gebhart/patrepeval huggingface dataset:
Quinone Imides. VI. Addition of Dienes to p-Quinone Sulfonimides (1951)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTQuinone Imides. VI. Addition of Dienes to p-Quinone SulfonimidesRoger Adams and C. Robert Walter Jr.Cite this: J. Am. Chem. Soc. 1951, 73, 3, 1152–1155Publication Date (Print):March 1, 1951Publication History Published online1 May 2002Published inissue 1 March 1951https://pubs.acs.org/doi/10.1021/ja01147a080https://doi.org/10.1021/ja01147a080research-articleACS PublicationsRequest reuse permissionsArticle Views108Altmetric-Citations3LEARN 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-Alertsclose Get e-Alerts
Conversion of cellulosic materials to ethanol (1995)

The plant cell wall can be regarded as a giant bag-like macromolecule in which crystalline bundles of cellulose are embedded in a covalently linked matrix of hemicellulose and lignin. This heterologous polymer represents the dominant form of biomass on earth and a formidable challenge for solubilization and bioconversion. Bioconversion of lignocellulose requires the saccharification of both the hemicellulose and cellulose. Hemicellulose is composed of a mixture of sugars and can be readily hydrolysed by dilute acid at 140°C to produce a syrup containing pentoses and hexoses. However, no organisms in nature rapidly and efficiently convert both pentoses and hexoses into a single product of value. Our laboratory has developed such an organism by genetic engineering. Recombinant strains of Gram-negative bacteria (Escherichia coli or Klebsiella oxytoca or Erwinia sp.) have been constructed in which genes encoding the ethanol pathway from Zymomonas mobilis (pdc and adh) were inserted into the chromosome. These strains now efficiently convert all of the component sugars of hemicellulose and (cellulose) into ethanol. The saccharification of cellulose is more difficult and more complex. An enzymatic approach is preferred but at least three classes of enzymes are needed: endoglucanase, exoglucanase, and β-glucosidase. Klebsiella oxytoca and Erwinia sp. possess the native ability to transport and metabolize cellobiose (also cellotriose, xylobiose, and xylotriose), minimizing the need for added β-glucosidase. K. oxytoca strain P2, an ethanol-producing recombinant, has been evaluated in simultaneous saccharification and fermentation experiments to determine optimal conditions and limits of performance. Temperature was varied between 32 and 40°C over a pH range of 5.0–5.8 with 100 g 1−1 of crystalline cellulose (Sigmacell 50, Sigma Chemical Company, St. Louis, MO) as the substrate and commercial cellulase (Spezyme CE; Genencor, South San Francisco, CA). A broad optimum for fermentation was observed which allowed the production of over 44 g ethanol 1−1 (82–87% of the maximum theoretical yield). Two optimal saccharification and fermentation conditions were identified for fermentation yield, pH 5.2 at 35°C and pH 5.5 at 32°C, which produced 47 g ethanol 1−1 in 144 h (0.48 g ethanol (g cellulose) −1). Although yields were reduced at the lowest cellulase levels tested (2–5 filter paper units (g cellulose)−1), ethanol production per unit enzyme was much higher.
Castration reversibly alters levels of cholecystokinin immunoreactivity within cells of three interconnected sexually dimorphic forebrain nuclei in the rat. (1987)

Three sexually dimorphic cell groups in the forebrain of the rat--the central part of the medial preoptic nucleus, the encapsulated part of the bed nucleus of the stria terminalis, and the posterodorsal part of the medial nucleus of the amygdala--are larger in males, contain a high density of gonadal-steroid-concentrating cells, and are thought to play important roles in the control of reproductive behavior and physiology. Since each of these regions contains a large number of cholecystokinin-immunoreactive cells, we used an indirect immunohistochemical method to examine the possibility that levels of this peptide are modulated by circulating gonadal steroids in adult male rats. Rats were castrated at 60 days of age, and one group each was pretreated with colchicine and then killed 3, 7, and 14 days after gonadectomy. Castration clearly decreased CCK immunoreactivity within cells of each region, with the most dramatic effects occurring 7 and 14 days after gonadectomy, and these effects were reversed by treatment with testosterone over a 14-day period. The results suggest that CCK levels within individual cells in each of the interconnected sexually dimorphic nuclei examined here are regulated by circulating gonadal steroids and may be related to the hormonal modulation of reproductive functions thought to be mediated by these cell groups.
Piezoelectric Polymer Transducers for Detection of Structural Defects in Aircraft. (1977)

A new, versatile thin flim material, PVF2 (poly-vinylidene fluoride), has been fabricated into sensors for ultrasonic transducers because of its outstanding piezoelectric properties as well as its mechanical strength and chemical stability. PVF2 has a compliance ten times higher than that found in ceramics, and its g-constant (voltage per unit stress) is very high. Since the material can be made into very thin films, very wide-band electro-acoustic transducers can be incorporated into sensors that are flexible, variable in shape and a wide range of sizes. This fabrication versatility along with its relatively low cost, and its attractive piezoelectric, mechanical strength, and chemical stability makes this material a prime candidate for a large range of applications to monitor or inspect aircraft structures. A number of inspection techniques have been explored and are discussed. These include acoustic impact testing for ball bearing wear and crack formation in metal structures; pulse-echo and transmission ultrasonics to inspect composites. (Author)
Mobile Gamma Spectrometry Evaluation of the Resume 99 Exercise (2002)

During the RESUME 99 exercise, the radiocaesium (Cs) activity in the surroundings of Gavle in central Sweden was mapped using car-borne gamma-ray spectrometry (CGS). The CGS data along with airborne gamma-ray spectrometry (AGS) data from the same area have been used to examine possible correlations between the CGS and AGS results, detector type and position, and geographical information, such as land-use and road type. The overall differences between various CGS results are small, while larger differences are found between AGS and CGS results. In general only little correlation was found with land-use and with road-type and width. The differences between AGS and CGS results arise because airborne detectors have a different field of view than a ground-based detector. From an analysis of the depth-dependency of AGS and CGS data for a depth-distributed source, it is found that the mean mass depth may be inferred from the ratio of AGS to CGS spectral count rates. Integration of AGS and CGS data requires a precise definition of quantities and units for reporting activity concentrations in a complicated geometry and care must be taken to translate AGS results into equivalent CGS quantities taking into account the spatial distribution of the radionuclides.
Selective killing of transformed cells by methotrexate with histidine deprivation or with alpha-amino alcohols. (1983)

The effects of amino acid deprivation and treatment with amino alcohols upon the growth, viability, and susceptibility to methotrexate (MTX) cytotoxicity were examined in BALB/3T3 cells and their virally transformed counterparts, SV-T2 cells. Cells were deprived of either histidine or tyrosine plus phenylalanine, or they were treated with amino alcohol analogues of histidine and tyrosine (histidinol and tyrosinol). When incubated in medium lacking histidine and supplemented with dialyzed serum (histidine-deficient medium), the BALB/3T3 cells remained viable for at least 3 days, but they ceased logarithmic growth, and the cell number reached an early plateau. In contrast, the SV-T2 cells continued to divide in histidine-deficient medium. Neither cell line ceased division in medium deficient in both phenylalanine and tyrosine. Incubation of the BALB/3T3 cells with 1.5 mM histidinol or 1.0 mM tyrosinol caused an early plateau similar to the effect of histidine deprivation. SV-T2 cells were not affected by these concentrations of histidinol or tyrosinol, but growth was arrested at higher concentrations. Any of the conditions used which caused a plateau in the number of BALB/3T3 cells substantially protected the treated cells from cell death caused by MTX. Therefore, pretreatment of BALB/3T3 cells with histidine deprivation, 1.5 mM histidinol, or 1.0 mM tyrosinol protected this cell line against MTX-induced cell death, while the same pretreatment conditions failed to protect SV-T2 cells. (SV-T2 cells were protected by 4.0 mM histidinol.) Thus, the ability of MTX to kill cells in vitro can be selectively modified by conditions which protect cells which retain normal growth control characteristics, but which do not protect virally transformed cells.
Slow calcium and potassium currents across frog muscle membrane: measurements with a vaseline‐gap technique. (1981)

1. A vaseline-gap voltage-clamp technique was used to record slow Ca2+ and K+ currents from frog skeletal muscle fibres loaded with the Ca2+ chelator EGTA. 2. K+ currents were increased when Mg2+ replaced external Ca2+, and they were abolished when internal K+ was replaced by tetraethylammonium (TEA+). Ca2+ currents could be studied in isolation in fibres loaded with (TEA)2EGTA. 3. Under maintained depolarization, Ca2+ currents slowly increase (half-time of 35 msec or more at 25 mV) and then decline to a steady value. Decline under repolarization is rapid (half-time of 6-7 msec) and complete. During an action potential, the Ca2+ influx through this system is probably less than the influx observed with tracers. 4. Ba2+, Sr2+, Ca2+, Mn2+ and Mg2+ can carry current across the membrane; Ni2+ and Co2+ cannot. Ca2+ currents are weakly blocked by external Mg2+.
Noninvasive imaging of macrophages in rheumatoid synovitis using <sup>11</sup>C‐(<i>R</i>)‐PK11195 and positron emission tomography (2008)

11C-(R)-PK11195 PET imaging allows noninvasive in vivo imaging of macrophages in rheumatoid synovitis and possibly even in subclinical synovitis. Noninvasive visualization of macrophages may be useful both for detecting early synovitis and for monitoring synovitis activity during treatment.
Use of an Influenza Antigen Microarray to Measure the Breadth of Serum Antibodies Across Virus Subtypes (2019)

The influenza virus remains a significant cause of mortality worldwide due to the limited effectiveness of currently available vaccines. A key challenge to the development of universal influenza vaccines is high antigenic diversity resulting from antigenic drift. Overcoming this challenge requires novel research tools to measure the breadth of serum antibodies directed against many virus strains across different antigenic subtypes. Here, we present a protocol for analyzing the breadth of serum antibodies against diverse influenza virus strains using a protein microarray of influenza antigens. This influenza antigen microarray is constructed by printing purified hemagglutinin and neuraminidase antigens onto a nitrocellulose-coated membrane using a microarray printer. Human sera are incubated on the microarray to bind antibodies against the influenza antigens. Quantum-dot-conjugated secondary antibodies are used to simultaneously detect IgG and IgA antibodies binding to each antigen on the microarray. Quantitative antibody binding is measured as fluorescence intensity using a portable imager. Representative results are shown to demonstrate assay reproducibility in measuring subtype-specific and cross-reactive influenza antibodies in human sera. Compared to traditional methods such as ELISA, the influenza antigen microarray provides a high throughput multiplexed approach capable of testing hundreds of sera for multiple antibody isotypes against hundreds of antigens in a short time frame, and thus has applications in sero-surveillance and vaccine development. A limitation is the inability to distinguish binding antibodies from neutralizing antibodies.
A microfluidic vibrating wire viscometer for operation at high pressure and high temperature (2011)

This article discusses a microfluidic vibrating wire viscometer with an internal volume of a few microliters. Accuracy of order ±10% for viscosities ranging from 0.1 to 100 cP is demonstrated for temperatures (10 °C-175 °C) and pressures (10-24,000 psi) suitable for oilfield use by prior calibration in air and toluene. Comparison between multiple data sets indicates that a large fraction of the discrepancy between literature values is systematic, indicating that future refinements may be possible with better interpretation. Confinement effects are evaluated and are not found to play a significant role, which is surprising since the ratio (6.6) of the fluid channel width to the wire diameter is very low.
Three-Phase Modular Permanent Magnet Brushless Machine for Torque Boosting on a Downsized ICE Vehicle (2005)

The paper describes a relatively new topology of 3-phase permanent magnet (PM) brushless machine, which offers a number of significant advantages over conventional PM brushless machines for automotive applications, such as electrical torque boosting at low engine speeds for vehicles equipped with downsized internal combustion engine (ICEs). The relative merits of feasible slot/pole number combinations for the proposed 3-phase modular PM brushless ac machine are discussed, and an analytical method for establishing the open-circuit and armature reaction magnetic field distributions when such a machine is equipped with a surface-mounted magnet rotor is presented. The results allow the prediction of the torque, the phase emf, and the self- and mutual winding inductances in closed forms, and provide a basis for comparative studies, design optimization and machine dynamic modeling. However, a more robust machine, in terms of improved containment of the magnets, results when the magnets are buried inside the rotor, which, since it introduces a reluctance torque, also serves to reduce the back-emf, the iron loss and the inverter voltage rating. The performance of a modular PM brushless machine equipped with an interior magnet rotor is demonstrated by measurements on a 22-pole/24-slot prototype torque boosting machine.
Signal processing techniques for efficient use of transmit diversity in wireless communications (2002)

A class of efficient strategies for exploiting transmit antenna diversity on fading channels is developed. These techniques, which we refer to as linear antenna precoding, asymptotically transform a nonselective Rayleigh fading channel into a nonfading, simple white marginally Gaussian noise channel with no intersymbol interference. Linear antenna precoding requires no additional power or bandwidth, and is also attractive in terms of computation, robustness and delay considerations.
Modulation of Immune Cell Responses by Human Mesenchymal Stem Cells. (2004)

Abstract Mesenchymal stem cells (hMSCs) are multipotent stem cells that have the capacity to differentiate into various lineages. These cells provide stromal support and can be utilized as a feeder layer for expansion of hematopoitic stem cells and embryonic stem cells. Furthermore, allo-transplanted MSCs are not rejected and have been shown to mediate immuno-modulatory functions in vitro. Also, MSCs have been found at the wound site at extended times. The mechanisms underlying MSC migration and immuno-modulation are still under investigation. Aim: To understand the factors involved in human MSC (hMSC) migration and their interaction with various immune cell types. Methods: Human MSCs were examined for the presence of cell surface receptors that may play a role in migration using quantitative RT-PCR. Next, hMSCs were co-cultured with purified immune cell types including dendritic cells (DCs), naïve T cells and NK cells. Following the co-culture, changes in the phenotype of the immune cells under activating conditions were analyzed using ELISA and functional assays. Results: Human MSCs express Toll receptors, especially TLR4, on their cell surface. The TLR4 on hMSCs is functional as seen by a several-fold increase in IL-6 and chemokine IL-8 upon incubation with TLR4 exogenous ligand lipopolysaccharide (LPS) and the endogenous ligand, soluble hyaluronic acid (sHA). When hMSCs were incubated with activated dendritic cells, there was a >50% decrease in TNF-α secretion and a >50% increase in IL-10 secretion. When hMSCs were incubated with naïve T cells, hMSCs decreased IFN-γ secretion and increased IL-4 secretion. Decreased IFN-γ was also seen when MSCs were incubated with NK cells. Conclusion: These results suggest that (i) hMSCs may respond to the signals generated by breakdown products of extracellular matrix (e.g. sHA) via TLR4 and assist in wound healing (ii) hMSCs immuno-modulatory effects are mediated by interacting with various immune cell types and altering their phenotypic response to a more tolerant and anti-inflammatory response.
Enhancing memory use in Simple Coma: Multiplexed Simple Coma (2002)

Scalable shared-memory multiprocessors that are designed as cache-only memory architectures (Coma) allow automatic replication and migration of data in the main memory. This enhances programmability by hopefully eliminating the need for data distribution strategies and page migration schemes. A variant of Coma called Simple Coma has been proposed as a lower-cost alternative to hardware-intensive systems like Flat Coma. However, we find that Simple Coma is quite slower than Flat Coma. The main reason is the high page mapping, unmapping, and transfer overhead caused by memory fragmentation in Simple Coma. We propose a solution to the memory fragmentation problem that we call Multiplexed Simple Coma. The idea is to allow multiple virtual pages to map into the same physical page at the same time, therefore compressing the page working set of the application. Multiplexed Simple Coma requires very little support over Simple Coma and reduces its execution time by about 40%. We find that Multiplexed Simple Coma can be very easily implemented with off-the-shelf processors. In addition, there is no need to be selective when choosing what virtual pages are to share the same physical page. Overall, although Multiplexed Simple Coma is still slower than Flat Coma, since it is cheaper to implement, it represents a good cost-performance design point.
Mehrstufige Redoxsysteme, LVII. Quartärsalze pyridinsubstituierter 1,3,5‐Triazine – eine neue Klasse zwei‐ bis vierstufiger, reversibler Redoxsysteme (1991)

Multi‐Step Redox Systems, LVII. – Quaternary Salts of Pyridyl‐Substituted 1,3,5‐Triazines – A New Class of Two‐ to Four‐Step Reversible Redox Systems The synthesis of 1,3,5‐triazines 3–5a–e substituted by one to three 4‐pyridinium rings [ N ‐substituents Me, Et, Benzyl, CH 2 C(O)NMe 2 , CH 2 CO 2 C(O)OEt] is described. According to voltammetric data 3–5 constitute a new type of redox systems with reversible electron transfer in two to four separate steps. Reduction by zinc or sodium amalgam in acetonitrile produces coloured stable solutions of radicals (SEM).
The regio- and stereoselectivities of the reaction of allyl acetates and silyl ketene acetals catalyzed by palladium(0) complexes: a new route to cyclopropane derivatives (1991)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe regio- and stereoselectivities of the reaction of allyl acetates and silyl ketene acetals catalyzed by palladium(0) complexes: a new route to cyclopropane derivativesC. Carfagna, L. Mariani, A. Musco, G. Sallese, and R. SantiCite this: J. Org. Chem. 1991, 56, 12, 3924–3927Publication Date (Print):June 1, 1991Publication History Published online1 May 2002Published inissue 1 June 1991https://pubs.acs.org/doi/10.1021/jo00012a027https://doi.org/10.1021/jo00012a027research-articleACS PublicationsRequest reuse permissionsArticle Views633Altmetric-Citations75LEARN 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
Introduction to Computational Micromechanics (Lecture Notes in Applied and Computational Mechanics) (2004)

Using clinical isolates of Pseudomonas aeruginosa, we studied the ability of imipenem to antagonize the activity of nine other antipseudomonal beta-lactam antimicrobial agents. Imipenem caused truncation of the zones of inhibition in a disk diffusion test for 91 to 100% of the strains, depending on the beta-lactam tested. Addition of subinhibitory concentrations of imipenem caused a fourfold or greater increase in MICs for 72 of 74 isolates and in 20 to 87% of the tests, again depending on the antibiotic tested. beta-Lactamase assays with both whole-cell suspensions and cell sonicates showed that exposure to subinhibitory concentrations of imipenem resulted in a beta-lactamase production supported the hypothesis that induction of beta-lactamase was responsible for antagonism. In hydrolysis studies with a beta-lactamase extract, most of the antagonized drugs were either not hydrolyzed or only poorly hydrolyzed. We conclude that imipenem induces significantly elevated levels of beta-lactamase in P. aeruginosa. This increase in beta-lactamase is associated with increased resistance of the organism to many other beta-lactam agents.