bluuebunny/crossref_metadata_2025_split huggingface dataset:
Online optical monitoring of polymer melting in a twin‐screw extruder
Authors: Bicalho Luciana Assumpção , Covas José António , Canevarolo Sebastião Vicente 
Published: July 2020

AbstractAn experimental setup containing a sliding online optical device is used to monitor in real‐time the melting process of a commercial polypropylene in a corotating intermeshing twin‐screw extruder. Turbidity and birefringence are measured at several axial locations upstream and along the first restrictive zone of the screw, where melting develops. The experiments are performed using different set barrel temperatures, extruder feed rates, and screw speeds, to generate distinct flow histories and, accordingly, changes in the onset and rate of melting of the polymer. The local flow conditions are characterized in terms of residence time distribution and data equivalent to axial pressure profiles. Turbidity and birefringence are sensitive to changes in the operating conditions providing a coherent description of melting. The onset of melting seems to take place in partially filled conveying elements, and then melting develops quickly as the latter become fully filled, and is completed well before flow through the kneading block.
Reactive Molecular Dynamics Study on the Effect of H2O on the Thermal Decomposition of Ammonium Dinitramide
Authors: Zeng Tao , Yang Rongjie , Li Dinghua , Li Jianmin , Guo Xiaoyan , Luo Peng 
Published: July 2020

AbstractAmmonium dinitramide (ADN) is a halogen‐free green oxidizer, which is widely used in energetic materials because of its positive oxygen balance and low characteristic signal. However, ADN is easy to absorb moisture, which affects its storage and safety performances. It is of great significance to study the effect of water on its thermal decomposition mechanism. In this paper, the thermal decomposition processes of the ADN with water contents of 0 %, 1 %, 2 %, 5 %, and 10 % are simulated by large‐scale reactive molecular dynamics simulations. The reaction pathway and the evolution of the main products are analyzed in detail. The results show that the ADN is not stable and decompose easily, namely ADN
NH3(NH4)+HN3O4(N3O4). The H2O has a significant effect on the thermal decomposition of the ADN. The water contents of 2 % and 5 % can better promote the decomposition of the ADN and the degree of decomposition is also more thorough.
Hazardous Properties of Molten Ammonium Dinitramide
Authors: Comet Marc , Schwartz Cédric , Oudot Franck , Schnell Fabien , Spitzer Denis 
Published: July 2020

AbstractThe purpose of this article is to alert our peers on the danger faced by those who carry out experiments involving molten ammonium dinitramide (ADN). In recent experiments aiming at preparing submicron particles of this compound, a preliminary study of the sensitivity to impact of molten ADN was performed. These first tests have shown that the sensitivity threshold of molten ADN to impact is more than one order of magnitude lower that the one on solid ADN (<0.25 J vs. 4 J) and similar to the one of nitroglycerin (<0.25 J), making liquid ADN extremely hazardous to handle. Detonation tests, which were performed in strong steel sheaths open to one end, have shown that the initiation of the detonation and its subsequent propagation occur both in solid and liquid ADN charges, having a diameter of only 4 mm. The critical diameter of solid ADN which is between 25 and 40 mm according to literature, is therefore decreased by at least an order of magnitude when ADN is placed in strong metallic confinement. On the other hand, the detonation of liquid ADN produces stronger destructive effects than the detonation of solid ADN, meaning that the detonation mechanisms of this explosive are different in its two physical states. In conclusion, liquid ADN must be considered in practice as a more hazardous and powerful explosive than solid ADN. This raises the issue of all experiments in which ADN is likely to be formed in molten state.
Foldability and chameleon propensity of fold‐switching protein sequences
Authors: Mezei Mihaly 
Published: July 2020

AbstractIt has been shown recently by Porter & Looger that a significant number of proteins exist that can form more than one stable fold. This note examines the sequences of these fold‐switching proteins by (a) calculating their foldability scores recently introduced by the present author and (b) comparing the propensity of chameleon sequences in fold switchers and in non fold switchers. It has been found that the average foldability score of the fold switchers indicates weaker foldability. As for the propensity of chameleon sequences of length 5 to 7 it was found, somewhat surprisingly, that there is only a very small difference between the fold switchers and the non fold switchers. Furthermore, when looking at amino acid propensities, for several amino acids there was even an opposing trend in the deviation of their propensities from the overall amino acid propensities.
Innate immune evasion by SARS‐CoV‐2: Comparison with SARS‐CoV
Authors: Bouayad Abdellatif 
Published: July 2020

SummarySARS‐CoV‐2 virus, a member of the Coronaviridae family, causes Covid‐19 pandemic disease with severe respiratory illness. Multiple strategies enable SARS‐CoV‐2 to eventually overcome antiviral innate immune mechanisms which are important components of viral pathogenesis. This review considers several mechanisms of SARS‐CoV‐2 innate immune evasion including suppression of IFN‐α/β production at the earliest stage of infection, mechanisms that exhaust natural killer cell‐mediated cytotoxicity, overstimulation of NLRP3 inflammasome and induction of a cytokine storm. A comparison with SARS‐CoV is made. Greater knowledge of these and other immune evasion tactics may provide us with improved possibilities for research into this novel deadly virus.
The role of endogenous retroviruses‐K in human cancer
Authors: Salavatiha Zahra , Soleimani‐Jelodar Rahim , Jalilvand Somayeh 
Published: July 2020

SummaryIt is known that human endogenous retroviruses (HERVs) constitute almost 8% of the human genome. Although the expression of HERVs from the human genome is tightly regulated, different exogenous and endogenous factors could trigger HERV activation. Aberrant expression of different HERVs may potentially cause a variety of diseases such as neurological and autoimmune diseases as well as cancer. It is suggested that HERV‐K can induce cancer through different mechanisms that are discussed. The interplay between some tumor viruses and HERV‐K seems to be a key player in progression of viral‐associated cancers because elevated levels of Rec and Np9 proteins are observed in several cancers. The frequent over expression of HERV proteins and some specific antibodies in cancer cells could be considered as suitable prognostic and therapeutic biomarkers in diagnosis and treatment of cancers. The expression of HERV proteins in cancers and development of immune responses against them may also be used as targets for cancer immunotherapy. Further studies are warranted to evaluate the role of HERVs in cancer formation and use of different HERV proteins in developing new diagnostic and therapeutic approaches for cancer treatments.
Sustainable development goal interactions: An analysis based on the five pillars of the 2030 agenda
Authors: Tremblay David , Fortier François , Boucher Jean‐François , Riffon Olivier , Villeneuve Claude 
Published: July 2020

AbstractThe 2030 Agenda calls for a change in thinking in order to implement sustainable development goals (SDGs) and targets as a system. To achieve this goal, the 2030 Agenda established five pillars (“5 Ps”): people, planet, prosperity, peace and partnership. Here, we present a classification of these SDGs and their targets based on the five pillars. Our aim is to improve our understanding of interactions by assessing whether potential synergies and trade‐offs are related to the classification of the targets. We surveyed 30 people and asked them to associate the content of target labels with the pillars. We classified SDG and targets according to an original quantification system. We determined whether the interactions were linked to similar or different classifications of the targets. We observed that the more similar the targets were in terms of classification, the more positive the interactions. We also noted that synergies exist between targets of different classifications. Our findings are useful for applying a systemic approach for policy coherence in sustainability analysis.
Okra‐Like Fe7S8/C@ZnS/N‐C@C with Core–Double‐Shelled Structures as Robust and High‐Rate Sodium Anode
Authors: Cao Dongwei , Kang Wenpei , Wang Wenhong , Sun Kaian , Wang Yuyu , Ma Ping , Sun Daofeng 
Published: July 2020

AbstractCore–multishelled structures with controlled chemical composition have attracted great interest due to their fascinating electrochemical performance. Herein, a metal–organic framework (MOF)‐on‐MOF self‐templated strategy is used to fabricate okra‐like bimetal sulfide (Fe7S8/C@ZnS/N‐C@C) with core–double‐shelled structure, in which Fe7S8/C is distributed in the cores, and ZnS is embedded in one of the layers. The MOF‐on‐MOF precursor with an MIL‐53 core, a ZIF‐8 shell, and a resorcinol–formaldehyde (RF) layer (MIL‐53@ZIF‐8@RF) is prepared through a layer‐by‐layer assembly method. After calcination with sulfur powder, the resultant structure has a hierarchical carbon matrix, abundant internal interface, and tiered active material distribution. It provides fast sodium‐ion reaction kinetics, a superior pseudocapacitance contribution, good resistance of volume changes, and stepwise sodiation/desodiation reaction mechanism. As an anode material for sodium‐ion batteries, the electrochemical performance of Fe7S8/C@ZnS/N‐C@C is superior to that of Fe7S8/C@ZnS/N‐C, Fe7S8/C, or ZnS/N‐C. It delivers a high and stable capacity of 364.7 mAh g−1 at current density of 5.0 A g−1 with 10 000 cycles, and registers only 0.00135% capacity decay per cycle. This MOF‐on‐MOF self‐templated strategy may provide a method to construct core–multishelled structures with controlled component distributions for the energy conversion and storage.
Stimuli‐Enabled Artificial Synapses for Neuromorphic Perception: Progress and Perspectives
Authors: Pan Xuan , Jin Tengyu , Gao Jing , Han Cheng , Shi Yumeng , Chen Wei 
Published: July 2020

AbstractBrain‐inspired neuromorphic computing is intended to provide effective emulation of the functionality of the human brain via the integration of electronic components. Recent studies of synaptic plasticity, which represents one of the most significant neurochemical bases of learning and memory, have enhanced the general comprehension of how the brain functions and have thereby eased the development of artificial neuromorphic devices. An understanding of the synaptic plasticity induced by various types of stimuli is essential for neuromorphic system construction. The realization of multiple stimuli‐enabled synapses will be important for future neuromorphic computing applications. In this Review, state‐of‐the‐art synaptic devices with particular emphasis on their synaptic behaviors under excitation by a variety of external stimuli are summarized, including electric fields, light, magnetic fields, pressure, and temperature. The switching mechanisms of these synaptic devices are discussed in detail, including ion migration, electron/hole transfer, phase transition, redox‐based resistive switching, and other mechanisms. This Review aims to provide a comprehensive understanding of the operating mechanisms of artificial synapses and thus provides the principles required for design of multifunctional neuromorphic systems with parallel processing capabilities.
Redox‐Active Polymers Connecting Living Microbial Cells to an Extracellular Electrical Circuit
Authors: Kaneko Masahiro , Ishihara Kazuhiko , Nakanishi Shuji 
Published: July 2020

AbstractMicrobial electrochemical systems in which metabolic electrons in living microbes have been extracted to or injected from an extracellular electrical circuit have attracted considerable attention as environmentally‐friendly energy conversion systems. Since general microbes cannot exchange electrons with extracellular solids, electron mediators are needed to connect living cells to an extracellular electrode. Although hydrophobic small molecules that can penetrate cell membranes are commonly used as electron mediators, they cannot be dissolved at high concentrations in aqueous media. The use of hydrophobic mediators in combination with small hydrophilic redox molecules can substantially increase the efficiency of the extracellular electron transfer process, but this method has side effects, in some cases, such as cytotoxicity and environmental pollution. In this Review, recently‐developed redox‐active polymers are highlighted as a new type of electron mediator that has less cytotoxicity than many conventional electron mediators. Owing to the design flexibility of polymer structures, important parameters that affect electron transport properties, such as redox potential, the balance of hydrophobicity and hydrophilicity, and electron conductivity, can be systematically regulated.
Crosslinking Strategies for 3D Bioprinting of Polymeric Hydrogels
Authors: GhavamiNejad Amin , Ashammakhi Nureddin , Wu Xiao Yu , Khademhosseini Ali 
Published: July 2020

AbstractThree‐dimensional (3D) bioprinting has recently advanced as an important tool to produce viable constructs that can be used for regenerative purposes or as tissue models. To develop biomimetic and sustainable 3D constructs, several important processing aspects need to be considered, among which crosslinking is most important for achieving desirable biomechanical stability of printed structures, which is reflected in subsequent behavior and use of these constructs. In this work, crosslinking methods used in 3D bioprinting studies are reviewed, parameters that affect bioink chemistry are discussed, and the potential toward improving crosslinking outcomes and construct performance is highlighted. Furthermore, current challenges and future prospects are discussed. Due to the direct connection between crosslinking methods and properties of 3D bioprinted structures, this Review can provide a basis for developing necessary modifications to the design and manufacturing process of advanced tissue‐like constructs in future.
Boronia (Rutaceae) is polyphyletic: Reinstating Cyanothamnus and the problems associated with inappropriately defined outgroups
Authors: Duretto Marco F. , Heslewood Margaret M. , Bayly Michael J. 
Published: July 2020

AbstractThe monophyly of Boronia (Rutaceae) was tested using 134 accessions of 120 species belonging to 39 genera from subfamily Amyridoideae. Taxa included representatives of all eight sections of Boronia plus species of most genera in the two main clades related to Boronia that had been identified by earlier studies. These samples included a good representation of genera from both rainforest and sclerophyllous biomes. Maximum parsimony and Bayesian inference analyses were performed using three plastid markers (psbA‐trnH, trnL‐trnF, rbcL) and two nuclear ribosomal markers (ITS, ETS). Separate analyses of plastid and nuclear sequences using either maximum parsimony or Bayesian inference analyses recovered similar topologies. Apart from Boronia, the broad generic relationships of previous analyses were largely supported. Boronia is polyphyletic with section Cyanothamnus being more closely related to a large clade containing genera found in rainforest, including Melicope, Acronychia and their relatives. The remaining seven sections of Boronia formed a strongly supported and isolated group. Boronia sensu stricto is sister to a clade containing the Cyanothamnus‐Melicope‐Acronychia clade plus a clade containing Euodia, Zieria and other small genera found in rainforest or sclerophyllous communities. Issues with circumscriptions of ingroups and outgroups for previous analyses of Boronia and the complex relationship between Australasian genera found in rainforest and sclerophyllous communities are both discussed. Cyanothamnus is reinstated at generic level. Appropriate nomenclatural changes are made to transfer all currently recognised series, species, subspecies and varieties of Boronia sect. Cyanothamnus to the genus Cyanothamnus.
Fetal head progression and regression on maternal pushing at term and labor outcome
Authors: Youssef A. , Brunelli E. , Azzarone C. , Di Donna G. , Casadio P. , Pilu G. 
Published: July 2020

AbstractObjectivesThe aim of our study was two‐fold. First, to evaluate the association between the change in the angle of progression (AoP) on maternal pushing and labor outcome. Second, to assess the incidence and clinical significance of the reduction of AoP on maternal pushing.MethodsThis was a prospective cohort study of nulliparous women with singleton pregnancy at term. AoP was measured at rest and on maximum Valsalva maneuver before the onset of labor, and the difference between AoP on maximum Valsalva and that at rest (ΔAoP) was calculated for each woman. Following delivery and data collection, we assessed the association between ΔAoP and various labor outcomes, including Cesarean section (CS), duration of the first, second and active second stages of labor, Apgar score and admission to the neonatal intensive care unit (NICU). The prevalence of women with reduction of AoP on maximum Valsalva maneuver (AoP‐regression group) was calculated and its association with the mode of delivery and duration of different stages of labor was assessed.ResultsOverall, 469 women were included in the analysis. Among these, 273 (58.2%) had spontaneous vaginal birth, 65 (13.9%) had instrumental delivery and 131 (27.9%) underwent CS. Women in the CS group were older, had narrower AoP at rest and on maximum Valsalva, higher rate of epidural administration and lower 1‐min and 5‐min Apgar scores in comparison with the vaginal‐delivery group. ΔAoP was comparable between the two groups. On Pearson's correlation analysis, AoP at rest and on maximum Valsalva maneuver had a significant negative correlation with the duration of the first stage of labor. ΔAoP showed a significant negative correlation with the duration of the active second stage of labor (Pearson's r, −0.125; P = 0.02). Cox regression model analysis showed that ΔAoP was associated independently with the duration of the active second stage (hazard ratio, 1.014 (95% CI, 1.003–1.025); P = 0.012) after adjusting for maternal age and body mass index. AoP reduction on maximum Valsalva was found in 73 (15.6%) women. In comparison with women who showed no change or an increase in AoP on maximum Valsalva, the AoP‐regression group did not demonstrate significant difference in maternal characteristics, mode of delivery, rate of epidural analgesia, duration of the different stages of labor or rate of NICU admission.ConclusionsIn nulliparous women at term before the onset of labor, narrower AoP at rest and on maximum Valsalva, reflecting fetal head engagement, is associated with a higher risk of Cesarean delivery. The increase in AoP from rest to Valsalva, reflecting more efficient maternal pushing, is associated with a shorter active second stage of labor. Fetal head regression on maternal pushing is present in about 16% of women and does not appear to have clinical significance. © 2020 International Society of Ultrasound in Obstetrics and Gynecology
Perinatal outcome of pregnancies with prenatal diagnosis of vasa previa: systematic review and meta‐analysis
Authors: Zhang W. , Geris S. , Al‐Emara N. , Ramadan G. , Sotiriadis A. , Akolekar R. 
Published: July 2020

ABSTRACTObjectivesTo derive accurate estimates of perinatal survival in pregnancies with and without a prenatal diagnosis of vasa previa based on a systematic review of the literature and meta‐analysis.MethodsA search of MEDLINE, EMBASE and The Cochrane Library was performed to review relevant citations reporting on the perinatal outcomes of pregnancies with vasa previa. We included prospective and retrospective cohort and population studies that provided data on pregnancies with a prenatal diagnosis of vasa previa or cases diagnosed at birth or following postnatal placental examination. Meta‐analysis using a random‐effects model was performed to derive weighted pooled estimates of perinatal survival (excluding stillbirths and neonatal deaths) and intact perinatal survival (additionally excluding hypoxic morbidity). Incidence rate difference (IRD) meta‐analysis was used to estimate the significance of differences in pooled proportions between cases of vasa previa with and those without a prenatal diagnosis. Heterogeneity between studies was estimated using Cochran's Q and the I2 statistic.ResultsWe included 21 studies reporting on the perinatal outcomes of 683 pregnancies with a prenatal diagnosis of vasa previa. There were three stillbirths (1.01% (95% CI, 0.40–1.87%)), five neonatal deaths (1.19% (95% CI, 0.52–2.12%)) and 675 surviving neonates, resulting in a pooled estimate for perinatal survival of 98.6% (95% CI, 97.6–99.3%). Based on seven studies that included cases of vasa previa with and without a prenatal diagnosis, the pooled perinatal survival in pregnancies without a prenatal diagnosis (61/118) was 72.1% (95% CI, 50.6–89.4%) vs 98.6% (95% CI, 96.7–99.7%) in cases with a prenatal diagnosis (224/226). Therefore, the risk of perinatal death was 25‐fold higher when a diagnosis of vasa previa was not made antenatally, compared with when it was (odds ratio (OR), 25.39 (95% CI, 7.93–81.31); P < 0.0001). Similarly, the risk of hypoxic morbidity was increased 50‐fold in cases with vasa previa without a prenatal diagnosis compared with those with a prenatal diagnosis (36/61 vs 5/224; OR, 50.09 (95% CI, 17.33–144.79)). The intact perinatal survival rate in cases of vasa previa without a prenatal diagnosis was significantly lower than in those with a prenatal diagnosis (28.1% (95% CI, 14.1–44.7%) vs 96.7% (95% CI, 93.6–98.8%)) (IRD, 73.4% (95% CI, 53.9–92.7%); Z = –7.4066, P < 0.001).ConclusionsPrenatal diagnosis of vasa previa is associated with a high rate of perinatal survival, whereas lack of an antenatal diagnosis significantly increases the risk of perinatal death and hypoxic morbidity. Further research should be undertaken to investigate strategies for incorporating prenatal screening for vasa previa into routine clinical practice. © 2021 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.
Historical development of rainfall‐runoff modeling
Authors: Peel Murray C. , McMahon Thomas A. 
Published: July 2020

AbstractRainfall‐runoff models are used across academia and industry, and the number and type have proliferated over time. In this primer we briefly introduce the key features of these models and provide an overview of their historical development and drivers behind those developments. To complete the discussion there is a brief section on model choice including model intercomparison. We also seek to clarify jargon terms for readers new to this area.This article is categorized under:
Science of Water > Hydrological Processes
Science of Water > Methods