gebhart/patrepeval huggingface dataset:
Synthesis, Structure, and Catalytic Properties of Bis[bis(sulfonamido)] Titanium Complexes (2000)

Reaction of the titanium tetraamide Ti(NMe2)4 with 2 equiv of racemic or resolved bis(sulfonamide) ligand resulted in the formation of the [bis(sulfonamido)]2Ti complexes (TiL2) and N,N-dimethylamine. We have characterized the resulting TiL2 complexes by X-ray crystallography and variable-temperature NMR spectrometry to explore differences in the bonding and geometry of the bis(sulfonamido) ligand in these complexes. When racemic ligand was used, the resulting TiL2 complexes consisted of the homochiral and heterochiral diastereomers. One of these heterochiral diastereomers was characterized by X-ray crystallography (7hetero). When resolved ligand was employed, it was found that the product composition was dependent on the size of the bis(sulfonamide) ligand employed in the synthesis. When the aryl group of the bis(sulfonamide) ligand was tolyl (1res), two diastereomeric compounds were observed that were in equilibrium. These complexes were the C2-6homo and Cs-6homo diastereomers. When the aryl group was 2,5-dimethylphenyl (Xyl) (3rac), the major product was determined to be the homochiral diastereomer, C2-8homo, by X-ray crystallography. The homochiral diastereomer generated from the bis(sulfonamide) ligand with the aryl group 5-chloro-2-methoxy phenyl (4res) also gave the homochiral diastereomer C2-9homo. By NMR spectrometry both C2-8homo and C2-9homo were found to be single diastereomers, and no signals that could be attributed to the Cs-symmetric counterparts to Cs-6homo were observed. The structures of C2-6homo, 7hetero, C2-8homo, and C2-9homo were determined. Although the geometries between the homochiral and heterochiral diastereomers are very different, the metrical parameters are not. Each of the titanium centers in these structures is eight-coordinate. The ligand was found to bind through one of the sulfonyl oxygens of each sulfonyl group as well as the sulfonamido nitrogens. The Ti−N distances of the sulfonamido groups range from 2.070(3) to 2.095(3) Å, while Ti−O sulfonyl distances range from 2.159(2) to 2.328(3) Å. The bis(sulfonamide) ligands used in this work have also been used in the asymmetric addition of diethylzinc to aldehydes. This reaction is very efficient and gives excellent enantioselectivity with a wide variety of aldehydes. To determine if the TiL2 complexes were involved in the catalysis, an equilibrium mixture of the diastereomers C2-6homo/Cs-6homo was used in the asymmetric addition and compared with the catalyst generated under the reaction conditions from the ligand 1res. Although the mixture of C2-6homo/Cs-6homo gave high enantioselectivity, it exhibited different enantioselectivity and turnover frequency from the catalyst generated from 1res.
Catching RNAs on chromatin using hybridization capture methods (2017)

The growing appreciation of the importance of long noncoding RNAs (lncRNAs), together with the awareness that some of these RNAs are associated with chromatin, has inspired the development of methods to detect their sites of interaction on a genome-wide scale at high resolution. Hybridization capture methods combine antisense oligonucleotide hybridization with enrichment of RNA from cross-linked chromatin extracts. These techniques have provided insight into lncRNA localization and the interactions of lncRNAs with protein to better understand biological roles of lncRNAs. Here, we review the core principles of hybridization capture methods, focusing on the three most commonly used protocols: capture hybridization analysis of RNA targets (CHART), chromatin isolation by RNA purification (ChIRP) and RNA affinity purification (RAP). We highlight the general principles of these techniques and discuss how differences in experimental procedures present distinct challenges to help researchers using these protocols or, more generally, interpreting the results of hybridization capture experiments.
High Performance Elastic Convolver with Parabolic Horns (1980)

It has been demonstrated that wideband convolvers can efficiently provide the important function of programmable matched filtering for continually changing codes in spread-spectrum comnunication systems. Because of the potentially low manufacturing costs, the development of truly highperformance elastic convolvers is very desirable. In this paper, an improved elastic convolver based on the parabolic-horn beam-compression technique will be reported. This convolver uses short (1-US) horns, accommodates waveforms with time-bandwidth products of 930, and provides an F-factor of -74 dBm with less than 0.5-dB ripple in output frequency response. The features to be described include: (1) A parabolic horn design procedure which takes into account SAW anisotropy. (2) A scheme for self-convolution suppression based on a dual-track geometry which suppresses this spurious output to more than 40 dB below the main convolution signal over the full device bandwidth. (3) The use of thin metalization to reduce the phase dispersion due to SAW propagation. (4) A simple outputcircuit concept for minimizing the electromagnetic long-line effect.
A QUANTITATIVE EVALUATION METHOD OF GROUND CONTROL POINTS FOR REMOTE SENSING IMAGE REGISTRATION (2014)

Ground control point (GCP) extraction is an essential step in automatic registration of remote sensing images. However the lack of quantitative and objective methods for analyzing the GCP quality becomes the bottleneck that prevents the broad development of automatic image registration. Although several measurements for evaluating the number, accuracy and distribution of GCPs have been proposed in recent years, some of them are redundant and the evaluation of dispersion is not efiective enough. In this paper, a method for an objective and quantitative evaluation of GCP quality is proposed. The proposed method consists of three parts: measurement calculation, cost function calculation and flnal validation. In the flrst part, two new measurements are proposed to evaluate the number, dispersion and isotropy of GCPs, and the root mean square of GCP residuals using leave- one-out method (RMSloo) is used to evaluate the accuracy. In the second part, seed cost functions are utilized to transform the measurements into a limited value range as well as to be desired on the ascending direction. Subsequently, all the seed cost functions are combined by a total cost function to provide an integrated evaluation. In the third part, the GCP scenario is validated by the accepted threshold depending on the value of the total cost function. To evaluate the performance of the proposed method, experiments using four typical emulated scenarios of GCP distribution and two sets of real GCPs in SAR images are considered. The results demonstrate that the proposed GCP evaluation method performs more efiectively than the existing methods, especially in the evaluation of dispersion quality.
Functional significance of aromatic amino acids from three peptide loops of the α7 neuronal nicotinic receptor site investigated by site‐directed mutagenesis (1991)

Three aromatic amino acids, Tyr92, Trp148 and Tyr187 belonging to three separate domains of the alpha 7-subunit of neuronal nicotinic acetylcholine receptor were mutated to phenylalanine, and the electrophysiological response of the resulting mutant receptors analyzed in the Xenopus oocyte expression system. All mutations significantly decreased the apparent affinities for acetylcholine and nicotine, and to a lesser extent, those for the competitive antagonists dihydro-beta-erythroidine and alpha-bungarotoxin. Other properties investigated, such as the voltage dependency of the ion response as well as its sensitivity to the open channel blocker QX222, were not significantly changed, indicating that the mutations affected selectively the recognition of cholinergic ligands by the receptor protein. The maximal rates for the rapid desensitization process were slightly modified, suggesting that the contribution of Tyr92, Trp148 and Tyr187 to the binding area might differ in the various conformations of the nicotinic receptor. Other mutations at nearby positions (S94N, W153F, G151D and G82E) did not affect the properties of the electrophysiological response. These data point to the functional significance of Tyr92, Trp148 and Tyr187 in the binding of cholinergic ligands and ion channel activation of the nicotinic receptor, thus supporting a multiple loop model [(1990) J. Biol. Chem. 265, 10430-10437] for the ligand binding area.
Formal Total Synthesis of the Algal Toxin (−)‐Polycavernoside A (2013)

A concise and largely catalysis-based approach to the potent algal toxin polycavernoside A (1) is described that intercepts a late-stage intermediate of a previous total synthesis; from there on, this challenging target can be reached in a small number of steps. Key to success was a sequence of a molybdenum-catalyzed ring-closing alkyne metathesis (RCAM) reaction to forge the macrocyclic frame, followed by a gold-catalyzed and strictly regioselective transannular hydroalkoxylation of the resulting cycloalkyne that allows the intricate oxygenation pattern of the macrolactone ring of 1 to be properly set. The required cyclization precursor 5 was assembled by the arguably most advanced fragment coupling process based on an Evans-Tishchenko redox esterification known to date, which was optimized to the extent that the precious coupling partners could be used in an almost equimolar ratio (6/7 1:1.3). The preparation of these building blocks features, inter alia, the power of the Sc(OTf)(3)-catalyzed Leighton crotylation as well as the superb selectivities of alkene cross metathesis, asymmetric keto-ester hydrogenation, and the Jacobsen epoxidation/epoxide resolution technologies.
Daily alternating administration of high-dose alpha-2b-interferon and interleukin-2 bolus infusion in metastatic renal cell cancer. A phase II study (1993)

In conclusion, daily alternating administration of alpha-rIFN and rIL-2 is effective in RCC with less toxicity, and the response rate is comparable to those of other immunotherapeutic schedules, including adoptive immunotherapeutic schedules, including adoptive immunotherapy and combinations of high-dose IL-2 and alpha-IFN.
Emergency contraception with mifepristone and levonorgestrel: mechanism of action (2002)

The mode of action of emergency contraception with mifepristone or levonorgestrel is primarily due to inhibition of ovulation rather than inhibition of implantation.
Catalytic site requirements for elementary steps in syngas conversion to oxygenates over promoted rhodium (1986)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCatalytic site requirements for elementary steps in syngas conversion to oxygenates over promoted rhodiumWolfgang M. H. Sachtler and Masaru IchikawaCite this: J. Phys. Chem. 1986, 90, 20, 4752–4758Publication Date (Print):September 1, 1986Publication History Published online1 May 2002Published inissue 1 September 1986https://pubs.acs.org/doi/10.1021/j100411a009https://doi.org/10.1021/j100411a009research-articleACS PublicationsRequest reuse permissionsArticle Views980Altmetric-Citations235LEARN 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 options Get e-Alerts
Fluorinated Nitrogen Heterocycles via Cyclization. I. Trifluoromethyl-2-pyridones from Fluorinated 1,3-Dicarbonyls and Cyanoacetamide (1965)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTFluorinated Nitrogen Heterocycles via Cyclization. I. Trifluoromethyl-2-pyridones from Fluorinated 1,3-Dicarbonyls and CyanoacetamideSeymour PortnoyCite this: J. Org. Chem. 1965, 30, 10, 3377–3380Publication Date (Print):October 1, 1965Publication History Published online1 May 2002Published inissue 1 October 1965https://doi.org/10.1021/jo01021a028RIGHTS & PERMISSIONSArticle Views290Altmetric-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 InReddit PDF (520 KB) Get e-Alerts Get e-Alerts
Anharmonic Decay of Optical Phonons (1966)

An expression is derived from perturbation theory for the lifetime of an optical phonon decaying into two acoustical phonons, and its temperature dependence. The strength of the interaction is expressed in terms of the Gr\"uneisen constant and the effect of a strain, equivalent to the instantaneous strain of an optical mode, on the frequency spectrum of a linear chain with alternating force constants. This interaction depends on the ratio of the acoustical and optical mode frequencies at the zone boundary. Fitting the theory to silicon, the optical mode at k = 0 has a calculated half-width at 300\ifmmode^\circ\else\textdegree\fi{}K of about 1.2% of its frequency. This result is compared with experimental data.
Analytic determination of the pinhole collimator's point-spread function and RMS resolution with penetration (2002)

Pinhole collimators are widely used to image small organs and animals. The pinhole response function (PRF) of knife-edge pinhole collimators has been estimated previously using geometric constructions without considering penetration and using "roll-off" models that employ an exponential model for the flux. An analytic expression for the PRF on the imaging plane that includes the effect of aperture penetration is derived in this paper by calculating the flux for photons passing through the aperture and those passing through the attenuating material. The PRF is then used to approximate the angular-dependent root-mean-square resolution in the directions parallel and perpendicular to the tilt of the point source. The corresponding aspect ratio is then obtained. The formulas are then compared with experimental data.
Normal root elongation requires arginine produced by argininosuccinate lyase in rice (2014)

Plant roots play an important role in the uptake of water and nutrients, structural support and environmental sensing, but the molecular mechanisms involved in root development are poorly understood in rice (Oryza sativa), which is characterized by a dense fibrous root system. Here we report a rice mutant (red1 for root elongation defect 1) with short roots. Morphological and physiological analyses showed that the mutant had a shorter length from the quiescent center (QC) to the starting point of the elongation zone but a similar cell size and number of lateral and crown roots compared with the wild type. Furthermore, the mutant had similar radial structure and nutrient uptake patterns to the wild type. Map-based cloning revealed that the mutant phenotype was caused by a point mutation of a gene encoding an argininosuccinate lyase (ASL), catalyzing the last step of arginine biosynthesis. The OsASL1 gene has two distinct transcripts, OsASL1.1 and OsASL1.2, which result from different transcription start sites, but only OsASL1.1 was able to complement the mutant phenotype. OsASL1.1 was expressed in both the roots and shoots. The protein encoded by OsASL1.1 showed ASL activity in yeast. OsALS1.1 was localized to the plastid. The short root of the mutant was rescued by exogenous addition of arginine, but not by other amino acids. These results indicate that arginine produced by ASL is required for normal root elongation in rice.
Development of a Scalable Synthesis of a Vascular Endothelial Growth Factor Receptor-2 Kinase Inhibitor: Efficient Construction of a 6-Etherified [1,2,4]Triazolo[1,5-<i>a</i>]pyridine-2-amine Core (2013)

A practical and scalable synthesis of the vascular endothelial growth factor receptor-2 (VEGFR-2) kinase inhibitor 1 has been developed. The key features of the process development include facile preparation of the key raw material 3-amino-4-fluorophenol, chemoselective nucleophilic aromatic substitution of 5-chloro-2-nitropyridine with phenol, a safe one-pot synthesis of a substituted urea using an isothiocyanate generated in situ from inexpensive materials, and improvement of the yield of acylation in the end game. The optimized six-step synthesis afforded 1·H2O in 54% overall yield, twice as much as the yield of the original synthesis, without chromatographic purification. In addition, a robust recrystallization procedure to afford the desired crystal form of 1 was also developed.
Critical role of inhomogeneities in pacing termination of cardiac reentry (2002)

Reentry around nonconducting ventricular scar tissue, a cause of lethal arrhythmias, is typically treated by rapid electrical stimulation from an implantable cardioverter defibrillator. However, the dynamical mechanisms of termination (success and failure) are poorly understood. To elucidate such mechanisms, we study the dynamics of pacing in one- and two-dimensional models of anatomical reentry. In a crucial realistic difference from previous studies of such systems, we have placed the pacing site away from the reentry circuit. Our model-independent results suggest that with such off-circuit pacing, the existence of inhomogeneity in the reentry circuit is essential for successful termination of tachycardia under certain conditions. Considering the critical role of such inhomogeneities may lead to more effective pacing algorithms. (c) 2002 American Institute of Physics.
Calibrations of Ultraviolet Excess as Metallicity Indicator of F,G,K Stars (1984)

For F,G,K stars, their photometric data and metallicity, [Fe/H] are collected and their correlations between (U-B) and [Fe/H] for each spectral group are examined, using a reference sequence which is defined by the stars in Woolley's catalogue and other reference sequences. Detailed examination shows that the reference sequence by Woolley's catalogue appears to be properly defined for the calculation of (U-B) of population I stars in the solar neighborhood. It is suggested that accuracies of metallicities derived from (U-B) can be improved if we derive the correlations between [Fe/H] and (U-B) from the stars in each spectral group.
Inhibitory effects of paeoniflorin on lysophosphatidylcholine-induced inflammatory factor production in human umbilical vein endothelial cells (2012)

Lysophosphatidylcholine (LPC) plays an important role in atherosclerosis through initiation of endothelial inflammation response. Paeoniflorin (PEF), isolated from the dry root of Paeonia, has been reported to exert an anti-inflammatory effect, but the exact mechanism is not fully understood. The aim of this study was to investigate the inhibitory effects of PEF on LPC-induced inflammatory factor production and the underlying mechanisms. In human umbilical vein endothelial cells (HUVECs), different concentrations (1, 10 or 100 µmol/l) of PEF were added 2 h prior to exposure to LPC (10 mg/l) for 24 h. The results showed that PEF significantly inhibited LPC-induced inflammatory factor production. In addition, PEF was also able to suppress the enhanced high mobility group box-1 (HMGB1) expression and release, upregulated expression of receptor for advanced glycation end product (RAGE), Toll-like receptor (TLR)-2 and TLR-4, and increased nuclear factor-κB (NF-κB) activity induced by LPC. Our results suggest that PEF suppresses LPC-induced inflammatory factor production through inhibition of the HMGB1-RAGE/TLR-2/TLR-4-NF-κB pathway.
Synthesis of Benzo[b]indeno[2,1-d]furanone Skeleton from Ninhydrin and Cyclohexane-1,3-dione Derivatives (2003)

Korea Research Institute of Bioscience and Biotechnology, 52 Oun, Yusong, Daejeon 305-333, KoreaReceived September 15, 2003Key Words : Benzo[b]indeno[2,1-d]furanone, Aromatization, Cyclohexane-1,3-dione, Iodine, MethanolRecently, we are interested in the aromatization reaction of2-acylcyclohexane-1,3-dione derivatives by using iodine inmethanol.
Design and Fabrication of Stretchable Multilayer Self-Aligned Interconnects for Flexible Electronics and Large-Area Sensor Arrays Using Excimer Laser Photoablation (2008)

Stretchable interconnects are fabricated on polymer substrates using metal patterns both as functional interconnect layers and as in situ masks for excimer laser photoablation. Single-layer and multilayer interconnects of various designs (rectilinear and “meandering”) have been fabricated, and certain “meandering” interconnect designs can be stretched up to 50% uniaxially while maintaining good electrical conductivity and structural integrity. This approach eliminates masks and microfabrication processing steps as compared to traditional fabrication approaches. Furthermore, this technology is scalable for large-area sensor arrays and electronic circuits, adaptable for a variety of materials and interconnects designs, and compatible with MEMS-based capacitive sensor technology.
Expression and immunohistochemical localization of heparan sulphate proteoglycan N‐syndecan in the migratory pathway from the rat olfactory placode (2002)

N-syndecan, a membrane-bound heparan sulphate proteoglycan, is abundantly present in the developing nervous system and thought to play important roles in the neurite outgrowth. In the present study, we examined the distribution of N-syndecan in the migratory route from the rat olfactory placode using immunohistochemistry and in situ hybridization. At embryonic day 15, both heparan sulphate and N-syndecan immunoreactivities were localized in and around the migrating cell clusters, which contained luteinizing hormone-releasing hormone (LHRH) and calbindin D-28k. Immunoreactivity for other glycosaminoglycan chains, such as chondroitin and keratan sulphate, and core proteins of the chondroitin sulphate proteoglycan, neurocan and phosphacan, were barely detected in the migratory pathway from the olfactory placode. By in situ hybridization histochemistry, N-syndecan mRNA was localized in virtually all of migrating neurons as well as in cells of the olfactory epithelium and the vomeronasal organ. N-syndecan immunoreactivity surrounded cells migrating along the vomeronasal nerves that were immunoreactive for neural cell adhesion molecules, NCAM, L1 and TAG-1. Considering that NCAM is implicated in the migratory process of LHRH neurons and specifically binds to heparan sulphate, it is likely that a heterophilic interaction between NCAM and N-syndecan participates in the neuronal migration from the rat olfactory placode.