gebhart/patrepeval huggingface dataset:
Palladium-Catalyzed Asymmetric Phosphination. Scope, Mechanism, and Origin of Enantioselectivity (2007)

Asymmetric cross-coupling of aryl iodides (ArI) with secondary arylphosphines (PHMe(Ar'), Ar' = (2,4,6)-R3C6H2; R = i-Pr (Is), Me (Mes), Ph (Phes)) in the presence of the base NaOSiMe3 and a chiral Pd catalyst precursor, such as Pd((R,R)-Me-Duphos)(trans-stilbene), gave the tertiary phosphines PMe(Ar')(Ar) in enantioenriched form. Sterically demanding secondary phosphine substituents (Ar') and aryl iodides with electron-donating para substituents resulted in the highest enantiomeric excess, up to 88%. Phosphination of ortho-substituted aryl iodides required a Pd(Et-FerroTANE) catalyst but gave low enantioselectivity. Observations during catalysis and stoichiometric studies of the individual steps suggested a mechanism for the cross-coupling of PhI and PHMe(Is) (1) initiated by oxidative addition to Pd(0) yielding Pd((R,R)-Me-Duphos)(Ph)(I) (3). Reversible displacement of iodide by PHMe(Is) gave the cation [Pd((R,R)-Me-Duphos)(Ph)(PHMe(Is))][I] (4), which was isolated as the triflate salt and crystallographically characterized. Deprotonation of 4-OTf with NaOSiMe3 gave the phosphido complex Pd((R,R)-Me-Duphos)(Ph)(PMeIs) (5); an equilibrium between its diastereomers was observed by low-temperature NMR spectroscopy. Reductive elimination of 5 yielded different products depending on the conditions. In the absence of a trap, the unstable three-coordinate phosphine complex Pd((R,R)-Me-Duphos)(PMeIs(Ph)) (6) was formed. Decomposition of 5 in the presence of PhI gave PMeIs(Ph) (2) and regenerated 3, while trapping with phosphine 1 during catalysis gave Pd((R,R)-Me-Duphos)(PHMe(Is))2 (7), which reacted with PhI to give 3. Deprotonation of 1:1 or 1.4:1 mixtures of cations 4-OTf gave the same 6:1 ratio of enantiomers of PMeIs(Ph) (2), suggesting that the rate of P inversion in 5 was greater than or equal to the rate of reductive elimination. Kinetic studies of the first-order reductive elimination of 5 were consistent with a Curtin-Hammett-Winstein-Holness (CHWH) scheme, in which pyramidal inversion at the phosphido ligand was much faster than P-C bond formation. The absolute configuration of the phosphine (SP)-PMeIs(p-MeOC6H4) was determined crystallographically; NMR studies and comparison to the stable complex 5-Pt were consistent with an RP-phosphido ligand in the major diastereomer of the intermediate Pd((R,R)-Me-Duphos)(Ph)(PMeIs) (5). Therefore, the favored enantiomer of phosphine 2 appeared to be formed from the major diastereomer of phosphido intermediate 5, although the minor intermediate diastereomer underwent P-C bond formation about three times more rapidly. The effects of the diphosphine ligand, the phosphido substituents, and the aryl group on the ratio of diastereomers of the phosphido intermediates Pd(diphos*)(Ar)(PMeAr'), their rates of reductive elimination, and the formation of three-coordinate complexes were probed by low-temperature 31P NMR spectroscopy; the results were also consistent with the CHWH scheme.
PhoP/PhoQ: macrophage‐specific modulators of <i>Salmonella</i> virulence? (1991)

The regulation of gene expression by the two-component regulatory system PhoP/PhoQ is necessary for Salmonella typhimurium survival within macrophages, defensin resistance, acid resistance, and murine typhoid fever pathogenesis. Salmonella experience multiple environments during mammalian infection and survival requires tightly regulated gene expression. After phagocytosis by macrophages, signal transduction by PhoQ results in the transcription of phoP-activated genes (pags) encoding proteins essential to bacterial survival and virulence. One such gene, pagC, encodes an envelope protein with amino acid similarity to an epithelial cell invasion protein of Yersina enterocolitica, Ail, and a bacteriophage lambda outer membrane protein, Lom. The PhoP and PhoQ proteins can also repress the synthesis of proteins, encoded by phoP repressed genes (prgs), when pags are maximally expressed. If prgs encode receptors for toxic compounds, prg repression may protect the cell within macrophages when pag expression is most necessary. At least one prg locus, prgH, is required for full S. typhimurium mouse virulence. Within the macrophage, different environments may stimulate a switch from pag to prg expression that is necessary to Salmonella survival. prg expression may also be necessary for surviving nonmacrophage environments. Study of the PhoP regulon should lead to the discovery of new virulence factors, increase knowledge of how gene regulation is essential to bacterial virulence, and perhaps lead to the development of better vaccines for typhoid fever.
Der Chemische Transport von Mischkristallen in den Systemen MnO/ZnO, FeO/ZnO und CoO/ZnO (1999)

Durch Chemischen Transport mit NH4Cl bzw. HCl (900 → 750 °C) gelingt es, feste Lösungen von MnO, FeO und CoO im Wurtzitgitter des ZnO darzustellen. Die Präparation der Lösungen von ZnO in MnO, FeO bzw. CoO hingegen gelang nur im Falle des FeO. Die Mischphasen fallen in Form von bis zu 10 mm großen Einkristallen an. Gitterkonstanten wurden bestimmt. UV-Vis-Spektren wurden aufgenommen und diskutiert. Die FeO-haltige Phase wurde mössbauerspektroskopisch untersucht. Chemical Vapor Transport of Solid Solutions. 3 Chemical Transport of MnO/ZnO, FeO/ZnO, and CoO/ZnO Mixed Crystals By means of chemical vapor transport using HCl as transport agent (950 → 750 °C) it is possible to prepare solid solutions of MnO, FeO, and CoO in the lattice of ZnO (wurtzite type). Preparation of solutions of ZnO in MnO, FeO resp. CoO however was possible only in the case of FeO. Single crystals up to 10 mm length could be prepared by this way. Lattice parameters have been determined. UV-Vis spectra have been measured and been discussed. Mössbauer spectra of the FeO containining compound have been recorded.
Rocking Chair Lithium Battery Based on Nanocrystalline TiO2 (Anatase) (1995)

LPI
Physical, Mechanical, and Macromolecular Properties of Starch Acetate during Extrusion Foaming Transformation (2006)

Due to the transformation of starch acetate during extrusion, the functional properties of extruded starch acetate-based foams were significantly affected by the extrusion process parameters. To obtain the optimum functional properties as packaging materials, it was necessary to analyze the functional proprieties of extruded starch acetate foams based on the morphological properties after extrusion transformation. Corn starch acetate with degree of substitution (DS) of 2.30 and potato starch acetate with DS of 1.09 were extruded with 10, 15, and 20% ethanol in a twin screw extruder using screw speeds of 110, 130, and 150 rpm and barrel temperatures of 130, 150, and 170 °C. A response surface design was applied to analyze the effects of ethanol content, screw speed, and barrel temperature on the physical properties (radial expansion ratio, unit and bulk densities, and water absorption index), mechanical properties (unit and bulk spring indices and compressibility), and macromolecular properties (scanning electron micrographs) of the extruded starch acetate foams. Ethanol content, barrel temperature, and screw speed had significant effects on the functional properties of extruded starch acetate foams. Because of the differences in molecular structure degradation in the corn and potato starch acetates, the functional properties of extruded corn starch acetate foams were higher than those of extruded potato starch foams. This was substantiated with significant macromolecular structural differences.
Preparation and purification of metal fluorides for crystals and glasses (1995)

Abstract The development of low‐loss fluoride glass fibres for transoceanic telecommunications led to an increased demand for inorganic fluorides with ultrahigh purity in respect of transition metals, rare earths and oxygen. This review paper describes the Merck Ltd strategy for achieving a wide range of metallic fluorides using methods of preparation and purification selected for a combination of technical efficacy and economic practicability. General preparative methods involving aqueous and non‐aqueous routes are described, together with purification methods such as ion exchange, zone refining and vacuum sublimation. The special role of ammonium fluoride complexes is discussed. The application of these general methods to the manufacture of fluoride glass components is described, with special reference to the ZBLAN formulation. Additional glass compositions and their individual requirements are also discussed. The parallel application of high‐purity metal fluorides in the growth of optical crystals is emphasised, the history of fluoride ultrapurification having begun with the early demand for high‐quality UV and IR crystals such as CaF 2 and LiF.
White emission magnetic nanoparticles as chemosensors for sensitive colorimetric and ratiometric detection, and degradation of ClO<sup>−</sup>and SCN<sup>−</sup>in aqueous solutions based on a logic gate approach (2015)

Fluorescent chemosensors for detecting single anions have been largely synthesized. However, the simultaneous detection and degradation of multiple anions remain a major challenge. Herein we report the synthesis of a white emission nanoprobe on the basis of a Coumarin-Rhodamine CR1-Eu complex coordinated to dipicolinic acid (dpa)-PEG-Fe3O4 nanoparticles for the selective detection of ClO(-) and SCN(-) ions on controlling by a logic gate. The obtained nanoprobe exhibits three individual primary colors (blue, green, and red) as well as white emission at different excitation energies. Interestingly, this nanoprobe shows a marked rose red to violet emission color change in response to ClO(-), a reversible violet to rose red emission color change in response to SCN(-), and high ClO(-) and SCN(-) selectivity and sensitivity with a detection limit of 0.037 and 0.250 nM, respectively. Furthermore, the SCN(-) and ClO(-) can degrade simultaneously through the redox reaction between ClO(-) and SCN(-).
MP RAGE: a three-dimensional, T1-weighted, gradient-echo sequence--initial experience in the brain. (1992)

The authors evaluated a recently developed sequence for magnetic resonance imaging of the brain. The three-dimensional, Fourier-transformed acquisitions require magnetization-prepared 180 degrees radio-frequency pulses and rapid gradient-echo (MP RAGE) sampling. The resulting T1-weighted images were compared with T1-weighted spin-echo (SE) images; both were obtained after paramagnetic contrast material was administered to 33 patients with known or suspected focal brain lesions. Image quality and contrast between gray and white matter were superior with the MP RAGE sequence compared with the T1-weighted SE sequence. The time for obtaining contiguous thin-section (1.3-2.5-mm) images was also comparable, with readily acquired multiplanar reformations obviating additional images. MP RAGE imaging depicted more focal lesions than did T1-weighted SE imaging and matched the number seen with T2-weighted SE imaging. Demonstration of paramagnetic contrast enhancement of lesions was comparable in most cases; however, three lesions showed greater enhancement on T1-weighted SE images and two others were seen only on the T1-weighted SE images. Thus, the MP RAGE sequence may provide an alternative to T1-weighted SE imaging.
Postnatal Malnutrition and Growth Retardation: An Inevitable Consequence of Current Recommendations in Preterm Infants? (2001)

Preterm infants inevitably accumulate a significant nutrient deficit in the first few weeks of life that will not be replaced when current RDIs are fed. This deficit can be directly related to subsequent postnatal growth retardation.postnatal growth retardation, preterm infants.
Low efficacy of a <i>Bacillus thuringiensis</i> (Berl.) formulation in Controlling the diamondback moth, <i>Plutella xylostella</i> (L.), in the Philippines (1988)

Abstract Neem ( Azadirachta indica ) seed kernel extracts were evaluated in cabbage fields in the Philippines for their ability to control the diamondback moth, Plutella xylostella (L.). The extracts were compared to synthetic insecticides and a Bacillus thuringiensis (Berl.) formulation ( thuricide hp ). The B.t . treatments (1 kg prod./ha) showed low efficacy in controlling P. xylostella . The assumption that this was due to higher UV‐radiation in the trial area could not be confirmed in a corresponding field experiment. Possible development of B.t . resistance in P. xylostella populations is discussed. Zusammenfassung über die geringe Wirksamkeit einer Bacillus thuringiensis (Berl.) Formulierung bei der Bekämpfung von Plutella xylostella auf den Philippinen Extrakte aus Niemsamen ( Azadirachta indica ) wurden In Kohlfeldern auf den Philippinen im Hinblick auf ihre Eignung zur Bekämpfung der Kohlmotte Plutella xylostella (L.) untersucht. Die Extrakte wurden mit synthetischen Insektiziden und einer Bacillus thuringiensis (Berl.)‐ Formulierung ( thuricide hp ) verglichen. Die B.t .‐Behandlungen zeigten einen geringen Bekämpfungseffekt bei P. xylostella . Die Annahme, daß dies auf stärkere UV‐Einstrahlung im Versuchsgebiet zurückzuführen sein könnte, ließ sich in einem entsprechend angelegten Feldversuch nicht bestätigen. Die mögliche Resistenzentwicklung gegen B.t . bei P. xylostella wird diskutiert.
Analytical driving functions for higher order Ambisonics (2008)

In this paper, we present the derivation and investigation of analytical expressions for the loudspeaker driving signals for higher order Ambisonics. The approach relies on the assumption of a continuous distribution of secondary sources on which sampling is performed to yield the actual loudspeaker signals for real-world implementations. For source-free volumes enclosed by the secondary source distribution, this formulation of Ambisonics leads to what is known as simple source approach. Since the simple source approach is theoretically well documented, we will depart from it and concentrate on the special case of a circular distribution of secondary point sources and derive analytical expressions for the driving signals. We furthermore derive a closed-form expression for the actual reproduced wave field for the circular secondary source distribution.
Dextran and Polymer Polyethylene Glycol (PEG) Coating Reduce Both 5 and 30 nm Iron Oxide Nanoparticle Cytotoxicity in 2D and 3D Cell Culture (2012)

Superparamagnetic iron oxide nanoparticles are widely used in biomedical applications, yet questions remain regarding the effect of nanoparticle size and coating on nanoparticle cytotoxicity. In this study, porcine aortic endothelial cells were exposed to 5 and 30 nm diameter iron oxide nanoparticles coated with either the polysaccharide, dextran, or the polymer polyethylene glycol (PEG). Nanoparticle uptake, cytotoxicity, reactive oxygen species (ROS) formation, and cell morphology changes were measured. Endothelial cells took up nanoparticles of all sizes and coatings in a dose dependent manner, and intracellular nanoparticles remained clustered in cytoplasmic vacuoles. Bare nanoparticles in both sizes induced a more than 6 fold increase in cell death at the highest concentration (0.5 mg/mL) and led to significant cell elongation, whereas cell viability and morphology remained constant with coated nanoparticles. While bare 30 nm nanoparticles induced significant ROS formation, neither 5 nm nanoparticles (bare or coated) nor 30 nm coated nanoparticles changed ROS levels. Furthermore, nanoparticles were more toxic at lower concentrations when cells were cultured within 3D gels. These results indicate that both dextran and PEG coatings reduce nanoparticle cytotoxicity, however different mechanisms may be important for different size nanoparticles.
Peptide Fragments of Laminin and Fibronectin Promote Migration (Haptotaxis and Chemotaxis) of Metastatic Cells (1984)

The migration of tumour cells through basement membranes and extracellular matrices is an integral component of tumour invasion and metastasis. Laminin (LMN) and fibronectin (FN) at 1-100 micrograms/ml promote the directed migration of metastatic murine melanoma cells 40-70-fold greater than controls in modified Boyden chambers. Antibodies abrogated the migration of cells in response to the respective protein. Preincubation of melanoma cells with plasma FN had no effect on subsequent migration to LMN or FN. The migration of these cells was largely related to substratum-attached molecules and increasing adhesion gradients of cells; this has been termed haptotaxis. Peptide fragments of both FN and LMN were isolated by affinity chromatography with monoclonal antibodies, heparin or other constituents. FN has two unique domains, 80-125 K and 66 K, which promote the adhesion of tumour cells, whereas only one appeared to be responsible for promoting migration. Peptides of LMN, isolated with heparin and monoclonal antibody, define a cell migration-promoting activity within the 200 K chains of LMN. Serum spreading factor and epinectin, the latter an adhesion molecule derived from squamous epithelial tumour cells, are also capable of promoting the migration of malignant cells. Thus, directed migration of metastatic tumour cells may be promoted with peptide fragments of adhesion molecules and blocked with the respective antibody.
Influence of Drug Solubility in the Formulation of Hydrophilic Matrices (1989)

(1989). Influence of Drug Solubility in the Formulation of Hydrophilic Matrices. Drug Development and Industrial Pharmacy: Vol. 15, No. 14-16, pp. 2197-2212.
Guaranteeing synchronous message deadlines with the timed token protocol (2003)

The problem of guaranteeing synchronous message deadlines in token ring networks in which the timed token medium access control protocol is used is discussed. Synchronous capacity, defined as the maximum time for which a node can transmit its synchronous messages every time it receives the token, is a key parameter in the control of synchronous message transmission. To ensure the transmission of synchronous messages before their deadlines, synchronous capacities must be properly allocated to individual nodes. Several synchronous capacity allocation schemes are analyzed in terms of their ability to satisfy deadline constraints of synchronous messages. It is shown that an inappropriate allocation of the synchronous capacities could cause message deadlines to be missed, even if the synchronous traffic is extremely low. The normalized proportional allocation scheme, which can guarantee the synchronous message deadlines for synchronous traffic of up to 33% of available utilization is proposed.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Preparation of Semiconductor Nanoparticle−Polyurea Composites Using Reverse Micellar Systems via an in Situ Diisocyanate Polymerization (1999)

The polymerization of diisocyanates, such as hexamethylene diisocyanate, via reaction with water to form polyurea (PUA), has been utilized to immobilize nanoparticles, when formed in reverse micelles. Metal sulfide nanoparticles (CdS, ZnS, coprecipitated CdS−ZnS, and ZnS-coated CdS), as well as TiO2, AgI, and Ag nanoparticles, were immobilized successfully without undesirable particle coagulation, by the simple addition of diisocyanate to the micellar solution. The resulting PUA composites consist of powder of 0.01−0.1 mm in size and where the immobilized nanoparticles are more or less exposed to the external surface, such that they are utilizable as photocatalysts for the generation of H2 from 2-propanol aqueous solution. With tolylene 2,4-diisocyanate used as monomer, the resulting PUA composite is soluble in both DMF and DMSO, and a nanoparticle-containing transparent film can therefore be prepared by casting the resulting DMSO solution onto a quartz sheet.
Enhanced Enzymatic Hydrolysis of Steam-Exploded Douglas Fir Wood by Alkali-Oxygen Post-treatment (2004)

Good enzymatic hydrolysis of steam-exploded Douglas fir wood (SEDW) cannot be achieved owing to the very high lignin content (>40%) that remains associated with this substrate. Thus, in this study, we investigated the use of alkali-oxygen treatment as a posttreatment to delignify SEDW and also considered the enzymatic hydrolyzability of the delignified SEDW. The results showed that under optimized conditions of 15% NaOH, 5% consistency, 110°C, and 3 h, approx 84% of the lignin in SEDW could be removed. The resulting delignified SEDW had good hydrolyzability, and cellulose-to-glucose conversion yields of over 90 and 100% could be achieved within 48 h with 20 and 40 filter paper units / g of cellulose enzyme loadings, respectively. It was also indicated that severe conditions, such as high NaOH concentration and high temperature, should not be utilized in oxygen delignification of SEDW in order to avoid extensive condensation of lignin and significant degradation of cellulose.
Towards a New Paradigm for Weather Modification Science and Technology (2006)

Weather modification science and technology development and implementation program plans have been created since 1946, and have collectively led to modern weather modification technologies. These modern weather modification technologies have helped the community at large for over 60 years. Recent technological and scientific advances, scientific community recommendations, and contemporary socioeconomic problems form the basis for constructing a new plan that facilitates the development and applications of modern weather modification technologies for more effectively benefiting society. Pending Congressional legislation adds urgency to a new approach for developing weather modification science and technology. This paper describes this new approach. The proposed approach encompasses a comprehensive agenda of fundamental and applied research and development efforts directed toward optimizing existing technologies used to manage “treatable” atmospheric processes and conditions, and to allow the development of select relevant innovative technologies. It will require a permanent, national program that administers its resources and oversees its activities. High-level implementation guidelines are also provided.