gebhart/patrepeval huggingface dataset:
Ce(IV)-<i>N</i>-Acetylglycine Initiated Graft Copolymerization of Methyl Methacrylate onto Chemically Modified Pineapple Leaf Fibers (1996)

Abstract A study of the graft copolymerization of methyl methacrylate (MMA) onto chemically modified pineapple leaf fiber (PALF) was carried out in the temperature range 40°-60°, using the eerie ammonium sulfate and N-acetylglycine (NAG) combination as initiator in an aqueous medium. Effects of variation of time and temperature; concentration of Ce(IV), NAG, MMA, and sulfuric acid; PALF amount; and also effects of some inorganic salts and organic solvent on percentage of graft yield have been investigated. On the basis of experimental findings, a kinetic scheme has been proposed. IR spectra of original chemically modified PALF and grafted PALF have been taken and their characteristic bands have been identified.
Solvometallurgical process for extraction of copper from chalcopyrite and other sulfidic ore minerals (2019)

Copper is extracted from sulfidic ores by a leaching-electrodeposition system, thereby producing metallic copper and regenerating the oxidizing agent FeCl<sub>3</sub>.
Triglyceride Form of Docosahexaenoic Acid Mediates Neuroprotection in Experimental Parkinsonism (2018)

Parkinson's disease (PD) is a neurodegenerative disorder of unknown etiology. The main treatment of PD consists of medication with dopamine-based drugs, which palliate the symptoms but may produce adverse effects after chronic administration. Accordingly, there is a need to develop novel neuroprotective therapies. Several studies suggest that omega-3 polyunsaturated fatty acids (<i>n</i>-3 PUFA) might provide protection against brain damage. Here, we studied several experimental models of PD, using striatal neuronal cultures, striatal slices, and mice, to assess the neuroprotective effects of docosahexaenoic acid (DHA), the main <i>n</i>-3 PUFA in the brain, administered in its triglyceride form (TG-DHA). Hence, we determined the beneficial effects of TG-DHA on neural viability following 6-hydroxydopamine (6-OHDA)-induced neurotoxicity, a well-established PD model. We also implemented a novel mouse behavioral test, the beam walking test, to finely assess mouse motor skills following dopaminergic denervation. This test showed potential as a useful behavioral tool to assess novel PD treatments. Our results indicated that TG-DHA-mediated neuroprotection was independent of the net incorporation of PUFA into the striatum, thus suggesting a tight control of brain lipid homeostasis both in normal and pathological conditions.
Deposition of Ni-Al coatings onto copper by mechanical/heat treatment (2013)

The transition layer formed upon deposition of Ni-Al coatings onto the surface of Cu substrates by using the technique of mechanical treatment followed by annealing was found to contain α-(Cu,Ni) solid solution, Cu9Al4, Ni3Al, NiAl, Ni2Al3, and NiAl3. The mechanism for formation of protective coating in the Ni-Al-Cu system was discussed.
Low-voltage electro-optical memory device based on NiO nanorods dispersed in a ferroelectric liquid crystal (2016)

A low-power nonvolatile memory device is fabricated by dispersing nickel oxide nanorods (nNiO) into a ferroelectric liquid crystal (FLC) host. The dipolar nNiO adsorbed ions in the FLC and thereby reduced the screening effect, which resulted in the enhanced memory behavior.
Stochastic weighted particle methods for population balance equations (2011)

A class of stochastic algorithms for the numerical treatment of population balance equations is introduced. The algorithms are based on systems of weighted particles, in which coagulation events are modelled by a weight transfer that keeps the number of computational particles constant. The weighting mechanisms are designed in such a way that physical processes changing individual particles (such as growth, or other surface reactions) can be conveniently treated by the algorithms. Numerical experiments are performed for complex laminar premixed flame systems. Two members of the class of stochastic weighted particle methods are compared to each other and to a direct simulation algorithm. One weighted algorithm is shown to be consistently better than the other with respect to the statistical noise generated. Finally, run times to achieve fixed error tolerances for a real flame system are measured and the better weighted algorithm is found to be up to three times faster than the direct simulation algorithm.
Synthetic Control of Thorium Polyoxo-Clusters in Metal–Organic Frameworks toward New Thorium-Based Materials (2019)

Control over the assembly of thorium-based polyoxo-clusters remains a great challenge because of their quick olation and oxolation reactions. Here, we report the synthesis and isolation of two pure phase thorium polyoxo-cluster-based metal–organic frameworks (Th-MOFs), Th-NU-1008 and Th-NU-1011. Crystal structures of these Th-MOFs reveal two distinct 8-connected polyoxo-clusters: a hexanuclear cluster [Th6(μ3-O)4(OH)4(H2O)6(HCOO)4] was observed in Th-NU-1008 and a tetranuclear cluster [Th4(μ3-O)2(OH)4(DMF)2(H2O)4] in Th-NU-1011 which has never been reported before among thorium species. In both Th-NU-1008 and Th-NU-1011, the tetratopic linker, 1,4-dibromo-2,3,5,6-tetrakis(4-carboxyphenyl) benzene, joins the clusters together, forming two three-periodic networks, each with csq topology. The Brunauer–Emmett–Teller (BET) surface areas calculated from the Ar isotherms are approximately 800 and 700 m2 g–1 for Th-NU-1008 and Th-NU-1011, respectively. Because the linkers are oriented orthogonal to each other in the two respective MOFs, a 32 Å hexagonal channel is observed in Th-NU-1008 while a 15 Å channel is observed in Th-NU-1011. This work opens a new avenue to construct unexplored Th-MOF materials with targeted polyoxo-cluster structures.
Type 2 Intramolecular <i>N</i>-Acylnitroso Diels−Alder Reaction:  Scope and Application to the Synthesis of Medium Ring Lactams (2004)

Heteroatom variants of the type 2 intramolecular Diels-Alder reaction provide an efficient method for the preparation of bridged bicyclic heterocycles. The type 2 variant of the intramolecular N-acylnitroso Diels-Alder reaction is an effective method for the synthesis of bridged bicyclic oxazinolactams. Structural studies of the cycloadducts have allowed for quantification of the deformations of the bridgehead functionalities and provided a strategy for the stereoselective synthesis of substituted seven- and eight-membered ring lactams. Diastereoselective cycloadditions followed by cleavage of the oxazine ring afford azepin-2-ones or azocin-2-ones.
Boundary Layer Transition on the High Lift T106A Low-Pressure Turbine Blade With an Oscillating Downstream Pressure Field (2008)

This paper presents the results of an experimental study of the interaction between the suction surface boundary layer of a cascade of low-pressure (LP) turbine blades and a fluctuating downstream potential field. A linear cascade equipped with a set of T106 LP turbine blades was subjected to a periodic variation of the downstream pressure field by means of a moving bar system at low-speed conditions. Measurements were taken in the suction surface boundary layer using 2D laser Doppler anemometry, flush-mounted unsteady pressure transducers and surface shear stress sensors. The Reynolds number, based on the chord and exit conditions, was 1.6×105. The measurements revealed that the magnitudes of the suction surface pressure variations induced by the oscillating downstream pressure field, just downstream of the suction peak, were approximately equal to those measured in earlier studies involving upstream wakes. These pressure field oscillations induced a periodic variation of the transition onset location in the boundary layer. Two turbulence levels were investigated. At a low level of inlet freestream turbulence of 0.5%, a separation bubble formed on the rear part of the suction surface. Unsteady measurements of the surface pressure revealed the presence of high-frequency oscillations occurring near the start of the pressure recovery region. The amplitude of these fluctuations was of the order of 7–8% of exit dynamic pressure, and inspection of the velocity field revealed the presence of Kelvin-Helmholtz-type shear layer vortices in the separated free shear layer. The frequency of these shear layer vortices was approximately one order-of-magnitude greater than the frequency of the downstream passing bars. At a higher inlet freestream turbulence level of 4.0%, which is more representative of real engine environments, separation was prevented by an earlier onset of transition. Oscillations were still observed in suction surface shear stress measurements at a frequency matching the period of the downstream bar, indicating a continued influence on the boundary layer from the oscillating pressure field. However, the shear layer vortices seen in the lower turbulence intensity case were not so clearly observed, and the maximum amplitude of suction surface pressure fluctuations was reduced.
Farnesyl-diphosphate synthase. Interplay between substrate topology, stereochemistry, and regiochemistry in electrophilic alkylations. (1993)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTFarnesyl-diphosphate synthase. Interplay between substrate topology, stereochemistry, and regiochemistry in electrophilic alkylations.V. Jo Davisson and C. Dale PoulterCite this: J. Am. Chem. Soc. 1993, 115, 4, 1245–1260Publication Date (Print):February 1, 1993Publication History Published online1 May 2002Published inissue 1 February 1993https://pubs.acs.org/doi/10.1021/ja00057a005https://doi.org/10.1021/ja00057a005research-articleACS PublicationsRequest reuse permissionsArticle Views767Altmetric-Citations27LEARN 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
Determination of Absolute Configurations of Carbinols of Annonaceous Acetogenins with 2-Naphthylmethoxyacetic Acid Esters (1998)

Structural elucidation of absolute configurations of the stereogenic centers of acetogenins of Annonaceae was performed using the modified Mosher's method. Thus, by replacing MTPA (methoxytrifluoromethylphenylacetic acid) by 2-NMA (naphthylmethoxyacetic acid), we were able to determine the absolute configuration of the stereogenic centers of rolliniastatin-2 by simple analysis of the 1H NMR spectra recorded at 400 MHz. Indeed, by comparing the differences of chemical shifts between the MTPA esters with those obtained with 2-NMA esters, we showed that we could take advantage of the long-range anisotropic effect of the naphthyl ring for the elucidation of the unsymmetrical systems.
A Novel Axially Chiral 2,2‘-Bipyridine <i>N,N</i><i>‘</i>-Dioxide. Its Preparation and Use for Asymmetric Allylation of Aldehydes with Allyl(trichloro)silane as a Highly Efficient Catalyst (2002)

[reaction: see text] New axially chiral 2,2'-bipyridine N,N'-dioxides were obtained by a new method that does not involve any procedures for the separation of enantiomers. One of the dioxides, (R)-3,3'-bis(hydroxymethyl)-6,6'-diphenyl-2,2'-bipyridine N,N'-dioxide, exhibited extremely high catalytic activity for the asymmetric allylation of aldehydes with allyl(trichloro)silane. The allylation of aromatic aldehydes proceeded in the presence of 0.01 or 0.1 mol % of the dioxide catalyst to give the corresponding homoallyl alcohols of up to 98% ee.
Clinical, Pathologic, and Immunohistochemical Characteristics of Gastrointestinal Stromal Tumors of the Colon and Rectum: Implications for Surgical Management and Adjuvant Therapies (2006)

The majority of gastrointestinal stromal tumors of the colon and rectum are high-risk. Patients with high-risk colorectal gastrointestinal stromal tumors have a significant likelihood of developing metastases that is associated with poor prognosis. These patients need to be closely followed for an extended period and should be considered for adjuvant therapy with tyrosine kinase inhibitors.
Fluorescence quenching and excitation transfer between semiconducting and metallic organic layers (2004)

Here we present a simple approach to study the interaction of singlet excitons with polarons in conjugated polymers in organic electronic devices. Interlayer quenching constants KIL of 1.5M−1 between a fluorescent molecule and a doped polymer in a layered sample demonstrates the importance of understanding the quenching of excited states in polymeric devices. A combination of Förster resonance energy transfer and quenching of photoluminescence between a fluorescent molecule and a conjugated polymer in its semiconducting and metallic states were studied. The polymer is a chiral 3-substituted polythiophene (POWT) and the fluorescent molecule is fluorescein bound to dextran (D-FITC). Bilayer samples with fluorescein on top of the POWT were fabricated and studied with absorption spectroscopy, fluorescence microscopy, and electrochemical doping methods. When POWT is electrochemically dedoped it is possible to enhance the photoluminescence in the polymer layer by excitation transfer from the fluorescein layer. Our results demonstrate that PL from the polythiophene disappears rapidly as soon as the layer is doped. As the doping of polymer layer increases the fluorescence from the fluorescein on top of the polymer decreases, due to excitation quenching. Models for excitation transfer and excitation quenching in POWT/FITC bilayer devices have been developed. This model predicts a linear relationship between the PL from the two molecules, in agreement with our experimental findings. These results are relevant for the development of electroluminescent devices or solar cells based on conjugated polymers.
Secure RFID tag or sensor with self-destruction mechanism upon tampering (2023)

A circuit board anti-tamper mechanism comprises a circuit board having a frangible portion, a trigger having a trigger spring, a trigger arming mechanism actuated by the trigger wherein the trigger arming mechanism is initially non-actuated, a force producing mechanism, a latch providing mechanical communication between the trigger arming mechanism and the force producing mechanism, wherein the latch initially retains the force producing mechanism in a refracted position. Arming pressure applied to the trigger sufficient to overcome the trigger spring force will actuate the trigger arming mechanism, causing the anti-tamper mechanism to be armed. Subsequent tampering with the anti-tamper mechanism results in a decrease of pressure on the trigger below the trigger spring force, thereby causing the trigger arming mechanism to actuate the latch, thereby releasing the force producing mechanism to apply force to the frangible portion of the circuit board, thereby breaking the circuit board.
Low pressure reverse osmosis membrane for rejection of heavy metals (2007)

Low Pressure Reverse Osmosis Membrane (LPROM) has been introduced to water and wastewater industries in the past few years due to the high cost of operational and maintenance of conventional high-pressure RO membrane system. LPROM may remove more than 90% of heavy metals depending on the operating conditions of the system. LPROM with operating pressure less than 100 psi is commercially available to make treatment system more affordable and cost effective. Therefore, the aim of this study was to produce high-quality drinking water using LPROM system by removing heavy metals and other contaminants. The main objective of this study was to evaluate the effectiveness of LPROM for rejection of heavy metals, under different operating parameters (i.e. pressure, feed concentrations and pH). A commercially available LPROM (ES20) system manufactured by Nitto Denko Company was used in this study. The experimental design was carried out using Response Surface Methodology (RSM). Two types of wastewater containing heavy metals (i.e. synthetic polluted water containing copper and magnesium from copper chloride and magnesium sulphate solutions, and raw water from exmining pool from Tasik Biru, Sarawak) were studied. The experimental study for copper showed that higher operating pressure increased permeate flux and higher feed concentration and pH values increased the percentage of removal. However, the two-way interaction parameter (i.e. pressure vs. pH, pressure vs. feed concentration and pH vs. feed concentration) showed insignificant effects in determining permeate flux and copper removal. For magnesium, all parameters and all two-way interaction were significant in determining the percentage of magnesium removal. The higher the operating pressure resulted in a higher permeate flux and percentage of magnesium removal. A higher the value of pH has caused a lower permeate flux. However, it will increase the percentage of magnesium removal. Besides, the higher the feed concentration of magnesium was also resulted the higher percentage of magnesium removal. The optimum range of operating pressure for both copper and magnesium removal was between 90 to 120 psi and at pH between 5.5 and 7.5. The optimum statistical model for these processes based on the experimental conditions of this study indicates that operating pressure was the most significant parameter in determining the permeate flux. However, the statistical analysis of heavy metals removal was statistically insignificant and showed that the range of parameters in the study appears to be less significant to develop a sensitive and comprehensive model. This was due to the transport or separation mechanism between micropollutants and membrane surface, effect of chemical characteristics as well as effect of metal complexation. As a conclusion, operating conditions such as operating pressure and pH must be taken into account when designing the LPROM system for an optimum process in order to achieve a better heavy metals removal with higher permeate flux.
Maximum Likelihood Estimation of Peers" Performance in P2P Networks (2004)

LSIR
BALB/c mice immunized with a combination of virus-like particles incorporating Kaposi sarcoma-associated herpesvirus (KSHV) envelope glycoproteins gpK8.1, gB, and gH/gL induced comparable serum neutralizing antibody activity to UV-inactivated KSHV (2017)

Infection with Kaposi sarcoma-associated herpesvirus (KSHV) is estimated to account for over 44,000 new cases of Kaposi sarcoma annually, with 84% occurring in Africa, where the virus is endemic. To date, there is no prophylactic vaccine against KSHV. KSHV gpK8.1, gB, and gH/gL glycoproteins, implicated in the virus entry into host cells, are attractive vaccine targets for eliciting potent neutralizing antibodies (nAbs) against virus infection. We incorporated gpK8.1, gB, or gH/gL on the surface of virus-like particles (VLPs) and characterized these VLPs for their composition, size, and functionality. To determine which viral glycoprotein(s) elicit the most effective serum-nAbs, we immunized BALB/c mice with gpK8.1, gB, or gH/gL VLPs individually or in combination. Neutralizing antibody assay revealed that sera from mice immunized with the VLPs inhibited KSHV infection of HEK-293 cells in a dose-dependent manner. As a single immunogen, gpK8.1 VLPs stimulated comparable nAb activity to that of UV-inactivated KSHV (UV-KSHV). In contrast, UV-KSHV stimulated higher titers of nAb compared to gB (p = 0.0316) or gH/gL (p = 0.0486). Mice immunized with the combination of gB and gH/gL VLPs had a better nAb response than those immunized with either gB (p = 0.0268), or gH/gL (p = 0.0397) as single VLP immunogens. Immunization with any VLP combination stimulated comparable nAb activity to UV-KSHV serum. Our data provide the first evidence that KSHV gpK8.1, gB, and gH/gL glycoproteins can be incorporated onto the surface of VLPs and used as prophylactic vaccine candidates, with potential to prevent KSHV infection.
Monocyte Chemoattractant Protein-1 Induces a Novel Transcription Factor That Causes Cardiac Myocyte Apoptosis and Ventricular Dysfunction (2006)

Monocyte chemoattractant protein-1 (MCP-1; CCL2)-mediated inflammation plays a critical role in the development of ischemic heart disease (IHD). However, the gene expression changes caused by signal transduction, triggered by MCP-1 binding to its receptor CCR2, and their possible role in the development of IHD are not understood. We present evidence that MCP-1 binding to CCR2 induces a novel transcription factor (MCP-induced protein [MCPIP]) that causes cell death. Gene microarray analysis showed that when expressed in hiuman embryonic kidney 293 cells, MCPIP induced apoptotic gene families before causing cell death. Mutagenesis studies showed that the structural features required for transcription factor-like activity were also required for causing cell death. Activation of caspase-3 was detected after MCPIP transfection and Z-VAD-fmk partially inhibited cell death. Cardiomyocyte-targeted expression of MCP-1 in mice caused death by heart failure at 6 months of age. MCPIP expression increased in parallel with the development of ventricular dysfunction. In situ hybridization showed the presence of MCPIP transcripts in the cardiomyocytes and immunohistochemistry showed that MCPIP was associated with the cardiomyocyte nuclei of apoptotic cardiomyocytes. CCR2 expression in cardiomyocytes increased with the development of IHD. MCPIP production induced by MCP-1 binding to CCR2 in the cardiomyocytes is probably involved in the development of IHD in this murine model. MCPIP transcript levels were much higher in the explanted human hearts with IHD than with nonischemic heart disease. These results provide a molecular insight into how chronic inflammation and exposure to MCP-1 contributes to heart failure and suggest that MCPIP could be a potential target for therapeutic intervention.
Determinismo y omnisciencia (2017)

En este trabajo abordaremos el problema del determinismo en la acción humana y de su relación con la omnisciencia (divina o natural). Argumentaremos sobre la inextricable conexión que existe entre ambos conceptos y el papel que desempeñan en nuestra comprensión de la libertad. Si, como intentaremos mostrar, la omnisciencia implica determinismo, no hay espacio para la libertad en su sentido más profundo. Semejante constatación nos obliga a redefinir la noción de libertad para que resulte compatible con las leyes del universo y con las leyes del pensamiento.
Life Cycle Assessment of Photovoltaics (2016)

This chapter overviews the life cycle environmental performance of photovoltaic (PV) technologies. The ISO Standards prescribe the four steps for conducting a life cycle assessment (LCA): goal and scope definition; life cycle inventory (LCI); life cycle impact assessment (LCIA); and interpretation. The life cycle Cumulative Energy Demand (CED) of a PV system is the sum total of the primary energy harvested from the geo-biosphere in order to supply the direct energy and material inputs used in all its life cycle stages. This chapter presents the most up-to-date estimates of energy payback time (EPBT), greenhouse gas (GHG) emissions, and heavy metal emissions from the life cycles of the currently commercial photovoltaic (PV) technologies. The emissions of toxic gases and heavy metals during the life cycle of a PV system are largely proportional to the amount of fossil fuel consumed during its various phases, in particular, processing and manufacturing PV materials.