Optical coupling of individual air-suspended carbon nanotubes to silicon microcavities.

Carbon nanotubes are a telecom band emitter compatible with silicon photonics, and when coupled to microcavities, they present opportunities for exploiting quantum electrodynamical effects. Microdisk resonators demonstrate the feasibility of integration into the silicon platform. Efficient coupling is achieved using photonic crystal air-mode nanobeam cavities. The molecular screening effect on nanotube emission allows for spectral tuning of the coupling. The Purcell effect of the coupled cavity-exciton system reveals near-unity radiative quantum efficiencies of the excitons in carbon nanotubes.

van der Waals Decoration of Ultra-High-Q Silica Microcavities for χ(2)-χ(3) Hybrid Nonlinear Photonics.

Optical nonlinear processes are indispensable in a wide range of applications, including ultrafast lasers, microscopy, and quantum information technologies. Among the diverse nonlinear processes, second-order effects usually overwhelm the higher-order ones, except in centrosymmetric systems, where the second-order susceptibility vanishes to allow the use of the third-order nonlinearity. Here we demonstrate a hybrid photonic platform whereby the balance between second- and third-order susceptibilities can be tuned flexibly. By decorating ultra-high-Q silica microcavities with atomically thin tungsten diselenide, we observe cavity-enhanced second-harmonic generation and sum-frequency generation with continuous-wave excitation at a power level of only a few hundred microwatts. We show that the coexistence of second- and third-order nonlinearities in a single device can be achieved by carefully choosing the size and location of the two-dimensional material. Our approach can be generalized to other types of cavities, unlocking the potential of hybrid systems with controlled nonlinear susceptibilities for novel applications.

Edaravone Administered Orally and Via Nasogastric Tube in Healthy Adults: A Comparative Bioavailability Phase 1 Study.

Intravenous edaravone is used to treat patients with amyotrophic lateral sclerosis. This randomized, open-label, two-way crossover, single-dose phase 1 study compared the relative bioavailability of a newly developed edaravone oral suspension when administered orally and via a nasogastric tube (NGT) as a model of percutaneous endoscopic gastrostomy tube administration in healthy adult subjects. Thirty-six subjects were randomly assigned to one of two groups, with 18 per group. Blood was collected pre- and post-dose for pharmacokinetic assessments; safety was evaluated. Plasma concentration-time profiles of unchanged edaravone were similar between administration routes. Comparative bioavailability analysis revealed that geometric least squares mean ratios (NGT/oral) for maximum plasma concentration and area under the plasma concentration-time curve from time zero to infinity of unchanged edaravone were 1.052 and 0.981, respectively. No serious adverse events or adverse drug reactions were reported. These results suggest that oral edaravone suspension can be administered directly to the stomach without dose adjustment via feeding tubes; both oral and NGT administration are well tolerated.

Robot-assisted laparoscopic partial gastrectomy combined with endoscopy for gastrointestinal stromal tumors with intraluminal growth: a report of two cases.

In cases of gastrointestinal stromal tumor (GIST) with intraluminal growth, determining the minimal resection line is difficult; however, the combined use of endoscopy can overcome this limitation. We performed robot-assisted partial gastrectomy with endoscopy for two cases of internally developed GISTs located on the posterior wall near the esophagogastric junction (EGJ). We confirmed the tumor location and determined minimal surgical margins using endoscopy. The double bipolar method (DBM), which is performed with Maryland bipolar forceps in the right hand and fenestrated bipolar forceps in the left hand, was used to reduce residual gastric damage and prevent tumor damage. The characteristics of robot-assisted surgery made it easier to precisely perform anastomosis of the upper part of the stomach, as compared with laparoscopic surgery, thus minimizing gastric deformity. Both patients were discharged without postoperative complications. In conclusion, robot-assisted partial gastrectomy using the DBM may represent a viable treatment option for gastric submucosal tumors close to the EGJ.

Food Effect Study to Assess the Impact on Edaravone Pharmacokinetic Profiles in Healthy Participants.

PURPOSE: The safety and efficacy of intravenous edaravone, a neuroprotectant used for the treatment of amyotrophic lateral sclerosis (ALS), have been shown in clinical trials. An oral suspension of edaravone has been developed, but the food effect on its pharmacokinetic profile has not been evaluated. This study aimed to assess the food effect on the pharmacokinetic profile of edaravone after oral administration and to investigate dosing regimens and administration instructions with different meal intake and timing. METHODS: Data from 3 Phase I clinical studies were used to evaluate the effect of food on the pharmacokinetic profiles of a single dose of edaravone oral suspension. In all 3 studies, participants received a single dose of edaravone with various meal conditions. Healthy Japanese adult male participants (Studies 1, 2, and 3) or female participants (Study 3) aged 20 to 45 years at the time of informed consent were included. FINDINGS: In Study 1, 6 participants were enrolled and 5 completed the study. Nine and 16 participants were treated in Studies 2 and 3, respectively, and all completed the study. The Cmax and AUC0-∞ of edaravone were lower when administered 30 minutes after a high-fat meal compared with those in a fasted condition (Study 1). Lower plasma edaravone concentrations (approximately within the first hour) and subsequent lower Cmax and AUC0-∞ were observed after administration of edaravone 4 hours after a high-fat meal (Study 2) or 2 hours after a low-fat meal (Study 3). The Cmax and AUC0-∞ of oral edaravone were generally similar and not affected when administered 8 hours after a high-fat meal, 4 hours after a low-fat meal, or 2 hours after a light meal relative to the fasted condition. Administration of edaravone 1 hour before a high-fat meal resulted in no effect on Cmax or AUC0-∞ relative to the fasted condition. Administration of edaravone in the fed or fasted conditions resulted in a similar urine pharmacokinetic profile. IMPLICATIONS: Oral administration of edaravone with a meal decreased the plasma concentration of edaravone. Oral administration of edaravone 8 hours after a high-fat meal, 4 hours after a low-fat meal, 2 hours after a light meal, and 1 hour before a high-fat meal showed no effect of food on the PK profile of unchanged edaravone compared with that observed under a fasted condition. CLINICALTRIALS: gov identifiers: NCT04481750, NCT04481789, and NCT05342597.

ortho-Substituted Aryldiazonium Design for the Defect Configuration-Controlled Photoluminescent Functionalization of Chiral Single-Walled Carbon Nanotubes.

Defect functionalization of single-walled carbon nanotubes (SWCNTs) by chemical modification is a promising strategy for near-infrared photoluminescence (NIR PL) generation at >1000 nm, which has advanced telecom and bio/medical applications. The covalent attachment of molecular reagents generates sp3-carbon defects in the sp2-carbon lattice of SWCNTs with bright red-shifted PL generation. Although the positional difference between proximal sp3-carbon defects, labeled as the defect binding configuration, can dominate NIR PL properties, the defect arrangement chemistry remains unexplored. Here, aryldiazonium reagents with π-conjugated ortho-substituents (phenyl and acetylene groups) were developed to introduce molecular interactions with nanotube sidewalls into the defect-formation chemical reaction. The functionalized chiral SWCNTs selectively emitted single defect PL in the wavelength range of ∼1230-1270 nm for (6,5) tubes, indicating the formation of an atypical binding configuration, different from those exhibited by typical aryl- or alkyl-functionalized chiral tubes emitting ∼1150 nm PL. Moreover, the acetylene-based substituent design enabled PL brightening and a subsequent molecular modification of the doped sites using click chemistry.

Formation of organic color centers in air-suspended carbon nanotubes using vapor-phase reaction.

Organic color centers in single-walled carbon nanotubes have demonstrated exceptional ability to generate single photons at room temperature in the telecom range. Combining the color centers with pristine air-suspended nanotubes would be desirable for improved performance, but all current synthetic methods occur in solution which makes them incompatible. Here we demonstrate the formation of color centers in air-suspended nanotubes using a vapor-phase reaction. Functionalization is directly verified by photoluminescence spectroscopy, with unambiguous statistics from more than a few thousand individual nanotubes. The color centers show strong diameter-dependent emission, which can be explained with a model for chemical reactivity considering strain along the tube curvature. We also estimate the defect density by comparing the experiments with simulations based on a one-dimensional exciton diffusion equation. Our results highlight the influence of the nanotube structure on vapor-phase reactivity and emission properties, providing guidelines for the development of high-performance near-infrared quantum light sources.

Universal Map of Gas-Dependent Kinetic Selectivity in Carbon Nanotube Growth.

Single-walled carbon nanotubes have been a candidate for outperforming silicon in ultrascaled transistors, but the realization of nanotube-based integrated circuits requires dense arrays of purely semiconducting species. In order to directly grow such nanotube arrays on wafers, control over kinetics and thermodynamics in tube-catalyst systems plays a key role, and further progress requires a comprehensive understanding of seemingly contradictory reports on the growth kinetics. Here, we propose a universal kinetic model that decomposes the growth rates of nanotubes into the adsorption and removal of carbon atoms on the catalysts, and we provide its quantitative verification by ethanol-based isotope labeling experiments. While the removal of carbon from catalysts dominates the growth kinetics under a low supply of precursors, resulting in chirality-independent growth rates, our kinetic model and experiments demonstrate that chiral angle-dependent growth rates emerge when sufficient amounts of carbon and etching agents are cosupplied. The kinetic maps, as a product of generalizing the model, include five types of kinetic selectivity that emerge depending on the absolute quantities of gases with opposing effects. Our findings not only resolve discrepancies existing in the literature but also offer rational strategies to control the chirality, length, and density of nanotube arrays for practical applications.

Single-molecule laser nanospectroscopy with micro-electron volt energy resolution.

Ways to characterize and control excited states at the single-molecule and atomic levels are needed to exploit excitation-triggered energy-conversion processes. Here, we present a single-molecule spectroscopic method with micro-electron volt energy and submolecular-spatial resolution using laser driving of nanocavity plasmons to induce molecular luminescence in scanning tunneling microscopy. This tunable and monochromatic nanoprobe allows state-selective characterization of the energy levels and linewidths of individual electronic and vibrational quantum states of a single molecule. Moreover, we demonstrate that the energy levels of the states can be finely tuned by using the Stark effect and plasmon-exciton coupling in the tunneling junction. Our technique and findings open a route to the creation of designed energy-converting functions by using tuned energy levels of molecular systems.

Deterministic transfer of optical-quality carbon nanotubes for atomically defined technology.

When continued device scaling reaches the ultimate limit imposed by atoms, technology based on atomically precise structures is expected to emerge. Device fabrication will then require building blocks with identified atomic arrangements and assembly of the components without contamination. Here we report on a versatile dry transfer technique for deterministic placement of optical-quality carbon nanotubes. Single-crystalline anthracene is used as a medium which readily sublimes by mild heating, leaving behind clean nanotubes and thus enabling bright photoluminescence. We are able to position nanotubes of a desired chirality with a sub-micron accuracy under in-situ optical monitoring, thereby demonstrating deterministic coupling of a nanotube to a photonic crystal nanobeam cavity. A cross junction structure is also designed and constructed by repeating the nanotube transfer, where intertube exciton transfer is observed. Our results represent an important step towards development of devices consisting of atomically precise components and interfaces.

Bioequivalence Study of Oral Suspension and Intravenous Formulation of Edaravone in Healthy Adult Subjects.

The neuroprotective agent edaravone is an intravenous treatment for amyotrophic lateral sclerosis. As intravenous administration burdens patients, orally administered treatments are needed. This phase 1, open-label, single-dose crossover study in 42 healthy adults evaluated bioequivalence of a 105-mg edaravone oral suspension and intravenous edaravone (60 mg/60 min). The evaluation was whether the 90% confidence intervals (CIs) for the ratio of the maximum plasma concentration (Cmax ) and area under the plasma concentration-time curve from time 0 to the last quantifiable time point and to infinity of unchanged edaravone were between the bioequivalence limit of 0.80 and 1.25. Metabolic profiles and elimination pathways were also compared between the 2 routes. Geometric mean ratios and 90%CIs of area under the plasma concentration-time curve from time 0 to the last quantifiable time point and to infinity for unchanged edaravone satisfied bioequivalence limits. The geometric mean ratio and its lower limit of 90%CI of Cmax of the 105-mg oral suspension compared with 60-mg intravenous formulations for unchanged edaravone fell within bioequivalence limits. Both formulations showed triphasic plasma concentration-time profiles of unchanged edaravone after reaching Cmax . Plasma concentrations of edaravone inactive metabolites after oral administration were higher than with intravenous administration. Edaravone in both routes underwent urinary excretion, mainly as the glucuronide conjugate and, to a lesser extent, as the sulfate conjugate. Urinary excretion of unchanged edaravone was low, and urinary relative composition ratios of unchanged edaravone and metabolites were similar for both formulations. These findings showed equivalent exposure of the 105-mg oral suspension of edaravone to the 60-mg intravenous formulation, supporting further investigation of the oral suspension for treating amyotrophic lateral sclerosis.

Evaluation of Pharmacokinetics, Safety, and Drug-Drug Interactions of an Oral Suspension of Edaravone in Healthy Adults.

Intravenous (IV) edaravone is approved as an amyotrophic lateral sclerosis (ALS) treatment. Because IV administration places a burden on patients, development of orally administered ALS treatments is needed. Therefore, 2 phase 1 studies of oral formulations of edaravone in healthy subjects examined the pharmacokinetics (PK), safety, racial differences, and drug-drug interactions (DDIs) and investigated the dose of the oral formulation considered to be bioequivalent to the approved dose of the IV formulation. Study 1 was a placebo-controlled, randomized, single-blind study of single-ascending-dose oral edaravone with the dose range of 30 to 300 mg (n = 56). Study 2 was conducted in 2 cohorts (n = 84); the first assessed DDIs with multiple-dose edaravone 120 mg/day given over 5 or 8 days (coadministered with single-dose rosuvastatin, sildenafil, or furosemide), and the second evaluated PK and racial (Japanese/White) differences in PK parameters with doses of 100-mg edaravone. The oral formulation of edaravone was well absorbed, and plasma concentrations of unchanged edaravone increased more than dose proportionally within the dose range of 30 to 300 mg. No effect of race on oral edaravone PK and no notable DDI effects possibly caused by orally administered edaravone were observed. The oral edaravone formulations were safe and tolerable under the assessed conditions. Mathematical modeling determined that equivalent exposures in plasma with the approved dose of the IV edaravone formulation, as reported previously, could be achieved when the oral edaravone formulation was administered at a dose of  ≈100 mg, with an absolute bioavailability of ≈60%.

Super-resolution fluorescence imaging of carbon nanotubes using a nonlinear excitonic process.

Highly efficient exciton-exciton annihilation process unique to one-dimensional systems is utilized for super-resolution imaging of air-suspended carbon nanotubes. Through the comparison of fluorescence signals in linear and sublinear regimes at different excitation powers, we extract the efficiency of the annihilation processes using conventional confocal microscopy. Spatial images of the annihilation rate of the excitons have resolution beyond the diffraction limit. We investigate excitation power dependence of the annihilation processes by experiment and Monte Carlo simulation, and the resolution improvement of the annihilation images can be quantitatively explained by the superlinearity of the annihilation process. We have also developed another method in which the cubic dependence of the annihilation rate on exciton density is utilized to achieve further sharpening of single nanotube images.

High ion adsorption densities of site-selective nitrogen doped carbon sheets prepared from natural lignin.

Carbon fibers and sheets were prepared from jet-milled natural chitin and cellulose samples, and from natural lignin sample using ice-templating technique, respectively. Nitrogen doping treatments using melamine were also performed for the carbon fibers and sheets. Electric double layer capacitor (EDLC) electrode properties of the prepared carbon fibers and sheets including the nitrogen doped samples were investigated with aqueous (sulfuric acid) and organic (tetraethylammonium tetrafluoroborate in propylene carbonate) electrolytes. It was found that the nitrogen doped lignin carbon sheets having very small specific surface area of 66 m2 g-1 show very high EDLC capacitances of 227 F g-1 and 80 F g-1 determined by charge-discharge measurements at current density of 50 mA g-1 for aqueous and organic electrolytes, respectively. X-ray photoelectron spectroscopy (XPS) measurements revealed that nitrogen atoms of the nitrogen doped lignin carbon sheets exist dominantly in pyridinic sites unlike other chitin and cellulose carbon fibers. We discussed that this site-selective nitrogen doping gives exceptionally high ion adsorption density per unit surface area of the nitrogen doped lignin carbon sheets.

[Resection of an Advanced Rectal Gastrointestinal Stromal Tumor Following Neoadjuvant Chemotherapy].

A 66-year-old man was referred to our hospital after being diagnosed with a pelvic tumor. A subsequent transperineal biopsy revealed spindle cells with CD34·c-kit(+). An enhanced computed tomography scan showed a giant rectal-derived tumor in the pelvis. The tumor was pressing on the urinary bladder and the prostate, and appeared to invade the posterior wall ofthese organs. The patient was diagnosed with rectal GIST, and neoadjuvant therapy with 400mg/day imatinib was initiated. Three months later, the tumor reduction rate was at 33.6%, and surgery was performed. The operative method applied was pelvic exenteration and ileal conduit, for local R0 resection. The patient has remained recurrence free for 2.5 years since the surgery.

Enhanced Single-Photon Emission from Carbon-Nanotube Dopant States Coupled to Silicon Microcavities.

Single-walled carbon nanotubes are a promising material as quantum light sources at room temperature and as nanoscale light sources for integrated photonic circuits on silicon. Here, we show that the integration of dopant states in carbon nanotubes and silicon microcavities can provide bright and high-purity single-photon emitters on a silicon photonics platform at room temperature. We perform photoluminescence spectroscopy and observe the enhancement of emission from the dopant states by a factor of ∼50, and cavity-enhanced radiative decay is confirmed using time-resolved measurements, in which a ∼30% decrease of emission lifetime is observed. The statistics of photons emitted from the cavity-coupled dopant states are investigated by photon-correlation measurements, and high-purity single photon generation is observed. The excitation power dependence of photon emission statistics shows that the degree of photon antibunching can be kept high even when the excitation power increases, while the single-photon emission rate can be increased to ∼1.7 × 107 Hz.

The prognostic impact of differentiation at the invasive front of biliary tract cancer.

BACKGROUND: The invasive front of tumor can provide prognostic information in many cancers. We investigated the prognostic morphological factors at the invasive front including tumor differentiation (Difinv ) and tumor budding (Bud) in biliary tract cancer (BTC). METHODS: The resected specimen from the 299 BTC patients were examined. Intrahepatic cholangiocarcinoma, extrahepatic cholangiocarcinoma, gallbladder cancer, and ampulla of Vater cancer were found in 16%, 48%, 17%, and 19%, respectively. Difinv grade (G) 3 and Bud foci ≥5 were found in 47% and 10%. Tumor with Difinv G3 showed the high frequencies of Bud, vascular invasion (Ve) and nodal metastasis (LN) compared to tumor with Difinv G1/2 (Bud: 21% vs 0%, Ve: 71% vs 50%, LN: 52% vs 36%). Multivariate analysis revealed that the independent predictors were Difinv G3 (HR: 1.71), Bud foci ≥5 (HR: 2.14), Ve (HR: 1.56) and LN (HR: 2.59) in overall survival and were positive resection margin (HR: 1.71), Difinv G3 (HR: 1.75), Ve (HR: 1.50), and LN (HR: 2.19) in relapse free survival. CONCLUSION: Poor differentiation at the invasive front of tumor was associated with poor prognosis and early relapse in BTC patients.

Comparison of postoperative early and late complications between pancreas-sparing duodenectomy and pancreatoduodenectomy.

PURPOSE: Pancreas-sparing duodenectomy (PSD) represents an alternative procedure to pancreatoduodenectomy (PD) for patients with duodenal neoplasms. METHODS: The postoperative early and late complications of 21 patients who underwent PSD between 1992 and 2014 were compared with those of 44 patients with soft pancreatic parenchyma who underwent PD between 2009 and 2014. RESULTS: The median operation time and blood loss were less in the PSD group than in the PD group (P < 0.001). The overall incidence of early complications was less in the PSD group than in the PD group (PSD with ampullectomy vs. PSD without ampullectomy vs. PD; 45.5 vs. 20.0 vs. 56.8 %). The incidence of pancreatic fistula formation and overall incidence of late complications were also less in the PSD group than in the PD group (P = 0.031, 0.020). There were no complications related to the pancreatic endocrine or exocrine functions in the PSD group. CONCLUSION: PSD is a less-invasive procedure and has the advantage over PD of preserving the pancreas.

Phase II study of the GPC3-derived peptide vaccine as an adjuvant therapy for hepatocellular carcinoma patients.

The recurrence rates of Hepatocellular carcinoma (HCC) are high, necessitating novel and effective adjuvant therapies. Therefore, we conducted a phase II study of glypican-3 (GPC3) peptide vaccine as an adjuvant therapy for HCC patients. Forty-one patients with initial HCC who had undergone surgery or radiofrequency ablation (RFA) were analyzed in this phase II, open-label, single-arm trial. Ten vaccinations were performed for 1 y after curative treatment. We also investigated case-control subjects, where selected patients treated surgically during the same period were analyzed. The expression of GPC3 in the available primary tumors was determined by immunohistochemical analysis. Six patients received RFA therapy while 35 received surgery. The recurrence rate tended to be lower in the 35 patients treated with surgery plus vaccination compared to 33 patients who underwent surgery alone (28.6% vs. 54.3% and 39.4% vs. 54.5% at 1 and 2 y, respectively; p = 0.346, 0.983). Twenty-five patients treated with surgery and vaccination had GPC3-positive tumors; the recurrence rate in this group was significantly lower compared to that in 21 GPC3-positive patients who received surgery only (24% vs. 48% and 52.4% vs. 61.9% at 1 and 2 y, respectively; p = 0.047, 0.387). The GPC3 peptide vaccine improved the 1-y recurrence rate in patients with GPC3-positive tumors. This study demonstrated that GPC3 expression by the primary tumor may be used as a biomarker in a putative larger randomized clinical trial to determine the efficacy of the GPC3-derived peptide vaccine.