bluuebunny/crossref_metadata_2025 huggingface dataset:
Formation Tracking Control of Multi‐Vehicle Systems
Authors: Dong Runsha , Geng Zhiyong
Published: October 2014

In this paper, the problem of trajectory tracking of multiple vehicles in a manner of rigid formation is studied. Each vehicle is modeled as a rigid body whose dynamics evolve on Euclidean groups and by which, both position and attitude of the vehicle are considered. The formation control problem of multiple vehicles is decomposed into decentralised control problems of pairs of a vehicle and its parent vehicle. A distributed control law is proposed for vehicles to track a predefined trajectory with desired formations. A numerical simulation is finally included to verify the theoretical results.
Genetic variation in GABRA2 moderates peer influence on externalizing behavior in adolescents
Authors: Villafuerte Sandra , Trucco Elisa M. , Heitzeg Mary M. , Burmeister Margit , Zucker Robert A.
Published: October 2014

Background

Genetic predisposition and environmental influences are both important factors in the development of problematic behavior leading to substance use in adolescence. Involvement with delinquent peers also strongly predicts adolescent externalizing behavior. Several lines of evidence support a role of GABRA2 on externalizing behavior related to disinhibition. However, whether this genetic association is influenced by the environment such as peer behavior remains unknown.

Methods

We examined the moderating role of GABRA2 genetic variation on the socialization model of delinquent peer affiliation (at ages 12–14 years) on externalizing behavior (at ages 15–17 years) in the Michigan Longitudinal Study (MLS) adolescent sample.

The sample consisted of 244 adolescents (75 females and 152 with at least one parent with a DSM‐IV lifetime alcohol dependence/abuse diagnosis). Peer delinquent activity reported by the participant and teacher‐reported adolescent externalizing behavior (Teacher Report Form (TRF) were assessed.

Results

No main effect of the GABRA2 SNP rs279826, which tags a large haplotype, on externalizing behavior was observed. However, there was a statistically reliable GABRA2 × peer delinquency interaction. The effect of peer delinquent involvement on externalizing scores and the rule breaking subscale is significantly stronger for those with the GG genotype compared to A‐carriers, whereas there was no effect of genotype on externalizing in the absence of peer delinquent involvement. No interaction was observed for the aggression subscale.

Conclusion

Our results suggest that the genetic effect of GABRA2 on externalizing behavior, more specifically on rule breaking is, at least in part, due to its effect on susceptibility to environmental exposure (i.e., peer delinquency).
Ionic liquid‐based aqueous biphasic systems as a versatile tool for the recovery of antioxidant compounds
Authors: Santos João H. , e Silva Francisca A. , Ventura Sónia P. M. , Coutinho João A. P. , de Souza Ranyere L. , Soares Cleide M. F. , Lima Álvaro S.
Published: October 2014

The comparative evaluation of distinct types of ionic liquid‐based aqueous biphasic systems (IL‐ABS) and more conventional polymer/salt‐based ABS to the extraction of two antioxidants, eugenol and propyl gallate, is focused. In a first approach, IL‐ABS composed of ILs and potassium citrate (C6H5K3O7/C6H8O7) buffer at pH 7 were applied to the extraction of two antioxidants, enabling the assessment of the impact of IL cation core on the extraction. The second approach uses ABS composed of polyethylene glycol (PEG) and potassium phosphate (K2HPO4/KH2PO4) buffer at pH 7 with imidazolium‐based ILs as adjuvants. Their application to the extraction of the compounds allowed the investigation of the impact of the presence/absence of IL, the PEG molecular weight, and the alkyl side chain length of the imidazolium cation on the partition. It is possible to maximize the extractive performance of both antioxidants up to 100% using both types of IL‐ABS. The IL enhances the performance of ABS technology. The data puts in evidence the pivotal role of the appropriate selection of the ABS components and design to develop a successful extractive process, from both environmental and performance points of view. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 31:70–77, 2015
Considerations for the process development of insect‐derived antimicrobial peptide production
Authors: Müller Hagen , Salzig Denise , Czermak Peter
Published: October 2014

Antimicrobial peptides (AMPs) could evolve into new therapeutic lead molecules against multi‐resistant bacteria. As insects are a rich source of AMP, the identification and characterization of insect‐derived AMPs is particularly emphasized. One challenge of bringing these molecules into market, e.g., as a drug, is to develop a cost‐efficient large‐scale production process. Due to the fact that a direct AMP isolation from insects is not economical and that chemical synthesis is recommended for peptide sizes below 40 amino acids, a viable option is heterologous AMP production. Therefore, previous knowledge concerning the expression of larger proteins can be adapted, but due to the AMP nature (e.g., small size, bactericide) additional challenges have to be faced during up and downstream processing. Nonetheless the bottleneck for large‐scale AMP production is the same as for proteins; mainly the downstream process. This review introduces opportunities for insect‐derived AMP production, like the choice of the expression system (based on previously derived data), depending on the AMP nature, as well as new purification strategies like elastin‐like peptide/intein based purification strategies. All of these aspects are discussed with regard to large‐scale processes and costs. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 31:1–11, 2015
Effects of copper on CHO cells: Cellular requirements and product quality considerations
Authors: Yuk Inn H. , Russell Stephen , Tang Yun , Hsu Wei‐Ting , Mauger Jacob B. , Aulakh Rigzen P. S. , Luo Jun , Gawlitzek Martin , Joly John C.
Published: October 2014

Recent reports highlight the impact of copper on lactate metabolism: CHO cell cultures with higher initial copper levels shift to net lactate consumption and yield lower final lactate and higher titers. These studies investigated the effects of copper on metabolite and transcript profiles, but did not measure in detail the dependences of cell culture performance and product quality on copper concentrations. To more thoroughly map these dependences, we explored the effects of various copper treatments on four recombinant CHO cell lines. In the first cell line, when extracellular copper remained above the limit of detection (LOD), cultures shifted to net lactate consumption and yielded comparable performances irrespective of the differences in copper levels; when extracellular copper dropped below LOD (∼13 nM), cultures failed to shift to net lactate consumption, and yielded significantly lower product titers. Across the four cell lines, the ability to grow and consume lactate seemed to depend on the presence of a minimum level of copper, beyond which there were no further gains in culture performance. Although this minimum cellular copper requirement could not be directly quantified, we estimated its probable range for the first cell line by applying several assumptions. Even when different copper concentrations did not affect cell culture performance, they affected product quality profiles: higher initial copper concentrations increased the basic variants in the recombinant IgG1 products. Therefore, in optimizing chemically defined media, it is important to select a copper concentration that is adequate and achieves desired product quality attributes. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 31:226–238, 2015
Electrochemical Characterisation of Nanoscale Liquid|Liquid Interfaces Located at Focused Ion Beam‐Milled Silicon Nitride Membranes
Authors: Sairi Masniza , Chen‐Tan Nigel , Neusser Gregor , Kranz Christine , Arrigan Damien W. M.
Published: October 2014

The electrochemical behaviour of single and arrayed nanoscale interfaces between two immiscible electrolyte solutions (single and array nanoITIES) is presented. The interfaces were formed at nanopores fabricated through the focused ion beam (FIB) milling of silicon nitride (SiN) membranes by using nanopores with approximately 30–80 nm radii and with pore‐to‐pore separations to pore radius ratios in the range of 16–32. Electrochemistry was performed through the interfacial transfer of tetrapropylammonium (TPrA+) across single and array nanoITIES between water and 1,6‐dichlorohexane. The ion‐transfer limiting current at the single nanoITIES was in excellent agreement with the current predicted by using an inlaid disc interface model. At nanoITIES arrays, experimental currents were lower than predicted for an array of inlaid interfaces, which is attributed to overlapped diffusion zones. As a result, FIB milling offers an attractive strategy to form nanoITIES for diverse investigations.
Quo vadis, chemometrics?
Authors: Vogt Frank
Published: October 2014

Assessing current trends in chemometric publications reveals that most projects utilize known methodologies and fall into the category “application.” There seems to be worrying little of true innovation unless one counts “fashions” assimilated from other fields. The field may have reached a crossroad: One path leads to chemometrics becoming a fully mature but stagnant tool for analytical chemists; the other path, that is, maintaining chemometrics as an active and widely recognized research field, requires opening new research areas for chemometricians. It is argued that hard modeling as opposed to the ubiquitous soft modeling may become such a new direction. Hard modeling would focus on investigating chemical mechanisms that give raise to measured data as opposed to empirically analyzing data.Furthermore, chemometricians in academia are responsible for preparing the next generation of chemometricians. Despite the need for chemometricians in the workforce, the number of young chemometricians is low and will remain low unless changes in chemistry curricula happen. This remains a challenge because there are fundamental issues that need to be overcome. Copyright © 2014 John Wiley & Sons, Ltd.
Rationally Designed Axially Chiral Diarylethene Switches with High Helical Twisting Power
Authors: Li Yannian , Wang Mengfei , Wang Hao , Urbas Augustine , Li Quan
Published: October 2014

Three rationally designed axially chiral diarylethene switches were synthesized and their application as chiral dopants for phototunable cholesteric liquid crystal devices was investigated. Design of these molecules was based on the combination of photochromic dithienylcyclopentene core with bridged binaphthyl units as chiral precursors. Aromatic groups were introduced to the molecules at 6,6′‐positions of binaphthyls through a Suzuki–Miyaura coupling reaction. Their helical twisting powers (HTPs) are significantly higher than those of the known chiral diarylethenes reported as chiral dopants so far. Photocyclization of these molecules upon light irradiation brought out dramatic variation in HTPs between different states. The primary colors, red, green, and blue, were obtained in reflection on light irradiation and with thermal stability. Moreover, a multi‐switchable photodisplay was demonstrated using one of these chiral molecular switches.
A Stereoselective Switch: Enantiodivergent Approach to the Synthesis of Isoflavanones
Authors: Doran Robert , Carroll Michael P. , Akula Ramulu , Hogan Bryan F. , Martins Marta , Fanning Séamus , Guiry Patrick J.
Published: October 2014

A modular six‐step asymmetric synthesis of two naturally occurring and three non‐natural isoflavanones containing tertiary α‐aryl carbonyls is reported. This synthetic route, utilising a Pd‐catalyzed decarboxylative asymmetric protonation, produces isoflavanones in excellent enantioselectivities from 76–97 %. A switch in the sense of stereoinduction was observed when different H+ sources were employed, showing the first example of dual stereocontrol in an asymmetric protonation reaction. The first enantioselective synthesis of the naturally occurring isoflavanones sativanone and 3‐o‐methylviolanone has been accomplished.
Enantioselective Degradation of Metalaxyl in Grape, Tomato, and Rice Plants
Authors: Wang Meiyun , Hua Xiude , Zhang Qing , Yang Yu , Shi Haiyan , Wang Minghua
Published: October 2014

Absract

Enantioselective biodegradation of chiral pesticide metalaxyl in grape, tomato, and rice plants under field conditions were studied. Metalaxyl enantiomers were completely separated with a resolution (Rs) of 5.01 by high‐performance liquid chromatography (HPLC) based on a cellulose tris (3‐chloro‐4‐methyl phenyl carbamate) chiral column (Lux Cellulose‐2). Metalaxyl enantiomers from matrixes were extracted by acetonitrile and purged using Cleanert Alumina‐A solid phase extraction (SPE). The linearity, recovery, precision, sensitivity, and matrix effect of the method were assessed. The result showed that significant stereoselectivity occurred in grape, tomato, and rice plants. In grape, (+)‐S‐metalaxyl with a half‐life of 5.5 d degraded faster than (–)‐R‐metalaxyl with that of 6.9 d, and the enantiomer fraction (EF) value reached 0.37 at 21 d. The same enantioselectivity was observed in tomato, and the half‐life was 2.2 d for the S‐enantiomer and 3.0 d for the R‐enantiomer. The EF values decreased from 0.49 of 0 d to 0.26 of 14 d. On the other hand, a preferential degradation of the R‐form was found in rice plants, with an EF value of 0.70 at 14 d, and the corresponding half‐life was 2.3 d for the R‐form and 2.8 d for the S‐form. Chirality 27:109–114, 2015. © 2014 Wiley Periodicals, Inc.
Rheology of suspensions of solid particles in power‐law fluids
Authors: Pal Rajinder
Published: October 2014

The viscous behaviour of concentrated suspensions of solid particles in non‐Newtonian power‐law fluids is discussed here. After a brief review of the existing models, new models are presented for the constant shear‐rate relative viscosity of concentrated suspensions with power‐law matrices. To validate the models, experimental work is carried out on the rheology of suspensions of glass beads in aqueous polymer solution using a controlled stress rheometer. The volume fraction of particles is varied from 0 to 44.9 %. The experimentally measured flow curves of suspensions are described satisfactorily using the proposed models.
Comparison of different kinetic models for the chlorohydrin process using real data from an industrial tubular reactor
Authors: Petric Ivan , Husanović Amel
Published: October 2014

The main objective of this study was to investigate how different kinetic models for the chlorohydrin process can influence the simulation results. In order to accomplish this objective, a simplified reactor model was developed and applied on the kinetic models. The simulation results were compared with actual process data (three different data sets) from an industrial tubular reactor in order to find the most appropriate kinetic model as well as to validate the model. The results of numerical simulations showed good agreement with the measured actual values. The influences of the reactor length, the input flow temperature and the entering molar flows of components on the process performance were studied using the validated mathematical model. The maximum molar flow rate of propylene oxide was achieved with temperature of the entering reaction mixture of 57 °C. The reactor length, the input flow temperature and the molar flows of components have the strongest influence on overall selectivity of propylene oxide related to propylene glycol.
Drug Delivery to the Malaria Parasite Using an Arterolane‐Like Scaffold
Authors: Fontaine Shaun D. , Spangler Benjamin , Gut Jiri , Lauterwasser Erica M. W. , Rosenthal Philip J. , Renslo Adam R.
Published: October 2014

Antimalarial agents artemisinin and arterolane act via initial reduction of a peroxide bond in a process likely mediated by ferrous iron sources in the parasite. Here, we report the synthesis and antiplasmodial activity of arterolane‐like 1,2,4‐trioxolanes specifically designed to release a tethered drug species within the malaria parasite. Compared with our earlier drug delivery scaffolds, these new arterolane‐inspired systems are of significantly decreased molecular weight and possess superior metabolic stability. We describe an efficient, concise and scalable synthesis of the new systems, and demonstrate the use of the aminonucleoside antibiotic puromycin as a chemo/biomarker to validate successful drug release in live Plasmodium falciparum parasites. Together, the improved drug‐like properties, more efficient synthesis, and proof of concept using puromycin, suggests these new molecules as improved vehicles for targeted drug delivery to the malaria parasite.
Olfactory ensheathing cells are the main phagocytic cells that remove axon debris during early development of the olfactory system
Authors: Nazareth Lynnmaria , Lineburg Katie E. , Chuah Meng Inn , Tello Velasquez Johana , Chehrehasa Fatemeh , St John James A. , Ekberg Jenny A.K.
Published: October 2014

During development of the primary olfactory system, axon targeting is inaccurate and axons inappropriately project within the target layer or overproject into the deeper layers of the olfactory bulb. As a consequence there is considerable apoptosis of primary olfactory neurons during embryonic and postnatal development and axons of the degraded neurons need to be removed. Olfactory ensheathing cells (OECs) are the glia of the primary olfactory nerve and are known to phagocytose axon debris in the adult and postnatal animal. However, it is unclear when phagocytosis by OECs first commences. We investigated the onset of phagocytosis by OECs in the developing mouse olfactory system by utilizing two transgenic reporter lines: OMP‐ZsGreen mice which express bright green fluorescent protein in primary olfactory neurons, and S100β‐DsRed mice which express red fluorescent protein in OECs. In crosses of these mice, the fate of the degraded axon debris is easily visualized. We found evidence of axon degradation at embryonic day (E)13.5. Phagocytosis of the primary olfactory axon debris by OECs was first detected at E14.5. Phagocytosis of axon debris continued into the postnatal animal during the period when there was extensive mistargeting of olfactory axons. Macrophages were often present in close proximity to OECs but they contributed only a minor role to clearing the axon debris, even after widespread degeneration of olfactory neurons by unilateral bulbectomy and methimazole treatment. These results demonstrate that from early in embryonic development OECs are the primary phagocytic cells of the primary olfactory nerve. J. Comp. Neurol. 523:479–494, 2015. © 2014 Wiley Periodicals, Inc.
Self‐Assembly of Imidazolium‐Based Surfactants in Magnetic Room‐Temperature Ionic Liquids: Binary Mixtures
Authors: Klee Andreas , Prevost Sylvain , Gradzielski Michael
Published: October 2014

The phase behaviour of binary mixtures of ionic surfactants (1‐alkyl‐3‐imidazolium chloride, CnmimCl with n=14, 16 and 18) and imidazolium‐based ionic liquids (1‐alkyl‐3‐methylimidazolium tetrachloroferrate, CnmimFeCl4, with n=2 and 4) over a broad temperature range and the complete range of compositions is described. By using many complementary methods including differential scanning calorimetry (DSC), polarised microscopy, small‐angle neutron and X‐ray scattering (SANS/SAXS), and surface tension, the ability of this model system to support self‐assembly is described quantitatively and this behaviour is compared with common water systems. The existence of micelles swollen by the solvent can be deduced from SANS experiments and represent a possible model for aggregates, which has barely been considered for ionic‐liquid systems until now, and can be ascribed to the rather low solvophobicity of the surfactants. Our investigation shows that, in general, CnmimCl is a rather weak amphiphile in these ionic liquids. The amphiphilic strength increases systematically with the length of the alkyl chain, as seen from the phase behaviour, the critical micelle concentration, and also the level of definition of the aggregates formed.
Promotion of Selective Pathways in Isomerizing Functionalization of Plant Oils by Rigid Framework Substituents
Authors: Christl Josefine T. , Roesle Philipp , Stempfle Florian , Müller Gerhard , Caporaso Lucia , Cavallo Luigi , Mecking Stefan
Published: October 2014

The 1,2‐(CH2P(1‐adamantyl)2)2C6H4 (dadpx) coordinated palladium complex [(dadpx)Pd(OTf)2] (1) is a catalyst precursor for the isomerizing methoxycarbonylation of the internal double bond of methyl oleate, with an unprecedented selectivity (96 %) for the linear diester 1,19‐dimethyl nonadecanedioate. Rapid formation of the catalytically active solvent‐coordinated hydride species [(dadpx)PdH(MeOH)]+ (3‐MeOH) is evidenced by NMR spectroscopy, and further isolation and X‐ray crystal structure analysis of [(dadpx)PdH(PPh3)]+ (3‐PPh3). DFT calculations of key steps of the catalytic cycle unravel methanolysis as the decisive step for enhanced selectivity and the influence of the rigid adamantyl framework on this step by destabilization of transition states of unselective pathways.
Optimal Total Planning for Incinerator Plants in an Urban Area
Authors: Sugahara Hideo , Arai Kenta , Kamata Naoki , Kato Masakazu
Published: October 2014

This paper proposes optimal total planning for incinerator plants (IPs) in a typical urban area, which includes a method of determining the number of plants and the capacities of the IPs. Burnable municipal refuse is disposed of sanitarily by high‐temperature incineration at the IPs. At the same time, power generation from waste (PGW) is being performed at many IPs to recover energy. At present, the amount of energy generated by PGW is greater than that of wind power or photovoltaic power generation. However, PGW has a limited generation efficiency and low generation output due to the smaller capacity of IPs. To overcome the above weakness, highly efficient PGW is necessary with total integration and scaling up of IPs. Regarding total integration and scaling up, operation in larger areas is favorable from the point of view of refuse volume and collection. In the planning stage, both the cost of IPs and refuse collection, which is important for refuse disposal, should be taken into account comprehensively. Optimal total planing for IPs can be performed in two stages. First, the disposal capacity Gk of an IP versus the number of plants K is decided by constraints. Gk is about the same for all K because of maintenance and refuse collection, and is greater than 300 tons per day in steps of 100 tons per day. Gk should be decided not only by refuse volume but also by cessation of operation at plants due to maintenance or faults. Second, the cost of each value of K is calculated based on the construction and operating costs of the IPs, income from selling the energy of PGW, and refuse collection costs. Therefore, the value of K with the minimum cost is selected as the optimal number of IPs. A numerical simulation of an area with a population of 3 million indicates that the optimal plant number is 4. At present there are eight or nine IPs in cities of 3 million people. The above cost reduction effect will be about 15% from the present value. Considering the situation of aging IPs, a decreasing trend in refuse volume, and the stringent financial conditions of local governments, the proposed method is very effective and realistic.
On the Preparation and Structure of Caesium Aluminium Tetrahydride
Authors: Krech Daniel , Zibrowius Bodo , Weidenthaler Claudia , Felderhoff Michael
Published: October 2014

A new tetragonal phase of CsAlH4 was observed after the precipitation of CsAlH4 from a diglyme solution with an inert solvent. This new phase and the previously described orthorhombic phase were characterized by a combination of X‐ray powder diffraction analysis and 27Al and 133Cs solid‐state NMR spectroscopy. The transformation of the tetragonal CsAlH4 phase into the orthorhombic CsAlH4 phase can be induced by thermal treatment, whereas the opposite process can be stimulated by mechanical treatment. The phase transformation processes are almost completely reversible and can be performed several times without any observable decomposition of CsAlH4. The structure of the tetragonal CsAlH4 phase (space group I41/a) was solved from X‐ray powder diffraction data, and the lattice parameters were determined to be a = 5.6732(4) and c = 14.2795(11) Å.
Chiroptical Signatures of Planar and Central Chirality in [2]Paracyclo[2](5,8)quinolinophane Derivatives
Authors: Mazzeo Giuseppe , Longhi Giovanna , Abbate Sergio , Buonerba Federica , Ruzziconi Renzo
Published: October 2014

Electronic and vibrational circular dichroism (ECD and VCD) spectra and specific optical rotation measurements at the sodium D‐line (OR) have been taken for thirteen chiral [2]paracyclo[2](5,8)quinolinophane derivatives and calculated by density functional theory. Besides the planar chirality from the paracyclophane moiety in all molecules, some of the investigated compounds also exhibit central chirality due to an asymmetric carbon atom in the side‐chain bound at C‐2 of the heterocyclic ring. Characteristic bands for each type of chirality were clearly identified in the VCD spectra in the CH‐stretching and mid‐IR regions, allowing assignment of absolute and relative configurations. ECD was found to be sensitive mostly, if not exclusively, to planar chirality, whereas OR was also very sensitive to central chirality. Configurational assignment of the different diastereomers by the present method provided results that are in agreement with those inferred from NOE‐NMR experiments.
Sensitivity analysis to unsteady perturbations of complex flows: a discrete approach
Authors: Browne Oliver M. F. , Rubio Gonzalo , Ferrer Esteban , Valero Eusebio
Published: October 2014

A discrete framework for computing the global stability and sensitivity analysis to external perturbations for any set of partial differential equations is presented. In particular, a complex‐step approximation is used to achieve near analytical accuracy for the evaluation of the Jacobian matrix. Sensitivity maps for the sensitivity to base flow modifications and to a steady force are computed to identify regions of the flow field where an input could have a stabilising effect. Four test cases are presented: (1) an analytical test case to prove the theory of the discrete framework, (2) a lid‐driven cavity at low Reynolds case to show the improved accuracy in the calculation of the eigenvalues when using the complex‐step approximation, (3) the 2D flow past a circular cylinder at just below the critical Reynolds number used to validate the methodology, and finally, (4) the flow past an open cavity presented to give an example of the discrete method applied to a convectively unstable case. The latter three (2–4) of the aforementioned cases were solved with the 2D compressible Navier–Stokes equations using a Discontinuous Galerkin Spectral Element Method. Good agreement was obtained for the validation test case, (3), with appropriate results in the literature. Furthermore, it is shown that for the calculation of the direct and adjoint eigenmodes and their sensitivity maps to external perturbations, the use of complex variables is paramount for obtaining an accurate prediction. Copyright © 2014 John Wiley & Sons, Ltd.
Diagnostic transitions in mild cognitive impairment by use of simple Markov models
Authors: Facal David , Guàrdia‐Olmos Joan , Juncos‐Rabadán Onésimo
Published: October 2014

Background

Mild cognitive impairment (MCI) is a complex entity, which can involve persistence of the symptoms, conversion to dementia or improvement. The aim was to study the transitions between normal cognitive ageing and three MCI subtypes by using Markov transition models for different intervals between baseline and the follow‐up assessment.

Methods

A total of 294 participants over 50 years old attending primary care centres were assessed and diagnosed at baseline as multi‐domain amnestic MCI (22 participants), single domain amnestic MCI (44), non‐amnestic MCI (non‐amnestic MCI) (26) or controls (202). We adopted an overlapping interval strategy by constructing six different mid‐point time intervals according to the time between the baseline and the follow‐up assessment. We used Markov transition models to study diagnostic changes in the groups in the different time intervals

Results

The rate of change was lowest in the control group. In the single domain amnestic MCI and non‐amnestic MCI groups, the same diagnosis was usually retained or changed to normal cognitive functioning. In the multi‐domain amnestic MCI group, the rate of transition to normal functioning was lowest, and the conversion to dementia was the highest of all groups. The best fit to the Markov models was found for the period between 18–21 months, whereas the worst fit was for the period between 9–15 months

Conclusions

Markov models provide a comprehensive view of transitions between MCI and normal cognitive functioning. Time interval strategies seem to provide a good opportunity to monitor diagnostic transitions, although wider intervals including subsequent assessments are needed. The low rates of conversion to dementia are discussed. Copyright © 2014 John Wiley & Sons, Ltd.
Combining Matching and Nonparametric Instrumental Variable Estimation: Theory and An Application to the Evaluation of Active Labour Market Policies
Authors: Frölich Markus , Lechner Michael
Published: October 2014

We show how instrumental variable and matching estimators can be combined in order to identify a broader array of treatment effects. Instrumental variable (IV) estimators are known to estimate effects only for the compliers, representing a subset of the entire population. By combining IV with matching, we can estimate the treatment effects for the always‐ and never‐takers as well. Since in many cases these groups are the (endogenous) outcome of some assignment process, such estimates also help in judging the implications of such a selection process. In our application to the effects of participation in active labour market programmes in Switzerland, we find large and lasting positive employment effects for the compliers, whereas the effects for the always‐ and never‐participants are small. In addition, the compliers have worse employment outcomes without treatment than those who participate in the programme with or without the intervention under investigation. This suggests that the earlier assignment policy of the caseworkers was inefficient in that the always‐participants were neither those unemployed who would experience the highest expected treatment effects nor those unemployed who had the largest need for assistance. Copyright © 2014 John Wiley & Sons, Ltd.
COUNTERSPACES AND THE NARRATIVE IDENTITY WORK OF OFFENDER‐LABELED AFRICAN AMERICAN YOUTH
Authors: Case Andrew D. , Hunter Carla D.
Published: October 2014

Through narrative identity work, offender‐labeled African American youth craft positive self‐concepts in the face of denigrating societal messages about their personhood. While past research suggests narrative identity work is largely intrapersonal, recent theory posits that it may also arise through individuals’ participation in counterspaces. This 9‐month ethnography explored how a group of offender‐labeled African American youth engaged in narrative identity work through participation in an intervention program that functioned as a counterspace. Findings from observations and interviews suggest youth engaged in narrative identity work by interfacing with the program's unique belief system, and roles, resources, and relationships within the program. These findings highlight specific interpersonal/setting mechanisms that facilitate the narrative identity work of offender‐labeled African American youth, while suggesting important implications for intervening with this population.
TOWARD THE DEVELOPMENT OF A MEASURE OF SOCIOPOLITICAL CONSCIOUSNESS: LISTENING TO THE VOICES OF SALVADORAN YOUTH
Authors: Baker Alison M. , Brookins Craig C.
Published: October 2014

A mixed methods approach was used to explore dimensions of sociopolitical development of youth in El Salvador. Photovoice was used to engage 2 groups of adolescents from a rural village to document and discuss their community. Using previous theory and models of sociopolitical development as a guide, themes were identified to inform the development of a quantitative measure we call sociopolitical consciousness. New and preexisting items were combined to create a measure that reflected the themes from the qualitative data. The resulting measure was completed by 682 Salvadoran high school students across 3 different community contexts; 7 factors were subsequently identified representing both individual and collective dimensions of sociopolitical consciousness. The study demonstrates how a contextualized research process can facilitate a synergy between the emic and etic dimensions of sociopolitical development.
Multiresidue analysis of 59 nonallowed substances and other contaminants in cosmetics
Authors: Zhan Jia , Ni Mei‐lin , Zhao Hai‐ying , Ge Xiao‐ming , He Xiao‐yu , Yin Ju‐yi , Yu Xue‐jun , Fan Yuan‐mu , Huang Zhi‐qiang
Published: October 2014

A method was developed for the determination of 59 glucocorticoids, sex hormones, nonsteroidal anti‐inflammatory drugs, antibiotics, and other contaminants in cosmetics simultaneously by ultra high performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry. Acetonitrile was used to extract the sample, and the mixed sorbents were dispersed for purification. With the optimal conditions, the optimized pretreatment processes led to no significant interference on analysis from an extremely complicated sample matrix, and the linear ranges of 59 analytes were 0–480.0 μg/kg with the correlation coefficients above 0.99 and the limits of quantification (S/N≥10) were 5–40 μg/kg. Statistical evaluation revealed that the average recoveries were in the range of 61.2–131.2%, and relative standard deviations were in the range of 2.0–22.8%, meanwhile the interday precision ranged from 3.8 to 21.8%. This method is simple, fast, and credible, and it can be applied to simultaneous screening and determination of various classes of substances under investigations illegally presented in cosmetic products, covering a wide diversity of polarities, and pKa values.
Computational simulation and preparation of fluorescent magnetic molecularly imprinted silica nanospheres for ciprofloxacin or norfloxacin sensing
Authors: Gao Bo , He Xin‐Ping , Jiang Yang , Wei Jia‐Tong , Suo Hui , Zhao Chun
Published: October 2014

A magnetic molecularly imprinted fluorescent sensor for the sensitive and convenient determination of ciprofloxacin or norfloxacin in human urine was synthesized and characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X‐ray diffraction, ultraviolet/visible spectroscopy, and fluorescence spectroscopy. Both cadmium telluride quantum dots and ferroferric oxide nanoparticles are introduced into the polymer for the rapid separation and detection of the target molecules. The synthesized molecularly imprinted polymers were applied to detect ciprofloxacin or its structural analog norfloxacin in human urine with the detection limit 130 ng/mL. A computational study was developed to evaluate the template–monomer geometry and interaction energy in the polymerization mixture to determine the reaction molar ratio of the template and monomer molecules.
Thermally Reversible Self‐Assembly of Nanoparticles via Polymer Crystallization
Authors: Kinnear Calum , Balog Sandor , Rothen‐Rutishauser Barbara , Petri‐Fink Alke
Published: October 2014

The directed self‐assembly of gold nanoparticles through the crystallization of surface‐grafted polyethylene oxide (PEO) in ethanol–water mixtures is described. This process is fully reversible and tunable through either the size of the core or the polymeric coating. Characterization by X‐ray scattering and electron microscopy of the self‐assembled structures reveals order at the nanoscale, typically not the case for thermoresponsive gold nanoparticles coated with lower or upper critical solution temperature polymers. A further novelty is the result of selective binding of calcium ions to the PEO in the fluid state: a reversible thermoresponsive transition become irreversible.

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Association of Medicare Part D Low‐Income Cost Subsidy Program Enrollment with Increased Fill Adherence to Clopidogrel After Coronary Stent Placement
Authors: Duru O. Kenrik , Edgington Sarah , Mangione Carol , Turk Norman , Tseng Chi‐Hong , Kimbro Lindsay , Ettner Susan
Published: October 2014

Study Objective

To determine the association between enrollment in the Medicare Part D low‐income subsidy (LIS) program, which reduces out‐of‐pocket medication costs, and fill adherence to the antiplatelet drug clopidogrel after coronary stent placement.

Design

Retrospective cohort study.

Data Source

Pharmacy claims database of a large national Medicare Part D insurer.

Patients

We selected a total of 2967 beneficiaries of a national Medicare Part D plan who had a coronary stent placed between April and December 2006 and were prescribed clopidogrel but were not preexisting users of clopidogrel. Of these patients, 504 were enrolled in the LIS program and 2463 were not.

Measurements and Main Results

We defined LIS status as enrollment in the LIS program at any point during the 12 months after the procedure. We examined the association between LIS status and good medication fill adherence to clopidogrel, defined as proportion of days covered of 80% or more, or discontinuation of clopidogrel over the 12‐month window starting from the date of their stent placement. We also identified patients with claims‐based diagnoses of major bleeding events while taking clopidogrel. For those patients, we calculated fill adherence only for the period between medication initiation and the onset of major bleeding and/or did not classify them as having inappropriately discontinued the medication. We created a propensity score predicting the propensity of being eligible for the LIS benefit and used inverse propensity score weighting with regression adjustment to generate estimates of the effect parameters. LIS enrollment was associated with a higher predicted likelihood of good clopidogrel fill adherence after stent placement (54.8% for LIS enrollees vs 47.6% for nonenrollees; p=0.008). No significant difference was noted between the two groups in predicted risk of discontinuing clopidogrel after stent placement (18.3% for LIS enrollees vs 21.0% for nonenrollees; p=0.21).

Conclusion

The LIS benefit was associated with better clopidogrel fill adherence after stent placement. Although clopidogrel is now available in generic form, our work underscores the need for efforts to identify and enroll patients in the LIS benefit who require costly antiplatelet medications for coronary heart disease.
Autism spectrum disorder: An omics perspective
Authors: Woods Alisa G. , Wormwood Kelly L. , Wetie Armand G. Ngounou , Aslebagh Roshanak , Crimmins Bernard S. , Holsen Thomas M. , Darie Costel C.
Published: October 2014

Current directions in autism spectrum disorder (ASD) research may require moving beyond genetic analysis alone, based on the complexity of the disorder, heterogeneity and convergence of genetic alterations at the cellular/functional level. Mass spectrometry (MS) has been increasingly used to study CNS disorders, including ASDs. Proteomic research using MS is directed at understanding endogenous protein changes that occur in ASD. This review focuses on how MS has been used to study ASDs, with particular focus on proteomic analysis. Other neurodevelopmental disorders have been investigated using MS, including fragile X syndrome (FXS) and Smith‐Lemli‐Opitz Syndrome (SLOS), genetic syndromes highly associated with ASD comorbidity.
Microstructural Refinement and Mechanical Properties of High‐Speed Niobium‐Microalloyed Railway Wheel Steel
Authors: Wu Si , Li Xiu‐Cheng , Zhang Juan , Shang Cheng‐jia , Misra Raja Devesh Kumar
Published: October 2014

The relationship between microstructure and mechanical properties was studied in a Nb‐bearing high‐speed railway wheel steel and compared with a traditional low‐alloyed medium carbon steel. The microstructure of medium carbon steel comprised of ferrite and pearlite and the percentage of ferrite was increased from 4 to 24% on the addition of 0.06 wt% Nb and the grain size was refined. The addition of Nb inhibited mixed microstructure and delayed the coarsening temperature of austenite grains from 880 to 960 °C. The yield strength of Nb‐bearing steel was increased from 385 to 455 MPa and the Charpy v‐notch energy at −20 °C was increased from 7.0 to 19.0 J with no apparent reduction in tensile strength. Niobium formulates grain refinement and transformation of austenite to ferrite and pearlite over a wide region of cooling rate (<10 °C s−1) and temperature range (530–690 °C) in the medium carbon steel. With the calculation of Thermal‐Calc software and solid solubility formula, Nb exists in the form of precipitates. The grain refining and precipitation strengthening are roles of niobium in promoting ferrite–pearlite transformation and improve toughness in the medium carbon steel.
Physicochemical, crystalline, and thermal properties of native and enzyme hydrolyzed Pueraria lobata (Willd.) Ohwi and Pueraria thomsonii Benth. starches
Authors: Xia Yuzhuo , Gao Wenyuan , Jiang Qianqian , Li Xia , Huang Luqi , Xiao Peigen
Published: October 2014

Starches isolated from the bulbs of Pueraria lobata (Willd.) Ohwi (PLO) and Pueraria thomsonii Benth. (PTB) were hydrolysed by glucoamylase for different lengths of time (2, 4, 8, 12, and 24 h). The hydrolysis results were compared by scanning electron microscope (SEM), X‐ray power diffractometer (XRD), and differential scanning calorimetry (DSC). The SEM results revealed that both of the PLO and PTB starches showed the same hydrolysis mechanism, which indicated that the glucoamylase primarily attacking the exterior of starch granules and then the interior. The results of XRD revealed the crystalline type of PTB starch changed from C‐type to A‐type with crystallinity reducing from 43.5 to 20.9% during the hydrolysis. Unlike PTB starch, the PLO starch did not show marked changes in crystalline style but lower degree of crystallinity was obtained from 32.4 to 13.7% during the hydrolysis. All the XRD results demonstrated that B‐type polymorph was preferentially degraded than A‐type polymorph in the C‐type starch. The DSC results revealed that both of the PLO and PTB starches showed decreased enthalpy of gelatinization (ΔHgel) and gelatinization temperature range (R)‐value after hydrolysis, while the gelatinization temperature (Tp) indicated different tendency, initially ranging from 68.6 to 64.3°C and then increasing to 67.8°C for PLO starch. While for PTB starch, the Tp‐value showed progressive reduction from 85.4 to 74.3°C during the whole process.
Hydrolysis of native and cross‐linked corn, tapioca, and sweet potato starches at sub‐gelatinization temperature using a mixture of amylolytic enzymes
Authors: Yussof Nor Shariffa , Utra Uthumporn , Alias Abd Karim
Published: October 2014

The objectives of this research were to investigate the capability of a new hydrolyzing enzyme to hydrolyze native and cross‐linked starches in the granular state and to examine the influence of cross‐linking on hydrolysis. Corn, tapioca, and sweet potato starches were chemically modified by cross‐linking with 1% epichlorohydrin. The native and cross‐linked starches were subjected to hydrolysis using a new commercial enzyme, STARGEN™ 001 (a blend of α‐amylase and glucoamylase), at 35°C for 24 h, and the physicochemical properties of the starches were determined at different time points. After hydrolysis, the dextrose equivalent (DE) values of corn and tapioca starch decreased significantly after being cross‐linked (from 52.5 to 48.8% and from 35.7 to 27.9%, respectively). However, the sweet potato starch underwent a minimal reduction in DE value (from 27.3 to 26.8%). Scanning electron micrographs revealed that all cross‐linked starches had less porous granules compared to native starches after being hydrolyzed. Enzymatic erosion occurred mainly on the surface of starch granules, and the pores deepened into the interior part of the granules. The swelling power and solubility of all three cross‐linked starch decreased significantly after hydrolysis. Cross‐linking had a greater effect on pasting properties but little influence on the gelatinization properties of starch. The pasting temperature of cross‐linked tapioca starch was undetectable due to high degree of cross‐linking (92.4%). This study showed that cross‐linking had a considerable impact on the hydrolysis of corn and tapioca starch in particular by reducing the swelling power and solubility of its granules.
Effects of moisture content on structural and dielectric properties of cassava starch films
Authors: Bergo Paulo , Moraes Isabel C. Freitas , Sobral Paulo J. do Amaral
Published: October 2014

In this work, it was evaluated the effect of moisture content on the structural and dielectric properties of cassava starch films by means of Fourier Transform infrared spectroscopy (FTIR), impedancimetric, and gravimetric analysis. The film samples were equilibrated in hermetically sealed desiccators, containing different saturated salts in water in order to promote activity of water between 0.11 and 0.85. The position and amplitude of the peaks in the “fingerprint” region of the FTIR spectra were changed due to the modifications in the interactions between the polymeric chains and water molecules. These effects may be related to the formation of semi‐crystalline regions in the film structure. The dielectric properties of the films were also strongly dependent on the moisture content, showing a non‐linear and a linear region, which was attributed to the domain of bound and free water in the film, respectively. The gravimetric analyzes showed the typical sigmoidal behavior, attributed to the way the water interacts with the biopolymer. Finally, the flexibility of the films increased with water content increasing.
Novel use of Acacia senegal (Super Gum™) and Anogeisus latifolia (Gatifolia SD) as functional ingredients in extruded snack products: Their role in manipulating product characteristics and modulating the potential glycaemic response of snack foods
Authors: Brennan Margaret A. , Derbyshire Emma , Tiwari Brijesh K. , Phillips Glyn O. , Ogasawara Takeshi , Brennan Charles S.
Published: October 2014

Acacia senegal (in the form of Super Gum™) and Anogeissus latifolia (in the form of gum Gatifolia SD) were used in the manufacture of ready to eat extruded cereal snack products. Inclusions rates were 0, 5, 10 and 15% w/w replacement levels for wheat flour from a control recipe. The inclusion of Super Gum™ and Gatifolia increased product expansion and reduced product density compared to a cereal flour based control snack product. Inclusion of the gum materials also decreased the hardness of the snack products whilst increasing the crispiness of the product (number of fracture peaks recorded during axial compression of samples). Glucose area under the curve (AUC) measurements obtained using in vitro digestion procedures illustrated that the potential glucose release of snack products was reduced by more than 30% by the inclusion of Gatifolia and Super Gum™ at 15% w/w compared to the control sample. Such a reduction in potential glucose release was not dose responsive. These results illustrate a potential nutritional benefit of the utilisation of Gatifolia and Super Gum™ in the ready to eat snack food sector of the food industry.