167 research outputs found
Diphosphination of ortho-quinone methide precursors with diphosphines
A fluorine anion-mediated diphosphination of ortho-quinone methide precursors (2-(chloromethyl)silyloxybenzenes) with diphosphines has been developed. The reaction proceeds smoothly under mild conditions (CH2Cl2 solvent, 0 °C) to form the corresponding 2-(phosphinomethyl)oxyphosphinobenzenes, which are potential bidentate ligands in metal catalysis. Additionally, some mechanistic investigations are also performed.Kato Y., Otomura N., Hirano K., et al. Diphosphination of ortho-quinone methide precursors with diphosphines. Tetrahedron Letters 60, 2014 (2019); https://doi.org/10.1016/j.tetlet.2019.06.055
Synthesis of DPPP- And DPPPEN-Type Bidentate Ligands by Ring-Opening Diphosphination of Methylene- And Vinylcyclopropanes under Visible-Light-Promoted Photoredox Catalysis
A ring-opening diphosphination of methylene- and vinylcyclopropanes with tetraaryldiphosphines (Ar2P-PAr2) has been developed to afford the corresponding 1,3-diphenylphosphinopropane- and 1,3-diphenylphosphinopentane-type bidentate ligands, respectively. The reaction proceeds under bromine cation-initiated, visible-light-promoted photoredox catalysis at ambient temperature. Owing to the ready availability of functionalized diphosphines, the electronically diverse MeO- and CF3-substituted bidentate ligands are also easily prepared.Kato Y., Otomura N., Hirano K., et al. Synthesis of DPPP- And DPPPEN-Type Bidentate Ligands by Ring-Opening Diphosphination of Methylene- And Vinylcyclopropanes under Visible-Light-Promoted Photoredox Catalysis. Journal of Organic Chemistry. 85(9), 5981-5994, (2020), 1 May 2020; © 2020 American Chemical Society. https://doi.org/10.1021/acs.joc.0c00417
Detection and Localization of Traffic Signals with GPS Floating Car Data and Random Forest
As Floating Car Data are becoming increasingly available, in recent years many research works focused on leveraging them to infer road map geometry, topology and attributes. In this paper, we present an algorithm, relying on supervised learning to detect and localize traffic signals based on the spatial distribution of vehicle stop points. Our main contribution is to provide a single framework to address both problems. The proposed method has been experimented with a one-month dataset of real-world GPS traces, collected on the road network of Mitaka (Japan). The results show that this method provides accurate results in terms of localization and performs advantageously compared to the OpenStreetMap database in exhaustivity. Among many potential applications, the output predictions may be used as a prior map and/or combined with other sources of data to guide autonomous vehicles
Kick velocity induced by magnetic dipole and quadrupole radiation
We examine the recoil velocity induced by the superposition of the magnetic
dipole and quadrupole radiation from a pulsar/magnetar born with rapid
rotation. The resultant velocity depends on not the magnitude, but rather the
ratio of the two moments and their geometrical configuration. The model does
not necessarily lead to high spatial velocity for a magnetar with a strong
magnetic field, which is consistent with the recent observational upper bound.
The maximum velocity predicted with this model is slightly smaller than that of
observed fast-moving pulsars.Comment: 10 pages, 3 color figure
A Clinical Study of Photodynamic Therapy for Superficial Esophageal Carcinoma by YAG-OPO Laser
A cooperative clinical study of photodynamic therapy (PDT) for superficial esophageal
carcinoma was conducted at 6 medical institution. PHE (2mg/kg) with high tumor
affinity was used as the oncotropic compound. The light source was a pulse wave YAG-OPO
laser with high penetration into the tissue. Irradiation was performed at an energy
density of 60–180 J/cm2 48–72 h after PHE administration. Eight lesions in 6 patients
were treated. All were type 0-II superficial carcinomas. The depth of invasion was EP–MM
for 6 lesions and SM for 2 lesions. A complete response (CR) was achieved in all
patients after one session of PDT. Five adverse events, including anemia and fever, were
reported by 4 patients, but all were WHO grade 2 or lower and transient. PDT using
PHE and YAG-OPO laser was therefore considered effective as a curative therapy for
superficial esophageal carcinoma
Cooperative Clinical Trial of Photodynamic Therapy for Early Gastric Cancer With Photofrin Injection® and YAG-OPO Laser
Background and Objective: Photodynamic therapy (PDT) treats malignant tumors using
photosensitizers and light. We employed a new pulse laser as the excitation light source
for PDT, i.e. an optical parametric oscillator (OPO) system pumped by a Q-switched
Nd:YAG laser, because it provides extremely high peak power
Hope in Adult Patients with Chronic Disease: Qualitative Study.
To identify the sources of hope for patients with chronic disease, a semi - structured interview was conducted with patients middle-aged and older, whose disease types and levels of activities of daily living limitations varied. Six patience - three with chronic kidney disease, one with rheumatoid arthritis, one with spinal cord injury, and another with lumbar spinal canal stenosis - were interviewed by a psychologist and an internist. It was determined that their sources greatly differed depending on individual circumstances, such as types and severity of disease, sources of joy and happiness, family structure, employment status, relationship with friends, etc. However, it also showed a stylization of hope dependent on individual experience; in other words, there was a tendency for patients to redefine their source of hope by setting attainable goals to match their limitations, or acknowledging what they have achieved and finding hope in maintaining their current state. We have determined that the sources of hope are comprised of two categories: [foundation and process of finding hope] and [specific goals and sources]. The former consists of: [stylization dependent on experience], [method and will], [use of external information], [intrinsic foundation], and [extrinsic foundation]. The latter consists of: [health], [source of joy and happiness], [family], and [social connections]
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