bluuebunny/crossref_metadata_2025 huggingface dataset:
A spin crossover porous hybrid architecture for potential sensing applications
Authors: Tissot Antoine , Kesse Xavier , Giannopoulou Styliani , Stenger Ingrid , Binet Laurent , Rivière Eric , Serre Christian
Published: November 2018

Spin crossover cations have been successfully synthesized in the pores of a mesoporous robust Metal–Organic Framework (MOF) MIL-100(Al) through sequential introduction of Fe(iii) cations and a sal2trien ligand.
Biocatalytically induced surface modification of the tobacco mosaic virus and the bacteriophage M13
Authors: Vignali Valentina , S. Miranda Barbara , Lodoso-Torrecilla Irene , van Nisselroy Cathelijn A. J. , Hoogenberg Bas-Jan , Dantuma Sybren , Hollmann Frank , de Vries Jan Willem , Warszawik Eliza M. , Fischer Rainer , Commandeur Ulrich , van Rijn Patrick
Published: November 2018

A one-step laccase induced free radical oxidation of the tobacco mosaic virus and bacteriophage M13 led to acrylate-functionalized viruses with customizable properties.
SecScan: a general approach for mapping disulfide bonds in synthetic and recombinant peptides and proteins
Authors: Denisov Stepan S. , Ippel Johannes H. , Mans Ben J. , Dijkgraaf Ingrid , Hackeng Tilman M.
Published: November 2018

Selenocysteine scanning (SecScan) is a novel technique to map disulfide networks in proteins independent of structure-based distance information and mass spectrometry.
Transition-metal-free α-arylation of nitroketones with diaryliodonium salts for the synthesis of tertiary α-aryl, α-nitro ketones
Authors: An Yang , Zhang Xiao-Ming , Li Ze-Yu , Xiong Wen-Hui , Yu Run-Dong , Zhang Fu-Min
Published: November 2018

Transition-metal-free α-arylation of α-nitroketones with diaryliodonium salts has been developed for the first time and applied in the synthesis of tiletamine.
Single-crystal GaN layer converted from β-Ga2O3films and its application for free-standing GaN
Authors: Li Yuewen , Xiu Xiangqian , Xiong Zening , Hua Xuemei , Xie Zili , Chen Peng , Liu Bin , Tao Tao , Zhang Rong , Zheng Youdou
Published: November 2018

Hexagonal GaN has been obtained by nitridating β-Ga2O3film despite structural mismatch between β-Ga2O3and GaN, and the conversion process has been investigated systematically.
A stochastic model study on the self-assembly process of a Pd2L4 cage consisting of rigid ditopic ligands
Authors: Takahashi Satoshi , Sasaki Yuya , Hiraoka Shuichi , Sato Hirofumi
Published: November 2018

Numerical analysis considering explicit conformational difference revealed the self-assembly process of a Pd2L4 cage containing rigid ditopic ligands.
Thermochemistry of germanium and organogermanium compounds
Authors: Becerra Rosa , Walsh Robin
Published: November 2018

This article reviews the current state of thermochemistry (enthalpies of formation) of germanium and organogermanium compounds.
The nature of binding of quinolate complex on the surface of ZnS quantum dots
Authors: Roy Shilaj , Bhandari Satyapriya , Manna Mihir , De Suranjan , Chattopadhyay Arun
Published: November 2018

Adsorption of HQ on ZnS Qdot surface occurs through Z-type binding with dangling sulphide by forming a 1 : 2 zinc complex.
Coupled double triplet state in singlet fission
Authors: Kim Hyungjun , Zimmerman Paul M.
Published: November 2018

The highly unusual state, 1(TT), is a coupled, double triplet state that has recently garnered significant attention.
Influence of chelate ring type on chelate–chelate and chelate–aryl stacking: the case of nickel bis(dithiolene)
Authors: Malenov Dušan P. , Veljković Dušan Ž. , Hall Michael B. , Brothers Edward N. , Zarić Snežana D.
Published: November 2018

Chelate–aryl stacking of nickel dithiolene and acac-type chelates are of similar strengths, while chelate–chelate stacking is stronger for dithiolene chelates.
Coexistence of piezoelectricity and magnetism in two-dimensional vanadium dichalcogenides
Authors: Yang Jianhui , Wang Anping , Zhang Shaozheng , Liu Jia , Zhong Zhicheng , Chen Liang
Published: November 2018

2D vanadium dichalcogenides are magnetic semiconductors with appreciable in-plane and vertical piezoelectricity, and are promising piezoelectric materials in spin devices.
Distinguishing the effects of altered morphology and size on the visible light-induced water oxidation activity and photoelectrochemical performance of BaTaO2N crystal structures
Authors: Hojamberdiev Mirabbos , Kawashima Kenta , Hisatomi Takashi , Katayama Masao , Hasegawa Masashi , Domen Kazunari , Teshima Katsuya
Published: November 2018

The effects of altered morphology and size on the visible light-induced water oxidation activity and photoelectrochemical performance of BaTaO2N crystal structures were studied.
Infrared heating of the top surface of a cyclonic spray chamber to improve the analytical performance of inductively coupled plasma optical emission spectrometry
Authors: Al Hejami Ahmed , Beauchemin Diane
Published: November 2018

Heating the top of a cyclonic spray chamber improves detection limits by up to 12 fold while increasing robustness.
Nature and nurture: confluence of pathway determinism with metabolic and chemical serendipity diversifiesMonascusazaphilone pigments
Authors: Chen Wanping , Feng Yanli , Molnár István , Chen Fusheng
Published: November 2018

This highlight maps111congeners ofMonascusazaphilone pigments on a unitary biosynthetic pathway and summarizes the causes for their diversity.
Neuronal dynamics in HfOx/AlOy-based homeothermic synaptic memristors with low-power and homogeneous resistive switching
Authors: Kim Sungjun , Chen Jia , Chen Ying-Chen , Kim Min-Hwi , Kim Hyungjin , Kwon Min-Woo , Hwang Sungmin , Ismail Muhammad , Li Yi , Miao Xiang-Shui , Chang Yao-Feng , Park Byung-Gook
Published: November 2018

Homeothermic synaptic behaviors with a wide range of temperature were demonstrated in CMOS-compatible HfOx/AlOy memristors.
Posttranscriptional spin labeling of RNA by tetrazine-based cycloaddition
Authors: Domnick Christof , Hagelueken Gregor , Eggert Frank , Schiemann Olav , Kath-Schorr Stephanie
Published: November 2018

Spin labeling ofin vitrotranscribed RNA by iEDDA click chemistry is demonstrated. This allows the determination of distance distributions between two nitroxide spin labels by PELDOR in a self-complementary RNA duplex.
Cascade reaction based synthetic strategies targeting biologically intriguing indole polycycles
Authors: Ciulla Maria Gessica , Zimmermann Stefan , Kumar Kamal
Published: November 2018

In this review, cascade reaction based synthesis strategies delivering biologically intriguing indole polycycles are presented.
Directed production of aurantizolicin and new members based on a YM-216391 biosynthetic system
Authors: Pei Zeng-Fei , Yang Min-Jie , Li Lei , Jian Xiao-Hong , Yin Yue , Li Dehai , Pan Hai-Xue , Lu Yinhua , Jiang Weihong , Tang Gong-Li
Published: November 2018

Aurantizolicin and new compound 3 with improved bioactivity were generated highly effectively by heterologous expression of an engineered YM-216391 biosynthetic gene cluster.
Synthesis of star thermoresponsive amphiphilic block copolymer nano-assemblies and the effect of topology on their thermoresponse
Authors: Cao Mengjiao , Nie Huijun , Hou Yuwen , Han Guang , Zhang Wangqing
Published: November 2018

Well-defined multi-arm star thermoresponsive block copolymer nano-assemblies of [poly(N-isopropylacrylamide)-block-polystyrene]n [(PNIPAM-b-PS)n] with n = 1, 2, 3 and 4 arms were synthesized by RAFT dispersion polymerization via polymerization-induced self-assembly.
Protrusion of nanospikes on cholesterol-containing microgels by reduction-responsive self-assembly in cell milieu and its influence on cell functions
Authors: Zhai Zihe , Zhang Wenbo , Ding Ning , Lin Xue , Gao Changyou
Published: November 2018

Protrusion of nanospikes observed in cell milieu on the surface of reduction-responsive microgels.
Antitumor component recognition from the Aconiti Lateralis Radix Praeparata and Glycyrrhizae Radix et Rhizoma herb pair extract by chemometrics and mean impact value
Authors: Fan Hailiu , Xuan Jianbang , Du Xinyun , Liu Ningzhi , Jiang Jianlan
Published: November 2018

CAR models for the Fuzi–Gancao herb pair were constructed by BP, SVR, GA and PSO, and used to fit experimental data. The main active antitumor components were recognized from MIVs based on the optimal CAR model.
Underwater superoleophobic polyurethane-coated mesh with excellent stability for oil/water separation
Authors: Yang Xianhou , Lang Daning , Wang Ziyuan , Cao Jingjing , Wu Ronglan , Wang Wei
Published: November 2018

Oil/water separation has been a challenge in chemical engineering for various applications.
Polypyrrole–MXene coated textile-based flexible energy storage device
Authors: Yan Jinfeng , Ma Yanan , Zhang Chuankun , Li Xingxing , Liu Weizhi , Yao Xinyu , Yao Shuai , Luo Shijun
Published: November 2018

A kind of smart and flexible SCs based on MXene-based textile have been fabricated by a “dipping and drying” method.
A critical review on arsenic removal from water using iron-based adsorbents
Authors: Hao Linlin , Liu Mengzhu , Wang Nannan , Li Guiju
Published: November 2018

The recent developments on iron-based adsorbents such as iron oxyhydroxides nanoparticles, zero-valent iron, bimetallic oxides, and iron oxyhydroxide-doped composite materials are fully discussed in this review.
Predictions and constructing explanations: an investigation into introductory chemistry students’ understanding of structure–property relationships
Authors: Kararo Alex T. , Colvin Rachel A. , Cooper Melanie M. , Underwood Sonia M.
Published: November 2018

The relationship between chemical structure and physical and chemical properties is essential to chemistry. Studies have shown that students have difficulty using structural representations to predict properties, which is not surprising because of the sequence of inferences that are required for sense-making. However, obtaining a nuanced model of students’ understanding depends on how information is elicited. This study investigated how the phrasing of the question prompt may elicit students’ understanding of structure–property relationships. Students were given a two-part assessment: (1) four multiple-choice questions assessing students’ self-reported abilities to predict structure–property relationships, and (2) three questions requiring students to predict, argue, and explain a boiling point trend. Two groups of students were selected to determine the sensitivity of the instrument (one with less explicit instruction of structure–property relationships and one with more explicit instruction). We found that Part I of the assessment was able to differentiate between these two groups of students. The group with more explicit instruction was further analyzed to determine how their prediction on a boiling point task connected to their arguments and explanations of the phenomenon. Even though 64% of students answered the boiling point ranking task correctly, the students typically provided less complete arguments as to why that structure had a higher boiling point. However, after scaffolding (i.e., providing relevant information for the phenomenon) and asking for an explanation, students’ responses began to include a much more mechanistic understanding, suggesting that having students provide explanations instead of constructing an argument would display their reasoning at a deeper level.
Hydrodynamics strongly affect the dynamics of colloidal gelation but not gel structure
Authors: de Graaf Joost , Poon Wilson C. K. , Haughey Magnus J. , Hermes Michiel
Published: November 2018

The gel network formed by attractive colloids is largely set by the pre-existence of structures upon quenching the system.
Prognostic values of E2F mRNA expression in human gastric cancer
Authors: Manicum Theasha , Ni Fubiao , Ye Yiming , Fan Xuhui , Chen Bi-Cheng
Published: November 2018

Gastric cancer (GC) is the second most frequent cause of cancer-related mortality in the world, with Eastern Asia having the highest incidence rates. E2F is a family of transcription factor proteins that has a variety of functions, which include control of cell cycle, cell differentiation, DNA damage response and cell death. E2F transcription factors are divided into two subfamilies: transcription activators (E2F transcription factors 1 (E2F1), 2 (E2F2) and 3a (E2F3a)) and repressors (E2F3b, E2F transcription factors 4 (E2F4), 5 (E2F5), 6 (E2F6), 7 (E2F7) and 8 (E2F8)). Studies have demonstrated that E2F had prognostic significance in a number of cancers. However, the entirety of the prognostic roles of E2F mRNA expression in GC has not yet been apparently determined. In the present study, the prognostic value of individual family members of E2F mRNA expression for overall survival (OS) was evaluated by using online Kaplan–Meier Plotter (KM Plotter) database. Our result demonstrated that high expressions of three family members of E2F (E2F1, E2F3, E2F4) mRNA were significantly associated with unfavourable OS in all GC patients. However, increased expressions of E2F2, E2F5, E2F6 and E2F7 were significantly associated with favourable OS, especially for higher clinical stages in GC patients. These results provided a better insight into the prognostic functions of E2F mRNA genes in GC. Although the results should be further verified in clinical trials, our findings may be a favourable prognostic predictor for the development of newer therapeutic drugs in the treatment of GC.
Analytical approximation of ZF Ricean rate in massive MIMO channels
Authors: Nyarko James K.N. , Xie Jian , Yao Rugui , Wang Yuexian , Wang Ling
Published: November 2018

The analytical approximation of the Ricean channel (non‐central Wishart) matrix is often analysed with the central Wishart matrix. This method falls short of exploiting the non‐zero Ricean channel mean to calculate the average zero‐forcing (ZF) massive multiple‐input and multiple‐output(MIMO) ergodic rate. In this Letter, the authors develop a new approach to accurately approximate the inverse Ricean channel, and determine the main diagonal. After which, optimal power allocation is used to maximise the ergodic rate. Numerical results validate the accuracy of the proposed approximation with the ideal channel.
Multiphase voltage regulator with small output ripple in both CCM and DCM
Authors: Zhang Shuyu , Zhao Menglian , Hu Rubo , Wu Xiaobo
Published: November 2018

A novel multiphase voltage regulator with small output ripple in both continuous conduction mode (CCM) and discontinuous conduction mode (DCM) is proposed. Mathematical analysis proves that the multiphase regulator has the smallest output ripple if phases are equally interleaved. The proposed regulator could minimise the output ripple through precisely interleaved phases by using a PLL‐based synchronous clock in CCM and a self‐adjusted staggered‐time generator in DCM. The design is validated by fabrication in 0.18 µm CMOS process. Test results show that the peak–peak values of output ripple are 6 and 9 mV with 4 and 0.3 A loads, respectively.
Adaptive frequency adjustment technique in current mode DC–DC converters for input voltage range extension
Authors: Xiao Zhiming , Zhao Guangshu , Wang Yu , Wang Huashu , Hu Weibo
Published: November 2018

This study presents a switching frequency adjustment technique that helps widen the input voltage range of a current mode DC–DC converter. Conventional current‐mode switching converters suffer the minimum on/off time restrictions that limit the input‐to‐output conversion ratio. This work introduces an additional regulation loop on top of an existing converter that regulates the switching period when the minimum on/off time limit is approached. Compared with a converter with fixed switching frequency, the proposed approach allows the free‐running switching to be set without being limited by the minimum on/off time. A boost topology with output voltage of 24 V was built based on the proposed approach, and the measured valid input voltage range was extended from 8–16 to 3–21 V by the proposed scheme under 1 MHz preset frequency. Since the slope‐compensation current, the inductor size, and the output capacitor are all optimised at 1 MHz and is not limited by the minimum on/off time which may lower the switching frequency of a conventional converter down to 450 kHz, the measured maximum available output current and the typical output voltage ripple under 12 V input achieved 1.57 A and 57 mV, respectively.
Spectro-interferometric observations of a sample of Be stars
Authors: Cochetti Y. R. , Arcos C. , Kanaan S. , Meilland A. , Cidale L. S. , Curé M.
Published: November 2018

Context. Be stars are rapid rotators surrounded by a gaseous disk envelope whose origin is still under debate. This envelope is responsible for observed emission lines and large infrared excess.

Aims. To progress in the understanding of the physical processes involved in the disk formation, we estimate the disk parameters for a sample of Be stars and search for correlations between these parameters and stellar properties.

Methods. We performed spectro-interferometric observations of 26 Be stars in the region of the Brγ line to study the kinematical properties of their disks through the Doppler effect. Observations were performed at the Paranal observatory with the VLTI/AMBER interferometer. This instrument provides high spectral (R ≃ 12 000) and high spatial (θmin = 4 mas) resolutions.

Results. We modeled 18 Be stars with emission in the Brγ line. The disk kinematic is described by a quasi-Keplerian rotation law, with the exception of HD 28497 that presents a one-arm density-wave structure. Using a combined sample, we derived a mean value for the velocity ratio V̅/V̅c = 0.75 (where Vc is the critical velocity), and found that rotation axes are probably randomly distributed in the sky. Disk sizes in the line component model are in the range of 2–13 stellar radii and do not correlate with the effective temperature or spectral type. However, we found that the maximum size of a stable disk correlates with the rotation velocity at the inner part of the disk and the stellar mass.

Conclusions. We found that, on average, the Be stars of our combined sample do not rotate at their critical velocity. However, the centrifugal force and mass of the star defines an upper limit size for a stable disk configuration. For a given rotation, high-mass Be stars tend to have more compact disks than their low-mass counterparts. It would be interesting to follow up the evolution of the disk size in variable stars to better understand the formation and dissipation processes of their circumstellar disks.
Photochemical escape of atomic C and N on Mars: clues from a multi-instrument MAVEN dataset
Authors: Cui J. , Wu X. -S. , Gu H. , Jiang F. -Y. , Wei Y.
Published: November 2018

Context. Photochemical escape of hot atoms is crucial to the long-term evolution of the Martian climate. For atomic C and N, photochemical escape is primarily driven by photodissociation (PD) of CO and N2.

Aims. Combining the Mars Atmosphere and Volatile Evolution (MAVEN) measurements of atmospheric neutral densities and solar EUV/X-ray irradiance, we perform a state-of-the-art analysis of atomic C and N escape on Mars.

Methods. For each MAVEN orbit, we calculated the hot C and N production rates in the dayside Martian upper atmosphere via PD, from which the escape rates are estimated using a simplified technique to parameterize the respective escape probabilities taking into account multiple collisions with ambient neutrals.

Results. The mean C and N escape rates are 1 × 1024 s−1 and 9 × 1024 s−1, appropriate for low to moderate solar activity conditions, and thermospheric PD makes a larger contribution to the total N escape than to the total C escape. The above differences highlight the importance of nascent energy, with more energetic nascent escaping atoms able to survive collisions with ambient neutrals more easily, thus extending down to deeper regions of the atmosphere. Solar cycle variation in C and N escape is revealed by our analysis, whereas solar zenith angle variation is absent for both species. These results could be explained by the fact that the production of nascent escaping atoms responds to varying solar illumination angle at low altitudes where the escape probability is negligible, but responds to varying level of solar EUV/X-ray irradiance at high altitudes where the atmosphere is essentially collisionless.
Study of the X-ray pulsar IGR J19294+1816 with NuSTAR: Detection of cyclotron line and transition to accretion from the cold disk
Authors: Tsygankov Sergey S. , Doroshenko Victor , Mushtukov Alexander A. , Lutovinov Alexander A. , Poutanen Juri
Published: November 2018

In the work we present the results of two deep broadband observations of the poorly studied X-ray pulsar IGR J19294+1816 obtained with the NuSTAR observatory. The source was observed during Type I outburst and in the quiescent state. In the bright state a cyclotron absorption line in the energy spectrum was discovered at Ecyc = 42.8 ± 0.7 keV. Spectral and timing analysis prove the ongoing accretion also during the quiescent state of the source. Based on the long-term flux evolution, particularly on the transition of the source to the bright quiescent state with luminosity around 1035 erg s−1, we conclude that IGR J19294+1816 switched to the accretion from the “cold” accretion disk between Type I outbursts. We also report the updated orbital period of the system.
Learning sparse representations on the sphere
Authors: Sureau F. , Voigtlaender F. , Wust M. , Starck J.-L. , Kutyniok G.
Published: November 2018

Many representation systems on the sphere have been proposed in the past, such as spherical harmonics, wavelets, or curvelets. Each of these data representations is designed to extract a specific set of features, and choosing the best fixed representation system for a given scientific application is challenging. In this paper, we show that one can directly learn a representation system from given data on the sphere. We propose two new adaptive approaches: the first is a (potentially multiscale) patch-based dictionary learning approach, and the second consists in selecting a representation from among a parametrized family of representations, the α-shearlets. We investigate their relative performance to represent and denoise complex structures on different astrophysical data sets on the sphere.
Contrast sensitivities in the Gaia Data Release 2
Authors: Brandeker Alexis , Cataldi Gianni
Published: November 2018

The source detection sensitivity of Gaia is reduced near sources. To characterise this contrast sensitivity is important for understanding the completeness of the Gaia data products, in particular when evaluating source confusion in lower resolution surveys such as photometric monitoring for transits. Here, we statistically evaluate the catalogue source density to determine the Gaia Data Release 2 source detection sensitivity as a function of angular separation and brightness ratio from a bright source. The contrast sensitivity from ∼0.4″ out to 12″ ranges in ΔG = 0–14 mag. We find the derived contrast sensitivity to be robust with respect to target brightness, colour, source density, and Gaia scan coverage.
Direct evidence of a full dipole flip during the magnetic cycle of a sun-like star
Authors: Boro Saikia S. , Lueftinger T. , Jeffers S. V. , Folsom C. P. , See V. , Petit P. , Marsden S. C. , Vidotto A. A. , Morin J. , Reiners A. , Guedel M. ,   the BCool Collaboration
Published: November 2018

Context.The behaviour of the large-scale dipolar field, during a star’s magnetic cycle, can provide valuable insight into the stellar dynamo and associated magnetic field manifestations such as stellar winds.

Aims.We investigate the temporal evolution of the dipolar field of the K dwarf 61 Cyg A using spectropolarimetric observations covering nearly one magnetic cycle equivalent to two chromospheric activity cycles.

Methods.The large-scale magnetic field geometry is reconstructed using Zeeman Doppler imaging, a tomographic inversion technique. Additionally, the chromospheric activity is also monitored.

Results.The observations provide an unprecedented sampling of the large-scale field over a single magnetic cycle of a star other than the Sun. Our results show that 61 Cyg A has a dominant dipolar geometry except at chromospheric activity maximum. The dipole axis migrates from the southern to the northern hemisphere during the magnetic cycle. It is located at higher latitudes at chromospheric activity cycle minimum and at middle latitudes during cycle maximum. The dipole is strongest at activity cycle minimum and much weaker at activity cycle maximum.

Conclusions.The behaviour of the large-scale dipolar field during the magnetic cycle resembles the solar magnetic cycle. Our results are further confirmation that 61 Cyg A indeed has a large-scale magnetic geometry that is comparable to the Sun’s, despite being a slightly older and cooler K dwarf.
The influence of temperature on algal biomass growth for biogas production
Authors: Pawlita-Posmyk Monika , Wzorek Małgorzata , Płaczek Małgorzata
Published: November 2018

The use of algae is gaining popularity in recent years. Algae can form a suitable substrate for biogas production because they are low in cellulose and have low lignin content. The paper contains a summary with the list of the algae species applied for the biogas production process to this date, coupled with the description of the characteristic conditions in which the process is conducted. The key importance factors during the production of biogas include, among others, grade of algae species used, temperature of the process, mode in which the material is supplied into the tank, mixing method, use of co-substrate, etc. This paper reports the results of the study involving the effect of various temperature conditions on the characteristics of the growth rate of algal biomass. The research was performed for the Chlorella vulgaris BA-0167 strain in the temperature range corresponding to the mesophilic fermentation processes in anaerobic conditions.
Rekonstruktionstechniken der posterioren Augenlidlamelle
Authors: Kopecky Adam , Rokohl Alexander , Heindl Ludwig
Published: November 2018

Große durchgreifende Liddefekte waren und sind eine der größten Herausforderungen in der ophthalmoplastischen Chirurgie. Ziel dieser Übersichtsarbeit ist es, verschiedene Rekonstruktionstechniken der hinteren Lidlamelle darzustellen sowie die Indikationen, Vor- und Nachteile der einzelnen Techniken herauszuarbeiten.
Mobile Applikationen in der psychotherapeutischen Praxis:
Chancen und Grenzen
Authors: Rathner Eva-Maria , Probst Thomas
Published: November 2018

Aufgrund der weiten Verbreitung von Gesundheits-Apps ist es von besonderer
Bedeutung, die Qualität in den Fokus zu rücken. Doch wie können Wirksamkeit und
Datenschutz für Leistungsträger, Leistungserbringer und End-User sichtbar
gemacht werden? Der Beitrag geht dieser Frage nach, damit informierte
Gesundheitsentscheidungen getroffen werden können.
Ein Thema, das es auszusitzen gilt, bis sich die Wogen
geglättet haben?
Authors: Wiegand-Grefe Silke , Flückiger Christoph
Published: November 2018

Bei den Vorbereitungen zu diesem Heft hatten wir im Herausgeberteam eine Debatte
darüber, inwieweit PiD auf das aktuell äußerst stark bewirtschaftete Thema
E-Mental-Health aufspringen sollte. Gibt es genügend neue Entwicklungen in diesem
Bereich, die es überhaupt zu berichten gäbe? Würden hier falsche Zeichen gesetzt?
Ist E-Mental-Health eine Konkurrenz für direkten PatientInnen-Kontakt? Würden wir
die Gräben eher öffnen als sie zu schließen?
Grundlagen der Optik
Authors: Buser Annemarie , Baumbach Peter , von Livonius Bettina
Published: November 2018

Als Augenarzt ist es sehr wichtig zu wissen, ob eine eingeschränkte Sehkraft refraktiv bedingt ist oder ob eine andere Pathologie dahintersteckt. Die Refraktion nimmt daher am Anfang einer jeden Augenuntersuchung einen wichtigen Stellenwert ein. Dafür ist es wichtig, die Grundgesetze der Optik zu kennen. So ist es bei der Anpassung von sphärischen und zylindrischen Gläsern interessant zu wissen, welche Eigenschaften die jeweiligen Linsen haben. Auch sollte man über die Strahlengänge und Brechungsgesetze bei der Anpassung von Brillengläsern und Prismen Bescheid wissen. Zudem sollte man bei der Verordnung von Brillengläsern Hornhautscheitelabstandsänderungen beachten und Umrechnungen für die Stärke von Kontaktlinsen kennen. Nur wenn man ein tieferes Verständnis für die Refraktion und die Korrektion fehlsichtiger Augen hat, kann man auch optimale Sehhilfen bei schwierigeren Refraktionsverhältnissen anpassen.
Acute on Chronic Liver Failure and Immune Dysfunction: A Mimic of Sepsis
Authors: Hensley Matthew , Deng Jane
Published: November 2018

Both the adaptive and innate arms of immunity are altered in patients with cirrhosis, which have both prognostic and clinical implications. Acute on chronic liver failure (ACLF), defined as decompensated cirrhosis with associated organ failure, carries a high risk of 28-day mortality and is marked by a significant inflammatory response. Patients with decompensated chronic liver disease display a shift from a chronic low-grade inflammatory state to one of intense inflammation, followed by the development of immunoparalysis. Considerable heterogeneity exists depending on the nature of the inciting cause and duration of ACLF. In this review, we will highlight the changes that immune cell populations in the liver undergo during decompensated liver disease, underscoring the immunological paradox between inflammation and increased susceptibility to infection that occurs during ACLF and progressive cirrhosis, as well as provide future perspectives regarding potentially useful biomarkers and possible avenues for treatment.
Perioperative Considerations in Liver Transplantation
Authors: Cortes Lopez Roxana , Steadman Randolph , Wray Christopher , Qadir Nida , Chang Steven Y. , Wang Tisha , Barjaktarevic Igor
Published: November 2018

Liver transplantation (LT) has the potential to cure patients with acute and chronic liver failure as well as a number of hepatic and biliary malignancies. Over time, due to the increasing demand for organs as well as improvements in the survival of LT recipients, patients awaiting LT have become sicker, and often undergo the procedure while critically ill. This trend has made the process of preoperative assessment and planning, intraoperative management, and postoperative management even more crucial to the success of LT programs. Multidisciplinary and specialized teams are essential and include anesthesiologists, surgeons, and intensivists. This article focuses on the preoperative evaluation, intraoperative care, and postoperative management of the liver transplant patient. Management relevant to the critically ill patient is discussed, with a focus on the management of postoperative cardiopulmonary conditions including the care of special populations such as those with hepatopulmonary syndrome and portopulmonary hypertension.
An Improved Method of Percutaneous Transhepatic Biliary Drainage Combining Ultrasound-Guided Bile Duct Puncture with Metal Stent Implantation by Fluoroscopic Guidance and Endoscopic Visualization as a One-Step Procedure: A Retrospective Cohort Study
Authors: Schmitz Daniel , Weller Niels , Doll Matthias , Weingärtner Simon , Pelaez Nuria , Reinmuth Gabriele , Hetjens Svetlana , Rudi Jochen
Published: November 2018

Aims In recently published comparative studies, it is reported that percutaneous transhepatic biliary drainage (PTBD) is less successful, causes more adverse events, and needs more re-interventions than endoscopic ultrasound-guided biliary drainage (EUS-BD) in patients with malignant extrahepatic bile duct obstruction when endoscopic retrograde cholangiopancreatography (ERCP) fails. Could an improved technique of PTBD produce better results to use this technique for further comparative studies with EUSBD?

Methods In our tertiary referral hospital, 116 prospectively documented, and retrospectively analyzed PTBDs with ultrasound guided ductal puncture were performed. In 16 of 30 PTBDs with metal stent implantation in malignant diseases, metal stent was inserted as a one-step procedure by endoscopic luminal guidance in the first session.

Results Fifteen of 16 (94%) or 14/16 (88%) of PTBDs with primary metal stent implantation were technically or clinically successful. Mainly the left liver was used as access route for PTBD. Procedure time was 68.1 minutes (25–118), fluoroscopic time: 18.6 minutes (3–46), and patient radiation exposure: 5957 μGy/m2 (471–17,569). In 2/16 (12.5%) patients, adverse events (1 × mild and 1 × moderate grade of severity) were documented. One re-intervention was necessary (0.1/patient) in the observation time of 6 months. The mean overall survival time was 163.2 (7–864) days after PTBD.

Conclusions PTBD with ultrasound-guided ductal puncture and primary metal implantation by endoscopic luminal guidance in patients with malignant extrahepatic bile duct obstruction showed good technical and clinical success and low adverse event and reintervention rates in our retrospective cohort study.

Clinical Trial Registration: ClinicalTrials.gov ID: NCT03541590.
Evaluation of Clinical Relevance of Drug–Drug Interaction Alerts Prior to Implementation
Authors: Meslin S. , Zheng W. , Day R. , Tay E. , Baysari M.
Published: November 2018

Introduction Drug–drug interaction (DDI) alerts are often implemented in the hospital computerized provider order entry (CPOE) systems with limited evaluation. This increases the risk of prescribers experiencing too many irrelevant alerts, resulting in alert fatigue. In this study, we aimed to evaluate clinical relevance of alerts prior to implementation in CPOE using two common approaches: compendia and expert panel review.

Methods After generating a list of hypothetical DDI alerts, that is, alerts that would have been triggered if DDI alerts were operational in the CPOE, we calculated the agreement between multiple drug interaction compendia with regards to the severity of these alerts. A subset of DDI alerts (n = 13), with associated patient information, were presented to an expert panel to reach a consensus on whether each alert should be included in the CPOE.

Results There was poor agreement between compendia in their classifications of DDI severity (Krippendorff's α: 0.03; 95% confidence interval: –0.07 to 0.14). Only 10% of DDI alerts were classed as severe by all compendia. On the other hand, the panel reached consensus on 12 of the 13 alerts that were presented to them regarding whether they should be included in the CPOE.

Conclusion Using an expert panel and allowing them to discuss their views openly likely resulted in high agreement on what alerts should be included in a CPOE system. Presenting alerts in the context of patient cases allowed panelists to identify the conditions under which alerts were clinically relevant. The poor agreement between compendia suggests that this methodology may not be ideal for the evaluation of DDI alerts. Performing preimplementation review of DDI alerts before they are enabled provides an opportunity to minimize the risk of alert fatigue before prescribers are exposed to false-positive alerts.
On the quantum-mechanics of a single photon
Authors: Kiessling Michael K.-H. , Tahvildar-Zadeh A. Shadi
Published: November 2018

It is shown that a Dirac(-type) equation for a rank-two bi-spinor field ψph on Minkowski (configuration) spacetime furnishes a Lorentz-covariant quantum-mechanical wave equation in position-space representation for a single free photon. This equation does not encounter any of the roadblocks that have obstructed previous attempts (by various authors) to formulate a quantum-mechanical photon wave equation. In particular, it implies that the photon wave function ψph yields conserved non-negative Born-rule-type quantum probabilities and that its probability current density four-vector transforms properly under Lorentz transformations. Moreover, the eigenvalues of the pertinent photon Dirac Hamiltonian and the vector eigenvalues of the photon momentum operator yield the familiar Einstein relations E = ℏω and p = ℏk, respectively. Furthermore, these spin-1 wave modes are automatically transversal without the need of an additional constraint on the initial data. Some comments on other proposals to set up a photon wave equation are supplied as well.
Nano-scale wave dispersion beyond the First Brillouin Zone simulated with inertia gradient continua
Authors: De Domenico Dario , Askes Harm
Published: November 2018

Nano-scale wave dispersion beyond the First Brillouin Zone is often observed as descending branches and inflection points when plotting frequency or phase velocity against the wave number. Modeling this with discrete chain models is hampered by their restricted resolution. A continuum model equipped with higher-order inertia gradients is here developed as a suitable and versatile alternative. This model can be derived from discrete chain models, thereby providing a lower-scale motivation for the higher-order gradient terms. The derived gradient model is without free parameters, as the material constants are calculated a priori by minimising the error with respect to the discrete chain response. Unlike asymptotic approximations that provide a best fit for vanishing wave numbers, the error is here minimised over the entire range of reduced wave numbers 0 to 1, which leads to a much improved accuracy beyond the First Brillouin Zone. The new gradient model has been validated against (i) phonon dispersion curves measured through neutron scattering experiments in bismuth, aluminum, and nickel and (ii) Molecular Dynamics (MD) flexural wave propagation simulations of carbon nanotubes. The model captures all qualitative aspects of the experimental and MD dispersion curves without requiring a bespoke curve fitting procedure. With the exception of one set of MD results, the accuracy of the gradient model is very good.
Atomic and electronic structure of the Si(331)-(12 × 1) surface
Authors: Zhachuk Ruslan , Coutinho José , Palotás Krisztián
Published: November 2018

We report on the investigation of the atomic and electronic structures of a clean Si(331)-(12 × 1) surface using a first-principles approach with both plane wave and strictly localized basis sets. Starting from the surface structure proposed by Zhachuk and Teys [Phys. Rev. B 95, 041412(R) (2017)], we develop significant improvements to the atomic model and localized basis set which are critical for the correct description of the observed bias dependence of scanning tunneling microscopy (STM) images. The size mismatch between the Si pentamers from the surface model and those seen by STM is explained within the context of the Tersoff-Hamann model. The energy barriers that separate different Si(331) buckled configurations were estimated, showing that the surface structure is prone to dynamic buckling at room temperature. It is found that empty electronic states on Si(331) are essentially localized on the pentamers with interstitials and under-coordinated Si sp2-like atoms between them, while filled electronic states are localized on under-coordinated Si sp3-like atoms and dimers on trenches. The calculated electronic density of states exhibits two broad peaks in the fundamental bandgap of Si: one near the valence band top and the other near the conduction band bottom. The resulting surface bandgap of 0.58 eV is in an excellent agreement with spectroscopy studies.
Experimental observation of drift wave turbulence in an inhomogeneous six-pole cusp magnetic field of MPD
Authors: Patel A. D. , Sharma M. , Ganesh R. , Ramasubramanian N. , Chattopadhyay P. K.
Published: November 2018

This paper presents a detailed study on the controlled experimental observation of drift wave instabilities in an inhomogeneous six pole cusp magnetic field generated by an in-house developed multi-pole line cusp magnetic field device [Patel et al., Rev. Sci. Instrum. 89, 043510 (2018)]. The device is composed of six axially symmetric cusps and non-cusp (in between two consecutive magnets) regions. The observed instability has been investigated in one of these non-cusp regions by controlling the radial plasma density gradient with changing pole magnetic field which is a unique feature of this device. It has been observed that the frequency of the instability changes explicitly with the density gradient. Moreover, the scale lengths of plasma parameters, frequency spectrum, cross-correlation function, and fluctuation level of plasma densities have been measured in order to identify the instability. The cross field drift velocity due to fluctuation in plasma parameters has been measured from the wave number-frequency S (kz, ω) spectrum and verified with the theoretical values obtained from density scale length formula. Further, from the S (kz, ω) spectrum, it has been found that the drift velocity alternates the sign in the consecutive non-cusp regions.
Joint measurability of quantum effects and the matrix diamond
Authors: Bluhm Andreas , Nechita Ion
Published: November 2018

In this work, we investigate the joint measurability of quantum effects and connect it to the study of free spectrahedra. Free spectrahedra typically arise as matricial relaxations of linear matrix inequalities. An example of a free spectrahedron is the matrix diamond, which is a matricial relaxation of the ℓ1-ball. We find that joint measurability of binary positive operator valued measures is equivalent to the inclusion of the matrix diamond into the free spectrahedron defined by the effects under study. This connection allows us to use results about inclusion constants from free spectrahedra to quantify the degree of incompatibility of quantum measurements. In particular, we completely characterize the case in which the dimension is exponential in the number of measurements. Conversely, we use techniques from quantum information theory to obtain new results on spectrahedral inclusion for the matrix diamond.
Thermal conductivity in self-assembled CoFe2O4/BiFeO3 vertical nanocomposite films
Authors: Zhang Chen , Huberman Samuel C. , Ning Shuai , Pelliciari Jonathan , Duncan Ryan A. , Liao Bolin , Ojha Shuchi , Freeland John W. , Nelson Keith A. , Comin Riccardo , Chen Gang , Ross Caroline A.
Published: November 2018

The thermal conductivity of self-assembled nanocomposite oxide films consisting of cobalt ferrite (CFO) spinel pillars grown within a single-crystal bismuth ferrite (BFO) perovskite matrix is described as a function of the volume fraction of the spinel. Single phase BFO and CFO had cross-plane thermal conductivities of 1.32 W m−1 K−1 and 3.94 W m−1 K−1, respectively, and the thermal conductivity of the nanocomposites increased with the CFO volume fraction within this range. A small increase (∼5%) in thermal conductivity for the pure CFO phase in the AC-demagnetized state was observed, suggesting possible magnon contributions. Steady state gray-medium based variance-reduced Monte Carlo simulations show consistent trends with experimental data on the dependence of thermal conductivity with the CFO volume fraction.
Understanding and predicting geometrical constraint ferroelectric charged domain walls in a BiFeO3 island via phase-field simulations
Authors: Peng Ren-Ci , Cheng Xiaoxing , Ma Ji , Huang Houbing , Ma Jing , Chen Long-Qing , Nan Ce-Wen
Published: November 2018

It has been known that ferroelectric charged domain walls (CDWs), which break the polarization continuity, may be electrically active with an elevated conductivity. However, the bound charge at CDWs may render them energetically unstable, and thus, forming CDWs naturally and manipulating them electrically is still challenging. Here, we theoretically utilize phase-field simulations to design spontaneously generated CDWs with center-type quad-domains in a single square-shaped BiFeO3 nanoisland. It is shown that the stability of the spontaneously emerging head-to-head domain walls with center-convergent quad-domains is mainly determined by three contributions, namely, the geometrical constraint from approximately 45°-tilted bottom edges, the electric boundary condition, and the necessary screening free charges to compensate head-to-head domain walls. It is demonstrated that the center-convergent quad-domains with head-to-head CDWs can be electrically switched to the center-divergent one with tail-to-tail CDWs, providing guidance for achieving ferroelectric domain-wall-based nanodevices with low-power dissipation.
Tuning martensitic transitions in (MnNiSi)0.65(Fe2Ge)0.35 through heat treatment and hydrostatic pressure
Authors: Chen Jing-Han , Us Saleheen Ahmad , Karna Sunil K. , Young David P. , Dubenko Igor , Ali Naushad , Stadler Shane
Published: November 2018

A first-order magneto-structural transition from a ferromagnetic orthorhombic TiNiSi-type martensite phase to a paramagnetic hexagonal Ni2In-type austenite phase was observed in (MnNiSi)0.65(Fe2Ge)0.35. In this work, we demonstrate that the first-order magneto-structural transition temperature for a given composition is tunable over a wide temperature range through heat treatment and hydrostatic pressure. The first-order transition temperature was reduced by over 100 K as the annealing temperature went from 600 to 900 °C, and this first-order transition was converted to second order when the sample was annealed at 1000 °C. The maximum magnetic-induced isothermal entropy change with μ0ΔH=7 T reaches −58 J/kg K for the sample annealed at 600 °C, and the relative cooling power reaches 558 J/kg for the sample annealed at 700 °C. Similar to the influence of annealing temperatures, the first-order martensitic transition temperatures were reduced as the application of hydrostatic pressure increased until they were converted to second order. Our results suggest that the (MnNiSi)0.65(Fe2Ge)0.35 system is a promising platform for tuning magneto-structural transitions and the associated magnetocaloric effects. Furthermore, a similar heat treatment methodology or application of hydrostatic pressure can be applied to MnNiSi-based shape memory alloys to tailor their working transition temperatures.
A- and B-exciton photoluminescence intensity ratio as a measure of sample quality for transition metal dichalcogenide monolayers
Authors: McCreary Kathleen M. , Hanbicki Aubrey T. , Sivaram Saujan V. , Jonker Berend T.
Published: November 2018

The photoluminescence (PL) in monolayer transition metal dichalcogenides (TMDs) is dominated by the recombination of electrons in the conduction band with holes in the spin-orbit split valence bands, and there are two distinct emission features referred to as the A-peak (ground state exciton) and B-peak (higher spin-orbit split state). The intensity ratio of these two features varies widely, and several contradictory interpretations have been reported. In this work, we analyze the room temperature PL from MoS2, MoSe2, WS2, and WSe2 monolayers and identify the underlying cause of observed variations in emission profile. We determine that PL variations arise from differences in the non-radiative recombination associated with defect densities. Therefore, the relative intensities of the A- and B-emission features can be used to qualitatively assess the non-radiative recombination and a low B/A ratio is indicative of low defect density and high sample quality. We also performed polarization-resolved PL measurements. Emission from TMD monolayers is governed by unique optical selection rules which make them promising materials for valleytronic operations. We observe a notably higher valley polarization in the B-exciton relative to the A-exciton. The high polarization is a consequence of the shorter B-exciton lifetime resulting from rapid relaxation of excitons from the B-exciton to the A-exciton of the valence band. Our work clarifies disparities reported in the literature relating to the emission profile and provides a straightforward means to assess sample quality.