cssi/SciSciGPT-SciSciNet huggingface dataset:
Nucleation and growth of cobalt films on NaCl. III. The effect of substrate temperature

The substrate temperature influences the initial crystal structure of nuclei and determines the thermal energy available for coalescence and recrystallization during film growth, which in turn determines the crystal structure, orientation, and grain size of the final film. Accordingly a substrate temperature of 20 °C favors the growth of polycrystalline h.c.p. films with a small average grain size; and high substrate temperatures (350 and 425 °C) favor the formation and growth of predominantly f.c.c films with either a large average grain size or a single crystal epitaxial overgrowth. A transition between the low- and high-temperature growth behavior is found to occur at a substrate temperature of 200 °C. In this case polycrystalline films of intermediate grain size and with equal numbers of h.c.p. and f.c.c. grains are formed. Die Substrattemperatur beeinflust die anfangliche Kristallstruktur der Keime und bestimmt die thermische Energie, die fur die Koaleszenz und Rekristallisation wahrend des Schichtwachwstums verfugbar ist. Diese bestimmen wiederum Kristallstruktur, Orientierung und Korngrose der endgultigen Schicht. So fordert eine Substrattemperatur von 20 °C das Wachstum von polykristallinen, hexagonal dichtgepackten Schichten mit einer kleinen mittleren Korngrose, und hohe Substrattemperturen (350 und 425 °C) fordern die Bildung und das Wachstum von vorherrschend kubisch flachenzentrierten Schichten mit entweder groser mittlerer Korngrose oder epitaxialem, einkristllinem Wachstum. Es wird ein Ubergang zwischen dem Niedertemperatur- und dem Hochtemperaturwachstumsverhalten bei einer Subsrattemperatur von 200 °C gefunden. In diesem Fall werden polykristalline Schichten mittlerer Korngrose und gleicher Anzahl von hexagonal dichtgepackten und kubisch flachenzentrierten Kornern gebildet.
Deuterium isotope analysis of methanol oxidation on mixed metal anode catalysts

The widely accepted mechanism for methanol oxidation on Pt based catalyst surfaces has held that the rate determining step is activation of water, and/or oxidation of surface-bound CO to CO2. In fact on pure Pt, water activation is always rate limiting at potentials negative of 0.6 V. Anode potentials greater than 0.4 V are outside the useful potential window of direct methanol fuel cells when using Nafion 117 at 60 °C. Enhancement of the water activation kinetics on Pt has been effected by the use of oxophilic transition metal promoters including Ru, W and Sn. For decades the search for improved methanol oxidation electrocatalysts has focused on water activation. A systematic deuterium isotope study on Pt black and two active mixed metal catalysts (PtRu and PtRuOsIr) shows that for each catalyst there is a characteristic transition potential above which the primary reaction in the rate-determining step changes from water activation to CH bond activation. On the mixed metal catalysts, this crossover potential is ca. 0.35 V, which is within the direct methanol fuel cell potential window (0–0.400 V). This study confirms that on these active catalysts there is a potential above which further improvements in water activation must be concomitant with acceleration of CH bond activation. Thus the catalyst search strategy involving Pt promoter metals must also consider the kinetic importance of CH bond activation.
The experimental verification of Handel's expressions for the hooge parameter

Abstract While Handel's theories of quantum 1/ f noise are still severely criticized, at present and his proposed expressions for α H seem to agree with experiments, it is proposed that these expressions can be treated as heuristic equations that describe the experiments. It is shown how one can discriminate between the various collision processes and how one can discriminate against trapping 1/ f noise.
NASA's flight-technology development program: a 650-Mbit/s laser communications testbed

ABSTRACTNASA-Goddard Space Flight Center (GSFC) is designing and building a 650 Mbps laser communications testbedfor the development of ifight qualifiable hardware suitable for near-term operation on geosynchronous-to-geosynchronous ( GEO-GEO)crosslink missions. The primary purpose for the program is to develop and optimize laser communications unique subsystems. The design incorporates technologies that have previously been developed at GSFC, such as the quaternary pulse position modulation (QPPM) receiver, the GaAIAs diode laser beam combiner, and the integrated low- power digital gimbal controller. Requirements for the testbed experiments are to optimize the acquisition processes; to fully simulate the long range (up to 21,000 km) and the fine tracking characteristics of two narrow-beam laser communications terminals; and to fully test communications performance which will include average and burst bit errorrates (BERs), effects of laser diode co-alignment, degradation due to internal and external stray light, and the impactof drifts in the optical components. Transmit-to-receive alignment techniques will also be tested and optimized. Tradestudies and analyses have been performed to optimize the aperture, laser power, pointing requirements, modulation,
Copper−Doxorubicin as a Nanoparticle Cargo Retains Efficacy with Minimal Toxicity

Repeated administration of chemotherapeutics is typically required for the effective treatment of highly aggressive tumors and often results in systemic toxicity. We have created a copper-doxorubicin complex within the core of liposomes and applied the resulting particle in multidose therapy. Copper and doxorubicin concentrations in the blood pool were similar at 24 h (∼40% of the injected dose), indicating stable circulation of the complex. Highly quenched doxorubicin fluorescence remained in the blood pool over tens of hours, with fluorescence increasing only with the combination of liposome disruption and copper trans-chelation. At 48 h after injection, doxorubicin fluorescence within the heart and skin was one-fifth and one-half, respectively, of fluorescence observed with ammonium sulfate-loaded doxorubicin liposomes. After 28 days of twice per week doxorubicin administration of 6 mg/kg, systemic toxicity (cardiac hypertrophy and weight and hair loss) was not detected with the copper-doxorubicin liposomes but was substantial with ammonium sulfate-loaded doxorubicin liposomes. We then incorporated two strategies designed to enhance efficacy, mTOR inhibition (rapamycin) to slow proliferation and therapeutic ultrasound to enhance accumulation and local diffusion. Tumor accumulation was ∼10% ID/g and was enhanced approximately 2-fold with the addition of therapeutic ultrasound. After the 28-day course of therapy, syngeneic tumors regressed to a premalignant phenotype of ∼(1 mm)(3) or could not be detected.
Supply-side approaches to the economic valuation of coastal and marine habitat in the Red Sea

Abstract The degradation of natural fish habitat in the ocean implies lost economic benefits. These value losses often are not measured or anticipated fully, and therefore they are mainly ignored in decisions to develop the coast for industrial or residential purposes. In such circumstances, the ocean habitat and its associated ecosystem are treated as if they are worthless. Measures of actual or potential economic values generated by fisheries in commercial markets can be used to assess a conservative (lower-bound) value of ocean habitat. With this information, one can begin to compare the values of coastal developments to the values of foregone ocean habitat in order to help understand whether development would be justified economically. In this paper, we focus on the economic value associated with the harvesting of commercial fish stocks as a relevant case for the Saudi Arabian portion of the Red Sea. We describe first the conceptual basis behind supply-side approaches to economic valuation. Next we review the literature on the use of these methods for valuing ocean habitat. We provide an example based on recent research assessing the bioeconomic status of the traditional fisheries of the Red Sea in the Kingdom of Saudi Arabia (KSA). We estimate the economic value of ecosystem services provided by the KSA Red Sea coral reefs, finding that annual per-unit values supporting the traditional fisheries only are on the order of $7000/km 2 . Finally, we develop some recommendations for refining future applications of these methods to the Red Sea environment and for further research.
Hexamer to Monomer Equilibrium of E. coli Hfq in Solution and Its Impact on RNA Annealing

The bacterial Sm-like protein Hfq forms a ring-shaped homo-hexamer that is necessary for Hfq to bind nucleic acids and to act in small noncoding RNA regulation. Using semi-native gels and fluorescence anisotropy, we show that Hfq undergoes a cooperative conformational change from monomer to hexamer around 1 μM protein, which is comparable to the in vivo concentration of Hfq and above the dissociation constant of the Hfq hexamer from many RNA substrates. Above 2 μM protein, Hfq hexamers associate in high-molecular-weight complexes. Mutations that impair RNA binding to the proximal face strongly destabilize the hexamer, while the mutation R16A near the outer rim prevents hexamer association. Stopped-flow fluorescence resonance energy transfer experiments showed that Hfq subunits interact within a few seconds, suggesting that Hfq monomers, hexamers and multi-hexamer complexes are in dynamic equilibrium. Finally, we show that Hfq is most active in RNA annealing when the hexamer is present. These results suggest that RNA binding is coupled to hexamer assembly and that the biochemical activity of Hfq reflects the equilibrium between different quaternary structures.
The effect of ionic strength on a Mg2+-ATPase and its relevance to the determination of (Na++K+)-ATPase

Abstract A ouabain-insensitive Mg 2+ -ATPase present in a microsomal fraction prepared from the dog submandibular gland was studied. This Mg 2+ -ATPase was inhibited by increasing concentrations of NaCl, KCl, RbCl and CsCl. The addition of an osmotically equal amount of sucrose was without effect. This inhibition was obtained over a pH range of from 6.3 to 8.8. The Mg 2+ -ATPase present in microsomes treated with NaI showed a similar inhibition. These results indicate that it is advisable to keep the ionic strength constant in solutions used to obtain (Na + +K + )-ATPase activities.
A mathematical theory of age structure in sexual populations: random mating and monogamous marriage models

Abstract Equations governing the size and age structure of a large population composed of two sexes are developed. It is assumed that the “significant” environment of the population —that which governs its mortality, nuptiality, and natality patterns and rates— remains constant. Two different social arrangements respecting reproduction are considered. It is assumed first that reproduction is by random mating; it is then assumed that reproduction is via strict monogamous marriage. The equations describing these two cases are coupled and nonlinear. In the case of the random mating model, the problem can be reduced to a single nonlinear integral equation. In the case of the monogamous marriage model, a system of partial differential-integral equations results. Applications of these equations to a population in stable growth and in transient growth are discussed.
Survey of Pest Infestation, Asthma, and Allergy in Low-income Housing

Low-income housing often has multiple indoor health risks. Among them, pest infestation, pesticide use, and pest allergens are recognized as common risks which affect residents’ health. Cockroach and rodent allergens are associated with morbidity and mortality of asthmatics. To characterize the levels of pest infestation, residents’ attitudes toward pest control, and the relationships among cockroaches, mice, cockroach allergen level, asthma and allergy rate in public housing, we interviewed residents from 358 randomly selected apartments in Gary, Indiana and assessed the environmental conditions. Dust samples were collected from 101 apartment kitchen floors to analyze for cockroach allergen (Bla g 1 and Bla g 2) levels. Eighty one percent of the apartments were found infested by cockroaches, mice, ants, spiders, or flies. In the 101 apartments evaluated, 98% of the kitchen dust samples had detectable levels of Bla g 1 allergen (≥0.4 U/g), 52% had ≥2 U/g, and 33% had ≥8 U/g of Bla g 1. Among the 1,173 residents, 13% and 9% had physician-diagnosed asthma and allergy, respectively. Existence of diagnosed asthmatic was positively correlated with mouse infestations.
Mixed convection above a heated horizontal surface

Abstract Buoyancy effects are determined analytically for the laminar boundary-layer region above an isothermally heated, semi-infinite horizontal surface located in a horizontal uniform stream. The flow conditions are determined under which the boundary layer consists of a forced-flow-dominated near region and a buoyancy-dominated far region connected by an intermediate region in which forced and natural convection are of comparable magnitude. Perturbation expansions are obtained for the near and far regions with results for the intermediate region being obtained by graphical interpolation. Although it is well-known that, at fixed Reynolds and Grashof number, the effect of buoyancy decreases monotonically as the Prandtl number increases, it is found for the present problem that, for fixed U∞ and ΔT, the effect of natural convection in gases is not only more important than in large-σ oils but also than in small-σ liquid metals; this is attributable to the relatively small kinematic viscosity and coefficient of thermal expansion of liquid metals. In any case, if ΔT ≲ 20°C then U∞ must be quite small (≲ 20 cm/s) if buoyancy effects are to become significant before turbulent transition occurs. Presentation of the theoretical results in terms of G/R 5 2 versus σ leads to a clear demarcation of the forced-convection, mixed-convection and natural-convection heat-transfer regimes.
Interactions of spironolactone with hepatic microsomal drug-metabolizing enzyme systems

Abstract The nature of the stimulation of hepatic microsomal drug-metabolizing enzymes by spironolactone was studied in male mice. Mice given spironolactone (100 mg/kg, i.p.) twice daily for 3 consecutive days exhibited increased liver weight and mierosomal protein content. The administration of spironolactone also stimulated the microsomal metabolism of hexobarbital in vitro, the disappearance of hexobarbital from the whole body of mice in vivo and reduced hexobarbital sleeping time. Increases were noted in the microsomal N-demethylation of ethylmorphine, oxidation of hexobarbital and hydroxylation of aniline. Moreover, prior treatment with spironolactone increased the levels of several components of the microsomal electron transport system which included NADPH-oxidase, NADPH-cytochrome c reductase, cytochrome P-450 and NADPH-cytochrome P-450 reductase. In addition, the stimulatory effects of ethylmorphine or hexobarbital on the rate of cytochrome P-450 reduction by NADPH were greater in microsomes from spironolactone-treated animals. In other studies, it was found that the addition of spironolactone to liver microsomes (1) inhibited the N-demethylation of ethylmorphine and (2) blocked the stimulatory effect of ethylmorphine on the reduction of cytochrome P-450. The results indicate that spironolactone is an inducer of hepatic microsomal drug-metabolizing enzymes in male mice. A proposed mechanism for spironolactone's interaction with these enzyme systems is discussed.
Should aminoglycoside antibiotics be abandoned

Background: Aminoglycosides can cause nephrotoxicity and ototoxicity. Alternatives are available. Methods: Surgical service antibiotic use, aminoglycoside toxicity, and perioperative culture/sensitivity results from July 1998 to June 1999 were reviewed. Results: Of 289 positive cultures in 243 patients, 92 cultures (32%) grew 151 Gram-negative rods (GNRs). Aminoglycosides were used in 26 patients and 4 of 26 (15%) suffered nephrotoxicity. Of the 112 GNRs tested against ceftazidime, 111 (99%) were sensitive to it which was significantly better than amikacin (56 of 61, 92%, P = 0.038), gentamicin (116 of 134, 87%, P <0.001), and tobramycin (67 of 81, 83%, P <0.001). The proportion sensitive to cefuroxime (26 of 30, 87%) was equivalent to the proportions sensitive to gentamicin (87%, P = NS) and tobramycin (83%, P = NS). Of the 35 GNRs that were resistant to gentamicin and/or tobramycin, 15 (43%) were Pseudomonas aeruginosa. Conclusions: Aminoglycosides produce a significant rate of nephrotoxicity. There are antibiotics with equal or better sensitivity profiles than aminoglycosides against GNRs and Pseudomonas. Aminoglycoside use is rarely, if ever, indicated.
An efficient synthetic strategy for obtaining 4-methoxy carbon isotope labeled combretastatin A-4 phosphate and other Z-combretastatins.

Human cancer and other clinical trials under development employing combretastatin A-4 phosphate (1b, CA4P) should benefit from the availability of a [11C]-labeled derivative for positron emission tomography (PET). In order to obtain a suitable precursor for addition of a [11C]methyl group at the penultimate step, several new synthetic pathways to CA4P were evaluated. Geometrical isomerization (Z to E) proved to be a challenge, but it was overcome by development of a new CA4P synthesis suitable for 4-methoxy isotope labeling.
Modulation of insulin signal transduction by eutopic overexpression of the receptor-type protein-tyrosine phosphatase LAR.

Protein-tyrosine phosphatases (PTPases) regulate insulin signaling by catalyzing the tyrosine dephosphorylation of the insulin receptor and its substrate proteins. Previous studies have implicated a PTPase localized to a cell membrane fraction in the regulation of the insulin receptor in situ. LAR (leukoyte antigen related) is a transmembrane PTPase in insulin-sensitive tissues with in vitro catalytic specificity for the insulin receptor kinase domain. When transfected into Chinese hamster ovary cells overexpressing the human insulin receptor (CHO-hlR), the LAR protein was processed as expected into an 85-kDa subunit containing the transmembrane and cytoplasmic domains. LAR was increased an average of 6-fold in clonal lines of stably transfected cells, and cell fractionation confirmed its localization in the cell membrane. After stimulation with 100 nM insulin, tyrosine phosphorylation of the insulin receptor was decreased by 31% at 1 min (P < 0.01) and by 42% at 10 min (P < 0.01), and that of IRS-1 was d...
Diode laser-CO2 laser heterodyne spectrometer - Measurement of 2sQ/1,1/ in 2 nu 2-nu 2 of NH3

A carbon dioxide laser has been coupled with a tunable diode laser spectrometer for heterodyne calibration of molecular spectra. The output of the diode laser is measured to be 10–15 MHz wide and is stable to within ±2 MHz. The frequency of the 2sQ(1,1) transition in the 2ν2 − ν2 band of ammonia is measured to be 949.44746(24) cm−1.
SU-FF-T-359: MapPhan with MapCHECK and Im'RT MatriXX for Real Gantry Angle IMRT QA

Purpose: A study was performed using two commercially available 2D detector array systems for IMRT patient specific QA by resetting all beam angels to gantry angle at zero degree and leaving all beam angles as planned to investigate and verify the dose delivery accuracy, limitation of the devices in the QA procedures. Method and Materials:Calibration was established at 0 degree beam angle, with the beam normal to the array plane. This study utilized one complicated head and neck IMRT plan with 9 fields (18 spitted fields). The Varian Eclipse treatment planning system (TPS) with Anisotropic Analytical Algorithm and Varian 21Ex LINAC were used for this study. The 2D array systems tested were MapCHECK with MapPhan from Sun Nuclear Corporation, and Im'RT MatriXX from IBA. Two QA phantoms were constructed by (1) MapPhan with MapCHECK and (2) solid water with MatriXX. The summed dose measured was compared to calculated one using two phantoms. Results: At gantry zero degree, 99.7% pass rate for MapPhan with MapCHECK was achieved using 3% and 3 mm DTA criteria in absolute mode and 99.2% for MatriXX. At true planned angle, 93.4% pass rate for MapPhan with MapCHECK and 93.0% for MatriXX. Conclusions: Although all arrays performed reasonably well in the composite dose for real gantry angles, it may indicate the loss of QA information in the composite. Since with the beam normal to the detector plane of 2D array, all measurement points carry the same information weight. Whereas delivery angles between normal and parallel, measurement carries varying amounts of weight for each point samples or not sampled depending on field size and beam angles. The application of a 2D array to real gantry angle IMRT QA requires careful considerations.
Structure and Mechanism of the M2 Proton Channel of Influenza A Virus

The integral membrane protein M2 of influenza virus forms pH-gated proton channels in the viral lipid envelope. The low pH of an endosome activates the M2 channel before haemagglutinin-mediated fusion. Conductance of protons acidifies the viral interior and thereby facilitates dissociation of the matrix protein from the viral nucleoproteins--a required process for unpacking of the viral genome. In addition to its role in release of viral nucleoproteins, M2 in the trans-Golgi network (TGN) membrane prevents premature conformational rearrangement of newly synthesized haemagglutinin during transport to the cell surface by equilibrating the pH of the TGN with that of the host cell cytoplasm. Inhibiting the proton conductance of M2 using the anti-viral drug amantadine or rimantadine inhibits viral replication. Here we present the structure of the tetrameric M2 channel in complex with rimantadine, determined by NMR. In the closed state, four tightly packed transmembrane helices define a narrow channel, in which a 'tryptophan gate' is locked by intermolecular interactions with aspartic acid. A carboxy-terminal, amphipathic helix oriented nearly perpendicular to the transmembrane helix forms an inward-facing base. Lowering the pH destabilizes the transmembrane helical packing and unlocks the gate, admitting water to conduct protons, whereas the C-terminal base remains intact, preventing dissociation of the tetramer. Rimantadine binds at four equivalent sites near the gate on the lipid-facing side of the channel and stabilizes the closed conformation of the pore. Drug-resistance mutations are predicted to counter the effect of drug binding by either increasing the hydrophilicity of the pore or weakening helix-helix packing, thus facilitating channel opening.
Structure and equilibria in triorganolead halide adduct formation

Abstract The Lewis acidities of triorganolead halides have been studied by 31P and 207Pb NMR spectroscopy and by calorimetry. The formation of 1:1 adducts with a variety of mono- and bidentate bases was demonstrated by the linearity of the plots of chemical shift versus (shift/conc.) 1 2 . The 207Pb chemical shifts of the bidentate adducts indicated only 5-coordinate lead and hence the absence of chelation. Towards triphenyllead chloride basicities varied in the order triethylphosphine oxide > tributylphosphine oxide ⩾ triphenylphosphine oxide > DMSO > tributylphosphine ⩾ pyridine. Triphenyllead chloride was found to be a stronger acid (larger K) than both triphenyllead bromide and triethyllead chloride. The effects of solvent on the equilibrium constants paralleled the trend reported previously for organotin halides. The equilibrium constant for adduct formation with triphenylphosphine oxide (TPPO) is slightly larger for triphenyllead chloride relative to triphenyltin chloride, confirming the expected increase in acidities down Group 14. X-Ray diffraction studies of triphenylphosphine oxide adducts of triphenyllead bromide and triphenyltin chloride showed both structures to be trigonal bipyramidal with the phenyl groups on the equatorial positions. Additionally, the structures are crystallographically isomorphous.
Boundary layer methods for certain nonlinear singularly perturbed optimal control problems

Abstract We shall examine the control problem consisting of the system dx dt = f 1 (x, z, u, t, ϵ) ϵ( dz dt ) = f 2 (x, z, u, t, ϵ) on the interval 0 ⩽ t ⩽ 1 with the initial values x(0, ϵ) and z(0, ϵ) prescribed, where the cost functional J(ϵ) = π(x(1, ϵ), z(1, ϵ), ϵ) + ∝01 V(x(t, ϵ), z(t, ϵ), u(t, ϵ), t, ϵ) dt is to be minimized. We shall restrict attention to the special problem where the fi's are linear in z and u, V is quadratic in z and independent of z when ϵ = 0, π and V are positive semidefinite functions of x and z, and V is a positive definite function of u. Under appropriate conditions, we shall obtain an asymptotic solution of the problem valid as the small parameter ϵ tends to zero. The techniques of constructing such asymptotic expansions will be stressed.
ETS activity as an estimator of respiratory rate of zooplankton populations. The significance of variations in environmental factors

Abstract The sensitivity of the ETS activity for some methodological variations is described. High ETS activity in Acartia tonsa Dana after death indicates that detrital material may bias the estimation of community metabolism from measured ETS activity of unsorted samples. Results from studies on the effects of variations in light condition, environmental temperature and salinity, population density, feeding condition, time after capture, chemical stress, and diurnal dependence, upon ETS activity and respiratory rate indicate that ETS activity responds more slowly than the respiratory rate to environmental changes. It is suggested that A. tonsa attains equilibrium ETS-activity after 3–4 days in the changed environment. High respiratory rate and ETS activity immediately after capture are believed to reflect the natural level of metabolic activity. For field application it is, therefore, recommended to use animals that have not been kept in the laboratory for any length of time. The slow response of ETS activity upon short-term variations in environmental factors, i.e. variations associated with the sampling procedure, makes the method superior to direct respiratory measurements on incubated animals.
Expression of angiogenic factors Cyr61 and tissue factor in uveal melanoma.

Objective To study the expression of angiogenic factors Cyr61 and tissue factor(TF) in uveal melanoma and its correlation with blood vessel density. Methods Suppression subtractive hybridization was used to identify genes that are differentially expressed between cell lines of uveal melanoma and normal uveal melanocytes. Expression of these genes was subsequently verified in primary uveal melanomas and correlated with the number of blood vessels in archival specimens by immunohistochemical analysis. Results Cyr61 and TF are expressed at elevated levels in cell lines of uveal melanoma compared with normal uveal melanocytes. Duplication of a region of chromosome arm 1p, encompassing the genes encoding Cyr61 and TF, was observed in the melanoma cell line used in the initial subtractive hybridization. Both genes are also expressed in primary uveal melanomas, and a correlation was found between expression of TF and the number of blood vessels in archival specimens. Conclusions Cyr61 and TF may contribute to the angiogenic phenotype associated with uveal melanoma. A region of chromosome arm 1p also may contain oncogenes or tumor suppressor genes pertinent to the origins of this type of ocular tumor. Clinical Relevance New immunotherapies have been devised for the treatment of cancer based on the expression of TF. Similar approaches may be effective in treating uveal melanoma.
Control of constrained discrete time linear systems using quantized controls

Abstract The theory of control of continuous-time systems with control constraints is extended to the case where the controls are of the form u i = n i / s , where n i is an integer and s is a scaling factor. These results permit the analysis of the controllability of digital control systems with quantized controls. They also provide the theoretical framework for recently suggested real-time suboptimal controllers, based on the application of artificial intelligence techniques. Such an application is presented at the end of the paper.
Vacuum-assisted resin transfer molding using tackified fiber preforms

A low cost composite fabrication process—tackified SCRIMP—is described for fabricating aerospace-grade composites based on tackification and vacuum-assisted resin transfer molding (VARTM). Tackification based on a commercial tackifier (FT 500 from 3M) was used to make the net-shape fiber preform. It was found that tackifier concentration and application conditions play important roles in governing the moldability of tackified fiber preforms. An epoxy resin (PR 500 from 3M) was used in the VARTM process-SCRIMP at high temperatures. Experimental results show that composites with high fiber content (> 60% by volume) can be manufactured at low cost using tackification. Effects of tackification methods on composite dimension control, void content and mechanical properties were investigated and compared in both RTM and SCRIMP.
Hypothermic Ischemic Arrest versus Hypothermie Potassium Cardioplegia in Human Beings

Abstract To determine if the addition of potassium enhances the myocardial protective effect of intracoronary perfusion hypothermia during aortic cross-clamping, 50 patients undergoing aortocoronary bypass grafting were studied in a randomized, prospective, double-blind fashion. Twenty-six patients received a cold crystalloid solution infused with a handheld syringe into the root of the cross-clamped aorta every 20 minutes, and 24 patients received the same solution but with 25 mEq/L of potassium chloride added, infused in a similar manner. Both groups were analyzed by mortality, rate of perioperative myocardial infarction (electrocardiographic changes, MB-CPK enzyme release, and preoperative and postoperative gated cardiac blood pool scans), intraoperative hemodynamic changes, intraoperative lactate determinations, postoperative arrhythmias, and requirement for pressor or intraaortic balloon pump support. One patient in the potassium cardioplegia group died (massive pulmonary embolism), and none in the hypothermic perfusion group died. Possible perioperative myocardial infarction was diagnosed by more than one marker in 4 of 26 patients in the hypothermic perfusion group and 5 of 24 patients in the potassium group ( p = 0.61). There were no differences between the two groups in terms of hemodynamic changes, lactate production, postoperative arrhythmias, or the need for postoperative hemodynamic support. This study in human beings could not demonstrate a specific protective effect of potassium, beyond that afforded by myocardial perfusion hypothermia and wash-out. The data suggest that myocardial hypothermia, achieved through cold intracoronary arterial perfusion, may be the most important beneficial component of so-called cardioplegia for attaining effective intraoperative myocardial preservation in human beings.
c-Rel-Dependent Priming of Naive T Cells by Inflammatory Cytokines

The intrinsic refractoriness of naive T cells for cytokine production is counteracted by cells of the innate immune system. Upon sensing danger via Toll-like receptors, these cells upregulate T cell costimulatory molecules and secrete cytokines that enhance T cell activation. We show that cytokine-mediated priming of naive T cells requires the NF-kappaB family member c-Rel. In resting naive cells c-Rel is associated primarily with IkappaBbeta, an inhibitory molecule that is not effectively degraded by TCR signals. Exposure of T cells to proinflammatory cytokines, TNF-alpha and IL-1beta, shifts c-Rel to IkappaBalpha-associated complexes that are readily targeted by the TCR. As a consequence, IL-2 and IFN-gamma mRNA are produced more quickly, and at higher levels, in cytokine-primed T cells. This mechanism does not operate in effector T cells where cytokine gene expression is c-Rel-independent. We propose that c-Rel plays a crucial role as a target of innate signals in T cells.
F-18 FDG PET imaging of metastases from soft tissue myoepithelioma.

Myoepithelioma is an uncommon tumor composed of epithelioid cells and chondromyxoid elements. Its diagnosis is exclusively histopathologic with complex histochemical characteristics. This neoplasm usually exhibits a low level of aggressiveness and is well treated with adequate surgical resection. Rare is the setting of diffuse soft tissue metastasis from malignant degeneration as reported in the following case presentation. In this case, F-18 FDG PET provides a comprehensive evaluation and staging in the postoperative and postradiation course of this rare neoplasm.
Sporogony of the oocysts of Isospora felis Wenyon, 1923 from the cat.

SYNOPSIS Sporogony of oocysts of Isospora felis from the cat was studied by observing the individual oocysts. Unsporulated oocysts were passed with the fresh feces. The sporont divided into 2 ball-like sporoblasts which elongated and changed into sporocysts each of which 4 sporozoites then formed. All of the sporulating oocysts completed sporulation at 20 C in 40 hr, at 25 C in 24 hr, at 30 C in 12 hr, and at 38 C in 8 hr. The percentages of oocysts which sporulated at 20, 25, 30 and 38 C were 96, 95, 95 and 95 respectively. No sporulation occurred at 45 C and 50 C when oocysts were incubated for 4 hr. These oocysts evidently died because, on reincubation at 30 C for 4 hr, they failed to develop.
The Neuronal Channel NALCN Contributes Resting Sodium Permeability and Is Required for Normal Respiratory Rhythm

Sodium plays a key role in determining the basal excitability of the nervous systems through the resting "leak" Na(+) permeabilities, but the molecular identities of the TTX- and Cs(+)-resistant Na(+) leak conductance are totally unknown. Here we show that this conductance is formed by the protein NALCN, a substantially uncharacterized member of the sodium/calcium channel family. Unlike any of the other 20 family members, NALCN forms a voltage-independent, nonselective cation channel. NALCN mutant mice have a severely disrupted respiratory rhythm and die within 24 hours of birth. Brain stem-spinal cord recordings reveal reduced neuronal firing. The TTX- and Cs(+)-resistant background Na(+) leak current is absent in the mutant hippocampal neurons. The resting membrane potentials of the mutant neurons are relatively insensitive to changes in extracellular Na(+) concentration. Thus, NALCN, a nonselective cation channel, forms the background Na(+) leak conductance and controls neuronal excitability.
The Constitution of Employee‐Abusive Organizations: A Communication Flows Theory

Given the range of destruction wrought by persistent employee abuse, it is crucial to understand how employee-abusive organizations (EAOs) come into being and persist. It is also essential to look beyond individualistic “bad apple” explanations to understand the phenomenon’s complexity but, to date, little scholarship does so. Indeed, there is insufficient theorizing about the phenomenon. To address this issue, we theorize how EAOs come into being, persist, and change though a confluence of communication flows. This article takes as a starting point and builds upon a message-flows typology from which we create a new theory that explains how EAOs develop and change. The theory identifies abusive message types and underscores how organizing occurs in confluences or synergies among the communication flows in which specific messages occur. We present a case study that drives the theory and illustrates the dynamism among communication flows. The case also illustrates change and the impact of worker resistance.
Assessment of Progression and Treatment Response of Optic Pathway Glioma with Positron Emission Tomography using α-[11C]Methyl-l-Tryptophan

Purpose To report the utility of positron emission tomography (PET) with α-[11C]methyl-l-tryptophan (AMT) for monitoring progression and response to treatment of an isolated optic pathway glioma (OPG) in a 16-year-old girl.
Prior transaction price induced smoothing: testing and calibrating the Quan–Quigley model at the disaggregate level

The quantitative partial adjustment model is described as theoretically optimal and rational appraiser behavior. Early research at the aggregate (or index) level supported this model and suggested a range in the adjustment parameter. Subsequent disaggregate (or individual property) level studies of appraiser behavior have provided limited testing and assessment of this approach. Despite no statistical evidence of smoothing behaviors from non‐appraisers, the results from this experiment indicated that prior transaction price knowledge did induce partial adjustment behaviors by expert appraisers. The present findings are combined with past empirical and experimental research to identify general adjustment parameter characteristics and to provide guidance in calibrating the model.
Chopping effect observed at cathodic arc initiation

Chopping of current and induction of high-voltage spikes has been observed at the rising edge of cathodic vacuum arcs. It is argued that current chopping at the rising edge is similar to the current chopping effect that is well known for the arc current approaching current-zero. Current chopping can generate high-voltage spikes, and thus, cathodic arc equipment should be protected against voltage spikes that exceed the system's nominal voltage by an order of magnitude.
Social Justice, Health Inequalities and Methodological Individualism in US Health Promotion

This article asserts that traditionally dominant models of health promotion in the US are fairly characterized by methodological individualism. This schema produces a focus on the individual as the node of intervention. Such emphasis results in a number of scientific and ethical problems. I identify three principal ethical deficiencies: first, the health promotions used are generally ineffective, which violates canons of distributive justice because scarce health resources are expended on interventions that are unlikely to produce health benefits. Second, the health promotions used tend to expand health inequalities between the affluent and the least well-off. Third, the health promotions used are likely to intensify stigma against the least well-off, a deficiency that itself may exacerbate the ‘densely-woven patterns of disadvantage’ that characterize life on the tail of the social gradient. Because Powers and Faden’s health sufficiency model of social justice argues that the amelioration of such clusters of disadvantage should be the primary ethical goal of public health policy, methodologically individualist models of health promotion are ethically deficient and should not stand as primary approaches for health promotion in a just social order.
Teaching NeuroImages: Short stature, imperforate anus, and polydactyly: When is a hypothalamic mass an incidentaloma?

A 4-year-old girl with history of polydactyly and imperforate anus surgeries presented with short stature. Brain MRI revealed a large hypothalamic hamartoma (figure). Pallister-Hall syndrome (PHS) was diagnosed. Biopsy was not indicated given stable and typical tumoral appearance. Annual evaluations, hormonal replacement, and medical genetics consult were recommended. Compared to sporadic hypothalamic hamartoma, patients with PHS tend to be less symptomatic and have minimal tumor growth.1 The etiology is an autosomal dominant or de novo GLI3 gene mutation.2 Neurologists and neuroradiologists should be familiar with PHS characteristics, surveillance, and symptomatic therapy as neurosurgery is not usually recommended.
Resection of Noncolorectal Nonneuroendocrine Liver Metastases: A Comparative Analysis

Background Although established for metastatic colorectal (CR) and neuroendocrine (NE) malignancies, the role of partial hepatectomy in management of metastases from other primaries (NCRNE) is not well-defined. Study design The objective of this retrospective study is to compare outcomes after partial hepatectomy for NCRNE, NE, and CR metastases and to identify factors associated with longterm survival for patients with NCRNE diseases. Tumor characteristics, treatments, and outcomes of 360 consecutive patients undergoing resection of NCRNE (n = 82), CR (n = 245), and NE (n = 33) hepatic metastases from 1995 to 2005 were analyzed. NCRNE tumors included breast (n = 20), sarcomas (n = 19), genitourinary (n = 18), melanoma (n = 11), and other (n = 14) cancers. The start date for followup and survival analyses was the date of partial hepatectomy. Results For patients with NCRNE, CR, and NE tumors, there were no marked differences in postoperative mortality (4%, 4%, and 9%) or complication (30%, 42%, and 42%) rates. Median overall survival was longest for NE patients (not yet reached) versus NCRNE and CR (both 44 months) patients (p 6 months (p = 0.08) and administration of chemoradiotherapy after resection (p = 0.06) might be associated with improved overall survival. Conclusions In selected patients, resection of NCRNE liver metastases can be done safely with survival similar to CR metastases. Delay of liver resection for at least 6 months and treatment with chemoradiotherapy after resection might be associated with improved longterm survival after partial hepatectomy.
Protective effects of antioxidant-fortified diet on renal function and metabolic profile in obese Zucker rat

Oxidative stress contributes to the pathophysiology of type 2 diabetes mellitus and its complications, including nephropathy. The current study was designed to test the hypothesis that a diet fortified with antioxidants would be beneficial to delay or prevent the progression of this disease. Male and female Zucker fa/fa rats were fed a control or an antioxidant (AO)-fortified diet starting at 4 weeks of age. Metabolic parameters, renal function, and renal histopathology were analyzed at 6, 13, and 20 weeks of age. Females on the AO diet had significantly lower blood glucose at 6 and 13 weeks, less severe renal pathology at 20 weeks, and higher glomerular filtration rates (GFR) at 20 weeks than age-matched females on the regular diet (P < 0.05). Metabolic parameters including blood glucose, insulin resistance, and serum cholesterol, and mean arterial pressure (MAP), worsened with age in both males and females, as expected. GFR decreased and renal pathology also became more severe with age. Finally, females on the AO diet had higher GFRs and lower MAP at 20 weeks than males on the same diet. This may denote a protective effect of the AO diet in females, but not in males. These findings may have implications for the role of antioxidants as therapy in humans with T2DM.
Iron and copper transport in yeast and its relevance to human disease

Recent progress in the field of copper and iron metabolism has resulted from a convergence of human and yeast genetics. The mechanisms of iron and copper transport are remarkably conserved between yeast and humans. Studies of the yeast homologs of human disease genes involved in metal homeostasis have shed light on the pathophysiology of these disorders.
The Elimination of the Leakage Current Effect for LCD Backlight Module Based on the Primary-side Control and the DPLL Technique

A new control method is proposed to eliminate the leakage current effect for backlight module in the LCD housing. First, a class D resonant inverter is employed to assess the system performance. Next, the primary-side control incorporating the DPLL technique is embedded in the backlight system, as a feedback mechanism, to reduce the influence of parasitic capacitance and to track an optimal operating frequency so that the leakage current effect is removed and, hence, the system efficiency and stability is improved. Complete mathematical analysis and design considerations are detailed. Experimental results agree with the theoretical predictions, and the parasitic capacitance in backlight system can be estimated by the derived mathematical models.
The wet and the dry: Traditional irrigation in Bali and Morocco

The comparative perspective is of central importance to effective analysis in human ecology. The present paper compares “traditional” irrigation systems in two quite disparate settings: east central Morocco and southeastern Bali. Bali, which has a tropical climate and a plentiful water supply, displays a highly collective approach to the organization of irrigation facilities. Morocco, which is essentially an arid country, displays, on the contrary, a much more individual, property-based approach to water regulation. The internal organization of these two regimes is described and their connection with more general cultural and ecological factors is traced, in an attempt to demonstrate that patterns of adaptation are susceptible to the same pattern of analysis as other aspects of social and cultural life. The contrast between the strongly group-oriented Balinese approach to water control and distribution and the highly individualistic Moroccan one is said to extend in an overall way to the two societies as a whole.
Wireless signal propagation path loss estimation

In this work, the power of the wireless interference received by the victim communication system in the spectrum-sharing scenario between two wireless communication systems is investigated. The path loss models are detailed, and simulation results are given. The interference analysis is important for successive interference mitigation processing, which aims to eliminate wireless interferences from both bases stations and mobile handsets of interfering communication system to the victim communication system.
Direction-Adaptive Partitioned Block Transform for Color Image Coding

The direction-adaptive partitioned block transform (DA-PBT) is proposed to exploit the directional features in color images to improve coding performance. Depending on the directionality in an image block, the transform either selects one of the eight directional modes or falls back to the nondirectional mode equivalent to the conventional 2-D DCT. The selection of a directional mode determines the transform direction that provides directional basis functions, the block partitioning that spatially confines the high-frequency energy, the scanning order that arranges the transform coefficients into a 1-D sequence for efficient entropy coding, and the quantization matrix optimized for visual quality. The DA-PBT can be incorporated into image coding using a rate-distortion optimized framework for direction selection, and can therefore be viewed as a generalization of variable blocksize transforms with the inclusion of directional transforms and nonrectangular partitions. As a block transform, it can naturally be combined with block-based intra or inter prediction to exploit the directionality remaining in the residual. Experimental results show that the proposed DA-PBT outperforms the 2-D DCT by more than 2 dB for test images with directional features. It also greatly reduces the ringing and checkerboard artifacts typically observed around directional features in images. The DA-PBT also consistently outperforms a previously proposed directional DCT. When combined with directional prediction, gains are less than additive, as similar signal properties are exploited by the prediction and the transform. For hybrid video coding, significant gains are shown for intra coding, but not for encoding the residual after accurate motion-compensated prediction.