bluuebunny/crossref_metadata_2025 huggingface dataset:
Vertical influence of temperature and precipitation on snow cover variability in the Yarlung Zangbo River basin, China
Authors: Ban Chunguang , Xu Zongxue , Zuo Depeng , Liu Xiaowan , Zhang Rui , Wang Jing
Published: July 2020

Seasonal snow cover in mountainous areas is a key source of water for downstream regions. The snow cover area (SCA) in the Northern Hemisphere has significantly decreased during the past decades in response to global warming. Therefore, it is necessary to investigate the primary factors controlling the spatiotemporal variabilities in the SCA in high altitude regions. In this study, based on remote sensing data of SCA, temperature, and precipitation in the Yarlung Zangbo River basin, Pearson's correlation analysis was used to identify the relative importance of temperature and precipitation on the SCA variability with altitude. The results showed that temperature played a more dominant role for the SCA than precipitation at all elevation during the period 2001–2017; three threshold altitudes at high, moderate, and low elevation were identified, and these threshold altitudes are dynamic and vary with time; the threshold altitude at high elevation was 5,925 ± 125 m, below which temperature (precipitation) was negatively (positively) correlated and above which temperature (precipitation) was positively (negatively) correlated with the SCA; the threshold altitude at moderate elevation was 3,200 ± 300 m, below which temperature (precipitation) was positively (negatively) correlated and above which temperature (precipitation) was negatively (positively) correlated with the SCA; the threshold altitude in low elevation regions was 2,100 ± 200 m. This study sheds light on the dominant climatic control factors on the variability in SCA in high altitude regions. These results have major implications for SCA and water resources availability under future climate change.
Corporate carbon dioxide emissions and the cost of debt financing: Evidence from the global tourism industry
Authors: Wang Ying‐Chieh , Feng Zhi‐Yuan , Huang Hua‐Wei
Published: July 2020

In this article, we investigate the value consequence of a firm's irresponsible environmental behavior, carbon dioxide emissions, through the lens of lenders and bondholders. We firstly find that a firm's carbon risk significantly enhances the cost of debt financing. In particular, we find that the positive nexus between a firm's carbon emissions and the cost of debt has a great discrepancy in countries which have different institutions, cultures, and strength of legal rights. Our empirical evidence suggests that corporate environment risk may raise default risk and ultimately provoke creditors to enhance their required returns. Furthermore, our findings also are consistent with the viewpoints of stakeholders and ethical theories.
Factors influencing the evolution of human‐driven rocky desertification in karst areas
Authors: Zhang Zhenming , Huang Xianfei , Zhou Yunchao
Published: July 2020

Karst rocky desertification has become one of the most important e‐environmental problems in China. The mechanisms of rocky desertification caused by land resources use, settlement expansion, population growth, and corresponding ecological responses are unclear. High‐resolution images of a typical karst plateau (Houzhai River Basin) acquired in 1978, 2005, and 2010 and data samples collected in the field in 2015 were used to quantitatively study the factors governing the evolution of rocky desertification driven by human activities. They comprehensively reveal its causes and influencing factors. Results suggest that the rocky desertification in the eastern and southern parts was, generally, more severe than in the western and northern parts of the study region. In the period from 1978 to 2015, no significant changes in the degree of (moderate) rocky desertification were observed. However, decreasing trends were observed for the no‐rocky areas, and slight decrease in rocky areas. The comprehensive indices of rocky desertification in 1978, 2005, 2010, and 2015 were 1.33, 1.24, 1.22, and 1.24, respectively. The rock outcrops in the no‐rocky desertification and potential rocky desertification areas were closely associated with the gravel content, slope gradient, and soil thickness, whereas those in the slight, moderate, and severe rocky desertification areas were primarily associated with the land use, gravel content, and slope gradient. The results suggest that the land use and human settlement were important factors determining the rocky desertification. The rocky desertification in the study area has improved during the period from 1978 to 2015. The main contribution to this improvement originated from the change in land use patterns. Therefore, reasonable management of land use and human settlement distribution can effectively reduce the rocky desertification in a karst area.
The effect of cathodic polarization on the corrosion behavior of X65 steel in seawater containing sulfate‐reducing bacteria
Authors: Lv Meiying , Li Xia , Du Min
Published: July 2020

Sulfate‐reducing bacteria (SRB) are one of the main reasons for the accelerated corrosion of steel. Cathodic polarization has been reported as an effective and economic method against marine corrosion, including microbiologically induced corrosion. However, the interaction between cathodic polarization and microbial activity has not been well defined. In this study, a fluorine‐doped tin oxide electrode is used to study the effect of cathodic current on SRB cells. Fluorescence microscopy results clearly show that the attachment degree of SRB is dependent on the electric quantity and current intensity. The large electric quantity and high cathodic current (400 mA/m2 × 30 h) can effectively inhibit bacterial attachment and subsequent biofilm formation. Furthermore, the effect of cathodic potential on the corrosion behavior of X65 steel in the presence of SRB is systematically investigated. Results show that the impressed charges, the increase of pH, and the formation of calcareous deposits on the electrode surface at the cathodic potential of −1,050 mV/SCE inhibit the attachment of SRB. In turn, the presence of SRB also interferes with the electrochemical reactions that occur during the polarization process, thus increasing the cathodic current. The interaction between SRB‐induced corrosion and the process of preventing corrosion by various cathodic potentials is discussed.
Microstructures and electrochemical behaviors of as‐cast magnesium alloys with enhanced compressive strengths and corrosion decomposition
Authors: Li Xuewu , Shi Tian , Li Ben , Zhou Xuegang , Zhang Chuanwei , He Zhenyan , Zhang Binbin , Zhang Qiaoxin
Published: July 2020

Rapidly disintegrating alloys with enhanced compressive strengths and corrosion rates are prepared for fracturing parts in petroleum extraction. Extrusion casting is used to prepare Mg–xZn–Zr alloys by adjusting zinc content. Mechanical and electrochemical behaviors are investigated to evaluate the practicability as decomposable materials. Superficial topographies, compositions, phases, and distributions are also characterized to determine the dissociative mechanism. The results make clear that matrixes and secondary structures with reticulate shapes arise on surfaces. The material also possesses enhanced compressive strength to guarantee stabilization and pressure‐holding ability among decomposition. Concurrently, with the increase of zinc content and decomposition time, galvanic corrosion aggravates resulting in gradually reduced corrosion potentials and accelerated decomposition rates. Rapid material dissolution mainly attributes to anode corrosion of matrixes, peeling of microparticles, and inferior tolerance of corrosive products to dissolution. Such work highlights potential applications of fracturing materials for ensuring rapid decomposition and guaranteeing stable stress tolerance.
Analysis of the Competition between Cyclization and Linear Chain Growth in Kinetically Controlled A2 + B2 Step‐Growth Polymerizations Using Modeling Tools
Authors: Romero‐Hernández Juan Enrique , Cruz‐Rosado Alfredo , Vivaldo‐Lima Eduardo , Palacios‐Alquisira Joaquín , Zolotukhin Mikhail G.
Published: July 2020

A mathematical model for the kinetics and chain length development in A2 + B2 step‐growth polymerization with competition between cyclization and linear chain growth is presented. The model requires two kinetic rate constants, one for the several reactions producing linear polymer molecules (k), and another one for chain length dependent cyclization (kc). The model describes well the qualitative behavior of the system, including the effects of initial monomer concentration and ratio of limiting to excess functional groups on degree of cyclization. The model is validated using two polymerization systems, a conventional A2 + B2 polymerization of hexamethylene diisocyanate (HDI) and poly(ethylene glycol) (PEG200), as well as the superacid catalyzed polyhydroxyalkylation of modified isatin and biphenyl. Four different kinetic rate constants for the four reactions producing linear polymer molecules are required in the second case.
Efficacy of injectable rib height on the heat transfer and entropy generation in the microchannel by affecting slip flow
Authors: Bahrami Dariush , Abbasian‐Naghneh Salman , Karimipour Aliakbar , Karimipour Arash
Published: July 2020

In this study, entropy generation analysis and forced convection heat transfer of Al2O3/water in the rectangular microchannel equipped with three injections were examined. The upper wall of the microchannel has a constant temperature while the lower wall is insulated. To improve heat transfer, the injection is performed through variable height ribs. The main objective is to investigate the effect of the height of injectable ribs on heat transfer, pressure drop, and entropy generation. Input variables include rib's height, Reynolds, and nanofluid volume fraction, while output variables are heat transfer, pressure drop, and entropy generation. The results showed that the higher the ribs height, the more heat transfer. The presence of injectable ribs results in a 46.4% enhancement in heat transfer, which, in turn, intensifies the pressure drop and the entropy generation by 234% and 45.3%, respectively. The effects of all input parameters on total entropy generation were also investigated. Finally, analysis of variance (ANOVA) methodology was used to examine the regression model reasonableness between the independent variables and the output variables. Using regression technique, three correlations were acquired for estimating average Nusselt, pressure drop, and entropy generation.
On a mixed Kernel Hilbert‐type integral inequality and its operator expressions with norm
Authors: Liu Qiong
Published: July 2020

By using some real analysis techniques, we study the structural characteristics of a multi‐parameter Hilbert‐type integral inequality with the hybrid kernel and obtain some equivalent conditions for this inequality. We also consider the operator expression of the equivalent inequalities. The conclusions not only integrate some results of references but also find some new Hilbert‐type integral inequalities with simple form by choosing suitable parameter values.
Adequacy of Protein and Energy Intake in Critically Ill Adults Following Liberation From Mechanical Ventilation Is Dependent on Route of Nutrition Delivery
Authors: Moisey Lesley L. , Pikul Jill , Keller Heather , Yeung Chi Yan Emily , Rahman Adam , Heyland Daren K. , Mourtzakis Marina
Published: July 2020

Background

Studies examining nutrition intake of critically ill patients following liberation from mechanical ventilation (LMV) are scarce. The objectives of this prospective, observational feasibility study were to quantify and assess protein and energy intake in hospitalized, critically ill patients following LMV, to determine barriers to optimal intake, and to report on the feasibility of recruiting and retaining patients into this study.

Methods

Adult patients requiring MV for >72 hours in a medical/surgical intensive care unit (ICU) were recruited. Protein and energy intakes were quantified up to 14 days following LMV. Patients also identified barriers to eating.

Results

Nineteen patients (mean age, 60 years [SD, 12 years]) were studied over 125 days. Over all study days, the median amounts of protein and energy consumed in comparison with amounts prescribed by dietitians were 46% (interquartile range [IQR], 26–100) and 71% (IQR, 38–100), respectively. When stratified by route of nutrition delivery, on days (n = 54) when patients consumed an oral diet as the sole nutrition source, median amounts of protein and energy consumed in comparison with those prescribed were only 27% (IQR, 15–41) and 47% (IQR, 29–66), respectively. The most frequently reported barriers to eating were poor appetite, early satiety, and taste changes.

Conclusions

Protein and calorie intake is below prescribed amounts for patients whose enteral nutrition is discontinued and an oral diet prescribed as sole nutrition source following LMV. Acceptable strategies to enhance nutrition intake in post‐ICU patients during the recovery stages of critical illness are needed.
Most reliable two‐terminal graphs with node failures
Authors: Brown Isaac , Graves Christina , Miller Brendan , Russell Tyler
Published: July 2020

A two‐terminal graph is an undirected graph with two specified target vertices. If each nontarget vertex of a two‐terminal graph fails independently with the same fixed probability (and edges and target vertices are perfectly reliable), the two‐terminal node reliability is the probability that the target vertices are in the same connected component in the induced subgraph of all operational nodes. A two‐terminal graph is uniformly most reliable if its node reliability polynomial is greater than or equal to that of all other two‐terminal graphs with the same fixed number of vertices, n, and edges, m. In this paper, we show that there is always a uniformly most reliable two‐terminal graph. Furthermore, with the additional restriction that the distance between the target vertices is at least three, we completely classify which values of n and m produce a uniformly most reliable graph and which do not.
Syntheses and Molecular Structures of Liquid Pyrophoric Hydridosilanes
Authors: Gerwig Maik , Böhme Uwe , Friebel Mike , Gründler Franziska , Franze Georg , Rosenkranz Marco , Schmidt Horst , Kroke Edwin
Published: July 2020

Trisilane, isotetrasilane, neopentasilane, and cyclohexasilane have been prepared in gram scale. In‐situ cryo crystallization of these pyrophoric liquids in sealed capillaries on the diffractometer allows access to the single crystal structures of these compounds. Structural parameters are discussed and compared to gas‐phase electron diffraction structures from literature and with the results from quantum chemical calculations. Significantly higher packing indices are found for the silanes compared to the corresponding alkanes. Radiation with ultraviolet light (365 nm) and parallel ESR (EPR) measurement shows that cyclohexasilane is easily split into radicals, which subsequently leads to the formation of branched and chain‐like oligomers. The other compounds form no radicals under these conditions. NMR spectra of all four compounds have been recorded.
Poverty and inequality in Odisha, India
Authors: Panda Sitakanta , Padhi Balakrushna
Published: July 2020

Odisha has gone on from being the most underdeveloped Indian state to be the state that has recorded the highest decline in poverty among the states. We undertake decomposition analyses to assess the redistributive changes in poverty and inequality over the period 1993–1994 and 2011–2012 across regions and social groups, examining the NSSO Consumer Expenditure Survey data. We find that while Odisha has succeeded in substantially reducing both rural and urban poverty incidence, this change has not met desirable subgroup‐specific variations. Among regions, southern and northern Odisha have not kept pace with coastal Odisha in poverty reduction during the study period. The rate of poverty reduction for the Scheduled Tribes and the Scheduled Castes has been dismal. Overall, we found the growth effects on poverty reduction to be more prominent over inequality effects and population shift effects on poverty, although these effects varied in contexts. While inequality in urban regions rose, it declined in rural regions. While at the state‐level, the within‐group inequality has declined between 2004–2005 and 2011–2012 (coincident with the present Naveen Patnaik rule); the between‐group inequality has increased during the period. Rural Odisha has seen a reduction in both within‐group and between‐group disparities, whereas urban Odisha has fared the opposite.
Effects of silane surface modified alumina nanoparticles on the mechanical, thermomechanical, and ballistic impact performances of epoxy/oxidized UHMWPE composites
Authors: Belgacemi Raouf , Derradji Mehdi , Trache Djalal , Mouloud Abdelrazak , Zegaoui Abdeldjalil , Mehelli Oussama , Khiari Karim
Published: July 2020

In this study, a new kind of hybrid material was prepared from various amounts of silane surface modified alumina nanoparticles, oxidized ultra high molecular weight polyethylene (UHMWPE) fibers, and epoxy resin. The reinforcing phases were selectively treated to achieve a fully connected network aiming an effective stress transfer between the constituents. The efficiency of the grafting mechanisms was confirmed by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The developed hybrid materials were tested for their mechanical, thermomechanical, and ballistic performances. The mechanical results, namely tensile and bending, confirmed the positive effects of increasing the nanofillers amounts up to 5 wt%. The thermochemical properties analyzed by dynamic mechanical analysis (DMA) revealed consequent improvements in the storage modulus and glass transition temperature upon the addition of the nanophase. In the meantime, the ballistic tests evaluated under the National Institute of Justice standard (NIJ standard‐0101.06‐IIA) also highlighted an improved kinetic energy absorption following the increase in the amounts of the discontinuous phase. Subsequent experimentations precisely quantified the required number of plies for an effective projectile stopping under the chosen standard. Overall, this study unraveled for the first time ever the benefits obtained from a fully connected hybrid network under both static and dynamic loads.
Enhanced mechanical, thermal, and barrier properties of poly (3‐hydroxybutyrate‐co‐3‐hydroxyhexanoate)/montmorillonite nanocomposites using silane coupling agent
Authors: Dong Jiaqi , Zhou Wanru , Su Yuhang , Ma Xiaojun
Published: July 2020

A nanocomposite of poly(3‐hydroxybutyrate‐co‐3‐hydroxyhexanoate) (PHBH)/montmorillonite (MMT) modified with silane coupling agent 3‐aminopropyltriethoxysilane (KH550) (PHBH/MMT/KH550) was prepared by solution casting method. The effects of KH550 content on properties of nanocomposites were comparatively investigated. According to the Fourier transform infrared spectra, the new chemical bonding between the PHBH and the MMT was formed by adding KH550. The crystallinity, thermal properties, mechanical properties, and barrier properties of the nanocomposites were improved because of the good dispersion of MMT. Compared with pure PHBH, a 220.05%, 158.25%, and 58.91% improvement in young's modulus, tensile strength, and elongation at break was obtained. The water vapor transmission coefficient was decreased by 113.30%. Moreover, it was notable that the nanocomposite possessed the optimal mechanical properties when the KH550 content was 5 wt%.The obtained results revealed that the nanocomposite will expand the practical application of PHBH base plastics as a substitute of traditional petrochemical materials.
Historical roots of pain management in infants: A bibliometric analysis using reference publication year spectroscopy
Authors: Anand Kanwaljeet J. S. , Roue Jean‐Michel , Rovnaghi Cynthia R. , Marx Werner , Bornmann Lutz
Published: July 2020

Retrospective evaluations of the historical role of previously published research are often fraught with subjective bias and misrepresentation, which leads to contested scientific claims. This paper investigates the historical roots of infant pain management using novel quantitative methods to identify the published literature and evaluate its relative importance. A bibliometric analysis named “reference publication year spectroscopy” (RPYS), was performed using the program CitedReferencesExplorer (CRExplorer) to avoid the subjectivity associated with comparative evaluations of individual research studies. Web of Science (WoS) search queries on infant‐related synonyms, pain‐related synonyms, and analgesia or anesthesia‐related synonyms were combined using the Boolean operator “AND,” to identify all publications related to pain management in infants. The RPYS analyses were based on 8697 papers in our publication set containing the citations for 86268 references. Selected cited publications were associated with peak citation years in 1951, 1954, 1957, 1965, 1987, 1990, 1997, 1999, and 2000. Subsequent analyses suggested that research on infant pain management made rapid progress during 1982‐1992. Landmark publications were defined as those belonging to the top 10% of the most frequently referenced publications for longer than 25 years. Through this analysis, we identified and ranked 24 landmark publications to illustrate the historical background and early research on infant pain management. From the first‐ever application of RPYS (an objective, reproducible approach to study the early history of any scholarly activity) to pain research, infant pain management appears rooted in the scientific rationale for neonatal pain perception, randomized trials of opioid anesthesia/analgesia, and studies describing the facial expressions and crying activity following heel‐lance procedures in newborns.
A novel diarylethene‐based fluorescence sensor with a benzohydrazide unit for the detection of Zn2+
Authors: Lu Mengmeng , Qiu Shouyu , Cui Shiqiang , Pu Shouzhi
Published: July 2020

A novel fluorescent sensor on the basis of diarylethene and benzohydrazide unit was successfully synthesized. Its photochromic and fluorescent switching properties have been studied in detail by the irradiation of UV‐visible (UV‐Vis) lights and the stimulus of Zn2+/EDTA. The sensor exhibited high sensitivity and selectivity toward Zn2+ in tetrahydrofuran, which is not interfered by other cations, especially of congener Cd2+. The fluorescence intensity enhanced 84 times along with a 44‐nm blue shift of the emission peak after adding Zn2+. The stoichiometric ratio between the sensor and Zn2+ was 1:1, and the limit of detection (LOD) was calculated as 5.60 × 10−9 mol L−1. Besides, the sensor was applied in the detection of practical water samples with high accuracy.
Effects of different ultrahigh molecular weight polyethylene contents on the formation and evolution of hierarchical crystal structure of high‐density polyethylene/ultrahigh molecular weight polyethylene blend fibers
Authors: Yang Zaixing , Shi Jiaji , Pan Xuefeng , Liu Boping , He Xuelian
Published: July 2020

In this paper, the blend fibers of ultrahigh molecular weight polyethylene (UHMWPE) and high‐density polyethylene (HDPE) were prepared by solution blending and gel spinning process. The uniformity of the blend fibers has been confirmed by rheological data and thermodynamic unimodal curve. They were further characterized by single fiber strength test, scanning electron microscopy, wide‐angle X‐ray diffraction, small‐angle X‐ray scattering, and so forth, to explore the structural evolution mechanism with the change of UHMWPE content. The results showed that when the molar content of UHMWPE was only 2.9 mol%, entanglement appeared in the structure of shish‐kebab, and when the proportion reached 20 mol%, an interlocking structure could be observed. With the increase of UHMWPE content, kebab began to be networked, and when the content reached 33 mol%, kebab's orientation reached its peak. After that, the interlocking network structure gradually improved. When the content reached 50 mol%, the shish's orientation reached saturation, and the shish‐kebab network became perfect. In addition, with the increase of UHMWPE content, stress‐induced recrystallization occurred on the wafer, some kebab would be converted into shish crystals, and when the content exceeded 50 mol%, the microfibers began to merge, and the wafer became denser, but still had entanglements. Our work has proposed a quantitative explanation for the evolution of hierarchical crystal structure of HDPE/UHMWPE blend fibers.
Cigarette, shisha, and electronic smoking and respiratory symptoms in Swiss children: The LUIS study
Authors: Mozun Rebeca , Ardura‐Garcia Cristina , de Jong Carmen C. M. , Goutaki Myrofora , Usemann Jakob , Singer Florian , Latzin Philipp , Kuehni Claudia E. , Moeller Alexander
Published: July 2020

Background

Smoking habits in adolescents are changing. We assessed active smoking of conventional cigarettes, e‐cigarettes and shishas in Swiss schoolchildren, studied risk factors and compared respiratory problems between smokers and non‐smokers.

Methods

We used data from LuftiBus in the school (LUIS), a school‐based survey of respiratory health of children carried out 2013 to 2016 in the canton of Zurich, Switzerland. Participants were asked about use of cigarettes, shishas, and electronic smoking devices (ESD), and current respiratory symptoms. We studied associations between smoking and risk factors using logistic regression.

Results

We included 3488 schoolchildren. Among 6 to 12‐year‐olds, 90/1905 (5%) had smoked occasionally (<once/week). Among 13 to 17‐year‐olds, 563/1583 (36%) had smoked occasionally of whom 414 smoked ESDs, 409 shishas, and 276 cigarettes. Among 13 to 17‐year‐olds who smoked frequently (≥once/week), 41/54 (76%) smoked cigarettes. A 22% of 15 to 17‐year‐olds (104/477) had used all three products. Smoking was more common in adolescents who were male (adjusted OR, 2.1; 95% CI, 1.7‐2.6), lived in rural areas (1.8, 95% CI, 1.2‐2.9 vs small urban), and whose mother (1.7, 95% CI, 1.3‐2.3) or father (1.5, 95% CI, 1.2‐1.9) smoked. Current respiratory symptoms like rhinitis, dyspnea, and wheeze were more common among frequent smokers (44%, 30%, 12%, respectively) and occasional smokers (32%, 22%, 13%) than in never smokers (29%,19%, 8%, P for trend <.05).

Conclusion

Smoking of shishas and ESDs is common among Swiss adolescents and often combined with smoking cigarettes. Adolescent smokers reported more respiratory symptoms than never smokers. We recommend smoking preventive strategies that include all forms of smoking.
Chemical constituents, clinical efficacy and molecular mechanisms of the ethanol extract of Abelmoschus manihot flowers in treatment of kidney diseases
Authors: Li Nan , Tang Haitao , Wu Liang , Ge Haitao , Wang Yurong , Yu Honglin , Zhang Xiuli , Ma Jimei , Gu Harvest F.
Published: July 2020

Abelmoschus manihot, also called as “Huangkui” in Chinese, is an annual flowering herb plant in the family of Malvaceae. As a traditional Chinese medicine, the ethanol extract of the flower in Abelmoschus manihot is made as Huangkui capsule and has been used for medication of the patients with kidney diseases. Its efficacy in clinical symptoms is mainly improving renal function and reducing proteinuria among the patients with chronic kidney disease, diabetic kidney disease or IgA nephropathy. The possible mechanism of Huangkui capsule treatment in kidney diseases may include reducing inflammation and anti‐oxidative stress, improving immune response, protecting renal tubular epithelial cells, ameliorating podocyte apoptosis, glomerulosclerosis and mesangial proliferation, as well as inhibiting renal fibrosis. In this review, we first described chemical constituents and pharmacokinetic characteristics in ethanol extract of the flower of Abelmoschus manihot. We then summarized the clinical and epidemiological relevancies of kidney diseases particularly in the mainland of China and discussed the possible molecular mechanisms of Huangkui capsule in the treatment of kidney diseases. Finally, we prospected further research on cellular and molecular mechanisms and application of this Chinese natural medicine in kidney diseases.
A noninvasive complementary study of an Egyptian polychrome cartonnage pigments using SEM, EPMA, and Raman spectroscopy
Authors: Gard Faramarz S. , Santos Diego M. , Daizo María B. , Mijares José L. , Bozzano Patricia B. , Danón Claudio A. , Reinoso María , Halac Emilia B.
Published: July 2020

Raman spectroscopy, optical microscopy, scanning electron microscopy (SEM), and electron probe microanalysis (EPMA) were used to study pigments on an Egyptian cartonnage from the Ptolemaic period (305–30 bc). The surface morphology of each color region was examined using backscattering (BS) and secondary electron imaging. SEM X‐ray energy dispersive spectrometry and EPMA wavelength dispersive spectroscopy provided semiquantitative chemical analysis of each pigment. Raman spectroscopy was used to identify the minerals associated with the pigments. This technique confirmed the presence of cinnabar (α‐HgS) in the red part of the fragments. A mixture of orpiment (As2S3) and bonazziite (β‐As4S4) and/or alacránite (As8S9) was detected in the yellow regions of the fragments. The orange pigment was confirmed to be a mixture of orpiment, uzonite (χ‐As4S5), and pararealgar (As4S4). Egyptian blue (CaCuSi4O10) and Egyptian green ((Cu,Ca)SiO3) pigments were detected from blue/green dark‐colored regions of the fragments.
Incorporating longitudinal biomarkers for dynamic risk prediction in the era of big data: A pseudo‐observation approach
Authors: Zhao Lili , Murray Susan , Mariani Laura H. , Ju Wenjun
Published: July 2020

Longitudinal biomarker data are often collected in studies, providing important information regarding the probability of an outcome of interest occurring at a future time. With many new and evolving technologies for biomarker discovery, the number of biomarker measurements available for analysis of disease progression has increased dramatically. A large amount of data provides a more complete picture of a patient's disease progression, potentially allowing us to make more accurate and reliable predictions, but the magnitude of available data introduces challenges to most statistical analysts. Existing approaches suffer immensely from the curse of dimensionality. In this article, we propose methods for making dynamic risk predictions using repeatedly measured biomarkers of a large dimension, including cases when the number of biomarkers is close to the sample size. The proposed methods are computationally simple, yet sufficiently flexible to capture complex relationships between longitudinal biomarkers and potentially censored events times. The proposed approaches are evaluated by extensive simulation studies and are further illustrated by an application to a data set from the Nephrotic Syndrome Study Network.
Antibacterial Activity of Graphdiyne and Graphdiyne Oxide
Authors: Zhu Zhiling , Bai Qiang , Li Shuo , Li Siheng , Liu Manhong , Du Fanglin , Sui Ning , Yu William W.
Published: July 2020

From manufacture to disposal, the interaction of graphdiyne based nanomaterials with living organisms is inevitable and crucial. However, the cytotoxic properties of this novel carbon nanomaterial are rarely investigated, and the mechanisms behind their cytotoxicity are totally unknown. In this study, the antibacterial activity of graphdiyne (GDY) and graphdiyne oxide (GDYO) is reported. GDY is capable of inhibiting broad‐spectrum bacterial growth while exerting moderate cytotoxicity on mammalian cells. In comparison, GDYO exhibits lower antibacterial activity than that of GDY. Then an alterable, synergetic antibacterial mechanism of GDY, involving wrapping bacterial membrane, membrane insertion and disruption, and reactive oxygen species generation is demonstrated, while the differential gene expression analysis indicates that GDY could only alter the bacterial metabolism slightly and the oxidative stress route may be a minor bactericidal factor. The investigation of the antibacterial behaviors of GDY based nanomaterials may provide useful guidelines for the future design and application of this novel molecular allotrope of carbon.
Folding at the Microscale: Enabling Multifunctional 3D Origami‐Architected Metamaterials
Authors: Lin Zhaowen , Novelino Larissa S. , Wei Heming , Alderete Nicolas A. , Paulino Glaucio H. , Espinosa Horacio D. , Krishnaswamy Sridhar
Published: July 2020

Mechanical metamaterials inspired by the Japanese art of paper folding have gained considerable attention because of their potential to yield deployable and highly tunable assemblies. The inherent foldability of origami structures enlarges the material design space with remarkable properties such as auxeticity and high deformation recoverability and deployability, the latter being key in applications where spatial constraints are pivotal. This work integrates the results of the design, 3D direct laser writing fabrication, and in situ scanning electron microscopic mechanical characterization of microscale origami metamaterials, based on the multimodal assembly of Miura‐Ori tubes. The origami‐architected metamaterials, achieved by means of microfabrication, display remarkable mechanical properties: stiffness and Poisson’s ratio tunable anisotropy, large degree of shape recoverability, multistability, and even reversible auxeticity whereby the metamaterial switches Poisson’s ratio sign during deformation. The findings here reported underscore the scalable and multifunctional nature of origami designs, and pave the way toward harnessing the power of origami engineering at small scales.
Effect of carbon fiber on properties of concrete with different W/C and its air‐entraining models
Authors: Liu Rui , Xiao Huigang , Liu Min , Li Yazhao , Geng Jishuang
Published: July 2020

The addition of carbon fiber can change plain concrete (PC) to a quasi‐ductile material and improve its flexural properties through sharing the tensile stress transduced from concrete matrix. However, the influence rule and its mechanism of air entrained by carbon fiber on properties of concrete with different water to cement ratios (W/C) is not clear at present. Therefore, this research aims to explore this influence rule and mechanism. Eighteen kinds of concrete samples with W/C of 0.25, 0.3, and 0.45 including 216 specimens in total were studied. Their mechanical and permeability‐related properties were tested, and carbon fiber's air‐entraining models were established. The results show that carbon fiber has effect of improving the flexural strength, compressive strength, and impermeability of concrete with W/C of 0.25, but when W/C increases, the effect of carbon fiber on improving the flexural strength, reducing the compressive strength and impermeability of concrete increases. The calculation results of the air‐entraining models suggest that one possible air‐entraining mechanism of carbon fiber can be summarized as that carbon fiber entrains more air into concrete as W/C increases, and another one can be summarized as that the air entrained by carbon fiber increases the connectivity of the pore structure of concrete.
Engineering small molecule nanodrugs to overcome barriers for cancer therapy
Authors: Ma Yuan , Mou Quanbing , Yan Deyue , Zhu Xinyuan
Published: July 2020

Small molecule nanodrugs consisting of pure drugs, drug‐drug dimers, drug‐drug conjugates, or drug derivatives could realize drug delivery by themselves without the aid of carriers, which have received abundant attention in recent decades. Avoiding the use of additional carriers, the yielded small molecule nanodrugs hold the following advantages: (a) high drug loading capacities (some of them could even reach up to 100%); (b) precise and tunable drug loading ration; and (c) no carrier‐induced long‐term toxicity. The past decade has witnessed rapid growth and advancements in this field. In this review, we will briefly introduce both in vitro “barriers” and in vivo barriers for drug delivery, and then summarize the most recent development of small molecule nanodrugs from the point of view how to engineer small molecule nanodrugs to overcome these barriers.
Deliberate decline: An emerging frontier for the study and practice of decarbonization
Authors: Rosenbloom Daniel , Rinscheid Adrian
Published: July 2020

Promoting low‐carbon innovation has long been a central preoccupation within both the practice and theory of climate change mitigation. However, deep lock‐ins indicate that existing carbon‐intensive systems will not be displaced or reconfigured by innovation alone. A growing number of studies and practical initiatives suggest that mitigation efforts will need to engage with the deliberate decline of carbon‐intensive systems and their components (e.g., technologies and practices). Yet, despite this realisation, the role of intentional decline in decarbonization remains poorly understood and the literature in this area continues to be dispersed among different bodies of research and disciplines. In response, this article structures the fragmented strands of research engaging with purposive decline, interrogating the role it may play in decarbonization. It does so by systematically surveying concepts with particular relevance for intentional decline, focusing on phase‐out, divestment, and destabilization.

This article is categorized under:

Decarbonizing Energy and/or Reducing Demand > Decarbonizing Energy and/or Reducing Demand
Thermodynamics of $$ \mathrm{T}\overline{\mathrm{T}} $$, $$ \mathrm{J}\overline{\mathrm{T}} $$, $$ \mathrm{T}\overline{\mathrm{J}} $$ deformed conformal field theories
Authors: Chakraborty Soumangsu , Hashimoto Akikazu
Published: July 2020

Abstract

We compute the Hagedorn temperature of

$$ \mu T\overline{T} $$

μT

T
¯

+

$$ {\varepsilon}_{+}J\overline{T} $$

ε
+

J

T
¯

+

$$ {\varepsilon}_{-}T\overline{J} $$

ε
−

T

J
¯

deformed CFT using the universal kernel formula for the thermal partition function. We find a closed analytic expression for the free energy and the Hagedorn temperature as a function of μ, ε
+, and ε

−
for the case of a compact scalar boson by taking the large volume limit. We also compute the Hagedorn temperature for the single trace deformed AdS
3
× S
1
× T
3
× S
3 using holographic methods. We identify black hole configurations whose thermodynamics matches the functional dependence on (μ, ε
+
, ε

−
) of the double trace deformed compact scalars.
Dark matter freeze out during an early cosmological period of QCD confinement
Authors: Berger Dillon , Ipek Seyda , Tait Tim M.P. , Waterbury Michael
Published: July 2020

Abstract

Standard lore states that there is tension between the need to accommodate the relic density of a weakly interacting massive particle and direct searches for dark matter. However, the estimation of the relic density rests on an extrapolation of the cosmology of the early Universe to the time of freeze out, untethered by observations. We explore a nonstandard cosmology in which the strong coupling constant evolves in the early Universe, triggering an early period of QCD confinement at the time of freeze out. We find that depending on the nature of the interactions between the dark matter and the Standard Model, freeze out during an early period of confinement can lead to drastically different expectations for the relic density, allowing for regions of parameter space which realize the correct abundance but would otherwise be excluded by direct searches.
Mortality of trauma patients treated at trauma centers compared to non-trauma centers in Sweden: a retrospective study
Authors: Candefjord Stefan , Asker Linn , Caragounis Eva-Corina
Published: July 2020

Objective

The main objective was to compare the 30-day mortality rate of trauma patients treated at trauma centers as compared to non-trauma centers in Sweden. The secondary objective was to evaluate how injury severity influences the potential survival benefit of specialized care.

Methods

This retrospective study included 29,864 patients from the national Swedish Trauma Registry (SweTrau) during the period 2013–2017. Three sampling exclusion criteria were applied: (1) Injury Severity Score (ISS) of zero; (2) missing data in any variable of interest; (3) data falling outside realistic values and duplicate registrations. University hospitals were classified as trauma centers; other hospitals as non-trauma centers. Logistic regression was used to analyze the effect of trauma center care on mortality rate, while adjusting for other factors potentially affecting the risk of death.

Results

Treatment at a trauma center in Sweden was associated with a 41% lower adjusted 30-day mortality (odds ratio 0.59 [0.50–0.70], p < 0.0001) compared to non-trauma center care, considering all injured patients (ISS ≥ 1). The potential survival benefit increased substantially with higher injury severity, with up to > 70% mortality decrease for the most critically injured group (ISS ≥ 50).

Conclusions

There exists a potentially substantial survival benefit for trauma patients treated at trauma centers in Sweden, especially for the most severely injured. This study motivates a critical review and possible reorganization of the national trauma system, and further research to identify the characteristics of patients in most need of specialized care.
Discovery of treatment for nerve agents targeting a new metabolic pathway
Authors: Glaros Trevor , Dhummakupt Elizabeth S. , Rizzo Gabrielle M. , McBride Ethan , Carmany Daniel O. , Wright Linnzi K. M. , Forster Jeffry S. , Renner Julie A. , Moretz Ruth W. , Dorsey Russell , Marten Mark R. , Huso Walker , Doan Alexander , Dorsey Carrie D. , Phillips Christopher , Benton Bernard , Mach Phillip M.
Published: July 2020

The inhibition of acetylcholinesterase is regarded as the primary toxic mechanism of action for chemical warfare agents. Recently, there have been numerous reports suggesting that metabolic processes could significantly contribute to toxicity. As such, we applied a multi-omics pipeline to generate a detailed cascade of molecular events temporally occurring in guinea pigs exposed to VX. Proteomic and metabolomic profiling resulted in the identification of several enzymes and metabolic precursors involved in glycolysis and the TCA cycle. All lines of experimental evidence indicated that there was a blockade of the TCA cycle at isocitrate dehydrogenase 2, which converts isocitrate to α-ketoglutarate. Using a primary beating cardiomyocyte cell model, we were able to determine that the supplementation of α-ketoglutarate subsequently rescued cells from the acute effects of VX poisoning. This study highlights the broad impacts that VX has and how understanding these mechanisms could result in new therapeutics such as α-ketoglutarate.
Epicardial access for VT ablation: analysis of two different puncture techniques, incidence of adhesions and complication management
Authors: Mathew Shibu , Feickert Sebastian , Fink Thomas , Rillig Andreas , Reissmann Bruno , Rottner Laura , Hashiguchi Naotaka , Wohlmuth Peter , Maurer Tilman , Lemes Christine , Metzner Andreas , Kuck Karl-Heinz , Ouyang Feifan
Published: July 2020

Introduction

Pericardial access for ablation of ventricular arrhythmias (VA) can be gained either by an anterior-oriented or inferior-oriented epicardial puncture under fluoroscopical guidance. We retrospectively sought to assess the safety of these two puncture techniques and the incidence of epicardial adhesions and introduce our algorithm for management of pericardial tamponade.

Methods and results

In 211 patients (61.4 ± 15.6 years, 179 males; 84.8%) 271 epicardial ablation procedures of VA were performed using either an anterior- or inferior-oriented approach for epicardial access. Puncture-related complications were systematically analyzed. Furthermore, the incidence of adhesions was evaluated during first and repeated procedures.

A total of 34/271 (12.5%) major complications occurred and 23/271 (8.5%) were directly related to epicardial puncture. The incidence of puncture-related major complications in the anterior and inferior group was 4/82 (4.9%) and 19/189 (10.1%), respectively. Pericardial tamponade was the most common major complication (15/271; 5.5%). Collateral damages of adjacent structures such as liver, colon, gastric vessels and coronary arteries occurred in 6/189 (3.2%) patients and only within the inferior epicardial access group. Adhesions were documented in 19/211 (9%) patients during the first procedure and in 47.1% if patients had 2 or more procedures involving epicardial access.

Conclusion

Anterior-oriented epicardial puncture shows an observed association to a reduced incidence of pericardial tamponades and overall puncture-related complications in epicardial ablation of VA. In cases of repeated epicardial access adhesions increase significantly and may lead to ablation failure.
Use of fertility treatments in BRCA1/2 mutation carriers and risk for ovarian and breast cancer: a systematic review
Authors: Huber D. , Seitz S. , Kast K. , Emons G. , Ortmann O.
Published: July 2020

Purpose

Mutations in the genes BRCA1 and BRCA2 represent a significant risk factor for ovarian and breast cancer. With increasing number and success rates, fertility protection and treatment are gaining importance also for BRCA1/2 mutation carriers. However, the effect on primary cancer risk and risk for recurrence remains unclear. This review analyses the published data on fertility treatment and risk of ovarian and breast cancer in BRCA1/2 mutation carriers.

Methods

In this review, we included all relevant articles published in English from 1995 to 2018. Literature was identified through a search on PubMed and Cochrane Library.

Results

We identified one retrospective cohort and one case–control study regarding the association of fertility treatments and ovarian cancer risk in BRCA mutation carriers. The studies show no increase in ovarian cancer risk. Furthermore, one case–control study on the association between fertility treatment and breast cancer risk in BRCA mutation carriers and one prospective cohort study on the long-term safety of medication used for fertility preservation in women with a history of breast cancer were identified. One of the studies shows a possible adverse effect for gonadotropin-containing medication.

Conclusion

Possible increases in cancer risk associated with fertility treatments in BRCA1/2 mutation carriers cannot be excluded at this time. Based on the existing studies, BRCA1/2 mutation carriers should not be generally excluded from fertility treatments. However, they have to be informed about limited data and possible increases in cancer risk.