gebhart/patrepeval huggingface dataset:
Atom probe tomography of space‐weathered lunar ilmenite grain surfaces (2020)

Abstract The surfaces of airless bodies, such as the Moon and asteroids, are subject to space weathering, which alters the mineralogy of the upper tens of nanometers of grain surfaces. Atom probe tomography ( APT ) has the appropriate 3‐D spatial resolution and analytical sensitivity to investigate such features at the nanometer scale. Here, we demonstrate that APT can be successfully used to characterize the composition and texture of space weathering products in ilmenite from Apollo 17 sample 71501 at near‐atomic resolution. Two of the studied nanotips sampled the top surface of the space‐weathered grain, while another nanotip sampled the ilmenite at about 50 nm below the surface. These nanotips contain small nanophase Fe particles (~3 to 10 nm diameter), with these particles becoming less frequent with depth. One of the nanotips contains a sequence of space weathering products, compositional zoning, and a void space (~15 nm in diameter) which we interpret as a vesicle generated by solar wind irradiation. No noble gases were detected in this vesicle, although there is evidence for 4 He elsewhere in the nanotip. This lunar soil grain exhibits the same space weathering features that have been well documented in transmission electron microscope studies of lunar and Itokawa asteroidal regolith grains.
A 2nd-Order Model of the Vertical Impedance of the Locomotor System During Human Walking (2019)

Objective: To design better shock absorbing prosthetic components, walking machines, or bionic legs, values and properties of the mechanical impedance of the locomotor system of able-bodied ambulators need to be determined. Methods: The representation of a simple 2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">nd</sup> -order shock absorption component (i.e., effective body mass, Me, supported by a stiffness, k, and damping, B, in parallel) was incorporated into a previously proposed rocker-based inverted pendulum model of walking to more accurately model the impedance associated with human walking, including the effects of shock absorption. Using system identification techniques and quantitative gait analysis data from able-bodied subjects (n = 7), the properties and values of the mechanical impedance for each subject's trial were determined. Results: It was determined that stiffness, k, increased linearly with walking speed while damping, B, increased with the square root of walking speed. Furthermore, the locomotor system behaves like an optimal underdamped mechanical system (i.e., damping ratio ζ of approximately 0.5-0.7). Conclusion: The locomotor system seems to behave like an optimal and adaptive low-pass filter in which the cutoff frequency is adjusted based on the locomotor's cadence. It could be hypothesized that this occurs due to the principle of conservation of the passenger's well-being: the fact that one of the locomotor's functional responsibilities is to prevent higher frequency vibrations that are harmful for the musculoskeletal system of the passenger. Significance: This is a holistic, simplified, and accurate model of the vertical leg mechanical impedance (locomotor system) that establishes parameters during walking over a range of speeds. These results can be used for the scientific design of better shock absorption prosthetic components and lower-limb prostheses, management of shock absorption related gait pathologies, or the design of human-like walking machines and rehabilitation robots.
Fabrication of Magnetic Tunneling Junctions with NaCl Barriers (2007)

We fabricated magnetic tunneling junctions (MTJs) with epitaxial NaCl(001) barriers grown on Fe(001). Thin magnetic layers were grown using a vacuum deposition system and junction patterns were formed using shadow masks installed in the deposition system. We confirmed that a barrier layer of NaCl(001) grows epitaxially on an Fe(001) bottom electrode layer but that the top layer of Fe is polycrystalline. The MTJs show nonlinear current–voltage characteristics and tunneling magneto-resistance (TMR) of ∼3% at room temperature. The observed TMR ratio is smaller than that expected for an epitaxial barrier with a fourfold symmetric crystal structure. Although the reason for this large discrepancy in TMR ratio between the MTJs with MgO barriers and those with NaCl barriers is unclear at this stage, novel materials such as a family of alkali halides have the potential to function as an applicable barrier for MTJs.
High specific output energy operation of a vacuum ultraviolet molecular fluorine laser excited at 66 MW/cm3 by an electric discharge (1990)

An output laser energy of 83 mJ, which corresponds to a specific output energy of 2.9 J/l, was obtained by exciting a 10 atm He/F2 gas mixture by an extremely intense electric discharge at a peak excitation rate of 66 MW/cm3. A fast rise of the voltage between the discharge electrodes prior to the discharge induction increases the breakdown voltage and, at the same time, improves the discharge stability resulting in an increase of the laser output and intrinsic efficiency.
Numerical analysis of a bdf2 modular grad-div Stabilization method for the Navier-Stokes equations (2018)

A second-order accurate modular algorithm is presented for a standard BDF2 code for the Navier-Stokes equations (NSE). The algorithm exhibits resistance to solver breakdown and increased computational efficiency for increasing values of grad-div parameters. We provide a complete theoretical analysis of the algorithms stability and convergency. Computational tests are performed and illustrate the theory and advantages over monolithic grad-div stabilizations.
Effect of Gentamicin on Growth and Differentiation of Human Mesenchymal Stem Cells (2008)

A tissue engineering approach using human mesenchymal stem cells (MSCs) can be used to regenerate bone/cartilage tissue. For effective tissue regeneration, cell cultivation under biologically safe conditions is essential. The objective of this study was to determine suitable antibiotic concentrations in culture media for MSCs while maintaining their inherent capabilities for proliferation and osteogenic/chondrogenic differentiation. When human MSCs were cultured with over 200 μg/mL of gentamicin, the rate of cell growth decreased significantly. In contrast, a concentration of 20 μg/mL gentamicin supported cell proliferation and differentiation capability very well and did not change the expression patterns of cell surface antigens (CD44+, CD105+, CD34-, CD45-). The concentration of 20 μg/ml is much higher than that of the MIC (Minimum Inhibition Concentration) of common bacteria, such as Staphylococcus aureus, Haemophilus influenzae and Escherichia coli. Therefore, we recommend 20 μg/mL of gentamicin in culture media for effective tissue regeneration to avoid bacterial contamination and maintain the osteogenic/chondrogenic capability of MSCs.
Voice capacity analysis of WLANS with channel access prioritizing mechanisms (2008)

Voice over IP applications in wireless networks have gained increasing popularity in recent years. As a delay-sensitive real-time application, a VoIP flow is usually given higher priority in accessing the shared wireless channel than delay-insensitive non-real-time flows. In contention-based wireless networks two widely used prioritizing MAC mechanisms are class-dependent arbitration interframe space and class-dependent contention window. In this article we propose an analytical model to evaluate the effect of the two mechanisms on voice capacity (the maximum number of two-way voice flow pairs supportable) of ad hoc mode and infrastructure mode wireless LANs. We show that the AIFS mechanism has a relatively strong effect on WLAN voice capacity in the ad hoc mode, but not in the infrastructure mode; and the CW mechanism, when properly configured, has a mild effect on voice capacity in both modes.
Rolling quantum dice with a superconducting qubit (2014)

One of the key challenges in quantum information is coherently manipulating the quantum state. However, it is an outstanding question whether control can be realized with low error. Only gates from the Clifford group---containing $\ensuremath{\pi}$, $\ensuremath{\pi}/2$, and Hadamard gates---have been characterized with high accuracy. Here, we show how the Platonic solids enable implementing and characterizing larger gate sets. We find that all gates can be implemented with low error. The results fundamentally imply arbitrary manipulation of the quantum state can be realized with high precision, providing practical possibilities for designing efficient quantum algorithms.
New Catalysts for Bisphenol A Polycarbonate Melt Polymerisation, 1. Kinetics of Melt Transesterification of Diphenylcarbonate with Bisphenol A (2001)

The catalytic activity of various compounds in the first stage of the melt transesterification of diphenyl carbonate and Bisphenol A (at 165°C) has been evaluated in order to identify new catalysts which may be of interest for the melt-phase preparation of Bisphenol A polycarbonate. Alkaline-earth and alkaline metals proved to be the most active catalysts; lanthanides were found to be rather active, while the catalytic activity of the other metals tested was much lower (except that of copper and cadmium). Some organic heterocyclic compounds were tested as transesterification catalysts as well, but they all had a very low activity.
Radiation‐induced PARP activation is enhanced through EGFR‐ERK signaling (2007)

We examined the impact of EGFR-ERK signaling on poly (ADP-ribose) polymerase (PARP) activation following ionizing irradiation of human prostate cancer (PCa) cell lines displaying marked differences in ERK dependence. PARP activation was indicated by the appearance of polyADP-ribose, the incorporation of P32-labelled NADH, and by cellular NADH. EGFR-ERK signaling was manipulated through ligand activation or signal interruption using the tyrphostin AG1478, or MEK inhibitor PD 184352. EGF activation of ERK prior to irradiation was associated with a marked increase in PARP activation and decreased survival in both cell lines. Prior inactivation of PARP protected both cell lines from the initial decrease in NAD+ and improved the survival of LNCaP cells following combined EGF and IR treatment. MEK inhibitor PD 184352 also reduced PARP activation and improved LNCaP survival following EGF and IR treatment. These data imply that PARP activation following exposure to ionizing radiation is enhanced through EGFR-ERK signaling.
Development of special PVC resins for long glass fibre reinforced composite sheets (2008)

The standard production of glass fibre reinforced PVC involves mixing and granulating the fibre and matrix before extrusion, which allows the use only of very short fibres. More recently a technique has been developed in which long or medium size fibres are arranged in a thin layer into which a dry blend of PVC resin with additives is dispersed using a high voltage electrical field. The product is then heated and pressed in a roll mill to obtain a stiff, impact resistant mat. Trials using a specially developed PVC resin that provides good gelation even without the application of shearing are reported. Significant improvements in flexural modulus and impact strength have been achieved. The sheet also shows good fire resistance and has attracted interest for applications including construction, transport (to provide weight saving) and furniture.
Opportunistic Feedback for Multiuser MIMO Systems With Linear Receivers (2007)

A novel multiuser scheduling and feedback strategy for the multiple-input multiple-output (MIMO) downlink is proposed in this paper. It achieves multiuser diversity gain without substantial feedback requirements. The proposed strategy uses per-antenna scheduling at the base station, which maps each transmit antenna at the base station (equivalently, a spatial channel) to a user. Each user has a number of receive antennas that is greater than or equal to the number of transmit antennas at the base station. Zero-forcing receivers are deployed by each user to decode the transmitted data streams. In this system, the base station requires users' channel quality on each spatial channel for scheduling. An opportunistic feedback protocol is proposed to reduce the feedback requirements. The proposed protocol uses a contention channel that consists of a fixed number of feedback minislots to convey channel state information. Feedback control parameters including the channel quality threshold and the random access feedback probability are jointly adjusted to maximize the average throughput performance of this system. Multiple receive antennas at the base station are used on the feedback channel to allow decoding multiple feedback messages sent simultaneously by different users. This further reduces the bandwidth of the feedback channel. Iterative search algorithms are proposed to solve the optimization for selection of these parameters under both scenarios that the cumulative distribution functions of users are known or unknown to the base station
Authors' Voluntary Retraction: H. Wilkie, A. Osei-Lah, B. Chioza, L. Nashef, D. McCormick, P. Asherson, and A.J. Makoff: Association of the μ-opioid receptor subunit gene and idiopathic generalized epilepsy. Neurology 2002;59:724–728 (2005)

We reported that two SNPs in OPRM1 (A118G and G-172T) were significantly associated with IGE.Unfortunately, a number of genotyping errors have recently come to light.Another research worker in our group has now repeated the genotyping in over 90% of the original DNA samples.Wherever there were discrepancies between the two sets of results, the genotyping was repeated twice more.The corrected results are presented in the table, which shows that neither SNP is significantly associated with IGE.Clearly our results do not now replicate the significant association reported by Sander et al. (Epilepsy Res 2000;39:57-61).As the main message of our paper is incorrect, we therefore wish to retract it.We sincerely apologise for inadvertently allowing erroneous data to reach the public domain.
[A case of retinochoroidal optic neuropathy]. (1997)

The patient was a 59-year-old male with impaired left vision. Before he was referred to this hospital, he was diagnosed as having optic nerve injury due to the trauma of a severe bruise on his left eye caused by a traffic accident, and relative afferent pupillary defect (RAPD) was negative. On his first examination in this department, RAPD was negative and funduscopy of the left eye demonstrated hyperemia of the optic disc and mild opacification at the posterior pole. Fluorescein fundus angiography showed circular hyperfluorescence around the optic disc and transverse linear hyperfluorescence appearing above and below the macula. From these findings a diagnosis of choloidal rupture was made. The form of choloidal rupture suggested an early stage of evulsion of the optic nerve. The impairment of visual acuity seemed to be caused by choloidal circulatory disturbance. The patient was therefore, had traumatic retinocholoidal optic neuropathy complicated by the rupture of the choloidal around the optic disc, disturbance of the optic disc, and opacification of the retinochoroid.
Increased aortic stiffness and blood pressure in non‐classic Pompe disease (2014)

Vascular abnormalities and glycogen accumulation in vascular smooth muscle fibres have been described in Pompe disease. Using carotid-femoral pulse wave velocity (cfPWV), the gold standard methodology for determining aortic stiffness, we studied whether aortic stiffness is increased in patients with Pompe disease. Eighty-four adult Pompe patients and 179 age- and gender-matched volunteers participated in this cross-sectional case-controlled study. Intima media thickness and the distensibility of the right common carotid artery were measured using a Duplex scanner. Aortic augmentation index, central pulse pressure, aortic reflexion time and cfPWV were assessed using the SphygmoCor® system. CfPWV was higher in patients than in volunteers (8.8 versus 7.4 m/s, p < 0.001). This difference was still present after adjustment for age, gender, mean arterial blood pressure (MAP), heart rate and diabetes mellitus (p = 0.001), and was shown by subgroup analysis to apply to the 40-59 years age group (p = 0.004) and 60+ years age group (p = 0.01), but not to younger age groups (p = 0.99). Except for a shorter aortic reflexion time (p = 0.02), indirect indicators of arterial stiffness did not differ between patients and volunteers. Relative to volunteers (20%), more Pompe patients had a history of hypertension (36%, p = 0.005), and the MAP was higher than in volunteers (100 versus 92 mmHg, p < 0.001). This study shows that patients with non-classic Pompe disease have increased aortic stiffness and blood pressure. Whether this is due to glycogen accumulation requires further investigation. To reduce the potential risk of cardiovascular diseases, we recommend that blood pressure and other common cardiovascular risk factors are monitored regularly.
Automatic depth map retrieval from digital holograms using a deep learning approach (2023)

Information extraction from computer-generated holograms using learning-based methods is a topic that has not received much research attention. In this article, we propose and study two learning-based methods to extract the depth information from a hologram and compare their performance with that of classical depth from focus (DFF) methods. We discuss the main characteristics of a hologram and how these characteristics can affect model training. The obtained results show that it is possible to extract depth information from a hologram if the problem formulation is well-posed. The proposed methods are faster and more accurate than state-of-the-art DFF methods.
Canine Lumbar Spinal Internal Fixation Techniques A Comparative Biomechanical Study (1986)

The stability (flexural rigidity) and strength of five canine spinal internal fixation techniques were quantitated and compared to each other and to the rigidity and strength of the intact spine. The techniques were applied to isolated canine lumbar spines (L2–L5) on which a complete spinal injury was surgically simulated at L3–L4. The spine‐implant preparations were subjected to four‐point bending and tested once to failure in flexion. The bending moment vs. L3–L4 angular deformation curves were recorded; rigidity and load sustained at failure (10° angular deformation) were compared. The combination of dorsal spinous process plate and dorsolateral vertebral body plate was the most rigid and most strong of the techniques tested. The dorsolateral vertebral body plate was the most rigid and most strong of the individual techniques, followed by the dorsal spinous process plate and the polymethylmethacrylate‐pin technique. Vertebral body crosspins provided the least strength and stability of any of the techniques tested.
The N-Methyl Derivatives of B2H7N (1949)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe N-Methyl Derivatives of B2H7NAnton B. Burg and Carl L. RandolphCite this: J. Am. Chem. Soc. 1949, 71, 10, 3451–3455Publication Date (Print):October 1, 1949Publication History Published online1 May 2002Published inissue 1 October 1949https://doi.org/10.1021/ja01178a056Request reuse permissionsArticle Views396Altmetric-Citations52LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (614 KB) Get e-Alertsclose Get e-Alerts
Poly(1,4‐Diethynylbenzene) Gradient Homojunction with Enhanced Charge Carrier Separation for Photoelectrochemical Water Reduction (2019)

As appealing photoelectrode materials for photoeletrochemical hydrogen evolution reaction (PEC HER), conjugated polymers still show poor PEC HER performance as a result of their serious recombination of photogenerated electrons and holes. Herein, a novel design of gradient homojunction is demonstrated by controlled copolymerization of 1,4-diethynylbenzene (DEB) and 1,3,5-triethynylbenzene (TEB). The as-built gradient distribution of TEB monomer in poly(1,4-diethynylbenzene) (pDEB) leads to continuous band bending engineering, which constitutes a gradient homojunction. Under AM 1.5G irradiation and in 0.1 m Na<sub>2</sub> SO<sub>4</sub> aqueous solution, the as-fabricated pDEB gradient homojunction exhibits a charge separation efficiency of 0.27% at 0.3 V versus reversible hydrogen electrode (RHE), which is 3.4 and 1.7 times higher than those for pure pDEB and the traditionally designed pDEB homojunction. As a result, the photocurrent of the pDEB gradient homojunction unprecedentedly reaches 55 µA cm<sup>-2</sup> at 0.3 V versus RHE, which is much higher than 19 µA cm<sup>-2</sup> for pure pDEB, 32 µA cm<sup>-2</sup> for the pDEB homojunction, and state-of-the-art organic photocathodes, e.g., g-C<sub>3</sub> N<sub>4</sub> (≈1-32 µA cm<sup>-2</sup> ). This work opens up a new window for the design of gradient homojunctions and will advance the exploration of high-performance organic photoelectrodes.
Estimation of the Chemical Diffusion Coefficient of H[sub 2]O in Ba[sub 3]Ca[sub 1.18]Nb[sub 1.82]O[sub (9−δ)] from Conductivity Measurements (2002)

Four-probe dc measurements were conducted on a polycrystalline material of composition which showed that the conductivity changed linearly with time during the initial stages when the atmosphere was changed from dry air to wet air, or vice versa. In order to analyze this transient conductivity change with time, a model was developed assuming rapid surface reaction. The model was then used to fit the experimental traces of conductivity vs. time, and estimate the chemical diffusion coefficient of over a range of temperatures from 400 to 900°C. The temperature dependence of the chemical diffusion coefficient could be described by an Arrhenius equation with an activation energy of The technique was also used to estimate the chemical diffusion coefficient of in © 2002 The Electrochemical Society. All rights reserved.
Interplay between Zika Virus and Peroxisomes during Infection (2019)

Zika virus (ZIKV) has emerged as an important human pathogen that can cause congenital defects in the fetus and neurological conditions in adults. The interferon (IFN) system has proven crucial in restricting ZIKV replication and pathogenesis. The canonical IFN response is triggered by the detection of viral RNA through RIG-I like receptors followed by activation of the adaptor protein MAVS on mitochondrial membranes. Recent studies have shown that a second organelle, peroxisomes, also function as a signaling platforms for the IFN response. Here, we investigated how ZIKV infection affects peroxisome biogenesis and antiviral signaling. We show that ZIKV infection depletes peroxisomes in human fetal astrocytes, a brain cell type that can support persistent infection. The peroxisome biogenesis factor PEX11B was shown to inhibit ZIKV replication, likely by increasing peroxisome numbers and enhancing downstream IFN-dependent antiviral signaling. Given that peroxisomes play critical roles in brain development and nerve function, our studies provide important insights into the roles of peroxisomes in regulating ZIKV infection and potentially neuropathogenesis.