bluuebunny/crossref_metadata_2025_split huggingface dataset:
Externally Controlled Nanomachines on Mesoporous Silica Nanoparticles for Biomedical Applications
Authors: Rühle Bastian , Saint‐Cricq Philippe , Zink Jeffrey I. 
Published: February 2016

AbstractMany machines (including nanomachines) consist of a solid support with moving parts that can undergo large amplitude motion to carry out specific tasks. In this Minireview, we will describe nanomachines that are supported on mesoporous silica nanoparticles that are typically 50–100 nanometers in diameter and have an array of open, readily accessible pores with an average width of a few nanometers. For triggering a large amplitude motion of the moving parts, we will focus primarily on external stimuli such as heat or light. As for the specific task the machines are carrying out, this Minireview will focus on the controlled release of pharmaceutically active agents in biomedical applications. We will discuss examples of how nanomachines can be used for remotely controlled cargo release and how existing machines that were originally designed to respond to internal physiological stimuli could be reconfigured to respond to external stimuli instead.
Limits of Molecular Dithienylethene Switches Caused by Ferrocenyl Substitution
Authors: Escribano Alejandra , Steenbock Torben , Herrmann Carmen , Heck Jürgen 
Published: February 2016

AbstractThe efficiency of photochromic switches can be modified by attaching organic or organometallic groups to the photochromic core. We studied ferrocene‐substituted dithienylethene switches differing by the size of the cycloalkene ring bridging the two thiophene groups. The results were compared with their chlorine‐substituted counterparts and an ethynyl‐ferrocene substituted switch published earlier by Guirado and co‐workers. From the measured UV/Vis spectra, both ferrocene‐substituted compounds were found to be considerably less likely to switch than the corresponding chlorine‐substituted ones. Kohn–Sham density functional theory calculations suggested that this is due to a multitude of energetically close‐lying excited states in the former, which may offer multiple pathways for excitation and relaxation, out of which only one leads to ring opening or closing. By contrast, the chlorine‐substituted switches have one energetically more isolated state that is responsible for the switching. The increase in the available excited states in the ferrocene‐substituted switches was attributed to mixing between orbitals from the ferrocene units and the π system of the bridge.
Window functions and sigmoidal behaviour of memristive systems
Authors: Georgiou P. S. , Yaliraki S. N. , Drakakis E. M. , Barahona M. 
Published: February 2016

SummaryA common approach to model memristive systems is to include empirical window functions to describe edge effects and nonlinearities in the change of the memristance. We demonstrate that under quite general conditions, each window function can be associated with a sigmoidal curve relating the normalised time‐dependent memristance to the time integral of the input. Conversely, this explicit relation allows us to derive window functions suitable for the mesoscopic modelling of memristive systems from a variety of well‐known sigmoidals. Such sigmoidal curves are defined in terms of measured variables and can thus be extracted from input and output signals of a device and then transformed to its corresponding window. We also introduce a new generalised window function that allows the flexible modelling of asymmetric edge effects in a simple manner. Copyright © 2016 John Wiley & Sons, Ltd.
Incremental validity of the episode size criterion in binge‐eating definitions: An examination in women with purging syndromes
Authors: Forney K. Jean , Bodell Lindsay P. , Haedt‐Matt Alissa A. , Keel Pamela K. 
Published: February 2016

ABSTRACTObjectiveOf the two primary features of binge eating, loss of control (LOC) eating is well validated while the role of eating episode size is less clear. Given the ICD‐11 proposal to eliminate episode size from the binge‐eating definition, the present study examined the incremental validity of the size criterion, controlling for LOC.MethodInterview and questionnaire data come from four studies of 243 women with bulimia nervosa (n = 141) or purging disorder (n = 102). Hierarchical linear regression tested if the largest reported episode size, coded in kilocalories, explained additional variance in eating disorder features, psychopathology, personality traits, and impairment, holding constant LOC eating frequency, age, and body mass index (BMI). Analyses also tested if episode size moderated the association between LOC eating and these variables.ResultsHolding LOC constant, episode size explained significant variance in disinhibition, trait anxiety, and eating disorder‐related impairment. Episode size moderated the association of LOC eating with purging frequency and depressive symptoms, such that in the presence of larger eating episodes, LOC eating was more closely associated with these features. Neither episode size nor its interaction with LOC explained additional variance in BMI, hunger, restraint, shape concerns, state anxiety, negative urgency, or global functioning.DiscussionTaken together, results support the incremental validity of the size criterion, in addition to and in combination with LOC eating, for defining binge‐eating episodes in purging syndromes. Future research should examine the predictive validity of episode size in both purging and nonpurging eating disorders (e.g., binge eating disorder) to inform nosological schemes. © 2016 Wiley Periodicals, Inc. (Int J Eat Disord 2016; 49:651–662)
Enzymatic synthesis of steryl ferulates
Authors: Schär Aline , Nyström Laura 
Published: February 2016

Steryl ferulates are plant sterols esterified to ferulic acid, a common phenolic acid. This esterification leads to sterol esters with improved biological properties, such as antioxidant activity. Commercially available and extracted steryl ferulates from rice bran are often limited in their sterol profiles. For further research and later food applications, a simple enzymatic esterification could address the lack of availability of single steryl ferulates. Whereas several enzymatic procedures for the esterification of steryl fatty acid esters have been published, no fully enzymatic procedure for steryl ferulates has been reported so far. We optimized both direct esterification of β‐sitosterol with ferulic acid as well as transesterification with ethyl ferulate yielding steryl ferulates. The reaction was catalyzed by a lipase from Candida rugosa, which lead to yields of 35 and 55% for the direct esterification and transesterification, respectively. Moreover, both reactions followed a similar time course over incubation. The enzyme activity was rather low, which is probably due to the specificity of the different isoenzymes of C. rugosa lipase. However, successful conditions for a fully enzymatic synthesis of steryl ferulates are reported for the first time.Practical applications: This enzymatic procedure leads to steryl ferulates, which do not need thorough purification, as no toxic catalysts were applied. This is especially an advantage when animal or human studies are conducted, which are needed for further evaluation of the potential health benefits of steryl ferulates. Further, it is less labor intensive than earlier published procedures using vinyl esters as substrates, which have to be synthesized and chromatographically purified.Steryl ferulates are enzymatically synthesized using two approaches: direct esterification of ferulic acid and transesterification from ethyl ferulate yielding steryl ferulates. The two systems are optimized by surface response methodology and compared. Resulting yields of steryl ferulates after five days of incubations are 35 and 55% for the esterification and transesterification, respectively.
Ultrafast electrokinetics
Authors: Rouhi Youssefi Mehrnaz , Diez Francisco Javier 
Published: February 2016

The influence of a high electric field applied on both fluid flow and particle velocities is quantified at large Peclet numbers. The experiments involved simultaneous particle image velocimetry and flow rate measurements. These are conducted in polydimethylsiloxane channels with spherical nonconducting polystyrene particles and DI water as the background flow. The high electric field tests produced up to three orders of magnitude higher electrokinetic velocities than any previous reports. The maximum electroosmotic velocity and electrophoretic velocity measured were 3.55 and 2.3 m/s. Electrophoretic velocities are measured over the range of 100 V/cm < E < 250 000 V/cm. The results are separated according to the different nonlinear theoretical models, including low and high Peclet numbers, and weak and strong concentration polarization. They show good agreement with the models. Such fast velocities could be used for flow separation, mixing, transport, control, and manipulation of suspended particles as well as microthrust generation among other applications.
Crop biotechnology: a pivotal moment for global acceptance
Authors: Hallerman Eric , Grabau Elizabeth 
Published: February 2016

AbstractThe development and judicious use of agricultural biotechnology offers important contributions to food security and sustainability. Key contributions include improved yield, heightened pathogen and herbivore resistance, enhanced nutrient content, improved product quality, reduced spoilage, as well as entirely new traits. While a first wave of genetically engineered (GE) crop products has been commercialized and contributed to yield, other products – some posing significant benefits to target populations in the developing world – have become mired in controversy. Public misconception about nutritional and ecological risks, fears about multinational corporate dominance, as well as regulatory inaction have delayed the approval and use of GE crops. With new GE lines ready to pass through regulatory oversight, many of which originate from developing countries, we regard this as a pivotal moment for global acceptance of agricultural biotechnology. However, we note that some countries, international regulators, and even biotechnology companies seem willing to forego useful applications of GE crops. We conclude that educating and informing the public to combat misperception, and implementing review of regulatory guidelines based on decades of experience can help to realize the benefits of GE for food security, human well‐being, and ecological sustainability.
Development and Scale Up of Enhanced ORR Pt‐based Catalysts for PEMFCs
Authors: van Schalkwyk F. , Pattrick G. , Olivier J. , Conrad O. , Blair S. 
Published: February 2016

AbstractHySA/Catalysis has developed Pt‐only materials supported on Vulcan and Ketjenblack carbon, at various Pt loadings in the form of the HySA‐V and HySA‐K series of catalysts. These materials have been proven on both an ex‐situ (TF‐RDE techniques) and in situ (single cell MEA testing) basis to be on par with state‐of‐the‐art commercial benchmark materials. Despite these development achievements high‐performance platinum alloy catalysts that address sluggish oxygen reduction reaction (ORR) kinetics are required in order to minimize the precious metal content and ultimately the cost of fuel cell catalysts. Conveyed in this paper is a systematic investigation of the effect of alloying counterpart deposition sequence on the electrochemical and physical properties of the dealloyed class of advance ORR catalysts at a laboratory synthesis scale. Progression from laboratory scale synthesis to pre‐commercial production is presented and in‐situ single cell performance of scaled dealloyed catalyst materials is given.
Molecular Aberrance in Papillary Thyroid Microcarcinoma Bearing High Aggressiveness: Identifying a “Tibetan Mastiff Dog” From Puppies
Authors: Li Dapeng , Gao Ming , Li Xiaolong , Xing Mingzhao 
Published: February 2016

ABSTRACTToday the most common differentiated thyroid cancer in many countries is papillary thyroid microcarcinoma (PTMC). Although the majority of PTMCs exhibit an indolent clinical course, a few possess high risk for aggressiveness with tumor invasion, metastasis, and even patient mortality. This imposes significant confusion and often dilemma in the clinical management of PTMC. The present review summarizes the molecular pathogenesis, particularly the major genetic alterations, of PTMC that may have prognostic values in assisting risk stratification of this cancer and identification of the most aggressive cases from the many well‐behaving cases. J. Cell. Biochem. 117: 1491–1496, 2016. © 2016 Wiley Periodicals, Inc.
Characterization of Digraphic Sequences with Strongly Connected Realizations
Authors: Hong Yanmei , Liu Qinghai , Lai Hong‐Jian 
Published: February 2016

AbstractLet be a sequence of of nonnegative integers pairs. If a digraph D with satisfies and for each i with , then d is called a degree sequence of D. If D is a strict digraph, then d is called a strict digraphic sequence. Let be the collection of digraphs with degree sequence d. We characterize strict digraphic sequences d
for which there exists a strict strong digraph .
Towards high‐resolution 4D flow MRI in the human aorta using kt‐GRAPPA and B1+ shimming at 7T
Authors: Schmitter Sebastian , Schnell Susanne , Uğurbil Kâmil , Markl Michael , Van de Moortele Pierre‐François 
Published: February 2016

PurposeTo evaluate the feasibility of aortic 4D flow magnetic resonance imaging (MRI) at 7T with improved spatial resolution using kt‐GRAPPA acceleration while restricting acquisition time and to address radiofrequency (RF) excitation heterogeneities with B1+ shimming.Materials and Methods4D flow MRI data were obtained in the aorta of eight subjects using a 16‐channel transmit/receive coil array at 7T. Flow quantification and acquisition time were compared for a kt‐GRAPPA accelerated (R = 5) and a standard GRAPPA (R = 2) accelerated protocol. The impact of different dynamic B1+ shimming strategies on flow quantification was investigated. Two kt‐GRAPPA accelerated protocols with 1.2 × 1.2 × 1.2 mm3 and 1.8 × 1.8 × 2.4 mm3 spatial resolution were compared.ResultsUsing kt‐GRAPPA, we achieved a 4.3‐fold reduction in net acquisition time resulting in scan times of about 10 minutes. No significant effect on flow quantification was observed compared to standard GRAPPA with R = 2. Optimizing the B1+ fields for the aorta impacted significantly (P <  0.05) the flow quantification while specific B1+ settings were required for respiration navigators. The high‐resolution protocol yielded similar flow quantification, but allowed the depiction of branching vessels.Conclusion7T in combination with B1+ shimming allows for high‐resolution 4D flow MRI acquisitions in the human aorta, while kt‐GRAPPA limits total scan times without affecting flow quantification. J. Magn. Reson. Imaging 2016;44:486–499.
A matrix‐exponential decomposition‐based time‐domain method for band structure calculation of one‐dimensional periodic structures
Authors: Su Xiao‐Xing , Wang Yue‐Sheng , Zhang Chuanzeng , Yu Yaxin 
Published: February 2016

SummaryA time‐domain method for calculating the band structure of one‐dimensional periodic structures is proposed. During the time‐stepping of the method, the column vector containing the spatially sampled field data is updated by multiplying with an iteration matrix. The iteration matrix is first obtained by using the matrix‐exponential decomposition technique. Then, the small nonzero elements of the matrix are pruned to improve its sparse structure, so that the efficiency of the matrix–vector multiplication involved in each time‐step is enhanced. The numerical results show that the method is conditionally stable but is much more stable than the conventional finite‐difference time‐domain (FDTD) method. The time‐step with which the method runs stably can be much larger than the Courant–Friedrichs–Lewy (CFL) limit. And moreover, the method is found to be particularly efficient for the band structure calculation of large‐scale structures containing a defect with a very high wave speed, where the conventional FDTD method may generally lose its efficiency severely. For this kind of structures, not only the stability requirement can be significantly relaxed, but also the matrix‐pruning operation can be very effectively performed. In the numerical experiments for large‐scale quasi‐periodic phononic crystal structures containing a defect layer, significantly higher efficiency than the conventional FDTD method can be achieved by the proposed method without an evident accuracy deterioration if the wave speed of the defect layer is relatively high. Copyright © 2016 John Wiley & Sons, Ltd.
Spatial and temporal trends in climatic variables in arid areas of northwest China
Authors: Geng Qingling , Wu Pute , Zhao Xining 
Published: February 2016

ABSTRACTThe trends of major climatic variables at annual and seasonal scales over the past 51 years (1960–2010) in arid areas of northwest (NW) China are investigated using the Mann–Kendall test. From the results it is clear that the majority of the trends (more than 94%) showed significant increasing tendency in three annual temperature indices, including the mean temperature (Tmean), the mean minimum temperature (Tmin) and mean maximum temperature (Tmax). For Tmax, however, the significant increase was mainly the result of more significant increases in autumn. The annual and seasonal precipitation (P) series showed positive as well as negative trends. Stations with negative trends were mainly located in the Loess plateau for all of the investigated spring, autumn and annual time series. The precipitation trends in the winter exhibited consistently positive values, but most of these trends were not significant. The annual and seasonal wind speed (U) decreased significantly at the majority of the stations. More stations showed significant decreasing trends in spring than those in other seasons. The variations in the annual and seasonal relative humidity (Rh) series were relatively stable over the region. Most time series showed non‐significant changes, although both positive and negative trends were detected. The results confirmed a particularly strong recent climate change in arid areas of NW China, especially in terms of temperature and wind speed.
Wave climate projections for Ireland for the end of the 21st century including analysis of EC‐Earth winds over the North Atlantic Ocean
Authors: Gallagher Sarah , Gleeson Emily , Tiron Roxana , McGrath Ray , Dias Frédéric 
Published: February 2016

ABSTRACTThis study aims to quantify the potential impact of global climate change on Ireland's marine resource, which is of significant economic and social importance. Global climate models predict warming of the Earth's atmosphere and oceans, which will consequently affect mean sea levels, the frequency and severity of extreme weather events, winds and ocean waves. Such changes need to be carefully assessed for long‐term marine and coastal planning. We derived future wave climate projections for Ireland using the EC‐Earth global climate model and the WAVEWATCH III wave model, by comparing the future 30‐year period 2070–2099 to 1980–2009 for the RCP4.5 and the RCP8.5 forcing scenarios. This data set is currently the highest resolution wave projection data set available for Ireland. EC‐Earth predicts decreases in means (up to 3%) and extremes (up to 14% for the 95th percentile) of 10 m wind speeds over the North Atlantic Ocean (5–75°N, 0–80°W) by the end of the century. Similarly, the model projections show decreases in the frequency and intensity of wind storms crossing Ireland but these changes are not statistically significant. The WAVEWATCH III model predicts an overall decrease in mean (up to 15%) and extreme (up to 15% for the 95th percentile) annual, boreal winter and summer significant wave heights around Ireland.
Changes in physical and gelling properties of freeze‐dried egg white as a result of temperature and relative humidity
Authors: Katekhong Wattinee , Charoenrein Sanguansri 
Published: February 2016

AbstractBACKGROUNDThe quality of dried egg white with respect to functional properties can be affected by storage conditions. The effect of temperature and relative humidity (RH) on changes in colour and gelling properties in freeze‐dried egg white (FDEW) during storage was investigated.RESULTSThe glass transition temperature (Tg) of FDEW decreased with increasing % RH. The colour of FDEW stored at 60 °C was darker yellow than those at 40 and 25 °C, particularly at high % RH. RH had no effect on hardness and water‐holding capacity (WHC) of gels made from FDEW stored at 25 °C for 1 week. However, hardness and WHC of gels from FDEW stored at higher temperatures; 40 °C, 48% RH and 60 °C, 11% RH dramatically increased. These results related to the differential scanning calorimeter thermograms which showed a broadening peak with lower enthalpy of protein denaturation. Moreover, the protein's SDS‐PAGE pattern in the samples stored at high temperatures or RH levels showed protein aggregation.CONCLUSIONStorage of FDEW at high temperature and RH levels induced protein conformation changes. These have contributed to protein aggregation which affected the gelling properties of FDEW. © 2016 Society of Chemical Industry
Characterisation of potato crisp effective porosity using micro‐CT
Authors: Renshaw Ryan C , Robinson John P , Dimitrakis Georgios A , Bows John R , Kingman Samuel W 
Published: February 2016

AbstractBACKGROUNDThe effective porosity is an important quantitative parameter for food products that has a significant effect on taste and quality. It is challenging to quantify the apparent porosity of fried potato crisps as they have a thin irregularly shaped cross section containing oil and water. This study uses a novel micro‐CT technique to determine the solid volume fraction and hence the effective porosity of three types of potato crisps: standard continuously fried crisps, microwaved crisps, and continuously fried ‘kettle’ crisps.RESULTSIt was found that continuously fried kettle crisps had the lowest effective porosity at 0.54, providing the desired crunchy taste and lower oil contents. Crisps produced using a microwave process designed to mimic the dehydration process of standard continuous fried crisps had an effective porosity of 0.65, which was very similar to the effective porosity of 0.63 for standard continuously fried crisps. The results were supported by the findings of a forced preference consumer test.CONCLUSIONThe effective porosity affects the product taste and is therefore a critical parameter. This study shows that micro‐CT analysis can be used to characterise the change in effective porosity of a thin irregularly shaped food product, caused by a change of cooking procedure. © 2016 Society of Chemical Industry