bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Three‐State System Based on Branched DNA Hybrids
Authors: He Shiliang , Richert Clemens 
Published: January 2018

AbstractThere is a need for materials that respond to chemical or physical stimuli through a change in their structure. While a transition between water‐soluble form and solid is not uncommon for DNA‐based structures, systems that transition between three different states at room temperature and ambient pressure are rare. Here we report the preparation of branched DNA hybrids with eight oligodeoxycytidylate arms via solution‐phase, H‐phosphonate‐based synthesis. Some hybrids assemble into hydrogels upon lowering the pH, acting as efficient gelators at pH 4–6, but can also transition into a more condensed solid state form upon exposure to divalent cations. Together with the homogeneous solutions that the i‐motif‐forming compounds give at neutral pH, three‐state systems result. Each state has its own color, if chromophores are included in the system. The assembly and gelation properties can be tuned by choosing the chain length of the arms. Their responsive properties make the dC‐rich DNA hybrids candidates for smart material applications.
Computational Study of the Aza‐Michael Addition of the Flavonoid (+)‐Taxifolin in the Inhibition of β‐Amyloid Fibril Aggregation
Authors: Ginex Tiziana , Trius Marta , Luque F. Javier 
Published: January 2018

AbstractInhibition of abnormal protein self‐aggregation is an attractive strategy against amyloidogenic diseases, but has found limited success due to the complexity of protein self‐assembly, the absence of fully reproducible aggregation assays, and the scarce knowledge of the inhibition mechanisms by small molecules. In this context, catechol‐containing compounds may lead to covalent adducts with amyloid fibrils that interfere with the aggregation process. In particular, the covalent adduct formed between the oxidized form of (+)‐taxifolin and an β‐amyloid (Aβ42) suggests the involvement of a specific recognition motif that enables the chemical reaction with Aβ42. In this study, we have examined the mechanisms implicated in the aza‐Michael addition of the o‐quinone species of (+)‐taxifolin with Aβ42 fibrils. The results support the binding of (+)‐taxifolin to the hydrophobic groove delimited by the edges defined by Lys16 and Glu22 residues in the fibril. The chemical reaction proceeds through the nucleophilic attack of the deprotonated amino group of a Lys16 residue in a process activated by the interaction between the o‐quinone ring with a vicinal Lys16 residue, as well as by a water‐assisted proton transfer, which is the rate‐limiting step of the reaction. This specific inhibition mechanism, which may explain the enhanced anti‐aggregating activity of oxidized flavonoids compared to fresh compounds, holds promise for developing disease‐modifying therapies.
Total Synthesis of Parvineostemonine by Structure Pattern Recognition: A Unified Approach to Stemona and Sarpagine Alkaloids
Authors: Gerlinger Christa K. G. , Krüger Sebastian , Gaich Tanja 
Published: January 2018

AbstractThrough structure pattern recognition based total synthesis we designed a synthesis in which two biogenetically unrelated natural product families (Stemona‐ and Sarpagine alkaloids) share 50 % of their synthetic sequence. In this report, the efficiency of such a strategic approach is demonstrated in the total synthesis of the Stemona alkaloid parvineostemonine, proceeding through a privileged intermediate that we have previously transformed into biogenetically completely unrelated Sarpagine alkaloids. In addition, we capitalized on the symmetry properties of the privileged intermediate, which was obtained as two regioisomers. After their separation by column chromatography the two regioisomers were converted to the corresponding pair of enantiomers by one transformation. To the best of our knowledge, this feature (conversion of regioisomers to enantiomers) has never been applied to natural product synthesis, and proved to be very valuable, since it allowed to obtain both optical antipodes of parvineostemonine in a single synthetic campaign. This not only enabled the determination of the previously undisclosed absolute configuration of the natural product, but gave 60–200 mg amounts of both enantiomers of the natural product.
Conformation change of hornet silk proteins in the solid phase in response to external stimulation
Authors: Kuroda Reiko , Kameda Tsunenori 
Published: January 2018

AbstractHornet silks adopt a variety of morphology such as fibers, sponge, films, and gels depending on the preparation methods. We have studied the conformation change of hornet silk proteins (Vespa mandarina) as regenerated films, using chiroptical spectrophotometer universal chiroptical spectrophotometer 1, which can measure true circular dichroism spectra without artifact signals that are intrinsic to solid‐state samples. The spectra showed that the proteins in films alter the conformation rapidly from the α‐helix to the coiled coil and then to a β‐sheet structure in response to heat/moisture treatment, but the transformation stopped at the coiled coil state when the sample was soaked in EtOH/water solution. Water is required for the α‐helix to the coiled coil transition, and extra energy is required for the further transition to a β‐sheet structure. This is the first successful circular dichroism study of fibril silk proteins to follow the conformation changes in the solid state. This work shows that proteins can undergo conformational changes easily even in the solid phase in response to external stimuli, and this can be traced by solid‐phase‐feasible chiroptical spectrophotometers. Application of unnatural stress to proteins gives valuable insights into their structure and characteristics.
Enzymatic decolourization of water using loofa sponge as cellular carrier: Immobilization and dye degradation performance
Authors: Mohammed Iman , Werner Anett , Schubert Markus , Hampel Uwe 
Published: January 2018

AbstractIn recent years, strong efforts have been made to develop sustainable biocatalytic decolourization processes for dye‐polluted water. In particular, dye‐oxidizing laccase enzymes immobilized on suitable carriers are promising candidates, and can be reused as long as the activity is sufficiently high.In this work, we propose, for the first time, a new methodology to immobilize laccase from Trametes hirsute on a naturally‐grown and decomposable cellular loofa sponge carrier and assess the capability to degrade dye‐polluted water. High immobilization activity is achieved and about 70 % residual activity remains after 8 cycles. Additionally, we determined homogenous and heterogeneous kinetic parameters for free and immobilized enzymes. The results reveal a four times higher Michaelis‐Menten constant of the laccase immobilized on the loofa due to mass transfer and mixing limitations in a packed bed bio‐reactor.The response surface methodology was applied to identify favourable operating conditions. In particular, dye concentration and treatment time determine the decolourization performance, while mixing velocity has only a minor effect. Eventually, the results demonstrated a remarkable dye removal capability with shorter treatment time compared to the previous studies on immobilized laccase reported in the literature.
On Equilibrium Shape of Charged Flat Drops
Authors: Muratov Cyrill B. , Novaga Matteo , Ruffini Berardo 
Published: January 2018

AbstractThe equilibrium shapes of two‐dimensional charged, perfectly conducting liquid drops are governed by a geometric variational problem that involves a perimeter term modeling line tension and a capacitary term modeling Coulombic repulsion. Here we give a complete explicit solution to this variational problem. Namely, we show that at fixed total charge a ball of a particular radius is the unique global minimizer among all sufficiently regular sets in the plane. For sets whose area is also fixed, we show that balls are the only minimizers if the charge is less than or equal to a critical charge, while for larger charge minimizers do not exist. Analogous results hold for drops whose potential, rather than charge, is fixed. © 2018 Wiley Periodicals, Inc.
Irish clinical and counselling psychologists' experiences and views of mandatory personal therapy during training: A polarisation of ethical concerns
Authors: McMahon Aisling 
Published: January 2018

Although there have been some recent changes in Ireland, the practice of mandating personal therapy during training has traditionally differed between counselling and clinical psychologists. Irish psychologists (n = 258: 170 clinical, 88 counselling) took part in a survey study of experiences and views regarding this practice. Counselling psychologists reported higher rates of lifetime and current attendance at personal therapy compared to clinical psychologists, and nearly all had experienced mandated personal therapy compared to a minority of the clinical group. However, the clinical psychologists had a high rate of attendance at personal therapy compared to that reported for their British peers, indicating a high regard for personal therapy amongst Irish clinicians despite the absence of a training mandate. Five factors were found to be independent predictors of agreement with mandating personal therapy during training—lifetime experience of personal therapy, being a counselling psychologist, experience of mandated therapy, being more recently qualified, and longer attendance at personal therapy. Thematic analysis of the psychologists' open responses regarding mandated therapy indicated that the majority believed that personal therapy was an important part of ethical, effective practice, and valuable in enhancing self‐awareness and learning from the client experience. Ethical concerns about a mandate were polarised between the two psychology specialisms, more counselling psychologists emphasising the dangers and questionable efficacy of psychologists practising psychotherapy without personal therapy experience, and more clinical psychologists questioning the efficacy and ethics of imposing a mandate on trainees. Recommendations are made regarding this issue for trainers of both specialisms.
A provably secure code‐based short signature scheme and its nontransferable variant
Authors: Rajabzadeh Asaar Maryam , Salmasizadeh Mahmoud , Aref Mohammad Reza 
Published: January 2018

SummarySignatures with partially message recovery in which some parts of messages are not transmitted with signatures to make them shorter are helpful where bandwidth is one of the critical concern. This primitive is especially used for signing short messages in applications such as time stamping, certified email services, and identity‐based cryptosystems. In this paper, to have quantum‐attack‐resistant short signatures, the first signature scheme with partially message recovery based on coding theory is presented. Next, it is shown that the proposal is secure under Goppa Parametrized Bounded Decoding and the Goppa Code Distinguishing assumptions in the random oracle model. Relying on the partially message recovery property, the proposal is shorter than Dallot signature scheme, the only provably secure and practical code‐based signature scheme, while it preserves Dallot signature efficiency. We should highlight that our scheme can be used as a building block to construct short code‐based signature schemes with special properties. To show this, we present a provably secure short designated verifier signature scheme, a nontransferable form of short signatures, which is used in electronic voting and deniable authentication protocols.
Dynamical facilitation of the ideal free distribution in nonideal populations
Authors: Street Garrett M. , Erovenko Igor V. , Rowell Jonathan T. 
Published: January 2018

AbstractThe ideal free distribution (IFD) requires that individuals can accurately perceive density‐dependent habitat quality, while failure to discern quality differences below a given perception threshold results in distributions approaching spatial uniformity. Here, we investigate the role of population growth in restoring a nonideal population to the IFD. We place a simple model of discrete patch choice under limits to the resolution by which patch quality is perceived and include population growth driven by that underlying quality. Our model follows the population's distribution through both breeding and dispersal seasons when perception limits differ in their likely influence. We demonstrate that populations of perception limited movers can approximate an IFD provided sufficient population growth; however, the emergent IFD would be temporally inconstant and correspond to reproductive events. The time to emergence of the IFD during breeding is shorter under exponential growth than under logistic growth. The IFD during early colonization of a community persists longer when more patches are available to individuals. As the population matures and dispersal becomes increasingly random, there is an oscillation in the observance of IFD, with peaks most closely approximating the IFD occurring immediately after reproductive events, and higher reproductive rates producing distributions closer to the IFD.
Fundamental contradictions among observational and experimental estimates of non‐trophic species interactions
Authors: Barner Allison K. , Coblentz Kyle E. , Hacker Sally D. , Menge Bruce A. 
Published: January 2018

AbstractThe difficulty of experimentally quantifying non‐trophic species interactions has long troubled ecologists. Increasingly, a new application of the classic “checkerboard distribution” approach is used to infer interactions by examining the pairwise frequency at which species are found to spatially co‐occur. However, the link between spatial associations, as estimated from observational co‐occurrence, and species interactions has not been tested. Here we used nine common statistical methods to estimate associations from surveys of rocky intertidal communities in the Northeast Pacific Ocean. We compared those inferred associations with a new data set of experimentally determined net and direct species interactions. Although association methods generated networks with aggregate structure similar to previously published interaction networks, each method detected a different set of species associations from the same data set. Moreover, although association methods generally performed better than a random model, associations rarely matched empirical net or direct species interactions, with high rates of false positives and true positives, and many false negatives. Our findings cast doubt on studies that equate species co‐occurrences to species interactions and highlight a persistent, unanswered question: how do we interpret spatial patterns in communities? We suggest future research directions to unify the observational and experimental study of species interactions, and discuss the need for community standards and best practices in association analysis.
Risk of stroke and bleeding in patients with heart failure and chronic kidney disease: a nationwide cohort study
Authors: Melgaard Line , Overvad Thure Filskov , Skjøth Flemming , Christensen Jeppe Hagstrup , Larsen Torben Bjerregaard , Lip Gregory Y.H. 
Published: January 2018

AbstractAimsThe aim of this study was to assess the prognostic value of chronic kidney disease (CKD) in relation to ischaemic stroke, intracranial haemorrhage, major bleeding, and all‐cause death in heart failure patients without atrial fibrillation.Methods and resultsIn this observational cohort study, heart failure patients without atrial fibrillation were identified using Danish nationwide registries. Risk of stroke, major haemorrhage, and death were calculated after 1 and 5 years to compare patients with and without CKD, ±dialysis [dialysis: CKD with renal replacement therapy (CKD‐RRT); no dialysis: CKD‐no RRT]. A total of 43 199 heart failure patients were included, among which 0.8% had CKD‐RRT and 5.9% had CKD‐no RRT. When compared with heart failure patients without CKD, both CKD‐RRT and CKD‐no RRT were associated with a higher 5 year rate of major bleeding (CKD‐RRT: adjusted hazard ratio (aHR): 2.91, 95% confidence interval (CI): 2.29 to 3.70; CKD‐no RRT: aHR: 1.28, 95% CI: 1.13 to 1.45) and all‐cause death (CKD‐RRT: aHR: 2.40, 95% CI: 2.07 to 2.77; CKD‐no RRT: aHR: 1.63, 95% CI: 1.55 to 1.73). For the endpoints of ischaemic stroke and intracranial bleeding, only CKD‐no RRT was associated with significantly higher 5 year rates (ischaemic stroke: aHR: 1.31, 95% CI: 1.13 to 1.52; intracranial haemorrhage: aHR: 1.66, 95% CI: 1.04 to 2.65).ConclusionsCompared with patients without CKD, among incident heart failure patients without atrial fibrillation, CKD both with and without dialysis was associated with a higher rate of major bleeding and all‐cause death. Only CKD‐no RRT was associated with a higher rate of ischaemic stroke and intracranial bleeding.
Improving Storage Stability of Pistachio Oil Packaged in Different Containers by Using Rosemary (Rosmarinus officinalis L.) and Peppermint (Mentha piperita) Essential Oils
Authors: Esmaeili Moein , Goli Sayed A. H. , Shirvani Atefe , Shakerardakani Ahmad 
Published: January 2018

In this study, the antioxidant capacity of rosemary (REO) and peppermint (PEO) essential oils along with butylated hydroxytoluene (BHT) is investigated on oxidative stability of pistachio oil packaged in glass and polyethylene terephthalate (PET). The essential oils (EOs) and their mixture are added at 1500 and 3000 ppm concentrations into the oil stored for 80 days at 60 °C under darkness. In order to evaluate the efficacy of antioxidants, peroxide value (PV), thiobarbituric acid, total phenolic compounds, oxidative stability index (OSI), conjugated dienes and trienes, free fatty acids (FFAs), and iodine value is measured at intervals of 20 days. The results show that natural antioxidants can reduce PV and FFA levels about five‐ and threefolds compared to control, respectively. The OSI in raw pistachio oil (16 h) reduces to 5 h, while in treated sample by REO the reduction is only to 13 h after storage. Generally, the results reveal that in all measured parameters, following order can be observed for antioxidant activity: 3000 ppm REO>3000 ppm PEO>100 ppm BHT >1500 ppm REO >1500 ppm mixed >1500 ppm PEO > control. Moreover, the findings show that glass container is better than PET to retard oxidation process.Practical Application: Pistachio oil is known as a functional and commercial oil that is susceptible to oxidation due to its high level of unsaturated fatty acids. In this work, rosemary and mint essential oils as natural antioxidant are applied for improving oxidation stability of pistachio oil.Antioxidant capacity of rosemary (REO) and peppermint (PEO) essential oils is investigated on oxidative stability of pistachio oil packaged in glass and polyethylene terephthalate (PET). The essential oils are added at 1500 and 3000 ppm concentrations into the oil stored for 80 days at 60 ºC under darkness. The results reveal that in all measured parameters, following order can be observed for antioxidant activity: 3000 ppm REO >3000 ppm PEO >100 ppm BHT >1500 ppm REO >1500 ppm mixed >1500 ppm PEO > control. The findings show that glass container is better than PET to retard oxidation process.
Capacitive coupling synchronizes autonomous microfluidic oscillators
Authors: Lesher‐Pérez Sasha Cai , Zhang Chao , Takayama Shuichi 
Published: January 2018

AbstractEven identically designed autonomous microfluidic oscillators have device‐to‐device oscillation variability that arises due to inconsistencies in fabrication, materials, and operation conditions. This work demonstrates, experimentally and theoretically, that with appropriate capacitive coupling these microfluidic oscillators can be synchronized. The size and characteristics of the capacitive coupling needed and the range of input flow rate differences that can be synchronized are also characterized. In addition to device‐to‐device variability, there is also within‐device oscillation noise that arises. An additional advantage of coupling multiple fluidic oscillators together is that the oscillation noise decreases. The ability to synchronize multiple autonomous oscillators is also a first step towards enhancing their usefulness as tools for biochemical research applications where multiplicate experiments with identical temporal‐stimulation conditions are required.
Response of braiding channel morphodynamics to peak discharge changes in the Upper Yellow River
Authors: Schuurman Filip , Ta Wanquan , Post Sander , Sokolewicz Marius , Busnelli Marcela , Kleinhans Maarten 
Published: January 2018

AbstractThe braiding intensity and dynamics in large braiding rivers are well known to depend on peak discharges, but the response in braiding and channel–floodplain transformations to changes in discharge regime are poorly known. This modelling study addresses the morphodynamic effects of increasing annual peak discharges in braiding rivers. The study site is a braiding reach of the Upper Yellow River. We estimated the effects on the larger‐scale channel pattern, and on the smaller‐scale bars, channel branches and floodplains. Furthermore, we determined the sensitivity of the channel pattern to model input parameters. The results showed that the dominant effect of a higher peak discharge is the development of chute channels on the floodplains, formed by connecting head‐cut channels and avulsive channels. Widening of the main channel by bank erosion was found to be less dominant. In addition, sedimentation on the bars and floodplains increased with increasing peak discharge. The model results also showed that the modelled channel pattern is especially sensitive to parametrization of the bed slope effect, whereas the effect of median grain size was found to be relatively small. Copyright © 2018 John Wiley & Sons, Ltd.
Outcomes utilizing intensity‐modulated radiotherapy in oropharyngeal cancers: Tonsils versus base of tongue
Authors: Kanakamedala Madhava R. , Giri Shankar P. G. , Hamilton Robert D. , Bhanat Eldrin , Vijayakumar Srinivasan 
Published: January 2018

AbstractBackgroundThe purpose of this study was to present the outcomes of oropharyngeal cancers treated with intensity‐modulated radiotherapy (IMRT) especially the differences between tonsillar and base of tongue (BOT) primaries.MethodsRetrospective analysis of 124 patients with biopsy proven squamous cell carcinomas of the oropharynx, treated with IMRT.ResultsHuman papillomavirus (HPV) association correlated with improvement in survivals in both tonsillar and BOT primaries. At the 2‐year median follow‐up, the cumulative incidences of locoregional recurrences were 8% in both the tonsil and BOT groups (P = .76) but the distant metastases were 8% in the tonsil group versus 26% in the BOT group (P = .009). Thirty percent of tonsil primaries has ≥N2c neck disease as compared to 54% of BOT. Incidence of distant metastases increases with advanced nodal classification, especially >N2c.ConclusionEven though the locoregional controls are excellent with IMRT and chemotherapy, these patients continue to fail distantly, particularly significant for the BOT group and for nodal stage >N2c.