gebhart/patrepeval huggingface dataset:
Can Artificial Intelligence Reliably Report Chest X-Rays?: Radiologist\n Validation of an Algorithm trained on 2.3 Million X-Rays (2018)

Background: Chest X-rays are the most commonly performed, cost-effective\ndiagnostic imaging tests ordered by physicians. A clinically validated AI\nsystem that can reliably separate normals from abnormals can be invaluble\nparticularly in low-resource settings. The aim of this study was to develop and\nvalidate a deep learning system to detect various abnormalities seen on a chest\nX-ray. Methods: A deep learning system was trained on 2.3 million chest X-rays\nand their corresponding radiology reports to identify various abnormalities\nseen on a Chest X-ray. The system was tested against - 1. A three-radiologist\nmajority on an independent, retrospectively collected set of 2000\nX-rays(CQ2000) 2. Radiologist reports on a separate validation set of 100,000\nscans(CQ100k). The primary accuracy measure was area under the ROC curve (AUC),\nestimated separately for each abnormality and for normal versus abnormal scans.\nResults: On the CQ2000 dataset, the deep learning system demonstrated an AUC of\n0.92(CI 0.91-0.94) for detection of abnormal scans, and AUC(CI) of\n0.96(0.94-0.98), 0.96(0.94-0.98), 0.95(0.87-1), 0.95(0.92-0.98),\n0.93(0.90-0.96), 0.89(0.83-0.94), 0.91(0.87-0.96), 0.94(0.93-0.96),\n0.98(0.97-1) for the detection of blunted costophrenic angle, cardiomegaly,\ncavity, consolidation, fibrosis, hilar enlargement, nodule, opacity and pleural\neffusion. The AUCs were similar on the larger CQ100k dataset except for\ndetecting normals where the AUC was 0.86(0.85-0.86). Interpretation: Our study\ndemonstrates that a deep learning algorithm trained on a large, well-labelled\ndataset can accurately detect multiple abnormalities on chest X-rays. As these\nsystems improve in accuracy, applying deep learning to widen the reach of chest\nX-ray interpretation and improve reporting efficiency will add tremendous value\nin radiology workflows and public health screenings globally.\n
The effects of transducer geometry on artifacts common to diagnostic bone imaging with conventional medical ultrasound (2012)

The portability, low cost, and non-ionizing radiation associated with medical ultrasound suggest that it has potential as a superior alternative to X-ray for bone imaging. However, when conventional ultrasound imaging systems are used for bone imaging, clinical acceptance is frequently limited by artifacts derived from reflections occurring away from the main axis of the acoustic beam. In this paper, the physical source of off-axis artifacts and the effect of transducer geometry on these artifacts are investigated in simulation and experimental studies. In agreement with diffraction theory, the sampled linear-array geometry possessed increased off-axis energy compared with single-element piston geometry, and therefore, exhibited greater levels of artifact signal. Simulation and experimental results demonstrated that the linear-array geometry exhibited increased artifact signal when the center frequency increased, when energy off-axis to the main acoustic beam (i.e., grating lobes) was perpendicularly incident upon off-axis surfaces, and when off-axis surfaces were specular rather than diffusive. The simulation model used to simulate specular reflections was validated experimentally and a correlation coefficient of 0.97 between experimental and simulated peak reflection contrast was observed. In ex vivo experiments, the piston geometry yielded 4 and 6.2 dB average contrast improvement compared with the linear array when imaging the spinous process and interlaminar space of an animal spine, respectively. This work indicates that off-axis reflections are a major source of ultrasound image artifacts, particularly in environments comprising specular reflecting (i.e., bone or bone-like) objects. Transducer geometries with reduced sensitivity to off-axis surface reflections, such as a piston transducer geometry, yield significant reductions in image artifact.
Effect of the plasmonic dispersion relation on the transmission properties of subwavelength cylindrical holes (2005)

We analyze subwavelength cylindrical holes in an optically thick metallic film with the metal described by a plasmonic model. We find that the dispersion diagram exhibits three distinct features that have a profound impact on the transmission of incident light through cylindrical holes. First, such holes always support propagating modes near the surface plasmon frequency, regardless of how small the holes are. Second, the fundamental plasmonic mode $({\mathrm{HE}}_{11})$ is located completely below the surface plasmon frequency and gives rise to a passband in the transmission spectrum. Third, when the radius of the holes is small, there exists a stop band, just above the surface plasmon frequency, where a normally incident plane wave does not transmit. Based on the dispersion analysis, we design both a single hole and a hole array in which propagating modes play a dominant role in the transport properties of incident light. These structures exhibit a different region of operation that has not been probed yet experimentally, while featuring a high packing density and diffractionless behavior.
Latest Ruggedized High Temperature Piezoresistive Transducers (2003)

In recent years, the need for semiconductor pressure transducers that can be used in applications that require operation in harsh environments that are corrosive, oxidizing, experiencing high vibration, and involving high temperatures has increased. Accordingly, not only must the stress-sensing network of these transducers be protected from these harsh environmental conditions in some way to enable the transducer to remain operational at high temperature over extended period of time, but the entire transducer structure, including: electrical contacts, lead-outs, interconnects and external wiring must also be protected. Results are presented showing test data for latest high temperature “leadless” dielectrically isolated (SOI) semiconductor piezoresistive transducers. Data is presented at temperatures for up to 1075°F illustrating the excellent zero shift and low span sensitivity to temperature. Methods of construction of these devices are also discussed. The results indicate that ruggedized, high frequency, piezoresistive transducers are now feasible and can be manufactured for the kinds of environments that exist under the most stressful jet engine conditions.
An Amphipathic α-Helical Decapeptide in Phosphatidylcholine Is an Effective Synthetic Lung Surfactant (1993)

An idealized model amphipathic alpha-helical decapeptide was synthesized and tested for efficacy as a totally synthetic lung surfactant in simple mixtures with dipalmitoylphosphatidylcholine (DPPC). Quasi-static lung compliance was restored to 92 +/- 3% of the unlavaged value at a pressure of 5 cm H2O in an in vitro lavaged rat lung model. A sustained improvement in gas exchange was also observed when guinea pigs were treated with the synthetic lung surfactant in an in vivo lavaged lung model. DPPC/peptide mixtures rapidly formed low surface tension films in the pulsating bubble surfactometer consistent with a mechanism in which the lipid and peptide mixture spreads rapidly in the lavaged lung to minimize the surface tension at the air/tissue interface. This decapeptide sequence is active in mixtures with DPPC whether the residues are in the all L or all D conformation. However, a peptide with identical sequence, but with alternating D and L amino acid residues, is relatively inactive. Positive charge interactions are not important since a peptide with formylated lysine residues is active. The activity of these decapeptides, with sequences unrelated to any of those in natural lung surfactants, shows that the classic amphipathic alpha-helical hypothesis may be useful in designing peptides that will be effective synthetic lung surfactants in binary mixtures with DPPC. The data demonstrate that a small water-soluble synthetic peptide containing an amphipathic alpha-helical structure combined solely with the major lipid of natural lung surfactant is effective in restoring lung compliance and gas exchange in surfactant-deficient lungs and may be useful in treatment of the respiratory distress syndromes.
A Comparison of Small-Scale Gas Turbine Control Schemes (2017)

Throughout the world there is pressure to increase distributed energy generation. Driving factors include for example political and environmental concerns in developed countries and reliability in places where centralized grid does not either exist or is too unreliable. The energy generation based on renewable fuels such as biogas is also usually decentralized. To answer this demand, the number of small-scale gas turbine combined heat and power (CHP) installations have increased. Due to its nature, the required power output of distributed generation is highly variable. The power output of decentralized power plant needs to follow the local consumption power need and thus it needs to be efficiently controlled. Therefore, the requirement for variable output necessitates that small-scale gas turbines are often run at part-loads. Previously, most of the installed small-scale gas turbines have been single-spool units with either fixed or variable speed shafts. Control schemes and part-load performance are somewhat different for the two setups. Recently, a two-spool gas turbine where the spools can be controlled independently has been proposed as a feasible alternative. The possibility to produce the desired power output with two spools, both having their own generator, which can be controlled independently of each other, offers significantly more possibilities for the control. Therefore, it might also offer better part-load performance. In this paper, the control schemes of three different small-scale gas turbines are compared. Especially, the part-load electrical efficiency is studied. The studied gas turbines are: a single-spool fixed speed, a single-spool variable speed driven, and a two-spool variable speed driven gas turbine. The part-load performance of different machines is studied and then compared against each other. Furthermore, some estimations are given on how the part-load performance of each machine fares against certain load profiles.
Solid‐state fluoroscopic imager for high‐resolution angiography: Parallel‐cascaded linear systems analysis (2004)

Cascaded linear systems based modeling techniques have been used in the past to predict important system parameters that have a direct impact on image quality. Such models are also useful in optimizing system parameters to improve image quality. In this work, detailed analysis of a solid-state fluoroscopic imaging system intended for high-resolution angiography is presented with the use of such a model. The imaging system analyzed through this model uses four 8 x 8 cm three-side buttable interlined charge-coupled devices (CCDs) specifically designed for high-resolution angiography and tiled in a seamless fashion to achieve a field of view (FOV) of 16 x 16 cm. Larger FOVs can be achieved by tiling more CCDs in a similar manner. The system employs a CsI:Tl scintillator coupled to the CCDs by straight (nontapering) fiberoptics and can potentially be operated in 78, 156, or 234 microm pixel pitch modes. The system parameters analyzed through this model include presampling modulation transfer function, noise power spectrum, and detective quantum efficiency (DQE). The results of the simulations performed indicate that DQE(0) in excess of 0.6 is achievable, with the imager operating at 156 microm pixel pitch, 30 frames/s, and employing a 450-microm-thick CsI:Tl scintillator, even at a low fluoroscopic exposure rate of 1 microR/frame. Further, at a nominal fluoroscopic exposure rate of 2.5 microR/frame there was no noticeable degradation of the DQE even at the 78 microm pixel pitch mode suggesting that it is feasible to perform high-resolution angiography hitherto unattainable in clinical practice.
Synthesis and characterization of modified bismaleimide/polysulfone semi‐interpenetrating polymer networks (2006)

Abstract The present work reports a new method of preparing semi‐interpenetrating polymer network (semi‐IPN) membranes through in situ polymerization of bismaleimide (BMI) within polysulfone (PSF). It was found that BMI could be polymerized at ambient conditions in the presence of a proton donor and PSF without the use of an initiator or a catalyst. Chemical structure characterization of these semi‐IPNs by Fourier transform infrared attenuated total reflection (FTIR‐ATR) revealed the possibility of imide cleavage and formation of amic acid when BMI polymerization was continued for a longer time while X‐ray photoelectron spectroscopy (XPS) revealed the protonation of imide nitrogen at shorter polymerization time. It was also found that size of thermoset BMI phase within the PSF thermoplastic has a significant impact on glass‐transition temperature of resulting semi‐IPN. By controlling the thermoset/thermoplastic phase separation of semi‐IPNs through dope composition and formation techniques, gas separation membranes with comparable selectivity and permeance that were up to 12 times higher than corresponding PSF membranes were formed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 369–379, 2006
Determination of phenoxy herbicides in water samples using phase transfer microextraction with simultaneous derivatization followed by GC‐MS analysis (2012)

A sensitive and accurate method for the determination of two model phenoxy herbicides, 4-chloro-2-methylphenoxy acetic acid and 4-chloro-2-methylphenoxy propanoic acid, in water is explained. This method utilizes a simple phase transfer catalyst-assisted microextraction with simultaneous derivatization. Factors affecting the performance of this method including pH of the aqueous matrix, temperature, extraction duration, type and amount of derivatization reagents, and type and amount of the phase transfer catalyst are examined. Derivatization and the use of phase transfer catalyst have proven to be especially vital for the resolution of the analytes and their sensitive determination, with an enrichment factor of 288-fold for catalyzed over noncatalyzed procedure. Good linearity ranging from 0.1 to 80 μg L(-1) with correlation of determination (r(2) ) between 0.9890 and 0.9945 were obtained. Previous reported detection limits are compared with our new current method. The low LOD for the two analytes (0.80 ng L(-1) for 4-chloro-2-methylphenoxy propanoic acid and 3.04 ng L(-1) for 4-chloro-2-methylphenoxy acetic acid) allow for the determination of low concentrations of these analytes in real samples. The absence of matrix effect was confirmed through relative recovery calculations. Application of the method to seawater and tap water samples was tested, but only 4-chloro-2-methylphenoxy propanoic acid at concentrations between 0.27 ± 0.01 and 0.84 ± 0.06 μg L(-1) was detected in seawater samples.
Scattering-initiated parametric noise in optical parametric chirped-pulse amplification (2015)

We experimentally study a new kind of parametric noise that is initiated from signal scattering and enhanced through optical parametric amplification. Such scattering noise behaves similarly to the parametric super-fluorescence in the spatial domain, yet is typically much stronger. In the time domain, it inherits the chirp of signal pulses and can be well compressed. We demonstrate that this scattering-initiated parametric noise has little influence on the amplified pulse contrast but can degrade the conversion efficiency substantially.
Noise analysis of grating-based x-ray differential phase contrast imaging (2010)

The sensitivity of x-ray radiographic images, meaning the minimal detectable change in the thickness or in the index of refraction of a sample, is directly related to the uncertainty of the measurement method. In the following work, we report on the recent development of quantitative descriptions for the stochastic error of grating-based differential phase contrast imaging (DPCi). Our model includes the noise transfer characteristics of the x-ray detector and the jitter of the phase steps. We find that the noise in DPCi depends strongly on the phase stepping visibility and the sample properties. The results are supported by experimental evidence acquired with our new instrument with a field of view of 50x70 mm(2). Our conclusions provide general guidelines to optimize grating interferometers for specific applications and problems.
Distance-Based k^m-Anonymization of Trajectory Data (2013)

The publication of trajectory data opens up new directions in studying human behavior, but it is challenging to perform in a privacy-preserving way. This is mainly because, the identities of individuals, whose movement is recorded in the data, can be disclosed, even after removing identifying information. Existing works to anonymize trajectory data offer privacy, but at a high data utility cost. This is because, they either do not produce truthful data, which is important in many applications, or are limited in their privacy specification component. This paper proposes an approach that overcomes these shortcomings by adapting km-anonymity to trajectory data and by using distance-based generalization. We also develop an effective and efficient anonymization algorithm, which is based on the apriori principle. Our experiments verify that this algorithm preserves data utility well, and it is fast and scalable.
Atomic force microscopy for high speed imaging using cantilevers with an integrated actuator and sensor (1996)

A cantilever with an integrated ZnO piezoelectric actuator in feedback with a piezoresistive sensor is utilized in an atomic force microscope (AFM) to achieve a new high speed imaging technique. The imaging bandwidth is increased from 0.6 to 6 kHz by bending the cantilever over sample topography with the actuator rather than moving the sample with a 2 in. piezotube. Images taken in the constant force mode with a 3 mm/s tip velocity of a sample containing 2 μm vertical steps are presented. The effects of electrical coupling from the actuator were eliminated by measuring the piezoresistor sensor with a lock-in amplifier.
Serum Antibodies to L-Type Calcium Channels in Patients with Amyotrophic Lateral Sclerosis (1992)

Antibodies to L-type voltage-gated calcium channels are present in the serum of patients with amyotrophic lateral sclerosis, and antibody titers correlate with the rate of disease progression. Together with previous data, these results suggest a role for autoimmune mechanisms in the pathogenesis of sporadic amyotrophic lateral sclerosis.
Broadband rectangular slotted plate antenna (2002)

In this paper, a single-layer single-element probe-fed slotted plate antenna is presented, which features a broad impedance bandwidth and low cross-polarisation levels. Experiments on its input impedance and radiation patterns show that, by thickening air-filled substrate supporting the plate, the impedance bandwidth reaches up to the order of 20%. Both the stable radiation patterns and the low cross-polarisation levels, typically, lower than -20 dB are observed across the pass-band. The 5.7-7.9 dBi gains are also obtained within the pass-band.
Composition-selective photochemical etching of compound semiconductors (1985)

Compound semiconductor materials differing only in the relative amounts of constituent atoms are very difficult to etch selectively using current chemical etching techniques. We have developed a photochemical etching process that solves this problem by utilizing the difference in band gap of GaAs1−xPx materials differing slightly in composition to produce a very high degree of etching selectivity between the materials. The concepts employed in this process have general applicability to other compound semiconductor material systems.
A Novel Linear-Non-Linear Digital Control for DC/DC Converter with Fast Transient Response (2006)

In this paper, a digitally controlled multimodule DC-DC converter with fast transient response, based on a linear-nonlinear control is presented. The proposed digital control improves the stability of the system, cuts off the effects of limit-cycle and reduces the recovery time, by making the "effective" bandwidth of the system independent of the bandwidth of the linear control loop and limits, at the same time, output voltage variations. The digital control is AVP-compatible and halves the recovery time. Preliminary hardware tests on a single phase step-down converter are reported. The experimental results match simulation ones, obtained by modelling system with Matlab/Aldec mixed environment. Implemented system shows fast transient responses comparable to analog controls.
Identification of Glutamic Acid Decarboxylase Autoantibody Heterogeneity and Epitope Regions in Type I Diabetes (1994)

Glutamic acid decarboxylase (GAD) is an autoantigen of the islet cell antibodies (ICAs) present in type I diabetes. GAD autoantibodies are also found in patients with stiffman syndrome and in certain ICA-positive individuals who rarely develop diabetes on long-term follow-up. This latter subset of ICA has been termed restricted or beta-cell-specific ICA because the antibodies react with only the beta-cells of the islet. By immunoprecipitation of recombinant GAD65 and GAD67 protein and protein fragments, 83% of sera from individuals with new-onset diabetes or prediabetes (n = 30) had GAD65 autoantibodies, but only 26% had GAD67 autoantibodies. In contrast, all restricted ICA sera (n = 6) had both GAD65 and GAD67 autoantibodies. In both types of sera, the binding of GAD67 autoantibodies could be blocked by preincubation of the serum with GAD65 and GAD67, but the binding of GAD65 autoantibodies could not be blocked by preincubation with GAD67. The titer of GAD65 autoantibodies was much higher in the restricted ICA sera (titer > 1:1,000) than in the sera from individuals with new-onset diabetes or prediabetes (titer < 1:100) and was reflected by the greater amount of GAD65 protein immunoprecipitated by restricted ICA sera (2.61 +/- 1.39 U) compared with sera from individuals with new-onset diabetes (0.51 +/- 0.34 U). The restricted ICA sera immunoprecipitated equimolar amounts of GAD65 protein fragments, suggesting a non-conformational or linear epitope; epitope mapping localized the major epitope region to amino acids 361-442 and a second minor epitope region to amino acids 1-195.(ABSTRACT TRUNCATED AT 250 WORDS)
Magnetic resonance‐guided thermal surgery (1993)

A demonstration of MR guided thermal surgery involved experiments with imaging of focused ultrasound in an MRI system, measurements of the thermal transients and a thermal analysis of the resulting images. Both the heat distribution and the creation of focused ultrasound lesions in gel phantoms, in vitro bovine muscle and in vivo rabbit muscle were monitored with magnetic resonance imaging. Thermal surgical procedures were modeled by an elongated gaussian heat source where heat flow is controlled by tissue thermal properties and tissue perfusion. Temperature profiles were measured with thermocouples or calculated from magnetic resonance imaging in agreement with the model. A 2-s T1-weighted gradient-refocused acquisition provided thermal profiles needed to localize the heat distribution produced by a 4-s focused ultrasound pulse. Thermal analysis of the images give an effective thermal diffusion coefficient of 0.0015 cm2/s in gel and 0.0033 cm2/s in muscle. The lesions were detected using a T2-weighted spin-echo or fast spin-echo pulse sequence in agreement with muscle tissue sections. Potential thermal surgery applications are in the prostate, liver, kidney, bladder, breast, eye and brain.