bluuebunny/crossref_metadata_2025 huggingface dataset:
A High‐Throughput Assay for Arylamine Halogenation Based on a Peroxidase‐Mediated Quinone–Amine Coupling with Applications in the Screening of Enzymatic Halogenations
Authors: Hosford Joseph , Shepherd Sarah A. , Micklefield Jason , Wong Lu Shin
Published: October 2014

Arylhalides are important building blocks in many fine chemicals, pharmaceuticals and agrochemicals, and there has been increasing interest in the development of more “green” halogenation methods based on enzyme catalysis. However, the screening and development of new enzymes for biohalogenation has been hampered by a lack of high‐throughput screening methods. Described herein is the development of a colorimetric assay for detecting both chemical and enzymatic arylamine halogenation reactions in an aqueous environment. The assay is based on the unique UV/Vis spectrum created by the formation of an ortho‐benzoquinone‐amine adduct, which is produced by the peroxidase‐catalysed benzoquinone generation, followed by Michael addition of either a halogenated or non‐halogenated arylamine. This assay is sensitive, rapid and amenable to high‐throughput screening platforms. We have also shown this assay to be easily coupled to a flavin‐dependent halogenase, which currently lacks any convenient colorimetric assay, in a “one‐pot” workflow.
The Action of Peroxyl Radicals, Powerful Deleterious Reagents, Explains Why Neither Cholesterol Nor Saturated Fatty Acids Cause Atherogenesis and Age‐Related Diseases
Authors: Spiteller Gerhard , Afzal Mohammad
Published: October 2014

Cells respond to alterations in their membrane structure by activating hydrolytic enzymes. Thus, polyunsaturated fatty acids (PUFAs) are liberated. Free PUFAs react with molecular oxygen to give lipid hydroperoxide molecules (LOOHs). In case of severe cell injury, this physiological reaction switches to the generation of lipid peroxide radicals (LOO.). These radicals can attack nearly all biomolecules such as lipids, carbohydrates, proteins, nucleic acids and enzymes, impairing their biological functions. Identical cell responses are triggered by manipulation of food, for example, heating/grilling and particularly homogenization, representing cell injury. Cholesterol as well as diets rich in saturated fat have been postulated to accelerate the risk of atherosclerosis while food rich in unsaturated fatty acids has been claimed to lower this risk. However, the fact is that LOO. radicals generated from PUFAs can oxidize cholesterol to toxic cholesterol oxides, simulating a reduction in cholesterol level. In this review it is shown how active LOO. radicals interact with biomolecules at a speed transcending usual molecule–molecule reactions by several orders of magnitude. Here, it is explained how functional groups are fundamentally transformed by an attack of LOO. with an obliteration of essential biomolecules leading to pathological conditions. A serious reconsideration of the health and diet guidelines is required.
HOMO Stabilisation in π‐Extended Dibenzotetrathiafulvalene Derivatives for Their Application in Organic Field‐Effect Transistors
Authors: Geng Yan , Pfattner Raphael , Campos Antonio , Wang Wei , Jeannin Olivier , Hauser Jürg , Puigdollers Joaquim , Bromley Stefan T. , Decurtins Silvio , Veciana Jaume , Rovira Concepció , Mas‐Torrent Marta , Liu Shi‐Xia
Published: October 2014

Three new organic semiconductors, in which either two methoxy units are directly linked to a dibenzotetrathiafulvalene (DB‐TTF) central core and a 2,1,3‐chalcogendiazole is fused on the one side, or four methoxy groups are linked to the DB‐TTF, have been synthesised as active materials for organic field‐effect transistors (OFETs). Their electrochemical behaviour, electronic absorption and fluorescence emission as well as photoinduced intramolecular charge transfer were studied. The electron‐withdrawing 2,1,3‐chalcogendiazole unit significantly affects the electronic properties of these semiconductors, lowering both the HOMO and LUMO energy levels and hence increasing the stability of the semiconducting material. The solution‐processed single‐crystal transistors exhibit high performance with a hole mobility up to 0.04 cm2 V−1 s−1 as well as good ambient stability.
Reactivity of Liquid Ammonia Solutions of the Zintl Phase K12Sn17 towards Mesitylcopper(I) and Phosphinegold(I) Chloride
Authors: Benda Christian B. , Waibel Markus , Köchner Tobias , Fässler Thomas F.
Published: October 2014

To gain more insight into the reactivity of intermetalloid clusters, the reactivity of the Zintl phase K12Sn17, which contains [Sn4]4− and [Sn9]4− cluster anions, was investigated. The reaction of K12Sn17 with gold(I) phosphine chloride yielded K7[(η2‐Sn4)Au(η2‐Sn4)](NH3)16 (1) and K17[(η2‐Sn4)Au(η2‐Sn4)]2(NH2)3(NH3)52 (2), which both contain the anion [(Sn4)Au(Sn4)]7− (1 a) that consists of two [Sn4]4− tetrahedra linked through a central gold atom. Anion 1 a represents the first binary AuSn polyanion. From this reaction, the solvate structure [K([2.2.2]crypt)]3K[Sn9](NH3)18 (3; [2.2.2]crypt=4,7,13,16,21,24‐hexaoxa‐1,10‐diazabicyclo[8.8.8]hexacosane) was also obtained. In the analogous reaction of mesitylcopper with K12Sn17 in the presence of [18]crown‐6 in liquid ammonia, crystals of the composition [K([18]crown‐6)]2[K([18]crown‐6)(MesH)(NH3)][Cu@Sn9](thf) (4) were isolated ([18]crown‐6=1,4,7,10,13,16‐hexaoxacyclooctadiene, MesH=mesitylene, thf=tetrahydrofuran) and featured a [Cu@Sn9]3− cluster. A similar reaction with [2.2.2]crypt as a sequestering agent led to the formation of crystals of [K[2.2.2]crypt][MesCuMes] (5). The cocrystallization of mesitylene in 4 and the presence of [MesCuMes]− (5 a) in 5 provides strong evidence that the migration of a bare Cu atom into an Sn9 anion takes place through the release of a Mes− anion from mesitylcopper, which either migrates to another mesitylcopper to form 5 a or is subsequently protonated to give MesH.
Lead Structures for New Antibacterials: Stereocontrolled Synthesis of a Bioactive Muraymycin Analogue
Authors: Spork Anatol P. , Büschleb Martin , Ries Oliver , Wiegmann Daniel , Boettcher Stefan , Mihalyi Agnes , Bugg Timothy D. H. , Ducho Christian
Published: October 2014

Naturally occurring muraymycin nucleoside antibiotics represent a promising class of novel antibacterial agents. The structural complexity suggests the investigation of simplified analogues as potential lead structures, which can then be further optimized towards highly potent antimicrobials. Herein we report studies on muraymycin‐derived potential lead structures lacking an aminoribose motif found in most naturally occurring muraymycins. We have identified a 5′‐defunctionalized motif to be ideal in terms of stability and chemical accessibility and have synthesized a full‐length muraymycin analogue based on this structure using a novel fully stereocontrolled route. The obtained 5′‐deoxy analogue of the natural product muraymycin C4 showed good inhibitory properties towards the bacterial target protein MraY, sufficient pharmacokinetic stability and no cytotoxicity against human cells, thus making it a promising lead for antibacterial drug development.
3‐Deazaneplanocin A and Neplanocin A Analogues and Their Effects on Apoptotic Cell Death
Authors: Tam Eric K. W. , Nguyen Tuan Minh , Lim Cheryl Z. H. , Lee Puay Leng , Li Zhimei , Jiang Xia , Santhanakrishnan Sridhar , Tan Tiong Wei , Goh Yi Ling , Wong Sze Yue , Yang Haiyan , Ong Esther H. Q. , Hill Jeffrey , Yu Qiang , Chai Christina L. L.
Published: October 2014

3‐Deazaneplanocin A (DzNep) is a potential epigenetic drug for the treatment of various cancers. DzNep has been reported to deplete histone methylations, including oncogenic EZH2 complex, giving rise to epigenetic modifications that reactivate many silenced tumor suppressors in cancer cells. Despite its promise as an anticancer drug, little is known about the structure–activity relationships of DzNep in the context of epigenetic modifications and apoptosis induction. In this study, a number of analogues of DzNep were examined for DzNep‐like ability to induce synergistic apoptosis in cancer cells in combination with trichostatin A, a known histone deacetylase (HDAC) inhibitor. The structure–activity relationship data thus obtained provide valuable information on the structural requirements for biological activity. The studies identified three compounds that show similar activities to DzNep. Two of these compounds show good pharmacokinetics and safety profiles. Attempts to correlate the observed synergistic apoptotic activities with measured S‐adenosylhomocysteine hydrolase (SAHH) inhibitory activities suggest that the apoptotic activity of DzNep might not be directly due to its inhibition of SAHH.
Organotopic organization of the primary Infrared Sensitive Nucleus (LTTD) in the western diamondback rattlesnake (Crotalus atrox)
Authors: Kohl Tobias , Bothe Maximilian S. , Luksch Harald , Straka Hans , Westhoff Guido
Published: October 2014

Pit vipers (Crotalinae) have a specific sensory system that detects infrared radiation with bilateral pit organs in the upper jaw. Each pit organ consists of a thin membrane, innervated by three trigeminal nerve branches that project to a specific nucleus in the dorsal hindbrain. The known topographic organization of infrared signals in the optic tectum prompted us to test the implementation of spatiotopically aligned sensory maps through hierarchical neuronal levels from the peripheral epithelium to the first central site in the hindbrain, the nucleus of the lateral descending trigeminal tract (LTTD). The spatial organization of the anatomical connections was revealed in a novel in vitro whole‐brain preparation of the western diamondback rattlesnake (Crotalus atrox) that allowed specific application of multiple neuronal tracers to identified pit‐organ‐supplying trigeminal nerve branches. After adequate survival times, the entire peripheral and central projections of fibers within the pit membrane and the LTTD became visible. This approach revealed a morphological partition of the pit membrane into three well‐defined sensory areas with largely separated innervations by the three main branches. The peripheral segregation of infrared afferents in the sensory epithelium was matched by a differential termination of the afferents within different areas of the LTTD, with little overlap. This result demonstrates a topographic organizational principle of the snake infrared system that is implemented by maintaining spatially aligned representations of environmental infrared cues on the sensory epithelium through specific neuronal projections at the level of the first central processing stage, comparable to the visual system. J. Comp. Neurol. 522:3943–3959, 2014. © 2014 Wiley Periodicals, Inc.
Active contraction of the cardiac ventricle and distortion of the microstructural architecture
Authors: Pezzuto S. , Ambrosi D.
Published: October 2014

The shortening of the myocardial fibers is the microstructural engine that produces the contraction of the cardiac muscle. The complex interplay between fibers shortening and elastic macroscopic strain is functional to the ejection of blood into the pulmonary and arterial networks. Here, we address the contraction of the left ventricle in a finite elasticity framework, adopting the ‘prolate ellipsoid’ geometry and the invariants‐based strain energy proposed by Holzapfel and Ogden, where the mechanical role of fibers and sheets is accounted for. We show that a microstructurally motivated mathematical model of active strain type reproduces the main indicators of normal cardiac function along the whole PV‐loop without introduction of any further ad hoc law. The bare‐bones mathematical model depends on one measurable parameter only, that is, the shortening ratio of the sarcomere units, which we assume to be nearly independent on the prestretch. Strict enforcement of incompressibility and novel treatment of boundary conditions are shown to be crucial to simulate the correct muscle torsion. Copyright © 2014 John Wiley & Sons, Ltd.
Visualization of Plasma and Tissue Binding Using Dose Fractions Parameter
Authors: Svennebring Andreas
Published: October 2014

A novel concept of dose fractions, based on the distribution of total bioavailable dose between the six combinations of location and binding state in Øie–Tozer's model is suggested as a way to visualize the distribution pharmacokinetics of a drug. The concept of dose fractions provides a sharper terminology in discussions of drug distribution allowing for a more precise description of the state and location of a drug within a system. In medicinal chemistry literature, the free fraction of a drug in plasma is a commonly discussed factor affecting the exposure to free drug while tissue binding is less well addressed. The free dose fraction, defined as the fraction of the bioavailable dose existing in free form, is suggested as a potentially valuable term for such discussions. Presently, drugs with high (>95%) plasma protein binding are viewed with skepticism, the rational behind which is questioned. The plasma protein bound dose fraction defined as the fraction of the total available dose, which is bound to plasma proteins, is suggested as a measure of the risk for problems related to fluctuations in free drug exposure due to variations in the concentration of drug binding plasma protein.
Structurally Characterized Antipyrine‐Based Dual Fluorescent Probe: Enhanced AlIII Selectivity of a Dinuclear ZnII Complex for Intracellular Sensing by a Displacement Approach
Authors: Lohar Sisir , Sengupta Archya , Chattopadhyay Ansuman , Matalobos Jesús Sanmartín , Das Debasis
Published: October 2014

The antipyrine‐based fluorescence probe daph, structurally characterized by single‐crystal X‐ray diffraction, can recognize both Zn2+ (at 520 nm, yellow) and Al3+ (at 490 nm, green). However, Al3+ selectivity is enhanced significantly when the dinuclear ZnII‐daph complex is used as a sensor, which senses Al3+ by a displacement approach. The binding constants of daph for Zn2+ and Al3+ are (4.9 ± 0.2) × 104 and (3 ± 0.1) × 105 M–1, respectively. The higher water solubility of the ZnII‐daph complex allows the detection of Al3+ in a greener way (0.1 M HEPES buffer, ethanol/water = 1:9, v/v, pH 7.4). Moreover, the detection limit of the ZnII‐daph complex for Al3+ is higher (2.5 × 10–9 M) than that of free daph (4.6 × 10–8 M). Alkali and alkaline‐earth metal ions, Cd2+, Hg2+, and Pb2+, and 3d metal ions do not interfere. Both daph and the ZnII‐daph complex are capable of intracellular Al3+ detection.
Photodriven Transfer Hydrogenation of Olefins
Authors: Leow Dasheng , Chen Ying‐Ho , Hung Tzu‐Hang , Su Ying , Lin Yi‐Zhen
Published: October 2014

An improved practical method for the photodriven diimide reduction of olefins was investigated. This catalyst‐free procedure proceeds at ambient temperature, utilizes air as oxidant and a lower hydrazine loading, and produces inert nitrogen gas as the sole byproduct. Several functional groups were tolerated, and in some cases, the reaction was chemoselective. Challenging substrates such as cinnamate ester derivatives and trans‐stilbene were reduced in excellent yields. The small amount of UVA rays emitted from a household compact fluorescent light bulb was proposed to enable the cis/trans isomerization of the diimide and to promote the loss of hydrogen from the diimide.
Unusual Reaction Constant for Hydride Transfer from a Carbanion to 9‐Arylxanthyliums
Authors: Liu Fengrui , Zhu Xiaoqing
Published: October 2014

The reaction constant (ρ) from the kinetics for hydride transfer from a carbanion (XH–) to 9‐arylxanthylium ions (9‐GPhXn+) in CH3CN was unusually negative. Thermodynamic analysis indicated that ρ for the simple hydride transfers (only involved with release and capture of a hydride anion) should be positive; this is in contrast to the kinetics results. Consequently, this reaction is not a simple hydride transfer. An “intermediate” was also found in the reaction system, the formation of which resulted in the unusual ρ.
Cinchona‐Derived Picolinamides: Effective Organocatalysts for Stereoselective Imine Hydrosilylation
Authors: Barrulas Pedro C. , Genoni Andrea , Benaglia Maurizio , Burke Anthony J.
Published: October 2014

Picolinamide–cinchona organocatalysts for the successful enantioselective reduction of ketomines were developed. For the first time, a new type of chiral Lewis base, a cationic species, is reported to efficiently organocatalyze the addition of trichlorosilane to imines. Excellent yields with good to high enantioselectivities (up to 91 %) were obtained in the reduction of differently substituted substrates. Noteworthy, remarkably high turnover frequencies for the hydrosilylation of imines were observed; the catalyst of choice proved to be active even at a loading of only 1 mol‐%. The loading was further reduced to 0.5 mol‐%, and for very short reaction times (15 min) very impressive asymmetric catalyst efficiency speed values were reached.
Whole‐cell biotransformation of oleanolic acid by free and immobilized cells of Nocardia iowensis: Characterization of new metabolites
Authors: Ludwig Benjamin , Geib Doris , Haas Christiane , Steingroewer Juliane , Bley Thomas , Muffler Kai , Ulber Roland
Published: October 2014

In this study, Nocardia iowensis was used to transform oleanolic acid (OA) into oleanane derivatives. The first derivative, which was found after 24 h of cultivation, was the known and already described OA methyl ester. After 1 week, two other derivatives (oleanonic acid methyl ester and an unknown metabolite) were identified as new products of a biotransformation by N. iowensis. These oleanane metabolites were characterized by HPLC, HPLC‐ESI‐MS, and HPLC‐1H NMR spectroscopy. The biotransformation was performed by suspended and immobilized cells (ICs) of N. iowensis. Cells immobilized in alginate beads were used in order to prepare a continuous process. The substrate uptake of free and ICs was similar, whereas the peak area of OA methyl ester of the ICs was only about 10% of the native cells. However, the final product (oleanonic acid methyl ester) concentrations were similar in both approaches, whereas the unknown metabolite 3 was only detected transiently in the medium of ICs. Based on these results, a new biosynthetic pathway for the biotechnological production of oleanonic acid methyl ester is proposed.
Ecological response of two hydro‐morphological similar pre‐dams to contrasting land‐use in the Rappbode reservoir system (Germany)
Authors: Friese Kurt , Schultze Martin , Boehrer Bertram , Büttner Olaf , Herzsprung Peter , Koschorreck Matthias , Kuehn Burkhard , Rönicke Helmut , Tittel Jörg , Wendt‐Potthoff Katrin , Wollschläger Ute , Dietze Maren , Rinke Karsten
Published: October 2014

Two morphologically similar pre‐dams (Hassel and Rappbode pre‐dams, Harz Mountains, Germany) of a large reservoir with different land use in their catchments were compared with respect to their physical, chemical, and biological properties in order to test if differences can be attributed to the different land use. In addition, local geology, soil types, and topography were evaluated in detail to distinguish its influence from that of present‐day land use. Despite a remarkable similarity in physical variables and stratification, the annual development of hydrochemistry and biology differed between Rappbode and Hassel pre‐dam. While the Hassel pre‐dam received much higher nitrogen and phosphorus inputs from the catchment, the Rappbode pre‐dam received more dissolved organic carbon. The quality of dissolved organic carbon also differed between the two catchments, indicating different sources. The higher residence time of Hassel pre‐dam amplified the effects of these inputs on the trophic state of both pre‐dams. The phytoplankton communities in summer were dominated by diatoms in the Rappbode pre‐dam and by cyanobacteria in the Hassel pre‐dam. In conclusion, land use appeared to be an important driver for the observed lake characteristics. However, it was itself strongly related to soil types and topography, which on the other hand influences the residence time of water within the catchments.
Interfacial separation and characterization of Al–PE composites during delamination of post‐consumer Tetra Pak materials
Authors: Zhang Sufeng , Luo Ke , Zhang Lulu , Mei Xingxian , Cao Shumiao , Wang Baiji
Published: October 2014

BACKGROUND

In order to understand Al–PE composite delamination during the separation process, interfacial separation and characterization of Al–PE composites during delamination were analyzed. The aim was to enrich the present theoretical analysis of Al–PE separation and to provideg new ideas for the recycling and reuse of post‐consumer Tetra Paks.

RESULTS

The composites delaminated into three layers, but the times for delamination of the two plastic layers were different. After separation, some plastics were present in the separation solvents analyzed by FTIR. Bright spots of unregular particles with scattered distribution on the surfaces of the three layers were Al, O and C, detected by SEM‐EDS.

CONCLUSIONS

During the separation reaction a mixed solution permeates into the interfaces of Al–PE composites; adhesive structures of the PE layers were destroyed and even dissolved into particles, thus interfacial adhesive failure and Al–PE separation occurred. However the different properties of the adhesive layers and the oxidation degree of PE fragments cause different separation speeds of the two interfaces adhered to each side of the Al foil. © 2014 Society of Chemical Industry
A Proof of a Conjecture of Ohba
Authors: Noel Jonathan A. , Reed Bruce A. , Wu Hehui
Published: October 2014

We prove a conjecture of Ohba that says that every graph G on at most vertices satisfies .
On the Multichromatic Number of s‐Stable Kneser Graphs
Authors: Chen Peng‐An
Published: October 2014

For positive integers n and s, a subset [n] is s‐stable if for distinct . The s‐stable r‐uniform Kneser hypergraph is the r‐uniform hypergraph that has the collection of all s‐stable k‐element subsets of [n] as vertex set and whose edges are formed by the r‐tuples of disjoint s‐stable k‐element subsets of [n]. Meunier () conjectured that for positive integers with , and , the chromatic number of s‐stable r ‐uniform Kneser hypergraphs is equal to . It is a generalized version of the conjecture proposed by Alon et al. (). Alon et al. () confirmed Meunier's conjecture for with arbitrary positive integer q. Lin et al. () studied the kth chromatic number of the Mycielskian of the ordinary Kneser graphs for . They conjectured that for . The case was proved by Mycielski (). Lin et al. () confirmed their conjecture for , or when n is a multiple of k or .

In this paper, we investigate the multichromatic number of the usual s ‐stable Kneser graphs . With the help of Fan's (1952) combinatorial lemma, we show that Meunier's conjecture is true for r is a power of 2 and s is a multiple of r, and Lin‐Liu‐Zhu's conjecture is true for .
Paleoenvironmental implications of two relative indicator rodent taxa during the Pleistocene to Holocene transition in south‐eastern Washington state, USA
Authors: LYMAN R. LEE
Published: October 2014

Local pollen data, diminution of body size of three ungulate species, and decreased mammalian richness and evenness all indicate grass decreased in abundance during the Pleistocene–Holocene transition (PHT) in eastern Washington state, USA. This paleoenvironmental history suggests that the abundance of remains of Microtus sp. should decrease as remains of Peromyscus maniculatus increase in abundance during the PHT. These two taxa have well‐known ecologies relative to one another. PHT sediments at the Marmes archeological site in south‐eastern Washington state are sorted into three chronologically sequent, isotaphonomic analytical units. Relative abundances of remains of Microtus sp. and P. maniculatus shift across the analytical units in the predicted manner whether raw abundances or rarified abundances are considered. These results suggest relative abundances of remains of Microtus sp. and P. maniculatus recovered from other sites may be used as relative indicators of paleohabitats. Their abundances at Homestead Cave, Utah, shift as predicted from the Late Pleistocene through the Early Holocene.
Antecedents or Effects of Being a Manager in the Nonprofit, Public, or Private Sector
Authors: Willems Jurgen
Published: October 2014

In this correspondence I postulate a complementary consideration to an article recently published in Nonprofit Management & Leadership: “Factors Attracting Individuals to Nonprofit Management over Public and Private Sector Management” (LeRoux and Feeney 2013). The aim of this correspondence is to provide avenues for further research based on an evaluation of the authors’ analysis and their embedded assumptions on causality and interdependency of the variables used. I perform an extended empirical analysis of the same data as used in LeRoux and Feeney (2013) in which inherent assumptions are adjusted based on available literature. Results show that their conclusions need nuancing, and that further research could focus on (1) a clearer distinction between antecedents and effects of sector of employment, and (2) the different relationships across sectors between work‐related variables, such as job satisfaction, job flexibility, or job clarity.
Bifactor Models of Personality and College Student Performance: A Broad versus Narrow View
Authors: McAbee Samuel T. , Oswald Frederick L. , Connelly Brian S.
Published: October 2014

Research in the area of personality traits and academic performance has been supported by consistent meta–analytic evidence demonstrating positive relationships between Conscientiousness and grade point average (GPA). However, academic performance is not solely a function of GPA but also a number of other important intellectual, interpersonal and intrapersonal behaviours. This wider criterion space opens up the possibility for many personality factors and their underlying facets to relate to academic performance. Using bifactor latent variable modelling, the current study investigates the six–factor HEXACO model of personality, along with their 24 underlying facets, for predicting students’ academic performance. Model results reveal interpretable and meaningful relationships between both broad factors and narrow personality facets in predicting college student outcomes. Implications for measurement, modelling and prediction are discussed. Copyright © 2014 European Association of Personality Psychology
Study of negative substitution and monomer self‐condensation effects on molar mass and structural characteristics of hyperbranched polyesters originating from a high‐functionality core
Authors: Emamikia Mohammad , Barikani Mehdi , Bakhshandeh Gholamreza
Published: October 2014

In order to provide more insight into the effect of core functionality on hyperbranched polymer characteristics, two series of hyperbranched polyesters (HBPEs) were synthesized by reacting 2,2‐bis(methylol)propionic acid (bis‐MPA) as AB2 monomer with both dipentaerythritol (DPE) and pentaerythritol as six (B6)‐ and four (B4)‐functional core molecules. The molar mass, composition and structure of HBPEs were determined with respect to the negative substitution logic and monomer self‐condensation effect. The molar masses and structures of HBPEs containing DPE core were less influenced by the negative effect of a reacted hydroxyl group on the reactivity of other hydroxyl groups in the same monomer unit. Thus, the use of DPE core in copolymerization with bis‐MPA monomer could help slightly to increase the molar mass of HBPEs. Conversely, the effect of self‐condensation of bis‐MPA on the molar mass reduction was more pronounced in the case of DPE hyperbranched polymers due to the A–B negative substitution effect. These two effects become more significant with increasing pseudo‐generation numbers of the HBPEs. © 2014 Society of Chemical Industry
Comparative proteomic analysis revealing the complex network associated with waterlogging stress in maize (Zea mays L.) seedling root cells
Authors: Yu Feng , Han Xuesong , Geng Cunjuan , Zhao Yanxin , Zhang Zuxin , Qiu Fazhan
Published: October 2014

Soil waterlogging is one of the major abiotic stresses affecting maize grain yields. To understand the molecular mechanisms underlying waterlogging tolerance in maize, the iTRAQ LC‐MS/MS technique was employed to map the proteomes of seedling root cells of the A3237 (tolerant inbred) and A3239 (sensitive inbred) lines under control and waterlogging conditions. Among the 3318 proteins identified, 211 were differentially abundant proteins (DAPs), of which 81 were specific to A3237 and 57 were specific to A3239. These DAPs were categorized into 11 groups that were closely related to the plant stress response, including metabolism, energy, transport, and disease/defense. In the waterlogged A3237 root cells, NADP‐malic enzyme, glutamate decarboxylase, coproporphyrinogen III oxidase, GSH S‐transferase, GSH dehydrogenase, and xyloglucan endotransglycosylase 6 were specifically accumulated to manage energy consumption, maintain pH levels, and minimize oxidative damage. The evaluations of five specific physiological parameters (alcohol dehydrogenase activity and GSH, malondialdehyde, adenosine 5'‐triphosphate, and nicotinamide adenine dinucleotide concentrations) were in agreement with the proteomic results. Moreover, based on the proteomic assay, eight representative genes encoding DAPs were selected for validation at the transcriptional level. qRT‐PCR revealed that the expression levels of these genes correlated with their observed protein abundance. These findings shed light on the complex mechanisms underlying waterlogging tolerance in maize. All MS data have been deposited into the ProteomeXchange with the identifier PXD001125 http://proteomecentral.proteomexchange.org/dataset/PXD001125.
Fumigant toxicity of basil oil compounds and related compounds to Thrips palmi and Orius strigicollis
Authors: Kim Kwang‐Ho , Yi Chang‐Geun , Ahn Young‐Joon , Kim Soon Il , Lee Sang‐Guei , Kim Jun‐Ran
Published: October 2014

BACKGROUND

This study was aimed at assessing the fumigant toxicity to adult Thrips palmi (a serious insect pest) and Orius strigicollis (a beneficial predator insect) of basil (Ocimum basilicum) essential oil compounds and structurally related compounds using vapour‐phase toxicity bioassays.

RESULTS

Against adult T. palmi, linalool (LD50 0.0055 mg cm−3) was the most toxic fumigant and was 15.2‐fold more effective than dichlorvos (0.0837 mg cm−3). Strong fumigant toxicity was also observed in pulegone (0.0095 mg cm−3), (±)‐camphor (0.0097 mg cm−3) and 1,8‐cineole (0.0167 mg cm−3). Moderate toxicity was produced by camphene, 3‐carene, (−)‐menthone, (+)‐α‐pinene, (+)‐β‐pinene, α‐terpineol and (−)‐α‐thujone (0.0215–0.0388 mg cm−3). Against adult O. strigicollis, dichlorvos (LD50 9.0 × 10−10 mg cm−3) was the most toxic fumigant, whereas the LD50 values of these compounds ranged from 0.0127 to >0.23 mg cm−3. Based upon the selective toxicity ratio, the compounds described are more selective than dichlorvos.

CONCLUSION

The basil oil compounds described merit further study as potential insecticides for control of T. palmi in greenhouses because of their generally lower toxicity to O. strigicollis and their greater activity as a fumigant than dichlorvos. © 2014 Society of Chemical Industry
Reliable mixed passive and filtering for semi‐Markov jump systems with randomly occurring uncertainties and sensor failures
Authors: Shen Hao , Wu Zheng‐Guang , Park Ju H.
Published: October 2014

This paper investigates the reliable mixed passive and
filtering problem for uncertain semi‐Markov jump delayed systems subject to sensor failures. The parameter uncertainties are randomly occurring with two stochastic variables, which are mutually independent and satisfy certain probabilistic distributions on the interval [0,1]. The objective is to focus on the design of a reliable filter ensuring the mixed passivity and
performance level of the resulting filtering error system in the presence of sensor failures. By using an improved reciprocally convex approach combined with a novel integral inequality, sufficient conditions of mixed passivity and
performance analysis for the considered systems are derived. Based on these, a desired reliable filter design method is developed, and the parameters of the filter are readily calculated by employing a simple expression of the desired filter. Three numerical examples are presented to demonstrate the effectiveness and the reduced conservatism of the proposed method. Copyright © 2014 John Wiley & Sons, Ltd.
Software process simulation—at a crossroads?
Authors: Zhang He , Raffo David , Birkhöltzer Thomas , Houston Dan , Madachy Raymond , Münch Jürgen , Sutton Stanley M
Published: October 2014

Software process simulation (SPS) has been evolving over the past two decades after being introduced to the software engineering community in the 1980s. At that time the SPS technology attracted a great deal of interest from both academics and practitioners in the software process community—even to the extent of being one of the recommended techniques for achieving multiple Key Process Areas of Level 4 of the Capability Maturity Model Integration. However, in recent years, the growth of SPS seems to have slowed along with the number of reported applications in industry. This article summarizes the special panel that was held during ICSSP 2012 whose goals were to assess whether this technology remains applicable to today's software engineering projects and challenges and to point out the most beneficial opportunities for future research and industry application. Copyright © 2014 John Wiley & Sons, Ltd.
Numerical Simulation of Flow‐Induced Wall Shear Stresses in Three Different Shapes of Multi‐Strand Steelmaking Tundishes
Authors: Siddiqui Md Irfanul Haque , Jha Pradeep Kumar
Published: October 2014

Tundish is an important vessel in the steelmaking circuitry where quality of steel can be optimized by carrying out various metallurgical operations. Nowadays, tundish is designed and operated to ensure maximum yield, superior cleanliness, and longer life. It is designed to operate at high temperatures and lined with different grades of expensive refractory materials. During casting process, lining material gradually erodes due to mechanical wear, chemical attack by slag, turbulent fluid flow, high temperature (creating softening), and thermal shock. In the present study, numerical investigations have been carried out to study the effect of three different tundish shapes (i.e., boat shape, T‐shape, and V‐shape) on flow‐induced wall shear stresses. It has been observed that designs of tundish have significant role on fluid flow behavior and hence on development of shear stresses on the walls. It is seen that the front and bottom walls of T‐shape tundish develops maximum wall shear stress. The back walls of T‐shape tundish has least effect on flow‐induced shear stress as compared to that of boat shape and V‐shape tundish. Velocity vectors at different planes have been compared to justify the results. Average wall shear stress values were found to be maximum for V‐shape tundish. Boat shape tundish exhibited minimum values of shear stress among the three different shape tundishes.
The effect of low shear on the development of fortified extruded rice products
Authors: Ayoub Ali , Liu Yankai , Miller Dennis D. , Rizvi Syed S. H.
Published: October 2014

Fortified extruded rice presents promising commercial opportunities for delivering nutrients and other functional ingredients to the global rice consuming population. Its formulation may be changed to suit the nutritional requirements of different target markets. The objective of this study was to develop a product line of prototypes that resemble the texture and appearance of natural rice grains, and have good retention of added nutrients. Extruded fortified rice was manufactured in a controlled mechanical shear extrusion process by first combining a mixture of fortified rice flour and water in a pre‐conditioner, then advancing the mixture along the length of an extruder barrel with a terminal extrusion die inserts in the shape of rice kernels. Extruded rice grains were evaluated for the degree of gelatinization, texture profile, and starch depolymerization. Retention of added vitamins and minerals was also measured. The cooked extruded grains had comparable texture to cooked commercial rice with good sensory characteristics. Based on the results, the key strategy in producing good quality extruded fortified starch is to achieve as high a degree of starch gelatinization in the extruded rice kernel as possible without inducing excessive starch breakdown.
Effect of dynamic high‐pressure microfluidization on the morphology characteristics and physicochemical properties of maize amylose
Authors: Tu Zongcai , Yin Yuebin , Wang Hui , Liu Guangxian , Chen Lili , Zhang Peng , Kou Yu , Zhang Lan
Published: October 2014

Maize amylose–water suspension (6% w/w) was subjected to single‐pass dynamic high‐pressure microfluidization (DHPM) treatment at 80, 120, 160, and 200 MPa, and changes in the morphology characteristics and physicochemical properties were compared with native maize amylose as a control sample. Laser scattering measurements of particle size demonstrated with microfluidization treatment at 80 MPa showed a slight decrease in mean diameter, while a significant increase was observed above 120 MPa. SEM analysis showed that the surface appearances of maize amylose were altered and the starch granules were partially gelatinized after DHPM treatment. The microfluidization treated maize amylose showed elevated light transmittance and swelling power. However, the solubility was decreased and no significant changes in the freeze–thaw stability. DSC analysis showed a decrease in gelatinization temperatures (To, Tc) and gelatinization enthalpy (ΔH) upon high‐pressure treatment. The texture profile analysis of the starch gel prepared from the suspension treated with high pressure obtained higher hardness and adhesiveness, lower cohesiveness and springiness. The results provide the basic information on the physicochemical properties of maize amylose treated at different microfluidized pressures and indicate the potential possibility of DHPM for starch modification.
Effect of high methoxy pectin and sucrose on pasting, rheological, and textural properties of modified starch systems
Authors: Gałkowska Dorota , Długosz Magda , Juszczak Lesław
Published: October 2014

Mixtures of high methoxy pectin, sucrose, and cross‐linked potato starch (acetylated distarch phosphate (ADP) and acetylated distarch adipate (ADA)) at concentrations of 2.5, 3.5, and 4.5% w/w were used to produce pastes and gels, which were characterized by RVA, steady shear, and oscillatory rheological measurements, and by textural testing. The pectin and sucrose components of the paste and gels affected their rheological and textural properties. The effect of starch concentration on the pasting parameters of the starch–pectin–sucrose systems depended on both amount of added starch and kind of modified starch, however, for each starch concentration both peak and final viscosities of the mixed systems were greater than these of the respective starch alone pastes. A domination of elastic properties over viscous features (G′>G″) were observed in the starch–pectin–sucrose systems, with increase in the values of storage and loss moduli with increase in starch concentration. The mixed systems appeared to be more rigid during the extrusion than the starch alone gels, with the values of textural parameters increasing with increase in starch concentration more in ADP than ADA systems.
Influence of starch oxidation and phosphorylation on thermal generation of carbohydrate radicals studied by electron paramagnetic resonance
Authors: Łabanowska Maria , Kurdziel Magdalena , Bidzińska Ewa , Wesełucha‐Birczyńska Aleksandra , Pawcenis Dominika , Łojewski Tomasz , Fortuna Teresa , Pietrzyk Sławomir , Przetaczek‐Rożnowska Izabela
Published: October 2014

Influence of starch modifications on the process of thermal generation of radicals in starch of different botanical origin was studied using electron paramagnetic spectroscopy. Potato, corn and spelt starches were subjected to chemical modifications: oxidation and phosphorylation. Samples of native and modified starches were thermally treated at 483 K, temperature usually used in baking processes. Stable, carbon‐centred radicals were formed at these conditions. Their amounts and character depended on the starch variety and on the kind of modification. Analysis of EPR signals allowed establishing the same mechanism of radical generation in all investigated samples of starch. However, the course of their formation process depended on different factors, such as the content of amylose and amylopectin fraction, phosphorus as well as carboxyl and carbonyl groups, botanical origin of starch and character of the starch modifications.
Influence of metal ions on thermal generation of carbohydrate radicals in native and modified starch studied by EPR
Authors: Łabanowska Maria , Kurdziel Magdalena , Bidzińska Ewa , Fortuna Teresa , Pietrzyk Sławomir , Przetaczek‐Rożnowska Izabela , Rożnowski Jacek
Published: October 2014

Influence of enrichment with ions from alkali (K), alkali‐earth (Mg) and d transition (Cu, Fe) metal groups of native and modified starches on the process of carbohydrate radicals generation has been studied using electron paramagnetic resonance (EPR) spectroscopy. This technique allows following the character and amount of created radicals, as well as the changes in coordination sphere of transition metal ions incorporated into starch matrix. The main difference between transition metal ions and the ions of alkali and alkali‐earth metals consisted in the character of their interactions with functional groups of starch. Transition metal ions coordinated glucose units of starch and influenced the mechanism of carbohydrate radical formation independently of the kind of starch modification. Interaction of starch, native and modified, with ions of alkali and alkali‐earth metals did not change the mechanism of radical generation, however, influenced their number. Contents of total metal ions found analytically by spectroscopic methods and by EPR allowed determination of the amount of transition metal ions engaged in interactions with starch matrix, as well as the differentiating of native and modified starch in respect of their metal ions adsorptive ability.
Exploring the surface morphology of developing wheat starch granules by using Atomic Force Microscopy
Authors: Waduge Renuka N. , Xu Song , Bertoft Eric , Seetharaman Koushik
Published: October 2014

Wheat starch granules from 7, 14, 21, 28, 35, 42, and 49 days after anthesis (DAA) were imaged using AFM. Starches were scanned in their native form as well as following exposure to iodine vapour in‐situ at 100% humidity. Starch at 7 DAA exhibited only one granule population, while starches at other maturities had two size populations. Starches from all stages of maturation exhibited blocklet structures. Larger fuzzy blocklets were observed at early stages while they became smaller and less fuzzy at subsequent stages of maturity. Furthermore, at all stages, small granules had larger fuzzy blocklets and higher surface roughness than the large granule counterpart; however the surface roughness of both small and large granule fractions decreased gradually with maturation. Amorphous growth ring of starch granules with ∼1 × 1 µm to ∼3 × 6 µm size islands were also observed. In‐situ iodine exposure demonstrated that iodine interacted with glucan polymers in the amorphous background first and then spread over to polymers on top of blocklets. Iodine‐glucan polymer interaction further increased the surface roughness.
Material properties of partially pregelatinized cassava starch prepared by mechanical activation
Authors: Zhang Yanjuan , Huang Zuqiang , Yang Cong , Huang Aimin , Hu Huayu , Gong Zhanqiang , Sun Guosong , Huang Kelin
Published: October 2014

This study has focused on the preparation of partially pregelatinized cassava starch (PPCS) by mechanical activation (MA) using a customized stirring ball mill. The changes in degree of gelatinization, crystal structure, particle size, surface morphology, powder characteristics, and pasting properties of cassava starch mechanically activated for different time were investigated by various characterizations. The results showed that MA could significantly destroy the crystal structure of starch granules, contributing to the increase of cold‐water solubility, flowability, and floodability, the variations of particle size and surface morphology, and the decrease in pasting temperature, viscosity of cooked PPCS paste, breakdown, and setback. It was also found that the PPCS with different degree of gelatinization could be prepared by controlling the milling time. With the unique properties induced by MA, the potential use of PPCS as excipient in pharmaceutical formulations is discussed.
A rapid method to obtaining moisture sorption isotherms of a starchy product
Authors: de Souza Thaís C. Lima , de Souza Hugo A. Lima , Pena Rosinelson da Silva
Published: October 2014

The static gravimetric method proposed by the COST 90 project has been traditionally used to obtain moisture sorption isotherms for food, but it is limited to high relative humidity levels because of the extremely long equilibrium time allow fungal growth on the sample. The aim of this study was to test the applicability of an alternative method to obtain the sorption isotherms of cassava starch. Adsorption and desorption dates were measured at 25°C using the classic (0.11<aw<0.96) and alternative methods (0.04<aw<0.92). The correlation between the isotherms obtained by the two methods was evaluated by comparing their simple linear regressions in which the Henderson linear model was fitted to the adsorption and desorption data (R2 ≥ 0.99). Student's t‐test showed that the angular and linear coefficients of the lines were statistically equal (p<0.05), indicating that the adsorption and desorption isotherms measured by the two methods were statistically the same. Therefore, the proposed alternative method can be used with excellent accuracy to measure sorption isotherms in cassava starch, and this alternative method can likely be used for other starchy products.
Molecular properties of octenyl succinic esters of mechanically activated Indica rice starch
Authors: Zhang Zhengmao , Zhao Siming , Xiong Shanbai
Published: October 2014

Indica rice starch was mechanically activated and then esterified by octenyl succinic anhydride (OSA). The molecular properties of the OSA‐starch were investigated by gel permeation chromatography, high performance size‐exclusion chromatography, FTIR spectroscopy, 1H NMR, 13C NMR spectroscopy. Modification by OSA could increase the molecular size or hydrodynamic volume of starch. As shown in FTIR spectrum of OSA‐starch, the relative intensity of characteristic peaks at 1724 and 1572/cm increased as the degree of substitution (DS) increased, which confirmed the esterification between OSA and starch. It can be concluded from the analysis of 1H NMR, and 13C NMR that the esterification between mechanically activated Indica rice starch and OSA should have occurred at 2‐OH, 3‐OH, and 6‐OH of glucose residue. As increasing DS decreased the relative intensity of the peak of chemical shift of 2‐OH in the 1H NMR spectrum of OSA‐starch, 2‐OH was possible the main substitution position.
Behaviour of starch exposed to microwave radiation treatment
Authors: Braşoveanu Mirela , Nemţanu Monica R.
Published: October 2014

This work is an overview of the literature in the area of microwave treatment of starch strongly related to changes in its physicochemical, functional and structural properties. The importance of good knowledge of the microwave parameters and starch dielectric properties is highlighted to avoid the improper microwave application on starch or starch‐based materials. Future perspectives of microwave processing of starch are suggested.