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1.
Dis Esophagus ; 2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38869095

RESUMO

Although esophageal cancers invading the muscularis mucosa (pT1a-MM) or submucosa (pT1b-SM) after endoscopic resection (ER) are associated with a risk of lymph node metastasis, details of metastatic recurrence after additional treatment remain unknown. We aimed to identify the risk factors for metastatic recurrence and recurrence patterns in patients receiving additional treatment after ER for esophageal cancer. Between 2006 and 2017, patients with pT1a-MM/pT1b-SM esophageal cancer who underwent ER with additional treatment (esophagectomy, chemoradiotherapy [CRT], and radiation therapy) at 21 institutions in Japan were enrolled. We evaluated the risk factors for metastatic recurrence after ER with additional treatment. Subsequently, the rate and pattern (locoregional or distant) of metastatic recurrence were investigated for each additional treatment. Of the 220 patients who received additional treatment, 57, 125, and 38 underwent esophagectomy, CRT, and radiation therapy, respectively. In the multivariate analysis, lymphatic invasion was the sole risk factor for metastatic recurrence after additional treatment (hazard ratio, 3.50; P = 0.029). Although the risk of metastatic recurrence with additional esophagectomy was similar to that with CRT (hazard ratio, 1.01; P = 0.986), the rate of locoregional recurrence tended to be higher with additional esophagectomy (80.0% (4/5) vs. 36.4% (4/11)), leading to a better prognosis in patients with metastatic recurrence after additional esophagectomy than CRT (survival rate, 80.0% (4/5) vs. 9.1% (1/11)). Patients with lymphatic invasion have a high risk of metastatic recurrence after ER with additional treatment for pT1a-MM/pT1b-SM esophageal cancer. Additional esophagectomy may result in a better prognosis after metastatic recurrence.

2.
BMC Public Health ; 24(1): 611, 2024 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-38408941

RESUMO

BACKGROUND: People with chronic hepatitis B (CHB) commonly experience social and self-stigma. This study sought to understand the impacts of CHB-related stigma and a functional cure on stigma. METHODS: Adults with CHB with a wide range of age and education were recruited from 5 countries and participated in 90-minute qualitative, semi-structured interviews to explore concepts related to CHB-associated stigma and its impact. Participants answered open-ended concept-elicitation questions regarding their experience of social and self-stigma, and the potential impact of reduced CHB-related stigma. RESULTS: Sixty-three participants aged 25 to 71 years (15 from the United States and 12 each from China, Germany, Italy, and Japan) reported emotional, lifestyle, and social impacts of living with CHB, including prejudice, marginalization, and negative relationship and work experiences. Self-stigma led to low self-esteem, concealment of CHB status, and social withdrawal. Most participants stated a functional cure for hepatitis B would reduce self-stigma. CONCLUSIONS: CHB-related social and self-stigma are widely prevalent and affect many aspects of life. A functional cure for hepatitis B may reduce social and self-stigma and substantially improve the health-related quality of life of people with CHB. Incorporating stigma into guidelines along with infectivity considerations may broaden the patient groups who should receive treatment.


Assuntos
Hepatite B Crônica , Hepatite B , Adulto , Humanos , Estados Unidos/epidemiologia , Hepatite B Crônica/psicologia , Qualidade de Vida , Estigma Social , Hepatite B/psicologia , Ásia , Europa (Continente)
3.
Appl Environ Microbiol ; 90(2): e0175323, 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38259078

RESUMO

White-rot fungi, such as Phanerochaete chrysosporium, are the most efficient degraders of lignin, a major component of plant biomass. Enzymes produced by these fungi, such as lignin peroxidases and manganese peroxidases, break down lignin polymers into various aromatic compounds based on guaiacyl, syringyl, and hydroxyphenyl units. These intermediates are further degraded, and the aromatic ring is cleaved by 1,2,4-trihydroxybenzene dioxygenases. This study aimed to characterize homogentisate dioxygenase (HGD)-like proteins from P. chrysosporium that are strongly induced by the G-unit fragment of vanillin. We overexpressed two homologous recombinant HGDs, PcHGD1 and PcHGD2, in Escherichia coli. Both PcHGD1 and PcHGD2 catalyzed the ring cleavage in methoxyhydroquinone (MHQ) and dimethoxyhydroquinone (DMHQ). The two enzymes had the highest catalytic efficiency (kcat/Km) for MHQ, and therefore, we named PcHGD1 and PcHGD2 as MHQ dioxygenases 1 and 2 (PcMHQD1 and PcMHQD2), respectively, from P. chrysosporium. This is the first study to identify and characterize MHQ and DMHQ dioxygenase activities in members of the HGD superfamily. These findings highlight the unique and broad substrate spectra of PcHGDs, rendering them attractive candidates for biotechnological applications.IMPORTANCEThis study aimed to elucidate the properties of enzymes responsible for degrading lignin, a dominant natural polymer in terrestrial lignocellulosic biomass. We focused on two homogentisate dioxygenase (HGD) homologs from the white-rot fungus, P. chrysosporium, and investigated their roles in the degradation of lignin-derived aromatic compounds. In the P. chrysosporium genome database, PcMHQD1 and PcMHQD2 were annotated as HGDs that could cleave the aromatic rings of methoxyhydroquinone (MHQ) and dimethoxyhydroquinone (DMHQ) with a preference for MHQ. These findings suggest that MHQD1 and/or MHQD2 play important roles in the degradation of lignin-derived aromatic compounds by P. chrysosporium. The preference of PcMHQDs for MHQ and DMHQ not only highlights their potential for biotechnological applications but also underscores their critical role in understanding lignin degradation by a representative of white-rot fungus, P. chrysosporium.


Assuntos
Dioxigenases , Phanerochaete , Lignina/metabolismo , Dioxigenases/genética , Dioxigenases/metabolismo , Phanerochaete/genética , Homogentisato 1,2-Dioxigenase/metabolismo , Proteínas/metabolismo , Peroxidases/genética , Peroxidases/metabolismo
4.
Opt Express ; 31(23): 37993-38003, 2023 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-38017917

RESUMO

Here, we report on the increase of the quality-factors of photonic crystal nanocavities fabricated by a CMOS-compatible process. We fabricated nanocavities with the same cavity design but used either a binary photomask or a phase-shift photomask in the photolithography step to assess the impact of the photomask-type on the fabrication accuracy of the air holes. We characterized 62 cavities using time-resolved measurements and the best cavity had a quality-factor of 6.65 × 106. All cavities exhibited a quality-factor larger than 2 million and the overall average was 3.25 × 106. While the estimated magnitude of the scattering loss due to the air hole variations in the 33 cavities fabricated with the phase-shift photomask was slightly lower than that in the 29 cavities fabricated with binary photomask, the phase-shift photomask did not provide a significant improvement in the fabrication accuracy. On average, the scattering loss in these samples is more than 3 times larger than that of nanocavities fabricated using electron-beam lithography, which indicates room for further improvement.

6.
Opt Express ; 31(9): 14317-14342, 2023 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-37157299

RESUMO

A Raman nanocavity laser can emit light into free space and into a properly designed waveguide adjacent to the cavity by mode coupling. In common device designs, the emission from the edge of this waveguide is relatively weak. However, a Raman silicon nanocavity laser with strong emission from the waveguide edge would be advantageous for certain applications. Here we investigate the increase in the edge emission that can be achieved by adding photonic mirrors to the waveguides adjacent to the nanocavity. We experimentally compare devices with and without photonic mirrors: the edge emission for devices with mirrors is 4.3 times stronger on average. This increase is analyzed using coupled-mode theory. The results indicate that the control of the round-trip phase shift (between the nanocavity and the mirror) and an increase of the quality factors of the nanocavity are important for further enhancement.

7.
Opt Express ; 31(10): 15495-15513, 2023 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-37157650

RESUMO

It is known that the quality factors (Q) of photonic crystal nanocavities vary from sample to sample due to air-hole fabrication fluctuations. In other words, for the mass production of a cavity with a given design, we need to consider that the Q can vary significantly. So far, we have studied the sample-to-sample variation in Q for symmetric nanocavity designs, that is, nanocavity designs where the positions of the holes maintain mirror symmetry with respect to both symmetry axes of the nanocavity. Here we investigate the variation of Q for a nanocavity design in which the air-hole pattern has no mirror symmetry (a so-called asymmetric cavity design). First, an asymmetric cavity design with a Q of about 250,000 was developed by machine learning using neural networks, and then we fabricated fifty cavities with the same design. We also fabricated fifty symmetric cavities with a design Q of about 250,000 for comparison. The variation of the measured Q values of the asymmetric cavities was 39% smaller than that of the symmetric cavities. This result is consistent with simulations in which the air-hole positions and radii are randomly varied. Asymmetric nanocavity designs may be useful for mass production since the variation in Q is suppressed.

8.
Infect Dis Ther ; 12(5): 1337-1349, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37067724

RESUMO

INTRODUCTION: Chronic hepatitis B (CHB) is one of the world's major healthcare problems, especially in the Western Pacific regions. This study describes the prevalence, incidence, treatment profiles and clinical and economic burden of chronic hepatitis B patients in Japan using the Japan Medical Data Center (JMDC) Claims Database. METHODS: This is a retrospective observational study. Prevalence cases were identified as patients with ≥ 1 inpatient or ≥ 2 outpatient CHB diagnoses and ≥ 2 records for hepatitis B tests or ≥ 1 prescription for CHB treatment between January 2010 and December 2019. Newly diagnosed CHB patients were defined as patients diagnosed from 2010 to 2018 with no history of the disease up to 2 years prior to the diagnosis. The index date is defined as the first CHB diagnosis day. We only used patients' data with ≥ 1-year post-index date. RESULTS: We identified 13,061 CHB prevalent cases (2010-2019), yielding a crude period prevalence of 0.32%. Newly diagnosed CHB patients (n = 1973; median age 52 years) were followed for a median period of 3.1 years, during which 15% received a CHB treatment. Entecavir was the most common first treatment (66%). During this period, 3.4% of the patients developed compensated cirrhosis (CC), 1.5% decompensated cirrhosis (DC) and 3.0% hepatocellular carcinoma (HCC). Around 43.3% of CHB patients were hospitalized at least once. Hospitalizations, treatment rates, serologic testing and screening for liver diseases increased as the severity of the disease progressed. The average total healthcare cost was 870,568 JPY (7779 USD) per person per year. DC and HCC resulted in the highest management costs. CONCLUSIONS: Chronic hepatitis B represents a high clinical and economic burden for patients and caregivers, given its morbidity and associated costs.

9.
J Gastroenterol ; 58(4): 346-357, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36633664

RESUMO

BACKGROUND: The guidelines recommend additional gastrectomy after noncurative endoscopic resection for early gastric cancers (EGCs). However, no additional treatment might be acceptable in some patients aged ≥ 85 years. We aimed to identify this patient group using the data in a highly aged area. METHODS: We enrolled patients aged ≥ 85 years after noncurative endoscopic resection for EGCs at 30 institutions of the Tohoku district in Japan between 2002 and 2017. Treatment selection and prognosis after noncurative endoscopic resection were investigated. Fourteen candidates were evaluated using the Cox model to identify risk factors for poor overall survival (OS) in patients with no additional treatment. RESULTS: Of 1065 patients aged ≥ 85 years, 143 underwent noncurative endoscopic resection. Despite the guidelines' recommendation, 88.8% of them underwent no additional treatment. The 5-year OS rates in those with additional gastrectomy and those with no additional treatment were 63.1 and 65.2%, respectively. Multivariate analysis showed independent risk factors for poor OS in patients with no additional treatment were the high-risk category in the eCura system (hazard ratio [HR], 2.91), Charlson comorbidity index (CCI) ≥ 3 (HR, 2.78), and male (HR, 2.04). In patients with no additional treatment, nongastric cancer-specific survival was low (69.0% in 5 years), whereas disease-specific survival rates were very high in the low- and intermediate-risk categories of the eCura system (100.0 and 97.1%, respectively, in 5 years). CONCLUSIONS: No additional treatment may be acceptable in the low- and intermediate-risk categories of the eCura system in patients aged ≥ 85 years with noncurative endoscopic resection for EGCs.


Assuntos
Ressecção Endoscópica de Mucosa , Neoplasias Gástricas , Humanos , Masculino , Estudos Retrospectivos , Resultado do Tratamento , Neoplasias Gástricas/cirurgia , Japão/epidemiologia , Gastrectomia , Mucosa Gástrica/cirurgia
10.
J Cancer Res Clin Oncol ; 149(4): 1521-1530, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35546359

RESUMO

PURPOSE: Little is known about the prognostic factors for survival after endoscopic submucosal dissection (ESD) in elderly patients with early gastric cancer (EGC). The aim of this study is to determine prognostic factors and a prediction model of 3-year survival after ESD for EGC in patients aged ≥ 85 years. METHODS: We retrospectively evaluated the clinical outcomes of 740 patients with EGC aged ≥ 85 years, who were treated by ESD at 30 institutions in Japan. Overall survival (OS) and disease-specific survival (DSS) were calculated with the Kaplan-Meier method. Prediction models for 3-year OS after ESD were estimated using the Cox proportional hazards model based on Uno's C-statistics. RESULTS: During the follow-up period, 309 patients died of any cause and 10 patients died of gastric cancer. OS and DSS after 3 years were 82.7% and 99.2%, respectively. No significant differences in OS were found among curability categories. The Cox proportional hazards model revealed the geriatric nutritional risk index (GNRI) and the Charlson comorbidity index (CCI) to be predictors of 3-year survival. We established a final model (EGC-2 model) expressed by GNRI - (2.2×CCI) with a cutoff value of 96. The overall survival rate was significantly lower in the model value < 96 group than in the model value ≥ 96 group (P < 0.001). CONCLUSIONS: The prediction model using GNRI and CCI will be useful to support decision-making for the treatment of EGC in elderly patients aged ≥ 85 years.


Assuntos
Ressecção Endoscópica de Mucosa , Neoplasias Gástricas , Idoso , Humanos , Estudos Retrospectivos , Neoplasias Gástricas/cirurgia , Ressecção Endoscópica de Mucosa/métodos , Gastrectomia , Detecção Precoce de Câncer , Resultado do Tratamento , Mucosa Gástrica
11.
Dig Dis Sci ; 68(5): 2050-2060, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36445654

RESUMO

BACKGROUND: Although additional treatment is considered for patients with esophageal squamous cell carcinoma (ESCC) invading into the muscularis mucosa (pT1a-MM) or submucosa (pT1b-SM) after endoscopic submucosal dissection (ESD), the actual benefits of this method remain to be elucidated. AIMS: We aimed to evaluate the prognostic benefits of additional treatment in such patients. METHODS: Between 2006 and 2017, we enrolled patients with pT1a-MM/pT1b-SM ESCC after ESD at 21 institutions in Japan. Overall survival (OS) and disease-specific survival (DSS) were compared between the additional treatment and follow-up groups after propensity score matching, to reduce the bias of baseline characteristics. A subgroup analysis was performed according to the pathological findings: category A, pT1a-MM but negative for lymphovascular invasion (LVI) and vertical margin (VM); category B, tumor invasion into the submucosa ≤ 200 µm but negative for LVI and VM; category C, others. RESULTS: Of 593 patients with pT1a-MM/pT1b-SM ESCC after ESD, 101 matched pairs were extracted after propensity score matching. The OSs were similar between the additional treatment and follow-up groups (80.6% vs. 78.6% in 5 years; P = 0.972). In a subgroup analysis, the OS in the additional treatment group was significantly lower than that in the follow-up group (65.7% vs. 95.2% in 5 years; P = 0.037) in category A, whereas OS did not significantly differ in category C (76.8% vs. 69.5% in 5 years; P = 0.360). CONCLUSIONS: Additional treatment after ESD in patients with pT1a-MM/pT1b-SM ESCC was not associated with an improved prognosis.


Assuntos
Ressecção Endoscópica de Mucosa , Neoplasias Esofágicas , Carcinoma de Células Escamosas do Esôfago , Humanos , Carcinoma de Células Escamosas do Esôfago/cirurgia , Carcinoma de Células Escamosas do Esôfago/patologia , Prognóstico , Neoplasias Esofágicas/patologia , Ressecção Endoscópica de Mucosa/métodos , Estudos Retrospectivos , Resultado do Tratamento
12.
Antivir Ther ; 27(3): 13596535221093856, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35695169

RESUMO

BACKGROUND: JNJ-73763989 comprises two hepatitis B virus (HBV)-specific, liver-targeted N-galactosamine-conjugated short interfering RNA triggers, JNJ-73763976 and JNJ-73763924. JNJ-73763989 pharmacokinetics, safety and tolerability were assessed in two phase 1 studies: Japanese (NCT04002752), and non-Japanese healthy participants and chronic hepatitis B (CHB) patients also receiving the HBV capsid assembly modulator JNJ-56136379 and a nucleos(t)ide analogue (NA) (NCT03365947). METHODS: Healthy participant cohorts were double-blind and randomized to receive a single subcutaneous JNJ-73763989 dose (non-Japanese participants, 35, 100, 200, 300 or 400 mg; Japanese participants, 25, 100 or 200 mg) or placebo. JNJ-73763976 and JNJ-73763924 plasma concentrations were assessed over 48 h. CHB patients received JNJ-73763989 200 mg every 4 weeks plus daily oral JNJ-56136379 250 mg and NA in an open-label fashion. Safety and tolerability were assessed through Day 28 (healthy participants) or Day 112 (patients). RESULTS: Thirty non-Japanese (n = 4/dose; placebo, n = 10) and 24 Japanese healthy participants (n = 6/dose; placebo, n = 6) were randomized. JNJ-73763976 and JNJ-73763924 exposure generally increased in a dose-proportional manner. Mean plasma half-life was 4-9 h. No differences between pharmacokinetic parameters were apparent between non-Japanese and Japanese healthy participants. In the 12 CHB patients, mean JNJ-73763976, JNJ-73763924 and JNJ-56136379 plasma concentrations 2 h post-dose on Day 29 were 663, 269 and 14,718 ng/mL, respectively. In both studies, all adverse events were mild/moderate. CONCLUSION: JNJ-73763976 and JNJ-73763924 had short plasma half-lives and exposure generally increased in a dose-proportional manner; there were no pharmacokinetic differences between Japanese and non-Japanese healthy adults. JNJ-73763989 with or without JNJ-56136379 and NA was generally safe and well tolerated.


Assuntos
Hepatite B Crônica , Adulto , Antivirais/efeitos adversos , Método Duplo-Cego , Vírus da Hepatite B/genética , Hepatite B Crônica/tratamento farmacológico , Humanos , Japão , Compostos Orgânicos , RNA Interferente Pequeno/uso terapêutico
13.
Dig Endosc ; 34(7): 1382-1391, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35702926

RESUMO

OBJECTIVES: We aimed to clarify the prognostic factors for patients with esophageal squamous cell carcinoma (ESCC) invading into the muscularis mucosa (pT1a-MM) or submucosa (pT1b-SM) after endoscopic submucosal dissection (ESD). METHODS: This retrospective study enrolled such patients at 21 institutions in Japan between 2006 and 2017. We evaluated 15 factors, including pathological risk categories for ESCC-specific mortality, six non-cancer-related indices, and treatment strategies. RESULTS: In the analysis of 593 patients, the 5-year overall and disease-specific survival rates were 83.0% and 97.6%, respectively. In a multivariate Cox analysis, male sex (hazard ratio [HR] 3.56), Charlson comorbidity index (CCI) ≥3 (HR 2.53), ages of 75-79 (HR 1.61) and ≥80 years (HR 2.04), prognostic nutrition index (PNI) <45 (HR 1.69), and pathological intermediate-risk (HR 1.63) and high-risk (HR 1.89) were prognostic factors. Subsequently, we developed a clinical risk classification for non-ESCC-related mortality based on the number of prognostic factors (age ≥75 years, male sex, CCI ≥3, PNI <45): low-risk, 0; intermediate-risk, 1-2; and high-risk, 3-4. The 5-year non-ESCC-related mortality rates for patients without additional treatment were 0.0%, 10.2%, and 45.8% in the low-, intermediate-, and high-risk groups, respectively. Meanwhile, the 5-year ESCC-specific mortality rates for the pathological low-, intermediate-, and high-risk groups were 0.3%, 5.3%, and 18.2%, respectively. CONCLUSIONS: We clarified prognostic factors for patients with pT1a-MM/pT1b-SM ESCC after ESD. The combined assessment of non-ESCC- and ESCC-related mortalities by the two risk classifications might help clinicians in deciding treatment strategies for such patients.


Assuntos
Ressecção Endoscópica de Mucosa , Neoplasias Esofágicas , Carcinoma de Células Escamosas do Esôfago , Humanos , Masculino , Idoso de 80 Anos ou mais , Idoso , Carcinoma de Células Escamosas do Esôfago/patologia , Neoplasias Esofágicas/patologia , Estudos Retrospectivos , Prognóstico , Mucosa/cirurgia , Mucosa/patologia , Resultado do Tratamento
14.
Diabetes Obes Metab ; 24(8): 1429-1438, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35491532

RESUMO

AIM: To evaluate the effect of canagliflozin, a sodium-glucose co-transporter-2 (SGLT2) inhibitor, on albuminuria and the decline of estimated glomerular filtration rate (eGFR) in participants with type 2 diabetes and microalbuminuria. METHODS: The CANPIONE study is a multicentre, randomized, parallel-group and open-labelled study consisting of a unique 24-week preintervention period, during which the rate of eGFR decline before intervention is estimated, followed by a 52-week intervention and a 4-week washout period. Participants with a geometric mean urinary albumin-to-creatinine ratio (UACR) of 50 and higher and less than 300 mg/g in two consecutive first-morning voids at two different time points, and an eGFR of 45 ml/min/1.73m2 or higher, are randomly assigned to receive canagliflozin 100 mg daily or to continue guideline-recommended treatment, except for SGLT2 inhibitors. The first primary outcome is the change in UACR, and the second primary outcome is the change in eGFR slope. RESULTS: A total of 258 participants were screened and 98 were randomized at 21 sites in Japan from August 2018 to May 2021. The mean baseline age was 61.4 years and 25.8% were female. The mean HbA1c was 7.9%, mean eGFR was 74.1 ml/min/1.73m2 and median UACR was 104.2 mg/g. CONCLUSIONS: The CANPIONE study will determine whether the SGLT2 inhibitor canagliflozin can reduce albuminuria and slow eGFR decline in participants with type 2 diabetes and microalbuminuria.


Assuntos
Diabetes Mellitus Tipo 2 , Inibidores do Transportador 2 de Sódio-Glicose , Albuminúria/epidemiologia , Canagliflozina/uso terapêutico , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/urina , Feminino , Taxa de Filtração Glomerular , Humanos , Japão/epidemiologia , Masculino , Pessoa de Meia-Idade , Inibidores do Transportador 2 de Sódio-Glicose/farmacologia , Inibidores do Transportador 2 de Sódio-Glicose/uso terapêutico
15.
Opt Express ; 30(7): 10694-10708, 2022 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-35473030

RESUMO

It has been shown that silicon photonic crystal nanocavities excited by spectrally narrow light can be used to detect ionized air. Here, to increase the range of possible applications of nanocavity-based sensing, the use of broadband light is considered. We find that the use of a superluminescent diode (SLD) as an excitation source enables a more reproducible detection of ionized air. When our photonic-crystal nanocavity is exposed to ionized air, carriers are transferred to the cavity and the light emission from the cavity decreases due to free carrier absorption. Owing to the broadband light source, the resonance wavelength shifts caused by the carriers in this system (for example, due to temperature fluctuations) do not influence the emission intensity. SLD-excited cavities could be useful to determine the density of ions in air quantitatively.

16.
Opt Express ; 29(15): 24396-24410, 2021 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-34614686

RESUMO

Nanocavity devices based on silicon that can operate in the 1.2-µm band would be beneficial for several applications. We fabricate fifteen cavities with resonance wavelengths between 1.20 and 1.23 µm. Experimental quality (Q) factors larger than one million are obtained and the average Q values are lower for shorter wavelengths. Furthermore, we observe continuous-wave operation of a Raman silicon laser with an excitation wavelength of 1.20 µm and a Raman laser wavelength of 1.28 µm. The Q values of the nanocavity modes used to confine the excitation light and the Raman scattered light are about half of those for our Raman silicon laser operating in the 1.55-µm band. Nevertheless, this device exhibits an input-output characteristic with a clear laser threshold. Finally, we consider the effect of the higher scattering probability at shorter wavelengths on the Raman laser performance in the 1.2-µm band.

17.
Opt Express ; 29(11): 16228-16240, 2021 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-34154190

RESUMO

The performance of a Raman silicon laser based on a high quality-factor nanocavity depends on the degree of free-carrier absorption, and this characteristic may be useful for certain applications. Here we demonstrate that laser oscillation in a Raman silicon nanocavity laser stops abruptly after an exposure to a weak flux of negatively ionized air for a few seconds. Spectral measurements reveal that the laser interruption is mainly caused by the transfer of extra electrons from the negatively ionized air molecules to the silicon nanocavity. These electrons affect the efficiency of the Raman laser by free carrier absorption. We find that the laser output gradually recovers as the extra electrons escape from the nanocavity and confirm that such a detection of ionized air is repeatable. These results show that a Raman silicon nanocavity laser can be used for the detection of ionized air with a high spatial resolution.

18.
Opt Express ; 29(11): 17053-17068, 2021 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-34154256

RESUMO

Raman silicon lasers based on photonic crystal nanocavities with a threshold of several hundred microwatts for continuous-wave lasing have been realized. In particular, the threshold depends on the degree of confinement of the excitation light and the Raman scattering light in the two nanocavity modes. Here, we report lower threshold values for Raman silicon nanocavity lasers achieved by increasing the quality (Q) factors of the two cavity modes. By using an optimization method based on machine learning, we first increase the product of the two theoretical Q values by a factor of 17.0 compared to the conventional cavity. The experimental evaluation demonstrates that, on average, the actually achieved product is more than 2.5 times larger than that of the conventional cavity. The input-output characteristic of a Raman laser with a threshold of 90 nW is presented and the lowest threshold obtained in our experiments is 40 nW.

19.
J Gastroenterol ; 56(7): 620-632, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33881632

RESUMO

BACKGROUND: We aimed to elucidate the risk of metastatic recurrence after endoscopic resection (ER) without additional treatment for esophageal squamous cell carcinomas (ESCCs) with tumor invasion into the muscularis mucosa (pT1a-MM) or submucosa (T1b-SM). METHODS: We retrospectively enrolled patients with pT1a-MM/pT1b-SM ESCC after ER at 21 institutions in Japan between 2006 and 2017. We compared metastatic recurrence between patients with and without additional treatment, stratified into category A (pT1a-MM with negative lymphovascular invasion [LVI] and vertical margin [VM]), B (tumor invasion into the submucosa ≤ 200 µm [pT1b-SM1] with negative LVI and VM), and C (others). Subsequently, using multivariate Cox analysis, we evaluated risk factors for metastatic recurrence after ER without additional treatment. RESULTS: We enrolled 593 patients, and metastatic recurrence occurred in 38 patients. Metastatic recurrence after additional treatment was significantly lower than that after no additional treatment in category C (9.1% vs. 23.6% in 5 years, p = 0.001), whereas no significant difference was noted in categories A (0.0% vs. 2.6%) and B (0.0% vs. 4.3%). In patients without additional treatment after ER, risk factors for metastatic recurrence were lymphatic invasion (hazard ratio [HR], 5.61), positive VM (HR, 4.55), and tumor invasion into the submucosa > 200 µm (HR, 3.25), and, but near half of the patients with metastatic recurrence had no further recurrence after salvage treatment, resulting in excellent 5-year disease-specific survival in categories A (99.6%) and B (100.0%). CONCLUSIONS: Closed follow-up with no additional treatment may be an acceptable option after ER in pT1a-MM/pT1b-SM1 ESCC with negative LVI and VM.


Assuntos
Ressecção Endoscópica de Mucosa/métodos , Carcinoma de Células Escamosas do Esôfago/terapia , Mucosa/fisiopatologia , Idoso , Distribuição de Qui-Quadrado , Estudos de Coortes , Ressecção Endoscópica de Mucosa/estatística & dados numéricos , Carcinoma de Células Escamosas do Esôfago/epidemiologia , Feminino , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Recidiva , Estudos Retrospectivos , Resultado do Tratamento
20.
Intern Med ; 60(4): 539-543, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-32999220

RESUMO

We herein report an extremely rare case of localized gastric amyloidosis (LGA) with morphological changes during the follow-up. A 71-year-old woman who had a depressed lesion with central elevation in the gastric lower body was diagnosed with LGA. Esophagogastroduodenoscopy at 10 years after the initial examination showed that the lesion had grown and changed morphologically, exhibiting a submucosal tumor-like appearance. Since the lesion was confined to the submucosa, the patient underwent endoscopic submucosal dissection. The final pathological diagnosis was amyloid light-chain (AL)-type LGA. This case may provide useful information regarding the natural history of AL-type LGA.


Assuntos
Amiloidose , Ressecção Endoscópica de Mucosa , Neoplasias Gástricas , Idoso , Amiloidose/diagnóstico , Endoscopia do Sistema Digestório , Feminino , Humanos
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