Search

In the late stages of nuclear burning for massive stars (M > 8 Mȯ), the production of neutrino-antineutrino pairs through various processes becomes the dominant stellar cooling mechanism. As the star evolves, the energy of these neutrinos increases and in the days preceding the supernova a significant fraction of emitted electron anti-neutrinos exceeds the energy threshold for inverse beta decay on free hydrogen. This is the golden channel for liquid scintillator detectors because the coincidence signature allows for significant reductions in background signals. We find that the kiloton-scale liquid scintillator detector KamLAND can detect these pre-supernova neutrinos from a star with a mass of 25 Mȯ at a distance less than 690 pc with 3σ significance before the supernova. This limit is dependent on the neutrino mass ordering and background levels. KamLAND takes data continuously and can provide a supernova alert to the community.

In the late stages of nuclear burning for massive stars (M > 8 Mȯ), the production of neutrino-antineutrino pairs through various processes becomes the dominant stellar cooling mechanism. As the star evolves, the energy of these neutrinos increases and in the days preceding the supernova a significant fraction of emitted electron anti-neutrinos exceeds the energy threshold for inverse beta decay on free hydrogen. This is the golden channel for liquid scintillator detectors because the coincidence signature allows for significant reductions in background signals. We find that the kiloton-scale liquid scintillator detector KamLAND can detect these pre-supernova neutrinos from a star with a mass of 25 Mȯ at a distance less than 690 pc with 3σ significance before the supernova. This limit is dependent on the neutrino mass ordering and background levels. KamLAND takes data continuously and can provide a supernova alert to the community.

A search for double-beta decays of 136Xe to excited states of 136Ba has been performed with the first phase data set of the KamLAND-Zen experiment. The 01+, 21+ and 22+ transitions of 0νββ decay were evaluated in an exposure of 89.5 kg⋅yr of 136Xe, while the same transitions of 2νββ decay were evaluated in an exposure of 61.8 kg⋅yr. No excess over background was found for all decay modes. The lower half-life limits of the 21+ state transitions of 0νββ and 2νββ decay were improved to T1/20ν(0+→21+)>2.6×1025 yr and T1/22ν(0+→21+)>4.6×1023 yr (90% C.L.), respectively. We report on the first experimental lower half-life limits for the transitions to the 01+ state of 136Xe for 0νββ and 2νββ decay. They are T1/20ν(0+→01+)>2.4×1025 yr and T1/22ν(0+→01+)>8.3×1023 yr (90% C.L.). The transitions to the 22+ states are also evaluated for the first time to be T1/20ν(0+→22+)>2.6×1025 yr and T1/22ν(0+→22+)>9.0×1023 yr (90% C.L.). These results are compared to recent theoretical predictions.

We report a measurement of the neutrino-electron elastic scattering rate of 862 keV Be7 solar neutrinos based on a 165.4 kt d exposure of KamLAND. The observed rate is 582±94(kt d)-1, which corresponds to an 862-keV Be7 solar neutrino flux of (3.26±0.52)×109cm-2s-1, assuming a pure electron-flavor flux. Comparing this flux with the standard solar model prediction and further assuming three-flavor mixing, a νe survival probability of 0.66±0.15 is determined from the KamLAND data. Utilizing a global three-flavor oscillation analysis, we obtain a total Be7 solar neutrino flux of (5.82±1.02)×109cm-2s-1, which is consistent with the standard solar model predictions.

We report a measurement of the neutrino-electron elastic scattering rate of 862 keV Be7 solar neutrinos based on a 165.4 kt d exposure of KamLAND. The observed rate is 582±94(kt d)-1, which corresponds to an 862-keV Be7 solar neutrino flux of (3.26±0.52)×109cm-2s-1, assuming a pure electron-flavor flux. Comparing this flux with the standard solar model prediction and further assuming three-flavor mixing, a νe survival probability of 0.66±0.15 is determined from the KamLAND data. Utilizing a global three-flavor oscillation analysis, we obtain a total Be7 solar neutrino flux of (5.82±1.02)×109cm-2s-1, which is consistent with the standard solar model predictions.

The reactor neutrino and gallium anomalies can be tested with a 3-4 PBq(75-100 kCi scale) 144Ce-144Pr antineutrino beta-source deployed at the centeror next to a large low-background liquid scintillator detector. Theantineutrino generator will be produced by the Russian reprocessing plant PAMayak as early as 2014, transported to Japan, and deployed in the KamiokaLiquid Scintillator Anti-Neutrino Detector (KamLAND) as early as 2015.KamLAND's 13 m diameter target volume provides a suitable environment tomeasure the energy and position dependence of the detected neutrino flux. Acharacteristic oscillation pattern would be visible for a baseline of about 10m or less, providing a very clean signal of neutrino disappearance into ayet-unknown, sterile neutrino state. This will provide a comprehensive test ofthe electron dissaperance neutrino anomalies and could lead to the discovery ofa 4th neutrino state for Delta_m^2 > 0.1 eV^2 and sin^2(2theta) > 0.05.

We propose to test for short baseline neutrino oscillations, implied by therecent reevaluation of the reactor antineutrino flux and by anomalous resultsfrom the gallium solar neutrino detectors. The test will consist of producing a75 kCi 144Ce - 144Pr antineutrino source to be deployed in the Kamioka LiquidScintillator Anti-Neutrino Detector (KamLAND). KamLAND's 13m diameter targetvolume provides a suitable environment to measure energy and positiondependence of the detected neutrino flux. A characteristic oscillation patternwould be visible for a baseline of about 10 m or less, providing a very cleansignal of neutrino disappearance into a yet-unknown, "sterile" state. Such ameasurement will be free of any reactor-related uncertainties. After 1.5 yearsof data taking the Reactor Antineutrino Anomaly parameter space will be testedat > 95% C.L.

We present results from the first phase of the KamLAND-Zen double-beta decay experiment, corresponding to an exposure of 89.5 kg yr of 136Xe. We obtain a lower limit for the neutrinoless double-beta decay half-life of T0v1/2 >1.9 × 1025 yr at 90% C.L. The combined results from KamLAND-Zen and EXO-200 give T0v1/2 > 3.4 × 1025 yr at 90% C.L., which corresponds to a Majorana neutrino mass limit of

Computational material discovery is under intense study owing to its ability to explore the vast space of chemical systems. Neural network potentials (NNPs) have been shown to be particularly effective in conducting atomistic simulations for such purposes. However, existing NNPs are generally designed for narrow target materials, making them unsuitable for broader applications in material discovery. Here we report a development of universal NNP called PreFerred Potential (PFP), which is able to handle any combination of 45 elements. Particular emphasis is placed on the datasets, which include a diverse set of virtual structures used to attain the universality. We demonstrated the applicability of PFP in selected domains: lithium diffusion in LiFeSO 4 F, molecular adsorption in metal-organic frameworks, an order-disorder transition of Cu-Au alloys, and material discovery for a Fischer-Tropsch catalyst. They showcase the power of PFP, and this technology provides a highly useful tool for material discovery., (© 2022. The Author(s).)

We present results from the first phase of the KamLAND-Zen double-beta decay experiment, corresponding to an exposure of 89.5 kg yr of (136)Xe. We obtain a lower limit for the neutrinoless double-beta decay half-life of T(1/2)(0ν)>1.9×10(25) yr at 90% C.L. The combined results from KamLAND-Zen and EXO-200 give T(1/2)(0ν)>3.4×10(25) yr at 90% C.L., which corresponds to a Majorana neutrino mass limit of <(120-250) meV based on a representative range of available matrix element calculations. Using those calculations, this result excludes the Majorana neutrino mass range expected from the neutrinoless double-beta decay detection claim in (76)Ge, reported by a part of the Heidelberg-Moscow Collaboration, at more than 97.5% C.L.

Premaxillary malposition is a difficult problem in cleft lip and palate repair. Orthopedic palatal devices are excellent in positioning the premaxilla, though they are somewhat cumbersome and require complex techniques in adjusting precisely the position of the premaxilla prior to repair. A new technique has been developed for premaxillary repositioning in conjunction with palatal shelf expansion and obturation. The procedure implements microplate fixation anterior to the premaxillary segment and linked to a palatal splint by adjustable elastics. The microplate is inserted through a nasal floor incision and secured by a tight submucosal tunnel through minimal dissection between the prolabium and premaxilla. The last hole of each microplate protrudes through the mucosa and is attached to a pin-retained palatal splint by an elastic chain. Differential tension is applied to the chains to allow gradual repositioning of the protruding maxilla while the splint expands and maintains positioning of the lateral palatal segments. These elastic retractors can be adjusted by staff in the outpatient office. During the past 2 years, this technique has been used successfully in 21 consecutive patients with unilateral or bilateral cleft lip and palate. Its technical ease and design allows simple adjustments to control premaxillary positioning and growth before definitive surgical closure.

This is a retrospective study of the frequency and factors that portend enophthalmos following orbital osteotomies and transposition for craniofacial malformations. Clinically obvious postoperative enophthalmos (POE) was noted in 23 (37.7 percent) of 61 patients undergoing such procedures. Postoperative enophthalmos was observed in 86 percent of Apert patients who had combined anteromedial orbital transposition and in 48 percent of patients with hypertelorbitism who had standard 360-degree osteotomies. In contrast, the incidence of postoperative enophthalmos was 21 percent following frontofacial (monobloc) or subcranial (Le Fort III) advancement. Postoperative enophthalmos also correlated with the occurrence of orbital fracture/fragmentation and with disruption of the periorbita. This study underscores the importance of establishing the correct relationship of the globe to the orbital rim (euophthalmos) while maintaining the spatial position of the eye, especially its anterior projection. Postoperative enophthalmos can be prevented by inserting bone grafts into orbital osteotomy gaps, correcting orbital volume/morphology following floor or wall outfracture/fragmentation, and preserving the periorbital supporting system.

Transplantation of bone should be preceded by careful assessment of the recipient site. The function of the transplanted bone as an interposition graft, as an onlay graft, or in restoration or construction of a missing part of the skeleton must be considered. Cortical bone provides superior mechanical strength and can be incorporated with plate fixation to span interposition defects. Membranous bone used as onlay grafts for augmentation of craniofacial skeletal contour has been shown to be superior to endochondral grafts in maintaining volume. The use of rigid fixation to secure onlay grafts may eliminate the differences in resorption seen with membranous versus endochondral bone. The vascularity and quality of soft tissue at the recipient site may necessitate the use of vascularized bone or composite free tissue transfer. The calvarium is the most popular donor site for bone grafts used in craniofacial skeletal procedures. This membranous bone undergoes less resorption and revascularizes faster than endochondral bone. Cranial bone has excellent mechanical strength due to its large cortical component. The calvarial donor site causes less discomfort to the patient compared with rib or iliac crest, and the scar is well hidden. Harvesting and shaping cranial bone require special expertise, and there is potential morbidity. In cartilage transplantation, the surgeon must take into account the properties of viscoelasticity, the intrinsic balanced system of forces, and immunologic privilege. Cartilage deformed by an external force will tend to return to its original shape unless the deformation is maintained for several months. Surgical carving produces changes in the balance of intrinsic tensile and expansile forces, causing distortion in cartilage shape. Distortion can be minimized by carving in balanced cross-section. Carved cartilage grafts should be used for special indications in rhinoplasty. Autogenous cartilage is the framework of choice in ear construction. Composite grafts incorporating cartilage have been used successfully in eyelid reconstruction. Fresh autogenous cartilage is preferable to preserved allogeneic sources, as the latter undergo eventual resorption because there are no viable chondrocytes to maintain the matrix.