bluuebunny/crossref_metadata_2025 huggingface dataset:
Insulin-dependent GLUT4 trafficking is not regulated by protein SUMOylation in L6 myocytes
Authors: Carmichael Ruth E. , Wilkinson Kevin A. , Craig Tim J.
Published: April 2019

Type-II Diabetes Mellitus (T2DM) is one of the fastest growing public health issues today, consuming 12% of worldwide health budgets and affecting an estimated 400 million people. One of the key pathological traits of this disease is insulin resistance at ‘glucose sink’ tissues (mostly skeletal muscle), and this remains one of the features of this disease most intractable to therapeutic intervention. Several lines of evidence have implicated the post-translational modification, SUMOylation, in insulin signalling and insulin resistance in skeletal muscle. In this study, we examined this possibility by manipulation of cellular SUMOylation levels using multiple different tools, and assaying the effect on insulin-stimulated GLUT4 surface expression in differentiated L6 rat myocytes. Although insulin stimulation of L6 myocytes produced a robust decrease in total cellular SUMO1-ylation levels, manipulating cellular SUMOylation had no effect on insulin-responsive GLUT4 surface trafficking using any of the tools we employed. Whilst we cannot totally exclude the possibility that SUMOylation plays a role in the insulin signalling pathway in human health and disease, our data strongly argue that GLUT4 trafficking in response to insulin is not regulated by protein SUMOylation, and that SUMOylation does not therefore represent a viable therapeutic target for the treatment of insulin resistance.
Performance of the Biomark HD real-time qPCR System (Fluidigm) for the detection of nasopharyngeal bacterial pathogens and Streptococcus pneumoniae typing
Authors: Olwagen Courtney P. , Adrian Peter V. , Madhi Shabir A.
Published: April 2019

Traditional qPCR assays for pneumococcal detection and serotype characterization require large sample volume, is expensive and labor intensive. We aimed to develop a quantitative nanofluidic Fluidigm assay to overcome some of these shortcomings. A quantitative Fluidigm assay was established to detect 11 bacterial pathogens, 55 pneumococcal serotypes and 6 serotypes of H. influenzae. The Fluidigm assay results were compared to conventional qPCR and culture. All reactions in the Fluidigm assay effectively amplified their respective targets with high sensitivity and specificity compared to qPCR. There was excellent concordance between qPCR and Fluidigm for detection of carriage prevalence (kappa > 0.75) and density (Rho > 0.95). Fluidigm identified an additional 7 (4.2%) serotypes over those detected by qPCR. There was a modest concordance between culture and Fluidigm for the majority of reactions detecting S. pneumoniae serotypes/serogroups (kappa > 0.6), with Fluidigm identifying an additional 113 (39.1%) serotypes. Discordant results between the three methods were associated with a low carriage density. The Fluidigm assay was able to detect common pneumococcal serotypes, H. influenzae serotypes, and other common nasopharyngeal bacterial organisms simultaneously. Deployment of this assay in epidemiological studies could provide better insight into the effect of PCV immunization on the nasopharyngeal microbiota in the community.
Carbon Catabolite Repression in Yeast is Not Limited to Glucose
Authors: Simpson-Lavy Kobi , Kupiec Martin
Published: April 2019

Cells adapt their gene expression and their metabolism in response to a changing environment. Glucose represses expression of genes involved in the catabolism of other carbon sources in a process known as (carbon) catabolite repression. However, the relationships between “poor” carbon sources is less characterized. Here we show that in addition to the well-characterized glucose (and galactose) repression of ADH2 (alcohol dehydrogenase 2, required for efficient utilization of ethanol as a carbon source), ADH2 expression is also inhibited by acetate which is produced during ethanol catabolism. Thus, repressive regulation of gene expression occurs also between “poor” carbon sources. Acetate repression of ADH2 expression is via Haa1, independently from the well-characterized mechanism of AMPK (Snf1) activation of Adr1. The response to extracellular acetate is attenuated when all three acetate transporters (Ady2, Fps1 and Jen1) are deleted, but these deletions do not affect the acetate response resulting from growth with glucose or ethanol as the carbon source. Furthermore, genetic manipulation of the ethanol catabolic pathway affects this response. Together, our results show that acetate is sensed intracellularly and that a hierarchical control of carbon sources exists even for “poor” carbon sources.
Counterion binding on coacervation of dioctyl sulfosuccinate in aqueous sodium chloride
Authors: Wang Shengbo , Chen Changlong , Shiau Bor-Jier , Harwell Jeffrey H.
Published: April 2019

A simple coacervate-forming system consisting of sodium dioctyl sulfosuccinate (DOSS) in aqueous NaCl solution was investigated by turbidity measurement, electromotive force measurement (EMF), dynamic light scattering (DLS), and cryogenic transmission electron microscopy (cryo-TEM) to reveal the role of counterion binding in the microstructural changes behind the evolution of the coacervate phase.
An “on–off–on” fluorescent nanoprobe for recognition of Cu2+ and GSH based on nitrogen co-doped carbon quantum dots, and its logic gate operation
Authors: Gao Yifang , Zhang Huilin , Shuang Shaomin , Han Hui , Dong Chuan
Published: April 2019

Novel nitrogen co-doped carbon dots (NCDs) were synthesized as a fluorescent “on–off–on” switch for the highly sensitive and selective sensing of Cu2+ and glutathione (GSH) by a straightforward pyrolysis route.
Oxidation of uranium(iv) mixed imido–amido complexes with PhEEPh and to generate uranium(vi) bis(imido) dichalcogenolates, U(NR)2(EPh)2(L)2
Authors: Tomson Neil C. , Anderson Nickolas H. , Tondreau Aaron M. , Scott Brian L. , Boncella James M.
Published: April 2019

This work provides new routes for the conversion of U(iv) into U(vi) bis(imido) complexes and offers new information on the manner in which the U(vi) compounds form.
Cyaphide–alkynyl complexes: metal–ligand conjugation and the influence of remote substituents
Authors: Furfari Samantha K. , Leech Matthew C. , Trathen Nicola , Levis Madeleine C. , Crossley Ian R.
Published: April 2019

A series of cyaphide–alkynyl complexes exhibits significant cooperativity between the electron accepting “–CP” ligand and remote alkynyl substituents, indicative of long-range communication.
Balancing ionic and H-bonding interactions for the formation of Au(i) hydrometallogels
Authors: Blasco Daniel , López-de-Luzuriaga José M. , Monge Miguel , Olmos M. Elena , Rodríguez-Castillo María
Published: April 2019

Complex [Au(9N-adenine)(PMe3)](CF3CO2) displays a supramolecular structure built up through ionic, π-stacking, C–H⋯O, C–H⋯N and C–H⋯Au interactions. This complex forms a stable hydrometallogel consisting of straight molecular nanowires.
Relevance of hydrogen bonding in CO2 capture enhancement within InOF-1: an energy and vibrational analysis
Authors: Lara-García Hugo A. , Landeros-Rivera Bruno , González-Zamora Eduardo , Aguilar-Pliego Julia , Gómez-Cortés Antonio , Martínez Ana , Vargas Rubicelia , Diaz Gabriela , Ibarra Ilich A.
Published: April 2019

DFT and experimental in situ results postulate four plausible CO2 adsorption mechanism for MeOH-functionalised InOF-1.
Few layer graphene does not affect the function and the autophagic activity of primary lymphocytes
Authors: Murera Diane , Malaganahalli Sowmya , Martín Cristina , Reina Giacomo , Fauny Jean-Daniel , Dumortier Hélène , Vázquez Ester , Bianco Alberto
Published: April 2019

Primary lymphocytes ensure their efficient function and maintenance through different mechanisms including autophagy. Few layer graphene does not affect either the viability and activation or the autophagic activity of B and T cells.
Tunable valley and spin splitting in 2H-VSe2/BiFeO3(111) triferroic heterostructures
Authors: Zhang Fang , Mi Wenbo , Wang Xiaocha
Published: April 2019

The non-volatile multiferroic control on the spin and valley degree is predicted in the 2H-VSe2/BFO(111) triferroic heterostructures.
A porous Au–Ag hybrid nanoparticle array with broadband absorption and high-density hotspots for stable SERS analysis
Authors: Li Kuanguo , Liu Guangju , Zhang Sheng , Dai Yanqiu , Ghafoor Sonia , Huang Wanxia , Zu Zewen , Lu Yonghua
Published: April 2019

An Au–Ag hybrid nanoparticle array with dense hotspots was constructed through a low-cost route for SERS detection with high sensitivity and stability.
Large-area superelastic graphene aerogels based on a room-temperature reduction self-assembly strategy for sensing and particulate matter (PM2.5 and PM10) capture
Authors: Yan Shuang , Zhang Gongzheng , Li Feibo , Zhang Li , Wang Sitong , Zhao Huhu , Ge Qi , Li Huanjun
Published: April 2019

Large-area multifunctional superelastic graphene aerogels (GAs) were successfully fabricated by a novel room-temperature reduction self-assembly (RTRS) strategy.
Selective synthesis of (1H-benzo[d]imidazol-2-yl)(phenyl)methanone and quinoxaline from aromatic aldehyde and o-phenylenediamine
Authors: Zhan Zhenzhen , Ma Haojie , Cui Xinfeng , Jiang Pengbo , Pu Jinghong , Zhang Yixin , Huang Guosheng
Published: April 2019

We have designed a general, inexpensive, and versatile method for the synthesis of (1H-benzo[d]imidazol-2-yl)(phenyl)methanone and the formation of C–N bonds via an aromatic aldehyde and o-phenylenediamine.
Copper-catalyzed three-component reaction of N-heteroaryl aldehydes, nitriles, and water
Authors: Bao Hanyang , Zhou Bingwei , Jin Hongwei , Liu Yunkui
Published: April 2019

A copper-catalyzed three-component reaction of N-heteroaryl aldehydes, nitriles, and water was achieved to afford N-heteroaroyl imides.
Chloroform as a CO surrogate: applications and recent developments
Authors: Mondal Krishanu , Halder Pallabi , Gopalan Greeshma , Sasikumar P. , Radhakrishnan K. V. , Das Parthasarathi
Published: April 2019

Transition-metal-catalyzed carbonylation reaction using chloroform as CO surrogate to synthesize carbonylated heterocyclic moieties.
Polymer-brush-decorated colloidal platelets: precision synthesis and self-assembly
Authors: Ohno Kohji , Masuda Shota , Ogawa Hiroki
Published: April 2019

Polymer-brush-decorated platelets produced through surface-initiated polymerization formed unique self-assembled structures in solution and in the bulk.
Recent synthetic applications of α-amido sulfones as precursors of N-acylimino derivatives
Authors: Marcantoni Enrico , Palmieri Alessandro , Petrini Marino
Published: April 2019

α-Amido sulfones can be directly used as N-acylimine or N-acyliminium ion precursors in several synthetic processes aimed at the preparation of nitrogen containing compounds. This review collects the most relevant and practical utilizations of α-amido sulfones appeared in the literature after 2005.
Unusual structural changes as a result of weathering benzofuran-based diarylethenes in simulated sunlight
Authors: Wu Tuoqi , Senior James , Bremner Glen , Finden Jeremy , Branda Neil R.
Published: April 2019

Two unusual products are observed when benzofuran-based diartylethenes are weathered in simulated sunlight.
Simultaneous local stabilisation and fault detection for continuous‐time T‐S fuzzy systems
Authors: Wu Yue , Dong Jiuxiang
Published: April 2019

In this study, a simultaneous local stabilisation and fault detection (FD) problem for Takagi‐Sugeno (T‐S) fuzzy systems is investigated. The authors' attention is focused on synthesising an FD observer and an observer‐based controller to achieve the objectives of local stabilisation and FD simultaneously. First, by establishing the relationship among the reachable set, the ellipsoid set and the objective area, a new local stabilisation criterion is proposed. The presented criterion guarantees that the state trajectory starting from a given local region can remain in this region even when the system is subject to disturbances and faults. Meanwhile, the FD observer is designed under a mixed framework such that the residual signal is robust to the persistent disturbance and sensitive to the fault. Different from some existing methods, via the proposed scheme, the state can be restricted into the modelling area so that the non‐linear control problem can be addressed by the T‐S fuzzy model approach effectively. Additionally, two different methods are utilised in the co‐design of the observer and the controller such that the disturbance is not required to be energy‐bounded. Finally, the effectiveness of the proposed approach is demonstrated by an example.
Kernel PCA for road traffic data non‐linear feature extraction
Authors: Yong‐dong Wang , Dong‐wei Xu , Peng Peng , Yi Liu , Gui‐jun Zhang , Xiao Xuemei
Published: April 2019

Road traffic data bring great challenges for data processing and traffic‐state analysis. The feature extraction is an effective way to make full use of road traffic data. Here, the authors explore the temporal correlation of road traffic data in time series and a new non‐linear feature extraction method for road traffic data, namely, kernel principal component analysis (PCA). The low‐dimensional road traffic data are mapped into the high‐dimensional space based on a kernel function, and then the PCA method is applied to conduct feature extraction in the high‐dimensional space. To have a clear comparison, the authors compare the kernel PCA method with a linear PCA‐based feature extraction method. The results show that the extracted features under kernel PCA are more useful than PCA and the kernel PCA method has a better compression effect than PCA under the same condition.
Reduced‐cost electromagnetic‐driven optimisation of antenna structures by means oftrust‐region gradient‐search with sparse Jacobian updates
Authors: Koziel Slawomir , Pietrenko‐Dabrowska Anna
Published: April 2019

Numerical optimisation plays more and more important role in the antenna design. Because of lack of design‐ready theoretical models, electromagnetic (EM)‐simulation‐driven adjustment of geometry parameters is a necessary step of the design process. At the same time, traditional parameter sweeping cannot handle complex topologies and large number of design variables. On the other hand, high computational cost of the conventional optimisation routines can be reduced using, e.g., surrogate‐assisted techniques. Still, direct optimisation of EM simulation antenna models is required at certain level of fidelity. This work proposes a reduced cost trust‐region algorithm with sparse updates of the antenna response Jacobian, decided based on relocation of the design variable vector between algorithm iterations and the update history. Our approach permits significant reduction of the optimisation cost (∼40% as compared to the reference algorithm) without affecting the design quality in a significant manner. Robustness of the proposed technique is validated using a set of benchmark antennas, statistical analysis of the algorithm performance over multiple initial designs, as well as investigating the effects of its control parameters that permit control efficiency vs. design quality trade‐off. Selected designs were fabricated and measured to validate the computational models utilised in the optimisation process.
Wideband radar cross‐section reduction of microstrip patch antenna using coding metasurface
Authors: Li Jianxing , Khan Tayyab Ali , Meng Xianjia , Chen Juan , Peng Gantao , Zhang Anxue
Published: April 2019

This article proposes a design of a microstrip patch antenna with reduced radar cross‐section (RCS) in a wide frequency band. The RCS of the patch antenna is reduced with the integration of an optimised coding metasurface. The coding metasurface is designed by placing artificial magnetic conductor (AMC) unit cells together to achieve a phase difference between 180 ± 37° within a wide frequency range. The out‐of‐band RCS for the proposed patch antenna is reduced >7 dB from 12.2 to 19.8 GHz, corresponding to a relative bandwidth of 48%, with a maximum reduction of 20 dB at 18 GHz. The operating frequency of the proposed antenna is 8.7 GHz and the RCS reduction is mainly in the Ku band. Both monostatic and bistatic RCS performance of the proposed patch antenna have been simulated and studied. The radiation performance of the proposed patch antenna is hardly influenced by the employment of the proposed coding metasurface. Details of the design considerations along with the simulation and measurement results are presented and discussed. The measured results are in a good agreement with the simulated ones, verifying the validity of the proposed antenna.
Helical resonator filters with improved multipactor performance exploiting rigorous modelling and the large gap approach
Authors: Salza Giuseppe , Goussetis George , Vicente Carlos , Kosmopoulos Savvas , Reglero Marta , Taroncher Máriam , Boria Vicente E. , Sidiropoulos Nikolas , Galdeano Jaione
Published: April 2019

The power handling capability of helical resonator filters is studied by means of the parallel plate model (employed in the European Cooperation for Space Standardisation) and more rigorous modelling techniques (like the one available in the commercial software tool SPARK3D™) as well as through an experimental test campaign. The results indicate that the parallel plate model provides conservative power handling capabilities for this class of filters, while rigorous modelling can better capture the impact of the geometrical features on multipactor evolution. Although the accuracy of the estimated power handling depends on the knowledge of the practical secondary emission yield values, the use of such rigorous modelling tools enables the design of helical resonator filters with improved power handling capability by exploiting the large gap approach, therefore opening opportunities to avoid additional dielectric fillings.
Radar HRRP target recognition via statistics‐based scattering centre set registration
Authors: Wang Jing‐jing , Liu Zheng , Li Tao , Ran Lei , Xie Rong
Published: April 2019

Due to the presence of noise and range resolution variation, each attribute of the scattering centre (SC) extracted from high‐resolution range profile (HRRP) data is a random variable fluctuating around the real attribute. For the scatterer‐based target recognition method, the extraction error will disturb the similarity measurement between SC sets and adversely affect the recognition performance. In this study, a novel approach for HRRP target recognition is proposed via the statistics‐based SC set registration. The attribute set of SCs is first characterised by a Gaussian mixture model (GMM) in which each Gaussian component represents the corresponding SC attributes containing the amplitude and position. Besides, the noise power and range resolution are taken into account into the GMM parameters, which enhances the recognition robustness against noise and resolution variation. Afterwards, based on the different stability of SC attributes against the variation of target‐sensor orientation, the weighted Gaussian quadratic form distance is developed to register the test Gaussian mixture with the templates. The resulting recognition method considers the statistical property of the estimated attribute of the SC and exhibits robust recognition performance. Experiments conducted on the measured data demonstrate the validity and robustness of the proposed method.
Rossby wave instability and high-frequency quasi-periodic oscillations in accretion discs orbiting around black holes
Authors: Varniere P. , Casse F. , Vincent F. H.
Published: April 2019

Context. The rather elusive high-frequency quasi-periodic oscillations (HFQPOs) observed in the X-ray light curve of black holes have been seen in a wide range of frequencies, even within one source. Also notable is the detection of “pairs” of HFQPOs with a close-to-integer ratio between the frequencies.

Aims. The aim of this paper is to investigate some of the possible observables that we could obtain from the Rossby wave instability (RWI) active in the accretion disc surrounding the compact object.

Methods. Using the newly developed GR-AMRVAC code able to follow the evolution of the RWI in a full general relativistic framework, we explore how RWI can reproduce observed HFQPO frequency ratios and whether or not it is compatible with observations. In order to model the emission coming from the disc we have linked our general relativistic simulations to the general relativistic ray-tracing GYOTO code and delivered synthetic observables that can be confronted with actual data from binary systems hosting HFQPOs.

Results. We demonstrate that some changes in the physical conditions prevailing in the part of the disc where RWI can be triggered lead to various dominant RWI modes whose ratio recovers frequency ratios observed in various X-ray binary systems. In addition we also show that when RWI is triggered near to the last stable orbit of a spinning black hole, the amplitude of the X-ray modulation increases with the spin of the black hole. Revisiting published data on X-ray binary systems, we show that this type of relationship actually exists in five systems where an indirect measurement of the spin of the black hole is available.
ALMA survey of Class II protoplanetary disks in Corona Australis: a young region with low disk masses
Authors: Cazzoletti P. , Manara C. F. , Baobab Liu H. , van Dishoeck E. F. , Facchini S. , Alcalà J. M. , Ansdell M. , Testi L. , Williams J. P. , Carrasco-González C. , Dong R. , Forbrich J. , Fukagawa M. , Galván-Madrid R. , Hirano N. , Hogerheijde M. , Hasegawa Y. , Muto T. , Pinilla P. , Takami M. , Tamura M. , Tazzari M. , Wisniewski J. P.
Published: April 2019

Context. In recent years, the disk populations in a number of young star-forming regions have been surveyed with the Atacama Large Millimeter/submillimeter Array (ALMA). Understanding the disk properties and their correlation with the properties of the central star is critical to understanding planet formation. In particular, a decrease of the average measured disk dust mass with the age of the region has been observed, consistent with grain growth and disk dissipation.

Aims. We aim to compare the general properties of disks and their host stars in the nearby (d = 160 pc) Corona Australis (CrA) star forming region to those of the disks and stars in other regions.

Methods. We conducted high-sensitivity continuum ALMA observations of 43 Class II young stellar objects in CrA at 1.3 mm (230 GHz). The typical spatial resolution is ~0.3′′. The continuum fluxes are used to estimate the dust masses of the disks, and a survival analysis is performed to estimate the average dust mass. We also obtained new VLT/X-shooter spectra for 12 of the objects in our sample for which spectral type (SpT) information was missing.

Results. Twenty-four disks were detected, and stringent limits have been put on the average dust mass of the nondetections. Taking into account the upper limits, the average disk mass in CrA is 6 ± 3 M⊕. This value is significantly lower than that of disks in other young (1–3 Myr) star forming regions (Lupus, Taurus, Chamaeleon I, and Ophiuchus) and appears to be consistent with the average disk mass of the 5–10 Myr-old Upper Sco. The position of the stars in our sample on the Herzsprung-Russel diagram however seems to confirm that CrA has an age similar to Lupus. Neither external photoevaporation nor a lower-than-usual stellar mass distribution can explain the low disk masses. On the other hand, a low-mass disk population could be explained if the disks were small, which could happen if the parent cloud had a low temperature or intrinsic angular momentum, or if the angular momentum of the cloud were removed by some physical mechanism such as magnetic braking. Even in detected disks, none show clear substructures or cavities.

Conclusions. Our results suggest that in order to fully explain and understand the dust mass distribution of protoplanetary disks and their evolution, it may also be necessary to take into consideration the initial conditions of star- and disk-formation process. These conditions at the very beginning may potentially vary from region to region, and could play a crucial role in planet formation and evolution.
Direct estimation of electron density in the Orion Bar PDR from mm-wave carbon recombination lines
Authors: Cuadrado S. , Salas P. , Goicoechea J. R. , Cernicharo J. , Tielens A. G. G. M. , Báez-Rubio A.
Published: April 2019

Context. A significant fraction of the molecular gas in star-forming regions is irradiated by stellar UV photons. In these environments, the electron density (ne) plays a critical role in the gas dynamics, chemistry, and collisional excitation of certain molecules.

Aims. We determine ne in the prototypical strongly irradiated photodissociation region (PDR), the Orion Bar, from the detection of new millimeter-wave carbon recombination lines (mmCRLs) and existing far-IR [13C II] hyperfine line observations.

Methods. We detect 12 mmCRLs (including α, β, and γ transitions) observed with the IRAM 30 m telescope, at ∼25″ angular resolution, toward the H/H2 dissociation front (DF) of the Bar. We also present a mmCRL emission cut across the PDR.

Results. These lines trace the C+/C/CO gas transition layer. As the much lower frequency carbon radio recombination lines, mmCRLs arise from neutral PDR gas and not from ionized gas in the adjacent H II region. This is readily seen from their narrow line profiles (Δv = 2.6 ± 0.4 km s−1) and line peak velocities (vLSR = +10.7 ± 0.2 km s−1). Optically thin [13C II] hyperfine lines and molecular lines – emitted close to the DF by trace species such as reactive ions CO+ and HOC+ – show the same line profiles. We use non-LTE excitation models of [13C II] and mmCRLs and derive ne = 60–100 cm−3 and Te = 500–600 K toward the DF.

Conclusions. The inferred electron densities are high, up to an order of magnitude higher than previously thought. They provide a lower limit to the gas thermal pressure at the PDR edge without using molecular tracers. We obtain Pth ≥ (2−4) × 108 cm−3 K assuming that the electron abundance is equal to or lower than the gas-phase elemental abundance of carbon. Such elevated thermal pressures leave little room for magnetic pressure support and agree with a scenario in which the PDR photoevaporates.
Analysis of an observer strategy for initial state reconstruction of wave-like systems in unbounded domains
Authors: Imperiale S. , Moireau P. , Tonnoir A.
Published: April 2019

We are interested in reconstructing the initial condition of a wave equation in an unbounded domain configuration from measurements available in time on a subdomain. To solve this problem, we adopt an iterative strategy of reconstruction based on observers and time reversal adjoint formulations. We prove the convergence of our reconstruction algorithm with perfect measurements and its robustness to noise. Moreover, we develop a complete strategy to practically solve this problem on a bounded domain using artificial transparent boundary conditions to account for the exterior domain. Our work then demonstrates that the consistency error introduced by the use of approximate transparent boundary conditions is compensated by the stabilization properties obtained from the use of the available measurements, hence allowing to still be able to reconstruct the unknown initial condition.
FR901483: Synthetic Efficiency Remains a Challenge
Authors: Ruan Zhuwei , Li Cheng , Shen Defeng , Huang Sha-Hua , Hong Ran
Published: April 2019

FR901483 is a unique alkaloid bearing an aza-tricyclic structure, a phosphate group, and a congested tertiary nitrogen center. This alkaloid was reported to be a potent immunosuppressant with antimetabolite ability. The unprecedented architecture has captured imagination of synthetic chemists since its isolation in 1996. To date, ten total or formal syntheses and several synthetic approaches to access the tricyclic core skeleton have been reported. In this review, we highlight the novel synthetic methods and strategies and discuss the synthetic challenge for meeting the criteria of drug development.

1 Introduction

2 Bioinspired Total Synthesis of FR901483

3 Non-bioinspired Approaches toward FR901483

4 Various Tactics for Accessing the Core Skeleton

5 Challenges for Efficiency
Spontaneous Early Resolution of an Iatrogenic Type A Aortic Dissection Following Coronary Angiography
Authors: Koza Yavuzer , Kaya Uğur , Taş Hakan , Koza Enise
Published: April 2019

A 74-year-old man was admitted with the diagnosis of non–ST-elevation myocardial infarction. During right coronary angiography, a coronary artery dissection extending into the proximal ascending aorta was noticed without hemodynamic compromise. Immediate computed tomography angiography showed no evidence of dissection in the ascending aorta. The patient remained hemodynamically stable with medical therapy alone. This case report highlights the importance of medical therapy in patients with uncomplicated iatrogenic aortic dissection.
Do Complication Rates of Ventricular Drain Placement Differ between Twist Drill and Burr Hole in Acute Hydrocephalus?
Authors: Brand Christine , Pala Andrej , Kielhorn Wilhelm , Wirtz Christian Rainer , Kapapa Thomas
Published: April 2019

Objective The aim of the study was to compare two techniques for external ventricular drainage (EVD) placement with respect to their complication rates.

Methods A retrospective descriptive study was performed to analyze all patients who had undergone EVD implantation for acute hydrocephalus between January 2010 and December 2013 with a focus on surgical technique and rate of complications. The burr hole technique (BHT) was used in one group and the twist-drill technique (TDT) in the other. Particular attention was paid to malposition, hemorrhage, and catheter-associated infection.

Results A total of 350 consecutive patients underwent EVD implantation for acute hydrocephalus: BHT was performed in 201 and TDT in 147 of the patients, whereas in two patients the technique used was unknown. The overall infection rate was 6.3% (n = 22). Fourteen patients (4%) in the BHT group developed an infection compared with eight patients (9.5%) in the TDT group (p = 0.154). In 16 (4.5%) of all cases, postoperative computed tomography revealed catheter-induced hemorrhage.

In one case (0.3%), surgery was necessary due to acute subdural hematoma. The difference between both techniques was not statistically significant (p = 0.343). In 44 (12.6%) of all cases, the position of the EVD tip was contralateral; in 36 (10.3%) of all cases, the EVD tip was in the brain parenchyma. The rate of malposition was 11.6% (n = 17) in the TDT group and 9.5% (n = 19) in the BHT group (p = 0.078).

Conclusion Neither technique showed significantly different numbers in terms of infection, malposition, and hemorrhagic complications. EVD implantation using the TDT is an adequate method compared with BHT. The advantages of TDT are clear: the duration of surgery is shorter, the size of the wound is smaller, and the surgeon is not confined to the operating room.
Inferior Vena Cava Filters—Current Role and Controversies
Authors: Kapoor Harit , Raissi Driss
Published: April 2019

Inferior vena cava filters (IVCFs) remain an indispensable part of an interventionalist's toolbox. Increased recognition of filter-related complications, largely from off-label use and casual approach to filter retrieval, has led to tremendous uncertainty surrounding their use. More stringent regulations on their use and development of newer and safer anticoagulants are gradually changing their role in the management of venous thromboembolism. Herein, the authors review the current role of IVCFs, indications for their use and retrieval, as well as filter-related complications.
Human Mandible Prenatal Morphogenesis
Authors: Kabak Sergey Lvovich , Zhuravleva Natalia Victorovna , Melnichenko Yuliya Michailovna
Published: April 2019

Introduction This study was performed with the aim of detecting the interaction between cartilaginous and bone tissues in the process of mandible morphogenesis in human embryos.

Material and Methods Whole-mount skeletal preparations, stained with Alcian blue and Alizarin red, as well as serial histological sections impregnated with silver and stained with hematoxylin and eosin were studied. A total of 48 human embryos/fetuses from 5 to 29 weeks of age were used.

Results In the mandible anlage, in addition to the woven bone, cartilaginous and chondroid tissues are present. Cartilaginous tissue islets are localized at the tip of the condylar and coronoid processes and also in the region of the mandibular symphysis. The chondroid tissue is incorporated into the bone in the region of the mandibular symphysis, along the edge of the coronoid process, and also in the alveolar part of the mandible.

Conclusion Meckel’s cartilage participates in the formation of the mandibular body, and its remains persist in the area of the mandibular symphysis until the second half of the prenatal development.
Profile of Pregnant Women with Gestational Diabetes Mellitus at Increased Risk for Large for Gestational Age Newborns
Authors: Tavares Maria da Glória Rodrigues , Lopes Érika Sales , Barros Rosy Anne de Jesus Pereira Araújo , Azulay Rossana Santiago de Sousa , Faria Manuel dos Santos
Published: April 2019

Objective Gestational diabetes mellitus (GDM) is associated with a higher risk of perinatal morbidity and mortality, and its main complication is the occurrence of large for gestational age (LGA) newborns. The present study aims to characterize pregnant women with GDM and to identify factors associated with the occurrence of LGA newborns in this population.

Methods A cross-sectional study was performed based on medical records of women whose prenatal care and delivery were performed at the Maternal and Child Unit of the Hospital Universitário of the Universidade Federal do Maranhão, state of Maranhão, Brazil. A total of 116 pregnant women diagnosed with GDM were included according to the criteria of the International Association of Diabetes and Pregnancy Study Groups (IADPSG).

Results The variables associated with LGA newborns after multivariate analysis were: obesity prior to pregnancy (OR = 11.6; 95% CI: 1.40–95.9), previous macrosomia (OR = 34.7; 95% CI: 4.08–295.3), high blood glucose levels in the 3rd trimester (OR = 2,67; 95% CI: 1.01–7.12) and combined change in the oral glucose tolerance test (OGTT) (fasting + postdextrose) (OR = 3.53; 95% CI: 1.25–14.2) = 1.17–10.6). Otherwise, insufficient weight gain during pregnancy reduced the risk for LGA newborns (OR = 0.04; 95% CI: 0.01–0.32).

Conclusion Obesity prior to pregnancy, previous macrosomia, high blood glucose levels in the 3rd trimester, and combined change in the OGTT were independent predictive factors for LGA newborns in pregnant women with GDM.
Venous Thrombosis in Children with Acute Lymphoblastic Leukemia Treated on DCOG ALL-9 and ALL-10 Protocols: The Effect of Fresh Frozen Plasma
Authors: Klaassen Irene , Zuurbier Charlotte , Hutten Barbara , van den Bos Cor , Schouten A. , Stokhuijzen Eva , van Ommen C.
Published: April 2019

Background Venous thromboembolism (VTE) is an important complication for treatment of acute lymphoblastic leukemia (ALL) in children. Especially, ALL treatment, with therapeutics such as asparaginase and steroids, increases the thrombotic risk by reduction in procoagulant and anticoagulant proteins. Replacement of deficient natural anticoagulants by administration of fresh frozen plasma (FFP) may have a preventive effect on the occurrence of VTE.

Methods We retrospectively analyzed all consecutive children (≤18 years) with ALL, treated on the Dutch Childhood Oncology Group (DCOG) ALL-9 and ALL-10 protocols at the Emma Children's Hospital Academic Medical Center between February 1997 and January 2012, to study the effect of FFP on VTE incidence, antithrombin and fibrinogen plasma levels, and VTE risk factors.

Results In total, 18/205 patients developed VTE (8.8%; 95% confidence interval [CI]: 4.9–12.7%). In all patients, VTE occurred after asparaginase administration. In total, 82/205 patients (40%) received FFP. FFP supplementation did not prevent VTE or alter plasma levels of antithrombin or fibrinogen. In the multivariate analysis, VTE occurred significantly more frequently in children ≥12 years (odds ratio [OR]: 3.89; 95% CI: 1.29–11.73) and treated according to the ALL-10 protocol (OR: 3.71; 95% CI: 1.13–12.17).

Conclusion FFP supplementation does not seem to be beneficial in the prevention of VTE in pediatric ALL patients. In addition, age ≥12 years and treatment according to the DCOG ALL-10 protocol with intensive and prolonged administration of asparaginase in combination with prednisone are risk factors. There is a need for effective preventive strategies in ALL patients at high risk for VTE.
Head and Neck Pain in Patients Presenting with Acute Aortic Dissection
Authors: Philip Stephen , Missov Emil , Gilon Dan , Hutchison Stuart , Khoynezhad Ali , Evangelista Arturo , Bonaca Mark , Conklin Lori , Appoo Jehangir , Di Eusanio Marco , Braverman Alan , Forteza Alberto , Montgomery Daniel , Nienaber Christoph , Isselbacher Eric , Eagle Kim
Published: April 2019

Background Head and neck pain is an atypical presentation of acute aortic dissection. Classic teaching associates this pain with proximal dissections, but this has not been extensively studied.

Methods Patients enrolled in the International Registry of Acute Aortic Dissection from January 1996 to March 2015 were included in this study. We analyzed the demographics, presentation, treatment, and outcomes of Type A aortic dissection patients presenting with head and neck pain (n = 812, 25.8%) and compared it with those without these symptoms (n = 2,341, 74.2%).

Results Patients with head and neck pain were more likely to be white, female, with a family history of aortic disease. Patients with head and neck pain had higher percentages of back pain (43.3% vs. 37.5%, p = 0.005) and chest pain (87.6% vs. 79.3%, p < 0.001). On imaging, a higher percentage of those with head and neck pain had arch vessel involvement (44.3% vs. 38%, p = 0.010) and intramural hematoma (11.7% vs. 8.1%, p = 0.003). Surgical management was more common in patients with head and neck pain (89.8% vs. 85.2%, p = 0.001). Regarding outcomes, patients with head and neck pain had significantly higher rates of stroke than those without head and neck pain (13% vs. 9.9%, p = 0.016); however, overall mortality was lower for those with head and neck pain (19.5% vs. 23%, p = 0.038). Those with head and neck pain only had higher overall mortality compared to those with head and neck pain with chest or back pain (34.6% vs. 19.9%, p = 0.013). A logistic regression of mortality revealed that preoperative hypotension and age > 65 years were significantly associated with increased mortality.

Conclusion Presence of head and neck pain in Type A dissection is associated with more arch involvement, intramural hematoma, and stroke. When isolating those with head and neck pain only, there appear to be a higher rate of comorbidity burden and higher overall mortality.
Significant change in threshold for plasma formation and evolution with small variation in copper alloys driven by a mega-ampere current pulse
Authors: Yates K. C. , Bauer B. S. , Fuelling S. , Awe T. J. , Hutchinson T. M. , Ivanov V. V. , Mei J. , Bauer R. S.
Published: April 2019

We report the first observation of a significant change in plasma formation and evolution caused by a small change in the material composition (metal alloy). Thick copper rod alloys were varied in the initial diameter from 0.5 mm to 1.59 mm and pulsed to 1 mega-ampere (MA) peak current in 100 ns with a surface magnetic field rising nearly linearly at 45–80 MG/μs. The copper rods were diagnosed with surface radiometry, two-frame laser shadowgraphy, two-frame surface emission imaging, and time resolved load current measurements. Diagnostics determined time resolved surface temperature, surface expansion rates, time of surface plasma formation, and the growth rates of surface instabilities. Data indicate that copper alloy Cu-145 (99.5% Cu, 0%–0.7% Te, 0%–0.012% P) undergoes surface plasma formation when the surface magnetic field reaches 3.0 ± 0.1 MG whereas Cu-101 (>99.99% Cu) forms surface plasma at 3.5 ± 0.2 MG. The Cu-145 alloys also reach higher peak temperatures and form surface instabilities earlier in the current pulse.
Configurational mapping significantly increases the efficiency of solid-solid phase coexistence calculations via molecular dynamics: Determining the FCC-HCP coexistence line of Lennard-Jones particles
Authors: Schieber Natalie P. , Shirts Michael R.
Published: April 2019

In this study, we incorporate configuration mapping between simulation ensembles into the successive interpolation of multistate reweighting (SIMR) method in order to increase phase space overlap between neighboring simulation ensembles. This significantly increases computational efficiency over the original SIMR method in many situations. We use this approach to determine the coexistence curve of face-centered cubic–hexagonal close-packed Lennard-Jones spheres using direct molecular dynamics and SIMR. As previously noted, the coexistence curve is highly sensitive to the treatment of the van der Waals cutoff. Using a cutoff treatment, the chemical potential difference between phases is moderate and SIMR quickly finds the phase equilibrium lines with good statistical uncertainty. Using a smoothed cutoff results in nonphysical errors in the phase diagram, while the use of particle mesh Ewald for the dispersion term results in a phase equilibrium curve that is comparable with previous results. The drastically closer free energy surfaces for this case test the limits of this configuration mapping approach to phase diagram prediction.
The role of memory in human strategy updating in optional public goods game
Authors: Xu Zhaojin , Li Ruyu , Zhang Lianzhong
Published: April 2019

Most research suggests that humans can optimize their behavior by imitating other humans. However, it remains unclear whether humans actually imitate others in real-life situations. To address this question, we conducted spatial public goods experiments with voluntary participation. In direct contrast to the prevailing view, the results of our experiments show that imitation plays an insignificant role in the decision making process. Furthermore, we found that the nature of human decision making relied more on their performances in the game’s earlier history rather than the performance they observed in others. The action that gained better results in one’s own history had a higher chance to be adopted even if this action did not work for the others.
Two-fluid plasma model for radial Langmuir probes as a converging nozzle with sonic choked flow, and sonic passage to supersonic flow
Authors: Howling A. A. , Guittienne Ph. , Furno I.
Published: April 2019

Using the Lambert function, Guittienne et al. [Phys. Plasmas 25, 093519 (2018)] derived two-fluid solutions for radial Langmuir probes in collisionless and isothermal plasma. In this Brief Communication, we point out the close analogy with classical compressible fluid dynamics, where the simultaneous flows of the ion and electron fluids experience opposite electrostatic body forces in the inward radial flow of the plasma, which behaves as a converging nozzle. Hence, the assumed boundary condition of sonic flow of the repelled species at the probe is explained as choked flow. The sonic passage from subsonic to supersonic flow of the attracted species at the sonic radius is also interpreted using classical fluid dynamics. Moreover, the Lambert function can provide a general solution for one-dimensional, isothermal compressible fluids, with several applications.
Franck-Condon factors by counting perfect matchings of graphs with loops
Authors: Quesada Nicolás
Published: April 2019

We show that the Franck-Condon Factor (FCF) associated with a transition between initial and final vibrational states in two different potential energy surfaces, having N and M vibrational quanta, respectively, is equivalent to calculating the number of perfect matchings of a weighted graph with loops that has P = N + M vertices. This last quantity is the loop hafnian of the (symmetric) adjacency matrix of the graph which can be calculated in O(P32P/2) steps. In the limit of small numbers of vibrational quanta per normal mode, our loop hafnian formula significantly improves the speed at which FCFs can be calculated. Our results more generally apply to the calculation of the matrix elements of a bosonic Gaussian unitary between two multimode Fock states having N and M photons in total and provide a useful link between certain calculations of quantum chemistry, quantum optics, and graph theory.
Bichaoticity induced by inherent birhythmicity during the oscillatory electrodissolution of silicon
Authors: Tosolini Anton , Patzauer Maximilian , Krischer Katharina
Published: April 2019

The electrodissolution of p-type silicon in a fluoride-containing electrolyte is a prominent electrochemical oscillator with a still unknown oscillation mechanism. In this article, we present a study of its dynamical states occurring in a wide range of the applied voltage–external resistance parameter plane. We provide evidence that the system possesses inherent birhythmicity, and thus at least two distinct feedback loops promoting oscillatory behavior. The two parameter regions in which the different limit cycles exist are separated by a band in which the dynamics exhibit bistability between two branches with different multimode oscillations. Following the states along one path through this bistable region, one observes that each branch undergoes a different transition to chaos, namely, a period doubling cascade and a quasiperiodic route with a torus-breakdown, respectively, making Si electrodissolution one of the few experimental systems exhibiting bichaoticity.
Experimental study of ion optics with square apertures for high-power ion thrusters
Authors: Madeev S. , Selivanov M. , Shagayda A. , Lovtsov A.
Published: April 2019

Large-diameter ion-optical systems are widely used in gridded ion thrusters for missions in near-earth space and for deep-space research. Ion sputtering of the accelerator grid is the main factor that limits the thruster’s life. The use of carbon-based materials with a lower sputtering rate compared to metal grids allows the thruster to increase its life more than four times. The most resistant to mechanical loads are grids made of carbon-carbon composite materials. Traditionally, ion optics grids use circular-shaped apertures with the centers located in the nodes of the hexagonal pattern. However, with this arrangement of holes, all carbon fibers in the carbon-carbon composite are cut, and this weakens the mechanical strength of the grid. Previously, the Keldysh Research Centre carried out computational studies of a new form of apertures, in which it is possible to preserve uncut fibers and thereby increase the mechanical strength of grids made of carbon-carbon composites. This paper presents the results of a comparative experimental study of the operational characteristics of ion optics with the traditional round shape of apertures and with the new shape of apertures, which are squares with rounded corners. Measurements of the accelerator grid currents depending on the accelerating voltage have shown that both traditional and new ion-optical systems have close perveance limits in which there is no direct ion impingement on the accelerator grid.