cssi/SciSciGPT-SciSciNet huggingface dataset:
Olefin epoxidation by alkyl hydroperoxide with a novel cross-bridged cyclam manganese complex: demonstration of oxygenation by two distinct reactive intermediates.

Olefin epoxidation provides an operative protocol to investigate the oxygen transfer process in nature. A novel manganese complex with a cross-bridged cyclam ligand, Mn IV (Me 2 EBC)(OH)2 2+ (Me 2 EBC = 4,11-dimethyl-1,4,8,-11-tetraazabicyclo[6.6.2]hexadecane), was used to study the epoxidation mechanism with biologically important oxidants, alkyl hydroperoxides. Results from direct reaction of the freshly synthesized manganese(lV) complex, [Mn(Me2EBC)(OH)2](PF6)2, with various olefins in neutral or basic solution, and from catalytic epoxidation with oxygen-labeled solvent, H 2 18 0, eliminate the manganese oxo moiety, Mn IV =O, as the reactive intermediate and obviate an oxygen rebound mechanism. Epoxidations of norbornylene under different conditions indicate multiple mechanisms for epoxidation, and cis-stilbene epoxidation under atmospheric 18 0 2 reveals a product distribution indicating at least two distinctive intermediates serving as the reactive species for epoxidation. In addition to alkyl peroxide radicals as dominant intermediates, an alkyl hydroperoxide adduct of high oxidation state manganese(lV) is suggested as the third kind of active intermediate responsible for epoxidation. This third intermediate functions by the Lewis acid pathway, a process best known for hydrogen peroxide adducts. Furthermore, the tert-butyl peroxide adduct of this manganese(lV) complex was detected by mass spectroscopy under catalytic oxidation conditions.
Uptake of three [3H]progestins by target tissues in vivo: Implications for the design of diagnostic imaging agents

We have investigated the tissue distribution of radioactivity for 0.5–4 h follwing the i.v. injection of three tritium-labeled progestins in estrogen-primed, immature rats. Whereas [3H]progesterone shows minimal uterine uptake (<0.7% injected dose per gram; %ID/g), the two higher affinity, synthetic progestins [3H]R 5020 (promegestrone) and [3H]ORG 2058 show highly selective uptake that reaches 4–5% ID/g by 1–3 h. The uterus to non-target tissue activity ratio at 2–4 h is approximately 12–20 for R 5020 and ORG 2058, but less than 2 for progesterone; the uterus to blood activity ratio for R 5020 is also high (approximately 15), but is lower for ORG 2058, possibly due to the accumulation of radiolabeled metabolites in the blood. The uterine uptake is selectively blocked by simultaneous injection of a large dose of unlabeled steroid, indicating that the uptake is mediated by a high affinity, low capacity binding system, presumably the progesterone receptor. Pronounced uptake is also observed by the liver and into fat, but is not receptor-mediated. The highly selective target tissue uptake by the two synthetic steroids, but not by progesterone, indicates that one must have ligands with sufficiently high affinity for the target tissue receptor, as well as low affinity for certain non-receptor binding proteins, in order to obtain adequate contrast between target and non-target tissues in dynamic uptake studies. These guidelines will be important in the development of suitable in vivo imaging agents based on the progesterone receptor.
The sensitive period and optimum dosage for induction of audiogenic seizure susceptibility by kanamycin in the Wistar rat.

Abstract The incidence and severity of audiogenic seizures in kanamycin (KM)-treated rat pups, from a Wistar strain which is inherently seizure-resistant, was analyzed as a function of (a) postnatal age at the time of KM injection (i.p.) and (b) KM dosage. The vigor of the pinna reflex response on postnatal day (PND) 28 was correlated with (a) age at the time of injection, (b) dosage and (c) individual audiogenic seizure severity scores on PND 28 or PND 32. The data indicate that PNDs 9–12 are the developmental period when the rat has its greatest sensitivity to induction of susceptibility to audiogenic seizures by KM. The pinna reflex data suggest that cochlear vulnerability to KM intoxication is also greatest during this period. The optimum dosage for the induction of susceptibility was 100 mg/kg × 4 days. Use of higher doses resulted in a reduction of both incidence and severity of audiogenic seizures. The pinna reflex generally exhibited a supranormal vigor in animals having the most severe seizures. The behavioral attributes of induced audiogenic seizures at postnatal ages of 28 and 32 days are described and discussed.
Recent developments in the field of atomic data for astrophysics

Recent developments in the field of atomic data for astrophysics are briefly reviewed, and significant changes which have resulted in new electron excitation-rate coefficients for fine-structure transitions are discussed. The effect of these findings on chemical abundance estimates in gaseous nebulae is addressed. It is concluded that the abovementioned coefficients can be increased considerably by resonance contribution. They can be sensitive to the positions of resonances, particularly if they are near threshold.
The role of alkenes produced during hydrous pyrolysis of a shale

Abstract Hydrous pyrolysis experiments conducted on Messel shale with D2O demonstrated that a large amount of deuterium becomes incorporated into the hydrocarbons generated from the shale kerogen. In order to understand the pathway of deuterium (and protium) exchange and the role of water during hydrous pyrolysis, we conducted a series of experiments using aliphatic compounds (1,13-tetradecadiene, 1-hexadecene, eicosane and dotriacontane) as probe molecules. These compounds were pyrolyzed in D2O, shale/D2O, and shale/H2O and the products analyzed by GC–MS. In the absence of powdered shale, the incorporation of deuterium from D2O occurred only in olefinic compounds via double bond isomerization. The presence of shale accelerated deuterium incorporation into the olefins and resulted in a minor amount of deuterium incorporation in the saturated n-alkanes. The pattern of deuterium substitution of the diene closely matched the deuterium distribution observed in the n-alkanes generated from the shale kerogen in the D2O/ shale pyrolyses. The presence of the shale also resulted in reduction (hydrogenation) of olefins to saturated n-alkanes with concomitant oxidation of olefins to ketones. These results show that under hydrous pyrolysis conditions, kerogen breakdown generates n-alkanes and terminal n-alkenes by free radical hydrocarbon cracking of the aliphatic kerogen structure. The terminal n-alkenes rapidly isomerize to internal alkenes via acid-catalyzed isomerization under hydrothermal conditions, a significant pathway of deuterium (and protium) exchange between water and the hydrocarbons. These n-alkenes simultaneously undergo reduction to n-alkanes (major) or oxidation to ketones (minor) via alcohols formed by the hydration of the alkenes.
High-dose preoperative radiation for cancer of the rectum: Impact of radiation dose on patterns of failure and survival

Abstract Purpose: A variety of dose-time schedules are currently used for preoperative radiation therapy of rectal cancer. An analysis of patients treated with high-dose preoperative radiation therapy was undertaken to determine the influence of radiation dose on the patterns of failure, survival, and complications. Methods and Materials: Two hundred seventy-five patients with localized rectal cancer were treated with high-dose preoperative radiation therapy. One hundred fifty-six patients received 45 Gy, ± 10% (low-dose group). Since 1985, 119 patients with clinically unfavorable cancers (fixed, low-lying, or deeply ulcerated) were given a higher dose, 55 Gy, ± 10%, using a shrinking field technique (high-dose group). All patients underwent curative resection. Median follow-up was 66 months in the low-dose group and 28 months in the high-dose group. Patterns of failure, survival, and complications were analyzed as a function of radiation dose. Results: Fourteen percent (38275) of the total group developed a local recurrence, 20% (31156) in the low-dose group as compared with 6% (7119) in the high-dose group. The actuarial local recurrence rate at 5 years was 20% for the low-dose group and 8% for the high-dose group, and approached statistical significance with p = .057. For tethered/fixed tumors the actuarial local recurrence rates at 5 years were 28% and 9%, respectively, with p = .05. Similarly, for low-lying tumors (less than 6 cm from the anorectal junction) the rates were 24% and 9%, respectively, with p = .04. The actuarial rate of distant metastasis was 28% in the low-dose group and 20% in the high-dose group and was not significantly different. Overall actuarial 5-year survival for the total group of patients was 66%. No significant difference in survival was observed between the two groups, despite the higher proportion of unfavorable cancers in the high-dose group. The incidence of complications was 2%, equally distributed between the two groups. Conclusion: High-dose preoperative radiation therapy for rectal cancer results in excellent local control rates. However, in clinically unfavorable cancers a higher dose (55 Gy) of preoperative radiation can be given safely with significantly improved local control. Careful clinical staging is helpful in selectively treating patients with unfavorable tumors to a higher preoperative radiation dose and thus optimizing their outcome.
Impact of Distant Charge Reversals within A Robust β-Barrel Protein Pore&

Among all beta-barrel pores, staphylococcal alpha-hemolysin (alphaHL), a heptameric transmembrane protein of known high-resolution crystal structure, features a high stability in planar lipid bilayers under a wide range of harsh experimental conditions. Here, we employed single-channel electrical recordings and standard protein engineering to explore the impact of two distant charge reversals within the interior of the beta-barrel part of the pore. The charge reversals were replacements of lysines with aspartic acids. A charge reversal within the structurally stiff region of the beta barrel near the pore constriction reduced the open-state current of the pore, but produced a quiet pore, showing current fluctuation-free channel behavior. In contrast, a charge reversal on the trans entrance, within the structurally flexible glycine-rich turn of the beta barrel, increased the open-state current and produced gating activity of the pore in the form of large-amplitude and frequent current fluctuations. Remarkably, cumulative insertion of the two distant charge reversals resulted in a large-amplitude permanent blockade of the beta barrel, as judged by both single-channel and macroscopic current measurements. The results from this work suggest that these distant charge reversals are energetically coupled, producing different impacts on the ionic transport, the unitary conductance and the open-state probability of the pore.
A challenge to chaotic itinerancy from brain dynamics.

Brain hermeneutics and chaotic itinerancy proposed by Tsuda are attractive characterizations of perceptual dynamics in the mammalian olfactory system. This theory proposes that perception occurs at the interface between itinerant neural representation and interaction with the environment. Quantifiable application of these dynamics has been hampered by the lack of definable history and action processes which characterize the changes induced by behavioral state, attention, and learning. Local field potentials measured from several brain areas were used to characterize dynamic activity patterns for their use as representations of history and action processes. The signals were recorded from olfactory areas (olfactory bulb, OB, and pyriform cortex) and hippocampal areas (entorhinal cortex and dentate gyrus, DG) in the brains of rats. During odor-guided behavior the system shows dynamics at three temporal scales. Short time-scale changes are system-wide and can occur in the space of a single sniff. They are predictable, associated with learned shifts in behavioral state and occur periodically on the scale of the intertrial interval. These changes occupy the theta (2–12 Hz), beta (15–30 Hz), and gamma (40–100 Hz) frequency bands within and between all areas. Medium time-scale changes occur relatively unpredictably, manifesting in these data as alterations in connection strength between the OB and DG. These changes are strongly correlated with performance in associated trial blocks (5–10 min) and may be due to fluctuations in attention, mood, or amount of reward received. Long time-scale changes are likely related to learning or decline due to aging or disease. These may be modeled as slow monotonic processes that occur within or across days or even weeks or years. The folding of different time scales is proposed as a mechanism for chaotic itinerancy, represented by dynamic processes instead of static connection strengths. Thus, the individual maintains continuity of experience within the stability of fast periodic and slow monotonic processes, while medium scale events alter experience and performance dramatically but temporarily. These processes together with as yet to be determined action effects from motor system feedback are proposed as an instantiation of brain hermeneutics and chaotic itinerancy.
Liquid crystal skin thermometry: an accurate reflection of core temperature?

Oesophageal, rectal, bladder, tympanic and pulmonary artery sites are used intraoperatively to measure body temperature. However, the temperatures measured at each site have different physiological and practical importance. The present two-part study sought to compare liquid crystal (CR) skin temperature with other temperature monitors which are used routinely during surgery. The first part compared CR with oesophageal (OS) temperature during general inhalational anaesthesia. The second part compared CR with OS, pulmonary artery (PA), and bladder (BL) temperatures during the periods of rapid temperature change associated with cardiopulmonary bypass (CPB). During the first part, the mean difference between OS and CR was −0.14 ± 0.85° C; this difference remained consistent over time (P < 0.05 by repeated measures analysis of variance). During the second part, the difference in temperature readings between CR and each of the other monitors remained consistent except for CR vs PA and CR vs OS during the cooling period of CPB, when the iced cardioplegia slush directly affected the PA and OS temperatures. This study suggests that CR, an inexpensive and noninvasive means of temperature monitoring, reflects trends in temperature changes in the clinical setting.
Conformation and Electronic Properties of Helical Cis-Polyacetylene

Abstract Recent experimental evidence indicates that cis-polyacetylene may exist in a helical conformation in addition to the well-known planar form. We report electronic structure calculations which demonstrate that planar cis-polyacetylene is indeed marginally unstable towards helix formation, but that the potential energy curve is essentially flat over a wide range of single-bond twist angles. This result is consistent with the fact that both the planar and the helical isomers are found experimentally. We employ a tight-binding model to investigate the band structure changes associated with helix formation.
Unbiased tensor-based morphometry: improved robustness and sample size estimates for Alzheimer's disease clinical trials.

Abstract Various neuroimaging measures are being evaluated for tracking Alzheimer's disease (AD) progression in therapeutic trials, including measures of structural brain change based on repeated scanning of patients with magnetic resonance imaging (MRI). Methods to compute brain change must be robust to scan quality. Biases may arise if any scans are thrown out, as this can lead to the true changes being overestimated or underestimated. Here we analyzed the full MRI dataset from the first phase of Alzheimer's Disease Neuroimaging Initiative (ADNI-1) from the first phase of Alzheimer's Disease Neuroimaging Initiative (ADNI-1) and assessed several sources of bias that can arise when tracking brain changes with structural brain imaging methods, as part of a pipeline for tensor-based morphometry (TBM). In all healthy subjects who completed MRI scanning at screening, 6, 12, and 24 months, brain atrophy was essentially linear with no detectable bias in longitudinal measures. In power analyses for clinical trials based on these change measures, only 39 AD patients and 95 mild cognitive impairment (MCI) subjects were needed for a 24-month trial to detect a 25% reduction in the average rate of change using a two-sided test (α = 0.05, power = 80%). Further sample size reductions were achieved by stratifying the data into Apolipoprotein E (ApoE) e4 carriers versus non-carriers. We show how selective data exclusion affects sample size estimates, motivating an objective comparison of different analysis techniques based on statistical power and robustness. TBM is an unbiased, robust, high-throughput imaging surrogate marker for large, multi-site neuroimaging studies and clinical trials of AD and MCI.
Towards BirthAlert—A Clinical Device Intended for Early Preterm Birth Detection

Preterm birth causes 1 million infant deaths worldwide every year, making it the leading cause of infant mortality. Existing diagnostic tests such as transvaginal ultrasound or fetal fibronectin either cannot determine if preterm birth will occur in the future or can only predict the occurrence once cervical shortening has begun, at which point it is too late to reverse the accelerated parturition process. Using iterative and rapid prototyping techniques, we have developed an intravaginal proof-of-concept device that measures both cervical bioimpedance and cervical fluorescence to characterize microstructural changes in a pregnant woman's cervix in hopes of detecting preterm birth before macroscopic changes manifest in the tissue. If successful, such an early alert during this “silent phase” of the preterm birth syndrome may open a new window of opportunity for interventions that may reverse and avoid preterm birth altogether.
Composite-shell finite element for the analysis of smart structures

Smart structures with active ceramic segments typically consist of piezoceramic layers bonded to elastic members. Analytical modeling of piezoceramics has been addressed by many authors. Developments to date allow one to model planar structures and homogeneous piezoceramic continua. Most smart structures with piezoceramic control layers have multi- layered plate and shell geometries distributed in three-dimensional space. In this study, a composite shell finite element is developed for modeling such structures. The element developed is a general quadrilateral shell with eight nodes and curved edges. This paper describes the development of the element including a method for modeling the excitations to the bonded piezoceramic. Analytical and experimental results are presented for a commercial bimorph validating the performance of the element.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Turbidite, Tectonic and Gravity Transport, Northern Apennine Mountains, Italy

The region now occupied by the Northern Apennine Mountains of Italy was deep sea from late Triassic or earliest Jurassic through much of the Miocene. In the early Oligocene a trough developed parallel with the axis of the later mountain system and was filled with sediments ascribed to turbidity currents, originating at the northwest. In early and middle Miocene the locus of deposition shifted northeastward; the source remained in the northwest. About the same time (late Oligocene or early Miocene) a series of submarine orogenic ridges developed, first west of the present Ligurian-Tyrrhenian coast, then progressively northeast in Tuscany. Argillaceous and marly sediments of late Jurassic, Cretaceous, and Eocene age slid from the crests of the rising ridges in a series of great imbricate slices which became more chaotic with distance of transport northeast. The tectonic ridges of Tuscany rose beneath a thick cover of the gravity-transported chaotic mass and this allochthonous material was involved in the uplifting and faulting of each ridge. Most of the ridges are overturned and thrust northeast. The youngest ridges, those of the mountain front facing the Po Plain and the Adriatic Sea, came into being at the end of the Miocene or in earliest Pliocene. Thus the turbidity-current transport of vast quantities of sediment from the northwest, the compressional movements and the tectonic transport northeast, and the resulting gravity transport of a great chaotic mass in the same direction occurred during brief and overlapping intervals of Cenozoic time.
Finite Element Method Modeling of Reflective Cracking Initiation and Propagation: Investigation of the Effect of Steel Reinforcement Interlayer on Retarding Reflective Cracking in Hot-Mix Asphalt Overlay

In overlaid pavements, working cracks in existing pavement systems propagate upward to the new pavement surface and cause reflective cracking, one of the most serious causes of deterioration in overlay systems. Several techniques to reduce reflective cracking have been introduced. However, the reflective cracking mechanism is not yet well understood. Fracture mechanics have been applied in pavement analysis to investigate crack development. A single-edge notched beam test was simulated with the finite element method with the cohesive zone model, which has been widely used to simulate a cohesive crack. The effects of steel reinforcement, interface, and hot-mix asphalt (HMA) properties on crack initiation time and crack propagation rate were investigated. A damage value, an indication of the degradation of the initial stiffness of the material in cohesive elements, was used to define the degree of softening and to trace crack formation. On the basis of elastic analysis, the crack initiation time for the rei...
Intracavitary therapeutic options in the management of cystic craniopharyngioma

Craniopharyngioma remains an entity of controversial management due to its critical anatomical relationships and its well-known recurrence tendency. Total resection, although desirable, is not always accomplished, and it is associated with potentially permanent endocrinological and visual deficits. Consequently, this situation has led to the development of new management strategies seeking lesser morbidity. Because a high percentage of these lesions are cystic, bleomycin and radioactive-emitting sources have been postulated as new therapeutic options with promising results. The information known to date regarding these substances is summarized and we perform a retrospective review of the clinical trials conducted over the past 30 years with special emphasis on outcome, morbidity, and mortality. Two cases from our institution are presented as examples of multimodality management. Overall, these newer options stand out as valid alternatives in the controversial management of these challenging tumors.
Instantons and wormholes for the universal hypermultiplet

Abstract In this paper we present supersymmetric instanton and non-supersymmetric wormhole solutions for the universal hypermultiplet sector of d = 4 N = 2 supergravity theories. Instantons and wormholes are constructed as saddle points dominating transition amplitudes between states of definite axionic shift charge, using an approach due to Coleman and Lee. Our solutions are constructed in terms of the conserved Noether charges associated with the global SU ( 2 , 1 ) symmetry of the universal hypermultiplet action. The conditions imposed by regularity on the charges are discussed.
3D multispecies nonlinear perturbative particle simulations of collective processes in intense particle beams for heavy ion fusion

Abstract Collective processes in intense charged particle beams for heavy ion fusion are studied using a 3D multispecies nonlinear perturbative particle simulation method, which solves self-consistently the nonlinear Vlasov–Maxwell equations. The newly-developed Beam Equilibrium Stability and Transport code is used to simulate the nonlinear stability properties of intense beam propagation, surface and body eigenmodes in a high-intensity beam, and the electron-ion two-stream instability, which occurs when a small population of (unwanted) electrons is present in the system.
Development of an introductory course on the modeling and control of Advanced Electric Vehicles

In January of 2010 the University of Detroit Mercy began offering a Graduate Certificate in Advanced Electric Vehicles. This program was intended as a means to quickly and effectively educate practicing engineers in the skills that they would need as the number of electric and hybrid-electric vehicles being produced increases. The program was initiated with the support of Ford Motor Company who has committed to sending at least 125 engineers through the program in its first five years of existence. A central element of this program is a course on the modeling and control of advanced electric vehicles. This paper describes the structure and content of this course, as well as the lessons learned and what they mean for the introductory system dynamics and control curriculum in general.
Comparison of stoop versus prone postures for a simulated agricultural harvesting task.

Abstract Physical and psychophysical differences between working in the stooped and prone postures were compared while performing a simulated agricultural harvesting task for 30 min. Fifteen male subjects participated. The measures used to compare the two postures included perceived discomfort, electromyography (EMG), and heart rate (HR). Average hamstrings localized discomfort (0–10 scale) was 6.17 (SD=2.9) for the stoop posture and 0.67 (SD=1.29) for the prone posture. Erector spinae and hamstring EMG RMS increased 68% and 18%, respectively, while mean power frequency for the hamstrings decreased 13% for the stoop task. Mean power frequency for the middle trapezius muscle decreased in both postures (stoop 4.13%, prone 3.79%). Average heart rate during the last work cycle was 35% greater than the resting heart rate for the stoop posture while average heart rate was 17% greater for the prone posture. Subjects worked on the prone workstation without rest during the 15 min work simulations with less discomfort, no localized fatigue in the back or leg muscles tested, and lower working heart rates than subjects working in the stoop posture.
Magnetic Circular Dichroism Studies XXIII [1] Magnetic Circular Dichroism Spectra of Indole Alkaloids

The magnetic circular dichroism spectra of a number of indole alkaloids show two B-terms of opposite sign in the 250–330 nm wavelength region associated with the 1Lb and 1La electronic transitions, the long wavelength, 1Lb, band being of positive sign, whereas both bands strongly overlap in absorption. Various substituents in different positions of the indole ring cause a red shift of both bands and a broadening of the long wavelength B-term. The sign pattern, howver, remains unchanged in all examples thus far investigated. Dihydroindole and oxindole, on the other hand, exhibit MCD. bands with the opposite sign sequence as compared to the indole chromophore. This observation allows identification of the indole chromophore in alkaloids from the sign pattern of the MCD. bands.
Boric acid poisoning

The autopsy findings in 3 fatal cases of boric acid poisoning are described in detail. The demonstration of intracytoplasmic inclusion bodies in the acinar cells of the pancreas is considered to have diagnostic significance. The literature on boric acid poisoning is reviewed, and the data relative to 83 fatal and 89 nonfatal cases are tabulated. In addition, various aspects of the subject, such as minimal lethal doses, blood and tissue concentrations, procedures for toxicologic analyses, and modes of absorption and elimination of the drug, are discussed.
Photoreceptor degeneration and retinal inflammation induced by very low-density lipoprotein receptor deficiency☆

Our previous studies have shown that very low-density lipoprotein receptor (VLDLR) is a negative regulator of the Wnt pathway. The present study showed that VLDLR gene knockout (Vldlr(-/-)) mice displayed impaired cone ERG responses at early ages. Immunostaining of mid-wavelength cones showed significantly decreased cone densities in the retina and shortened cone outer segments in Vldlr(-/-) mice. At older ages, Vldlr(-/-) mice displayed declined rod ERG responses, decreased layers of photoreceptor nuclei, reduced rhodopsin levels and decreased levels of 11-cis retinal, the chromophore of visual pigments. As shown by fluorescein angiography and permeability assay, Vldlr(-/-) mice had severe retinal vascular leakage. ZO-1, a tight junction protein, was down-regulated in Vldlr(-/-) mouse retinae, further supporting the impaired blood-retinal barrier. Double staining of pericytes and endothelial cells in retinal sections revealed that neovasculature in Vldlr(-/-) mice lacks pericyte coverage, suggesting impaired maturation of retinal vasculature in Vldlr(-/-) mice. Staining of adherent leukocytes in the retinal vasculature revealed significant leukostasis in Vldlr(-/-) mice. Moreover, Vldlr(-/-) mice displayed up-regulated expression of multiple pro-inflammatory factors and activated NF-kappaB and HIF-1 alpha, key regulators of inflammation. These findings suggest that deficiency of VLDLR leads to retinal degeneration and inflammation.
High yield of 12C(d,n)13N and 14N(d,n)15O reactions in the plasma focus pinch

Abstract Our experiments have established that 12C(d,n)13N and 14N(d,n)15O reaction yields inside 12C+D and 14N+D plasmas of focused discharges are ≈1% of the simultaneous D-D fusion yield for 10% of 12C and/or 14N atoms doped into D2 gas. The data set a low limit, at n > 1021 cm−3, for the density of high-reactivity plasma domains, which are identifiable with localized “hot spots” of earlier experiments.
Image detection under low-level illumination

Image detection under low-light-level conditions is treated as a hypothesis-testing problem in which the observations are modeled as a shot-noise process. Since computing the likelihood ratio for shot-noise processes is not feasible, the use of a one-dimensional test statistic obtained by filtering and sampling the observations is proposed. The filter is chosen to maximize a generalized signal-to-noise ratio. The likelihood ratio for the one-dimensional test statistic is evaluated numerically by inverting the corresponding characteristic function under each hypothesis. >
Freezing Controlled by Natural Convection

Experiments were performed for freezing under conditions where the liquid phase is either above or at the fusion temperature (i.e., superheated or nonsuperheated liquid). The liquid was housed in a cylindrical containment vessel whose surface was maintained at a uniform, time-invariant temperature during a data run, and the freezing occurred on a cooled vertical tube positioned along the axis of the vessel. The phase change medium was n-eicosane, a paraffin which freezes at about 36/sup 0/C (97/sup 0/F). In the presence of liquid superheating, the freezing process is drastically slowed and ultimately terminated by the natural convection in the liquid. The terminal size of the frozen layer an the time at which freezing terminates can be controlled by setting the temperature parameters which govern the intensity of the natural convection. The stronger the natural convection, the thinner the frozen layer an the shorter the freezing time. In the absence of liquid superheating, a cylindrical frozen layer grows continuously as predicted by theory, but the growth rate is higher than the predictions because of the presence of whisker-like dendrites on the freezing surface.
Optimization Study of Solid‐State Electrochromic Devices Based on WO 3 / Lithium ‐ Polymer Electrolyte / V 2 O 5 Structures

Transmissive solid-state electrochromic devices based on the structure of WO[sub 3]/lithium-polymer electrolyte/V[sub 2]O[sub 5] were optimized for potential large-area window applications. The electrochromic layer thicknesses, polymer molecular weights, lithium-containing electrolytes, preassembly lithium-ion injection amounts, and transparent conductor substrates were systematically investigated for large optical modulation and fast response of the devices. The transmittance of the optimized device at 633 nm can be switched between 74 and 12% in 1 min. The coloring and bleaching voltages were [minus]1.8 and 1.2 V, respectively.
Covalent binding of benzene and its metabolites to DNA in rabbit bone marrow mitochondria in vitro

Abstract Rabbit bone marrow mitochondria, stripped of their outer membrane (mitoplasts), have been shown to carry out the NADPH-dependent bioactivation of radiolabelled benzene in vitro to metabolites capable of covalently binding to mtDNA, thereby inhibiting transcription. The metabolites of benzene produced in bone marrow cells by the microsomal cytochrome P-450 are thought to be phenol, catechol, hydroquinone and p-benzoquinone (Andrews et al., Life Sci., 25 (1979) 567; Irons et al., Chem.-Biol. Interact., 30 (1980) 241). Incubation of mitoplasts from rabbit bone marrow cells in vitro with varying concentrations of the putative microsomal metabolites showed a concentration-dependent inhibition of RNA synthesis. The 50% inhibitory molar concentration (IC50) for each metabolite was determined to be: 1,2,4-benzenetriol, 6.3 × 10−7; p-benzoquinone, 2 × 10−6; phenol, 2.5 × 10−5; hydroquinone, 5 × 10−5; catechol, 2 × 10−3; benzene, 1.6 × 10−2. DNA, isolated from rabbit bone marrow cell or rat liver mitoplasts prelabelled in DNA with [3H]dGTP and exposed to [14C]benzene in vitro, was enzymatically hydrolyzed to nucleosides which were chromatographed on a Sephadex LH-20 column to separate free nucleosides from nucleoside-adducts. The elution profiles indicated that rat liver mtDNA contained six guanine nucleoside-adducts and rabbit bone marrow cell mtDNA contained seven guanine nucleoside-adducts. Incubation of bone marrow mitoplasts in vitro in the presence of benzene and the hydroxyl radical scavenger, mannitol, resulted in the inhibition of formation of four of the guanosine-adducts. When [3H]dATP was substituted as the prelabelled precursor nucleotide, the LH-20 column profile indicated that two adenine nucleoside-adducts were also formed from benzene in vitro. Furthermore, a comparison of the Sephadex LH-20 column profiles of purine adducts derived from [14C]benzene- and [3H]dGMP-labelled mtDNA with profiles generated by individually incubating each of the putative unlabelled metabolites with bone marrow mitoplasts in vitro has indicated that p-benzoquinone, phenol, hydroquinone and 1,2,4-benzenetriol form adducts with guanine. One of the two adenosine-adducts may arise from hydroquinone; the compound forming the other adduct is unknown at the present time. Exposure of mitoplasts to catechol in vitro resulted in the formation of a guanine nucleoside-adduct that was present in rat liver mtDNA but absent from the DNA isolated from rabbit bone marrow cell mitoplasts exposed to [14C]benzene in vitro. This suggests that catechol is probably not a major metabolite of benzene formed in bone marrow cell mitochondria.
Oxygen-isotope record of sea level and climate variations in the Sulu Sea over the past 150,000 years

THE Sulu Sea is located in the 'warm pool' of the western Pacific Ocean, where mean annual temperatures are the highest of anywhere on Earth. Because this large heat source supplies the atmosphere with a significant portion of its water vapour and latent heat, understanding the climate history of the region is important for reconstructing global palaeoclimate and for predicting future climate change. Changes in the oxygen isotope composition of planktonic foraminifera from Sulu Sea sediments have previously been shown to reflect changes in the planetary ice volume at glacial–interglacial and millenial timeseales, and such records have been obtained for the late Pleistocene epoch and the last deglaciation1–3. Here I present results that extend the millenial time resolution record back to 150,000 years before present. On timescales of around 10,000 years, the Sulu Sea oxygen-isotope record matches changes in sea level deduced from coral terraces on the Huon peninsula4. This is particularly the case during isotope stage 3 (an interglacial period 23,000 to 58,000 years ago) where the Sulu Sea oxygen-isotope record deviates from the SPECMAP deep-ocean oxygen-isotope record5. Thus these results support the idea4,6 that there were higher sea levels and less continental ice during stage 3 than the SPECMAP record implies and that sea level during this interglacial was just 40–50 metres below present levels. The subsequent rate of increase in continental ice volume during the return to full glacial conditions was correspondingly faster than previously thought.
PROFUSE BLEEDING FROM DIVERTICULAR DISEASE OF THE COLON.

Massive bleeding may be caused by either diverticular disease or neoplasia of the colon, but it is more likely to be due to the former, particularly when there is no bleeding after control of the initial episode. When bleeding is of a lesser degree, and especially when it persists or recurs, it is more likely to come from neoplastic disease.
A theorem-proving language for experimentation

Because of the large number of strategies and inference rules presently under consideration in automated theorem proving, there is a need for developing a language especially oriented toward automated theorem proving. This paper discusses some of the features and instructions of this language. The use of this language permits easy extension of automated theorem-proving programs to include new strategies and/or new inference rules. Such extendability will permit general experimentation with the various alternative systems.
Fatigue crack propagation in trip steels

The fatigue crack propagation behavior of a class of metastable austenitic steels called TRIP steels has been investigated. The alloy composition was chosen to have theMs well below room temperature and theMD above room temperature after thermomechanical processing. A simple theoretical model of fatigue crack propagation (FCP) based on fracture mechanics was developed. Fatigue crack propagation tests on SEN specimens at various stress intensity ranges (ΔK) were carried out, and two stage plastic-carbon replica were used to observe the fracture surface of the FCP specimens. To a first approximation, both the experimental and theoretical results followed the usual relationship between ΔK and FCP rates;i.e. da/dn ∝ (ΔK).4 The fatigue fracture surface contained fatigue striations, quasicleavage and elongated dimples; a reflection of the complex structure of TRIP steels. A beneficial effect of strain induced martensite transformation with regards to fatigue crack propagation was found. TRIP steels showed better FCP properties than a number of alloy steels of similar strength levels and compared favorably with mar aging steels in the low ΔK range.
Activity‐dependent regulation of calcium‐binding proteins in the developing rat olfactory bulb

Intracellular calcium, important in a variety of second messenger cascades, is regulated in part by calcium-binding proteins such as calretinin, parvalbumin, and calbindin. These proteins are highly concentrated in the rat main olfactory bulb and are localized in distinct neuronal populations. In the present study, postnatal expression was characterized immunohistochemically in normal rats and in rats with functional olfactory deprivation caused by unilateral naris closure, a manipulation that attenuates electrical activity in the bulb. Bulbs were examined from rats that had undergone naris closure or sham surgery on either postnatal day 1 (P1) or P30 and were allowed varying subsequent survival times. Each of the calcium-binding proteins showed both distinct patterns of early expression and differential susceptibility to olfactory restriction. For example, at P10, the densest immunoreactivity was observed for calretinin, a protein whose expression was the least affected by naris closure. After occlusion from P1-P30, there was a 30% reduction in the density of calbindin-immunoreactive profiles in the glomerular layer, and parvalbumin-immunoreactive profiles were reduced by 64% in the external plexiform layer. Unlike many other changes induced by deprivation, the effects of olfactory restriction on calbindin and parvalbumin expression were not age dependent: naris closure from P30–P60 caused similar substantial decreases in calbindin and parvalbumin immunoreactivities. These data demonstrate that the expression of calbindin and parvalbumin in rat bulb is regulated, in part, by afferent activity that is associated with full sensory experiences. The reductions of these calcium-binding proteins following olfactory deprivation are likely to be commensurate with altered control of intracellular calcium. J. Comp. Neurol. 387:12–26, 1997. © 1997 Wiley-Liss, Inc.
Wet-Drum Magnetic Separation of Dense-Medium Slurries Containing Fine Coal Refuse

ABSTRACT Laboratory testing was carried out to evaluate the performance of a wet-drum magnetic separator (WDMS) when treating magnetite dense-medium slurries containing fine bituminous coal refuse material. Test variables included slurry feed rate, magnetite-to-coal ratio, and size distribution of the coal refuse. The separations were carried out with and without the application of ultrasonic energy. The performance of the WDMS was evaluated based on the purity of the magnetic concentrate and recovery of magnetic material. As expected, the purity of the products depended on the operating conditions, whereas magnetic recovery was essentially independent of operating conditions. Moreover, under many conditions, the purity of the magnetic material increased slightly after ultrasonic treatment. For selected tests, the size distributions of the magnetic material were determined for both the magnetic concentrate and nonmagnetic streams. This analysis indicated that after demagnetization, the size distributions ...
Cell size in Russet Burbank potato tubers with various levels of nitrogen and soil moisture tensions

Russet Burbank potatoes were grown at levels of added nitrogen of 0, 135, and 270 kg/ha and soil moisture tensions (SMT) of 0.5 and 1.0 atm. With all combinations, there was a consistent gradient of larger to smaller starch-storage parenchyma cells from stem end to bud end of mature tubers.
Recent improvements in dental materialsthat the operative dentist should know

In evaluating dental materials research, the author cites the introduction of a composite epoxide resin with qualities both superior and inferior to the conventional acrylic resin . The protective and strengthening functions of the cement base ore defined. Also indicated are the variables determining the success or failure of silicate cement. Present and future research is being directed at the amalgam restoration—the failure of some and the development of spherical alloys.
Addiction Severity Index Scores and Urine Drug Screens at Baseline as Predictors of Graduation From Drug Court

Graduation rates from drug courts are impressive and are often attributed to the delivered treatments. However, it is unclear whether graduation rates are bolstered by low severity of drug use problems upon entry into drug court. To address this question, this study examined the relationship between baseline substance use severity and graduation rates among 251 drug court clients. Results revealed that participants with subthreshold drug composite scores on the Addiction Severity Index (ASI) were significantly more likely to graduate than those scoring in the mild-to-moderate or severe range. Furthermore, results revealed that participants who provided a drug-negative baseline urine were significantly more likely to graduate than those who provided a drug-positive baseline urine. A binary logistic regression analysis revealed that ASI drug composite score, urine screen, race, and years educated were statistically significant predictors of drug court graduation.
Association between DNA methylation and shortened survival in patients with advanced colorectal cancer treated with 5-fluorouracil based chemotherapy.

Purpose: There are no good genomic markers of survival in patients with advanced colorectal cancer. The CpG island methylator phenotype (CIMP) marks a distinctive pathway in colorectal cancer. We sought to determine the prognostic significance of CIMP in advanced colorectal cancer patients treated with 5-fluorouracil (5-FU) in an Eastern Cooperative Oncology Group clinical trial. Experimental Design: We studied 188 patients enrolled on protocol E2290, a five-arm trial comparing 5-FU, 5-FU in combination with N -phosphonoacetyl-l-aspartic acid, oral leucovorin, i.v. leucovorin, or IFNα-2a in patients with advanced colorectal cancer. Methylation of MINT1, MINT31, hMLH1, p14 ARF , and p16 INK4a in DNA extracted from formalin-fixed paraffin-embedded specimens was evaluated by combined bisulfite restriction analysis, and methylation of MINT2 was studied by methylation-specific PCR. Results: Methylation frequencies were 21% for MINT1 , 23% for MINT2 , 24% for MINT31 , 4% for hMLH1 , 11% for p14 ARF , and 17% for p16 INK4a . Methylation of MINT1, MINT31, p14 ARF , and p16 INK4a were correlated, as expected. There was no association between methylation and clinicopathologic factors or response to therapy. Methylation of MINT1, MINT31, p14 ARF , or p16 INK4a was associated individually with shortened overall survival. Hazard ratios were 1.51 ( P = 0.05) for MINT1 , 1.70 ( P = 0.006) for MINT31 , 2.22 ( P = 0.001) for p14 ARF , and 1.51 ( P = 0.05) for p16 INK4a . Concurrent methylation of two or more genes of the CIMP-associated subset ( MINT1, MINT31, p14 ARF and p16 INK4a ) defined a group of cases with markedly reduced overall survival and hazard ratio was 3.22 ( P Conclusions: CIMP is associated with poor survival in advanced colorectal cancer patients.
An output feedback precompensator for nonlinear DAE systems with control-dependent state-space

This note considers singular systems of nonlinear differential and algebraic equations (DAEs) whose constrained state space depends on the control inputs. A state-space realization of such systems cannot be derived independently of the controller design. An output feedback precompensator is derived, which results in a modified DAE system whose state-space is invariant under any feedback control law and can be used for output feedback controller synthesis. Its application is illustrated by a nonlinear electrical circuit example.
Dependability metrics to assess safety-critical systems

Metrics are commonly used in engineering as measures of the performance of a system for a given attribute. For instance, in the assessment of fault tolerant systems, metrics such as the reliability, R(t) and the Mean Time To Failure (MTTF) are well-accepted as a means to quantify the fault tolerant attributes of a system with an associated failure rate, /spl lambda/. Unfortunately, there does not seem to be a consensus on comparable metrics to use in the assessment of safety-critical systems. The objective of this paper is to develop two metrics that can be used in the assessment of safety-critical systems, the steady-state safety, S/sub ss/, and the Mean Time To Unsafe Failure (MTTUF). S/sub ss/ represents the evaluation of the safety as a function of time, in the limiting case as time approaches infinity. The MTTUF represents the average or mean time that a system will operate safely before a failure that produces an unsafe system state. A 3-state Markov model is used to model a safety-critical system with the transition rates computed as a function of the system coverage C/sub sys/, and the hazard rate /spl lambda/(t). Also, /spl lambda/(t) is defined by the Weibull distribution, primarily because it allows one to easily represent the scenarios where the failure rate is increasing, decreasing, and constant. The results of the paper demonstrate that conservative estimates for lower bounds for both S/sub ss/ & the MTTUF result when C/sub sys/ is assumed to be a constant regardless of the behavior of /spl lambda/(t). The derived results are then used to evaluate three example systems.