gebhart/patrepeval huggingface dataset:
The reduction by deuterium on platinum black of exo-2-norbornyl* and endo-2-norbornyl* to norbornane-2-d1 occurs with predominant retention of configuration (1991)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe reduction by deuterium on platinum black of exo-2-norbornyl* and endo-2-norbornyl* to norbornane-2-d1 occurs with predominant retention of configurationT. Randall Lee and George M. WhitesidesCite this: J. Am. Chem. Soc. 1991, 113, 1, 368–369Publication Date (Print):January 1, 1991Publication History Published online1 May 2002Published inissue 1 January 1991https://pubs.acs.org/doi/10.1021/ja00001a058https://doi.org/10.1021/ja00001a058research-articleACS PublicationsRequest reuse permissionsArticle Views82Altmetric-Citations3LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts
Projection reconstruction balanced fast field echo for interactive real‐time cardiac imaging (2001)

A balanced fast field echo (FFE) sequence (also referred to as true fast imaging with steady precession (true FISP)), based on projection reconstruction (PR) is evaluated in combination with real-time reconstruction and interactive scanning capabilities for cardiac function studies. Cardiac image sequences obtained with the balanced PR-FFE method are compared with images obtained with a spin-warp (2D Fourier transform (2DFT)) technique. In particular, the representation of motion artifacts in both techniques is investigated. Balanced PR-FFE provides a similar contrast to spin-warp-related techniques, but is less sensitive to motion artifacts. The use of angular undersampling within balanced PR-FFE is examined as a means to increase temporal resolution while causing only minor artifacts. Furthermore, a modification of the profile order allows the reconstruction of PR images at different spatial and temporal resolution levels from the same data. This study shows that balanced PR-FFE is a robust tool for cardiac function studies.
Wald statistic for model order selection in superposition models (2002)

A consistent model selection algorithm is presented for superimposed signal models. The proposed method is motivated by the Wald statistic and reduces the computational complexity of procedures based on the minimum description length (MDL) principle. The procedure is suggested when a noncyclostationary signal model or short data length prevents use of covariance rank test. For maximum model-order K, the procedure provides O(K) computational savings over an MDL test. Additionally, a proof establishes the consistency of a least-squares estimator using overparametrized. models. Finite sample performance of the proposed model selection method is studied via Monte Carlo simulations for estimating the multipath delays and amplitudes of a chirp signal.
Interleukin-1β (2005)

From the University of Colorado Health Sciences Center, Denver, CO The author has no financial interests to disclose.
Synthesis, Characterization, and Reactivity of Group 12 Metal Thiocarboxylates, M(SOCR)2Lut2 [M = Cd, Zn; R = CH3, C(CH3)3; Lut = 3,5-Dimethylpyridine (Lutidine)] (1997)

A series of group 12 metal thiocarboxylate species, M(SOCR)(2)Lut(2) [M = Cd, Zn; R = CH(3), C(CH(3))(3); Lut = 3,5-dimethylpyridine (lutidine)], were synthesized to investigate their potential to act as precursors for the formation of metal sulfide materials. These species were expected to undergo thiocarboxylic anhydride elimination to give stoichiometric metal sulfides and remove the organic supporting ligands cleanly. These species were characterized by (1)H, (13)C, and (where appropriate) (113)Cd NMR spectroscopies, TGA, elemental analysis, and single-crystal X-ray diffraction. The spectroscopic and analytical data were consistent with the formulas identified above, and in the solid state the compounds are monomeric with approximate tetrahedral metal coordination environments and monodentate S-bond thiocarboxylate ligands. Crystal data for Cd(SOCCH(3))(2)Lut(2): crystallized in the triclinic space group P&onemacr;, with a = 8.267(1) Å, b = 9.467(1) Å, c = 14.087(1) Å, alpha = 94.04(1) degrees, beta = 91.49(1) degrees, gamma = 104.03(1) degrees, and Z = 2. Thermal decomposition of these compounds in the solid state or in solution resulted in formation of the corresponding metal sulfide at low temperatures, as seen by powder X-ray diffraction. Evidence for thiocarboxylic anhydride elimination was documented by NMR in solution phase reactions. The effects on thiocarboxylic anhydride elimination, resulting from varying M, R, or solvent media, were examined by heating NMR tube solutions of M(SOCR)(2)Lut(2) in pyridine or toluene. Heating toluene or pyridine solutions of Cd(SOCCH(3))(2)Lut(2) resulted in formation of nanocrystalline, sphalerite CdS, as determined by X-ray diffraction and TEM. These preliminary reactivity studies have revealed the great potential of this highly tailorable chemical system as precursors to group 12 metal sulfido species.
Two‐dimensionally extended aromatic polyamines for optimization of charge‐transporting properties by partial oxidation (2009)

Abstract This article describes the synthesis of the two‐dimensionally extended aromatic polyamines by polycondensation between the tri‐ sec ‐amine monomer and p ‐phenylenediamine‐based dibromide, the polyradical generation by chemical and electrochemical oxidations, and the hole‐transporting properties. The molecular weights ( M n ) of the polyamines, 3a and 3b , were 7700 and 5000, respectively, and both polymers were very soluble in the typical organic solvents, ensuring a good film formation capability by a spin‐coating technique. The thermal stability of the aromatic polyamines, elucidated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), was quite high. More important, the cross‐conjugated structure is essential for the controlled radical generation and the maintenance of the radical stability. Cyclic voltammograms of the neutral polyamines in the presence of 1 vol % of trifluoroacetic acid and the intervalence bands of the partially oxidized polyamines with NOPF 6 revealed that the generated radicals delocalize over the p ‐phenylenediamine moieties. The half‐life of the polyradicals was about 12 h even under ambient conditions, which allowed us to fabricate and measure the hole‐only devices. The charge‐transporting properties of the polyamines were dramatically changed by the partial oxidation (20 mol %/aminium unit) with NOPF 6 . The neutral polyamines showed the conventional injection‐limit behaviors, whereas the hole‐transporting behaviors of the polyradicals are bulk‐limit and highly dependent on the chemical structure. The efficient hole‐transport of the all‐conjugated poly(aminium cationic radical)s was for the first time realized for the polyradical of 3b . © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 4577–4586, 2009
Arterial spin labelling and diffusion-weighted imaging in paediatric brain tumours (2019)

ADC and CBF values are useful for differentiating certain histological subtypes, and separating low- and high-grade paediatric brain tumours. The threshold values presented here are in agreement with previously published studies, as well as a new patient cohort. If ADC and CBF values acquired in the same tumour are combined, the diagnostic accuracy is optimised.
Biosynthetic Studies of Reticulol, an Isocoumarin, by13C-NMR Spectroscopy (1977)

Biosynthetic pathway of reticulol was studied by 13C-NMR spectroscopy on 13C-labeled compound and degradation experiment of 14C-labeled compound. The results indicated that the carbon skeleton of the reticulol molecule was the polyacetate in origin and the methoxy group of reticulol was derived from the methyl of methionine.
The Drosophila MBD2/3 protein mediates interactions between the MI-2 chromatin complex and CpT/A-methylated DNA (2004)

Methyl-DNA binding proteins play an important role in epigenetic gene regulation. The Drosophila genome encodes a single protein (MBD2/3) with extended homologies to the vertebrate methyl-DNA binding proteins MBD2 and MBD3. However, very little is known about its functional properties. We have now characterized an MBD2/3 null mutant allele that is viable and fertile. This mutation caused a strong dominant suppression of position-effect variegation and also resulted in a high rate of chromosome segregation defects during early embryogenesis. Confocal analysis of mutant embryos showed local displacement of MI-2 from DNA and indicated that MBD2/3 is associated with only a subset of MI-2 complexes. In addition, band shift experiments demonstrated a specific binding of MBD2/3 to CpT/A-methylated DNA, which reflects the endogenous DNA methylation pattern of Drosophila. Consistently, the localization of MBD2/3 was disrupted in embryos with reduced levels of DNA methylation. Our data provide novel insights into the function of MBD2/3 proteins and strongly suggest the existence of methylation-dependent chromatin structures in Drosophila.
Unimolecular dissociation rates of the chlorobenzene cation prepared by multiphoton ionization (1984)

We have studied the unimolecular reaction C6H5Cl+→C6H+5 +Cl as a function of internal energy by using multiphoton ionization (MPI) on a supersonically cooled jet of chlorobenzene to prepare the excited parent ion. Specific rate constants k(E) were obtained from an analysis of the distorted C6H+5 peak shape in a time-of-flight (TOF) mass spectrometer. Decomposition in the wavelength region 265–270 nm is shown to proceed by two-photon ionization followed by one-photon absorption. The internal energy of the excited parent ion is characterized in a separate experiment which measures the photoelectron kinetic energy distribution, obtained over the same wavelength range. The specific rate constants found in this study compare well with previous literature values, thus validating this MPI TOF technique for the determination of ion decomposition rates.
Surface-Enhanced Optical Nonlinearities of Nanostructured Fractal Materials (1997)

Localization of optical excitations in fractal metal nanocomposites, such as colloidal aggregates, self-affine and semicontinuous films, results in strong enhancements of optical nonlinearities. The localized modes of fractals cover a broad spectral range, from the visible to the far-infrared. Results of both theoretical and experimental studies of enhanced nonlinear optical responses of fractal nanostructures are considered.
P‐63: A New Transparent Plastic Substrate having High Heat Resistance and Low Retardation for Flexible Displays (2008)

Abstract We have been developing a new transparent plastic substrate for flexible displays. The plastic substrate (OPS substrate) is composed of a newly developed base film (OPS film) and hard coat layers. The OPS substrate has excellent physical properties such as high transparency, low retardation and high heat resistance over 200°C. The coefficient of thermal expansion (CTE) is relatively low as 40–45ppm. The dimensional changes under various conditions including temperature and humidity were directly observed by using CCD camera. The electrical properties of the OPS substrate sputtered Indium Tin Oxide (ITO) at various temperatures were evaluated. The OPS substrate sputtered ITO at 200°C shows low sheet resistance as 10Ω/□ and it is almost same as that of glass substrate sputtered ITO under the same condition.
Axially asymmetric metal alkyls. Part 5. Synthesis and reduction to ZrIIIspecies of Group 4 metallepines [ML(η-C5H5)2][L =(2-CHRC6H4)22–, R = H, M = Ti, Zr, or Hf)], isomers of [ZrL(η-C5H5)2](R = SiMe3), and meso-[M{1,8-(CHSiMe3)2C10H6}(η-C5H5)2](M = Zr or Hf); X-ray crystal structures of [TiL(η-C5H5)2](R = H) and λ- and δ-RS-[ZrL(η-C5H5)2](R = SiMe3) (1987)

Treating [MCl2(η-C5H4R′)2] with a di-Grignard reagent and/or a dilithium reagent based on (2-CHRC6H4)22–(L) yields the metallacycles [ML(η-C5H4R′)2](R = R′= H, M = Ti, Zr, or Hf; R = H, R′= SiMe3, M = Zr)(5), and a mixture of diastereoisomers of λ-RS- and δ-RS-[ZrL(η-C5H5)2](R = SiMe3)(6a), and λ-RR-and δ-SS-[ZrL(η-C5H5)2](R = SiMe3)(6b). Compound (6a) was readily converted to (6b) by photolysis in hexane. The ‘strained’ metallacycles meso-[M{1,8-(CHSiMe3)2C10H6}(η-C5H5)2](M = Zr or Hf)(7) were prepared from an intrinsically unstable dilithium reagent. Reduction of (5),(6a) and (6b), and (7) chemically and electrochemically shows that the generated d1 species are stable at ca. 20 °C except for M = Hf, and that for (5)[and possibly (6a) and (6b)] reduction is associated with metal–carbon bond rupture. The structures of (5)(M = Ti) and (6a) have been established from single-crystal X-ray diffraction data [Ti–Cα 2.207Å, Cα–Ti–Cα 87·8°, dihedral angle between phenyl groups, φ 62.2°; Zr–Cα 2.338Å, Cα–Zr–Cα 98.3(2)°, φ 73.6°].
Precision finishing with magnetorheological (MR) jet technology (2005)

As optical components' shape becomes more complex, and requirements on the precision get tighter, new, and more versatile polishing processes are required. Conformal, free form or steep concave optics are important examples of optics that are difficult to finish using conventional techniques due to mechanical interferences and steep local slopes. One suitable way to polish such shapes is by using a jet of abrasive/fluid mixture. A fundamental property of a fluid jet is that it begins to lose its coherence as the jet exits a nozzle resulting in instability of the material removal rate, and is therefore unsuitable for deterministic finishing. A method of jet stabilization has been proposed, developed and demonstrated whereby the jet of magnetorheological fluid is magnetized by an axial magnetic field when it flows from the nozzle. It has been shown that a magnetically stabilized jet of MR polishing fluid generates a reproducible material removal function (polishing spot) at a distance of several tens of centimeters from the nozzle. The technology is most attractive for the finishing of complex shapes like free form optics, steep concaves and cavities. Results will be presented showing the ability to use this technique to finish a variety of optical components.
Interface Peptides as Structure-based Human Immunodeficiency Virus Reverse Transcriptase Inhibitors (1995)

Reverse transcriptases from both human immunodeficiency viruses type 1 and 2 are obligatory dimers. A tryptophan-rich repeat motif that is highly conserved between these proteins, as well as in the reverse transcriptase from simian immunodeficiency virus, has been postulated to be involved in hydrophobic subunit interactions. A synthetic 19-mer peptide covering part of this tryptophan repeat motif was recently shown to inhibit human immunodeficiency viruses type 1 reverse transcriptase subunit dimerization (Divita, G., Restle, T., Goody, R. S., Chermann, J.-C., and Baillon, J. G. (1994) J. Biol. Chem. 269, 13080-13083). In the present study, we show that the same peptide can also inhibit human immunodeficiency virus type 2 reverse transcriptase subunit dimerization, suggesting that the same inhibitors might be used as agents against both viruses as well as against variants of human immunodeficiency virus type 1 that differ from the variant against which they were developed. Under appropriate experimental conditions, e.g. at acidic pH, this peptide is also able to induce the dissociation of the enzyme from human immunodeficiency virus type 1.
Compressive Online Video Background–Foreground Separation Using Multiple Prior Information and Optical Flow (2018)

In the context of video background–foreground separation, we propose a compressive online Robust Principal Component Analysis (RPCA) with optical flow that separates recursively a sequence of video frames into foreground (sparse) and background (low-rank) components. This separation method operates on a small set of measurements taken per frame, in contrast to conventional batch-based RPCA, which processes the full data. The proposed method also leverages multiple prior information by incorporating previously separated background and foreground frames in an n-ℓ1 minimization problem. Moreover, optical flow is utilized to estimate motions between the previous foreground frames and then compensate the motions to achieve higher quality prior foregrounds for improving the separation. Our method is tested on several video sequences in different scenarios for online background–foreground separation given compressive measurements. The visual and quantitative results show that the proposed method outperforms other existing methods.
Preparation and Characterization of Bifunctional Unilamellar Vesicles for Enhanced Immunosorbent Assays (1993)

Small unilamellar phospholipid vesicles with covalently attached biotin and horseradish peroxidase (HRP) were prepared and characterized in terms of hydrodynamic diameter, amount and activity of immobilized enzyme, and number of biotin molecules on the outer vesicle surface. In addition, the specific adsorption of these bifunctional vesicles and commercially available biotin-labeled horseradish peroxidase (B-HRP) to antibiotin antibody (ABA) coated polystyrene microtiter plate wells was examined. At low antibody surface densities, the signal (delta A/min) generated by the vesicles adsorbed to the surface was approximately 100 times higher than the signal generated by B-HRP. It was also found that the biotin-conjugated vesicles were able to compete effectively with free biotin in solution for surface ABA sites. These results indicate that this type of vesicle may be used in competitive and sandwich-type enzyme-linked immunoassays to improve the detection limits, increase the signal, and decrease the reaction time necessary to detect a given analyte concentration in solution.
1.5×10−9 Ωcm2 Contact resistivity on highly doped Si:P using Ge pre-amorphization and Ti silicidation (2015)

Record-low contact resistivity (pc) for n-Si, down to 1.5×10−9 Q-cm2, is achieved on Si:P epitaxial layer. We confirm that Ti silicidation reduces the pc for n-Si, while an additional Ge pre-amorphization implantation (PAI) before Ti silicidation further extends the pc reduction. In situ doped Si:P with P concentration of 2×1021 cm−3 is used as the substrate, and dynamic surface anneal (DSA) boosts P activation. In addition, TiOx based metal-insulator-semiconductor (MIS) contact is also studied on Si:P but is found to suffer from low thermal stability.
Fluorescence enhancement from single DNA molecules confined in SiO 2 nanochannels (2010)

We demonstrate that the detected emission intensity from YOYO-labeled DNA molecules confined in 180 nm deep Si/SiO2 nanofunnels changes significantly and not monotonically with the width of the funnel, an emission enhancement that is only detected for emitted light polarized parallel to the channel. We explain the enhancement effect as being due to optical phenomena in the channels. The enhancement effect may be of importance for quantitative fluorescence microscopy and for experiments with a tight photon budget.
ChemInform Abstract: α‐HALOALLYLLITHIUM SPECIES. COUPLING WITH ALKYL BROMIDES (1981)

Abstract Aus Allylchlorid (I) wird mit Lithium‐diisopropylamid das Anion hergestellt, das mit zahlreichen Bromiden zu den substituierten Allylbromiden (II) umgesetzt wird.
Dominant and nondominant distal radius microstructure: Predictors of asymmetry and effects of a unilateral mechanical loading intervention (2021)

Most information about distal radius microstructure is based on the non-dominant forearm, with little known about the factors that contribute to bilateral asymmetries in the general population, or what factors may influence bilateral changes over time. Here, we analyzed bilateral high resolution peripheral quantitative computed tomography (HRpQCT) data collected over a 12-month period as part of a clinical trial that prescribed a well-controlled, compressive loading task to the nondominant forearm. Baseline data from 102 women age 21-40, and longitudinal data from 66 women who completed the 12-month trial, were examined to determine factors responsible for side-to-side asymmetries in bone structure and change in structure over time. Cross-sectionally, the dominant radius had 2.4%-2.7% larger cross-sectional area, trabecular area, and bone mineral content than the nondominant radius, but no other differences were noted. Those who more strongly favored their dominant arm had significantly more, thinner, closely spaced trabecular struts in their dominant versus nondominant radius. Individuals assigned to a loading intervention had significant bilateral gains in total bone mineral density (2.0% and 1.2% in the nondominant versus dominant sides), and unilateral gains in the nondominant (loaded) cortical area (3.1%), thickness (3.0%), bone mineral density (1.7%) and inner trabecular density (1.3%). Each of these gains were significantly predicted by loading dose, a metric that included bone strain, number of cycles, and strain rate. Within individuals, change was negatively associated with age, meaning that women closer to age 40 experienced less of a gain in bone versus those closer to age 21. We believe that dominant/nondominant asymmetries in bone structure reflect differences in habitual loads during growth and past ability to adapt, while response to loading reflects current individual physiologic capacity to adapt.
Hydrothermal treatment of Novelose 330 results in high yield of resistant starch type 3 with beneficial prebiotic properties and decreased secondary bile acid formation in rats (2006)

Annealing and heat-moisture treatment (HMT) are shown to be suitable methods to increase the yield of resistant starch type 3 (RS3) from Novelose 330 by up to 75%. Peak temperatures of approximately 121 degrees C were used to produce to a sufficiently high thermal stability of the hydrothermal modified RS3 products for a wide range of applications. HMT significantly increased the crystallinity up to 40%. An in vivo feeding experiment with Wistar rats showed that fermentation of Novelose 330 dominated in the proximal colon, but degradation of HMT-Novelose was more dominant in the distal colon, leading to higher butyrate concentrations in this segment of the large bowel. Large-bowel surface and crypt length increased in the proximal colon in rats fed the Novelose 330-containing diet. In contrast, after the intake of HMT-Novelose, maximal values were found in the distal segment. The lower pH and higher butyrate concentration of the caecal and colonic contents significantly suppressed the formation of secondary bile acids in RS3-fed rats. The formation of secondary bile acids was inhibited more strongly by HMT-Novelose than by Novelose 330. The Ki-67-immunopositive epithelial cells in the colon of RS3-fed rats indicated the establishment of an optimal balance in the dynamic process of mucosal regeneration. HMT provides a method for the economical production of a high-quality RS3 with dominating prebiotic properties in the distal colon for health-promoting applications.
Aziridination of Alkenes Using N‐Iodo‐N‐potassio‐p‐toluenesulfonamide as a Nitrene Precursor. (2003)

Abstract For Abstract see ChemInform Abstract in Full Text.