bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mesophase Structure‐Enabled Electrostrictive Property in Nylon‐12‐Based Poly(ether‐block‐amide) Copolymers
Authors: Wongwirat Thumawadee , Wang Minghuan , Huang Yanfei , Treufeld Imre , Li Ruipeng , Laoratanakul Pitak , Manuspiya Hathaikarn , Zhu Lei 
Published: July 2019

AbstractTo search for alternative electrostrictive polymers and to understand the underlying mechanism, the structure‐ferroelectric/electrostrictive property relationship for nylon‐12‐based poly(ether‐b‐amide) multiblock copolymers (PEBAX) is investigated. Two PEBAX samples are studied, namely, P6333 and P7033 with 37 and 25 mol.% of soft poly(tetramethylene oxide) (PTMO) blocks, respectively. In both samples, poorly hydrogen‐bonded mesophase facilitates electric field‐induced ferroelectric switching. Meanwhile, the longitudinal electrostrictive strain (S1)–electric field (E) loops are obtained at 2 Hz. Different from conventional poly(vinylidene fluoride‐co‐trifluoroethylene) [P(VDF‐TrFE)]‐based terpolymers, uniaxially stretched nylon‐12‐based PEBAX samples exhibit negative S1, that is, shrinking rather than elongation in the longitudinal direction. This is attributed to the unique conformation transformation of nylon‐12 crystals during ferroelectric switching. Namely, at a zero electric field, crystalline nylon‐12 chains adopt a more or less antiparallel arrangement of amide groups. Upon high‐field poling, ferroelectric domains are enforced with more twisted chains adopting a parallel arrangement of amide groups. Meanwhile, extensional S1 is observed for P6333 at electric fields above 150 MV m−1. This is attributed to the elongation of the amorphous phases (i.e., amorphous nylon‐12 and PTMO). Therefore, competition between shrinking S1 from mesomorphic nylon‐12 crystals (i.e., nanoactuation) and elongational S1 from amorphous phases determines the ultimate electrostriction behavior in stretched PEBAX films.
Tumor‐derived exosomes (TDEs): How to avoid the sting in the tail
Authors: Wan MeiHua , Ning Bo , Spiegel Sarah , Lyon Christopher J. , Hu Tony Y. 
Published: July 2019

AbstractExosomes are abundantly secreted extracellular vesicles that accumulate in the circulation and are of great interest for disease diagnosis and evaluation since their contents reflects the phenotype of their cell of origin. Tumor‐derived exosomes (TDEs) are of particular interest for cancer diagnosis and therapy, since most tumor demonstrate highly elevated exosome secretion rates and provide specific information about the genotype of a tumor and its response to treatment. TDEs also contain regulatory factors that can alter the phenotypes of local and distant tissue sites and alter immune cell functions to promote tumor progression. The abundance, information content, regulatory potential, in vivo half‐life, and physical durability of exosomes suggest that TDEs may represent a superior source of diagnostic biomarkers and treatment targets than other materials currently under investigation. This review will summarize current information on mechanisms that may differentially regulate TDE biogenesis, TDE effects on the immune system that promote tumor survival, growth, and metastasis, and new approaches understudy to counteract or utilize TDE properties in cancer therapies.
Fat suppression for ultrashort echo time imaging using a novel soft‐hard composite radiofrequency pulse
Authors: Ma Ya‐Jun , Jerban Saeed , Jang Hyungseok , Chang Eric Y. , Du Jiang 
Published: July 2019

PurposeTo design a soft‐hard composite pulse for fat suppression and water excitation in ultrashort echo time (UTE) imaging with minimal short T2signal attenuation.MethodsThe composite pulse contains a narrow bandwidth soft pulse centered on the fat peak with a small negative flip angle (–α) and a short rectangular pulse with a small positive flip angle (α). The fat magnetization experiences both tipping‐down and ‐back with an identical flip angle and thus returns to the equilibrium state, leaving only the excited water magnetization. Bloch simulations, as well as knee, tibia, and ankle UTE imaging studies, were performed to investigate the effectiveness of fat suppression and corresponding water signal attenuation. A conventional fat saturation (FatSat) module was used for comparison. Signal suppression ratio (SSR), defined as the ratio of signal difference between non‐fat‐suppression and fat‐suppression images over the non‐fat‐suppression signal, was introduced to evaluate the efficiency of the composite pulse.ResultsNumerical simulations demonstrate that the soft‐hard pulse has little saturation effect on short T2water signals. Knee, tibia, and ankle UTE imaging results suggest that comparable fat suppression can be achieved with the soft‐hard pulse and the FatSat module. However, much less water saturation is induced by the soft‐hard pulse, especially for short T2tissues, with SSRs reduced from 71.8 ± 6.9% to 5.8 ± 4.4% for meniscus, from 68.7 ± 5.5% to 7.7 ± 7.6% for bone, and from 62.9 ± 12.0% to 4.8 ± 3.2% for the Achilles tendon.ConclusionThe soft‐hard composite pulse can suppress fat signals in UTE imaging with little signal attenuation on short T2tissues.
Analysis of different phase unwrapping methods to optimize quantitative susceptibility mapping in the abdomen
Authors: Bechler Eric , Stabinska Julia , Wittsack Hans‐Jörg 
Published: July 2019

PurposeQuantitative susceptibility mapping (QSM) is heavily impacted by phase processing of gradient echo imaging data. So far, phase unwrapping algorithms have mostly been developed and tested for neuroimaging applications. In this work, a numerical human abdomen phantom was created and used to assess the feasibility of different phase unwrapping algorithms in abdominal QSM. Furthermore, in vivo data were acquired to evaluate consistency with the simulations.MethodsLaplacian‐based, quality‐guided region growing and graph‐cuts unwrapping techniques were evaluated using the numerical phantom as well as an in vivo measurement. As a quality metric, root mean square error (RMSE) was calculated in order to analyze the performance of the examined unwrapping algorithms. Subsequently, susceptibility maps were generated from the resulting phase maps and compared to the ground truth. The evaluation was carried out on the whole phantom as well as individual organs.ResultsGraph‐cuts led to the most accurate and robust results among the investigated unwrapping methods. The other algorithms showed severe errors in regions with large susceptibility changes (i.e., around the lungs). Deviations from the ground‐truth susceptibility were higher than in the previous brain simulations for all tested algorithms.ConclusionGraph‐cuts–based unwrapping algorithms should be preferred in QSM studies in the human abdomen, where large susceptibility changes occur. For further improvement of QSM studies, unwrapping algorithms should be optimized for abdominal applications.
An exact branch‐and‐price algorithm for multitasking scheduling on unrelated parallel machines
Authors: Xiong Xiaoyun , Zhou Peng , Yin Yunqiang , Cheng T. C. E. , Li Dengfeng 
Published: July 2019

AbstractWe consider the multitasking scheduling problem on unrelated parallel machines to minimize the total weighted completion time. In this problem, each machine processes a set of jobs, while the processing of a selected job on a machine may be interrupted by other available jobs scheduled on the same machine but unfinished. To solve this problem, we propose an exact branch‐and‐price algorithm, where the master problem at each search node is solved by a novel column generation scheme, called in‐out column generation, to maintain the stability of the dual variables. We use a greedy heuristic to obtain a set of initial columns to start the in‐out column generation, and a hybrid strategy combining a genetic algorithm and an exact dynamic programming algorithm to solve the pricing subproblems approximately and exactly, respectively. Using randomly generated data, we conduct numerical studies to evaluate the performance of the proposed solution approach. We also examine the effects of multitasking on the scheduling outcomes, with which the decision maker can justify making investments to adopt or avoid multitasking.
Maintaining systems with heterogeneous spare parts
Authors: Abdul‐Malak David T. , Kharoufeh Jeffrey P. , Maillart Lisa M. 
Published: July 2019

AbstractWe consider the problem of optimally maintaining a stochastically degrading, single‐unit system using heterogeneous spares of varying quality. The system's failures are unannounced; therefore, it is inspected periodically to determine its status (functioning or failed). The system continues in operation until it is either preventively or correctively maintained. The available maintenance options include perfect repair, which restores the system to an as‐good‐as‐new condition, and replacement with a randomly selected unit from the supply of heterogeneous spares. The objective is to minimize the total expected discounted maintenance costs over an infinite time horizon. We formulate the problem using a mixed observability Markov decision process (MOMDP) model in which the system's age is observable but its quality must be inferred. We show, under suitable conditions, the monotonicity of the optimal value function in the belief about the system quality and establish conditions under which finite preventive maintenance thresholds exist. A detailed computational study reveals that the optimal policy encourages exploration when the system's quality is uncertain; the policy is more exploitive when the quality is highly certain. The study also demonstrates that substantial cost savings are achieved by utilizing our MOMDP‐based method as compared to more naïve methods of accounting for heterogeneous spares.
Placenta Stem/Stromal Cell–Derived Extracellular Vesicles for Potential Use in Lung Repair
Authors: Kim Sally Yunsun , Joglekar Mugdha V. , Hardikar Anandwardhan A. , Phan Thanh Huyen , Khanal Dipesh , Tharkar Priyanka , Limantoro Christina , Johnson Jancy , Kalionis Bill , Chrzanowski Wojciech 
Published: July 2019

AbstractMany acute and chronic lung injuries are incurable and rank as the fourth leading cause of death globally. While stem cell treatment for lung injuries is a promising approach, there is growing evidence that the therapeutic efficacy of stem cells originates from secreted extracellular vesicles (EVs). Consequently, EVs are emerging as next‐generation therapeutics. While EVs are extensively researched for diagnostic applications, their therapeutic potential to promote tissue repair is not fully elucidated. By housing and delivering tissue‐repairing cargo, EVs refine the cellular microenvironment, modulate inflammation, and ultimately repair injury. Here, the potential use of EVs derived from two placental mesenchymal stem/stromal cell (MSC) lines is presented; a chorionic MSC line (CMSC29) and a decidual MSC cell line (DMSC23) for applications in lung diseases. Functional analyses using in vitro models of injury demonstrate that these EVs have a role in ameliorating injuries caused to lung cells. It is also shown that EVs promote repair of lung epithelial cells. This study is fundamental to advancing the field of EVs and to unlock the full potential of EVs in regenerative medicine.
OLFM4 Expression in Ductal Carcinoma In Situ and in Invasive Breast Cancer Cohorts by a SWATH‐Based Proteomic Approach
Authors: Valo Isabelle , Raro Pedro , Boissard Alice , Maarouf Amine , Jézéquel Pascal , Verriele Véronique , Campone Mario , Coqueret Olivier , Guette Catherine 
Published: July 2019

AbstractHuman olfactomedin‐4 (OLFM4) is a secreted protein involved in a variety of cellular functions including proliferation, differentiation, apoptosis, and cell adhesion. OLFM4 expression has been studied in several tumor types including gastric, colorectal, lung, and endometrioid cancers where it has been suggested to be an independent favorable or unfavorable prognostic marker. For breast cancer, the clinical significance of OLFM4 is still unclear. In the present study, SWATH‐MS is used as a tool for the robust identification and quantification of breast tissue proteins. SWATH‐MS data show that OLFM4 expression is higher in DCIS than in invasive breast cancer. In‐depth analysis of the breast tumor proteome show that OLFM4 is a favorable pronostic marker. Serum OLFM4 levels in peripheral blood are also analyzed by ELISA in 825 cases, including 94 cases of healthy individuals, 61 cases of non‐invasive breast tumor (DCIS) and 670 cases of breast cancer (BC). It is found that serum OLFM4 levels are significantly higher in the DCIS cohort and in the breast cancer cohort compared with the healthy controls. This result suggests that circulating OLFM4 could be an interesting biomarker of early breast cancer. Data are available via ProteomeXchange with identifier PXD014194.
The impact of horizontal atmospheric resolution in modelling air–sea heat fluxes
Authors: Wu Peili , Roberts Malcolm , Martin Gill , Chen Xiaolong , Zhou Tianjun , Vidale Pier L. 
Published: July 2019

AbstractClimate modes as simulated by global climate models are often found to be considerably weaker than are observed. One possibility is that coarse‐resolution climate models do not capture turbulent air–sea fluxes sufficiently. Ensemble experiments with the same atmospheric configuration of the Met Office Hadley Centre climate model, forced with observed sea‐surface temperatures (SST) and at three different horizontal model resolutions (approximately 130, 60 and 25 km), are used to test the sensitivity of air–sea surface heat and moisture fluxes. We find that, although global mean budgets at the three resolutions are very similar, substantial differences appear in regional air–sea flux patterns. Increased model resolution consistently enhances zonal‐mean air–sea fluxes in the mid–high latitudes while suppressing heat fluxes in the low latitudes and weakening the Hadley Circulation. In the North Atlantic, annual mean surface heat fluxes into the atmosphere along the Gulf Stream/North Atlantic Current and over the sub‐polar gyre can increase by up to 10 W/m2 when atmospheric model resolution increases from 130 to 60 km. In the Pacific, increased model resolution tends to weaken the Walker Circulation with increased heat fluxes from the east but markedly reduced fluxes from the western Pacific, leading to significantly improved precipitation over the tropical western Pacific and the Maritime Continent. Changes in air–sea heat fluxes come about mainly as a result of changed near‐surface ventilation. Generally, increasing resolution strengthens surface winds and reduces specific humidity in the mid–high latitudes while weakening surface winds over the Tropics and subtropics.
Impact of atmospheric conditions and levels of urbanization on the relationship between nocturnal surface and urban canopy heat islands
Authors: Feng Jia‐Li , Cai Xiao‐Ming , Chapman Lee 
Published: July 2019

AbstractPrevious investigations of urban heat islands (UHI) are primarily focused either on the canopy heat island intensity (aUHII) derived from weather stations, or on the surface urban heat island intensity (sUHII) derived from satellite instruments. Research of the relationship between sUHII and aUHII (the sUHII‐aUHII relationship) is limited and this study attempts to further progress this possibility by examining the night‐time sUHII‐aUHII relationship for three factors: season, wind speed (WS), and basic land‐use categories modified from local climate zones (urban/suburban), in Birmingham, United Kingdom. Using high‐resolution datasets of canopy air temperature from Birmingham Urban Climate Laboratory and land surface temperature from the MODIS instrument aboard the Terra and Aqua satellites, with a unique methodology of regression analysis, confidence ellipse analysis of covariance (ANCOVA), and 2‐D Kolmogorov–Smirnov (K‐S) tests, statistical evidence is provided to present the varying patterns and magnitudes between sUHII and aUHII. The significance of the impact of the three considered factors is clearly supported by the statistical tests. The results indicate that satellite data can be used to infer aUHII with a higher confidence for low WS conditions. Results also demonstrate better confidence in the approach for summer and spring seasons, and for more urbanized sites. Indeed, the analysis potentially indicates that wind advection is a key factor for the investigation of the sUHII‐aUHII relationship. Overall, the methods used here are transferable to other cities and/or can be used to guide further research to explore the sUHII‐aUHII relationship under other environmental conditions.
Event‐triggered filter design for Markovian jump delay systems with nonlinear perturbation using quantized measurement
Authors: Xia Weifeng , Zheng Wei Xing , Xu Shengyuan 
Published: July 2019

SummaryThis paper deals with the problem of mixed passivity and H∞ filter design for a class of Markovian jump delay systems with nonlinear perturbation under event‐triggered scheme and quantization. Firstly, based on an integral inequality, a new sufficient condition for the stochastic stability and performance analysis of the filtering error system is proposed. Secondly, a mode‐dependent condition for the solvability of the filter design problem is given in terms of linear matrix inequalities (LMIs). The filter parameters can be derived using feasible solutions of the presented LMIs. Finally, three numerical examples are given to illustrate the effectiveness and advantages of the proposed filter design method.
Robust FOPID controller design for fractional‐order delay systems using positive stability region analysis
Authors: Zhang Shuo , Liu Lu , Cui Xinshu 
Published: July 2019

SummaryIn this paper, a robust fractional‐order PID (FOPID) controller design method for fractional‐order delay systems is proposed based on positive stability region (PSR) analysis. Firstly, the PSR is presented to improve the existing stability region (SR) in D‐decomposition method. Then, the optimal fractional orders λ and μ of FOPID controller are achieved at the biggest three‐dimensional PSR, which means the best robustness. Given the optimal λ and μ, the other FOPID controller parameters kp, ki, kd can be solved under the control specifications, including gain crossover frequency, phase margin, and an extended flat phase constraint. In addition, the steps of the proposed robust FOPID controller design process are listed at length, and an example is given to illustrate the corresponding steps. At last, the control performances of the obtained robust FOPID controller are compared with some other controllers (PID and FOPI). The simulation results illustrate the superior robustness as well as the transient performance of the proposed control algorithm.
Is your playing field unleveled? U.S. defense contracts and foreign firm lobbying
Authors: Kim Jin Hyung 
Published: July 2019

AbstractResearch SummaryPrior research in political strategy shows that political capital is critical in achieving desirable nonmarket strategy outcomes. Less attention has been paid to the fact that firms vary in their ability to acquire political capital. Foreign firms, which typically suffer from the liability of foreignness, have difficulty acquiring and strengthening political capital in a host country. Drawing on the literatures on political capital, the liability of foreignness, and certification, I argue that relying on outside political capital—that is, hiring outside lobbyists—helps foreign multinational enterprises (MNEs) achieve better nonmarket outcomes, thanks to outside lobbyists' certifying role as political insiders. Empirically, the study examines U.S. Department of Defense weapons‐system prime contracts awarded to 20,301 U.S. and foreign‐owned defense contractors from 1998 through 2006. This study has theoretical and practical implications for studies on political capital, international business, and nonmarket strategies.Managerial SummaryPolitical capital is assumed to be critical in nonmarket strategy to achieve positive firm outcomes, particularly in industries where political and regulatory players play an important role. However, due to certain industry or firm characteristics, some firms are at a disadvantaged position in acquiring and consolidating the political capital they need. In this research, I argue that one of the factors creating such disadvantage is foreignness. The results indicate that for those foreign firms with a liability of foreignness, relying on outside lobbyists is beneficial to overcome the disadvantages and to achieve better nonmarket outcomes because outside professional lobbyists can ease information flows between political and regulatory players and foreign firms through their trustworthiness as political insiders.
Under pressure: Reputation, ratings, and inaccurate self‐reporting in the nursing home industry
Authors: Ody‐Brasier Amandine , Sharkey Amanda 
Published: July 2019

AbstractResearch SummaryThis paper examines firms' strategic responses to reputational pressures in a critical healthcare domain—the U.S. nursing home industry. We investigate whether organizations improved in terms of care quality following an exogenous change in the required number of nursing hours associated with star‐based ratings to which nursing homes are subject. We show that although firms at risk of losing a star tended to self‐report higher staffing levels after the policy change, these reported increases were not associated with improvements in an important patient outcome—bedsores. These findings are consistent with false reporting of staffing data, or insufficient or ineffective hiring practices. Although we cannot definitively establish the existence of false reporting, supplementary analyses offer little support for the latter two possibilities.Managerial SummaryThird‐party ratings systems often stipulate that firms meet certain standards to attain a favorable evaluation. Firms must make strategic decisions about whether and how to comply with these. This paper examines firms' strategic responses to changes in the required number of nursing hours associated with star‐based ratings in the nursing home industry. Our results indicate that firms at risk of losing a star responded by reporting staffing increases. However, we find no concurrent improvement in a patient outcome that previous research suggests should change as a result of increased staffing. We investigate whether the lack of improvement may be due to insufficient or ineffective hiring, and find scant evidence of either one. Although we lack direct evidence of false reporting, our findings suggest this as a strong possibility.