bluuebunny/crossref_metadata_2025 huggingface dataset:
Computertomografie des Auges
Authors: Rauch Maximilian , Greschus Susanne
Published: June 2019

CT-Befunde an den Augen sind häufig Nebenbefunde bei Hals- oder Schädeluntersuchungen. Eine gezielte CT der Augen ist z. B. bei einer vermuteten Bulbusperforation oder zur Suche intraokulärer Fremdkörper indiziert. Der vorliegende Artikel behandelt Veränderungen des Bulbus oculi, die in der CT festgestellt werden können und geht auch auf den Strahlenschutz ein, der bei jeder CT in besonderer Weise zu berücksichtigen ist.
Alternative Mobilization by Means of a Novel Orthesis in Patients after Amputation
Authors: Barth Udo , Wasseroth Klaus , Halloul Zuhir , Meyer Frank
Published: June 2019

Introduction The mobilization of patients with diabetic foot syndrome after surgical treatment by debridement or partial amputation is usually difficult in daily practice and in inpatient care.

Aim and Method A case report – with a representative case showing the innovative possibilities of an alternative mobilization option by means of a new orthesis (“iWALK 2.0®”; IWALKFree® Inc., Mansfield, Ontario, Canada) after surgical therapy of diabetic gangrene, exemplified by the successful clinical course.

Results The inpatient admission of a 59-year-old male patient revealed septic gangrene of the right foot in insulin-dependent diabetes mellitus. After admission and initial diagnosis, the calculated antibiotics therapy and initial surgical rehabilitation of the right foot took place. After stabilization and control of the infection, the minor amputation was performed at the Bona-Jäger line without primary wound closure, wound care was provided by vacuum sealing. Complicated by pre-existing peroneal paralysis of the contralateral leg following herniated disc, mobilization could be accomplished out of the wheelchair using a novel “free-hand” orthesis “iWALK 2.0” and a walker with physiotherapeutic support. Thus, while simultaneously relieving the operated foot, self-sufficient mobilization at a later time was possible. This gave the patient a positive attitude to life in addition to more independence.

Conclusion The successful application of the “free-hand” site “iWALK 2.0” under the listed clinical constellation thus suggests that it is a clear alternative of “postoperative rehabilitation” in the diagnosis of a surgically treated diabetic foot gangrene after minor amputation with a consolidated wound while ultimately serving to achieve a more comprehensive level of experience for targeted use with a clearly defined indication.
Akzeptanz verbindlicher Vorsorgeuntersuchungen – Ergebnisse einer Elternbefragung in Hessen
Authors: Santos Jaquelin , Klein Ulrich , Herb Stefan , Kieslich Matthias
Published: June 2019

Ziel der Studie 2008 trat in Hessen das Hessische Kindergesundheitsschutz-Gesetz in Kraft. Seither ist die Wahrnehmung der Früherkennungsuntersuchungen U1 bis U9 verpflichtend. Die Umsetzung des Gesetzes obliegt dem Hessischen Kindervorsorgezentrum (HKVZ), welches Eltern und Erziehungsberechtigte zu den anstehenden Untersuchungen (U4 bis einschließlich U9) einlädt. Um eine Rückmeldung bezüglich dessen Arbeit und Informationen über die Akzeptanz des Gesetzes zu erhalten, wurde erstmals im Rahmen des Qualitätsmanagements eine Befragung der Eltern und Erziehungsberechtigten durch das HKVZ durchgeführt. Hierbei wurden folgende Fragestellungen geklärt: Wie ist die Akzeptanz der gesetzlich verpflichtenden Vorsorgeuntersuchungen bei hessischen Eltern? Wie steht es um den Bekanntheitsgrad und die Limitierung des Gesetzes?

Methodik Zusätzlich zur Einladung für die U7a haben alle Eltern und Erziehungsberechtigten im Rahmen der Befragung einen Fragebogen erhalten, den sie ausgefüllt und portofrei an das HKVZ zurücksenden sollten. Es handelte sich um eine schriftliche und anonyme Befragung. Die Auswertung erfolgte im HKVZ.

Ergebnisse Besonders hervorzuheben sind 3 resultierende Ergebnisse: Die Frage, ob im Rahmen der Vorsorgeuntersuchung gesundheitliche Probleme beim Kind festgestellt wurden, beantworteten 8,94% der Eltern und Erziehungsberechtigten mit „Ja“. Daraus ließe sich schließen, dass bei nahezu jedem neunten im Rahmen einer Vorsorge untersuchten Kind gesundheitliche Problematiken festgestellt wurden. Angegebene Gründe für eine verpasste Vorsorgeuntersuchung waren vergleichsweise trivial. 96,53% der Befragten hatten bisher keine Vorsorgeuntersuchung verpasst, nur 2,88% beantworteten diese Frage mit „Ja“ und 0,59% haben hier keine Angaben gemacht. Als häufigster Grund für eine verpasste Untersuchung wurde mit 1,59% angegeben, dass diese einfach „vergessen“ wurde. Mit 1,12% wurden in der Kategorie „sonstiges“ eine Erkrankung des Kindes, sowie Auslandsaufenthalte als häufigste Gründe für eine verpasste Vorsorgeuntersuchung genannt. Bei 0,35% war der Grund Schwierigkeiten bei der Terminvereinbarung mit dem Arzt. Der Bekanntheitsgrad des Hessischen Kindergesundheitsschutz-Gesetzes lag bei 94,12% der Befragten. Die positiven Bewertungen der durch das HKVZ versendeten Briefe (84,06% gut bis sehr gut) spiegelt die Akzeptanz des Gesetzes wieder. Im Hinblick auf weitere Zahlen bezüglich der Effektivität der klinischen Kindervorsorgeuntersuchungen, zeigt die Limitierung der Studie, dass es wichtig wäre, in diesem Kontext weitere klinische Versorgungsforschungsstudien durchzuführen.
Isolierte Ziegen- und Schafsmilchallergie
Authors: Tomsitz D. , Reidenbach K. , Kugler C. , Biedermann T. , Darsow U.
Published: June 2019

Ein 23-jähriger Patient erlitt mehrere anaphylaktische Reaktionen nach dem Verzehr von Schafsmilch- und Ziegenmilchkäse bei gleichzeitiger Toleranz von Kuhmilchprodukten. Die Pricktestung und die serologische Diagnostik zeigten eine Sensibilisierung gegen Ziegen- und Schafsmilch. Eine orale Provokation mit Kuhmilch sowie Rohmilch wurde vertragen. Wir diagnostizierten eine isolierte Ziegenmilch- und Schafsmilchallergie und empfahlen eine konsequente Meidung von Ziegenmilch- und Schafsmilchprodukten.
LC-MS- and NMR-Guided Isolation of Monoterpene Dimers from Cultivated Thymus vulgaris Varico 3 Hybrid and Their Antityrosinase Activity
Authors: Stefanis Ilias , Hadjipavlou-Litina Dimitra , Bilia Anna-Rita , Karioti Anastasia
Published: June 2019

Targeted isolation based on a combination of NMR and HPLC-PDA-MS of a dichloromethane extract of Thymus vulgaris Varico 3 aerial parts afforded one new p-cymene dimer, 6,3′,4′-trihydroxy-5,5′-diisopropyl-2,2′-dimethylbiphenyl (1), together with two known p-cymene derivatives (2 and 3), as well as five known compounds, namely, thymol (4), oleanolic acid (5), ursolic acid (6), cirsimaritin (7), and xanthomicrol (8). The structural elucidation of all compounds was performed by spectroscopic analyses, including 1D and 2D NMR, and HRESIMS experiments. The biphenyls were assayed for their inhibitory activity on tyrosinase. Compounds 2 and 3 showed negligible activity on tyrosinase, while compound 1 effectively inhibited the enzyme with 35% (± 0.3) inhibitory activity, higher than the inhibition of the reference compound kojic acid (18.6 ± 0.02).
The European Society of Skeletal Radiology Quiz 2018
Authors: Ladas Andreas , Campbell Robert , O'Connor Philip J.
Published: June 2019

This article consists of a series of clinical cases presented during the ESSR Quiz session at the 25th Annual Meeting of the European Society of Musculoskeletal Radiology in Amsterdam 2018. The first section contains the clinical information and an initial set of images for each case. The second section reveals the answers along with additional imaging followed by a short discussion about the pathologic processes presented. This article provides self-assessment and at the same time refreshes the reader's knowledge about some common and not-so-common clinical conditions that a radiologist may encounter during clinical practice.
Correlations between P53 Mutation Status and Texture Features of CT Images for Hepatocellular Carcinoma
Authors: Wu Hongzhen , Chen Xin , Chen Jiawei , Luo Yuqi , Jiang Xinqing , Wei Xinhua , Tang Wenjie , Liu Yu , Liang Yingying , Liu Weifeng , Guo Yuan
Published: June 2019

Objectives To investigate the performance of texture analysis in characterizing P53 mutations of hepatocellular carcinomas (HCCs) based on computed tomography (CT).

Methods A total of 63 HCC patients underwent CT scans and were tested for P53 mutations. Patients were divided into two groups of P53(−) and P53(+) according to the P53 scores. First- and second-order texture features were computed from the CT images and compared between groups using independent Student's t-test. A Spearman's correlation coefficient was used for correlations to assess the relationship between the different P53 sores and CT data. The performance of texture features in differentiating the P53 mutations of HCC was assessed using receiver operating characteristic analysis.

Results The mean values of angular second moment (ASM; mean = 0.001) and contrast (mean = 194.727) for P53(−) were higher than those of P53(+). Meanwhile the mean values of correlation (mean = 0.735), sum variance (mean = 1,111.052), inverse difference moment (IDM; mean = 0.090), and entropy (mean = 3.016) for P53(−) were lower than those of P53(+). Significant correlations were found between P53 scores and ASM (r =  − 0.439), contrast (r =  − 0.263), correlation (r = 0.551), sum of squares (r = 0.282), sum variance (r = 0.417), IDM (r = 0.308), and entropy (r = 0.569). Five texture parameters (ASM, contrast, correlation, IDM, and entropy) were predictive of P53 mutation status, with areas under the curve ranging from 0.621 to 0.792.

Conclusions There was a direct relationship between P53 mutations and gray-level co-occurrence matrix, but not with histograms for HCC patients. Correlation and entropy seemed to be the most promising in differentiating P53 (−) from P53(+).
Two-Hourly versus Three-Hourly Feeding in Very Low-Birth-Weight Infants: A Systematic Review and Meta-Analysis
Authors: Razak Abdul
Published: June 2019

Objective This study aimed to systematically review and meta-analyze the benefits and side effects of 3-hourly versus 2-hourly feeding intervals in very low-birth-weight (VLBW) infants.

Study Design Database search include PubMed and Cochrane CENTRAL databases from inception until March 3, 2019. The author extracted the data from included studies and used Cochrane-GRADE approach to assess the quality of the evidence.

Results Seven studies—four randomized controlled trials (RCTs) and three observational studies—involving 952 infants were included in the review. The pooled analyses of RCTs showed no significant differences in the outcomes: time to reach full enteral feeding, necrotizing enterocolitis, feed intolerance, and hypoglycemia. Infants fed 3-hourly regain birth weight earlier than infants fed 2-hourly (3 RCTs; 350 participants; mean difference [95% confidence interval] −1.12 [−2.16 to −0.08]; I2 = 0%; p = 0.04). The evidence was downgraded to low quality due to risk of bias and imprecision for all outcomes. Two studies found a subgroup of infants, younger and smaller, reach full enteral feeds earlier when fed 2-hourly compared with 3-hourly.

Conclusion Low-quality evidence suggests feeding 3-hourly is comparable to 2-hourly feeding in VLBW infants. However, extremely low-birth-weight infants reach full enteral feeds earlier when fed 2-hourly compared with 3-hourly. Further, sufficient powered trials are needed.
Cerebral Venous Thrombosis: Reviewing Pathophysiology, Diagnosis, and Treatment Strategies
Authors: O'Keefe Yasmin A. , Kranz Peter G. , Dombrowski Keith E. , Kolls Brad J. , James Michael L.
Published: June 2019

This review discusses cerebral venous thrombosis (CVT), including diagnosis and treatment strategies, a rare class of stroke that, if unrecognized or untreated, can have devastating effects. Thrombosis of one or many cerebral veins leads to propagation of thrombosis and impaired cerebral venous drainage. Diagnosis is made using a combination of history and imaging, particularly computed tomography (CT) venogram, which demonstrates thrombosis. Currently, acute treatment consists of heparin infusion with transition to long-term oral anticoagulation. Further research, especially on prevention, endovascular therapy, and the role of newer anticoagulants (direct oral anticoagulants [DOACs]) is necessary and ongoing.
Type 2 Valvular Heart Disease Affects Decision Making for Anticoagulation in Patients with Atrial Fibrillation: The UMBRIA-Fibrillazione Atriale Prospective Study
Authors: Vedovati Maria Cristina , Reboldi Gianpaolo , Agnelli Giancarlo , Verdecchia Paolo ,   on Behalf of the Umbria-Fibrillazione Atriale Investigators
Published: June 2019

Background Valvular heart disease (VHD) and atrial fibrillation (AF) often coexist.

Aim We investigated whether type 2 VHD (other than moderate-severe rheumatic mitral stenosis or mechanical heart valve) influences the prescription of anticoagulants in AF.

Methods Umbria-Fibrillazione Atriale is a prospective multicenter registry in patients with AF. For the purpose of this study, type 2 VHD patients were propensity matched with non-VHD counterparts in a 1:1 ratio. Patients with type 1 VHD (moderate-severe mitral stenosis or mechanical heart valve) were excluded.

Results We identified 2,212 patients with AF and excluded 46 because data on VHD were unavailable. Type 2 VHD was present in 426 patients (19.7%). Before registry entry visit, 77.1% of type 2 VHD and 66.8% of non-VHD patients were on anticoagulants. At discharge, 90.8 and 85.2% of patients, respectively, were on anticoagulants. After propensity-score matching, 386 patient-pairs were created. In the matched sample, the likelihood of being on anticoagulants before (odds ratio [OR]: 1.43, 95% confidence interval [CI]: 1.02–2.01, p = 0.036) and after (1.63, 95% CI: 1.04–2.57, p = 0.034) the entry visit was higher in type 2 VHD than in non-VHD patients. Patients with type 2 VHD were 70% more likely to receive vitamin K antagonists (VKAs) (OR: 1.70, 95% CI: 1.28–2.27, p < 0.001), and 32% less likely to receive non–vitamin K oral anticoagulants (NOACs; OR: 0.68, 95% CI: 049–0.94, p = 0.011) than non-VHD patients.

Conclusion VKAs consistently outperformed NOACs as preferred treatment option in patients with type 2 VHD. This could potentially deny to these patients the well-established benefits of NOACs observed in phase III trials.
Multifractal features of spatial variation in construction land in Beijing (1985–2015)
Authors: SONG Zhijun , YU Linjun
Published: June 2019

Over the last 30 years, Beijing has experienced rapid development. The city’s spatial pattern and changes are extremely complicated. Therefore, to reveal the spatial patterns at different scales and levels, the construction land in Beijing within the 6th ring road in 1985, 1999, 2008, and 2015, was analyzed using global and local multifractal analyses. The global analysis shows that, over the past 30 years, the development of new construction land in this region experienced a process that transformed it from being a hierarchical spatial structure with a low-evolution intensity (1985) to being a spatial structure with a higher evolution intensity and multi-scale differential development (1999, 2008) with a hierarchical spatial system (one main urban area with a number of satellite towns) (2015). Local analysis further shows that the spatial pattern of the construction land in this region tended to be simplified over the past 30 years. The construction land in this region displays specific evolutionary characteristics with the increase in breadth (q) and intensity (Dq) and a multifractal dimension spectrum (f(a) – a(q)) and dominant spectrum at various spatial scales over a four-year period. In general, the influence of high-density areas on the spatial pattern of the construction land is decreasing, while the influence of low-density areas is increasing. Based on this, this paper also summarizes the theoretical value of multifractal analysis in economic geography research, highlighting its advantages, limitations, and application range, and presents the technical analysis process and other suggestions for future research.
Influence of size parameters and magnetic field intensity upon the amplification characteristics of magnetic flux concentrators
Authors: Zhang Xiaoming , Bi Yu , Chen Guobin , Liu Jun , Li Jie , Feng Kaiqiang , Lv Chen , Wang Wanjun
Published: June 2019

The design principle of the magnetic flux concentrators (MFCs) is studied by finite element method (FEM) and experiment. Firstly, the establishment process of the FEM model in Comsol Multiphysics is elaborated. Based on the simulation model, the magnetic amplification distributions of different shaped MFCs is compared, and the shape design principle of the MFC is obtained. Then, the influence of size parameters on the magnetic amplification of T, triangle, and trapezoid shaped MFCs is analyzed, and the size design principle of the MFCs is obtained. Additionally, the linear working range of the three MFCs is compared. To verify the simulation results, the MFCs are prepared using 1j79 permalloy. The experimental platform is established to acquire the magnetic gain under different magnetic fields. Based on the results, the linear working range of the MFCs is analyzed. And the influence of size parameters on the magnetic gain is tested. The experimental results are compared with the simulation ones to verify the validity of the model.
Power enhancement for millimeter-wave extended interaction radiation sources by using the TM31-mode scheme
Authors: Bi Liangjie , Meng Lin , Yin Yong , Xu Che , Zhu Sairong , Peng Ruibin , Zeng Fanbo , Chang Zhiwei , Wang Bin , Li Hailong , Zhang Ping
Published: June 2019

The application of a TM31 mode scheme in extended interaction radiation sources permits the use of higher beam power and larger power capacity for power enhancement as compared with that of the conventional fundamental mode in the millimeter-wave band. To support this point, the effect of coupling cavities on the electromagnetic characteristics of the TM31 and fundamental modes is studied. This study shows that the TM31 mode can build up (1) a weaker TM11-like field in the gaps which has the same typical distribution pattern as that of a conventional fundamental mode at the same frequency and (2) two extra parts of field energy to support larger coupling cavities. To demonstrate this feature, we observe the field distribution and strength by injecting a certain wave power in two cavities, which are predicted to resonate in the TM31 and fundamental modes at the same frequency. The mode analysis and the beam-wave interaction are discussed to analyze the feasibility of the TM31 mode scheme. Through particle-in-cell simulations, the maximum output power over 26.3 kW is obtained at the desired frequency when the beam voltage and current are 61 kV and 3 A, respectively. The TM31 mode scheme could be a promising candidate for achieving high power in millimeter-wave extended interaction radiation sources.
Characterization of a self-damped pendulum for vibration isolation
Authors: Vallat Aodren , Naveh Yoav , Winterflood John , Ju Li , Blair David G.
Published: June 2019

In many sensitive measurement systems such as gravitational wave detectors, multistage low-loss vacuum-compatible suspension chains are required to effectively isolate the test mass from seismic disturbances. These chains usually have high quality factor normal modes which require damping. A technique termed “self-damping” in which the motion of orthogonal modes of the same stage mass is deliberately viscously cross-coupled to each other—thereby damping both modes—was engineered into the suspension chains used in an 80 m suspended high-power optical cavity. In this report, we investigate in detail the performance of a single stage of these chains. We model the system using numerical simulation and compare this with experimental measurements with different damping parameters in order to optimize the self-damping obtained using this technique.
Magnetic anisotropy of half-metallic Co2FeAl ultra-thin films epitaxially grown on GaAs(001)
Authors: Lai Bolin , Zhang Xiaoqian , Lu Xianyang , Yang Long , Wang Junlin , Chen Yequan , Zhao Yafei , Li Yao , Ruan Xuezhong , Wang Xuefeng , Du Jun , Liu Wenqing , Wang Fengqiu , He Liang , Liu Bo , Xu Yongbing
Published: June 2019

Single crystalline Co2FeAl films with different thicknesses varying from 3.6 to 10.6 nm have been grown on GaAs (001) using Molecule Beam Epitaxy (MBE). The magnetic characteristics were investigated by in-situ magneto-optical Kerr effect (MOKE). For all the samples, the angle dependent magnetization energy has a relatively high and steep peak around [110] direction which is the hard axis, and a wide basin from [11¯0] to [100] which is the range of the easy axis. More interestingly, the magnetic anisotropy includes a strong uniaxial component due to the Co2FeAl/GaAs interface, a cubic one from Co2FeAl crystalline structure, and an unexpected localized anisotropy term around the [110] direction. All the three anisotropy components overlap their own hard axis around [110] direction resulting in a steep energy barrier, which leads to unusual inverted hysteresis loops around [110]. Our findings add a building block for using half-metallic Co2FeAl thin films in the application of magnetic storage devices.
Fabrication of a (K,Na)NbO3-based lead-free 1-3 piezocomposite for high-sensitivity ultrasonic transducers application
Authors: Jiang Laiming , Chen Ruimin , Xing Jie , Lu Gengxi , Li Runze , Jiang Yue , Kirk Shung K. , Zhu Jianguo , Zhou Qifa
Published: June 2019

Ultrasonic imaging is a well-established powerful medical diagnosis tool at present. However, commercial ultrasonic transducers are commonly made of toxic lead-based piezoelectric materials. Thus, it is vital to develop lead-free alternatives with satisfactory performance. This study presents the development of a phase boundary-engineered (K,Na)NbO3-based lead-free 1-3 piezocomposite and its application on high-sensitivity ultrasonic imaging transducers. A modified dice-and-fill technique was used to manufacture the microscale piezocomposite, by which the ceramic pillars were miniaturized to a width of 55 μm with a kerf of 15 μm. Improved acoustic and electrical properties were obtained in the new piezocomposite, and ultrasonic imaging transducers were further designed and fabricated based on the composite. The fabricated transducers exhibit enhanced performance with a high center frequency (16 MHz), a broad bandwidth (83%), and a very low insertion loss (9.8 dB), outperforming state-of-the-art transducers based on other lead-free materials. Imaging capability of the transducers was evaluated via ex vivo imaging of a porcine eyeball, indicating that this lead-free piezocomposite has many attractive properties in developing environment-friendly high-sensitivity ultrasonic devices for biomedical imaging applications.
Molecular dynamics simulations of isothermal reactions in Al/Ni nanolaminates
Authors: Smith Grant D. , Bedrov Dmitry , Hooper Justin
Published: June 2019

Molecular dynamics simulations of reactions in Al/Ni layered systems have been carried out under isothermal conditions for a wide range of temperatures and several system sizes. An embedded atom method potential, known to reasonably reproduce the phase behavior of Al/Ni, was employed. Simulations revealed reaction mechanisms involving an initial fast process and much slower more complex longer-time reactions. The initial reaction process consists of diffusion of Ni from the pure solid Ni phase into the molten Al phase, resulting in the formation of an Al-rich Al/Ni liquid. The initial reaction ends when the Al/Ni liquid becomes saturated in Ni and solid Al/Ni phases begin to form at the interfaces between the pure solid Ni phase and the Al/Ni liquid. The growth of these solid phases is intrinsically slow compared to the formation of the liquid and is further slowed by the need for Ni to diffuse through the growing interfacial Al/Ni solid phases. Analysis of the initial Al/Ni liquid forming process indicates Fickian behavior with the Ni diffusion coefficient exhibiting Arrhenius temperature dependence. The longer-time slow reaction process(es) resulting in the growth of Al/Ni solid phases do not lend themselves to detailed numerical analysis because of the complex dependence of the Ni transport on the detailed nature of the interfacial layers.
Multifractal analysis of diurnal temperature range over Southern Spain using validated datasets
Authors: Herrera-Grimaldi P. , García-Marín A. P. , Estévez J.
Published: June 2019

Multifractal properties of diurnal temperature range (DTR) have been analyzed in this work, using validated data of maximum and minimum temperature from 197 weather stations in Southern Spain (Andalusia region). DTR is a crucial factor to characterize the regional climate, providing more information than the average daily temperature. Apart from climate change studies, one of the most important applications of DTR in Agrometeorology is as an input variable in the solar radiation or reference evapotranspiration estimation models based on the temperature. With the aim of obtaining a detailed information for different time scales, different multifractal approaches have been applied. Different quality control methods such as range/limits or persistence tests were previously applied in order to detect incorrect and anomalous values, being discarded in the subsequent analysis. The DTR scaling of moments has been analyzed and the moment scaling exponent function K(q) has been obtained, finding some differences between weather stations. In addition, multifractal dimension (D1) and multifractal degree (MD) were also estimated, revealing differences at coastal and inland locations that show heterogeneity across the region, including its multifractal nature and its invariance for a range of scales. The nonlinear characterization carried out in this work improves the understanding of DTR as an indicator of climate changes, and it can have a very positive impact on the calibration of regional models for estimating solar radiation or reference evapotranspiration based on the temperature. This multifractal characterization can be used to group stations with similar nonlinear dynamics, regardless of their geographical features, in such a way that more accurate coefficients than conventional ones are used.
Achieving high electron mobility in AlInGaN/GaN heterostructures: The correlation between thermodynamic stability and electron transport properties
Authors: Sanyal Indraneel , Lee Yen-Chang , Chen Yu-Chih , Chyi Jen-Inn
Published: June 2019

A significant improvement in electron mobility has been achieved by several authors on AlInGaN/GaN heterostructures by adding a small amount of Ga to the AlInN alloy. In this study, we propose that thermodynamic stability plays an important role in controlling the electron transport properties of these heterostructures. A quantitative investigation of the thermodynamic stability of the AlInGaN barrier has been carried out analytically, for a wide range of compositions (0.5 ≤ Al ≤ 0.8; In = 0.2, 0.15, 0.1). A slow change in the thermodynamic stability is observed when the Ga atoms replace only the Al atoms. In contrast, a significant improvement in thermodynamic stability is observed when the indium atoms are replaced by the Ga atoms in the same Al0.83In0.17N layer. It is found that the Al content in the range of 65%–70% with 10% In exhibits the highest thermodynamic stability within the calculated composition range owing to the significant reduction in total elastic strain in the barrier. Thereby, it leads to the highest electron mobility, as evidenced by the experimental observations in this work, i.e., electron mobility of 2090 cm2/V s with a sheet carrier density of 1.09 × 1013 cm−2. Therefore, the thermodynamic stability apart from commonly observed scattering mechanisms may at least be partially held to be responsible for the consistent improvement in electron mobility in AlInGaN/GaN heterostructures.
A simulation-based model for understanding the time dependent x-ray drive asymmetries and error bars in indirectly driven implosions on the National Ignition Facility
Authors: Masse L. , Clark D. , MacLaren S. , Berzak Hopkins L. , Haan S. , Khan S. , Kritcher A. , Kyrala G. , Landen O. , Lindl J. , Ma T. , Patel P. , Ralph J. , Salmonson J. , Tipton R. , Weber C.
Published: June 2019

Time-dependent low-mode asymmetries are believed to play a leading role in limiting the performance of current inertial confinement fusion implosions on the National Ignition Facility (NIF) [E. I. Moses et al., Phys. Plasmas 16, 041006 (2009)]. These long wavelength modes are initiated and driven by asymmetries in the x-ray flux from the hohlraum; however, the underlying hydrodynamics of the implosion also act to modify and amplify these asymmetries. We present here a simulation-based model connecting the time-dependent drive asymmetry seen by the capsule to the measured inflight and hot spot symmetries. This approach is based on a Green's function analysis for which we evaluate the response of the capsule to impulses of drive asymmetry at a series of times. Our model sheds new light on the sensitivity to the drive asymmetry of an imploded capsule, giving a new tool for design. Inverting the problem and finding the drive asymmetry needed to match the experimental data allow us to tightly constrain the drive asymmetry seen by the capsule, providing an error estimate on the result. Doing so, we are able to point out when and how the complex hohlraum simulations start to deviate from what they should obtain to match the experimental data. Ultimately, we project to use this model to make some experimental recommendations to fix the time-dependent low-mode asymmetry of indirectly driven implosions and identify additional measurements to further constrain the asymmetries with a view to improving target design on the NIF.
Nanofocusing on gold planar nanotip arrays
Authors: Wei Dong , Xin Zhaowei , Chen Mingce , Hu Chai , Zhang Xinyu , Wang Haiwei , Xie Changsheng
Published: June 2019

Nanofocusing of incident light in the visible and infrared regions is achieved using tapered metallic nanostructures (TMNSs). Illumination under 633 nm excitation produces a very small (∼40 nm in the x-direction), very bright spot with a specific geometry, demonstrating near-field nanofocusing of the incident beam to the deep subwavelength scale. The key processes, including a theoretical understanding, numerical calculation, and a near-field optical measurement involving the metallic planar nanotip arrays, are discussed. As in the lightning-rod effect, there is a large number of surface states to accommodate free electrons, resulting in a very high surface density distribution of the free electrons over the nanoapexes. A theoretical model for calculating the free-electron distribution based on the surface energy state of the nanoapex is established. The spread of free electron oscillation, including the guiding of free electrons towards nearby planar nanoapexes to obtain near-field nanofocusing is examined. As the lightning-rod effect is a broadband phenomenon, the TMNSs are also examined in the far-infrared (far-IR) region, at the typical far-IR wavelength of 10.274 μm. It should be noted that the IR radiation can also be focused into a linear light-spot of ∼20 nm, far beyond the IR diffraction limit. A metasurface constructed by the orderly arrangement of TMNSs highlights their potential in applications such as surface enhanced Raman spectroscopy, ray absorbing materials, and low-cost nanolithography.
Enhancing the resilience of energy systems: Optimal deployment of wave energy devices following coastal storms
Authors: Korde Umesh A.
Published: June 2019

Isolated coastal areas and remote islands may be particularly vulnerable to damage from powerful storms, storm surges, and flooding. Because wave energy converters are designed to survive rough seas and can be transported by sea, they could potentially play a role in poststorm operations and contribute to power-grid recovery. To that end, this paper addresses questions such as how many devices would need to be deployed and in what sequence, in order to optimize some performance index that includes, as functions of time, both, the energy needed and the energy converted by the device units. In this work, the wave-by-wave dynamics of the devices are controlled to optimize mean power conversion over 20 min, assuming sea-state stationarity over that period. Sea-state variations between 20 min and 13 h are found to be small (relative to variations between 13 and 60 h) for a candidate deployment site near a Caribbean island. Targeting deployment over 5–7 days, two optimization schemes are considered: (i) maximization of the power conversion capacity over a specified time interval and (ii) minimization of the time taken to deploy the desired conversion capacity. With the wave energy devices controlled for optimal conversion over successive 20-min periods, the optimization is carried out over the number of converter units added as a function of time. The results indicate that optimal deployment sequences can be evaluated for given conversion capacity/recovery-time targets and the type of recovery desired [strategies (i) or (ii) above]. However, depending on the energy richness of the “normal” wave climate at the deployment site, cost-effective recovery may require closer consideration of the trade-offs among device configurations, size, and number of units needed for desired capacity. The potential for wave energy devices to power early recovery operations and to support power-grid black-start could be worth considering further as a means to enhance the resilience of coastal and island energy systems.
The first passage problem for stable linear delay equations perturbed by power law Lévy noise
Authors: Högele Michael A. , Pavlyukevich Ilya
Published: June 2019

This article studies a linear scalar delay differential equation subject to small multiplicative power tail Lévy noise. We solve the first passage (the Kramers) problem with probabilistic methods and discover an asymptotic loss of memory in this non-Markovian system. Furthermore, the mean exit time increases with the power of the small noise amplitude, whereas the prefactor accounts for memory effects. In particular, we discover a nonlinear delay-induced exit acceleration due to a non-normal growth phenomenon. Our results are illustrated by the example of a linear delay oscillator driven by α-stable Lévy flights.
1D photonic crystal filled with low-temperature plasma for controlling broadband microwave transmission
Authors: Yao Jingfeng , Yuan Chengxun , Li Hui , Wu Jian , Wang Ying , Kudryavtsev Anatoly A. , Demidov Vladimir I. , Zhou Zhongxiang
Published: June 2019

A 1D plasma photonic crystal (PPC) is filled with plasmas and slab dielectrics in a large volume cylindrical glow discharge device. The parameters of the PPC are designed to meet the transmission condition of broadband microwave (1.5GHz-12GHz) according to the photonic crystal theory in which the thickness of the plasma is comparable to the wavelength. The transmission characteristics of broadband microwave in this plasma photonic crystal are demonstrated experimentally. The experiments show some unique characteristics of microwave in the PPCs, and the physical explanations for the phenomenon have been given based on the photonic crystal theory. And then, the features of the PPCs are compared to the corresponding photonic crystals (PCs) through both experiments and simulations. The results show that plasma slabs in PCs can change the band structure and influence the transmission of microwaves, which can be useful to the design of microwaves devices with PPCs.
Study of Alfven eigenmodes stability in plasma with multiple NBI driven energetic particle species
Authors: Varela J. , Spong D. A. , Garcia L. , Todo Y. , Huang J. , Murakami M.
Published: June 2019

The aim of this study is to analyze the destabilization of Alfven Eigenmodes (AEs) by multiple energetic particle (EP) species in DIII-D and LHD discharges. We use the reduced MHD equations to describe the linear evolution of the poloidal flux and the toroidal component of the vorticity in a full 3D system, coupled with equations of density and parallel velocity moments for the energetic particle species, including the effect of the acoustic modes, diamagnetic currents, and helical couplings. We add the Landau damping and resonant destabilization effects using a closure relation. The simulations with multiple neutral beam injector (NBI) lines show three different regimes: the nondamped regime where the multibeam AE growth rate is larger compared to the growth rate of the AEs destabilized by the individual NBI lines, the interaction regime where the multibeam AE growth rate is smaller than the single NBI AEs, and the damped regime where the AEs are suppressed. Operations in the damped regime require EP species with different density profile flatness or gradient locations. In addition, the AE growth rate in the interaction regime is further reduced if the combined NBI lines have similar beam temperatures and the β of the NBI line with a flatter EP density profile increases. Then, optimization trends are identified in DIII-D high poloidal β and LHD low density/magnetic field discharges with multiple NBI lines as well as the configuration requirements to operate in the damped and interaction regimes. DIII-D simulations show a decrease in the n = 2 to 6 AE growth rate and n = 1 AE are stabilized in the LHD case. The helical coupling effects in LHD simulations lead to a transition from the interaction to the damped regime of the n = 2, –8, 12 helical family.
Asymptotics of a catenoid liquid bridge between two spherical particles with different radii and contact angles
Authors: Wang Zekun , Yang Hongtao , Huang Chao , Liu Moubin
Published: June 2019

A liquid bridge between two neighboring particles is commonly observed in nature and various industrial processes. An accurate prediction of the profile of a liquid bridge is significantly important in particulate flows, while it is an analytically challenging task as well. In this paper, we develop an asymptotic solution for a catenoid liquid bridge profile, which is the minimal surface ensuring the minimum total surface energy. Our asymptotic solution is based on a rapid convergent predictor-corrector algorithm that considers different factors including boundary conditions, volume conservation, and geometrical relations while providing the relationship between the liquid bridge profile, bridge radius, half-filling angles, and creeping distances. Therefore, this asymptotic solution of the catenoid of the liquid bridge is applicable to general scenarios of any two neighboring particles of either equal or different sizes having identical or different contact angles. In order to validate the proposed asymptotic solution, we performed comprehensive experiments where the observed and predicted liquid bridge profiles and the resultant capillary forces from both the approaches are found closely matching. Moreover, we also investigate and report the influence of the radii ratio, contact angles, particle distances, and the liquid bridge volumes on its profiles.
Temple occupation and the tempo of collapse at Angkor Wat, Cambodia
Authors: Carter Alison K. , Stark Miriam T. , Quintus Seth , Zhuang Yijie , Wang Hong , Heng Piphal , Chhay Rachna
Published: June 2019

Significance

The Angkorian Empire was Southeast Asia’s largest premodern polity. Its ancient temple of Angkor Wat has been a religious center since its construction in the 12th century CE and remains a contemporary icon for the wider Angkor polity, even appearing on Cambodia’s flag. Our paper draws from intensive excavations in the Angkor Wat enclosure to present a fine-grained chronological analysis of the temple’s use history. We focus on where people lived in the temple complex rather than on the temple itself, and identify a chronometric gap that does not fully correlate with documented historical events. This granular study of Angkor Wat’s historical sequence contributes to understanding the tempo of organizational change taking place during Angkor’s collapse.
GABA-stimulated adipose-derived stem cells suppress subcutaneous adipose inflammation in obesity
Authors: Hwang Injae , Jo Kyuri , Shin Kyung Cheul , Kim Jong In , Ji Yul , Park Yoon Jeong , Park Jeu , Jeon Yong Geun , Ka Sojeong , Suk Sujin , Noh Hye Lim , Choe Sung Sik , Alfadda Assim A. , Kim Jason K. , Kim Sun , Kim Jae Bum
Published: June 2019

Accumulating evidence suggests that subcutaneous and visceral adipose tissues are differentially associated with metabolic disorders. In obesity, subcutaneous adipose tissue is beneficial for metabolic homeostasis because of repressed inflammation. However, the underlying mechanism remains unclear. Here, we demonstrate that γ-aminobutyric acid (GABA) sensitivity is crucial in determining fat depot-selective adipose tissue macrophage (ATM) infiltration in obesity. In diet-induced obesity, GABA reduced monocyte migration in subcutaneous inguinal adipose tissue (IAT), but not in visceral epididymal adipose tissue (EAT). Pharmacological modulation of the GABA
B
receptor affected the levels of ATM infiltration and adipose tissue inflammation in IAT, but not in EAT, and GABA administration ameliorated systemic insulin resistance and enhanced insulin-dependent glucose uptake in IAT, accompanied by lower inflammatory responses. Intriguingly, compared with adipose-derived stem cells (ADSCs) from EAT, IAT-ADSCs played key roles in mediating GABA responses that repressed ATM infiltration in high-fat diet-fed mice. These data suggest that selective GABA responses in IAT contribute to fat depot-selective suppression of inflammatory responses and protection from insulin resistance in obesity.
Ratiometric two-photon microscopy reveals attomolar copper buffering in normal and Menkes mutant cells
Authors: Morgan M. Thomas , Bourassa Daisy , Harankhedkar Shefali , McCallum Adam M. , Zlatic Stephanie A. , Calvo Jenifer S. , Meloni Gabriele , Faundez Victor , Fahrni Christoph J.
Published: June 2019

Significance

Impaired copper regulation has been implicated in a range of human diseases, yet the current mechanistic understanding of intracellular copper homeostasis remains incomplete. While Cu(I)-selective synthetic fluorescent probes could shed light on copper homeostasis within living cells by dynamically reporting intracellular Cu(I) availability, the affinity range of previously employed probes was insufficient to achieve significant metallation in the presence of glutathione (GSH) at normal physiological concentrations. Employing an air-stable phosphine-based ligand design, we devised a ratiometric indicator capable of competing for Cu(I) at attomolar buffered levels. Contrary to prior assumptions, our ratiometric imaging data indicate that intracellular Cu(I) is not buffered directly by GSH but by thiol ligands of still higher affinity.
Hsp90 of
E. coli
modulates assembly of FtsZ, the bacterial tubulin homolog
Authors: Balasubramanian Anuradha , Markovski Monica , Hoskins Joel R. , Doyle Shannon M. , Wickner Sue
Published: June 2019

Significance

Hsp90 is a molecular chaperone that participates in protein remodeling and activation. We previously demonstrated that Hsp90 causes cell filamentation when highly expressed in
E. coli
. Here we show that cells filament due to overexpression of Hsp90
Ec
because FtsZ, a bacterial tubulin homolog essential for cell division, fails to assemble into FtsZ rings. In vitro, Hsp90
Ec
interacts with FtsZ and inhibits FtsZ polymerization. Moreover,
E. coli
deleted for the Hsp90
Ec
gene,
htpG
, turn over FtsZ more rapidly than wild-type cells, and the length of Δ
htpG
cells is reduced compared to wild-type cells. Altogether, these results suggest that Hsp90
Ec
is a modulator of cell division, and imply that the polypeptide-holding function of Hsp90 may be a biologically important chaperone activity.
Conceptualisations ofxoshbaxti(‘happiness / prosperity’) andbaxt(‘fate / luck’) in Persian
Authors: Sharifian Farzad , Bagheri Mehri
Published: June 2019

This paper explores conceptualisations ofxoshbaxti(‘happiness / prosperity’) andbaxt(‘fate / luck’) in Persian, adopting a combined historical and contemporary analysis. The expressionxoshbaxticonsists of the free morphemesxosh(‘pleasant’) andbaxt(‘fate’).

The root ofbaxtoriginates from the Proto-Indo-European language (bʰeh₂g). An historical analysis returning all the way to the Proto-Indo-Iranian religion shows that the concept ofbaxtcaptured the idea of a pre-determined destiny by conceptualisingBhagaas a god who dispenses fortune. Data from a number of Persian encyclopaedias, dictionaries and weblogs, as well as a word association task carried out by a group of speakers of Persian, revealed thatxoshbaxtiin contemporary Persian is largely associated with what is considered to be a “good” married life. Overall, the findings of this study illustrate the usefulness of combining diachronic and synchronic approaches when analysing cultural conceptualisations. The study also shows that attempts to trace the historical roots of cultural conceptualisations may benefit from insights gained in other fields, such as the history of religions. In this context, the multidisciplinary nature of the newly developed field of Cultural Linguistics provides an effective basis for cross-disciplinary openness, which has the potential to deepen the scope of analyses undertaken.
A corpus-based study of composite predicates in Early Modern English dialogues
Authors: Wang Ying
Published: June 2019

Composite predicates (CPs), that is, complex predicate structures comprising a light verb and an eventive noun
(e.g., make a move or give a speech) are common in Present-day English and are particularly
characteristic of spoken language. The aim of the paper is to trace language changes involving CPs from 1560 to 1760, a period in
which the use of CPs has not yet received adequate scholarly attention. Specifically, the study examines the frequencies, lexical
productivity and syntactic patterns of CPs in two types of Early Modern English (EModE) dialogues, drawn from Trial Proceedings and Drama
Comedy sampled in A Corpus of English Dialogues 1560–1760 – a 1.2-million word computerized corpus of EModE
speech-related texts. The results reveal significant differences between the two types of dialogue and shed light on the
development of CPs in association with grammaticalization and lexicalization.
IL-27 promotes the expansion of self-renewing CD8+ T cells in persistent viral infection
Authors: Huang Zhe , Zak Jaroslav , Pratumchai Isaraphorn , Shaabani Namir , Vartabedian Vincent F. , Nguyen Nhan , Wu Tuoqi , Xiao Changchun , Teijaro John R.
Published: June 2019

Chronic infection and cancer are associated with suppressed T cell responses in the presence of cognate antigen. Recent work identified memory-like CXCR5+ TCF1+ CD8+ T cells that sustain T cell responses during persistent infection and proliferate upon anti-PD1 treatment. Approaches to expand these cells are sought. We show that blockade of interferon type 1 (IFN-I) receptor leads to CXCR5+ CD8+ T cell expansion in an IL-27– and STAT1-dependent manner. IFNAR1 blockade promoted accelerated cell division and retention of TCF1 in virus-specific CD8+ T cells. We found that CD8+ T cell–intrinsic IL-27 signaling safeguards the ability of TCF1hi cells to maintain proliferation and avoid terminal differentiation or programmed cell death. Mechanistically, IL-27 endowed rapidly dividing cells with IRF1, a transcription factor that was required for sustained division in a cell-intrinsic manner. These findings reveal that IL-27 opposes IFN-I to uncouple effector differentiation from cell division and suggest that IL-27 signaling could be exploited to augment self-renewing T cells in chronic infections and cancer.