gebhart/patrepeval huggingface dataset:
Ultrasound coefficient of nonlinearity imaging (2015)

Imaging the acoustical coefficient of nonlinearity, β, is of interest in several healthcare interventional applications. It is an important feature that can be used for discriminating tissues. In this paper, we propose a nonlinearity characterization method with the goal of locally estimating the coefficient of nonlinearity. The proposed method is based on a 1-D solution of the nonlinear lossy Westerfelt equation, thereby deriving a local relation between β and the pressure wave field. Based on several assumptions, a β imaging method is then presented that is based on the ratio between the harmonic and fundamental fields, thereby reducing the effect of spatial amplitude variations of the speckle pattern. By testing the method on simulated ultrasound pressure fields and an in vitro B-mode ultrasound acquisition, we show that the designed algorithm is able to estimate the coefficient of nonlinearity, and that the tissue types of interest are well discriminable. The proposed imaging method provides a new approach to β estimation, not requiring a special measurement setup or transducer, that seems particularly promising for in vivo imaging.
Model predictive control for compensation of cyclic organ motions in teleoperated laparoscopic surgery (2006)

During teleoperated laparoscopic surgery with robots, periodic deformations of organs due to respiratory movements may be critical disturbances for surgeons manipulating the robot. Indeed, the surgeon has to manually compensate for these motions if accurate gestures are needed, like, e.g., during suturing. This paper proposes a repetitive model predictive control scheme for driving a surgical robot toward the reference trajectory defined by the surgeon while rejecting cyclic disturbances due to the respiratory motion. A new cost function is proposed for an unconstrained generalized predictive control scheme based on a multiple input-output model of the surgical robot. Contributions of the controller output to the reference tracking task and to the disturbance rejection task are split and computed separately, so that their respective efficiency can be independently weighted. The proposed control scheme is validated through simulations and experimental in vivo results using a surgical robot.
Inspiratory Obstruction (1970)

Obstructing lesions of the trachea and larynx which cause a predominantly inspiratory obstruction can be satisfactorily diagnosed by measuring both F.I.V.(1) and F.E.V.(1). Chronic airways obstruction involving intrathoracic airways produces a much lower F.E.V.(1)/F.I.V.(1) percentage than normal, whereas obstruction to larynx and trachea causes a raised F.E.V.(1)/F.I.V.(1) percentage. If flow-volume measurements are not available the F.E.V.(1)/F.I.V.(1) percentage should provide a simple and useful method for diagnosis of upper airways obstruction.In one of the patients reported a predominantly inspiratory obstruction caused CO(2) retention. In patients with airways obstruction the correlation between Pco(2) and F.I.V.(1) was found to be the same as between Pco(2) and F.E.V.(1). This suggests that respiratory failure can be caused by either inspiratory or expiratory airways obstruction and that neither is of greater importance in producing CO(2) retention.
Successful Amelioration of Mitochondrial Optic Neuropathy Using the Yeast NDI1 Gene in a Rat Animal Model (2010)

The present study reports successful manifestation of LHON-like symptoms in rats and demonstrates the potential of the NDI1 gene therapy on mitochondrial optic neuropathies. Our results indicate a window of opportunity for the gene therapy to be applied successfully after the onset of the disease symptoms.
Topological and mutational analysis of KpsM, the hydrophobic component of the ABC‐transporter involved in the export of polysialic acid in <i>Escherichia coli</i> K1 (1994)

The 17 kb kps gene cluster of Escherichia coli K1, which encodes the information required for synthesis, assembly and translocation of the polysialic acid capsule of E. coli K1, is divided into three functional regions. Region 3 contains two genes, kpsM and kpsT, essential for the transport of capsule polymer across the cytoplasmic membrane. The hydrophobicity profile of KpsM suggests that it is an integral membrane protein while KpsT contains a consensus ATP-binding site. KpsM and KpsT belong to the ATP-binding cassette (ABC) superfamily of membrane transporters. In this study, we investigate the topology of KpsM within the cytoplasmic membrane using beta-lactamase fusions and alkaline phosphatase sandwich fusions. Our analysis provides evidence for a model of KpsM having six membrane-spanning regions, with the N- and C-terminal domains facing the cytoplasm, and a short domain within the third periplasmic loop, which we refer to as the SV-SVI linker localizing in the membrane. Protease digestion studies are consistent with regions of KpsM exposed to the periplasmic space. In vivo cross-linking studies provide support for dimerization of KpsM within the cytoplasmic membrane. Linker-insertion and site-directed mutagenesis define the N-terminus, the first cytoplasmic loop, and the SV-SVI linker as regions that are important for the function of KpsM in K1 polymer transport.
Acute hepatitis in rats expressing human hepatitis B virus transgenes. (1995)

The molecular mechanisms responsible for hepatocyte death and the events leading to viral clearance in hepatitis B virus (HBV) infections are not well understood. Elucidation of the mechanisms involved have been complicated by the difficulty of infecting human hepatocytes with HBV in vitro and the lack of an appropriate animal model. We report an animal model of human HBV infection by in vivo transfection. We have directly introduced a replication-competent, cloned HBV construct into rat liver by using a membrane fusion-promoting cationic lipid. HBV mRNA and 3.2-kb HBV DNA were expressed in the liver by this in vivo transfection method. In the majority of rats, HBV virions and hepatitis B e antigen were found in the blood 3-7 days after transfection, after which antibody to the e antigen appeared. Two to three weeks after the transfection, glutamic-pyruvic transaminase levels were elevated in serum, hepatocyte death and lymphocyte infiltration were observed in the vicinity of the portal vein of liver, and HBV virions were no longer detected in the serum. Thus, transfection of HBV into rats resulted in histological and serological changes comparable to HBV-induced acute hepatitis in humans. In contrast, no hepatocellular injury was observed in T-lymphocyte-deficient nude rats transfected with the same HBV construct, and viremia was substantially prolonged, providing direct evidence that T lymphocytes play an essential role in liver cell injury and in the clearance of HBV. This rat hepatitis model will be useful for studying pathogenesis of HBV infection.
Nitric Oxide Regulation of Gene Transcription via Soluble Guanylate Cyclase and Type I cGMP-dependent Protein Kinase (1999)

Nitric oxide (NO) regulates the expression of multiple genes but in most cases its precise mechanism of action is unclear. We used baby hamster kidney (BHK) cells, which have very low soluble guanylate cyclase and cGMP-dependent protein kinase (G-kinase) activity, and CS-54 arterial smooth muscle cells, which express these two enzymes, to study NO regulation of the human fos promoter. The NO-releasing agent Deta-NONOate (ethanamine-2,2'-(hydroxynitrosohydrazone)bis-) had no effect on a chloramphenicol acetyltransferase (CAT) reporter gene under control of the fos promoter in BHK cells transfected with an empty vector or in cells transfected with a G-kinase Ibeta expression vector. In BHK cells transfected with expression vectors for guanylate cyclase, Deta-NONOate markedly increased the intracellular cGMP concentration and caused a small (2-fold) increase in CAT activity; the increased CAT activity appeared to be from cGMP activation of cAMP-dependent protein kinase. In BHK cells co-transfected with guanylate cyclase and G-kinase expression vectors, CAT activity was increased 5-fold in the absence of Deta-NONOate and 7-fold in the presence of Deta-NONOate. Stimulation of CAT activity in the absence of Deta-NONOate appeared to be largely from endogenous NO since we found that: (i) BHK cells produced high amounts of NO; (ii) CAT activity was partially inhibited by a NO synthase inhibitor; and (iii) the inhibition by the NO synthase inhibitor was reversed by exogenous NO. In CS-54 cells, we found that NO increased fos promoter activity and that the increase was prevented by a guanylate cyclase inhibitor. In summary, we found that NO activates the fos promoter by a guanylate cyclase- and G-kinase-dependent mechanism.
Binuclear ‘oxidative isomerization’ as a model for surface reactions. Intramolecular character and kinetic profile of iodomethyldi-iridium(<scp>II</scp>): µ-methylenedi-iridium(<scp>III</scp>) conversion that follows di-iodomethane addition to [Ir(CO)(PPh<sub>3</sub>)(µ-pz)]<sub>2</sub>(Hpz = pyrazole) (1989)

Isomerization of the di-iridium(II) complex [Ir2(CO)2(PPh3)2(µ-pz)2(CH2I)(I)](2, Hpz = pyrazole) to the di-iridium(III) methylene complex [Ir2(CO)2(PPh3)2(µ-pz)2(µ-CH2)(I)2](7) which occurs on reflux in benzene solution has been found to be intramolecular by mass spectrometric analysis of isotope distribution (13C and 2H) in isotopomers of (7) formed from (2) containing 13CO or C2H2I groups or both, and the (2)–(7) conversion shows first-order behaviour which is conspicuously retarded by added PPh3; an X-ray crystal structure determination for compound (7) confirms that the two Ir centres lie outside bonding range at 3.432(1)Å with tetrahedral µ-CH2.
Non-destructive evaluation techniques for prosthetic heart valves based on hologram interferometry. Part I. (1993)

The development of a technique applying hologram interferometry, which is a non-destructive, non-contact, full-field, highly sensitive method is reported. The valve under investigation is placed in a test chamber which has windows providing optical access. Deformations of the valve leaflets due to pressure loading are recorded by hologram interferometry. The resulting interferogram clearly indicates the existence of any defects or structural anomalies which may be present in the valve material. Three modifications to this technique, intended for qualitative and quantitative non-destructive valve screening tests are described. The proposed technique is expected to become an effective means of detecting hidden defects of replacement heart valves; it is thus considered as a prospective tool for quality control, particularly in the manufacture of bioprosthetic valves, where initial sites of late calcification and degeneration might be identified. The application of holographic non-destructive testing may therefore substantially improve the quality and durability of heart valve substitutes.
Planning with abstraction (1986)

Intelligent problem solvers for complex domains must have the capability of reasoning abstractly about tasks that they are called upon to solve. The method of abstraction presented here allows one to reason analogically and hierarchically, making both the task of formalizing domain theories easier for the system designer, as well as allowing for increased computational efficiencies. It is believed that reasoning about concepts that share structure is essential to improving the performance of automated planning systems by allowing one to apply previous compuational effort expended in the solution of one problem to a broad range of new problems.
Simultaneous Measurements of Electronic Conduction and Raman Response in Molecular Junctions (2008)

Electronic conduction through single molecules is affected by the molecular electronic structure as well as by other information that is extremely difficult to assess, such as bonding geometry and chemical environment. The lack of an independent diagnostic technique has long hampered single-molecule conductance studies. We report simultaneous measurement of the conductance and the Raman spectra of nanoscale junctions used for single-molecule electronic experiments. Blinking and spectral diffusion in the Raman response of both p-mercaptoaniline and a fluorinated oligophenylyne ethynylene correlate in time with changes in the electronic conductance. Finite difference time domain calculations confirm that these correlations do not result from the conductance modifying the Raman enhancement. Therefore, these observations strongly imply that multimodal sensing of individual molecules is possible in these mass-producible nanostructures.
Interactions between <i>jointless</i> and Wild-Type Tomato Tissues during Development of the Pedicel Abscission Zone and the Inflorescence Meristem (1999)

The jointless mutation of tomato results in the formation of flower pedicels that lack an abscission zone and inflorescence meristems that revert to vegetative growth. We have analyzed periclinal chimeras and mericlinal sectors of jointless and wild-type tissue to determine how cells in different meristem layers (L1, L2, and L3) and their derivatives interact during these two developmental processes. Cells in the inner meristem layer, L3, alone determined whether the meristem maintained the inflorescence state or reverted to vegetative growth. Moreover, L3 derivatives determined whether a functional pedicel abscission zone formed. Limited and disorganized autonomous development of wild-type L2-derived cells occurred when they overlay mutant tissue. Adjacent mutant and wild-type L3-derived tissues in pedicels developed autonomously, indicating little or no lateral communication. Only the outermost L3-derived cells within the pedicel were capable of orchestrating normal pedicel development in overlying tissues, revealing the special status of those cells as coordinators of development for L1- and L2-derived cells, whereas the innermost L3-derived cells developed autonomously but did not influence the development of other cells.
Design for Stable Lasing of an Indirect Injection THz Quantum Cascade Laser Operating at Less Than 2 THz (2017)

In order to realize high temperature lasing of low frequency (< 2 THz) terahertz quantum cascade lasers (THz QCLs), selective carrier injection into an upper lasing level using an indirect injection (II) scheme is an effective method for inducing population inversion. The II scheme is realized with a four-level system. However, a three-level system that operates at low applied bias voltages causes additional lasing at higher frequencies (4～5 THz). By detuning the wave functions at the three lasing levels operating at low bias voltages, we were able to operate an II scheme THz QCL at a single stable frequency. Utilizing the higher injection selectivity, achieved through an indirect scattering-assisted injection process combined with diagonal emission, we were able to demonstrate stable operation of an AlGaAs/GaAs QCL operating at 1.89 THz at temperatures up to 160 K.
Volatility and liquidity in futures markets (1996)

We study the provision of liquidity in futures markets as price volatility changes. For both active and inactive contracts, customer trading costs do not increase with volatility. However, for three of the four contracts studied, the nature of liquidity supply changes with volatility. Specifically, for relatively inactive contracts, customers as a group trade more with each other (and less with market makers) on higher volatility days. By contrast, for the most active contract, trading between customers and market makers increases with volatility. We also find that market makers' income per contract decreases with volatility for one of the least active contracts in our sample, but is not significantly affected by volatility for the other contracts. These results are consistent with the idea that, for inactive contracts (where the cost of market making is relatively high), market makers are hurt by volatility, and customers step forward to provide liquidity through standing limit orders.
<title>Magnetostatic Wave Devices For Microwave Signal Processing</title> (1980)

Basic devices required for analog microwave signal processing have been demonstrated using magnetostatic wave propagation in epitaxial yttrium iron garnet films. 100 nsec delay lines with bandwidths of 400 MHz, dispersive delay lines with differential delays of 200 nsec and bandwidths of 1 GHz and a programmable tapped delay line, all operating at S-band through X-band, are described. The operation of a new type of device, a signal-to-noise enhancer or power expander, is discussed which has the opposite characteristic to the more familiar microwave limiter. All these devices share the unique features of operation directly at microwave frequencies and frequency tunability via the strength of the magnetic bias field which is required for their operation.
AAPH-mediated antioxidant reactions of secoisolariciresinol and SDG (2007)

Secoisolariciresinol (SECO ) is the major lignan found in flaxseed (Linum usitatissimum L.) and is present in a polymer that contains secoisolariciresinol diglucoside (SDG ). SECO, SDG and the polymer are known to have a number of health benefits, including reduction of serum cholesterol levels, delay in the onset of type II diabetes and decreased formation of breast, prostate and colon cancers. The health benefits of SECO and SDG may be partially attributed to their antioxidant properties. To better understand their antioxidant properties, SECO and SDG were oxidized using 2,2'-azobis(2-amidinopropane), an in vitro model of radical scavenging. The major lignan radical-scavenging oxidation products and their formation over time were determined. SDG was converted to four major products, which were the result of a phenoxyl radical intermediate. One of these products, a dimer of SDG, decomposed under the reaction conditions to form two of the other major products, and . SECO was converted to five major products, two of which were also the result of a phenoxyl radical intermediate. The remaining products were the result of an unexpected alkoxyl radical intermediate. The phenol oxidation products were stable under the reaction conditions, whereas two of the alcohol oxidation products decomposed. In general, only one phenol group on the lignans was oxidized, suggesting that the number of phenols per molecule may not predict radical scavenging antioxidant ability of lignans. Finally, SECO is a superior antioxidant to SDG, and it may be that the additional alcohol oxidation pathway contributes to its greater antioxidant ability.
FUNCTIONING STRUMA OVARH (1951)

CHILDRESS, TEXAS FROM THE DEPARTMENT OF SURGERY OF CLEVELAND CITY HOSPITAL AND THE SCHOOL OF MEDICINE, WESTERN RESERVE UNIVERSITY, CHILDRESS, OHIO
Watching osteogenesis: Life monitoring of osteogenic differentiation using an osteocalcin reporter (2011)

Human bone marrow-derived mesenchymal stem cells have the potential to differentiate into several cell types such as osteoblasts, chondrocytes, and adipocytes. When cultured under appropriate medium conditions stem cells can be directed toward the osteoblast lineage in vitro. Progression of osteogenic differentiation is accompanied by changes in the expression pattern of several marker proteins including bone-specific alkaline phosphatase (bALP), collagen I (Col I), and osteocalcin (OC) and can be analyzed by well-established methods like immunohistochemical staining and quantitative RT-PCR. Furthermore, expression of fluorescent protein driven by an osteogenesis promoter facilitates online monitoring of proceeding osteogenic differentiation in transiently transfected human bone marrow-derived cells. In the present study we established a new double reporter gene construct comprising OC promoter-driven expression of green fluorescent protein and constitutive expression of red fluorescent protein-tagged histone H2B for transient transfection of primary human bone cells (HBCs). Osteogenic differentiation of transiently transfected cells was visualized by fluorescence microscopy. Immunohistochemical analysis and RT-PCR confirmed the progression into the osteo-specific lineage of transfected cells. Transfection efficiency was determined by fluorescence-activated cell sorting (FACS).
Photolytic preparation of metal-metal bonds between some Group VI and Group IV metals (1967)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPhotolytic preparation of metal-metal bonds between some Group VI and Group IV metalsJohn K. RuffCite this: Inorg. Chem. 1967, 6, 8, 1502–1504Publication Date (Print):August 1, 1967Publication History Published online1 May 2002Published inissue 1 August 1967https://pubs.acs.org/doi/10.1021/ic50054a016https://doi.org/10.1021/ic50054a016research-articleACS PublicationsRequest reuse permissionsArticle Views65Altmetric-Citations35LEARN 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
Monitoring system calls for anomaly detection in modern operating systems (2013)

Host-based intrusion detection systems monitor systems in operation for significant deviations from normal (and healthy) behaviour. Many approaches have been proposed in the literature. Most of them, however, do not consider even the basic attack prevention mechanisms that are activated by default on today's many operating systems. Examples of such mechanisms include Address Space Layout Randomization and Data Execution Prevention. With such security methods in place, attackers are forced to perform additional actions to circumvent them. In this research, we conjecture that some of these actions may require the use of additional system calls. If so, one can trace such attacks to discover attack patterns that can later be used to enhance the detection power of anomaly detection systems. The purpose of this short paper is to motivate the need to investigate the impact of attack on system calls while trying to overcome these prevention mechanisms.
Adding crumb rubber into exterior wall materials (2002)

In Arizona US, most houses are built with walls covered by stuccos/coatings/mortars. This paper presents an explorative investigation of adding crumb rubber into stuccos/coatings/mortars. A series of experiments are conducted to examine the thermal and mechanical performance of the crumb rubber mixes. The results show that, the mixes with crumb rubber do exhibit more desirable performances like being high in crack-resistance and thermal insulation, and low in thermal expansion/contraction. The drawback for the crumb rubber mixes is the reduction in compressive strength, but which can be compensated by other means. As a site experiment, an area of 100 square-feet of crumb rubber coatings for two mix designs is sprayed on a tire-adobe wall. After being sprayed more than 14 months, the coatings apparently are in good condition. Significance of this study is that this practice, if accepted, will yield improved products that consume large quantities of crumb rubber.