gebhart/patrepeval huggingface dataset:
Protocols for Harmonized Quantification and Noise Reduction in Low-Dose Oncologic 18F-FDG PET/CT Imaging (2018)

Oncologic <sup>18</sup>F-FDG PET/CT acquisition and reconstruction protocols need to be optimized for both quantitative and detection tasks. To date, most studies have focused on either quantification or noise, leading to quantitative harmonization guidelines or appropriate noise levels. We developed and evaluated protocols that provide harmonized quantitation with optimal amounts of noise as a function of acquisition parameters and body mass. <b>Methods:</b> Multiple image acquisitions (<i>n</i> = 17) of the International Electrotechnical Commission/National Electrical Manufacturers Association PET image-quality phantom were performed with variable counting statistics. Phantom images were reconstructed with 3-dimensional ordered-subset expectation maximization (OSEM3D) and point-spread function (PSF) for harmonized quantification of the contrast recovery coefficient of the maximum pixel value (<i>CRC</i> <sub><i>max</i></sub> ). The lowest counting statistics that resulted in compliance with European Association of Nuclear Medicine recommendations for <i>CRC</i> <sub><i>max</i></sub> and <i>CRC</i> <sub><i>max</i></sub> variability were used as optimization metrics. Image noise in the liver of 48 typical oncologic <sup>18</sup>F-FDG PET/CT studies was analyzed with OSEM3D and PSF harmonized reconstructions. We also evaluated 164 additional <sup>18</sup>F-FDG PET/CT reconstructed list-mode images to derive analytic expressions that predict image quality and noise variability. Phantom-to-subject translational analysis was used to derive optimized acquisition and reconstruction protocols. <b>Results:</b> For harmonized quantitation levels, PSF reconstructions yielded decreased noise and lower <i>CRC</i> <sub><i>max</i></sub> variability than regular OSEM3D reconstructions, suggesting they could enable a decreased activity regimen for matched performance. <b>Conclusion:</b> PSF reconstruction with a 7-mm postprocessing filter can provide harmonized quantification performance and acceptable image noise levels with injected activity, duration, and mass settings using a 260 MBq⋅s/kg acquisition parameter at scan time. Similarly, OSEM3D with a 5-mm postprocessing filter can provide similar performance with 401 MBq⋅s/kg.
Laser flash photolysis study of anthracene/viologen charge transfer complex in non-polar, dealuminated zeolites (2004)

A charge-transfer anthracene/viologen complex has been assembled within two purposely-prepared, non-polar Beta zeolite samples devoid of framework negative charge and positive cations. IR spectroscopy (absence of silanol groups), vapor adsorption (preferent n-hexane adsorption over water) and powder X ray diffraction (high crystallinity with minimum structural defects) indicate the “hydrophobic”, low-polarity characteristics of the Beta zeolite samples used. Laser flash photolysis upon 532 nm selective excitation of the charge-transfer band shows that the photogenerated radical ions live hundreds of μs. This is the same time scale as for conventional, polar faujasites with high Al content. We suggest that in our non-polar zeolite the compartmentalized space and the ability of zeolites to participate in electron transfer processes are the main factors contributing to the remarkable lifetime increase of radical ions.
Selective focusing through inhomogeneous media: the DORT method (2002)

The DORT method (Decomposition de l'Operateur de Retournement Temporel) applies to ultrasonic detection and focusing with arrays of transducers. It is a signal analysis method based on the invariance of ultrasonic propagation under time reversal. It requires the measurement of the inter element impulse responses of the the propagating medium for all pair of elements in the array. A hermitian matrix called the time reversal operator is deduced from these responses and diagonalized. The eigenvectors are then used to perform selective focusing. This method is applied here to phase aberration correction. Experiments with weakly and strongly aberrating medium are shown.
Auditing Network Traffic and Privacy Policies in Oculus VR. (2021)

Virtual reality (VR) is an emerging technology that enables new applications but also introduces privacy risks. In this paper, we focus on Oculus VR (OVR), the leading platform in the VR space, and we provide the first comprehensive analysis of personal data exposed by OVR apps and the platform itself, from a combined networking and privacy policy perspective. We experimented with the Quest 2 headset, and we tested the most popular VR apps available on the official Oculus and the SideQuest app stores. We developed OVRseen, a methodology and system for collecting, analyzing, and comparing network traffic and privacy policies on OVR. On the networking side, we captured and decrypted network traffic of VR apps, which was previously not possible on OVR, and we extracted data flows (defined as ). We found that the OVR ecosystem (compared to the mobile and other app ecosystems) is more centralized, and driven by tracking and analytics, rather than by third-party advertising. We show that the data types exposed by VR apps include personally identifiable information (PII), device information that can be used for fingerprinting, and VR-specific data types. By comparing the data flows found in the network traffic with statements made in the apps' privacy policies, we discovered that approximately 70% of OVR data flows were not properly disclosed. Furthermore, we provided additional context for these data flows, including the purpose, which we extracted from the privacy policies, and observed that 69% were sent for purposes unrelated to the core functionality of apps.
Reactivation of Optic Nerve Head Astrocytes by TGF-β2 and H2O2Is Accompanied by Increased Hsp32 and Hsp47 Expression (2009)

TGF-beta2 increased Hsp32 after short-term treatment and Hsp47 after longer periods in cultured human ONH astrocytes. H(2)O(2) increased both Hsp32 and -47 levels. No effects on Hsp60 and -70 levels were induced by TGF-beta2 and H(2)O(2). These results may provide further insights into the cellular stress responses of reactive human ONH astrocytes. Further extensive studies are needed to examine the potential roles of Hsps in the ONH of glaucomatous eyes.
Catalytic aftertreatment of NOx from diesel exhaust (2015)

AccessScience is an authoritative and dynamic online resource that contains incisively written, high-quality educational material covering all major scientific disciplines. An acclaimed gateway to scientific knowledge, AccessScience is continually expanding the ways it can demonstrate and explain core, trustworthy scientific information that inspires and guides users to deeper knowledge.
Differential treatment effect on measures of neurologic exam, functional impairment and patient self-report in multiple sclerosis (2001)

The observations in this study show that the relative sensitivity to change in acute or subacute deterioration in MS patients, is low for the MSFC and high for the GNDS. It is obvious from this study that such a treatment can have a differential effect on measurements of functional impairment, rating of neurologic examination and patient self-report.
Introduction course in particle image velocimetry (2004)

Particle image velocimetry (PIV) is a technique which enables instantaneous measurement of the flow velocity at several positions in a plane. The working principle is quite simple (c.f. figure 1): the flow is seeded with light reflecting particles (usually smoke is used in air and glass beads in water), a light sheet illuminates the particles in the measurement plane and a camera is used to take two exposures of the illuminated plane. The two exposures should be taken within a short interval, so that the same particles are caught in both exposures. The two exposures can be taken either as a double exposure of one image or as two different images. The double exposure technique is based on an autocorrelation and this results in an directional ambiguity (since it is impossible to tell whether an imaged particle was in the first or second exposure), thus the flow can only be in one direction when this method is used. Hence, the method with two images and cross-correlation is more commonly used and the remaining part of this introduction will deal with this technique. A good reference book which deals with most of the aspects of PIV is Raffel et al. (1998).
A Numerical Exploration of Parameter Dependence in Power Optimal Flapping Flight (2006)

A computational framework for analyzing and designing efficient flapping flight vehicles is presented. Two computational tools are considered: a Betz Criterion code proposed by Hall et. al., and an accelerated, unsteady, potential flow solver. The parameters considered in this paper are: the flapping frequency, the flapping amplitude in both up-down and forward-aft directions, and the addition of a mid-wing hinge for articulated flapping flight. The flapping kinematics are represented using harmonics. Three numerical experiments are examined for the flapping flight analysis. The first experiment involves sweeping through a basic flapping flight parametric design space. The second experiment minimizes flight power at a given flight condition using a quasi-Newton optimization. The third experiment demonstrates the conversion of the problem from a wake only analysis to a 3-D flapping wing geometry.
A METHOD TO EVALUATE THE BENEFIT OF ENERGY-ABSORBING MATERIAL FOR SIDE IMPACT PROTECTION (1987)

There are many opinions on the injury reducing benefit of energy-absorbing material for side impact protection. The objective of this study was to develop a methodology to link reductions in biomechanical responses due to force-limiting material to projections of injury mitigation in real-world side impact crashes, and to use this approach to evaluate the potential injury reducing benefit for the chest and abdomen of crushable material in the side door and armrest. Using a simulation of the human impact response, a range in crush force was determined which effectively reduced a peak biomechanical response from that obtained with a rigid impact. The range in constant crush force depended on the velocity of impact. The higher the velocity of impact, the higher the level of crush force to achieve a reduction in the peak response. National crash severity study (NCSS) field accident data for car-to-car side impacts provided information on the occupant exposure and injury as a function of the change in velocity of the struck vehicle. Based on various experimental studies, the velocity of the side door at contact with the occupant's chest is similar to the change in velocity of the struck vehicle (about 60% of the closing speed of the striking vehicle). The chest impact velocity in the simulation was assumed equal to the observed change in velocity in the NCSS data. This related the simulation data to real-world injury data. Reductions in biomechanical response were related to lower injury risk. This enabled a calculation of a reduction in injured occupants for the velocity range in which the energy absorbing material was effective. The greatest reduction in seriously injured occupants was found with relatively soft energy absorbing materials that are effective in the lower-speed (change in velocity = 4 -8 m/s) crashes, whereas padding was negligibly effective in high-speed crashes (change in velocity greater than 10 m/s). (TRRL)
Advanced FD-SOI and Beyond Low Temperature SmartCut™ Enables High Density 3-D SoC Applications (2019)

Beyond 65FD-SOI, 28FD-SOI, and 22FD-SOI production granted technologies, SmartCut™ development supports both advanced FD-SOI and low temperature SOI roadmaps. Ultrathin SOI and BOX materials developments are reported, including 4-nm SOI and 15-nm BOX layers, with performances close to production-grade (SOI layer thickness variation at wafer and device scale, SOI layer defect density). To support 3-D sequential integration, layer transfer at low temperature (below 500 °C) with SmartCut is demonstrated, on the path to a cost effective option. Best in class-equivalent to Epi bulk-SOI layers thickness variability at device scale is demonstrated. Excellent SOI and BOX layers thickness uniformities at wafer level are also highlighted while layer integrity from surface to crystalline defect density point of view are already compliant with development grade requirements.
Sources of systematic error in proton density fat fraction (PDFF) quantification in the liver evaluated from magnitude images with different numbers of echoes (2017)

The purpose of this work was to investigate sources of bias in magnetic resonance imaging (MRI) liver fat quantification that lead to a dependence of the proton density fat fraction (PDFF) on the number of echoes. This was a retrospective analysis of liver MRI data from 463 subjects. The magnitude signal variation with TE from spoiled gradient echo images was curve fitted to estimate the PDFF using a model that included monoexponential R<sub>2</sub> * decay and a multi-peak fat spectrum. Additional corrections for non-exponential decay (Gaussian), bi-exponential decay, degree of fat saturation, water frequency shift and noise bias were introduced. The fitting error was minimized with respect to 463 × 3 = 1389 subject-specific parameters and seven additional parameters associated with these corrections. The effect on PDFF was analyzed, notably the dependence on the number of echoes. The effects on R<sub>2</sub> * were also analyzed. The results showed that the inclusion of bias corrections resulted in an increase in the quality of fit (r<sup>2</sup> ) in 427 of 463 subjects (i.e. 92.2%) and a reduction in the total fitting error (residual norm) of 43.6%. This was largely a result of the Gaussian decay (57.8% of the reduction), fat spectrum (31.0%) and biexponential decay (8.8%) terms. The inclusion of corrections was also accompanied by a decrease in the dependence of PDFF on the number of echoes. Similar analysis of R<sub>2</sub> * showed a decrease in the dependence on the number of echoes. Comparison of PDFF with spectroscopy indicated excellent agreement before and after correction, but the latter exhibited lower bias on a Bland-Altman plot (1.35% versus 0.41%). In conclusion, correction for known and expected biases in PDFF quantification in liver reduces the fitting error, decreases the dependence on the number of echoes and increases the accuracy.
Decreased Deposition of Beta-Amyloid 1-38 and Increased Deposition of Beta-Amyloid 1-42 in Brain Tissue of Presenilin-1 E280A Familial Alzheimer’s Disease Patients (2020)

Familial Alzheimer's Disease (FAD) caused by Presenilin-1 (PS1) mutations is characterized by early onset, cognitive impairment, and dementia. Impaired gamma secretase function favors production of longer beta-amyloid species in PS1 FAD. The PS1 E280A mutation is the largest FAD kindred under study. Here, we studied beta-amyloid deposits in PS1 E280A FAD brains in comparison to sporadic Alzheimer's disease (SAD). We analyzed cortices and cerebellum from 10 FAD and 10 SAD brains using immunohistochemistry to determine total beta-amyloid, hyperphosphorylated tau (pTau), and specific beta-amyloid peptides 1-38, 1-40, 1-42, and 1-43. Additionally, we studied beta-amyloid subspecies by ELISA, and vessel pathology was detected with beta-amyloid 1-42 and truncated pyroglutamylated beta-amyloid antibodies. There were no significant differences in total beta-amyloid signal between SAD and FAD. Beta-amyloid 1-38 and 1-43 loads were increased, and 1-42 loads were decreased in frontal cortices of SAD when compared to FAD. Beta-amyloid species assessment by ELISA resembled our findings by immunohistochemical analysis. Differences in beta-amyloid 1-38 and 1-42 levels between SAD and FAD were evidenced by using beta-amyloid length-specific antibodies, reflecting a gamma secretase-dependent shift in beta-amyloid processing in FAD cases. The use of beta-amyloid length-specific antibodies for postmortem assessment of beta-amyloid pathology can differentiate between SAD and PS1 FAD cases and it can be useful for identification of SAD cases potentially affected with gamma secretase dysfunction.
Affinity Thresholds for Naive CD8+ CTL Activation by Peptides and Engineered Influenza A Viruses (2011)

High-avidity interactions between TCRs and peptide + class I MHC (pMHCI) epitopes drive CTL activation and expansion. Intriguing questions remain concerning the constraints determining optimal TCR/pMHCI binding. The present analysis uses the TCR transgenic OT-I model to assess how varying profiles of TCR/pMHCI avidity influence naive CTL proliferation and the acquisition of effector function following exposure to the cognate H-2K(b)/OVA(257-264) (SIINFEKL) epitope and to mutants provided as peptide or in engineered influenza A viruses. Stimulating naive OT-I CD8(+) T cells in vitro with SIINFEKL induced full CTL proliferation and differentiation that was largely independent of any need for costimulation. By contrast, in vitro activation with the low-affinity EIINFEKL or SIIGFEKL ligands depended on the provision of IL-2 and other costimulatory signals. Importantly, although they did generate potent endogenous responses, infection of mice with influenza A viruses expressing these same OVA(257) variants failed to induce the activation of adoptively transferred naive OT-I CTLps, an effect that was only partially overcome by priming with a lipopeptide vaccine. Subsequent structural and biophysical analysis of H2-K(b)OVA(257), H2-K(b)E1, and H2-K(b)G4 established that these variations introduce small changes at the pMHCI interface and decrease epitope stability in ways that would likely impact cell surface presentation and recognition. Overall, it seems that there is an activation threshold for naive CTLps, that minimal alterations in peptide sequence can have profound effects, and that the antigenic requirements for the in vitro and in vivo induction of CTL proliferation and effector function differ substantially.
New synthesis of pyrrolidine derivatives via the chromacyclobutanes generated from enynes and Fischer carbene complexes (1992)

Pyrrolidine derivatives have been synthesized via chromacyclobutanes formed from the Fischer carbene complex 2b and the aza-enyne 5a; a mechanism is suggested on the basis of the products that are formed.
Association of carotid intima-media thickness with cardiovascular risk factors and patient outcomes in advanced chronic kidney disease: the RRI-CKD study (2020)

Background: Chronic kidney disease (CKD) is associated with accelerated atherosclerosis and an increased risk of adverse cardiovascular disease (CVD) outcomes. The relationships of intima-media thickness (IMT), a measure of subclinical atherosclerosis, with traditional and nontraditional risk factors and with adverse outcomes in CKD patients are not well-established. Methods: IMT, clinical characteristics, cardiovascular risk factors, and clinical outcomes were measured in 198 subjects from the Renal Research Institute (RRI) CKD study, a four-center prospective cohort of patients with estimated glomerular filtration rate (eGFR) ≤ 50 mL/min/1.73 m2 not requiring renal replacement therapy. Results: The patients averaged 61 ± 14 years of age; the mean eGFR was 29 ± 12 mL/min/1.73 m2. Maximum IMT was more closely associated with traditional cardiovascular risk factors, including age, diabetes, dyslipidemia, and systolic blood pressure, than with nontraditional risk factors or with eGFR. Higher values of maximum IMT were also independently associated with clinical CVD and with other markers of subclinical CVD. Maximum IMT ≥ 2.6 mm was predictive of the composite endpoint of CVD events and death (hazard ratio (HR): 5.47 (95% confidence interval (CI): 2.97 – 10.07, p < 0.0001)) but was not related to progression to end-stage renal disease (HR: 1.67 (95% CI: 0.74 – 3.76, p = 0.21)). Conclusion: In patients with advanced pre-dialysis CKD, higher maximum IMT was associated with traditional cardiovascular risk factors, CVD, and other markers of subclinical CVD and was an independent predictor of cardiovascular events and death. Additional research is needed to examine the clinical utility of IMT in the risk stratification and clinical management of patients with CKD.
Plasma oscillations in a 6-kW magnetically shielded Hall thruster (2014)

Plasma oscillations from 0–100 kHz in a 6-kW magnetically shielded Hall thruster are experimentally characterized with a high-speed, optical camera. Two modes are identified at 7–12 kHz and 70–90 kHz. The low frequency mode is found to be azimuthally uniform across the thruster face, while the high frequency oscillation is peaked close to the centerline-mounted cathode with an m = 1 azimuthal dependence. An analysis of these results in the context of wave-based theory suggests that the low frequency wave is the breathing mode oscillation, while the higher frequency mode is gradient-driven. The effect of these oscillations on thruster operation is examined through an analysis of thruster discharge current and a comparison with published observations from an unshielded variant of the thruster. Most notably, it is found that although the oscillation spectra of the two thrusters are different, they exhibit nearly identical steady-state behavior.
In vivo quantitative imaging of normal and cancerous breast tissue using broadband diffuse optical tomography (2010)

In vivo breast imaging with instrumentation that combines FD and CW NIR data acquisition in a single spectral reconstruction produces more accurate hemoglobin, water, and lipid results relative to FD data alone.
Near-angle polarization light scattering measurements of polished surfaces using a Mueller Matrix Imaging Scatterometer (2005)

Near-angle polarization light scattering measurements of polished surfaces using a Mueller Matrix Imaging Scatterometer are performed and results presented. Muller Matrix Movies are presented to aid in visualization of the multidimensional Mueller Matrix BRDF space.
Neuronal identity defines α-synuclein and tau toxicity (2022)

Abstract Pathogenic α-synuclein and tau are critical drivers of neurodegeneration and their mutations cause neuronal loss in patients. Whether the underlying preferential neuronal vulnerability is a cell-type intrinsic property or a consequence of increased expression levels is an open question. Here, we explore cell-type specific α-synuclein and tau expression in human brain datasets and use deep phenotyping as well as brain-wide single-cell RNA sequencing of &gt;200 live neuron types in fruit flies to ask which cellular environments react most to α-synuclein or tau toxicity. We detect phenotypic and transcriptomic evidence of differential neuronal vulnerability independent of α-synuclein or tau expression levels. Comparing vulnerable with resilient neurons enabled us to identify molecular signatures associated with these differential responses. We used these to verify, and then predict resilient and vulnerable neuron subtypes in human brains. This confirms substantia nigra dopaminergic neurons to be sensitive to α-synuclein, and we predict pathogenic tau vulnerable and protected cortical neuron subtypes. Our work indicates that cellular determinants confer selective vulnerability to specific types of amyloid toxicity, thus paving the way to leverage neuronal identity to uncover modifiers of neurodegeneration-associated toxic proteins.