gebhart/patrepeval huggingface dataset:
Hydrophobically Modified Hydroxyethyl Starch:  Synthesis, Characterization, and Aqueous Self-Assembly into Nano-Sized Polymeric Micelles and Vesicles (2007)

Hydroxyethyl starch (HES) is a water soluble semisynthetic polysaccharide that is used as a plasma volume expander and cryoprotectant. In order to produce a fully biodegradable amphiphilic polymer, HES was esterified with lauric, palmitic, and stearic acids under mild reaction conditions using dicyclohexyl carbodiimide (DCC) and dimethylaminopyridine (DMAP). The molar substitution of the acyl chains (MSfatty acid) was determined with 1H NMR spectroscopy, while the conformational state of the hydrocarbon chains in the graft copolymer was determined using Raman spectroscopy. Furthermore, the aqueous self-assembly of the modified polymer was studied using dynamic light scattering (DLS) and transmission electron microscopy (TEM). Results show the formation of 20 to 30 nm micelles, and 250 to 350 nm polymeric vesicles. Electron spin resonance (ESR) spectroscopy was used to study the microenvironment of a hydrophobic spin probe loaded inside the formed nanodispersion. It was possible to identify the location of the probe and its distribution between the micelles and vesicles. Finally, the hydrophobically modified HES might find use as a potential drug carrier, warranting the future investigation of its ability to encapsulate and deliver drug candidates.
Identification of Polymorphonuclear Leukocyte and HL-60 Cell Receptors for Adhesins of<i>Streptococcus gordonii</i>and<i>Actinomyces naeslundii</i> (2000)

Interactions of oral streptococci and actinomyces with polymorphonuclear leukocytes (PMNs), mediated by sialic acid- and Gal/GalNAc-reactive adhesins, respectively, result in activation of the PMNs and thereby may contribute to the initiation of oral inflammation. Sialidase treatment of PMNs or HL-60 cells abolished adhesion of Streptococcus gordonii but was required for adhesion of Actinomyces naeslundii. The same effects of sialidase were noted for adhesion of these bacteria to a major 150-kDa surface glycoprotein of either PMNs or undifferentiated HL-60 cells and to a 130-kDa surface glycoprotein of differentiated HL-60 cells. These glycoproteins were both identified as leukosialin (CD43) by immunoprecipitation with a specific monoclonal antibody (MAb). Adhesion of streptococci and actinomyces to a 200-kDa minor PMN surface glycoprotein was also detected by bacterial overlay of untreated and sialidase-treated nitrocellulose transfers, respectively. This glycoprotein was identified as leukocyte common antigen (CD45) by immunoprecipitation with a specific MAb. CD43 and CD45 both possess extracellular mucinlike domains in addition to intracellular domains that are implicated in signal transduction. Consequently, the interactions of streptococci and actinomyces with the mucinlike domains of these mammalian cell surface glycoproteins result not only in adhesion but, in addition, may represent the initial step in PMN activation by these bacteria.
A color fingerprint of video shot for content identification (2004)

In this paper we propose a novel space-time color feature representation for video shot and apply it to content identification. In this representation the shot is cut into <i>k</i> equal size segments, and each segment is represented by a blending image formed through averaging the pixels' values of each frame in this segment along time direction. Each blending image is then divided into equal size blocks, and two color patterns named major and minor colors among mean R,G,B are extracted for each block. Hence each shot can be represented by a fixed-length string. The experiment shows this representation is not only robust to image quality reduction, frame size and frame rate change, but also to color distortion such as brightness/contrast adjustment. We also give a video similarity measure based on this color feature to identify shot chunks. We conducted experiment on 100 video clips, and quite low error rates can be achieved when identifying small size shot chunks with significant color distortion. From the experiment we believe that this color feature is a compact and robust representation for video content, and effective for content identification.
Comparison of the Cross-linking Characteristics of Porcine Heart Valves Fixed with Glutaraldehyde or Epoxy Compounds (1993)

The concerns about currently available bioprosthetic heart valves are calcification, long-term durability, and functional and hemodynamic performance. These concerns are all more or less related to the cross-linking reagents, glutaraldehyde or formaldehyde, used in fixing bioprostheses. To address these concerns, the authors undertook the development of a porcine heart valve cross-linked with an epoxy compound. This study compared the cross-linking characteristics, shrink temperature, and moisture content of porcine heart valves fixed with epoxy compounds or glutaraldehyde. Two types of epoxy compounds, Denacol EX-313 and EX-810, or a 0.625% glutaraldehyde were used to fix the porcine aortic valves procured from a slaughter house. Samples of each group were removed at various elapsed fixation times. The shrink temperature and moisture content of the valvular leaflet and distinct layers of aortic wall of each sample were measured. Fresh porcine aortic valve was used as a control. It was found that the shrink temperature of the glutaraldehyde leaflet was the highest, whereas the moisture content of the EX-313 leaflet was the greatest among the three test groups. No significant difference in shrink temperature was observed among the epoxy compound fixed inner, middle, outer, and entire aortic walls. This implied that the cross-linking density of the epoxy compound valve was uniform throughout the entire aortic wall. The same also was observed for the glutaraldehyde fixed aortic wall.(ABSTRACT TRUNCATED AT 250 WORDS)
Stochastic network optimization with non-convex utilities and costs (2010)

This work considers non-convex optimization of time averages of network attributes in a general stochastic network. This includes maximizing a non-concave utility function of the time average throughput vector in a time-varying wireless system, subject to network stability and to an additional collection of time average penalty constraints. We develop a simple algorithm that meets all desired stability and penalty constraints, and, subject to a convergence assumption, yields a time average vector that is a local optimum of the desired utility function. We also consider algorithms that yield ¿local near optimal¿ solutions, where the distance to a local optimum can be made as small as desired with a corresponding tradeoff in average delay. Our solution uses Lyapunov optimization with a combination of stochastic dual and primal-dual techniques. We also discuss the relative advantages and disadvantages of these techniques.
A theoretical analysis of the optimal electrode thickness and porosity (2018)

<p>Using electrodes or catalytic layers that are porous increases the reactive surface area but also the distance that ions and electrons have to travel. Thicker electrodes, through their larger surface area, reduce the activation overpotential but increase the ohmic losses. There will therefore be an electrode thickness for which the voltage losses are minimal, corresponding to a maximum energy efficiency. Simple approximate relations are derived here for the value of this optimal thickness, for both Tafel and linearised Butler-Volmer kinetics. We additionally optimise the power density of Galvanic cells, the capacity of battery electrodes, and the porosity of both particulate and foam-like electrodes. For this analysis we introduce an intuitive new definition of the electrode effectiveness factor. An accurate explicit current-voltage expression, including the transition from linear to Tafel kinetics and from a single to a doubled Tafel slope, is obtained. The present analysis is limited to a configuration where ions and electrons enter and leave at opposite sides of the electrode, as in most stacks, and applies only when mass transfer effects can be neglected. These results can nonetheless be useful for optimization of various electrochemical devices including fuel cells, batteries, flow batteries, electrochemical reactors, and electrolysers.</p>
Loop gain of a spacecraft switched shunt power system (1994)

A novel approach of deriving the loop gain of a spacecraft switched shunt power system is presented. The system hardware elements contain both the analog and the digital components. Transfer functions of the analog circuits are easily identified employing the conventional approach. Gain function of the digital block is however conceived following a quite unconventional route. The digital gain is shown to include the effects of comparator thresholds, digital clock, shift register, sinusoidal amplitude, and ac frequency. The dependence of the digital gain on voltage thresholds, clocking period, and the integrational property of threshold comparator is expected. The dependence on sinusoidal amplitude contradicts the traditional concept of small signal analysis. The overall loop gain in the analytic form yields a computational result that matches the actual measurement very well. This fact proves, to some extent, the validity of the digital gain function and the basis of its derivation.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Submaximal exercise testing with near-infrared spectroscopy in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome patients compared to healthy controls: a case–control study (2015)

Relative to controls, participants with ME/CFS demonstrated higher RPE, lower TTI, and reduced dO2Hb and dHHb during repetitive handgrip exercise, although considerable variance was observed. With further study, submaximal exercise testing may prove useful for stratifying patients with a lower propensity for inducing PEM, and have the ability to establish baseline intensities for exercise prescription.
Computational structure of a biological motion-detection system as revealed by local detector analysis in the fly’s nervous system (1989)

The computations performed by individual movement detectors are analyzed by intracellularly recording from an identified direction-selective motion-sensitive interneuron in the fly's brain and by comparing these results with model predictions based on movement detectors of the correlation type. Three main conclusions were drawn with respect to the movement-detection system of the fly: (1) The essential nonlinear interaction between the two movement-detector input channels can be characterized formally by a mathematically almost perfect multiplication process. (2) Even at high contrasts no significant nonlinearities seem to distort the time course of the movement-detector input signals. (3) The movement detectors of the fly are not perfectly antisymmetrical; i.e., they respond with different time courses and amplitudes to motion in their preferred and null directions. As a consequence of this property, the motion detectors can respond to some degree to stationary patterns whose brightness is modulated in time. Moreover, the direction selectivity, i.e., the relative difference of the responses to motion in the preferred and null directions, depends on the contrast and on the spatial-frequency content of the stimulus pattern.
Polyrotaxane Networks Formed via Rotaxanation Utilizing Dynamic Covalent Chemistry of Disulfide (2008)

Polyrotaxane networks were synthesized from a mixture of poly(crown ether)s (2−5) as a trunk polymer and dumbbell-shaped bifunctional secondary ammonium salt 6 bearing a disulfide linkage and bulky end caps as a cross-linking agent in the presence of a catalytic amount of benzenethiol via a reversible thiol−disulfide interchange reaction. Trunk polymers 2−4 were prepared by copolymerization of bis(hydroxymethyl)dibenzo-24-crown-8-ether 1 and comonomers. Poly(crown ether) 5 bearing a poly(tetrahydrofuran) (PTHF) spacer was also synthesized from 1 and PTHF with 4,4′-methylenebis(phenyl isocyanate) (MDI) in N,N-dimethylacetamide (DMAc) at room temperature. The treatment of these poly(crown ether)s (2−5) with axle component 6 in the presence of benzenethiol gave the corresponding polyrotaxane networks (7−10) in quantitative yields. We confirmed the cross-linking process by monitoring the 1H NMR spectral change during the polymerization. Thermal properties, swelling, and dynamic viscoelasticity of these polyrotaxane networks were evaluated. Polyrotaxane network 10 bearing 5 afforded higher swelling and elasticity than those of other networks because of the flexibility of the trunk polymer as wheel components.
Application of Nanofluids in Engine Cooling System (2008)

<div class="htmlview paragraph">This paper made use of the strengthening heat-transfer character of nanofluids and applied nanofluids to engine cooling system. CFD numerical simulation method was employed to analyze the application value of nanofluids in engine cooling. The simulation results indicated that nanofluids could enhance engine heat dissipating capacity and Cu-water nanofluids had better heat-transfer capability. It was also found that the more concentrated of the nanoparticles, the more enhanced of the engine heat dissipating capacity. When the concentration reached 5%, the heat dissipating capacity would increase by 44.1%. With a remarkable enhancement on heat-transfer capability, the workload of the pump of engine cooling system only increased by 6%, which could be acceptable.</div>
Music Onset Detection Based on Resonator Time Frequency Image (2008)

This paper describes a new method for music onset detection. The novelty of the approach consists mainly of two elements: the time-frequency processing and the detection stages. The resonator time frequency image (RTFI) is the basic time-frequency analysis tool. The time-frequency processing part is in charge of transforming the RTFI energy spectrum into more natural energy- change and pitch-change cues that are then used as input elements for the detection of music onsets by detection tools. Two detection algorithms have been developed: an energy-based algorithm and a pitch-based one. The energy-based detection algorithm exploits energy-change cues and performs particularly well for the detection of hard onsets. The pitch-based algorithm successfully exploits stable pitch cues for the onset detection in polyphonic music, and achieves much better performances than the energy-based algorithm when applied to the detection of soft onsets. Results for both the energy-based and pitch-based detection algorithms have been obtained on a large music dataset.
Determining the Effects of Abscisic Acid Drenches on Evapotranspiration and Leaf Gas Exchange of Tomato (2011)

It is common for plants in the retail market to receive inadequate water and lose aesthetic value within a short period of time. The plant hormone abscisic acid (ABA) is naturally produced in response to drought conditions and reduces transpiration (E) by closing the stomata. Thus, ABA may lengthen shelf life of retail plants by reducing water loss. Two studies were conducted to look at effects of ABA on plant water use and shelf life over a 13-day period and short-term effects of ABA on leaf physiology. The objective of the short-term study was to determine how quickly 100-mL drenches of 250 mg·L −1 ABA solution affect leaf gas exchange of tomatoes ( Solanum lycopersicum ‘Supersweet 100’). ABA drenches reduced stomatal conductance ( g S ), E, and photosynthetic rate (P n ) within 60 min. After 2 h, E, g s , and P n were reduced by 66%, 72%, and 55% respectively, compared with the control plants. In the13-day study, ABA was applied to tomatoes as a 100-mL drench at concentrations ranging from 0 to 1000 mg·L −1 and ABA effects on water use and time to wilting were quantified. Half of the plants were not watered after ABA application, whereas the other plants were watered as needed. In general, higher ABA concentrations resulted in less water use by both well-watered and unwatered plants. ABA delayed wilting of unwatered plants by 2 to 8 days (dependent on the dose) as compared with control plants. In well-watered plants, ABA reduced daily evapotranspiration (ET) for 5 days, after which there were no further ABA effects. Negative side effects of the ABA application were rate-dependent chlorosis of the lower leaves followed by leaf abscission. These studies demonstrate that ABA drenches rapidly close stomata, limit transpirational water loss, and can extend the shelf life of retail plants by up to 8 days, which exemplifies its potential as a commercially applied plant growth regulator.
Identifying influential spreaders in complex networks (2010)

Networks portray a multitude of interactions through which people meet, ideas are spread, and infectious diseases propagate within a society. Identifying the most efficient in a network is an important step to optimize the use of available resources and ensure the more efficient spread of information. Here we show that, in contrast to common belief, the most influential spreaders in a social network do not correspond to the best connected people or to the most central people (high betweenness centrality). Instead, we find: (i) The most efficient spreaders are those located within the core of the network as identified by the k-shell decomposition analysis. (ii) When multiple spreaders are considered simultaneously, the distance between them becomes the crucial parameter that determines the extend of the spreading. Furthermore, we find that-- in the case of infections that do not confer immunity on recovered individuals-- the infection persists in the high k-shell layers of the network under conditions where hubs may not be able to preserve the infection. Our analysis provides a plausible route for an optimal design of efficient dissemination strategies.
Supervised Self-taught Learning: Actively transferring knowledge from unlabeled data (2009)

We consider the task of Self-taught Learning (STL) from unlabeled data. In contrast to semi-supervised learning, which requires unlabeled data to have the same set of class labels as labeled data, STL can transfer knowledge from different types of unlabeled data. STL uses a three-step strategy: (1) learning high-level representations from unlabeled data only, (2) re-constructing the labeled data via such representations and (3) building a classifier over the re-constructed labeled data. However, the high-level representations which are exclusively determined by the unlabeled data, may be inappropriate or even misleading for the latter classifier training process. In this paper, we propose a novel Supervised Self-taught Learning (SSTL) framework that successfully integrates the three isolated steps of STL into a single optimization problem. Benefiting from the interaction between the classifier optimization and the process of choosing high-level representations, the proposed model is able to select those discriminative representations which are more appropriate for classification. One important feature of our novel framework is that the final optimization can be iteratively solved with convergence guaranteed. We evaluate our novel framework on various data sets. The experimental results show that the proposed SSTL can outperform STL and traditional supervised learning methods in certain instances.
Edge-based placement of camera and light source for object recognition and location (2002)

The selection and placement of cameras and light sources for a vision task is an essential step in both autonomous visual sensing and standard industrial applications. A technique is presented that determines the three-dimensional region of light-source locations such that one or more specified object edges will be detected with a given edge operator. The method uses a task description that includes a list of object edges and the edge operator to be used in order to derive constraints on image contrast, surface irradiance, and light-source location. The combination of this method with prior results on camera and light-source placement can be applied to object recognition and location tasks.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Biofuels (2009)

Abstract This chapter describes the Biomass Research and Development Initiative (BRDI) through which government acts as entrepreneur. BRDI's use of public financial resources leverages both public- and private-sector R＆D. The use of public resources to support public- and private-sector R＆D lessens barriers to innovation and creates a cost-sharing environment conducive for making domestic biofuels cost competitive with gasoline. It is this cost-sharing environment that is the technology infrastructure.
Portable Sensor for the Detection of Choline and Its Derivatives Based on Silica Isoporous Membrane and Gellified Nanointerfaces (2017)

A portable amperometric ion sensor was fabricated by integrating silica isoporous membrane (SIM) and organogel composed of polyvinyl chloride and 1,2-dichloroethane (PVC-DCE) on a 3D-printed polymer chip. The detection of ionic species in aqueous samples could be accomplished by adding a microliter of sample droplet to the sensor and by identifying the ion-transfer potential and current magnitude at the water/organogel interface array templated by SIM. Thanks to the ultrasmall channel size (2-3 nm in diameter), high channel density (4 × 10<sup>8</sup> μm<sup>-2</sup>), and ultrathin thickness (80 nm) of SIM, the ensemble of nanoscopic water/organogel (nano-W/Gel) interface array behaved like a microinterface with two back-to-back hemispherical mass diffusion zones. So, the heterogeneous ion-transfer across the nano-W/Gel interface array generated a steady-state sigmoidal current wave. The detection of choline (Ch) and its derivatives, including acetylcholine (ACh), benzoylcholine (BCh), and atropine (AP), in aqueous samples was examined with this portable sensor. Using differential pulse stripping voltammetry (DPSV), the quantification of these analytes was achieved with a limit of detection (LOD) down to 1 μM. Moreover, the portable ion sensor was insensitive to various potential interferents that might coexist in vivo, owing to size-/charge-based selectivity and antifouling capacity of SIM. With this priority, the portable ion sensor was able to quantitatively determine Ch and its derivatives in diluted urine and blood samples. The LODs for Ch, ACh, AP, and BCh in urine were 1.12, 1.30, 1.08, and 0.99 μM, and those for blood samples were 3.61, 3.38, 2.32, and 1.81 μM, respectively.
Competition between 24:5n-3 and ALA for Δ6 desaturase may limit the accumulation of DHA in HepG2 cell membranes (2007)

The use of Delta 6 desaturase (D6D) twice in the conversion of alpha-linolenic acid (ALA; 18:3n-3) to docosahexaenoic acid (DHA; 22:6n-3) suggests that this enzyme may play a key regulatory role in the synthesis and accumulation of DHA from ALA. We examined this using an in vitro model of fatty acid metabolism to measure the accumulation of the long-chain metabolites of ALA in HepG2 cell phospholipids. The accumulation of ALA, eicosapentaenoic acid (20:5n-3), docosapentaenoic acid (22:5n-3), and 24:5n-3 in cell phospholipids was linearly related to the concentration of supplemented ALA over the range tested (1.8-72 microM). The accumulation of the post-D6D products of 22:5n-3, 24:6n-3 and DHA, in cell phospholipids was saturated at concentrations of >18 microM ALA. Supplementation of HepG2 cells with preformed DHA revealed that, although the accumulation of DHA in cell phospholipids approached saturation, the level of DHA in cell phospholipids was significantly greater compared with the accumulation of DHA from ALA, indicating that the accumulation of DHA from ALA was not limited by incorporation. The parallel pattern of accumulation of 24:6n-3 and DHA in response to increasing concentrations of ALA suggests that the competition between 24:5n-3 and ALA for D6D may contribute to the limited accumulation of DHA in cell membranes.