gebhart/patrepeval huggingface dataset:
SU‐E‐I‐28: Pitch and Noise in Abdominal Multi‐Detector CT (2011)

Purpose: To quantify the effect of pitch on noise in abdominal multi‐detector CT. Methods: The standard acrylic abdominal CTDI phantom was modified so that it could be supported on the gantry shroud and remain stationary during a helical multi‐detector CT image acquisition. The table top height was positioned 1 cm below the phantom so that the table could move during helical image acquisition without touching the phantom. The phantom was scanned with the x‐ray tube voltage, x‐ray tube anode current, reconstructed slice thickness, multi‐detector selection and reconstruction kernel typically employed in a standard abdominal protocol for the different pitches available. On a given unit only the pitch was varied. The pixel standard deviation (noise) for four small (100 mm2) centrally located regions of interest were measured and averaged. Sixteen slice and 64 slice multi‐detector CT scanners were studied. On both scanners the standard filtered backprojection image reconstruction (FBP) algorithm was utilized. Results: On both the 16 slice and 64 slice scanners the noise varied to a reasonable approximation with the square root of the pitch for pitches ranging from ∼0.5 to ∼1.0. On the 16 slice scanner the noise increased only slightly when the pitch was changed from 1.375 to 1.75 Conclusions: In the cases of the CT scanners studied our results support the widely accepted fact that noise in an abdominal (noncardiac) mode multi‐detector helical CT image varies with pitch (and to the first order with the square root of the pitch) for pitches up to one when the FBP algorithm is employed. Our results do not support this fact when the pitch is increased above 1.0 and in particular as the pitch is increased to 1.75.
Host-guest complexation. 45. A highly preorganized chromogenic spherand indicator system specific for sodium and lithium ions (1988)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHost-guest complexation. 45. A highly preorganized chromogenic spherand indicator system specific for sodium and lithium ionsDonald J. Cram, Richard A. Carmack, and Roger C. HelgesonCite this: J. Am. Chem. Soc. 1988, 110, 2, 571–577Publication Date (Print):January 1, 1988Publication History Published online1 May 2002Published inissue 1 January 1988https://pubs.acs.org/doi/10.1021/ja00210a043https://doi.org/10.1021/ja00210a043research-articleACS PublicationsRequest reuse permissionsArticle Views396Altmetric-Citations45LEARN 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 InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts
Quantitative detection of changes in the leaf‐mesophyll tonoplast proteome in dependency of a cadmium exposure of barley (<b><i>Hordeum vulgare</i></b> L.) plants (2009)

Although the vacuole is the most important final store for toxic heavy metals like cadmium (Cd(2+)), our knowledge on how they are transported into the vacuole is still insufficient. It has been suggested that Cd(2+) can be transported as phytochelatin-Cd(2+) by an unknown ABC transporter or in exchange with protons by cation/proton exchanger (CAX) transporters. To unravel the contribution of vacuolar transporters to Cd(2+) detoxification, a quantitative proteomics approach was performed. Highly purified vacuoles were isolated from barley plants grown under minus, low (20 microM), and high (200 microM) Cd(2+ )conditions and protein levels of the obtained tonoplast samples were analyzed using isobaric tag for relative and absolute quantitation (iTRAQ). Although 56 vacuolar transporter proteins were identified, only a few were differentially expressed. Under low-Cd(2+) conditions, an inorganic pyrophosphatase and a gamma-tonoplast intrinsic protein (gamma-TIP) were up-regulated, indicating changes in energization and water fluxes. In addition, the protein ratio of a CAX1a and a natural resistance-associated macrophage protein (NRAMP), responsible for vacuolar Fe(2+) export was increased. CAX1a might play a role in vacuolar Cd(2+) transport. An increase in NRAMP activity leads to a higher cytosolic Fe(2+) concentration, which may prevent the exchange of Fe(2+) by toxic Cd(2+). Additionally, an ABC transporter homolog to AtMRP3 showed up-regulation. Under high Cd(2+) conditions, the plant response was more specific. Only a protein homologous to AtMRP3 that showed already a response under low Cd(2+) conditions, was up-regulated. Interestingly, AtMRP3 is able to partially rescue a Cd(2+)-sensitive yeast mutant. The identified transporters are good candidates for further investigation of their roles in Cd(2+) detoxification.
Correspondenceless Ego-Motion Estimation Using an IMU (2006)

Mobile robots can be easily equipped with numerous sensors which can aid in the tasks of localization and ego-motion estimation. Two such examples are Inertial Measurement Units (IMU), which provide a gravity vector via pitch and roll angular velocities, and wide-angle or panoramic imaging devices. As the number of powerful devices on a single robot increases, an important problem arises in how to fuse the information coming from multiple sources to obtain an accurate and efficient motion estimate. The IMU provides real-time readings which can be employed in orientation estimation, while in principle an Omnidirectional camera provides enough information to estimate the full rigid motion (up to translational scale). However, in addition to being computationally overwhelming, such an estimation is traditionally based on the sensitive search for feature correspondences between image frames. In this paper we present a novel algorithm that exploits information from an IMU to reduce the five parameter motion search to a three-parameter estimation. For this task we formulate a generalized Hough transform which processes image features directly to avoid searching for correspondences. The Hough space is computed rapidly by re-treating the transform as a convolution of spherical images.
Erratum: Electron Paramagnetic Resonance of Beef Heart Ferricytochrome c (1968)

Peer Reviewed
Asymmetric Synthesis of (+)‐Altholactone: A Styryllactone Isolated from Various <i>Goniothalamus</i> Species (2008)

The asymmetric total synthesis of (+)-altholactone (1), a member of the styryllactone family of natural products displaying cytotoxic and antitumor activities, is described. Key steps include a RAMP-hydrazone alpha-alkylation (RAMP=(R)-1-amino-2-methoxymethylpyrrolidine) of 2,2-dimethyl-1,3-dioxan-5-one, a boron-mediated aldol reaction, a six- to five-membered ring acetonide shuffling, an oxidative 1,5-diol to delta-lactone conversion and a stereoselective ring-closure to generate the annulated tetrahydrofuran moiety with inversion of configuration.
Enhancement of disease by neutralizing antiviral antibodies in the absence of primed antiviral cytotoxic T cells (1993)

The effects of neutralizing antibodies on the disease course in mice infected with the noncytopathic lymphocytic choriomeningitis virus (LCMV) were evaluated. Whereas non-neutralizing antisera exhibiting high enzyme-linked immunosorbent assay titers had no effect on T cell responses and their consequences, neutralizing antisera modulated them variably. Neutralizing antibodies were able to prevent lethal choriomeningitis after intracerebral infection with a neurotropic LCMV-isolate (ARMSTRONG) although they could not control local virus replication. The same antibodies exhibited little or no protective effect on choriomeningitis induced by LCMV-WE, a viscerotrope isolate. Surprisingly, these antibodies rendered mice much more susceptible to choriomeningitis after intracerebral infection with LCMV DOCILE, a very rapidly spreading lymphocyto-viscerotrope virus; in this situation antibodies prevented overwhelming infection which causes deletion of immunopathogenic cytotoxic T cell responses. Thus preexisting neutralizing antiviral antibodies had little influence on local virus spread in peripheral tissues but they reduced hematogenic spread and infection of antigen-presenting cells; thereby they influenced the primary cytotoxic T cell (CTL) response and indirectly modulated the extent of T cell-mediated immunopathology in peripheral organs. These results may explain why vaccines inducing neutralizing antibodies but no CTL may enhance an immunopathological disease caused by challenge infection with a noncytopathic virus.
DSM-IV field trials for oppositional defiant disorder and conduct disorder in children and adolescents (1994)

DSM-IV definitions of oppositional defiant disorder and conduct disorder are somewhat better than DSM-III-R definitions in terms of internal consistency and test-retest agreement, and the validity of the DSM-IV definition of oppositional defiant disorder is slightly better than that of DSM-III-R.
GMPLS Control Plane Network Design With Resilience Guarantees (2010)

A one-to-one association between data and control channels has traditionally existed in transport networks. Being the control plane embedded in the data plane, the design of the former, as well as its resilience, has been addressed in the latter's one. However, a main GMPLS architectural requirement is to provide a clean separation between control and data planes. In this sense, the control plane in GMPLS networks may describe a different topology than the data plane, even realized over a separated IP network. As a consequence of this, data and control network design become no more linked in such scenarios. To the best of our knowledge, no works in the literature have addressed an independent design of the control plane in GMPLS-enabled networks regardless of the data plane. In this paper, we provide a method to obtain the optimal GMPLS control plane design, minimizing the network Capital Expenditures (CAPEX) while matching specific resilience requirements. To this goal, the problem of finding an optimal control plane topology that ensures a certain resilience level is formulated as a non-linear combinatorial model. This model, however, does not scale properly for large backbone networks. In view of this, a constructive linear method is also presented and its optimality validated through simulations on several reference network scenarios. Furthermore, its benefits in terms of total execution time are also highlighted.
Development of a Demister for a Waste Evaporator Using a Hydrophobic Membrane Filter (1994)

A demister using a hydrophobic porous membrane made from polytetrafluoroethylene was developed to improve the decontamination factor (DF) of a waste evaporator. The demister removes the radioactive mist in steam generated from the evaporator.A large-scale membrane module (membrane surface area: 3 m1) for the demister was newly designed, and its steam permeation rate and DF were experimentally examined using steam containing simulated mist (5 wt% Na2SO4 solution). The steam permeation rate decreases due to adhesion of removed mist on the membrane surface, but it is maintained at ∼0.35 of the initial value through falling of the mist from the membrane surface due to the mist particles’ own weight. The DF of the demister, using a membrane having less than a 0.7-μm pore diameter, is >5 × 103. The total DF of the evaporator with the new demister is estimated to be >5 × 107.
ChemInform Abstract: UMSETZUNGEN VON CYCLOPROPYLLITHIUM MIT HALOGENBENZOLEN (1973)

Abstract Cyclopropyl‐Li (II) und Halogenbenzole (I), (V) bzw. (VIII) liefern beim Erhitzen in Äther Cyclopropylbenzole und Biphenyle, daneben findet Enthalogenierung statt: Aus (Ia)‐(Ic) werden jeweils Cyclopropylbenzol (III), das Biphenyl (IV) und Benzol gebildet; im Falle von (Ic) entsteht außerdem noch Biphenyl (l 1% Ausbeute).
Histogenesis and ultrastructure of pancreatic islet graft microvasculature. Evidence for graft revascularization by endothelial cells of host origin. (1995)

In previous studies we have demonstrated that syngeneic and xenogeneic pancreatic islet grafts are revascularized within a 10 to 14-day period after transplantation. With the combined use of intravital and electron microscopy, as well as immunohistochemistry using a set of species-specific or -crossreacting antibodies to endothelial cell antigens, we investigated 1) the origin of the endothelium of the newly formed capillaries in free pancreatic islet isografts (hamster-->hamster) and xenografts (rat-->hamster), and 2) the ultrastructural characteristics of these microvessels. Intravital microscopy demonstrated that newly formed microvessels grow from the vascular bed of the host muscle tissue into the islet grafts. Immunohistochemical analysis of host tissue and transplanted islets with antibodies against factor VIII (recognizing both hamster and rat factor VIII), bovine PECAM-1 (CD31; endoCAM, crossreacting with hamster but not rat PECAM-1), and rat ICAM-1 (CD54, non-crossreacting with hamster ICAM-1) showed that the transplanted rat islets were revascularized by endothelium of hamster (host) origin. At an ultrastructural level, the endothelial lining of the newly formed microvessels showed diaphragmatic fenestration, a characteristic feature of endothelial cells of pancreatic islets in situ. On the basis of these findings we suggest that pancreatic islet transplantation may take a unique position in the field of organ transplantation, since the generally proposed mechanisms of endothelial cell-dependent antigen recognition as a trigger of graft rejection may not be transferred to islet grafts, containing microvessels lined by endothelial cells of host origin.
Numerical Analysis on the Extruded Volume and Length Ratios of Backward Tube to Forward Rod in Combined Extrusion Processes (2006)

This paper is concerned with forward rod extrusion combined simultaneously with backward tube extrusion process in both steady and transient states. The analysis has been conducted in numerical manner by employing a rigid-plastic finite element method. AA 2024 aluminum alloy was selected as a model material for analysis. Among many process parameters, major design factors chosen for analysis include frictional condition, thickness of tube in backward direction, punch corner radius, and die corner radius. The main goal of this study is to investigate the material flow characteristics in combined extrusion process, i.e. forward rod extrusion combined simultaneously with backward tube extrusion process. Simulation results have been summarized in term of relationships between process parameters and extruded length and volume ratios, and between process parameters and force requirements, respectively. The extruded length ratio is defined as the ratio of tube length extruded in backward direction to rod length extruded in forward direction, and the volume ratio as that of extruded volume in backward direction to that in forward direction, respectively. It has been revealed from the simulation results that material flow into both backward and forward directions are mostly influenced by the backward tube thickness, and other process parameters such as die corner radius etc. have little influence on the volume ratio particularly in steady state of combined extrusion process. The pressure distributions along the tool-workpiece interface have been also analyzed such that the pressure exerted on die is not so significant in this particular process such as combined operation process. Comparisons between multi-stage forming process in sequence operation and one stage combined operation have been also made in terms of forming load and pressure exerted on die. The simulation results shows that the combined extrusion process has the greatest advantage of lower forming load comparing to that in sequence operation.
Two Dimensional Arrays for Real Time 3D Intravascular Ultrasound (2004)

We have previously described 2D arrays operating at up to 10.0 MHz consisting of several thousand elements for transthoracic cardiac imaging and over a hundred elements for intracardiac imaging using 7 Fr to 12 Fr catheters. We have begun to explore forward viewing real time 3D phased array intravascular ultrasound, which may require imaging depths of a few centimeters to look down the axis of a vessel to view vulnerable atherosclerotic plaque. We used a noncoaxial based cable technology that allowed 100 signal wires to be placed inside a4.8 French IVUS lumen with an inner diameter of 1.3 mm. We pursued two different fabrication technologies for the building of the transducers. Each transducer was constructed in the forward viewing configuration to allow simultaneous real time B-scans, C-scans and volumetric rendering of vessels and vascular stents distal to the catheter tip. In order to obtain the desired penetration depth, each transducer was constructed to operate at 10.0 MHz. The first method included an ordered array of 11 x 11 = 121 elements. In order to conform to the round aperture of the IVUS lumen, the comers were cut off, resulting in a total of 97 signal channels. Real time images include a 4 mm diameter vessel in a tissue mimicking phantom, an expanded stent and a stent in an excised sheep aorta. The second method is based upon a laser dicing technique that cuts the individual elements in a random pattern. This resulted in 61 signal channels. Real time 3D images of the AIUM test object were made with this transducer.
Stopped-Flow Analysis of Substrate Binding to Neuronal Nitric Oxide Synthase (1999)

The kinetics of binding L-arginine and three alternative substrates (homoarginine, N-methylarginine, and N-hydroxyarginine) to neuronal nitric oxide synthase (nNOS) were characterized by conventional and stopped-flow spectroscopy. Because binding these substrates has only a small effect on the light absorbance spectrum of tetrahydrobiopterin-saturated nNOS, their binding was monitored by following displacement of imidazole, which displays a significant change in Soret absorbance from 427 to 398 nm. Rates of spectral change upon mixing Im-nNOS with increasing amounts of substrates were obtained and found to be monophasic in all cases. For each substrate, a plot of the apparent rate versus substrate concentration showed saturation at the higher concentrations. K(-)(1), k(2), k(-)(2), and the apparent dissociation constant were derived for each substrate from the kinetic data. The dissociation constants mostly agreed with those calculated from equilibrium spectral data obtained by titrating Im-nNOS with each substrate. We conclude that nNOS follows a two-step, reversible mechanism of substrate binding in which there is a rapid equilibrium between Im-nNOS and the substrate S followed by a slower isomerization process to generate nNOS'-S: Im-nNOS + S if Im-nNOS-S if nNOS'-S + Im. All four substrates followed this general mechanism, but differences in their kinetic values were significant and may contribute to their varying capacities to support NO synthesis.
Initial Flight Tests of the NASA F-15B Propulsion Flight Test Fixture (2002)

Flights of the F-15B/Propulsion Flight Test Fixture (PFTF) with a Cone Drag Experiment (CDE) attached have been accomplished at NASA Dryden Flight Research Center. Mounted underneath the fuselage of an F-15B airplane, the PFTF provides volume for experiment systems and attachment points for propulsion experiments. A unique feature of the PFTF is the incorporation of a six-degree-of-freedom force balance. The force balance mounts between the PFTF and experiment and measures three forces and moments. The CDE has been attached to the force balance for envelope expansion flights. This experiment spatially and inertially simulates a large propulsion test article. This report briefly describes the F-15B airplane, the PFTF, and the force balance. A detailed description of the CDE is provided. Force-balance ground testing and stiffness modifications are described. Flight profiles and selected flight data from the envelope expansion flights are provided and discussed, including force-balance data, the internal PFTF thermal and vibration environment, a handling qualities assessment, and performance capabilities of the F-15B airplane with the PFTF installed.
Comments on the Doorway State in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi mathvariant="normal">Pb</mml:mi></mml:mrow><mml:mprescripts/><mml:mrow/><mml:mrow><mml:mn>206</mml:mn></mml:mrow><mml:mrow/><mml:mrow/></mml:mmultiscripts></mml:mrow></mml:math> (1973)

The neutron capture cross section of $^{206}\mathrm{Pb}(n, \ensuremath{\gamma})$ has been measured with high resolution at the Oak Ridge electron linear accelerator. The capture results show that the reported ${s}_{\frac{1}{2}}$ doorway in $^{206}\mathrm{Pb}$ is not observed in the photon channel.
Gelation Mechanism of Erythromycin Ethylsuccinate During Crystallization (2018)

In this paper, the gelation mechanism of erythromycin ethylsuccinate (EES) during crystallization is investigated for the first time. The generated semisolid gel-like phase exhibited a 3D fibrillar network morphology and the typical rheological properties of gels. The fibers inside the gel-like phase were confirmed to be new types of EES solvates using powder X-ray diffraction, thermogravimetric analysis/differential scanning calorimetry, and gas chromatography. The gelation and crystallization regions in EES-1-propanol solid–liquid phase diagram were determined. Analyses of solvent parameters showed that moderate solvent polarity may promote EES gelation. Fourier transform infrared spectra, nuclear magnetic resonance spectra, and scanning electron microscopy analyses indicated that through intermolecular hydrogen bonds, EES and solvent molecules assembled into fibers via crystallographic mismatch branching growth. The fibers intertwined into a 3D network microstructure and formed a gel-like phase, completely immobilizing the solution.
Oxidative cyclisations of o-substituted anilines and benzoic acids with manganese dioxide (1968)

In a neutral medium, oxidation by manganese dioxide of N-o-aminophenyl-, N-o-aminobenzyl-, and N-o-carboxyphenyl-amines gave benzimidazoles, quinazolones, and benzoxazinones, respectively. Similarly, o-alkylbenzoic acids yielded phthalides. Reaction mechanisms and spectral data of various products are discussed.
Streptococcal Surface Proteins Activate the Contact System and Control Its Antibacterial Activity (2012)

Group G streptococci (GGS) are important bacterial pathogens in humans. Here, we investigated the interactions between GGS and the contact system, a procoagulant and proinflammatory proteolytic cascade that, upon activation, also generates antibacterial peptides. Two surface proteins of GGS, protein FOG and protein G (PG), were found to bind contact system proteins. Experiments utilizing contact protein-deficient human plasma and isogenic GGS mutant strains lacking FOG or PG showed that FOG and PG both activate the procoagulant branch of the contact system. In contrast, only FOG induced cleavage of high molecular weight kininogen, generating the proinflammatory bradykinin peptide and additional high molecular weight kininogen fragments containing the antimicrobial peptide NAT-26. On the other hand, PG protected the bacteria against the antibacterial effect of NAT-26. These findings underline the significance of the contact system in innate immunity and demonstrate that GGS have evolved surface proteins to exploit and modulate its effects.