Electrically driven europium-doped GaN microdisk.

For the practical implementation of microdisk resonators as active nanophotonic devices, it is essential that they can be electrically driven. However, it is difficult to inject current in such small-scale devices without severely degrading their optical properties. We demonstrate the successful fabrication of an electrically injected microdisk based on Eu-doped GaN, in which an SiO2 spacer is used to prevent the interaction of the metal contact with the optical resonances. The microdisk shows Eu-related emission upon electrical injection and from the observed resonance peak, a cavity quality (Q)-factor of 3400 is concluded.

First Observation of Electron Scattering from Online-Produced Radioactive Target.

We successfully performed electron scattering off unstable nuclei which were produced online from the photofission of uranium. The target ^{137}Cs ions were trapped with a new target-forming technique that makes a high-density stationary target from a small number of ions by confining them in an electron storage ring. After developments of target generation and transportation systems and the beam stacking method to increase the ion beam intensity up to approximately 2×10^{7} ions per pulse beam, an average luminosity of 0.9×10^{26} cm^{-2} s^{-1} was achieved for ^{137}Cs. The obtained angular distribution of elastically scattered electrons is consistent with a calculation. This success marks the realization of the anticipated femtoscope which clarifies the structures of exotic and short-lived unstable nuclei.

Measurement of the first ionization potential of lawrencium, element 103.

The chemical properties of an element are primarily governed by the configuration of electrons in the valence shell. Relativistic effects influence the electronic structure of heavy elements in the sixth row of the periodic table, and these effects increase dramatically in the seventh row--including the actinides--even affecting ground-state configurations. Atomic s and p1/2 orbitals are stabilized by relativistic effects, whereas p3/2, d and f orbitals are destabilized, so that ground-state configurations of heavy elements may differ from those of lighter elements in the same group. The first ionization potential (IP1) is a measure of the energy required to remove one valence electron from a neutral atom, and is an atomic property that reflects the outermost electronic configuration. Precise and accurate experimental determination of IP1 gives information on the binding energy of valence electrons, and also, therefore, on the degree of relativistic stabilization. However, such measurements are hampered by the difficulty in obtaining the heaviest elements on scales of more than one atom at a time. Here we report that the experimentally obtained IP1 of the heaviest actinide, lawrencium (Lr, atomic number 103), is 4.96(+0.08)(-0.07) electronvolts. The IP1 of Lr was measured with (256)Lr (half-life 27 seconds) using an efficient surface ion-source and a radioisotope detection system coupled to a mass separator. The measured IP1 is in excellent agreement with the value of 4.963(15) electronvolts predicted here by state-of-the-art relativistic calculations. The present work provides a reliable benchmark for theoretical calculations and also opens the way for IP1 measurements of superheavy elements (that is, transactinides) on an atom-at-a-time scale.

Size dependence of quantum efficiency of red emission from GaN:Eu structures for application in micro-LEDs.

GaN-based micro-LEDs typically suffer from a size-dependent efficiency due to the relatively long carrier lifetime and sidewall-related recombination effects. We demonstrate that for red-emitting Eu-doped GaN, sidewall-related recombination is hardly an issue for emission efficiency. We determine the photoluminescence quantum efficiency (PL QE) of Eu-related emission as a function of the size of square structures ranging from 3 to 192 µm. With the support of finite-difference time-domain simulations, we show that the light extraction efficiency and material losses are responsible for the decrease in PL QE for large sizes. For sizes smaller than 24 µm, there is an influence of the sidewall-related non-radiative recombination of carriers on the PL QE; however, it is only minor as a result of the limited carrier diffusion lengths in the Eu-doped material. These properties combined with the high efficiency of luminescence indicate the potential of this material for micro-LED applications.

Reduction of respiratory motion artifacts in gadoxetate-enhanced MR with a deep learning-based filter using convolutional neural network.

OBJECTIVES: To reveal the utility of motion artifact reduction with convolutional neural network (MARC) in gadoxetate disodium-enhanced multi-arterial phase MRI of the liver. METHODS: This retrospective study included 192 patients (131 men, 68.7 ± 10.3 years) receiving gadoxetate disodium-enhanced liver MRI in 2017. Datasets were submitted to a newly developed filter (MARC), consisting of 7 convolutional layers, and trained on 14,190 cropped images generated from abdominal MR images. Motion artifact for training was simulated by adding periodic k-space domain noise to the images. Original and filtered images of pre-contrast and 6 arterial phases (7 image sets per patient resulting in 1344 sets in total) were evaluated regarding motion artifacts on a 4-point scale. Lesion conspicuity in original and filtered images was ranked by side-by-side comparison. RESULTS: Of the 1344 original image sets, motion artifact score was 2 in 597, 3 in 165, and 4 in 54 sets. MARC significantly improved image quality over all phases showing an average motion artifact score of 1.97 ± 0.72 compared to 2.53 ± 0.71 in original MR images (p < 0.001). MARC improved motion scores from 2 to 1 in 177/596 (29.65%), from 3 to 2 in 119/165 (72.12%), and from 4 to 3 in 34/54 sets (62.96%). Lesion conspicuity was significantly improved (p < 0.001) without removing anatomical details. CONCLUSIONS: Motion artifacts and lesion conspicuity of gadoxetate disodium-enhanced arterial phase liver MRI were significantly improved by the MARC filter, especially in cases with substantial artifacts. This method can be of high clinical value in subjects with failing breath-hold in the scan. KEY POINTS: • This study presents a newly developed deep learning-based filter for artifact reduction using convolutional neural network (motion artifact reduction with convolutional neural network, MARC). • MARC significantly improved MR image quality after gadoxetate disodium administration by reducing motion artifacts, especially in cases with severely degraded images. • Postprocessing with MARC led to better lesion conspicuity without removing anatomical details.

Hepatobiliary phase hypointense nodule without arterial phase hyperenhancement as a risk factor for late recurrence (>1 year) of hepatocellular carcinoma after surgery.

AIM: To evaluate the value of magnetic resonance imaging (MRI) features, including liver stiffness measured by magnetic resonance elastography (MRE) and the presence of hepatobiliary phase (HBP) hypointense nodule without arterial phase hyperenhancement (APHE), for predicting late recurrence (>1 year) after surgery for hepatocellular carcinoma (HCC). MATERIALS AND METHODS: This retrospective study included 124 consecutive patients who had undergone surgery for HCC and preoperative MRI. After excluding patients with early recurrence within 1 year after surgery, 89 patients were analysed. Preoperative MRI images were reviewed by a radiologist to record imaging findings, including (1) liver stiffness by MRE, (2) size of the HCCs, (3) number of HCCs, and (4) presence of HBP hypointense nodule without APHE. Pathological findings included tumour grade, vascular/biliary/capsule invasion, and fibrosis stage of the liver. Considering imaging/pathological findings and patients' characteristics as dependent variables, Cox proportional hazards model analysis was performed to identify independent factors associated with late recurrence after surgery. RESULTS: The median follow-up period was 37.3 months. During follow-up, 29 patients (32.5%) developed late recurrence after surgery. In multivariate analysis, underlying liver disease (viral hepatitis) and presence of HBP hypointense nodules without APHE (p=0.010 and 0.033, respectively) were independently associated with disease-free survival (DFS). Kaplan-Meier analysis revealed that patients with HBP hypointense nodules without APHE had a significantly lower DFS rate than those without the nodule (39.2% versus 74.1% at 3 years after surgery, p=0.008). CONCLUSION: The presence of HBP hypointense nodules without APHE was an indicator of late recurrence after surgery for HCC.

Hyperphosphatemic familial tumoral calcinosis secondary to fibroblast growth factor 23 (FGF23) mutation: a report of two affected families and review of the literature.

Hyperphosphatemic familial tumoral calcinosis (HFTC), secondary to fibroblast growth factor 23 (FGF23) gene mutation, is a rare genetic disorder characterized by recurrent calcified masses. We describe young Lebanese cousins presenting with HFTC, based on a retrospective chart review and a prospective case study. In addition, we present a comprehensive review on the topic, based on a literature search conducted in PubMed and Google Scholar, in 2014 and updated in December 2017. While the patients had the same previously reported FGF23 gene mutation (homozygous c.G367T variant in exon 3 leading to a missense mutation), they presented with variable severity and age of disease onset (at 4 years in patient 1 and at 23 years in patient 2). A review of the literature revealed several potential patho-physiologic pathways of HFTC clinical manifestations, some of which may be independent of hyperphosphatemia. Most available treatment options aim at reducing serum phosphate level, by stimulating renal excretion or by inhibiting intestinal absorption. HFTC is a challenging disease. While the available medical treatment has a limited and inconsistent effect on disease symptomatology, surgical resection of calcified masses remains the last resort. Research is needed to determine the safety and efficacy of FGF23 replacement or molecular therapy, targeting the specific genetic aberration. Hyperphosphatemic familial tumoral calcinosis is a rare genetic disorder characterized by recurrent calcified masses, in addition to other visceral, skeletal, and vascular manifestations. It remains a very challenging disease.

First Elastic Electron Scattering from

The first elastic electron scattering has been successfully performed at the self-confining radioactive-isotope ion target (SCRIT) facility, the world's first electron scattering facility for SCRIT technique achieved high luminosity (over 10^{27} cm^{-2} s^{-1}, sufficient for determining the nuclear shape) with only 10^{8} target ions. While ^{132}Xe used in this time as a target is a stable isotope, the charge density distribution was first extracted from the momentum transfer distributions of the scattered electrons by comparing the results with those calculated by a phase shift calculation.

A survey of the implementation status of selected infection control strategies in neonatal intensive care units in Japan.

BACKGROUND: Infection control strategies are implemented in all neonatal intensive care units (NICUs); however, the details of the strategies seem to differ among institutions. The purpose of this survey was to investigate the current implementation status of infection control strategies in NICUs in Japan and to identify and recommend appropriate strategies for the prevention of outbreaks in neonatal units. METHODS: This survey documented the current implementation status and methods of selected infection prevention and control measures (active surveillance cultures and standard precaution) in 453 Japanese NICUs/neonatal units registered with the Japan Society of Perinatal and Neonatal Medicine, using questionnaires, in May 2018. FINDINGS: The response rate was 48.1% (level I institutions, 25.5%; level II, 55.9%; level III, 64.2%). Surveillance cultures were performed every week and targeted all bacteria in most units. The proportion of level III institutions that experienced outbreaks over the previous five years was significantly higher than that of level II institutions (55% vs 27%, P=0.0003). However, wearing a mask was less frequently recommended in level III institutions (55.7%) than in level II institutions (67.9%). Meticillin-resistant Staphylococcus aureus (MRSA) was the most frequently reported bacterial pathogen responsible for NICU outbreaks. CONCLUSION: Infection prevention and control practices regarding active pathogen surveillance cultures and the use of barrier precautions varied widely in Japanese neonatal units. National guidelines and evidence-based recommendations are needed to rationalize and standardize current infection prevention and control practices in neonatal units in Japan.

Promotion in solid phase reaction of Pt/SiO x bilayer film by electron-orbital-selective-excitation.

A thermally impossible positive free energy reaction can proceed by electron-orbital-selective excitation. When the Si 2p core level is photo-excited in Pt/SiO x bilayer films, Coulomb repulsion at the final two-hole state localized in the valence band by an interatomic Auger transition induces dissociation of the O atom and formation of a Si-Pt bond. Consequently, Pt2Si silicide is formed by a positive free energy reaction. Under a single particle excitation of the valence band, low probability of the coexistence of the two-hole state for picosecond order suppresses to allow the reaction to proceed.

Glucosylceramide synthase and glycosphingolipid synthesis.

In mammalian cells, there are two major classes of sphingolipids---sphingomyelin and glycosphingolipids (GSLs)--both of which are synthesized from the hydrophobic molecule ceramide. The synthesis of most GSLs begins with glucosylation of ceramide to form glucosylceramide (GlcCer), which, in turn, serves as the source of 300-400 GSLs. Although most of these GSLs have been characterized chemically, the biological functions of ceramide glycosylation and GSLs still remain enigmatic. The recent description of a GSL-deficient cell line and isolation of cDNA for GlcCer synthase provide new insights into GSL functions.

Converting an insulating silicon nanochain to a conducting carbon nanotube by electrical breakdown.

Electrical breakdowns of individual silicon nanochains, in which silicon nanoparticles are covered with and connected by oxide alternatively forming nanowires, are studied by in situ transmission electron microscopy using a microprobe system. Individual silicon nanochains can endure a current typically as large as 10(0) nA, and we found that a silicon nanochain can be converted to a nanotube by applying a current as large as 10(1) nA. In the nanotubes, some silicon particles are left. Experimental results suggest that nanotubes are heavily distorted carbon nanotubes, which are formed through the aggregation of contaminating carbon on the nanochain surface and the evaporation of the oxide core due to Joule heating.

Effects of raloxifene and hormone replacement therapy on forearm skin elasticity in postmenopausal women.

OBJECTIVES: Hormone replacement therapy (HRT) increases skin elasticity in postmenopausal women. However, the effects of raloxifene, a selective estrogen receptor modulator (SERM), on skin degenerative changes in postmenopausal women remain unknown. We investigated whether raloxifene increases skin elasticity, similar to HRT, in postmenopausal women. METHODS: In a 12-month trial, 17 postmenopausal women (mean age, 66.4+/-7.8 years) received continuous raloxifene treatment (60 mg/day), 19 women (56.2+/-6.4 years) received continuous 17-beta estradiol treatment using a patch (0.72 mg/2 days) plus cyclic medroxyprogesterone acetate (2.5mg/day, for 12 days/month), and 11 women (58.1+/-7.3 years) did not receive either therapy. In each subject, the skin elasticity of the forearm was measured using a suction device at baseline and at 12 months after the start of the study. RESULTS: Raloxifene and HRT significantly increased skin elasticity from 52.4+/-3.8% and 64.1+/-7.2% at baseline to 55.1+/-4.7% and 67.4+/-7.4% after 12 months, respectively (P<0.05, each), but the untreated subjects did not exhibit any significant change in skin elasticity during the study. The delta value for skin elasticity was significantly higher among the raloxifene and HRT subjects than among the untreated subjects (P<0.05, each). CONCLUSIONS: These findings suggest that raloxifene may have a beneficial effect on skin elasticity, which undergoes degenerative changes in postmenopausal women, in addition to its effects on bone metabolism.

KEKCB electron cyclotron resonance charge breeder at TRIAC.

The KEKCB is an electron cyclotron resonance (ECR) ion source for converting singly charged ions to multicharged ones at Tokai Radioactive Ion Accelerator Complex. By using the KEKCB, singly charged gaseous and nongaseous ions were converted to multicharged ones of A/q approximately 7 with efficiencies of 7% and 2%, respectively. The conversion efficiency was found to be independent of the lifetime of the radioactive nuclei having lifetimes of the order of one second. Three collimators located at the entrance and the exit of the KEKCB defined the beam axis and facilitated beam injection. Grinding and washing the surfaces of aluminum electrode and plasma chamber dramatically reduced impurities originating from the ECR plasma of the KEKCB.

Size-dependent uptake of electrically neutral amphipathic polymeric nanoparticles by cell-sized liposomes and an insight into their internalization mechanism in living cells.

Size-dependent uptake behaviors of electrically neutral amphipathic polymeric nanoparticles in cell-sized liposomes and living cells were investigated. Kinetic analyses and the particle size distribution suggested a size-dependent penetration mechanism (size threshold: 3.1 nm). The definite size-dependent uptake provides a new insight into the interactions between nanomaterials and living cells.

Impact of the structures of macrocyclic Michael acceptors on covalent proteasome inhibition.

Molecules that have a reactive functional group within a macrocycle represent a class of covalent inhibitor. The relationship between reactivity and affinity for the target is cooperative and complicated. An understanding and characterization of this class of inhibitor are vital for the development of covalent inhibitors as drug candidates. Herein, we describe a systematic analysis of structure-activity relationships using a series of syringolin analogues, which are irreversible covalent inhibitors of proteasomes. We investigate the detailed mechanistic effects of the macrocycles on affinity and reaction rate.

Conjugated estrogen plus medroxyprogesterone does not impair blood rheological properties in hypertensive postmenopausal women.

OBJECTIVES: Hypertension and estrogens are both prothrombotic. We used the microchannel method to investigate whether hormone replacement therapy (HRT) with conjugated equine estrogen (CEE) plus medroxyprogesterone acetate (MPA) affects blood flow through the microchannels in hypertensive postmenopausal women being treated with antihypertensive drugs and in normotensive postmenopausal women. METHODS: Sixty-two consecutive postmenopausal women were randomly assigned to a hypertensive HRT group (n=16), hypertensive control group (n=15), normotensive HRT group (n=16) and normotensive control group (n=15). Each HRT group received CEE 0.625 mg plus MPA 2.5 mg daily orally for 12 months. Both hypertensive groups were being treated with antihypertensive drugs before the study. Microvascular blood flow was assessed on the basis of blood passage time, the time required for 100 microl of whole blood to pass through a cylinder, was determined before and 12 months after the start of HRT by the microchannel method (micro channel array flow analyzer). RESULTS: CEE plus MPA therapy did not change blood passage time in any of the groups. Microscopic observation showed that the whole blood passed smoothly through the microchannels in every group. CONCLUSIONS: CEE plus MPA therapy may not impair blood flow through the microchannels in hypertensive postmenopausal women receiving antihypertensive drugs or in normotensive postmenopausal women. However, administration of CEE plus MPA to postmenopausal women with hypertension warrants caution against the occurrence of thromboembolic events.

Elevated arterial stiffness in postmenopausal women with osteoporosis.

OBJECTIVES: Osteoporosis and increased pulse wave velocity (PWV) are cardiovascular risk factors. We investigated the relationship between PWV and bone mass in the lumbar spine in postmenopausal women. METHODS: We studied the PWV in 95 women; 38 postmenopausal women with normal spinal bone mineral density (BMD), 32 osteopenic postmenopausal women, and 25 osteoporotic postmenopausal women. The brachial-ankle PWV (baPWV) was measured using an automated device. The BMD of the lumbar spine (L2-L4) was measured using dual-energy X-ray absorptiometry. RESULTS: After adjusting for age and years since menopause, women with osteoporosis had a significantly higher baPWV than those with normal BMD (1500 +/- 220 cm/s versus 1340 +/- 215 cm/s; P < 0.05), but no significant differences in baPWV were seen between the osteoporotic and osteopenic groups or between the osteopenic and normal BMD groups. In univariate regression analysis, the baPWV was significantly negatively correlated with BMD (r = -0.450, P < 0.01), and significantly positively correlated with age (r = 0.601, P < 0.01), years since menopause (r = 0.577, P < 0.01), systolic blood pressure (r = 0.295, P < 0.01), and diastolic blood pressure (r = 0.264, P < 0.05), but was not with other variables. In multivariate regression analysis, the baPWV was significantly correlated with BMD (P < 0.05), but not with other variables. CONCLUSIONS: Postmenopausal women with osteoporosis may have elevated arterial stiffness, suggesting that osteoporotic postmenopausal women may have a higher risk of cardiovascular disease.

Solution structure and ligand-binding site of the carboxy-terminal SH3 domain of GRB2.

BACKGROUND: Growth factor receptor-bound protein 2 (GRB2) is an adaptor protein with three Src homology (SH) domains in the order SH3-SH2-SH3. Both SH3 domains of GRB2 are necessary for interaction with the protein Son of sevenless (Sos), which acts as a Ras activator. Thus, GRB2 mediates signal transduction from growth factor receptors to Ras and is thought to be a key molecule in signal transduction. RESULTS: The three-dimensional structure of the carboxy-terminal SH3 domain of GRB2 (GRB2 C-SH3) was determined by NMR spectroscopy. The SH3 structure consists of six beta-strands arranged in two beta-sheets that are packed together perpendicularly with two additional beta-strands forming the third beta-sheet. GRB2 C-SH3 is very similar to SH3 domains from other proteins. The binding site of the ligand peptide (VPP-PVPPRRR) derived from the Sos protein was mapped on the GRB2 C-SH3 domain indirectly using 1H and 15N chemical shift changes, and directly using several intermolecular nuclear Overhauser effects. CONCLUSIONS: Despite the structural similarity among the known SH3 domains, the sequence alignment and the secondary structure assignments differ. We therefore propose a standard description of the SH3 structures to facilitate comparison of individual SH3 domains, based on their three-dimensional structures. The binding site of the ligand peptide on GRB2 C-SH3 is in good agreement with those found in other SH3 domains.

Structural characterization of a novel glycoinositolphospholipid from the parasitic nematode, Ascaris suum.

A novel glycosphingolipid containing inositol phosphate as an acidic group has been demonstrated in whole tissues of the porcine roundworm, Ascaris suum. The thin layer chromatographic pattern of the total acidic glycolipid revealed the presence of several components, of which a major component (named AGL) with positive reactions toward both orcinol-sulfuric acid (sugar) and molybdate (phosphate) spray reagents was isolated and purified by the use of successive column chromatography on DEAE-Sephadex and silicic acid (latrobeads). From structural studies including compositional sugar analysis, hydrogen fluoride degradation, methylation analysis, periodate oxidation, proton magnetic resonance spectroscopy and fast atom bombardment mass spectrometry, the structure of AGL was deduced to be Gal alpha 1-2Ins(1-->)-P-Cer. Aliphatic constituents were lignoceric acid and its 2-hydroxy homologue as the principal fatty acids, and octadecasphinganine and branched heptadecasphinganine as the major sphingoids.