bluuebunny/crossref_metadata_2025 huggingface dataset:
The 2‐D Structure of Foreshock‐Driven Field Line Resonances Observed by THEMIS Satellite and Ground‐Based Imager Conjunctions
Authors: Wang Boyi , Nishimura Yukitoshi , Zhang Hui , Shen Xiao‐Chen , Lyons Larry , Angelopoulos Vassilis , Ebihara Yusuke , Weatherwax Allan , Gerrard Andrew J. , Frey Harald U.
Published: July 2019

Recent studies of Pc5‐band (150–600 s) ultralow frequency waves found that foreshock disturbances can be a driver of dayside compressional waves and field line resonance, which are two typical Pc5 wave modes in the dayside magnetosphere. However, it is difficult to find spatial structure of dayside Pc5 waves using a small number of satellites or ground magnetometers. This study determines 2‐D structure of dayside Pc5 waves and their driver by utilizing coordinated observations by the THEMIS satellites and the all‐sky imager at South Pole during two series of Pc5 waves on 29 June 2008. These Pc5 waves were found to be field line resonances (FLRs) and driven by foreshock disturbances. The ground‐based all‐sky imager at South Pole shows that periodic poleward moving arcs occurred simultaneously with the FLRs near the satellite footprints over ~3° latitude and had the same frequencies as FLRs. This indicates that they are the auroral signature of the FLRs. The azimuthal distribution of the FLRs in the magnetosphere and their north‐south width in the ionosphere were further determined in the 2‐D images. In the first case, the FLRs distribute symmetrically in the prenoon and postnoon regions with out‐of‐phase oscillation as the odd toroidal mode in the equatorial plane. In the second case, the azimuthal wavelengths of the 350–500 s and 300–450 s period waves were ~8.0 and ~5.2 Re in the equatorial plane. It also shows a fine azimuthal structure embedded in the large‐scale arcs, indicating that a high azimuthal wave number (m ~ 140) mode wave coupled with the low‐wave number FLRs.
Electron Energization by Parallel Electric Fields in Poloidal Standing Waves
Authors: Damiano P. A. , Kim E.‐H. , Johnson J. R. , Porazik P.
Published: July 2019

A hybrid gyrofluid‐kinetic electron model is adapted and used to simulate poloidal standing modes for different electron temperatures and azimuthal mode numbers. As in previous studies of toroidal standing modes, mirror force effects lead to increased parallel potential drops, monoenergetic electron energization, and wave energy dissipation as the ambient electron temperature is increased. A similar trend is also observed when the electron temperature is held fixed and the azimuthal mode number increased—owing to the narrowing of the azimuthal flux tube width, which necessitates more electron energization to carry the increased parallel current density. In both cases, the increase in electron energization eventually leads to more rapid decreases in the parallel current with time because of the dissipation of wave energy.
Strong stress-composition coupling in lithium alloy nanoparticles
Authors: Seo Hyeon Kook , Park Jae Yeol , Chang Joon Ha , Dae Kyun Sung , Noh Myoung-Sub , Kim Sung-Soo , Kang Chong-Yun , Zhao Kejie , Kim Sangtae , Yuk Jong Min
Published: July 2019

The stress inevitably imposed during electrochemical reactions is expected to fundamentally affect the electrochemistry, phase behavior and morphology of electrodes in service. Here, we show a strong stress-composition coupling in lithium binary alloys during the lithiation of tin-tin oxide core-shell nanoparticles. Using in situ graphene liquid cell electron microscopy imaging, we visualise the generation of a non-uniform composition field in the nanoparticles during lithiation. Stress models based on density functional theory calculations show that the composition gradient is proportional to the applied stress. Based on this coupling, we demonstrate that we can directionally control the lithium distribution by applying different stresses to lithium alloy materials. Our results provide insights into stress-lithium electrochemistry coupling at the nanoscale and suggest potential applications of lithium alloy nanoparticles.
The structural basis of N-acyl-α-amino-β-lactone formation catalyzed by a nonribosomal peptide synthetase
Authors: Kreitler Dale F. , Gemmell Erin M. , Schaffer Jason E. , Wencewicz Timothy A. , Gulick Andrew M.
Published: July 2019

Nonribosomal peptide synthetases produce diverse natural products using a multidomain architecture where the growing peptide, attached to an integrated carrier domain, is delivered to neighboring catalytic domains for bond formation and modification. Investigation of these systems can lead to the discovery of new structures, unusual biosynthetic transformations, and to the engineering of catalysts for generating new products. The antimicrobial β-lactone obafluorin is produced nonribosomally from dihydroxybenzoic acid and a β-hydroxy amino acid that cyclizes into the β-lactone during product release. Here we report the structure of the nonribosomal peptide synthetase ObiF1, highlighting the structure of the β-lactone-producing thioesterase domain and an interaction between the C-terminal MbtH-like domain with an upstream adenylation domain. Biochemical assays examine catalytic promiscuity, provide mechanistic insight, and demonstrate utility for generating obafluorin analogs. These results advance our understanding of the structural cycle of nonribosomal peptide synthetases and provide insights into the production of β-lactone natural products.
Variational consistent histories as a hybrid algorithm for quantum foundations
Authors: Arrasmith Andrew , Cincio Lukasz , Sornborger Andrew T. , Zurek Wojciech H. , Coles Patrick J.
Published: July 2019

Although quantum computers are predicted to have many commercial applications, less attention has been given to their potential for resolving foundational issues in quantum mechanics. Here we focus on quantum computers’ utility for the Consistent Histories formalism, which has previously been employed to study quantum cosmology, quantum paradoxes, and the quantum-to-classical transition. We present a variational hybrid quantum-classical algorithm for finding consistent histories, which should revitalize interest in this formalism by allowing classically impossible calculations to be performed. In our algorithm, the quantum computer evaluates the decoherence functional (with exponential speedup in both the number of qubits and the number of times in the history) and a classical optimizer adjusts the history parameters to improve consistency. We implement our algorithm on a cloud quantum computer to find consistent histories for a spin in a magnetic field and on a simulator to observe the emergence of classicality for a chiral molecule.
Multiple origins of prokaryotic and eukaryotic single-stranded DNA viruses from bacterial and archaeal plasmids
Authors: Kazlauskas Darius , Varsani Arvind , Koonin Eugene V. , Krupovic Mart
Published: July 2019

Single-stranded (ss) DNA viruses are a major component of the earth virome. In particular, the circular, Rep-encoding ssDNA (CRESS-DNA) viruses show high diversity and abundance in various habitats. By combining sequence similarity network and phylogenetic analyses of the replication proteins (Rep) belonging to the HUH endonuclease superfamily, we show that the replication machinery of the CRESS-DNA viruses evolved, on three independent occasions, from the Reps of bacterial rolling circle-replicating plasmids. The CRESS-DNA viruses emerged via recombination between such plasmids and cDNA copies of capsid genes of eukaryotic positive-sense RNA viruses. Similarly, the rep genes of prokaryotic DNA viruses appear to have evolved from HUH endonuclease genes of various bacterial and archaeal plasmids. Our findings also suggest that eukaryotic polyomaviruses and papillomaviruses with dsDNA genomes have evolved via parvoviruses from CRESS-DNA viruses. Collectively, our results shed light on the complex evolutionary history of a major class of viruses revealing its polyphyletic origins.
Author Correction: Rapid fabrication of reinforced and cell-laden vascular grafts structurally inspired by human coronary arteries
Authors: Akentjew Tamara L. , Terraza Claudia , Suazo Cristian , Maksimcuka Jekaterina , Wilkens Camila A. , Vargas Francisco , Zavala Gabriela , Ocaña Macarena , Enrione Javier , García-Herrera Claudio M. , Valenzuela Loreto M. , Blaker Jonny J. , Khoury Maroun , Acevedo Juan Pablo
Published: July 2019

An amendment to this paper has been published and can be accessed via a link at the top of the paper
Many-body simulation of two-dimensional electronic spectroscopy of excitons and trions in monolayer transition metal dichalcogenides
Authors: Tempelaar Roel , Berkelbach Timothy C.
Published: July 2019

Indications of coherently interacting excitons and trions in doped transition metal dichalcogenides have been measured as quantum beats in two-dimensional electronic spectroscopy, but the microscopic principles underlying the optical signals of exciton-trion coherence remain to be clarified. Here we present calculations of two-dimensional spectra of such monolayers based on a microscopic many-body formalism. We use a parameterized band structure and a static model dielectric function, although a full ab initio implementation of our formalism is possible in principle. Our simulated spectra are in excellent agreement with experiments, including the quantum beats, while revealing the interplay between excitons and trions in molybdenum- and tungsten-based transition metal dichalcogenides. Quantum beats are confirmed to unambiguously reflect the exciton-trion coherence time in molybdenum compounds, but are shown to provide a lower bound to the coherence time for tungsten analogues due to a destructive interference from coexisting singlet and triplet trions.
AIEE Active Nanoassemblies of Pyrazine Based Organic Photosensitizers as Efficient Metal-Free Supramolecular Photoredox Catalytic Systems
Authors: Dadwal Shruti , Deol Harnimarta , Kumar Manoj , Bhalla Vandana
Published: July 2019

Pyrazine derivatives DIPY, TETPY and CNDIPY have been designed and synthesized which form fluorescent supramolecular assemblies in mixed aqueous media due to their AIEE and ICT characteristics. Among all the derivatives, the assemblies of TETPY and CNDIPY show strong absorption in the visible region with high absorption coefficients, low HOMO-LUMO gap, and high photostability. Further, the supramolecular nanoassemblies of TETPY and CNDIPY show excellent potential to generate reactive oxygen species (ROS) under the visible light irradiation. Owing to their strong absorption in the visible region and ROS generation ability, the supramolecular nanoassemblies of TETPY and CNDIPY act as efficient photoredox catalytic systems for carrying out (a) oxidative amidation of aromatic aldehydes (b) hydroxylation of boronic acid and (c) oxidative homocoupling of benzylamines under mild conditions such as aqueous media, aerial environment, and natural sunlight as a source of irradiation. All the mechanistic investigations suggest the participation of in-situ generated ROS in the organic transformations upon light irradiation.
Evaluation of a digitally-enabled care pathway for acute kidney injury management in hospital emergency admissions
Authors: Connell Alistair , Montgomery Hugh , Martin Peter , Nightingale Claire , Sadeghi-Alavijeh Omid , King Dominic , Karthikesalingam Alan , Hughes Cian , Back Trevor , Ayoub Kareem , Suleyman Mustafa , Jones Gareth , Cross Jennifer , Stanley Sarah , Emerson Mary , Merrick Charles , Rees Geraint , Laing Chris , Raine Rosalind
Published: July 2019

We developed a digitally enabled care pathway for acute kidney injury (AKI) management incorporating a mobile detection application, specialist clinical response team and care protocol. Clinical outcome data were collected from adults with AKI on emergency admission before (May 2016 to January 2017) and after (May to September 2017) deployment at the intervention site and another not receiving the intervention. Changes in primary outcome (serum creatinine recovery to ≤120% baseline at hospital discharge) and secondary outcomes (30-day survival, renal replacement therapy, renal or intensive care unit (ICU) admission, worsening AKI stage and length of stay) were measured using interrupted time-series regression. Processes of care data (time to AKI recognition, time to treatment) were extracted from casenotes, and compared over two 9-month periods before and after implementation (January to September 2016 and 2017, respectively) using pre–post analysis. There was no step change in renal recovery or any of the secondary outcomes. Trends for creatinine recovery rates (estimated odds ratio (OR) = 1.04, 95% confidence interval (95% CI): 1.00–1.08, p = 0.038) and renal or ICU admission (OR = 0.95, 95% CI: 0.90–1.00, p = 0.044) improved significantly at the intervention site. However, difference-in-difference analyses between sites for creatinine recovery (estimated OR = 0.95, 95% CI: 0.90–1.00, p = 0.053) and renal or ICU admission (OR = 1.06, 95% CI: 0.98–1.16, p = 0.140) were not significant. Among process measures, time to AKI recognition and treatment of nephrotoxicity improved significantly (p < 0.001 and 0.047 respectively).
Recent Advances in Antimicrobial Hydrogels
Authors: Kunduru Konda Reddy , Domb Abraham J.
Published: July 2019

Antibiotic resistance in pathogens is a global healthcare challenge. Localized application of antimicrobial materials is a good choice to overcome antimicrobial resistance. A hydrogel matrix is one of the prominent choices for the localized application of antimicrobials. Hydrogels are fabricated from either natural or synthetic polymers. They contain a three-dimensional network with crosslinked hydrophilic polymer chains and retain a large amount of water. Hydrogels have been applied for various biomedical purposes such as drug delivery, tissue engineering, wound care, and implant coating. In this chapter, we discuss recent advancements in antimicrobial hydrogels. Various antimicrobial hydrogel categories possessing inherent antimicrobial activities and hydrogels loaded with antimicrobial materials such as metal nanoparticles, antibiotics, peptides and other molecules are discussed.
Overview of Antimicrobial Resistance and Nanoparticulate Drug Delivery Approach to Combat Antimicrobial Resistance
Authors: Saravanan Muthupandian , Ashagrie Melaku , Ali Omar , Ramachandran Balajee
Published: July 2019

Although high numbers of novel antibiotics are available in the market currently, it is still a challenge to treat intracellular pathogens. These therapeutic agents always need to be used in high doses, as their antibiotic concentrations are often sub-therapeutic. This is expensive and results in adverse systemic and localized side effects. The current rising threat of antibiotic resistance further complicates the treatment of intracellular pathogenic diseases. As a result, there is a crucial need for methods and systems that enable physicians to attain therapeutically effective intracellular concentrations of those antibiotics. In this scenario, the use of drug delivery systems carrying antibiotics showing targeted and effective antibacterial activity in vitro need to be considered and given due attention. Incorporating or encapsulating antibacterial drugs within these unique drug delivery systems offers better control of pharmacokinetic behavior of the active bactericidal molecule. Such new and advanced methods will replace old conventional antibiotics, which are becoming unusable due to resistance or toxicity. They are vital in rescuing the last-line therapeutic antibiotics through advancing the therapeutic index, broadening the antibiotic antimicrobial spectrum and avoiding failure due to membrane permeability problems, and thus shortening the current time required by classical treatments and reducing the extent of drug resistance. Hence, new and improved drug carriers have been established for treating intracellular pathogens, including antibiotics loaded into hydrogels, liposomes, micelles, polymeric carriers, and metal nanoparticles. This chapter focuses on the role of a drug delivery system as a potential tool against intracellular bacterial pathogens.
Kolbe–Schmitt type reaction under ambient conditions mediated by an organic base
Authors: Sadamitsu Yuta , Okumura Akira , Saito Kodai , Yamada Tohru
Published: July 2019

The combined use of carbon dioxide and an organic base for resorcinols realized a Kolbe–Schmitt type reaction under ambient conditions.
Controlled release of hydrogen sulfide significantly reduces ROS stress and increases dopamine levels in transgenic C. elegans
Authors: Ali Rafat , Pal Hilal Ahmad , Hameed Rohil , Nazir Aamir , Verma Sandeep
Published: July 2019

A novel peptide based system has been developed that exhibits slow and sustained H2S release thereby reducing hydrogen peroxide-induced oxidative stress and increasing dopamine levels in a transgenic C. elegans model.
DABCO-mediated [3+3] annulation of para-quinamines: access to functionalized 1,2,4-triazinone derivatives
Authors: Zhu Yannan , Jin Hongxing , Huang You
Published: July 2019

A new [3+3]-annulation of p-quinamines and nitrile imines for affording 1,2,4-triazinone derivatives with excellent yields and excellent diastereoselectivity.
Solvation dynamics: improved reproduction of the time-dependent Stokes shift with polarizable empirical force field chromophore models
Authors: Heid Esther , Schmode Stella , Chatterjee Payal , MacKerell Alexander D. , Schröder Christian
Published: July 2019

The inclusion of polarizability slows down the computed solvation dynamics due to interactions of induced dipoles, improving agreement to experiment.
Rapid flow-through fractionation of biomass to preserve labile aryl ether bonds in native lignin
Authors: Zhou Hao , Xu Jia Yun , Fu Yingjuan , Zhang Haiguang , Yuan Zaiwu , Qin Menghua , Wang Zhaojiang
Published: July 2019

Effective isolation of lignin containing native aryl ether linkages.
Integrated microfluidic systems with sample preparation and nucleic acid amplification
Authors: Yin Juxin , Suo Yuanjie , Zou Zheyu , Sun Jingjing , Zhang Shan , Wang Beng , Xu Yawei , Darland Diane , Zhao Julia Xiaojun , Mu Ying
Published: July 2019

Integrated microfluidic systems with sample preparation and nucleic acid amplification can increase treatment efficiency and improve care.
A comprehensive DFT study on the sensing abilities of cyclic oligothiophenes (nCTs)
Authors: Sajid Hasnain , Ayub Khurshid , Mahmood Tariq
Published: July 2019

Linear conducting polymers are extensively studied as sensors for various analytes, whereas studies on cyclic analogues are limited.
Self-assembly of graphene-encapsulated antimony sulfide nanocomposites for photoredox catalysis: boosting charge transfer via interface configuration modulation
Authors: Zhang Bei-Bei , Huang Ming-Hui , Dai Xiao-Cheng , Li Tao , Li Yu-Bing , Hou Shuo , He Yunhui , Xiao Guangcan , Xiao Fang-Xing
Published: July 2019

Charge transfer over Sb2S3–GR nanocomposites was tuned by exquisite interface configuration engineering, which results in enhanced photoredox performances under visible light irradiation.
Ratiometric emission NIR-fluorescent probe for the detection of lysosomal pH in living cells andin vivo
Authors: Niu Weifen , Jia Juan , Li Junkai , Zhang Chao , Yun Keming
Published: July 2019

A lysosome-targeted ratiometric emission NIR-fluorescent probe for monitoring the lysosomal pH changes at a cellular level and LPS-mediated inflammationin vivo.
Oxidant speciation and anionic ligand effects in the gold-catalyzed oxidative coupling of arenes and alkynes
Authors: Hofer Manuel , de Haro Teresa , Gómez-Bengoa Enrique , Genoux Alexandre , Nevado Cristina
Published: July 2019

The mechanism of the gold-catalyzed oxidative cross-coupling of arenes and alkynes has been studied in detail combining stoichiometric experiments with putative reaction intermediates and DFT calculations.
Shortest range length to measure the total radiated power
Authors: Derat Benoît , Hamberger Gerhard F. , Michaelsen Fabian
Published: July 2019

Total radiated power (TRP) is a key performance metric in over‐the‐air (OTA) testing of wireless devices. The TRP is evaluated by integration of the power density over a surface enclosing the device under test (DUT). In principle, this total power flow shall be independent from the surface. However, the power received at the instrumentation in a given polarisation typically relates to the intensity of the corresponding component of the impinging E‐field. In the far‐field, the E‐field magnitude and power density are straightforwardly related, but not in the near‐field. Therefore, the measured TRP generally depends on the scanned surface and test distance. This study introduces a closed‐form expression for the measured power integrated over a surface surrounding the DUT, including the influence of the probe. The formulas are first applied to simulated spherical testing systems, where three different measurement probes coupled to a DUT model radiating at 28 GHz. Results are then validated experimentally in two spherical scanners, using physical samples of one of the modelled probes and the DUT. Both numerical and experimental results confirm the Fraunhofer distance as a lower bound range length for OTA TRP evaluation with negligible influence from the measurement probe.
Moving target detection based on OFDM radar
Authors: Zhang Houyuan , Zhang Yun , Qi Xin , Zong Chengge
Published: July 2019

The study combines the general hardware platform of the radar system and wireless communication system, as well as applies it in a real detecting scenario. To detect target, the periodogram‐based estimation algorithms based on the signal of orthogonal frequency‐division multiplexing (OFDM) is introduced. According to range‐Doppler (R‐D) spectrum, as an enhanced detection algorithm of constant false alarm rate (CFAR), a radar‐target detection method, also referred to as binary successive target cancellation, is presented. This research has important theoretical significance for the communication radar‐integrated detection technology, and the research results have essential application value for the technology of radar target detection as well as the fusion and development of wireless communication technology.
Research on radar clutter recognition method based on LSTM
Authors: Song Li , Shengli Wang , Dingbao Xie
Published: July 2019

Considering the increasingly complex electromagnetic environment of radar detection, it still contains a lot of clutter after target detection, which is a challenging problem for subsequent target tracking. A radar clutter recognition method based on long short‐term memory (LSTM) neural network is proposed here. This method can further identify clutter points after target detection and improve the quality of target tracking. LSTM neural network is trained and compared with K nearest neighbour method and support vector machine. It is found that the clutter recognition accuracy of this method is up to 86.3%, which is 12.2 and 4.1% higher than the latter two methods. At the same time, the target loss rate of this method is only 16.6%, which is 18.3 and 5.7% lower than the latter two methods respectively. The experimental results show that the radar clutter recognition method based on LSTM neural network is effective.
Formation of complex organic molecules in ice mantles: An ab initio molecular dynamics study
Authors: Inostroza Natalia , Mardones Diego , Cernicharo Jose , Zinnecker Hans , Ge Jixing , Aria Nelson , Fuentealba Patricio , Cardenas Carlos
Published: July 2019

We present a detailed simulation of a dust grain covered by a decamer of (CH3OH)10-ice-mantle, bombarded by an OH− closed-shell molecule with kinetic energies from 10–22 eV. The chemical pathways are studied through Born-Oppenheimer (ab initio) molecular dynamics. The simulations show that methanol ice-mantles can be a key generator of complex organic molecules (COMs). We report the formation of COMs such as methylene glycol (CH2(OH)2) and the OCH2OH radical, which have not been detected yet in the interstellar medium (ISM). We discuss the chemical formation of new species through the reaction of CH3OH with the hydroxyl projectile. The dependence of the outcome on the kinetic energy of the projectile and the implications for the observation and detection of these molecules might explain why the methoxy radical (CH3  ⋅ ) has been observed in a wider range of astrophysical environments than the hydroxymethyl (CH2OH ⋅) isomer. Because of the projectile kinetic energies required for these reactions to occur, we suggest that these processes are likely relevant in the production of COMs in photodissociation and shock regions produced by high-velocity jets and outflows from young stellar objects.
Differences Between Bimodal and Unimodal Force-time Curves During Countermovement Jump
Authors: Peng Hsien-Te , Song Chen-Yi , Chen Zong-Rong , Wang I-Lin , Gu Chin-Yi , Wang Li-I
Published: July 2019

This study aimed to explore the biomechanical differences between single and double peak ground reaction force-time curves during the countermovement jump with respect to kinematics, kinetics, and coordination of the lower extremities. Twenty-five college students were stratified into a single peak curve group and a double peak curve group. Eight infrared cameras and two force platforms were synchronized to collect the data. Independent t-tests were performed with groups for each dependent kinematic, kinetic and time of the joint extensor concentric contraction variable. Repeated one-way analysis of variance measurements were performed for the time of the ankle, knee and hip extensor concentric contraction in each group. The double peak curve was associated with larger jump height, reactive strength index modified, rate of force development, impulse, hip, knee and ankle flexion, extension angular displacement, and hip and knee moments (p<0.05). The double peak curve group revealed a better hip, knee and ankle (proximal to distal) timing of extensor concentric contractions sequence of the lower extremities during the countermovement jump (p<0.05). The double peak curve group exhibited a more effective countermovement jump movement with respect to biomechanics compared to the single peak curve group.
Anti-plasmodial Effects of Zanthoxylum zanthoxyloides
Authors: Goodman Christopher Dean , Hoang An Thuy , Diallo Drissa , Malterud Karl Egil , McFadden Geoffrey I. , Wangensteen Helle
Published: July 2019

Zanthoxylum zanthoxyloides, syn. Fagara zanthoxyloides, is a tree growing in West Africa and is used in traditional medicine against a variety of diseases, including malaria. In the work reported here, root bark and stem bark extracts of this tree, as well as compounds isolated from the extracts, have been investigated for activity in vitro against chloroquine-sensitive and chloroquine-resistant strains of Plasmodium falciparum. In addition, toxicity against nauplii of the brine shrimp Artemia salina has been studied. Dichloromethane extracts of the root bark and stem bark, and a methanol extract of the stem bark, showed anti-parasitic activity towards chloroquine-sensitive as well as chloroquine-resistant P. falciparum, with IC50 values between 1 and 10 µg/mL. Among the isolated compounds, bis-dihydrochelerythrinyl ether, buesgenine, chelerythrine, γ-fagarine, skimmianine, and pellitorine were the most active, with IC50 values of less than 5 µg/mL. The dichloromethane extracts were toxic to brine shrimp nauplii, with LC50 values of less than 1 µg/mL. Methanol extracts were much less toxic (LC50 between 50 and 100 µg/mL). Among the isolated substances, bis-dihydrochelethrinyl ether was the most toxic (LC50 ca. 2 µg/mL).
Neue Therapieoptionen mit kontinuierlich gemessenen Glukosedaten – Empfehlungen für die Praxis
Authors: Seufert Jochen , Deiss Dorothee , Gölz Stefan , Haak Thomas , Klausmann Gerhard , Kroeger Jens , Lobmann Ralf , Pfeiffer Andreas F.H. , Schnell Oliver , Seibold Alexander , Siegmund Thorsten , Ziegler Ralph
Published: July 2019

Kontinuierliches Glukosemonitoring (Continuous Glucose Monitoring – CGM) ist heute fest in Konsensusempfehlungen und Leitlinien zur Verbesserung der glykämischen Kontrolle bei Menschen mit insulinpflichtigem Diabetes mellitus verankert. In der täglichen Praxis werden im Besonderen HbA1c, Glukosevariabilität und Hypoglykämien durch die Nutzung von CGM positiv beeinflusst. Der Stellenwert von CGM bei Therapieentscheidungen wächst und birgt weitere vielfältige Potenziale. Dieser Übersichtsartikel stellt dar, welche Therapieoptionen auf der Basis von CGM-Daten bestehen, wie das ambulante Glukoseprofil und Trendpfeile Therapieentscheidungen beeinflussen können und welche Schulungskonzepte für Patienten angeboten werden. Auch werden zukünftige Felder für die Anwendung von CGM erörtert und diskutiert.
Replacement Therapy in Patients with Von Willebrand Disease—Indications and Monitoring
Authors: Nowak-Göttl Ulrike , Miesbach Wolfgang , Koscielny Jürgen , Dempfle Carl-Erik , Maegele Marc , Prondzinski Mario von Depka , Westrup Dagmar , Spannagl Michael
Published: July 2019

In patients with von Willebrand disease (VWD), replacement therapy may be indicated in the case of spontaneous bleeding, surgical interventions and injuries/trauma or as a prophylaxis of spontaneous bleeding episodes. The deficient von Willebrand factor (VWF) is replaced with or without factor VIII (FVIII). Dual VWF/FVIII concentrates can be beneficial in the case of low FVIII level, while repeated dosing may lead to very high FVIII levels, with a potential thrombogenic effect in individual VWD patients. An excessive FVIII:C increase can be limited by using a VWF product with a low level of FVIII, achieving a haemostatic adequate FVIII:C increase after 6 to 12 hours. Replacement therapy in patients with VWD shall be individualised considering VWD type, history and risk of bleeding and risk of thrombosis, as well as indication and the individually variable VWF and FVIII increase. Deviations from the dosages and minimum trough levels mentioned in guidelines or recommendations can be considered in justified cases. The objective of this review is to provide recommendations for specific constellations of replacement therapy based on the VWD-specific guidelines available in Europe, the available evidence, own experiences and the consensus of the interdisciplinary German author group.
Smoking during Pregnancy and Adverse Birth and Maternal Outcomes in California, 2007 to 2016
Authors: Ratnasiri Anura W.G. , Gordon Lauren , Dieckmann Ronald A. , Lee Henry C. , Parry Steven S. , Arief Vivi N. , DeLacy Ian H. , Lakshminrusimha Satyan , DiLibero Ralph J. , Basford Kaye E.
Published: July 2019

Objective This study aimed to determine associations between maternal cigarette smoking and adverse birth and maternal outcomes.

Study Design This is a 10-year population-based retrospective cohort study including 4,971,896 resident births in California. Pregnancy outcomes of maternal smokers were compared with those of nonsmokers. The outcomes of women who stopped smoking before or during various stages of pregnancy were also investigated.

Results Infants of women who smoked during pregnancy were twice as likely to have low birth weight (LBW) and be small for gestational age (SGA), 57% more likely to have very LBW (VLBW) or be a preterm birth (PTB), and 59% more likely to have a very PTB compared with infants of nonsmokers. During the study period, a significant widening of gaps developed in both rates of LBW and PTB and the percentage of SGA between infants of maternal smokers and nonsmokers.

Conclusion Smoking during pregnancy is associated with a significantly increased risk of adverse birth and maternal outcomes, and differences in rates of LBW, PTB, and SGA between infants of maternal smokers and nonsmokers increased during this period. Stopping smoking before pregnancy or even during the first trimester significantly decreased the infant risks of LBW, PTB, SGA, and the maternal risk for cesarean delivery.
Low Bioactive Vitamin D Is Associated with Pregnancy-Induced Hypertension in a Cohort of Pregnant HIV-Infected Women Sampled Over a 23-Year Period
Authors: Van Winden Kristi R. , Bearden Allison , Kono Naoko , Frederick Toni , Operskalski Eva , Stek Alice , Pandian Raj , Barton Lorayne , Kovacs Andrea
Published: July 2019

Objective To examine the association of vitamin D insufficiency and risk of pregnancy-induced hypertension (PIH) among human immunodeficiency virus (HIV)-infected pregnant women.

Study Design This is a retrospective cohort study evaluating the impact of low maternal vitamin D levels on PIH and perinatal outcomes among HIV-infected pregnant women receiving care at an urban HIV center from 1991 to 2014.

Results A total of 366 pregnant women were included, of which 11% developed PIH. Lower levels of 25-hydroxyvitamin D (25(OH)D) and bioactive 1,25-dihydroxyvitamin D (1,25(OH)2D) were associated with increased HIV disease activity. 25(OH)D levels were not significantly associated with the incidence of PIH. Higher 1,25(OH)2D levels were associated with reduced incidence of PIH in univariate (odds ratio, OR: 0.87 [95% confidence interval, CI: 0.79–0.95], p = 0.004) and multivariate (OR: 0.88 [95% CI: 0.80–0.97], p = 0.010) analyses. No association was found between 25(OH)D levels and other obstetric outcomes. Lower 1,25(OH)2D levels were associated with group B Streptococcus colonization (OR: 0.92 [95% CI: 0.86–0.99]) and low birth weight (LBW) (OR: 0.90 [95% CI: 0.83–0.98]) on multivariate analysis. Mean 1,25(OH)2D levels were significantly lower in women with preterm delivery and LBW infants.

Conclusion Lower bioactive vitamin D levels are related to PIH in HIV-infected women. This association may be related to the coexistence of abnormal placental vitamin D metabolism and abnormal placental implantation.
Design and implementation of a low temperature, inductance based high frequency alternating current susceptometer
Authors: Riordan E. , Blomgren J. , Jonasson C. , Ahrentorp F. , Johansson C. , Margineda D. , Elfassi A. , Michel S. , Dell’ova F. , Klemencic G. M. , Giblin S. R.
Published: July 2019

We report on the implementation of an induction based, low temperature, high frequency ac susceptometer capable of measuring at frequencies up to 3.5 MHz and at temperatures between 2 K and 300 K. Careful balancing of the detection coils and calibration allow a sample magnetic moment resolution of 5 × 10−10 Am2 at 1 MHz. We discuss the design and characterization of the susceptometer and explain the calibration process. We also include some example measurements on the spin ice material CdEr2S4 and iron oxide based nanoparticles to illustrate functionality.
Evaluation of a photoacoustic bone-conduction vibration system
Authors: Wadamori N.
Published: July 2019

This article proposes a bone conduction vibrator that is based on a phenomenon by which audible sound can be perceived when vibrations are produced using a laser beam that is synchronized to the sound and these vibrations are then transmitted to an auricular cartilage. To study this phenomenon, we measured the vibrations using a rubber sheet with similar properties to those of soft tissue in combination with an acceleration sensor. We also calculated the force level of the sound based on the mechanical impedance and the acceleration in the proposed system. We estimated the formant frequencies of specific vibrations that were synchronized to five Japanese vowels using this phenomenon. We found that the vibrations produced in the rubber sheet caused audible sound generation when the photoacoustic bone conduction vibration system was used. It is expected that a force level that is equal to the reference equivalent threshold force level can be achieved at light intensities that lie below the safety limit for human skin exposure by selecting an irradiation wavelength at which a high degree of optical absorption occurs. It is demonstrated that clear sounds can be transmitted to the cochlea using the proposed system, while the effects of acoustic and electric noise in the environment are barred. Improvements in the vibratory force levels realized using this system will enable the development of a novel hearing aid that will provide an alternative to conventional bone conduction hearing aids.
Wide-ranging control of carrier lifetimes in n-type 4H-SiC epilayer by intentional vanadium doping
Authors: Murata K. , Tawara T. , Yang A. , Takanashi R. , Miyazawa T. , Tsuchida H.
Published: July 2019

Wide-ranging control of carrier lifetimes in n-type epilayers by vanadium (V) doping is attempted toward not only developing a buffer layer to prevent the stacking fault expansion but also improving switching loss in 4H-SiC-based bipolar devices. Control of V doping concentrations in lightly and highly nitrogen (N)-doped epilayers was achieved within the range of 1012–1015 cm−3 by changing the input flow rates of vanadium tetrachloride. Photoluminescence (PL) and deep-level transient spectroscopy analyses revealed that incorporated V atoms create the PL bands within the range of 0.8–1.0 eV, and densities of the deep center at the V3+/4+ acceptor level (Ec − 0.97 eV) increase linearly with V doping concentrations. Accordingly, V doping shortens the minority carrier lifetimes in lightly N-doped epilayers from 3 μs to 40 ns as well as lifetimes in highly N-doped epilayers down to 20 ns at 20 °C, achieving intrawafer carrier lifetime uniformities of 3–10% σ/mean. Furthermore, V doping during epitaxial growth exhibited a nonsignificant memory effect and the V-doped epilayers showed high thermal stability against postprocessing by 1700 °C. We also demonstrated PiN diodes with a 2.4 μm-thick N + V-doped buffer layer (N: 1 × 1018 and V: 1 × 1014 cm−3), showing no degradation after a stress test for 1 h under a direct current density of 600 A/cm2.
Spin-mapping approach for nonadiabatic molecular dynamics
Authors: Runeson Johan E. , Richardson Jeremy O.
Published: July 2019

We propose a trajectory-based method for simulating nonadiabatic dynamics in molecular systems with two coupled electronic states. Employing a quantum-mechanically exact mapping of the two-level problem to a spin-12 coherent state, we use the Stratonovich-Weyl transform to construct a classical phase space of a spin vector constrained to a spherical surface whose radius is consistent with the quantum magnitude of the spin. In contrast with the singly excited harmonic oscillator basis used in Meyer-Miller-Stock-Thoss (MMST) mapping, the theory requires no additional projection operators onto the space of physical states. When treated under a quasiclassical approximation, we show that the resulting dynamics are equivalent to those generated by the MMST Hamiltonian. What differs is the value of the zero-point energy parameter as well as the initial distribution and the measurement operators used in constructing correlation functions. For various spin-boson models, the results of the method are seen to be a significant improvement compared to both standard Ehrenfest dynamics and linearized semiclassical MMST mapping, without adding any computational complexity.
Domain wall motion in stoichiometric LiTaO3 induced by low-energy electron beam
Authors: Kianirad Hoda , Laurell Fredrik , Canalias Carlota
Published: July 2019

Scanning electron microscopy was used to study the mobility of domain walls in vapor-transport equilibrated stoichiometric LiTaO3. By using low-acceleration voltage, switching occurs solely for polarization pointing up domains, resulting in fast domain-wall motion. When the incoming electron beam was more energetic with larger penetration depth, the switching instead occurred for polarization pointing down domains. Our results are discussed in terms of the interaction of the scanning electron beam with the polarization-screening charges at the crystal surface.
Bi-layer blood vessel mimicking microfluidic platform for antitumor drug screening based on co-culturing 3D tumor spheroids and endothelial layers
Authors: Shi Wentao , Reid Lara , Huang Yongyang , Uhl Christopher G. , He Ran , Zhou Chao , Liu Yaling
Published: July 2019

Two-dimensional (2D) cell culture is not ideal for traditional drug screening, because 2D culture does not accurately mimic the physiological microenvironment of tumor cells. Thus, a drug-screening system which more closely mimics the microenvironment of in vivo tumors is necessary. Here, we present a biomimicking bilayer microfluidic device that can facilitate antitumor drug screening. The microfluidic device consists of two polydimethylsiloxane (PDMS) pieces with channels which are separated by a semipermeable membrane to allow water, oxygen, and nutrition supply, while preventing cell migration. The channels embedded on the two PDMS pieces overlap each other over a long distance to ensure a larger exchange area to mimic the blood vessel-tumor model. High concentrations of endothelial cells (EC) are first seeded onto the membrane through the apical channel, and after a two-day culture, a confluent EC monolayer forms. Tumor spheroid-laden Matrigel is then seeded into the basal channel. After the Matrigel is cured, the device is ready for drug testing. Paclitaxel is used as the model drug for testing. Confocal microscopy and ImageJ are used to assess the efficacy of different concentrations of paclitaxel, and optical coherence tomography (OCT) is employed to determine the tumor volumetric change after the drug treatment. The results indicate that the proposed bilayer microfluidic device in combination with confocal and OCT optical characterization provide an efficient platform for antitumor drug testing.
Confinement-controlled rectification in a geometric nanofluidic diode
Authors: Dal Cengio S. , Pagonabarraga I.
Published: July 2019

Recent experiments with electrolytes driven through conical nanopores give evidence of strong rectified current response. In such devices, the asymmetry in the confinement is responsible for the non-Ohmic response, suggesting that the interplay of entropic and enthalpic forces plays a major role. Here, we propose a theoretical model to shed light on the physical mechanism underlying ionic current rectification. By use of an effective description of the ionic dynamics, we explore the system’s response in different electrostatic regimes. We show that the rectification efficiency, as well as the channel selectivity, is driven by the surface-to-bulk conductivity ratio Dukhin length rather than the electrical double layer overlap.
A high bandwidth microelectromechanical system-based nanopositioner for scanning tunneling microscopy
Authors: Alipour Afshin , Coskun M. Bulut , Moheimani S. O. Reza
Published: July 2019

Limited Z-axis bandwidth of piezotube scanners employed in conventional Scanning Tunneling Microscopes (STMs) has been a major limiting factor in achieving high scan speeds in STM applications. Slow Z-axis dynamics of typical piezotube scanners combined with the weight of the STM tip/tip holder assembly, that the scanner has to carry, substantially limit the achievable Z-axis bandwidth in both imaging and lithography modes. To tackle this issue, we propose a high bandwidth microelectromechanical-system-based nanopositioner to be integrated into an existing STM scanner. The device is designed to replace the STM tip and fine Z-positioning mechanisms in the conventional STM setup, while providing an order of magnitude higher bandwidth in Z axis. The device is microfabricated using double silicon-on-isolator technology, and standard cleanroom processes. Experiments show that tunneling current between the device tip and a highly ordered pyrolytic graphite sample can be successfully established and maintained in air using the proposed device in a feedback loop. Results indicate that the proposed device uniquely combines a very high resolution and a large stroke with a substantially larger Z-axis bandwidth compared to that of conventional STM piezotube scanners, enabling higher scanning speeds in STM operations.
Kinetics of environmentally assisted cracking in SiNx barrier films
Authors: Luo Hao , Wang Baolin , Kim Kyungjin , Graham Samuel , Pierron Olivier N. , Zhu Ting
Published: July 2019

Kinetics of environmentally assisted subcritical cracking in SiNx barrier films is studied by in situ optical microscopy experiments and quantum chemical molecular orbital theory simulations. The activation volume of 0.83–1.11 cm3/mol and the activation energy of 138 kJ/mol (1.43 eV) are experimentally measured for subcritical crack growth in moist air. The quantum chemical simulations reveal the molecular mechanism of stress corrosion in mechanically strained SiNx under water attack, and the predicted activation energy and activation volume are in good agreement with the experimental results. The combined experimental and modeling studies provide a fundamental understanding of subcritical crack growth in SiNx barrier films for flexible electronic device applications.
Scaling behavior of plasma waves universal regardless of geometry and mode conversion
Authors: Liebendorfer Adam
Published: July 2019

Invariant imbedding applied to equations for plasma dynamics helps understand wave motions found in the coronal loops of the sun.
Frequency characteristics of a gas coupled-cavity ring laser
Authors: Zolotoverkh I.I. , Lariontsev E.G.
Published: July 2019

Based on a theoretical model describing the lasing dynamics in a gas ring laser (GRL) with coupled cavities, we have investigated the frequency characteristics of radiation. The conditions are found under which an increase in the scale factor is the largest. The regime of frequency locking of counterpropagating waves is studied. It is shown that the lock-in region in a GRL with an antiphase optical coupling of the cavities remains the same as without an additional cavity. The conditions are determined under which multistability of the radiation characteristics arises in a coupled-cavity GRL. In the numerical solution of the equations of the considered theoretical model, three branches of the frequency response are found.
Frequency and energy characteristics of a Cu – Ne laser at different durations of the leading edge of the excitation pulse
Authors: Bokhan P.A. , Gugin P.P. , Zakrevskii Dm.E. , Lavrukhin M.A.
Published: July 2019

The lasing characteristics of a copper vapour laser in a tube with forced heating, having a length of 50 cm and a diameter of 2 cm, excited by a train of pulses are investigated. Comparative studies of the frequency and energy characteristics of the laser are performed with a leading edge duration of the excitation pulse of ∼25 ns (when the capacitance discharges through a thyratron and a magnetic compression line) and ∼3 and 1 ns (using circuits with a high-speed switch – kivotron). It is shown that a decrease in the leading edge duration gives rise to an increase in the optimal pulse repetition rate up to ∼30 kHz, the generation efficiency up to 3.2 % and the generation power per unit length over 100 W m−1. The results obtained confirm the concept of limiting the frequency and energy characteristics of a copper vapour laser due to the insufficient rate of energy input into the plasma at high prepulse electron concentrations.
Basal CHK1 activity safeguards its stability to maintain intrinsic S-phase checkpoint functions
Authors: Michelena Jone , Gatti Marco , Teloni Federico , Imhof Ralph , Altmeyer Matthias
Published: July 2019

The DNA replication machinery frequently encounters impediments that slow replication fork progression and threaten timely and error-free replication. The CHK1 protein kinase is essential to deal with replication stress (RS) and ensure genome integrity and cell survival, yet how basal levels and activity of CHK1 are maintained under physiological, unstressed conditions is not well understood. Here, we reveal that CHK1 stability is controlled by its steady-state activity during unchallenged cell proliferation. This autoactivatory mechanism, which depends on ATR and its coactivator ETAA1 and is tightly associated with CHK1 autophosphorylation at S296, counters CHK1 ubiquitylation and proteasomal degradation, thereby preventing attenuation of S-phase checkpoint functions and a compromised capacity to respond to RS. Based on these findings, we propose that steady-state CHK1 activity safeguards its stability to maintain intrinsic checkpoint functions and ensure genome integrity and cell survival.