gebhart/patrepeval huggingface dataset:
Interaction Force Estimation Using Extended State Observers: An Application to Impedance-Based Assistive and Rehabilitation Robotics (2019)

This letter presents a force observer that estimates the external interaction forces from the measured joint position and joint actuation for a class of robotic manipulators. This is done without an explicit (physical) force or torque sensor, through an extended state observer (ESO) assuming a known model of the dynamics of the manipulator. It is designed to be capable of estimating relatively fast time-varying external forces. The main result shows that the proposed ESO is theoretically able to estimate unknown time-varying external forces to an arbitrary accuracy for any initial condition starting in a given compact set. Simulation results demonstrate the effectiveness of the proposed ESO. Moreover, first experimental evaluations with a healthy subject and a poststroke patient on a rehabilitation robotic platform show the feasibility of the approach in this context and highlight the importance of the quality of the dynamic model.
Modeling Type-4 Wind in Weak Grids (2018)

An existing wind power plant at ERCOT experienced poorly damped and undamped low-frequency oscillations at 3 ~ 4 Hz under weak grid condition. The objective of this paper is to shed the insight of the oscillation mechanism through linear system analysis. Two simplified models are developed and compared against a detailed model for Type-4 wind with weak grid interconnection. The detailed model includes grid-side converter's outer power/voltage control, inner current controls, phase-locked loop (PLL), and transmission line electromagnetic dynamics. The first simplified model uses a first-order delay to replace the current control loop and ignores the transmission line dynamics and PLL. The second simplified model uses the same assumptions except that PLL is considered. Linearized system block diagrams for the two simplified models are derived and compared. The mechanism of the low-frequency oscillations are explained using eigenvalue analysis and the Root-Locus method. The root causes are identified as weak grid, high wind power export, low voltage, and low PLL bandwidth. Further, the simplified model considering PLL dynamics is more accurate in low-frequency oscillation mode identification and system stability prediction.
Investigation of direct flux measurements in switched reluctance motors (2008)

This paper investigates the use embedded magnetic field sensors in estimating the torque produced by a switched reluctance motor. Recent advances in nanomaterials have enabled the development of very compact magnetic field sensors based on the Giant Magneto Resistive (GMR) effect. This provides a direct measurement of internal magnetic flux levels of an electric machine during operation. With this capability, results are applied analytically to a switched reluctance motor to measure the flux distribution across the surface of a stator tooth. This data is then used in a discrete form of the Maxwell stress tensor to approximate the net torque at the motor shaft. Detailed results are given from a finite element study of a commercially produced switched reluctance motor.
Microtissue engineering root canal dentine with crosslinked biopolymeric nanoparticles for mechanical stabilization (2018)

This study highlighted the potential of root canal dentine microtissue engineering with crosslinked chitosan nanoparticle to improve radicular strain distribution patterns in instrumented canals.
Phase Evolution and Formation Process of Compound during Ball Milling of a Mixture of Ti and B Powders (1993)

A powder premix of Ti and B (Ti:B=1:2) was vibratory ball milled with steel balls of six sizes ranging from φ4.76 to φ25.4 mm, at powder/ball weight ratios ranging from 1/50 to 1/200, to investigate the effects of milling ball size and powder/ball weight ratio on the formation of Ti-B compound during milling. The formation process was studied by X-ray diffraction analysis and SEM observation of the milled powders. During milling, the temperature of the milling container was measured by a thermocouple attached to the side-surface of the container. The phase of the milled powders in general changed from the mixture of the elementary Ti and B to an amorphous phase and then to a crystalline compound phase. This sequence of the phase change is similar to that in the phase change process of combustion synthesis proposed by Merzhanov. An exothermic temperature spike was observed during milling when milled with steel balls of the size of φ19.1 mm or more. During this temperature increase, the amorphous phase rapidly changed into the crystalline compound phase and fine particles in a size range from several tens to several hundreds of nanometers were formed. On the other hand, no temperature spike was observed when milled with balls of the size of φ17.5 mm or less. The phase change from amorphous to crystalline and the formation of the fine particles occurred gradually. Both the ball size and the powder/ball weight ratio affected the exothermic behavior, the milling time required to start the temperature spike and the magnitude of the temperature increase.
Emotional state recognition in customer service dialogues through telephone line (2011)

An automatic monitoring technique has been developed for the detection of the degree of the discontentment of the customer during a spontaneous conversation between the customer and the dispatcher through telephone. After the acoustic preprocessing clause sized segments were classified according to its emotional content, using support vector machine (SVM) classifier. A 15 sec long monitoring window was selected, and the clauses, which were automatically classified as “discontent” emotion, were counted in this window. Then, the window was moved forward, by 10 sec time steps. On the base of this monitoring technique it is possible to sign when the discontentment level has reached a critical “alarm level”.
Rapid crystallization of T4 lysozyme by intermolecular disulfide cross-linking (1994)

In an attempt to facilitate crystallization, engineered cysteines were used to promote formation of a 'back-to-back' dimer that occurs in different crystal forms of wild-type and mutant T4 lysozymes. The designed double mutant, N68C/A93C, in which the surface residues Asn68 and Ala93 were replaced by cysteines, formed dimers in solution and crystallized isomorphously to wild-type, but at a much faster rate. Overall, the mutant structure remained very similar to wild-type despite the formation of two intermolecular disulfide bridges. The crystals of cross-linked dimers ahd thermal factors somewhat lower than wild-type, indicating reduced mobility, but did not diffract to noticeably higher resolution. Introduction of the same cross-links was also used to obtain crystals in a different space group of a T4 lysozyme mutant that could not be crystallized previously. The results suggest that the formation of the lysozyme dimer is a critical intermediate in the formation of more than one crystal form and that covalent cross-linking of the intermediate accelerates nucleation and facilitates crystal growth. The disulfide cross-links are located on the 'back' of the molecule and formation of the cross-linked dimer appears to leave the active sites completely unobstructed. Nevertheless, the cross-linked dimer is completely inactive. One explanation for this behavior is that the disulfide bridges prevent hinge-bending motion that may be required for catalysis. Another possibility is that the formation of the dimer increases the overall bulk of the enzyme and prevents its access to the susceptible glycosidic bonds within the cell wall substrate.
Abrogation of Insulin-like Growth Factor-I (IGF-I) and Insulin Action by Mevalonic Acid Depletion (2004)

The vasculoprotective effects of hydroxy-3-methylglutaryl (HMG)-CoA reductase inhibitors (statins) correlate with cholesterol lowering. HMG-CoA reductase inhibitors also disrupt cellular processes by the depletion of isoprenoids and dolichol. Insulin and insulin-like growth factor (IGF) signaling appear particularly prone to such disruption as intracellular receptor processing requires dolichol for correct N-glycosylation, whereas downstream signaling through Ras requires the appropriate prenylation (farnesol). We determined how HMG-CoA reductase inhibition affected the mitogenic effects of IGF-I and metabolic actions of insulin in 3T3-L1 cells and examined the respective roles of receptor glycosylation and Ras prenylation. IGF-I- and insulin-induced proliferation was significantly reduced by all statins tested, although cerivastatin (10 nm) had the greatest effect (p < 0.005). Although inhibitors of Ras prenylation induced similar results (10 microm FTI-277 89% +/- 7.4%, p < 0.01), the effect of HMG-CoA reductase inhibition could only be partially reversed by farnesyl pyrophosphate refeeding. Treatment with statins resulted in decreased membrane expression of receptors and accumulation of proreceptors, suggesting disruption of glycosylation-dependent cleavage. Glycosylation inhibitors inhibited IGF-I-induced proliferation (tunicamycin p < 0.005, castanospermine p < 0.01, deoxymannojirimycin p < 0.01). High concentrations of statin were necessary to impair insulin-mediated glucose uptake (300 nm = 33% +/- 12% p < 0.05), and this process was not effected by farnesyl transferase inhibition. Gycosylation inhibitors mimicked the effect of statin treatment (tunicamycin p < 0.001, castanospermine p < 0.05, deoxymannojirimycin p < 0.05), and there was insulin proreceptor accumulation. These data imply that HMG-CoA reductase inhibitors disrupt IGF-I signaling by combined effects on Ras prenylation and IGF receptor glycosylation, whereas insulin signaling is only affected by disrupted receptor glycosylation.
Isolation and characterization of the Escherichia coli htrD gene, whose product is required for growth at high temperatures (1992)

Those genes in Escherichia coli defined by mutations which result in an inability to grow at high temperatures are designated htr, indicating a high temperature requirement. A new htr mutant of E. coli was isolated and characterized and is designated htrD. The htrD gene has been mapped to 19.3 min on the E. coli chromosome. Insertional inactivation of htrD with a mini-Tn10 element resulted in a pleiotropic phenotype characterized by a severe inhibition of growth at 42 degrees C and decreased survival at 50 degrees C in rich media. Furthermore, htrD cells were sensitive to H2O2. Growth rate analysis revealed that htrD cells grow very slowly in minimal media supplemented with amino acids. This inhibitory effect has been traced to the presence of cysteine in the growth medium. Further studies indicated that the rate of cysteine transport is higher in htrD cells relative to the wild type. All of these results, taken together, indicate that the htrD gene product may be required for proper regulation of intracellular cysteine levels and that an increased rate of cysteine transport greatly affects the growth characteristics of E. coli.
Optimal digital feedback control systems counting computation time of control laws (1984)

Recently, the multivariable control theory studied up to date can be applied to many practical controlling problems. However, when the time constant of the plant is short and the dynamic order of the plant is high, the time delay arising from the computation time of control laws can not be neglected. In this paper, the author treats such a problem and proposes design methods of linear optimal regulators and optimal servosystems in which the delay arising from the computation time is counted properly.
Rapid Synthesis of Ferromagnetic La <sub> 1− <i>x</i> </sub> Na <sub> <i>x</i> </sub> MnO <sub>3</sub> (0.00≤ <i>x</i> ≤0.25) by the Solution Combustion Method (2007)

Rapid synthesis of sodium‐substituted lanthanum manganite phases is reported by the solution combustion method using oxalyl dihydrazide (ODH), as fuel. As‐synthesized compounds are amorphous in nature; crystallinity was observed on heating at 800°C for 5 min. Structural parameters were determined by the Rietveld refinement method using powder X‐ray diffraction data. Parent LaMnO 3 compound crystallizes in the orthorhombic structure (space group Pbnm No. 62). Sodium‐substituted compounds crystallize with rhombohedral symmetry (space group R‐ 3 c , No.167). On increasing the sodium content, unit cell volume decreases and Mn–O–Mn bond angle increases. The fourier transform infrared spectrum shows two absorption bands around 600 and 400 cm −1 for the compositions x =0.0, 0.05, and 0.10. Mn 3+ /Mn 4+ ratio was determined by iodometric titration. Electrical resistivity measurements reveal a composition‐controlled metal to insulator transition ( T M–I ), the maximum T M–I was observed for the composition La 0.85 Na 0.15 MnO 3 at 285 K. Increase in magnetic moment is observed with increase in crystallite size. Room temperature vibrating sample magnetometer data indicate that for the composition up to x =0.10, the compounds are paramagnetic whereas composition with x =0.15, 0.20, and 0.25 show magnetic moments 34, 39, and 33 emu/g, respectively.
Cerebral postischemic reperfusion‐induced demethylation of the protein phosphatase 2A catalytic subunit (2002)

Brain reperfusion after a period of global ischemia induces changes in the phosphorylation state of a great number of proteins. Neuronal responses to ischemia and reperfusion are quite different depending on the brain region, and phosphorylation changes may be implicated in this tissue-specific response. For this reason, we have used both biochemical and immunohistochemical methods to investigate the potential role of PP2A, the most abundant Ser/Thr phosphatase in the brain, in ischemic injury. PP2A activity as measured with phosphorylase a as substrate was slightly inhibited after 30 min ischemia followed by 30 min reperfusion, and this inhibition correlated with an increased S6K1 and ERK1/2 phosphorylation. Using a monoclonal antibody unable to recognize the methylated form of PP2Ac, we demonstrated that the catalytic subunit of PP2A (PP2Ac) was highly methylated in the brain. In addition, the postischemic reperfusion-induced changes in PP2Ac methylation were studied in sections from cerebral cortex, hippocampus and striatum. Regional differences in PP2Ac methylation were observed within control brains, and the postischemic reperfusion caused a generalized demethylation of PP2Ac. Those regions in the control brains containing highest levels of methylated PP2Ac were the most intensively demethylated after reperfusion and corresponded to the regions most vulnerable to ischemic damage.
F-18 Labeling Protocol of Peptides Based on Chemically Orthogonal Strain-Promoted Cycloaddition under Physiologically Friendly Reaction Conditions (2012)

We introduce the high-throughput synthesis of various (18)F-labeled peptide tracers by a straightforward (18)F-labeling protocol based on a chemo-orthogonal strain-promoted alkyne azide cycloaddition (SPAAC) using aza-dibenzocyclootyne-substituted peptides as precursors with (18)F-azide synthon to develop peptide based positron emission tomography (PET) molecular imaging probes. The SPAAC reaction and subsequent chemo-orthogonal purification reaction with azide resin proceeded quickly and selectively under physiologically friendly reaction conditions (i.e., toxic chemical reagents-free, aqueous medium, room temperature, and pH ≈7), and provided four (18)F-labeled tumor targetable bioactive peptides such as cyclic Arg-Gly-Asp (cRGD) peptide, bombesin (BBN), c-Met binding peptide (cMBP), and apoptosis targeting peptide (ApoPep) in high radiochemical yields as direct injectable solutions without any HPLC purification and/or formulation processes. In vitro binding assay and in vivo PET molecular imaging study using the (18)F-labeled cRGD peptide also demonstrated a successful application of our (18)F-labeling protocol.
DNA vaccination favours memory rather than effector B cell responses (1999)

Following priming and boosting of mice with a DNA vector pEE6DeltaS-hCGss expressing sequences encoding a transmembrane version of the beta-chain of human chorionic gonadotropin (hCGbeta), we failed to detect appreciable levels of specific antibody. However, subsequent challenge with hCG protein in Ribi adjuvant elicited a strong and rapid secondary immune response. This response was of comparable magnitude to that produced following priming, boosting and challenge with protein in adjuvant. Thus, DNA vaccination with this vector is as efficient in generating B cell memory as is conventional immunization, but the memory generation occurs in the absence of an overt effector response. Despite an overall similar level of specific antibody, the DNA-vaccinated mice produced hCG-specific antibodies biased towards IgG2a and IgG2b isotypes, whereas the protein-vaccinated mice produced higher levels of IgG1 antibodies. Both Th1 and Th2 cytokines (interferon-gamma (IFN-gamma) and IL-4) were lower in the spleens of the DNA-immunized animals compared with the protein-Ribi-immunized animals, possibly suggesting a different level of helper T cell response to the two different modes of immunization.
Identification and characterization of additional flagellin genes from Vibrio anguillarum (1996)

Previously, the flagellar filament of Vibrio anguillarum was suggested to consist of flagellin A and three additional flagellin proteins, FlaB, -C, and -D. This study identifies the genes encoding FlaB, -C, and -D and a possible fifth flagellin gene that may encode FlaE. The flagellin genes map at two separate DNA loci and are most similar to the four polar flagellin genes of Vibrio parahaemolyticus, also located at two DNA loci. The genetic organization of these two loci is conserved between both organisms. For each gene, in-frame deletions of the entire gene, the 5' end, and the 3' end were made. Mutant analysis showed that each mutation, except those in flaE, caused a loss of flagellin from the filament. However, no obvious structural loss in the filament, as determined by electron microscopy, and only slight decreases in motility were seen. Virulence analysis indicated that all but two of the mutations gave a wild-type phenotype. The 5'-end deletions of flaD and flaE decreased virulence significantly (>10(4)-fold) of infections via both the intraperitoneal and immersion routes. These results indicate that, like FlaA, FlaD and FlaE may also be involved in virulence.
Biopolymer-Based Nanoparticles for Drug Delivery (2012)

Nanotechnology can be used to modify drug delivery by various approaches. Bio-polymer based nanoparticles represent a well-established option to formulate drug delivery systems. New therapeutic compounds are often insoluble or poorly soluble in water, which is a major factor in causing irregular and insufficient absorption, and reduced bioavailability of the drug. Increased dissolution rate can be achieved by decreasing the particle size to nanometer range. Another common reason for the reduced efficacy of the therapeutic compounds is their poor delivery to the desired site of action. Advanced nanoparticle formulations can be used to provide controlled release profiles or they can be combined with ligands for targeted drug delivery. Considering the current needs to produce stable nanoparticle systems for the controlled and actively targeted drug release, the versatile group of biopolymers may offer these functionalities. \n\nOne topic of this work was to set-up the electrospray apparatus for the production of poly(lactic acid) (PLA) drug nanoparticles. By utilizing electrospray, it was possible to produce spherical drug-loaded PLA-particles with approximately 200 to 800 nm diameters. The main benefits of the electrospray method were to control the particle size as well as the possibility to entrap both hydrophobic and hydrophilic drugs into the polymeric nanoparticles. \n\nSecond topic of this work was to utilize amphiphilic proteins, hydrophobins, to provide a layer around the drug nanoparticles that can be functionalized by protein engineering techniques. Adsorption of the protein onto the particle surface restricted the particle growth after the nanoparticles were formed, and it also produced a layer around the hydrophobic drug that was possible to functionalize further. Hydrophobin-mediated nanoparticle synthesis was a fast and effective process that was also easy to up-scale. \n\nAs third topic, nanofibrillar celluloses (NFCs) from various origins were studied as alternative biopolymer carriers for drug nanoparticles. The nanostructured cellulose matrix, an aerogel, prevented the aggregation of the hydrophobin coated nanoparticles during the freeze-drying and storage. Controlled drug release applications could be designed and enabled by utilizing the various modifications of NFC matrices. \n\nAs a result of this thesis, knowledge about the versatile biopolymer-based materials was provided as a means to construct stable nanoparticle formulations that can offer versatile applications for pharmaceutical nanotechnology.
Signaling pathways mediating the response to hypertrophic stress in the heart. (1999)

Cardiac hypertrophy is an increase in the mass of the heart. It is a major risk factor for the development of myocardial infarction and congestive heart failure, diseases that afflict millions of patients worldwide. Hypertrophy can be caused by intrinsic defects of the proteins of the contractile apparatus of the heart, or by extrinsic stimuli such as hypertension. In this review, we will focus on the cytosolic signal transduction pathways that mediate the hypertrophic response to extrinsic stimuli. Although a large number of signaling molecules have been implicated in the hypertrophic response, we will review data that, we believe, suggest there may be only a few molecules that serve as signaling funnels through which many hypertrophic signals must pass on their way to the nucleus. These include the stress response protein kinases (the stress-activated protein kinases or SAPKs, and, possibly, the p38 kinases) and calcineurin. These molecules have as their primary targets transcription factors, many of which have been implicated in the complex yet stereotypic genetic response to hypertrophic stress. In most cases, it is not possible at present to complete the link from hypertrophic stimulus through a specific signaling molecule and a specific transcription factor to the induction of a specific gene that initiates a particular biologic response. We will attempt to identify some of the most important areas where major questions remain in the hopes of stimulating further research into this major cause of death and disability.