We demonstrate controlled squeezing of visible light waves into nanometer-sized optical cavities. The light is perpendicularly confined in a few-nanometer-thick SiO2 film sandwiched between Au ...claddings in the form of surface plasmon polaritons and exhibits Fabry-Perot resonances in a longitudinal direction. As the thickness of the dielectric core is reduced, the plasmon wavelength becomes shorter; then a smaller cavity is realized. A dispersion relation down to a surface plasmon wavelength of 51 nm for a red light, which is less than 8% of the free-space wavelength, was experimentally observed. Any obvious breakdowns of the macroscopic electromagnetics based on continuous dielectric media were not disclosed for 3-nm-thick cores.
Dental biomaterials are widely used in all areas of routine dental practice. There are mainly two methods for their application. Firstly, dental biomaterials are placed into living tissues, such as ...teeth, to fill the space. Secondly, dental devices such as crown and bridge restorations and dentures are fabricated using various materials to restore the morphology and function of the dentition.
Crown and bridge restorations are one of the main treatment methods used by general practitioners to achieve lifelike restoration of form and function. The recent introduction of osseointegrated implants has expanded the application of crown and bridge restorations for partially edentulous patients.
Mechanical durability and precision fit are mandatory requirements for crowns and bridges. The development of various casting alloys and precise casting systems has contributed to the successful use of metal‐based restorations. However, patient requests for more aesthetic and biologically ‘safe’ materials has led to an increased demand for metal‐free restorations.
There is also a growing demand to provide all‐ceramic restorations more routinely. New materials such as highly sintered glass, polycrystalline alumina, zirconia based materials and adhesive monomers, will assist dentists to meet this demand. In addition, new fabrication systems combined with computer‐assisted fabrication systems (dental CAD/CAM) and various networks are now available. Dental technology was centred on lost‐wax casting technology but we now face a revolution in crown and bridge fabrication.
This article reviews the history and recent status of dental CAD/CAM, the application of CAD/CAM fabricated tooth‐coloured glass ceramic crowns, and the application of all‐ceramic crowns and bridges using CAD/CAM fabricated zirconia based frameworks.
Calves are fed milk and milk replacer for their growth until approximately 2 mo after birth. During this period, their abomasa produce curd and whey from milk. It has been thought that curd formation ...is important for digestion and absorption of milk nutrients and immune substances in calves. However, no study has been done observing abomasal contents in neonatal calves after first ingestion of first milking colostrum. Here we report curd formation in neonatal calves and its physiological function with a focus on immunoglobulin absorption. We first examined curd formation by ultrasonography in 3 neonatal calves after first ingestion of first-milking colostrum. Between 0.5 and 8 h after colostrum ingestion, a curd was visualized as a large echogenic image with a clear outline, which was surrounded by an anechoic image corresponding to whey. We next compared serum IgG and IgA concentrations in 10 calves fed the pooled colostrum and 7 calves fed the whey solution that did not coagulate into curds. Serum from 1 calf in the pooled colostrum sample set was excluded due to incomplete curd formation in that the whole colostrum did not coagulate into a large mass of curd and a portion of the colostrum remained as its residue caseins detectable from the abomasal fluid. Serum IgG and IgA concentrations were significantly higher in the 9 calves fed the colostrum than the 7 calves fed the whey solution. One calf exhibiting incomplete curd formation showed low levels of serum IgG and IgA after ingestion, similar to the calves fed the whey solution. These results indicate that curd formation is associated with IgG and IgA absorption in neonatal calves after first ingestion of colostrum.
Quadrature phase-shift keying homodyne transmission has been demonstrated using a polarization-multiplexed pilot carrier generated in a transmitter and a LiNbO/sub 3/-based hybrid module in a ...receiver for self-homodyne detection at 20 Gb/s. No degradation in receiver sensitivity was observed up to a linewidth of 30 MHz. Furthermore, we obtained error-free operation with a bit-error rate of less than 10/sup -11/. The proposed scheme can provide stable real-time multilevel modulation/demodulation formats, free from linewidth requirements, to enhance spectral efficiency.
Optical patch antennas sandwiching dielectrics between metal layers have been used as deep subwavelength building blocks of metasurfaces for perfect absorbers and thermal emitters. However, for ...applications of these metasurfaces for optoelectronic devices, wiring to each electrically isolated antenna is indispensable for biasing and current flow. Here we show that geometrically engineered metallic wires interconnecting the antennas can function to synchronize the optical phases for promoting coherent resonance, not only as electrical conductors. Antennas connected with optimally folded wires are applied to intersubband infrared photodetectors with a single 4-nm-thick quantum well, and a polarization-independent external quantum efficiency as high as 61% (responsivity 3.3 A W
, peak wavelength 6.7 μm) at 78 K, even extending to room temperature, is demonstrated. Applications of synchronously wired antennas are not limited to photodetectors, but are expected to serve as a fundamental architecture of arrayed subwavelength resonators for optoelectronic devices such as emitters and modulators.
Neonatal calves show a remarkable increase in serum IgG levels after first ingestion of colostrum. They can absorb high-molecular IgG from colostrum in the small intestine by nonspecific ...receptor-independent fluid pinocytosis within 24 h after birth. However, little is known about the temporal changes in serum small-molecule metabolites, such as carbohydrates and AA, in neonatal calves after first colostrum ingestion. In this study, we examined temporal changes in serum metabolites of neonatal calves after first ingestion of colostrum by comprehensive 2-dimensional gas chromatography mass spectrometry (GC×GC-MS). Forty serum samples obtained from 5 calves at 8 time points between 0 and 12 h after first colostrum ingestion were analyzed in triplicate by GC×GC-MS. Multivariate analyses of 120 GC×GC-MS results revealed significant variations in the serum metabolites, primary individual differences among the calves, and secondary temporal changes within each individual calf. Several serum metabolites increased temporally after ingestion in each calf, but only a limited number of compounds were increased universally in all 5 calves. Eight compounds, including oligosaccharides such as lactose, were associated with temporal changes in IgG. Some essential AA that must be supplied from the diet increased temporally after ingestion, but differed from the temporal pattern of the oligosaccharides and IgG. These results suggest that the colostral contents may be absorbed by complex mechanisms that include intestinal pinocytosis for IgG and oligosaccharides, along with others such as specific transporters in the intestinal epithelial cells for AA in calves.
Lanthanoid series are unique in atomic elements. One reason is because they have 4f electronic states forbidding electric-dipole (ED) transitions in vacuum and another reason is because they are very ...useful in current-day optical technologies such as lasers and fiber-based telecommunications. Trivalent Er ions are well-known as a key atomic element supporting 1.5 μm band optical technologies and also as complex photoluminescence (PL) band deeply mixing ED and magnetic-dipole (MD) transitions. Here we show large and selective enhancement of ED and MD radiations up to 83- and 26-fold for a reference bulk state, respectively, in experiments employing plasmonic nanocavity arrays. We achieved the marked PL enhancement by use of an optimal design for electromagnetic (EM) local density of states (LDOS) and by Er-ion doping in deep subwavelength precision. We moreover clarify the quantitative contribution of ED and MD radiations to the PL band, and the magnetic Purcell effect in the PL-decay temporal measurement. This study experimentally demonstrates a new scheme of EM-LDOS engineering in plasmon-enhanced photonics, which will be a key technique to develop loss-compensated and active plasmonic devices.
An overview of the CONQUEST linear scaling density functional theory (DFT) code is given, focusing particularly on the scaling behaviour on modern high-performance computing platforms. We demonstrate ...that essentially perfect linear scaling and weak parallel scaling (with fixed number of atoms per processor core) can be achieved, and that DFT calculations on millions of atoms are now possible.
Toward drastic enhancement of thermoelectric power factor, quantum confinement effect proposed by Hicks and Dresselhaus has intrigued a lot of researchers. There has been much effort to increase ...power factor using step-like density-of-states in two-dimensional electron gas (2DEG) system. Here, we pay attention to another effect caused by confining electrons spatially along one-dimensional direction: multiplied 2DEG effect, where multiple discrete subbands contribute to electrical conduction, resulting in high Seebeck coefficient. The power factor of multiple 2DEG in GaAs reaches the ultrahigh value of ~100 μWcm
K
at 300 K. We evaluate the enhancement rate defined as power factor of 2DEG divided by that of three-dimensional bulk. The experimental enhancement rate relative to the theoretical one of conventional 2DEG reaches anomalously high (~4) in multiple 2DEG compared with those in various conventional 2DEG systems (~1). This proposed methodology for power factor enhancement opens the next era of thermoelectric research.
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