gebhart/patrepeval huggingface dataset:
Mechanism of [2 + 2] cycloaddition and related reactions between electron donors and electron acceptors. Perepoxide quasi-intermediate and its roles in the reactions of 1.DELTA.g molecular oxygen with olefins (1975)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMechanism of [2 + 2] cycloaddition and related reactions between electron donors and electron acceptors. Perepoxide quasi-intermediate and its roles in the reactions of 1.DELTA.g molecular oxygen with olefinsSatoshi Inagaki and Kenichi FukuiCite this: J. Am. Chem. Soc. 1975, 97, 26, 7480–7484Publication Date (Print):December 1, 1975Publication History Published online1 May 2002Published inissue 1 December 1975https://doi.org/10.1021/ja00859a015RIGHTS & PERMISSIONSArticle Views1260Altmetric-Citations51LEARN 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 (588 KB) Get e-Alerts Get e-Alerts
Self-healing mechanisms in smart protective coatings: A review (2018)

Self-healing coatings inspired by biological systems possess the ability to repair physical damage or recover functional performance with minimal or no intervention. This article provides a comprehensive and updated review on the advantages and limitations associated with common autonomous and non-autonomous self-healing mechanisms in protective organic coatings used for anti-corrosion purposes. The autonomous healing mechanisms are often enabled by embedding polymerizable healing agents or corrosion inhibitors in the coating matrices. For non-autonomous mechanisms, the healing effects are induced by external heat or light stimuli, which trigger the chemical reactions or physical transitions necessary for bond formation or molecular chain movement.
Total ozone determination by spectroradiometry in the middle ultraviolet (1979)

A method has been developed to determine total ozone from multispectral measurements of the direct solar irradiance. The total ozone is determined by a least squares fit to the spectrum between 290 nm and 380 nm. The aerosol extinction is accounted for by expanding it in a power series in wavelength; use of the linear term proved adequate. A mobile laboratory incorporating a sky scanner has been developed and used to obtain data to verify the method. Sun tracking, wavelength setting of the double monochromator, and data acquisition are under control of a minicomputer. Results obtained at Wallops Island, Virginia, and Palestine, Texas, agree well with simultaneous Dobson and Canterbury spectrometer and balloon ECC ozonesonde values. The wavelength calibration of the monochromator and the values for the normalized ozone absorption are the most important factors in an accurate determination of total ozone.
Identification of Hemoglobin and Two Serine Proteases in Acid Extracts of Calcium Containing Kidney Stones (1989)

By stepwise extraction of kidney stones, first with 10% acetic acid then 0.1 M EDTA, three pools of protein material have been obtained. The soluble material from the acid extract showed well defined bands when analyzed by sodium dodecyl sulfate (SDS) gel electrophoresis, and amino acid sequence analysis of peptides identified hemoglobin as a common constituent. From one stone neutrophil elastase has been identified along with another serine protease of unknown origin. The second pool of material which was soluble in EDTA showed a smear on SDS gel electrophoresis while the third pool consisted of the insoluble matrix. The finding of proteolytic enzymes opens up the possibility that limited proteolysis might be involved in the stone forming process.
A four-column theory for the origin of the genetic code: tracing the evolutionary pathways that gave rise to an optimized code (2009)

The driving force during this process is not the minimization of translational error, but positive selection for the increased diversity and functionality of the proteins that can be made with a larger amino acid alphabet. Nevertheless, the code that results is one in which translational error is minimized. We define a cost function with which we can compare the fitness of codes with varying numbers of amino acids, and a barrier function, which measures the change in cost immediately after addition of a new amino acid. We show that the barrier is positive if an amino acid is added into a column with dissimilar properties, but negative if an amino acid is added into a column with similar physical properties. Thus, natural selection favours the assignment of amino acids to the positions that they occupy in the final code.
Scaling Laws in Aeolian Sand Transport (2011)

We report on wind tunnel measurements on saltating particles in a turbulent boundary layer and provide evidence that over an erodible bed the particle velocity in the saltation layer and the saltation length are almost invariant with the wind strength, whereas over a nonerodible bed these quantities vary significantly with the air friction speed. It results that the particle transport rate over an erodible bed does not exhibit a cubic dependence with the air friction speed, as predicted by Bagnold, but a quadratic one. This contrasts with saltation over a nonerodible bed where the cubic Bagnold scaling holds. Our findings emphasize the crucial role of the boundary conditions at the bed and may have important practical consequences for aeolian sand transport in a natural environment.
Increased expression of Galectin-1 in carcinoma-associated stroma predicts poor outcome in prostate carcinoma patients (2000)

peer reviewed
<i>N</i> ‐Acetylcysteine ameliorates skeletal muscle pathophysiology in <i>mdx</i> mice (2008)

Duchenne muscular dystrophy (DMD) is a severe degenerative muscle disease caused by a mutation in the gene encoding dystrophin, a protein linking the cytoskeleton to the extracellular matrix. In this study we investigated whether the antioxidant N-acetylcysteine (NAC) provided protection against dystrophic muscle damage in the mdx mouse, an animal model of DMD. In isolated mdx muscles, NAC prevented the increased membrane permeability and reduced the force deficit associated with stretch-induced muscle damage. Three-week-old mdx mice were treated with NAC in the drinking water for 6 weeks. Dihydroethidium staining showed that NAC treatment reduced the concentration of reactive oxygen species (ROS) in mdx muscles. This was accompanied by a significant decrease in centrally nucleated fibres in muscles from NAC-treated mdx mice. Immunoblotting showed that NAC treatment decreased the nuclear protein expression of NF-kappaB, a transcription factor involved in pro-inflammatory cytokine expression. Finally, we show that NAC treatment reduced caveolin-3 protein levels and increased the sarcolemmal expression of beta-dystroglycan and the dystrophin homologue, utrophin. Taken together, our findings suggest that ROS play an important role in the dystrophic pathogenesis, both in terms of activating damage pathways and in regulating the expression of some dystrophin-associated membrane proteins. These results offer the prospect that antioxidants such as NAC could have therapeutic potential for DMD patients.
Second bioluminescence‐activating component in the luminous fungus <i>Mycena chlorophos</i> (2016)

Mycena chlorophos is an oxygen-dependent bioluminescent fungus. The mechanisms underlying its light emission are unknown. A component that increased the bioluminescence intensity of the immature living gills of M. chlorophos was isolated from mature M. chlorophos gills and chemically characterized. The bioluminescence-activating component was found to be trans-3,4-dihydroxycinnamic acid and its bioluminescence activation was highly structure-specific. <sup>13</sup> C- and <sup>18</sup> O-labelling studies using the immature living gills showed that trans-3,4-dihydroxycinnamic acid was synthesized from trans-4-hydroxycinnamic acid in the gills by hydroxylation with molecular oxygen as well as by the general metabolism, and trans-3,4-dihydroxycinnamic acid did not produce hispidin (detection-limit concentration: 10 pmol/1 g wet gill). Addition of 0.01 mM hispidin to the immature living gills generated no bioluminescence activation. These results suggested that the prompt bioluminescence activation resulting from addition of trans-3,4-dihydroxycinnamic acid could not be attributed to the generation of hispidin. Copyright © 2016 John Wiley & Sons, Ltd.
Immunogenic Cell Death and Immunotherapy of Multiple Myeloma (2019)

Over the past decades, immunotherapy has demonstrated a prominent clinical efficacy in a wide variety of human tumors. For many years, apoptosis has been considered a non-immunogenic or tolerogenic process whereas necrosis or necroptosis has long been acknowledged to play a key role in inflammation and immune-related processes. However, the new concept of "immunogenic cell death" (ICD) has challenged this traditional view and has granted apoptosis with immunogenic abilities. This paradigm shift offers clear implications in designing novel anti-cancer therapeutic approaches. To date, several screening studies have been carried out to discover <i>bona fide</i> ICD inducers and reveal the inherent capacity of a wide variety of drugs to induce cell death-associated exposure of danger signals and to bring about <i>in vivo</i> anti-cancer immune responses. Recent shreds of evidence place ER stress at the core of all the scenarios where ICD occur. Furthermore, ER stress and the unfolded protein response (UPR) have emerged as important targets in different human cancers. Notably, in multiple myeloma (MM), a lethal plasma cell disorder, the elevated production of immunoglobulins leaves these cells heavily reliant on the survival arm of the UPR. For that reason, drugs that disrupt ER homeostasis and engage ER stress-associated cell death, such as proteasome inhibitors, which are currently used for the treatment of MM, as well as novel ER stressors are intended to be promising therapeutic agents in MM. This not only holds true for their capacity to induce cell death, but also to their potential ability to activate the immunogenic arm of the ER stress response, with the ensuing exposure of danger signals. We provide here an overview of the up-to-date knowledge regarding the cell death mechanisms involved in situations of ER stress with a special focus on the connections with the drug-induced ER stress pathways that evoke ICD. We will also discuss how this could assist in optimizing and developing better immunotherapeutic approaches, especially in MM treatment.
Learning in Retirement Institutes: The Impact on the Lives of Older Adults (2003)

(2003). Learning in Retirement Institutes: The Impact on the Lives of Older Adults. The Journal of Continuing Higher Education: Vol. 51, No. 1, pp. 2-11.
In situ detection of tandem DNA repeat length (1996)

A simple method for scoring short tandem DNA repeats is presented. An oligonucleotide target, containing tandem repeats embedded in a unique sequence, was hybridized to a set of complementary probes, containing tandem repeats known lengths. Single-stranded loops structures formed on duplexes containing a mismatched (different) number of tandem repeats. No loop structure formed on duplexes containing a matched (identical) number of tandem repeats. The matched and mismatched loop structures were enzymatically distinguished and differentially labeled by treatment with S1 nuclease and the Klenow fragment of DNA polymerase.
Reengineering CCA-adding enzymes to function as (U,G)- or dCdCdA-adding enzymes or poly(C,A) and poly(U,G) polymerases (2006)

CCA-adding enzymes build and repair the 3'-terminal CCA sequence of tRNA. These unusual RNA polymerases use either a ribonucleoprotein template (class I) or pure protein template (class II) to form mock base pairs with the Watson-Crick edges of incoming CTP and ATP. Guided by the class II Bacillus stearothermophilus CCA-adding enzyme structure, we introduced mutations designed to reverse the polarity of hydrogen bonds between the nucleobases and protein template. We were able to transform the CCA-adding enzyme into a (U,G)-adding enzyme that incorporates UTP and GTP instead of CTP and ATP; we transformed the related Aquifex aeolicus CC- and A-adding enzymes into UU- and G-adding enzymes and Escherichia coli poly(A) polymerase into a poly(G) polymerase; and we transformed the B. stearothermophilus CCA-adding enzyme into a poly(C,A) polymerase by mutations in helix J that appear, based on the apoenzyme structure, to sterically limit addition to CCA. We also transformed the B. stearothermophilus CCA-adding enzyme into a dCdCdA-adding enzyme by mutating an arginine that interacts with the incoming ribose 2' hydroxyl. Most importantly, we found that mutations in helix J can affect the specificity of the nucleotide binding site some 20 A away, suggesting that the specificity of both class I and II enzymes may be dictated by an intricate network of hydrogen bonds involving the protein, incoming nucleotide, and 3' end of the tRNA. Collaboration between RNA and protein in the form of a ribonucleoprotein template may help to explain the evolutionary diversity of the nucleotidyltransferase family.
Random Signal Method of Nonlinear Amplitude Distortion Measurement (1971)

The degree and orders of nonlinearity of a system can be determined by the use of a random test signal. A Gaussian-distributed random signal with a uniform power spectral density except for a narrow spectral notch is used as an input test signal. The power within the notch at the system output is a measure of the degree of system nonlinearity. Relative variations of the output power within the notch with input loading identify the orders of nonlinearity.
Nicotinic acid-adenine dinucleotide phosphate-sensitive calcium stores initiate insulin signaling in human beta cells (2002)

Recent studies suggest a role for autocrine insulin signaling in beta cells, but the mechanism and function of insulin-stimulated Ca(2+) signals is uncharacterized. We examined Ca(2+)-dependent insulin signaling in human beta cells. Two hundred nanomolar insulin elevated [Ca(2+)](c) to 284 +/- 27 nM above baseline in approximately 30% of Fura-4F-loaded cells. Insulin evoked multiple Ca(2+) signal waveforms, 60% of which included oscillations. Although the amplitude of Ca(2+) signals was dose-dependent between 0.002 and 2,000 nM, the percentage of cells responding was highest at 0.2 nM insulin, suggesting the interaction of stimulatory and inhibitory pathways. Ca(2+)-free solutions did not affect the initiation of insulin-stimulated Ca(2+) signals, but abolished the second phase of plateaus/oscillations. Likewise, inositol 1,4,5-trisphosphate (IP(3)) receptor antagonists xestospongin C and caffeine selectively blocked the second phase, but not the initiation of insulin signaling. Thapsigargin and 2,5-di-tert-butylhydroquinone (BHQ) blocked insulin signaling, implicating sarcoplasmic/endoplasmic Ca(2+)-ATPase (SERCA)-containing Ca(2+) stores. Insulin-stimulated Ca(2+) signals were insensitive to ryanodine. Injection of the CD38-derived Ca(2+) mobilizing metabolite, nicotinic acid-adenine dinucleotide phosphate (NAADP), at nanomolar concentrations, evoked oscillatory Ca(2+) signals that could be initiated in the presence of ryanodine, xestospongin C, and Ca(2+)-free solutions. Desensitizing concentrations of NAADP abolished insulin-stimulated Ca(2+) signals. Insulin-stimulated Ca(2+) signals led to a Ca(2+)-dependent increase in cellular insulin contents, but not secretion. These data reveal the complexity of insulin signal transduction and function in human beta cells and demonstrate functional NAADP-sensitive Ca(2+) stores in a human primary cultured cell type.
A comparison of lipids from liver and hepatoma subcellular membranes (1986)

Subcellular fractions of nuclei, mitochondria, endoplasmic reticulum, plasma membrane and cytosol were prepared from liver and hepatoma 7288CTC. Marker enzyme activities, biochemical compositions and electron microscopy were used to establish purity. Hepatoma NADH: cytochrome C reductase and 5'-nucleotidase exhibited abnormal subcellular distributions. The lipids from the subcellular fractions were examined in detail. Mitochondria and plasma membranes were characterized by elevated percentages of diphosphatidylglycerol and sphingomyelin, respectively, in both tissues. All hepatoma subcellular fractions contained dramatically elevated levels of sphingomyelin and cholesterol, two components that form preferential strong complexes in vitro. The fatty acid composition of hepatoma sphingomyelin differed markedly from liver and, unlike liver, did not exhibit organelle specific compositions. Some hepatoma lipid classes contained reduced percentages of palmitate while others contained higher levels. Hepatoma phosphatidylcholine and phosphatidylethanolamine from organelles contained lower percentages of long chain polyunsaturated fatty acids than liver. Generally, unique fatty acid profiles exhibited by individual phospholipid classes of liver subcellular fractions were absent or much reduced in the hepatoma. The ratios of oleate to vaccenate were near one for most of the phospholipid classes of most liver fractions, but all hepatoma classes, with few exceptions, contained a much higher percentage of oleate in all subcellular fractions. The hypothesis is proposed that the origin of some acyl moieties for the biosynthesis of various hepatoma lipid classes differs from liver sources. The possible changes in acyl pools, sources and compartments for complex lipid biosynthesis could result in change in the quantities of molecular species that could contribute to the abnormal properties of the hepatoma membranes.
Systemic therapy after first-line docetaxel in metastatic castration-resistant prostate cancer (2008)

There is no accepted standard systemic treatment for patients with castration resistant prostate cancer and progressive disease after docetaxel. Novel agents are in phase II and III clinical testing in this setting.
Analysis of a piecewise linear trend of average surface temperature in the mathematical model of multifractal dynamics (2015)

In this work the model of variations of average annual temperature of the Northern Hemisphere of the Earth is constructed. On its basis, in this research, the main regularities of temporary variability of temperature over the period from 1000 to 2010 have been revealed with the help of application of methods of multi-fractal dynamics. Over the period of 1010 years there were founded 26 periods and for each of them a value of fractal dimension of was settled. Also, the function of jumps of difference = - 0 (where 0 is an equilibrium value of fractal dimension) describing the dynamics of fractal dimension for the period under consideration was constructed. The question of correlation of a historical process and behavior of function has been discussed.
Late Pleistocene sediments and environmental change at Plaza Creek, Falkland Islands, South Atlantic (1998)

Late Pleistocene organic-rich sediments exposed in coastal bluffs near the head of Plaza Creek, East Falkland, have yielded conventional and AMS 14C dates of between 36 and 28 ka BP, and possess a pollen spectrum dominated by grasses, indicating a vegetation assemblage similar to that of the present day. Although some sample dates are anomalous and contamination by non-contemporaneous carbon cannot be ruled out entirely, the age estimates are consistent with evidence and dates from Antarctica, South America and the amphi-North Atlantic for climate shifts to interstadial conditions at around that time. The organic-rich units are developed in and enclosed by deposits attributed to processes of periglacial mass wasting. Grain-size characteristics suggest that these sediments may have been emplaced by solifluction, shallow translational landsliding and surface wash in at least five mass-wasting episodes. Some of the mass-wasting sediments might correlate with solifluction deposits above and below a podsolic soil dated to 26 ka BP at San Carlos, East Falkland, and with periods of cirque and valley glaciation identified in the uplands of the Falkland Islands. The similarity between late Pleistocene interstadial, Holocene and present-day pollen assemblages, and the lack of vegetation change within these periods, is characteristic of most cool temperate Southern Ocean islands, and may reflect the lack of sensitivity of the vegetation to climate change and/or a lack of climate variability for the time intervals covered. © 1998 John Wiley & Sons, Ltd.
Invasive Cervical Cancer and Intrauterine Device Use (1991)

Although the hypothesis that intrauterine device (IUD) use might promote cervical cancer has been considered since the introduction of IUDs in the early 1900s, previous studies are inconclusive. Data collected in interviews with 481 invasive cervical cancer cases and 801 general population controls from Birmingham, Chicago, Denver, Miami and Philadelphia were used to address this issue. These data were analysed to determine the relationship between IUD use and the risk of cervical cancer, with consideration of the type of IUD (copper and inert) and duration of use. A non-significant reduced risk of cervical cancer was associated with copper IUD use, indicated by an adjusted odds ratio (OR) of 0.6 (95% Cl: 0.3-1.2), but virtually no effect was found for inert IUD use (OR = 1.1, 95% Cl: 0.9-1.7). Decreased risk with increased duration of copper IUD use supports a possible protective effect of copper IUD use on the development of invasive cervical cancer.
Synthetic and structural studies on syringolin A and B reveal critical determinants of selectivity and potency of proteasome inhibition (2009)

Syrbactins, a family of natural products belonging either to the syringolin or glidobactin class, are highly potent proteasome inhibitors. Although sharing similar structural features, they differ in their macrocyclic lactam core structure and exocyclic side chain. These structural variations critically influence inhibitory potency and proteasome subsite selectivity. Here, we describe the total synthesis of syringolin A and B, which together with enzyme kinetic and structural studies, allowed us to elucidate the structural determinants underlying the proteasomal subsite selectivity and binding affinity of syrbactins. These findings were used successfully in the rational design and synthesis of a syringolin A-based lipophilic derivative, which proved to be the most potent syrbactin-based proteasome inhibitor described so far. With a K(i)' of 8.65 +/- 1.13 nM for the chymotryptic activity, this syringolin A derivative displays a 100-fold higher potency than the parent compound syringolin A. In light of the medicinal relevance of proteasome inhibitors as anticancer compounds, the present findings may assist in the rational design and development of syrbactin-based chemotherapeutics.