Ultra-Wideband Vertical Transition in Coplanar Stripline for Ultra-High-Speed Digital Interfaces

A design method for an ultra-wideband coplanar-stripline-based vertical transition that can be used for ultra-high-speed digital interfaces is proposed. A conventional via structure, based on a differential line (DL), inherently possesses performance limitations (<10 GHz) due to difficulties in maintaining constant line impedance and smooth electric field transformation, in addition to the effects of signal skews, FR4 fiber weave, and unbalanced EM interferences. DL-based digital interfaces may not meet the demands of ultra-high-speed digital data transmission required for the upcoming 6G communications. The use of a coplanar stripline (CPS), a type of planar balanced line (BL), for the vertical transition, along with the ultra-wideband DL-to-CPS transition, mostly removes the inherent and unfavorable issues of the DL and enables ultra-high-speed digital data transmission. The design process of the transition is simplified using the analytical design formulas, derived using the conformal mapping method, of the transition. The characteristic line impedances of the transition are calculated and found to be in close agreement with the results obtained from EM simulations. Utilizing these results, the CPS-based vertical transition, maintaining the characteristic line impedance of 100 Ω, is designed and fabricated. The measured results confirm its ultra-wideband characteristics, with a maximum of 1.6 dB insertion loss and more than 10 dB return loss in the frequency range of DC to 30 GHz. Therefore, the proposed CPS-based vertical transition offers a significantly wider frequency bandwidth, i.e., more than three times that of conventional DL-based via structures.

Search for Boosted Dark Matter in COSINE-100

We search for energetic electron recoil signals induced by boosted dark matter (BDM) from the galactic center using the COSINE-100 array of NaI(Tl) crystal detectors at the Yangyang Underground Laboratory. The signal would be an excess of events with energies above 4 MeV over the well-understood background. Because no excess of events are observed in a 97.7  kg·yr exposure, we set limits on BDM interactions under a variety of hypotheses. Notably, we explored the dark photon parameter space, leading to competitive limits compared to direct dark photon search experiments, particularly for dark photon masses below 4 MeV and considering the invisible decay mode. Furthermore, by comparing our results with a previous BDM search conducted by the Super-Kamionkande experiment, we found that the COSINE-100 detector has advantages in searching for low-mass dark matter. This analysis demonstrates the potential of the COSINE-100 detector to search for MeV electron recoil signals produced by the dark sector particle interactions.

Design of a Common-Mode Rejection Filter Using Dumbbell-Shaped Defected Ground Structures Based on Equivalent Circuit Models

An efficient design method is proposed for a compact common-mode rejection (CMR) filter utilizing dumbbell-shaped defected ground (DS-DG) structures and gap-coupled stub (GCS) resonators. A CMR filter for differential lines helps to improve the signal integrity of high-speed digital signals on printed circuit boards. The proposed CMR filter design is based on the equivalent circuit models, while the previous designs depended heavily on the DS-DG structure optimization using the EM simulations. The proposed CMR filter effectively rejects the common-mode components while minimally affecting the differential signals. To prove the simplified design approach, a fifth-order Chebyshev band-stop filter is designed with three DS-DG structures and two GCS resonators. From the simulated and measured results, it is found that the proposed CMR filter provides ~90% fractional frequency bandwidth with more than 20 dB of common-mode rejection ratio and less than 0.6 dB of insertion loss of the differential signal.

Respiratory microbiome profiles are associated with distinct inflammatory phenotype and lung function in children with asthma

BACKGROUND

Respiratory microbiome studies have fostered our understanding of various phenotypes and endotypes of heterogeneous asthma. However, the relationship between the respiratory microbiome and clinical phenotypes in children with asthma remains unclear. We aimed to identify microbiome-driven clusters reflecting the clinical features of asthma and their dominant microbiotas in children with asthma.

METHODS

Induced sputum was collected from children with asthma, and microbiome profiles were generated via sequencing of the V3-V4 region of the 16S rRNA gene. Cluster analysis was performed using the partitioning around medoid clustering method. The dominant microbiota in each cluster was determined using the Linear Discriminant Effect Size analysis. Each cluster was analyzed for association among the dominant microbiota, clinical phenotype, and inflammatory cytokine.

RESULTS

Eighty-three children diagnosed with asthma were evaluated. Among four clusters reflecting the clinical characteristics of asthma, cluster 1, dominated by Haemophilus and Neisseria, demonstrated lower post-bronchodilator (BD) forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) than that in the other clusters and more mixed granulocytic asthma. Neisseria negatively correlated with pre-BD and post-BD FEV1/FVC. Haemophilus and Neisseria positively correlated with programmed death-ligand (PD-L)1.

CONCLUSION

To our knowledge, this study is the first to analyze the relationship between an unbiased microbiome-driven cluster and clinical phenotype in children with asthma. The cluster dominated by Haemophilus and Neisseria showed fixed airflow obstruction and mixed granulocytic asthma, which correlated with PD-L1 levels. Thus, microbiome-driven unbiased clustering can help identify new asthma phenotypes related to endotypes in childhood asthma.

Stepwise evolution of a butterfly supergene via duplication and inversion

Supergenes maintain adaptive clusters of alleles in the face of genetic mixing. Although usually attributed to inversions, supergenes can be complex, and reconstructing the precise processes that led to recombination suppression and their timing is challenging. We investigated the origin of the BC supergene, which controls variation in warning coloration in the African monarch butterfly, Danaus chrysippus. By generating chromosome-scale assemblies for all three alleles, we identified multiple structural differences. Most strikingly, we find that a region of more than 1 million bp underwent several segmental duplications at least 7.5 Ma. The resulting duplicated fragments appear to have triggered four inversions in surrounding parts of the chromosome, resulting in stepwise growth of the region of suppressed recombination. Phylogenies for the inversions are incongruent with the species tree and suggest that structural polymorphisms have persisted for at least 4.1 Myr. In addition to the role of duplications in triggering inversions, our results suggest a previously undescribed mechanism of recombination suppression through independent losses of divergent duplicated tracts. Overall, our findings add support for a stepwise model of supergene evolution involving a variety of structural changes.

This article is part of the theme issue ‘Genomic architecture of supergenes: causes and evolutionary consequences’.

Brain charts for the human lifespan

Over the past few decades, neuroimaging has become a ubiquitous tool in basic research and clinical studies of the human brain. However, no reference standards currently exist to quantify individual differences in neuroimaging metrics over time, in contrast to growth charts for anthropometric traits such as height and weight1. Here we assemble an interactive open resource to benchmark brain morphology derived from any current or future sample of MRI data ( http://www.brainchart.io/ ). With the goal of basing these reference charts on the largest and most inclusive dataset available, acknowledging limitations due to known biases of MRI studies relative to the diversity of the global population, we aggregated 123,984 MRI scans, across more than 100 primary studies, from 101,457 human participants between 115 days post-conception to 100 years of age. MRI metrics were quantified by centile scores, relative to non-linear trajectories2 of brain structural changes, and rates of change, over the lifespan. Brain charts identified previously unreported neurodevelopmental milestones3, showed high stability of individuals across longitudinal assessments, and demonstrated robustness to technical and methodological differences between primary studies. Centile scores showed increased heritability compared with non-centiled MRI phenotypes, and provided a standardized measure of atypical brain structure that revealed patterns of neuroanatomical variation across neurological and psychiatric disorders. In summary, brain charts are an essential step towards robust quantification of individual variation benchmarked to normative trajectories in multiple, commonly used neuroimaging phenotypes.

Experimental demonstration of a 4,294,967,296-QAM-based Y-00 quantum stream cipher template carrying 160-Gb/s 16-QAM signals

We demonstrate a 4,294,967,296-quadrature amplitude modulation (QAM) based Y-00 quantum stream cipher system carrying a 160-Gb/s 16-QAM signal transmitted over 320-km SSMF. The ultra-dense QAM cipher template is realized by an integrated two-segment silicon photonics I/Q modulator.

Giant Zero Bias Anomaly due to Coherent Scattering from Frozen Phonon Disorder in Quantum Point Contacts

We demonstrate an unusual manifestation of coherent scattering for electron waves in mesoscopic quantum point contacts, in which fast electron dynamics allows the phonon system to serve as a quasistatic source of disorder. The low-temperature conductance of these devices exhibits a giant (≫2e^{2}/h) zero bias anomaly (ZBA), the features of which are reproduced in a nonequilibrium model for coherent scattering from the "frozen" phonon disorder. According to this model, the ZBA is understood to result from the in situ electrical manipulation of the phonon disorder, a mechanism that could open up a pathway to the on-demand control of coherent scattering in the solid state.

Search for a Dark Matter-Induced Annual Modulation Signal in NaI(Tl) with the COSINE-100 Experiment

We present new constraints on the dark matter-induced annual modulation signal using 1.7 years of COSINE-100 data with a total exposure of 97.7 kg yr. The COSINE-100 experiment, consisting of 106 kg of NaI(Tl) target material, is designed to carry out a model-independent test of DAMA/LIBRA's claim of WIMP discovery by searching for the same annual modulation signal using the same NaI(Tl) target. The crystal data show a 2.7  cpd/kg/keV background rate on average in the 2-6 keV energy region of interest. Using a χ-squared minimization method we observe best fit values for modulation amplitude and phase of 0.0092±0.0067  cpd/kg/keV and 127.2±45.9  d, respectively.

Genetics and evidence for balancing selection of a sex-linked colour polymorphism in a songbird

Colour polymorphisms play a key role in sexual selection and speciation, yet the mechanisms that generate and maintain them are not fully understood. Here, we use genomic and transcriptomic tools to identify the precise genetic architecture and evolutionary history of a sex-linked colour polymorphism in the Gouldian finch Erythrura gouldiae that is also accompanied by remarkable differences in behaviour and physiology. We find that differences in colour are associated with an ~72-kbp region of the Z chromosome in a putative regulatory region for follistatin, an antagonist of the TGF-β superfamily genes. The region is highly differentiated between morphs, unlike the rest of the genome, yet we find no evidence that an inversion is involved in maintaining the distinct haplotypes. Coalescent simulations confirm that there is elevated nucleotide diversity and an excess of intermediate frequency alleles at this locus. We conclude that this pleiotropic colour polymorphism is most probably maintained by balancing selection.

First Direct Search for Inelastic Boosted Dark Matter with COSINE-100

A search for inelastic boosted dark matter (IBDM) using the COSINE-100 detector with 59.5 days of data is presented. This relativistic dark matter is theorized to interact with the target material through inelastic scattering with electrons, creating a heavier state that subsequently produces standard model particles, such as an electron-positron pair. In this study, we search for this electron-positron pair in coincidence with the initially scattered electron as a signature for an IBDM interaction. No excess over the predicted background event rate is observed. Therefore, we present limits on IBDM interactions under various hypotheses, one of which allows us to explore an area of the dark photon parameter space that has not yet been covered by other experiments. This is the first experimental search for IBDM using a terrestrial detector.

Diagnostic Performance of Multidetector Computerized Tomography in the Detection of Abdominal Complications Early and Late After Liver Transplantation: A 10-Year Experience

BACKGROUND

Multidetector computerized tomography (MDCT) is considered to be a fast noninvasive diagnostic technique for the evaluation of postoperative complications in patients with liver transplantation (LT). However, its role has not been fully established in the diagnosis for detecting complications after liver transplantation. The aim of this work was to evaluate the diagnostic performance of MDCT for detecting abdominal complications in the early and late periods after LT.

METHODS

We retrospectively enrolled 75 patients who had undergone LT from March 2006 to January 2010, followed by MDCT from March 2006 to November 2017. Patients were divided into 2 groups according to the timing after LT: within the first 3 months (early period) or ≥3 months after LT (late period). We evaluated vascular, biliary, and other complications on MDCT. Angiography, endoscopic retrograde cholangiography, and percutaneous transhepatic cholangiography were used as reference standards.

RESULTS

We initially found 77 complications in 45 patients (60.0%) with the use of MDCT. After comparison with the reference standards, 83 complications were diagnosed in 49 patients (65.3%). Forty-seven complications (34 vascular, 10 biliary, 3 other complications) were diagnosed in 33 patients (44.0%) during the early period, and 36 complications (6 vascular, 20 biliary, 10 other complications) were detected in 27 patients (36.0%) in the late period. The sensitivity, specificity, and diagnostic accuracy of MDCT for diagnosing overall complications were, respectively, 93.6%, 90.2%, and 92.0% in the early period (for vascular complications: 97.1%, 92.6%, and 94.3%,; for biliary complications: 80.0%, 100%, and 97.7%) and 77.8%, 98.1%, and 89.8% in the late period (for vascular complications: 83.3%, 100%, and 98.9%; for biliary complications: 65.0%, 98.6%, and 90.9%).

CONCLUSIONS

Although MDCT in the late period should be interpreted with caution in patients with suspected biliary complication, MDCT is a reliable diagnostic technique for the identification of early and late abdominal complications after LT.

Tunable quad-band transmission response, based on single-layer metamaterials

We investigated the electromagnetically induced transparency (EIT)-like effects in planar metamaterials (MMs) at microwave (GHz) frequencies. The specific MMs that were used in this study consist of cut-wire resonator/ring resonator, which achieved the dual EIT-like effects in a single-layer through the bright- and quasi-dark-mode coupling and the lattice mode coupling. In addition, by varying the distance between the two resonators, the quad-band EIT spectral response in the microwave region was obtained, and the group refractive index at the EIT-like resonance of proposed design reached up to 4,000. This study provides the design approach to the multispectral EIT-like effects and might suggest potential applications in a variety of fields, for example, low-loss slow-light device, multiple switching sensor, and other sensing devices.

Depressive Symptoms, Falls, and Fear of Falling in Old Korean Adults: The Korean Longitudinal Study on Health and Aging (KLoSHA)

Fall is a common cause of disability and death in old adults, and much research has been focused on identifying risk factors and developing preventive measures. Yet the majority of preceding research has been focused on physical performance. This study aims to evaluate the association between fall and depressive symptoms in community-dwelling elderly. Cross-sectional data of 431 men and 546 women was collected from old Korean adults living in Seongnam, Korea. Geriatric fall assessment was conducted by self-report questionnaires. Depressive symptoms were assessed by the Center for Epidemiologic Studies Depression Scale. Results indicated that depressive symptoms were associated with both fall and fear of falling in old adults. A clear gender difference was newly discovered, as depression played a stronger role in women. These results imply that clinicians should consider the negative affect of geriatric patients when assessing fall risk. Also, measures against depression might be effective in reducing falls.

Activated leucocyte cell adhesion molecule (ALCAM/CD166) regulates T cell responses in a murine model of food allergy

Food allergy is a major public health problem. Studies have shown that long-term interactions between activated leucocyte cell adhesion molecule (ALCAM/CD166) on the surface of antigen-presenting cells, and CD6, a co-stimulatory molecule, influence immune responses. However, there are currently no studies on the functions of ALCAM in food allergy. Therefore, we aimed to identify the functions of ALCAM in ovalbumin (OVA)-induced food allergy using ALCAM-deficient mice. Wild-type (WT) and ALCAM-deficient (ALCAM^-/- ) mice were sensitized intraperitoneally and with orally fed OVA. The mice were killed, and parameters related to food allergy and T helper type 2 (Th2) immune responses were analysed. ALCAM serum levels increased and mRNA expression decreased in OVA-challenged WT mice. Serum immunoglobulin (Ig)E levels, Th2 cytokine mRNA and histological injuries were higher in OVA-challenged WT mice than in control mice, and these were attenuated in ALCAM^-/- mice. T cell proliferation of total cells, CD3⁺ CD4⁺ T cells and activated T cells in immune tissues were diminished in OVA-challenged ALCAM^-/- mice. Proliferation of co-cultured T cells and dendritic cells (DCs) was decreased by the anti-CD6 antibody. In addition, WT mice sensitized by adoptive transfer of OVA-pulsed ALCAM^-/- BM-derived DCs showed reduced immune responses. Lastly, serum ALCAM levels were higher in children with food allergy than in control subjects. In this study, serum levels of ALCAM were elevated in food allergy-induced WT mice and children with food allergy. Moreover, immune responses and T cell activation were attenuated in OVA-challenged ALCAM^-/- mice. These results indicate that ALCAM regulates food allergy by affecting T cell activation.

Femtosecond electron-phonon lock-in by photoemission and x-ray free-electron laser

The interactions that lead to the emergence of superconductivity in iron-based materials remain a subject of debate. It has been suggested that electron-electron correlations enhance electron-phonon coupling in iron selenide (FeSe) and related pnictides, but direct experimental verification has been lacking. Here we show that the electron-phonon coupling strength in FeSe can be quantified by combining two time-domain experiments into a "coherent lock-in" measurement in the terahertz regime. X-ray diffraction tracks the light-induced femtosecond coherent lattice motion at a single phonon frequency, and photoemission monitors the subsequent coherent changes in the electronic band structure. Comparison with theory reveals a strong enhancement of the coupling strength in FeSe owing to correlation effects. Given that the electron-phonon coupling affects superconductivity exponentially, this enhancement highlights the importance of the cooperative interplay between electron-electron and electron-phonon interactions.

Relationship between sputum clusterin levels and childhood asthma

BACKGROUND

Clusterin is a sensitive cellular biosensor of oxidative stress and has been studied as a biomarker for inflammation-associated diseases. Clusterin levels in childhood asthma have not been evaluated.

OBJECTIVES

(1) To evaluate sputum clusterin levels in children with asthma compared to a control group. (2) To assess the relationships between sputum clusterin levels and airway inflammation, pulmonary function, and bronchial hyperresponsiveness.

METHODS

This study included 170 children aged 5-18 years with stable asthma (n = 91), asthma exacerbation (n = 29), or no asthma (healthy controls; n = 50). Induced sputum, pulmonary function, and methacholine challenge tests were performed. Stable asthma was classified into two groups according to the severity. Clusterin levels in sputum were measured using an enzyme-linked immunosorbent assay.

RESULTS

Children with stable asthma had a higher clusterin level than healthy controls [4540 (3872-5651) pg/mL vs. 3857 (1054-4369) pg/mL, P < 0.001]. The clusterin level was also more elevated in eosinophil-dominant sputum than in non-eosinophilic sputum in stable asthma [5094 (4243-6257) pg/mL vs. 4110 (1871-4839) pg/mL, P = 0.0017]. Clusterin levels were associated with asthma severity. Paradoxically, clusterin levels were lower during asthma exacerbation than in stable asthma [1838 (350-4790] pg/mL vs. 4540 (3872-5651) pg/mL, P < 0.001]. Clusterin levels were strongly correlated with the methacholine concentration that caused a 20% decrease in the forced expiratory volume in 1 s (r = -0.617, P < 0.001); there was no significant correlation between clusterin levels and other pulmonary function parameters.

CONCLUSIONS AND CLINICAL RELEVANCE

Clusterin levels were altered in children with stable asthma and asthma exacerbation because of its antioxidant and anti-inflammatory effects. Clusterin may be a marker that reflects airway inflammation and severity of symptoms, and it can be used in the assessment and management of childhood asthma.

Effectiveness of 100 Beats per Minute Music on Cardiopulmonary Resuscitation Compression Rate Education: A Manikin Study

Introduction

Recent cardiopulmonary resuscitation (CPR) guidelines emphasize the importance of high-quality chest compression. The aim of this study is to determine the effect of education using music on the chest compression rate.

Methods

This randomised, open-labeled study enrolled 81 medical students. They were randomly divided into three groups. After they were educated in CPR according to the American Heart Association 2010 guidelines, they performed 100 chest compressions using a mannequin capable of collecting each compression depth and speed. After that, the control group received a verbal feedback about their own results. The metronome group was also notified of their own results, and listened to the metronome sound at 100 beats per minute (bpm). The music group listened to the music (about 100 bpm). Twenty-four hours after their CPR education, chest compressions were performed again with the method identical to the first evaluation. The results were compared using multivariate analysis of variances.

Result

Compression rate (bpm): There was a significant difference between the control (mean, 110.4; 95% CI: 104.4, 116.5) and metronome group (mean, 98.5; 95% CI: 91.6, 105.4) after education (p=0.01). There was a significant difference between control and music group (mean, 98.2; 95% CI: 94.6, 101.8) after education (p<0.001) There were no differences between the music and metronome group before or after education (p=0.50, p=0.94). However, the variance of music group was significantly less than the metronome group (p=0.01). Compression depth (inches): there was no difference between the groups according to the CPR education method. (Control: 1.8±0.3; Metronome group: 1.6±0.2; Music group: 1.7±0.3 p=0.09)

Conclusion

Both education method of using music and metronome are more effective than conventional method. However the effect of using music may be better than using metronome.

Strong Spin-Phonon Coupling Mediated by Single Ion Anisotropy in the All-In-All-Out Pyrochlore Magnet Cd_{2}Os_{2}O_{7}

Spin-phonon coupling mediated by single ion anisotropy was investigated using optical spectroscopy and first-principles calculations in the all-in-all-out pyrochlore magnet Cd_{2}Os_{2}O_{7}. Clear anomalies were observed in both the phonon frequencies and linewidths at the magnetic ordering temperature. The renormalization of the phonon modes was exceptionally large, signifying the presence of an unconventional magnetoelastic term from large spin-orbit coupling. In addition, the relative phonon frequency shifts show a strong correlation with the modulation of noncubic crystal field by the corresponding lattice distortion. Our observation establishes a new type of spin-phonon coupling through single ion anisotropy, a second-order spin-orbit coupling term, in Cd_{2}Os_{2}O_{7}.

Increased expression of bitter taste receptors in human allergic nasal mucosa and their contribution to the shrinkage of human nasal mucosa

OBJECTIVE

Bitter taste receptors (TAS2Rs) are expressed in the extraoral tissues, where they possess various physiological functions. This study is to characterize TAS2Rs expression in normal and allergic nasal mucosa and analyse nasal symptom after challenge with bitter tastes to evaluate their pathophysiological function in normal and allergic nasal mucosa.

METHODS

The expression levels of TAS2Rs (TAS2R4, 5, 7, 10, 14, 39, and 43) in nasal mucosa were investigated by real-time PCR, Western blot, and immunohistochemistry. The expression levels of TAS2Rs and Ca(2+) imaging in cultured epithelial cells were measured after stimulation with type 2 cytokines (IL-4, IL-5, and IL-13) or bitter tastes. Nasal symptoms in control subjects and allergic rhinitis patients using visual analogue score and acoustic rhinometry were evaluated before and after stimulation with bitter tastes. Vascular diameter of rat nasal septum was measured before and after treatment with bitter tastes.

RESULTS

TAS2Rs tested here were expressed in nasal mucosa where they were commonly distributed in superficial epithelium, submucosal glands, and endothelium. Their expression levels are increased in allergic nasal mucosa and up-regulated in cultured epithelial cells simulated with type 2 cytokines. After treatment with bitter tastes, intracellular Ca(2+) signalling was increased in cultured epithelial cells, and vascular constriction was found in rat nasal septum. Increased nasal patency was observed in human nasal mucosa without pain or sneezing.

CONCLUSION AND CLINICAL RELEVANCE

TAS2Rs are constitutively expressed in human nasal mucosa and their expression levels are increased in allergic nasal mucosa, where they could potentially contribute to shrinkage of normal and allergic nasal mucosa.

First-Line Use of Core Needle Biopsy for High-Yield Preliminary Diagnosis of Thyroid Nodules

BACKGROUND AND PURPOSE

Although core needle biopsy was introduced as a diagnostic alternative to fine-needle aspiration, the utility and safety of core needle biopsy for thyroid nodules in a large population has yet to be studied comprehensively. We evaluate core needle biopsy yields on a large-scale basis to investigate its potential in the preliminary diagnosis of thyroid nodules.

MATERIALS AND METHODS

Between March 2005 and December 2013, 2448 initially detected thyroid nodules from 2120 consecutive patients who underwent core needle biopsy were retrospectively evaluated. Of these, 72 thyroid nodules from 63 patients were excluded due to prior fine-needle aspiration attempts. The inconclusive and conclusive result rates, diagnostic accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and unnecessary surgery rate of core needle biopsy were evaluated.

RESULTS

With core needle biopsy as the first-line method, the inconclusive result rate was 11.9% (283/2376) and the conclusive result rate was 88.1% (2093/2376). The diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of core needle biopsy for the diagnosis of malignancy were 96.7% (1160/1200), 89.7% (347/387), 100% (813/813), 100% (347/347), and 95.3% (813/853), respectively. There were no major complications and 12 minor complications.

CONCLUSIONS

We have demonstrated that first-line use of core needle biopsy may well improve diagnostic accuracy in thyroid nodules, reducing inconclusive or false-negative results and unnecessary operations. Such benefits underscore the promising role of core needle biopsy in managing thyroid nodules and optimizing related surgical decision-making.

Ion gyroscale fluctuation measurement with microwave imaging reflectometer on KSTAR

Ion gyroscale turbulent fluctuations with the poloidal wavenumber k_θ ∼ 3 cm^-1 have been measured in the core region of the neutral beam (NB) injected low confinement (L-mode) plasmas on Korea superconducting tokamak advanced research. The turbulence poloidal wavenumbers are deduced from the frequencies and poloidal rotation velocities in the laboratory frame, measured by the multichannel microwave imaging reflectometer. Linear and nonlinear gyrokinetic simulations also predict the unstable modes with the normalized wavenumber k_θρ_s ∼ 0.4, consistent with the measurement. Comparison of the measured frequencies with the intrinsic mode frequencies from the linear simulations indicates that the measured ones are primarily due to the E × B flow velocity in the NB-injected fast rotating plasmas.

IgE cross-reactivity of peanut with walnut and soybean in children with food allergy

BACKGROUND

Peanut allergies are common and can be life-threating for sensitised individuals. Peanut allergens share significant amino acid homology with those of other legumes and tree nuts, but their cross-reactivity still remains unclear.

OBJECTIVE

We sought to determine the clinical significance of the cross-reactivity of peanut allergens with those of walnut and soybean.

METHODS

Pooled sera from eight subjects with both peanut and walnut specific IgE were investigated in an inhibition test. After the sera were incubated with either peanut or walnut protein extracts, the quantity of IgE antibodies against the peanut and walnut was measured using an immunoCAP test. Likewise, pooled sera from 18 subjects with both peanut and soybean specific IgE antibodies were incubated with either peanut or soybean protein extracts and evaluated with a peanut and soybean immunoCAP test. SDS-PAGE and immunoblotting were also performed with peanut, walnut and soybean protein extracts and relevant sera.

RESULTS

Peanut specific IgE was inhibited up to 20% and 26% by walnut and soybean protein extracts, respectively. In reverse, walnut and soybean specific IgE were inhibited up to 21% and 23% by peanut protein extracts, respectively. In the immunoblot analysis, pooled serum from the subjects with peanut specific IgE antibodies reacted with walnut protein extracts significantly.

CONCLUSION

Although the clinical significance of the cross-reactivity of peanut specific IgE with walnut and soybean protein extracts has not been established, we believe that individuals who are allergic to peanuts need to be cautious about consuming walnuts and soybeans.

Effects of age, replicative lifespan and growth rate of human nucleus pulposus cells on selecting age range for cell-based biological therapies for degenerative disc diseases

Autologous disc cell implantation, growth factors and gene therapy appear to be promising therapies for disc regeneration. Unfortunately, the replicative lifespan and growth kinetics of human nucleus pulposus (NP) cells related to host age are unclear. We investigated the potential relations among age, replicative lifespan and growth rate of NP cells, and determined the age range that is suitable for cell-based biological therapies for degenerative disc diseases. We used NP tissues classified by decade into five age groups: 30s, 40s, 50s, 60s and 70s. The mean cumulative population doubling level (PDL) and population doubling rate (PDR) of NP cells were assessed by decade. We also investigated correlations between cumulative PDL and age, and between PDR and age. The mean cumulative PDL and PDR decreased significantly in patients in their 60s. The mean cumulative PDL and PDR in the younger groups (30s, 40s and 50s) were significantly higher than those in the older groups (60s and 70s). There also were significant negative correlations between cumulative PDL and age, and between PDR and age. We found that the replicative lifespan and growth rate of human NP cells decreased with age. The replicative potential of NP cells decreased significantly in patients 60 years old and older. Young individuals less than 60 years old may be suitable candidates for NP cell-based biological therapies for treating degenerative disc diseases.

Sarcopenia as a Predictor of Future Cognitive Impairment in Older Adults

OBJECTIVES

We investigated the association between the indices of sarcopenia and future risk of cognitive impairment in older adults.

DESIGN

Community-based prospective cohort study.

SETTING

Community.

PARTICIPANTS

A total of 297 participants aged ≥65 years without cognitive impairment at baseline (mean age, 71.9 ± 6.6 years; men:women, 158:139) and who underwent cognitive evaluation at the 5-year follow-up.

MEASUREMENTS

Sarcopenia parameters including appendicular lean mass (ALM), handgrip strength, and the Short Physical Performance Battery (SPPB) score at baseline were compared according to the later progression of mild cognitive impairment (MCI) and/or dementia. The operational criteria suggested by the Foundation for the National Institutes of Health Sarcopenia Project were used. We performed multivariate logistic regression analysis to identify the independent indicators of the progression of cognitive impairment.

RESULTS

Among the 297 participants, 242 (81.5%) remained cognitively normal (nonprogression group), whereas 55 (18.5%) showed progression of cognitive impairment (50 subjects (16.8%) to MCI and 5 subjects (1.7%) to dementia) (progression group). Compared with the nonprogression group, subjects in the progression group were older, had a lower educational level, and had lower physical function as assessed by the SPPB; a higher percentage were depressed. Other baseline markers of sarcopenia, including the ALM-to-body mass index ratio and handgrip strength did not differ significantly between the groups. The association between a low SPPB score (<9) and progression of cognitive impairment was maintained after adjustment for conventional risk factors for cognitive impairment (hazard ratio 2.222, 95% confidence interval 1.047-4.716, P = 0.038).

CONCLUSION

Decreased physical performance, as assessed by the SPPB, but not other markers of sarcopenia, was independently associated with the risk of later cognitive impairment in older adults.

Optical Spectroscopic Studies of the Metal-Insulator Transition Driven by All-In-All-Out Magnetic Ordering in 5d Pyrochlore Cd(2)Os(2)O(7)

We investigated the metal-insulator transition (MIT) driven by all-in-all-out (AIAO) antiferromagnetic ordering in the 5d pyrochlore Cd(2)Os(2)O(7) using optical spectroscopy and first-principles calculations. We showed that the temperature evolution in the band-gap edge and free carrier density were consistent with rigid upward (downward) shifts of electron (hole) bands, similar to the case of Lifshitz transitions. The delicate relationship between the band gap and free carrier density provides experimental evidence for the presence of an AIAO metallic phase, a natural consequence of such MITs. The associated spectral weight change at high energy and first-principles calculations further support the origin of the MIT from the band shift near the Fermi level. Our data consistently support that the MIT induced by AIAO ordering in Cd(2)Os(2)O(7) is not close to a Slater type but instead to a Lifshitz type.

Pandemic influenza virus, pH1N1, induces asthmatic symptoms via activation of innate lymphoid cells

BACKGROUND

The pandemic strain of the influenza A virus (pH1N1) in 2009 caused many complications in patients. In this study, we introduce asthmatic symptoms as a complication of pH1N1 infection in children, not having a relationship with asthma history. The aim of this study was to quantify asthmatic symptoms in pH1N1-infected children and elucidate the underlying mechanisms of airway hyper-responsiveness (AHR) induced in a murine model of pH1N1 infection.

METHODS

As a retrospective study, pH1N1-infected children who were hospitalized with moderate to severe acute asthmatic symptoms were enrolled and administered a methacholine challenge test (MCT) at 3 months post-discharge. Additionally, the induction of AHR by pH1N1 infection was measured by MCT in wild-type and Rag1(-/-) mice. The effect of the innate immune response on the development of AHR following pH1N1 infection was investigated.

RESULTS

More than 70% of the pH1N1-infected children without a pre-infection diagnosis of asthma had a negative response on the MCT. None of these children had recurrent wheezing or asthma during the 3 years following pH1N1 infection. The development of AHR in pH1N1-infected mice was associated with an elevation in IL-33 and innate lymphoid cells 2 (ILC2).

CONCLUSIONS

This study demonstrates that pH1N1 infection directly induces transient asthmatic symptoms in patients regardless of their medical history. pH1N1 infection was shown to stimulate the rapid development of AHR and Th2-type cytokine secretion in mice via the activation of ILC2; it may be activated independently of adaptive immunity.

Serum 25-hydroxyvitamin D level and the risk of mild cognitive impairment and dementia: the Korean Longitudinal Study on Health and Aging (KLoSHA)

OBJECTIVE

The association of low vitamin D status with mild cognitive impairment (MCI), a preclinical condition that can lead to dementia, has not yet been fully explored. Our aim was to investigate the association between vitamin D status and the future risk of MCI and dementia in older adults.

DESIGN, SETTING AND PARTICIPANTS

We conducted a population-based prospective study as a part of the Korean Longitudinal Study on Health and Aging. Four hundred and twelve elderly participants who completed evaluations of cognitive function and metabolic parameters in 2005-2006 and 2010-2011 were analysed.

MAJOR OUTCOME MEASURE

The rate of development of MCI or dementia during the study period was compared according to baseline vitamin D status. Binary logistic regression analysis was performed to investigate any independent association between vitamin D status and the risks of MCI or dementia.

RESULTS

Among 405 subjects that remained after excluding seven demented subjects at baseline, 338 subjects remained unchanged or improved in their diagnosis for cognitive function during the study period, whereas 67 subjects showed progression to MCI or dementia. When analyzing 236 subjects whose baseline mini-mental state examination (MMSE) scores were <27, severe vitamin D deficiency at baseline, defined as <25 nmol/l, was independently associated with the progression of cognitive impairment. Among 297 subjects who were normal at baseline, 50 acquired MCI and 247 remained normal. Severe vitamin D deficiency was also independently associated with the development of MCI when analyzing 145 subjects whose baseline MMSE scores were <27.

CONCLUSION

Severe vitamin D deficiency was independently associated with the future risk of MCI as well as dementia, especially in older adults whose baseline MMSE scores had decreased only modestly.

Direct characterization of photoinduced lattice dynamics in BaFe2As2

Ultrafast light pulses can modify electronic properties of quantum materials by perturbing the underlying, intertwined degrees of freedom. In particular, iron-based superconductors exhibit a strong coupling among electronic nematic fluctuations, spins and the lattice, serving as a playground for ultrafast manipulation. Here we use time-resolved X-ray scattering to measure the lattice dynamics of photoexcited BaFe₂As₂. On optical excitation, no signature of an ultrafast change of the crystal symmetry is observed, but the lattice oscillates rapidly in time due to the coherent excitation of an A_1g mode that modulates the Fe–As–Fe bond angle. We directly quantify the coherent lattice dynamics and show that even a small photoinduced lattice distortion can induce notable changes in the electronic and magnetic properties. Our analysis implies that transient structural modification can be an effective tool for manipulating the electronic properties of multi-orbital systems, where electronic instabilities are sensitive to the orbital character of bands.

In BaFe₂As₂, the lattice couples strongly to the magnetic and electronic degrees of freedom, providing a way to control them. Here, by means of time-resolved X-ray scattering, the authors measure rapid lattice oscillations, which can induce changes in the material's electronic and magnetic properties.

Responses of osteoblastic cell line MC3T3-E1 cell to the calcium channel blocker diltiazem and verapamil

The effects of the calcium channel blockers, diltiazem and verapamil, on osteoblastic functions were investigated in cultured osteoblastic cells MC3T3-E1. DNA synthesis was evaluated by the incorporation of [3H]thymidine, and collagen synthesis by measuring the incorporation of [3H]proline into collagenase-digestible protein (CDP) and noncollagen protein (NCP). Diltiazem inhibited the DNA synthesis of osteoblastic cells by up to 57.6 and 54.6% at concentrations of 25 and 50 microM. Verapamil also significantly inhibited DNA synthesis by up to 61.6 and 40.9% at concentrations of 25 and 50 microM. The percent control of CDP formation were decreased by up to 76.7% in 5 microM and 44.3% in 50 microM of diltiazem. Verapamil also decreased CDP synthesis to 49.7% at 10 microM and 32.6% at 50 microM. NCP synthesis was decreased by the calcium channel blocker but inhibition of the CDP formation was greater than that of NCP. The calculated percent collagen synthesis was decreased at a calcium channel blocker concentration of 10 microM. The inhibitory effects of diltiazem and verapamil on percent collagen synthesis were not reversed by increasing the calcium concentration of culture media by either 1 or 5 mM. From this study, we conclude that calcium channel blockers have a direct inhibitory effect on osteoblastic function. Long-term administration of diltiazem or verapamil produces adverse effects on normal bone metabolism.

Quasi 3D ECE imaging system for study of MHD instabilities in KSTAR

A second electron cyclotron emission imaging (ECEI) system has been installed on the KSTAR tokamak, toroidally separated by 1/16th of the torus from the first ECEI system. For the first time, the dynamical evolutions of MHD instabilities from the plasma core to the edge have been visualized in quasi-3D for a wide range of the KSTAR operation (B0 = 1.7∼3.5 T). This flexible diagnostic capability has been realized by substantial improvements in large-aperture quasi-optical microwave components including the development of broad-band polarization rotators for imaging of the fundamental ordinary ECE as well as the usual 2nd harmonic extraordinary ECE.

The influence of surgical factors on dislocation of the meniscal bearing after Oxford medial unicompartmental knee replacement: a case-control study

The aim of this study was to evaluate the risk factors for dislocation of the bearing after a mobile-bearing Oxford medial unicompartmental knee replacement (UKR) and to test the hypothesis that surgical factors, as measured from post-operative radiographs, are associated with its dislocation From a total of 480 UKRs performed between 2001 and 2012, in 391 patients with a mean age of 66.5 years (45 to 82) (316 female, 75 male), we identified 17 UKRs where bearing dislocation occurred. The post-operative radiological measurements of the 17 UKRs and 51 matched controls were analysed using conditional logistic regression analysis. The post-operative radiological measurements included post-operative change in limb alignment, the position of the femoral and tibial components, the resection depth of the proximal tibia, and the femoral component-posterior condyle classification. We concluded that a post-operative decrease in the posterior tibial slope relative to the pre-operative value was the only significant determinant of dislocation of the bearing after medial Oxford UKR (odds ratio 1.881; 95% confidence interval 1.272 to 2.779). A post-operative posterior tibial slope < 8.45° and a difference between the pre-operative and post-operative posterior tibial slope of > 2.19° may increase the risk of dislocation.

Protein Profile in Corpus Luteum during Pregnancy in Korean Native Cows

Steroidogenesis requires coordination of the anabolic and catabolic pathways of lipid metabolism, but the profile of proteins associated with progesterone synthesis in cyclic and pregnant corpus luteum (CL) is not well-known in cattle. In Experiment 1, plasma progesterone level was monitored in cyclic cows (n = 5) and pregnant cows (n = 6; until d-90). A significant decline in the plasma progesterone level occurred at d-19 of cyclic cows. Progesterone level in abbatoir-derived luteal tissues was also determined at d 1 to 5, 6 to 13 and 14 to 20 of cyclic cows, and d-60 and -90 of pregnant cows (n = 5 each). Progesterone level in d-60 CL was not different from those in d 6 to 13 CL and d-90 CL, although the difference between d 6 to 13 and d-90 was significant. In Experiment 2, protein expression pattern in CL at d-90 (n = 4) was compared with that in CL of cyclic cows at d 6 to 13 (n = 5). Significant changes in the level of protein expression were detected in 32 protein spots by two-dimensional polyacrylamide gel electrophoresis (2-DE), and 23 of them were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Six proteins were found only in pregnant CL, while the other 17 proteins were found only in cyclic CL. Among the above 6 proteins, vimentin which is involved in the regulation of post-implantation development was included. Thus, the protein expression pattern in CL was disorientated from cyclic luteal phase to mid pregnancy, and alterations in specific CL protein expression may contribute to the maintenance of pregnancy in Korean native cows.

Improvement in survival associated with embolisation of spontaneous portosystemic shunt in patients with recurrent hepatic encephalopathy

BACKGROUND

Spontaneous portosystemic shunt (SPSS) is a frequent cause of recurrent hepatic encephalopathy (HE) in patients with cirrhosis.

AIM

To assess the effectiveness and optimal candidate selection for embolisation of SPSS, for the treatment of recurrent HE in patients with cirrhosis.

METHODS

This retrospective cohort study compared 17 patients with recurrent HE who achieved complete occlusion of SPSS by angiographic embolisation and 17 control patients.

RESULTS

Most baseline characteristics were similar in the two groups. The 2-year HE recurrence rate was significantly lower in the embolisation than in the control group (39.9% vs. 79.9%, P = 0.02), whereas their 2-year overall survival rates were similar (64.7% vs. 53.4%, P = 0.98). Model for end-stage liver disease (MELD) and Child-Turcotte-Pugh (CTP) score were significant predictors of 2-year patient mortality in the embolisation group. Analysis of patients with MELD <15 in the absence of hepatocellular carcinoma (HCC) showed that 2-year overall survival rate was significantly higher in the embolisation group than in the control group (100% vs. 60%, P = 0.03). The median changes in MELD (-1.6 vs. 2.5, P < 0.01), CTP score (-3 vs. 0, P < 0.01), and liver volume (61 mL vs. -117 mL; P = 0.046) at 1 year significantly favoured the embolisation group. Serious clinical complications after embolisation occurred only in patients who had MELD ≥15 and/or HCC at baseline, with all six dying within 1 year.

CONCLUSIONS

Embolisation of a large spontaneous portosystemic shunt may be associated with improved survival and liver function, as well as prevention of hepatic encephalopathy in cirrhotic patients with recurrent hepatic encephalopathy and modestly preserved liver function.

Band offsets in YSZ/InGaZnO4 heterostructure system

The energy discontinuity in the valence band (deltaE(v)) of Y2O3-stabilized ZrO2 (YSZ)/InGaZnO4 (IGZO) heterostructures was obtained from X-ray photoelectron spectroscopy (XPS) measurements. The YSZ exhibited a bandgap of 4.4 eV from absorption measurements. A value of deltaE(v) = 0.57 +/- 0.12 eV was obtained by using Ga 2P3/2, Zn 2p3/2 and In 3d5/2 energy levels as references. This implies a conduction band offset (deltaE(c)) of 0.63 eV in YSZ/InGaZnO4 heterostructures and a nested interface band alignment.

Planar Hall magnetoresistive aptasensor for thrombin detection

The use of aptamer-based assays is an emerging and attractive approach in disease research and clinical diagnostics. A sensitive aptamer-based sandwich-type sensor is presented to detect human thrombin using a planar Hall magnetoresistive (PHR) sensor in cooperation with superparamagnetic labels. A PHR sensor has the great advantages of a high signal-to-noise ratio, a small offset voltage and linear response in the low-field region, allowing it to act as a high-resolution biosensor. In the system presented here, the sensor has an active area of 50 µm × 50 µm with a 10-nm gold layer deposited onto the sensor surface prior to the binding of thiolated DNA primary aptamer. A polydimethylsiloxane well of 600-µm radius and 1-mm height was prepared around the sensor surface to maintain the same specific area and volume for each sensor. The sensor response was traced in real time upon the addition of streptavidin-functionalized magnetic labels on the sensor. A linear response to the thrombin concentration in the range of 86 pM-8.6 µM and a lower detection limit down to 86 pM was achieved by the proposed present method with a sample volume consumption of 2 µl. The proposed aptasensor has a strong potential for application in clinical diagnosis.

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.

Impact of liver fibrosis on prognosis following liver resection for hepatitis B-associated hepatocellular carcinoma

BACKGROUND

This study aims to evaluate the impact of liver fibrosis severity on prognosis following liver resection among HBV-HCC patients.

METHODS

Data were extracted from a prospective database of 189 HBV-HCC patients treated at Mount Sinai between 1995 and 2008. Fibrosis staging of each surgical resection specimen using the modified Ishak method was performed by a single liver pathologist.

RESULTS

A wide range of Ishak fibrosis stage was observed among this patient population, with 29% having established cirrhosis (Ishak stage 6). Ishak stage 6 was independently associated with poor overall and recurrence-free survival. In patients with Ishak stage 1-5, Ishak stage did not affect survival; rather, tumour size was associated with poor overall survival, and tumour size, histologic activity index and serum AFP>20 ng ml(-1) were associated with poor recurrence-free survival. In patients with Ishak stage 6, poorly differentiated histology and tumour size were associated with poor overall survival, and tumour size was associated with poor recurrence-free survival.

CONCLUSION

HBV-HCC develops with varying degrees of underlying liver fibrosis; however, progressive liver fibrosis does not affect the outcomes following resection until cirrhosis is reached. Established cirrhosis, as defined histologically by Ishak stage 6, is an independent predictor of poor overall and recurrence-free survival among these patients.

Anti-bacterial and anti-toxic immunity induced by a killed whole-cell-cholera toxin B subunit cholera vaccine is essential for protection against lethal bacterial infection in mouse pulmonary cholera model

The lack of appropriate animal model for studying protective immunity has limited vaccine development against cholera. Here, we demonstrate a pulmonary cholera model conferred by intranasal administration of mice with live Vibrio cholerae. The bacterial components, but not cholera toxin, caused lethal and acute pneumonia by inducing massive inflammation. Intranasal immunization with Dukoral, comprising killed whole bacteria and recombinant cholera toxin B subunit (rCTB), developed both mucosal and systemic antibody responses with protection against the lethal challenge. Either rCTB-free Dukoral or rCTB alone partially protected the mice against the challenge. However, reconstitution of rCTB-free Dukoral with rCTB restored full protection. Parenteral immunization with Dukoral evoked strong systemic immunity without induction of mucosal immunity or protection from the challenge. These results suggest that both anti-bacterial and anti-toxic immunity are required for protection against V. cholerae-induced pneumonia, and this animal model is useful for pre-clinical evaluation of candidate cholera vaccines.

Temperature evolution of itinerant ferromagnetism in SrRuO3 probed by optical spectroscopy

The temperature (T) dependence of the optical conductivity spectra σ(ω) of a single crystal SrRuO(3) thin film is studied over a T range from 5 to 450 K. We observed significant T dependence of the spectral weights of the charge transfer and interband d-d transitions across the ferromagnetic Curie temperature (T(c) ∼ 150 K). Such T dependence was attributed to the increase in the Ru spin moment, which is consistent with the results of density functional theory calculations. T scans of σ(Ω,T) at fixed frequencies Ω reveal a clear T(2) dependence below T(c), demonstrating that the Stoner mechanism is involved in the evolution of the electronic structure. In addition, σ(Ω,T) continues to evolve at temperatures above T(c), indicating that the local spin moment persists in the paramagnetic state. This suggests that SrRuO(3) is an intriguing oxide system with itinerant ferromagnetism.

Electric-field-induced polar order and localization of the confined electrons in LaAlO3/SrTiO3 heterostructures

With ellipsometry, x-ray diffraction, and resistance measurements we investigated the electric-field effect on the confined electrons at the LaAlO3/SrTiO3 interface. We obtained evidence that the localization of the electrons at negative gate voltage is induced, or at least enhanced, by a polar phase transition in SrTiO3 which strongly reduces the lattice polarizability and the subsequent screening. In particular, we show that the charge localization and the polar order of SrTiO3 both develop below ∼50  K and exhibit similar, unipolar hysteresis loops as a function of the gate voltage.

Enhancement patterns of hepatocellular carcinomas on multiphasicmultidetector row CT: comparison with pathological differentiation

OBJECTIVE

The objective of this study was to determine the incidence of typical and atypical enhancement patterns of hepatocellular carcinomas (HCCs) on multiphasic multidetector row CT (MDCT) and to correlate the enhancement patterns and morphological image findings of HCC with the degree of tumour differentiation.

METHODS

MDCT images of 217 patients with 243 surgically proven HCCs were evaluated through consensus reading by two radiologists. Our MDCT protocol was composed of precontrast, arterial, portal and delayed phases. The reviewers analysed the CT images for degree of attenuation; relative timing of washout; presence of dysmorphic intratumoral vessels, aneurysms and necrosis; tumour size; tumour margin; presence of pseudocapsule; intratumoral heterogeneity; and determined enhancement pattern. The imaging features were correlated with tumour differentiation using Fisher's exact test or the χ(2) test.

RESULTS

Among 243 HCCs, 137 (56.4%) showed the typical enhancement pattern of HCC, which is arterial enhancement and washout on portal or equilibrium phase images. In the arterial phase, 190 of 243 (78.2%) HCCs showed hypervascularity, with approximately three quarters of poorly differentiated (PD) (34 of 45, 75.6%) and moderately differentiated (MD) HCCs (92 of 123, 74.8%) showing washout during the portal or delayed phases, vs only 50% of well-differentiated (WD) HCCs (11 of 22; p<0.048). The presence of intratumoral vessels and aneurysms, tumour necrosis, attenuation of precontrast, the relative timing of washout, intratumoral attenuation heterogeneity, tumour margin and tumour size were correlated with the pathological differentiation of HCCs (p<0.05).

CONCLUSION

A typical enhancement of HCCs on MDCT was not unusual (43.6%) and WD and PD HCCs account for most of the atypical enhancement patterns. Early washout favoured MD and PD HCCs rather than WD HCCs, whereas in our study the presence of intratumoral aneurysm was a highly specific finding for PD HCC.

Evaluation of sulfur and multi-walled carbon nanotube composite synthesized by dissolution and precipitation for Li/S batteries

An elemental sulfur and multi-walled carbon nanotube (S-MWNT) composite was synthesized by dissolving sulfur in ammonium sulfides and then precipitating on MWNT. Morphology observation by scanning electron microscopy (SEM) confirmed that S-MWNT product was successfully prepared by incorporating sulfur into MWNT network. Without additional conducting material, the S-MWNT composite cathodes were prepared for electrochemical tests. The properties measured in discharge-charge cycling test showed that the composite had the initial discharge capacity of 1024 mAh g(-1), which is about 61% sulfur utilization. However, in the subsequent cycling, the capacities faded. To determine the reason of rapid capacity drop, S-MWNT composite cathodes were compared in the cycling tests with varying three kinds of electrolytes and the cathode was subjected to physical force by rolling. The changes in the cycle performances proved that the deterioration of S-MWNT composite cathodes was not related to the electrolytes but to physical bonding that may not maintain the conducting path between sulfur and MWNT.

Estimating divergence dates and substitution rates in the Drosophila phylogeny

An absolute timescale for evolution is essential if we are to associate evolutionary phenomena, such as adaptation or speciation, with potential causes, such as geological activity or climatic change. Timescales in most phylogenetic studies use geologically dated fossils or phylogeographic events as calibration points, but more recently, it has also become possible to use experimentally derived estimates of the mutation rate as a proxy for substitution rates. The large radiation of drosophilid taxa endemic to the Hawaiian islands has provided multiple calibration points for the Drosophila phylogeny, thanks to the "conveyor belt" process by which this archipelago forms and is colonized by species. However, published date estimates for key nodes in the Drosophila phylogeny vary widely, and many are based on simplistic models of colonization and coalescence or on estimates of island age that are not current. In this study, we use new sequence data from seven species of Hawaiian Drosophila to examine a range of explicit coalescent models and estimate substitution rates. We use these rates, along with a published experimentally determined mutation rate, to date key events in drosophilid evolution. Surprisingly, our estimate for the date for the most recent common ancestor of the genus Drosophila based on mutation rate (25–40 Ma) is closer to being compatible with independent fossil-derived dates (20–50 Ma) than are most of the Hawaiian-calibration models and also has smaller uncertainty. We find that Hawaiian-calibrated dates are extremely sensitive to model choice and give rise to point estimates that range between 26 and 192 Ma, depending on the details of the model. Potential problems with the Hawaiian calibration may arise from systematic variation in the molecular clock due to the long generation time of Hawaiian Drosophila compared with other Drosophila and/or uncertainty in linking island formation dates with colonization dates. As either source of error will bias estimates of divergence time, we suggest mutation rate estimates be used until better models are available.

Radiofrequency ablation combined with transcatheter arterial embolisation in rabbit liver: investigation of the ablation zone according to the time interval between the two therapies

OBJECTIVES

This study was designed to evaluate the extent of the radiofrequency ablation zone in relation to the time interval between transcatheter arterial embolisation (TAE) and radiofrequency ablation (RFA) and, ultimately, to determine the optimal strategy of combining these two therapies for hepatocellular carcinoma.

METHODS

15 rabbits were evenly divided into three groups: Group A was treated with RFA alone; Group B was treated with TAE immediately followed by RFA; and Group C was treated with TAE followed by RFA 5 days later. All animals underwent perfusion CT (PCT) scans immediately after RFA. Serum liver transaminases were measured to evaluate acute liver damage. Animals were euthanised for pathological analysis of ablated tissues 10 days after RFA. Non-parametric analyses were conducted to compare PCT indices, the RFA zone and liver transaminase levels among the three experimental groups.

RESULTS

Group B showed a significantly larger ablation zone than the other two groups. Arterial liver perfusion and hepatic perfusion index represented well the perfusion decrease after TAE on PCT. Although Group B showed the most elevated liver transaminase levels at 1 day post RFA, the enzymes decreased to levels that were not different from the other groups at 10 days post-RFA.

CONCLUSIONS

When combined TAE and RFA therapy is considered, TAE should be followed by RFA as quickly as possible, as it can be performed safely without serious hepatic deterioration, despite the short interval between the two procedures.

Small hypervascular hepatocellular carcinomas: value of diffusion-weighted imaging compared with "washout" appearance on dynamic MRI

OBJECTIVE

To compare the value of diffusion-weighted MRI (DWI) with the venous "washout" appearance during dynamic MRI for the assessment of small arterial hypervascular lesions in cirrhotic liver.

METHODS

After exclusion of benign hypervascular lesions, including haemangiomas and subcapsular non-tumorous arterioportal shunts, indicated by typical imaging features, a total of 109 small arterial hypervascular lesions (0.5-3.0 cm in the longest diameter) in 65 patients with cirrhosis who underwent gadopentetate dimeglumine-enhanced dynamic MRI and DWI (b=50, 400, 800 s mm(-2)) at 1.5 T during a 16-month period were retrospectively analysed to determine the presence of venous washout during dynamic imaging or sustained hyperintensity upon increasing the b factor size on DWI.

RESULTS

Among the 99 hypervascular hepatocellular carcinomas (HCCs), sustained hyperintensity on DWI (92/99, 93%) was more prevalent than the washout appearance (72/99, 72%) on dynamic MRI (p<0.001). Depending on the lesion size, subcentimetre-sized HCCs had a significantly lower prevalence of venous washout (13/30, 43%) than the sustained hyperintensity on DWI (27/30, 90%) (p=0.001). In all 10 hypervascular benign conditions, there was no venous washout on dynamic MRI and no sustained hyperintensity on DWI. Sensitivity and specificity for diagnosis of hypervascular HCCs were 92.9% and 100% in DWI and 72% and 100% in dynamic MRI, respectively.

CONCLUSION

Compared with the venous washout during dynamic imaging, DWI provides more reliable information in the MRI assessment of small hypervascular HCCs, distinguishing them from atypical hypervascular benign or pseudolesions. DWI could complement the early diagnosis of small hypervascular HCCs that do not display venous washout during dynamic imaging.

New limits on interactions between weakly interacting massive particles and nucleons obtained with CsI(Tl) crystal detectors

New limits are presented on the cross section for weakly interacting massive particle (WIMP) nucleon scattering in the KIMS CsI(Tℓ) detector array at the Yangyang Underground Laboratory. The exposure used for these results is 24 524.3  kg·days. Nuclei recoiling from WIMP interactions are identified by a pulse shape discrimination method. A low energy background due to alpha emitters on the crystal surfaces is identified and taken into account in the analysis. The detected numbers of nuclear recoils are consistent with zero and 90% confidence level upper limits on the WIMP interaction rates are set for electron equivalent energies from 3 to 11 keV. The 90% upper limit of the nuclear recoil event rate for 3.6-5.8 keV corresponding to 2-4 keV in NaI(Tℓ) is 0.0098 counts/kg/keV/day, which is below the annual modulation amplitude reported by DAMA. This is incompatible with interpretations that enhance the modulation amplitude such as inelastic dark matter models. We establish the most stringent cross section limits on spin-dependent WIMP-proton elastic scattering for the WIMP masses greater than 20  GeV/c2.