13 research outputs found
Non-volatile hybrid optical phase shifter driven by a ferroelectric transistor
Optical phase shifters are essential elements in photonic integrated circuits
(PICs) and function as a direct interface to program the PIC. Non-volatile
phase shifters, which can retain information without a power supply, are highly
desirable for low-power static operations. Here a non-volatile optical phase
shifter is demonstrated by driving a III-V/Si hybrid metal-oxide-semiconductor
(MOS) phase shifter with a ferroelectric field-effect transistor (FeFET)
operating in the source follower mode. Owing to the various polarization states
in the FeFET, multistate non-volatile phase shifts up to 1.25{\pi} are obtained
with CMOS-compatible operation voltages and low switching energy up to 3.3 nJ.
Furthermore, a crossbar array architecture is proposed to simplify the control
of non-volatile phase shifters in large-scale PICs and its feasibility is
verified by confirming the selective write-in operation of a targeted FeFET
with a negligible disturbance to the others. This work paves the way for
realizing large-scale non-volatile programmable PICs for emerging computing
applications such as deep learning and quantum computing
Non-volatile optical phase shift in ferroelectric hafnium zirconium oxide
A non-volatile optical phase shifter is a critical component for enabling
large-scale, energy-efficient programmable photonic integrated circuits (PICs)
on a silicon (Si) photonics platform. While ferroelectric materials like BaTiO3
offer non-volatile optical phase shift capabilities, their compatibility with
complementary metal-oxide-semiconductor (CMOS) fabs is limited. Hence, the
search for a novel CMOS-compatible ferroelectric material for non-volatile
optical phase shifting in Si photonics is of utmost importance. Hafnium
zirconium oxide (HZO) is an emerging ferroelectric material discovered in 2011,
which exhibits CMOS compatibility due to the utilization of high-k dielectric
HfO2 in CMOS transistors. Although extensively studied for ferroelectric
transistors and memories, its application in photonics remains relatively
unexplored. Here, we show the optical phase shift induced by ferroelectric HZO
deposited on a SiN optical waveguide. We observed a negative change in
refractive index at a 1.55 um wavelength in the pristine device regardless of
the direction of an applied electric filed. We achieved approximately pi phase
shift in a 4.5-mm-long device with negligible optical loss. The non-volatile
multi-level optical phase shift was confirmed with a persistence of > 10000 s.
This phase shift can be attributed to the spontaneous polarization within the
HZO film along the external electric field. We anticipate that our results will
stimulate further research on optical nonlinear effects, such as the Pockels
effect, in ferroelectric HZO. This advancement will enable the development of
various devices, including high-speed optical modulators. Consequently,
HZO-based programmable PICs are poised to become indispensable in diverse
applications, ranging from optical fiber communication and artificial
intelligence to quantum computing and sensing
“Peel cutting” – A new cutting method for difficult-to-cut workpieces with hard oxide surfaces
Anti-mumps IgM antibody positive rate with sudden sensorineural hearing loss using second-generation enzyme immunoassay : A retrospective, multi-institutional investigation in Hokkaido, Japan
Objective: Although elevated anti-mumps IgM antibody levels were reported in 5.7%-7.2% of Japanese patients with sudden sensorineural hearing loss (SSNHL), there were several reports of false-positive cases, such as the continually IgM positive case and the IgM positive case in normal adults. To improve specificity, the new enzyme immuno assay (EIA) anti-mumps IgM antibody measurement kit was introduced in December 2009. This study re-examined the frequency of anti mumps IgM antibody test positivity with SSNHL using the new measurement kit and compared the results with those from a previous report that used old kit. Methods: This is a retrospective multi-institutional study involving patients diagnosed with SSNHL who exhibited the anti-mumps IgM antibody. We compared the positive rate of anti-mumps IgM antibody and the annual average number of mumps cases per sentinel in Hokkaido between the patients in the present study and patients previously evaluated. Results: Overall, 100 patients with SSNHL were enrolled. One case (1.0%) was positive for anti mumps IgM antibody. Of the 69 patients evaluated in the previous study, 5 cases (7.2%) were positive for anti-mumps IgM antibody. The positive rate of the anti-mumps IgM antibody in the present cases was significantly lower than that previously reported (p = 0.042). The annual average number of mumps cases per sentinel in Hokkaido of the present and previous surveillance period was 34.47 and 42.77, respectively; no significant difference was seen in these data (p = 0.4519). Conclusion: The present study revealed that 1.0% of SSNHL was positive for the anti-mumps IgM antibody using the new EIA-IgM measurement kit. After the introduction of the new EIA-IgM measurement kit, anti-mumps IgM antibody positive rate with SSNHL significantly decreased, indicating that the proportion of asymptomatic mumps among etiology of SSNHL may be lower than those previously reported
Anti-mumps IgM antibody positive rate with sudden sensorineural hearing loss using second-generation enzyme immunoassay : A retrospective, multi-institutional investigation in Hokkaido, Japan
Late-onset Cerebrotendinous Xanthomatosis with a Novel Mutation in the CYP27A1 Gene
Cerebrotendinous xanthomatosis (CTX) is a rare, autosomal recessive, inborn disruption in bile acid synthesis characterized by severe systemic xanthomas, cataracts and neurological injuries occurring before adolescence without elevation of the serum cholesterol or triglyceride levels. CTX is caused by a deficiency of the mitochondrial enzyme sterol 27-hydroxylase, which is encoded by the CYP27A1 gene. We herein report a 50-year-old Japanese woman with late-onset CTX who had no relevant symptoms before the development of bilateral Achilles tendon xanthomas in middle age. A genetic analysis revealed a compound heterozygous mutation in the CYP27A1 gene with a previously known missense mutation (NM_000784.3:c.1421 G>A) and a novel frame shift mutation of NM_000784.3:c.1342_1343insCACC
Propensity score–weighted analysis of chemotherapy after PD-1 inhibitors versus chemotherapy alone in patients with non–small cell lung cancer (WJOG10217L)
BackgroundStudies have suggested that chemotherapy after immune checkpoint inhibitors may confer an improved response for non–small cell lung cancer (NSCLC). However, potential selection bias in such studies has not been addressed. We therefore applied propensity score analysis to investigate the efficacy of chemotherapy after PD-1 inhibitor treatment (CAP) compared with chemotherapy alone.MethodsWe conducted a retrospective observational cohort study for patients treated at 47 institutions across Japan between April 1, 2014 and July 31, 2017. Eligible patients had advanced or recurrent NSCLC who have undergone chemotherapy. Patients subsequently treated with chemotherapy (docetaxel with or without ramucirumab, S-1 or pemetrexed) either after PD-1 inhibitor therapy (CAP cohort) or alone (control cohort) were included. The primary end point was objective response rate (ORR). Inverse probability weighting (IPW) was applied to adjust for potential confounding factors.ResultsA total of 1439 patients (243 and 1196 in the CAP and control cohorts, respectively) was available for unadjusted analysis. Several baseline characteristics—including age, histology, EGFR or ALK genetic alterations, and brain metastasis—differed significantly between the two cohorts. After adjustment for patient characteristics with the IPW method, ORR was 18.9% for the CAP cohort and 11.0% for the control cohort (ORR ratio 1.71; 95% CI 1.19 to 2.46; p=0.004). IPW-adjusted Kaplan-Meier curves showed that median progression-free survival (PFS) for the CAP and control cohorts was 2.8 and 2.7 months (IPW-adjusted HR 0.95; 95% CI 0.80 to 1.12; p=0.55), and median overall survival (OS) was 9.2 and 10.4 months (IPW-adjusted HR 1.05; 95% CI 0.86 to 1.28; p=0.63), respectively.ConclusionsAfter accounting for selection bias by propensity score analysis, CAP showed a significantly higher ORR compared with chemotherapy alone, with the primary end point of ORR being achieved. However, these results did not translate into a PFS or OS advantage, suggesting that prior administration of PD-1 inhibitors may result in a synergistic antitumor effect with subsequent chemotherapy, but that such an effect is transient. CAP therefore does not appear to achieve durable tumor control or confer a lasting survival benefit