cssi/SciSciGPT-SciSciNet huggingface dataset:
Quantitative analysis of changes in amino acids levels for cucumber (Cucumis sativus) exposed to nano copper

Abstract The increasing usage of nanopesticides in agriculture poses a concern to plant crops due to unknown implications of engineered nanomaterials (ENMs). Targeted metabolomics can provide both qualitative and quantitative information at a molecular level to investigate the response of plants to emerging environmental stressors, such as nanopesticides. Here we describe a detailed protocol for the extraction and analysis of plant metabolites, specifically 23 amino acids in plants, using hydrophilic interaction liquid chromatography coupled to triple quadrupole mass spectrometry (HILIC-LC-MS/MS). Sufficient separation of 23 amino acids was achieved, without the need for derivatization, on an HILIC column with an MS/MS detector in a single run of 12 min with high sensitivity, selectivity and robustness and low LOD (0.005–15 ng/mL) and LOQ (0.02–50 ng/mL). A simple and efficient method to effectively extract amino acids from plant tissues was developed with a high recovery rate (80–120%). The protocol was then applied to determine the levels of amino acids in cucumber plants exposed to various environmentally-relevant levels of nano copper (nCu at 0, 200, 400, and 800 mg/kg soil; harvested in 60 days). Dose-dependent changes in amino acid levels were found; 13 amino acids were upregulated due to nCu stress, particularly, tyrosine increased 6.1, 8.2, and 11.0 fold after exposure to 200, 400 and 800 mg/kg nCu, respectively. The change in amino acid levels suggests an active defense response of the cucumber plant to nCu stress. We demonstrate that the HILIC-LC-MS/MS method is an effective and efficient technique to analyze underivatized amino acids in plant samples.
Assessment of machine-learning techniques in predicting lithofluid facies logs in hydrocarbon wells

AbstractWireline log interpretation is a well-exercised procedure in the oil and gas industry with all its added value from exploration to production stages. It becomes even more important when it ...
Solutal convection in porous media: Comparison between boundary conditions of constant concentration and constant flux

We numerically examine solutal convection in porous media, driven by the dissolution of carbon dioxide (CO2) into water---an effective mechanism for CO2 storage in saline aquifers. Dissolution is associated with slow diffusion of free-phase CO2 into the underlying aqueous phase followed by density-driven convective mixing of CO2 throughout the water-saturated layer. We study the fluid dynamics of CO2 convection in the single aqueous-phase region. A comparison is made between two different boundary conditions in the top of the formation: (i) a constant, maximum aqueous-phase concentration of CO2, and (ii) a constant, low injection-rate of CO2, such that all CO2 dissolves instantly and the system remains in single phase. The latter model is found to involve a nonlinear evolution of CO2 composition and associated aqueous-phase density, which depend on the formation permeability. We model the full nonlinear phase behavior of water-CO2 mixtures in a confined domain, consider dissolution and fluid compressibility, and relax the common Boussinesq approximation. We discover new flow regimes and present quantitative scaling relations for global characteristics of spreading, mixing, and a dissolution flux in two- and three-dimensional media for both boundary conditions. We also revisit the scaling behavior of Sherwood number (Sh) with Rayleigh number (Ra), which has been under debate for porous-media convection. Our measurements from the solutal convection in the range 1, 500<Ra<135, 000 show that the classical linear scaling Sh ~ Ra is attained asymptotically for the constant-concentration case. Similarly linear scaling is recovered for the constant-flux model problem.
Building a Home: Everyday Placemaking in a Toxic Neighborhood:

Why do residents of a contaminated area actively organize to formalize their land tenure and continually invest scarce resources in the fortification of their homes, despite their high-risk locatio...
Dynamic Crowding Regulates Transcription

The nuclear environment is highly crowded by biological macromolecules, including chromatin and mobile proteins, which alter the kinetics and efficiency of transcriptional machinery. These alterations have been described, both theoretically and experimentally, for steady-state crowding densities; however, temporal changes in crowding density ("dynamic crowding") have yet to be integrated with gene expression. Dynamic crowding is pertinent to nuclear biology because processes such as chromatin translocation and protein diffusion lend to highly mobile biological crowders. Therefore, to capture such dynamic crowding and investigate its influence on transcription, we employ a three-pronged, systems-molecular approach. A system of chemical reactions represents the transcription pathway, the rates of which are determined by molecular-scale simulations; Brownian dynamics and Monte Carlo simulations quantify protein diffusion and DNA-protein binding affinity, dependent on macromolecular density. Altogether, this approach shows that transcription depends critically on dynamic crowding as the gene expression resultant from dynamic crowding can be profoundly different than that of steady-state crowding. In fact, expression levels can display both amplification and suppression and are notably different for genes or gene populations with different chemical and structural properties. These properties can be exploited to impose circadian expression, which is asymmetric and varies in strength, or to explain expression in cells under biomechanical stress. Therefore, this work demonstrates that dynamic crowding nontrivially alters transcription kinetics and presents dynamic crowding within the bulk nuclear nanoenvironment as a novel regulatory framework for gene expression.
Interrogating the impact of KIR ligand mismatch in engraftment following HLA-disparate stem cell transplantation

The effects of donor-derived natural killer (NK) cell alloreactivity on disease relapse and transplant-related mortality following allogeneic stem cell transplantation have been described while the impact of recipient-derived NK cell alloreactivity on donor engraftment is not well known. Epitopes of HLA Class I molecules act as ligands for NK cell killer immunoglobulin-like receptors (KIR) regulating their cytotoxicity. As such, NK cell alloreactivity is predictable from KIR ligand mismatches between donors and recipients. We analyzed the impact of KIR ligand mismatch (KIR-L-MM) on donor engraftment in 70 cord blood transplants (CBT) and 26 haploidentical transplants (HaploSCT). In CBT, host-versus-graft-directed KIR-L-MM predicted primary graft failure; an effect not mitigated by use of ATG. This trend was most significant with HLA-C KIR-L-MM. In addition, graft-versus-host-directed KIR-L-MM predicted the dominant cord blood unit in double CBT. In the limited HaploSCT cohort, host-versus-graft-directed KIR-L-MM did not predict graft failure. Time to neutrophil engraftment was unaffected by KIR-L-MM in either CBT or HaploSCT. The direction of KIR-L mismatch may be a parameter to consider when selecting CBT units to ensure successful engraftment. The role of KIR-L-MM in CBT and HaploSCT engraftment merits further exploration in a large transplant database.
Prostate-specific antigen testing after the US Preventive Services Task Force recommendation: a population-based analysis of electronic health data.

This study describes longitudinal trends in the use of prostate-specific antigen (PSA)-based testing in two geographically distinct healthcare systems following the 2011 US Preventive Services Task Force (USPSTF) recommendations against routine PSA screening. We analyzed population-based health claims data from 253,139 men aged 40–80 who were enrolled at two US healthcare systems. We assessed trends in the percentage of eligible men receiving ≥ 1 PSA test per year by time period (2000–2008, 2009–2011, 2012–2014), age (40–54, 55–69, 70–80), and race (white, black, other, unknown), and conducted a joinpoint regression analysis. Men aged 55–69 and 70–80 years of all races had similar use of PSA testing between 2000 and 2011, ranging between 47 and 56% of eligible men by year, while only 22–26% of men aged 40–54 had a PSA test per year during this period. Overall, the percentage of men receiving at least one PSA test per year decreased by 26% between 2009–2011 and 2012–2014, with similar trends across race and age groups. PSA testing declined significantly after 2011 (annual percent change = − 11.28). Following the 2011 USPSTF recommendations against routine PSA screening, declines in PSA testing were observed among men of all races and across all age groups in two large US healthcare systems.
Impact of Dissolved Organic Matter on Porewater Hg and MeHg Concentrations in St. Louis River Estuary Sediments

Inorganic mercury in sediments are a potential source of bioaccumulative methylmercury in the aquatic food web; however, in many cases total mercury concentrations in the sediment alone cannot pred...
Higgs Boson Cross Section Interpretation Using the EFT Approach

As detailed in Chap. 7, the measurement of the Higgs boson cross section in a fiducial region results in a model-independent measurement. In addition, the measured cross sections are corrected for detector effects (unfolded), resulting in particle-level cross sections that can be compared directly to different theoretical predictions. In this chapter, we will use the effective field theory (EFT) framework, detailed in Chap. 2, as a tool to interpret our results in terms of constraints on anomalous Higgs boson interactions.
La discrétion: by Faïza Guène, Paris, Plon, 2020, 256 pp., €19.00 (softcover), ISBN 978-2-2592-8244-4

At just nineteen years old, Faiza Guene published her first novel, Kiffe kiffe demain (Hachette Litteratures, 2004). With more than 400,000 copies sold, Guene's remarkable literary debut recounts w...
Development and Validation of the Secondary Transition Fidelity Assessment

In this study, we examined the structural validity of the Secondary Transition Fidelity Assessment (STFA), a measure of secondary schools’ use of programs and practices demonstrated by research to ...
Prevention of ethanol withdrawal seizures in mice by local anesthetics and dextro-propranolol.

It has been previously reported from this laboratory that the systemic administration of nonsedative doses of the local anesthetic lidocaine (Xylocaine®; Astra Pharmaceutical Products, Inc., Worcester, Mass.) prevents ethanol withdrawal seizures in mice (Freund, 1973b). Lidocaine, however, is rapidly metabolized and is not effective orally as a cardiac antiarrhythmic agent. The β-adrenergic blocking drug d-,l-propranolol (Inderal®; Ayerst Laboratories, New York, N.Y.), a racemic mixture containing equal proportions of dextro- (d-) and levo- (l-) propranolol, has a local anesthetic potency approximately equal to lidocaine (Morales-Aguilera and Williams, 1965). In contrast to lidocaine, however, propranolol is orally absorbable and has a much longer duration of action. Both the d- and the l- optical isomers of propranolol have the same local anesthetic potency, but d-propranolol has less than 1/100 the β-adrenergic blocking potency of the l- form (Barrett and Cullum, 1968). Therefore, it appears theoretically possible to take advantage of the long-lasting local anesthetic effect and oral absorbability of d-propranolol with its nearly absent β-adrenergic blocking properties.
Microbial Oxidation of Gaseous Hydrocarbons

Publisher Summary Prior to 1970, most of the activity on microbial oxidation of gaseous hydrocarbons was concentrated in Foster's laboratory in Texas and in Quayle's laboratory in Sheffield, England. The methylotrophic bacteria can be classified into two major classes, depending on whether they are obligate or facultative. The obligate methylotrophs have three subgroups: first—those with a type I membrane structure can utilize methane and have the ribulose monophosphate pathway of carbon assimilation, second—those with a type II membrane structure can grow on methane and have the Icl – -serine pathway, and third—those with no internal membrane structure are unable to use methane and have the ribulose monophosphate pathway.
Base Composition of Fractions of Nuclear and Nucleolar Ribonucleic Acid Obtained by Sedimentation and Chromatography

Abstract Sufficient quantities of various nuclear and nucleolar ribonucleic acid fractions were obtained by repeated density gradient sedimentations for analysis of base composition determined by optical density, as well as base composition determined by labeling with 32P-orthophosphate, reaction with formaldehyde, and chromatography on methylated serum albumin columns. The base compositions determined by optical density of 45, 35, and 28 S nucleolar ribonucleic acid fractions were identical within the limits of experimental error. A similar result was obtained for base composition, determined by labeling with 32P-orthophosphate, of these fractions each of which had a ratio of adenylic plus uridylic acid to guanylic plus cytidylic acid (A + U:G + C) of approximately 0.6. These results support the conclusions of previous studies that 28 S ribonucleic acid is a product of 45 S ribonucleic acid synthesized in the nucleolus. Evidence that the hydrogen bonding of these fractions differed was obtained by studies with formaldehyde which suggest that 90% of the amino groups in 35 and 45 S ribonucleic acid are hydrogen-bonded as compared to 75% in the 28 S ribonucleic acid in the nucleolar ribonucleic acid fractions. Analyses of the extranucleolar nuclear ribonucleic acid and total nuclear ribonucleic acid indicate that a 45 S ribonucleic acid is formed in the extranucleolar ribonucleic acid which has a ratio of adenylic plus uridylic acid to guanylic plus cytidylic acid (A + U:G + C) of 1.16 by 32P base analysis. It seems possible that this ribonucleic acid may be the precursor of the 18 S ribonucleic acid and messenger ribonucleic acid which is rich in adenine and uridine.
Why Do Malfeasant Politicians Maintain Political Support? Testing the 'Uninformed Voter' Argument

Repeated studies have shown that politicians in mature democracies accused of corruption are typically not punished at the polls. Existing explanations focus on rational trade-offs by policy-minded voters and institutionally-driven constraints. I analyze another factor: distribution of electorate's political awareness. A common regression approach likely suffers from bias due to potential underlying selection mechanisms. My identification strategy rests on a simple framework which shows that this bias is invariably downward, irrespective of the direction of the hypothesized effect. Less-informed voters are found to be significantly more likely to vote for incumbents accused of corruption relative to clean incumbents than their well-informed counterparts. An across-the-board increase in political awareness would systematically reduce the support for malfeasant incumbents. Results are not sensitive to omission of potential confounds, endogeneity of voter awareness to scandal occurrence, alternative measurement of incumbent support and voter information, variation in the nature of incumbent corruption, and parametric modeling assumptions.
Synergy of collaborative technologies in healthcare and biomedicine

In this talk will not provide solutions to problems or cover every aspect of a problem, but will address how SYNERGIES of COLLABORATIVE TECHNOLOGIES may offer partial solutions to a few of these major problems in HEALTHCARE and BIOMEDICINE. In particular, an introduction to Healthcare-Biomedicine Challenges will be given and a small number of Synergies of Technologies will be discussed to make the focus point. These synergies are: Synergy-1: Secure Health Information Exchange (HIEx); Synergy-2: Smart Homes for People at need; Synergy-3: ER Ultrasound Monitoring; Synergy-4: Brain Activities & Surgery. Finally, the talk ends with discussion and conclusions for future directions.
Sleep Duration Varies as a Function of Glutamate and GABA in Rat Pontine Reticular Formation

The oral part of the pontine reticular formation (PnO) is a component of the ascending reticular activating system and plays a role in the regulation of sleep and wakefulness. The PnO receives glutamatergic and GABAergic projections from many brain regions that regulate behavioral state. Indirect, pharmacological evidence has suggested that glutamatergic and GABAergic signaling within the PnO alters traits that characterize wakefulness and sleep. No previous studies have simultaneously measured endogenous glutamate and GABA from rat PnO in relation to sleep and wakefulness. The present study utilized in vivo microdialysis coupled on-line to capillary electrophoresis with laser-induced fluorescence to test the hypothesis that concentrations of glutamate and GABA in the PnO vary across the sleep/wake cycle. Concentrations of glutamate and GABA were significantly higher during wakefulness than during non-rapid eye movement sleep and rapid eye movement sleep. Regression analysis revealed that decreases in glutamate and GABA accounted for a significant portion of the variance in the duration of non-rapid eye movement sleep and rapid eye movement sleep episodes. These data provide novel support for the hypothesis that endogenous glutamate and GABA in the PnO contribute to the regulation of sleep duration.
Consecuencias distributivas de las politicas de ajuste. Una revision de metodologias

This paper is a review of the different methologies that have been used to trace de distributional effects of adjustment policies. It categorizes these methodologies into those that are qualitative versus quantitative, and those that are general equilibrium versus partial equilibrium. Each method is evaluated and data requirements are described. The review provides a range of approaches and can be used to select a method to apply to a particular country. The complexity of the issue is such that one integrated
Occupy's predicament: the moment and the prospects for the movement.

Occupy Wall Street has stalled in its attempt to make a transition from a moment to a movement. It had a sizable impact upon the presidential election, driving America's political centre of gravity toward the left, but has been unable or unwilling to evolve beyond its original core into a ‘full-service movement’ that welcomes contributions from a wide range of activists at varying levels of commitment and skill and plausibly campaigns for substantial reforms. In contrast to earlier American social movements of the twentieth century, the Occupy movement began with a large popular base of support. Propped up by that support, its ‘inner movement’ of core activists with strong anarchist and ‘horizontalist’ beliefs transformed the political environment even as they disdained formal reform demands and conducted decisions in a demanding, fully participatory manner. But the core was deeply suspicious of the ‘cooptive’ and ‘hierarchical’ tendencies of the unions and membership organizations – the ‘outer movement’ – whose supporters made up the bulk of the participants who turned out for Occupy's large demonstrations. The ‘inner movement's’ awkward fit with that ‘outer movement’ blocked transformation into an enduring structure capable of winning substantial reforms over time. When the encampments were dispersed by governmental authorities, the core lost its ability to convert electronic communications into the energy and community that derive from face-to-face contact. The outlook for the effectiveness of the movement is decidedly limited unless an alliance of disparate groups develops to press for reforms within the political system.
Oxidative Phosphorylation in Fractionated Bacterial Systems XXVII. THE NATURE OF NONHEME IRON IN MYCOBACTERIUM PHLEI

Previous studies have indicated that nonheme iron may function as an electron carrier in the succinate oxidase pathway of Mycobacterium phlei. The nature and distribution of this component in the bacterium were investigated. A modified method for the quantitative determination of nonheme iron in mammalian and bacterial electron transport systems was developed. The bacterial electron transport particles accounted for only one-fifth of the total protein but were found to contain half of the total iron. In keeping with their electron transport function, the particles contained 89% of the heme iron of the extract. Nonheme iron was released in the ferrous state from particulate and supernatant fractions following boiling with trichloracetic acid. The release of iron from the particulate protein was found to be inhibited by mercurials. This inhibitory action of mercurials was reversed by mercaptoethanol or cysteine. In contrast, mercurials did not inhibit the release of iron from the supernatant protein, but the iron was released in the ferric state. A relation between sulfhydryl groups and iron content was indicated by the action of mercurials. The labile sulfide and flavin adenine dinucleotide content of the bacterial preparations was lower than the content of nonheme iron.
Characterization of a DNA polymerase from the hyperthermophile archaea Thermococcus litoralis. Vent DNA polymerase, steady state kinetics, thermal stability, processivity, strand displacement, and exonuclease activities.

We have isolated, cloned, and characterized a DNA polymerase from the hyperthermophile archaea Thermococcus litoralis, the Tli DNA polymerase (also referred to as Vent DNA polymerase). The enzyme is extremely thermostable, having a half-life of 8 h at 95 degrees C and about 2 h at 100 degrees C. Pseudo-first-order kinetics at 70 degrees C reveal an extremely low Km for a primed M13mp18 substrate (0.1 nM), coupled with a relatively high Km for dNTPs (50 microM). Accompanying extension rates are on the order of 1000 nucleotides/min. Synthesis by the polymerase is largely distributive, adding an average of 7 nucleotides/initiation event. This distributive synthesis can generate products of at least 10,000 bases. Tli DNA polymerase contains a 3‘–>5‘ exonuclease activity that enhances the fidelity of replication by the enzyme (Mattila, P., Korpela, J., Tenkanen, T. and Pitkanen, K. (1991) Nucleic Acids Res. 19, 4967-4973). A 2-amino acid substitution within the conserved exonuclease domain abolishes both double and single strand-dependent exonuclease activity, without altering kinetic parameters for polymerization on a primed single-stranded template. Strand displacement activity by the mutated and unmutated forms increases with increasing temperature and is enhanced in the exonuclease-deficient form of the enzyme.
Structurally diverse amphiphiles exhibit biphasic modulation of GABAA receptors: similarities and differences with neurosteroid actions.

Background and purpose: Some neurosteroids, notably 3α-hydroxysteroids, positively modulate GABAA receptors, but sulphated steroids negatively modulate these receptors. Recently, other lipophilic amphiphiles have been suggested to positively modulate GABA receptors. We examined whether there was similarity among the actions of these agents and the mechanisms of neurosteroids. Significant similarity would affect theories about the specificity of steroid actions. Experimental approach: Xenopus laevis oocytes were challenged with Triton X-100, octyl-β-glucoside, capsaicin, docosahexaenoic acid and sodium dodecyl sulphate (SDS), along with different GABA concentrations. Key results: These compounds have both positive and negative effects on GABA currents, which can be accentuated according to the degree of receptor activation. A low GABA concentration (1 µM) promoted potentiation and a high concentration (20 µM) promoted inhibition of current, except for SDS that inhibited function even at low GABA concentrations. Amphiphile inhibition was characterized by enhanced apparent desensitization and by weak voltage dependence, similar to pregnenolone sulphate antagonism. We then tested amphiphile effects on mutated receptor subunits that are insensitive to negative (α1V256S) and positive (α1Q241L or α1N407A/Y410F) steroid modulation. Negative regulation by amphiphiles was nearly abolished in α1V256S-mutated receptors, but potentiation was unaffected. In α1Q241L- or α1N407A/Y410F-mutated receptors, potentiation by amphiphiles remained intact. Conclusions and implications: Structurally diverse amphiphiles have antagonist actions at GABAA receptors very similar to those of sulphated neurosteroids, while the potentiating mechanisms of these amphiphiles are distinct from those of neurosteroid-positive modulators. Thus, such antagonism at GABAA receptors does not have a clear pharmacophore requirement.
Hot-electron effects in the two-dimensional superconductor-insulator transition

The parallel magnetic field tuned two-dimensional superconductor-insulator transition has been investigated in ultrathin films of amorphous Bi. The resistance is found to be independent of temperature on both sides of the transition below approximately $120\phantom{\rule{0.3em}{0ex}}\mathrm{mK}$. Several observations suggest that this regime is not intrinsically ``metallic'' but results from the failure of the films' electrons to cool. The onset of this temperature-independent regime can be moved to higher temperatures by either increasing the measuring current or the level of electromagnetic noise. Temperature scaling is successful above $120\phantom{\rule{0.3em}{0ex}}\mathrm{mK}$. Electric field scaling can be mapped onto temperature scaling by relating the electric fields to elevated electron temperatures. These results cast doubt in the case of ultrathin films on the existence of an intrinsic metallic regime and on the independent determination of the correlation length and dynamical critical exponents obtained by combining the results of electric field and temperature scaling.
Patient Electronic Health Records as a Means to Approach Genetic Research in Gastroenterology

Electronic health records (EHRs) are being increasingly utilized and form a unique source of extensive data gathered during routine clinical care. Through use of codified and free text concepts identified using clinical informatics tools, disease labels can be assigned with a high degree of accuracy. Analysis linking such EHR-assigned disease labels to a biospecimen repository has demonstrated that genetic associations identified in prospective cohorts can be replicated with adequate statistical power and novel phenotypic associations identified. In addition, genetic discovery research can be performed utilizing clinical, laboratory, and procedure data obtained during care. Challenges with such research include the need to tackle variability in quality and quantity of EHR data and importance of maintaining patient privacy and data security. With appropriate safeguards, this novel and emerging field of research offers considerable promise and potential to further scientific research in gastroenterology efficiently, cost-effectively, and with engagement of patients and communities.
The solar zenith angle dependence of desert albedo

[1] Most land models assume that the bare soil albedo is a function of soil color and moisture but independent of solar zenith angle (SZA). However, analyses of the Moderate Resolution Imaging Spectroradiometer (MODIS) Bidirectional Reflectance Distribution Function (BRDF) and albedo data over thirty desert locations indicate that bare soil albedo does vary with SZA. This is further confirmed using the in situ data. In particular, bare soil albedo normalized by its value at 60° SZA can be adequately represented by a one-parameter formulation (1 + C)/(1 + 2C * cos(SZA)) or a two-parameter formulation (1 + B1 * f1(SZA) + B2 * f2(SZA)). Using the MODIS and in situ data, the empirical parameters C, B1, and B2 are taken as 0.15, 0.346 and 0.063. The SZA dependence of soil albedo is also found to significantly affect the modeling of land surface energy balance over a desert site.
Occupation against Occupation: Space and Anticolonial Resistance

“The colonial world,” Frantz Fanon wrote in The Wretched of the Earth, “is a world divided into compartments … a world cut in two.” Mapping the geographic rationality of colonial domination allows us, Fanon insists, to “mark out the lines on which a decolonized society will be organized.” In this article, I sketch either side of the dialectic to which Fanon gestures–the spatial logic of colonial power, and the spatial logic of anticolonial protest. My analysis focuses on apartheid South Africa, a context wherein the spatial rationality of colonial power was rendered with a particular clarity. Working toward a thematic of anticolonial occupation, I highlight three unique but imbricated sites of resistance: settlement, transportation, and urbanity. From the particular example of antiapartheid resistance, I argue, we can begin to develop a spatial theory of anticolonial struggle that might be brought to bear upon the neoliberal present.
The temporal relationship between hepatic GSH loss, heme oxygenase induction, and cytochrome P450 loss following intraperitoneal aluminum administration to mice.

Abstract The time- and dose-dependent accumulation of aluminum (Al) in liver and its effect on several hepatic systems were investigated in female Swiss-Webster mice given intraperitoneal (ip) Al lactate. A single dose of 50, 75, or 100 mg Al/kg produced significant depletion of hepatic glutathione (GSH) and cytochrome P450 (P450) and an increase in heme oxygenase (HO) activity when measured at 6 hr. However, no increase in hepatic malondialdehyde (MDA) was seen at this time. Using a dose of 100 mg Al/kg, Al rapidly accumulated in liver (0.29 ± 0.03 vs 0.12 ± 0.04 μg Al/mg protein at 6 hr). Hepatic GSH was significantly depleted at 2, 4, and 6 hr postdosing, HO activity was significantly increased at 6, 12, 24, 48, and 96 hr postdosing, hepatic cytochrome P450 was decreased at 12, 18, 24, and 48 hr postdosing, while hepatic MDA was not significantly elevated until 24 hr postdosing. Twenty-four hours following three daily doses of 50 mg Al/kg, HO activity was increased, P450 levels were depleted, and hepatic Al content was significantly increased, although hepatic MDA was unaffected. We conclude that parenteral Al produces a course of hepatic damage that begins with GSH depletion and proceeds through a sustained increase in HO activity, with cytochrome P450 loss being an early event and production of hepatic MDA being a late event.
A new simple and rapid LC–ESI-MS/MS method for quantification of plasma oxysterols as dimethylaminobutyrate esters. Its successful use for the diagnosis of Niemann–Pick type C disease

Two oxysterols, cholestan-3β,5α,6β-triol (C-triol) and 7-ketocholesterol (7-KC), have been recently proposed as diagnostic markers of Niemann-Pick type C (NP-C) disease, representing a potential alternative diagnostic tool to the more invasive and time consuming filipin test in cultured fibroblasts. Usually, the oxysterols are detected and quantified by liquid chromatography-tandem mass spectrometry (LC-MS/MS) method using atmospheric pressure chemical ionization (APCI) or electro-spray-ionization (ESI) sources, after a variety of derivatization procedures to enhance sensitivity. We developed a sensitive LC-MS/MS method to quantify the oxysterols in plasma as dimethylaminobutyrate ester, suitable for ESI analysis. This method, with an easy liquid-phase extraction and a short derivatization procedure, has been validated to demonstrate specificity, linearity, recovery, lowest limit of quantification, accuracy and precision. The assay was linear over a concentration range of 0.5-200ng/mL for C-triol and 1.0-200ng/mL for 7-KC. Intra-day and inter-day coefficients of variation (CV%) were <15% for both metabolites. Receiver operating characteristic analysis estimates that the area under curve was 0.998 for C-triol, and 0.972 for 7-KC, implying a significant discriminatory power for the method in this patient population of both oxysterols. In summary, our method provides a simple, rapid and non-invasive diagnostic tool for the biochemical diagnosis of NP-C disease.
Modulation of Receptors for Thyrotropin‐Releasing Hormone by Benzodiazepines: Brain Regional Differences

The benzodiazepines (BZDs) chlordiazepoxide (CDE), diazepam (DZM), and flurazepam (FLM) inhibited receptor binding for thyrotropin-releasing hormone (TRH) with low micromolar potency. In contrast, numerous other categories of drugs were previously shown to be inactive. Scatchard analysis of competition data suggested that the BZDs reduced TRH receptor affinity, consistent with competitive inhibition. Receptors from amygdala, retina, and pituitary appeared more sensitive to inhibition by BZDs than those from hypothalamus, hippocampus, spinal cord, or cerebellum. The latter four regions also gave shallower inhibition curves. CDE revealed an apparently biphasic dissociation of [3-Me-His2]TRH([3H]MeTRH) from amygdala membranes at 4 degrees C, with kinetics similar to those with TRH. These results suggest that TRH receptors in the brain are heterogeneous and that certain BZDs in high therapeutic concentrations may exert central effects through actions at TRH receptors or coupled proteins.
Design and implementation of two-dimensional FIR digital filters with nonrectangular arrays

A new technique for the design of two-dimensional FIR digital filters is presented in this paper. A high-order impulse response array of a filter may be optimally truncated to give a low-order impulse response array. In general, such low-order arrays are nonrectangular. A method for implementing the filters is presented. Examples of the design and implementation techniques are included.
Thomas Paine and Robert Treat Pain: A Case of Mistaken Identity

Lesser points out there is a confusion, unusual in these days of precise scholarship, in the Thomas Paine bibliography, caused not by the authorship of the song, "Adams and Liberty," also known as "The Boston Patriotic Song," but by the errors which enabled the work to appear in two of the four complete editions of Thomas Paine's works. The real author of the song is Robert Treat Paine, Jr., a prominent Massachusetts Federalist, and the son of one of the signers of the Declaration of Independence.Â The author corrects this error.
Interpenetrating network of metal polymer composites (INMPC) of polycarbonate

Alliage zinc-etain dans une matrice a la temperature de ramollissement au cours de l'ecoulement du polycarbonate
Inhibition of low-density lipoprotein oxidation by nitric oxide. Potential role in atherogenesis.

The effects of nitric oxide (.NO) and nitrovasodilators on the oxidation of low-density lipoprotein (LDL) have been studied. S-Nitroso-N-acetylpenicillamine (SNAP) and sodium nitroprusside (SNP) inhibited Cu(2+)- and 2,2'-azobis-2-amidinopropane hydrochloride-dependent oxidation of LDL as monitored by oxygen consumption and the formation of thiobarbituric acid-reactive substances, conjugated dienes, and lipid hydroperoxides. In the case of SNP, inhibition of LDL oxidation occurred only when the incubation mixture was irradiated with visible light. SNAP, however, exerted a dose-dependent inhibition of Cu(2+)-catalyzed oxidation of LDL even in the dark. Addition of .NO dissolved in deoxygenated buffer also inhibited the progression of LDL oxidation. Mouse peritoneal macrophages were less able to degrade LDL that had been oxidized in the presence of SNAP. Using an .NO electrode, it was estimated that a continuous production of .NO (< or = 760 nM/min) could retard the progression of LDL oxidation. We propose that .NO can inhibit LDL oxidation by acting as a chain-breaking antioxidant that is capable of scavenging carbon-centered and peroxyl radicals. Biological implications of this novel .NO antioxidant property are discussed in relation to atherogenesis and contrasted to the prooxidant property of .NO when generated in the presence of superoxide.
Effect of the Excess Volume of Lattice Defects on the Enthalpy of Formation and Desorption Temperature of Metal Hydrides

Metal and complex hydrides offer very promising prospects for hydrogen storage that reach the DOE targets for 2015. However, slow sorption kinetics and high release temperature must be addressed to make automotive applications feasible. Reducing the enthalpy of formation by destabilizing the hydride reduces the heat released during the hydrogenation phase and conversely allows desorption at a lower temperature. High-energy ball milling has been shown to decrease the release temperature, increase reaction kinetics and lower the enthalpy of formation in certain cases. Increased surface and grain boundary energy could play a role in reducing the enthalpy of formation, but the predicted magnitude is too small to account for experimental observations. As the particle and grain sizes are reduced considerably under high-energy treatments, structural defects and deformations are introduced. These regions can be characterized by an excess volume due to deformations in the lattice structure, and have a significant effect on the material properties of the hydride. We propose a thermodynamic model that characterizes the excess energy present in the deformed regions to explain the change in physical properties of metal hydrides. An experimental investigation using the TEM to study the effect of lattice deformations and other nanostructures on the desorption process is underway.Copyright © 2007 by ASME
Determination of the Electric Field Intensities in a Mid-Infrared Spectroelectrochemical Cell Using Attenuated Total Reflection Spectroscopy with the Otto Optical Configuration

The normalized mean-squared electric field intensities in a thin-layer spectroelectrochemical cell with the attenuated total reflection (ATR) optical configuration have been determined and are compared with those for the overlayer-ATR and normal ATR methods. The components of the system were ZnSe or Ge hemispherical internal reflection elements, a Au metal electrode, and water. The calculations were performed for two different values of the molar absorption coefficient for water, namely, k = 0.133 (at 1635 cm-1) and k = 0.010 (at 1885 cm-1). It was determined that the electric field enhancements in the overlayer-ATR cell can also be found in the thin-layer (TL) ATR cell. This is important in that the TL-ATR cell allows greater control over the surface properties of the chosen electrode material.
On the Number of Sum-Free Sets

Cameron and Erdos have considered the question: how many sum-free sets are contained in the first n integers; they have shown that the number of sum-free sets contained within the integers {n3 , n 3 + 1, . . . , n} is c.2 n 2 . We prove that the number of sets contained within {1, 2, . . . , n} is o(2n(1/2+e)) for every e > 0.
Microvoids and defect chemistry at the SiSiO2 interface studied by positron annihilation depth profiling

Abstract A low energy positron beam (few keV) has been used to study device quality dry thermal SiO 2 layers (∼ 50 nm thick) on Si(100). By tuning the beam energy over the range 0–10 keV to vary implantation depth, and by accounting for positron diffusion as well as annihilation in SiO 2 and Si, depth profiles of material properties are obtained which sense material, defect, and electric field properties. The unusual observation of ortho-positronium 3γ-decay at the interface demonstrates that microvoids > 1 nm in size are present in these oxides, apparently an intrinsic consequence of the thermal oxidation process. The microvoid signal increases with annealing, possibly due to initiation of the interfacial oxide decomposition reaction. Reversible hydrogen uptake and desorption are also observed, illustrating the interface sensitivity of positron studies.
Citric acid cycle biomimic on a carbon electrode

The citric acid cycle is one of the main metabolic pathways living cells utilize to completely oxidize biofuels to carbon dioxide and water. The overall goal of this research is to mimic the citric acid cycle at the carbon surface of an electrode in order to achieve complete oxidation of ethanol at a bioanode to increase biofuel cell energy density. In order to mimic this process, dehydrogenase enzymes (known to be the electron or energy producing enzymes of the citric acid cycle) are immobilized in cascades at an electrode surface along with non-energy producing enzymes necessary for the cycle to progress. Six enzymatic schemes were investigated each containing an additional dehydrogenase enzyme involved in the complete oxidation of ethanol. An increase in current density is observed along with an increase in power density with each additional dehydrogenase immobilized on an electrode, reflecting increased electron production at the bioanode with deeper oxidation of the ethanol biofuel. By mimicking the complete citric acid cycle on a carbon electrode, power density was increased 8.71-fold compared to a single enzyme (alcohol dehydrogenase)-based ethanol/air biofuel cell.
Increased risk of a positive test for antibody to hepatitis B core antigen (anti-HBC) in autologous blood donors

Controversy exists about the suitability of blood from autologous donors for homologous use. We compared the infectious disease test results of 426 autologous donors, designated by donor history as suitable for homologous use, to those of 86,138 volunteer donations collected over the same 5 month period. Although donor characteristics differed, the relative risk of a positive test for anti-HBc in the autologous group was 2.09. When 413 autologous donors were compared to 413 volunteer donors matched for age, sex, and zip code, the relative risk of a positive test for anti-HBc in the autologous group was 3.2. If anti-HBc is a marker for non-A, non-B hepatitis transmissibility, then our autologous group is not as safe as our volunteer donors. We recommend that autologous blood, even when designated by donor history and laboratory screening results as suitable for homologous transfusion, not be used for other than the intended autologous recipient.
Learning during middle age: a resistance to stress?

Acute stressful experience enhances subsequent learning in males and impairs learning in females. These sex differences emerge soon after puberty in adulthood. Whether these opposite effects of stress on learning extend into older age is unknown. To examine this, young adult (2–3 months) and middle aged (17–18 months) Fischer 344 rats of both sexes were exposed to an acute stressor of brief tailshocks and trained 24 h later with classical eyeblink conditioning using a trace paradigm. Whereas stressful experience enhanced conditioning in adult males and impaired conditioning in adult females, it had no effect whatsoever on conditioning in the aging animals of either sex. There was no effect of aging itself on acquisition of the conditioned response, suggesting that trace conditioning is not necessarily compromised during this period of life. Together, these data indicate that associative learning in the aging animal is resistant to both the negative and positive consequences of stressful experience.
A double-heterojunction doped-channel pseudomorphic power HEMT with a power density of 0.85 W/mm at 55 GHz

The authors report the DC characteristics and RF performances of a 50*0.2- mu m/sup 2/ AlGaAs/InGaAs/GaAs pseudomorphic HEMT with a doped InGaAs channel. A transconductance as high as 760 mS/mm and a maximum current density of 800 mA/mm leads to a power density of 0.85 W/mm with 3.3-dB gain and 22.1% power-added efficiency at 55 GHz. >
Dissociation of the lipid-enzyme complex of hormone-sensitive lipase using high density lipoprotein or apolipoprotein A-I

Abstract Hormone-sensitive lipase in homogenates of adipose tissue occurs as a large, lipid-rich complex including several acylhydrolase activities that emerge quantitatively in the void volume on gel filtration chromatography (2% agarose). Incubation with intact human plasma high density lipoprotein or with lipidfree apolipoprotein A-I, however, disrupted the lipid-rich complex almost completely and most of the enzyme activity eluted from a 2% agarose column at about V e = 2.3 × V o . This use of the detergent-like properties of apolipo-protein A-I may be of value for dissociation of other lipid-associated or membrane-bound enzymes.
Synthesis of uridine 5′-(2-acetamido-2,4-dideoxy-4-fluoro-α-d-galactopyranosyl) diphosphate and uridine 5′-(2-acetamido-2,6-dideoxy-6-fluoro-α-d-glucopyranosyl) di-phosphate

Abstract Benzyl 2-acetamido-3,6-di- O -benzyl-2-deoxy-α- d -glucopyranoside was converted into its 4- O -(methylsulfonyl) derivative ( 2 ) by treatment with methane-sulfonyl chloride in pyridine. Displacement of the methylsulfonyloxy group of 2 with fluoride ion afforded benzyl 2-acetamido-3,6-di- O -benzyl-2,4-dideoxy-4-fluoro-α- d -galactopyranoside, which on hydrogenolysis, followed by acetylation, furnished 2-acetamido-1,3,6-tri- O -acetyl-2,4-dideoxy-4-fluoro- d -galactopyranose. Treatment of this and of 2-acetamido-1,3,4-tri- O -acetyl-2,6-dideoxy-6-fluoro- d -glucopyranose with trimethylsilyl trifluoromethanesulfonate in 1,2-dichloroethane at ∼50° afforded the 4-deoxy-4-fluoro- or the 6-deoxy-6-fluoro-oxazolines ( 5 ) and ( 11 ), respectively. Reaction of 5 and 11 with dibenzyl phosphate in 1,2-dichloroethane produced the α-linked dibenzyl phosphate derivatives 6 and 12 , respectively. Catalytic hydrogenation of 6 provided 2-acetamido-3,6-di- O -acetyl-2,4-dideoxy-4-fluoro-α- d -galactopyranosyl phosphate ( 7 ), and that of 12 gave 2-acetamido-3,4-di- O -acetyl-2,6-dideoxy-6-fluoro-α- d -glucopyranosyl phosphate ( 13 ). Coupling of 7 and 13 with uridine 5′-monophosphomorpholidate in dry pyridine at ∼37°, followed by O -deacetylation, furnished the title compounds, respectively, isolated and characterized as their respective dilithium salts.
Generalized Seniority and the Surface Delta Interaction

It is shown that the surface delta interaction (SDI), which can be defined as a delta interaction $\ensuremath{\delta}({\ensuremath{\Omega}}_{12})$ in the angles of the interacting particles (with the additional assumption that all radial integrals are equal), provides a very simple coupling scheme for configurations of identical particles (i.e., maximum isospin) involving degenerate mixed orbits. This scheme, a generalization of the well-known seniority scheme, can be conveniently expressed in terms of "quasispin." It is shown that the SDI is a sum of a term which is a scalar with respect to quasispins and a term which is proportional to the number of particles. The well-known pairing interaction, like the SDI, is diagonal with respect to quasispin but is not a quasispin scalar. Thus for configurations of an even number of identical particles in mixed degenerate orbits coupled by an SDI, the ground-state energy of the seniority zero ground state varies linearly with the number of particles. We can also apply the BCS method and express the excited states in terms of quasiparticle configurations. For identical nucleons in degenerate orbits coupled by an SDI, we obtain the exact energies of the ground-state and low-lying levels.
Preservation of cells sorted individually onto microscope slides with a fluorescence-activated cell sorter

Fluorescence-activated cell sorters permit analyses and separation of cell populations based on light scatter and surface immunofluorescence parameters. Since a sorter can deposit individually identifiable cells onto a microscope slide, it was considered of interest to combine the flow measurements with analyses available on cells adhering to a surface as in, for example, morphological studies, cytoplasmic immunofluorescent staining, and mRNA in situ hybridization. A necessary condition for these studies is the preservation of cell structures after sorting. We report here a procedure suitable for this purpose. The most important features of this procedure are A) reducing the saline content of the sorter sheath fluid to about 0.0015 M (one-hundredth that of normal saline) to prevent cell damage due to hypertonicity during drying, and B) coating the substrate with a thin layer of newborn calf serum to promote the adherence of the cells to the substrate during subsequent fixing and staining.