bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and Antibacterial Evaluation of 1,2,3‐Triazole‐based Quinazolines Using Click Chemistry in the Presence of Salophen Schiff Base Ligand
Authors: Kazemi Shaghayegh Sadat , Keivanloo Ali , Nasr‐Isfahani Hossein , Amin Amir Hossein
Published: May 2018

The reaction of 2‐chloro‐4‐(prop‐2‐ynyloxy)quinazoline or 2‐chloro‐N‐(prop‐2‐ynyl)quinazolin‐4‐amine with aromatic azides in the presence of the salophen Schiff base ligand afforded new derivatives of 1,2,3‐triazole‐based quinazoline scaffold in high‐to‐excellent reaction yields. The main advantage of this procedure is that the toxicity of the copper catalyst used could be decreased to 2 mol% by complexation with the salophen ligand. All the synthesized compounds were screened for their in vitro antibacterial activities against the Gram‐positive and Gram‐negative bacteria using the well‐diffusion method.
Perceived organizational obstruction: A mediator that addresses source–target misalignment between abusive supervision and OCBs
Authors: Mackey Jeremy D. , McAllister Charn P. , Brees Jeremy R. , Huang Lei , Carson Jack E.
Published: May 2018

We examine perceived organizational obstruction as a mediator in the relationship between abusive supervision and subordinates' organizational citizenship behaviors directed toward organizations. We seek to provide a nuanced understanding of why subordinates who perceive supervisory mistreatment would target organizations with behavioral responses. Specifically, we study the implications of examining relationships between inconsistent sources of social exchange perceptions (e.g., supervisory perceptions) and targets of social exchange behaviors (e.g., organizational responses), which we refer to as social exchange source–target misalignment. Results from 3 studies (Study 1: n = 109; Study 2: n = 213; Study 3: n = 228) demonstrate evidence that abusive supervision is indirectly and negatively associated with organizational citizenship behaviors directed toward organizations through perceived organizational obstruction and that this conditional indirect effect is stronger for subordinates who perceive higher levels of supervisor organizational embodiment than others. Examining the social exchange tandem of perceived organizational obstruction and supervisor organizational embodiment provides a novel and useful means of aligning sources and targets of negative social exchange relationships across subordinates, supervisors, and organizations in order to advance our understanding of the social exchange antecedents and consequences of perceived organizational obstruction.
Quality perception, purchase intention, and the impact of information on the evaluation of refined Pacific cupped oysters (Crassostrea gigas) by Dutch consumers
Authors: van Houcke Jasper , Altintzoglou Themistokilis , Linssen Jozef , Luten Joop
Published: May 2018

BACKGROUND

Oyster refinement using land‐based pond systems is a new activity in the Dutch oyster sector. It increases the oyster's tissue weight and changes its sensorial properties. However, the response of Dutch consumers towards refined oysters is unknown. The research aim was to gain insight into the importance of oyster quality parameters, drivers for oyster consumption, and acceptance of refined oysters by Dutch consumers, taking into account the information given to them about the product and process.

RESULTS

Taste, texture, and odor are the most important oyster quality characteristics for Dutch consumers. The outcome of questionnaires showed that willingness to buy and pay is influenced by factors such as the oysters' country of origin, cultivation area, and flavor profile. Refinement did not affect willingness to buy and pay. Furthermore Dutch consumers seem to have a preference for the flavor profile of refined oysters. Consumer evaluation showed that refined Pacific cupped oysters were perceived as sweeter compared with non‐refined oysters. When information on the cultivation process was disclosed, overall appreciation of refined oysters by consumers increased.

CONCLUSION

New insights in the importance of oyster quality characteristics for Dutch consumers are generated that can be used in the development of refined Pacific cupped oysters. © 2018 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
Inhibiting tumor necrosis factor‐alpha at time of induced intervertebral disc injury limits long‐term pain and degeneration in a rat model
Authors: Evashwick‐Rogler Thomas W. , Lai Alon , Watanabe Hironobu , Salandra Jonathan M. , Winkelstein Beth A. , Cho Samuel K. , Hecht Andrew C. , Iatridis James C.
Published: May 2018

Background

Painful intervertebral disc (IVD) degeneration has tremendous societal costs and few effective therapies. Intradiscal tumor necrosis factor‐alpha (TNFα) is commonly associated with low back pain, but the direct relationship remains unclear.

Purpose

Treatment strategies for low back pain require improved understanding of the complex relationships between pain, intradiscal pro‐inflammatory cytokines, and structural IVD degeneration. A rat in vivo lumbar IVD puncture model was used to 1) determine the role of TNFα in initiating painful IVD degeneration, and 2) identify statistical relationships between painful behavior, IVD degeneration, and intradiscal pro‐inflammatory cytokine expression.

Methods

Lumbar IVDs were punctured anteriorly and injected with TNFα, anti‐TNFα, or saline and compared with sham and naive controls. Hindpaw mechanical hyperalgesia was assayed weekly to determine pain over time. 6‐weeks post‐surgery, animals were sacrificed, and IVD degeneration, IVD height, and intradiscal TNFα and interleukin‐1 beta (IL‐1β) expressions were assayed.

Results

Intradiscal TNFα injection increased pain and IVD degeneration whereas anti‐TNFα alleviated pain to sham level. Multivariate step‐wise linear regression identified pain threshold was predicted by IVD degeneration and intradiscal TNFα expression. Pain threshold was also linearly associated with IVD height loss and IL‐1β.

Discussion

The significant associations between IVD degeneration, height loss, inflammation, and painful behavior highlight the multifactorial nature of painful IVD degeneration and the challenges to diagnose and treat a specific underlying factor. We concluded that TNFα is an initiator of painful IVD degeneration and its early inhibition can mitigate pain and degeneration. Intradiscal TNFα inhibition following IVD injury may warrant investigation for its potential to alter downstream painful IVD degeneration processes.
Promise, progress, and problems in whole disc tissue engineering
Authors: Gullbrand Sarah E. , Smith Lachlan J. , Smith Harvey E. , Mauck Robert L.
Published: May 2018

Intervertebral disc degeneration is frequently implicated as a cause of back and neck pain, which are pervasive musculoskeletal complaints in modern society. For the treatment of end stage disc degeneration, replacement of the disc with a viable, tissue‐engineered construct that mimics native disc structure and function is a promising alternative to fusion or mechanical arthroplasty techniques. Substantial progress has been made in the field of whole disc tissue engineering over the past decade, with a variety of innovative designs characterized both in vitro and in vivo in animal models. However, significant barriers to clinical translation remain, including construct size, cell source, culture technique, and the identification of appropriate animal models for preclinical evaluation. Here we review the clinical need for disc tissue engineering, the current state of the field, and the outstanding challenges that will need to be addressed by future work in this area.
Thyroid Microcalcifications in the Absence of Identifiable Nodules and Their Association With Thyroid Cancer
Authors: Whittle Carolina , García Marisol , Horvath Eleonora , Slater Jeannie , Carrasco Carmen
Published: May 2018

Objectives

To determine ultrasound (US) and clinical findings of thyroid microcalcifications in the absence of a nodule and their association with the risk of malignancy.

Methods

The Institutional Review Board approved a 5‐year retrospective study. Twenty‐one patients with clustered or scattered thyroid microcalcifications in the absence of nodules on US images who underwent fine‐needle aspiration biopsies (FNABs) were included. Demographic and clinical data, US findings, and pathologic results were registered. Patients with a suspicion of malignancy or papillary thyroid carcinoma (PTC) on FNAB underwent thyroidectomy. Patients with benign results on FNAB underwent clinical and US surveillance.

Results

The mean age of the 21 patients was 33.2 years (29.5 years in patients with PTC patients and 39.4 years in those with benign findings; P = .034). Eleven of 21 patients had clustered microcalcifications (9 had cancer), and 10 of 21 patients had scattered microcalcifications (4 of 10 had cancer; P = 0.063). Sixty‐two percent of the patients had FNAB findings that were suspicious for cancer or had a diagnosis of cancer. Eleven of 13 patients had surgical thyroidectomy performed in our institution; in all cases, Hashimoto thyroiditis was confirmed. Univariate and multivariate analysis showed that only age was significant (odds ratio, 0.9; P < .05).

Conclusions

Our study suggests that the presence of thyroid microcalcifications without a nodule is suspicious for PTC. We found that both patterns were suspicious for PTC, particularly in young patients. Special concern arises for those clustered microcalcifications on a background of Hashimoto thyroiditis.
A Comparison of 1‐ and 3.2‐MHz Low‐Intensity Pulsed Ultrasound on Osteogenesis on Porous Titanium Alloy Scaffolds: An In Vitro and In Vivo Study
Authors: Feng Lifang , Liu Xiaohan , Cao Hongjuan , Qin Limei , Hou Wentao , Wu Lin
Published: May 2018

Objectives

Low‐intensity pulsed ultrasound (LIPUS) combined with porous scaffolds can be used as a new therapy to treat bone defect repair. The aim of this study was to evaluate the effects of 1 and 3.2 MHz LIPUS on osteogenesis on porous Ti64 alloy scaffolds for both in vitro and in vivo studies.

Methods

Scaffolds were randomly divided into the high‐frequency ultrasound group, low‐frequency ultrasound group, and control group. Mouse pre‐osteoblast cells were cultured with porous Ti‐6Al‐4V scaffolds in vitro to evaluate cell proliferation and differentiation. In addition, scaffolds were implanted into rabbit mandibular defects in vivo. The effects of LIPUS on bone regeneration were evaluated by observing the micro–computed tomography (micro‐CT), toluidine blue staining, and von Kossa staining.

Results

The results revealed no significant difference in the cell counting kit‐8 values between the ultrasound groups and control groups (P > .05). Compared with the control group, ultrasound promoted alkaline phosphatase activity and osteocalcin levels of the cells on the scaffolds (P < .05), but there was no significant difference between the two frequencies. In addition, histomorphologic analyses revealed that the volume and amount of new bone formation increased and that bone maturity improved in the ultrasound groups compared with the control group, but no significant difference was noted between the two frequencies.

Conclusions

Under the present experimental conditions, LIPUS promoted osteoblast differentiation and promoted bone maturity on porous Ti64 scaffolds. No significant differences were noted between the two frequencies.
BOOK REVIEW
Authors: Parsons Timothy
Published: May 2018

RAY, G. CARLETON and JERRY McCORMICK‐RAY. 2003. Coastal‐Marine Conservation: Science and Policy. Blackwell Publishing. ISBN 0‐63‐205537‐5 (paperback). xiv + 327 p. US $70.
BOOK REVIEW
Authors: George Robert Y.
Published: May 2018

HERRING, PETER. 2002. The Biology of the Deep Ocean. Oxford University Press. ISBN 0‐19‐854955‐5 (paperback). Reprinted 2003 (with corrections). ix + 314 p. US $45.
BOOK REVIEW
Authors: Whitlatch Robert B.
Published: May 2018

RAILKIN, ALEXANDER I. 2004. Marine Biofouling: Colonization Processes and Defenses. CRC Press. ISBN 0‐8493‐1419‐4 (hardbound). 303 p. US $140.
BOOK REVIEW
Authors: Vazquez Jorge
Published: May 2018

MARTIN, SEELYE. 2004. An Introduction to Ocean Remote Sensing. Cambridge University Press. ISBN 0‐521‐80280‐6 (hardcover). xxvii + 426 p. US $75.
BOOK REVIEW
Authors: Lesht Barry M.
Published: May 2018

MORTIMER, CLIFFORD H. 2004. Lake Michigan in Motion: Responses of an Inland Sea to Weather, Earth‐Spin, and Human Activities. University of Wisconsin Press. ISBN 0‐299‐17834‐X (paperback). xix + 310 p. US $25; also available as ISBN 0‐299‐17830‐7 (cloth cover) US $45.
BOOK REVIEW
Authors: Youngbluth Marsh , Båmstedt Ulf
Published: May 2018

JOHNSON, WILLIAM S., and DENNIS M. ALLEN. 2005. Zooplankton of the Atlantic and Gulf Coasts: A Guide to Their Identification and Ecology. Johns Hopkins University Press. ISBN 0‐8018‐8168‐4 (paperback). xii + 379 p. US $45; also available as ISBN 0‐8018‐8019‐X (hardcover) US $80.
BOOK REVIEW
Authors: Weyhenmeyer Gesa A.
Published: May 2018

MAGNUSON, JOHN J., TIMOTHY K. KRATZ, and BARBARA J. BENSON (eds.). 2006. Long‐Term Dynamics of Lakes in the Landscape: Long‐Term Ecological Research on North Temperate Lakes. Oxford University Press. ISBN 978‐0‐19‐513690‐6 (hardcover). xix + 400 p. US $90.
BOOK REVIEW
Authors: Muller Andrew C.
Published: May 2018

CHAMBERLIN, SEAN W., and TOMMY D. DICKEY. 2008. Exploring the World Ocean. McGraw‐Hill Companies Inc. ISBN 978‐0‐07‐331276‐7 (paperback). xxi + 394 p. US $104.
BOOK REVIEW
Authors: Kristensen Erik
Published: May 2018

HOGARTH, PETER J. 2007. The Biology of Mangroves and Seagrasses, 2nd edition. Oxford University Press. ISBN 978‐0‐19‐856871‐1 (paperback). x + 273 p. US $55; also available as ISBN 978‐0‐19‐856870‐4 (hardcover) US $120.
BOOK REVIEW
Authors: Parrow Matthew W.
Published: May 2018

GRANÉLI, EDNA AND JEFFERSON T. TURNER. 2006. ECOLOGY OF HARMFUL ALGAE. ECOLOGICAL STUDIES 189, SPRINGER, NEW YORK. ISBN 3‐540‐32209‐4 (HARDCOVER). XXVI + 413 P.
BOOK REVIEW
Authors: Hausmann Sonja
Published: May 2018

SMOL, JOHN P. 2008. Pollution of Lakes and Rivers ‐ A Paleoenvironmental Perspective 2nd edition. Blackwell Publishing. ISBN‐13: 978‐1‐4051‐5913‐5. 396 p. US$ 59.95
BOOK REVIEW
Authors: Falkowski Paul G. , Ruskin Sari G.
Published: May 2018

MICHAEL D. KING, CLAIRE L. PARKINSON, KIM C. PARTINGTON and ROBIN G. WILLIAMS (Eds.). 2007. Our Changing Planet. Cambridge University Press. ISBN 978‐0521828703, 400 p. US $45.00
BOOK REVIEW
Authors: Scheffer Marten
Published: May 2018

CRAIG R.ALLEN AND C.S. HOLLING (Eds.) 2008. Discontinuities in Ecosystems and other Complex Systems. Columbia University Press, New York. ISBN 978‐0231144445. 288 p. US$84.50
BOOK REVIEW
Authors: Francour Patrice
Published: May 2018

MICHAEL J. ANGUILLETTA, Jr. 2009. Thermal adaptation. A theoretical and empirical synthesis. Oxford University Press. ISBN 978‐0‐19‐857087‐5. 289 pp. US$135
BOOK REVIEW
Authors: Weinbauer Markus G.
Published: May 2018

MARK E. RITCHIE 2010. Scale, Heterogeneity, and the Structure and Diversity of Ecological Communities. Princeton University Press. ISBN‐13: 978‐0‐691‐09070‐2. pp. 229 $35
BOOK REVIEW
Authors: Kleypas Joan A.
Published: May 2018

ULF RIEBESELL, VICTORIA J. FABRY, LINA HANSSON, AND JEAN‐PIERRE GATTUSO (Eds.) 2010. Guide to Best Practices for Ocean Acidification Research and Data Reporting. European Commission, Publications Office of the European Union. ISBN 978‐92‐79‐11118‐1 260 pp.
BOOK REVIEW
Authors: Sime‐Ngando Télesphore
Published: May 2018

BARTON L. L. and NORTHUP D. E. 2011. Microbial Ecology Wiley‐Blackwell, ISBN 978‐0‐470‐04817‐7. 407 pp $104.95
BOOK REVIEW
Authors: Alekseev Victor
Published: May 2018

LAMPERT, W. 2011. Daphnia: Development of a Model Organism in Ecology and Evolution. Excellence in Ecology, Volume 21. International Ecology Institute Publishers, Oldendorf/Luhe, ISSN 0932‐2205. 250 pp. $35
Nonionic Dendritic and Carbohydrate Based Amphiphiles: Self‐Assembly and Transport Behavior
Authors: Prasad Suchita , Achazi Katharina , Schade Boris , Haag Rainer , Sharma Sunil K.
Published: May 2018

Herein, a new series of non‐ionic dendritic and carbohydrate based amphiphiles is synthesized employing biocompatible starting materials and studied for supramolecular aggregate formation in aqueous solution. The dendritic amphiphiles 12 and 13 possessing poly(glycerol) [G2.0] as hydrophilic unit and C‐10 and C‐18 hydrophobic alkyl chains, respectively, exhibit low critical aggregation concentration (CAC) in the order of 10−5m and hydrodynamic diameters in the 8–10 nm range and supplemented by cryogenic transmission electron microscopy. Ultraviolet‐visible (UV‐Vis) and fluorescence spectroscopy suggests the effective solubilization of hydrophobic guests by the self‐assembled architectures, with the nanotransporters 12 and 13 possessing the highest encapsulation efficiency of 80.74 and 98.03% for curcumin. Efficient uptake of encapsulated curcumin in adenocarcinomic human alveolar basal epithelial (A549) cells is observed by confocal laser scanning microscopy. Amphiphiles 12 and 13 are non‐cytotoxic at the concentrations studied, however, curcumin encapsulated samples efficiently reduce the viability of A549 cells in vitro. Experimental studies indicate the ability of amphiphile 13 to encapsulate 1‐anilinonaphthalene‐8‐sulfonic acid (ANS) and curcumin with binding constant of 1.16 × 1055m−1 and 1.43 × 106m−1, respectively. Overall, our findings demonstrate the potential of these dendritic amphiphiles for the development of prospective nanocarriers for the solubilization of hydrophobic drugs.
Dual Ag/ZnO‐Decorated Micro‐/Nanoporous Sulfonated Polyetheretherketone with Superior Antibacterial Capability and Biocompatibility via Layer‐by‐Layer Self‐Assembly Strategy
Authors: Deng Yi , Yang Lei , Huang Xiaobing , Chen Junhong , Shi Xiuyuan , Yang Weizhong , Hong Min , Wang Yuan , Dargusch Matthew S. , Chen Zhi‐Gang
Published: May 2018

Polyetheretherketone is attractive for dental and orthopedic applications due to its mechanical attributes close to that of human bone; however, the lack of antibacterial capability and bioactivity of polyetheretherketone has substantially impeded its clinical applications. Here, a dual therapy implant coating is developed on the 3D micro‐/nanoporous sulfonated polyetheretherketone via layer‐by‐layer self‐assembly of Ag ions and Zn ions. Material characterization studies have indicated that nanoparticles consisting of elemental Ag and ZnO are uniformly incorporated on the porous sulfonated polyetheretherketone surface. The antibacterial assays demonstrate that Ag‐decorated sulfonated polyetheretherketone and Ag/ZnO‐codecorated sulfonated polyetheretherketone effectively inhibit the reproduction of Gram‐negative and Gram‐positive bacteria. Owing to the coordination of micro‐/nanoscale topological cues and Zn induction, the Ag/ZnO‐codecorated sulfonated polyetheretherketone substrates are found to enhance biocompatibility (cell viability, spreading, and proliferation), and hasten osteodifferentiation and ‐maturation (alkaline phosphate activity (ALP) production, and osteogenesis‐related genetic expression), compared with the Ag‐decorated sulfonated polyetheretherketone and the ZnO‐decorated sulfonated polyetheretherketone counterparts. The dual therapy Ag/ZnO‐codecorated sulfonated polyetheretherketone has an appealing bacteriostatic performance and osteogenic differentiation potential, showing great potential for dental and orthopedic implants.
Low‐Temperature Sintering of Stereocomplex‐Type Polylactide Nascent Powder: From Compression Molding to Injection Molding
Authors: Fu Meirui , Liu Zhenwei , Bai Dongyu , Ling Fangwei , Bai Hongwei , Zhang Qin , Fu Qiang
Published: May 2018

Stereocomplex (SC) crystallization between poly(l‐lactide) (PLLA) and poly(d‐lactide) (PDLA) exhibits tremendous potential to improve the properties of polylactide (PLA), but the practical processing of SC‐type PLA (SC‐PLA) is significantly hindered by the insufficient melt stability and serious degradation after complete melting of SC crystallites over 240 °C. In a previous work, powder metallurgy inspired low‐temperature (180–210 °C) compression sintering is proposed to fabricate SC‐PLA products from its nascent powder. However, its industrial application is still challenging mainly due to the low production efficiency (half an hour is required) as well as the weak ability to fabricate products with complex shapes. In this work, an effort to rapidly fabricate complex‐shaped SC‐PLA products using low‐temperature injection molding technology is reported, where SC‐PLA nascent powder is partially melted. To ensure appropriate powder flowability, small amounts of glyceryl monostearate are incorporated as a lubricant. The results show that, both the self‐nucleation and flow‐induced nucleation effects facilitate the SC crystallization across the interfaces between adjacent unmelted powder particles, which considerably shortens the sintering cycle to about 2 min. In this way, complex‐shaped SC‐PLA products (such as gears) with superb performance are successfully fabricated by injection molding for the first time.
Complete families of smooth space curves and strong semistability
Authors: Benoist Olivier
Published: May 2018

We construct the first non‐trivial examples of complete families of non‐degenerate smooth space curves, and show that the base of such a family cannot be a rational curve. Both results rely on the study of the strong semistability of certain vector bundles.
Geometrical proofs for the global solvability of systems
Authors: Bergamasco Adalberto Panobianco , Parmeggiani Alberto , Zani Sérgio Luís , Zugliani Giuliano Angelo
Published: May 2018

We study a linear operator associated with a closed non‐exact 1‐form b defined on a smooth closed orientable surface M of genus . Here we present two proofs that reveal the interplay between the global solvability of the operator and the global topology of the surface. The first result brings an answer for the global solvability when the system is defined by a generic Morse 1‐form. Necessary conditions for the global solvability bearing on the sublevel and superlevel sets of primitives of a smooth 1‐form b have already been established; we also present a more intuitive proof of this result.
Inhibition is impaired in children with obsessive‐compulsive symptoms but not in those with tics
Authors: Mancini Christian , Cardona Francesco , Baglioni Valentina , Panunzi Sara , Pantano Patrizia , Suppa Antonio , Mirabella Giovanni
Published: May 2018

Background: Impaired inhibitory control is thought to be a core deficit in psychiatric disorders where patients exhibit problems with controlling urges. These problems include the urge to perform movements typical of Tourette syndrome and the urge to execute compulsive actions typical of obsessive‐compulsive disorder. However, the picture emerging from studies that address this issue is controversial. Furthermore, most studies have only focused on reactive control (the ability of subjects to react to a stop signal), but not on proactive control (the ability of patients to shape their response strategies in anticipation of known task demands).

Objectives: We assessed reactive and proactive inhibitory control in drug naïve children/adolescents affected by Tourette syndrome, obsessive‐compulsive disorder, and in those in which the 2 disorders co‐occur.

Methods: Reaching version of the stop signal task and of a simple reaction time task were given to 37 unmedicated patients (mean age ± SD, 11.0 ± 2.3) and to 37 healthy age‐ and gender‐matched controls (mean age ± SD, 10.8 ± 1.6).

Results: Both reactive and proactive inhibition scaled with the severity of obsessive‐compulsive symptoms, but not with those of tic symptoms (ie, inhibitory control in uncomplicated Tourette patients was comparable with that of healthy controls).

Conclusions: We suggest that the cognitive mechanisms underlying tics and compulsions controls are likely to be different. Possibly the preserved ability to suppress actions in uncomplicated Tourette patients allows them to experience a greater feeling of self‐control, and this fact might play a key role in evolution of the disorder beyond adolescence. © 2018 International Parkinson and Movement Disorder Society
A Monte Carlo Method to Quantify the Effect of Reactor Residence Time Distribution on Polyolefins Made with Heterogeneous Catalysts: Part II ‐ Packing Density Effects
Authors: Romero Jazmin , Soares João B. P.
Published: May 2018

The residence time distribution of reactors used to produce polyolefins commercially has a significant impact on many of their properties. This effect often goes unnoticed, since the concept of reactor residence time is often poorly understood even among chemical engineers. In the first part of this series of articles, it is shown how the reactor residence time distribution has a marked impact on the particle size distribution of polyolefin particles using a new Monte Carlo model. In this article, the Monte Carlo model is combined with a drop and roll algorithm to predict how reactor residence time distribution affects the packing density of the polyolefin particles.
An efficient, partitioned ensemble algorithm for simulating ensembles of evolutionary MHD flows at low magnetic Reynolds number
Authors: Jiang Nan , Schneier Michael
Published: May 2018

Studying the propagation of uncertainties in a nonlinear dynamical system usually involves generating a set of samples in the stochastic parameter space and then repeated simulations with different sampled parameters. The main difficulty faced in the process is the excessive computational cost. In this paper, we present an efficient, partitioned ensemble algorithm to determine multiple realizations of a reduced Magnetohydrodynamics (MHD) system, which models MHD flows at low magnetic Reynolds number. The algorithm decouples the fully coupled problem into two smaller subphysics problems, which reduces the size of the linear systems that to be solved and allows the use of optimized codes for each subphysics problem. Moreover, the resulting coefficient matrices are the same for all realizations at each time step, which allows faster computation of all realizations and significant savings in computational cost. We prove this algorithm is first order accurate and long time stable under a time step condition. Numerical examples are provided to verify the theoretical results and demonstrate the efficiency of the algorithm.
Stability analysis of several first order schemes for the Oldroyd model with smooth and nonsmooth initial data
Authors: Zhang Tong , Qian Yanxia
Published: May 2018

In this article, we develop several first order fully discrete Galerkin finite element schemes for the Oldroyd model and establish the corresponding stability results for these numerical schemes with smooth and nonsmooth initial data. The stable mixed finite element method is used to the spatial discretization, and the temporal treatments of the spatial discrete Oldroyd model include the first order implicit, semi‐implicit, implicit/explicit, and explicit schemes. The ‐stability results of the different numerical schemes are provided, where the first‐order implicit and semi‐implicit schemes are the ‐unconditional stable, the implicit/explicit scheme is the ‐almost unconditional stable, and the first order explicit scheme is the ‐conditional stable. Finally, some numerical investigations of the ‐stability results of the considered numerical schemes for the Oldroyd model are provided to verify the established theoretical findings.
Inverse optimal control for asymptotic trajectory tracking of discrete‐time stochastic nonlinear systems in block controllable form
Authors: Elvira‐Ceja Santiago , Sanchez Edgar N.
Published: May 2018

This paper concerns an inverse optimal control–based trajectory tracking of discrete‐time stochastic nonlinear systems. It is assumed that the nonlinear system can be transformed to the so called nonlinear block controllable form. Additionally, the synthesized control law minimizes a cost functional, which is posteriori determined. In contrast to the optimal control technique, this scheme avoids to solve the stochastic Hamilton‐Jacobi‐Bellman equation, which is not an easy task. Based on a discrete‐time stochastic control Lyapunov function, the proposed optimal controller is analyzed. The proposed approach is applied successfully to the two degrees‐of‐freedom helicopter with uncertainties in real time.
A trajectory‐based sampling strategy for sequentially refined metamodel management of metamodel‐based dynamic optimization in mechatronics
Authors: Lefebvre Tom , De Belie Frederik , Crevecoeur Guillaume
Published: May 2018

Dynamic optimization problems based on computationally expensive models that embody the dynamics of a mechatronic system can result in prohibitively long optimization runs. When facing optimization problems with static models, reduction in the computational time and thus attaining convergence can be established by means of a metamodel placed within a metamodel management scheme. This paper proposes a metamodel management scheme with a dedicated sampling strategy when using computationally demanding dynamic models in a dynamic optimization problem context. The dedicated sampling strategy enables to attain dynamically feasible solutions where the metamodel is locally refined during the optimization process upon satisfying a feasibility‐based stopping condition. The samples are distributed along the iterate trajectories of the sequential direct dynamic optimization procedure. Algorithmic implementation of the trajectory‐based metamodel management is detailed and applied on two case studies involving dynamic optimization problems. These numerical experiments illustrate the benefits of the presented scheme and its sampling strategy on the convergence properties. It is shown that the acceleration of the solution time of the dynamic optimization problem can be achieved when evaluating the metamodel that is lower than 90% compared to the computationally expensive model.
Preparation and characterization of temperature‐ and pH‐responsive diblock copolymers and their silica‐coated nanoparticles
Authors: Yang Zhenglong , Fu Kangyu , Yu Jing , Zhou Peiting , Cheng Zhihao
Published: May 2018

Multiresponsive amphiphilic poly(N,N‐dimethylaminoethyl methacrylate)‐b‐poly(N‐isopropylacrylamide) (PDMAEMA‐b‐PNIPAM) was successfully synthesized by reversible addition‐fragmentation chain transfer polymerization. Poly(N,N‐dimethylaminoethyl methacrylate)‐b‐poly(N‐isopropylacrylamide) has thermal and pH stimuli responsiveness. Their lower critical solution temperature and hydrodynamic radius can be adjusted by varying the copolymer composition, block length, solution pH, and temperature. In addition, a convenient method has been established to prepare cross‐linked silica‐coated nanoparticles with PDMAEMA‐b‐PNIPAM micelles as a template, resulting in good organic/inorganic hybrid nanoparticles defined as 175 to 220 nm. The structure and morphology were characterized by proton nuclear magnetic resonance (1HNMR), Fourier‐transform infrared spectroscopy (FT‐IR), transmission electron microscopy (TEM), and transmission electron microscopy‐energy dispersive X‐ray spectroscopy (TEM‐EDS).
Pediatric superior vena cava syndrome: An evidence‐based systematic review of the literature
Authors: Nossair Fadi , Schoettler Peter , Starr Joanne , Chan Anthony K. C. , Kirov Ivan , Paes Bosco , Mahajerin Arash
Published: May 2018

Superior vena cava syndrome (SVCS) results in vascular, respiratory, and neurologic compromise. A systematic search was conducted to determine the prevalence of pediatric SVCS subtypes and identify clinical characteristics/treatment strategies that may influence overall outcomes. Data from 101 case reports/case series (142 patients) were analyzed. Morbidity (30%), mortality (18%), and acute complications (55%) were assessed as outcomes. Thrombosis was present in 36%, with multi‐modal anticoagulation showing improved outcome by >50% (P = 0.004). Infant age (P = 0.04), lack of collaterals (P = 0.007), acute complications (P = 0.005), and clinical presentation may have prognostic utility that could influence clinical decisions and surveillance practices in pediatric SVCS.
Associations between neutrophil recovery time, infections and relapse in pediatric acute myeloid leukemia
Authors: Løhmann Ditte J. A. , Asdahl Peter H. , Abrahamsson Jonas , Ha Shau‐Yin , Jónsson Ólafur G. , Kaspers Gertjan J. L. , Koskenvuo Minna , Lausen Birgitte , De Moerloose Barbara , Palle Josefine , Zeller Bernward , Hasle Henrik
Published: May 2018

Background

Children with acute myeloid leukemia (AML) treated similarly show different toxicity and leukemic responses. We investigated associations between neutrophil recovery time after the first induction course, infection and relapse in children treated according to NOPHO‐AML 2004 and DB AML‐01.

Procedure

Newly diagnosed patients with AML with bone marrow blast <5% between day 15 after the start of the treatment and the start of second induction course, and in complete remission after the second induction course were included (n = 279). Neutrophil recovery time was defined as the time from the start of the course to the last day with absolute neutrophil count <0.5 × 109/l. Linear and Cox regressions were used to investigate associations.

Results

Neutrophil recovery time after the first induction course was positively associated with neutrophil recovery time after the remaining courses, and longer neutrophil recovery time (≥25 days) was associated with increased risk of grade 3–4 infections (hazard ratio 1.4, 95% confidence interval [CI], 1.1–1.8). Longer neutrophil recovery time after the first induction (>30 days) was associated with the increased risk of relapse (5‐year cumulative incidence: 48% vs. 42%, hazard ratio 1.7, 95% CI, 1.1–2.6) for cases not treated with hematopoietic stem cell transplantation in first complete remission.

Conclusion

Longer neutrophil recovery time after the first induction course was associated with grade 3–4 infections and relapse. If confirmed, this knowledge could be incorporated into risk stratification strategies in pediatric AML.
Energy‐absorption performance of composite corrugated plates with corrugated‐shape ditch plug initiator
Authors: Liu Zhihui , Jiang Hongyong , Ren Yiru , Qian Zhansen , Yuan Fuh‐Gwo
Published: May 2018

To improve the energy‐absorbing capacity of composite corrugated plate, the axial impact responses under axial quasi‐static crush loading is numerically studied and compared. Both the intra‐ply damage and delamination interface damage are considered. To accurately capture the progressive damage propagation, the failure material is modeled with a stiffness degradation method combined with the exponential damage evolution laws. To improve the crush performance, a novel corrugated‐shape ditch plug initiator (CDP) is proposed. The effects of extensive parameters including the ditch width and the inner geometry are carried out. Results show that well agreements between the numerical model and experimental results are identified on failure modes and energy‐absorption characteristics. The corrugated plate with CDP can increase the specific energy absorption by 20.3% than non‐plug initiator. The total of energy absorption is the decreasing function with respect to the width of ditch. The crushing performance can be improved due to the change in the inner geometry parameters. POLYM. COMPOS., 40:1708–1717, 2019. © 2018 Society of Plastics Engineers
The Limits of Primary Radiation Forces in Bulk Acoustic Standing Waves for Concentrating Nanoparticles
Authors: Reyes Christopher , Fu Lin , Suthanthiraraj Pearlson P. A. , Owens Crystal E. , Shields C. Wyatt , López Gabriel P. , Charbonneau Patrick , Wiley Benjamin J.
Published: May 2018

Acoustic waves are increasingly used to concentrate, separate, and pattern nanoparticles in liquids, but the extent to which nanoparticles of different size and composition can be focused is not well‐defined. This article describes a simple analytical model for predicting the distribution of nanoparticles around the node of a 1D bulk acoustic standing wave over time as a function of pressure amplitude, acoustic contrast factor (i.e., nanoparticle and fluid composition), and size of the nanoparticles. Predictions from this model are systematically compared to results from experiments on gold nanoparticles of different sizes to determine the model's accuracy in estimating both the rate and the degree of nanoparticle focusing across a range of pressure amplitudes. The model is further used to predict the minimum particle size that can be focused for different nanoparticle and fluid compositions, and those predictions are tested with gold, silica, and polystyrene nanoparticles in water. A procedure combining UV‐light and photoacid is used to induce the aggregation of nanoparticles to illustrate the effect of nanoparticle aggregation on the observed degree of acoustic focusing. Overall, these findings clarify the extent to which acoustic resonating devices can be used to manipulate, pattern, and enrich nanoparticles suspended in liquids.
Monodispersed Bioactive Glass Nanoparticles Enhance the Osteogenic Differentiation of Adipose‐Derived Stem Cells through Activating TGF‐Beta/Smad3 Signaling Pathway
Authors: Guo Yi , Xue Yumeng , Niu Wen , Chen Mi , Wang Min , Ma Peter X. , Lei Bo
Published: May 2018

It is important to understand the interaction mechanisms between nanomaterials and adipose‐derived stem cells for biomedical application. Nanoscale bioactive glass has positive effects on guiding osteoblasts differentiation and bone regeneration. However, the effects and molecular mechanism of monodispersed bioactive glass nanoparticles on the osteogenic differentiation of adipose‐derived stem cells are still not clear up to now. In this study, the effects and underlying molecular mechanism of monodispersed bioactive glass nanoparticles on the osteogenic differentiation of adipose‐derived stem cells are investigated in minute detail. The results show that nanoparticles (100–200 nm) can be absorbed by stem cells and is distributed in cytoplasm and nucleus. In both culture conditions (normal and osteoinductive), nanoparticles (80 µg mL−1) can significantly enhance the osteogenic differentiation of stem cells through upregulating the alkaline phosphatase activity, osteogenic genes and protein expressions, as well as calcium deposition. Further study suggests that the activation of transforming growth factor‐beta/Smad3 signaling pathway plays an important role in the osteogenic differentiation of adipose‐derived stem cells enhanced by monodispersed nanoparticles. This study may have important implications for better understanding of stem cells fate induced by monodispersed nanoparticles and provide a promising approach toward stem cells‐based bone regeneration.
Neuromorphic Computing with Memristor Crossbar
Authors: Zhang Xinjiang , Huang Anping , Hu Qi , Xiao Zhisong , Chu Paul K.
Published: May 2018

Neural networks, one of the key artificial intelligence technologies today, have the computational power and learning ability similar to the brain. However, implementation of neural networks based on the CMOS von Neumann computing systems suffers from the communication bottleneck restricted by the bus bandwidth and memory wall resulting from CMOS downscaling. Consequently, applications based on large‐scale neural networks are energy/area hungry and neuromorphic computing systems are proposed for efficient implementation of neural networks. Neuromorphic computing system consists of the synaptic device, neuronal circuit, and neuromorphic architecture. With the two‐terminal nonvolatile nanoscale memristor as the synaptic device and crossbar as parallel architecture, memristor crossbars are proposed as a promising candidate for neuromorphic computing. Herein, neuromorphic computing systems with memristor crossbars are reviewed. The feasibility and applicability of memristor crossbars based neuromorphic computing for the implementation of artificial neural networks and spiking neural networks are discussed and the prospects and challenges are also described.
Spectral Characteristics of Mn2+ Doped Na5Lu9F32 Single Crystals
Authors: Yi Ran , Hu Jianxu , Xia Haiping , Zhang Jianli , Zhu Yongsheng , Chen Baojiu
Published: May 2018

Mn2+ ion doped Na5Lu9F32 single crystals are grown by an improved Bridgman method. The absorption and fluorescence spectrum of single crystals in the range of 300–800 nm are measured to investigate the spectral properties. Fluorescent band centered at 550 nm was observed in the fluorescence spectrum of the crystals corresponding to the 4T1(4G) → 6A1(6S) transition of the Mn2+ ion. An excitation peak of 400 nm is observed in the excitation spectrum due to the charge transfer transition of electrons from the ground state to the conduction band. The calculated values for the crystal field (Dq) and Racah parameters indicate that a stable cubic crystal structure of Mn2+ ion surrounded by eight F− ligands can be formed with the introduction of Mn2+ ion into Na5Lu9F32 single crystals.
The effect of topical piperine combined with narrowband UVB on vitiligo treatment: A clinical trial study
Authors: Shafiee Anoosh , Hoormand Mahmood , Shahidi‐Dadras Mohammad , Abadi Alireza
Published: May 2018

Vitiligo is the most common acquired hypopigmentary disease in the community. Piperine as an herbal extract derived from black pepper has strong impact on the melanocyte proliferation and adverse side effects less than synthetic drugs such as corticosteroids. For the first time, this study was aimed to evaluate the effect of topical piperine combined with narrowband ultraviolet B (NB‐UVB) on vitiligo treatment. In this double‐blind clinical trial, 63 patients with facial vitiligo were randomly divided into 2 groups: treated with piperine (case) and placebo (control). Also, both groups received NB‐UVB phototherapy every other day for 3 months. In the case group, 10 patients have burning sensation on their skin areas (p value = .002). Also, redness of the treated areas was observed in 6 patients (p value = .028). Both side effects were temporary. Regarding repigmentation at time intervals of 1, 2, and 3 months after treatment, its level in the case group was significantly higher than the control group (p value < .001). Based on our findings, the combination therapy with NB‐UVB/topical piperine has more influence on facial vitiligo than that of NB‐UVB alone. It could be concluded that the simultaneous use of NB‐UVB and topical piperine has a remarkable effect on treatment of vitiligo.
Comparative analysis of symmetric division deg index as potentially useful molecular descriptor
Authors: Furtula Boris , Ch. Das Kinkar , Gutman Ivan
Published: May 2018

There are several dozens of vertex–degree–based (VDB) molecular structure descriptors currently studied and proposed to be used in quantitative structure‐property/activity relationships (QSPR/QSAR) researches. Among them, just a couple are recognized as promising and worth of practical applications. One of the newest is the symmetric division deg index (SDD). This article is devoted to a thorough multifaceted analysis of SDD and its comparison with other VDB topological indices. We show that the applicative potential of SDD is comparable to already well‐established VDB structure descriptors. Additionally, some of conducted tests indicate its supremacy over other VDB molecular indices.
Computational strategies for predicting free radical scavengers' protection against oxidative stress: Where are we and what might follow?
Authors: Galano Annia , Raúl Alvarez‐Idaboy Juan
Published: May 2018

Oxidative stress, which is frequently induced by an overproduction of free radicals (FR), poses a high risk to human health. Thus, finding efficient strategies for scavenging FR is a research area of current interest. Among many other aspects, this involves identifying chemical compounds capable of offering antioxidant protection (AOP) and quantifying such protection. This review summarizes different computational approaches that can contribute to gain a deeper knowledge on this subject. Several reaction mechanisms that may contribute to AOP are discussed, as well as some key factors influencing their relative importance including the chemical nature of the reacting FR, the polarity of the environment and the pH in aqueous solution. Kinetics‐based analyses to characterize antioxidants, through their FR scavenging activity, are presented. Trends in such activity, from the data currently available in the literature are provided. Some key aspects, regarding AOP, that still deserves further investigation, are discussed.
Determination of carbon isotope ratios for honey samples by means of a liquid chromatography/isotope ratio mass spectrometry system coupled with a post‐column pump
Authors: Kawashima Hiroto , Suto Momoka , Suto Nana
Published: May 2018

Rationale

Liquid chromatography/isotope ratio mass spectrometry (LC/IRMS) has been used to authenticate and trace products such as honey, wine, and lemon juice, and compounds such as caffeine and pesticides. However, LC/IRMS has several disadvantages, including the high cost of the CO2 membrane and blocking by solidified sodium persulfate. Here, we developed an improved system for determining carbon isotope ratios using LC/IRMS.

Methods

The main improvement was the use of a post‐column pump. Using the improved system, we determined δ13C values for glucose with high accuracy and precision (0.1‰ and 0.1‰, respectively; n = 3). The glucose, fructose, disaccharide, trisaccharide, and organic acid constituents of honey samples were analyzed using LC/IRMS.

Results

The δ13C values for glucose, fructose, disaccharides, trisaccharides, and organic acids ranged from −27.0 to −24.2‰, −26.8 to −24.0‰, −28.8 to −24.0‰, −27.8 to −22.8‰, and − 30.6 to −27.4‰, respectively. The analysis time was a third to a half of that required for analysis by previously reported methods.

Conclusions

The column flow rate could be arbitrarily adjusted with the post‐column pump. We applied the improved method to 26 commercial honey samples. Our results can be expected to be useful for other researchers who use LC/IRMS.
Fault‐tolerant leader‐follower formation control of marine surface vessels with unknown dynamics and actuator faults
Authors: Zhang Jin‐Xi , Yang Guang‐Hong
Published: May 2018

This paper concentrates on the leader‐follower formation control problem for marine surface vessels with unknown nonlinear dynamics and actuator faults. The unknown inertia matrix and multiplicative fault render the existing methods infeasible. To solve this problem, a low‐complexity prescribed performance controller is first proposed without the help of auxiliary neural/fuzzy systems or adaptive mechanisms. A modification technique is further adopted to relax the initial condition, such that global closed‐loop stability is guaranteed. Finally, simulation results illustrate the above theoretical results.