cssi/SciSciGPT-SciSciNet huggingface dataset:
Initial displacement of the intra-articular surface after articular fracture correlates with PTA in C57BL/6 mice but not "superhealer" MRL/MpJ mice.

Posttraumatic arthritis (PTA) occurs commonly after articular fracture and may arise, in part, from joint surface incongruity after injury. MRL/MpJ (MRL) "super-healer" mice are protected from PTA compared to C57BL/6 (B6) mice following articular fracture. However, the relationship between the initial displacement of the articular surface, biologic response, and susceptibility to PTA after fracture remains unclear. The objective of this study was to assess whether joint incongruity after articular fracture, as measured by in vivo micro-computed tomography (microCT), could predict pathomechanisms of PTA in mice. B6 and MRL mice (n = 12/strain) received a closed articular fracture (fx) of the left tibial plateau. Articular incongruity was quantified as bone surface deviations (BSD) for each in vivo microCT scan obtained from pre-fx to 8 weeks post-fx, followed by histologic assessment of arthritis. Serum concentrations of bone formation (PINP) and bone resorption (CTX-I) biomarkers were quantified longitudinally. Both strains showed increases in surface incongruity over time, as measured by increases in BSD. In B6 mice, acute surface incongruity was significantly correlated to the severity of PTA (R 2 = 0.988; p = .0006), but not in MRL mice (R 2 = 0.224; p = .220). PINP concentrations significantly decreased immediately post-fx in B6 mice (p = .023) but not in MRL mice, indicating higher bone synthesis in MRL mice. MRL/MpJ mice demonstrate a unique biologic response to articular fracture such that the observed articular bone surface displacement does not correlate with the severity of subsequent PTA. Clinical Relevance: Identifying therapies to enhance acute biologic repair following articular fracture may mitigate the risk of articular surface displacement for PTA.
Propranolol inhibits cavernous vascular malformations by β1 adrenergic receptor antagonism in animal models

Propranolol, a pleiotropic β-adrenergic blocker, has been anecdotally reported to reduce cerebral cavernous malformations (CCMs) in humans. However, propranolol has not been rigorously evaluated in animal models, nor has its mechanism of action in CCM been defined. We report that propranolol or its S(-) enantiomer dramatically reduced embryonic venous cavernomas in ccm2 mosaic zebrafish, whereas R-(+)-propranolol, lacking β antagonism, had no effect. Silencing of the β1, but not β2, adrenergic receptor mimicked the beneficial effects of propranolol in a zebrafish CCM model, as did the β1-selective antagonist metoprolol. Thus, propranolol ameliorated cavernous malformations by β1 adrenergic antagonism in zebrafish. Oral propranolol significantly reduced lesion burden in 2 chronic murine models of the exceptionally aggressive Pdcd10/Ccm3 form of CCM. Propranolol or other β1-selective antagonists may be beneficial in CCM disease.
Revisiting the Syntax of Monsters in Uyghur

This paper is written in response to Shklovsky and Sudo (2014), who propose a syntactic analysis of Uyghur indexical shift, a process by which embedded indexicals, such as "you" and "I" are interpr...
First-Principles Hydrothermal Synthesis Design to Optimize Conditions and Increase the Yield of Quaternary Heteroanionic Oxychalcogenides

Hydrothermal synthesis exploits solvent properties, temperature, and pressure to control reaction equilibrium among heterogeneous phases to promote the formation of targeted products, often single-...
Examining an Indirect Pathway from the Variety of Stressful Life Events to Violent Victimization through Acquired Psychological Symptoms

The effects of stressful life events on violent victimization have been well established. The existing literature, however, remains relatively limited in examining the indirect association between ...
EXPPO: EXecution Performance Profiling and Optimization for CPS Co-simulation-as-a-Service

Abstract A co-simulation may comprise several heterogeneous federates with diverse spatial and temporal execution characteristics. In an iterative time-stepped simulation, a federation exhibits the Bulk Synchronous Parallel (BSP) computation paradigm in which all federates perform local operations and synchronize with their peers before proceeding to the next round of computation. In this context, the lowest performing (i.e., slowest) federate dictates the progression of the federation logical time. One challenge in co-simulation is performance profiling for individual federates and entire federations. The computational resource assignment to the federates can have a large impact on federation performance. Furthermore, a federation may comprise federates located on different physical machines as is the case for cloud and edge computing environments. As such, distributed profiling and resource assignment to the federation is a major challenge for operationalizing the co-simulation execution at scale. This paper presents the Execution Performance Profiling and Optimization (EXPPO) methodology, which addresses these challenges by using execution performance profiling at each simulation execution step and for every federate in a federation. EXPPO uses profiling to learn performance models for each federate, and uses these models in its federation resource recommendation tool to solve an optimization problem that improves the execution performance of the co-simulation. Using an experimental testbed, the efficacy of EXPPO is validated to show the benefits of performance profiling and resource assignment in improving the execution runtimes of co-simulations while also minimizing the execution cost.
Understanding the 30-day mortality burden after revision total knee arthroplasty.

Background In revision total knee arthroplasty (TKA), information regarding perioperative mortality risk is essential for careful decision-making. This study aimed to elucidate the (1) overall 30-day mortality rate and (2) 30-day mortality rate stratified by age, comorbidity, and septic vs aseptic failure after revision TKA. Methods The American College of Surgeons National Surgical Quality Improvement Program was reviewed for all patients undergoing revision TKA from 2011 to 2019. A total of 32,354 patients who underwent TKA were identified and categorized as mortality (n = 115) or mortality-free (n = 32,239). Patient characteristics were compared between cohorts and further stratified by septic and aseptic failure. Results The overall 30-day mortality rate was 0.36%. The percentage of deaths per age group (normalized per 1000) was 0% (18-29 years), 0% (30-39 years), 0.18% (40-49 years), 0.13% (50-59 years), 0.14% (60-69 years), 0.40% (70-79 years), 1.25% (80-89 years), and 6.93% (90+ years). The percentage of deaths per American Society of Anesthesiologists (ASA) class was 0.30% (ASA 1), 0.06% (ASA 2), 0.39% (ASA 3), 2.41% (ASA 4), and 14.29% (ASA 5). Septic revision (P < .001), general anesthesia (P < .001), body mass index ≤ 24.9 (P < .001), and insulin-dependent diabetes (P = .039) were associated with an increased risk of mortality. Conclusions Increasing age, greater comorbidity burden, underweight or normal body mass index, insulin-dependent diabetes, septic revision, and general anesthesia were all associated with an increased risk of mortality after revision TKA. Notably, 1 in 80 patients aged 80-89 years died after revision TKA compared to 1 in 720 patients aged 60-69 years. Patients who underwent septic revision had a 4-fold increase in mortality compared to aseptic revision. Our stratified assessment of mortality provides a more individualized estimation of risk that can be used for patient counseling in revision TKA.
Analysis of 100 Most-Viewed YouTube Toothbrushing Videos

Purpose: Parental education regarding the importance of toothbrushing and how to brush children's teeth is a key factor influencing pediatric oral health and You Tube videos have become a popular source of health information. The purpose of this study was to examine the descriptive features of the 100 most frequently viewed English-language YouTube toothbrushing videos and evaluate their usefulness relative to professional guidelines.Methods: A structured YouTube web search identified the 100 most frequently viewed toothbrushing videos during a six-month period (10/1/17 - 4/30/18). Two independent evaluators assessed each video for consistency with professional recommendations using a priori criteria. Each video was also assessed for descriptive characteristics, user engagement, and content. Comparative analyses by video source (health care professionals, commercial, and independent media) were performed, and an exploratory regression model was used to test the relationship between video characteristics and usefulness for parent education.Results: The top 100 YouTube videos were most often posted by independent media outlets (78%), targeted toward children (70%), and less than 2 minutes long (56%). Few videos aligned with professional recommendations regarding toothbrushing frequency (38%), toothbrushing duration (24%), amount of toothpaste (21%), fluoride toothpaste use (19%), post-brushing behavior (10%), toothbrush selection (4%), and toothbrush replacement (3%). A stepwise bidirectional regression model found that videos posted by health care professionals were significantly more likely to contain recommendations consistent with professional recommendations compared with other upload sources.Conclusion: The most frequently viewed toothbrushing videos were not uploaded to the Internet by health care professionals. Videos uploaded by health care professionals contained significantly higher counts of professional recommendations however, they differed in audio and visual format and production style compared to those from commercial and independent media sources.
Artificial foliage with remarkable quantum conversion efficiency in bicarbonate to formate

An efficient heterogeneous immobilized device for the photoreduction of bicarbonate to formate was achieved by a thin-film semiconductor with metallophthalocyanines. The two-layer devices were fabricated by the deposition of (TiO2 or Cu2O) and zinc or cobalt phthalocyanines as photosensitizer onto an SiO2 disc.
Group differences in MEG-ICA derived resting state networks: Application to major depressive disorder.

Abstract Functional magnetic resonance imaging (fMRI) studies have revealed the existence of robust, interconnected brain networks exhibiting correlated low frequency fluctuations during rest, which can be derived by examining inherent spatio-temporal patterns in functional scans independent of any a priori model. In order to explore the electrophysiological underpinnings of these networks, analogous techniques have recently been applied to magnetoencephalography (MEG) data, revealing similar networks that exhibit correlated low frequency fluctuations in the power envelope of beta band (14–30 Hz) power. However, studies to date using this technique have concentrated on healthy subjects, and no method has yet been presented for group comparisons. We extended the ICA resting state MEG method to enable group comparisons, and demonstrate the technique in a sample of subjects with major depressive disorder (MDD). We found that the intrinsic resting state networks evident in fMRI appeared to be disrupted in individuals with MDD compared to healthy participants, particularly in the subgenual cingulate, although the electrophysiological correlates of this are unknown. Networks extracted from a combined group of healthy and MDD participants were examined for differences between groups. Individuals with MDD showed reduced correlations between the subgenual anterior cingulate (sgACC) and hippocampus in a network with primary nodes in the precentral and middle frontal gyri. Individuals with MDD also showed increased correlations between insulo-temporal nodes and amygdala compared to healthy controls. To further support our methods and findings, we present test/re-test reliability on independent recordings acquired within the same session. Our results demonstrate that group analyses are possible with the resting state MEG-independent component analysis (ICA) technique, highlighting a new pathway for analysis and discovery. This study also provides the first evidence of altered sgACC connectivity with a motor network. This finding, reliable across multiple sessions, suggests that the sgACC may partially mediate the psychomotor symptoms of MDD via synchronized changes in beta-band power, and expands the idea of the sgACC as a hub region mediating cognitive and emotional symptomatic domains in MDD. Findings of increased connectivity between the amygdala and cortical nodes further support the role of amygdalar networks in mediated depressive symptomatology. Clinical trials identifier NCT00024635 (ZIA-MH002927-04)
The Saga of 3He

He is one of the few isotopes that were created in the Big Bang. It can therefore provide clues about the earliest processes in the universe. But as [ Rood et al .][1] explain in their Perspective, detecting and interpretingHe signatures can be difficult both in space and on Earth because there are multiple sources for the isotope. The next generation of radio telescopes should be able to provideHe data of sufficient accuracy to constrain models of the chemical evolution of our galaxy. [1]: http://www.sciencemag.org/cgi/content/full/295/5556/804
Family Treatment of Preschool Behavior Problems

ObjectiveBehavioral problems in youth pose a serious mental health and social issue with early-onset problems associated with particular risk for continuation across the lifespan. Given these risks...
Eigenvalue fields of hyperbolic orbifolds

In this paper, we prove that if F is a non-elementary subgroup of O o (n,1,R), with n > 2, then the eigenvalue field of Γ has infinite degree over Q.
Students as Experimental Participants: A Defense of the ‘Narrow Data Base

We investigate the extent to which using students as experimental participants creates problems for causal inference. First, we discuss the impact of student subjects on a study’s internal and external validity. In contrast to common claims, we argue that student subjects do not intrinsically pose a problem for a study’s external validity. Second, we use simulations to identify situations when student subjects are likely to constrain experimental inferences. We show that such situations are relatively limited; any convenience sample poses a problem only when the size of an experimental treatment effect depends upon a characteristic on which the convenience sample has virtually no variance. Third, we briefly survey empirical evidence that provides guidance on when researchers should be particularly attuned to taking steps to ensure appropriate generalizability from student subjects. We conclude with a discussion of the practical implications of our findings. In short, we argue that student subjects are not an inherent problem to experimental research; moreover, the burden of proof - of student subjects being a problem - should lie with critics rather than experimenters.
Cocycle Knot Invariants, Quandle Extensions, and Alexander Matrices

The theory of quandle (co)homology and cocycle knot invariants is rapidly being developed. We begin with a summary of these recent advances. One such advance is the notion of a dynamical cocycle. We show how dynamical cocycles can be used to color knotted surfaces that are obtained from classical knots by twist-spinning. We also demonstrate relations between cocycle invariants and Alexander matrices.
A citation analysis of the quantitative/qualitative methods debate's reflection in sociology research

AbstractThis study examines how the social sciences' debate between qualitative and quantitative methods is reflected in the citation patterns of sociology journal articles. Citation analysis revealed that quantitative articles were more likely to cite journal articles than monographs, while qualitative articles were more likely to cite monographs than journals. Quantitative articles cited other articles from their own quantitative-dominated journals but virtually excluded citations to articles from qualitative journals, while qualitative articles cited articles from the quantitative-dominated journals as well as their own qualitative-specialized journals. Discussion and conclusions include this study's implications for library collection development.
Basic Biology, Good Field Notes, and Synthesizing across Your Career

Ichthyology and herpetology remain in need of well-done studies in basic biology and ecology, life history, or natural history for many species. Even for well-studied areas in the United States, the percentage of species for which basic information is lacking or for which better information is needed, based on state or regional faunal books, ranged from about 10 to 35% for fish species, and about 5 to 31% for herps. For Mexico the need was even greater, with the basic biology of approximately 45% of the fish fauna poorly known. Part of the need for better information stems from perceptions by some that basic studies are less desirable than works grounded in theory or modeling. But basic biological information is the foundation for and critical to virtually all syntheses or meta-analyses. Thus, publication of good basic biology in appropriate journals is extremely valuable to one's discipline, and many peer-reviewed journals like Copeia remain amenable to publishing such information. In recent years, gradu...
Integrated waveguide/thermocouple sensor for liquid properties

A torsional and longitudinal waveguide was introduced several years ago and shown to be effective for measuring various properties of liquids, including viscosity, density and temperature. The instrument is simply a specially constructed, thin rod (waveguide), one end of which is inserted into the liquid slurry. Torsional or extensional waves are generated in the rod, via a magnetostrictive mechanism, by passing a current through a coil which fits over the dry end of the rod. Liquid properties are correlated to different attributes of the waves (e.g., speed and amplitude) that travel down the rod and reflect off the end that is inserted into the liquid. Different properties of the material can be determined using waveguides of different cross-section. Noncircular rods are used to measure density, while viscosity is measured with circular rods. Since temperature affects these same wave attributes it would be desirable to have an independent measure of the temperature. This is accomplished by using a thermocouple sheath as the sensor part of the waveguide. In this way, the influence of temperature can be decoupled from the other properties of interest. In addition, the temperature is measured at the same point where the other properties of the liquid are being measured. The basic design of the sensor will be presented along with experimental results.
A Linux-based tool for hardware bring up, Linux development, and manufacturing

In this paper we describe Bare Metal Linux (BML), a cut-down version of Linux® 2.6 that requires no firmware, has an in-memory root file system, and runs without a virtualization layer. We designed and implemented BML in order to accelerate the bring up of POWER5TM-based systems. The use of BML allows testing and validation of the POWERS-based system to be conducted in parallel with the standard path, which involves the bring up of a hypervisor, the partition firmware, and the operating system. BML, which has fast boot times and can be modified quickly, is used in fault detection during chip manufacturing, POWER5 chip verification, system-board verification, and benchmarking for performance. BML is also used to reproduce and resolve problems in Linux.
Inversion of Spin Polarization and Tunneling Magnetoresistance in Spin-Dependent Tunneling Junctions

An inversion of spin polarization has been observed in spin-dependent tunneling (SDT) junctions with ${\mathrm{Ta}}_{2}{\mathrm{O}}_{5}$ and ${\mathrm{Ta}}_{2}{\mathrm{O}}_{5}/{\mathrm{Al}}_{2}{\mathrm{O}}_{3}$ barriers. The resistance of an SDT junction is found to be lower with magnetization of the ferromagnetic electrodes aligned antiparallel under specific voltage configurations. The tunneling magnetoresistance effect changes sign with applied voltage and varies from $+1%$ to $\ensuremath{-}4%$ at room temperature. This inversion is believed to be due to the change in sign with bias of the spin polarization of one of the two electrodes. The strong dependence on voltage suggests negative spin polarization could arise from the densities of states for spins being different at the two electrode/barrier interfaces.
Eyeglasses and children's schemata

The role of framed eyeglasses in children's person schemata was examined. American first graders (35 girls, 36 boys), rated by their teachers as low, medium, or high in cognitive development, judged peers photographed with and without glasses for physical attractiveness, school performance, conduct, sociability, and sociometric choice. There was a general same-sex bias in the children's ratings. The stimulus persons tended to be rated lower in attractiveness (especially if they were girls), school performance, and conduct when they were wearing glasses than when they were not wearing glasses. Glasses negatively influenced sociometric choice, but only for the most cognitively developed children. These results indicated that adults' stereotypes about people who wear glasses eventually become part of children's person schemata.
13C Nmr Spectra of Methyl Deoxyfluoro-β-D-Galactopyranosides and Their Per-O-Acetyl Derivatives

Abstract Methyl 6-deoxy-6-fluoro-β-d-galactopyranoside has been obtained by treatment of methyl β-d-galactopyranoside with diethyl-aminosulfur trifluoride (DAST). Improvements over the existing syntheses of methyl 2, 3-di-O-benzyl-4-deoxy-4-fluoro-β-d-galacto-pyranoside from the corresponding 6-O-substituted 4-O-arylsul-fonyl-d-gluco derivatives are described. 13C NMR spectra of a series of methyl deoxyfluoro-β-d-galactopyranosides and their per-O-acetyl derivatives have been measured. The data obtained can be used as an aid for the interpretation of 13C NMR spectra of deoxyfluoro-β-d-galactopyranose-containing oligosaccharides and related substances.
Grasp mapping using locality preserving projections and kNN regression

In this paper, we propose a novel mapping approach to map a human grasp to a robotic grasp based on human grasp motion trajectories rather than grasp poses, since the grasp trajectories of a human grasp provide more information to disambiguate between different grasp types than grasp poses. Human grasp motions usually contain complex and nonlinear patterns in a high-dimensional space. In this paper, we reduced the high-dimensionality of motion trajectories by using locality preserving projections (LPP). Then, a Hausdorff distance was performed to find the k-nearest neighbor trajectories in the reduced low-dimensional subspace, and k-nearest neighbor (kNN) regression was used to map a demonstrated grasp motion by a human hand to a robotic hand. Several experiments were designed and carried out to compare the robotic grasping trajectory generated with and without the trajectory-based mapping approach. The regression errors of the mapping results show that our approach generates more robust grasps than using only grasp poses. In addition, our approach has the ability to successfully map a grasp motion of a new grasp demonstration that has not been trained before to a robotic hand.
High-finesse interferometers

A detailed plan for the construction and use of a nonconfocal cavity used as a high-finesse interferometer is presented. The interferometer has a free spectral range of 15 GHz, with a finesse of over 30,000.
Microanalysis of complex tissue lipids by high-performance thin-layer chromatography☆

We have developed a high-performance thin-layer chromatographic method, not involving preliminary column chromatography, for separating mixtures of nonpolar lipids, glycosphingolipids, and phospholipids in one dimension. Three or four consecutive developing solvent systems are used. More than 20 different lipid subclasses can be separated using this procedure. Reproducible results have been obtained by careful control of variables. In addition, a simple and rapid fractionation procedure, using Sep-Pak silica cartridges, has been developed to concentrate neutral glycosphingolipids from biological membranes, e.g., erythrocytes, so that patients with sphingolipidosis can be easily identified.
Non-Continuum Mass Transport in Solid Oxide Fuel Cell Anodes by the Lattice Boltzmann Method

At the length scales and temperatures present in a typical SOFC, both continuum and non-continuum transport of fuel and product species are important. Fuel and product transport through a representative, microscopic, two-dimensional (2D) channel present in the porous anode of a solid oxide fuel cell (SOFC) is examined. Non-continuum transport, which can be broken down into the slip, transition and free molecular regimes, is modeled for a ternary system (H2 , H2 O, and N2 ) using the Stefan-Maxwell (SM) model, the Dusty-Gas (DG) model and the lattice Boltzmann method (LBM). Results obtained show that the LBM can provide a suitable framework for continuum as well as non-continuum transport in a SOFC up to the transition regime. LBM can also handle complex porous geometries, which are currently intractable by other modeling approaches, e.g. SM and DG. However, further work is required to extend the range of application of the present LBM to the free-molecular flow regime.Copyright © 2006 by ASME
A new function of Nell-1 protein in repressing adipogenic differentiation

A theoretical inverse relationship has long been postulated for osteogenic and adipogenic differentiation (bone versus adipose tissue differentiation). This inverse relationship in theory at least partially underlies the clinical entity of osteoporosis, in which marrow mesenchymal stem cells (MSCs) have a predilection for adipose differentiation that increases with age. In the present study, we assayed the potential anti-adipogenic effects of Nell-1 protein (an osteoinductive molecule). Using 3T3-L1 (a human preadipocyte cell line) cells and human adipose-derived stromal cells (ASCs), we observed that adenoviral delivered (Ad)-Nell-1 or recombinant NELL-1 protein significantly reduced adipose differentiation across all markers examined (Oil red O staining, adipogenic gene expression [Pparg, Lpl, Ap2]). In a prospective fashion, Hedgehog signaling was assayed as potentially downstream of Nell-1 signaling in regulating osteogenic over adipogenic differentiation. In comparison to Ad-LacZ control, Ad-Nell-1 increased expression of hedgehog signaling markers (Ihh, Gli1, Ptc1). These studies suggest that Nell-1 is a potent anti-adipogenic agent. Moreover, Nell-1 signaling may inhibit adipogenic differentiation via a Hedgehog dependent mechanism.
Influence of Transplacentally Acquired Antibody on Neonatal Susceptibility to Canine Distemper Virus in Gnotobiotic Dogs

In utero acquisition of protective levels of neutralizing antibody to canine distemper virus (CDV) was observed in four litters of colostrum-deprived gnotobiotic and specific-pathogen-free puppies. Pregnant bitches with high antibody titers passively transferred antibody to these pups transplacentally in average titers of 1:7 to 1:16 per litter. Maternally derived antibody protected neonatal pups from otherwise fatal infection with virulent CDV. Protection was associated with a transient lymphopenia and viremia and temporary suppression of lymphocyte responses to phytohemagglutinin-P. The precise mechanisms involved in the resolution of infection with canine distemper virus (CDV) in dogs have not been delineated. Susceptible dogs, when challenged with virulent virus, experience a generalized infection of lymphoid organs initially and subsequently show involvement of epithelial cells (particularly respiratory) and the central nervous system. Recovery is correlated with development of virusspecific cell-mediated [1] and humoral antibody [2, 3] responses beginning five to nine days after infection.
Crystal structure of (18-crown-6)potassium(I) [(1,2,3,4,5-η)-cyclo-hepta-dien-yl][(1,2,3-η)-cyclo-hepta-trien-yl]cobalt(I).

The reaction of bis­(anthracene)cobaltate(−I) with excess cyclo­hepta­triene, C7H8, resulted in a new 18-electron cobaltate containing two different seven-membered ring ligands, based on single-crystal X-ray diffraction. The asymmetric unit of this structure contains two independent cation–anion pairs of the title complex, [K(18-crown-6)][Co(η3-C7H7)(η5-C7H9)], where 18-crown-6 stands for 1,4,7,10,13,16-hexa­oxa­cyclo­octa­decane (C12H24O6), in general positions and well separated. Each (18-crown-6)potassium cation is in contact with the η3-coordinating ligand of one cobaltate complex. Each η3-coordinating ligand behaves as an allylic anion whose exo-diene moiety is bent away from the allylic plane, and thus is not involved directly in the bonding. The metal-coordinating portions of the anionic η5 ligands are planar and one of these ligands is modeled as disordered over two positions, with occupancy ratio 0.699 (5):0.301 (5), such that one orientation is rotated by one carbon atom with respect to the other. The diffraction intensities were integrated according to non-merohedral twin law [-1 0 0/0 -1 0/0.064 0 1], a 180° rotation about reciprocal lattice axis [001], and the masses of the twin domains refined to equal amounts. As both ligands are formally coordinated as anions, the cobalt atom is best considered to be CoI. This compound is of inter­est as the first to possess cyclo­hepta­trienyl and cyclo­hepta­dienyl ligands in an anionic metal complex.
Proton NMR study of the equilibria between cyclic disilthianes and trisilthianes

Abstract The equilibria in solution between the tetra-atomic ring structure of tetramethylcyclodisilthiane and the hexa-atomic ring structure of hexamethylcyclotrisilthiane were studied by proton nuclear magnetic resonance spectroscopy. Equilibrium constants determined at various temperatures and dilutions show that in accordance with the principle of Le Chatelier high (low) temperatures and high (low) dilutions favor the formation of thesmaller (larger) sized ring structure. The ring strain energy in the cyclic dimer is about 3 kcal per monomer unit.
Linear discriminant analysis of regional ejection fractions in the diagnosis of coronary artery disease.

We studied the application of linear discriminant analysis to the computer assisted interpretation of rest and exercise gated blood pool studies. Data were obtained in 45 patients in whom the presence or absence of coronary artery disease was determined by coronary angiography. Automated analysis of regional ejection fractions using a linear discriminant function (LDF) was compared to the fully automated calculation of global ejection fraction and to the subjective evaluation of wall motion. A LDF constructed from the data for the first 31 consecutive patients correctly classified 25/31 (81%). The change in global ejection fraction correctly classified 24/31 (77%) and wall motion analysis 25/31 (81%). In a distint group of 14 patients the same LDF correctly classified 12/14 (86%), global ejection fraction 9/14 (64%) and wall motion analysis 10/14 (71%).
Aspects of multilook SAR tomography

Interferometric and particularly tomographic processing at full resolution of data acquired by very high resolution SAR systems allows accurate 3D imaging and monitoring of buildings and infrastructures. Recently it has been shown that implementing a light data multilooking leads to a dramatical increase of the density of monitored pixels. In this work we investigate different options for performing the the multilook operation in SAR Tomography and we analyze their performances in terms of detection capabilities of single scatterers.
Daunorubicin and daunorubicinol pharmacokinetics in plasma and tissues in the rat.

Recent evidence suggests that 13-hydroxy metabolites of anthracyclines may contribute to cardiotoxicity. This study was designed to determine the pharmacokinetics of daunorubicin and the 13-hydroxy metabolite daunorubicinol in plasma and tissues, including the heart. Fisher 344 rats received 5 mg kg−1 daunorubicin i.v. by bolus injection. Rats were killed at selected intervals for up to 1 week after daunorubicin administration for determination of concentrations of daunorubicin and daunorubicinol in the plasma, heart, liver, kidney, lung, and skeletal muscle. Peak concentrations of daunorubicin were higher than those of daunorubicinol in the plasma (133±7 versus 36±2 ng ml−1;P<0.05), heart (15.2±1.4 versus 3.4±0.4 μg g−1;P<0.05), and other tissues. However, the apparent elimination half-life of daunorubicinol was longer than that of daunorubicin in most tissues, including the plasma (23.1 versus 14.5 h) and heart (38.5 versus 19.3 h). In addition, areas under the concentration/time curves (AUC∞) obtained for daunorubicinol exceeded those found for daunorubicin in almost all tissues, with the ratios being 1.9 in plasma and 1.7 in the heart. The ratio of daunorubicinol to daunorubicin concentrations increased dramatically with time from <1 at up to 1 h to 87 at 168 h in cardiac tissue. Thus, following daunorubicin injection, cumulative exposure (AUC∞) to daunorubicinol was greater than that to daunorubicin in the plasma and heart. If daunorubicinol has equivalent or greater potency than daunorubicin in causing impairment of myocardial function, it may make an important contribution to the pathogenesis of cardiotoxicity.
Digestion of cooked starches from different food sources by porcine α-amylase

Abstract The rate, limit and products of porcine α-amylase (EC.3.2.1.1) hydrolysis of cooked starches differ with starch source. The major controlling factors appear to be the amylose:amylopectin ratio and the gel age. The limit of hydrolysis of freshly prepared gels after 4 h treatment ranged from 70·5% for wrinkled pea (Pisum sativum) Cv. Scout to 92·2% for potato (Solanum tuberosum) starches. Ageing the gels before enzyme treatment reduced the limit of hydrolysis of the legume starches but not the cereal starches. The rate of hydrolysis of the α-amylase-susceptible fraction of the starches was unaffected. The maltose:maltotriose ratio in the hydrolysis products for the cereals was 1:0·90 whereas that for the legumes ranged from 1:0·84 to 1:0·60. The differing ratios appear to be related to the amylose:amylopectin ratio.
Macroporous Electrically Conducting Carbon Networks by Pyrolysis of Isocyanate-Cross-Linked Resorcinol-Formaldehyde Aerogels

Carbon (C) aerogels are made by pyrolysis of resorcinol-formaldehyde (RF) aerogels under Ar, and they combine electrical conductivity with a high open mesoporosity. However, because macropores are known to facilitate mass transfer, macroporous C-aerogels could be useful for application in separations or as fuel cell and battery electrodes. Macropores are typically incorporated in C-aerogels during gelation of the RF precursors by using either “hard” templating with silica or polystyrene beads, or “soft” templating with surfactants. Here, we report an alternative method, where open macroporosity is introduced by pyrolyzing RF aerogels whose skeletal nanoparticles have been cross-linked covalently with an isocyanate-derived polymer that coats conformally the entire RF framework. The structural, physical, and chemical evolution of the X-RF network was monitored at various stages during pyrolysis by DSC, TGA, SEM, N2 adsorption porosimetry, and 13C NMR. The accumulated evidence shows that the cross-linker fir...
Hidden Histidine Radical Rearrangements upon Electron Transfer to Gas-Phase Peptide Ions. Experimental Evidence and Theoretical Analysis

Protonated peptides containing histidine or arginine residues and a free carboxyl group (His-Ala-Ile, His-Ala-Leu, Ala-His-Leu, Ala-Ala-His-Ala-Leu, His-Ala-Ala-Ala-Leu, and Arg-Ala-Ile) form stable anions upon collisional double electron transfer from Cs atoms at 50 keV kinetic energies. This unusual behavior is explained by hidden rearrangements occurring in peptide radical intermediates formed by transfer of the first electron. The rearrangements occur on a ∼120 ns time scale determined by the radical flight time. Analysis of the conformational space for (His-Ala-Ile + H)+ precursor cations identified two major conformer groups, 1a+−1m+ and 5a+−5h+, that differed in their H-bonding patterns and were calculated to collectively account for 39% and 60%, respectively, of the gas-phase ions. One-electron reduction in 1a+ and 5a+ triggers exothermic hydrogen atom migration from the terminal COOH group onto the His imidazole ring, forming imidazoline radical intermediates. The intermediate from 5a is characte...
Endogenous activation of metabotropic glutamate receptors modulates GABAergic transmission to gonadotropin-releasing hormone neurons and alters their firing rate: A possible local feedback circuit

Gonadotropin-releasing hormone (GnRH) neurons are the primary central regulators of fertility, receiving input from GABAergic afferents via GABAA receptors. We tested whether metabotropic glutamate receptors (mGluRs) regulate GABA transmission to GnRH neurons and GnRH neuronal firing pattern. Whole-cell recordings were performed under conditions isolating ionotropic GABA postsynaptic currents (PSCs) in brain slices. The broad-spectrum mGluR agonist 1-aminocyclopentane-1,3-dicarboxylic acid (ACPD) decreased the frequency of GABAA-mediated spontaneous PSCs in a reversible manner. Amplitude and kinetics were not altered, suggesting that afferent GABA neurons are the primary targets. TTX eliminated the effects of ACPD in most tested neurons. Group II [2-(2,3-dicarboxycyclopropyl) glycine] and III (l-AP-4) mGluR agonists mediated this response; a group I agonist (3,5-dihydroxyphenylglycine) was not effective. The broad-spectrum antagonist α-methyl-4-carboxyphenylglycine (MCPG) and/or (RS)-α-cyclopropyl-4-phosphonophenylglycine (CPPG) (group III antagonist) enhanced spontaneous PSC frequency, particularly when initial frequency was low, suggesting that endogenous activation of mGluRs regulates GABA transmission to GnRH neurons. Extracellular recordings were used to evaluate GnRH neuron firing rate within the network. ACPD reduced firing rate, and MCPG plus CPPG had an opposite effect, indicating that mGluRs help control excitability of the GnRH network. GnRH neurons express vesicular glutamate transporters, suggesting they may corelease this transmitter. Simulation of firing activity in a GnRH neuron decreased PSC frequency in that cell, an effect blocked by antagonism of mGluRs but not GnRH receptors. These results demonstrate an inhibition of GABAergic inputs to GnRH neurons by mGluRs via a presynaptic mechanism. Through this mechanism, local glutamate milieu, possibly contributed by GnRH neurons themselves, plays an important role in modulating GnRH release and the central regulation of fertility.
Immersion Teachers: What Can We Learn from Them?

Although French immersion student performance has been studied extensively for over 20 years, immersion teachers' practices and beliefs have not. By examining descriptions of immersion teaching, we can identify several principles of practice that can be generalized to all second-language learning situations.
Synthesis and characterization of a covalently bound self-assembled macrocycle monolayer thin film for nonlinear optical materials

Synthesis and characterization of covalently bound self-assembled 5,10,15,20-Tetra(4- pyridyl)-21H,23H-porphine (TPyP) monolayer superlattices on various oxide surfaces such as fused silica, glass or silicon are described. The monomolecular thin film structures are characterized by UV-visible ((lambda) max equals 447 nm) and FTIR-ATR spectroscopy. In addition, x-ray photoelectron spectroscopy (XPS) and secondary ion mass spectroscopy (SIMS) studies are used to confirm the formation of a self-assembled monolayer on the fused- silica surface. Attractive features in these complexes are their second-order nonlinear optical properties, which are enhanced by the completely delocalized (pi) -electrons. Second harmonic generation measurements have been used to determine the uniformity of the film, the relative and absolute magnitudes of nonzero elements of the nonlinear susceptibility, (Chi) (2), and the average molecular orientation of the chromophores.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Fashionable successions and popular rages

Naples is not the only place that has its fashionable successions and popular rages; a much larger city than it, is at one time full of liver complaints, at another of …
Engineered large area fabrication of ordered InGaAs-GaAs nanotube arrays

Strain induced self-rolling semiconductor micro and nanotubes and related structures represent a new class of building blocks of nanotechnology. They are formed when strained planar bilayers are released from the substrate by selectively removing the sacrificial layer. Compared to other nanotechnology building blocks, one of the main advantages is the precise positioning capability due to top down fabrication approach. In this article, we demonstrate the fabrication of perfectly aligned arrays of InGaAs/GaAs nanotubes and the dispersion of freestanding semiconductor nanotubes into solution and onto foreign substrates. In addition, we systematically investigate the crystal orientation dependence of the rolling direction by using a wheel configuration. Other aspects of formation process are also discussed.
Neurochemical organization of inferior pulvinar complex in squirrel monkeys and macaques revealed by acetylcholinesterase histochemistry, calbindin and Cat-301 immunostaining, and Wisteria floribunda agglutinin binding.

To investigate whether the inferior pulvinar complex has a common organization in different primates, the chemoarchitecture of the visual thalamus was re-examined in squirrel monkeys (Saimiri sciureus) and macaques (Macaca mulatta). The inferior pulvinar (PI) complex consisted of multiple subdivisions and encompassed the classic PI, and adjacent ventral parts of the lateral and medial pulvinar (PL and PM, respectively). In keeping with nomenclature suggested previously for macaques, the PI subdivisions were termed the posterior, medial, central, lateral, and lateral-shell (PIP, PIM, PIC, PIL, and PIL-S). In both species, PIP was intense for calbindin, light for acetylcholinesterase (AChE), and very light for Wisteria floribunda agglutinin (WFA) histochemistry. The PIM was calbindin poor, AChE rich, and moderate for WFA. The PIC was calbindin intense, lighter for AChE, and exhibited little WFA binding. PIL and PIL-S contained populations of large calbindin or WFA cells that were more numerous in PIL-S. Although staining with the monoclonal antibody Cat-301 differed between macaques and squirrel monkeys, the same subdivisions were displayed. Moderately dense, patchy Cat-301 stain was found in PIM of macaques, whereas in squirrel monkeys PIM was light. Connections of the rostral dorsolateral (DLr) and middle temporal (MT) areas of visual cortex in squirrel monkeys were compared with PI subdivisions revealed by the newer histochemical methods in the same cases. The major connections of DLr were with PIC and of MT were with PIM. J. Comp. Neurol. 409:452–468, 1999. © 1999 Wiley-Liss, Inc.
Attack robustness of cascading model with node weight

Considering the node weight and the effect of the neighboring nodes, we introduce a method to define the initial load of a node in a network and propose a cascading model. Our aim is to explore how to allocate the initial load and select some nodes to be protected so as to maximize the network robustness against cascading failures. According to the distribution of the node weight and the normalized effect of the neighboring nodes, we focus on investigating different roles of high-load and low-load nodes and the correlation between some parameters in our model and the strongest robust level of a network against cascading failures. We obtain by the numerical simulations the optimal values of the parameters in our model at which the network can reach the strongest robust level against cascading failures. In addition, we find that the effect of two attacks strongly depends on the parameters of the node weight and the normalized effect of the neighboring nodes, i.e., the network robustness of attacking the low-load nodes has a positive correlation with the parameter of the node weight, while has a negative correlation with the parameter of the normalized reaction of the neighboring nodes. While the result of attacking the high-load nodes is almost on the contrary. Finally, we verify the numerical results by the theoretical analysis.
The current activated pressure assisted densification technique for producing nanocrystalline materials

The harnessing of length-scale-dependent material properties has been an area of intense research in the past two decades. Retention of nanocrystalline features in fully dense bulk materials has been particularly elusive. Recently the current activated pressure assisted densification (CAPAD) technique has emerged as one of the most successful methods for the production of functional and structural nanocrystalline materials with large sizes. In this article we review some ongoing efforts in using the CAPAD technique for producing single component and nanocomposite systems from nanocrystalline powders. The properties of these nanocrystalline materials include improved light transmittance and magnetic properties caused by interfacial coupling ofanti-ferromagnetic/ferrimagnetic phases.
Protein-independent Folding Pathway of the 16 S rRNA 5′ Domain

Evolution of the ribosome from an RNA catalyst suggests that the intrinsic folding pathway of the rRNA dictates the hierarchy of ribosome assembly. To address this possibility, we probed the tertiary folding pathway of the 5' domain of the Escherichia coli 16S rRNA at 20 ms intervals using X-ray-dependent hydroxyl radical footprinting. Comparison with crystallographic structures and footprinting reactions on native 30S ribosomes showed that the RNA formed all of the predicted tertiary interactions in the absence of proteins. In 20 mM MgCl2, many tertiary interactions appeared within 20 ms. By contrast, interactions between H6, H15 and H17 near the spur of the 30S ribosome evolved over several minutes, likely due to mispairing of a central helix junction. The kinetic folding pathway of the RNA corresponded to the expected order of protein binding, suggesting that the RNA folding pathway forms the basis for early steps of ribosome assembly.
THE ROLE OF VARIABLE VISCOSITY IN THE STABILITY OF CHANNEL FLOW

Abstract The stability of plane Poiseuille flow is studied for liquids exhibiting exponential viscosity-temperature dependence. In contrast to previously published studies, viscosity and temperature fluctuations are included in the formulation. Equations describing the evolution of small, two-dimensional disturbances are derived and the stability problem is formulated as an eigenvalue problem for a set of two ordinary differential equations. A Chebyshev collocation discretization method leads to a generalized matrix eigenvalue problem which is solved by the QZ algorithm. It is found that an imposed wall temperature difference, Δ T − , is always destabilizing. The instability region in the wavenumber-Reynolds number plane grows considerably as Δ T − increases. The influence of Prandtl number, temperature fluctuations and viscosity fluctuations on the flow stability/instability is small. However, their influence on the margin of stability for small wavenumbers is appreciable.