cssi/SciSciGPT-SciSciNet huggingface dataset:
Test of radiologist performance in interpreting bedside chest examinations on a workstation

A book cassette containing both a conventional film-screen radiographic system (FR) and a phosphor storage radiographic plate (SR) was used to obtain simultaneous bedside chest images in 22 patients in the Post Operative Cardiac and Surgical Intensive Care Units (ICUs). Twenty-five potential findings of normal structures, lung and pleural disease, and life support devices were recorded for each image in a five point rating format. The FR images are all considered of good diagnostic quality. The original FR films, the laser digitized FR images (DF) displayed on a workstation (WS), and the SR images displayed on a WS were compared. The WS viewing was on a 1 K X 1.2 K, 8 bit monitor. Free adjustment of window level, window width, and black-white inversion was allowed. Magnification allowed access to the 2 K data set. ROC analysis supports the null hypothesis that there is no difference in the diagnostic yield of good quality bedside obtained FR, DF made from good quality FR viewed on a workstation, and SR viewed on a workstation. Analysis of the subset of interstitial and airspace edema indicated that readers gave higher scores for interstitial disease on the WS for both false positive and true positive findings.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Chemical applications of topology and group Theory. XXIV: Chiralization of chemically significant polyhedra [1]

Permutation group-theoretical methods are used to study the chiralization of achiral polyhedral skeletons with v vertices by successive ligand replacement. Starting from the fully symmetrical ligand partition (ν), such chiralization processes may be characterized either by the minimum number of ligand replacement steps m, or the minimum number of different kinds of ligandsi, required to destroy all improper rotations. These parameters are trivially related to the lowest degree chiral ligand partition(s) as determined by the subduction of the skeleton point group G into the corresponding symmetric groupS ν by the procedure of Ruch and Schonhofer. Two different chiralization pathways with different values ofm andi are found for the octahedron, cube, hexagonal bipyramid, and icosahedron. Many less symmetrical chemically significant polyhedra have the degree 2 ligand partition (v - 2, 2) as the lowest degree chiral ligand partition and thus have only one chiralization pathway. Such polyhedra include the bicapped tetrahedron, trigonal prism, capped octahedron, bisdisphenoid, square antiprism, 4, 4, 4-tricapped trigonal prism, 4-capped square antiprism, 4,4-bicapped square antiprism, and the cuboctahedron.
Krein-Langer Factorizations via Pole Triples

A theorem by Krein and Langer asserts existence of factorizations of special type for operator functions in a generalized Schur class, i. e., meromorphic operator functions defined on the unit disk and such that their Nevanlinna-Pick kernel has a fixed finite number of negative squares. A different view and proof of this theorem are presented, based on description of pole data of meromorphic operator functions in terms of pole pairs and pole triples. A criterion for existence, and a parametrization, of operator functions in a generalized Schur class with given pole triple is obtained.
Obstructions to Concordance for Thickenings

This paper gives the details promised in [19]. In this form it is essentially the author's doctoral thesis presented to the University of Cambridge. We consider the following problem: suppose one is given a smooth or piecewise linear manifold, M m and an automorphism, h: M * M in the appropriate category. When does there exist a path of automorphisms joining h to the identity. The problem in this form is exceedingly difficult, and apart from the case of surfaces and the Alexander trick, very little is known. It is however possible to formulate a simpler problem and make some progress. For this we ask that there exist a homeomorphism, (in the category) H: M x I--+ M x I, which is the identity on M x 0 and h on M x 1. This is the problem of concordance or quasi-isotopy classification. Certain results of Cerf, [2], indicate that at least for 2-connected manifolds without boundary of dimension > 9 concordance and isotopy give the same classification. There is, however, an example of Siebenmann which shows that in general this is not so. It is clear that a necessary condition in the case of both questions is the existence of a homotopy joining h to the identity. So we ask for an obstruction theory for deforming such a homotopy into a concordance. In this paper we show that when M is a thickening of a suitably connected CW-complex K, which is also a suspension, we may interpret the obstructions as elements of the group of thickenings of the suspension of K. I would like to acknowledge the invaluable help and encouragement given to me by my advisors, Professor C. T. C. Wall and Professor A. Haefliger; as well as to the Science Research Council and Trinity College, Cambridge for their generous support.
A preliminary study of DC magnetron sputtered NiAl-Hf coatings

Crystalline NiAl-0.1Hf coatings, ∼20-μm thick, were deposited onto CMSX-4® substrates using direct current (DC) magnetron sputtering. The as-deposited coatings were found to be single phase, consisting of β-NiAl (B2 structure). Annealing in argon at 1000 °C for 1 h resulted in densification of the coatings and in increased adhesion between the coatings and the substrate. Microstructural and compositional changes of the coating system after isothermal oxidation were studied using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) techniques. The mechanical properties of the coatings were studied via nanoindentation in the as-deposited condition, after annealing, and following various oxidation heat treatments. The hardness and modulus of the coatings were observed to correlate with oxidation time. Extended oxidation resulted in decreased hardness due to grain growth, precipitate coarsening and the diffusion of solutes into and out of the coating. The results are discussed relative to conventional CVD aluminide coatings.
Algorithm for a modified Martin-Stanford equation of state

Abstract An algorithm is described which calculates pressures as a function of temperatures and volumes down to and below the critical volume. It will operate with only critical pressure, temperature, volume, and normal boiling point or sublimation temperatures as input parameters. It also provides the option of using vapor-pressure, isochoric and/or liquid density data to improve its predictive ability. Two equations of state are available options. the algorithm calculates the vapor pressure, coexistence line, and relative amounts of liquid and vapor. Its utility is demonstrated by application to hydrogen, helium, neon, carbon dioxide, water, ammonia, argon, and methane, which cover the range of normal values for critical compressibility. Coefficients are given to accurately calculate PVT data for hydrogen, neon, helium, argon, methane, carbon dioxide, ammonia, and water.
Is There Still a Role for Ultrafiltration in the Management of Acute Heart Failure? CARRESS and Beyond

The Cardiorenal Rescue Study in Acute Decompensated Heart Failure (CARRESS-HF) trial was a prospective, randomized study comparing ultrafiltration versus pharmacological therapy in the treatment of acute decompensated heart failure (ADHF) complicated by cardiorenal syndrome Bart et al. (N Eng J Med 367:2296–2304, 1). The study found that ultrafiltration was inferior to pharmacological therapy, resulting in a significant increase in serum creatinine and serious adverse events while producing no significant difference in weight loss. The CARRESS trial calls into question the viability of ultrafiltration as a preferable treatment strategy in ADHF patients with cardiorenal syndrome.
Cancer therapy based on oncogene addiction

Tumor cells contain multiple mutations, yet they often depend on continued expressed of a single oncoprotein for survival. Targeting these proteins has led to dramatic responses. Unfortunately, patients usually progress, through drug resistance or adaptive resistance through reprogramming of signaling networks. The Ras-MAPK pathway provides examples of these successes and failures, and has revealed unexpected degrees of oncogene addiction and signaling complexity that are likely to be useful lessons for the future of targeted therapy.
The Mechanism of Experimental Exophthalmos

The experimental observations were confined to the dog. In this animal the entire orbital contents, with the exception of the lacrimal gland, are enclosed in a conical fascial sheath. The base of the cone surrounds the orbital margins in front and its apex is attached to the foramina at the posterior of the orbit. The superior surface of the sheath is composed of alternating layers of elastic and connective tissue, directly continuous with which are strands of smooth-muscle fibers. Electrical stimulation of the cephalic end of the cut vagosympathetic trunk causes a circular contraction of the cone-shaped sheath, squeezing the eye forward into the position seen in exophthalmos. The action and independent contraction of the sheath have been carefully established. The importance of the conical sheath is illustrated by the fact that the surgical removal of a strip of the sheath establishes a chronic enophthalmos. From the Department of Physiology and the Division of Experimental Medicine, The Mayo Foundation. Submitted for publication July 15, 1935.
Gravity current flow past a circular cylinder: forces, wall shear stresses and implications for scour

The flow of compositional gravity currents past circular cylinders mounted above a wall is investigated numerically. Two- and three-dimensional Navier-Stokes simulations are employed to quantify the force load on the cylinder, along with the friction velocity at the bottom wall near the cylinder, for Reynolds numbers in the range of 2000-45 000. While two-dimensional simulations accurately capture the impact stage, they are seen to overpredict the force and friction velocity fluctuations throughout the transient stage. Comparisons between gravity current and constant-density flows past circular cylinders show that the impact and transient stages are unique to gravity current flows. During the quasi-steady stage, on the other hand, the wake structures and the values of the drag, the peak-to-peak lift, the vortex shedding frequency and the friction velocity below the cylinder are comparable. The friction velocity below the cylinder depends chiefly on the Reynolds number formed with the front velocity and the gap width. The maximum friction velocity at impact is about 60 % larger than during the quasi-steady stage or in a constant-density flow. This raises the possibility of aggressive erosion behaviour at impact, which may occur in a spanwise localized fashion because of the larger friction velocity near the lobes.
Nanoscience: Dark-hot resonances

The resonant behaviour of clusters of gold nanoparticles has been tuned by gradually bringing the particles together. The approach could have many applications, including chemical and biological sensing.
Estimating Object Rotation And Scale Using Correlation Filters

Recently, much attention has been paid to designing correlation filters that provide distortion-invariant pattern recognition. However, optical correlators can also be used to estimate the orientation and scale change in the object being observed. This paper presents two new methods for designing correlation filters that are aimed at determining the in-plane rotation and scale changes present in the input image (relative to a reference image). These methods assume that a known object is present in the input plane and that its rotation and scale are to be estimated. The first method is capable of determining both rotation and scale changes simultaneously. The second method assumes that the scale is fixed and estimates only the in-plane rotation. Both methods should prove useful in applications in which one needs to estimate the object orientation. Several simulation results are included to quantify the estimation accuracies and the computational complexities of the two methods.
Pediatric neck abscesses: changing organisms and empiric therapies.

Objective: To examine the causative organisms in pediatric neck infections, delineate risk factors in methicillin-resistant Staphylococcus aureus (MRSA) pediatric neck infections, and define patient populations that should be empirically treated with MRSA sensitive antibiotics. Study Design: Retrospective chart review. Methods: Two hundred twenty-eight consecutive patients were reviewed, ages 0 to 17, presenting at a tertiary care center between 1999 and 2007 with computed tomography proven neck abscesses. Characteristics of patients with differing causative organisms were compared. Results: Forty-eight percent of all pediatric patients' with head and neck abscesses had S. aureus as the causative organism, 29% of which were community-acquired MRSA—recent years showed that up to 66% of pediatric neck abscesses were MRSA culture positive. When comparing MRSA infections vs. other causative organisms multiple clinical characteristics were found which did not help to differentiate those patients at a higher risk for MRSA. Characteristics which did trend to predict an MRSA infection were few. For example, the average age of patients with MRSA was 32.5 months compared with only 16 months for the methicillin-sensitive S. aureus patients. MRSA sensitivities and resistances were also examined. Conclusions: This study presents a large cohort of pediatric neck abscess patients, in which the emergence and characteristics of MRSA are shown. As community-acquired MRSA infections become more prevalent, empiric antibiotic therapy must be considered. The results of this study show that the incidence of MRSA has greatly increased and clinical risk factors are not helpful in choosing those patients which may be at higher risk for an MRSA infection.
In Situ UV Raman Study of the NOx Trapping and Sulfur Poisoning Behavior of Pt/Ba/γ-Al2O3 Catalysts

In situ Raman experiments excited with 244 nm radiation are carried out on Pt/γ-Al2O3 and Pt/Ba/γ-Al2O3 catalysts. The addition of Ba allows the normal catalyst to store substantial amounts of NOx as Ba nitrates under lean burn conditions. Dilute amounts of NO and/or SO2 plus O2 in N2 are flowed over the catalysts, with the temperatures and concentrations chosen to simulate the NOx trapping and sulfur poisoning characteristics encountered in normal operation. Adsorbed species observed on Pt/γ-Al2O3 are nitrite/nitro species and sulfate on γ-Al2O3 and NO on Pt. On Pt/Ba/γ-Al2O3, in situ UV Raman spectra showed typical NOx trap behavior: NOx and SOx are stored as Ba(NO3)2 and BaSO4 during lean conditions and released at higher temperatures in H2 flow. Prolonged SO2 exposure eventually deactivates the catalyst for NOx storage. The sulfate purged by heating to 500 °C in H2 is not completely removed from the catalyst, since it can reappear at lower temperature without additional exposure to SO2. On both Pt/γ-...
Chronic ethanol exposure leads to divergent control of dopaminergic synapses in distinct target regions

Neuroadaptations following chronic exposure to alcohol are hypothesized to play important roles in alcohol-induced alterations in behavior, in particular increased alcohol drinking and anxiety like behavior. Dopaminergic signaling plays a key role in reward-related behavior, with evidence suggesting it undergoes modification following exposure to drugs of abuse. A large literature indicates an involvement of dopaminergic signaling in response to alcohol. Using a chronic inhalation model of ethanol exposure in mice, we have begun to investigate the effects of alcohol intake on dopaminergic signaling by examining protein levels of tyrosine hydroxylase and the dopamine transporter, as well as monoamine metabolites in three different target fields of three different dopaminergic nuclei. We have focused on the dorsal lateral bed nucleus of the stria terminalis because of the reported involvement of dorsal lateral bed nucleus of the stria terminalis dopamine in ethanol intake, and the nucleus accumbens and dorsal striatum because of their dense dopaminergic innervation. After either a chronic intermittent exposure or continuous exposure regimen, mice were killed, and tissue punches collected from the dorsal lateral bed nucleus of the stria terminalis, nucleus accumbens, and striatum for Western analysis. Strikingly, we found divergent regulation of tyrosine hydroxylase and dopamine transporter protein levels across these three regions that was dependent upon the means of exposure. These data thus suggest that distinct populations of catecholamine neurons may be differentially regulated by ethanol, and that ethanol and withdrawal interact to produce differential adaptations in these systems.
Small sample tests for the equality of intraclass correlation coefficients under unequal family sizes

Abstract In this paper, the test for equality of several intraclass correlation coefficients is proposed when the sample size is small. First, we consider a case with two populations. The exact null distribution of the test statistic is derived. We use a Monte Carlo simulation study and find that the performance of our new test is superior to the tests that were proposed by Young and Bhandary (1998). Work is then extended to develop a test for three intraclass correlation coefficients. Monte Carlo simulation studies are also conducted to compare our new test and the test that was proposed by Bhandary and Alam (2000). Based on our simulation result, we recommend our new test in practice when the sample sizes are small.
APOE ɛ4 is associated with postictal confusion in patients with medically refractory temporal lobe epilepsy

Summary This study examined the relationship between the APOE ɛ4 allele and postictal confusion in patients with medically intractable temporal lobe epilepsy (TLE). Patients with at least one ɛ4 allele ( n =22) were three times more likely to exhibit postictal confusion (68%) than the 63 patients without ɛ4 (43%). These preliminary results demonstrate that APOE ɛ4 is associated with an increased risk of postictal confusion in patients with medically intractable TLE, suggesting possible dysfunction in neuronal recovery mechanisms.
Augmented reading: presenting additional information without penalty

We present a new interaction technique for computer-based reading tasks. Our technique leverages users' peripheral vision as a channel for information transfer by using a video projector along with a computer monitor. In our experiment, users of our system acquired significantly more information than did users in the control group. The results indicate that our technique conveys extra information to users nearly "for free," without adversely affecting their comprehension or reading times.
Luna 20 - Mineral chemistry of spinel, pleonaste, chromite, ulvospinel, ilmenite and rutile.

Review of some of the results of a reflection microscopy and electron microprobe study performed on a part of the Luna 20 soil sample designated as the East Coast Consortium aliquot. The study is restricted to analyses of the oxides of Fe, Ti, Mg, Mn, Cr, and Al in this sample. The spinel mineral group, ilmenite and rutile only are discussed.
Time of day and water temperature modify the physiological stress response in green sturgeon, Acipenser medirostris.

Abstract The effects of time of day and water temperature on the acute physiological stress response were investigated in young-of-the-year green sturgeon ( Acipenser medirostris ). The response to a 1-min air-emersion stressor was assessed during the day (08.00 h) and at night (20.00 h), as well as after acclimation to either 11 °C or 19 °C. Blood samples were collected prior to stress and at several times after exposure to the stressor, and plasma concentrations of cortisol, lactate, and glucose were determined. The magnitudes of cortisol (19.1 ng ml −1 vs. 4.9 ng ml −1 ) and lactate (190.6 mg l −1 vs. 166.7 mg l −1 ) were significantly higher in fish stressed at night when compared with the day. There were no significant differences in glucose levels between time periods. Although, acclimation temperature did not affect peak cortisol concentrations (56.7 and 50.3 ng ml −1 at 11 °C and 19 °C, respectively), the duration of the response was significantly extended at 11 °C. Post-stressor lactate increases were similar between temperature groups, but at 11 °C post-stressor glucose levels were significantly increased through 6 h, suggesting stressor-induced glycogenolysis and gluconeogenesis or decreased glucose utilization. These data demonstrate that the physiological stress response in green sturgeon is modified by both time of day and temperature.
Early studies of magnetized-fluidized beds

Abstract The early Eastern European literature on the effects of magnetic fields on fluidized beds of magnetizable particles is reviewed. Other works by Western authors during this period are also included. A number of independent observations reported in the Western literature over the past decade were found to be described earlier by the Russian and Bulgarian researchers. These included the operating regimes, bed pressure drop and expansion, as well as several applications of the phenomena. However, since most of this earlier work was published in Russian and Bulgarian Journals, it is not well known to most fluidization practitioners.
Thermal permeability enhancement of blocky rocks: One-dimensional flows

Abstract A conceptual model is presented to describe permeability enhancement within competent blocky rock masses subjected to temperature changes. The model accomodates a ubiquitously jointed, isothermal and initially stressed mass into which fluid of a different temperature is injected. The transient behaviour of the coupled fluid flow and transport system is described using a 1-D or radial upwind weighted, conductive-advective transport model. Heat production from, and thermal volume change of, the surrounding matrix blocks is described analytically via a convolution product with individual blocks represented as equivalent spheres. The assumption of full lateral restraint for control volumes within the blocky mass results in stress redistribution not being explicitly represented. No attempt is made to satisfy stress equilibrium conditions. The model is used to identify the manner and rate at which fluid permeability enhancement processes develop within a representative granite rock mass. Thermal effects are shown to be significant.
Decreased pulmonary damage in primates with inhalation injury treated with high-frequency ventilation

Objective This study compared two forms of high-frequency ventilation (HFV) with conventional volume ventilation (CON) in a primate model of inhalation injury to determine whether ventilatory mode was a determinant of pulmonary damage. Summary Background Data The authors previously reported that the prophylactic use of high-frequency flow interruption in patients with bronchoscopically diagnosed inhalation injury requiring mechanical ventilatory support resulted in a significant decrement in mortality. They hypothesized that a reduction in ventilatory mode induced pulmonary damage was in part responsible for their clinical results
Endovascular Repair of Abdominal Aortic Aneurysm does not Improve Early Survival versus Open Repair in Patients Younger than 60 Years

Objectives Multiple randomised trials have demonstrated lower perioperative mortality after endovascular aneurysm repair (EVAR) compared to open surgical repair for infrarenal abdominal aortic aneurysms (AAAs). However, in these trials the mortality advantage for EVAR is being lost within 2 years of repair and the patients evaluated are relatively older with no study specifically comparing EVAR and open repair for patients younger than 60 years of age.
Derivation of Models for the Interacting Electrons in Cu-O Superconductors

Key questions for theory of high temperature superconductors involve the nature of the electronic system: the minimum essential Hamiltonian and the low energy states of such Hamiltonians. To attempt to answer these questions we are carrying out studies using constrained density functional (CDF) methods to identify the relevant electronic states and realistic values of the parameters, combined with exact calculations on the reduced model Hamiltonians. The CDF calculations lead to a 3-band Hubbard model for Cu-O planes with parameters in general agreement with high energy spectroscopies and low energy magnetic excitations. We describe a modified Lanczos method to carry out large many-body calculations and give a representative result, where we find the spectra are described by the 1-band Hubbard model in regimes which imply spin interactions beyond the usual Heisenberg form.
Systemic distribution of woodchuck hepatitis virus in the tissues of experimentally infected woodchucks

Abstract To better assess the extent of the tissue tropism of mammalian hepadnaviruses, 10 tissues from each of six woodchucks were examined for the presence and state of woodchuck hepatitis virus (WHV) nucleic acids 15 months after experimental WHV infection. The tissues examined were peripheral blood lymphocytes, lymph node, spleen, bone marrow, thymus, pancreas, kidney, ovary, testis, and liver. Tissue samples from three chronically infected animals and three animals with serologic patterns of recovery (serum: WHsAg − , anti-WHc + , anti-WHs + , WHV DNA − ) from acute WHV infection were analyzed in parallel by in situ hybridization and Southern and Northern blot techniques. WHV nucleic acids were detected in several individual tissues from each animal examined, although not all tissues in every animal contained WHV. Substantial differences were observed among the various tissues and animals with respect to the frequency, level, and intratissue distribution of WHV nucleic acids, as well as the presence of different viral genomic forms. Active WHV DNA replication was present only in the liver and spleen of the chronically infected animals. No evidence of ongoing WHV DNA replication was found in any of the tissues from the recovered animals. WHV DNA was homogeneously distributed among all hepatocytes in the livers of the chronic carriers. By contrast, WHV DNA in all the extrahepatic tissues, and in the livers of the recovered animals, was detected only in scattered foci of cells.
A small-molecule scaffold induces autophagy in primary neurons and protects against toxicity in a Huntington disease model.

Autophagy is an intracellular turnover pathway. It has special relevance for neurodegenerative proteinopathies, such as Alzheimer disease, Parkinson disease, and Huntington disease (HD), which are characterized by the accumulation of misfolded proteins. Although induction of autophagy enhances clearance of misfolded protein and has therefore been suggested as a therapy for proteinopathies, neurons appear to be less responsive to classic autophagy inducers than nonneuronal cells. Searching for improved inducers of neuronal autophagy, we discovered an N10-substituted phenoxazine that, at proper doses, potently and safely up-regulated autophagy in neurons in an Akt- and mTOR-independent fashion. In a neuron model of HD, this compound was neuroprotective and decreased the accumulation of diffuse and aggregated misfolded protein. A structure/activity analysis with structurally similar compounds approved by the US Food and Drug Administration revealed a defined pharmacophore for inducing neuronal autophagy. This pharmacophore should prove useful in studying autophagy in neurons and in developing therapies for neurodegenerative proteinopathies.
Trimethylamine N-Oxide Stabilizes RNA Tertiary Structure and Attenuates the Denaturating Effects of Urea

Trimethylamine N-oxide (TMAO) and urea are osmolytes. Osmolytes allow cells to remain viable in harsh or extreme environments. Both TMAO and urea are found in shark and rays at approximate molar ratios of 1:2, respectively. At this ratio TMAO nearly completely counteracts the destabilizing effects that urea has on proteins. We ask whether RNA, which is denatured by urea, is stabilized by TMAO in a manner similar to that seen for proteins. We found that TMAO stabilizes Escherichia coli tRNAfmet tertiary structure and counteracts the denaturing effects of urea at the same ratios found for proteins. Cation binding usually drives RNA tertiary structure formation. These results suggest that tertiary structure stability is not only sensitive to cations but also to the aqueous composition and properties of the solvent. We propose that tertiary structure folding is driven by unfavorable interactions between TMAO and the phosphodiester backbone.
Bound States in a Debye-Hückel Potential

This is a study of some of the properties of the discrete energy levels of an electron in an exponentially shielded Coulomb potential, which is known in plasma physics as the Debye-H\"uckel potential and in nuclear physics as the Yukawa potential. A system with this potential possesses a finite number of bound states and these states are not degenerate with respect to the orbital angular momentum. First-order perturbation theory is used to obtain simple, analytical expressions for estimating the energy levels; the approximations appear to be quite accurate for large values of the Debye length. The perturbation calculations lead to an estimate of the number of bound states as a function of the Debye length. The matrix elements of the Hamiltonian for this potential are calculated in the representation of the hydrogen atom wave functions. The Hamiltonian matrix may serve as a convenient starting point for several other methods of computing the energy levels.
Random Wavelet Transformation and its Properties

A discrete random wavelet transformation is defined as a random field of stochastic integrals of translates and dilates of a compactly supported wavelet function with respect to a fractional Brownian motion. It is shown that the transformation exhibits several properties analogous to the ones demonstrated previously for the `classical' wavelet transformation of a fractional Brownian motion. Moreover, some important advantages of the transformation defined here, over its `classical' counterpart, are demonstrated.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Tribological Properties and Surface Chemistry of Silicon Carbide at Temperatures to 1500° C

Silicon carbide surfaces were heated to 1500 C in a vacuum and analyzed at room temperature with X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES). The basic unit of the surfaces was considered as a plane of a tetrahedron of either SiC4 and CSi4 composition. AES spectra were obtained from 250-1500 C, with an analysis depth of 1 nm revealed the presence of little Si and mostly graphite. XPS analysis depth was 2 nm or less, and Si was found in the second 1 nm. Sliding friction tests with single-crystal silicon carbide in contact with iron in a vacuum were characterized by a stock-slip value. The coefficient of friction increased with increasing temperature up to 400 C, then decreased with increasing temperature from 400-600 C. Reheating surfaces to 800 C after preheating them to that temperature produced no changes in AES readings. It is concluded that the maximum density of silicon and silicon-carbide is at 800 C, and the higher the sliding temperature, the more metal that is transferred.
Properly estimating the liquidity effect: why accounting for stationarity and outliers is important

Abstract The impulse responses of the federal funds rate to innovations in the non-borrowed reserves are re-examined. The rolling responses reveal that, by correcting for the non-stationarity of the data and including the error correcting terms in the VARs, the liquidity effect found by Christiano and Eichenbaum 1991 , Christiano and Eichenbaum 1992b , and 1994 ) is shortened from six to two months. The rolling responses also locate an outlier between the non-borrowed reserves and the funds rate in May 1980. Once the observation of May 1980 is excluded from the samples, the evidence of the liquidity effect becomes much weaker.
50 years of protein acetylation: from gene regulation to epigenetics, metabolism and beyond

In 1964, Vincent Allfrey and colleagues reported the identification of histone acetylation and with deep insight proposed a regulatory role for this protein modification in transcription regulation. Subsequently, histone acetyltransferases (HATs), histone deacetylases (HDACs) and acetyl-Lys-binding proteins were identified as transcription regulators, thereby providing compelling evidence for his daring hypothesis. During the past 15 years, reversible protein acetylation and its modifying enzymes have been implicated in many cellular functions beyond transcription regulation. Here, we review the progress accomplished during the past 50 years and discuss the future of protein acetylation.
Effects of neonatal castration or treatment with dihydrotestosterone on numbers of neurons in the rat superior cervical sympathetic ganglion

Abstract There is a normal sexual dimorphism in the number of neurons in the rat superior cervical sympathetic ganglion (SCG), with adult males having more neurons in this ganglion than females 15 . We confirm this finding here, report that this sex difference is not present at birth and that neonatal castration of males reduces the adult sex difference. These results indicate that perinatal levels of circulating testicular hormones play a role in regulating the numbers of neurons in the SCG. Treatment of neonatal rats with testosterone propionate or estradiol significantly increases the number of neurons in the SCG. To determine whether this effect is primary androgenic or estrogenic, the effects of dihydrotestosterone, on SCG neuron number were investigated. Dihydrotestosterone, unlike testosterone, is not aromatized to estradiol intracellularly. There was no difference in the number of neurons between animals injected from birth with vehicle or dihydrotestosterone. This difference in effects between dihydrotestosterone and testosterone suggests that the actions of testosterone may be via aromatization to estradiol, rather than action at an androgen receptor.
Error Detection in the Presence of Synchronization Loss

Cyclic codes are very attractive for error detection because of their low cost encoding and decoding circuits, and because of their high guaranteed minimum distance, but they suffer from very poor protection when word frame synchronization is lost. This note suggests starting the encoder and decoder circuits in an essentially random state, instead of the usual all-zero state. Under this condition of operation it is shown that the undetected error rate against synchronization loss is 2^{-p} where p is the number of parity check bits.
HPLC analysis of algal pigments: a comparison exercise among laboratories and recommendations for improved analytical performance

Abstract Pure individual and mixed pigment standards were distributed among Joint Global Ocean Flux Study (JGOFS) pigment analysts to estimate the variability of their spectrophotometric and chromatographic systems. To monitor the integrity of the pigments during the comparison exercise, chlorophyll and carotenoid standards were archived and periodically analyzed by high-performance liquid chromatography (HPLC). Pigment standards stored in the dark under nitrogen at − 20 °C were found to be stable for periods of at least one year. Results from three separate intercalibration exercises document a better agreement for spectrophotometric analyses than for HPLC. For the spectrophotometric comparisons, 90% of the pigments analyzed by participant laboratories were within ± 6% of the mean “consensus” values. By contrast, 65 and 85% of the laboratories agreed to within ± 10 and ± 20%, respectively, when chromatographic analyses were compared. Chlorophyll absorption measurements obtained with a diode array-type spectrophotometer were 6–9% lower than those obtained with monochromator-type spectrophotometers. These underestimates probably result from chlorophyll fluorescence contamination associated with the optical configuration of the diode array spectrophotometer. It was also determined that HPLC methods which are not capable of separating monovinyl chlorophyll a from divinyl chlorophyll a can produce 15–25% overestimates of total chlorophyll a concentration in Prochlorococcus -dominated oceanic waters. A simple dichromatic approach is described for eliminating this variable source of error caused by co-elution of these structurally-related pigments. The use of internal standards and periodic calibration checks with external standards is highly recommended for improving analytical performance.
Analysis, design, and implementation of a high-efficiency full-wave rectifier in standard CMOS technology

In this paper we present analysis, design, and implementation of a high-efficiency active full-wave rectifier in standard CMOS technology. The rectifier takes advantage of the dynamic voltage control of its separated n-well regions, where the main rectifying PMOS elements have been implemented in order to eliminate latch-up and body effect. To minimize rectifier dropout and improve AC---DC power conversion efficiency (PCE), all the MOSFET switching elements have been pushed into deep triode region to minimize their resistance along the main current path during conduction. A prototype rectifier was implemented in the AMI 0.5-μm 3M/2P n-well CMOS process. An input sinusoid of 5 V peak at 0.5 MHz produced 4.36 V DC output across a $$1\,\hbox{k}\Upomega\Vert 1\,\mu\hbox{F}$$ load, resulting in a measured PCE of 84.8%.
Interactions of an azomercurial with proteins

Abstract With a colored mercurial, 4-( p -dimethylaminobenzeneazo)phenylmercuric acetate, it is possible to measure the thiol content of proteins from shifts in visible absorption spectra or from changes in optical density as mercurial is concentrated in an aqueous, protein-containing phase. The latter procedure is more precise and gives values of 0.66, 1.83, and about 4 for the number of moles of —SH per mole of bovine serum albumin, β-lactoglobulin, and ovalbumin, respectively. Differences in reactivity of thiols can also be distinguished.
Array-based multiplex analysis of DNA methylation in breast cancer tissues

Abnormal DNA methylation is well established for cancer cells, but a methylation-based diagnostic test is yet to be developed. One of the problems is insufficient accuracy of cancer detection in heterogeneous clinical specimens when only a single gene is analyzed. A new technique was developed to produce a multigene methylation signature in each sample, and its potential for selection of informative genes was tested using DNA from formalin-fixed, paraffin-embedded breast cancer tissues. Fifty-six promoters were analyzed in each of 138 clinical specimens by a microarray-based modification of the previously developed technique. Specific methylation signatures were identified for atypical ductal hyperplasia, ductal carcinoma in situ, and invasive ductal carcinoma. Informative promoters selected by Fisher's exact test were used for composite biomarker design using naive Bayes algorithm. All informative promoters were unmethylated in disease compared with normal tissue. Cross-validation showed 72.4% sensitivity and 74.7% specificity for detection of ductal car-cinoma in situ and invasive ductal carcinoma, and 87.5% sensitivity and 95% specificity for detection of atypical ductal hyperplasia. These results indicate that informative cancer-specific methylation signatures can be detected in heterogeneous tissue specimens, suggesting that a diagnostic assay can then be developed.
The effects of nicotinamide on apoptosis and blood-brain barrier breakdown following traumatic brain injury

Nicotinamide has been shown to protect against many of the pathophysiological factors associated with both ischemic and traumatic brain injuries. The present study evaluated the neuroprotective effect of nicotinamide on the breakdown of the blood-brain barrier (BBB) and apoptosis expression following traumatic brain injury (TBI). Animals were prepared with a unilateral cortical contusion injury (CCI). Fifteen minutes following injury the animals received either nicotinamide (500 mg/kg, ip) or 0.9% saline. The animals were perfused at 5, 24, and 72 h post-injury. BBB integrity was assessed by endogenous rat IgG immunoreactivity. Recent studies have shown that IgG immunoreactivity is a reliable measure of BBB integrity. The results indicated that IgG immunoreactivity was greatest at 5 h and declined at 24 h after injury. Nicotinamide significantly reduced IgG expression at every time point following injury. Apoptosis was examined using the TUNEL method. The results indicated that TUNEL immunoreactivity peaked at 24 h. TUNEL(+) cells were classified morphologically as nonapoptotic (Type I) or apoptotic (Type II) to verify that the neuroprotective effects of nicotinamide occur by inhibiting apoptosis or necrosis. Administration of nicotinamide significantly reduced the expression of all TUNEL(+) cells in the tissue surrounding the lesion cavity. Specifically there was a significant reduction in the number of Type I, Type II, and Total TUNEL(+) cells in the nicotinamide-treated animals. In addition, nicotinamide reduced lesion cavity expansion 72 h following CCI. These findings suggest that nicotinamide reduces BBB breach and neuronal cell loss acutely following injury and that these reductions may account for the beneficial behavioral effects seen in previous studies.
Colorectal carcinoma antigens detected by hybridoma antibodies

Hybridoma cells which secrete colorectal carcinoma-specific antibodies have been produced and used to study the antigenic structure of these tumor cells. Nineteen antibodies have been studied in detail, and 15 of these are colorectal carcinoma specific. Only two antibodies reactive with carcinoembryonic antigen (CEA) have been discovered and five other antibodies that react with distinct epitopes on the cell surface have been defined. Several antigens with distinct molecular characteristics have been shown to exist by use of hybridoma antibodies. Six hybridoma antibodies have been shown to mediate antibody-dependent cell-mediated cytotoxicity (ADCC).
Explantation of an AcrySof Natural intraocular lens because of a color vision disturbance.

Purpose To describe a patient who complained of color vision disturbance after implantation of a clear intraocular lens (IOL) in one eye and a yellow IOL in the other. Design Interventional case report. Methods A 50-year-old woman complained of binocular imbalance and “yellow vision” in her left eye after implantation of a visible blue light–filtering yellow IOL. A clear IOL had been implanted in her right eye 1 month before. She requested explantation of the yellow IOL. Results The yellow IOL was exchanged for a clear one, which resolved the unbalanced color vision. Conclusions Patients may be intolerant of the color disturbance that results when dissimilarly colored IOLs are implanted. It is advisable to avoid this practice.
Electrical properties of crystalline PbxSn1−xTe0.5Se0.5 thin films

Electrical conductivity in the dark, s, and thermoelectric power, S, of PbxSn1�x Te0.5Se0.5 films with x ¼ 0.4, 0.6, 0.8, and 1 were studied for films annealed at 473 K in the temperature range 300–473 K, while the Hall voltage was investigated at room temperature. The temperature dependence of s revealed an intrinsic conduction mechanism above 370 K, while for temperatures less than 370 K an extrinsic conduction is dominant. Both activation energy, DE1, and the energy gap, Eg, were found to decrease with increasing Sn content. This decrease of Eg with increasing Sn content revealed that band inversion exists. The variation of S with temperature revealed that the investigated samples are non-degenerate semiconductors with p-type conduction. Also, the Fermi energy, EF, was determined from the linear variation of S with 1/T in the intrinsic range. The compositional dependence of the room temperature Hall constant, RH (0.21–0.38 cm 3 /Coul.), hole carrier’s concentration, p (2.9–1.6 � 10 19 cm �3 ), Hall mobility, mH (0.88–0.03 cm 2 /V s), and effective mass, m*/me (0.28–0.78) are given.
"Reading" "Methods" "Texts": How Research Methods Texts Construct Political Science

This article reports on an interpretive content analysis of fourteen research methods texts. We read them as a genre—exploring their structural and rhetorical features—to address two questions: To ...
Category‐Based and Feature‐Based Cognitive Processes in Job Impressions

Widely accepted cognitive models of job attitudes suggest that a person's job attitude results from the linear combination of attitudes toward individual job features (feature-based processing). This is a relatively difficult cognitive process. We suggest that people act to economize scarce cognitive resources by using knowledge about job categories to generate job impressions when presented with category-consistent job features. People use feature-based processing when presented with job features that are inconsistent with a job category. Our results suggest that impressions do depend on the descriptive consistency of job features with a job category. The implications of the model for job perceptions in the workplace are discussed.
Distribution of VIP- and NPY-like immunoreactivities in rat main olfactory bulb.

Abstract The distribution of vasoactive intestinal peptide (VIP)-and neuropeptide Y (NPY)-like immunoreactivities in the Sprague-Dawley rat main olfactory bulb was analysed using the peroxidase-antiperoxidase light microscopic immunocytochemical technique. VIP-like immunoreactivity was most prominently localized within a large number of intermediate-sized neurons whose perikarya and extensively branched varicose processes remained confined to the external plexiform layer (EPL). A few small short-axon type neurons in the mitral cell layer and granule cell layer (GRL) and even fewer large neurons in the glomerular layer (GL)/EPL border region contained immunoreactivity for VIP as well. Neuropeptide Y-like immunoreactivity (NPY-I) was principally localized within sparsely distributed large multipolar neurons of the deep GRL and within axons distributed with diminishing density from deep to superficial GRL. In addition, dense NPY-I was localized within very few large superficial short-axon type neurons of the GL/EPL border region. The restricted laminar and cellular distribution of NPY-I and VIP-I suggests that both peptides may act to modulate granule cell activity, and therefore, indirectly, olfactory bulb output.