bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Residual Water and Microwave Heating on the Half‐Life of the Reagents and Reactive Intermediates in Peptide Synthesis
Authors: Pernille Tofteng A. , Pedersen Søren L. , Staerk Dan , Jensen Knud J.
Published: June 2012

Precise microwave heating has changed the way many small molecules are being synthesized and, currently, the field of solid‐phase peptide synthesis is undergoing dramatic changes owing to the use of microwave heating. To fully reap the benefits of precise microwave heating for the formation of amide bonds in peptide synthesis, it is important to understand the kinetics of formation and break‐down of activated esters and their N‐acylation of the nascent peptide chain at elevated temperatures. Herein, we present systematic studies of, first, the rate of formation of activated esters by NMR spectroscopy and, second, their N‐acylation during peptide synthesis. A study of the amount of residual water in the solvents revealed a significant effect on electrophilic reagents and intermediates. This observation was expanded into a general study of microwave heating in peptide synthesis.
H2 Production by Renewables Photoreforming on Pt–Au/TiO2 Catalysts Activated by Reduction
Authors: Gallo Alessandro , Montini Tiziano , Marelli Marcello , Minguzzi Alessandro , Gombac Valentina , Psaro Rinaldo , Fornasiero Paolo , Dal Santo Vladimiro
Published: June 2012

Bimetallic Pt–Au nanoparticles supported on reduced anatase nanocrystals represent a new class of promising photocatalysts with high activity in hydrogen production by photoreforming of aqueous solution of renewable feedstock, such as ethanol and glycerol. The catalysts are easily obtained by metal impregnation of commercial TiO2, followed by a reductive treatment. Remarkably, deeper catalyst pre‐reduction results in enhanced photoactivity. When ethanol is used as sacrificial agent, under both UV‐A or simulated sunlight irradiation, H2 is the most abundant product in the gas stream whereas, in the case of glycerol, significant amounts of CO2 have also been detected, indicating a more efficient oxidation of the organic sacrificial agent. The presence of bimetallic Pt–Au nanoparticles and of Ti3+ sites/O2− vacancies in the bulk structure of titania are two key parameters to maximize light absorption and feedstock activation, finally resulting in good photocatalytic performances.
Trophic resources and emergent food web attributes in rivers of the Lake Victoria Basin: a review with reference to anthropogenic influences
Authors: Masese Frank O. , McClain Michael E.
Published: June 2012

The ecology of Lake Victoria and rivers draining its 180 000 km2 basin has changed over the past century in response to growing anthropogenic influences that have altered basal resources, trophic status and interactions and river flow regimes. Impacts on the ecology of the lake are well known, but little attention has focused on the ecological status of rivers supplying ecological services to the majority of the basin's over 30 million inhabitants. In this paper, we review existing research on the ecological status of streams and rivers in the Lake Victoria Basin (LVB) and evaluate how they fit into emerging models of riverine ecosystem function in the tropics. Studies to date indicate that allochthonous sources dominate inputs to food webs in forested headwaters and savanna mid‐reaches of rivers in the LVB, although transfer pathways vary with position in the river. Although riparian vegetation phenology and hydrologic run‐off pathways control the spatial and temporal fluxes of energy inputs in headwater streams; animals play increasingly important roles in savanna mid‐reaches. Over the last half century, food web studies have revealed widespread omnivory and a tendency toward increased omnivory among fishes whose diets were more specialized prior to the introduction of Lates niloticus and the ecological changes in the lake. Ecological patterns and processes in LVB rivers generally fit emerging models for the tropics, but studies completed to‐date do not find autotrophic energy sources to be important. The findings of this review highlight the importance of specific management actions and needs for future research. Copyright © 2012 John Wiley & Sons, Ltd.
Tetrathiafulvalene‐Type Electron Donors Bearing Biimidazole Moieties: Multifunctional Units with Hydrogen Bonding Abilities
Authors: Murata Tsuyoshi , Nakasuji Kazuhiro , Morita Yasushi
Published: June 2012

New tetrathiafulvalene (TTF)‐based electron‐donor molecules having 4,4′‐ and 2,2′‐biimidazole units (1 and 2, respectively) as hydrogen bonding units were designed and synthesized. Cyclic voltammetry showed that both 1 and 2 possess strong electron‐donating abilities close to that of TTF with two‐stage reversible redox processes. In the crystal structure of 1, uniform π stacking, side‐by‐side S···S interactions of the TTF moiety, and multiple hydrogen bonds of the biimidazole unit via crystalline water molecules contribute to the formation of a two‐dimensional donor layer. The crystal structure of 2 was constructed by one‐dimensional ribbons formed by complementary hydrogen bonds characteristic to 2,2′‐biimidazole and side‐by‐side S···S interactions on the TTF moiety. In the charge‐transfer salt of 2 with iodine, which included the (I82–)n one‐dimensional comb‐like structure as the anion part, the N–H···I hydrogen bond anchored the donor molecule in the cavity of the (I82–)n chain. Complex formation of 1 and 2 with tetracyanoquinodimethane afforded mixed‐valence charge‐transfer complexes showing semiconducting behaviors (room temperature conductivities = 10–3 and 10–1 S cm–1, respectively).
THE DYNAMICS OF MEDICAL CARE USE IN THE BRITISH HOUSEHOLD PANEL SURVEY
Authors: Kohn Jennifer L. , Liu Jing Shi
Published: June 2012

We explore whether medical care use is persistent over a long panel using 18 waves of the British Household Panel Survey. Of particular interest is high medical care use because a few high users account for a disproportionate amount of use while many individuals use no medical care in a given year. If health is a primary driver of medical care demand, and we control for health, then past medical care use should be uninformative for future use. However, we find that conditional on health, other covariates and unobservable heterogeneity, medical care use remains significantly persistent. “No use” and “high use” are more strongly persistent, and persistence is generally stronger for women, those in poor health, and at older ages. We find that unobservable heterogeneity explains between 10% and 25% of the variation in medical care use. This heterogeneity is significantly correlated with both medical care use and health over our long panel. These findings have implications for the econometric modeling of medical care demand and suggest that policies aimed to reduce aggregate medical care spending by improving health, particularly the health of seniors, may be less effective than projected using static models. Copyright © 2012 John Wiley & Sons, Ltd.
Identifying challenges and barriers in the delivery of primary healthcare at the district level: a study in one Thai province
Authors: Tejativaddhana Phudit , Briggs David , Fraser John , Minichiello Victor , Cruickshank Mary
Published: June 2012

In 2001, the universal health coverage policy was adopted by Thailand with primary healthcare (PHC) as the major focus of the policy. In order to understand the structural and institutional factors affecting the implementation of PHC in rural Thailand, a qualitative study, utilising individual interviews with national and provincial policy decision makers, community health directors, heads of hospital primary care units, chiefs of district health offices, heads of health centres and community representatives, from one rural province was undertaken. Findings showed that the sustainability of PHC service provision under the administration of community hospitals is problematic as barriers exist at the policy and operational levels and access to PHC for all citizens may not be achieved until these barriers are addressed. Furthermore, although PHC needs to be acknowledged and implemented by all stakeholders within the health industry and government, the roles and responsibilities of the stakeholders in health services management at the district level need to be clarified. Copyright © 2012 John Wiley & Sons, Ltd.
Prediction of hydrocarbon enthalpies of formation by various thermochemical schemes
Authors: Wilson Brent R. , DeYonker Nathan J. , Wilson Angela K.
Published: June 2012

The correlation consistent composite approach (ccCA) has been used to compute the enthalpies of formation (ΔHf′s) for 60 closed‐shell, neutral hydrocarbon molecules selected from an established set (Cioslowski et al., J. Chem. Phys. 2000, 113, 9377). This set of thermodynamic values includes ΔHf's for hydrocarbons that span a range of molecular sizes, degrees of aromaticity, and geometrical configurations, and, as such, provides a rigorous assessment of ccCA's applicability to a variety of hydrocarbons. The ΔHf's were calculated via atomization energies, isodesmic reactions, and hypohomodesmotic reactions. In addition, for 12 of the aromatic molecules in the set that are larger than benzene, the energies of ring‐conserved isodesmic reactions were used to calculate the ΔHf′s. Using an atomization energy approach to determine the ΔHf′s, the lowest mean absolute deviation (MAD) from experiment achieved by ccCA for the 60 hydrocarbons was 1.10 kcal mol−1. The use of the mixed Gaussian/inverse exponential complete basis set extrapolation scheme (ccCA‐P) in conjunction with hypohomodesmotic reaction energies resulted in a MAD of 0.87 kcal mol−1. This value is compared with MADs of 1.17, 1.18, and 1.28 kcal mol−1 obtained via the Gaussian‐4 (G4), Gaussian‐3 (G3), and Gaussian‐3(MP2) [G3(MP2)] methods, respectively (using the hypohomodesmotic reactions). © 2012 Wiley Periodicals, Inc.
Towards high resolution membrane‐based pharmaceutical separations
Authors: Vanneste Johan , Ormerod Dominic , Theys Gert , Van Gool Dennis , Van Camp Bart , Darvishmanesh Siavash , Van der Bruggen Bart
Published: June 2012

BACKGROUND

In this work the possibility of using membrane cascades to carry out difficult pharmaceutical separations was explored. The effect of configuration on process yield, time and cost was studied for a challenging industrial separation: the separation of an intermediate I (MW 221 g mol−1) from an impurity, ethylene bromide (MW 188 g mol−1).

RESULTS

All cascade configurations studied were capable of increasing the purity from a fairly low value, namely 26% to the 90% requirement. The results from the cascade modeling showed that the product yield effectively increased from 35.5% to 84.3% by adding two stages. From a cost analysis of a kilo scale plant it was derived that a two‐stage cascade with large area modules yielded the smallest total cost of € 515 082. A 7.0% decrease in cost of product loss or a 7.6% increase in membrane skid cost rendered a single stage economically optimal despite the low product yields. However, if at least six other separations with a comparable process time are carried out each year, then even three stages become economically optimal.

CONCLUSION

High resolution separations are technically feasible with membrane cascades. The economic viability of membrane cascades increases dramatically with the cost of the product and the utilization of the equipment. Copyright © 2012 Society of Chemical Industry
A Combined Logarithmic Bound on the Chromatic Index of Multigraphs
Authors: Plantholt* Michael
Published: June 2012

For a multigraph G, the integer round‐up of the fractional chromatic index provides a good general lower bound for the chromatic index . For an upper bound, Kahn 1996 showed that for any real there exists a positive integer N so that whenever . We show that for any multigraph G with order n and at least one edge, ). This gives the following natural generalization of Kahn's result: for any positive reals , there exists a positive integer N so that + c whenever . We also compare the upper bound found here to other leading upper bounds.
Parallel MR imaging
Authors: Deshmane Anagha , Gulani Vikas , Griswold Mark A. , Seiberlich Nicole
Published: June 2012

Parallel imaging is a robust method for accelerating the acquisition of magnetic resonance imaging (MRI) data, and has made possible many new applications of MR imaging. Parallel imaging works by acquiring a reduced amount of k‐space data with an array of receiver coils. These undersampled data can be acquired more quickly, but the undersampling leads to aliased images. One of several parallel imaging algorithms can then be used to reconstruct artifact‐free images from either the aliased images (SENSE‐type reconstruction) or from the undersampled data (GRAPPA‐type reconstruction). The advantages of parallel imaging in a clinical setting include faster image acquisition, which can be used, for instance, to shorten breath‐hold times resulting in fewer motion‐corrupted examinations. In this article the basic concepts behind parallel imaging are introduced. The relationship between undersampling and aliasing is discussed and two commonly used parallel imaging methods, SENSE and GRAPPA, are explained in detail. Examples of artifacts arising from parallel imaging are shown and ways to detect and mitigate these artifacts are described. Finally, several current applications of parallel imaging are presented and recent advancements and promising research in parallel imaging are briefly reviewed. J. Magn. Reson. Imaging 2012;36:55–72. © 2012 Wiley Periodicals, Inc.
The influence of Indian Ocean sea surface temperature on the variability of monsoon rainfall over India
Authors: Nayagam Lorna R. , Rajesh J. , Ram Mohan H. S.
Published: June 2012

This study focuses on the spatial and temporal variability of southwest monsoon (SWM) and northeast monsoon (NEM) rainfall over India, after the 1976–1977 regime shift. Through wavelet analysis the dominant mode of variability in the SWM and NEM rainfall is found to be in the 2–8‐year scale (ENSO band). Therefore, scale‐averaged wavelet power (SAP) of SWM (SAPSWM) and NEM (SAPNEM) rainfall obtained from a high‐resolution dataset for the period 1977–2001 was subjected to empirical orthogonal function analysis, in order to understand the homogenous regions of rainfall variability. As the study utilizes SAP, the decadal variability is observed in the spatial and temporal patterns of rainfall. The maximum variability of SAPSWM rainfall is found to be in the 2–4‐year period, whereas, for the SAPNEM rainfall, the biennial mode explains the variability over the core region of NEM rainfall. Significant power is also observed in the 4‐year period. The evolution of the principal components (PCs) is consistent with the above/below normal rainfall received over the region. Similar analysis has been carried out also for the SAP of monthly sea surface temperature (SAPSST) over Indian Ocean for the months from January to September. Compared with any other month, the decadal changes of the PCs of SAPSWM and SAPNEM rainfall are highly correlated with the decadal variations of PC1 of SAPSST for the month of March. Therefore, the relation between the rainfall and SST was explained using SAPSST for the month of March. Significant biennial power is also observed in March SST over southeast Indian Ocean (85–110°E and 5–40°S) after the climate shift of 1976. In order to identify any change in the relation between NEM rainfall and SAPSST (March) before and after 1976, a correlation between NEM rainfall and PC1 of SAPSST (March) was found for the period 1951–1975 and 1977–2001. Results show that correlation has increased after 1976. Therefore, this PC can be made use of in the prediction of NEM rainfall. Copyright © 2012 Royal Meteorological Society
Optimization of the geopotential heights information used in a rainfall‐based weather patterns classification over Austria
Authors: Brigode Pierre , Bernardara Pietro , Gailhard Joel , Garavaglia Federico , Ribstein Pierre , Merz Ralf
Published: June 2012

Classifications of atmospheric circulation patterns are useful tools to improve the description of the climate of a given region and the analysis of meteorological situations. In particular, weather pattern (WP) classifications could be used to improve the description of spatial heavy rainfall. Here, a bottom‐up approach, previously used to build WP classification in France, is applied for the definition of a WP classification useful for the description of Austrian heavy rainfall. The optimal spatial extent and the optimal position of the geopotential fields to be taken into account for a WP classification is studied. The proposed WP classification is shown to be coherent with the general knowledge on synoptic situations responsible for heavy rainfall over Austria. Moreover, the classification has good performances in terms of heavy rainfall spatial description compared to 152 COST 733 classifications defined in the same region. In particular, we show that the choice of spatial extent of the geopotential fields, their position and their characteristics is relevant for capturing physical information on synoptic situations responsible for heavy rainfall and that it can improve WP classification performances. Copyright © 2012 Royal Meteorological Society
Rotator cuff tear reduces muscle fiber specific force production and induces macrophage accumulation and autophagy
Authors: Gumucio Jonathan P. , Davis Max E. , Bradley Joshua R. , Stafford Patrick L. , Schiffman Corey J. , Lynch Evan B. , Claflin Dennis R. , Bedi Asheesh , Mendias Christopher L.
Published: June 2012

Full‐thickness tears to the rotator cuff can cause severe pain and disability. Untreated tears progress in size and are associated with muscle atrophy and an infiltration of fat to the area, a condition known as “fatty degeneration.” To improve the treatment of rotator cuff tears, a greater understanding of the changes in the contractile properties of muscle fibers and the molecular regulation of fatty degeneration is essential. Using a rat model of rotator cuff injury, we measured the force generating capacity of individual muscle fibers and determined changes in muscle fiber type distribution that develop after a full thickness rotator cuff tear. We also measured the expression of mRNA and miRNA transcripts involved in muscle atrophy, lipid accumulation, and matrix synthesis. We hypothesized that a decrease in specific force of rotator cuff muscle fibers, an accumulation of type IIb fibers, and an upregulation in fibrogenic, adipogenic, and inflammatory gene expression occur in torn rotator cuff muscles. Thirty days following rotator cuff tear, we observed a reduction in muscle fiber force production, an induction of fibrogenic, adipogenic, and autophagocytic mRNA and miRNA molecules, and a dramatic accumulation of macrophages in areas of fat accumulation. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1963–1970, 2012
The kinematics and stability of single‐radius versus multi‐radius femoral components related to Mid‐range instability after TKA
Authors: Stoddard James E. , Deehan David J. , Bull Anthony M.J. , McCaskie Andrew W. , Amis Andrew A.
Published: June 2012

There continues to be some dissatisfaction with the function of total knee arthroplasties (TKA). “Mid‐range instability” has been linked to multi‐radius femoral components allowing transient ligament slackness and instability during knee flexion. Single‐radius designs have been introduced to avoid this. We compared the kinematics and stability of eight natural knees versus multi‐radius and single‐radius TKAs in vitro. The loading conditions imposed across the range of active knee extension were anterior–posterior drawer forces, internal–external rotation torques, and varus–valgus moments. Significant differences were not found between the biomechanical behavior of the two TKAs. Both were significantly different from the natural knee in allowing greater anterior drawer laxity near extension, probably caused by excision of the anterior cruciate ligament, but no difference occurred beyond 30° flexion. No differences were found for any of the other degrees‐of‐freedom of movement. A geometric analysis suggested that the multi‐radius design may tense the MCL more than the single‐radius in mid‐flexion, contrary to expectation. These kinematic and stability tests did not find mid‐range instability of the knees, and so they could not demonstrate enhanced mid‐range stability of the single‐radius TKA over the older multi‐radius implant. This suggests that mid‐range instability may relate to unrecognized ligament laxity during surgery, rather than being inherent to a specific feature of implant design. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31:53–58, 2012
Age‐related changes in gap junctional intercellular communication in osteoblastic cells
Authors: Genetos Damian C. , Zhou Zhiyi , Li Zhongyong , Donahue Henry J.
Published: June 2012

Aging demonstrates deleterious effects upon the skeleton which can predispose an individual to osteoporosis and related fractures. Despite the well‐documented evidence that aging decreases bone formation, there remains little understanding whereby cellular aging alters skeletal homeostasis. We, and others, have previously demonstrated that gap junctions—membrane‐spanning channels that allow direct cell‐to‐cell conductance of small signaling molecules—are critically involved in osteoblast differentiation and skeletal homeostasis. We examined whether the capacity of rat osteoblastic cells to form gap junctions and respond to known modulators of gap junction intercellular communication (GJIC) was dependent on the age of the animal from which they were isolated. We observed no effect of age upon osteoblastic Cx43 mRNA, protein or GJIC. We also examined age‐related changes in PTH‐stimulated GJIC. PTH demonstrated age‐dependent effects upon GJIC: Osteoblastic cells from young rats increased GJIC in response to PTH, whereas there was no change in GJIC in response to PTH in osteoblastic cells from mature or old rats. PTH‐stimulated GJIC occurred independently of changes in Cx43 mRNA or protein expression. Cholera toxin significantly increased GJIC in osteoblastic cells from young rats compared to those from mature and old rats. These data demonstrate an age‐related impairment in the capacity of osteoblastic cells to generate functional gap junctions in response to PTH, and suggest that an age‐related defect in G protein‐coupled adenylate cyclase activity at least partially contributes to decreased PTH‐stimulated GJIC. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1979–1984, 2012
First steps in the development of a psychological test on the effects of food on mental well‐being
Authors: Geier Uwe , Hermann Ina , Mittag Kathrin , Buchecker Kirsten
Published: June 2012

How do you feel after drinking milk or soy milk? The aim of this preliminary study was to find out if it is possible to measure the psychological effects of staple food items using a consumer test (according to DIN 10974), assessing the mental state of the participants. Results of two tests with dairy products and non‐dairy milk substitutes, two vegetable tests, and two tests with bakery products are presented and discussed in the context of the further development of a standardized and validated test to measure the effects of food on the human mental state. Copyright © 2012 Society of Chemical Industry
The Depletion of Substituted Phenolic Stabilizers by Conjugate C‐Addition to Acrylic Monomers in Multicomponent Systems
Authors: Pavlinec Juraj , Kleinová Angela , Moszner Norbert
Published: June 2012

The depletion of selected substituted phenol stabilizers from systems simulating self‐etching dental adhesives is studied. If the adhesive monomer is an acrylate derivative, the stabilizer disappears quickly. Experimental results support the hypothesis that the phenol stabilizers are depleted from the system via a non‐radical reaction with the acrylic double bond in addition to the free‐radical mechanism. The C‐conjugate addition of aryloxide anions to the acrylate double bonds (the Michael reaction) is proposed as the reaction mechanism. The rate of the acid‐catalyzed Michael addition between acrylate monomers and phenolic stabilizers depends on the strength of the acidic catalyst.

magnified image
Estimating Kinetic Parameters for the Spontaneous Polymerization of Glycidol at Elevated Temperatures
Authors: Weiss Maximilian E. R. , Paulus Florian , Steinhilber Dirk , Nikitin Anatoly N. , Haag Rainer , Schütte Christof
Published: June 2012

The ring‐opening polymerization of glycidol at elevated temperatures is investigated. To improve the synthesis of dendritic polyether polyols, experiments are carried out without initiator to identify the influence of thermal side reactions. This results in a step‐growth polymerization caused by the spontaneous combination of monomers. Kinetic parameters of the side reactions are estimated by fitting simulated number‐ and weight‐average molecular weights to the experimental values measured at different reaction times during the polymerization. The reactions are conducted at three different temperatures of 90, 105, and 120 °C. It is shown that thermal side reactions lead to high dispersities of the final product and are highly sensitive to the reactor operating temperature.

magnified image
Nonlinear wave equations of carrier type on manifolds
Authors: Antunes Gladson , Lopez Ivo F. , da Silva Maria Darci G. , Araújo Geraldo M.
Published: June 2012

In this paper, we investigate the existence and uniqueness of a solution for differential equations of the carrier type on lateral boundary Σ of the cylinder Q, cf. (1). The main point is to transform this initial value problem into a differential operator equation of the type , cf. (6). The operator is defined in Section 2, and it acts in Sobolev spaces on Γ, boundary of Ω. The initial value problem (6) is investigated in Section 3 by the method of Faedo–Galerkin. Thus, we obtain the existence of a weak solution for (6), and in Section 4, we prove its uniqueness. Copyright © 2012 John Wiley & Sons, Ltd.
Impairment of tumor‐initiating stem‐like property and reversal of epithelial–mesenchymal transdifferentiation in head and neck cancer by resveratrol treatment
Authors: Hu Fang‐Wei , Tsai Lo‐Lin , Yu Chuan‐Hang , Chen Pei‐Ni , Chou Ming‐Yung , Yu Cheng‐Chia
Published: June 2012

Scope

Recent reports have demonstrated that head and neck cancer‐derived tumor‐initiating cells (HNC‐TICs) presented high tumorigenic, chemoradioresistant, metastatic properties, and were coupled with gain of epithelial–mesenchymal transition (EMT) characteristics. The aim of this study was to investigate the chemotherapeutic effect and regulatory mechanisms of resveratrol on HNC‐TICs.

Methods and results

We first observed that the treatment of resveratrol significantly downregulated the ALDH1 activity and CD44 positivity of head and neck cancer (HNC) cells in a dose‐dependent manner (p < 0.05). Moreover, resveratrol treatment reduced self‐renewal property and stemness genes signatures (Oct4, Nanog, and Nestin) expression in sphere‐forming HNC‐TICs. Additionally, the repressive effect of resveratrol on in vitro malignant properties including invasiveness/anchorage‐independent growth was mediated by regulating productions of EMT markers Slug, ZEB1, N‐cadherin, E‐cadherin, and Vimentin. Importantly, an in vivo nude mice model showed that resveratrol treatment to xenograft tumors by oral gavage reduced tumor growth, stemness, and EMT markers in vivo. Lastly, synergistic effect of resveratrol and conventional chemotreatment attenuated tumor‐initiating cells property in HNC‐TICs.

Conclusions

Our results demonstrated that resveratrol would be a valuable therapeutics clinically in combination with conventional chemotherapy treatment modalities for malignant HNCs by elimination of tumor‐initiating stem‐like and EMT properties.
NMR spectroscopic characterization of new 2,3‐dihydro‐1,3,4‐thiadiazole derivatives
Authors: Carrión M. Dora , López‐Cara Luisa C. , Chayah Mariem , Choquesillo‐Lazarte Duane , Gallo Miguel A. , Espinosa Antonio , Entrena Antonio , Camacho M. Encarnación
Published: June 2012

The 1H and 13C NMR resonances of twenty‐seven 2,2‐dimethyl‐5‐(2‐nitrophenyl‐5‐substituted)‐2,3‐dihydro‐1,3,4‐thiadiazoles, and twenty‐seven 3‐acyl‐5‐(2‐amino‐5‐substituted)‐2,2‐dimethyl‐2,3‐dihydro‐1,3,4‐thiadiazoles were assigned completely using the concerted application of one‐dimensional and two‐dimensional experiments (DEPT, HMQC and HMBC). NOESY experiments, X‐ray crystallography and conformational analysis confirm the preferred conformation of these compounds. Copyright © 2012 John Wiley & Sons, Ltd.
A combined FIC‐TDG finite element approach for the numerical solution of coupled advection–diffusion–reaction equations with application to a bioregulatory model for bone fracture healing
Authors: Sapotnick A. , Nackenhorst U.
Published: June 2012

Numerical schemes for the approximative solution of advection–diffusion–reaction equations are often flawed because of spurious oscillations, caused by steep gradients or dominant advection or reaction. In addition, for strong coupled nonlinear processes, which may be described by a set of hyperbolic PDEs, established time stepping schemes lack either accuracy or stability to provide a reliable solution. In this contribution, an advanced numerical scheme for this class of problems is suggested by combining sophisticated stabilization techniques, namely the finite calculus (FIC‐FEM) scheme introduced by Oñate et al. with time‐discontinuous Galerkin (TDG) methods. Whereas the former one provides a stabilization technique for the numerical treatment of steep gradients for advection‐dominated problems, the latter ensures reliable solutions with regard to the temporal evolution. A brief theoretical outline on the superior behavior of both approaches will be presented and underlined with related computational tests. The performance of the suggested FIC‐TDG finite element approach will be discussed exemplarily on a bioregulatory model for bone fracture healing proposed by Geris et al., which consists of at least 12 coupled hyperbolic evolution equations. Copyright © 2012 John Wiley & Sons, Ltd.
Topology optimization of MEMS considering etching uncertainties using the level‐set method
Authors: Jang Gang‐Won , van Dijk Nico P. , van Keulen Fred
Published: June 2012

Because of the specific fabrication process of microsystems, the geometric uncertainties are relatively large compared with the size of the structures. However, the performance of microstructures is very sensitive to these uncertainties especially when slender structural members are included in the design. This paper presents a level‐set‐based topology optimization method for robust microelectromechanical systems. The presented method focuses on the effects of geometric uncertainties on the performance of microelectromechanical systems in the topology optimization. The geometric uncertainties arising from the etching process are treated as bounded‐but‐unknown uncertainties. This approach can be used to obtain designs with optimal performance for the worst‐case. The etching uncertainties can be conveniently included in topology optimization using the level‐set method. The signed distance property of the level‐set function allows easy construction of under‐etched and over‐etched structures. Therefore, models with variable etching‐induced uncertainties can be easily constructed. The effectiveness of the proposed approach is demonstrated using benchmark problems including compliance minimization and compliant‐mechanism design problems. Although the reinitialization scheme used to maintain the signed‐distance property can cause problems in the optimization process, this effect is limited using an approximate Heaviside function with a relatively large bandwidth. Copyright © 2012 John Wiley & Sons, Ltd.
Adaptive atomistic‐to‐continuum modeling of propagating defects
Authors: Moseley Philip , Oswald Jay , Belytschko Ted
Published: June 2012

An adaptive atomistic‐to‐continuum method is presented for modeling the propagation of material defects. This method extends the bridging domain method to allow the atomic domain to dynamically conform to the evolving defect regions during a simulation, without introducing spurious oscillations and without requiring mesh refinement. The atomic domain expands as defects approach the bridging domain method coupling domain by fine graining nearby finite elements into equivalent atomistic subdomains. Additional algorithms coarse grain portions of the atomic domain to the continuum scale, reducing the degrees of freedom, when the atomic displacements in a subdomain can be approximated by FEM or extended FEM elements to within a certain homogeneity tolerance. The extended FEM approximations are created by fitting the broken inter‐atomic bonds of fractured surfaces and dislocation slip planes. Because atomic degrees of freedom are maintained only where needed for each timestep, the solution retains the advantages of multiscale modeling, with a reduced computational cost compared with other multiscale methods. Copyright © 2012 John Wiley & Sons, Ltd.
A fast method for binary programming using first‐order derivatives, with application to topology optimization with buckling constraints
Authors: Browne P. A. , Budd C. , Gould N. I. M. , Kim H. A. , Scott J. A.
Published: June 2012

We present a method for finding solutions of large‐scale binary programming problems where the calculation of derivatives is very expensive. We then apply this method to a topology optimization problem of weight minimization subject to compliance and buckling constraints. We derive an analytic expression for the derivative of the stress stiffness matrix with respect to the density of an element in the finite‐element setting. Results are presented for a number of two‐dimensional test problems.Copyright © 2012 John Wiley & Sons, Ltd.
Outcomes of fetuses with small head circumference on second‐trimester ultrasonography
Authors: Deloison Benjamin , Chalouhi Gihad E. , Bernard Jean‐Pierre , Ville Yves , Salomon Laurent J.
Published: June 2012

Objective

We examined the outcomes of pregnancies in which the fetal head circumference (HC) was below the 5th centile at the routine second‐trimester scan.

Materials and Methods

We retrospectively analysed outcomes of 18 377 women according to HC Z scores at second‐trimester ultrasound examination between 2001 and 2008. We collected all major malformations, intrauterine deaths and other abnormal outcomes.

Results

Six hundred seventy‐four fetuses (3.7%) had an HC below the 5th centile. Twenty‐one major malformations were noted, consisting mainly of neurological abnormalities (3.1%). There were seven intra uterine fetal death (1.3%). Of all the fetuses, 26% were lost to follow‐up. Outcome and neurological development was normal in 467 cases, based on neonatal examination and/or parent or general practitioner reports. Major abnormalities were noted in respectively 26.2%, 3.0% and 1.1% of fetuses with Z scores < −2.5, ‐2.5 to −2.0, and −2 to −1.645, compared with 0.3% of fetuses with normal HC (p < 10–4).

Conclusion

A head circumference below the 5th centile at second‐trimester scan is associated with various abnormalities, especially neurological disorders. The outcome was worse when the HC was smaller. An HC Z score below −2.5 was strongly associated with neurological and chromosomal abnormalities. Conversely, an HC Z score below −1.645 but above −2, excluding cases with prenatally diagnosed malformations, seems to be reassuring for favorable neonatal outcome. © 2012 John Wiley & Sons, Ltd.
Latest Advances in Psychiatry XI: from personality disorders to schizophrenia
Authors: Laight Katherine
Published: June 2012

Personalised medicine in psychiatry: from diagnosis to treatment was the theme of this year's Latest Advances in Psychiatry symposium, held in London in March and, as usual, the meeting was a resounding success.
Doctors' understanding of antipsychotic associated hyperprolactinaemia
Authors: Walsh James , Lees Emma
Published: June 2012

Hyperprolactinaemia secondary to antipsychotic use is associated with numerous shortand long‐term side‐effects. Unfortunately, there is some concern that clinicians tend to underestimate these side‐effects and also fail to fully inform patients or monitor them adequately. In view of these concerns, we carried out a survey to assess psychiatrists' and trainees' knowledge and practice regarding hyperprolactinaemia associated with antipsychotic use.
Synthesis and photovoltaic properties of conjugated side chains polymers with different electron‐withdrawing and donating end groups
Authors: Gu Zhaojie , Deng Lijun , Luo Hao , Guo Xia , Li Haohao , Cao Zhencai , Liu Xunshan , Li Xinwei , Huang Hongyan , Tan Yingzi , Pei Yong , Tan Songting
Published: June 2012

A series of novel low band gap polymers containing conjugated side chains with 4,7‐dithien‐5‐yl‐2,1,3‐benzodiathiazole and different electron‐withdrawing end groups of aldehyde (PT‐DTBTCHO), 2‐ethylhexyl cyanoacetate (PT‐DTBTCN), 1,3‐diethyl‐2‐thiobarbituric acid (PT‐DTBTDT), and electron‐donating end group of 2‐methylthiophene (PT‐DTBTMT) have been designed and synthesized. All polymers exhibit good solubility in common organic solvents, film‐forming ability, and thermal stability. These conjugated polymers show the broad ultraviolet‐visible absorption and the narrow optical band gaps in the range of 1.65–1.90 eV. Through changing the end group of conjugated side chains, the photophysical properties and energy levels of the polymers were tuned effectively. Bulk heterojunction solar cells based on the blend of these polymers and (6,6)‐phenyl‐C61‐butyric acid methyl ester (PC61BM) reached the best power conversion efficiency (PCE) of 2.72%. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Synthesis and characterization of electrophosphorescent jacketed conjugated polymers
Authors: Zhang Wei , Jin Hao , Zhou Feng , Shen Zhihao , Zou Dechun , Fan Xinghe
Published: June 2012

A monomer containing bent side chains with oxadiazole unit was synthesized. And it was copolymerized with polyfluorene at different ratios. The photophysical and electrochemical properties of the copolymers were characterized. The results show that the introduction of the oxidiazole‐containing side chains into the polymer reduces the lowest unoccupied molecular orbital level. And the steric hindrance of the side groups can effectively suppress the aggregation of the polymer backbones. Electroluminescent devices were fabricated with a configuration of indium tin oxide (ITO)/poly(3,4‐ethylenedioxythiophene (PEDOT):PSS/Sample/Ca/Al. All of the devices emit blue light. The device of the copolymer PFOXD50 shows the best performance with the maximum luminance of 1033 cd/m2 and the maximum current efficiency of 0.29 cd/A. Then a cyclometalated iridium complex monomer (ppy)2Ir(BrPhPyBr) was copolymerized with PFOXD50 at different ratios. The devices with the same configuration emit orange light. The efficiency generally increases with the increasing Ir content. Among them, the device of the copolymer PFOXDIr7 shows the best performance with the maximum luminance of 846 cd/m2 and the maximum current efficiency of 0.61 cd/A. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Combined Resistance and Aerobic Exercise is Better than Resistance Training Alone to Improve Functional Performance of Haemodialysis Patients — Results of a Randomized Controlled Trial
Authors: Orcy Rafael B , Dias Pamela S , Seus Thamires LC , Barcellos Franklin C , Bohlke Maristela
Published: June 2012

Background and Purpose

This study aims to compare the effects of combined resistance and aerobic exercise with a resistance programme alone on functional performance among haemodialysis patients.

Design

The design was a randomized controlled trial.

Setting

The setting was the dialysis unit of a Brazilian university hospital.

Patients

Haemodialysis patients were assigned to one kind of intervention or another.

Intervention

The patients were assigned to receive the resistance exercise combined with an aerobic training or to maintain an ongoing resistance programme alone for a period of 10 weeks.

Main outcome measure

The functional performance of patients was assessed before and after the intervention through the 6‐minute walk test (6MWT). The difference over time of the 6MWT was compared between the groups through two‐way repeated‐measures ANOVA.

Results

Thirteen patients were allocated for each group of intervention. The difference in distance walked before and after intervention in the combined training group was of +39.7 ± 61.4 m, and the difference in the resistance training group was of −19.2 ± 53.9 m, p = 0.02.

Conclusions

Although the best protocol of exercise for patients on dialysis is not yet clear, in our sample of haemodialysis patients the combination of aerobic and resistance training was more effective than resistance training alone to improve functional performance. Copyright © 2012 John Wiley & Sons, Ltd.
Comprehensive quantitative measurement of folate polyglutamates in human erythrocytes by ion pairing ultra‐performance liquid chromatography/tandem mass spectrometry
Authors: van Haandel Leon , Becker Mara L. , Williams Todd. D. , Stobaugh John F. , Leeder J. Steven
Published: June 2012

RATIONALE

The erythrocyte folate pool is reflective of an individual's long‐term folate status; however, comprehensive quantitative determination of the various folate isoforms including polyglutamation (Glun) status has posed an analytical problem. Factors complicating such analysis are the absence of authentic (isotope‐labeled) standards and the large number of potential analytes. The present work presents high‐throughput analytical methodology for the indirect comprehensive quantitation of the erythrocyte folate pool with commercially available standards.

METHODS

The erythrocyte folate pool was determined comprehensively by utilizing a cascade of three complementary ultra‐performance liquid chromatography (UPLC) tandem mass spectrometry (MS/MS) assays. In a first assay utilizing ion‐pairing UPLC/MS/MS the relative (%) polyglutamation distribution (Glu3‐10) of 5‐methyltetrahydrofolate, tetrahydrofolate and 5‐formyltetrahydrofolate is determined in a thermal extract obtained from packed erythrocytes, not requiring analytical standards. Quantitation of the erythrocyte folate pool was accomplished by performing two additional stable isotope dilution UPLC/MS/MS assays to determine whole blood and plasma folate content, utilizing commercially available [13C5]‐labeled analogs of the Glu1 analytes. Based on the values provided by each individual assay the comprehensive erythrocyte folate content could be calculated.

RESULTS

The various assays have been validated for intra‐ and inter‐run precision, accuracy, linearity and are robust. The method was sensitive enough to measure the comprehensive erythrocyte folate distribution in a Down's syndrome patient with extremely low folate, bearing the C677T mutation in the gene encoding for methylenetetrahydrofolate reductase.

CONCLUSIONS

The erythrocyte folate pool can be comprehensively quantitated by running three complementary UPLC/MS/MS assays. The present assays are robust and allow for high‐throughput analysis. The method can be utilized to support larger investigations that investigate the relationship between folate isoform and polyglutamation distribution and disease pathogenesis. Copyright © 2012 John Wiley & Sons, Ltd.
Synthesis of Anionic Spin Crossover Complexes with Schiff Base like Ligands
Authors: Schlamp Stephan , Schulten Johanna , Betz Richard , Bauch Tobias , Mudring Anja Verena , Weber Birgit
Published: June 2012

The reaction of neutral iron(II) complexes of tetradentate Schiff base like ligands with the pseudohalogenides SCN–, OCN–, and CN– as monodentate axial ligands was investigated. In solution the formation of octahedral complexes could be confirmed and it was possible to follow a spin transition by T‐dependent 1H NMR spectroscopy. In the solid only pentacoordinate complexes were obtained and the X‐ray structure of five monoanionic pentacoordinate iron(II) complexes and an interesting trinuclear complex are discussed.
Successful Fusion of the Proximal Tibiofibular Joint with Osteogenic Protein-1 (OP-1) Augmentation
Authors: Delos Demetris , Schneidkraut Jason , Rodeo Scott
Published: June 2012

Proximal tibiofibular joint (PTFJ) instability is rare, but when encountered can be difficult to manage. Previously reported forms of treatment, including cast immobilization, soft tissue repairs and reconstructions, and fibular head resection have met with limited success. Another option is PTFJ arthrodesis—however, fusion can be difficult and ankle pain after surgery is not uncommon. In this report, we present a novel surgical technique used to treat PTFJ instability. It is a form of PTFJ arthrodesis that utilizes the osteoinductive agent recombinant human osteogenic protein (rhOP-1) to help achieve fusion, in conjunction with a fibular osteotomy to unload the PTFJ and to preserve normal rotator mobility of the distal fibula during ankle motion. We have used this technique in two patients with successful results; one of whom required revision after two previous failed attempts at PTFJ fusion and the other who had a previous diagnosis of underlying collagen disorder. Their case studies are presented in detail in this report.
What We Hope, What We Fear, What We Expect: Possible Scenarios for the Future of the Eurozone
Authors: Kunstein Tobias , Wessels Wolfgang
Published: June 2012

Financial, economic and sovereign debt crises have called into question macro-economic and monetary integration in Europe in general, and the future of the eurozone in particular. It is possible that even the future of the European Union (EU) as a whole is at stake. Starting with the reforms of European economic governance hitherto agreed, this article develops three scenarios for the eurozone and explores their possible impact on the EU in general. The mix of procedures, both inside and outside the EU legislative framework and with varying groups of participants, offers a starting point for the emergence of an ‘Optimal Institutional Architecture’.
WNT‐3a modulates platelet function by regulating small GTPase activity
Authors: Steele Brian M. , Harper Matthew T. , Smolenski Albert P. , Alkazemi Naheda , Poole Alastair W. , Fitzgerald Desmond J. , Maguire Patricia B.
Published: June 2012

DVL
and
DAAM‐1
colocalise by fluorescence microscopy (View interaction)
Traumatic Mallet Toe of the Hallux in a Paediatric Patient: A Case Report
Authors: Jason Chow , Alvin Pun , Richard Freihaut
Published: June 2012

We describe a case of traumatic avulsion fracture of the distal phalanx of the hallux in a paediatric patient. The patient had a Salter Harris type III fracture of the distal phalanx with 40% of the articular cartilage involved and a clinical extension lag. We treated the injury nonoperatively with applying a fibreglass dorsiflexion interphalangeal plaster for 6 weeks. An excellent outcome was achieved with normal range of interphalangeal motion and solid painless union of fracture at 12 weeks.