Search

Although transcatheter aortic valve replacement (TAVR) has demonstrated favorable outcomes in randomized studies, there remains a sizable group of patients in whom TAVR may be futile. Characterizing the survival rate in a wide array of patients undergoing TAVR can help develop effective strategies for improving the allocation of medial resources.The aim of this study was to develop a risk model to estimate 1-year mortality after TAVR from a representative nationwide registry in Japan.The J-TVT (Japan Transcatheter Valve Therapies) registry contains complete data, including 1-year outcomes, on patients undergoing TAVR in Japan. A total of 17,655 patients underwent TAVR between 2013 and 2018. They were randomly divided into 2 groups in a 7:3 ratio to form a derivation cohort of 12,316 patients and a validation cohort of 5,339 patients. A risk model was constructed for 1-year mortality in the derivation cohort, and its discrimination and calibration were assessed in the validation cohort.The mean age of all registered patients was 84.4 years, and 68.8% were women. The mean body size area was 1.43 mA prediction model for 1-year survival following TAVR derived from a national clinical database performed well and should aid physicians managing TAVR patients.

Few studies have evaluated transcatheter aortic valve implantation (TAVI) beyond 5 years. We investigated long-term outcomes (≥5 years) and transcatheter heart valve (THV) performance in patients who had undergone TAVI at least 5 years previously, based on annual follow-up. We reviewed 114 consecutive patients who were of high surgical risk or inoperable and underwent TAVI for severe aortic stenosis from October 2009 to November 2013. There was no lost to follow-up, and median time to death or latest follow-up was 5.0 years (range: 0.1 to 8.5). Structural valve degeneration (SVD) was defined on transthoracic echocardiography (TTE) as follows: (1) mean pressure gradient ≥20 mm Hg with a >10 mm Hg increase from the post-TAVI baseline, and/or (2) moderate or severe transvalvular regurgitation. The mean patient age was 82.7 ± 6.4 years, and 37.7% of patients were men. Median Society of Thoracic Surgeons score was 7.6% (interquartile range 5.8 to 10.9). TTE ≥5 years was 76.1% complete (51 of 67 patients who survived ≥5 years postoperatively). The estimated cumulative survival rates at 1, 3, 5, and 7 years were 88.6%, 72.8%, 58.8%, and 45.3%, respectively. Albumin

Al0.24Ga0.76N thin film surfaces were irradiated simultaneously with CF4 plasma and ultraviolet (UV) at wavelengths of 280 and 310 nm. The UV wavelength and intensity were varied without changing the plasma-generating conditions. These UV photon energies were larger than the band-gap energy of AlGaN film. A compositional change in the simultaneously-irradiated surface depended on the UV wavelength. The 280-nm UV irradiation caused a greater degree of nitrogen deficiency than that introduced by 310-nm UV irradiation, causing the Ga- and Al-rich surface. Moreover, the 280-nm UV irradiation increased the amounts of F atoms and CFx fluorocarbons incorporated into the surface, in comparison with CF4 plasma-only irradiation. In contrast, the 310-nm UV irradiation reduced the amount of the incorporated F atoms and hardly increased the amount of the incorporated CFx fluorocarbons from those caused by CF4 plasma-only irradiation. These became more prominent with increasing UV intensity. These UV wavelength-dependent results can be discussed in terms of four factors: the UV photogenerated-hole-assisted oxidation, the localized surface plasmon resonance, the UV-induced migration of gallium and aluminum vacancies forming stable complexes with F, and the sticking of F-related radicals from CF4 plasma onto the surface.

TiO2 thin films were treated with plasma with the assistance of external heating. This plasma was produced with an O2 dielectric barrier discharge (DBD) at atmospheric and near-atmospheric gas pressures. For comparison, the samples were annealed in O2 gas and also treated with O2 DBD plasma alone. The effects of these treatments on photocatalytic activity were compared by evaluating the photodecomposition of methylene blue dye in aqueous solution. The photocatalytic activity of the heat-assisted plasma-treated sample was the most enhanced among the treatment processes. The net photodecomposition of the heat-assisted plasma-treated sample was slightly higher than or comparable to that of TiO2 anatase-phase nanoparticle powder. The photocatalytic activity enhancement can be attributed to an increase in the effective concentration of photogenerated carriers on the surface. This increase is driven by the synergistic effect between an increase in the depletion layer width and an increase in the optical absorption due to the crystalline transition from the bronze to the anatase phases. This crystalline transition occurred at a lower temperature than the annealing transformation temperature.

Al0.24Ga0.76N thin film surfaces were etched with CF4 plasma, with and without the assistance of near-ultraviolet (UV) irradiation. The near-UV source was a black light lamp, which emitted wavelengths of 300–400 nm. The chemical compositions and morphologies of surfaces etched under the two plasma conditions were compared, to clarify the effect of near-UV irradiation on the properties of the AlGaN surface. Near-UV irradiation during CF4 plasma etching reduced the amounts of F atoms, AlFx fluorides, and GaFx fluorides incorporated into the surface, and enhanced the amount of CFx fluorocarbons. Near-UV irradiation did not influence the depth distribution of incorporated fluorine-related impurities, or the degree of nitrogen deficiency caused in the surface. These compositional changes in the surface occurred irrespective of the gas pressure. Near-UV irradiation caused a significant change in the morphology of surfaces etched at high gas pressure (13 Pa), as the etching time was increased to 60 and 100 min. Near-UV irradiation did not change the morphologies of surfaces etched at lower gas pressures (1.3 and 6.7 Pa), irrespective of etching time.

The thermal stability, in terms of cycle and rate performances at 80 °C, and its safety related to lithium ion batteries composed of a LiFePO 4 cathode and SiO anode are investigated. Based on an STEM-EELS analysis, the SiO powder is found to have an amorphous structure, in which nanosized Si particles (Si-rich phase) are uniformly dispersed in the SiO 2 matrix (SiO 2 -rich phase). During the charge/discharge cycling, the cell exhibits a satisfactory cycle performance with a discharge capacity retention of 93.6% and a voltage retention of 93.9% at the 1500 th cycle. Also, the charge and discharge capacity retentions at 10 C are 97.5% and 94.7%, respectively, together with a limited polarization, demonstrating its high rate performance. Furthermore, a 1.16 Ah LiFePO 4 /SiO laminated cell shows negligible voltage and temperature changes during the nail penetration test. The Li concentration in the active material (Si-rich phase) is found to be almost the same as that in the SiO 2 -rich phase after the test. This high thermal stability and safety may be due to the formed layer from the SiO 2 matrix, preventing any side reaction from occurring on the Si surface and isolating the internal current path during the nail penetration.

Compositional and morphological changes in Al 0.24 Ga 0.76 N surfaces etched by CF 4 and Ar plasmas were investigated in order to clarify the effect of fluorine impurities incorporated in the surface by the CF 4 plasma. The CF 4 plasma effectively incorporated the fluorine impurities in the surface even at a short etching time. A small number of the incorporated fluorine impurities only contributed to the formations of Al(OH) x F y and GaF x on the surface even as the etching time increased. Although the CF 4 and Ar plasma etchings preferentially remove nitrogen atoms from the surfaces, the preferential removal induced by the CF 4 plasma etching was suppressed compared with the case of the Ar plasma etching. The CF 4 plasma etching caused a smooth surface regardless of the gas pressure and the etching time, whereas the Ar plasma etching changed the surface morphology depending on the gas pressure and the etching time. The incorporation of the fluorine impurities, which bonded with the cation vacancies such as gallium and aluminum vacancies introduced in the surface by the plasma etching, was considered to concern the suppression of the preferential removal and the formation of the smooth surface.

Damage characteristics of n-GaN thin film surfaces etched by ultraviolet (UV) light-assisted He plasmas at various gas pressures have been investigated from the viewpoint of the UV light irradiation effect. During the plasma etching, the surface is additionally irradiated with UV light emitted from a black light lamp. The peak wavelength of the emitted UV light corresponds to that of the GaN band-gap energy. The result is compared with that obtained only by use of He plasma. A morphological change in the surface etched by the UV light-assisted He plasma depends on gas pressure, whereas the He plasma only does not cause the morphological change in the surface regardless of gas pressure. The additional UV light irradiation causes a morphological change in the surface etched for a long time of more than 60 min at high gas pressures between 6.7 and 13 Pa. The morphology of the surface etched at a low gas pressure of 1.3 Pa does not change from that of the as-grown surface even with increasing etching time. The additional UV light irradiation also enhances the etch depth and suppresses a decrease in N/Ga ratio at the surface compared with that obtained only by use of the He plasma.

A face centered cubic (FCC) type Mg–Sc hydride (Mg0.8Sc0.2Hx phase) was prepared by an ultra-high pressure (UHP) technique generating an 8 GPa hydrogen pressure. Reversible hydrogen releasing and restoring behaviors have been observed by a differential scanning calorimeter (DSC) measurement at a 0.5 MPa hydrogen pressure. The hydrogen releasing temperature was lower by around 70 K than that of MgH2. The structural analysis using a Rietveld refinement of the synchrotron X-ray diffraction patterns indicated that the FCC phase was preserved without decomposition after the reproducible hydrogen releasing and restoring reactions.

Novel quaternary hydrides Mg 7− x A x TiH 16− x (A = Li, Na, K) have been synthesized by use of an ultrahigh-pressure (UHP) technique. The Rietveld refinements for synchrotron X-ray diffraction (XRD) patterns suggest that added LiH and NaH greatly enhanced the yield of the Mg 7 TiH 16 phase. The unit cell volumes of the Mg 7− x A x TiH 16− x phases were increased with increasing the amount and the ionic radii of the alkali metals. The reversibility of the hydrogen releasing and restoring reactions was much improved by the addition of alkali metal hydrides. The reversible hydrogen storage capacities were around 3–4 wt.% for the Mg 7− x A x TiH 16− x phases on the pressure–composition isotherm (PCI) measurements. Obtained enthalpy values tend to be reduced with reducing the Δ H of the alkali metals.

Co 3 O 4 nanoparticles are prepared via converting cobalt oxide subunits in a cobalt metal-organic framework (Co 3 (NDC) 3 (DMF) 4 , NDC = 2,6-naphthalene- dicarboxylate; DMF = N,N′-dimethylformamide) by pyrolysis in air. The as-prepared Co 3 O 4 shows an agglomerated secondary structure with an average diameter of around 250 nm comprised of small primary Co 3 O 4 particles with a size of about 25 nm. This agglomerated structure favors the enhanced capacity, improved rate capability and prolonged cycle life as an electrode material for lithium ion batteries.

We have studied the effects of water vapor remote plasma treatment (H2O RPT) on emission from Si-doped and undoped n-type GaN films grown on c-face sapphire substrates by the atmospheric-pressure metalorganic chemical vapor deposition method. We found by photoluminescence (PL) spectroscopy at 77 K that H2O RPT enhanced violet emission from the n-type GaN films, similarly to the previously observed enhancing effect on blue emission from Mg-doped p-type GaN films. We also observed that H2O RPT reduced the intensity of ESR signal comprising of two peaks detected at 4.2 K in undoped n-type films and increased their resistivity measured at room temperature. We ascribe the enhancing effect of H2O RPT to the passivation of non-radiative recombination centers by hydrogen produced by H2O RPT. We formed GaN p–n diodes from the layer structure of p-GaN:Mg/n-GaN:Si/sapphire, and carried out electroluminescence (EL) measurements of the diodes at 77 K. We observed that EL intensity was also enhanced by H2O RPT.

We describe two cases of intractable pneumothorax that were attributed to a bronchopleural fistula (BPF) after radiofrequency ablation of lung tumors. In both cases, radiofrequency ablation induced necrosis of the lung tissue between the pleural space and the bronchus. The bronchopleural fistula formed after sloughing of the necrotic tissue. Management of the bronchopleural fistula was quite challenging, requiring frequent treatments, including pleurodesis, endobronchial management, and/or surgical repair. In one of the patients, air leakage persisted despite these efforts, and the patient died of acute pneumonia 52 days after the procedure. Although it is rare, with an incidence of 0.6% (2/334) at our institution, intractable pneumothorax due to bronchopleural fistula should be recognized as a risk associated with radiofrequency ablation of lung tumors.

A 56-year-old man had a lung metastasis from hepatocellular carcinoma 4.7 cm x 3.4 cm in size located directly adjacent to the pulmonary hilar vessels. The tumor was treated with radiofrequency ablation combined with earlier bronchial arterial chemoembolization and subsequent radiation therapy. A complete remission of the tumor has been observed for 6 months since completion of therapy. Considering that complete treatment of such an intermediate-sized tumor adjacent to the large vessels is usually difficult with radiofrequency ablation alone, this result suggests a possible role for combined therapy for pulmonary neoplasms.

The crystal orientation of GaN films deposited on fused quartz substrates by rf planar magnetron sputtering using a mesh to guard against plasma exposure was investigated by X-ray diffraction. Sample films were deposited at constant N 2 gas pressure and input power at a range of substrate temperatures between 84°C and 600°C. It was found that GaN films with good crystal orientation can be produced by rf sputtering with the c -axis of GaN crystals oriented normal to the substrate surface in almost all films produced. The crystal 0 0·2 orientation was good at substrate temperatures exceeding 300°C, however, films deposited at 600°C peeled from the substrate. The fine mesh installed to protect the film from exposure to plasma was found to be very useful for depositing films with a good crystal orientation of 0 0·2, and the best crystal orientation was realized for a film deposited by sputtering with a target to mesh separation of 30 mm.

InGaN multiple quantum well laser diode (LD) wafer that lased at 400 nm was shown to have the InN mole fraction, x , of only 6% in the wells. Nanometer-probe compositional analysis showed that the fluctuation of x was as small as 1% or less, which is the resolution limit. However, the wells exhibited a Stokes-like shift (SS) of 49 meV and an effective localization depth E 0 was estimated by time-resolved photoluminescence (TRPL) measurement to be 35 meV at 300 K. Since the effective electric field due to polarization in the wells is estimated to be as small as 286 kV/cm, SS is considered to originate from an effective bandgap inhomogeneity. Because the well thickness fluctuation was insufficient to produce SS or E 0 , the exciton localization is considered to be an intrinsic phenomenon in InGaN material. Indeed, bulk cubic In 0.1 Ga 0.9 N, which does not suffer any polarization field or thickness fluctuation effect, exhibited an SS of 140 meV at 77 K and similar TRPL results. The origin of the localization is considered to be due to the large bandgap bowing and In clustering in InGaN material. Such shallow and low density localized states are leveled by injecting high density carriers under the lasing conditions for the 400 nm LDs.

Ultraviolet (UV) InGaN/AlGaN double-heterostructure (DH) light-emitting diodes (LEDs) with an external quantum efficiency of 7.5%, an output power of 5 mW and an emission wavelength of 371 nm were developed. High-power UV LEDs are obtained using an InGaN active layer with a thickness of 400 A instead of a GaN active layer. The localized energy states caused by In composition fluctuation in the InGaN active layer are related to the high efficiency of the InGaN-based LEDs.

The use of wildflowers has become popular for creating aesthetic public landscaping. As weeding costs are rather expensive, automation of weeding would help reduce maintenance costs. In this study, as a step towards automation of weeding, identification of plants for wildflower gardens was performed by image processing. Shape feature analysis was applied to the binary images to identify the plant as one of four species (aster, pansy, treasure flower, and California Poppy). As features, roundness, first invariant central moment, area, and perimeter were studied for each plant type. Mahalanobis’ generalized distance was used in identification of the plants. The results showed that the best shape features for identifying these plants were roundness and first invariant central moment.

We have studied the optical gain and its suppression mechanism of In x Ga 1− x N multiple quantum well structures with different indium compositions. The variable stripe length method and the up-conversion method were employed in this research. It was found that the optical gain spectra became broad and the differential gain decreased with increasing the indium composition. These results indicated that inhomogeneous broadening affected not only spontaneous emission but also stimulated emission. The rise time of photoluminescence under a strong excitation condition was changed from 0.95 ps to 12.4 ps depending on the indium composition. Assuming the rise time reflects the relaxation lifetime from the absorption edge energy to population inversion levels, our calculation suggested that long rise times led to gain suppression in In x Ga 1− x N laser diodes with larger indium compositions.

Editor: A 69-year-old man with liver cirrhosis as a result of hepatitis C virus was admitted to our department. He had a history of surgical resection of hepatocellular carcinoma (HCC) 6 years earlier. Thereafter, two new foci of HCC developed and each was treated with a combination of transcatheter chemoembolization (TACE) and radiofrequency (RF) ablation. At the current admission, another tumor with a diameter of 1.7 cm had developed in the periphery of the medial segment. The patient was admitted in anticipation of RF ablation of this tumor under computed tomographic (CT) fluoroscopic guidance. Our institution does not require an institutional review board approval for retrospective reports such as this. Plain CT images for targeting immediately before RF ablation showed dilation of the intrahepatic bile duct in the left lobe and soft tissue density within the expanded left hepatic duct as the causes of biliary dilation. Because we speculated that cholangitis may possibly develop after RF ablation of the liver with biliary dilation, the scheduled RF ablation was cancelled. Laboratory data obtained the same day showed serum total bilirubin level of 2.18 mg/dL (normal range, 0.33–1.28 mg/dL). Dynamic CT and magnetic resonance imaging were subsequently performed to evaluate the mass within the left hepatic duct. In addition to the tumor in the medial segment, a hypervascular tumor 3.2 cm in diameter directly adjacent to the left hepatic duct was demonstrated in the lateral segment. The mass within the left hepatic duct did not enhance after contrast medium administration, likely indicating hemobilia caused by hemorrhage from the tumor in the lateral segment invading into the left hepatic duct. Six days later, the serum total bilirubin level returned to the previous level and repeat CT images showed that biliary dilation substantially improved, accompanied by spontaneous resolution of hemobilia. Because of limited hepatic function, the patient was not a suitable candidate for surgical resection. RF ablation was also inappropriate because the tumor in the lateral segment involved the left hepatic duct. Therefore, it was selected to perform TACE. On hepatic arteriography, the tumor in the medial segment was supplied by the medial segmental artery and the tumor in the lateral segment was supplied mainly by a branch of the lateral segmental artery. To reduce the possible risk of hepatic failure, hepatic abscess, and biloma after TACE, we performed superselective embolization of each tumor. A microcatheter (Renegade; Boston Scientific, Natick, MA) was selectively introduced into the arteries supplying each tumor, and TACE was performed with injection of a mixture of 1.2 mL iodized oil (Lipiodol; Laboratoire Andre Guerbet, Aulnay-sous-Bois, France) and 12 mg epirubicin (Kyowa-Hakko, Tokyo, Japan), followed by gelatin sponge particles, for the tumor in the medial segment. The tumor in the lateral segment was then treated in the same fashion, but with 0.8 mL iodized oil and 8 mg epirubicin before administration of gelatin sponge particles. On plain CT images immediately after TACE, part of the iodized oil accumulation in the tumor in the lateral segment seemed to protrude into the left hepatic duct (Figure, part a) and dense iodized oil accumulation was seen in the entire tumor in the medial segment (Figure, part a). No immediate complications occurred and the patient was discharged 10 days after TACE. Eighteen days after TACE, the patient returned to our department because with jaundice and severe back pain. Laboratory data on admission showed markedly increased serum total bilirubin and amylase levels of 8.03 mg/dL and 1,000 IU/L (normal range, 38–125 IU/L), respectively. On dynamic CT images, marked dilation of the intrahepatic and common bile duct was demonstrated. Iodized oil accumulation within the left hepatic duct was no longer visible (Figure, part b), and at the bottom of the common bile duct was a high-density deposit (Figure, part c), which was believed to represent sloughed tumor with iodized oil accumulation and the cause of biliary obstruction. Subsequent endoscopic examination revealed the oral protrusion markedly expanding and the sloughed tumor obstructing the ampulla of Vater and protruding into the lumen of the duodenum (Figure, part d). Endoscopic sphincterotomy was then performed and two pieces of tumor migrated into the duodenum. Immediately after the endoscopic therapy, the patient’s back pain resolved. The serum amylase level decreased promptly and returned to normal level 2 days later. The serum total bilirubin level gradually decreased and returned to baseline level 1 month after the endoscopic therapy. Although tumor thrombus into the portal vein is a common feature in the development of HCC, intraductal tumor involvement is not as widely recognized. Kojiro et al (1) reported 24 cases of HCC with prominent tumor growth in the bile duct among 259 autopsy and surgical cases, with a prevalence of approximately 9%. Intraductal tumor is usually associated with large HCC with volumes of more than 40% of the whole liver (1) and associated with varying degree of jaundice at admission or during the course of the disease (1–3). HCC with intraductal tumor involvement is DOI: 10.1097/01.RVI.0000200055.74822.ED Letters to the Editor

The main goal of this study was to develop a method to diagnose when roots had sufficiently recovered from transplanting injury. Plant responses to light intensity, such as changes in stem diameter and vapour transpiration, were measured. The light intensity was varied by a pseudo random signal. Cross-correlation functions of light intensity and plant responses were calculated to understand the similarity of the response to the input quantitatively. The results showed that the recovery from the transplanting injury could be diagnosed when the response time lag of plant stem diameters from the top to the lower part of the plant approached the original pre-transplanting level.