gebhart/patrepeval huggingface dataset:
Polysaccharide-Based Polyanion–Polycation–Polyanion Ternary Systems. A Preliminary Analysis of Interpolyelectrolyte Interactions in Dilute Solutions (2011)

The present contribution deals with the preparation and characterization of ternary mixtures of polysaccharides with potential applications in the field of tissue engineering. Two natural polyanions, i.e., alginate and hyaluronic acid, and a polycation, a lactose-modified chitosan (chitlac), were mixed in dilute conditions. The miscibility between the three components was explored in the presence of different amounts of supporting simple salt. These analyses allowed to identify the experimental conditions avoiding polymer phase separation and leading to either solution of independent polymers or soluble nonstoichiometric interpolyelectrolyte complexes. The characterization of the interpolyelectrolyte complexes was tackled by means of viscometry, light scattering, fluorescence quenching, and energy transfer. The electrostatic interactions taking place among the different polyelectrolytes led to synergistic effects on the viscosity of the polymer mixtures which strongly depend on the ionic strength. It has been found that, starting from binary soluble complexes of alginate and chitlac, the addition of hyaluronan led to the dissolution of the complexes. At variance, the addition of alginate to a phase-separated binary mixture of hyaluronan and chitlac led to the formation of soluble complexes composed of all three polysaccharides and, eventually, to their dissolution. In addition, the results showed that at low ionic strength the overall properties of the ternary mixtures depend on their order of mixing.
Reversible control of solubility using functionalized nanoparticles (2016)

The paper provides a novel method for the reversible control of solubility by use of functionalized nanoparticles. The nanoparticles are functionalized with functional groups that can act as a co-solvent or anti-solvent and thus can induce either dissolution or crystallization. The process is reversible, as the solution will go back to its original state when the nanoparticles are removed. The use of magnetic nanoparticles facilitates this reversibility. Reductions in solubility (and thus crystallization) were demonstrated for d-mannitol-water, sodium chloride-water and fenofibrate-ethyl acetate systems. An increase in solubility (and thus dissolution) was demonstrated for the benzoic acid-water system and the 4-nitrophenol-water system. Reversible manipulation of solubility can be used to reduce solvent usage in dissolution and crystallization by elimination of the need for an antisolvent or co-solvent.
Detection of Trace Glucose on the Surface of a Semipermeable Membrane Using a Fluorescently Labeled Glucose-Binding Protein: A Promising Approach to Noninvasive Glucose Monitoring (2013)

We were able to measure trace amounts of glucose on the skin surface that appear to follow blood glucose levels. The present results show modest correlation with blood glucose. Nonetheless, this method may present a noninvasive alternative to tracking glucose trends.
Functional Survey for Heterologous Sugar Transport Proteins, Using Saccharomyces cerevisiae as a Host (2011)

Molecular transport is a key process in cellular metabolism. This step is often limiting when using a nonnative carbon source, as exemplified by xylose catabolism in Saccharomyces cerevisiae. As a step toward addressing this limitation, this study seeks to characterize monosaccharide transport preference and efficiency. A group of 26 known and putative monosaccharide transport proteins was expressed in a recombinant Saccharomyces cerevisiae host unable to transport several monosaccharides. A growth-based assay was used to detect transport capacity across six different carbon sources (glucose, xylose, galactose, fructose, mannose, and ribose). A mixed glucose-and-xylose cofermentation was performed to determine substrate preference. These experiments identified 10 transporter proteins that function as transporters of one or more of these sugars. Most of these proteins exhibited broad substrate ranges, and glucose was preferred in all cases. The broadest transporters confer the highest growth rates and strongly prefer glucose. This study reports the first molecular characterization of the annotated XUT genes of Scheffersomyces stipitis and open reading frames from the yeasts Yarrowia lipolytica and Debaryomyces hansenii. Finally, a phylogenetic analysis demonstrates that transporter function clusters into three distinct groups. One particular group comprised of D. hansenii XylHP and S. stipitis XUT1 and XUT3 demonstrated moderate transport efficiency and higher xylose preferences.
Use of Methacrylate-Modified Chitosan to Increase the Durability of Dentine Bonding Systems (2014)

This study aimed at investigating the effect of a methacrylate-modified chitosan on the durability of adhesive interfaces to improve the clinical performance of dental restorations. Chitosan was modified with methacrylic acid (Chit-MA70) on 16% of the amino groups. Viscosity, rheology, and (1)H NMR spectroscopy were performed to characterize the modified polysaccharide. Chit-MA70 was blended into a primer of an "etch-and-rinse" experimental adhesive system and tested on human teeth. The presence of methacrylate moieties and of residual positive charges on the polysaccharide chain allowed Chit-MA70 to covalently bind to the restorative material and electrostatically interact with demineralized dentin. The Chit-MA70 containing an adhesive system showed values of the immediate bond strength (26.0 ± 8.7 MPa) comparable to the control adhesive system (25.5 ± 8.7 MPa). However, it was shown that upon performing thermo-mechanical cycling treatment of the dental restoration on human teeth, the adhesive with the methacrylate-modified chitosan, in variance with the control adhesive, did not show any decrease in the bond strength (28.4 ± 8.8 MPa). The modified chitosan is proposed as a component of the "etch-and-rinse" adhesive system to efficiently improve the durability of dental restorations.
Possible mechanisms of switching in symmetrical two-ports based on 2D photonic crystals with magneto-optical resonators (2013)

We analyze possible mechanisms of switching in two-ports based on 2D photonic crystals (PhCs) with a magneto-optical resonator. The input and output waveguides can be side or front coupled with the resonator. The resonator operates with a dipole mode. In the switch with front coupling in the nonmagnetic state the standing dipole mode provides equal nonzero wave amplitudes in the input and output waveguides and therefore transmission of the signal from the input to output waveguides. This is the state on. The applied magnetic field normal to the plane of the PhC rotates the standing dipole mode by 90° setting the nodes in the input and output waveguides. This corresponds to the state off. On the contrary, in the switch with side coupling and nonmagnetized resonator, the standing dipole mode excited by a wave in the input waveguide has its node in the output waveguide. Therefore, the signal is reflected from the input port. This corresponds to the state off of the switch. Magnetization by a DC magnetic field produces a rotating dipole pattern in the cavity. Due to this rotating, the mode signal passes from the input port to the output one and this is the state on.
Spatial Object Tracking System Based on Linear Optical Sensor Arrays (2016)

This paper presents a low-cost novel motion tracking system using linear optical sensor arrays supplemented by a 9DOF inertial measurement unit. Each pair of the linear sensor modules is capable of tracking the 2D location of an active infrared LED light source (marker). The presented tracking system combines two of these modules to realize spatial position tracking of the LED light source. The proposed system efficiently amalgamates inertial data with optical tracking estimates to extract attitude, minimize power requirement, and improve positional accuracy. The tracking system enables high-speed, high-accuracy, and low-cost position and attitude tracking for a wide range of applications. The detailed hardware design and performance evaluation experiments of this approach are also reported. The performance of the proposed tracking system was evaluated by measuring the tracking error with respect to known trajectories of the LED light source from different distances.
Computer-aided stability analysis of spinning spacecraft with on-board liquids (1988)

A new computer algorithm identifies the dynamic equilibrium states of spinning spacecraft that contain liquids in complex, arbitrarily shaped tank configurations. This algorithm has been implemented in a computer program that determines whether liquid shifts can relocate, reorient, or destabilize a spacecraft's nominal spin axis. The program determines whether the desired spin axis is dynamically stable, estimates the extent of the stable region, and locates other possible stable states (energy traps). The algorithm is described, its theoretical basis is discussed, and a numerical example is given for a spacecraft with manifolded propellant tanks. The numerical results manifest the wobble-amplification effect described by McIntyre and others, in which a rigid-body dynamic imbalance causes the spin axis to tilt further than would be expected from simple rigid body considerations. The computer analyses generally agree with published theoretical results. Some differences, however, are identified and explained.
Design of a High-Efficiency 2.45-GHz Rectenna for Low-Input-Power Energy Harvesting (2012)

This letter presents a high-efficiency 2.45-GHz rectenna that can harvest low input RF power effectively. A new antenna with a simple structure and high gain of 8.6 dBi is proposed for the rectenna. The antenna is designed to directly match the rectifying circuit at 2.45 GHz and mismatch it at the second and third harmonics so that the use of bandpass filter between the antenna and rectifying circuit can be eliminated. The rectenna shows a maximum conversion efficiency of 83% with a load resistance of 1400 Ω. Furthermore, the overall conversion efficiency can remain 50% for the low, -17.2 dBm (corresponding power density 0.22 μW/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ) input power level.
MicroRNA silencing of tumor suppressor DLC-1 promotes efficient hepatitis C virus replication in primary human hepatocytes (2010)

The collective results of this study suggest a novel mechanism of HCV infection-associated miRNA-mediated regulation of a tumor suppressor protein that has the ability to influence cell proliferation and HCV infection-mediated liver cancer.
Electrically-controlled polymeric gels as active materials in adaptive structures (1991)

This paper presents several applications of ionizable polymeric gels that are capable of undergoing substantial expansions and contractions when subjected to changing pH environments, temperature, or solvent. Conceptual designs for smart, electrically activated devices exploiting this phenomenon are discussed. These devices have the possibility of being manipulated via active computer control as large displacement actuators for use in adaptive structures. The enabling technology of these novel devices is the use of compliant containers for the gels and their solvents, removing the difficulties associated with maintaining a bath for the gels. Though most of these devices are designed using properties well discussed in the literature, some presented near the end of this paper make use of conclusions that the authors have drawn form the literature and their own experimental work. Those conclusions about the basic mechanisms of electromechanical gels are discussed in the third part of this paper and a complete set of governing equations describing these mechanisms are presented in the fourth section. This paper concludes with a discussion of some of the ramifications of the above system of equations and a discussion on gel-driven devices and on the control of such devices. 24 refs., 6 figs., 1 tab.
Design of an Adaptive Scanning Optical Microscope for Simultaneous Large Field of View and High Resolution (2006)

In microsystems applications from micro-assembly to biological observation and manipulation, the optical microscope remains one of the most important tools. However, it suffers from the well known trade-off between resolution and field of view. Traditional solutions involve moving the sample under the microscope using a moving stage or moving the microscope itself, and switching between low and high magnification objective lenses. In this paper, we present a new optical microscope design that uses a 2-dimensional high speed, high precision steering mirror system to scan the sample. By stitching the images together as a mosaic, we have the potential to achieve both high resolution and large field of view. Working in coordination with a deformable mirror, this arrangement offers certain advantages over the current state of the art in demanding spatial-temporal observations. We describe the theory of operation, our design methodology, and present a preliminary simulated design. A reduced functionality experimental prototype has been constructed to demonstrate the basic efficacy of the concept and we demonstrate with both biological and micro-assembly examples.
High precision cavity ringdown spectrometer for carbon dioxide monitoring (2004)

A compact cavity ringdown spectrometer measures ambient concentration levels of CO2 in air with a precision of better than 0.065 ppm for 117 hours of continuous operation. The instrument demonstrates 0.14 ppm measurement variation over a 15°C ambient temperature range.
A generalized approach to parallel magnetic resonance imaging (2001)

Parallel magnetic resonance (MR) imaging uses spatial encoding from multiple radiofrequency detector coils to supplement the encoding supplied by magnetic field gradients, and thereby to accelerate MR image acquisitions beyond previous limits. A generalized formulation for parallel MR imaging is derived, demonstrating the relationship between existing techniques such as SMASH and SENSE, and suggesting new algorithms with improved performance. Hybrid approaches combining features of both SMASH-like and SENSE-like image reconstructions are constructed, and numerical conditioning techniques are described which can improve the practical robustness of parallel image reconstructions. Incorporation of numerical conditioning directly into parallel reconstructions using the generalized approach also removes a cumbersome and potentially error-prone sensitivity calibration step involving division of two distinct in vivo reference images. Hybrid approaches in combination with numerical conditioning are shown to extend the range of accelerations over which high-quality parallel images may be obtained.
Identification of a New Family of Prenylated Volatile Sulfur Compounds in <i>Cannabis</i> Revealed by Comprehensive Two-Dimensional Gas Chromatography (2021)

<i>Cannabis sativa</i> L. produces over 200 known secondary metabolites that contribute to its distinctive aroma. Studies on compounds traditionally associated with the scent of this plant have focused on those within the terpenoid class. These isoprene-derived compounds are ubiquitous in nature and are the major source of many plant odors. Nonetheless, there is little evidence that they provide the characteristic "skunk-like" aroma of <i>cannabis</i>. To uncover the chemical origins of this scent, we measured the aromatic properties of <i>cannabis</i> flowers and concentrated extracts using comprehensive two-dimensional gas chromatography equipped with time-of-flight mass spectrometry, flame ionization detection, and sulfur chemiluminescence. We discovered a new family of volatile sulfur compounds (VSCs) containing the prenyl (3-methylbut-2-en-1-yl) functional group that is responsible for this scent. In particular, the compound 3-methyl-2-butene-1-thiol was identified as the primary odorant. We then conducted an indoor greenhouse experiment to monitor the evolution of these compounds during the plant's lifecycle and throughout the curing process. We found that the concentrations of these compounds increase substantially during the last weeks of the flowering stage, reach a maximum during curing, and then drop after just one week of storage. These results shed light on the chemical origins of the characteristic aroma of <i>cannabis</i> and how volatile sulfur compound production evolves during plant growth. Furthermore, the chemical similarity between this new family of VSCs and those found in garlic (<i>allium sativum</i>) suggests an opportunity to also investigate their potential health benefits.
Limulus amoebocyte lysate test via an open-microcavity optical biosensor (2018)

Almost since its discovery, Limulus amoebocyte lysate (LAL) testing has been an important part of the pharmaceutical quality control toolkit. It allows for in vitro endotoxin testing, which has replaced tests using animals, such as using rabbits' thermal response to judge pyrogenicity of test samples, thus leading to a less expensive and faster test of parenteral pharmaceuticals and medical devices that contact blood or cerebrospinal fluid. However, limited by the detection mechanisms of the LAL assays currently used in industry, further improvement in their performance is challenging. To address the growing demand on optimizing LAL assays for increased test sensitivity and reduced assay time, we have developed an LAL assay approach based on a detection mechanism that is different from those being used in industry, namely, gel-clot, turbidimetric, and chromogenic detection. Using a unique open-microcavity photonic-crystal biosensor to monitor the change in the refractive index due to the reaction between LAL regents and endotoxins, we have demonstrated that this approach has improved the LAL assay sensitivity by 200 times compared with the commercial standard methods, reduced the time needed for the assay by more than half, and eliminated the necessity to incubate the test samples. This study opens up the possibility of using the significantly improved LAL assays for a wide range of applications.
Maggiemycin and anhydromaggiemycin: Two novel anthracyclinone antitumor antibiotics. Isolation, structures, partical synthesis and biological properties. (1989)

Two new anthracyclinone antitumor antibiotics, maggiemycin (6, NSC-D344012) and anhydromaggiemycin (8) have been isolated from a culture of an unspeciated Streptomyces (ATCC No. 39235). Bioautography against Bacillus subtilis was used for the preliminary detection of these anthracyclinones. Structures were proposed based on their UV-visible, IR, 1H NMR, 13C NMR spectra, electron impact (EI) and high-resolution EI-MS and confirmed by partial synthesis and a direct correlation with epsilon-rhodomycinone. Both the anthracyclinones are active against KB, P388 and L1210 murine tumor cell lines; however, anhydromaggiemycin was more active than maggiemycin. A number of related anthracyclinones have also been prepared and their biological activity has been determined. The structure-activity relationship of these new anthracyclinones is also discussed.
Estimation of Displacement Vectors and Strain Tensors in Elastography Using Angular Insonifications (2004)

In current practice, only one out of three components of the tissue displacement vector and one of nine components of the strain tensor are accurately estimated and imaged in ultrasound elastography. Since, only the axial component of both the displacement and strain are imaged, other important elastic parameters, such as shear strains and the Poisson's ratio, also are not imaged. Moreover, reconstruction of the Young's modulus would be significantly improved if all components of the strain tensor were available. In this paper, we describe a new method for estimating all the components of the tissue displacement vector following a quasi-static compression. The method uses displacements estimated from radiofrequency echo-signals along multiple ultrasound beam insonification directions. At each spatial location in the compressed medium, orthogonal tissue displacements in both the axial and lateral direction with respect to the direction of the applied compression are estimated by curve fitting angular displacement vector data calculated for all insonification directions. Following displacement estimation in orthogonal directions, components of the corresponding normal and shear strain tensors are estimated. Simulation and experimental results demonstrate the utility of this technique for the computation of the normal and shear strain tensors.
Adaptive analog equalization and receiver front-end control for multilevel partial-response transmission over metallic cables (1996)

This paper deals with multilevel partial-response class-IV (PRIV) transmission over unshielded twisted-pair (UTP) cables. Specifically, transmission at a rate of 155.52 Mb/s over data-grade UTP cables for local-area networking is considered. As a low-complexity method used to compensate for cable-length dependent signal distortion, adaptive analog equalization with two controlled parameters is proposed: one parameter determines a frequency-independent receiver gain, the other parameter controls the transfer characteristic of a variable analog receive-filter section. For the stepwise design of the transmit and receive filters, a combination of analytic techniques and simulated annealing is employed. First, the variable equalizer section, then the remaining fixed analog receive filter section are developed and finally the analog transmit filter is determined. The paper also describes the adjustment of the equalizer section, and the control of the sampling phase in the receiver front-end. The two equalizer parameters are controlled by an algorithm that operates on the sampled signals and adjusts these parameters to optimum settings independently of the sampling phase. The latter is controlled by a decision-directed phase-locked loop algorithm that becomes effective when equalization has been achieved. The dynamic behaviour and mean-square error in steady-state obtained with these control algorithms are investigated.