bluuebunny/crossref_metadata_2025 huggingface dataset:
Call for improved design and reporting in soft tissue sarcoma studies: A systematic review and meta‐analysis of chemotherapy and survival outcomes in resectable STS
Authors: Istl Alexandra C. , Ruck Jessica M. , Morris Carol D. , Levin Adam S. , Meyer Christian F. , Johnston Fabian M.
Published: February 2019

New evidence and systemic therapies demand an updated analysis of chemotherapy for soft tissue sarcoma. We completed a meta‐analysis of chemotherapy in localized STS, assessing OS, PFS, and local and distant recurrence (local recurrence‐free survival [LRFS] and distant recurrence‐free survival [DRFS]). Ten studies, totaling 3157 patients, were included. A pooled analysis for 5‐year OS, progression‐free survival, LRFS, and DRFS showed no benefit of chemotherapy over locoregional therapy alone for all‐comers or site‐specific STS. We make recommendations to improve outcome reporting and quality indices.
Animals in the Brain
Authors: Mulroy Eoin , Balint Bettina , Adams Matthew E. , Campion Tom , Merello Marcelo , Bhatia Kailash P.
Published: February 2019

Background

Pareidolic associations are commonly used in medical education to enhance perception of radiological abnormalities. A number of animal‐inspired neuroradiological pareidolias have been defined which should alert clinicians to specific movement disorder diagnoses.

Methods

A review of the published literature detailing neuroradiological abnormalities in movement disorder syndromes was conducted, looking specifically for established animal‐inspired pareidolic associations.

Results

A number of animal‐inspired neuroradiological patterns with specific movement disorder associations have been defined. These include eye of the tiger sign, face of the panda sign, swallow tail sign, hummingbird sign, Mickey Mouse sign, ears of the lynx sign, dragonfly cerebellum, tadpole sign, tigroid/leopard skin sign, and bat wing sign.

Conclusion

Pareidolias represent a quick and easy way of enhancing perception, thereby improving the efficiency and accuracy of image analysis. Movement disorder physicians should keep in mind these associations, given that they will likely facilitate scan analysis.
Microwave‐induced thermoacoustic tomography through an adult human skull
Authors: Yan An , Lin Li , Liu Changjun , Shi Junhui , Na Shuai , Wang Lihong V.
Published: February 2019

Purpose

To demonstrate the feasibility of microwave‐induced thermoacoustic tomography (TAT) of adult human brain.

Methods

We analyzed the electric field distribution radiated from an antenna to acquire homogeneous illumination. We first imaged the anatomical structures in a rat's trunk to validate the thermoacoustic contrast in vivo. We then imaged an agar cylinder through an adult human skull ex vivo to demonstrate transcranial penetration of both microwave and ultrasound. We also analyzed the specific absorption rate to show the conformance to the safety standard for human electromagnetic exposure.

Results

We successfully acquired cross‐sectional images of the rat's trunk in vivo. Major blood vessels and organs are clearly visible. The transcranial image shows that TAT can image through the adult human skull and reveal an agar enclosed by the skull.

Conclusions

Microwave‐induced TAT of a rat's trunk in vivo and an agar phantom through an adult human skull ex vivo has been demonstrated experimentally. This study demonstrates both the TAT contrasts in vivo and the capability of transcranial imaging, showing potential of TAT for adult human brain imaging with high contrast and penetration.
Digital Image Analysis as a Technique for Alewife Fecundity Estimation in a New Hampshire River
Authors: Sullivan Kevin M. , Bailey Michael M. , Berlinsky David L.
Published: February 2019

Fecundity estimates are important in fisheries management to determine the reproductive potential and spawning stock biomass of a population. Traditional methods for determining these estimates, however, have been time consuming and tedious, often requiring long-term sample storage in toxic preservatives. Recently, studies incorporated the use of scanners and image analysis software to produce equally reliable fish fecundity estimates. This study was undertaken to demonstrate the application of this technique with Alewife Alosa pseudoharengus, “a species of concern.” Ovaries were collected from fish ranging in size from 25 to 34 cm throughout their annual spawning migration (Newmarket, New Hampshire) and used to compare fecundity estimated gravimetrically following long-term storage and by use of a flatbed scanner. Gonadosomatic indices were calculated throughout the collection period but were not found to differ over time. Comparisons within ovaries demonstrated that oocyte size and number did not differ among anterior, center, and posterior sections. Fecundity estimates did not differ between the two methods and increased with fish age and size ranging from 121,000 and 130,200 oocytes/female (25 cm) to 332,500 and 364,900 oocytes/females (34 cm), respectively. These results demonstrate that fecundity estimates using digital image analysis software were equally reliable as those produced by traditional methods but were generated more quickly and with less reliance on toxic preservatives.
Film‐insert injection compression molding for reinforced polycarbonate with woven glass fiber oriented 90/0°, ± 45°
Authors: Solorza‐Nicolas Omar , Hernandez‐Moreno Hilario , Susarrey‐Huerta Orlando , Romero‐Partida Nestor
Published: February 2019

A manufacturing method is proposed using two conventional methods, film insert molding and compression molding, to obtain rectangular of the size of 250 × 35 × 2.5 mm specimens of polycarbonate reinforced with 4% mat fibers glass with orientations 90/0° and ±45°, to investigate, disorientation of the fibers. A Finite Element Method was performed, using Moldflow to determine initial conditions to predict the behavior of the polymer during the compaction stage and then manufacture the mold. Physical tests were performed using a conventional injection machine, based on the results previously obtained in the simulation. Woven fiberglass did not require a chemical treatment previously to achieve adhesion between the two types of polycarbonate. Specimens of polycarbonate reinforced at 0/90° and ±45° orientation have demonstrated small fiber orientation distortion. For the case of 0/90° specimens, the maximum deviation is show in the specimen with 2.58° which represent a misalignment cause by compression stage which also happened in 0° where the maximum standard deviation is 0.98°. Measurements for the +45° fibers, the standard deviation is 2.60° and 2.23° for −45°. According to ASTM D3039, the deviation of fiber, are within the tolerance to be characterized and obtain the mechanical properties. POLYM. ENG. SCI., 59:E372–E379, 2019. © 2019 Society of Plastics Engineers
Synthesis and characterization of an efficient flame retardant based on aromatic ring and phosphate ester for epoxy resin
Authors: Tian Li , Li Xiang , Wang Lurong , Zhang Yabin , Cui Jinfeng , Guo Junhong , Yang Baoping
Published: February 2019

An efficient phosphorous flame retardant rich in aromatic rings was synthesized and introduced into epoxy resin. The flame retardant properties of the resultant composites were studied, and the results were compared with those of 5 wt% tris(bis(4‐((diphenoxyphosphoryl)oxy)phenyl)methyl) benzene‐1,3,5‐tricarboxylate (DHPP‐OH‐BAC), 10 wt% DHPP‐OH‐BAC and 15 wt.% DHPP‐OH‐BAC samples. The results showed that the 15% DHPP‐OH‐BAC sample had the best flame retardancy effect, a limiting oxygen index of 33.6%, and UL‐94 V‐0 level. A cone calorimeter experiment showed that the addition of flame retardant can significantly reduce the amount of smoke and heat. Macroscopic digital photographs, scanning electron micrographs and thermogravimetric analysis results further revealed that DHPP‐OH‐BAC can exhibit high char yields. The flame retardancy mechanism of DHPP‐OH‐BAC was preliminarily shown by pyrolysis‐gas chromatography–mass spectrometry analysis. The test results show that a high‐efficiency phosphorous flame retardant rich in aromatic rings was successfully developed. POLYM. ENG. SCI., 59:E406–E413, 2019. © 2019 Society of Plastics Engineers
Cover Image, Volume 75, Issue 3
Authors: Stella de Freitas Thais F , Stout Michael J , Sant'Ana Josué
Published: February 2019

The front cover image is based on the Research Artice Effects of exogenous methyl jasmonate and salicylic acid on rice resistance to Oebalus pugnax by Thais F Stella de Freitas et al., DOI: 10.1002/ps.5174. Image Credit: Thais Fernanda Stella de Freitas, Federal University of Rio Grande do Sul.

image
Robotic‐assisted minimally invasive esophagectomy versus the conventional minimally invasive one: A meta‐analysis and systematic review
Authors: Jin Dacheng , Yao Liang , Yu Jun , Liu Rong , Guo Tiankang , Yang Kehu , Gou Yunjiu
Published: February 2019

Background

Conventional video‐assisted minimally invasive esophagectomy (MIE) is safe and associated with low rates of morbidity and mortality, but the two‐dimensional monitor reduces eye‐hand harmony and viewing yield. Robotic‐assisted minimally invasive esophagectomy (RAMIE) with its virtual reality simulators offers a realistic three‐dimensional environment that facilitates dissection in the narrow working space, but it is expensive and requires longer operative time. Therefore, the aim of this meta‐analysis was to assess the safety and feasibility of RAMIE versus MIE in patients with esophageal cancer.

Material and Methods

PubMed, EMBASE, Cochrane library, and Chinese Biomedical Literature databases were systematically searched up to 21 September 2018 for case‐controlled studies that compared RAMIE with MIE.

Result

Eight case‐controlled studies involving 1862 patients (931 under RAMIE and 931 under MIE) were considered. No statistically significant difference between the two techniques was observed regarding R0 resection rate (OR = 1.1174, P = 0.8647), conversion to open (OR = 0.7095, P = 0.7519), 30‐day mortality rate (OR = 0.8341, P = 0.7696), 90‐day mortality rate (OR = 0.3224, P = 0.3329), in‐hospital mortality rate (OR = 0.3733, P = 0.3895), postoperative complications, number of harvested lymph nodes (mean difference [MD] = 0.8216, P = 0.2039), operation time (MD = 24.3655 min, P = 0.2402), and length of stay in hospitals (LOS) (MD = −5.0228 day, P = 0.1342). The meta‐analysis showed that RAMIE was associated with a significantly fewer estimated blood loss (EBL) (MD = −33.2268 mL, P = 0.0075). And the vocal cord palsy rate was higher in the MIE group compared with RAMIE, and the difference was significant (OR = 0.5696, P = 0.0447).

Conclusion

This meta‐analysis indicated that RAMIE and MIE display similar feasibility and safety when used in esophagectomy. However, randomized controlled studies with larger sample sizes are needed to evaluate the benefit and harm in patients with esophageal cancer undergoing RAMIE.
Autonomous tracking of an oceanic thermal front by a Wave Glider
Authors: Zhang Yanwu , Rueda Carlos , Kieft Brian , Ryan John P. , Wahl Christopher , O’Reilly Thomas C. , Maughan Thom , Chavez Francisco P.
Published: February 2019

Temporal variation in the structure and location of dynamic ocean features make them challenging to observe. Beyond requiring sufficient persistence and speed of the sensor platform, effective observation is augmented by autonomous feature detection coupled with adaptive localization of mapping effort. These capabilities enable observations to remain localized within and around features of interest, thereby enhancing spatial and temporal resolution in their depiction. A Wave Glider is a wave‐propelled unmanned surface vehicle with solar energy collection to support payload and a backup propeller in calm sea state. The efficiency of this platform enables persistence (months), and its propulsion system provides speed (~1 m/s). Building on these capabilities, we aim at enabling the Wave Glider to autonomously recognize and track oceanic features that have strong surface expressions, accessible to near‐surface sensors. We present a method of using a Wave Glider to autonomously track an oceanic thermal front known to have biological importance and dynamic evolution. In October 2017, this method was applied to tracking and mapping an upwelling front in Monterey Bay, CA, over 39 hr. The field result demonstrates adaptive localization of mapping based on autonomous feature detection.
Top management team demographic‐faultline strength and strategic change: What role does environmental dynamism play?
Authors: Richard Orlando Curtae' , Wu Jie , Markoczy Livia Anna , Chung Yunhyung
Published: February 2019

Research summary

Drawing on the demographic faultline perspective and the concept of attribute‐specific faultlines, we investigate the effect of top management team (TMT) relationship‐related (gender, age, educational level) and task‐related (functional background, tenure) faultline strengths on strategic change. In a panel study (2003–2015), we find that TMT relationship‐related faultline strength (especially educational‐level) negatively influences strategic change whereas TMT task‐related faultline strength positively affects strategic change. Environmental dynamism reduces the negative effect of TMT gender and educational‐level faultline strengths on strategic change while in fact revealing a notable positive effect between TMT age‐faultline strength and strategic change. Additionally, environmental dynamism strengthens the positive effects of task‐related TMT faultline strength on strategic change. We offer theoretical and practical implications to both the demographic faultlines and upper echelons research domains.

Managerial summary

Top management teams (TMTs) in firms can fracture into subgroups based on demographic characteristics (e.g., age, gender, and education level) as well as based on task‐related characteristics (e.g., functional background, and tenure). We call the former relationship‐related faultlines and the latter task‐related faultlines. We predict and find that stronger relationship based faultlines hinders between subgroup cohesion, reducing TMTs' ability to initiate strategic change. We also predict and find that stronger task‐related faultlines facilitate inter‐subgroup knowledge‐sharing, improving TMTs' ability to initiate strategic change. We find that environmental dynamism reduces the negative effect of most relationship‐related faultlines (except age where this effect is positive) on strategic change, while strengthening the positive effect of task‐related faultline strengths on strategic change.
Foundations of entrepreneurial strategy
Authors: Gans Joshua S. , Stern Scott , Wu Jane
Published: February 2019

Research Summary

This paper develops an integrated framework linking the nature of the entrepreneurial choice process to the foundations of entrepreneurial strategy. Because entrepreneurs face many alternatives that cannot be pursued at once, entrepreneurs must adopt (implicitly or explicitly) a process for choosing among entrepreneurial strategies. The interplay between uncertainty and learning has the consequence that commitment‐free analysis yields multiple, equally viable alternatives from which one must be chosen. This endogenous gap between optimization and choice is a central paradox confronting entrepreneurs. Resolving this allows for a reformulation of the foundations of entrepreneurial strategy, emphasizing the role of choice rather than the centrality of the strategic environment.

Managerial Summary

The central strategic challenge for an entrepreneur is how to choose: entrepreneurs often face multiple potential strategies for commercializing their idea but due to the constraint of limited resources, cannot pursue them all at once. At the same time, entrepreneurs are venturing into new domains and as such, must choose under conditions of high uncertainty with only noisy learning available. This paper explores the interplay between these unique conditions that shape the entrepreneurial choice process, finding that often, the process will not yield a single best strategy but instead several equally attractive strategic alternatives. A key implication is that entrepreneurs cannot simply choose what not to do, but instead must proactively decide which equally viable alternatives to leave behind when choosing an entrepreneurial strategy.
Modeling Growth: Consequences from Selecting Samples by Size
Authors: Goodyear C. Phillip
Published: February 2019

Simulated size–age observations were collected from hypothetical populations with known growth to quantify potential bias in estimates of growth and mortality that can result from size‐selective sampling. The population lengths at ages were normally distributed around means predicted by published von Bertalanffy (VB) equations for the Striped Marlin Kajikia audax or Vermilion Snapper Rhomboplites aurorubens. Parameter estimates for the VB equation were accurate when the data were collected with random and age‐stratified sampling. Size‐stratified sampling caused important bias in estimates of length at age and fitted VB parameters. The bias increased with the coefficient of variation of mean size at age and total mortality. It became more severe when sampling effort was increased to compensate for low sample numbers in bins within the upper tail of the distribution of sizes in the populations. Error occasionally exceeded 100% for asymptotic length L∞ and 50% for the Brody growth coefficient K. When a random sample was supplemented with ≤10% large fish, the bias was sometimes greater than that observed when a completely size‐stratified design was used. Such error could corrupt the reliability of analyses that depend on VB parameters. For Striped Marlins, natural mortality computed with the Pauly (1980) equation using results from length‐selective sampling strategies often deviated 50% or more from the values predicted using the “true” growth coefficients. Potential for nonrepresentative sampling of lengths at age should be routinely described when VB models are first published and should be considered whenever the growth estimates are later used for other purposes.
The action of long strings in supersymmetric field theories
Authors: Solberg Tomer , Yutushui Mykhailo
Published: February 2019

Abstract

Long strings emerge in many Quantum Field Theories, for example as vortices in Abelian Higgs theories, or flux tubes in Yang-Mills theories. The actions of such objects can be expanded in the number of derivatives, around a long straight string solution. This corresponds to the expansion of energy levels in powers of 1/L, with L the length of the string. Doing so reveals that the first few terms in the expansions are universal, and only from a certain term do they become dependent on the originating field theory. Such classifications have been made before for bosonic strings. In this work we expand upon that and classify also strings with fermionic degrees of freedom, where the string breaks D = 4, N = 1 SUSY completely. An example is the confining string in N = 1 SYM theory. We find a general method for generating supersymmetric action terms from their bosonic counterparts, as well as new fermionic terms which do not exist in the non-supersymmetric case. These terms lead to energy corrections at a lower order in 1/L than in the bosonic case.
Open minimal strings and open Gelfand-Dickey hierarchies
Authors: Aleshkin Konstantin , Belavin Vladimir
Published: February 2019

Abstract

We study the connection between minimal Liouville string theory and generalized open KdV hierarchies. We are interested in generalizing Douglas string equation formalism to the open topology case. We show that combining the results of the closed topology, based on the Frobenius manifold structure and resonance transformations, with the appropriate open case modification, which requires the insertion of macroscopic loop operators, we reproduce the well-known result for the expectation value of a bulk operator for the FZZT brane coupled to the general (q, p) minimal model. The matching of the results of the two setups gives new evidence of the connection between minimal Liouville gravity and the theory of Topological Gravity.
Plane partition realization of (web of) $$ \mathcal{W} $$-algebra minimal models
Authors: Harada Koichi , Matsuo Yutaka
Published: February 2019

Abstract

Recently, Gaiotto and Rapčák (GR) proposed a new family of the vertex operator algebra (VOA) as the symmetry appearing at an intersection of five-branes to which they refer as Y algebra. Procházka and Rapčák, then proposed to interpret Y algebra as a truncation of affine Yangian whose module is directly connected to plane partitions (PP). They also developed GR’s idea to generate a new VOA by connecting plane partitions through an infinite leg shared by them and referred it as the web of W-algebra (WoW). In this paper, we demonstrate that double truncation of PP gives the minimal models of such VOAs. For a single PP, it generates all the minimal model irreducible representations of W-algebra. We find that the rule connecting two PPs is more involved than those in the literature when the U(1) charge connecting two PPs is negative. For the simplest nontrivial WoW,

$$ \mathcal{N} $$

N

= 2 superconformal algebra, we demonstrate that the improved rule precisely reproduces the known character of the minimal models.
Bradycardia During Laparoscopic Surgeries: A Retrospective Cohort Study
Authors: Dabush‐Elisha Inbal , Goren Or , Herscovici Aviram , Matot Idit
Published: February 2019

Background

A recent analysis found bradycardia during laparoscopy as a potential early warning sign of cardiac arrest. Knowledge regarding bradycardia frequency and its consequences during laparoscopy is limited.

Methods

Using the computerized record database, files of 9915 patients undergoing laparoscopic surgery, between June 2008 and August 2013 at a tertiary, academic medical center, were screened for intraoperative bradycardia (heart rate <50 beats/min for at least three consecutive measures).

Results

Intraoperative bradycardia occurred in 1540 (15.5%) patients, in the majority (945, 61.3%) heart rate decreased to <45 beats/min. Mean (SD) duration of bradycardia was 14.8 (16.8) min. Bradycardia was more prevalent in males, older patients, smokers, patients with comorbidities and those treated with β, α and calcium channel blockers. The majority of events were related to CO2 insufflation and bolus opioid administration. In 1343 (87%), noteworthy decreases in blood pressure were recorded; the average (SD) drop in systolic blood pressure was 35 (21) mmHg. Pharmacological intervention to alleviate bradycardia was used in up to 23% of episodes. Bradycardia did not result in intraoperative cardiac arrest, neither did it increase the frequency of intensive care unit admission or mortality rate.

Conclusion

Bradycardia is common during laparoscopy. Despite being more prevalent in older and sicker patients, bradycardia did not significantly affect outcome, suggesting that routine preventive measures do not need to be implemented. Rather, intraoperative bradycardia events should be wisely followed with prompt response, when hemodynamic perturbations occur, the threshold of which is yet to be defined.
Proposal of a Scoring Scale to Estimate Risk of the Discontinuation of S‐1 Adjuvant Monotherapy in Patients with Stage II to III Gastric Cancer: A Multi‐Institutional Dataset Analysis
Authors: Iizuka Akimitsu , Kanda Mitsuro , Ito Seiji , Mochizuki Yoshinari , Teramoto Hitoshi , Ishigure Kiyoshi , Murai Toshifumi , Asada Takahiro , Ishiyama Akiharu , Matsushita Hidenobu , Tanaka Chie , Kobayashi Daisuke , Fujiwara Michitaka , Murotani Kenta , Kodera Yasuhiro
Published: February 2019

Background

Discontinuation of postoperative S‐1 adjuvant monotherapy is a frequent problem in the management of patients with gastric cancer.

Methods

A total of 355 stage II/III gastric cancer patients who underwent gastrectomy and adjuvant S‐1 were retrospectively analyzed using a multicenter dataset. We randomly assigned patients into either discovery or validation cohort in a 2:1 ratio. In the discovery cohort, 29 parameters were assessed as candidate factors to predict discontinuation of S‐1 adjuvant within 6 months. A scoring system was designed using independent risk factors identified by the multivariate analysis. Reproducibility was tested in the validation cohort.

Results

Overall, 92 patients (25.9%) discontinued the treatment within 6 months because of adverse effects. Age, preoperative urea nitrogen (UN) and the preoperative albumin‐to‐bilirubin index (ALBI) showed the highest area under the curve (AUC) for the discontinuation of S‐1 adjuvant within 6 months in each category: body status, blood tests and indices. In the multivariate analysis, age ≥ 64 years, preoperative UN ≥ 15.2 mg/dl and preoperative ALBI ≥ −0.265 were identified as independent risk factors. A scoring scale consisting of these three factors was developed for the prediction of drug discontinuation and demonstrated a greater AUC (0.728) than that of each of the three constituents. The time to treatment discontinuation decreased incrementally as the risk score increased. The reproducible findings were confirmed in the validation cohort.

Conclusions

We identified risk factors and developed a scoring scale to predict S‐1 adjuvant monotherapy discontinuation in patients with stage II/III gastric cancer.
Maxwell–Stefan model of multicomponent ion transport inside a monolayer Nafion membrane for intensified chlor-alkali electrolysis
Authors: Sijabat R. R. , de Groot M. T. , Moshtarikhah S. , van der Schaaf J.
Published: February 2019

A mathematical model based on a generalized Maxwell–Stefan equation has been developed to describe multicomponent ion and water transport inside a cation-exchange membrane. This model has been validated using experimental data and has been used to predict concentration profiles, membrane potential drop, and transport numbers of ions and water for the chlor-alkali process at increased current densities. Several improvements have been made to previously developed Maxwell–Stefan models. In our model, the generalized Maxwell–Stefan equation is written in terms of concentration instead of mole fraction and the fixed group (membrane) concentration is assumed to be constant. We have adapted the Augmented matrix method using the built-in partial differential equation parabolic elliptic (pdepe) solver in Matlab®, and both the concentration and the electrical potential gradients have been solved simultaneously. The boundary conditions are determined with the Donnan equilibrium at the membrane–solution interface. We have also employed semi-empirical correlations to define the Maxwell–Stefan diffusivities inside the membrane. For the bulk diffusivities, we applied the correlations for the concentrated solution instead of the values at infinite dilution. With the diffusivities presented in this work, the model shows a better fit to the experimental data than with previously reported fitted diffusivities. Prediction of the sodium transport number and water transport number is generally good, whereas the deviations with regard to membrane potential might also be related to issues with the experimental data. The model predicts an increase in both sodium and water transport numbers at increased current density operation of chlor-alkali production.

Graphical abstract
Universal and Nonuniversal Aperture‐to‐Length Scaling of Opening Mode Fractures Developing in a Particle‐Based Lattice Solid Model
Authors: Mayrhofer Franziska , Schöpfer Martin P. J. , Grasemann Bernhard
Published: February 2019

Opening‐mode fractures, such as joints, veins, and dykes, frequently exhibit power‐law aperture‐to‐length scaling, with scaling exponents typically ranging from 0.5 to 2. However, published high quality outcrop data and continuum‐based numerical models indicate that fracture aperture‐to‐length scaling may be nonuniversal, with scaling being superlinear for short fractures and sublinear for long fractures. Here we revisit these published results by means of a particle‐based lattice solid model, which is validated using predictions from linear elasticity and linear elastic fracture mechanics. The triangular lattice model composed of breakable elastic beams, with strengths drawn from a Weibull distribution, is used to investigate the fracture aperture‐to‐length scaling that emerges in a plate subjected to extension. The modeled fracture system evolution is characterized by two stages which are separated by the strain at which peak‐stress occurs. During the pre‐peak‐stress stage, aperture‐to‐length scaling is universal with a power‐law exponent of about one. Shortly after the material has attained its maximum load bearing capacity, which coincides with the formation of a multiple‐segment fracture zone, aperture‐to‐length scaling becomes nonuniversal, with power‐law exponents being consistent with earlier studies. The results presented here confirm that deviation from universal scaling laws is a consequence of fracture interaction. More specifically, the onset of nonuniversal aperture‐to‐length scaling coincides with the formation of a multiple‐segment fracture zone.
Transdimensional Bayesian Attenuation Tomography of the Upper Inner Core
Authors: Pejić Tanja , Hawkins Rhys , Sambridge Malcolm , Tkalčić Hrvoje
Published: February 2019

Following the linearized attenuation tomography from our previous study (Pejić et al., 2017,https://doi.org/10.1002/2016JB013692), we perform hierarchical transdimensional Bayesian tomography of the upper ≈400 km of the inner core, using 398 globally distributedt∗estimates. The results are in good agreement with the ones obtained through linearized tomography: they show more complex attenuation pattern than the purely hemispherical one, and the noise estimated from the hierarchical inversion is in good agreement with estimates obtained from the Discrepancy Principle in the previous study. The attenuation pattern we observe gives more weight to the geodynamical models that couple the thermal anomalies of the lowermost mantle to the inner core boundary.
Groundwater Inflow Toward a Preheated Volcanic Conduit: Application to the 2018 Eruption at Kīlauea Volcano, Hawai'i
Authors: Hsieh P. A. , Ingebritsen S. E.
Published: February 2019

The many successes in volcano forecasting over the past several decades owe mainly to pattern recognition, both in monitoring data and the geologic record. During the early stages of the 2018 Kīlauea eruption, the conceptual model of Stearns (1925, https://doi.org/10.1007/BF02719505), based on the explosive 1924 Kīlauea eruption, was highly influential. This model postulates that explosions are triggered by liquid water inflow into a recently vacated magma conduit. Modern quantitative modeling approaches, supplemented by hydrogeologic data unavailable in 1925, yield a more nuanced view. Results demonstrate that liquid water inflow would likely be delayed by months to years, owing to the inability of liquid water to transit a zone of very hot rock surrounding the conduit. The exercise demonstrates the use of physically based modeling to supplement traditional volcano forecasting approaches during an ongoing event.
Convection Initiation Resulting From the Interaction Between a Quasi‐Stationary Dryline and Intersecting Gust Fronts: A Case Study
Authors: Bai Lanqiang , Meng Zhiyong , Huang Yipeng , Zhang Yunji , Niu Shuzhen , Su Tao
Published: February 2019

This study explores the convection initiation (CI) of a high‐impact squall line that occurred in central eastern China on 3 June 2009 based on observations and numerical modeling. The CI occurred in a scenario in which a set of intersecting gust fronts, organized in a distinct scalloped pattern, propagated toward an area of enhanced moisture produced by a near‐surface convergence line. This convergence line developed in a quasi‐stationary dryline zone. The dryline primed the preconvective environment by deepening the moist layer prior to the arrival of the intersecting gust fronts. The onset of CI occurred approximately 30 min after these intersecting gust fronts passed through the CI location, which was on the dry side of the dryline. Although these gust fronts acted as a strong signal for CI potential, CI did not occur along the entire length of the scalloped pattern of the intersecting gust fronts. The exact locations of the initiated convective cells were at the vertices of the scalloped pattern. An idealized simulation using a cloud model was conducted, demonstrating that the vertex regions were characterized by more favorable dynamical conditions for CI compared to the nonvertex regions along the scalloped outflow boundary. The greater CI probability over the vertex region was attributed to the greater magnitudes and larger vertical and horizontal extents of updrafts.
Implementation of the Vector Vorticity Dynamical Core on Cubed Sphere for Use in the Quasi‐3‐D Multiscale Modeling Framework
Authors: Jung Joon‐Hee , Konor Celal S. , Randall David
Published: February 2019

The dynamical core that predicts the three‐dimensional vorticity rather than the momentum, which is called Vector‐Vorticity Model (VVM), is implemented on a cubed sphere. Its horizontal coordinate system is not restricted to orthogonal, while the vertical coordinate is orthogonal to the horizontal surface. Accordingly, all the governing equations of the VVM, which are originally developed with Cartesian coordinates, are rewritten in terms of general curvilinear coordinates. The local coordinates on each cube surface are constructed with the gnomonic equiangular projection. Using global channel domains, the VVM on the cubed sphere has been evaluated by (1) advecting a passive tracer with a bell‐shaped initial perturbation along an east‐west latitude circle and along a north‐south meridional circle and (2) simulating the evolution of barotropic and baroclinic instabilities. The simulated results with the cubed‐sphere grids are compared to analytic solutions or those with the regular longitude‐latitude grids. The convergence with increasing spatial resolution is also quantified using standard error norms. The comparison shows that the solutions with the cubed‐sphere grids are quite reasonable for both linear and nonlinear problems when high resolutions are used. With coarse resolution, degeneracy appears in the solutions of the nonlinear problems such as spurious wave growth; however, it is effectively reduced with increased resolution. Based on the encouraging results in this study, we intend to use this model as the cloud‐resolving component in a global Quasi‐Three‐Dimensional Multiscale Modeling Framework.
Collaboration Reveals What’s Beneath the Surface
Authors: Goss Heather
Published: February 2019

How do scientists look underground? Answering questions about Earth’s interior requires an attack from many angles.
Modern Warming Is Undoing Millennia of Arctic Ice Cover
Authors: Cartier Kimberly
Published: February 2019

Plants and rocks at the edges of glaciers have been entombed in ice for more than 40,000 years. Modern warming, unmatched in 115,000 years, is now uncovering these landscapes.
House Hearing Stresses Climate Change’s Links to Ocean Health
Authors: Showstack Randy
Published: February 2019

Backed by new Democratic congressional leadership determined to focus on science, experts call for swift action to avoid or limit irreparable environmental harm.
A chemiluminescence method for the determination of mercury(ii) ions by tuning the catalytic activity of gold nanoparticles with ethylenediamine
Authors: Wang Meiling , Kong Yafang , Li Ying , Huang Yongxin , Fan Aiping
Published: February 2019

A turn-on and an ultrasensitive chemiluminescence detection method for mercuric ions was developed.
Palladium-catalyzed cross-coupling of unactivated alkylzinc reagents with 2-bromo-3,3,3-trifluoropropene and its application in the synthesis of fluorinated amino acids
Authors: Lou Yue-Guang , Wang An-Jun , Zhao Liang , He Lin-Feng , Li Xiao-Fei , He Chun-Yang , Zhang Xingang
Published: February 2019

A palladium-catalyzed cross-coupling of unactivated alkylzinc reagents with 2-bromo-3,3,3-trifluoropropene (BTP) has been developed, which was used as a key step to prepare a series of trifluoromethylated and difluoromethylated amino acids.
Flower-like Fe7S8/Bi2S3 superstructures with improved near-infrared absorption for efficient chemo-photothermal therapy
Authors: Cao Qing , Guo Xin , Zhang Wenlong , Guan Guoqiang , Huang Xiaojuan , He Shu-Ang , Xu Mingdong , Zou Rujia , Lu Xinwu , Hu Junqing
Published: February 2019

Hydrophilic flower-like Fe7S8/Bi2S3 superstructures with improved near-infrared absorption and photostability for good chemo-photothermal synergistic therapeutic effect.
A fluorescein-based chemosensor for “turn-on” detection of Hg2+ and the resultant complex as a fluorescent sensor for S2− in semi-aqueous medium with cell-imaging application: experimental and computational studies
Authors: Mohammad Hasan , Islam Abu Saleh Musha , Prodhan Chandraday , Ali Mahammad
Published: February 2019

A fluorescein hydrazone based probe selectively recognizes Hg2+ ion with live cell imaging application.
Bimetallic Cu–Mn B spinel oxide catalyzed oxidative synthesis of 1,2-disubstituted benzimidazoles from benzyl bromides
Authors: Sharma Rohit , Sofi Firdoos Ahmad , Rana Preeti , Bharatam Prasad V.
Published: February 2019

Cu–Mn B (a heterogeneous catalyst) catalyzed synthesis of 1-benzyl-2-phenyl-1H-benzo[d]imidazoles is reported.
In situnitroso formation induced structural diversity of uranyl coordination polymers
Authors: Kong Xiang-He , Hu Kong-Qiu , Wu Qun-Yan , Mei Lei , Yu Ji-Pan , Chai Zhi-Fang , Nie Chang-Ming , Shi Wei-Qun
Published: February 2019

This work presents three possible pathways that could exist in thein situreaction system. Structural analysis of these compounds revealed that the introduction of nitroso group exerted significant influences on the conformations of ligands, skeletons and 3D structures.
Bimolecular proximity of a ruthenium complex and methylene blue within an anionic porous coordination cage for enhancing photocatalytic activity
Authors: Fang Yu , Xiao Zhifeng , Kirchon Angelo , Li Jialuo , Jin Fangying , Togo Tatsuo , Zhang Liangliang , Zhu Chengfeng , Zhou Hong-Cai
Published: February 2019

An anionic coordination cage encapsulates the catalyst and the substrate within its cavity, circumvent the charge repulsion, thus promotes the activity in the photocatalysis.
Promoting sulfur immobilization by a hierarchical morphology of hollow carbon nanosphere clusters for high-stability Li–S battery
Authors: Chen Mingqi , Su Zhe , Jiang Kai , Pan Yankai , Zhang Yayun , Long Donghui
Published: February 2019

Efficiency of physical sulfur immobilization is enhanced through a hierarchical morphology of hollow carbon nanosphere clusters (HNCNs).
Synthesis of 1,2,4-oxadiazolidines via [3+2] cycloaddition of nitrones with carbodiimides
Authors: Chen Yuan , Fuyue Liuting , Wang Gangqiang , Wang Hang , Lu Chun , Guo Haibing , St. Amant Chiara , Sun Shaofa , Xing Yalan
Published: February 2019

An efficient [3+2] cycloaddition of nitrones and carbodiimides has been developed.
Polynitroxide-grafted-graphene: a superior cathode for lithium ion batteries with enhanced charge hopping transportation
Authors: Lu Chengyi , Pan Guang , Huang Qiaogao , Wu Haitao , Sun Wang , Wang Zhenhua , Sun Kening
Published: February 2019

The emergence of organic nitrogen-oxide (NO) radical polymers has brought hope in the pursuit of high performance lithium-ion batteries (LIBs).
Novel phthalocyanine-based polymeric micelles with high near-infrared photothermal conversion efficiency under 808 nm laser irradiation for in vivo cancer therapy
Authors: Li Lu , Yang Qingzhu , Shi Lei , Zheng Nannan , Li Zeyu , Li Kai , Qiao Shupei , Jia Tao , Sun Tiedong , Wang Yue
Published: February 2019

Novel phthalocyanine molecule 4OCSPC with deep NIR absorbance showed excellent photothermal therapy property for cancer cells.
New hysteresis‐current‐controlled buck converter with AC sensing techniques
Authors: Lei C.‐C. , Hwang Y.‐S. , Chen J.‐J. , Ku Y.‐T.
Published: February 2019

A new hysteresis‐current‐controlled buck converter with alternating current (AC) sensing techniques is presented in this Letter. The proposed AC sensing technique senses the inductor current ripple by sensing the voltage at two terminals of the inductor. Accompanying with hysteresis‐current‐controlled technique and a type‐III compensator, the transient response can be accelerated. The simulation result shows the response time is 0.7 µs when the load current switch from 150 to 600 mA and the maximum efficiency is 94.6%.
Analytical modelling of the linear switched reluctance motor with segmental translator
Authors: Golzarzadeh Milad , Ganji Babak
Published: February 2019

Because of similar structure and operation principles, the linear switched reluctance motor (LSRM) has all advantages of rotary switched reluctance motor. Also, segmental translator LSRM (STLSRM) has the capability to produce higher output power/weight when it is compared with the conventional LSRM. Due to the high advantages of the STLSRM, electromagnetic modelling of this motor is considered in this study. By the direct solution of the field equations, an analytical model is introduced for the STLSRM by which the static characteristic of flux‐linkage with a phase for various phase currents and different translator positions is determined. Having this static characteristic, dynamic analysis of the motor is then carried out based on the phase voltage equation to predict the phase current and instantaneous thrust waveforms. Due to the high speed of the developed model, it can be utilised appropriately for the initial sizing of the machine where accuracy can be traded with time‐saving. Applying the proposed analytical model to a typical three‐phase STLSRM, simulation results are presented and they are validated using the finite element (FE) calculations.
Design and analysis of all‐optical 1‐to‐2 line decoder based on linear photonic crystal
Authors: Mondal Haraprasad , Sen Mrinal , Goswami Kamanashis
Published: February 2019

A new design of 1‐to‐2 line all‐optical logic decoder has been proposed based on a two‐dimensional photonic crystal (PhC) structure. The decoder operates based on the principle of optical interference within the PhC waveguides. An optical bias has been used to generate high‐logic states at zero input conditions. Simulations explore a high contrast ratio, in the order of 11.3 dB, for both the output ports of the device. Response times have been calculated from the transient responses of the output ports, and are found as 0.65 and 0.77 ps for the ports 1 and 2, respectively. These results in a bit rate of ≃625 Gbps, considering the worst‐case scenario. Phase sensitivity analysis has also been performed which shows that the device output is quite sensitive to the differences in phases of the bias and signals. However, a strategy has been proposed to make the same insensitive to the phase changes. Finally, the small footprint (in the order of 234 μm2); standard operating wavelength; and silicon‐based design of the decoder, along with its said merits, make the device highly potential for on‐chip photonic‐integrated‐circuit applications.
Reliability model of MMC‐based flexible interconnection switch considering the effect of loading state uncertainty
Authors: Liu Wenxia , Xu Yahui
Published: February 2019

Flexible interconnection switch (FIS) is a power electronic device applied to electrical distribution system to realise the flexible control of power flow. Due to the fact that the reliability of FIS tends to be influenced by its operating conditions and dynamic characteristics during its actual operation, it is of significance to characterise the effects of loadings on reliability of FIS. Therefore, an improved reliability model of FIS is proposed, considering the state uncertainty of current and voltage loadings. First, the structural reliability model of modular multilevel converter (MMC) is established. Next, in view of the uncertainty of source and load in distribution network, Monte Carlo simulation is used to deal with the random current loadings, thus the equivalent reliability model of insulated gate bipolar transistor module is built. Then, considering the arm's voltage loading sharing mechanism, a state‐dependent arm reliability model is built. Finally, an eight‐state reliability model for the entire FIS is developed, and Markov‐based analytical method is used to solve it. With the standard test system as well as the actual project in Hangzhou are taken as the testing systems, the reliability indices of FIS are calculated and compared with the field data. The numerical results validate the validity of the proposed model.
High resolution optical spectroscopy of the N2-rich comet C/2016 R2 (PanSTARRS)
Authors: Opitom C. , Hutsemékers D. , Jehin E. , Rousselot P. , Pozuelos F. J. , Manfroid J. , Moulane Y. , Gillon M. , Benkhaldoun Z.
Published: February 2019

Context. Early observations of comet C/2016 R2 (PanSTARRS) have shown that the composition of this comet is very peculiar. Radio observations have revealed a CO-rich and HCN-poor comet and an optical coma dominated by strong emission bands of CO+ and, more surprisingly, N2+.

Aims. The strong detection of N2+ in the coma of C/2016 R2 provided an ideal opportunity to measure the 14N∕15N isotopic ratio directly from N2+ for the first time, and to estimate the N2∕CO ratio, which is an important diagnostic to constrain formation models of planetesimals, in addition to the more general study of coma composition.

Methods. We obtained high resolution spectra of the comet in February 2018 when it was at 2.8 au from the Sun. We used the UVES spectrograph of the European Southern Observatory Very Large Telescope, complemented with narrowband images obtained with the TRAPPIST telescopes.

Results. We detect strong emissions from the N2+ and CO+ ions, but also CO2+, emission lines from the CH radical, and much fainter emissions of the CN, C2, and C3 radicals that were not detected in previous observations of this comet. We do not detect OH or H2O+, and we derive an upper limit of the H2O+∕CO+ ratio of 0.4, implying that the comet has a low water abundance. We measure a N2+/CO+ ratio of 0.06 ± 0.01. The non-detection of NH2 indicates that most of the nitrogen content of the comet is in N2. Together with the high N2+/CO+ ratio, this could indicate a low formation temperature of the comet or that the comet is a fragment of a large differentiated Kuiper Belt object. The CO2+/CO+ ratio is 1.1 ± 0.3. We do not detect 14N15N+ lines and can only put a lower limit on the 14N∕15N ratio (measured from N2+) of about 100, which is compatible with measurements of the same isotopic ratio for NH2 and CN in other comets. Finally, in addition to the [OI] and [CI] forbidden lines, we detect for the first time the forbidden nitrogen lines [NI] doublet at 519.79 and 520.03 nm in the coma of a comet.