Design of photonic-crystal surface-emitting lasers with enhanced in-plane optical feedback for high-speed operation

Photonic-crystal surface-emitting lasers (PCSELs) use the two-dimensional (2D) resonance at the band-edge of a photonic crystal for lasing, and they feature various outstanding functionalities such as high-brightness lasing, arbitrary shaping of beam patterns and on-chip 2D beam steering. In this paper, to investigate the applicability of PCSELs for high-speed operation, we design PCSELs with enhanced in-plane optical feedback, which enable single-mode lasing inside a circular region the diameter of which is less than 10 µm. To realize a strong in-plane confinement of the lasing mode, we increase the one-dimensional coupling coefficients between counter-propagating waves through the careful design of the lattice points. We also introduce an in-plane heterostructure composed of two photonic crystals with different photonic bandgaps and utilize reflection at the boundary of the two photonic crystals in addition to the optical feedback at the band-edge of each photonic crystal. By using three-dimensional finite-difference time-domain method (3D-FDTD), we confirm that the proposed hetero-PCSELs can achieve single-mode lasing operation inside a 9-µm-diameter and possibly realize a 3-dB modulation bandwidth larger than 40 GHz.

Calculation of road accessibility for the rural population in the Shikoku Island of Japan using GIS

Background

The United Nations has defined 17 Sustainable Development Goals as a blueprint for helping ensure the health and well-being of our world by 2030. The global goals address challenges we face including poverty, inequality, climate, environmental, peace and prosperity. The goals each have targets and indicators to help measure success. Indicator #9.1.1 is defined as “Proportion of the rural population who live within 2 km of an all-season road”, which can aid in understanding multiple areas of human well-being including access to food, health care, education and in support of economic development. By understanding access to infrastructure, we can focus on affordable and equitable access for all. We focused on the Shikoku Island of Japan and calculated indicator #9.1.1 using spatial analysis.

Methods

We utilized data from three sources listed below. Cho-cho-moku boundaries population data from the Esri Japan corporation. Metropolitan Employment Area data from the Center for Spatial Information Science at the University of Tokyo. Emergency transport road data from the MLIT of Japan. We conducted proximity analysis with Geographic Information System (GIS) and estimated population of the target area using the area ratio of the target area to the original Cho-cho-moku area.

Results

The percentage of the rural population who live within 2 km of an all-season road is 79.5% and those who have no access to an all-season road in the Shikoku Island is 20.5%.

Conclusions

We found the proportion of the rural population that cannot reach an all-season road by calculating indicator #9.1.1. 20.5% of the rural population in the Shikoku Island of Japan may have difficulties accessing essential services such as health care, education, food, and may have difficulties with economic development. By understanding accessibility to road infrastructure, we were able to identify areas at risk for access. We can work towards creating more equitable access in a next step.

Key messages

By conducting spatial analysis with GIS, we can identify areas at risk for access to infrastructure. we can focus on creating more affordable and equitable access for all by understanding access to infrastructure such as health care, education and food.

Laser-Beam-Patterned Topological Insulating States on Thin Semiconducting MoS_{2}

Identifying the two-dimensional (2D) topological insulating (TI) state in new materials and its control are crucial aspects towards the development of voltage-controlled spintronic devices with low-power dissipation. Members of the 2D transition metal dichalcogenides have been recently predicted and experimentally reported as a new class of 2D TI materials, but in most cases edge conduction seems fragile and limited to the monolayer phase fabricated on specified substrates. Here, we realize the controlled patterning of the 1T^{'} phase embedded into the 2H phase of thin semiconducting molybdenum-disulfide by laser beam irradiation. Integer fractions of the quantum of resistance, the dependence on laser-irradiation conditions, magnetic field, and temperature, as well as the bulk gap observation by scanning tunneling spectroscopy and theoretical calculations indicate the presence of the quantum spin Hall phase in our patterned 1T^{'} phases.

P832LDL-C levels on statins and cardiovascular event risk in stable coronary artery disease: An observation from the REAL-CAD study

Background

The relation between very low on-treatment low-density lipoprotein cholesterol (LDL-C) level and the cardiovascular event risk is still unclear in patients receiving the same doses of statins.

Methods

From the REAL-CAD study comparing high-dose with low-dose pitavastatin therapy in Japanese patients with stable coronary artery disease, 11105 patients without reported non-adherence for the study drug were divided into 3 groups according to the on-treatment LDL-C level at 6-month (<70 mg/dL, 70–100 mg/dL, and ≥100 mg/dL; N=1016, N=3078, and N=1665 in the pitavastatin 1 mg/day stratum; N=2431, N=2524, and N=391 in the pitavastatin 4 mg/day stratum). Primary outcome measure was a composite of cardiovascular death, non-fatal myocardial infarction, non-fatal ischemic stroke, or unstable angina requiring emergent admission.

Results

In the pitavastatin 1 mg/day stratum, cumulative 4-year incidence of the primary outcome measure was not significantly different across the 3 groups (5.0%, 5.7%, and 5.2%, P=0.51), while in the 4 mg/day stratum, it was significantly higher in the LDL-C ≥100 mg/dL group than in other groups (4.5%, 3.4%, and 9.1%, P<0.001). The adjusted risks of the LDL-C <70 mg/dL group relative to the LDL-C 70–100 mg/dL group (reference) remained insignificant for the primary outcome measure in both 1 mg/day and 4 mg/day strata (HR 0.84, 95% CI 0.58–1.18, P=0.32, and HR 1.25, 95% CI 0.88–1.79, P=0.22). The adjusted risk of LDL-C ≥100 mg/dL group relative to the reference group was not significant for the primary outcome measure in the 1 mg/day stratum (HR 0.82, 95% CI 0.60–1.11, P=0.21), while it was highly significant in the 4 mg/day stratum (HR 3.32, 95% CI 2.08–5.17, P<0.001). In the on-treatment LDL-C ≥100 mg/dL group in the 4 mg/day stratum, LDL-C increased by 6.3 mg/dL from baseline to 6-month despite dose escalation of pitavastatin from 1 mg/day to 4 mg/day, suggesting the presence of unreported poor adherence in this small subgroup.

Adjusted Effects of On-treatment LDL-C

Conclusions

Very low on-treatment LDL-C level (<70 mg/dL) was not associated with lower cardiovascular event risk compared with moderately low on-treatment LDL-C level (70–100 mg/dL) in patients receiving the same doses of statins. Too much emphasis on the target LDL-C strategy might mislead the clinical practice.

Acknowledgement/Funding

The Comprehensive Support Project for Clinical Research of Lifestyle-Related Disease of the Public Health Research Foundation.

P5600Surgical reconstruction of type A aortic dissection in octogenarians

Introduction

Because the population is aging, the indication for surgical reconstruction in older patients will increase. Japan is especially facing the most aging society worldwide. However, surgical reconstruction of type A aortic dissection (AADA) in patients who are octogenarians is not often performed because of the decision of the patient or surgeon. We examined the outcome of surgical reconstruction of AADA in octogenarians.

Method

Over 4 years, 132 cases of surgical reconstruction of AADA were analyzed. Twenty-five consecutive octogenarians with AADA were retrospectively reviewed. In our institution, we recommend an emergent operation to the patient or family in all generations unless they reject it for some reason.

Results

Operative factors in octogenarians with AADA were not significantly different compared with those in patients aged younger than 79 years (n=107) (operation: 238±11 vs. 246±5 min, p=0.54; cardiopulmonary bypass: 147±7.4 vs. 154±3.5 min, p=0.42; aortic-clamp: 114±6.0 vs. 120±2.8 min, p=0.36; hypothermic-arrest: 43±2.7 vs. 42±1.3 min, p=0.81). The overall mortality rate was 24.0% (n=6). The mortality rate was no difference between younger patients and octogenarians (OR: 2.7, 95% CI: 0.86–8.21, p=0.08). Furthermore, MACE (Major Adverse Cardiac Event) and the postoperative stroke rate were not significantly different between the two groups (OR: 1.5, 95% CI: 0.52–3.93, p=0.42; OR: 0.77, 95% CI: 0.16–2.59, p=0.69, respectively).

Conclusion

In AADA, the outcome of emergent surgical reconstruction in octogenarians is acceptable. Even with the risk of aging, surgeons should consider aggressive surgical reconstruction in octogenarians.

P4731Procedure-related acute thrombosis after surgical left atrial appendage occlusion for atrial fibrillation

Background/Introduction

Left atrial appendage (LAA) occlusion is an effective strategy for thromboembolism prevention in patients with atrial fibrillation (AF), and the novel methods of occlusion is various. The acute thrombosis after percutaneous LAA occlusion devices has been recently reported, but thrombus formation after surgical LAA occlusion is still unclear.

Purpose

This study aimed to analyse the incidence and prognosis of thrombus formation on closure stump line in patients with AF who underwent surgical LAA occlusion.

Methods

This study retrospectively analised the data from patients treated with two methods of surgical LAA closure, resection or clipping, from January 2014 to November 2018.

Results

A total of 187 consecutive patients with AF underwent surgical LAA closure (31 clipping and 156 stapler resection). 170 patients (91%) underwent cardiac CT for LAA imaging on postoperative day 2. The incidence of acute procedure-related thrombus formation in full cohort was 19% (35 cases). The incidence of acute thrombus in patients with clipping and resection was 19% and 16%, respectively (Fisher's exact test, p=0.8). All of 35 patients who had thrombus on LAA closure stump line underwent cardiac CT again 3 months after the primary CT. In all patients with secondary cardiac CT, thrombus on LAA closure stump line disappeared. No symptomatic thromboembolism occurred during the follow-up from operation to secondary CT scan.

Conclusion(s)

Thrombus formation on stump after surgical LAA closure may often occur on acute phase. The optimal LAA imaging and anti-coagulation therapy after surgical LAA occlusion will prevent patients with acute thrombus from thromboembolism.

P1831Prediction of cardiovascular events by atheromatous plaques detected by non-obstructive general angioscopy: two-year results of EAST-NOGA Registry

Background

Non-obstructive general angioscopy (NOGA) has revealed the intimal damages or atheromatous plaques as well as its spontaneous rupture of the aorta. Recent study revealed that plaque debris or different size of cholesterol crystals were detected in the blood above the spontaneous ruptured aortic plaque observed by NOGA and these plaque materials might cause the peripheral organ damages as the embolic source. These various morphological changes may cause the acute aortic events or atheroembolic events on the peripheral organs, such as brain, kidney, peripheral artery and so on.

Purpose

EAST-NOGA (Evaluation of AtheroSclerotic and rupture events by Non-Obstructive General Angioscopy) is a multi-center prospective observational study to assess the relationship between the findings of NOGA and future cardiovascular events.

Methods

Five hundred and seventy-seven patients with atherosclerotic cardiovascular disease who underwent NOGA study. The major cerebrocardiovascular events including cardiovascular death, non-fatal myocardial infarction, non-fatal cerebral infarction, and acute aortic syndrome were accumulated during the 2-year follow-up after NOGA study.

Results

The median number of aortic atheromatous plaques was 6 [IQR: 3–12]. A total of 514 patients were followed up (89.1%). The mean follow-up duration was 757±120 days. Major adverse cardiovascular events developed in 23 (4.5%) during 2 years follow-up. Patients with MACE and cerebral infarction, had significantly greater number of aortic atheromatous plaques (11 [5–19] vs. 6 [3–11], p<0.001, 12 [4–20] vs. 6 [3–12], p=0.014, respectively). In a univariate analysis, the number of aortic atheromatous plaques and ruptured plaque were significant predictors of MACE (HR: 1.09 95% confidence interval 1.05–1.14, p<0.001) and (HR: 1.12, 95% confidence interval 1.02–1.23, p=0.02). In a multivariate logistic analysis, the number of aortic atheromatous plaques is one of the independent predictors of MACE (HR 1.05, 95% confidence interval 1.00–1.10, p=0.032).

Conclusion

The number of atheromatous plaques identified by NOGA has a significant relation to the onset of cerebral infarction, which suggest the atheromatous plaque were vulnerable and ruptured spontaneously, then cause the aortogenic cerebral infarction. The NOGA study would be useful for predicting the futured atheroembolic events.

Acknowledgement/Funding

None

Health-care resource use and current treatment of adult atopic dermatitis patients in Japan: A retrospective claims database analysis

The real-world evidence on the profiles of patients suffering from atopic dermatitis (AD) in Japan is sparse. A retrospective claim database analysis was conducted to estimate the health-care resource use (HCRU) and current AD treatment. Data from October 2013 to September 2016 were extracted from the JMDC (Tokyo, Japan) claims database. HCRU was assessed by a comparison of AD patients and matched non-AD controls. A multivariate analysis was performed to estimate HCRU attributable to AD. AD patients (n = 39 893) have more claims of certain diagnoses such as rhinitis, viral and fungal infections, sleep disorders and conjunctivitis as well as higher HCRU (outpatient visits, prescriptions of AD-related and non-AD-related medications, phototherapy, laboratory tests) than matched non-AD controls (n = 39 893). Treatment pattern analysis included treatment-naive patients (n = 8478) and previously treated AD patients (n = 30 109). Approximately 20% of previously treated patients were on the continuous systemic treatment during 18-month follow up. Systemic corticosteroids were the most frequently used systemic treatments. Oral cyclosporin was less frequently used in both groups, but for the longest duration. Almost half of previously treated patients with oral cyclosporin continued treatment for more than 3 months. In conclusion, HCRU was higher in AD patients than non-AD controls, indicating a high burden of the disease imposed on AD patients. Continuous administration of systemic treatment, such as oral cyclosporin, systemic corticosteroids and phototherapy, observed in AD patients sheds light on the difficulties of managing AD in Japanese clinical practise.

Recurrent Aphthous Stomatitis Caused by Cytomegalovirus, Herpes Simplex Virus, and Candida Species in a Kidney Transplant Recipient: A Case Report

Recipients of organ transplants are immunosuppressed and at high risk of oral infection. Oral diseases are often neglected compared with infections of other organs that typically confer higher morbidity. However, severe local symptoms hinder oral intake, decrease quality of life, and are sometimes lethal. Here we describe a case of a 57-year-old woman who developed recurrent aphthous stomatitis after kidney transplantation; the cause of the infection was complex and included cytomegalovirus, herpes simplex virus, and Candida species. Since misdiagnosis of oral diseases impairs patient quality of life and increases morbidity, clinicians should be aware of possible etiologies of oral infections in renal transplant recipients.

Effective multiple sideband generation using an electro-optic modulator for a multiple isotope magneto-optical trap

Herein, we report an effective method for the generation of radio-frequency (RF) sidebands in an electro-optic modulator for the simultaneous magneto-optical trapping of two isotopes. This is achieved by switching the RF signals alternately, which suppresses the generation of unwanted frequency signals and improves the laser power per sideband. The generated sidebands are successfully applied to a dual-rubidium-isotope magneto-optical trap (MOT), which results in an increased number of trapped atoms. This simple, flexible, and robust technique can be implemented in experiments that require a large number of atoms in multiple-isotope MOTs and for various applications.

Search for CP Violation in Neutrino and Antineutrino Oscillations by the T2K Experiment with 2.2×10^{21} Protons on Target

The T2K experiment measures muon neutrino disappearance and electron neutrino appearance in accelerator-produced neutrino and antineutrino beams. With an exposure of 14.7(7.6)×10^{20} protons on target in the neutrino (antineutrino) mode, 89 ν_{e} candidates and seven anti-ν_{e} candidates are observed, while 67.5 and 9.0 are expected for δ_{CP}=0 and normal mass ordering. The obtained 2σ confidence interval for the CP-violating phase, δ_{CP}, does not include the CP-conserving cases (δ_{CP}=0, π). The best-fit values of other parameters are sin^{2}θ_{23}=0.526_{-0.036}^{+0.032} and Δm_{32}^{2}=2.463_{-0.070}^{+0.071}×10^{-3}  eV^{2}/c^{4}.