Magnetic Breakdown and Topology in the Kagome Superconductor CsV_{3}Sb_{5} under High Magnetic Field.

The recently discovered layered kagome metals of composition AV_{3}Sb_{5} (A=K, Rb, Cs) exhibit a complex interplay among superconductivity, charge density wave order, topologically nontrivial electronic band structure and geometrical frustration. Here, we probe the electronic band structure underlying these exotic correlated electronic states in CsV_{3}Sb_{5} with quantum oscillation measurements in pulsed fields up to 86 T. The high-field data reveal a sequence of magnetic breakdown orbits that allows the construction of a model for the folded Fermi surface of CsV_{3}Sb_{5}. The dominant features are large triangular Fermi surface sheets that cover almost half the folded Brillouin zone. These sheets have not yet been detected in angle resolved photoemission spectroscopy and display pronounced nesting. The Berry phases of the electron orbits have been deduced from Landau level fan diagrams near the quantum limit without the need for extrapolations, thereby unambiguously establishing the nontrivial topological character of several electron bands in this kagome lattice superconductor.

Two-dimensional overdamped fluctuations of the soft perovskite lattice in CsPbBr3.

Lead halide perovskites exhibit structural instabilities and large atomic fluctuations thought to impact their optical and thermal properties, yet detailed structural and temporal correlations of their atomic motions remain poorly understood. Here, these correlations are resolved in CsPbBr3 crystals using momentum-resolved neutron and X-ray scattering measurements as a function of temperature, complemented with first-principles simulations. We uncover a striking network of diffuse scattering rods, arising from the liquid-like damping of low-energy Br-dominated phonons, reproduced in our simulations of the anharmonic phonon self-energy. These overdamped modes cover a continuum of wave vectors along the edges of the cubic Brillouin zone, corresponding to two-dimensional sheets of correlated rotations in real space, and could represent precursors to proposed two-dimensional polarons. Further, these motions directly impact the electronic gap edge states, linking soft anharmonic lattice dynamics and optoelectronic properties. These results provide insights into the highly unusual atomic dynamics of halide perovskites, relevant to further optimization of their optical and thermal properties.

Observing the Suppression of Superconductivity in RbEuFe_{4}As_{4} by Correlated Magnetic Fluctuations.

In this Letter, we describe quantitative magnetic imaging of superconducting vortices in RbEuFe_{4}As_{4} in order to investigate the unique interplay between the magnetic and superconducting sublattices. Our scanning Hall microscopy data reveal a pronounced suppression of the superfluid density near the magnetic ordering temperature in good qualitative agreement with a recently developed model describing the suppression of superconductivity by correlated magnetic fluctuations. These results indicate a pronounced exchange interaction between the superconducting and magnetic subsystems in RbEuFe_{4}As_{4}, with important implications for future investigations of physical phenomena arising from the interplay between them.

Evaluation of a single-pass with biphasic intravenous contrast medium injection CT protocol for the assessment of complications post-simultaneous pancreas-kidney transplant.

AIM: To evaluate the use of a single-pass with biphasic intravenous contrast medium injection computed tomography (CT) protocol to provide diagnostic quality CT studies for the assessment of complications post-simultaneous pancreas-kidney transplant (SPK). MATERIALS AND METHODS: This was an audit of practice and the need for informed consent was waived. The protocol was used in consecutive patients undergoing CT to exclude intra-abdominal sepsis post-SPK between June and December 2015. Single CT acquisition of the abdomen and pelvis was initiated 70 seconds after the start of biphasic contrast medium injection (66 ml at 1.2 ml/s, followed by 34 ml at 2.4 ml/s, 370 mg iodine/ml). The named transplant pancreas vessels were identified and the attenuation values of the blood within were measured. Diagnostic quality was confirmed if values were >211 HU and >80 HU in the arteries and veins, respectively. RESULTS: Thirteen CT studies were performed in 10 patients. CT studies were excluded due to complete pancreatic necrosis, and transplant superior mesenteric artery (SMA) thrombus with pancreatic head ischaemia causing effacement of the transplant superior mesenteric vein (SMV). Diagnostic quality of the analysed CT studies were confirmed with mean attenuation value of blood >211 HU in the transplant pancreatic arteries (SMA=259.0±51.4 HU, splenic artery=245.3±37.5 HU), and >80 HU in the pancreatic veins (SMV=195.4±36.2 HU, splenic vein=185.1±54.2 HU). CONCLUSION: Diagnostic quality CT studies were obtained using the single-pass CT protocol. Radiation exposure to patients may be reduced with this protocol, while permitting simultaneous assessment of parenchymal and vascular complications post-SPK.

Unconventional superconductivity in Ba(0.6)K(0.4)Fe2As2 from inelastic neutron scattering.

A new family of superconductors containing layers of iron arsenide has attracted considerable interest because of their high transition temperatures (T(c)), some of which are >50 K, and because of similarities with the high-T(c) copper oxide superconductors. In both the iron arsenides and the copper oxides, superconductivity arises when an antiferromagnetically ordered phase has been suppressed by chemical doping. A universal feature of the copper oxide superconductors is the existence of a resonant magnetic excitation, localized in both energy and wavevector, within the superconducting phase. This resonance, which has also been observed in several heavy-fermion superconductors, is predicted to occur when the sign of the superconducting energy gap takes opposite values on different parts of the Fermi surface, an unusual gap symmetry which implies that the electron pairing interaction is repulsive at short range. Angle-resolved photoelectron spectroscopy shows no evidence of gap anisotropy in the iron arsenides, but such measurements are insensitive to the phase of the gap on separate parts of the Fermi surface. Here we report inelastic neutron scattering observations of a magnetic resonance below T(c) in Ba(0.6)K(0.4)Fe(2)As(2), a phase-sensitive measurement demonstrating that the superconducting energy gap has unconventional symmetry in the iron arsenide superconductors.

Association between shortened cervical length at 34-36 weeks' gestation and term labour in Asian women.

Cervical length was measured at 34-36 weeks' gestation by transvaginal ultrasound. The purpose of measurement of cervical length before term was to reveal the association with the onset of term labour. This was a retrospective study of 362 women who were delivered at term at Mizmedi hospital, between August 2006 and November 2011. There was significant linear correlation between cervical length and the scan-to-labour interval in women with labour before 41 weeks. The measurement of cervical length at 34-36 weeks' gestation might be helpful in predicting the onset of term labour before 41 weeks.

Biosorption of uranium(VI) from aqueous solution by biomass of brown algae Laminaria japonica.

The uranium(VI) adsorption efficiency of non-living biomass of brown algae was evaluated in various adsorption experimental conditions. Several different sizes of biomass were prepared using pretreatment and surface-modification steps. The kinetics of uranium uptake were mainly dependent on the particle size of the prepared Laminaria japonica biosorbent. The optimal particle size, contact time, and injection amount for the stable operation of the wastewater treatment process were determined. Spectroscopic analyses showed that uranium was adsorbed in the porous inside structure of the biosorbent. The ionic diffusivity in the biomass was the dominant rate-limiting factor; therefore, the adsorption rate was significantly increased with decrease of particle size. From the results of comparative experiments using the biosorbents and other chemical adsorbents/precipitants, such as activated carbons, zeolites, and limes, it was demonstrated that the brown algae biosorbent could replace the conventional chemicals for uranium removal. As a post-treatment for the final solid waste reduction, the ignition treatment could significantly reduce the weight of waste biosorbents. In conclusion, the brown algae biosorbent is shown to be a favorable adsorbent for uranium(VI) removal from radioactive wastewater.

Effect of Fermi surface nesting on resonant spin excitations in Ba(1-x)K(x)Fe2As2.

We report inelastic neutron scattering measurements of the resonant spin excitations in Ba(1-x)K(x)Fe(2)As(2) over a broad range of electron band filling. The fall in the superconducting transition temperature with hole doping coincides with the magnetic excitations splitting into two incommensurate peaks because of the growing mismatch in the hole and electron Fermi surface volumes, as confirmed by a tight-binding model with s(±)-symmetry pairing. The reduction in Fermi surface nesting is accompanied by a collapse of the resonance binding energy and its spectral weight, caused by the weakening of electron-electron correlations.

Protective effect of antioxidant supplementation in sperm-preparation medium against oxidative stress in human spermatozoa.

BACKGROUND: Oxidative stress induced by reactive oxygen species (ROS) is associated with an impaired fertilization ability of spermatozoa. We investigated the effects of adding antioxidants to a sperm preparation medium on the functional parameters of the spermatozoa. METHODS: Spermatozoa were washed with Ham's F-10 media containing the antioxidants, ethylenediaminetetraacetic acid (EDTA) and catalase, at various concentrations, and then the ROS levels in sperm suspensions, and the forward motility, acrosome reaction, DNA integrity and lipid peroxidation of the spermatozoa were assessed. RESULTS: The ROS levels were significantly lower in sperm suspensions washed with the antioxidants (196 approximately 312 rlu; relative light units) than in control sperm (604 rlu, P < 0.05). The addition of 10 microM EDTA to the sperm preparation medium significantly improved the motility of the spermatozoa compared with the control group, the groups containing EDTA at other concentrations and the groups containing catalase. Catalase significantly increased the acrosome reaction rate of the spermatozoa. Both EDTA and catalase significantly decreased the DNA fragmentation rate of the spermatozoa. However, the antioxidants did not reduce lipid peroxidation. CONCLUSIONS: Supplementing sperm preparation medium with EDTA or catalase significantly improved the overall functional parameters of the spermatozoa by reducing the ROS levels.

The 2014 liver ultrasound tracking benchmark.

The Challenge on Liver Ultrasound Tracking (CLUST) was held in conjunction with the MICCAI 2014 conference to enable direct comparison of tracking methods for this application. This paper reports the outcome of this challenge, including setup, methods, results and experiences. The database included 54 2D and 3D sequences of the liver of healthy volunteers and tumor patients under free breathing. Participants had to provide the tracking results of 90% of the data (test set) for pre-defined point-landmarks (healthy volunteers) or for tumor segmentations (patient data). In this paper we compare the best six methods which participated in the challenge. Quantitative evaluation was performed by the organizers with respect to manual annotations. Results of all methods showed a mean tracking error ranging between 1.4 mm and 2.1 mm for 2D points, and between 2.6 mm and 4.6 mm for 3D points. Fusing all automatic results by considering the median tracking results, improved the mean error to 1.2 mm (2D) and 2.5 mm (3D). For all methods, the performance is still not comparable to human inter-rater variability, with a mean tracking error of 0.5-0.6 mm (2D) and 1.2-1.8 mm (3D). The segmentation task was fulfilled only by one participant, resulting in a Dice coefficient ranging from 76.7% to 92.3%. The CLUST database continues to be available and the online leader-board will be updated as an ongoing challenge.

Elevated serum nicked and urinary beta-core fragment hCG in preeclamptic pregnancies.

OBJECTIVE: To determine whether different molecular forms of hCG in serum and urine are elevated in preeclamptic pregnancies. METHODS: Forty-three pregnant women were studied: 25 preeclamptic women and 18 normotensive women. Immediately after blood and urine samples were collected, the protease inhibitors leupeptin (0.35 mM) and phenanthroline (22 mM) were added. Various molecular forms of hCG in serum (complete hCG, nonnicked hCG, complete free beta hCG) and in urine (complete hCG, beta-core fragment hCG) were measured by matched immunoassays with a common enzyme-labeled tracer antibody. The nicked hCG assay used a coating of beta-subunit monoclonal antibody with the addition of scavenger antibody to remove nonnicked hCG. Mann-Whitney U test and chi 2 test were used for statistical analyses. RESULTS: Preeclamptic women had significantly higher median (range) levels of serum complete and nicked hCG than did normotensive women (3620 [850-12,000] versus 2420 [310-4840] ng/mL, P = .024; and 102 [45-275] versus 71 [11-143] ng/mL, P = .010, respectively). Both median (range) urinary complete hCG-creatinine and beta-core fragment-creatinine ratios were significantly higher in preeclamptic women than in normotensive women (37.6 [0.5-185] versus 11.3 [1.9-54], P = .013; and 11.8 [2-67] versus 5.3 [0.3-29], P = .009, respectively). CONCLUSIONS: Various molecular forms of hCG in serum and urine were significantly higher in preeclamptic than in normotensive pregnancies.

Partial anatomical and physiological characterization and dissociated cell culture of the nervous system of the marine mollusc Aplysia kurodai.

Snail nervous systems are powerful tools for neurobiological studies as the biophysical properties of the giant neurons and their neural circuits can be examined in relation to specific behaviors of animals. The marine mollusc Aplysia californica is particularly useful for analyzing the components of learning and memory at the molecular and cellular levels. Here we partially examined the nervous systems of two species (A. kurodai and A. juliana) commonly found along the Korean coast in comparison with that of A. californica, one of the American marine snails. A. kurodai appeared to be identical to A. californica in both anatomical and physiological properties of the nervous system. A. juliana could be distinguished from A. californica in certain morphological aspects of the nervous system. The hemolymph either from A. kurodai or from A. juliana was required for effectively elongating neurite outgrowth of A. kurodai neurons in dissociated cell culture. The cultured cells retained neuronal properties such as neurite outgrowth, synapse formation, and generation of action potentials. The sensory cells of A. kurodai in dissociated cultures showed a response to serotonin (5-HT) of spike broadening and enhanced membrane excitability as in intact ganglia. Therefore, the nervous system and dissociated neuronal culture of A. kurodai may be useful for studying learning and memory in the context-of well-defined neural circuits of A. californica.

Antioxidant effects of extracts from Cassia tora L. prepared under different degrees of roasting on the oxidative damage to biomolecules.

The effects of water extracts from Cassia tora L. (WECT) treated with different degrees of roasting (unroasted and roasted at 150, 200, and 250 degrees C) on the oxidative damage to deoxyribose, DNA, and DNA base in vitro were investigated. It was found that WECT alone induced a slight strand breaking of DNA. In the presence of Fe(3+)/H(2)O(2), WECT accelerated the strand breaking of DNA at a concentration of 2 microg/mL; however, it decreased with increasing concentrations (>5 microg/mL) of WECT. WECT also accelerated the oxidation of deoxyribose induced by Fe(3+)-EDTA/H(2)O(2) at a concentration of 0.2 mg/mL but inhibited the oxidation of deoxyribose induced by Fe(3+)-EDTA/H(2)O(2)/ascorbic acid. Furthermore, WECT accelerated the oxidation of 2'-deoxyguanosine (2'-dG) to form 8-OH-2'-dG induced by Fe(3+)-EDTA/H(2)O(2). The prooxidant action of WECT on the oxidation of 2'-dG was in the order of unroasted > roasted at 150 degrees C > roasted at 200 degrees C > roasted at 250 degrees C. The decrease in the prooxidant activity of the roasted sample might be due to the reduction in its anthraquinone glycoside content or the formation of antioxidant Maillard reaction products after roasting. Thus, WECT exhibited either a prooxidant or an antioxidant property in the model system that was dependent on the activities of the reducing metal ions, scavenging hydroxyl radical, and chelating ferrous ion.

A case of nephrogenic diabetes insipidus caused by obstructive uropathy due to prostate cancer.

Nephrogenic diabetes insipidus (DI) secondary to chronic urinary tract obstruction is a rare disease. The exact cause is unknown but it is likely that increased collecting duct pressures cause damage to the tubular epithelium, resulting in insensitivity to the action of arginine-vasopressin (AVP). A 77-year-old man complaining of polyuria and polydipsia was treated with alpha glucosidase inhibitor under the impression of polyuria due to diabetes mellitus. But his symptoms did not improve. Water deprivation and AVP administration study revealed that the patient had nephrogenic DI. Urinary tract obstruction due to an enlarged prostate was suggested as a principal cause of nephrogenic DI. The patient underwent transurethral resection of the prostate and bilateral subcapsular orchiectomy. After surgery, the urine osmolarity was normalized and the patient became symptom-free. We report a case of nephrogenic DI due to obstructive uropathy which was cured by surgery eliminating obstruction.

Spectral analysis of fetal heart rate variability as a predictor of intrapartum fetal distress.

OBJECTIVE: To evaluate the usefulness of power spectral analysis on fetal heart rate variability as a new diagnostic method of fetal distress. STUDY DESIGN: Among 76 pregnant women who underwent computerized electronic fetal monitoring and cord blood gas analysis, we divided them into three groups: normal fetus group (36); presumed distress group (26); and acidemic distress group (14). In order to perform linear analysis on the raw data of the fetal heart rate, after resampling, we performed Fourier transformation and investigated power distributions among very low frequency (VLF), low frequency (LF), high frequency (HF) bands, and autonomic balance (LF/HF). RESULTS: The results of the spectral analysis showed that in normal fetus group, the difference in the distribution of power spectrums of VLF, LF and HF was significantly higher than in presumed distress group and acidemic distress group. In fetal distress, the LF and VLF value (< or = 0.0023, > or = 0.0437) were good predictors (sensitivity 97.5%, 75.0% and specificity 86.1%, 94.4%). The LF value (< or = 0.0013) was a good predictor in fetal acidemia (sensitivity 97.5% and specificity 86.1%). CONCLUSIONS: A computerized spectral analysis of fetal heart rate variation is a good predictor of fetal distress, which is made automatically and objectively.

Hearing loss due to noise trauma.

Three different types of noise-induced hearing loss have been reported in the literature. The two less common types are described here. Three cases of these two types from our clinic are reported. Since these 2 types of noise-induced hearing loss often involve low frequencies it is important to recognize them in compensation cases.

Interaction of kanamycin and noise exposure.

The amount of hair cell damage in the cochleas of guinea pigs after exposure to different experimental conditions suggests that a 'safe' level of kanamycin has a potentiating effect on damage due to noise. Such an effect lasts more than 20 days after the cessation of the drug administration.

Magnetically driven suppression of nematic order in an iron-based superconductor.

A theory of superconductivity in the iron-based materials requires an understanding of the phase diagram of the normal state. In these compounds, superconductivity emerges when stripe spin density wave (SDW) order is suppressed by doping, pressure or atomic disorder. This magnetic order is often pre-empted by nematic order, whose origin is yet to be resolved. One scenario is that nematic order is driven by orbital ordering of the iron 3d electrons that triggers stripe SDW order. Another is that magnetic interactions produce a spin-nematic phase, which then induces orbital order. Here we report the observation by neutron powder diffraction of an additional fourfold-symmetric phase in Ba1-xNaxFe2As2 close to the suppression of SDW order, which is consistent with the predictions of magnetically driven models of nematic order.