gebhart/patrepeval huggingface dataset:
Notes: Simplified Zinc-Copper Couple for Use in Preparing Cyclopropanes from Methylene Iodide and Olefins (1959)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTNotes: Simplified Zinc-Copper Couple for Use in Preparing Cyclopropanes from Methylene Iodide and OlefinsR Shank and Harold ShechterCite this: J. Org. Chem. 1959, 24, 11, 1825–1826Publication Date (Print):November 1, 1959Publication History Published online21 July 2003Published inissue 1 November 1959https://pubs.acs.org/doi/10.1021/jo01093a630https://doi.org/10.1021/jo01093a630research-articleACS PublicationsRequest reuse permissionsArticle Views1031Altmetric-Citations92LEARN 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
Two-dimensional excitons in three-dimensional hexagonal boron nitride (2013)

The recombination processes of excitons in hexagonal boron nitride (hBN) have been probed using time-resolved photoluminescence. It was found that the theory for two-dimensional (2D) exciton recombination describes well the exciton dynamics in three-dimensional hBN. The exciton Bohr radius and binding energy deduced from the temperature dependent exciton recombination lifetime is around 8 Å and 740 meV, respectively. The effective masses of electrons and holes in 2D hBN deduced from the generalized relativistic dispersion relation of 2D systems are 0.54mo, which are remarkably consistent with the exciton reduced mass deduced from the experimental data. Our results illustrate that hBN represents an ideal platform to study the 2D optical properties as well as the relativistic properties of particles in a condensed matter system.
An Automatic SAR-Based Change Detection Method for Generating Large-Scale Flood Data Records: The UK as a Test Case (2019)

The main objective of this study is to introduce and evaluate a SAR-based flood mapping algorithm enabling the automatic generation of a large-scale flood record from the ENVISAT ASAR data archive. The flood mapping algorithm is based on a change detection approach and requires an automatic selection of optimal reference images. The flood mapping algorithm is applied to selected pairs of images to sequentially generate a record of flood extent maps. False alarms caused by water-like areas are reduced using auxiliary data sources such as the Height Above Nearest Drainage (HAND) index derived from topography data. The proposed method is applied to several ENVISAT WS ASAR datasets acquired over the UK and results are validated with a flood extent map derived from aerial photography. Results presented in this paper demonstrate the effectiveness of the methodology.
Proposals for structure and effect of methylalumoxane based on mass balances and phase separation experiments (1995)

Abstract Methylaluminoxane prepared from trimethylaluminium on a surface of ice mainly can be described as [Al 4 O 3 (CH 3 ) 6 ] 4 . This is shown through analysis, phase separation experiments with diethyl ether and molecular weight determinations in benzene, 1, 4‐dioxane, tetrahydrofuran and trimethylaluminium. It is discussed that the reason for forming this ball‐like structure is the saturation of four coordinated Al 4 O 3 (CH 3 ) 6 . This molecule has a cavern which contains a solvent molecule or a molecule of trimethylaluminium. The consequences for the formation of the catalytically active structure together with metallocene are discussed.
The Swedish-ESO Submillimeter Telescope (SEST) (1988)

Les caracteristiques principales du telescope suedois-ESO de 15 m de diametre et a longueur d'onde submillimetrique sont presentees ainsi que les resultats des premieres mesures astronomiques
Embryo-rescue Culture in `Galia' Male Parental Line Melon [Cucumis melo (L.) var. reticulatus Ser.] (2005)

Embryo abortion and empty seeds after self-pollination occur in some transgenic (ACO antisense) `Galia' male parental lines. An embryo-rescue system in this melon was developed to save potential viable embryos. To obtain the best and reliable embryo-rescue technique, several parameters were used including an improved (five new supplements) nutrient medium (named E-21) from the E-20A basic medium (Sauton and Dumax de Vaulx, 1987), an inoculation system (removing the embryo from the seed or intact seed), and the use of different fruit harvesting dates of the wild type and a transgenic `Galia' male parental line. Fruits of wild type (WT) and transgenic (ACO gene in antisense orientation) `Galia' male parental line were harvested at 4, 10, 17, 24, and 30 days after pollination (DAP). Fruits were surface sterilized by dipping in a 20% commercial bleach solution for 30 minutes. Subsequently, seeds were removed from fruit under sterile conditions. These seeds were either used to dissect the embryos or placed directly with the hilum facing E-20A or E-21 medium. Seedlings from all treatments were transferred to E-21 elongation medium, incubated 4 weeks, and transferred to soil to evaluate growth. The efficiency of this technique was greater when the time after pollination (4, 10, 17, 24, and 30 DAP) to rescue the embryos was increased. Thus, 30 DAP was the best time to rescue the embryos. The number of rescued embryos using E-21 medium was greater than with E-20A. We did not find any significant differences in survival efficiency rate between WT and transgenic embryos. We have obtained a competent embryo-rescue technique for WT and transgenic `Galia' male parental line, which can be applied to rescue valuable GMO hybrid-melon embryos.
The Variable Internal Structure of the Mycoplasma penetrans Attachment Organelle Revealed by Biochemical and Microscopic Analyses: Implications for Attachment Organelle Mechanism and Evolution (2017)

Although mycoplasmas have small genomes, many of them, including the HIV-associated opportunist <i>Mycoplasma penetrans</i>, construct a polar attachment organelle (AO) that is used for both adherence to host cells and gliding motility. However, the irregular phylogenetic distribution of similar structures within the mycoplasmas, as well as compositional and ultrastructural differences among these AOs, suggests that AOs have arisen several times through convergent evolution. We investigated the ultrastructure and protein composition of the cytoskeleton-like material of the <i>M. penetrans</i> AO with several forms of microscopy and biochemical analysis, to determine whether the <i>M. penetrans</i> AO was constructed at the molecular level on principles similar to those of other mycoplasmas, such as <i>Mycoplasma pneumoniae</i> and <i>Mycoplasma mobile</i> We found that the <i>M. penetrans</i> AO interior was generally dissimilar from that of other mycoplasmas, in that it exhibited considerable heterogeneity in size and shape, suggesting a gel-like nature. In contrast, several of the 12 potential protein components identified by mass spectrometry of <i>M. penetrans</i> detergent-insoluble proteins shared certain distinctive biochemical characteristics with <i>M. pneumoniae</i> AO proteins, although not with <i>M. mobile</i> proteins. We conclude that convergence between <i>M. penetrans</i> and <i>M. pneumoniae</i> AOs extends to the molecular level, leading to the possibility that the less organized material in both <i>M. pneumoniae</i> and <i>M. penetrans</i> is the substance principally responsible for the organization and function of the AO.<b>IMPORTANCE</b><i>Mycoplasma penetrans</i> is a bacterium that infects HIV-positive patients and may contribute to the progression of AIDS. It attaches to host cells through a structure called an AO, but it is not clear how it builds this structure. Our research is significant not only because it identifies the novel protein components that make up the material within the AO that give it its structure but also because we find that the <i>M. penetrans</i> AO is organized unlike AOs from other mycoplasmas, suggesting that similar structures have evolved multiple times. From this work, we derive some basic principles by which mycoplasmas, and potentially all organisms, build structures at the subcellular level.
Performances of a PCB-based Loop Antenna Inductive Sensor for Partial Discharges Detection (2022)

This paper presents the test results of an electrically small loop antenna sensor towards detecting the radiated magnetic field due to partial discharge (PD) activities. The loop antenna prototype was printed on an FR-4 substrate with a thickness of 1.6 mm, featuring a compact size of 20 mm $\times20$ mm $\times1.7$ mm. The proposed sensor, initially simulated with Ansys HFSS software, has a resonant frequency of about 100 MHz. Its detection capability for three types of partial discharges (i.e., corona, surface and internal PDs) has been evaluated. Laboratory experiments showed that the evaluated loop spiral antenna is appropriate for the detection of the three types of PDs. Indeed, the results show a peak-to-peak voltage equal to 22.87 mV, 74.8 mV, and 79.72 mV, respectively, for corona, surface, and internal PDs, with a frequency spectrum showing a maximum at 42.19 MHz, 16.41 MHz, and 35.1 MHz, respectively. Lastly, the performance of the proposed small loop sensor was compared to that of the commercial HFT sensor. The results show that the two sensors present comparative sensitivity for the three types of PD.
Gas-phase reactions on platinum. Synthesis and crystal structure of anti- tetramantane, a large diamondoid fragment (1976)

anti-Tetramantane, a C22H28 hydrocarbon having the regular topology of the diamondoid lattice, has been synthesised by a double homologation of diamantane, the key step involving a ring expansion–cyclisation reaction of a polycyclic diene in hydrogen in the gas phase on a platinum-silica catalyst; the structure has been established by an X-ray crystal analysis.
Stimulating debate: ethics in a multidisciplinary functional neurosurgery committee (2006)

Multidisciplinary healthcare committees meet regularly to discuss patients' candidacy for emerging functional neurosurgical procedures, such as Deep Brain Stimulation (DBS). Through debate and discussion around the surgical candidacy of particular patients, functional neurosurgery programs begin to mold practice and policy supported both by scientific evidence and clear value choices. These neurosurgical decisions have special considerations not found in non-neurologic committees. The professional time used to resolve these conflicts provides opportunities for the emergence of careful, ethical practices simultaneous with the expansion of therapy applications.
Role of Small Ice Shelves in Sea‐level Rise (2009)

This chapter contains sections titled: Introduction Model Description Results Conclusions References
Analysis of ignition of a porous energetic material (1999)

Abstract A theory of ignition is presented to analyse the effect of porosity on the time to ignition of a semi-infinite porous energetic solid subjected to a constant energy flux. An asymptotic perturbation analysis, based on the smallness of the gas-to-solid density ratio and the largeness of the activation energy, is utilized to describe the inert and transition stages leading to thermal runaway. As in the classical study of a nonporous solid, the transition stage consists of three spatial regions in the limit of large activation energy: a thin reactive–diffusive layer adjacent to the exposed surface of the material where chemical effects are first felt, a somewhat thicker transient–diffusive zone and, finally, an inert region where the temperature field is still governed solely by conductive heat transfer. Solutions in each region are constructed at each order with respect to the density-ratio parameter and matched to one another using asymptotic matching principles. It is found that the effects of porosity provide a leading-order reduction in the time to ignition relative to that for the nonporous problem, arising from the reduced amount of solid material that must be heated and the difference in thermal conductivities of the solid and gaseous phases. A positive correction to the leading-order ignition-delay time, however, is provided by the convective flow of gas out of the solid, which stems from the effects of thermal expansion and removes energy from the system. The latter phenomenon is absent from the corresponding calculation for the nonporous problem and produces a number of modifications at the next order in the analysis arising from the relative transport effects associated with the gas flow.
Concurrent chromomycosis and aspergillosis of the maxillary sinus. (2004)

The authors describe a rare case of an infection of both the chromomycosis and aspergillosis of the maxillary sinus in an immunocompetent 72-year-old female who presented with progressive visual loss and dull aching pain of the left eye. Sinuscopy of the left maxillary sinus showed swelling of the mucosa with clay-like materials. Biopsy from the left maxillary sinus showed the typically characteristic morphology of chromomycosis and culture from sinus tissue which yielded Aspergillus. The patient responded to a combination therapy of surgical excision and antifungal agent.
BD +28 1494 : a multimode delta Scuti pulsator. (1985)

Observations photometriques en B et V durant un intervalle de trois mois en 1983-84. L'analyse donne quatre frequences; on conclut que des modes non radiaux sont presents dans cette etoile
The Red Balloon (2010)

DARPA's network challenge to find ten red balloons is inspiring for the multimedia community to imagine the possibilities of automated image searching with real-world scene matching and geolocation capability at a massive scale.
Dissipative solitons generation and amplification in erbium-doped fibers operating at 1.55 µm (2014)

International audience
α-Helical peptidic scaffolds to target α-synuclein toxic species with nanomolar affinity (2021)

α-Synuclein aggregation is a key driver of neurodegeneration in Parkinson's disease and related syndromes. Accordingly, obtaining a molecule that targets α-synuclein toxic assemblies with high affinity is a long-pursued objective. Here, we exploit the biophysical properties of toxic oligomers and amyloid fibrils to identify a family of α-helical peptides that bind to these α-synuclein species with low nanomolar affinity, without interfering with the monomeric functional protein. This activity is translated into a high anti-aggregation potency and the ability to abrogate oligomer-induced cell damage. Using a structure-guided search we identify a human peptide expressed in the brain and the gastrointestinal tract with analogous binding, anti-aggregation, and detoxifying properties. The chemical entities we describe here may represent a therapeutic avenue for the synucleinopathies and are promising tools to assist diagnosis by discriminating between native and toxic α-synuclein species.
Observations on recent increase in mortality from asthma. (1968)

The mortality attributed to asthma has increased annually in England and Wales from 1960 to 1965. The increase is more pronounced at ages 5 to 34 years than at older ages and is most pronounced at ages 10 to 14 years. In this last age group the mortality increased nearly eight times in seven years, and in 1966 asthma accounted for 7% of all deaths. No comparable increase has been observed in any other country, but smaller increases at ages 10 to 19 years have been observed in Australasia, Japan, western Europe, and the United States. There is no evidence to suggest that there has been any change in diagnostic habits, certification of deaths, or methods of classification which could account for the increase in Great Britain, and it is concluded that the increase is real. General practitioners' records provide no evidence of an increase in prevalence and it seems probable that there has been an increase in case fatality. No environmental hazards are known which could have increased the severity of the disease, and the possibility has to be considered that the increase may be due to new methods of treatment. Corticosteroids have been used increasingly since 1952, and in Great Britain the use of pressurized aerosols containing sympathomimetics has increased rapidly since 1960.
A GASEOUS-FUEL FAST BREEDER REACTOR (1960)

The feasibllity of a gaseous uranium hexafluoride fueled fast breeder reactor using sodium cooling is discussed. The major difficulty appears to be the mechanical complexity involved in a very large number of small-bore tubes for containing the UF/sub 6/, which must be either individually valved-off or connected into a high-pressure header. (C.J.G.)
Gastroprotective Effect and Chemical Constituents of Flabellaria paniculata (Malpighiaceae) (2019)

Leaves from <i>Flabellaria paniculata</i> Cav (Malpighiaceae) are used in traditional medicine for wound dressing, and to treat ulcers and inflammation in Nigeria. The present study evaluates the gastroprotective activity of the ethyl acetate fraction of the methanolic leaf extract and reports on the chemical constituents from the fraction. The methanolic crude extract and solvent fractions (100 mg/kg, PO) were screened using an ethanol-induced ulcer model. The activity of the most active EtOAc fraction (25, 50, and 100 mg/kg, PO) was further evaluated in indomethacin and pylorus ligation-induced ulcer models. The EtOAc fraction was chromatographed and chemical structures of the isolated compounds were elucidated by nuclear magnetic resonance spectroscopy. The MeOH extract of <i>F. paniculata</i> and EtOAc fraction from this extract displayed significant gastroprotective effects. Two triterpenoids (friedelin and friedelinol), two steroids (sitosterol and sitosterol-β-d-glucoside), and a flavonoid glycoside (kaempferol-3-<i>O-α</i>-l-rhamnopyranosyl-(1→6)-β-d-glucopyranoside) were identified from the EtOAc fraction. This is the first report on the isolation of these compounds from the plant. The identified compounds could be responsible in part for the observed gastroprotective effect of the EtOAc fraction.
Multidrug resistance in oncology: diagnostic and therapeutic approaches (1999)

Resistance to anticancer drugs is often mediated by the overexpression of a membrane pump able to extrude many xenobiotics out of the tumour cells. The most frequently expressed of these pumps is called P-glycoprotein and is encoded by a gene called MDR1 (for multidrug resistance). There could be great clinical interest for investigating the expression of this gene or of its product in patients' tumours, as well as in developing ways of circumventing this mechanism of resistance. Multidrug resistance can be diagnosed in tumours by molecular biology techniques (gene expression at the mRNA level), by immunological techniques (quantification of P-glycoprotein itself) or by functional approaches (measuring dye exclusion). Numerous studies have tried to use the MDR status of tumours as a predictor of response to treatment, but they have not yet reached definitive conclusions to allow the use of this approach in routine determinations. This is because no consensus has emerged concerning the optimal technique and the best conditions for MDR determination. Continuous efforts are still required for defining appropriate standardization of the techniques. The development of MDR modulators for the treatment of resistant tumours is a promising approach requiring rigorous clinical trials with successive phase I, phase II and phase III studies. Phase I can be omitted when the reverter is already being used in therapeutics; phase II should be performed using a sequential design, in order to prove the inefficacy of the anticancer therapy before combining it to a modulator; and phase III must only be undertaken after the demonstration that responders can be recruited by the combination. However, the effect of some reverters on anticancer drug pharmacokinetics may hamper rapid evaluation. Several drugs are good candidates for MDR modulation, but definitive results are still lacking for the introduction of such combinations in standard therapeutic protocols.
Recent acheivement on diluted magnetic semiconductor and new perspective of magnetoresistive sensor (2011)

International audience
Search for Long-Lived Particles Decaying in the CMS End Cap Muon Detectors in Proton-Proton Collisions at $\sqrt s$ =13 TeV (2021)

A search for long-lived particles (LLPs) produced in decays of standard model (SM) Higgs bosons is presented. The data sample consists of 137 fb^{-1} of proton-proton collisions at sqrt[s]=13 TeV, recorded at the LHC in 2016-2018. A novel technique is employed to reconstruct decays of LLPs in the end cap muon detectors. The search is sensitive to a broad range of LLP decay modes and to masses as low as a few GeV. No excess of events above the SM background is observed. The most stringent limits to date on the branching fraction of the Higgs boson to LLPs subsequently decaying to quarks and τ^{+}τ^{-} are found for proper decay lengths greater than 6, 20, and 40 m, for LLP masses of 7, 15, and 40 GeV, respectively.