bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Threat on Police Officers' Shooting Behavior: Anxiety, Action Specificity, and Affective Influences on Perception
Authors: Nieuwenhuys Arne , Cañal‐Bruland Rouwen , Oudejans Raôul R. D.
Published: February 2012

In the current study, we investigated the impact of threat and response mode on police officers' distance perception and shooting behavior in relation to a suspect that approached with a knife. To manipulate threat and increase anxiety, the suspect carried either a plastic knife (low threat) or an electrical knife (high threat). Regarding the manipulation of response mode, officers provided either an actual shooting response or indicated their shot verbally. In both cases, perceptual judgments of shooting distances were assessed through visual matching. Results show that high threat led to earlier shooting, but only for actual shooting responses. Although high threat generally induced more anxiety, perceptual judgments remained unaffected by threat and indicated systematic underestimations of the distance to the suspect. It is suggested that in the online control of action, increased anxiety does not affect distance perception but alters the functional relationship between distance and perceived threat, thereby causing officers to shoot the approaching suspect at an earlier stage. Copyright © 2012 John Wiley & Sons, Ltd.
Developmental origins of obesity: Early feeding environments, infant growth, and the intestinal microbiome
Authors: Thompson Amanda L.
Published: February 2012

Objectives:

Pediatric overweight and obesity are growing problems worldwide, with increasing prevalence among even infants and young children. The refractory nature of early overweight necessitates identifying the factors contributing to early excess weight gain for successful intervention. Early feeding practices may be particularly important in shaping long‐term vulnerability to obesity. How and what infants are fed can influence weight gain, adiposity, and energy metabolism during infancy and across the life course through a number of interacting physiological and behavioral pathways. This article argues that these biological mechanisms interact with the social and behavioral context of infant feeding to create differential vulnerability to later obesity.

Methods:

This article reviews recent research on the potential mechanisms linking infant feeding and risk of later obesity, focusing on the emerging role of microflora colonization.

Results:

The nutritive and non‐nutritive components of breastmilk, formula and solid foods and the practices surrounding feeding shape the infant metabolome, programming growth rates and body composition, altering metabolism and physiology, promoting differential microfloral colonization, and shaping behavioral responses to foods and eating.

Conclusion:

The occurrence of chronic disease precursors at increasingly younger ages and the tendency of overweight young children to become overweight adolescents and adults underscore the importance of understanding this complex early exposure and intervening early to prevent the development of obesity in increasingly weight‐promoting environments. Am. J. Hum. Biol. 2012. © 2012 Wiley Periodicals, Inc.
New craniodental material of Pronothodectes gaoi Fox (Mammalia, “Plesiadapiformes”) and relationships among members of Plesiadapidae
Authors: Boyer Doug M. , Scott Craig S. , Fox Richard C.
Published: February 2012

Plesiadapidae are a family of Paleogene mammals thought to have phylogenetic affinities with modern Primates. We describe previously unpublished dentitions and the first skull and isolated petrosals of the plesiadapid Pronothodectes gaoi, collected from middle Tiffanian localities of the Paskapoo Formation in Alberta. Other species of Pronothodectes, traditionally considered the most basal members of the Plesiadapidae, occur at earlier, Torrejonian horizons in Montana, Wyoming, and Alberta. Classification of P. gaoi as a species of Pronothodectes has proved controversial; accordingly, we use the newly available samples and the more extensively preserved specimens to re‐evaluate the generic affinities of this species. Included in our study are comparisons with craniodental material known for other plesiadapids and plesiadapiforms. Cladistic analysis of craniodental characters is used to assess the hypothesis that P. gaoi and other species in this genus are basal members of the Plesiadapidae. The new dental evidence confirms that P. gaoi lacks derived character states of other plesiadapids except for a variably present fissuring of the m3 hypoconulid. Moreover, several aspects of the cranium seem to be more primitive in P. gaoi (i.e., more like nonplesiadapid plesiadapiforms) than in later occurring plesiadapids, such as Plesiadapis tricuspidens and Plesiadapis cookei. Cladistic analysis of craniodental morphology supports a basal position of P. gaoi among species of Plesiadapidae, with the exception of other species of Pronothodectes. The basicranium of P. gaoi preserves a laterally placed bony canal for the internal carotid neurovascular system, suggesting that this was the ancestral condition for the family. Am J Phys Anthropol, 2012. © 2012 Wiley Periodicals, Inc.
Natural rubber/multiwalled carbon nanotube composites developed with a combined self‐assembly and latex compounding technique
Authors: Peng Zheng , Feng Chunfang , Luo Yongyue , Li Yongzhen , Yi Zhifeng , Kong L.X.
Published: February 2012

Carbon nanotubes (CNTs), with their high aspect ratio and exceptionally high mechanical properties, are excellent fillers for composite reinforcement if they are uniformly dispersed without aggregation. Combining the latex compounding and self‐assembly techniques, we prepared a novel natural rubber (NR)/multiwalled carbon nanotube (MWCNT) composite. Before self‐assembly, the MWCNTs were treated with mixed acid to ensure that the MWCNTs were negatively charged under an alkaline environment. The structure of the MWCNTs was tested with Fourier transform infrared spectroscopy. The properties of composites with different MWCNT loadings were characterized with transmission electron microscopy, scanning electron microscopy, thermogravimetric analysis, and tensile testing. The results indicate that the MWCNTs were homogeneously distributed throughout the NR matrix as single tubes and had good interfacial adhesion with the NR phase when the MWCNT loading was less than 3 wt %. In particular, the addition of the MWCNT led to a remarkable reinforcement in the tensile strength, with a peak value of 31.4 MPa for an MWCNT content of 2 wt %, compared to the pure prevulcanized NR (tensile strength = 21.9 MPa). The nanocomposites reinforced with MWCNTs should have wide applications because of the notable improvement in these important properties. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Effect of zinc borate on the fire and thermal degradation behaviors of a poly(3‐hydroxybutyrate‐co‐4‐hydroxybutyrate)‐containing intumescent flame retardant
Authors: Zhang Rui , Huang Hua , Yang Wei , Xiao Xifu , Hu Yuan
Published: February 2012

The aim of this study was to investigate the effect of zinc borate (ZnB) on the fire and thermal degradation behaviors of a poly(3‐hydroxybutyrate‐co‐4‐hydroxybutyrate) [P(3,4)HB]‐containing intumescent flame retardant (IFR). The IFR system was composed of ammonium polyphosphate, pentaerythritol, and melamine. The fire properties of P(3,4)HB/IFR/ZnB blends were evaluated by limited oxygen index, Underwriters Laboratories 94, microscale combustion calorimetry (MCC), and cone calorimetry (CONE) testing. The results of MCC and CONE show that the peak heat release rate, which is an important indicator of material fire hazard, of P(3,4)HB/IFR decreased when a small amount of the IFR was substituted by ZnB. The thermal degradation behavior of the P(3,4)HB/IFR/ZnB blends were measured by thermogravimetric analysis and thermogravimetric analysis–infrared (TG–IR) spectrometry. The data of TG–IR showed that the flammable gas products of P(3,4)HB released during the thermal degradation process were greatly decreased. Scanning electron microscopy analysis revealed that more compact char residues were observed with the incorporation of ZnB. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Effects of thiophene units on substituted benzothiadiazole and benzodithiophene copolymers for photovoltaic applications
Authors: Ding Ping , Zou Yingping , Chu Cheng‐Che , Xiao Dequan , Hsu Chain‐Shu
Published: February 2012

Two conjugated copolymers, poly{4,7‐[5,6‐bis(octyloxy)]benzo(c)(1,2,5)thiadiazole‐alt‐4,8‐di(2‐ethylhexyloxyl)benzo[1,2‐b:3,4‐b]dithiophene} (P1) and poly(2‐{5‐[5,6‐bis(octyloxy)‐4‐(thiophen‐2‐yl)benzo(c)(1,2,5)thiadiazol‐7‐yl] thiophen‐2‐yl}‐4,8‐di(2‐ethylhexyloxyl)benzo(1,2‐b:3,4‐b)dithiophene) (P2), composed of benzodithiophene and 5,6‐dioctyloxybenzothiadiazole derivatives with or without thiophene units were synthesized via a Stille cross‐coupling polymerization reaction. These copolymers are promising for applications in bulk heterojunction solar cells because of their good solubility, proper thermal stability, moderate hole mobility, and low band gap. The photovoltaic properties of these copolymers were investigated on the basis of blends of the different polymer/(6,6)‐phenyl‐C71‐butyric acid methyl ester (PC71BM) weight ratios under AM1.5G illumination at 100 mW/cm2. The device with indium tin oxide/poly(3,4‐ethylene dioxythiophene):poly(styrene sulfonate)/P2:PC71BM (1 : 2 w/w)/Ca/Al gave a relatively better photovoltaic performance with a power conversion efficiency of 1.55%. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Plasticization of polylactide with block copolymers of ethylene glycol and propylene glycol
Authors: Kowalczyk Marcin , Pluta Miroslaw , Piorkowska Ewa , Krasnikova Nelli
Published: February 2012

In this study, plasticization of polylactide (PLA) with PEG–PPG–PEG triblock copolymers was examined. Two different copolymers were utilized, with molecular weight of 1100 and 1900 g mol−1, and with PEG contents of 10 and 50 wt %, respectively. A PPG plasticizer with molecular weight of 1000 g mol−1, close to that of PPG block in the copolymers, was also used for comparison. Melt blends containing 10 and 15 wt % of the plasticizers were prepared. Thermal properties, mechanical properties, and structure of quenched and annealed films of the blends were studied. The crystallization driven phase separation occurred in all the annealed blends but led to different structures depending on the plasticizer used. Distinct inclusions of the plasticizer were visible under the scanning electron microscope only in PLA with PPG but not in the blends of PLA with the copolymers. The drawability of the plasticized systems was improved when compared with neat PLA. In the quenched and annealed blends, elongations at break at the level of 5 and 0.7, respectively, were reached. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Influence of plasticizers suggests role of topology in polymer solidification at high cooling rates
Authors: Piccarolo Stefano , Poulose Anesh Manjaly , Luzio Alessandro
Published: February 2012

Although solidification in processing determines short‐ and long‐term properties, methods for understanding polymer crystallization mostly rely on real time experiments. Their evidences being drawn on time scales farther apart with respect to those experienced in processing. Nor significant outcomes have been so far drawn with approaches mimicking the typical processing times, the Continuous Cooling Transformation methods. Use of these techniques has indeed been limited to a heuristic interpretation of the structure developed under extreme solidification conditions without suggesting alternative routes to the understanding or even clues to the many open questions on polymer crystallization under realistic solidification conditions. If the mechanisms inferred from realtime methods cannot in principle be translated to processing conditions the oxymoron is not overcome. In this work, we compare the influence of a plasticizer on the density drop with cooling rate, and therefore on the disappearance of any long range order crystalline phases, observed after fast controlled quenching of polyethylene terephthalate (PET) and polybutylene terephthalate (PBT). The plasticizer enhances significantly the maximum cooling rate at which PET still shows long range order crystalline phases, whereas barely modifies the situation for PBT. On the basis of a series of concurrent clues, we suggest that the complex inherent topology of macromolecular melts introduces a timescale on polymer crystallization lying in the range of the solidification conditions experienced in processing. Although melt topology is known to determine in many instances polymer solidification, all approaches so far proposed to describe the development of polymer crystallization overlook or even neglect any explicit dependence of such mechanisms on parameters like the molecular weight between entanglements. Albeit the arguments are feeble they all concur to raise several questions even on the contradictory role of nucleating agents under the extreme conditions experienced in processing. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
The role of dislocations for the plastic deformation of semicrystalline polymers as investigated by multireflection X‐ray line profile analysis
Authors: Spieckermann Florian , Polt Gerald , Wilhelm Harald , Kerber Michael , Schafler Erhard , Zehetbauer Michael J.
Published: February 2012

Wide angle X‐ray experiments evaluated by recent developments of X‐ray line profile analysis allow for the detection of the presence of dislocations as well as to determine their density in crystalline materials. The application to semicrystalline polymers not only provides information on the crystal size and the dislocations but—in combination with in situ deformation—also information on the evolution of these microstructural parameters. Investigations on cold rolled and on uniaxially compressed samples of α‐phase isotactic polypropylene (α‐iPP) as well as poly(3‐hydroxybutyrate) (P3HB) are presented. The synchrotron experiments reveal a dislocation governed deformation process in α‐iPP. P3HB, however, deforms by a process not including dislocation generation. Here, microcracking and strain localization in the amorphous phase seem to be the predominant deformation mechanisms. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Properties of ultra‐high‐molecular‐weight polyethylene with a structure modified by plastic deformation and electron‐beam irradiation
Authors: Cybo Jerzy , Maszybrocka Joanna , Duda Piotr , Bartczak Zbigniew , Barylski Adrian , Kaptacz Sławomir
Published: February 2012

To improve the functional properties of polyethylene in a polymer–metal kinematic system, ultra‐high‐molecular‐weight polyethylene (UHMWPE) was subjected to light deformation by uniaxial compression [permanent true strain (ef) = 0.14–0.32] and postdeformation electron‐beam irradiation (with a dose of 26–52 kGy). X‐ray examinations demonstrated that no significant reorientation of the lamellar structure occurred upon compression. The textures of all of the samples, except for the sample deformed at ef = 0.32, were nearly random. In the exception, a very weak axial texture developed. However, the treatment applied (deformation and electron‐beam irradiation) significantly changed the structure of the material. A considerable increase in the crosslinked fraction and the crystalline band absorption in the Fourier transform infrared spectra were observed in the modified samples. This indicated a noticeable increase in the degree of spatial ordering within a structure, although the overall crystallinity increased only slightly. The effect of such restructuring was evidenced by microscopic observations of the near‐surface layer of the UHMWPE samples subjected to unidirectional sliding interaction with a CoCr alloy for 100 h (in a block‐ring tribological system). It was found that for the predeformed (ef = 0.14–0.21) and electron‐irradiated (dose of 52 kGy) samples, the operational load imposed on the system resulted in a considerable reduction in the thickness of the plastically deformed near‐surface layer and in a decreasing amount of lamellae oriented flat‐on compared to the neat unmodified UHMWPE subjected to the same test. The recorded tribological wear (mass decrement) decreased up to fivefold in comparison to that of the initial material. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Resistance of UHMWPE to plastic deformation and wear and the possibility of its enhancement through modification by radiation
Authors: Cybo Jerzy , Maszybrocka Joanna , Barylski Adrian , Kansy Jerzy
Published: February 2012

The operational durability of a kinematical polymer–metal system, required in many applications, including endoprostheses used for the total knee or hip joint arthoplasty, depends largely on high resistance to wear and permanent deformation of the polymer cup, especially in its near‐surface layer, contacting with the metal part. In this study, the wear and deformation resistance of two ultra high molecular weight polyethylene (UHMWPE) grades used in arthoplasty, GUR1020 and GUR1050, as well as the possibilities of its enhancement by radiation treatment were studied in detail. An influence of the molecular characteristic of these grades on functional properties, including permanent plastic deformation, microhardness, elastic modulus, coefficient of the micromechanical wear were studied. The properties of GUR 1050 of higher molecular weight were found advantageous over GUR 1020 grade. It was also confirmed that irradiation with electron beam is an effective method of modification, resulting in an improvement of both resistance to permanent deformation and wear of UHMWPE. It was demonstrated that microhardness, Young's modulus, and wear resistance coefficient increase proportionally to the irradiation dose applied. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Transcriptional profile of native CD271+ multipotential stromal cells: Evidence for multiple fates, with prominent osteogenic and Wnt pathway signaling activity
Authors: Churchman Sarah M. , Ponchel Frederique , Boxall Sally A. , Cuthbert Richard , Kouroupis Dimitrios , Roshdy Tarek , Giannoudis Peter V. , Emery Paul , McGonagle Dennis , Jones Elena A.
Published: February 2012

Objective

Controversy surrounds the identity and functionality of rare bone marrow–derived multipotential stromal cells (BM‐MSCs), including their differentiation capabilities, their relationship to pericytes and hematopoiesis‐supporting stromal cells, and the relevance of their culture‐expanded progeny in studies of skeletal biology and development of cell‐based therapies. The aim of this study was to clarify the nature of candidate BM‐MSCs by profiling transcripts that reflect different aspects of their putative functions in vivo.

Methods

Rare, sorted BM‐derived CD45−/low CD271bright (CD271) cells were analyzed using 96‐gene expression arrays focused on transcripts relevant to mesenchymal‐lineage differentiation (toward bone, cartilage, fat, or muscle), hematopoietic and stromal support, and molecules critical to skeletal homeostasis. These cells were compared to matched CD45+ CD271− hematopoietic‐lineage cells, culture‐expanded MSCs, and skin fibroblasts. When feasible, transcription was validated using flow cytometry.

Results

CD271 cells had a transcriptional profile consistent with the multiple fates of in vivo MSCs, evident from the observed simultaneous expression of osteogenic, adipogenic, pericytic, and hematopoiesis‐supporting genes (e.g., SP7 [osterix], FABP4 [fatty acid binding protein 4], ANGPT1 [angiopoietin 1], and CXCL12 [stromal cell–derived factor 1], respectively). Compared to culture‐expanded MSCs and fibroblasts, CD271 cells exhibited greater transcriptional activity, particularly with respect to Wnt‐related genes (>1,000‐fold increased expression of FRZB [secreted frizzled‐related protein 3] and WIF1 [Wnt inhibitory factor 1]). A number of transcripts were identified as novel markers of MSCs.

Conclusion

The native, BM‐derived in vivo MSC population is endowed with a gene signature that is compatible with multiple functions, reflecting the topographic bone niche of these cells, and their signature is significantly different from that of culture‐expanded MSCs. This indicates that studies of the biologic functions of MSCs in musculoskeletal diseases, including osteoporosis and osteoarthritis, should focus on in vivo MSCs, rather than their culture‐adapted progeny.
Abnormal bone quality in cartilage oligomeric matrix protein and matrilin 3 double‐deficient mice caused by increased tissue inhibitor of metalloproteinases 3 deposition and delayed aggrecan degradation
Authors: Groma Gergely , Xin Wei , Grskovic Ivan , Niehoff Anja , Brachvogel Bent , Paulsson Mats , Zaucke Frank
Published: February 2012

Objective

Cartilage oligomeric matrix protein (COMP) and matrilin 3 are extracellular matrix proteins that are abundant in cartilage. As adaptor molecules, both proteins bridge and stabilize macromolecular networks consisting of fibrillar collagens and proteoglycans. Mutations in the genes coding for COMP and matrilin 3 have been linked to human chondrodysplasias, while in mice, deficiency in COMP or matrilin 3 does not cause any pronounced skeletal abnormalities. Given the similar functions of COMP and matrilin 3 in the assembly and stabilization of the extracellular matrix, our aim was to determine whether these proteins could functionally compensate for each other.

Methods

To assess this putative redundancy of COMP and matrilin 3, we generated COMP/matrilin 3 double‐deficient mice and performed an in‐depth analysis of their skeletal development.

Results

At the newborn stage, the overall skeletal morphology of the double mutants was normal, but at 1 month of age, the long bones were shortened and the total body length reduced. Peripheral quantitative computed tomography revealed increased metaphyseal trabecular bone mineral density in the femora. Moreover, the degradation of aggrecan in the cartilage remnants in the metaphyseal trabecular bone was delayed, paralleled by increased deposition of tissue inhibitor of metalloproteinases 3 (TIMP‐3). The structure and morphology of the growth plate were grossly normal, but in the center, focal closures were observed, a phenotype very similar to that described in matrix metalloproteinase 13 (MMP‐13)–deficient mice.

Conclusion

We propose that a lack of COMP and matrilin 3 leads to increased deposition of TIMP‐3, which causes partial inactivation of MMPs, including MMP‐13, a mechanism that would explain the similarities in phenotype between COMP/matrilin 3 double‐deficient and MMP‐13–deficient mice.
Benchmarking of next‐generation biofuels from a process perspective
Authors: Voll Anna , Marquardt Wolfgang
Published: February 2012

Recently, novel biofuel candidates have been proposed by catalysis research. To guide follow‐up research activities efficiently, it must be assessed whether large‐scale production of such next‐generation biofuels is competitive in comparison with established biofuels like ethanol. However, it is very time‐consuming to provide complete process designs for all alternatives, especially as important data are missing in the early development phase. Instead, reaction network flux analysis (RNFA) has been introduced recently for rapid screening of production routes to bridge the gap between catalysis research and process design. Using this approach, mass balances are formulated for a network of possible reactions such that multi‐objective optimization techniques can be applied to identify the attractive pathways with high performance. Typical performance indicators like total annualized cost or environmental impact are adapted to the requirements of the early design phase and integrated in the flux analysis. In this paper, production performance indicators of ten novel biofuel candidates are compared to those of methanol, ethanol, butanol, and methane as reference fuels using RNFA. While some pathways already show an encouraging performance, the reaction yield of others must be increased significantly, if the target product should qualify as promising fuel candidates. © 2012 Society of Chemical Industry and John Wiley & Sons, Ltd
Comparison of adjustment methods for stratified two‐sample tests in the context ofROCanalysis
Authors: Zou Kelly H. , Carlsson Martin O. , Yu Ching‐Ray
Published: February 2012

We compare several nonparametric and parametric weighting methods for the adjustment of the effect of strata. In particular, we focus on the adjustment methods in the context of receiver‐operating characteristic (ROC) analysis. Nonparametrically, rank‐based vanElteren's test and inverse‐variance (IV) weighting using the area under theROCcurve (AUC) are examined. Parametrically, the stratifiedt‐test andIVAUCweighted method are applied based on a binormal monotone transformation model. Stratum‐specific, pooled, and adjusted estimates are obtained. The pooled and adjustedAUCs are estimated. We illustrate and compare these weighting methods on a multi‐center diagnostic trial and through extensiveMonte‐Carlo simulations.
Reaction kinetics in the plasma membrane
Authors: Kalay Ziya
Published: February 2012

A great puzzle in science is establishing a bottom up understanding of life by revealing how a collection of molecules gives rise to a living cell that can survive, communicate, and reproduce. In the confines of physics, chemistry, or material science laboratories where it possible to study complex interactions between molecules in a well‐defined environment, our understanding of collective behavior is substantially developed. However, the environment in which molecules of a biological cell perform their functions is far from ideal or controllable. The environment inside cellular regions such as the plasma membrane is heterogeneous and dynamic, and functional molecules such as proteins are both dynamic and promiscuous, as they interact with countless other molecules. This makes it extremely challenging to grasp the inner mechanism of the cells, both experimentally and theoretically. On the bright side, this presents scientists with a colorful playground that waits to be explored: the mesoscopic world inside the cell. This review covers some of the recent experimental and theoretical developments in the study of molecular interactions in the plasma membrane, viewed as a heterogeneous medium where the number of reactants can be small, sometimes countable, and its implications for biological function.
Functional classification of membrane transporters and channels based on filtered TM/non‐TM amino acid composition
Authors: Schaadt N. S. , Helms V.
Published: February 2012

Membrane transporters catalyze the transport of small solute molecules across biological barriers such as lipid bilayer membranes. As the experimental annotation of which proteins transport which substrates is incomplete it is highly desirable to develop computational methods that can assist in the classification and substrate annotation of putative membrane transport proteins. Here, we determined the similarity of membrane transporter sequences annotated in the Transport Classification Database (Saier et al., Nucleic Acids Res 2006, 34, D181‐D186) and Arabidopsis thaliana membrane transporters annotated in the database Aramemnon (Schwacke et al., Plant Physiol 2003, 131, 16‐26). The similarity measure was based on the amino acid composition either considering the full sequences or separately in the transmembrane (TM) and external parts of the sequences. We considered four different substrate sets and three different subfamilies and tried to classify the given proteins into these classes. Family or substrate prediction based on the simple amino acid frequency had an average accuracy of 76%. The differentiation between TM and non‐TM regions led to an improved accuracy of 80% on average. © 2012 Wiley Periodicals, Inc. Biopolymers 97:558–567, 2012.
Extraction and characterization of a natural rubber from Euphorbia characias latex
Authors: Spanò Delia , Pintus Francesca , Mascia Claudia , Scorciapino Mariano Andrea , Casu Mariano , Floris Giovanni , Medda Rosaria
Published: February 2012

A natural rubber was identified and characterized for the first time in the latex of the perennial Mediterranean shrub Euphorbia characias. Four different methods, i.e., acetone, acetic acid, trichloroacetic acid, and Triton® X‐100, followed by successive treatments with cyclohexane/ethanol, were employed to extract the natural rubber. The rubber content was shown to be 14% (w/v) of the E. characias latex, a low content compared with that of Hevea brasiliensis (30–35%) but a similar content to other rubber producing plants. E. characias rubber showed a molecular weight of 93,000 with a Mw/Mn of 2.9. 1H NMR, 13C NMR, and FTIR analysis revealed the characteristic of the cis‐1,4‐polyisoprene typical of natural rubber. These results provided novel insight into latex components and will ultimately benefit the broader understanding of E. characias latex composition. © 2012 Wiley Periodicals, Inc. Biopolymers 97: 589–594, 2012.
Age‐Related Differences in Ethnic Prejudice: Evidence of the Mediating Effect of Right‐Wing Attitudes
Authors: Franssen Vicky , Dhont Kristof , Hiel Alain Van
Published: February 2012

The present study revealed age‐related differences in ethnic prejudice in a heterogeneous (total N = 1,308) and a representative (N = 800) sample, using measures of blatant and subtle prejudice. The relationship between age and blatant and subtle prejudice was found to be fully mediated by right‐wing social‐cultural attitudes (i.e. authoritarianism and cultural conservatism). Copyright © 2012 John Wiley & Sons, Ltd.
Synthesis of C8‐Arylamine‐Modified 2′‐Deoxyadenosine Phosphoramidites and their Site‐Specific Incorporation into Oligonucleotides
Authors: Szombati Zita , Baerns Sabrina , Marx Andreas , Meier Chris
Published: February 2012

Adducts of C8‐(N‐acetyl)‐arylamines and 2′‐deoxyadenosine were synthesised by palladium‐catalysed CN cross‐coupling chemistry. These 2′‐dA adducts were converted into the corresponding 3′‐phosphoramidites and site‐specifically incorporated into DNA oligonucleotides, which were characterised by mass spectrometry, UV thermal‐stability assays and circular dichroism. These modified oligonucleotides were also used in EcoRI restriction assays and in primer‐extension studies with three different DNA polymerases. The incorporation of the 2′‐dA lesion close to the EcoRI restriction site dramatically reduced the susceptibility of the DNA strand to cleavage; this indicates a significant local distortion of the DNA double helix. The incorporation of the acetylated C8‐2′‐dA‐phosphoramidites into 20‐mer oligonucleotides failed, however, because the N‐acetyl group was lost during the deprotection process. Instead the corresponding C8‐NH‐2′‐dA‐modified oligonucleotides were obtained. The effect of the C8‐NH‐arylamine‐dA lesion on the replication by DNA polymerases was clearly dependent both on the polymerase used and on the arylamine‐dA damage.
Tailoring a Stabilized Variant of Hydroxynitrile Lyase from Arabidopsis thaliana
Authors: Okrob Daniel , Metzner Julia , Wiechert Wolfgang , Gruber Karl , Pohl Martina
Published: February 2012

The R‐selective hydroxynitrile lyase from Arabidopsis thaliana (AtHNL) cannot be applied for stereoselective cyanohydrin syntheses in aqueous media because of its limited stability at pH<5, which is required in order to suppress the uncatalyzed racemic cyanohydrin formation. To stabilize AtHNL we designed a surface‐modified variant incorporating 11 changes in the amino acids on the protein surface. Comparative characterization of the variant and the wild‐type enzyme showed a broadened pH optimum towards the acidic range, along with enhancement of activity by up to twofold and significantly increased pH‐ and thermostabilities. The effect can most probably be explained by a shift of the isoelectic point from pH 5.1 to 4.8. Application of the variant for the synthesis of (R)‐cyanohydrins in an aqueous/organic two‐phase system at pH 4.5 demonstrated the high stereoselectivity and robustness of the variant relative to the wild‐type enzyme, which is immediately inactivated under these conditions.
Service user involvement in risk assessment and management: The Transition Inventory
Authors: Kroner Daryl G.
Published: February 2012

Background

Drawing on self‐prediction theory and the positive benefits of increasing health service user participation in risk assessments, the Transition Inventory (TI) was developed. It is an aid to the assessment of areas that people anticipate will be of difficulty in the next stage of transition, for example from open hospital to the community.

Aims

The aim of this paper is to determine reliability and convergent/discriminant validity data for the TI and its subscales, including behavioral impulsivity, social pressure, substance misuse, financial/employment, leisure, negative affect, interpersonal and family concerns and social alienation.

Methods

Eighty‐eight male offenders coming towards the end of a period of imprisonment were asked to complete the TI. Their results were compared with the staff‐rated Measures of Criminal Attitudes and Associates (MCAA) scale, alcohol blame and causation of crime items. Comparisons with the MCAA's antisocial intent scale, which is a future‐orientated scale, and the associates scale allowed for convergent/discriminant validity to be examined with TI scales. With a community offender sample, TI results were used to predict researcher ratings.

Results

The TI scales demonstrated adequate internal consistency. Overall, the MCAA's antisocial intent scale had higher correlations with the TI than with a nonfuture‐orientated scale. TI scales also demonstrated convergent validity with other measures and preliminary predictive validity with researcher ratings.

Conclusions/implications for practice

The TI provides a way to increase service user involvement in the assessments that determine when and how they transfer to settings where they will have more independence. Copyright © 2012 John Wiley & Sons, Ltd.
Multivariate evaluation of the correlation between retention data and molecular descriptors of antiepileptic hydantoin analogs
Authors: Djaković‐Sekulić Tatjana , Smoliński Adam , Trišović Nemanja , Ušćumlić Gordana
Published: February 2012

Molecular properties relevant to pharmacokinetics of two sets of newly synthesized hydantoin derivatives based on two well‐known drugs (Nirvanol and Phenytoin) were studied. Properties under consideration were either determined empirically by reversed‐phase high‐performance thin‐layer chromatography or calculated by the use of established theoretical medicinal chemistry/drug design software. These properties represent selected structural features of analytes, which affect their processes of absorption, distribution, metabolism, excretion, and toxicity. Principal component analysis was used to visualize the differences between six mobile phase modifiers used as well as similarities between 24 analyzed compounds. To find appropriate quantitative relationships betweenRM, Wfor the tested compounds and molecular descriptors, stepwise regression, partial least squares (PLS), and robust PLS were used. The best results were obtained with robust PLS. Copyright © 2012 John Wiley & Sons, Ltd.
Coclustering—a useful tool for chemometrics
Authors: Bro Rasmus , Papalexakis Evangelos E. , Acar Evrim , Sidiropoulos Nicholas D.
Published: February 2012

Nowadays, chemometric applications in biology can readily deal with tens of thousands of variables, for instance, in omics and environmental analysis. Other areas of chemometrics also deal with distilling relevant information in highly information‐rich data sets. Traditional tools such as the principal component analysis or hierarchical clustering are often not optimal for providing succinct and accurate information from high rank data sets. A relatively little known approach that has shown significant potential in other areas of research iscoclustering, where a data matrix is simultaneously clustered in its rows and columns (objects and variables usually).

Coclustering is the tool of choice when only a subset of variables is related to a specific grouping among objects. Hence, coclustering allows aselectnumber of objects to share a particular behavior on aselectnumber of variables.

In this paper, we describe the basics of coclustering and use three different example data sets to show the advantages and shortcomings of coclustering. Copyright © 2012 John Wiley & Sons, Ltd.
Facile Carbon–Fluorine Bond Activation and Subsequent Functionalisation of 1,1‐Difluoroethylene and Tetrafluoroethylene Promoted by Adjacent Metal Centres
Authors: Slaney Michael E. , Anderson D. Jason , Ristic‐Petrovic Dusan , McDonald Robert , Cowie Martin
Published: February 2012

The bridging fluoroolefin ligands in the complexes [Ir2(CH3)(CO)2(μ‐olefin)(dppm)2][OTf] (olefin=tetrafluoroethylene, 1,1‐difluoroethylene; dppm=μ‐Ph2PCH2PPh2; OTf−=CF3SO3−) are susceptible to facile fluoride ion abstraction. Both fluoroolefin complexes react with trimethylsilyltriflate (Me3SiOTf) to give the corresponding fluorovinyl products by abstraction of a single fluoride ion. Although the trifluorovinyl ligand is bound to one metal, the monofluorovinyl group is bridging, bound to one metal through carbon and to the other metal through a dative bond from fluorine. Addition of two equivalents of Me3SiOTf to the tetrafluoroethylene‐bridged species gives the difluorovinylidene‐bridged product [Ir2(CH3)(OTf)(CO)2(μ‐OTf)(μ‐CCF2)(dppm)2][OTf]. The 1,1‐difluoroethylene species is exceedingly reactive, reacting with water to give 2‐fluoropropene and [Ir2(CO)2(μ‐OH)(dppm)2][OTf] and with carbon monoxide to give [Ir2(CO)3(μ‐κ1:η2‐CCCH3)(dppm)2][OTf] together with two equivalents of HF. The trifluorovinyl product [Ir2(κ1‐C2F3)(OTf)(CO)2(μ‐H)(μ‐CH2)(dppm)2][OTf], obtained through single CF bond activation of the tetrafluoroethylene‐bridged complex, reacts with H2 to form trifluoroethylene, allowing the facile replacement of one fluorine in C2F4 with hydrogen.
Size‐Dependent Surface Activity of Rutile and Anatase TiO2 Nanocrystals: Facile Surface Modification and Enhanced Photocatalytic Performance
Authors: Xiang Guolei , Wang Yang‐Gang , Wu Di , Li Tianyang , He Jie , Li Jun , Wang Xun
Published: February 2012

The size‐dependent surface activity of titania was illustrated through the formation of ultrafine nanocrystals with clean surfaces. It was demonstrated that, when the size of the nanocrystals was small enough, their surface activity could be significantly enhanced, as evidenced by the formation of transparent macroassemblies, their increased dispersity in various solvents, the facile modification of their surface by organic molecules at room temperature, their strong visible‐light absorption through coordination with peroxide, and highly enhanced photocatalytic performance.
Charged Behaviour from Neutral Ligands: Synthesis and Properties of N‐Heterocyclic Pseudo‐amides
Authors: Thatcher Robert J. , Johnson David G. , Slattery John M. , Douthwaite Richard E.
Published: February 2012

Deprotonation of the 1‐isopropyl‐3‐(phenylamino)pyridin‐1‐ium iodide gives the corresponding neutral betaine, which is formalised as a pyridinium‐amido ligand when coordinated to a metal. Spectroscopic, structural and theoretical methods have been used to investigate the metal–ligand bonding, ligand dynamics and electron distribution. Collectively, the data show that the ligand can be characterised as a pseudo‐amide and is a strong donor akin to alkyl phosphines and N‐heterocyclic carbenes. Furthermore, rotation about both N substituent CN bonds occurs, which is in contrast to the two alternative pyridinium positional isomers that exhibit neutral resonance structures. For comparison, compounds and complexes derived from norharman were prepared, which contain an additional CC bond supporting conjugation and the accessibility of a neutral resonance structure. Notwithstanding the formal neutral structure, norharman‐derived ligands are comparably strong donors, and have the additional advantage of exhibiting stability to dioxygen and water.
Synthesis and Characterization of a Singlet Delocalized 2,4‐Diimino‐1,3‐disilacyclobutanediyl and a Silylenylsilaimine
Authors: Zhang Shu‐Hua , Xi Hong‐Wei , Lim Kok Hwa , Meng Qingyong , Huang Ming‐Bao , So Cheuk‐Wai
Published: February 2012

The synthesis and characterization of a singlet delocalized 2,4‐diimino‐1,3‐disilacyclobutanediyl, [LSi(μ‐CNAr)2SiL] (2, L: PhC(NtBu)2, Ar: 2,6‐iPr2C6H3), and a silylenylsilaimine, [LSi(NAr)SiL] (3), are described. The reaction of three equivalents of the disilylene [LSiSiL] (1) with two equivalents of ArNCNAr in toluene at room temperature for 12 h afforded [LSi(μ‐CNAr)2SiL] (2) and [LSi(NAr)SiL] (3) in a ratio of 1:2. Compounds 2 and 3 have been characterized by NMR spectroscopy and X‐ray crystallography. Compound 2 was also investigated by theoretical studies. The results show that compound 2 possesses singlet biradicaloid character with an extensive electronic delocalization throughout the Si2C2 four‐membered ring and exocyclic CN bonds. Compound 3 is the first example of a silylenylsilaimine, which contains a low‐valent silicon center and a silaimine substituent. A mechanism for the formation of 2 and 3 is also proposed.
A Non‐damaging Method to Analyze the Configuration and Dynamics of Nitrotyrosines in Proteins
Authors: Díaz‐Moreno Irene , Nieto Pedro M. , Del Conte Rebecca , Gairí Margarida , García‐Heredia José M. , De la Rosa Miguel A. , Díaz‐Quintana Antonio
Published: February 2012

Often, deregulation of protein activity and turnover by tyrosine nitration drives cells toward pathogenesis. Hence, understanding how the nitration of a protein affects both its function and stability is of outstanding interest. Nowadays, most of the in vitro analyses of nitrated proteins rely on chemical treatment of native proteins with an excess of a chemical reagent. One such reagent, peroxynitrite, stands out for its biological relevance. However, given the excess of the nitrating reagent, the resulting in vitro modification could differ from the physiological nitration. Here, we determine unequivocally the configuration of distinct nitrated‐tyrosine rings in single‐tyrosine mutants of cytochrome c. We aimed to confirm the nitration position by a non‐destructive method. Thus, we have resorted to 1H‐15N heteronuclear single quantum coherence(HSQC) spectra to identify the 3J(NH) correlation between a 15N‐tagged nitro group and the adjacent aromatic proton. Once the chemical shift of this proton was determined, we compared the 1H‐13C HSQC spectra of untreated and nitrated samples. All tyrosines were nitrated at ε positions, in agreement to previous analysis by indirect techniques. Notably, the various nitrotyrosine residues show a different dynamic behaviour that is consistent with molecular dynamics computations.
Regulation of π‐Stacked Anthracene Arrangement for Fluorescence Modulation of Organic Solid from Monomer to Excited Oligomer Emission
Authors: Hinoue Tomoaki , Shigenoi Yuta , Sugino Misa , Mizobe Yuji , Hisaki Ichiro , Miyata Mikiji , Tohnai Norimitsu
Published: February 2012

The construction and precise control of the face‐to‐face π‐stacked arrangements of anthracene fluorophores in the crystalline state led to a remarkable red shift in the fluorescence spectrum due to unprecedented excited oligomer formation. The arrangements were regulated by using organic salts including anthracene‐1,5‐disulfonic acid (1,5‐ADS) and a variety of aliphatic amines. Because of the smaller number of hydrogen atoms at the edge positions and the steric effect of the sulfonate groups, 1,5‐ADS should prefer face‐to‐face π‐stacked arrangements over the usual edge‐to‐face herringbone arrangement. Indeed, as the alkyl substituents were lengthened, the organic salts altered their anthracene arrangement to give two‐dimensional (2D) edge‐to‐face and end‐to‐face herringbone arrangements, one‐dimensional (1D) face‐to‐face zigzag and slipped stacking arrangements, a lateral 1D face‐to‐face arrangement like part of a brick wall, and a discrete monomer arrangement. The monomer arrangement behaved as a dilute solution even in the close‐packed solid state to emit deep blue light. The 1D face‐to‐face zigzag and slipped stacking of the anthracene fluorophores caused a red shift of 30–40 nm in the fluorescence emission with respect to the discrete arrangement, probably owing to ground‐state associations. On the other hand, the 2D end‐to‐face stacking induced a larger red shift of 60 nm, which is attributed to the excimer fluorescence. Surprisingly, the brick‐like lateral face‐to‐face arrangement afforded a remarkable red shift of 150 nm to give yellow fluorescence. This anomalous red shift is probably due to excited oligomer formation in such a lateral 1D arrangement according to the long fluorescence lifetime and little shift in the excitation spectrum. The regulation of the π‐stacked arrangement of anthracene fluorophores enabled the wide modulation of the fluorescence and a detailed investigation of the relationships between the photophysical properties and the arrangements.
Highly Chemoselective Calcium‐Catalyzed Propargylic Deoxygenation
Authors: Meyer Vera J. , Niggemann Meike
Published: February 2012

A calcium‐catalyzed direct reduction of propargylic alcohols and ethers has been accomplished by using triethylsilane as a nucleophilic hydride source. At room temperature a variety of secondary propargylic alcohols was deoxygenated to the corresponding hydrocarbons in excellent yields. Furthermore, for the first time, a catalytic deoxygenation of tertiary propargylic alcohols was generally applicable. The same protocol was suitable for an efficient reduction of secondary as well as tertiary propargylic methyl, benzyl and allyl ethers. Substrates containing an additional keto‐, ester or secondary hydroxyl function were reduced with exceptional chemoselectivity at the propargylic position.
Photooxygenation of a Microbial Arene Oxidation Product and Regioselective Kornblum–DeLaMare Rearrangement: Total Synthesis of Zeylenols and Zeylenones
Authors: Palframan Matthew J. , Kociok‐Köhn Gabriele , Lewis Simon E.
Published: February 2012

We report the enantioselective total syntheses of zeylenol (+)‐1, as well as its congeners (−)‐7 and 16, and of 3‐O‐debenzoylzeylenone 28. To this end, a new variant of the Kornblum–DeLaMare rearrangement, which utilises neighbouring‐group participation to impart regioselectivity, has been developed. The approach employs photooxygenation of building blocks derived from a microbial arene oxidation product.
CFD Simulation and LDA Measurement of the Fluid Flow in Fluid Phase Resonance Mixing
Authors: Schmalfuß Silvio , Säuberlich Ralph , Sommerfeld Martin
Published: February 2012

Beim Fluidphasenresonanzmischen wird eine flüssige Phase in einem Behälter über ein Gaspolster mit harmonisch schwingendem Wechseldruck beaufschlagt und so zu Schwingungen angeregt. Dieses Verfahren wird als instationäre Strömung zweier getrennter Phasen mit der CFD‐Software OpenFOAM simuliert und die Ergebnisse werden durch Messungen mit einem Einkomponenten‐Laser‐Doppler‐Anemometer verifiziert.
Xanthan Sulfuric Acid: An Efficient Bio‐supported and Recyclable Solid Acid Catalyst for the Synthesis of 2‐Aryl Thiadiazolo Benzimidazoles
Authors: Kuarm B. Suresh , Janardan B. , Crooks Peter A. , Rajitha B.
Published: February 2012

Xanthan sulfuric acid is an efficient solid acid catalyst for the preparation of 2‐aryl benzimidazoles in excellent yields. This method is applicable for the reaction of benzo[c][1,2,5]thiadiazole‐4,5‐diamine with aldehydes by simple physical grinding at room temperature. The salient features of the present methodology is cheaper process, easy synthesis of stable catalyst and the catalyst can be easily recycled without significant loss of activity.