gebhart/patrepeval huggingface dataset:
Electron Capture Dissociation and<sup>13</sup>C,<sup>15</sup>N Depletion for Deuterium Localization in Intact Proteins after Solution-Phase Exchange (2003)

For localization of deuterium atoms after solution-phase exchange with D2O, intact proteins are often digested prior to analysis by mass spectrometry (MS) and tandem MS (MS/MS). Amelioration of limitations associated with this approach (e.g., <70% sequence coverage and some D atom scrambling during MS/MS) were sought using intact proteins and two newer methods applied to tracking H/D exchange dynamics for the first time. Using 2-4-fold signal enhancements through depletion of 13C and 15N isotopes and implementing the new MS/MS technique of electron capture dissociation (ECD) yielded an increased number of c and z* ions observed (43 vs 25) for recombinant yeast ubiquitin (9.3 kDa). Initial determination of D atom content in consecutive c ion series (c4-c7, c28, c31, c32, and c33) was demonstrated. The improved ion signal and experiment speed combined with narrower isotopic distributions markedly increases the degree of localization and feasibility of ECD-based MS/MS after solution-phase H/D exchange.
Free Radicals and Mitochondria Dysfunction in Excitotoxicity and Neurodegenerative Disease (1999)

The study of neurodegenerative diseases has begun converging with the previously disparate fields of free radical pathophysiology, excitotoxin-mediated neuronal death and mitochondrial physiology. This convergence has been prompted by increasing evidence that excitatory amino acids and free radical toxicity contribute to neuronal apoptosis (1) and to the etiology of chronic neurodegenerative diseases (2–12). Moreover, a growing body of evidence implicates mitochondrial energetic and oxidative dysfunction, due to congenital genetic defects, and perhaps to radical-induced mutations and oxidative enzyme impairment, in several neurodegenerative disorders (reviewed by [5,6,13–17]).
General and Efficient Approaches to Fused [1,2-<i>a</i>]Pyrroles and [1,2-<i>a</i>]Indoles (1997)

2-[(Benzotriazol-1-yl)methyl]pyrroles 4a−c, and 15a,b and -indoles 23, prepared as previously reported,1,2 were converted into the corresponding fused [1,2-a]pyrroles 8a−c, and 18a,b and fused [1,2-a]indoles 25, 27 by intramolecular cyclizations; the formations of 25 and 27 involve [3 + 2] and [3 + 3] annulations. The benzotriazolyl-CH-ring moieties of intermediates 8a,b, 18a,b, 25, and 27 were further elaborated: (i) acylation of 8a and subsequent reduction and elimination promoted by LiAlH4 to give product 6; (ii) nucleophilic displacements of the benzotriazolyl moiety with NaCN, NaSPh, and Grignard reagents to afford compounds 9, 11, 12, 20, 29, and 32, respectively; (iii) base-assisted eliminations of benzotriazole from 8b and 18a to form the unsaturated fused [1,2-a]pyrroles 10 and 17; (iv) reactions of 18b and 25 with α,β-unsaturated ketone and aldehyde followed by acid-assisted elimination of the benzotriazolyl group to yield tricyclic compound 21 and product 31; and (v) Lewis acid promoted dimerization of 27 to form the fused indolo[3,2-b]carbazole 33.
Stable Haploid Cultured Cell Lines from frog Embryos (1970)

Two haploid cell lines have been established from androgenetic embryos of the frog, Rana pipiens; one line has been maintained in culture for 150 generations, the other for 200 generations. Karyotypes of the two lines agree well with the standard for the species although some chromosomes show small differences in length. The cells multiply in the same defined basal medium used for culture of other anuran cell lines; this medium consists of the usual amino acids, vitamins, and serum macromolecules plus an exogenous purine source. Both the haploids resemble "permanent" cell lines in their prolonged multiplication in culture. The two lines differ in their mode of growth, one being epithelial-like, the other forming an overlapping meshwork of fibroblast-like cells. Both have the low plating efficiency characteristic of "unaltered" cells. These two lines are exceptional in their ability to compete successfully with the diploid variants which arise by endomitosis or cell fusion and which usually overgrow the haploid population. The more vigorous line, RPH 68.2A, should provide the long-desired haploid material for genetic studies in cell culture.
Mechanism of Graham's reaction (1981)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMechanism of Graham's reactionRobert A. Moss, Joanna Wlostowska, Wenjeng Guo, Michal Fedorynski, James P. Springer, and Jordan M. HirshfieldCite this: J. Org. Chem. 1981, 46, 24, 5048–5050Publication Date (Print):November 1, 1981Publication History Published online1 May 2002Published inissue 1 November 1981https://doi.org/10.1021/jo00337a061RIGHTS & PERMISSIONSArticle Views864Altmetric-Citations23LEARN 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 (441 KB) Get e-AlertscloseSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts
1.7 kV/1.0 mΩcm<sup>2</sup>normally-off vertical GaN transistor on GaN substrate with regrown p-GaN/AlGaN/GaN semipolar gate structure (2016)

A normally-off vertical GaN-based transistor on a bulk GaN substrate with low specific on-state resistance of 1.0 mΩ·cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and high off-state breakdown voltage of 1.7 kV is presented. P-GaN/AlGaN/GaN triple layers are epitaxially regrown over V-shaped grooves formed over the drift layer. The channel utilizes so-called semi-polar face with reduced sheet carrier concentration at the AlGaN/GaN interface, which enables high threshold voltages of 2.5 V and stable switching operations. Note that formation of carbon-doped insulating GaN layer formed on p-GaN well layer underneath the channel suppresses the punch-through current at off-state between the source and drain, which enables good off-state characteristics. The fabricated high-current vertical transistor achieves successful fast switching at 400V/15A. These results indicate that the demonstrated vertical GaN transistor is very promising for future high power switching applications.
A study of oleic acid and 2,4-DHB acid aerosols using an IR-VUV-ITMS: insights into the strengths and weaknesses of the technique (2009)

An investigation of oleic acid and 2,4-dihydroxybenzoic (DHB) acid aerosols was carried out using an aerosol mass spectrometer with pulsed lasers for vaporization and ionization and an ion trap for mass analysis. The extent of ion fragmentation was studied as a function of both vaporization energy and ionization wavelength. Low CO2 laser energies in the vaporization stage and near-threshold single photon ionization resulted in the least fragmented mass spectra. For DHB, only the molecular ion was observed, but for oleic acid fragmentation could not be eliminated. Tandem MS of the main fragment peak from oleic acid was carried out and provided a tool for compound identification. Photoionization efficiency curves were also collected for both DHB and oleic acid and the appearance energies of both parent and fragment ions were measured. Evidence for fragmentation occurring post-ionization is given by the similar appearance energies for both the parent and fragment ions. The results from this study were compared with those from similar experiments undertaken with time-of-flight (TOF) mass analyzers. The degree of fragmentation in the ion trap was considerably higher than that seen with TOF systems, particularly for oleic acid. This was attributed to the long storage interval in the ion trap which allows time for metastable ions to decay. Differences in the degree of fragmentation between the ion trap and TOF studies also provided further evidence for fragmentation occurring post-ionization. For 2,4-dihydroxybenzoic acid, the long delay prior to mass analysis also allowed time for reactions with background gases, in this case water, to occur.
Single-Molecule Vibrational Spectroscopy and Microscopy (1998)

Vibrational spectra for a single molecule adsorbed on a solid surface have been obtained with a scanning tunneling microscope (STM). Inelastic electron tunneling spectra for an isolated acetylene (C2H2) molecule adsorbed on the copper (100) surface showed an increase in the tunneling conductance at 358 millivolts, resulting from excitation of the C-H stretch mode. An isotopic shift to 266 millivolts was observed for deuterated acetylene (C2D2). Vibrational microscopy from spatial imaging of the inelastic tunneling channels yielded additional data to further distinguish and characterize the two isotopes. Single-molecule vibrational analysis should lead to better understanding and control of surface chemistry at the atomic level.
An efficient modified probabilistic neural network hardware implementation for zero crossing thresholded binary signals (2002)

An efficient form of the modified probabilistic neural network is developed for the detection of Doppler shifted zero crossing thresholded binary chirp signals and other similar signals. The normal modified probabilistic neural network algorithm is based on a Gaussian radial basis function and the Euclidean distance measure requiring complex arithmetic operations. By using a simple tophat radial basis function and hamming distance measure in conjunction with binary signals it is possible to simplify the repetitive arithmetic operations to produce a more efficient form of the modified probabilistic neural network. This new form can produce more accurate correlator detector outputs than a multiple correlator detector system for moderate to high signal to noise ratios.
Rosiglitazone impacts negatively on bone by promoting osteoblast/osteocyte apoptosis (2004)

Thiazolidinediones (TZDs) increase peripheral tissue insulin sensitivity in patients with type 2 diabetes mellitus by activating the nuclear receptor peroxisome proliferator-activated receptor gamma (PPARgamma). In bone marrow stromal cell cultures and in vivo, activation of PPARgamma by high doses (20 mg/kg/day) of TZDs has been reported to alter stem cell differentiation by promoting commitment of progenitor cells to the adipocytic lineage while inhibiting osteoblastogenesis. Here, we have examined the in vivo effects of low-dose rosiglitazone (3 mg/kg/day) on bone, administered to mice by gavage for 90 days. Rosiglitazone-treated mice had increased weight when compared with controls, with no significant alterations in serum levels of glucose, calcium or parathyroid hormone (PTH). Bone mineral density (BMD) at the lumbar vertebrae (L1-L4), ilium/sacrum, and total body was diminished by rosiglitazone treatment. Histologically, bone was characterized by decreased trabecular bone volume and increased marrow space with no significant change in bone marrow adipocity. Decreased osteoblast number and activity due to increased apoptotic death of osteoblasts and osteocytes was apparent while osteoclast parameters and serum levels of osteocalcin, alkaline phosphatase activity, and leptin were unaltered by rosiglitazone treatment. Therefore, the imbalance in bone remodeling that follows rosiglitazone administration arises from increased apoptotic death of osteogenic cells and diminished bone formation leading to the observed decrease in trabecular bone volume and BMD. These novel in vivo effects of TZDs on bone are of clinical relevance as patients with type 2 diabetes mellitus and other insulin resistant states treated with these agents may potentially be at increased risk of osteoporosis.
1-(2-Hydroxy-2-methyl-3-phenoxypropanoyl)indoline-4-carbonitrile Derivatives as Potent and Tissue Selective Androgen Receptor Modulators (2014)

We present a novel series of selective androgen receptor modulators (SARMs) which shows excellent biological activity and physical properties. 1-(2-Hydroxy-2-methyl-3-phenoxypropanoyl)-indoline-4-carbonitriles showed potent binding to the androgen receptor (AR) and activated AR-mediated transcription in vitro. Representative compounds demonstrated diminished activity in promoting the intramolecular interaction between the AR carboxyl (C) and amino (N) termini. This N/C-termini interaction is a biomarker assay for the undesired androgenic responses in vivo. In orchidectomized rats, daily administration of a lead compound from this series showed anabolic activity by increasing levator ani muscle weight. Importantly, minimal androgenic effects (increased tissue weights) were observed in the prostate and seminal vesicles, along with minimal repression of circulating luteinizing hormone (LH) levels and no change in the lipid and triglyceride levels. This lead compound completed a two week rat toxicology study, and was well tolerated at doses up to 100 mg/kg/day, the highest dose tested, for 14 consecutive days.
Amine, Melamine, and Amide<i>N</i>-Halamines as Antimicrobial Additives for Polymers (2010)

N-chloro-2,2,6,6-tetramethyl-4-piperidinol laurate (Cl-TMPL) was prepared by reacting 2,2,6,6-tetramethyl-4-piperidinol hydrochloride (TMP·HCl) with lauroyl chloride, followed by chlorination with sodium dichloroisocyanurate. The chemical structure of Cl-TMPL was characterized with FT-IR, NMR, DSC, and TGA analyses. The antimicrobial performance of Cl-TMPL against Gram-positive and Gram-negative bacteria was compared with 1-chloro-3-dodecyl-5,5-dimethylhydantoin (Cl-DDMH), a amide N-halamine, and chloro-2,4-diamino-6-dodecyl-1,3,5-triazine (Cl-DADT), a melamine (imino) N-halamine. The three classes of N-halamines were used as additives for polyurethane (PU). Visible light transparency data indicated that up to 6% of Cl-DDMH or Cl-DADT could be compatibly mixed with PU, but Cl-TMPL had low compatibility with PU at higher than 2% of Cl-TMPL. With the same additive content, Cl-DDMH and Cl-DADT provided more powerful antimicrobial and biofilm-controlling effects than Cl-TMPL. In stability studies, however, PU samples with Cl-TMPL released the lowest amount of active chlorine into the immersing solution, suggesting the highest stability of the antimicrobial and biofilm-controlling efficacy.
<i>Science Translational Medicine</i> Podcast: 6 April 2011 (2011)

A conversation with David M. Holtzman about the challenges of developing new treatments for Alzheimer's disease.
Graphene-based composites (2011)

Graphene has attracted tremendous research interest in recent years, owing to its exceptional properties. The scaled-up and reliable production of graphene derivatives, such as graphene oxide (GO) and reduced graphene oxide (rGO), offers a wide range of possibilities to synthesize graphene-based functional materials for various applications. This critical review presents and discusses the current development of graphene-based composites. After introduction of the synthesis methods for graphene and its derivatives as well as their properties, we focus on the description of various methods to synthesize graphene-based composites, especially those with functional polymers and inorganic nanostructures. Particular emphasis is placed on strategies for the optimization of composite properties. Lastly, the advantages of graphene-based composites in applications such as the Li-ion batteries, supercapacitors, fuel cells, photovoltaic devices, photocatalysis, as well as Raman enhancement are described (279 references).
ChemInform Abstract: New Juglomycins. (1989)

Abstract A presumed precursor (I) of the juglomycins is isolated (space group P2 1 2 1 2 1 with Z=4) which in solution (acetone‐d6) forms an equilibrium with hemi‐ketal (II).
Operation parameters optimization of butadiene extraction distillation based on neural network (2011)

In this paper, based on the material balance, we used Aspen plus software to make sensitivity analysis of separation performance of the key component and the operational parameters. We quantitatively analyze the influence between the component parameters and the process. At last, we used the neural network to forecast the solvent ratio on diffident C4 feed and calculated the optimization solvent. At the end of the paper, we used the actual production data to test the validity of the model. On the view of reducing the energy consumption and ensuring the product quality, the research result told us that solvent ratio could be reduced nearly one percentage point.
Prefetching Policies for Remote Walkthroughs. (2002)

We present a 3D data streaming approach for remote walkthroughs, that integrates local optimization techniques for realtime rendering with prefetching techniques for remote scene graphs. Especially culling methods, that don&apos;t possess frame to frame coherence, can successfully be combined with remote scene databases, if the prefetching algorithm is adapted accordingly. We present a quantitative transmission policy, that takes the limited bandwidth of the network and the limited memory available at the client computer into account.
Antibody persistence following MeNZB vaccination of adults and children and response to a fourth dose in toddlers (2011)

Immune response to MeNZB was most sustained in adults. In infants, bactericidal titres decayed almost to baseline by 7 months after dose 3. Toddlers showed marked immune response following a fourth dose suggesting memory. Persisting antibody is likely to be necessary for ongoing protection, as seen with serogroup C meningococci.
Maximal Nerve Excitability Testing vs Electroneuronography (1980)

In an article published in 1977, Adour et al compared electroneuronography (neuromyography) with maximal nerve excitability testing (NET) and reached the conclusion that the prognostic value of the latter was more reliable in facial paralysis. Further analysis of the results of Adour et al leads, however, to the opposite conclusion and illustrates how one may avoid the pitfalls that exist in using electrical stimulation to evaluate facial nerve function. Certainly, electroneuronography (ENoG) is not a foolproof method and experience is needed in order to avoid errors in technique and to achieve reproducible results. The great advantage of ENoG vs maximal NET is the quantitative analysis of the number of degenerated fibers and the assessment of an accurate degeneration profile in Bell's palsy.
A Novel Type of Mechanical Power Transmission Array for Switching Densely – Arrayed Actuator Systems (2006)

This paper proposes a novel type mechanical transmission system for driving arrayed elements. The main advantage of this system is that it is able to operate individually arrayed elements with high-power. It was fabricated by MEMS technologies, and was confirmed that we are able to individually drive the arrayed elements by selectively driving tulip-shaped electrostatic clutch devices that transmit large power coming from a single power source. The transmitted stroke was 20 µ m for this experiment.
Instrumentation for Color Measurement (1972)

Modern photoelectric color-measuring instruments include: (a) spectrophotometers, with which the spectral reflectance curve of the sample is determined and CIE tristimulus values—the usual end result of color measurement—are obtained by simultaneous or subsequent integration; (b) colorimeters, in which the combination of the spectral-power distribution of the instrument source and the spectral response of its photodetector are adjusted by modifying filters to make the instrument approximately direct reading in CIE coordinates within linear transformations. The appropriate use of colorimeters is the measurement of small color differences between similar samples. This paper describes typical color-measuring spectrophotometers and tristimulus colorimeters and discusses their precision and accuracy for measuring color coordinates and color differences.
An energy management IC for bio-implants using ultracapacitors for energy storage (2010)

We present the first known energy management IC to allow low-power systems, such as biomedical implants, to optimally use ultracapacitors instead of batteries as their chief energy storage elements. The IC, fabricated in a 0.18 μm CMOS process, consists of a switched-capacitor DC-DC converter, a 4 nW bandgap voltage reference, a high-efficiency rectifier to allow wireless recharging of the capacitor bank, and a switch matrix and digital control circuitry to govern the stacking and unstacking of the ultracapacitors. The stacking procedure allows for more than 98% of the initial energy stored in the capacitors to be removed before the output voltage drops unsuitably low. The DC-DC converter achieves a peak efficiency of 51% for loads between 10 and 100 μW, operates for input voltages between 1.25 and 2.5 V.
Assessing rare earth element mineral deposit types and links to environmental impacts (2013)

Rare earth elements (REEs) have a crucial role in modern environmental and medical technologies, leading to a continuously growing demand for these elements. The relatively modest scale of the global REE mining sector means that the REE mineral deposit type knowledge base is small compared to more well-known styles of mineralisation. In this paper, we present a new classification scheme for differing REE mineral deposit types, outline the geological processes that cause REE enrichments, define characteristic grades and tonnages, and provide information on the environmental impact associated with REE mining, extraction and processing. Although current global REE supply is dominated by production from carbonatites, REEs are in fact found in a wide variety of deposits, including magmatic alkaline complex- and rhyolite-hosted REE mineralisation, REE-enriched iron oxide-copper–gold deposits, and REEs within heavy mineral sands, amongst others. Critically, REE mineralogy is linked to environmental risks during mining and refining, especially aspects such as radioactive U–Th, the use of harmful chemicals during processing and greenhouse gas emissions; future REE supply therefore needs to consider and address these environmental risks.