gebhart/patrepeval huggingface dataset:
Organosilicon derivatives of phosphazenes. 9. New cyclic phosphazenes with (trimethylsilyl)methyl side groups: x-ray crystal structure of [NP(CH2SiMe3)2]3 and its conversion to (NPMe2)3 (1991)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTOrganosilicon derivatives of phosphazenes. 9. New cyclic phosphazenes with (trimethylsilyl)methyl side groups: x-ray crystal structure of [NP(CH2SiMe3)2]3 and its conversion to (NPMe2)3Harry R. Allcock, William D. Coggio, Masood. Parvez, and Michael L. TurnerCite this: Organometallics 1991, 10, 3, 677–683Publication Date (Print):March 27, 1991Publication History Published online1 May 2002Published inissue 27 March 1991https://pubs.acs.org/doi/10.1021/om00049a029https://doi.org/10.1021/om00049a029research-articleACS PublicationsRequest reuse permissionsArticle Views157Altmetric-Citations8LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-AlertscloseSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts
A neutrophil chemotatic factor derived from C'5 upon interaction of guinea pig serum with endotoxin. (1969)

Upon activation of the complement system in guinea pig serum by endotoxin, a factor chemotactic for polymorphonuclear leukocytes is generated. This chemotactic factor has an approximate molecular weight (M.W.) of 15,000 and is independent of three minor chemotactic factors (M.W. τ;150,000, ∼68,000 and <4000) present in normal, heat-inactivated or EDTA-treated guinea pig serum. Purified, radiolabeled guinea pig C′3 and C′5 were used to determine whether the 15,000 M.W. chemotactic factor generated in serum was derived from either of these components. Endotoxin was incubated with guinea pig serum to which had been added either 125I C′3 or 125I C′5. Gel filtration elution profiles of the reaction mixtures revealed that both C′3 and C′5 were cleaved in endotoxin-treated serum. Moreover, the 15,000 M.W. chemotactic factor was identified with a cleavage product of C′5 but not of C′3. In addition, rabbit anti-guinea pig C′5, but not anti-C′3, significantly inhibited the activity of the 15,000 M. W. chemotactic factor. We conclude that the majority of chemotactic activity found in whole guinea pig serum after interaction with endotoxin is a product cleaved from C′5.
Separation and Determination of Yellow Gardenia Pigments for Food and Iridoid Constituents in Gardenia Fruits by Micellar Electrokinetic Chromatography. (1998)

Micellar electrokinetic chromatography (MEKC) methods were developed for analyzing crocin and crocetin yellow gardenia pigments, and geniposide and gardenoside in gardenia fruits. Crocin and crocetin pigments were successfully separated by MEKC with a 20 mM SDS solution in 50 mM phosphate buffer (pH 7.0) containing 20% acetonitrile and another MEKC method with a 20 mM ammonium formate buffer (pH 7.0) containing 2.0% butyl acrylate/butyl methacrylate/methacrylic acid copolymer sodium salts (BBMA). Geniposide and gardenoside were also successfully separated by MEKC with a 20 mM sodium dodecyl sulfate (SDS) solution in 30 mM borate buffer (pH 8.5). The crocin and crocetin yellow pigments were extracted from food samples (candies and noodles) by solid-phase extraction cartridges and analyzed by MEKC with SDS. The geniposide and gardenoside in gardenia fruits grown in different habitats were determined by the developed technique.
Indirect methods to estimate hidden population. (2017)

Estimating the prevalence of the so-called "hidden populations" can be challenging, because the identification of its members is difficult due to their socially sanctionable or illegal behaviors. This article provides a critical review of the most widely used methods for estimating the size of a hard-to-reach population. All are indirect methods, based on incomplete data sources. Depending on the available data, one method can be more appropriate than another. Besides, each method must fulfill a number of requirements, and each one may be subject to specific risk of bias. To choose the most suitable method, an accurate evaluation of the available data is necessary, and. if possible several methods should be used simultaneously to be able to compare the results and to critically evaluate if these results fit with the reality.
A new paradigm about HERV-K102 particle production and blocked release to explain cortisol mediated immunosenescence and age-associated risk of chronic disease. (2015)

The majority of chronic diseases in the aging adult are thought to relate to immune aging characterized by dominant immunosuppression and paradoxically, concomitant inflammation. This is known collectively as immunosenescence. The main change thought to be controlling immune aging is the age-related decline in dehydroepiandrosterone (DHEA) and corresponding increase in cortisol; the net effect which decreases the DHEA/cortisol ratio. Exactly how this translates to immunosuppression and concomitant inflammation remains unclear. Recently a new component of the human innate immune system has been discovered. Human endogenous retrovirus K102 (HERV-K102) is a replication-competent foamy retrovirus unique to humans which has been implicated in chronic diseases. Accumulating evidence suggests that HERV-K102 may defend the host against viral infections, as well as against breast and other cancers. Particles are produced in activated monocytes and released into vacuoles but do not bud through the cell surface. This renders macrophages foamy, while the release of particles is only through cell lysis. New evidence presented here suggests DHEA but not DHEA-S may specifically bind and inactivate alpha-fetoprotein (AFP). AFP is a well-established immunosuppressive factor which importantly, also blocks cell lysis induction in macrophages through the 67 kilodalton (kD) AFP receptor (AFPr). Here, it is proposed that a decreased DHEA/cortisol ratio may favor the accumulation of foamy macrophages reflecting the cortisol induction of HERV-K102 particle production concomitant with the blocked release of particles by secreted AFP. This is a new paradigm to explain how cortisol-mediated immunosenescence can result in the persistence of foamy macrophages, and how this relates to risk of chronic disease.
Optimal multivariable LQG control using a single diophantine equation (1987)

The general solution of the optimal LQG problem using the polynomial equation approach involves the solution of a couple of two-sided matrix polynomial equations. The conditions under which a single one-sided equation which is related to the original two (the ‘implied’ diophantine equation) yields the unique optimal controller are derived in this paper. The result has considerable relevance to aspects such as computation and self-tuning control applications.
Noise performance of magneto-inductive cables (2014)

Magneto-inductive (MI) waveguides are metamaterial structures based on periodic arrangements of inductively coupled resonant magnetic elements. They are of interest for power transfer, communications and sensing, and can be realised in a flexible cable format. Signal-to-noise ratio is extremely important in applications involving signals. Here, we present the first experimental measurements of the noise performance of metamaterial cables. We focus on an application involving radiofrequency signal transmission in internal magnetic resonance imaging (MRI), where the subdivision of the metamaterial cable provides intrinsic patient safety. We consider MI cables suitable for use at 300 MHz during 1H MRI at 7 T, and find noise figures of 2.3–2.8 dB/m, together with losses of 3.0–3.9 dB/m, in good agreement with model calculations. These values are high compared to conventional cables, but become acceptable when (as here) the environment precludes the use of continuous conductors. To understand this behaviour, we present arguments for the fundamental performance limitations of these cables.
Calculation of the Response of a Composite Plate to Localized Dynamic Surface Loads Using a New Wave Number Integral Method (2005)

This study is motivated by the need for an efficient and accurate tool to analyze the wave field produced by localized dynamic sources on the surface or the interior of isotropic plates and anisotropic composite laminates. A semi-analytical method based on the wave number integral representation of the elastodynamic field is described that reduces the overall computational effort significantly over other available methods. This method is used to calculate the guided wave field produced in a thin unidirectional graphite/epoxy composite laminate by a dynamic surface point load. The results are compared with those obtained from a finite element analysis, showing excellent agreement, except for minor differences at higher frequencies. A recently discovered feature of the calculated surface motion, namely, a spatially periodic “phase reversal” of the main pulse with propagation distance, is observed in both cases. The present work is expected to be helpful in developing impact damage monitoring systems in defect-critical structural components through real time analysis of acoustic emission wave forms.
[Preparation of hard tooth structure with Excimer lasers. In vitro study]. (1989)

The present study will show, that caries removal and conditioning of tooth surfaces by an (ArF)*-Excimer-Laser is an alternative to conventional preparation methods without thermal and mechanical irritations. This promises caries removal without pain to the patient. The photoablative process leads to retentive surfaces of the treated cavities. These findings promise good results in adhesive techniques. In vitro studies show, that photoablation of dental tissue is effective enough to make clinical usage possible.
Application d'une méthode de perturbation à l'étude de résonateurs à quartz présentant des modes d'épaisseur à énergie piégée (1984)

L'élaboration d'un modèle analytique simple pour la description des vibrations d'un résonateur à énergie piégée nécessite l'abandon de nombreux coefficients élastiques. Nous proposons une méthode de perturbation pour la prise en considération des principaux d'entre eux. Nous mettons ainsi en évidence les mécanismes de couplages entre modes, dont l'effet sur la fréquence est évalué, pour des caractéristiques données du résonateur.
Energy-Constrained Dynamic Resource Allocation in a Heterogeneous Computing Environment (2011)

Energy-efficient resource allocation within clusters and data centers is important because of the growing cost of energy. We study the problem of energy-constrained dynamic allocation of tasks to a heterogeneous cluster computing environment. Our goal is to complete as many tasks by their individual deadlines and within the system energy constraint as possible given that task execution times are uncertain and the system is oversubscribed at times. We use Dynamic Voltage and Frequency Scaling (DVFS) to balance the energy consumption and execution time of each task. We design and evaluate (via simulation) a set of heuristics and filtering mechanisms for making allocations in our system. We show that the appropriate choice of filtering mechanisms improves performance more than the choice of heuristics (among the heuristics we tested).
Investment Casting in Silica Aerogels (2000)

This paper describes the experimental observation of the casting and solidification process in silica aerogel molds. The form filling process and the time dependent temperature field are detected with a NIR-CCD camera utilizing the transparency of aerogels. The as-cast microstructure is related to the solidification conditions. The experiments were made with AlSi7 and AlSi7Mg0.5 alloys. The potential of silica aerogels as a mold material is discussed.
A NOVEL UHF RFID SLOT COUPLED METALLIC TAG ANTENNA FOR STEEL-BAR APPLICATIONS (2014)

In this paper, we propose a novel UHF RFID coupled slot metallic tag antenna with a radome. The proposed tag antenna consists of a frequency tuning slot, imaginary part tuning slot, real part tuning stub, micro-chip, and radome. The RFID tag antenna was designed and fabricated for use in the Korean and Japanese UHF band of 916.7 to 923.5MHz. The measured 3dB frequency bandwidth is 914 to 926MHz. The measured read range is 11.5m on a metallic surface. Details of the proposed tag antenna design, as well as simulated and measured results are presented and discussed.
Functionality of a novel overload resistant silicon high pressure sensing element (2009)

This paper presents a novel miniaturized overload resistant piezoresistive silicon high-pressure sensor for a pressure range up to 500 MPa. The novel composite element is made of a solid body silicon chip with implanted piezoresistive resistors. A solid body glass substrate is jointed to the silicon by anodic bonding. The operating mode is based on mechanical strain of all-round pressurized silicon and mechanical mismatched substrate. This paper also presents the verification of the functionality on the basis of repeatable metrological investigations with 200 MPa of experimental designs and analytical investigations as well as finite element analysis.
High voltage research (breakdown strengths of gaseous and liquid insulators). Semiannual report, October 1, 1977--March 31, 1978. [Summaries of research activities at Oak Ridge National Laboratory] (1978)

The work on gas mixtures is focused on combinations of gases consisting of strongly electron-attaching components and one or more electron slowing-down components. Hypotheses based on the positions of electronically excited states are borne out experimentally in the low pressure (<1000 torr) breakdown measurements. The high pressure work shows dramatically the importance of the electron scattering cross section on breakdown strength by comparing Ar with Ne as single gases and in mixtures with SF/sub 6/. Although the ionization cross section for Ar is very much greater than that for Ne, Ar is a superior buffer gas. A theoretical discussion is given which describes the relation between the dielectric strength of a gas to its physical parameters including the electron attachment cross section, the ionization cross section, the ionization potential, and the electron energy distribution function. Also discussed is the importance of perfluorination in hydrocarbons to effect an increase in the electron attachment cross section and electron affinity and a decrease in the ionization cross section, and hence an increase in dielectric strength. Attachment rates were measured as a function of the mean electron energy for a comprehensive list of perfluorocarbons. Breakdown voltages were determined for SF/sub 6/ and for SF/sub 6/ (20%)/N/sub 2/(80%) as a function of temperature from -15/sup 0/C to 85/sup 0/C. Environmental aspects of gas dielectrics pertaining to gas decomposition and toxicity were studied.
Near‐IR Absorbing Solar Cell Sensitized With Bacterial Photosynthetic Membranes (2012)

Current interest in natural photosynthesis as a blueprint for solar energy conversion has led to the development of a biohybrid photovoltaic cell in which bacterial photosynthetic membrane vesicles (chromatophores) have been adsorbed to a gold electrode surface in conjunction with biological electrolytes (quinone [Q] and cytochrome c; Magis et al. [2010] Biochim. Biophys. Acta 1798, 637-645). Since light-driven current generation was dependent on an open circuit potential, we have tested whether this external potential could be replaced in an appropriately designed dye-sensitized solar cell (DSSC). Herein, we show that a DSSC system in which the organic light-harvesting dye is replaced by robust chromatophores from Rhodospirillum rubrum, together with Q and cytochrome c as electrolytes, provides band energies between consecutive interfaces that facilitate a unidirectional flow of electrons. Solar I-V testing revealed a relatively high I(sc) (short-circuit current) of 25 μA cm(-2) and the cell was capable of generating a current utilizing abundant near-IR photons (maximum at ca 880 nm) with greater than eight-fold higher energy conversion efficiency than white light. These studies represent a powerful demonstration of the photoexcitation properties of a biological system in a closed solid-state device and its successful implementation in a functioning solar cell.
Solution processed sodium chloride interlayers for efficient electron extraction from polymer solar cells (2012)

We investigate a solution-processable, non-toxic sodium chloride (NaCl) interlayer for aluminum cathodes in organic solar cells. The electron extraction at the cathode interface is strongly improved upon the insertion of NaCl leading to power conversion efficiencies of up to 2.9% as compared to 1.8% efficient devices without interlayer. Scanning electron and kelvin probe force microscopy studies reveal that the formation of NaCl crystals causes a decrease of the aluminum work function by more than 300 mV. By impedance spectroscopy, we found evidence that the NaCl crystals improve the energetic alignment at the polymer/metal interface.
Computer modelling of superconducting film type fault current limiters (1999)

Investigations are being carried out into the use of superconductors as fault current limiters. The authors are investigating devices constructed from various high T/sub c/ materials. Of particular interest are limiters constructed from superconducting YBCO thick films on YSZ substrates. In order to predict the limiting characteristics of a fault current limiter and to optimise the design parameters, an accurate numerical simulation has been developed. This model includes measured data in the form of E-J characteristics, thermal properties and R-T data. Data sets for different materials can be selected in order to compare the performance of candidate materials. A major concern during limiting is the way that heat is generated in the superconducting film. The authors' simulation treats the superconductor and substrate as a number of small elements in order to determine the temperature distribution within the film and substrate. Further additions model the heat loss mechanisms to the surrounding environment. This thermal model is included in an overall FCL model, which includes voltage sources and line or load impedances. One can use this model to accurately predict the current-time waveforms achievable with typical limiters, and to easily explore the effect of a change in operating conditions.
On aurait dit un âne mais elle était trop bête (1990)

On aurait dit un ne mais elle tait trop bte Guycioutier Jacques FrasiakTu voudrais bien crire Autrement.Voir natre sous ta main, Sous tes yeux, Quelque forme Qui ne te rappelle rien, Mais c'est en vain : Tu es condamn. Guillevic Art potique v^iathy, on aurait dit un ne, mais elle tait trop bte !On pouvait lui reprocher son caractre irascible ou sa rancune, mais c'tait lui faire injure de douter de son intelligence.
Selection of Co-Substrate and Aeration Conditions for Vanillin Production by Escherichia coli JM109/pBB1 (2004)

Yeast extract, Luria-Bertani medium and tryptone were tested as co-substrates for vanillin production from ferulic acid by resting cells of Escherichia coli JM109/pBB1.
Avian Retroviral Protease and Cellular Aspartic Proteases are Distinguished by Activities on Peptide Substrates (1989)

The avian sarcoma/leukemia virus protease (PR), purified from avian myeloblastosis virus has a native molecular mass of 26 kDa, suggesting a dimer structure. The enzymatic activity of PR has been characterized using synthetic peptide substrates. PR is most active at pH 5.5, 35 degrees C and 2-3 M NaCl. Under these conditions PR cleaves decapeptides which are resistant in low ionic strength. This high, nonphysiological, salt concentration also increases the proteolytic activity of a cellular aspartic protease, pepsin. PR and pepsin show additional similarities: they both cleave a synthetic decapeptide at the same Tyr-Pro bond in low and high salt, while the cleavage site preferences of human renin and cathepsin-D in this substrate are altered at high salt concentrations. In addition, iodination of the tyrosine residue in this decapeptide causes an increase in the rates of hydrolysis by both PR and pepsin. However, Km values are too high to be estimated accurately for PR using Tyr-Pro and Tyr(I)-Pro decapeptides as substrates. Comparison of the digestion products of two additional decapeptides, altered in a single amino acid residue, shows that PR cleaves at fewer sites than all three cellular enzymes. Furthermore pepstatin, a strong inhibitor of pepsin, renin, and cathepsin-D has little effect on PR.
TYPE OF DISTURBANCE AND ECOLOGICAL HISTORY DETERMINE STRUCTURAL STABILITY (2007)

This study aims to reveal whether complexity, namely, community and trophic structure, of chronically stressed soil systems is at increased risk or remains stable when confronted with a subsequent disturbance. Therefore, we focused on a grassland with a history of four centuries of patchy contamination. Nematodes were used as model organisms because they are an abundant and trophically diverse group and representative of the soil food web and ecosystem complexity. In a field survey, a relationship between contaminants and community structures was established. Following, two groups of soil mesocosms from the field that differed in contamination level were exposed to different disturbance regimes, namely, to the contaminant zinc and a heat shock. The zinc treatment revealed that community structure is stable, irrespective of soil contamination levels. This implies that centuries of exposure to contamination led to adaptation of the soil nematode community irrespective of the patchy distribution of contaminants. In contrast, the heat shock had adverse effects on species richness in the highly contaminated soils only. The total nematode biomass was lower in the highly contaminated field samples; however, the biomass was not affected by zinc and heat treatments of the mesocosms. This means that density compensation occurred rapidly, i.e., tolerant species quickly replaced sensitive species. Our results support the hypothesis that the history of contamination and the type of disturbance determine the response of communities. Despite that ecosystems may be exposed for centuries to contamination and communities show adaptation, biodiversity in highly contaminated sites is at increased risk when exposed to a different disturbance regime. We discuss how the loss of higher trophic levels from the entire system, such as represented by carnivorous nematodes after the heat shock, accompanied by local biodiversity loss at highly contaminated sites, may result in detrimental effects on ecosystem functions.
ChemInform Abstract: Catalytic and Highly Regioselective Cross‐Coupling of Aromatic C—H Substrates. (2008)

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.