bluuebunny/crossref_metadata_2025 huggingface dataset:
Microwave‐promoted piperidination of halopyridines: a comparison between Ullmann, Buchwald–Hartwig and uncatalysed SNAr reactions
Authors: Yaunner Ricardo S. , Barros José C. , da Silva Joaquim F. M.
Published: May 2012

A comparative study between the most used methodologies for the preparation of piperidinyl pyridines (Buchwald–Hartwig reaction, Ullmann reaction and nucleophilic aromatic substitution (SNAr)) by microwave‐assisted piperidination of halopyridines is reported. Our results suggest that the Ullmann reaction is most effective for less reactive halopyridines, while uncatalysed SNAr is sufficient for more reactive ones. Copyright © 2012 John Wiley & Sons, Ltd.
ZnI2‐promoted homologation of ferrocenylacetylene and aldehydes: an efficient synthesis of ferrocene‐containing allenes
Authors: Chen Shufeng , Shi Jinxiang , Wang Binglong , Zhao Haiying , Li Baoguo
Published: May 2012

A concise and efficient protocol for the first synthesis of ferrocene‐containing allenes based on the homologation reaction of ferrocenylacetylene and aldehydes promoted by ZnI2 was developed. The present method was applicable to many kinds of substituted aldehydes, providing good to excellent yields of ferrocene‐containing allenes. Copyright © 2012 John Wiley & Sons, Ltd.
Stability of some aryllithiums in the presence of cyano group: synthesis of biaromatic cyanoarylboronic acids and silanes
Authors: Durka Krzysztof , Gontarczyk Krzysztof , Kliś Tomasz , Serwatowski Janusz , Woźniak Krzysztof
Published: May 2012

Lithium diisopropylamine (LDA)‐mediated deprotonation reactions of halogenated cyanobenzyloxy‐benzenes and cyanobiphenyls were investigated. The resultant organolithium derivatives were converted into the corresponding arylboronic acids or silanes. It was found that the stability of the obtained aryllithiums towards isomerization to the respective benzyllithiums depends strongly on the number of fluorine atoms in the phenyl ring and on the position of the cyano group. Halogenated cyanobiaryls were selectively deprotonated in the position flanked by two halogen atoms; however, the yield depended strongly on the reaction conditions. Addition of LDA to the cyano group was observed on the lithiation of 4‐cyano‐3′,5′‐dichlorobiphenyl rather than deprotonation. Copyright © 2012 John Wiley & Sons, Ltd.
Synthesis and electrochemical properties of hollow polyaniline microspheres by a sulfonated polystyrene template
Authors: Tan Yong‐Tao , Ran Fen , Wang Ling‐Ren , Kong Ling‐Bin , Kang Long
Published: May 2012

Hollow polyaniline microspheres (HMsPANI) for supercapacitors were prepared successfully with sulfonated polystyrene microspheres as the template. The prepared electrode materials of HMsPANI consisted of nanoparticles and, thus, had a hierarchical structure. The electrochemical behaviors of the materials were investigated with cyclic voltammetry and galvanostatic charge–discharge tests. A maximum specific capacitance of 421 F/g was achieved in a 1M H2SO4 solution, with the potential ranging from −0.2 to 0.8 V (vs a saturated calomel electrode), in a three‐electrode glass cell at room temperature for the HMsPANI electrode. This suggested its potential application in electrochemical capacitors. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Surface modification of polycaprolactone monofilament by low pressure oxygen plasma
Authors: Gupta Bhuvanesh , Krishnanand Kumar , Deopura B. L. , Atthoff Björn
Published: May 2012

Surface modification of polycaprolactone filament has been carried out using a low pressure oxygen plasma to introduce active centers in the form of radicals, peroxides, and hydroperoxides on the surface. Evaluation by 2, 2‐diphenyl‐1‐picrylhydrazyl method shows that there is an optimum value of exposure time, gas pressure, and discharge power for the generation of the maximum concentration of such groups. The plasma exposure time was thereafter varied to study the extent of the surface modification introduced by the plasma. It was found that only a short time of exposure to the oxygen plasma was necessary to make the surface highly wettable and polar with increased surface energy and work of adhesion. Surface chemical analysis by X‐ray photoelectron spectroscopy revealed that this happens because of oxidation of the top layer of the filament, which occurs primarily by the breaking of bonds and incorporation of oxygen containing functionalities. Morphological and topographical observations by scanning electron microscopy and atomic force microscopy revealed that etching is pronounced at longer exposure times leading to a rougher surface with hill‐valley features. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Study on high‐solid content Si/PU polyurethane dispersion with PES/PPG composite soft segment
Authors: Zhang Faxing , Wei Xiaoli , Xiao Zhongliang
Published: May 2012

A polyol consists of silicone chains and epoxy acrylate structures, referred to as silicon polyether (PES), was used to prepare crosslinked Si/PU dispersions. Both PES and propylene oxide glycol (PPG) were mixed as soft segments. The effects weight ratios of PES to PPG on properties of the resultant polyurethane dispersions were studied. Morphology and properties of the Si/PU dispersions were characterized by particle size, transmission electron microscopy (TEM), and viscometer. It is shown that the Si/PU dispersions possessed wider particle size distribution and higher average particles diameter because of the use of PES, which contains crosslinked silicone side chains. The Si/PU dispersions have higher solid content as compared to the conventional water‐based polyurethane, because of the volume fraction ratio of bigger particle to small particle from the Si/PU dispersions. As increasing weight ratio of PES to PPG, the solid content of the Si/PU dispersions increased firstly, and then decreased. When the ratio ranges from 4 : 10 to 5 : 10, solid content of the Si/PU dispersions is up to 55%. It was also noticed that apparent viscosity of the Si/PU dispersions decreased with increasing PES to PPG ratio. In the Si/PU dispersions, solid content was increased and viscosity was decreased by the use of PES. Therefore, PES is a potential compound for the application of PU dispersions. In addition, stability of the crosslinked Si/PU dispersions decreases slightly at high‐ and low‐temperature; however, which can meet the basical requirements. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
The influence of melt‐mixing process conditions on electrical conductivity of polypropylene/multiwall carbon nanotubes composites
Authors: Tambe Pankaj B. , Bhattacharyya Arup R. , Kulkarni Ajit R.
Published: May 2012

The influence of melt‐mixing parameters on the development of “network‐like” structure of multiwall carbon nanotubes (MWNTs) in injection‐molded polypropylene (PP)/MWNTs composites was assessed through AC electrical conductivity measurements. A higher melt‐mixing temperature (260°C as compared to 200, 220, and 240°C) at a fixed rotational speed of the screws (150 rpm) and at a fixed mixing time (15 min) has yielded maximum improvement in electrical conductivity in PP/MWNTs composites of 3 wt % MWNTs content. Next to higher melt‐mixing temperature, a variation in the melt‐mixing time has also led to a variation in electrical conductivity of the composites. Raman spectroscopic analysis revealed an increase in the ratio of intensity due to G‐band over that of D‐band (IG/ID) of the MWNTs in the “skin” region as compared to the “core” region of the injection‐molded composites irrespective of the melt‐mixing conditions. Microscopic observations could not provide much insight into the variation of MWNTs network‐like structure in various PP/MWNTs composites. An attempt has been made to understand the variation of network‐like structure of MWNTs in PP/MWNTs composites as a function of melt‐mixing parameters through electrical conductivity measurements, Raman spectroscopic analysis, and morphological investigations. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Effect of interfacial chemistry on the linear rheology and thermal stability of poly(arylene ether nitrile) nanocomposite films filled with various functionalized graphite nanoplates
Authors: Zhan Yingqing , Meng Fanbin , Yang Xulin , Wei Junji , Yang Jian , Zou Yanke , Guo Heng , Zhao Rui , Liu Xiaobo
Published: May 2012

Poly(arylene ether nitrile) (PEN) nanocomposites filled with functionalized graphite nanoplates (GNs) were prepared by a simple solution‐ casting method and then characterized by rheometer and thermogravimetric analysis (TGA). This study investigates how the surface treatment of GNs affects the GN dispersion state. The linear rheological test indicated that the 4‐aminophenoxyphthalonitrile‐grafted GN (GN‐CN) presented better dispersion in PEN matrix than purified GN because the corresponding composite showed the lower rheological percolation threshold, which was further confirmed by scanning electron microscopy and solution experiments. The TGA revealed that the presence of 4‐aminophenoxyphthalonitrile‐grafted GN retarded the depolymerization evidently compared with that of purified GN, showing remarkable increase in the temperatures corresponding to a weight loss of 5 wt % (increased by 21°C) and maximum rate of decomposition (increased by 9°C). Both the dispersion state and the surface functionalization of GN are very important to the thermal stability of PEN matrix. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Thermal degradation behaviors and flame retardancy of epoxy resins with novel silicon‐containing flame retardant
Authors: Gao Ming , Wu Weihong , Xu Zhi‐qiang
Published: May 2012

A novel macromolecular silicon‐containing intumescent flame retardants (Si‐IFR) was synthesized, and its structure was a caged bicyclic macromolecule containing phosphorus‐silicon characterized by IR. Epoxy resins (EP) were modified with Si‐IFR to get the flame retardant EP, whose flammability and burning behavior were characterized by UL 94 and limiting oxygen index (LOI). Twenty percentage of weight of Si‐IFR was doped into EP to get 27.5% of LOI and UL 94 V‐0. The degradation behavior of the flame retardant EP was studied by thermogravimetry, differential thermogravimetry, scanning electron microscopy, and X‐ray photoelectron spectroscopy analysis. The experimental results exhibited that when EP/Si‐IFR was heated, the phosphorus‐containing groups firstly decompose to hydrate the char source‐containing groups to form a continuous and protective carbonaceous char, which changed into heat‐resistant swollen char by gaseous products from the nitrogen‐containing groups. Meanwhile, SiO2 reacts with phosphate to yield silicophosphate, which stabilizes the swollen char. The barrier properties and thermal stability of the swollen char are most effective in resisting the transport of heat and mass to improve the flame retardancy and thermal stability of EP. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Photochromic behavior of naphthopyran in styrene–butadiene–styrene elastomer thin films: Effect of stretching of film and linker
Authors: Zhao Xiancai , Wang Guang , Zhang Kuo
Published: May 2012

Thermoplastic elastomers of styrene–butadiene–styrene (SBS) triblock copolymers containing grafts of naphthopyran as side‐chain polymer were prepared by polymerization of naphthopyran acrylate monomer with a solution of SBS in tetrahydrofuran. Thin films of all grafted SBS polymers displayed photochromism, the decoloration kinetics of naphthopyran in the films was modeled by fitting biexponential equations to the photochromic decay curves after UV light irradiation. Stretching of the grafted SBS film at room temperature affected the fading rate constant k1 of the naphthopyran. The length of linker between photochromic naphthopyran moiety and the acrylate unit in monomer also affected the fading rate constant k1 of the naphthopyran in SBS elastomers. This study presents an example of tuning the photochromic properties of naphthopyran via two approaches, polymer structure, and stretching of films. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Study on reaction kinetics of epoxy resin cured by a modified dicyandiamide
Authors: Feng Libang , Wang Yulong , Wang Yanping , Liu Hao , Zhao Jianchang
Published: May 2012

To improve the disadvantage of the low reactivity and reduce the high curing temperature of epoxy resin cured by dicyandiamide (DICY), DICY is chemically modified with phenyl hydrazine and a new curing agent, LB‐A, is developed in this research. The structure, the curing behavior, and reaction kinetics of LB‐A curing epoxy resin are investigated. Results show that the DICY is modified successfully and the well‐defined structure of DICY is destroyed after modification. Consequently, a new curing agent in a noncrystal form is resulted. Thereupon, the reactivity and compatibility between the epoxy resin and the curing agent are improved appreciably using LB‐A instead of DICY. Meanwhile, the curing temperature and activation energy of the curing reaction decrease outstanding, whereas the rate constant increases remarkably. In addition, the compressive strength and the adhesive strength in shear by tension loading of the resulting epoxy resins have been increased using LB‐A instead of DICY as the curing agent. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Diffusivity of alcohols in amorphous polystyrene
Authors: Bernardo Gabriel
Published: May 2012

Gravimetry is used to study the diffusion of a homologous series of alcohols (Cn, with n = 1, 2, 3, 4, 6, 10, and 16) in amorphous polystyrene at temperatures from 35 to 145°C, that is both below and above the polymer glass transition temperature of 100°C. All the mass uptake results are well described by a simple Fickian model (for t < t1/2) and are used to calculate the corresponding diffusion coefficients using the thin‐film approximation. At any particular temperature, the alcohols Cn with n = 3, 4, and 6 possess very similar diffusivities despite the fact that the chain length doubles from C3 to C6. This peculiar diffusivity behavior is explained based on the variation of the polymer–solvent chemical affinity along the homologous series. As expected, at any particular temperature, the diffusivity decreases considerably from C6 to C10 and from C10 to C16. For each alcohol, its log(D) increases linearly with the decrease in liquid viscosity associated with an increase in temperature. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Covalent immobilization of β‐galactosidase onto electrospun nanofibers of poly (AN‐co‐MMA) copolymer
Authors: El‐Aassar M. R. , Al‐Deyab Salem S. , Kenawy El‐Refaie
Published: May 2012

Immobilization of β‐galactosidase in poly (acrylonitrile‐co‐methyl methacrylate) poly (AN‐co‐MMA) Nanofibers was studied by electrospinning, and a spacer‐arm i.e., (Polyethyleneimine (PEI)) was covalently attached by the reaction of carbonyl groups of Poly (AN‐co‐MMA) nanofibers. β‐galactosidase was then covalently immobilized through the spacer‐arm of the Poly (AN‐co‐MMA) nanofibers by using glutaraldehyde (GA) as a coupling agent. Nanofibers mode of interaction was proven by FTIR and thermal gravimetric analysis and supported by morphological changes recognized through SEM examination. Factors affecting the modification process such as PEI concentration, reaction time, and reaction temperature have been studied. Its influence on the amount of coupled PEI was consequently correlated to the changes of the catalytic activity and the retained activity of immobilized enzyme, the main parameters judging the success of the immobilization process. Evidences of Poly (AN‐co‐MMA) nanofibers modification were extracted from morphological changes recognized through SEM examination. The maximum activity (Vmax) and michaelis constant (Km) of immobilized enzyme were found to be 8.8 μmole/min mg protein and 236.7 mM, respectively. Stabilities of the immobilized β‐galactosidase were obviously improved. The optimum temperature for β‐galactosidase immobilized on the spacer‐arm attached nanofiber was 5°C higher than that of the free enzyme and was also significantly broader. The immobilized β‐galactosidase had better resistance to temperature inactivation than did the free form. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Fundamental thermo‐mechanical property modeling of triglyceride‐based thermosetting resins
Authors: La Scala John , Wool Richard P.
Published: May 2012

The glass transition temperature (Tg) of acrylated triglycerides was clearly a function of the level of acrylation of triglyceride‐based polymers and was modeled using simple empirical relationships. We began by calculating the distribution of unsaturation sites in plant oils. We assumed a binomial distribution of chemical functionality that was added to these unsaturation sites to calculate the distribution of epoxides, acrylates, and reacted acrylates to predict the crosslink density, thermal softening, and dynamic mechanical behavior. The glass transition temperatures of n‐acrylated triglycerides were used as the relaxation temperatures of acrylated oils with a broad distribution of functionality for prediction of the modulus as a function of temperature. Essentially, the percent drop in the elastic modulus is equal to the percentage of n‐acrylated triglycerides in the acrylated oil with Tg less than that of the ambient temperature. The tan (δ) was also accurately predicted based on the percentage change of n‐functional triglycerides as the temperature changes from one relaxation temperature to the next. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Recruitment of the threatened mussel Margaritifera margaritifera in relation to mussel population size, mussel density and host density
Authors: Arvidsson Björn L. , Karlsson Jens , Österling Martin E.
Published: May 2012

Anthropogenic, abiotic factors are considered the main cause of recruitment failure of unionid mussels, including the freshwater pearl mussel (Margaritifera margaritifera). This large‐scale investigation instead examined the relationship between biotic factors and mussel recruitment.

Mussel population size and density were positively related to recruitment and to juvenile mussel density. Juvenile mussel density appeared to be the more accurate measure of recruitment of the two.

Host fish density of young‐of‐the‐year and older brown trout (Salmo trutta) were positively related to recruitment. Moreover, the mean density of both age classes of fish, when grouped into density classes, was positively related to juvenile mussel density, an effect that decreased at trout densities above 10 trout 100 m‐2.

Mussel population size and density were relatively more important to recruitment than trout density.

To increase recruitment of juvenile mussels, managers should apply measures that increase mussel density, and trout density up to about 10 trout 100 m‐2 in proximity to mussel beds. Mussel beds may also be managed; one possible measure within small and sparse mussel populations may be to concentrate the remaining mussels in areas where trout density is high. Likewise, young‐of‐the‐year trout may also be moved to areas of high mussel density, as young trout individuals tend not to move far during their first year. This may increase mussel larval infection rates and mussel recruitment. Copyright © 2012 John Wiley & Sons, Ltd.
Skull Mechanics and the Evolutionary Patterns of the Otic Notch Closure in Capitosaurs (Amphibia: Temnospondyli)
Authors: Fortuny Josep , Marcé‐Nogué Jordi , Gil Lluis , Galobart Àngel
Published: May 2012

Capitosaurs were among the largest amphibians that have ever lived. Their members displayed an amphibious lifestyle. We provide new information on functional morphology data, using finite element analysis (FEA) which has palaeoecological implications for the group. Our analyses included 17 taxa using (2D) plate models to test four loading cases (bilateral, unilateral and lateral bitings and skull raising system simulation). Our results demonstrates that, when feeding, capitosaurs concentrated the stress at the circumorbital region of the capitosaur skull and cranial sutures probably played a key role in dissipating and absorbing the stress generated during biting. Basal members (as Wetlugasaurus) were probably less specialized forms, while during Middle‐ and Late Triassic the group radiated into different ecomorphotypes with closed otic notch forms (as Cyclotosaurus) resulting in the strongest skulls during biting. Previous interpretations discussed a trend from an open to closed otic notch associated with lateral repositioning of the tabular horns, but the analysis of the skull‐raising system reveals that taxa exhibiting posteriorly directed tabular horns display similar results during skull raising to those of closed otic notch taxa. Our results suggest that various constraints besides otic notch morphology, such as the elongation of the tabular horns, snout length, skull width and position, and size of the orbits affect the function of the skull. On the light of our results, capitosaur skull showed a trend to reduce the stresses and deformation during biting. Capitosaurs could be considered crocodilian analogues as they were top‐level predators in fluvial and brackish Triassic ecosystems. Anat Rec, , 2012. © 2012 Wiley Periodicals, Inc.
Quality management of body donation program at the University of Padova
Authors: Porzionato Andrea , Macchi Veronica , Stecco Carla , Mazzi Anna , Rambaldo Anna , Sarasin Gloria , Parenti Anna , Scipioni Antonio , De Caro Raffaele
Published: May 2012

Quality management improvement has become a recent focus of attention in medical education. The program for the donation of bodies and body parts (Body Donation Program) at the University of Padova has recently been subjected to a global quality management standard, the ISO 9001:2008 certification. The aim of the present work is to show how the above standard is useful in enhancing the efficiency of body donation procedures and the quality and output of medical education. The program is managed by means of the following interlinked procedures: the collection of body donations, death certificates, data, and body parts from living donors; the transportation and identification of cadavers; the management of bodies, body parts, equipment, instruments, purchasing of necessary materials, and setting up anatomical training sessions; the management of preventive and corrective actions; the management of documents and registration; the management of internal and external quality audits; and the review of outcomes and improvement planning. Monitoring indicators are identified in the numbers of donors and of donated body parts per year, education sessions, and satisfaction of learners and donors, as evaluated by questionnaires. The process management approach, the integrated involvement of medical, technical, and administrative staff in defining procedures, and the application of monitoring indicators allow quality improvement in all aspects of the Body Donation Program. Anat Sci Educ. © 2012 American Association of Anatomists.
Observer‐based Reliable Control for Discrete Time Systems: An Average Dwell Time Approach
Authors: Du Dongsheng , Jiang Bin , Shi Peng , Mao Zehui
Published: May 2012

This paper deals with the problem of reliable control for discrete time systems with actuator failures. The actuator is assumed to fail occasionally and can recover over a time interval. During the time of suffering failures, the considered closed‐loop system is assumed unstable. Using an average dwell time method and under the condition that the activation time ratio between the system without actuator failures and the system with actuator failures is not less than a specified constant, an observer‐based feedback controller is developed in terms of linear matrix inequalities such that the resulting closed‐loop system is exponentially stable. An example is included to demonstrate the effectiveness of the proposed approach.
Use of a greasy effluent floater treatment station from the slaughterhouse for biosurfactant production
Authors: Borges Wesley da Silva , Cardoso Vicelma Luiz , Resende Miriam Maria de
Published: May 2012

Most commercially available surfactants are produced from petroleum. However, increasing concerns about the environment have stimulated the search for biosurfactant production. This work examines biosurfactant production from the greasy effluent floater treatment station from the slaughterhouse of poultry and pigs. The biosurfactant production was evaluated using two strains of Pseudomonas aeruginosa [American Type Culture Collection (ATCC) 9027 and 10145] in a kinetic study to determine which strain produces a higher rhamnolipid concentration, which is characterized by the rhamnose concentration. The strain of P. aeruginosa was selected via a central composite design based on the following variables: fat concentration, nitrogen concentration, added ammonium nitrate (AN), and brewery residual yeast (BRY). The preliminary results show that the P. aeruginosa strain ATCC 10145 produced biosurfactant more efficiently than ATCC 9027. After optimizing the variables that were studied, the best fat, BRY, and AN concentrations (in g/L) were found to be 12, 15, and 0, respectively.
Lipid composition is a determinant for human defensin hnp1 selectivity
Authors: Gonçalves Sónia , Abade João , Teixeira Alexandre , Santos Nuno C.
Published: May 2012

Human neutrophil peptide 1 (HNP1) is a human defensin with antimicrobial activity against different bacteria (both Gram‐positive and negative), fungi, and viruses. HNP1 is stored in the cytoplasmic azurophilic granules of neutrophils. To elucidate the mode of action of this antimicrobial peptide, studies based on its lipid selectivity were carried out. Large unilamellar vesicles with different lipid compositions were used as biomembranes model systems (mammal, fungal, and bacterial models). Changes on the intrinsic fluorescence of HNP1 upon membrane binding/insertion show that HNP1 has quite distinct preferences for mammalian and fungal membrane model systems. HNP1 showed low interaction with glucosylceramide rich membranes, but high sterol selectivity: it has a higher partition for ergosterol‐containing membranes (as fungal membranes) and lower interaction with cholesterol‐containing membranes (as in mammalian cells). These results reveal that lipid selectivity is a determinant step for HNP1 action. Fluorescence quenching data obtained using acrylamide indicate that HNP1 interacts with membranes without a full insertion in the lipid bilayer. Generalized polarization of laurdan indicates a change in membrane fluidity in the presence of HNP1 for POPC membranes but not for ergosterol‐enriched membranes. © 2012 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 98:313‐321, 2012.
Plant biofarming: Novel insights for peptide expression in heterologous systems
Authors: Barbosa Viana Antônio Américo , Pelegrini Patrícia Barbosa , Grossi‐de‐Sá Maria Fátima
Published: May 2012

Peptide expression methods have been widely studied and developed from many different biological sources. The cultivation of prokaryotic and eukaryotic cells has proven to be efficient for the expression of foreign peptides in several heterologous systems, including bacteria, insects, yeasts, and mammals. Earlier reports brought up new insights for the improvement of expressed products to not only increase the production rate of desired peptides but also reproduce desirable post‐translational modifications and even to reduce the risk of allergenicity when those products are aimed for human use. The development of bioreactor systems provided the optimization of cell growth conditions to scale up the amounts of expressed peptides. On the other hand, different cell systems and mutants provided a plethora of possible peptide modifications. Hence, in this report, we describe the many organisms and systems used for the large scale production of several macromolecules with relevance in health and agriculture. We also bring into discussion plant biofarming in the moss Physcomitrella patens and its recent adaptations, as a cost‐effective and efficient approach in the production of more complex heterologous proteins, given the fact that its glycosylation pattern can be engineered to avoid allergenicity to humans (common to plant‐derived glycoproteins). © 2012 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 98: 416‐427, 2012.
Formation of Hierarchical Pore Structures in Zn/ZSM‐5 to Improve the Catalyst Stability in the Aromatization of Branched Olefins
Authors: Kim Yeon Ho , Lee Kyung Hee , Nam Chang‐Mo , Lee Jae Sung
Published: May 2012

Three Zn/ZSM‐5 catalysts with Si/Al ratios of 17, 33, and 42 were treated with a weak base (Na2CO3) to create a hierarchical microporous–mesoporous system and to improve the catalyst stability in the aromatization of 2‐methly‐2‐butene, a model compound that represented branched olefin byproducts that are produced from fluidized catalytic cracking. The Si/Al ratio of the parent ZSM‐5 had a critical effect on the nature of the modified pore system. Thus, for Zn/ZSM‐5 with a Si/Al ratio of 42, a hierarchical microporous–mesoporous system was formed in which intraparticle bimodal mesopores were in the form of cavities and cylinders, the latter of which connected internal micropores to the external surface of the catalyst. This pore structure was most suitable for enhancing the tolerance to coking and brought a dramatic increase in the catalyst stability in the aromatization of 2‐methyl‐2‐butene.
Insights into the Mechanism of Reaction of [(C5Me5)2SmII(thf)2] with CO2 and COS by DFT Studies
Authors: Castro Ludovic , Labouille Stéphanie , Kindra Doug R. , Ziller Joseph W. , Nief Francois , Evans William J. , Maron Laurent
Published: May 2012

Reaction mechanisms for the oxidative reactions of CO2 and COS with [(C5Me5)2Sm] have been investigated by means of DFT methods. The experimental formation of oxalate and dithiocarbonate complexes is explained. Their formation involve the samarium(III) bimetallic complexes [(C5Me5)2Sm‐CO2‐Sm(C5Me5)2] and [(C5Me5)2Sm‐COS‐Sm(C5Me5)2] as intermediates, respectively, ruling out radical coupling for the formation of the oxalate complex.
Mechanism of the Tyrosine Ammonia Lyase Reaction—Tandem Nucleophilic and Electrophilic Enhancement by a Proton Transfer
Authors: Pilbák Sarolta , Farkas Ödön , Poppe László
Published: May 2012

Quantum mechanics/molecular mechanics calculations in tyrosine ammonia lyase (TAL) ruled out the hypothetical Friedel–Crafts (FC) route for ammonia elimination from L‐tyrosine due to the high energy of FC intermediates. The calculated pathway from the zwitterionic L‐tyrosine‐binding state (0.0 kcal mol−1) to the product‐binding state ((E)‐coumarate+H2NMIO; −24.0 kcal mol−1; MIO=3,5‐dihydro‐5‐methylidene‐4H‐imidazol‐4‐one) involves an intermediate (IS, −19.9 kcal mol−1), which has a covalent bond between the N atom of the substrate and MIO, as well as two transition states (TS1 and TS2). TS1 (14.4 kcal mol−1) corresponds to a proton transfer from the substrate to the N1 atom of MIO by Tyr300OH. Thus, a tandem nucleophilic activation of the substrate and electrophilic activation of MIO happens. TS2 (5.2 kcal mol−1) indicates a concerted CN bond breaking of the N‐MIO intermediate and deprotonation of the pro‐S β position by Tyr60. Calculations elucidate the role of enzymic bases (Tyr60 and Tyr300) and other catalytically relevant residues (Asn203, Arg303, and Asn333, Asn435), which are fully conserved in the amino acid sequences and in 3D structures of all known MIO‐containing ammonia lyases and 2,3‐aminomutases.
New Bithiazole‐Based Sensitizers for Efficient and Stable Dye‐Sensitized Solar Cells
Authors: He Jinxiang , Guo Fuling , Li Xin , Wu Wenjun , Yang Jiabao , Hua Jianli
Published: May 2012

A series of new push–pull organic dyes (BT‐I–VI), incorporating electron‐withdrawing bithiazole with a thiophene, furan, benzene, or cyano moiety, as π spacer have been synthesized, characterized, and used as the sensitizers for dye‐sensitized solar cells (DSSCs). In comparison with the model compound T1, these dyes containing a thiophene moiety between triphenylamine and bithiazole display enhanced spectral responses in the red portion of the solar spectrum. Electrochemical measurement data indicate that the HOMO and LUMO energy levels can be tuned by introducing different π spacers between the bithiazole moiety and cyanoacrylic acid acceptor. The incorporation of bithiazole substituted with two hexyl groups is highly beneficial to prevent close π–π aggregation, thus favorably suppressing charge recombination and intermolecular interaction. The overall conversion efficiencies of DSSCs based on bithiazole dyes are in the range of 3.58 to 7.51 %, in which BT‐I‐based DSSCs showed the best photovoltaic performance: a maximum monochromatic incident photon‐to‐current conversion efficiency (IPCE) of 81.1 %, a short‐circuit photocurrent density (Jsc) of 15.69 mA cm−2, an open‐circuit photovoltage (Voc) of 778 mV, and a fill factor (ff) of 0.61, which correspond to an overall conversion efficiency of 7.51 % under standard global AM 1.5 solar light conditions. Most importantly, long‐term stability of the BT‐I–III‐based DSSCs with ionic‐liquid electrolytes under 1000 h of light soaking was demonstrated and BT‐II with a furan moiety exhibited better photovoltaic performance of up to 5.75 % power conversion efficiency.
CuII‐Catalyzed Asymmetric Hydrosilylation of Diaryl‐ and Aryl Heteroaryl Ketones: Application in the Enantioselective Synthesis of Orphenadrine and Neobenodine
Authors: Sui Yao‐Zong , Zhang Xi‐Chang , Wu Jun‐Wen , Li Shijun , Zhou Ji‐Ning , Li Min , Fang Wenjun , Chan Albert S. C. , Wu Jing
Published: May 2012

With certain amounts of sodium tert‐butoxide and tert‐butanol as additives, catalytic amounts of an inexpensive and easy‐to‐handle copper source Cu(OAc)2⋅H2O, a commercially available and air‐stable non‐racemic dipyridylphosphine ligand, as well as the stoichiometric desirable hydride donor polymethylhydrosiloxane (PMHS), formed a versatile in situ catalyst system for the enantioselective reduction of a broad spectrum of prochiral diaryl and aryl heteroarylketones in air, in high yields and with good to excellent enantioselectivities (up to 96 %). In particular, the practical viability of this process was evinced by its successful applications in the asymmetric synthesis of optically enriched potent antihistaminic drugs orphenadrine and neobenodine.
Intermolecular chiral assemblies in R(−) and S(+) 2‐butanol detected by microcalorimetry measurements
Authors: Cogan Uri , Shpigelman Avi , Portnaya Irina , Rutenberg Abraham , Scolnik Yosef , Shinitzky Meir
Published: May 2012

Supramolecular chiral assemblies of R(−) and S(+) 2‐butanol, in their neat form or when dissolved in their nonchiral isomer isobutanol, were evaluated by isothermal titration calorimetry (ITC) ensuing mixing. Dilution of 0.5 M solution of R(−) 2‐butanol in isobutanol into the latter liberated heat of several calories per mole, which was approximately double than that obtained in parallel dilutions of S(+) 2‐butanol in isobutanol. The ITC dilution profiles indicated an estimate of about 100 isobutanol solvent molecules surrounding each of the 2‐butanol enantiomers, presumably arranged in chiral configurations, with different adopted order between the isomers. Mixings of neat R and S 2‐butanol were followed by endothermic ITC profiles, indicating that, in racemic 2‐butanol, both the supramolecular order and the intermolecular binding energies are lower than in each of the neat chiral isomers. The diversion from symmetrical ITC patterns in these mixings indicated again a subtle difference in molecular organization between the neat enantiomers. It should be noted that the presence of impurities, α‐pinene and teterhydrofuran, at a level totaling 0.5%, did not influence the ITC heat flow profiles. The findings of this study demonstrate for the first time that chiral solutes in organic solvents are expected to acquire asymmetric solvent envelopes that may be different between the enantiomers, thus broadening this phenomenon beyond the previously demonstrated cases in aqueous solutions. Chirality 24:500–505, 2012. © 2012 Wiley Periodicals, Inc.
Mercury in Thermal Power Plants: Chemical Behavior and Possibilities for Separation
Authors: Scheffknecht Günter , Farr Silvio , Heidel Barna , Schwämmle Tobias , Brechtel Kevin
Published: May 2012

Die weitere Absenkung der Emissionen von Quecksilber aus fossil befeuerten Kraftwerken erfordert eine Verbesserung der bestehenden Rauchgasreinigungssysteme oder den Einsatz von neuen oder adaptierten Prozessen. Dabei können spezielle Adsorbentien, zur Quecksilberoxidation verbesserte SCR‐DeNOx‐Katalysatoren oder Additive zur Quecksilberumwandlung und Abscheidung in nassen Rauchgasentschwefelungsanlagen eigesetzt werden. Da die chemischen Zusammenhänge der verschiedenen Quecksilberspezies von den Betriebsparametern der einzelnen Rauchgasreinigungsanlagen abhängen, ist ein detailliertes Verständnis der Vorgänge bei der Quecksilberrückhaltung von großer Bedeutung.
Computer‐assisted image analysis of human cilia and Chlamydomonas flagella reveals both similarities and differences in axoneme structure
Authors: O'Toole Eileen T. , Giddings Thomas H. , Porter Mary E. , Ostrowski Lawrence E.
Published: May 2012

In the past decade, investigations from several different fields have revealed the critical role of cilia in human health and disease. Because of the highly conserved nature of the basic axonemal structure, many different model systems have proven useful for the study of ciliopathies, especially the unicellular, biflagellate green alga Chlamydomonas reinhardtii. Although the basic axonemal structure of cilia and flagella is highly conserved, these organelles often perform specialized functions unique to the cell or tissue in which they are found. These differences in function are likely reflected in differences in structural organization. In this work, we directly compare the structure of isolated axonemes from human cilia and Chlamydomonas flagella to identify similarities and differences that potentially play key roles in determining their functionality. Using transmission electron microscopy and 2D image averaging techniques, our analysis has confirmed the overall structural similarity between these two species, but also revealed clear differences in the structure of the outer dynein arms, the central pair projections, and the radial spokes. We also show how the application of 2D image averaging can clarify the underlying structural defects associated with primary ciliary dyskinesia (PCD). Overall, our results document the remarkable similarity between these two structures separated evolutionarily by over a billion years, while highlighting several significant differences, and demonstrate the potential of 2D image averaging to improve the diagnosis and understanding of PCD. © 2012 Wiley Periodicals, Inc
Role of Well‐Being Therapy in Achieving a Balanced and Individualized Path to Optimal Functioning
Authors: Ruini Chiara , Fava Giovanni A.
Published: May 2012

A specific psychotherapeutic strategy for increasing psychological well‐being and resilience, well‐being therapy (WBT), based on Ryff's conceptual model, has been developed and tested in a number of randomized controlled trials. The findings indicate that flourishing and resilience can be promoted by specific interventions leading to a positive evaluation of one's self, a sense of continued growth and development, the belief that life is purposeful and meaningful, the possession of quality relations with others, the capacity to manage effectively one's life and a sense of self‐determination. A decreased vulnerability to depression, mood swings and anxiety has been demonstrated after WBT in high‐risk populations. School interventions based on the principles of WBT have been found to yield both promotion of well‐being and decrease of distress compared with control groups. The differential technical characteristics and indications of WBT are described, with a special reference to the promotion of an individualized and balanced path to achieve optimal human functioning, avoiding the polarities in positive psychological dimensions. Copyright © 2012 John Wiley & Sons, Ltd.

Key Practitioner Message

A specific psychotherapeutic strategy, well‐being therapy, for modifying the levels of psychological well‐being has been developed and tested.

In controlled trials, it has yielded significant benefits in clinical populations, particularly as to vulnerability to affective alterations.

Well‐being therapy may help in achieving flexibility and balance in psychological dimensions that underlie optimal human functioning.

Best results are achieved when it is applied to the sub‐acute phase of mood and anxiety disorders, in a sequential model.

Well‐being therapy may have a preventive role in general populations and particularly in children.
Early complexity supports development of motor behaviors in the first months of life
Authors: Dusing Stacey C. , Thacker Leroy R. , Stergiou Nicholas , Galloway James C.
Published: May 2012

Complexity in motor behavior is a hallmark of healthy systems. The purpose of this study was to investigate postural complexity during development of early motor behaviors and under two conditions. Twenty‐two infants participated from 1 to 6 months of age. Linear and nonlinear measures of displacement of the center of pressure at the base of support were used to quantify magnitude and temporal structure of postural control. Behavioral coding was used to quantify the emergence of midline head control and early reaching. Results suggest that infants have complexity in postural control strategies early in development. This complexity decreases as infants learn motor behaviors, even when magnitude of the postural variability does not change. Infants were able to adapt the magnitude of postural control variability under different conditions. We propose that infants proceed through three stages which support the infant's ability to adapt motor behaviors. © 2012 Wiley Periodicals, Inc. Dev Psychobiol 55: 404–414, 2013
Efficient Triplet–Triplet Annihilation Upconversion with Platinum(II) Bis(arylacetylide) Complexes That Show Long‐Lived Triplet Excited States
Authors: Ji Shaomin , Wu Wanhua , Zhao Jianzhang , Guo Huimin , Wu Wenting
Published: May 2012

NN–PtII–bis(acetylide) complexes [NN = 4,4′‐bis(tert‐butyl‐2,2′‐bipyridine) (dbbpy)] with ethynylpyrene (Pt‐2) or 4‐ethynyl‐1,8‐naphthalimide ligands (Pt‐3) that show long‐lived 3IL triplet excited states (τT = 118.0 μs) were used as new triplet sensitizers for triplet–triplet annihilation (TTA) based upconversion (UC). UC quantum yields of up to 18.1 % were observed. We found that the triplet–triplet energy‐transfer (TTET) processes, which are crucial for the TTA UC, were improved by up to 150‐fold and 250‐fold with Pt‐2 (Stern–Volmer quenching constant KSV = 5.70 × 105 M–1) and Pt‐3 (KSV = 9.64 × 105 M–1), respectively, relative to the model complex dbbpy–PtII–bis(phenylacetylide) (Pt‐1) (KSV = 3.80 × 103 M–1). The efficient upconversion is attributed to the long‐lived triplet excited states as well as the high T1‐state energy level of the sensitizers Pt‐2 and Pt‐3.
Polyfunctional β‐Dicarbonyl Compounds by Michael Addition Reactions of Ester Enolates to α‐Benzylidene and α‐Alkylidene‐β‐dicarbonyl Compounds
Authors: Holan Martin , Pohl Radek , Císařová Ivana , Jahn Ullrich
Published: May 2012

The scope and stereoselectivity of the Michael addition of ester enolates to α‐benzylidene and α‐alkylidene β‐dicarbonyl compounds was studied. Most substrates reacted in good to excellent yields. Michael acceptors bearing carboxylic functionalities reacted directly in the β‐position, whereas aldol and Michael addition competed with unsaturated ketones. The diastereoselectivity of the process is dependent on the substitution pattern of the Michael acceptor and the geometry of the enolate. (Z)‐Enolates add to unsaturated malonates or dibenzoylmethane derivatives with good anti‐selectivity, whereas (E)‐enolates afforded the syn‐diastereomers predominately. Unsaturated nitriles and Meldrum's acid derivatives reacted with low diastereoselectivity. A stereochemical model is proposed that accounts for all experimental results and allows the stereochemical outcome to be predicted.
Chemical Bonding in Coronene, Isocoronene, and Circumcoronene
Authors: Popov Ivan A. , Boldyrev Alexander I.
Published: May 2012

Chemical‐bonding analysis in coronene, isocoronene, and circumcoronene has been performed by using the Adaptive Natural Density Partitioning (AdNDP) method. This analysis revealed that coronene and isocoronene have two globally delocalized concentric π‐systems. Circumcoronene does not have globally delocalized π‐systems; instead, it has seven local sextets and can be represented by a single Clar structure. Thus, today there are a few known polycyclic aromatic hydrocarbons with two concentric π‐systems, but there are as yet no examples of such molecules with three or more concentric π‐systems. The results revealed by the AdNDP analysis are consistent with the results obtained by the current‐density maps, NICS and NICSZZ indices as well as MCI, PDI, Iring and δ indices.
Structure of the O‐Polysaccharide of Providencia alcalifaciens O22 Containing D‐Glyceramide 2‐Phosphate
Authors: Ovchinnikova Olga G. , Kocharova Nina A. , Bialczak‐Kokot Magdalena , Shashkov Alexander S. , Rozalski Antoni , Knirel Yuriy A.
Published: May 2012

O‐Polysaccharides (O‐antigens) are highly diverse glycopolymers present on the cell surface of Gram‐negative bacteria, including the human opportunistic pathogen Providencia alcalifaciens. They define serospecificity of strains and are used for the serotyping of bacteria. In this work, a phosphorylated O‐polysaccharide was isolated from P. alcalifaciens O22 and analyzed by chemical methods, ESI‐MS, and 1H, 13C, and 31P NMR spectroscopy. It was found to contain two unusual components, 2‐acetamido‐4‐amino‐2,4,6‐trideoxy‐D‐galactose (D‐FucNAc4N) and D‐glyceramide 2‐phosphate (D‐GroAN‐2‐P), the latter being identified for the first time in bacterial polysaccharides. The structure of the trisaccharide repeating unit of the O‐polysaccharide was established to be 4)‐(D‐GroAN‐2‐P‐3‐)‐‐D‐GalNAc‐(14)‐‐D‐Gal‐(13)‐‐D‐FucNAc4N‐(1.
A Conductometric Sensor Specific for Cationic Surfactants
Authors: Hnaien Mouna , Dzyadevych Sergei , Lagarde Florence , Jaffrezic‐Renault Nicole
Published: May 2012

In this work, a fast, sensitive and miniaturised conductometric sensor based on interdigitated electrodes, working in differential mode, was developed for the determination of cationic surfactants. The membrane was composed of a polymer (PVC), a plasticizer (dinonylphtalate (DNP)) and a carrier (sodium tetraphenylborate (NaBΦ4)). The sensor response was linear from at least 10−9 M to 10−2 M for dodecyltrimethylammonium (DTA+). No significant loss of sensor response was observed after 8 weeks. The sensor exhibited a lower sensitivity and a narrower dynamic range for tetrabutylammonium, decyltrimethylammonium and cetyltrimethylammonium cationic surfactants. A ten times lower sensitivity was observed for laurylsulfate anionic surfactant, (LS−).
Direct Electrochemistry and Electrocatalytic Properties of Hemoglobin Immobilized on Carbon Nanotubes Ionic Liquid Electrode
Authors: Moheimanian Niloofar , Raoof Jahan Bakhsh , Safavi Afsaneh , Ojani Reza
Published: May 2012

Hemoglobin (Hb) was directly immobilized on a multiwalled carbon nanotubes ionic liquid electrode by immersing this electrode in a solution consisting of Hb and 1‐octyl‐pyridinium chloride as an ionic liquid. The immobilized Hb displayed a pair of well‐defined cyclic voltammetric peaks with a formal potential of −0.187 V in acetate buffer solution, pH 5.0. This modified electrode exhibits fast response, a long linearity range, a low detection limit, high stability and excellent sensitivity through hydrogen peroxide detection with a detection limit (3σ) of 3.18 µM. The electrode was also used for electrocatalysis and voltammetric determination of oxygen and trichloroacetic acid.