bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamic analysis of strain localization in water‐saturated clay using a cyclic elasto‐viscoplastic model
Authors: Shahbodagh Khan B. , Mirjalili M. , Kimoto S. , Oka F.
Published: October 2013

A computational framework is presented for dynamic strain localization and deformation analyses of water‐saturated clay by using a cyclic elasto‐viscoplastic constitutive model. In the model, the nonlinear kinematic hardening rule and softening due to the structural degradation of soil particles are considered. In order to appropriately simulate the large deformation phenomenon in strain localization analysis, the dynamic finite element formulation for a two‐phase mixture is derived in the updated Lagrangian framework. The shear band development is shown through the distributions of viscoplastic shear strain, the axial strain, the mean effective stress, and the pore water pressure in a normally consolidated clay specimen. From the local stress–strain relations, more brittleness is found inside the shear bands than outside of them. The effects of partially drained conditions and mesh‐size dependency on the shear banding are also investigated. The effect of a partially drained boundary is found to be insignificant on the dynamic shear band propagation because of the rapid rate of applied loading and low permeability of the clay. Using the finer mesh results in slightly narrower shear bands; nonetheless, the results manifest convergency through the mesh refinement in terms of the overall shape of shear banding and stress–strain relations. Copyright © 2013 John Wiley & Sons, Ltd.
Modeling progressive failures in rock slopes with non‐persistent joints using the numerical manifold method
Authors: An Xinmei , Ning Youjun , Ma Guowei , He Lei
Published: October 2013

Rock slope failure is a complex process that usually involves both opening/sliding along pre‐existing discontinuities as well as fracturing of intact rock bridges. Discontinuity persistence is an important factor governing rock slope instabilities. However, traditional slope failure analysis assumes persistent discontinuities, and rock slope fails along a predefined persistent continuous potential failure surface because of the limitations of the analysis tools. This paper proposes the numerical manifold method (NMM) incorporated with a Mohr–Coulomb criterion‐based fracturing algorithm to simulate the progressive failure of rock slopes with non‐persistent joints. Detailed fracturing algorithm is first presented. Then, the NMM enabling fracturing is calibrated through simulating an edge‐cracked plate and the Brazilian test. Lastly, the developed code is applied to investigate the failure process of rock slopes involving non‐persistent joints. Numerical results indicate that the proposed method can capture the opening/sliding along existing discontinuities, the fracturing in intact rock bridges and the final kinematic release. Progressive slope failure is well exhibited. Copyright © 2013 John Wiley & Sons, Ltd.
Bounding surface SANICLAY plasticity model for cyclic clay behavior
Authors: Seidalinov Gaziz , Taiebat Mahdi
Published: October 2013

Natural clays are anisotropic in their in situ state and have an undisturbed shear strength in excess of the remolded strength. In addition, most of the structures founded on clay deposits must be designed to withstand cyclic loads such as earthquakes or ocean waves. When subjected to cyclic loadings, clay exhibits complex response. A realistic modeling of clay response under irregular loading requires an appropriate description of the stress‐strain relationship. This paper extends the formulation of a Simple ANIsotropic CLAY plasticity (SANICLAY) model by incorporation of a bounding surface formulation for simulation of clay response under cyclic loading. The most important elements of the proposed formulation are incorporation of bounding surface plasticity concept with proper repositioning of the projection center and adoption of a new damage parameter. These have led to significantly improved simulation of clay response in cyclic loading. The model is developed with the aim of maintaining the simplicity and yet including an adequate level of sophistication for successful modeling of the key features of clay response. The formulation is presented in detail followed by validation of the model demonstrating its capabilities in capturing a number of important characteristic features of clay response in cyclic loading. Copyright © 2013 John Wiley & Sons, Ltd.
Fast algorithms for convex cost flow problems on circles, lines, and trees
Authors: Orlin James B. , Vaidyanathan Balachandran
Published: October 2013

We develop efficient algorithms to solve convex cost flow problems where the underlying graph is a circle, a line, or a tree. Each node i has an associated supply/demand b( i). The cost of sending flow on arc ( i, j) is a piecewise linear convex function fij defined over . Let n be the number of nodes and m = O(n) be the total number of pieces of all the convex functions. A flow x is feasible if the imbalances on all nodes are nonnegative. Excess stored on node i has an associated linear cost . We show that the problem on a circle can be transformed into an equivalent problem on a line in O( n) time. Thereafter, we develop an algorithm that solves the problem on a line in time, where sort( n) is the time to sort n real numbers and is the inverse Ackermann function. We also prove that when the nodes lie on a tree, the problem can be solved in time using the dynamic tree data structure. We describe applications in areas such as distributed computing, lot‐sizing, computational biology, computational music, and transportation. © 2013 Wiley Periodicals, Inc. NETWORKS, Vol. 62(4), 288–296 2013
The multi‐commodity pickup‐and‐delivery traveling salesman problem
Authors: Hernández‐Pérez Hipólito , Salazar‐González Juan‐José
Published: October 2013

Abstract–

The “multi‐commodity Pickup‐and‐Delivery Traveling Salesman Problem” (m‐PDTSP) is a generalization of the well‐known “Traveling Salesman Problem” in which cities correspond to customers providing or requiring known amounts of m different products, and the vehicle has a known capacity. Each customer must be visited exactly once by the vehicle serving the demands of the different products while minimizing the total travel distance. It is assumed that a unit of a product collected from a customer can be supplied to any other customer that requires this product. We introduce a mixed integer linear programming model for the m‐PDTSP, discuss a classical decomposition technique, describe valid inequalities to strengthen the linear programming relaxation of the model, and detail separation procedures to develop a branch‐and‐cut procedure. Computational experiments on randomly generated instances with up to 30 customers, three products, and small vehicle capacities are analyzed. © 2013 Wiley Periodicals, Inc. NETWORKS, Vol. 63(1), 46–59 2014
A template‐based adaptive large neighborhood search for the consistent vehicle routing problem
Authors: Kovacs Attila A. , Parragh Sophie N. , Hartl Richard F.
Published: October 2013

Abstract–

The importance of customer satisfaction was identified by many industries as a key factor of competitive advantage. So, for companies in the small package shipping industry, it can be reasonable to increase the service quality even at the expense of transportation cost to gain customer loyalty. These companies noticed that customer satisfaction can be increased by providing consistent service in the form of visiting customers with the same driver at approximately the same time of the day over a certain time period. Motivated by this real‐world problem, the consistent vehicle routing problem (ConVRP) combines traditional vehicle routing constraints with the requirements for service consistency. This article presents a fast solution method called template‐based adaptive large neighborhood search for the described problem. Compared to state‐of‐the‐art heuristics, the developed algorithm is highly competitive on the available benchmark instances. Additionally, new test instances are provided. These seem to be more challenging due to the variation of different model parameters and consequently help to identify interesting effects. Finally, a relaxed variant of the original ConVRP is presented. In this variant, the departure times from the depot can be delayed to adjust the service times of the customers. Experiments show that allowing later departure times considerably improves the solution quality under tight consistency requirements. © 2013 Wiley Periodicals, Inc. NETWORKS, Vol. 63(1), 60–81 2014
Finding least fuel emission paths in a network with time‐varying speeds
Authors: Qian Jiani , Eglese Richard
Published: October 2013

Abstract–

This article considers the problem of finding a route and schedule for a vehicle starting from a depot, visiting a set of customers, and returning to the depot, in a time‐dependent network where the objective is to minimize the greenhouse gas emissions. In this formulation, the speeds of the vehicle as well as the routes chosen are decision variables subject to limits determined by the level of congestion on the roads at the time. Two methods are proposed to find the optimal strategy for a single route. One is a time‐increment‐based dynamic programming method, and the other is a new heuristic approach. In addition, a case study is carried out, which compares the performances of these methods, as well as the least polluting routes with the shortest time routes between two customer nodes. © 2013 Wiley Periodicals, Inc. NETWORKS, Vol. 63(1), 96–106 2014
Solving the close‐enough arc routing problem
Authors: Hà Minh Hoàng , Bostel Nathalie , Langevin André , Rousseau Louis‐Martin
Published: October 2013

The close‐enough arc routing problem has an interesting real‐life application to routing for meter reading. In this article, we propose a new mathematical formulation for this problem. We analyze our formulation and compare it with two formulations in the literature. We also develop branch‐and‐cut algorithms to solve the problem to optimality. We present computational results for instances based on three types of graphs: directed, undirected, and mixed. Copyright © 2013 Wiley Periodicals, Inc. NETWORKS, Vol. 63(1),
107–118 2014
Branch‐and‐cut algorithms for the vehicle routing problem with trailers and transshipments
Authors: Drexl Michael
Published: October 2013

This article studies the vehicle routing problem with trailers and transshipments (VRPTT), a practically relevant, but challenging, generalization of the classical vehicle routing problem. The article makes three contributions: (i) Building on a nontrivial network representation, two mixed‐integer programming formulations for the VRPTT are proposed. (ii) Based on these formulations, five different branch‐and‐cut algorithms are developed and implemented. (iii) The computational behavior of the algorithms is analyzed in an extensive computational study, using a large number of test instances designed to resemble real‐world VRPTTs.Copyright © 2013 Wiley Periodicals, Inc. NETWORKS, Vol. 63(1), 119–133 2014
Forty years of periodic vehicle routing
Authors: Campbell Ann Melissa , Wilson Jill Hardin
Published: October 2013

The periodic vehicle routing problem (PVRP) first appeared in 1974 in a paper about garbage collection (Beltrami and Bodin, Networks 4 (1974), 65–74). The wide applicability and versatility of the problem has led to a vast body of literature addressing both novel applications and solution methods. This article discusses the wide array of circumstances and settings in which the PVRP has been applied and describes the development of solution methods, both exact and heuristic, for the PVRP. As with many core research problems, many variants have been proposed. We will describe additional problem variants and extensions, as well as discuss the future of research for the PVRP. © 2013 Wiley Periodicals, Inc. NETWORKS, Vol. 63(1), 2–15 2014
The dispatching problem on multitrack territories: Heuristic approaches based on mixed integer linear programming
Authors: Boccia Maurizio , Mannino Carlo , Vasilyev Igor
Published: October 2013

Trains running through railway lines often accumulate some delay. When this happens, rescheduling and rerouting decisions must be quickly taken in real time. Despite the fact that even a single wrong decision may deteriorate the performance of the whole railway network, this complex optimization task is still basically performed by human operators. In very recent years, the interest of train operators to implement automated decision systems has grown. Not incidentally, the railway application section (RAS) of INFORMS has issued a challenge devoted to this problem concomitantly with the INFORMS Annual Meeting 2012. In this article, we describe two heuristic approaches to solve the RAS problem based on a mixed integer linear programming formulation, and we report computational results on the three RAS instances and on an additional set of instances defined on a more congested network. Computational results on the challenge test bed show that our algorithms positively compare with other approaches to the RAS problem. © 2013 Wiley Periodicals, Inc. NETWORKS, Vol. 62(4), 315–326 2013
Incomplete service and split deliveries in a routing problem with profits
Authors: Archetti Claudia , Bianchessi Nicola , Speranza M. Grazia , Hertz Alain
Published: October 2013

In this article, we study a variant of the capacitated team orienteering problem, that is the problem where a fleet of vehicles, each with a constraint on the time available, is given to serve profitable customers with the objective of maximizing the collected profit. We study the variant where customers may be only partially served (incomplete service) and, if beneficial, also by more than one vehicle (split deliveries). We will analyze the maximum theoretical increase of the profit due to the incomplete service and to the split deliveries. We also computationally measure such increase on a set of instances, by means of an exact algorithm on small/medium size instances and of two heuristics on instances of larger size. © 2013 Wiley Periodicals, Inc. NETWORKS, Vol. 63(2), 135–145 2014
Local discontinuous galerkin approximation of convection‐dominated diffusion optimal control problems with control constraints
Authors: Zhou Zhaojie , Yu Xiaoming , Yan Ningning
Published: October 2013

In this article, we investigate local discontinuous Galerkin approximation of stationary convection‐dominated diffusion optimal control problems with distributed control constraints. The state variable and adjoint state variable are approximated by piecewise linear polynomials without continuity requirement, whereas the control variable is discretized by variational discretization concept. The discrete first‐order optimality condition is derived. We show that optimization and discretization are commutative for the local discontinuous Galerkin approximation. Because the solutions to convection‐dominated diffusion equations often admit interior or boundary layers, residual type a posteriori error estimate in L2 norm is proved, which can be used to guide mesh refinement. Finally, numerical examples are presented to illustrate the theoretical findings. © 2013 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 30: 339–360, 2014
How to use published complete case results from weight loss studies in a missing data sensitivity analysis
Authors: Cresswell Lynne , Mander Adrian P.
Published: October 2013

Objective

In randomized controlled trials of weight loss interventions, high dropout rates are a problem resulting in a large amount of missing outcome data. It is common for participants with missing data to be excluded from analysis (complete‐case analysis). The aim of this article is to demonstrate how published complete‐case results can be used to explore how study results would change depending on assumptions about dropout weight loss.

Methods

The methods are based on three extensions to a method for obtaining baseline observation carried forward (BOCF) results from complete‐case results. The first extension is a generalization to any dropout weight loss. Second, to show that it is not necessary to assume that dropout weight loss is the same in each treatment arm. Third, to show that variation in dropout weight loss can be incorporated. Using these extensions, sensitivity analyses to the missing data can be conducted via the use of plots.

Results

The methods are demonstrated using two examples of published results from studies of weight loss interventions. It is also shown how the BOCF method could be useful to meta‐analysts.

Conclusion

By using simple plots, readers can explore how different assumptions about dropout weight loss affect the results of published weight loss trials.
Obesity bias in training: Attitudes, beliefs, and observations among advanced trainees in professional health disciplines
Authors: Puhl Rebecca M. , Luedicke Joerg , Grilo Carlos M.
Published: October 2013

Objective

This study examined weight bias among students training in health disciplines and its associations with their perceptions about treating patients with obesity, causes of obesity, and observations of weight bias by instructors and peers.

Methods

Students (N = 107) enrolled in a post‐graduate health discipline (Physician Associate, Clinical Psychology, Psychiatric Residency) completed anonymous questionnaires to assess the above variables.

Results

Students reported that patients with obesity are a common target of negative attitudes and derogatory humor by peers (63%), health‐care providers (65%), and instructors (40%). Although 80% of students felt confident to treat obesity, many reported that patients with obesity lack motivation to make changes (33%), lead to feelings of frustration (36%), and are non‐compliant with treatment (36%). Students with higher weight bias expressed greater frustration in these areas. The effect of students' weight bias on expectations for treatment compliance of patients with obesity was partially mediated by beliefs that obesity is caused by behavioral factors.

Conclusions

Weight bias is commonly observed by students in health disciplines, who themselves report frustrations and stereotypes about treating patients with obesity. These findings contribute new knowledge about weight bias among students and provide several targets for medical training and education.
Lower NLRP3 inflammasome activity in NAG‐1 transgenic mice is linked to a resistance to obesity and increased insulin sensitivity
Authors: Wang Xingya , Chrysovergis Kali , Kosak Justin , Eling Thomas E.
Published: October 2013

Objective

The NLRP3 inflammasome plays an important regulatory role in obesity‐induced insulin resistance. NSAID activated gene‐1 (NAG‐1) is a divergent member of the TGF‐β superfamily. NAG‐1 Tg mice are resistant to dietary‐ and genetic‐induced obesity and have improved insulin sensitivity. The objective was to examine whether NLRP3 inflammasome activity is associated with this observed phenotype in NAG‐1 Tg mice.

Methods

Key components of the NLRP3 inflammasome were examined in NAG‐1 Tg mice on both regular and high fat diet (HFD) conditions.

Results

The expression of caspase‐1 and ASC, key components of the NLRP3 inflammasome, is significantly reduced at mRNA and protein levels in white adipose tissue (WAT) of NAG‐1 Tg mice. HFD increases the expression of caspase‐1 and ASC in WT mice, but their expression is reduced in NAG‐1 Tg mice. Furthermore, there is reduced IL‐18, IL‐1β, and TNF‐α expression in the WAT of NAG‐1 Tg mice. NAG‐1 Tg mice have significantly lower serum leptin and insulin levels and reduced expression of macrophage infiltration markers (F4/80, CD11b, and CD11c) in WAT.

Conclusions

The study suggests the lower NLRP3 inflammasome activity may play a role in the resistance of NAG‐1 Tg mice to diet‐induced obesity and improved insulin sensitivity.
Associations of maternal pre‐pregnancy and gestational body size with offspring longitudinal change in BMI
Authors: Lawrence Gabriella M. , Shulman Shani , Friedlander Yechiel , Sitlani Colleen M. , Burger Ayala , Savitsky Bella , Granot‐Hershkovitz Einat , Lumley Thomas , Kwok Pui‐Yan , Hesselson Stephanie , Enquobahrie Daniel , Wander Pandora L. , Manor Orly , Siscovick David S. , Hochner Hagit
Published: October 2013

Objectives

Studies demonstrate associations between changes in obesity‐related phenotypes and cardiovascular risk. Although maternal pre‐pregnancy BMI (mppBMI) and gestational weight gain (GWG) may be associated with adult offspring adiposity, no study has examined associations with obesity changes. Associations of mppBMI and GWG with longitudinal change in offspring's BMI (ΔBMI) were examined, and whether associations are explained by offspring genetics was assessed.

Methods

A birth cohort of 1400 adults, with data at birth, age 17 and 32 years was used. After genotyping offspring, genetic scores, predictive of exposures and outcome were created, and linear regression models with and without scores were fit to examine the associations of mppBMI and GWG with ΔBMI.

Results

A one SD change in mppBMI and GWG was associated with a 0.83 and a 0.75 kg/m² increase in ΔBMI, respectively. The association between mppBMI and offspring ΔBMI was slightly attenuated (12%) with the addition of genetic scores. In the GWG model, a significant substantial 28.2% decrease in the coefficient was observed.

Conclusions

This study points to an association between maternal excess weight in pregnancy and offspring BMI change from adolescence to adulthood. Genetic factors may account, in part, for GWG/ΔBMI association. These findings broaden observations that maternal obesity‐related phenotypes have long‐term consequences for offspring health.
CCDC3 is specifically upregulated in omental adipose tissue in subjects with abdominal obesity
Authors: Ugi Satoshi , Maeda Shiro , Kawamura Yoshihiro , Kobayashi Masa‐aki , Imamura Minako , Yoshizaki Takeshi , Morino Katsutaro , Sekine Osamu , Yamamoto Hiroshi , Tani Toru , Rokushima Masatomo , Kashiwagi Atsunori , Maegawa Hiroshi
Published: October 2013

Objective

The aim of this study was to search for novel markers of visceral adiposity.

Methods

Visceral (omental) and subcutaneous adipose tissues were obtained from 43 Japanese men. Microarray analysis using total RNA from visceral and subcutaneous adipose tissues obtained from five men with abdominal obesity and five nonobese men was first conducted. Then the expression pattern of candidate genes identified in the human study in mouse models of adiposity was examined.

Results

Among 30,500 genes evaluated, the mRNA expression of CCDC3 (encoding coiled‐coil domain‐containing protein 3) was upregulated in omental adipose tissues from abdominally obese subjects (3.07‐fold) but not in subcutaneous adipose tissues (0.89‐fold). Similar expression patterns were found in two distinct mouse models of obesity. In the analysis of all 43 men, CCDC3 mRNA levels in omental, but not in subcutaneous adipose tissue, were positively correlated with waist circumference and body mass index. CCDC3 was predicted to be a secretory protein, which was confirmed by western blotting, as overexpressed CCDC3 was secreted into the culture media.

Conclusions

The expression of CCDC3 is specifically increased in visceral adipose tissues in abdominally obese subjects. These results suggest that CCDC3 is a potential biomarker for estimating visceral adiposity.
Extended LMI representatives for stability and stabilization of discrete‐time Takagi‐Sugeno fuzzy systems
Authors: Zhang Hui , Liu Mingxi , Shi Yang , Sheng Jie
Published: October 2013

In this paper, we study the stability conditions and stabilization problem of Takagi‐Sugeno systems under the discrete‐time framework. By introducing slack matrices, we obtain extended stability condition in an LMI form. Both parallel distributed compensation (PDC) control law, and non‐PDC control law are studied. Finally, we give an example to compare our results with other methods. Copyright © 2013 John Wiley & Sons, Ltd.
New results on dynamic output feedback control for Markovian jump systems with time‐varying delay and defective mode information
Authors: Wei Yanling , Qiu Jianbin , Karimi Hamid Reza , Wang Mao
Published: October 2013

This paper investigates the problem of delay‐dependent dynamic output feedback control for a class of discrete‐time Markovian jump linear systems (MJLSs). The systems under consideration are subject to time‐varying delay and defective mode information. The defective transition probabilities comprise of three types: exactly known, uncertain, and unknown. By employing a two‐term approximation for the time‐varying delay, the original MJLSs can be equivalently converted into a feedback interconnection form, which contains a forward subsystem with constant time‐delays and a feedback one with norm‐bounded uncertainties. Then, based on the scaled small‐gain theorem, the problem is therefore recast as an control problem in the face of uncertainties via an input–output framework. It is shown that the explicit expressions of the desired controller gains can be characterized in terms of strict linear matrix inequalities via some linearization techniques. Simulation studies are performed to illustrate the effectiveness and less conservatism of the proposed methods. Copyright © 2013 John Wiley & Sons, Ltd.
The Impact of Earnings Disregards on the Behavior of Low‐Income Families
Authors: Matsudaira Jordan D. , Blank Rebecca M.
Published: October 2013

This paper investigates the impact of changes in earnings disregards for welfare assistance received by single mothers following welfare reform in 1996. Some states adopted much higher earnings disregards (women could work full‐time and still receive substantial welfare benefits), while other states did not. We explore the effect of these changes on women's labor supply and income using several data sources and multiple estimation strategies. Our results indicate these changes had little effect on labor supply or income. We show this is because surprisingly few women used the earnings disregards. We discuss several explanations for why this might occur.
Enhanced chemical reworkability of DGEBA thermosets cured with rare earth triflates using aromatic hyperbranched polyesters (HBP) and multiarm star HBP‐b‐poly(ε‐caprolactone) as modifiers
Authors: Tomuta Adrian M. , Fernández‐Francos Xavier , Ferrando Francesc , Ramis Xavier , Serra Àngels
Published: October 2013

A hyperbranched aromatic polyester (HBPOH) has been synthesized, and poly(ε‐caprolactone) arms have been grown on some of its end hydroxyl groups (HBPCL). These modifiers have been used in cationic diglycidyl ether of bisphenol A formulations cured with ytterbium triflate as cationic initiator. The effect of HBPOH and HBPCL on the curing kinetics has been studied using differential scanning calorimetry (DSC). The obtained materials have been characterized by dynamomechanical analysis, DSC, thermogravimetric analysis and mechanical tests. The modifiers are incorporated into the thermosetting network because of the participation of the end hydroxyl groups in the cationic curing of epoxides by the activated monomer mechanism. Homogeneous thermosets have been obtained with a remarkable increase in impact strength without sacrificing elastic modulus or hardness. A compromise between the rigid structure of the aromatic hyperbranched core and the flexibilizing effect of the poly(ε‐caprolactone) arms is believed to be responsible for the overall thermal and mechanical properties of the materials. The use of these polymeric modifiers increases the thermal stability of the resulting materials because of the low degradability of the aromatic ester groups in the hyperbranched core and the incorporation of the modifier into the network structure. However, the presence of such ester groups makes them reworkable by hydrolysis or alcoholysis in an alkaline medium, thus opening a way for recovery of valuable substrates. Copyright © 2013 John Wiley & Sons, Ltd.
Syntheses and flame retarding properties of DOPO polymers, melamine polymers, and DOPO‐melamine copolymers
Authors: Lee Wen‐Lung , Liu Lung‐Chang , Chen Chien‐Ming , Lin Jian‐Shian
Published: October 2013

The 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO) polymers, melamine polymers, and DOPO‐melamine copolymers have been successfully synthesized, and their flame retarding properties have also been investigated by blending with polypropylene (PP)/styrene‐ethylene‐butylene‐styrene (SEBS) alloys. Experimental results establish that all of them are good polymeric flame retardants. No blooming or color stains occur when they are incorporated into PP/SEBS alloys. Among lab‐made polymeric flame retardants, DOPO‐ melamine copolymers exhibit the best thermal stability and nonflammability. PP/SEBS alloys containing DOPO‐melamine copolymers display comparable thermal resistance and flame retarding behavior (Td = 290°C; char yield: 15.6%, LOI: 23, and flammability: UL‐94 V0) as the alloys containing common commercial flame retardants (i.e., DOPO, melamine, and ammonium polyphosphate). Copyright © 2013 John Wiley & Sons, Ltd.
Utilization of PVPA and its effect on the material properties and biocompatibility of PVA electrospun membrane
Authors: Franco Rose Ann , Sadiasa Alexander , Lee Byong‐Taek
Published: October 2013

This study aims to investigate on the effect of the addition of polyvinylphosphonic acid (PVPA) on the material properties and biocompatibility of a polyvinyl alcohol (PVA) polymer tissue engineering scaffold fabricated by electrospinning process. Stabilization of the membranes was carried out by heat application. Fourier transform infrared spectroscopy confirmed the presence of PO bonds and P–OH bonds and increase in the atomic percentage of phosphorus in Energy Dispersive Spectroscopy (EDS) indicated successful incorporation of PVPA to the PVA. Scanning electron microscope fiber morphology and microstructure showed that addition of PVPA reduced the average fiber diameter of the scaffold. After 1 hr of phosphate buffered saline immersion, scaffolds were observed to swell to almost 200% of their original weight. Increased tensile strength was observed at 0.1% PVPA addition but reduced values were observed when the concentration was greater than 0.1%. Cytocompatibility was examined with M3CT3‐E1 preosteoblast cells through cell viability after exposure to extract solutions and Live/Dead cell staining. Cell proliferation was quantified by MTT assay; cell adhesion was visualized by scanning electron microscope and confocal microscopy images. Bone regeneration was also observed and quantified using histomorphometric analysis and histological staining methods after implantation in rat calvarium for 4 weeks. Copyright © 2013 John Wiley & Sons, Ltd.
Thermal stability and electrochemical performance of Polyaniline/Pr6O11 composites
Authors: Li Hui , Wang Shaoxu , Huang Zihang , Han Liangjun , Zhang Shihui , Li Yini , Tan Zhicheng
Published: October 2013

In order to describe the influence of Pr6O11 on thermal and electrochemical performance of polyaniline (PANI), PANI/Pr6O11 composites were synthesized by in situ polymerization in the presence of sulfosalicylic acid (as dopant). The composites obtained was characterized by scanning electron microscope, Fourier transform infrared spectra, and X‐ray diffraction. The thermal stability of the composites was investigated by thermogravimetry and derivative thermogravimetry. Finally, the comparative analysis on the electrochemical properties of PANI/Pr6O11 composites electrodes, such as cyclic voltammetry, electrochemical impedance spectroscopy, and constant current charge–discharge test, was conducted under similar conditions. Scanning electron microscope, infrared, and X‐ray diffraction results show that interaction exists between PANI and Pr6O11, and the composites are more crystalline than pure PANI. Thermogravimetry and derivative thermogravimetry analyses indicate that PANI/Pr6O11 composites and pure PANI have similar thermal stability. Moreover, the studies regarded to capacitive properties show that the electrochemical performance of the composites is improved greatly when Pr6O11 is added in small amount. However, with increasing the amount of Pr6O11, the electrochemical performance of the composites become worse, which indicates a large amount of Pr6O11 has a negative effect on the capacitance. These results suggest that PANI is still in the conductive form after inserting the Pr6O11, and the capacitance performance of PANI can be improved only by a low percentage of Pr6O11. Copyright © 2013 John Wiley & Sons, Ltd.
The genetic complexity of common cancers and the promise of personalized medicine: is there any hope?
Authors: Arnedos Monica , Vielh Philippe , Soria Jean‐Charles , Andre Fabrice
Published: October 2013

Molecular characterization of frequent cancers has shown that these entities actually include a very large number of rare genomic diseases. The progression of each of these rare diseases is being driven by specific genomic alterations, leading to abnormal proteins that can be targeted. Based on this observation, several personalized medicine programmes have been launched. They consist in profiling the tumour samples from each patient, identifying key oncogenic drivers, and treating the patient accordingly. Several preliminary data suggest that this approach is feasible and could lead to anti‐tumour effects that are currently modest. Several reasons could explain why personalized medicine programmes only report modest activity to targeted agents. First, the identification of key oncogenic drivers among several genomic alterations can be challenging. Second, the intratumour heterogeneity could lead to the emergence of resistant clones. Finally, several genomic alterations could contribute to cancer progression. These observations are leading to the second generation of personalized medicine trials, where targeted therapies are combined with each other and with immunotherapeutics, and where patients are selected to present a tumour with a low level of genetic instability. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Dendritic cells in IBD pathogenesis: an area of therapeutic opportunity?
Authors: Bates Jennifer , Diehl Lauri
Published: October 2013

Dysfunction of the mucosal immune system plays an important role in inflammatory bowel disease (IBD) pathogenesis. Dendritic cells are emerging as central players based on both our increasing understanding of how genetic susceptibility impacts the mucosal immune system and the key role of dendritic cells in regulating response to gut microflora. We discuss areas of therapeutic opportunity in this evolving landscape. © 2013 The Authors. Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.
Somatic alterations as the basis for resistance to targeted therapies
Authors: Blair Brian G , Bardelli Alberto , Park Ben Ho
Published: October 2013

Recent advances in genetics and genomics have revealed new genes and pathways that are somatically altered in human malignancies. This wealth of knowledge has translated into molecularly defined targets for therapy over the past two decades, serving as key examples that translation of laboratory findings can have great impact on the ability to treat patients with cancer. However, given the genetic instability and heterogeneity that are characteristic of all human cancers, drug resistance to virtually all therapies has emerged, posing further and future challenges for clinical oncology. Here we review the history of targeted therapies, including examples of genetically defined cancer targets and their approved therapies. We also discuss resistance mechanisms that have been uncovered, with an emphasis on somatic genetic alterations that lead to these phenotypes. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Identification and use of biomarkers in treatment strategies for triple‐negative breast cancer subtypes
Authors: Lehmann Brian D , Pietenpol Jennifer A
Published: October 2013

Triple‐negative breast cancer (TNBC) is a heterogeneous disease with distinct molecular subtypes that respond differentially to chemotherapy and targeted agents. The absence of high‐frequency molecular alterations and a limited number of known biomarkers have limited the development of therapeutic strategies for the disease. Herein, we summarize the results of the first round of targeted therapy approaches in TNBC and discuss new preclinical strategies. Common themes emerge from the proposed strategies, such as the use of biomarkers to identify tumours with genomic instability, targeting adapted molecular states resulting from tumour suppressor loss, and targeting altered metabolic pathways. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Using the molecular classification of glioblastoma to inform personalized treatment
Authors: Olar Adriana , Aldape Kenneth D
Published: October 2013

Glioblastoma is the most common and most aggressive diffuse glioma, associated with short survival and uniformly fatal outcome, irrespective of treatment. It is characterized by morphological, genetic and gene‐expression heterogeneity. The current standard of treatment is maximal surgical resection, followed by radiation, with concurrent and adjuvant chemotherapy. Due to the heterogeneity, most tumours develop resistance to treatment and shortly recur. Following recurrence, glioblastoma is quickly fatal in the majority of cases. Recent genetic molecular advances have contributed to a better understanding of glioblastoma pathophysiology and disease stratification. In this paper we review basic glioblastoma pathophysiology, with emphasis on clinically relevant genetic molecular alterations and potential targets for further drug development. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Pathology in drug discovery and development
Authors: Jubb Adrian M , Koeppen Hartmut , Reis‐Filho Jorge S
Published: October 2013

The rapid pace of drug discovery and drug development in oncology, immunology and ophthalmology brings new challenges; the efficient and effective development of new targeted drugs will require more detailed molecular classifications of histologically homogeneous diseases that show heterogeneous clinical outcomes. To this end, single companion diagnostics for specific drugs will be replaced by multiplex diagnostics for entire therapeutic areas, preserving tissue and enabling rapid molecular taxonomy. The field will move away from the development of new molecular entities as single agents, to which resistance is common. Instead, a detailed understanding of the pathological mechanisms of resistance, in patients and in preclinical models, will be key to the validation of scientifically rational and clinically effective drug combinations. To remain at the heart of disease diagnosis and appropriate management, pathologists must evolve into translational biologists and biomarker scientists. Herein, we provide examples of where this metamorphosis has already taken place, in lung cancer and melanoma, where the transformation has yet to begin, in the use of immunotherapies for ophthalmology and oncology, and where there is fertile soil for a revolution in treatment, in efforts to classify glioblastoma and personalize treatment. The challenges of disease heterogeneity, the regulatory environment and adequate tissue are ever present, but these too are being overcome in dedicated academic centres. In summary, the tools necessary to overcome the 'whens' and 'ifs' of the molecular revolution are in the hands of pathologists today; it is a matter of standardization, training and leadership to bring these into routine practice and translate science into patient benefit. This Annual Review Issue of the Journal of Pathology highlights the central role for pathology in modern drug discovery and development. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Vitamin B12 deficiency: The great masquerader
Authors: Dobrozsi Sarah , Flood Veronica H. , Panepinto Julie , Scott J. Paul , Brandow Amanda
Published: October 2013

Vitamin B12 deficiency is rare in children, with nonspecific symptoms including failure to thrive, vomiting, anorexia, and neurologic changes with or without hematologic disturbances. The neuropathy can be severe and irreversible. We report four cases of children with B12 deficiency secondary to adult type pernicious anemia, a presumed transport protein abnormality, and a metabolic defect. All demonstrated neurologic compromise that improved after initiation of B12 therapy. Hematologic manifestations may be preceded by constitutional, gastrointestinal, or neurologic changes, and must raise concern for B12 deficiency. Therapy should be initiated promptly in this setting to prevent irreversible neuropathy. Pediatr Blood Cancer 2014;61:753–755. © 2013 Wiley Periodicals, Inc.
A phase II trial of a multi‐agent oral antiangiogenic (metronomic) regimen in children with recurrent or progressive cancer
Authors: Robison Nathan J. , Campigotto Federico , Chi Susan N. , Manley Peter E. , Turner Christopher D. , Zimmerman Mary Ann , Chordas Christine A. , Werger Annette M. , Allen Jeffrey C. , Goldman Stewart , Rubin Joshua B. , Isakoff Michael S. , Pan Wilbur J. , Khatib Ziad A. , Comito Melanie A. , Bendel Anne E. , Pietrantonio Jay B. , Kondrat Laura , Hubbs Shannon M. , Neuberg Donna S. , Kieran Mark W.
Published: October 2013

Background

Preclinical models show that an antiangiogenic regimen at low‐dose daily (metronomic) dosing may be effective against chemotherapy‐resistant tumors. We undertook a prospective, open‐label, single‐arm, multi‐institutional phase II study to evaluate the efficacy of a “5‐drug” oral regimen in children with recurrent or progressive cancer.

Procedure

Patients ≤21 years old with recurrent or progressive tumors were eligible. Treatment consisted of continuous oral celecoxib, thalidomide, and fenofibrate, with alternating 21‐day cycles of low‐dose cyclophosphamide and etoposide. Primary endpoint was to assess, within eight disease strata, activity of the 5‐drug regimen over 27 weeks. Blood and urine angiogenesis markers were assessed.

Results

One hundred one patients were enrolled; 97 began treatment. Median age was 10 years (range: 191 days–21 years); 47 (49%) were female. Disease strata included high‐grade glioma (HGG, 21 patients), ependymoma (19), low‐grade glioma (LGG, 12), bone tumors (12), medulloblastoma/primitive neuroectodermal tumor (PNET, 8), leukemia (4), neuroblastoma (3), and miscellaneous tumors (18). Treatment was generally well tolerated; most common toxicities were hematologic. Twenty‐four (25%) patients completed 27 weeks therapy without progression, including HGG: 1 (5%), ependymoma: 7 (37%), LGG: 7 (58%), medulloblastoma/PNET: 1, neuroblastoma: 1, and miscellaneous tumors: 7 (39%). Best response was complete response (one patient with medulloblastoma), partial response (12), stable disease (36), progressive disease (47), and inevaluable (1). Baseline serum thrombospondin levels were significantly higher in patients successfully completing therapy than in those who progressed (P = 0.009).

Conclusion

The 5‐drug regimen was well tolerated. Clinical activity was demonstrated in some but not all tumor strata. Pediatric Blood Cancer 2014;61:636–642. © 2013 The Authors Pediatric Blood & Cancer Published by Wiley Periodicals, Inc.
All‐straw‐fiber composites: Benzylated straw as matrix and additional straw fiber reinforced composites
Authors: Chen Jianqiang , Su Meng , Ye Judi , Yang Zhen , Cai Zhengchun , Yan Han , Hong Jianguo
Published: October 2013

With the aim to utilize the waste biomass of wheat straw, all‐straw‐fiber composites were elaborately manufactured though producing plastic benzylated wheat straw (BWS) as matrix and reinforced by additional straw fibers (ASF). The extent of benzylation for wheat straw was greatly improved with the aid of ball milling pretreatment for 4 h. BWS yielded higher weight percent gain (WPG) under the same reaction conditions with the benzylation of wood flour, lower glass transition temperature (Tg) as well as better flowability upon heating compared to benzylated mulberry branches (BMB) with comparable WPG. All‐straw‐fiber composites performed higher ASF loading capacity and better mechanical properties with optimum ASF content than BMB based composites and by benzylation decreased water absorption significantly. SEM provided evidence for strong adhesion in the interface between BWS and ASF. From the overall performance, the All‐straw‐fiber composites can be regarded as a potential alternative to wood plastic composites. POLYM. COMPOS., 35:419–426, 2014. © 2013 Society of Plastics Engineers
Preparation and characterization of conductive and magnetic PPy/Fe3O4/Ag nanocomposites
Authors: Mo Zunli , Gou Hao , He Jingxian , Wang Jun , Guo Ruibin
Published: October 2013

In this article, conductive and magnetic nanocomposites composed of polypyrrole (PPy), magnetite (Fe3O4) nanoparticles (NPs), silver (Ag) NPs, have been successfully synthesized with a two step process. First, the PPy/Fe3O4 was prepared by the ultrasonic in situ polymerization. Next, the PPy/Fe3O4/Ag was synthesized through the electrostatic adsorption. The products were characterized by fourier‐transform infrared (FTIR) spectroscopy, Scanning electron microscopy (SEM), Thermogravimetric (TG), conductivity and magnetization analysis, and the results showed that the Ag NPs with the good conductivity coated uniformly on the surface of PPy/Fe3O4 and improved the conductivity of PPy/Fe3O4/Ag composites. In addition, as compared with PPy/Fe3O4, PPy/Fe3O4/Ag composites also have the excellent electro‐magnetic property and enhanced thermostability. POLYM. COMPOS., 35:450–455, 2014. © 2013 Society of Plastics Engineers
Preparation and characterization of polyaniline/Turkish Huntite‐hydromagnesite composites
Authors: Şen Ferhat , Madakbaş Seyfullah , Kahraman Memet Vezir
Published: October 2013

The aim of this study was to improve thermal stability of polyaniline (PANI) by adding Turkish Huntite. PANI was synthesized and PANI/Turkish Huntite composites were prepared by adding various proportions of huntite to aniline. The chemical structures of the samples were investigated by Fourier transform infrared spectroscopy. Thermal properties of the composites were determined by thermogravimetric analysis and differential scanning calorimetry. The surface morphologies of the samples were investigated by a scanning electron microscopy. The obtained results proved that the composite system is more thermally stable than the pure PANI. POLYM. COMPOS., 35:456–460, 2014. © 2013 Society of Plastics Engineers