gebhart/patrepeval huggingface dataset:
Acoustic lens for capacitive micromachined ultrasonic transducers (2014)

Capacitive micromachined ultrasonic transducers (CMUTs) have great potential to compete with traditional piezoelectric transducers in therapeutic ultrasound applications. In this paper we have designed, fabricated and developed an acoustic lens formed on the CMUT to mechanically focus ultrasound. The acoustic lens was designed based on the paraxial theory and made of silicone rubber for acoustic impedance matching and encapsulation. The CMUT was fabricated based on the local oxidation of silicon (LOCOS) and fusion-bonding. The fabricated CMUT was verified to behave like an electromechanical resonator in air and exhibited wideband response with a center frequency of 2.2 MHz in immersion. The fabrication for the acoustic lens contained two consecutive mold castings and directly formed on the surface of the CMUT. Applied with ac burst input voltages at the center frequency, the CMUT with the acoustic lens generated an output pressure of 1.89 MPa (peak-to-peak) at the focal point with an effective focal gain of 3.43 in immersion. Compared to the same CMUT without a lens, the CMUT with the acoustic lens demonstrated the ability to successfully focus ultrasound and provided a viable solution to the miniaturization of the multi-modality forward-looking endoscopes without electrical focusing.
Reprocessable 3D-Printed Conductive Elastomeric Composite Foams for Strain and Gas Sensing (2019)

Mechanically robust, highly compressible, and conductive thermoplastic polyurethane/carbon black foams were successfully fabricated via 3D printing. Thixotropic inks were formulated by dispersing nanoclay, carbon black, and polymer in an organic solvent, and then 3D multifunctional sensors were prepared by direct ink writing (DIW). Sequential removal of solvent and nanoclay yielded a porous polymer/carbon black structure, which maintained excellent elasticity and compression cyclability. The presence of carbon black in the foams led to good electrical conductivity and stable piezoresistive sensing signals at a strain of up to 80%, including the ability to distinguish human motions. Complementary to a decrease in resistance upon compression, the foam can be used as a gas sensor device, as exposure to volatile organic compounds causes the polymer to swell and an increase in resistance. The printed conductive foams can be easily recycled and reprocessed by dissolution in an organic solvent and subsequent re-3D printing, with little detriment to performance.
Oligodendrocyte Apoptosis Mediated by Caspase Activation (1999)

Treatment with NGF causes long-term cultures of oligodendrocytes to die via a yet undefined mechanism mediated by the p75 neurotrophin receptor. The p75 receptor belongs to the TNF receptor superfamily of molecules, which includes Fas and p55 TNF receptors. The Fas and TNF receptors use adaptor molecules to recruit and activate caspase-8 to the receptor. Using a combination of immunohistochemical and Western blotting assays, we have examined caspase activity during NGF-induced apoptosis. Interestingly, although caspase-1 [interleukin-1beta-converting enzyme (ICE)], caspase-2, caspase-3, and caspase-8 were expressed in oligodendrocytes, only caspase-1, -2, and -3 were activated after NGF treatment, whereas caspase-8 was not. These data suggest that the mechanism of apoptosis by NGF through the p75 receptor is different from TNF and Fas-mediated killing. gamma Radiation of oligodendrocytes also activated a similar subset of caspases as NGF, indicating that NGF-induced oligodendrocyte apoptosis uses a similar cell death execution mechanism as injury models. This consolidates a potential role of the p75 neurotrophin receptor during stress and inflammatory conditions.
Nitrous Oxide Effects on Isolated Myocardium (1990)

This study examined in vitro myocardial depression by 50% N2O. Maximal isometric contractions of guinea pig right ventricular papillary muscles were studied in Tyrode's superfusate at 37 degrees C within a gas-tight chamber. Superfusate (pH at 7.45) and chamber were equilibrated with 95% O2/5% CO2. After control measurements in 95% O2, muscles were studied with 50% N2 and 50% N2O (45% O2/5% CO2) in random order with an intervening and final recovery in oxygen. Muscles were field stimulated after rest and at 0.1-3 Hz. At 37 degrees C, muscle performance deteriorated over time with exposure to reduced oxygen; therefore, identical experiments were performed at 30 degrees C in which no systematic deterioration occurred. Peak tension and maximum rate of tension development (dT/dtmax) were compared for each stimulation rate. At both temperatures, N2O caused a 10-15% depression of contractility as compared to that observed with nitrogen. In a second protocol, muscles were studied at 37 degrees C in 26 mM K+ Tyrode's solution with 0.10 microM isoproterenol to study enhanced contractions mediated by slow (Ca2(+)-channel-dependent) action potentials. Rested-state double stimulations were used (stimulus interval, 250-600 ms) resulting in a first rested-state contraction followed by a second contraction (C2) with rapid initial tension development. The muscles were exposed to nitrogen and N2O as in the force-frequency experiments and did not deteriorate over time. In this setting, N2O also caused a 10-15% depression of C2 contractility as compared with nitrogen. Another set of muscles was studied in 95% O2 to which 0.5% halothane or 1% isoflurane was added before exposure to nitrogen and N2O. The combined depressant action of N2O with either halothane or isoflurane did not differ from that predicted by the simple addition of independent effects; there was no evidence of synergism. Furthermore, N2O (50%) alone depressed dT/dtmax in a manner similar to that of 0.5% halothane and different from that of 1.0% isoflurane. Experiments conducted in iso-osmolar 40 mM Na+ Tyrode's solution, in which activator Ca2+ arose from the sarcoplasmic reticulum Ca2+, also showed greater depression by N2O than nitrogen. N2O (50%) is a myocardial depressant independent of concurrent hypoxic effects with a pattern and magnitude of contractile depression similar to that of 0.5% halothane.
ARTERY Society guidelines for validation of non-invasive haemodynamic measurement devices: Part 1, arterial pulse wave velocity (2010)

The last 15 years have seen an explosion of interest in large artery haemodynamics, and arterial stiffness in particular. A number of devices are now available to assess arterial stiffness, and although many are in routine use, they do not necessarily provide identical information. The aim of this statement is to provide guidelines for the process of validating new devices. The focus of the article is aortic pulse wave velocity. We hope that equipment manufacturers, and researchers will both find these guidelines helpful, and that they will allow greater standardization of aortic pulse wave velocity measurements.
ChemInform Abstract: STRUCTURE OF THE MAJOR METABOLITE OF 1‐ALLYL‐3,5‐DIETHYL‐6‐CHLOROURACIL NEW BICYCLIC BARBITURIC ACID DERIVATIVES (1975)

Abstract Aus lyAllyl‐3,5‐diäthyl‐6‐chler‐uracil (I), dem wirksamen Bestandteil von Acluracil, entsteht als Metabolit der Bicyclus (II).
Electrochemical Reaction in Single Layer MoS<sub>2</sub>: Nanopores Opened Atom by Atom (2015)

Ultrathin nanopore membranes based on 2D materials have demonstrated ultimate resolution toward DNA sequencing. Among them, molybdenum disulfide (MoS2) shows long-term stability as well as superior sensitivity enabling high throughput performance. The traditional method of fabricating nanopores with nanometer precision is based on the use of focused electron beams in transmission electron microscope (TEM). This nanopore fabrication process is time-consuming, expensive, not scalable, and hard to control below 1 nm. Here, we exploited the electrochemical activity of MoS2 and developed a convenient and scalable method to controllably make nanopores in single-layer MoS2 with subnanometer precision using electrochemical reaction (ECR). The electrochemical reaction on the surface of single-layer MoS2 is initiated at the location of defects or single atom vacancy, followed by the successive removals of individual atoms or unit cells from single-layer MoS2 lattice and finally formation of a nanopore. Step-like features in the ionic current through the growing nanopore provide direct feedback on the nanopore size inferred from a widely used conductance vs pore size model. Furthermore, DNA translocations can be detected in situ when as-fabricated MoS2 nanopores are used. The atomic resolution and accessibility of this approach paves the way for mass production of nanopores in 2D membranes for potential solid-state nanopore sequencing.
Combing RGB and Depth Map Features for human activity recognition (2012)

We study the problem of human activity recognition from RGB-D sensors when the skeletons are not available. The skeleton tracking in Kinect SDK works well when the human subject is facing the camera and there are no occlusions. In surveillance or senior home monitoring scenarios, the camera is usually mounted higher than human subjects and there may be occlusions. Consequently, the skeleton tracking does not work well. In RGB image based activity recognition, a popular approach that can handle cluttered background and partial occlusions is the interest point based approach. When both RGB and depth channels are available, one can still use the interest point based approach. But there are questions on whether we should extract interest points independently on each channel or extract interest points from one of the channels. The goal of this paper is to compare the performances of different ways of extracting interest points. In addition, we have developed a depth map based descriptor. We show that the best performance is achieved when we extract interest points solely from RGB channels, and combine the RGB based descriptors and depth map based descriptors.
Three‐colour confocal microscopy with improved colocalization capability and cross‐talk suppression (1996)

A confocal microscope set-up has been modified so that three different fluorescent markers can be studied. The three fluorophores (FITC, Texas Red and Cy5) are detected at the same time, i.e. simultaneous scanning is employed. We have shown that simultaneous scanning optimizes the precise overlay of the three colour components of an image (in contrast with sequential scanning where shifts between the colour components may occur). To suppress optical cross-talk between the three fluorophores, intensity-modulated multiple-beam scanning, IMS, has been employed. Cross-talk between the fluorescence signals has been measured. Results show that cross-talk is virtually eliminated by using the IMS technique. Measurements have been performed on a triple-stained immunofluorescence specimen in order to show the applicability of the technique in biological research. Results are presented that show that the technique presented here improves the accuracy of colocalization, position and intensity measurements for studies on stationary as well as on dynamic structures.
Improving channel mobility in graphene-FETs by minimizing surface phonon scattering - A simulation study (2010)

In graphene-based field-effect transistors (graphene FETs), the carrier channel mobility is strongly influenced by substrate and gate dielectric materials. In this paper, we theoretically investigated the carrier channel mobility for the graphene-FET. Surface phonon (SP) scattering, screened Coulomb scattering, acoustic phonon and optical phonon scattering mechanisms are considered in the mobility calculation. Applying Mahan's theory, the SP scattering in a gate stack structure is evaluated. It is found that SP scattering plays an important role especially in high-k dielectrics. The charged impurity and SP scattering can be suppressed effectively by inserting a polymer layer between the gate dielectric and graphene. The thickness of the polymer layer, however, should be carefully selected to balance the channel carrier mobility enhancement and gate control ability. Our calculation results are consistent with previous calculations and experimental observations.
Biphoton holographic storage in Methyl Orange and Ethyl Orange dyes (1994)

Biphoton holograms are recorded by a He-Ne laser in Methyl Orange and Ethyl Orange dyes on exposure to a 514.5-nm argon-ion laser, and the dynamic of holographic recording is reported. The recording utilizes an unusual photochemistry that is due to either to a triplet-triplet transition from a long-lived triplet lower state of the cis configuration or a transition back to the trans state.
Modular Advanced Oxidation Process Enabled by Cathodic Hydrogen Peroxide Production (2015)

Hydrogen peroxide (H2O2) is frequently used in combination with ultraviolet (UV) light to treat trace organic contaminants in advanced oxidation processes (AOPs). In small-scale applications, such as wellhead and point-of-entry water treatment systems, the need to maintain a stock solution of concentrated H2O2 increases the operational cost and complicates the operation of AOPs. To avoid the need for replenishing a stock solution of H2O2, a gas diffusion electrode was used to generate low concentrations of H2O2 directly in the water prior to its exposure to UV light. Following the AOP, the solution was passed through an anodic chamber to lower the solution pH and remove the residual H2O2. The effectiveness of the technology was evaluated using a suite of trace contaminants that spanned a range of reactivity with UV light and hydroxyl radical (HO(•)) in three different types of source waters (i.e., simulated groundwater, simulated surface water, and municipal wastewater effluent) as well as a sodium chloride solution. Irrespective of the source water, the system produced enough H2O2 to treat up to 120 L water d(-1). The extent of transformation of trace organic contaminants was affected by the current density and the concentrations of HO(•) scavengers in the source water. The electrical energy per order (EEO) ranged from 1 to 3 kWh m(-3), with the UV lamp accounting for most of the energy consumption. The gas diffusion electrode exhibited high efficiency for H2O2 production over extended periods and did not show a diminution in performance in any of the matrices.
Language identification in unknown signals (2000)

This paper describes algorithms and software developed to characterise and detect generic intelligent language-like features in an input signal, using Natural Language Learning techniques: looking for characteristic statistical "language-signatures" in test corpora. As a first step towards such species-independent language-detection, we present a suite of programs to analyse digital representations of a range of data, and use the results to extrapolate whether or not there are language-like structures which distinguish this data from other sources, such as music, images, and white noise. We assume that generic species-independent communication can be detected by concentrating on localised patterns and rhythms, identifying segments at the level of characters, words and phrases, without necessarily having to "understand" the content.We assume that a language-like signal will be encoded symbolically, i.e. some kind of character-stream. Our language-detection algorithm for symbolic input uses a number of statistical clues: data compression ratio, "chunking" to find character bit-length and boundaries, and matching against a Zipfian type-token distribution for "letters" and "words". We do not claim extensive (let alone exhaustive) empirical evidence that our language-detection clues are "correct"; the only real test will come when the Search for Extra-Terrestrial Intelligence finds true alien signals. If and when true SETI signals are found, the first step to interpretation is to identify the language-like features, using techniques like the above. Our current research goal is to apply Natural Language Learning techniques to the identification of "higher-level" grammatical and semantic structure in a linguistic signal.
Estimating size in incremental software development projects (2005)

The motivation for this work is derived from the current interest in speeding up development schedules. A key implication of the shift to more rapid development methods is the growing emphasis on fixed time and fixed effort delivered during such projects. However, there appears to be little work that addresses the impacts of dealing with bound effort levels. The result of binding time and effort is to deprive project managers of the normal parameters that are used in trade-offs. The paper attempts to introduce a quantitative analytical framework for modelling effort-boxed development in order to uncover the effects on the overall development effort and the potential leverage that can be derived from incremental delivery in such projects. Models that predict product size as an exponential function of the development effort are used in the paper to explore the relationships between effort and the number of increments, thereby providing new insights into the economic impact of incremental approaches to effort-boxed software projects.
The computer boys take over: computers, programmers, and the politics of technical expertise (2011)

Of all of the revolutionary technological innovations of the 20th century, none is as widely recognized, as celebrated, or as profoundly influential as the invention of the electronic digital computer. But like all great social and technological developments, the revolution of the twentieth century didn't just happen. It had to be made to happen, and made to happen by people, not impersonal processes. In The Computer Boys Take Over, Nathan Ensmenger describes the emergence of a new breed of technical specialists -- programmers, systems analysts, and data processing managers -- who built their careers around the powerful new technology of electronic computing. It was these largely anonymous specialists who built the systems that transformed the novel technology of electronic computing from a scientific curiosity into the most powerful and ubiquitous technology of the modern era. Known collectively as whiz kids, hackers, and gurus, they were alternatively admired for their technical prowess and despised for their eccentric mannerisms and the disruptive potential of the technologies they developed. As the systems that they built and maintained became central to the operations of our modern computerized society, they became the focus of a series of critiques of the social and organizational impact computerization. To many of their contemporaries, it seemed the computer were taking over, not just in the corporate setting, but also in government, politics, and society in general. Ensmenger follows the rise of the boys as they struggled to establish a role for themselves within traditional organizational, professional, and academic hierarchies. Was programming a black art, a legitimate science, or an industrial discipline? Were specialists more like scientists, engineers, managers, or clerical workers? What was the appropriate relationship between technical expertise and other, more traditional forms of social, political, and organizational power? In telling the story of these influential but unrecognized revolutionaries, Ensmenger provides a nuanced social history of the computerization of modern society that highlights the many ways in which even the most complex technologies are nevertheless fundamentally human constructions.
Microtubules Underlie Dysfunction in Duchenne Muscular Dystrophy (2012)

Duchenne muscular dystrophy (DMD) is a fatal X-linked degenerative muscle disease caused by the absence of the microtubule-associated protein dystrophin, which results in a disorganized and denser microtubule cytoskeleton. In addition, mechanotransduction-dependent activation of calcium (Ca(2+)) and reactive oxygen species (ROS) signaling underpins muscle degeneration in DMD. We show that in muscle from adult mdx mice, a model of DMD, a brief physiologic stretch elicited microtubule-dependent activation of NADPH (reduced-form nicotinamide adenine dinucleotide phosphate) oxidase-dependent production of ROS, termed X-ROS. Further, X-ROS amplified Ca(2+) influx through stretch-activated channels in mdx muscle. Consistent with the importance of the microtubules to the dysfunction in mdx muscle, muscle cells with dense microtubule structure, such as those from adult mdx mice or from young wild-type mice treated with Taxol, showed increased X-ROS production and Ca(2+) influx, whereas cells with a less dense microtubule network, such as young mdx or adult mdx muscle treated with colchicine or nocodazole, showed little ROS production or Ca(2+) influx. In vivo treatments that disrupted the microtubule network or inhibited NADPH oxidase 2 reduced contraction-induced injury in adult mdx mice. Furthermore, transcriptome analysis identified increased expression of X-ROS-related genes in human DMD skeletal muscle. Together, these data show that microtubules are the proximate element responsible for the dysfunction in Ca(2+) and ROS signaling in DMD and could be effective therapeutic targets for intervention.
Noninvasive evaluation of sympathetic nervous system in human heart by positron emission tomography. (1990)

The noninvasive functional characterization of the cardiac sympathetic nervous system by imaging techniques may provide important pathophysiological information in various cardiac disease states. Hydroxyephedrine labeled with carbon 11 has been developed as a new catecholamine analogue to be used in the in vivo evaluation of presynaptic adrenergic nerve terminals by positron emission tomography (PET). To determine the feasibility of this imaging approach in the human heart, six normal volunteers and five patients with recent cardiac transplants underwent dynamic PET imaging after intravenous injection of 20 mCi [11C]hydroxyephedrine. Blood and myocardial tracer kinetics were assessed using a regions-of-interest approach. In normal volunteers, blood 11C activity cleared rapidly, whereas myocardium retained 11C activity with a long tissue half-life. Relative tracer retention in the myocardium averaged 79 +/- 31% of peak activity at 60 minutes after tracer injection. The heart-to-blood 11C activity ratio exceeded 6:1 as soon as 30 minutes after tracer injection, yielding excellent image quality. Little regional variation of tracer retention was observed, indicating homogeneous sympathetic innervation throughout the left ventricle. In the transplant recipients, myocardial [11C]hydroxyephedrine retention at 60 minutes was significantly less (-82%) than that of normal volunteers, indicating only little non-neuronal binding of the tracer in the denervated human heart. Thus, [11C]hydroxyephedrine, in combination with dynamic PET imaging, allows the noninvasive delineation of myocardial adrenergic nerve terminals. Tracer kinetic modeling may permit quantitative assessment of myocardial catecholamine uptake, which will in turn provide insights into the effects of various disease processes on the neuronal integrity of the heart.