Efficient total syntheses of natural pterin glycosides: limipterin and tepidopterin

The key, versatile precursors N-2-(N,N-dimethylaminomethylene)-1'-O-(4-methoxybenzyl)-3-[2-(4-nitrophenyl)ethyl]biopterin (29a) and its ciliapterin analog (29b) were prepared, respectively, from D-xylose (in 14 steps) and L-xylose (in 11 steps). Treatment of 29a and 29b with 3,4,6-tri-O-acetyl-2-deoxy-2-phthalimido-beta-D-glucopyranosyl bromide in the presence of silver triflate and tetramethylurea, followed by removal of the protecting groups, led to the first selective syntheses of limipterin (3) and tepidopterin (5), respectively

Synthetic studies on pterin glycosides: the first synthesis of 2′-O-(α-d-glucopyranosyl)biopterin

L-Rhamnose was led, in a 14-step-sequence, to N2-(N,N-dimethylaminomethylene)-1′-O-(4-methoxybenzyl)-3-[2-(4-nitrophenyl)ethyl]biopterin (23), an appropriately protected precursor for 2′-O-glycosylation, while 4,6-di-O-acetyl-2,3-di-O-(4-methoxybenzyl)-α-d-glucopyranosyl bromide (32), a novel glycosyl donor, was efficiently prepared from d-glucose in 8 steps. The first synthesis of 2′-O-(α-d-glucopyranosyl)biopterin (2a) was achieved by treatment of the key intermediate 23 with 32 in the presence of silver triflate and tetramethylurea, followed by successive removal of the protecting groups

Report on 2023 Jamaica Online Volunteer Activity: As a Training for Primary School Teachers, Coordinated by Naruto University of Education and Ministry of Education, Youth and Information

departmental bulletin pape

Substellar Companions to Evolved Intermediate-Mass Stars: HD 145457 and HD 180314

We report the detections of two substellar companions orbiting around evolved intermediate-mass stars from precise Doppler measurements at Subaru Telescope and Okayama Astrophysical Observatory. HD 145457 is a K0 giant with a mass of 1.9 M_sun and has a planet of minimum mass m_2sini=2.9 M_J orbiting with period of P=176 d and eccentricity of e=0.11. HD 180314 is also a K0 giant with 2.6 M_sun and hosts a substellar companion of m_2sin i=22 M_J, which falls in brown-dwarf mass regime, in an orbit with P=396 d and e=0.26. HD 145457 b is one of the innermost planets and HD 180314 b is the seventh candidate of brown-dwarf-mass companion found around intermediate-mass evolved stars.Comment: 16 pages, 4 figures, accepted for publication in PAS

Detection of a low-eccentricity and super-massive planet to the subgiant HD 38801

We report the detection of a large mass planet orbiting around the K0 metal-rich subgiant HD38801 ($V=8.26$) by precise radial velocity (RV) measurements from the Subaru Telescope and the Keck Telescope. The star has a mass of $1.36M_{\odot}$ and metallicity of [Fe/H]= +0.26. The RV variations are consistent with a circular orbit with a period of 696.0 days and a velocity semiamplitude of 200.0\mps, which yield a minimum-mass for the companion of 10.7\mjup and semimajor axis of 1.71 AU. Such super-massive objects with very low-eccentricities and hundreds of days period are uncommon among the ensemble of known exoplanets

A Substellar Companion in a 1.3 yr Nearly-circular Orbit of HD 16760

We report the detection of a substellar companion orbiting the G5 dwarf HD 16760 from the N2K sample. Precise Doppler measurements of the star from Subaru and Keck revealed a Keplerian velocity variation with a period of 466.47+-0.35 d, a semiamplitude of 407.71+-0.84 m/s, and an eccentricity of 0.084+-0.003. Adopting a stellar mass of 0.78+-0.05 M_Sun, we obtain a minimum mass for the companion of 13.13+-0.56 M_JUP, which is close to the planet/brown-dwarf transition, and the semimajor axis of 1.084+-0.023 AU. The nearly circular orbit despite the large mass and intermediate orbital period makes this companion unique among known substellar companions.Comment: 14 pages, 2 figures, accepted for publication in Ap

Single-Session Versus Staged Multivessel Optimal IVUS-Guided PCI in Patients With CCS or NSTE-ACS

[Background] There are no studies comparing single-session vs staged multivessel intravascular ultrasound (IVUS)-guided percutaneous coronary intervention (PCI) in patients with chronic coronary syndrome (CCS) or non–ST-segment-elevation acute coronary syndrome (NSTE-ACS). [Objectives] The authors aimed to compare single-session vs staged multivessel IVUS-guided PCI in patients with CCS or NSTE-ACS. [Methods] The OPTIVUS-Complex PCI study multivessel cohort was a prospective multicenter single-arm trial enrolling 1, 021 patients with CCS or NSTE-ACS undergoing multivessel PCI including left anterior descending coronary artery using IVUS aiming to meet the prespecified OPTIVUS criteria for optimal stent expansion. We compared single-session vs staged multivessel PCI. The primary endpoint was a composite of death, myocardial infarction, stroke, or any coronary revascularization. [Results] There were 246 patients (24.1%) undergoing single-session multivessel PCI, and 775 patients (75.9%) undergoing staged multivessel PCI. There was a wide variation in the prevalence of single-session multivessel PCI across the participating centers. The staged multivessel PCI group more often had complex coronary anatomy such as 3-vessel disease, chronic total occlusion, and calcified lesions requiring an atherectomy device compared with the single-session multivessel PCI group. The rates of PCI success, procedural complications, and meeting OPTIVUS criteria were not different between groups. The cumulative 1-year incidence of the primary endpoint was not different between single-session and staged multivessel PCI groups (9.0% vs 10.8%, log-rank P = 0.42). After adjusting confounders, the effect of single-session multivessel PCI relative to staged multivessel PCI was not significant for the primary endpoint (HR: 0.95; 95% CI: 0.58-1.55; P = 0.84). [Conclusions] Single-session and staged multivessel IVUS-guided PCI had similar 1-year outcomes

On-Orbit Operations of A Power System For Japan’s Venus Explorer Akatsuki

This paper describes on-orbit operations of a power system for Japan’s Venus explorer Akatsuki. It was launched on May 20, 2010, and approached Venus on December 7, 2010, but orbit insertion failed because of a propulsion system malfunction. After the failure, the spacecraft stayed on an orbit nearer to the sun than Venus for 5 years before successfully entering an orbit around Venus in 2015. Telemetry data that show radiation degradation of the solar arrays, and here analytical results by the relative damage coefficients method are presented. The capacity loss of the batteries was successfully suppressed by lowering the state of charge and temperature. We plan to extend the mission period from 4.5 years to longer than 9 years to obtain more fruitful scientific results

Report on the visit and research in El Salvador, February and March, 2023

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Details on the effect of very short dual antiplatelet therapy after drug-eluting stent implantation in patients with high bleeding risk: insight from the STOPDAPT-2 trial

Previously we briefly reported the effect of 1-month dual antiplatelet therapy (DAPT) for patients with high bleeding risk (HBR) receiving percutaneous coronary intervention (PCI) in the STOPDAPT-2 trial, but full analysis data have not been available. We conducted post hoc subgroup analysis regarding the effect of very short DAPT for HBR patients in STOPDAPT-2 trial. The primary endpoint was a 1-year composite of cardiovascular (cardiovascular death, myocardial infarction, definite stent thrombosis, or stroke) and bleeding (TIMI major/minor bleeding) outcomes. Major secondary endpoints were 1-year cardiovascular composite endpoint and bleeding endpoint. HBR was defined by the academic research consortium (ARC) HBR criteria. Among the 3009 study patients, 1054 (35.0%) were classified as HBR and 1955 (65.0%) were as non-HBR. There were no significant interactions between HBR/non-HBR subgroups and the assigned DAPT group on the primary endpoint (HBR; 3.48% vs. 5.98%, HR 0.57, 95% CI 0.32-1.03, and non-HBR; 1.81% vs. 2.36%, HR 0.78, 95% CI 0.42-1.45; P for interaction = 0.48), the major secondary cardiovascular endpoint (HBR; 3.07% vs. 4.03%, HR 0.77, 95% CI 0.40-1.48, and non-HBR; 1.41% vs. 1.61%, HR 0.89, 95% CI 0.43-1.84; P for interaction = 0.77), and the major secondary bleeding endpoint (HBR; 0.41% vs. 2.71%, HR 0.15, 95% CI 0.03-0.65, and non-HBR; 0.40% vs. 0.85%, HR 0.48, 95% CI 0.14-1.58; P for interaction = 0.22). In conclusion, the effects of 1-month DAPT for the primary and major secondary endpoints were consistent in HBR and non-HBR patients without any significant interactions. The benefit of 1-month DAPT in reducing major bleeding was numerically greater in HBR patients.Clinical trial registration Short and optimal duration of dual antiplatelet therapy after everolimus-eluting cobalt-chromium stent-2 [STOPDAPT-2]; NCT02619760