Search

Abstract Objective Among standard treatments for infantile spasms, adrenocorticotropic hormone (ACTH) is reported as the best treatment, but ACTH is ineffective in one‐half of the patients. To establish precision medicine, we examined pharmacoresistance of focal epileptic spasms (ES), generalized ES, and generalized ES combined with focal seizures, diagnosed based on the revised seizure classification of ILAE in 2017. Methods We conducted a retrospective nationwide study in Japan on the long‐term seizure outcome of ES. Long‐term seizure outcome was evaluated by seizure‐free rate, seizure‐free period, and Kaplan‐Meier curve. Seizure‐free was defined as seizure control for longer than 2 months. Results From the medical history of 501 patients, 325 patients had generalized ES only (GES group) at the start of the first treatment, 125 patients had generalized ES after focal seizure onset (FS‐GES group), seven patients had focal ES after focal seizure onset (FS‐FES group), and 24 patients had generalized ES combined with focal seizures after focal seizure onset (FS‐GES + FS group). Seizure‐free period of ES (generalized ES and focal ES) [mean (95% confidence interval)] was 2.7 (0.0‐5.4) months in GES group, 1.1 (0.1‐2.2) months in FS‐GES group, 1.0 (0.2‐1.9) months in FS‐GES + FS group, and 0.1 (−0.2‐0.5) months in FS‐FES group. Seizure‐free rate, seizure‐free period, and Kaplan‐Meier curve of generalized ES were almost the same in GES group and FS‐GES group, with characteristics of superior response to ACTH. Mean seizure‐free period of generalized ES combined with focal seizures was significantly shorter in FS‐GES + FS group than in GES group. Mean seizure‐free period of focal ES in FS‐FES group was extremely short with exceedingly early relapse. Significance Pharmacoresistance was different in generalized ES, focal ES, and generalized ES combined with focal seizures. ES with focal features or with focal seizures may have focal lesions, thus consider surgical options earlier in the course.

Citrullinemia is the earliest identifiable biochemical abnormality in neonates with intrahepatic cholestasis due to a citrin deficiency (NICCD) and it has been included in newborn screening panels using tandem mass spectrometry. However, only one neonate was positive among 600,000 infants born in Sapporo city and Hokkaido, Japan between 2006 and 2017. We investigated 12 neonates with NICCD who were initially considered normal in newborn mass screening (NBS) by tandem mass spectrometry, but were later diagnosed with NICCD by DNA tests. Using their initial NBS data, we examined citrulline concentrations and ratios of citrulline to total amino acids. Although their citrulline values exceeded the mean of the normal neonates and 80% of them surpassed +3 SD (standard deviation), all were below the cutoff of 40 nmol/mL. The ratios of citrulline to total amino acids significantly elevated in patients with NICCD compared to the control. By evaluating two indicators simultaneously, we could select about 80% of patients with missed NICCD. Introducing an estimated index comprising citrulline values and citrulline to total amino acid ratios could assure NICCD detection by NBS.

In this study, an array of Mo cones for volcano-structured Spindt-type microelectron emitters were fabricated. A recently developed triode high power pulsed magnetron sputtering system was used to control the positive plasma potential and efficiently accelerate ion species. By applying a proper positive voltage to the additional electrode, the authors obtained good cone shapes with high aspect ratios in a water-cooled microcavity structure made of two resist layers, which was previously impossible by conventional vacuum evaporation techniques. The effects of ion acceleration on the alignment of ions along the normal direction, as well as on the stress in the deposited film, are discussed. The former is important for the formation of sharp cones, while the latter is crucial for achieving stable fabrication. [ABSTRACT FROM AUTHOR]

The authors have developed a highly sensitive, compact image sensor comprising a field emitter array (FEA) and a high-gain avalanche rushing amorphous photoconductor (HARP) target with the ultimate aim of developing an ultrahigh sensitivity, compact, high-definition television camera. Double-gated field emitters have the advantage of a compact electron beam focusing system; however, image intensities reproduced by a sensor with the double-gated, Spindt-type field emitter array with the focusing electrode stacked 1.5 μm above the gate electrode were nonuniform owing to low electron beam current. The minimum required electron beam current extracted from the double-gated field emitter array is considered for possible use with the sensor. Furthermore, a suitable field emitter array pitch to balance the electron beam current and the electrostatic-focusing lens strength was simulated. For the sensor's design guidelines, a field emitter array pitch of approximately 3 μm would be reasonable in the case of employing the volcano-structured, doublegated, Spindt-type field emitter array with the focusing electrode placed 0.2 μm below the gate electrode hole. Based on simulation results, an image sensor with the volcano-structured, Spindt-type, 3.1-μm-pitch FEA with the focusing electrode placed 0.2 μm below the gate electrode hole was fabricated. It was confirmed that the minimum electron beam current extracted from the volcano-structured FEA was approximately 2 lA/pix, and the sensor could obtain images with improved image intensity uniformity by utilizing the electrostatic-focusing effect. These results indicate that the volcano-structured, double-gated, Spindt-type FEA is potentially suitable for high-definition television FEA-HARP image sensors. [ABSTRACT FROM AUTHOR]

Double-gated Spindt-type field emitter arrays with volcano structures were fabricated using a double-layered photoresist as a lift-off layer for image sensor application. The gate aperture height and emitter tip angle were varied to optimize the device structure, wherein the gate aperture height was changed by controlling the etch-back time during the gate opening process and the emitter tip angle was changed by selecting the emitter material. The Ni emitter had a narrow tip angle while the Mo emitter had wider tip angle. For the formation of the Mo emitter, a thick Ni buffer layer was necessary to prevent delamination. Electron beam focusing characteristics were evaluated using the scanning slit method, and it was found that both a higher gate aperture and a wider tip angle facilitated better beam focusing. A wider tip angle, however, increased the operating voltage of the field emitter arrays. Additionally, a higher gate aperture did not affect the operational voltage. Therefore, a narrow tip angle with a higher gate aperture produced the best result among our tested samples. [ABSTRACT FROM AUTHOR]

Graphene was used as the topmost electrode for a metal-oxide-semiconductor planar-type electron emission device. With several various layers, graphene as a gate electrode on the thin oxide layer was directly deposited by gallium vapor-assisted chemical vapor deposition. The maximum efficiency of the electron emission, defined as the ratio of anode current to cathode current, showed no dependency on electrode thickness in the range from 1.8 nm to 7.0 nm, indicating that electron scattering on the inside of the graphene electrode is practically suppressed. In addition, a high emission current density of 1–100 mA/cm2 was obtained while maintaining a relatively high electron emission efficiency of 0.1%–1.0%. The graphene-oxide-semiconductor planar-type electron emission device has great potential to achieve both high electron emission efficiency and high electron emission current density in practical applications. [ABSTRACT FROM AUTHOR]

We report optically modulated electron emission from gated p-type silicon field emitter arrays (Si-FEAs). The device's "volcano" structure is designed to control the photoexcitation of electrons by transmitting light through the small gate aperture, thereby minimizing the photogeneration of slow diffusion carriers outside the depletion region in the tip. Compared to that in the dark, the emission current was enhanced by more than three orders of magnitude in the high field region when irradiated with blue laser pulses. Results from the time-resolved measurements of photoassisted electron emission showed that these possess the same response as the laser pulse with no discernible delay. These results indicate that the volcano device structure is effective at eliminating the generation of diffusion carriers and that a fully optimized FEA is promising as a photocathode for producing high-speed modulated electron beams. [ABSTRACT FROM AUTHOR]

To improve the thrust density of electrospray thrusters using ionic liquids as the propellant, we have fabricated a high-density emitter array utilizing the fabrication technique of a field emitter array (FEA) or gated nano electron sources. The density of the emitter array can reach approximately 4 million cm−2, which is four orders of magnitude higher than that of conventional electrospray thrusters. Performing deep reactive ion etching from the back side of the same structure as FEAs and removing their Ni cones by dilute nitric acid, we have successfully fabricated sub-μm scale capillary emitters with self-aligned extractor electrodes and ionic liquid reservoirs behind them. Current measurements were also conducted with EMI-BF4 and EMI-DCA as the propellant. Although the ion was not extracted with EMI-BF4 owing to its electrochemical reaction with the electrodes, both positive and negative ion currents were detected using EMI-DCA, where the current density exceeded that of conventional electrospray thrusters. [ABSTRACT FROM AUTHOR]

Solid source diffusions of phosphorus (P) and boron (B) into the half-inch (12.5 mm) minimal silicon (Si) wafers by spin on dopants (SOD) have been systematically investigated and the physical-vapor-deposited (PVD) titanium nitride (TiN) metal gate minimal silicon-on-insulator (SOI) complementary metal–oxide–semiconductor (CMOS) field-effect transistors (FETs) have successfully been fabricated using the developed SOD thermal diffusion technique. It was experimentally confirmed that a low temperature oxidation (LTO) process which depresses a boron silicide layer formation is effective way to remove boron-glass in a diluted hydrofluoric acid (DHF) solution. It was also found that top Si layer thickness of SOI wafers is reduced in the SOD thermal diffusion process because of its consumption by thermal oxidation owing to the oxygen atoms included in SOD films, which should be carefully considered in the ultrathin SOI device fabrication. Moreover, normal operations of the fabricated minimal PVD-TiN metal gate SOI-CMOS inverters, static random access memory (SRAM) cells and ring oscillators have been demonstrated. These circuit level results indicate that no remarkable particles and interface traps were introduced onto the minimal wafers during the device fabrication, and the developed solid source diffusion by SOD is useful for the fabrication of functional logic gate minimal SOI-CMOS integrated circuits. [ABSTRACT FROM AUTHOR]