November 2014

A kinetic study has been made of the inhibiting action of s‐trinitrobenzene and its derivatives on the initiation of styrene polymerization. The effect of −CH3, −OH, −OCH3, −NH2, −Cl, −CO2C2H5 as substituents was investigated. The nitro compounds were found to be weak inhibitors of styrene polymerization. They bring about a well defined inhibition period during which the reaction mixture usually darkens. During the inhibition phase the rate of polymerization gradually increases, but the rate of polymerization afterwards is lower than during the noninhibited process. It concerns the fact that the initial inhibitor transforms to a retarder about 20 times weaker. In the light of this the basic equations of inhibition followed by retardation have been derived. Such are, for example, equations for the polymerization rate, for the kinetics of inhibitor consumption, and also a formula for determining the duration of the inhibition phase on the basis of dilatometric data. Procedures have also been developed for determining the inhibition and retardation constants and the stoichiometric coefficient indicating number of radicals deactivated by one molecule of inhibitor. The inhibition constants (as well as retardation constants) have been shown to obey the Hammett rule in the case of substituents of small volume (−H, −CH3, −OCH3, −Cl). The inhibition reactivity of the compounds is the higher, the higher the electron acceptor properties of the substituent. In the case of the −CO2C2H5 group the activity is below that expected from the Hammett rule, which is evidently the result of a decrease in conjugation. In the case of OH and NH2 substituents the activity is much above that given by the rule, because the hydrogen bond has an additional electron acceptor effect on the nitro group.
Investigation of the reaction of organomagnesium compounds with the salts of heavy metals, and the use of organomagnesium compounds and their complexes for polymerization
Authors: Erusalimskiǐ B. L. , Fo‐Sung Wang , Kavunenko A. P.
Published: November 2014

The behavior of some systems of the type MgRX−MenXn in the presence of free radical acceptors has been studied with the purpose of throwing some light on the nature of the reaction magnified image.

It is shown that such agents affect neither the yield nor the ratio of hydrocarbons noted above. This indicates the absence of free radical stages in this reaction. Data have been obtained on the polymerization of some olefins and dienes in the presence of the systems [G4H9MgI + (C4H9)2Mg]−TiXn. The organomagnesium compounds have been found capable of initiating the polymerization of isoprene in the absence of titanium salts. The polyisoprene produced in this case contains 96–99% of 3,4‐unite.
Study of degradation of polyphosphates in aqueous solution
Authors: Thilo E. , Wieker W.
Published: November 2014

Cyclic trimetaphosphate is formed along with monophosphate and some di‐ and triphosphate on the degradation of chainlike polyphosphates in aqueous solution at pH 8 and 60°C. This degradation is catalytically accelerated by many metal salts. The kinetic examination of the degradation reaction in the presence of some selected metal salts shows that its catalytic effect is closely connected with the ion exchange capacity of the polyphosphates. The higher the affinity of a metal cation to the polyphosphate, i.e., the stronger it is bound, the higher is its catalytic activity. This increases in the order K < Na < Li < Ba < Sr < Ca < Mg < Al. From the kinetics of the degradation reaction it follows, contrary to our previous investigations, that degradation does not occur only from the chain end but statistically over the whole polymer molecule and that the formation of trimetaphosphate is not connected with the formation of the monophosphate. A new scheme of reaction for the formation of the cyclic trimetaphosphate from the chainlike polyphosphates is developed. According to this the primary step of the degradation consists of an intramolecular “phosphorylation” of the polyphosphate, which is then followed by hydrolysis of the trimetaphosphate.
Mechanism of protective action of benzene rings in radiolysis of polystyrene
Authors: Pravednikov A. N. , Shen‐Kan In
Published: November 2014

The crosslinking energy in the radiolysis of polystyrene is 100‐fold that of polyethylene, whereas the free radical yield in the radiation of linear paraffins is only 5–6 times as much as that from alkylaromatic compounds. Therefore, the high radiation stability of polystyrene cannot be explained by the conventional scheme for the action of the benzene rings. In order to explain the high radiation stability of polystyrene the mechanism of the reactions taking place during radiolysis of the polymer must be examined. A hydrogen atom liberated as the result of rupture of a C–H bond under the action of radiation may react in two ways: (1) abstraction of a hydrogen atom from the aliphatic chain, and (2) addition to the double bond of the benzene ring with the formation of a free radical of the cyclohexadienyl type. Owing to the low rate of diffusion in the solid polymers and the high rate of reaction with atomic hydrogen, the radicals formed in this way should be in the immediate vicinity of the primary radical. Interaction of the latter with the radical formed by removal of a hydrogen atom from the aliphatic chain will lead to the formation of crosslinks. The interaction between the primary radical and the radical of the cyclohexadienyl type may take place in the following two ways. The radicals may recombine with each other to form crosslinks or they may engage in a disproportionation reaction. Disproportionation will lead to restoration of the initial state and hence to the dissipation of energy without crosslink formation. This will result in a drop in efficiency of the crosslinking process, the energy for the formation of one crosslink increasing. In order to obtain experimental verification of the above conceptions as to the mechanism of interaction of the primary and cyclohexadienyl radicals, the radiolysis of deuterated toluene C4H5CD3 was studied at the temperature of liquid nitrogen. The addition to the benzene ring of a deuterium atom formed on rupture of a C–D bond under the action of radiation and the subsequent disproportionation of the cyclohexadienyl and primary radicals should, owing to the isotope effect, lead to transition of deuterium atoms from the aliphatic chain to the ring. The results obtained showed that the rate of these processes should exceed by at least 5–6 fold the rate of the processes leading to crosslinkage. It thus follows that the high radiation stability of polystyrene is to a considerable extent associated with disproportionation of the primary and cyclohexadienyl radicals.
Oxidative transformations in cellulose molecules
Authors: Ivanov V. I. , Lenshina N. Ya. , Ivanova V. S.
Published: November 2014

It is shown that in all cellulose specimens isolated from plant tissues there are non‐hydroxyl groups in the 1‐, 2‐, 3‐, and 6‐positions of some of the glucose repeating unite. The presence of trace amounts of these groups changes the physical and chemical properties of the cellulose. For the purpose of studying the effect of the functional groups on the stability of the glucoside bond in the cellulose molecule and also to obtain oxidized products of importance by themselves, we have investigated the possible paths of cellulose oxidation. As an extension of previous work devoted to the primary oxidative reactions of cellulose we have studied oxidation by sodium periodate with subsequent oxidation by nitrogen oxides. This procedure yielded products containing 220 COOH groups per 100 glucose residues. These groups are in the 2‐, 3‐, and 6‐positions. The reactions showed that in opened pyran rings there is hindrance to the oxidation of primary OH groups. In contrast to other methods, which give products with not more than 50% of the theoretical number of dicarboxyl groups, the successive oxidation of cellulose by sodium periodiate yielded theoretical amounts of dicarboxycellulose with respect to carboxyl group content. The oxidation products obtained have a fibrous structure, dissolve in dilute aqueous sodium hydroxide, are relatively resistant to acid hydrolysis, are stable in air, and contain only traces of nitrogen, in contrast to dicarboxy‐ and monocarboxycelluloses. This type of oxidized cellulose, which we have termed tricarboxycellulose, possesses high and selective ion exchange properties, allowing cations, among them proteins, to be separated. This new type of oxidized fibrous cellulose permits a new direction to be developed in paper chromatography.
Synthesis of new derivatives of cellulose and other polysaccharides
Authors: Rogovin Z. A. , Derevitskaya V. A. , Tun Sun' , Weǐ‐Gan Chzhan , Gal'Braikh L. S.
Published: November 2014

A method has been developed for the synthesis of esters of cellulose and ω‐amino acids and a preliminary study has been made of their properties. Experiments have been made on their modification through the reactive amino groups. The esters of ω‐chlorovaleric and ω‐chloroenanthic acids as well as the mixed esters of acetic and chlorovaleric acids were synthesized and the properties of this new type of cellulose esters have been investigated. Various monocarboxylcellulose amides have been synthesized. The hydrazides of the carboxylated polysaccharides were prepared, and a number of reactions were carried out with the objective of further modifying the properties of these polysaccharides. Cellulose‐polyamide graft copolymers with the polyamide molecule in the side chain were prepared. The synthesis of the graft copolymers of dicarboxycellulose and polyamides of which each elementary unit of the main chain contained two side chains of low molecular polyamides were carried out.
“Weak links” in polysaccharide chains as related to modified groups
Authors: Rånby Bengt G.
Published: November 2014

Celluloses of different origin are hydrolyzed at different rates in acid medium both in fiber form (heterogeneous process) and in solution (homogeneous process). On the basis of measurements for well purified samples of commercial wood and cotton celluloses, molecularly dissolved in concentrated phosphoric acid, it was recently proposed that the fact that initial rates of hydrolysis are higher for wood cellulose than for cotton cellulose is largely related to inductive effects from modified (electrophilic) groups, e.g., carboxyls and carbonyls. Some of these groups are no doubt introduced during purification processes involving oxidative bleaching. It is possible that some of the modified groups are of native origin, but they are few (less than one modified group for 400 glucose units). The probable mechanisms for the influence on the rate of hydrolysis of modified groups, e.g., inductive and steric effects, rearrangements of the ring structure, are discussed in relation to the present knowledge of polysaccharide reactions. The concepts of inductive effects are supported by evidence from the hydrolysis of hemicelluloses and other polysaccharides containing uronic acid groups.
Initiating directed synthesis of modified celluloses by nitrogen oxides
Authors: Ermolenko I. N. , Kaputsky F. N.
Published: November 2014

In connection with a scheme, previously suggested by the author, for the mechanism of oxidation of cellulose by nitrogen oxides which explains the selectivity of the process, experiments were conducted which confirm that the role of N2O3 constitutes interaction with cellulose macroradicals generated in the previous reaction with NO2(N2O4). Addition of nitrogen oxides under the action of phosphoric acid solutions to cellulose leads to an increase in the content of bound phosphorus in the products, determined as the function which is present in the form of molecular compounds, including H3PO4, cellulose, and possibly HNO3.
Radiation copolymerization of acrylonitrile with polystyrene and perchlorovinyl
Authors: Usmanov Kh. U. , Musaev U. N. , Tillaev R. S.
Published: November 2014

With the objective of obtaining polymers with new, valuable properties in recent years considerable importance has been attached to the synthesis of graft and block copolymers. Such copolymers combine the properties of their polymeric constituents. In order to form graft and block copolymers it is necessary that the starting material possess active centers, which may be groups capable of forming free radicals. To carry out a graft or block copolymerization various chemical and physical methods yielding polymeric free radicals are employed. One of the new methods of synthesizing graft and block polymers is the radiation method. In the present work the results of experiments on the formation of graft polystyrene and perchlorovinyl polymers with acrylonitrile by the action of gamma rays are presented. Co™ served as radiation source. The reaction was carried out by subjecting a swollen polystyrene film in acrylonitrile to doses of 1 × 106−4 × 106 r. The resultant product was separated from the homo‐polymer by extraction. As the results obtained have shown, the percentage of grafting over the range studied increases with increasing radiation dose. The monomer unit to polymer ratio has been calculated from data on the nitrogen content. Also a graft polymer of perchlorovinyl and acrylonitrile was obtained by preliminary irradiation of perchlorovinyl in the presence of air. The thermomechanical properties of the resultant polymers were investigated. The results showed that graft polymers of polystyrene and perchlorovinyl possess greater thermal stability than the initial polymers. In the study the radiation polymerization of acrylonitrile was also carried out and the viscosity of polyacrylonitrile solutions was measured.
Identification of linear B‐cell epitopes within Tarp ofChlamydia trachomatis
Authors: Zhu Shanli , Feng Yan , Chen Jun , Lin Xiaoyun , Xue Xiangyang , Chen Shao , Zhong Xiaozhi , Li WenShu , Zhang Lifang
Published: November 2014

Chlamydia trachomatisis one of the most prevalent sexually transmitted pathogens. There is currently no commercially available vaccine againstC.trachomatis. Chlamydial translocated actin‐recruiting phosphoprotein (Tarp) can induce cellular and humoral immune responses in murine models and has been regarded as a potential vaccine candidate. In this report, the amino acid sequence of Tarp was analyzed using computer‐assisted techniques to scan B‐cell epitopes, and six possible linear B‐cell epitopes peptides (aa80–95, aa107–123, aa152–170, aa171–186, aa239–253 and aa497–513) with high predicted antigenicity and high conservation were investigated. Sera from mice immunized with these potential immunodominant peptides was analyzed by ELISA, which showed that epitope 152–170 elicited serum immunoglobulin G (IgG) response and epitope 171–186 elicited both serum IgG and mucosal secretory immunoglobulin A response. The response of immune sera of epitope 171–186 to endogenous Tarp antigen obtained from the Hela229 cells infected withC.trachomatiswas confirmed by Western blot and indirect fluorescence assay. In addition, binding of the antibodies against epitope 171–186 to endogenous Tarp was further confirmed by competitive ELISA. Our results demonstrated that the putative epitope (aa171–186) was an immunodominant B‐cell epitope of Tarp. If proven protective and safe, this epitope, in combination with other well‐documented epitopes, might be included into a candidate epitope‐based vaccine againstC.trachomatis. Copyright © 2014 European Peptide Society and John Wiley & Sons, Ltd.
Autotaxin-LPA Axis Regulates hMSC Migration by Adherent Junction Disruption and Cytoskeletal Rearrangement Via LPAR1/3-Dependent PKC/GSK3β/β-Catenin and PKC/Rho GTPase Pathways
Authors: Ryu Jung Min , Han Ho Jae
Published: November 2014

Bioactive molecules and stem cell-based regenerative engineering is emerging a promising approach for regenerating tissues. Autotaxin (ATX) is a key enzyme that regulates lysophosphatidic acid (LPA) levels in biological fluids, which exerts a wide range of cellular functions. However, the biological role of ATX in human umbilical cord blood-derived mesenchymal stem cells (hMSCs) migration remains to be fully elucidated. In this study, we observed that hMSCs, which were stimulated with LPA, accelerated wound healing, and LPA increased the migration of hMSCs into a wound site in a mouse skin wound healing model. In an experiment to investigate the effect of LPA on hMSC migration, ATX and LPA increased hMSC migration in a dose-dependent manner, and LPA receptor 1/3 siRNA transfections inhibited the ATX-induced cell migration. Furthermore, LPA increased Ca2+ influx and PKC phosphorylation, which were blocked by Gαi and Gαq knockdown as well as by Ptx pretreatment. LPA increased GSK3β phosphorylation and β-catenin activation. LPA induced the cytosol to nuclear translocation of β-catenin, which was inhibited by PKC inhibitors. LPA stimulated the binding of β-catenin on the E-box located in the promoter of the CDH-1 gene and decreased CDH-1 promoter activity. In addition, the ATX and LPA-induced increase in hMSC migration was blocked by β-catenin siRNA transfection. LPA-induced PKC phosphorylation is also involved in Rac1 and CDC42 activation, and Rac1 and CDC42 knockdown abolished LPA-induced F-actin reorganization. In conclusion, ATX/LPA stimulates the migration of hMSCs through LPAR1/3-dependent E-cadherin reduction and cytoskeletal rearrangement via PKC/GSK3β/β-catenin and PKC/Rho GTPase pathways. Stem Cells  2015;33:819–832
Induced Pluripotent Stem Cells Restore Function in a Human Cell Loss Model of Open-Angle Glaucoma
Authors: Abu-Hassan Diala W. , Li Xinbo , Ryan Eileen I. , Acott Ted S. , Kelley Mary J.
Published: November 2014

Normally, trabecular meshwork (TM) and Schlemm's canal inner wall endothelial cells within the aqueous humor outflow pathway maintain intraocular pressure within a narrow safe range. Elevation in intraocular pressure, because of the loss of homeostatic regulation by these outflow pathway cells, is the primary risk factor for vision loss due to glaucomatous optic neuropathy. A notable feature associated with glaucoma is outflow pathway cell loss. Using controlled cell loss in ex vivo perfused human outflow pathway organ culture, we developed compelling experimental evidence that this level of cell loss compromises intraocular pressure homeostatic function. This function was restored by repopulation of the model with fresh TM cells. We then differentiated induced pluripotent stem cells (iPSCs) and used them to repopulate this cell depletion model. These differentiated cells (TM-like iPSCs) became similar to TM cells in both morphology and expression patterns. When transplanted, they were able to fully restore intraocular pressure homeostatic function. This successful transplantation of TM-like iPSCs establishes the conceptual feasibility of using autologous stem cells to restore intraocular pressure regulatory function in open-angle glaucoma patients, providing a novel alternative treatment option. Stem Cells  2015;33:751–761
Acute Loss of Cited2 Impairs Nanog Expression and Decreases Self-Renewal of Mouse Embryonic Stem Cells
Authors: Kranc Kamil R. , Oliveira Daniel V. , Armesilla-Diaz Alejandro , Pacheco-Leyva Ivette , Catarina Matias Ana , Luisa Escapa Ana , Subramani Chithra , Wheadon Helen , Trindade Marlene , Nichols Jennifer , Kaji Keisuke , Enver Tariq , Bragança José
Published: November 2014

Identifying novel players of the pluripotency gene regulatory network centered on Oct4, Sox2, and Nanog as well as delineating the interactions within the complex network is key to understanding self-renewal and early cell fate commitment of embryonic stem cells (ESC). While overexpression of the transcriptional regulator Cited2 sustains ESC pluripotency, its role in ESC functions remains unclear. Here, we show that Cited2 is important for proliferation, survival, and self-renewal of mouse ESC. We position Cited2 within the pluripotency gene regulatory network by defining Nanog, Tbx3, and Klf4 as its direct targets. We also demonstrate that the defects caused by Cited2 depletion are, at least in part, rescued by Nanog constitutive expression. Finally, we demonstrate that Cited2 is required for and enhances reprogramming of mouse embryonic fibroblasts to induced pluripotent stem cells. Stem Cells  2015;33:699–712
Novel non‐coherent and half‐coherent receivers for amplify‐and‐forward relaying
Authors: Khan Fahd Ahmed , Chen Yunfei , Alouini Mohamed‐Slim
Published: November 2014

Consider a system in which the signal is transmitted from the source to the destination via a relay. The source–relay link and the relay–destination link are assumed to have Rician fading. For such a system, in this paper, we propose a novel non‐coherent receiver that detects the signal without knowledge of channel state information (CSI). In addition, we also propose novel receivers for the situation when only partial CSI is available at the destination; that is, channel knowledge of either the source–relay link or the relay–destination link, but not both, is available. These receivers are termed as “half‐coherent receivers” because they have the CSI of only one of the two links in the system. These half‐coherent receivers can be used in applications in which only the relay can afford additional complexity (e.g., the relay may be a base station) and includes a channel estimation module to acquire channel knowledge of the source–relay link or only the destination includes the channel estimation module to acquire channel knowledge of the relay–destination link. The symbol error rate performances of the proposed receivers for M‐ary frequency‐shift keying are derived for Rician fading. Numerical results show that considerable performance gains can be achieved by using these new receivers, especially at a low signal‐to‐noise ratio where the gain is needed most. Copyright © 2014 John Wiley & Sons, Ltd.
Botulinum Toxin A Injection to Facial and Cervical Paraspinal Muscles in a Patient With Stiff Person Syndrome: A Case Report
Authors: Pakeerappa Praveen N. , Birthi Pravardhan , Salles Sara
Published: November 2014

Stiff person syndrome (SPS) is a rare neurologic disorder of unknown etiology characterized by increased resting muscle tone, progressive rigidity, and stiffness of the axial musculature. We present a case of a 48‐year‐old male patient with SPS who experienced facial and neck muscle spasms that were uncontrolled with oral medications and the use of an intrathecal baclofen pump. Botulinum toxin A injections into the bilateral masseter and neck paraspinal muscles provided pain relief and spasm control, illustrating the use of botulinum toxin A injections in the small muscles of face and neck in patients with SPS.
Comparison of the Thickness of Lateral Abdominal Muscles Between Pregnant Women With and Without Low Back Pain
Authors: Rostami Mohsen , Noormohammadpour Pardis , Mansournia Mohammad Ali , Hantoushzadeh Sedigheh , Farahbakhsh Farzin , Nourian Ruhollah , Kordi Ramin
Published: November 2014

Objectives

To compare the thickness of the external oblique, internal oblique, and transversus abdominis muscles in pregnant subjects with and without low back pain (LBP) by the use of ultrasound to measure thickness.

Design

A case‐control study.

Setting

An academic and tertiary care referral spine and sports medicine center.

Participants

Fifty pregnant women with LBP during pregnancy and 54 pregnant control subjects.

Methods

Case and control subjects were matched for body mass index, gestational age, and number of previous pregnancies. A multiple linear regression model with adjustment for the gestational age of the subjects, as the potential confounder of the primary outcomes, was used to evaluate the association between LBP appearance and abdominal muscles thickness of the subjects.

Main Outcome Measures

The thickness of lateral abdominal muscles was measured by ultrasound with the subject in a hook‐lying position on the examination table.

Results

We found that there was no significant difference between pregnant subjects with and without LBP in terms of the thickness of external oblique, internal oblique, and transversus abdominis muscles.

Conclusion

These findings suggest that other factors rather than the thickness of core stabilizing muscles are influential in the etiology of LBP during pregnancy. We hypothesize that enlargement of uterus during pregnancy might influence the thickness of the lateral abdominal muscles.