bluuebunny/crossref_metadata_2025_split huggingface dataset:
Applying the ambitious science teaching framework in undergraduate biology: Responsive talk moves that support explanatory rigor
Authors: Grinath Anna S. , Southerland Sherry A. 
Published: October 2018

AbstractOrchestrating opportunities for students to engage in scientific talk in the classroom is challenging for most teachers and even more so for novice teaching assistants (TAs) who typically instruct introductory science laboratories at the postsecondary level. This study was designed to understand how TA moves are related to instances of scientific discourse in the classroom (meaning discourse that includes a high degree of explanatory rigor). For this, we examined the enactment of a planned “elicitation discussion” that took place in 26 sections of a general biology laboratory for nonscience majors. Our research was driven by two‐related questions: What patterns of discourse emerged? What TA discursive moves were related to high levels of explanatory rigor in student talk? Using conversation analysis, four distinct patterns of discourse were identified, each representing different levels of explanatory rigor. Regression analysis revealed that the type of question the TA used to initiate classroom talk was not significantly related to the students’ explanatory rigor. Rather, the most important aspect of TA talk for elevating the explanatory rigor of student discourse was TA responses to student contributions to TA's initiating questions. The implications of these findings for TA professional development are discussed.
Immunosuppression Agent Cyclosporine Reduces Self-Renewal and Vessel Regeneration Potentiation of Human Endothelial Colony Forming Cells
Authors: Sim Seen-Ling , Alexis Josue , Roy Edwige , Shafiee Abbas , Khosrotehrani Kiarash , Patel Jatin 
Published: October 2018

AbstractEndothelial colony forming cells (ECFC) and mesenchymal stem cells (MSC) combined have great potential to be used for cell therapy of ischemic vascular diseases. However, to improve allogeneic stem cell engraftment the use of immunosuppression, such as cyclosporine has been suggested. Our aim was to assess the impact of cyclosporine on hind limb revascularisation upon MSC and ECFC combination therapy. Balb/c immunocompetent mice subjected to hind limb ischemia (right femoral artery ligation) were given both human ECFC and MSC (weekly intramuscular injections) with or without cyclosporine (daily injection). Surprisingly, mice receiving cyclosporine had a significant decrease in reperfusion based on laser Doppler imaging compared to vehicle controls and had poorer limb survival. In vitro, the downstream calcineurin target NFATC4 was highly expressed in the self-renewing fraction of ECFCs. ECFCs cultured with cyclosporine had reduced colony formation capacity and tube formation in Matrigel. Lastly, ECFC displayed increased proliferation and loss of capacity for long term culture when in the presence of cyclosporine clearly showing a loss of quiescence and progenitor function. Our findings demonstrate the deleterious impact of cyclosporine on ECFC function, with significant impact on ECFC-based allogeneic cellular therapy. Stem Cells Translational Medicine 2019;8:162&7
The use of weight adjusted for height rather than body mass index to assess growth trajectory: Results from a population‐based cohort
Authors: Araújo Joana , Ramos Elisabete , Mishra Gita D. , Severo Milton 
Published: October 2018

We compared different growth models parameterizations regarding (i) adjustment of weight‐for‐height, as denoted by body mass index (BMI); (ii) adjustment for different covariates, ie, age or height; and (iii) the use of different smoothing methods, ie, polynomial, fractional polynomial, or linear splines. A total of 11 459 measurements of weight and height from 719 participants were used, obtained from the EPITeen cohort at 13, 17, and 21 years, and extracted from child health books. The individual growth curves were modeled using mixed‐effects polynomial, fractional polynomial, and linear splines, and each model parameterization included as covariate age or height. The goodness‐of‐fit of the model parametrizations was compared using the relative squared error (RSE) and the relative absolute error (RAE). The adjustment of weight‐for‐height as denoted by BMI was found to be biased, especially for extreme values of height and presented the worst fit indexes from all model parameterizations tested (RSE = 12.46%; RAE = 22.63%). Regardless of the smoothing method, the weight‐for‐height retrieved the best fit indexes in comparison to the adjustment for age. With regard to the smoothing methods and comparing weight‐for‐height model parameterizations, the fractional polynomial model performed better (RSE = 0.75%; RAE = 5.70%), followed by linear splines (RSE = 0.77%; RAE = 5.82%), and conventional polynomial (RSE = 0.91%; RAE = 6.82%). Therefore, growth modeling in pediatric age should be based on the modeling of weight‐for‐height because the use of BMI leaves residual confounding for height. Regarding the smoothing methods, although differences were relatively small, the fractional polynomials performed better in comparison to conventional polynomials and linear splines.
Picoanalysis of Drugs in Biofluids with Quantitative Label‐Free Surface‐Enhanced Raman Spectroscopy
Authors: Turzhitsky Vladimir , Zhang Lei , Horowitz Gary L. , Vitkin Edward , Khan Umar , Zakharov Yuri , Qiu Le , Itzkan Irving , Perelman Lev T. 
Published: October 2018

AbstractThe enormous increase of Raman signal in the vicinity of metal nanoparticles allows surface‐enhanced Raman spectroscopy (SERS) to be employed for label‐free detection of substances at extremely low concentrations. However, the ultimate potential of label‐free SERS to identify pharmaceutical compounds at low concentrations, especially in relation to biofluid sensing, is far from being fully realized. Opioids are a particular challenge for rapid clinical identification because their molecular structural similarities prevent their differentiation with immunolabeling approaches. In this paper, a new method called quantitative label‐free SERS (QLF‐SERS) which involves the formation of halide‐conjugated gold nanoclusters trapping the analyte of interest near the SERS hot spots is reported, and it is demonstrated that it yields a 105 fold improvement in the detection limit over previously reported results for the entire class of clinically relevant opioids and their metabolites. Measurements of opioid concentrations in multicomponent mixtures are also demonstrated. QLF‐SERS has comparable detection limits as currently existing laboratory urine drug testing techniques but is significantly faster and inexpensive and, therefore, can be easily adapted as part of a rapid clinical laboratory routine.
Paper Origami‐Inspired Design and Actuation of DNA Nanomachines with Complex Motions
Authors: Zhou Lifeng , Marras Alexander E. , Huang Chao‐Min , Castro Carlos E. , Su Hai‐Jun 
Published: October 2018

AbstractSignificant progress in DNA nanotechnology has accelerated the development of molecular machines with functions like macroscale machines. However, the mobility of DNA self‐assembled nanorobots is still dramatically limited due to challenges with designing and controlling nanoscale systems with many degrees of freedom. Here, an origami‐inspired method to design transformable DNA nanomachines is presented. This approach integrates stiff panels formed by bundles of double‐stranded DNA connected with foldable creases formed by single‐stranded DNA. To demonstrate the method, a DNA version of the paper origami mechanism called a waterbomb base (WBB) consisting of six panels connected by six joints is constructed. This nanoscale WBB can follow four distinct motion paths to transform between five distinct configurations including a flat square, two triangles, a rectangle, and a fully compacted trapezoidal shape. To achieve this, the sequence specificity of DNA base‐pairing is leveraged for the selective actuation of joints and the ion‐sensitivity of base‐stacking interactions is employed for the flattening of joints. In addition, higher‐order assembly of DNA WBBs into reconfigurable arrays is achieved. This work establishes a foundation for origami‐inspired design for next generation synthetic molecular robots and reconfigurable nanomaterials enabling more complex and controllable motion.
Polymersomes: Breaking the Glass Ceiling?
Authors: Chidanguro Tamuka , Ghimire Elina , Liu Cheyenne H. , Simon Yoan C. 
Published: October 2018

AbstractPolymer vesicles, also known as polymersomes, have garnered a lot of interest even before the first report of their fabrication in the mid‐1990s. These capsules have found applications in areas such as drug delivery, diagnostics and cellular models, and are made via the self‐assembly of amphiphilic block copolymers, predominantly with soft, rubbery hydrophobic segments. Comparatively, and despite their remarkable impermeability, glassy polymersomes (GPs) have been less pervasive due to their rigidity, lack of biodegradability and more restricted fabrication strategies. GPs are now becoming more prominent, thanks to their ability to undergo stable shape‐change (e.g., into non‐spherical morphologies) as a response to a predetermined trigger (e.g., light, solvent). The basics of block copolymer self‐assembly with an emphasis on polymersomes and GPs in particular are reviewed here. The principles and advantages of shape transformation of GPs as well as their general usefulness are also discussed, together with some of the challenges and opportunities currently facing this area.
Mitigating Human IAPP Amyloidogenesis In Vivo with Chiral Silica Nanoribbons
Authors: Faridi Ava , Sun Yunxiang , Okazaki Yutaka , Peng Guotao , Gao Jie , Kakinen Aleksandr , Faridi Pouya , Zhao Mei , Javed Ibrahim , Purcell Anthony W. , Davis Thomas P. , Lin Sijie , Oda Reiko , Ding Feng , Ke Pu Chun 
Published: October 2018

AbstractAmyloid fibrils generally display chirality, a feature which has rarely been exploited in the development of therapeutics against amyloid diseases. This study reports, for the first time, the use of mesoscopic chiral silica nanoribbons against the in vivo amyloidogenesis of human islet amyloid polypeptide (IAPP), the peptide whose aggregation is implicated in type 2 diabetes. The thioflavin T assay and transmission electron microscopy show accelerated IAPP fibrillization through elimination of the nucleation phase and shortening of the elongation phase by the nanostructures. Coarse‐grained simulations offer complementary molecular insights into the acceleration of amyloid aggregation through their nonspecific binding and directional seeding with the nanostructures. This accelerated IAPP fibrillization translates to reduced toxicity, especially for the right‐handed silica nanoribbons, as revealed by cell viability, helium ion microscopy, as well as zebrafish embryo survival, developmental, and behavioral assays. This study has implicated the potential of employing chiral nanotechnologies against the mesoscopic enantioselectivity of amyloid proteins and their associated diseases.
Wireless, Battery‐Free Epidermal Electronics for Continuous, Quantitative, Multimodal Thermal Characterization of Skin
Authors: Krishnan Siddharth R. , Su Chun‐Ju , Xie Zhaoqian , Patel Manish , Madhvapathy Surabhi R. , Xu Yeshou , Freudman Juliet , Ng Barry , Heo Seung Yun , Wang Heling , Ray Tyler R. , Leshock John , Stankiewicz Izabela , Feng Xue , Huang Yonggang , Gutruf Philipp , Rogers John A. 
Published: October 2018

AbstractPrecise, quantitative measurements of the thermal properties of human skin can yield insights into thermoregulatory function, hydration, blood perfusion, wound healing, and other parameters of clinical interest. The need for wired power supply systems and data communication hardware limits, however, practical applicability of existing devices designed for measurements of this type. Here, a set of advanced materials, mechanics designs, integration schemes, and wireless circuits is reported as the basis for wireless, battery‐free sensors that softly interface to the skin to enable precise measurements of its temperature and thermal transport properties. Calibration processes connect these parameters to the hydration state of the skin, the dynamics of near‐surface flow through blood vessels and implanted catheters, and to recovery processes following trauma. Systematic engineering studies yield quantitative metrics in precision and reliability in real‐world conditions. Evaluations on five human subjects demonstrate the capabilities in measurements of skin hydration and injury, including examples of continuous wear and monitoring over a period of 1 week, without disrupting natural daily activities.
Spontaneous Reshaping and Splitting of AgCl Nanocrystals under Electron Beam Illumination
Authors: Tian Xuezeng , Anand Utkarsh , Mirsaidov Utkur , Zheng Haimei 
Published: October 2018

AbstractAgCl is photosensitive and thus often used as micromotors. However, the dynamics of individual AgCl nanoparticle motion in liquids upon illumination remains elusive. Here, using liquid cell transmission electron microscope (TEM), AgCl nanocrystals reshaping and splitting spontaneously in an aqueous solution under electron beam illumination are observed. It is found that the AgCl nanocrystals are negatively charged in the liquid environment, where the charge induces a repulsive Coulomb force that reshapes and stretches those nanocrystals. Upon extensive stretching, the AgCl nanocrystal splits into small nanocrystals and each nanocrystal retracts back into cuboid shapes due to the cohesive surface. This analysis shows that each nanocrystal maintains a single crystal rocksalt structure during splitting. The splitting of AgCl nanocrystals is analogous to the electrified liquid droplets or other reported the Coulomb fission phenomenon, but with distinctive structural properties. Revealing of the dynamic behavior of AgCl nanocrystals opens the opportunity to explore their potential applications as actuators for nanodevices.
A Gelatin Microdroplet Platform for High‐Throughput Sorting of Hyperproducing Single‐Cell‐Derived Microalgal Clones
Authors: Li Ming , van Zee Mark , Riche Carson T. , Tofig Bobby , Gallaher Sean D. , Merchant Sabeeha S. , Damoiseaux Robert , Goda Keisuke , Di Carlo Dino 
Published: October 2018

AbstractMicroalgae are an attractive feedstock organism for sustainable production of biofuels, chemicals, and biomaterials, but the ability to rationally engineer microalgae to enhance production has been limited. To enable the evolution‐based selection of new hyperproducing variants of microalgae, a method is developed that combines phase‐transitioning monodisperse gelatin hydrogel droplets with commercial flow cytometric instruments for high‐throughput screening and selection of clonal populations of cells with desirable properties, such as high lipid productivity per time traced over multiple cell cycles. It is found that gelatin microgels enable i) the growth and metabolite (e.g., chlorophyll and lipids) production of single microalgal cells within the compartments, ii) infusion of fluorescent reporter molecules into the hydrogel matrices following a sol–gel transition, iii) selection of high‐producing clonal populations of cells using flow cytometry, and iv) cell recovery under mild conditions, enabling regrowth after sorting. This user‐friendly method is easily integratable into directed cellular evolution pipelines for strain improvement and can be adopted for other applications that require high‐throughput processing, e.g., cellular secretion phenotypes and intercellular interactions.
Core–Shell Hybrid Nanowires with Protein Enabling Fast Ion Conduction for High‐Performance Composite Polymer Electrolytes
Authors: Fu Xuewei , Wang Yu , Fan Xin , Scudiero Louis , Zhong Wei‐Hong 
Published: October 2018

AbstractIncorporating nanofillers is one of the promising approaches for simultaneously boosting the ionic conductivity and mechanical properties of solid polymer electrolytes (SPEs). However, effectively creating faster ion‐conduction pathways via nanofillers still remains a big challenge. Herein, core–shell protein–ceramic nanowires for more efficiently building fast ion‐conduction networks in SPEs are reported. The core–shell protein–ceramic nanowires are fabricated via in situ growth of protein coating on the electrospun TiO2 nanowires in a subtly controlled protein‐denaturation process. It is demonstrated that the core–shell protein@TiO2 nanowires effectively facilitate ion‐conduction. As a result, the ionic conductivity, mechanical properties, electrochemical stability, and even Li+ transference number of the SPEs with core–shell protein@TiO2 nanowires are significantly enhanced. The contributions from the 1D morphology of the protein@TiO2 nanowires, and more importantly, the favorable protein structure for further promoting ion‐conduction at the polymer–filler interfaces are analyzed. It is believed that the protein plays a pivotal role in dissociating lithium salts, which benefits from the strong interactions between protein and ions, making the protein serve as a unique “natural channel” for rapidly conducting Li+. This study initiates an effective method of promoting ionic conductivity and constructing faster ion‐conduction networks in SPEs via combining bio‐ and nanotechnology.
High‐Motility Visible Light‐Driven Ag/AgCl Janus Micromotors
Authors: Wang Xu , Baraban Larysa , Nguyen Anh , Ge Jin , Misko Vyacheslav R. , Tempere Jacques , Nori Franco , Formanek Petr , Huang Tao , Cuniberti Gianaurelio , Fassbender Jürgen , Makarov Denys 
Published: October 2018

AbstractVisible light‐driven nano/micromotors are promising candidates for biomedical and environmental applications. This study demonstrates blue light‐driven Ag/AgCl‐based spherical Janus micromotors, which couple plasmonic light absorption with the photochemical decomposition of AgCl. These micromotors reveal high motility in pure water, i.e., mean squared displacements (MSD) reaching 800 µm2 within 8 s, which is 100× higher compared to previous visible light‐driven Janus micromotors and 7× higher than reported ultraviolet (UV) light‐driven AgCl micromotors. In addition to providing design rules to realize efficient Janus micromotors, the complex dynamics revealed by individual and assemblies of Janus motors is investigated experimentally and in simulations. The effect of suppressed rotational diffusion is focused on, compared to UV light‐driven AgCl micromotors, as a reason for this remarkable increase of the MSD. Moreover, this study demonstrates the potential of using visible light‐driven plasmonic Ag/AgCl‐based Janus micromotors in human saliva, phosphate‐buffered saline solution, the most common isotonic buffer that mimics the environment of human body fluids, and Rhodamine B solution, which is a typical polluted dye for demonstrations of photocatalytic environmental remediation. This new knowledge is useful for designing visible light driven nano/micromotors based on the surface plasmon resonance effect and their applications in assays relevant for biomedical and ecological sciences.
Extensive exploration of a novel rat model of Parkinson's disease using partial 6‐hydroxydopamine lesion of dopaminergic neurons suggests new therapeutic approaches
Authors: Vetel Steven , Sérrière Sophie , Vercouillie Johnny , Vergote Jackie , Chicheri Gabrielle , Deloye Jean‐Bernard , Dollé Frédéric , Bodard Sylvie , Tronel Claire , Nadal‐Desbarats Lydie , Lefèvre Antoine , Emond Patrick , Chalon Sylvie 
Published: October 2018

AbstractParkinson's disease (PD) is characterized by the degeneration of dopaminergic (DA) neurons constituting the nigrostriatal pathway. Neuroinflammation, related to microglial activation, plays an important role in this process. Exploration of animal models of PD using neuroimaging modalities allows to better understand the pathophysiology of the disease. Here, we fully explored a moderate lesion model in the rat in which 6‐hydroxydopamine was unilaterally delivered in three sites along the striatum. The degenerative process was assessed through in vivo Positron Emission Tomography (PET) imaging and in vitro autoradiographic quantitation of the striatal dopamine transporter (DAT) and immunostaining of tyrosine hydroxylase (TH). The microglial activation was studied through in vitro autoradiographic quantitation of the 18 kDa translocator protein (TSPO) in the striatum and CD11b staining in the SN. In addition, a targeted metabolomics exploration was performed in both these structures using mass spectrometry coupled to HPLC. Our results showed a reproducible decrease in the striatal DAT density associated with a reduction in the number of TH‐positive cells in the SN and striatum, reflecting a robust moderate degeneration of nigrostriatal DA neurons. In addition, we observed strong microglia activation in both the striatum and SN ipsilateral to the lesion, highlighting that this moderate degeneration of DA neurons was associated with a marked neuroinflammation. Our metabolomics studies revealed alterations of specific metabolites and metabolic pathways such as carnitine, arginine/proline, and histidine metabolisms. These results bring new insights in the PD mechanism knowledge and new potential targets for future therapeutic strategies.
Effects of Climate‐Related Stream Factors on Patterns of Individual Summer Growth of Cutthroat Trout
Authors: Uthe P. , Al‐Chokhachy R. , Shepard B. B. , Zale A.V. , Kershner J. L. 
Published: October 2018

AbstractColdwater fishes are sensitive to abiotic and biotic stream factors, which can be influenced by climate. Distributions of inland salmonids in North America have declined significantly, with many of the current strongholds located in small headwater systems that may serve as important refugia as climate change progresses. We investigated the effects of discharge, stream temperature, trout biomass, and food availability on summer growth of Yellowstone Cutthroat Trout Oncorhynchus clarkii bouvieri, a species of concern with significant ecological value. Individual size, stream discharge, sample section biomass, and temperature were all associated with growth, but had differing effects on energy allocation. Stream discharge had a positive relationship with growth rates in length and mass; greater rates of prey delivery at higher discharges probably enabled trout to accumulate reserve tissues in addition to structural growth. Temperature effects were positive but not significant, and support in growth models was limited, likely due to the cold thermal regimes of the study area. The strength of the discharge effect on growth suggests that climate adaptation strategies for coldwater fishes that focus solely on thermal characteristics may be misleading and highlights the importance of considering multiple factors, including hydrologic regimes, in conservation planning.