gebhart/patrepeval huggingface dataset:
Comparison of Benzodiazepine-Like Compounds Using Topological Analysis and Genetic Algorithms (1998)

Four compounds within a set of ligands for the benzodiazepine receptors are characterized by their electron density maps at different resolution levels and reconstructed from calculated structure factors. The resulting complex three-dimensional density maps are first simplified into connected graphs using topological analysis. Then, an original genetic algorithm method, GAGS (Genetic Algorithm for Graph Similarity search), is developed and implemented in order to compare the connected graphs. Finally, the analysis of the best solutions of the algorithm are expressed in terms of functional group superimpositions. The GAGS analysis is applied to different resolution levels of the electron density maps and the resulting models are compared in order to assess the influence of the resolution on the resulting pharmacophore models.
Nanocomposite Materials: Polyhedral Silsesquioxanes (2005)

Abstract The unique properties of nanocomposites have revolutionized the field of materials science. Polyhedral oligomeric silsesquioxane (POSS) is one of the widely used nanostructured materials for the synthesis of hybrid nanocomposites. POSS nanocrystals have been incorporated as building blocks of controllable shapes into polymers to form hybrid materials exhibiting improved properties. A variety of polymerization techniques have been used in the preparation of POSS‐containing hybrids. Incorporation of POSS into polymers can result in substantial improvement in physical properties of the polymers, such as low dielectric constants, increased glass‐transition temperatures, low coefficient of thermal expansion, enhanced thermal stability, mechanical strength, as well as improved oxidation resistance and reduction in flammability, oxygen permeability, heat evolution, and viscosity during processing. The most interesting POSS‐polymer has been the development of POSS–poly(carbonate‐urea)urethane that is used in medical applications owing to its enhanced biocompatibility and antithrombogenesity. These composites are materials of choice in the fabrication of various cardiovascular devices, such as artificial heart valves, stent‐grafts, bypass grafts, microvascular beds, and other biomedical devices including breast implants, and as scaffolds for tissue engineering.
Coplanar waveguides in silicon with low attenuation and slow wave reduction (2007)

This paper presents coplanar waveguide structures with low attenuation and slow-wave reduction implemented in standard silicon technologies and suitable for frequencies of up to 40 GHz. Optimization and modelling of slow-wave coplanar waveguides (SW-CPW) is provided here and compared to standard CPW models. An on-chip SW-CPW attenuation of 0.25 dB/mm at 40 GHz is obtained, compared with 2.8 dB/mm for a standard CPW. As an application, a non-linear transmission line (NLTL) was designed using SW-CPW sections. This NLTL can sharpen the pulse rise time by 75%. This work demonstrates the feasibility and advantage of using SW-CPW techniques to build all-silicon pulse-compression NLTLs using commercial silicon foundry processes.
ChemInform Abstract: Attempted Simmons—Smith Reaction on β‐Alkylthio‐α,β‐unsaturated Ketones: A Regiospecific Synthesis of 2,4‐Disubstituted Thiophenes. (2013)

Abstract Simmons—Smith reaction of β‐methylthioketones of type (I) affords a direct entry to give 2,4‐disubstituted thiophenes.
The Phosphorescence of Tetraphenylmethane and Certain Related Substances (1939)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Phosphorescence of Tetraphenylmethane and Certain Related SubstancesDaniel B. ClappCite this: J. Am. Chem. Soc. 1939, 61, 2, 523–524Publication Date (Print):February 1, 1939Publication History Published online1 May 2002Published inissue 1 February 1939https://pubs.acs.org/doi/10.1021/ja01871a504https://doi.org/10.1021/ja01871a504research-articleACS PublicationsRequest reuse permissionsArticle Views833Altmetric-Citations60LEARN 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
Tests of a grazing-incidence ring resonator free-electron laser (1991)

The authors describe operational experience of the first free-electron laser (FEL) using a grazing-incidence ring resonator. The Boeing FEL optical cavity was changed from a simple concentric cavity using two spherical mirrors to a larger grazing-incidence ring resonator. Initial tests showed that poorly positioned ring focus and unreliable pointing alignment resulted in reduced and structured FEL output. Later efforts concentrated on improving the resonator alignment techniques and lowering the single-pass losses. FEL performance and reliability have significantly improved due to better ring alignment. The alignment procedure and recent lasing results are described. The effect the electron beam has on lasing is also discussed. Measurements are presented showing FEL temporal output and wavelength are sensitive to electron beam energy variation.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>
One‐step synthesis of novel 2,4‐diaminopyrimidine antifolates from bridged alicyclic ketones and cyanoguanidine (1999)

Abstract A convenient one‐step reaction with cyanoguanidine was used to convert alicyclic ketones to previously undescribed 2,4‐diamino‐5,6,7,8‐tetrahydroquinazolines with a one‐, two‐, or three‐carbon bridge in the carbocyclic ring. Although the yields of the desired products were modest, the principal advantage of this one‐step process was that it provided easy access to a variety of novel bridged heterocyclic ring systems whose synthesis from sterically hindered ketones by other methods would have required multiple steps with an even lower overall yield. The products were tested as inhibitors of dihydrofolate reductases from Pneumocystis carinii, Toxoplasma gondii , and rat liver with a view to examining the effect of a space‐filling bridge on binding. The most potent and selective compound in the group was 4,6‐diamino‐3,5‐diazatricyclo[7.2.1.0 2,7 ]dodeca‐2,4,6‐triene ( 13 ), whose potency and selectivity approached those of trimethoprim, a drug commonly used to treat P. carinii and T. gondii infection. 3,5‐Diamino‐4,6‐diazatricyclo[6.2.1.0 2,7 ]‐undeca‐2,4,6‐triene ( 14 ), the analog of 13 with a one‐carbon rather than a two‐carbon bridge showed similar potency and selectivity against the T. gondii enzyme, but was a weak and nonselective inhibitor of P. carinii dihydrofolate reductase. The other compounds tested were likewise weak and nonselective.
[The efficiency of the use of cerebrolysin in optic nerve diseases in children of different age]. (2005)

The purpose of the study was to evaluate the efficiency of cerebrolysin used in partial atrophies of the optic nerve in relation to the method of drug injection and to whether treatment was used in combination with percutaneous electrostimulation of the optic nerve. The study was based on the results of clinical and electrophysiological studies of 646 children (810 eyes) aged 8 weeks to 18 years. All the examinees were divided into 4 groups: 1) patients in whom cerebrolysin was administered as retrobulbar injections made once daily; 2) those in whom cerebrolysion was injected in combination with microcirculation-improving agents through the irrigation system into the retrobulbar and Tenon space; 3) patients who received cerebrolysin only through the irrigation system; 4) those in whom the agents affecting the microcirculatory bed in the optic nerve system were administered through the irrigation system. Cerobrolysin has turned out to be highly effective as a drug that improved the outcomes of percutaneous stimulation of the optic nerve due to the use of two-stage treatment of children with partial atrophy of the optic nerve of various genesis, involving irrigation therapy supplemented by cerebrolysin and vascular agents at the first stage and percutaneous stimulation of the optic nerve at the second one.
Detection of Linear and Cubic Interpolation in JPEG Compressed Images (2005)

A novel algorithm is introduced that can detect the presence of interpolation in images prior to compression as well as estimate the interpolation factor. The interpolation detection algorithm exploits a periodicity in the second derivative signal of interpolated images. The algorithm performs well for a wide variety of interpolation factors, both integer factors and non-integer factors. The algorithm performance is noted with respect to a digital camera's "digital zoom" feature. Overall the algorithm has demonstrated robust results and might prove to be useful for situations where an original resolution of the image determines the action of an image processing chain.
Copper-mediated oxidative [3 + 2]-annulation of nitroalkenes and pyridinium imines: efficient synthesis of 3-fluoro- and 3-nitro-pyrazolo[1,5-a]pyridines (2020)

An efficient route to pyrazolo[1,5-a]pyridines by Cu(OAc)2-promoted oxidative [3 + 2]-annulation of nitroalkenes with in situ generated pyridinium imines is developed. The reaction with α-fluoronitroalkenes enables the first preparative synthesis of 3-fluoro-pyrazolo[1,5-a]pyridines. Cycloaddition with α-unsubstituted nitroalkenes provides access to 3-nitro-pyrazolo[1,5-a]pyridines in excellent yields. A broad transformation scope was demonstrated. Both electron-rich and electron-deficient nitroalkenes as well as different aminopyridinium salts can be used for the assembly of the target pyrazolo[1,5-a]pyridines. The related aza-heterocycles, namely, pyrazolo[1,5-a]pyrazines and pyrazolo[1,5-b]pyridazines, were successfully prepared via the present methodology. The possible mechanism of the reaction is discussed.
ChemInform Abstract: REACTIONS OF BORON TRICHLORIDES WITH SILYLAMINES CONTAINING SILICON‐HYDROGEN BONDS (1980)

Abstract Reaktionen von B‐ trichlorid mit Di‐ und Trisilylaminen, die mindestens eine Si‐H‐Bindung enthalten, werden untersucht.
Error characterization and mitigation for 16nm MLC NAND flash memory under total ionizing dose effect (2016)

This paper studies the system-level reliability of 16nm MLC NAND flash memories under total ionizing dose (TID) effect. Errors that occur in the parts under TID effect are characterized at multiple levels. Results show that faithful data recovery only lasts until 9k rad. Data errors observed in irradiated flash samples are strongly asymmetric. To improve the reliability of the parts, we study error mitigation methods that consider the specific properties of TID errors. First, we implement a novel data representation scheme that stores data using the relative order of cell voltages. The representation is more robust against uniform asymmetric threshold voltage shift of floating gates. Experimental results show that the scheme reduces errors at least by 50% for blocks with less than 3k program/erase cycles and 10k rad. Second, we conduct empirical evaluations of memory scrubbing schemes. Based on the results, we identify a scheme that refreshes cells without doing block erasure. Evaluation results show that parts under this scrubbing scheme survive up to 8k PECs and 57k rad total doses.
Synthesis and optical properties of self-assembled 2D layered organic-inorganic perovskites for optoelectronics (2012)

L'innovation de la technologie de pointe et l'exigence du marché électronique se concentrent toujours sur l'électronique bon marché, qui présente une fabrication facile, avec des performances sans cesse améliorées. Les pérovskites hybrides organiques-inorganiques, qui combinent les propriétés des semi-conducteurs organiques et inorganiques, sont des candidats prometteurs pour de futurs dispositifs opto-électroniques. L énergie de liaison des excitons et la force d'oscillateur sont très élevées dans ces systèmes, ce qui rend possible leurs applications à température ambiante. Dans cette thèse, nous avons étudié des couches minces auto-assemblées de molécules de pérovskite (R-NH3)2PbX4. En modifiant la structure R, des pérovskites avec des propriétés optimisées (propriétés optiques d émission, rugosité de surface et photostabilité) ont été découvertes. Nous avons aussi développé des méthodes pour fabriquer des cristaux massifs et des nanoparticules de pérovskites, et nous avons créé de nouveaux cristaux de pérovskite mixtes: (RNH3)2PbYxX4-x et AB-(NH3)2PbX4. Des cavités verticales en régime de couplage fort ont été réalisées avec ces matériaux, l émission du polariton de basse énergie a été observée à température ambiante.
Field Verification Program (Aquatic Disposal). Impact of Open-Water Disposal of Black Rock Harbor Dredged Material on Benthic Recolonization at the FVP (Field Verification Program) Site. (1987)

Abstract : This report describes the effects of the disposal of dredged Black Rock Harbor (BRH) sediments on the ambient (predisposal) community and the mode and pattern of recolonization at the Field Verification Program (FVP) site. The recolonization process was measured by documenting the rate of recruitment of the FVP site by the dominant species and comparing this with the ambient (reference) community. The parameters used to describe recolonization anc convergence with the ambient system are species numbers, abundances of numerically dominant species, degree of infaunalization (successional stage), and depth of biogenic mixing of the bottom sediments (another measure of infaunalization). Both quantitative grab samples and the REMOTS interface camera were used to assess recolonization.
Analysis of Traffic Signals on an SDN for Detection and Classification of a Man-in-the-Middle Attack (2018)

Software-defined networking (SDN) has the potential to revolutionize the management capabilities of a highly distributed communications environment. Yet, adoption of SDN is contingent on a thorough analysis of security implications. In this paper, we investigate a man-in-the-middle (MITM) attack that exploits the centralized topological view critical to SDN operations. In particular, we present a new scheme for detection and classification of the attack at the network layer. We apply wavelet analysis to detect anomalous conditions introduced by the MITM attack using traffic signals collected at network switch ports. We then identify unique characteristics of reported anomalies in the collected traffic signals to build a classification framework. Other cyber events, such as a distributed denial-of-service and network congestion, are presented to the detection scheme to validate its general applicability. Overall, we successfully demonstrate the capability to detect and classify the MITM attack in addition to other cyber events at the network layer, thereby contributing to the security of SDN.
Equilibria and UV-Spectral Characteristics of BrCl, BrCl2−, and Br2Cl− Species in 1,2-Dichloroethane − Stereoselectivity and Kinetics of the Electrophilic Addition of these Species to Alkenes (2001)

UV/Vis spectrophotometric measurements have been used to determine the equilibrium constants and the absorption spectra of Bu4N+Br2Cl− and Bu4N+BrCl2− species in 1,2-dichloroethane (DCE) at 25 °C. The formation constants and the absorption spectra of BrCl from Br2 and Cl2 and of Bu4N+Cl3− species from Bu4N+Cl− and Cl2 were also determined in this solvent at 25 °C. The kinetics and the products of bromochlorination of several aryl-substituted olefins with BrCl, with Br2 in the presence of an excess of Bu4N+Cl− (Br2/Cl−), and with BrCl in the presence of an excess of Bu4N+Cl− (BrCl/Cl−) were investigated in DCE at different temperatures. The kinetics and product distribution data for the reactions with Br2/Cl− or BrCl/Cl− are interpreted on the basis of a mechanism involving a product- and rate-determining nucleophilic attack by chloride on the olefin-halogen (Br2 or BrCl) π complex. The data relating to the electrophilic addition of BrCl are interpreted in terms of the initial formation of a 1:1 olefin−BrCl π complex, the ionization of which, catalyzed by a second halogen molecule, gives a bromonium (or β-bromocarbenium) BrCl2− ion pair able to collapse to the corresponding bromochloro adducts. A significant proportion of the ion pair intermediates may, however, actually be present as bromonium (or β-bromocarbenium) Br2Cl− and Br3− ion pairs, and the collapse of these should be responsible for the formation of the dibromides in BrCl addition.
Non-fermenting Gram Negative Bacilli Associated with Acute Respiratory Infections in Children in Madras (1987)

Non-fermenting Gram negative bacilli (NFGNB) were isolated as the most predominant organism from children suffering from acute respiratory illness (ARI) and accounted for 40 out of 151 children reported in the study. Five of the NFGNB were isolated in pure culture and all of them were from children having lower respiratory infection. The isolation of NFGNB was higher when the duration of illness exceeded 7 days (44 per cent) as compared to 22 per cent with less than 7 days duration (P=0.03X). Detailed identification studies on 61 isolates of NFGNB showed that 56 (92 per cent) of them belonged to Pseudomonas pseudoalkaligenes alkaligenes group. Four strains were identified as Ps. pseudomallei group and one as Ps. stutzeri. The majority of the NFGNB isolates showed multidrug resistance.
Magnetic Switching Properties of GMR Spin-Valves Using SyAF Free Layers (2002)

GMR spin-valve type multilayers using a synthetic antiferromagnets (SyAF) free layers consisting of Co90Fe10(t1)/Ru(d)/Co90Fe10(t2) were deposited on a SiO2/Si substrate by using an ultrahigh vacuum magnetron sputtering system and a metal mask. Giant magnetoresistance curves of these multilyers exhibited two types of curves (normal and inverse like type), depending on the magnitude relation of t1 and t2. The magnetization switching field of SyAF free layers was independent of the Ru thickness(d), suggesting that the switching field is independent of the magnitude of the antiferromagnetic interlayer exchange coupling, and was proportional to (t1+t2)⁄Δt, which is in good agreement with the coherent rotation model with perfect antiparallel alignment during magnetization reversal of the SyAF.
Structure and magnetic properties of sputtered hard/soft multilayer magnets (2003)

The films with HM=(Pr,Dy)(Fe,Co,Nb,B)5.5 and SM=Fe, FeCo were prepared by sputtering and subsequent heat treatment. The coercivity of Ti-buffered (Pr,Dy)(Fe,Co,Nb,B)5.5 single-layer film with 320 nm thickness is as large as 18.8 kOe at room temperature. X-ray diffraction results reveal that the Pr2Fe14B-type phase is randomly oriented in almost all the multilayer films. For the multilayers of Ti(30 nm)/[HM(16 nm)Fe(x nm)]×20/Ti(30 nm)/Si(substrate), the remanence increases and the coercivity decreases with the addition of Fe content, in comparison with the results of the single-layer film and the maximum energy product of 14.8 MGOe is obtained at x=3.0. A noticeable shoulder on the demagnetization curve is observed at low temperatures. When Fe65Co35 is used as the SM component rather than Fe, similar results are found. The enhancement of the magnetic properties in the nanocomposite multilayer films is explained by means of the exchange coupling between the SM and/or HM nanograins of the intra- and interlayers.
Synthesis and Spectroscopic Characterization of Azolium Picrate Salts (2008)

Abstract Tetrazoles are valuable intermediates for the synthesis of energetic materials and combined with energetic anions such as azide, dinitramide, nitrate or picrate give compounds with interesting energetic properties. Azolium picrate salts with the following cations were prepared in high yields and purities: 1‐methyl‐5‐amino‐ 1H ‐tetrazolium ( 1a ), 1,4‐dimethyl‐5‐amino‐ 1H ‐tetrazolium ( 2a ), 1‐methylguanazinium ( 3a ) and 1,3‐dimethyl‐5‐amino‐ 1H ‐tetrazolium ( 4a ). The compounds were fully characterized by elemental analysis, mass spectrometry and vibrational and multinuclear NMR ( 1 H, 13 C and 15 N) spectroscopies. The thermal behavior of the picrate salts was assessed by DSC (Differential Scanning Calorimetry) measurements revealing high thermal stabilities. In addition, the long‐term stabilities of compounds 1a and 4a was assessed by TSC (Thermal Safety Calorimetry). Lastly, all compounds described here are stable to water and can easily be prepared on a large scale from cheap starting materials, making them of interest as new energetic compounds.
The hepatitis B virus MHBst167 protein is a pleiotropic transactivator mediating its effect via ubiquitous cellular transcription factors. (1997)

C-terminally truncated surface proteins of hepatitis B virus (HBV) are frequently translated from genomically integrated viral sequences. They may be relevant for hepatocarcinogenesis by stimulating gene expression. First, we examined the transactivating potential of middle hepatitis B surface protein truncated at amino acid (aa) position 167 (MHBst167) on the HBV regulatory element. In transient cotransfection assays using Chang liver or HepG2 cell lines and chloramphenicol acetyltransferase (CAT) reporter constructs only the HBV enhancer I, but no other HBV regulatory elements like the X promoter, the S1 or S2 promoter or the enhancer II/core promoter could be stimulated by MHBst167. Since there is no evidence for a direct interaction of MHBst167 with DNA, we subsequently analysed whether cellular transcription factors were involved in mediating transactivation. This was tested both with isolated transcription-factor-binding sites and in the natural context of viral and cellular promoter elements. Deletion analysis and electrophoretic mobility shift assays revealed that Sp1, AP1 and NF-kappa B can mediate transactivation by MHBst167. No involvement of CREB, NF1 or the liver-specific factor C/EBP was found. These data indicate that MHBst167 is a pleiotropic, non-liver-specific transactivator which exerts its effect via ubiquitous cellular transcription factors that are also involved in the regulation of expression of cellular genes relevant for proliferation and inflammation.