gebhart/patrepeval huggingface dataset:
Intensity Non-uniformity Correction in MR Imaging Using Residual Cycle Generative Adversarial Network (2020)

Purpose: Correcting or reducing the effects of voxel intensity non-uniformity (INU) within a given tissue type is a crucial issue for quantitative MRI image analysis in daily clinical practice. In this study, we present a deep learning-based approach for MRI image INU correction. Method: We developed a residual cycle generative adversarial network (res-cycle GAN), which integrates the residual block concept into a cycle-consistent GAN (cycle-GAN). In cycle-GAN, an inverse transformation was implemented between the INU uncorrected and corrected MRI images to constrain the model through forcing the calculation of both an INU corrected MRI and a synthetic corrected MRI. A fully convolution neural network integrating residual blocks was applied in the generator of cycle-GAN to enhance end-to-end raw MRI to INU corrected MRI transformation. A cohort of 30 abdominal patients with T1-weighted MR INU images and their corrections with a clinically established and commonly used method, namely, N4ITK were used as a pair to evaluate the proposed res-cycle GAN based INU correction algorithm. Quantitatively comparisons were made among the proposed method and other approaches. Result: Our res-cycle GAN based method achieved higher accuracy and better tissue uniformity compared to the other algorithms. Moreover, once the model is well trained, our approach can automatically generate the corrected MR images in a few minutes, eliminating the need for manual setting of parameters. Conclusion: In this study, a deep learning based automatic INU correction method in MRI, namely, res-cycle GAN has been investigated. The results show that learning based methods can achieve promising accuracy, while highly speeding up the correction through avoiding the unintuitive parameter tuning process in N4ITK correction.
Obstacle - slope avoidance and velocity control of wheeled mobile robots using fuzzy reasoning (2009)

This paper gives the fuzzy velocity control of a mobile robot motion in an unknown environment with slopes and obstacles. The model of the vehicle has two driving wheels and the angular velocities of the two wheels are independently controlled. When the vehicle is moving towards the target and the sensors detect an obstacle or slopes, an avoiding strategy and velocity control are necessary. We proposed a fuzzy reactive navigation strategy of collision-free motion and velocity control in an unknown environment with slopes and obstacles. Outputs of the fuzzy controller are the angular speed difference between the left and right wheels of the vehicle and the vehicle velocity. The simulation results show the effectiveness and the validity of the obstacle avoidance behavior in an unknown environment and velocity control of the proposed fuzzy control strategy.
Pectic substances–water. I. Structural changes in the polygalacturonide chains during water adsorption (1956)

Abstract An apparatus suitable for studying adsorption of water vapor both volumetrically and gravimetrically is described. Water vapor isotherms of highly esterified pectin, sodium pectate and pectic acid were determined. Equatorial and meridional spacings of the x‐ray diffraction patterns were measured as a function of equilibrium water content in these materials. The interchain separations, as measured by the changes in the equatorial spacings of x‐ray reflections, follow the shape of the adsorption isotherms. In esterified pectin and sodium pectate, the fiber repeat period increases until 5 molecules of water content per 3 galacturonide residues are adsorbed, thereafter remaining constant. The fiber period of pectic acid is constant throughout water adsorption.
Diagnostic Measurements on Rotary Arcs in Hollow Polymeric Cylinders (2005)

Rotary arcs in hollow polymeric cylinders have been monitored using electrical and optical techniques. The arcs burning within hollow cylinders were driven by electromagnetic forces. The arc voltage, current, dielectric strength below the arc gap, the optical emissions from the chamber were measured along with high-speed photography. The diameters of the hollow cylinders and magnitude of the applied magnetic field were varied. The arc voltage, especially the extinction peak prior to current zero, increased for larger bore cylinders and higher magnetic fields. By comparing the arc voltage waveforms and arc photographs, this was shown to be because the arcs were elongated. Luminosity was detected even after current zero, when polytetrafluoroethylene was in the arc chamber. The extensive experimental results obtained have enabled empirical mathematical expressions to be derived which yield approximate indications of current interruption capabilities under different operating conditions.
Pharmacokinetics of pancreatic polypeptide in man. (1978)

Pure bovine pancreatic polypeptide (PP) was infused into 23 healthy subjects at doses of 1, 3, and 5 pmol/kg/min over 60 minutes and plasma PP was measured by radioimmunoassay. During the infusions mean plasma levels of 203 +/- 34, 575 +/- 73, and 930 +/- 48 pmol/l respectively were achieved. Mean disappearance half time on stopping the infusion was 6.9 +/- 0.3 min (mean +/- SEM). The metabolic clearance rate was 5.1 +/- 0.2 ml/kg/min (mean +/- SEM) and the apparent volume of distribution was calculated to be 51 +/- 3 ml/kg (mean +/- SEM). This study provides for the first time pharmacokinetic data for PP in man.
Microscopic rate constants for the acetate ion catalyzed isomerization of 5-androstene-3,17-dione to 4-androstene-3,17-dione: a model for steroid isomerase (1991)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMicroscopic rate constants for the acetate ion catalyzed isomerization of 5-androstene-3,17-dione to 4-androstene-3,17-dione: a model for steroid isomeraseBaifei Zeng and Ralph M. PollackCite this: J. Am. Chem. Soc. 1991, 113, 10, 3838–3842Publication Date (Print):May 1, 1991Publication History Published online1 May 2002Published inissue 1 May 1991https://pubs.acs.org/doi/10.1021/ja00010a028https://doi.org/10.1021/ja00010a028research-articleACS PublicationsRequest reuse permissionsArticle Views263Altmetric-Citations43LEARN 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
Comparison of biphasic and reordered fat suppression for dynamic breast MRI (2007)

This method will allow robust fat suppression with virtually no extension in imaging time for dynamic contrast-enhanced (DCE)-MRI.
Context based coding of binary shapes by object boundary straightness analysis (2004)

A new lossless compression scheme for bilevel images targeted at binary shapes of image and video objects is presented. The scheme is based on a local analysis of the digital straightness of the causal part of the object boundary, which is used in the context definition for arithmetic encoding. Tested on individual images of binary shapes and binary layers of digital maps the algorithm outperforms PWC, JBIG and MPEG-4 CAE. On the binary shapes the code lengths are reduced by 21%, 25%, and 42%, respectively. On the maps the reductions are 34%, 32%, and 59%, respectively. The algorithm is also more efficient than the state-of-the-art and more complex free tree coder for most of the binary shape and map test images.
Electron transport in strained Si layers on Si1−<i>x</i>Ge<i>x</i> substrates (1993)

Results on the in-plane electron drift velocities and mobilities in strained Si layers grown on Si1−xGex substrates are reported for 300 and 77 K. High-field drift velocities are calculated by Monte Carlo simulations and low-field mobilities by numerical solution of Boltzmann’s equation including intra- and intervalley phonon and impurity scattering mechanisms. Significant improvements of drift velocities relative to bulk Si are found for electric fields up to several 10 kV/cm, while saturation occurs at the bulk values for both temperatures. A much stronger mobility enhancement of 74% is obtained at 300 K compared to 36% at 77 K, which is consistent with recent experimental results.
Simulation of the residential lumber supply chain (2004)

We describe the lumber supply chain for a case study of a large home builder, extending through multiple tiers from the homebuyer to the lumber company. The builder required its framing subcontractor to accept the risk for lumber cost fluctuations. Under this agreement, the framing subcontractor provided a fixed lumber cost, which could only periodically adjusted. The lumber supply chain leading to the framing subcontractor was found to be of long and variable duration. The function of the builder-framer/lumber yard-lumber company portion of the supply chain was simulated in order to evaluate the cost effectiveness of this strategy, using historical records of lumber prices to model commodity price fluctuations. Based on the simulation results, the risk transfer strategy appears to induce a risk premium generally in excess of the true commodity price risk.
Rapid calculation of polar molecular surface area and its application to the prediction of transport phenomena. 1. Prediction of intestinal absorption (1999)

A method for the rapid computation of polar molecular surface area (PSA) is described. It is shown that consideration of only a single conformer when computing PSA gives an excellent correlation with intestinal absorption data-as good as previously reported methods employing multiple conformers. Circumventing a time-consuming conformational analysis opens the possibility of computationally screening large numbers of compounds for problems relating to absorption prior to synthesis. The robustness of the criterion for identifying poorly absorbed compounds (PSA >/= 140 A(2)) is illustrated through its application to a diverse test set of 74 drugs. The PSA-based method is also compared to an experimental method for absorption prediction recently described in the literature.
Human Sterol 27-Hydroxylase (CYP27) Overexpressor Transgenic Mouse Model (2002)

CYP27-overexpressed transgenic mice were generated with the use of a human full-length CYP27 coding region cloned into a ubiquitous expression vector. Positive transgenic mice were identified by tail DNA genotyping and high fecal 27-hydroxycholesterol content. The levels of 27-hydroxycholesterol were found to be 3-5 times higher in the circulation and the tissues of the overexpressed mice when compared with littermate controls. There were no gross morphological differences between the overexpressed mice and their controls. Total cholesterol and triglyceride levels were not affected by overexpression of CYP27. Serum lathosterol was also normal, suggesting a normal rate of cholesterol synthesis. Serum levels of 7alpha-hydroxycholesterol were unaffected, suggesting a normal rate of bile acid formation in the pathway involving cholesterol 7alpha-hydroxylase. Biliary bile acid composition was slightly affected by CYP27 overexpression in female but not in male mice. Fecal levels of neutral steroids were slightly but significantly increased in overexpressor female mice but not in male mice. Levels of 24-hydroxycholesterol in the circulation were significantly reduced in the overexpressed mice, probably as a consequence of a recently described catabolic pathway involving CYP27. Combined with the results of our previous work on mice with a disruption of the CYP27 gene, the present results suggest that the levels of 27-hydroxycholesterol are not of critical importance for cholesterol homeostasis in mice.
Dimensionality of Excitons in InGaN-Based Light Emitting Devices (2000)

Temperature dependence of radiative and non-radiative recombination times has been investigated in InxGa1–xN based light emitting devices by employing time-resolved luminescence spectroscopy. The mean In-composition (x value) assessed in this study is 10%, 20% and 30% whose emissions at 300 K correspond to near ultraviolet (390 nm), violet (422 nm) and blue (471 nm), respectively. It was found that the degree of exciton localization was enhanced with increasing In-composition in InxGa1–xN active layers, and that the zero-dimensional feature was revealed best of all in the sample with x = 30%, where radiative recombination time was almost constant (4 to 6 ns) in the temperature range from 20 to 300 K. The internal quantum efficiency of this sample was estimated to exceed 70% at 300 K. It is likely that such high efficiency is a result of zero-dimensionality because capture cross-sections to non-radiative recombination centers are greatly reduced once excitons are trapped at deep localization centers.
A constraint-based architecture for local search (2002)

Combinatorial optimization problems are ubiquitous in numerous practical applications. Yet most of them are challenging, both from computational complexity and programming standpoints. Local search is one of the main approaches to address these problems. However, it often requires sophisticated incremental algorithms and data structures, and considerable experimentation. This paper proposes a constraint-based, object-oriented, architecture to reduce the development time of local search algorithms significantly. The architecture consists of declarative and search components. The declarative component includes invariants , which maintain complex expressions incrementally, and differentiable objects , which maintain properties that can be queried to evaluate the effect of local moves. Differentiable objects are high-level modeling concepts, such as constraints and functions, that capture combinatorial substructures arising in many applications. The search component supports various abstractions to specify heuristics and meta-heuristics. We illustrate the architecture with the language Comet and several applications, such as car sequencing and the progressive party problem. The applications indicate that the architecture allows for very high-level modeling of local search algorithms, while preserving excellent performance.
Broad-Band Microwave Transmission Characteristics from a Single Measurement of the Transient Response (1968)

A technique is presented for the measurement of the transmission and reflection scattering coefficients of microwave networks by Fourier analysis of the sampled transient response of the network to impulsive or steplike waveforms. It is demonstrated that the method can reduce errors due to mismatch of the components of the measurment system by sampling the response over a finite time domain window that excludes unwanted reflected components. A review is made of the errors introduced due to aliasing, truncation, and noiselike sources such as timing jitter and additive noise, and a description is then given of an experimental system to evaluate the technique, based on use of a 12-GHz sampling oscilloscope for measurement of the transient response and a suitable form of the fast Fourier transform algorithm. Measurements on some typical wide-band components are presented, and it is concluded that for very broad-band measurements with moderate resolution the method has a potential accuracy of about ±0.1 dB and ±1°, with a significant reduction in mismatch errors.
The effect of topically applied antihistaminic drugs on the mammalian capillary bed. (1949)

1. It has been shown that the antihistaminic drugs, not related to acetylcholine, have a vasoconstrictor action on the precapillary sphincters of the mammalian capillary bed, while histamine has a vasodilator action. This demonstrates that both drugs compete for the same site of action. 2. It has been shown that acetyleholine and antihistaminic compounds having the choline group exert a vasodilator effect upon the capillary bed. Further, although washing the bed counteracts the effect of the latter compounds, it is necessary to apply an antispasmodic drug to counteract the effect of the former. 3. It has been shown that antispasmodic drugs have at best only a slight vasoconstrictor action upon the capillary bed. 4. The vasodilator action of 8-chlorotheophyllin is more potent than the vasoconstrictor action of diphenhydramine. However, the effect is not upon the precapillary sphincters but upon the vessels having more muscular coats (arterioles). 5. The vasoconstrictor effect produced by the antihistaminics on the capillary bed is produced at dilutions which are of the same order of magnitude as those obtained in animals or humans after oral or intravenous administration. Further, such vasoconstriction explains the decrease in Trypan Blue extravasation in animals, the decrease in the wheal and flare reaction in humans and the reduction in the tuberculin skin reaction. 6. The cyclization of the terminal amine group to form a morpholine group decreases the vasoconstrictor action of diphenhydramine. However, cyclization to form the imidazole group does not decrease the vasoconstrictor action of an antihistaminic. The substitution of a thenyl or halogenated thenyl group for either the phenyl or pyridyl group results in a decrease in vasoconstrictor action.
Molecular Design Strategies for Optimizing the Nonlinear Optical Properties of Chiral Crystals (2008)

A simple theoretical framework is presented to identify the key molecular properties and macromolecular arrangements leading to high second-order nonlinear optical (NLO) activity of chiral crystals. In chiral materials, maximum second harmonic generation (SHG) efficiency is predicted for an antiparallel molecular arrangement of Λ-like chromophores. This prediction is in stark contrast to the majority of previous crystal engineering efforts for second-order NLO materials, which have been focused almost exclusively on the construction of crystals exhibiting high degrees of polar order. Methods for possible rational electrostatic control of crystal structure by appropriate molecular design are considered.
An Information Model for Kerberos Version 5 (2013)

This document describes an information model for Kerberos version 5 from the point of view of an administrative service. There is no standard for administrating a Kerberos 5 Key Distribution Center (KDC). This document describes the services exposed by an administrative interface to a KDC.
The heterogeneous catalytic reaction between carbon monoxide and nitrous oxide over manganous oxide and cobalto-cobaltic oxide (1978)

The catalytic reaction between carbon monoxide and nitrous oxide has been studied on MnO from 493 to 573 K and on Co 3 O 4 from 383 to 493 K. The apparent activation energy on MnO was 130 ± 4 kJ mol −1 , while for Co 3 O 4 , a change from 31 ± 4 to 105 ± 4 kJ mol −1 was observed at 450 K. The rate-controlling step for the catalytic reaction on MnO was associated with the surface reaction between carbon monoxide and nitrous oxide in a manner similar to that previously reported for NiO, while for Co 3 O4, the rate-determining step was related to the formation of an intermediate surface carbonate. The changes in E A may be a consequence of the surface reaction proceeding via a concerted redox reaction in the low temperature region and then to a stepwise mechanism at higher temperatures resulting from the presence of structurally and energetically different forms of the intermediate surface carbonate.
ChemInform Abstract: Organophosphorus Compounds. Part 18. Oxidation of Tertiary Alicyclic Amines with Elemental Sulfur in Hexamethylphosphoric Triamide (HMPA). Oxidative Rearrangements of Hexahydroazepines and Octahydroazocines to Bis(3‐pyrrolyl)polysulfides. (1978)

Abstract Bei der im Titel erwähnten Oxidation der cyclischen Amine (Ia) und (Ib) [ R: ‐Me, ‐CH2 ‐CH2‐Ph) werden die Thiolactame (II) isoliert.
Role of Lipopolysaccharides in Antibiotic Resistance and Bacteriophage Adsorption of <i>Escherichia coli</i> K-12 (1971)

Novobiocin-supersensitive (NS) mutants which could not grow on plates containing 40 mug or less of novobiocin per ml were isolated from Escherichia coli strain JE1011 (derived from E. coli K-12). Most of these NS mutants were found to have incomplete lipopolysaccharides (LPS), and they lack phosphate diester bridges in their backbone structure, with or without total loss of heptose, to which the phosphate diester is linked, and consequently lack external outer-core oligosaccharides. The phosphate diester bridges in the LPS backbone are apparently very important in forming a cell surface structure resistant to the penetration of antibiotics such as novobiocin, spiramycin, and actinomycin D. NS mutants, with incomplete LPS, lacking phosphates in their backbone structure were found to be resistant to phage T4, and those which also lacked heptose were resistant to phages T4 and T7. In contrast to the generally accepted idea that resistances to phages T3, T4, and T7 are linked genetically, no NS mutant was found to be resistant to T3. The possible structures of the receptors for T4 and T7 are discussed. The positions of novobiocin-supersensitive genes on the chromosome of several of the NS mutants defective in LPS were mapped. The genes were designated lpcA (between ara and lac) and lpcB (between 55 min and 60 min). The latter seemed to be a group of several related genes.
Graphene exfoliation in organic solvents and switching solubility in aqueous media with the aid of amphiphilic block copolymers (2012)

The successful exfoliation of graphite to graphene sheets in a liquid phase via tip sonication was achieved. A number of solvents were examined for several time periods and it was found that o-dichlorobenzene (o-DCB) and N-methyl-1,2-pyrolidone (NMP) are ideal solvents to exfoliate graphite and produce stable dispersions of graphene. The exfoliated graphene dispersions were characterized by complementary techniques including AFM, DLS, TGA and Raman. Furthermore, treatment of stable dispersions of exfoliated graphene sheets in NMP with poly[styrene-b-(2-vinylpyridine)] block copolymer, under acidic conditions, resulted in aqueous solubilization of graphene. Similar results were obtained, i.e. transfer of graphene from the organic to the aqueous phase, when the poly(isoprene-b-acrylic acid) block copolymer was added on exfoliated graphene in NMP.