bluuebunny/crossref_metadata_2025 huggingface dataset:
Naturally Occurring and Nature-derived Polymers as Injectable Hydrogels
Authors: Draghi Lorenza
Published: July 2021

Hydrogels from naturally occurring polymers have been the focus of intense research for many decades, in an effort to mimic the complex and hierarchical structure of biological tissues. One of the main reasons for this interest is that they can offer to cells a highly hydrated environment and many similarities with their native extracellular matrix, both in structure and chemistry. When hydrogels are intended for cell embedding or in vivo injection, naturally occurring materials also have on their side unparalleled gelation mechanisms, with sol–gel transition entailing only minimal deviation from cells ideal conditions. Although derivatives of natural materials have attracted enormous research efforts for the fine-tuning of their properties, this chapter largely focuses on unmodified biopolymers with a sol–gel transition suitable for injection and cell encapsulation and on their gelation properties in particular.
Rheological Aspects of Hydrogel Processing
Authors: De Maeseneer T. , Cardinaels R.
Published: July 2021

To screen and design hydrogels for specific applications, the ability to characterize and tailor their rheological properties is essential. During the processing and application of hydrogels, rheology plays a threefold role to determine the processability (= injectability or printability) of the materials, to determine their macroscopic mechanical performance in the end-use application together with the evolution from the liquid-like state under processing conditions toward the more solid-like state in the end-use application and finally to act as an indirect structure probing technique. In the present chapter, an overview is given of the different rheological characterization techniques and the material properties resulting from these characterizations. The material properties are subdivided into linear viscoelastic properties, which are characteristic for the small deformation behavior, and non-linear viscoelastic properties that characterize the response to large deformations. In the latter category, both non-linear deformations experienced during use as well as the flow behavior relevant for processing are considered. In addition, a critical overview is given of the main experimental challenges that complicate the rheological characterization of hydrogels. Finally, a brief introduction is given to microrheology, which provides the possibility for non-contact, high-throughput, local characterization of the rheological properties on minute sample quantities.
Bioprinting Hydrogels and Tissue Engineering
Authors: Majid M. , Guo J. L. , Kim Y. , Melchiorri A. J. , Mikos A. G.
Published: July 2021

Hydrogels have often been utilized for bioprinting, the three-dimensional printing of cells and/or bioactive molecules for tissue engineering, because of their ability to be processed at low temperatures and low shear forces that are favorable for cell encapsulation. The design of a hydrogel bioink requires the consideration of several key parameters that include the material formulation, the cell type(s) within the bioink, and the printing methodology. The selection of these parameters requires the consideration of the biochemical and physical properties of the hydrogel as well as the potential effects of hydrogel encapsulation and printing on cell behavior. Advances in hydrogel design and printing technology have ultimately enabled the fabrication of constructs for two-dimensional tissues as well as three-dimensional hollow, solid, and anatomical structures. This chapter provides an overview of the design parameters involved in the creation of hydrogel bioinks and also describes the advances in the fabrication of biomimetic tissue engineering constructs using hydrogel bioprinting.
Hydrogels–Blood Interactions
Authors: Jerca F. A. , Stancu I. C. , Jerca V. V. , Giol E. D.
Published: July 2021

Blood contact biomaterials need to fulfill a strict set of rules to be implanted and used within the human body. In the present chapter, we briefly describe the basic tissue responses upon the implantation of biomaterials, focusing on the interactions established at the surface of the polymer–blood interface and within the surrounding biological environment. Hemocompatibility assessment methods such as thrombosis, coagulation, partial thromboplastin time (PTT), platelet adhesion and aggregation, or hemolysis assays are discussed, together with a description of their principles. In addition, an overview of the ongoing hemocompatibility investigations on natural- and synthetic-based hydrogels is provided. Special attention is given to the intrinsic anti-thrombogenic properties of synthetic hydrogels based on poly(2-hydroxyethyl methacrylate), poly(ethylene glycol) and zwitterionic polymers, while natural hydrogels are discussed as inherent biomaterials or as tools to improve the hemocompatibility of other biomaterials via surface modification strategies. Overall, the importance of hemocompatibility assessment, even as preliminary investigations, is directly shown to be a requirement, in general, for implantable biomaterials and, in particular, for injectable hydrogels targeting blood-contacting applications.
Immuno-response and Hydrogels
Authors: Yang Hyeong-Cheol , Kim Yongjoon , Wu Lele
Published: July 2021

Immune reactions affect tissue regeneration and restoration as well as the occurrence and resolution of inflammation around biomaterials. Various kinds of immunomodulating techniques are being developed to acquire optimized immune reactions for local tissue regeneration. The strategies for immunomodulation are different depending on the types of scaffolds, targeted tissue, conditions of hosts, etc. Hydrogels are the most biocompatible biomaterials for tissue engineering, as they can provide highly hydrated environments similar to natural conditions. In accordance with the tremendous increase in the use of 3D printing technologies, various types of hydrogels are being applied as printing materials in the field of tissue engineering. Implanted hydrogels inevitably induce immune reactions, which will influence 3D-printing-induced tissue regeneration eventually. Understanding the immune-properties of hydrogels is undoubtedly advantageous for designing and constructing the biocompatible 3D hydrogels. In this chapter, basic immuno properties of hydrogels such as collagen, gelatin and alginate are described, and the relationship between immune reactions and tissue regenerations is also discussed. Furthermore, several techniques for immunomodulation using the hydrogels to enhance healing and regenerative processes are introduced.
Solvothermal synthesis and structural characterization of three polyoxotitanium-organic acid clusters
Authors: Kazimierczuk Katarzyna , Milanesio Marco , Dołęga Anna , Palin Luca , Walencik Maja , Jurkowski Michał , Conterosito Eleonora
Published: July 2021

Crystal structures of three novel titanium oxo-clusters with different cores and ligands obtained by an easy and convenient solvothermal method.
Label-free determination of liver cancer stages using surface-enhanced Raman scattering coupled with preferential adsorption of hydroxyapatite microspheres
Authors: Gao Siqi , Lin Yamin , Zheng Mengmeng , Lin Yating , Lin Kecan , Xie Shusen , Yu Yun , Lin Juqiang
Published: July 2021

Label-free albumin targeted analysis method by utilizing HAp to adsorb–release HSA, with the conjunction of SERS for screening liver cancer at different tumor (T) stages.
Single-metal-atom catalysts supported on graphdiyne catalyze CO oxidation
Authors: Sun Chunyan , Huang Simin , Huang Mengru , Zhang Xiangrui , Xu Shusheng , Wang Hui , Chen Yanyan , Shi Xue-Rong
Published: July 2021

CO oxidation by four M@GDY single-atom catalysts (M = Pt, Rh, Cu, and Ni) is studied by van der Waals density functional theory. The non-noble Cu@GDY exhibits a CO oxidation activity comparable to the noble Rh@GDY and Pt@GDY, while Ni@GDY does not.
Multifunctional Zn–Ln (Ln = Eu and Tb) heterometallic metal–organic frameworks with highly efficient I2 capture, dye adsorption, luminescence sensing and white-light emission
Authors: Gao Wei , Wei Han , Wang Cui-Li , Liu Jie-Ping , Zhang Xiu-Mei
Published: July 2021

Zn–Eu/Tb HMOFs were synthesized as luminescence sensors for Fe3+ and TNP with high sensitivity and selectivity and they show the high capacity to adsorb iodine and NR dyes. Meanwhile, the trimetallic doped Zn3Eu1.5Tb0.5 emits white light.
Comparing coordination uranyl(vi) complexes with 2-(1H-imidazo[4,5-b]phenazin-2-yl)phenol and derivatives
Authors: Hiti E. A. , Wilkinson G. R. , Ariyarathna I. R. , Tutson C. D. , Hardy E. E. , Maynard B. A. , Miliordos E. , Gorden A. E. V.
Published: July 2021

The synthesis, characterization, emission, and electronic spectroscopy for complexes of derivatives of 2-(1H-imidazo[4,5-b]phenazin-2-yl)phenol with uranyl (UO22+) and copper (Cu2+) are detailed.
Temporal-spatial-energy resolved advance multidimensional techniques to probe photovoltaic materials from atomistic viewpoint for next-generation energy solutions
Authors: Kumar Vishal , Nisika  , Kumar Mukesh
Published: July 2021

Advanced characterization tools capable of probing material properties multi-dimensionally at high spatial, temporal and energy resolutions are presented.
Novel porous starch/alginate hydrogels for controlled insulin release with dual response to pH and amylase
Authors: Chen Yaqiong , Song Hongdong , Huang Kai , Guan Xiao
Published: July 2021

A novel porous starch/alginate hydrogel system successfully achieved the goal of triggered release on pH and α-amylase changes. Furthermore, the insulin release rate can be reduced by increasing the thickness of the high amylose maize starch film.
A quantitative model for a nanoscale switch accurately predicts thermal actuation behavior
Authors: Crocker Kyle , Johnson Joshua , Pfeifer Wolfgang , Castro Carlos , Bundschuh Ralf
Published: July 2021

A predictive statistical mechanical model enables design of, and reveals mechanistic insight into, thermal actuation of composite DNA-nanoparticle devices.
Metal-free, oxidative decarboxylation of aryldifluoroacetic acid with the formation of the ArS–CF2 bond
Authors: Zhang Yifang , Wang Qian , Peng Yi , Gong Haiying , Chen Hua , Deng Hongmei , Hao Jian , Wan Wen
Published: July 2021

A metal-free, oxidative decarboxylative reaction of aryldifluoroacetic acids with disulfides or thiols under mild reaction conditions has been developed. It is an efficient radical cross-coupling method for synthesis of difluoromethylthio ethers.
Preparation of hyper-cross-linked hydroxylated polystyrene for adsorptive removal of methylene blue
Authors: Li Fada , Liu Jun , Liu Wenxiu , Xu Yuanyuan , Cao Yiwen , Chen Bo , Xu Mancai
Published: July 2021

This study presents the preparation of hyper-cross-linked hydroxylated polystyrene (HCPS-OH) resins using dichloromethane as an external cross-linker for the adsorption of methylene blue.
Access to 6-hydroxy indolizines and related imidazo[1,5-a]pyridines through the SN2 substitution/condensation/tautomerization cascade process
Authors: Duan Guiyun , Liu Hao , Zhang Liqing , Yuan Chunhao , Li Yongchao , Ge Yanqing
Published: July 2021

A simple and efficient cascade reaction was developed for the construction of hydroxy substituted indolizines from pyrrole-2-carbaldehydes and commercially available 4-halogenated acetoacetic esters.
A bifunctional lead–iron oxyfluoride, PbFeO2F, that functions as a visible-light-responsive photoanode and an electrocatalyst for water oxidation
Authors: Mizuochi Ryusuke , Izumi Kazunari , Inaguma Yoshiyuki , Maeda Kazuhiko
Published: July 2021

The PbFeO2F serves as a bifunctional material for a water-oxidation photoanode workable under a wide range of visible light and a water-oxidation electrocatalyst operatable at a relatively low overpotential.
The impact of representations of chemical bonding on students’ predictions of chemical properties
Authors: Farheen Ayesha , Lewis Scott E.
Published: July 2021

Representations are ubiquitous in chemistry. They are part of the chemistry language instructors use to communicate chemistry phenomenon to students. Literature calls in support of learning with multiple representations, but there is a pre-requisite for students to learn from a single representation. In this exploratory study, 1086 students in second semester general chemistry were randomly assigned to one of four representations showing bonding of sulfur dioxide: chemical formula, Lewis dot structure, an image of a ball and stick model, or an image of a space filling model. Students were asked to predict chemical properties of sulfur dioxide: relative bond length, molecular polarity, and the strongest intermolecular force with a water molecule. Using the lens of Multimedia Learning Theory on Learning with Text and Visual Representations, analyses of students’ prediction of chemical properties and the features cited when making predictions was conducted. Effect sizes were used to describe variations among representations in terms of how students predicted bond length, polarity and intermolecular forces. Meaningful differences were found across representations in students’ ability to correctly predict relative bond length and molecular polarity. These explorations generated the following hypotheses: (1) chemical formula leads students to depend on chemical conventions, (2) Lewis dot structure hinders predicting polarity when it shows an inaccurate shape, and (3) visual representations of ball and stick and space filling cue students to rely on visual estimations more than the other representations. Upon further testing, these hypotheses can inform instructors how to introduce representations and in the decision-making process of which representations to use to convey or assess a specific chemical property.
Hollow and highly diastereoselective face-rotating polyhedra constructed through rationally engineered facial units
Authors: Tang Xiao , Li Zhihao , Liu Haoliang , Qu Hang , Gao Wenbin , Dong Xue , Zhang Shilin , Wang Xinchang , Sue Andrew C.-H. , Yang Liulin , Tan Kai , Tian Zhongqun , Cao Xiaoyu
Published: July 2021

The rationally engineered facial units, TAT-m and TAT-p, resulted in distinct diastereoselectivity of face-rotating polyhedra (FRP).
Colloidal aggregation in anisotropic liquid crystal solvent
Authors: Sudha Devika Gireesan , Ochoa Jocelyn , Hirst Linda S.
Published: July 2021

We report on colloidal aggregation in the nematic liquid crystal phase. Luminescent colloids are self-assembled in situ, providing a unique method to study large-scale hierarchical assembly in an anisotropic solvent.
A multifunctional covalently linked graphene–MOF hybrid as an effective chemiresistive gas sensor
Authors: Jayaramulu Kolleboyina , Esclance DMello Marilyn , Kesavan Kamali , Schneemann Andreas , Otyepka Michal , Kment Stepan , Narayana Chandrabhas , Kalidindi Suresh Babu , Varma Rajender S. , Zboril Radek , Fischer Roland A.
Published: July 2021

The covalent linkage of graphene acid (GA) with amine-functionalized UiO-66-NH2via an amide bond. The resultant hybrid GA@UiO-66-NH2 acts as a chemiresistive CO2 sensor wth significant efficiency owing to its unique structural features.
Colloidal synthesis of Au nanomaterials with a controlled morphology and crystal phase via the [Au(i)-oleylamine] complex
Authors: Wang Gang , Ma Chen , Zheng Long , Chen Ye
Published: July 2021

A comprehensive overview of morphology- and crystal phase-controlled synthesis of Au nanomaterials via the [Au(I)-oleylamine] complex and their promising applications.
Interfacial polymerization of MOF “monomers” to fabricate flexible and thin membranes for molecular separation with ultrafast water transport
Authors: Cui Xiaolei , Kong Guodong , Feng Yang , Li Longting , Fan Weidong , Pang Jia , Fan Lili , Wang Rongming , Guo Hailing , Kang Zixi , Sun Daofeng
Published: July 2021

The “ordered porous monomers” of MOFs are interfacially assembled into thin and flexible membranes economically, which exhibit efficient dye separation with ultrafast water transport properties even after being rolled up and enlarged to a large area.
Marked enhancement of electrocatalytic activities for gas-consuming reactions by bimodal mesopores
Authors: Dong Ling-Yu , Hu Xu , Du Yun-Zhe , Ge Rui , Hao Guang-Ping , Lu An-Hui
Published: July 2021

Bimodal mesoporous carbon-based electrocatalysts delivered markedly enhanced activities for gas-consuming reactions, which highlights the importance of pore geometry engineering towards advanced electrocatalysts.
Immobilized enzymes in inorganic hybrid nanoflowers for biocatalytic and biosensing applications
Authors: Liang Xiao , Liu Yong , Wen Kai , Jiang Wei , Li Quanshun
Published: July 2021

Immobilized enzymes in inorganic hybrid nanoflowers for biocatalytic and biosensing applications.
Reversible dehydration–hydration process in stable bismuth-based hybrid perovskites
Authors: Babaryk A. A. , Pérez Y. , Martínez M. , Mosquera M. E. G. , Zehender M. H. , Svatek S. A. , Antolín E. , Horcajada P.
Published: July 2021

Unusual reversible dehydration-hydration process of a stable bismuth-based hybrid perovskite with good optoelectronic properties and exceptional stability.
Silicon-based two-dimensional chalcogenide of p-type semiconducting silicon telluride nanosheets for ultrahigh sensitive photodetector applications
Authors: Lin Chang-Yu , Ulaganathan Rajesh Kumar , Sankar Raman , Murugesan Raghavan Chinnambedu , Subramanian Ambika , Rozhin Alex , Firdoz Shaik
Published: July 2021

We demonstrate an outstanding visible light photodetector fabricated with high-quality 2D silicon telluride single crystal grown by chemical vapor transport technique.
Retention of perylene diimide optical properties in solid-state materials through tethering to nanodiamonds
Authors: Almuhana Asia R. Y. , Langer Philipp , Griffin Sarah L. , Lodge Rhys W. , Rance Graham A. , Champness Neil R.
Published: July 2021

Nanodiamond-perylene diimide composites retain solution phase optical properties of the parent perylene diimide dye in the solid state.
Alkyl chain regulation: distinctive odd–even effects of mechano-luminescence and room-temperature phosphorescence in alkyl substituted carbazole amide derivatives
Authors: Tu Liangjing , Che Weilong , Li Shuhui , Li Xiaoning , Xie Yujun , Li Zhen
Published: July 2021

A series of carbazole amide derivatives with different lengths from methyl to octyl (CAC-N, N = 1–8). Compounds with even-numbered alkyl chains exhibit mechanoluminescence (ML) property, however, no ML is observed in the odd-numbered counterparts.
The anti-cancer drug dabrafenib is not cardiotoxic and inhibits cardiac remodelling and fibrosis in a murine model of hypertension
Authors: Meijles Daniel N. , Cull Joshua J. , Cooper Susanna T.E. , Markou Thomais , Hardyman Michelle A. , Fuller Stephen J. , Alharbi Hajed O. , Haines Zoe H.R. , Alcantara-Alonso Viridiana , Glennon Peter E. , Sheppard Mary N. , Sugden Peter H. , Clerk Angela
Published: July 2021

Raf kinases signal via extracellular signal-regulated kinases 1/2 (ERK1/2) to drive cell division. Since activating mutations in BRAF (B-Raf proto-oncogene, serine/threonine kinase) are highly oncogenic, BRAF inhibitors including dabrafenib have been developed for cancer. Inhibitors of ERK1/2 signalling used for cancer are cardiotoxic in some patients, raising the question of whether dabrafenib is cardiotoxic. In the heart, ERK1/2 signalling promotes not only cardiomyocyte hypertrophy and is cardioprotective but also promotes fibrosis. Our hypothesis is that ERK1/2 signalling is not required in a non-stressed heart but is required for cardiac remodelling. Thus, dabrafenib may affect the heart in the context of, for example, hypertension. In experiments with cardiomyocytes, cardiac fibroblasts and perfused rat hearts, dabrafenib inhibited ERK1/2 signalling. We assessed the effects of dabrafenib (3 mg/kg/d) on male C57BL/6J mouse hearts in vivo. Dabrafenib alone had no overt effects on cardiac function/dimensions (assessed by echocardiography) or cardiac architecture. In mice treated with 0.8 mg/kg/d angiotensin II (AngII) to induce hypertension, dabrafenib inhibited ERK1/2 signalling and suppressed cardiac hypertrophy in both acute (up to 7 d) and chronic (28 d) settings, preserving ejection fraction. At the cellular level, dabrafenib inhibited AngII-induced cardiomyocyte hypertrophy, reduced expression of hypertrophic gene markers and almost completely eliminated the increase in cardiac fibrosis both in interstitial and perivascular regions. Dabrafenib is not overtly cardiotoxic. Moreover, it inhibits maladaptive hypertrophy resulting from AngII-induced hypertension. Thus, Raf is a potential therapeutic target for hypertensive heart disease and drugs such as dabrafenib, developed for cancer, may be used for this purpose.
Postnatal inflammation in ApoE−/− mice is associated with immune training and atherosclerosis
Authors: Noye Ellesandra C. , Bekkering Siroon , Limawan Albert P. , Nguyen Maria U. , Widiasmoko Lisa K. , Lu Hui , Pepe Salvatore , Cheung Michael M. , Menheniott Trevelyan R. , Wallace Megan J. , Moss Timothy J. , Burgner David P. , Short Kirsty R.
Published: July 2021

Background and aims: Preterm birth is associated with increased risk of cardiovascular disease (CVD). This may reflect a legacy of inflammatory exposures such as chorioamnionitis which complicate pregnancies delivering preterm, or recurrent early-life infections, which are common in preterm infants. We previously reported that experimental chorioamnionitis followed by postnatal inflammation has additive and deleterious effects on atherosclerosis in ApoE−/− mice. Here, we aimed to investigate whether innate immune training is a contributory inflammatory mechanism in this murine model of atherosclerosis.

Methods: Bone marrow-derived macrophages and peritoneal macrophages were isolated from 13-week-old ApoE−/− mice, previously exposed to prenatal intra-amniotic (experimental choriomanionitis) and/or repeated postnatal (peritoneal) lipopolysaccharide (LPS). Innate immune responses were assessed by cytokine responses following ex vivo stimulation with toll-like receptor (TLR) agonists (LPS, Pam3Cys) and RPMI for 24-h. Bone marrow progenitor populations were studied using flow cytometric analysis.

Results: Following postnatal LPS exposure, bone marrow-derived macrophages and peritoneal macrophages produced more pro-inflammatory cytokines following TLR stimulation than those from saline-treated controls, characteristic of a trained phenotype. Cytokine production ex vivo correlated with atherosclerosis severity in vivo. Prenatal LPS did not affect cytokine production capacity. Combined prenatal and postnatal LPS exposure was associated with a reduction in populations of myeloid progenitor cells in the bone marrow.

Conclusions: Postnatal inflammation results in a trained phenotype in atherosclerosis-prone mice that is not enhanced by prenatal inflammation. If analogous mechanisms occur in humans, then there may be novel early life opportunities to reduce CVD risk in infants with early life infections.
Online Consumer Reviews on Hearing Health Care Services: A Textual Analysis Approach to Examine Psychologically Meaningful Language Dimensions
Authors: Manchaiah Vinaya , Swanepoel De Wet , Bennett Rebecca J.
Published: July 2021

Purpose

The study examined psychologically meaningful language dimensions (i.e., social and emotional dimensions, health dimensions, and personal concerns) within online consumer reviews on hearing health care services using an automated textual analysis approach.

Method

Nine thousand six hundred twenty-two consumer reviews of hearing health care services, including an open-ended question (i.e., free text response to the prompt “share details of your own experience at this place”) and an overall rating (on a 5-point scale ranging from “very good” to “very poor”) were extracted from
Google.com
from 40 different cities across the United States. In addition, some metadata about the cities (i.e., region, population size, median age, percentage of older adults) were also recorded. Text responses were analyzed using the automated Linguistic Inquiry and Word Count software for selected language dimensions. The language dimensions of online hearing health care reviews were descriptively compared with language dimensions observed in the natural language of typical bloggers. Language dimensions from free text responses were correlated with quantitative overall experience ratings.

Results

Automated linguistic analysis showed that consumer reviews on hearing health care services had higher social processes, positive emotions, hearing, health, money, and work, and lower negative emotions and time-awareness when compared to typical bloggers. Examining the association between overall experience rating and the language dimensions revealed two broad findings. First, higher engagement of consumers in terms of social processes, positive emotions, hearing, and work dimensions was related to higher experience ratings. Second, higher engagement of consumers in terms of negative emotions, time awareness, and money was related to lower experience ratings.

Conclusions

Online reviews contain information about various dimensions (i.e., social and emotional dimensions as well as personal concerns) that have bearing toward the way in that they rate their health care experiences. Automated linguistic analysis of consumer reviews appears helpful in identifying gaps in service delivery that may influence consumer experience.
Unmasking the history of 3C 293 with LOFAR sub-arcsecond imaging
Authors: Kukreti Pranav , Morganti Raffaella , Shimwell Timothy W. , Morabito Leah K. , Beswick Robert J. , Brienza Marisa , Hardcastle Martin J. , Sweijen Frits , Jackson Neal , Miley George K. , Moldon Javier , Oosterloo Tom , de Gasperin Francesco
Published: July 2021

Active galactic nuclei show episodic activity, which can be evident in galaxies that exhibit restarted radio jets. These restarted jets can interact with their environment, leaving signatures on the radio spectral energy distribution. Tracing these signatures is a powerful way to explore the life of radio galaxies. This requires resolved spectral index measurements over a broad frequency range including low frequencies. We present such a study for the radio galaxy 3C 293, which has long been thought to be a restarted galaxy on the basis of its radio morphology. Using the International LOFAR telescope (ILT) we probed spatial scales as fine as ~0.2′′ at 144 MHz, and to constrain the spectrum we combined these data with Multi-Element Radio Linked Interferometer Network and Very Large Array archival data at frequencies up to 8.4 GHz that have a comparable resolution. In the inner lobes (~2 kpc), we detect the presence of a spectral turnover that peaks at ~225 MHz and is most likely caused by free-free absorption from the rich surrounding medium. We confirm that these inner lobes are part of a jet-dominated young radio source (spectral age ≲0.17 Myr), which is strongly interacting with the rich interstellar medium of the host galaxy. The diffuse emission surrounding these lobes on scales of up to ~4.5 kpc shows steeper spectral indices (Δα ~ 0.2–0.5, S ∝ ν−α) and a spectral age of ≲0.27 Myr. The outer lobes (extending up to ~100 kpc) have a spectral index of α ~ 0.6–0.8 from 144–4850 MHz with a remarkably uniform spatial distribution and only mild spectral curvature (Δα ≲ 0.2). We propose that intermittent fuelling and jet flow disruptions are powering the mechanisms that keep the spectral index in the outer lobes from steepening and maintain the spatial uniformity of the spectral index. Overall, it appears that 3C 293 has gone through multiple (two to three) epochs of activity. This study adds 3C 293 to the new sub-group of restarted galaxies with short interruption time periods. This is the first time a spatially resolved study has been performed that simultaneously studies a young source as well as the older outer lobes at such low frequencies. This illustrates the potential of the International LOFAR telescope to expand such studies to a larger sample of radio galaxies.
Inferring magnetic helicity spectrum in spherical domains: Method and example applications
Authors: Prabhu A. P. , Singh N. K. , Käpylä M. J. , Lagg A.
Published: July 2021

Context. Obtaining observational constraints on the role of turbulent effects for the solar dynamo is a difficult, yet crucial, task. Without such knowledge, the full picture of the operation mechanism of the solar dynamo cannot be formed.

Aims. The magnetic helicity spectrum provides important information about the α effect. Here we demonstrate a formalism in spherical geometry to infer magnetic helicity spectra directly from observations of the magnetic field, taking into account the sign change of magnetic helicity across the Sun’s equator.

Methods. Using an angular correlation function of the magnetic field, we develop a method to infer spectra for magnetic energy and helicity. The retrieval of the latter relies on a fundamental definition of helicity in terms of linkage of magnetic flux. We apply the two-scale approach, previously used in Cartesian geometry, to spherical geometry for systems where a sign reversal of helicity is expected across the equator on both small and large scales.

Results. We test the method by applying it to an analytical model of a fully helical field, and to magneto-hydrodynamic simulations of a turbulent dynamo. The helicity spectra computed from the vector potential available in the models are in excellent agreement with the spectra computed solely from the magnetic field using our method. In a next test, we use our method to obtain the helicity spectrum from a synoptic magnetic field map corresponding to a Carrington rotation. We observe clear signs of a bihelical spectrum of magnetic helicity, which is in complete accordance to the previously reported spectra in literature from the same map.

Conclusions. Our formalism makes it possible to infer magnetic helicity in spherical geometry, without the necessity of computing the magnetic vector potential. It has many applications in solar and stellar observations, but can also be used to analyse global magnetoconvection models of stars and to compare them with observations.
Heating of the solar chromosphere in a sunspot light bridge by electric currents
Authors: Louis Rohan E. , Prasad Avijeet , Beck Christian , Choudhary Debi P. , Yalim Mehmet S.
Published: July 2021

Context. Resistive Ohmic dissipation has been suggested as a mechanism for heating the solar chromosphere, but few studies have established this association.

Aims. We aim to determine how Ohmic dissipation by electric currents can heat the solar chromosphere.

Methods. We combine high-resolution spectroscopic Ca II data from the Dunn Solar Telescope and vector magnetic field observations from the Helioseismic and Magnetic Imager (HMI) to investigate thermal enhancements in a sunspot light bridge. The photospheric magnetic field from HMI was extrapolated to the corona using a non-force-free field technique that provided the three-dimensional distribution of electric currents, while an inversion of the chromospheric Ca II line with a local thermodynamic equilibrium and a nonlocal thermodynamic equilibrium spectral archive delivered the temperature stratifications from the photosphere to the chromosphere.

Results. We find that the light bridge is a site of strong electric currents, of about 0.3 A m−2 at the bottom boundary, which extend to about 0.7 Mm while decreasing monotonically with height. These currents produce a chromospheric temperature excess of about 600−800 K relative to the umbra. Only the light bridge, where relatively weak and highly inclined magnetic fields emerge over a duration of 13 h, shows a spatial coincidence of thermal enhancements and electric currents. The temperature enhancements and the Cowling heating are primarily confined to a height range of 0.4−0.7 Mm above the light bridge. The corresponding increase in internal energy of 200 J m−3 can be supplied by the heating in about 10 min.

Conclusions. Our results provide direct evidence for currents heating the lower solar chromosphere through Ohmic dissipation.
An all-sky sample of intermediate- to high-mass OBA-type eclipsing binaries observed by TESS
Authors: IJspeert L. W. , Tkachenko A. , Johnston C. , Garcia S. , De Ridder J. , Van Reeth T. , Aerts C.
Published: July 2021

Context.Intermediate- to high-mass stars are the least numerous types of stars, and they are less well understood than their more numerous low-mass counterparts in terms of their internal physical processes. Modelling the photometric variability of a large sample of main-sequence intermediate- to high-mass stars in eclipsing binary systems will help to improve the models for such stars.

Aims.Our goal is to compose a homogeneously compiled sample of main-sequence intermediate- to high-mass OBA-type dwarfs in eclipsing binary systems from TESS photometry. We search for binaries with and without pulsations and determine their approximate ephemerides.

Methods.Our selection starts from a catalogue of dwarfs with colours corresponding to those of OBA-type dwarfs in the TESS Input Catalog. We develop a new automated method aimed at detecting eclipsing binaries in the presence of a strong pulsational and/or rotational signal relative to the eclipse depths and apply it to publicly available 30-min cadence TESS light curves.

Results.Using targets with TESS magnitudes below 15 and cuts in the 2MASS magnitude bands ofJ − H < 0.045 andJ − K < 0.06 as the most stringent criteria, we arrive at a total of 189 981 intermediate- to high-mass candidates, 91 193 of which have light curves from at least one of two data reduction pipelines. The eclipsing binary detection and subsequent manual check for false positives resulted in 3155 unique OBA-type eclipsing binary candidates.

Conclusions.Our sample of eclipsing binary stars in the intermediate- to high-mass regime allows for future binary (and asteroseismic) modelling with the aim to better understand the internal physical processes in this hot part of the main sequence.
The unidentified infrared bands and the spectrum of atomic hydrogen
Authors: Zagury Frédéric
Published: July 2021

This letter compares the footprints on a spectral axis of the main unidentified infrared emission bands (UIBs) with the recombination lines of atomic hydrogen. The comparison shows striking correspondences, suggesting that atomic hydrogen may be involved in the production of UIBs.
12C/13C ratio and CNO abundances in the classical very old metal-poor dwarf HD 140283
Authors: Spite M. , Spite F. , Barbuy B.
Published: July 2021

Context. The isotope abundances provide powerful diagnostics of the chemical enrichment in our Galaxy. The star HD 140283 is one of the best-studied very metal-poor dwarf stars. It is very old, and the chemical abundance in this star is a good witness of the chemical composition of the matter in the early Galaxy.

Aims. The aim of this work is to measure the precise abundances of carbon, nitrogen, oxygen, and mainly the 12C/13C isotopic ratio in this very old metal-poor star in order to have a good reference for the computations of the chemical evolution of the Galaxy.

Methods. We used very high spectral resolution data, with extremely high signal-to-noise ratios obtained with the spectrographs ESPaDOnS at the CFHT, ESPRESSO at the VLT, and HARPS at the ESO 3.6 m telescope.

Results. For the first time, we were able to measure the 12C/13C ratio in a very old metal-poor dwarf that was born at the very beginning of the Galaxy: 12C/13C = 33−6+12. We also obtained a precise determination of the abundance of the CNO elements in this star. These abundances give information about the early composition of the cloud from which HD 140283 was formed. They suggest that the effect of super-asymptotic giant branch stars or fast-rotating massive stars was significant in the early Galaxy.
Bottom-Up derivatives of tree expressions
Authors: Attou Samira , Mignot Ludovic , Ziadi Djelloul
Published: July 2021

In this paper, we extend the notion of (word) derivatives and partial derivatives due to (respectively) Brzozowski and Antimirov to tree derivatives using already known inductive formulae of quotients. We define a new family of extended regular tree expressions (using negation or intersection operators), and we show how to compute a Brzozowski-like inductive tree automaton; the fixed point of this construction, when it exists, is the derivative tree automaton. Such a deterministic tree automaton can be used to solve the membership test efficiently: the whole structure is not necessarily computed, and the derivative computations can be performed in parallel. We also show how to solve the membership test using our (Bottom-Up) partial derivatives, without computing an automaton.
Changes in the Total Solar Irradiance and climatic effects
Authors: Schmutz Werner K.
Published: July 2021

The correlation between the averaged reconstructed March temperature record for Kyoto, Japan, and the reconstructed Total Solar Irradiance (TSI) over 660 years from 1230 to 1890 gives evidence with 98% probability that the Little Ice Age with four cold periods is forced by variations of TSI. If the correlation is restricted to the period 1650–1890, with two cold periods in the 17th and 19th century and for which two independent reconstructed March temperature records are available, the probability of solar forcing increases to 99.99%. As solar irradiance variations have a global effect there has to be a global climatic solar forcing impact. However, by how much global temperature were lower during these minima and with what amplitude TSI was varying is not accurately known. The two quantities, global temperature and TSI, are linked by the energy equilibrium equation for the Earth system. The derivation of this equation with respect to a variation of the solar irradiance has two terms: A direct forcing term, which can be derived analytically and quantified accurately from the Stefan-Boltzmann law, and a second term, describing indirect influences on the surface temperature. If a small TSI variation should force a large temperature variation, then it has to be the second indirect term that strongly amplifies the effect of the direct forcing. The current knowledge is summarized by three statements:

During the minima periods in the 13th, 15/16th, 17th, and 19th centuries the terrestrial climate was colder by 0.5–1.5 °C;

Indirect Top-down and Bottom-up mechanisms do not amplify direct forcing by a large amount, i.e. indirect solar forcing is of the same magnitude (or smaller) as direct solar forcing;

The radiative output of the Sun cannot be lower by more than 2 Wm−2 below the measured present-day TSI value during solar cycle minimum.

These three statements contradict each other and it is concluded that at least one is not correct. Which one is a wrong statement is presently not known conclusively. It is argued that it is the third statement and it is speculated that over centennial time scales the Sun might vary its radiance significantly more than observed so far during the last 40 years of space TSI measurements. To produce Maunder minimum type cold climate excursions, a TSI decrease of the order of 10 Wm−2 is advocated.
Triglyceride-Glucose Index Predicts Adverse Events in Patients with Acute Coronary Syndrome: A Meta-Analysis of Cohort Studies
Authors: Li Juying , Ren Ling , Chang Cheng , Luo Lin
Published: July 2021

The triglyceride-glucose (TyG) index, a recently proposed indicator for insulin resistance, has been related with cardiovascular risks. We aimed to summarize the association between TyG index and incidence of major adverse cardiovascular events (MACEs) in patients with acute coronary syndrome (ACS). Cohort studies demonstrating the association between TyG index and incidence of MACEs in ACS patients with multivariate adjusted analyses were identified by search of PubMed, Embase, and Web of Science databases. A random-effekt model incorporating the heterogeneity was applied to pool the results. Eight cohort studies with 19 611 participants were included. Results showed that compared to those with the lowest category of TyG index, ACS patients with the highest category of TyG index were independently associated with higher risk of MACEs [risk ratio (RR): 1.94, 95% confidence interval (CI): 1.47–2.56, I2=85%, p <0.001). Subgroup analyses showed consistent results in patients with ST-segment elevated myocardial infarction or non-ST segment elevated ACS, in patients with or without diabetes, and in patients after percutaneous coronary intervention. Results were consistent in studies with TyG index analyzed as continuous variable (RR for per standard deviation increment of TyG index: 1.59, 95% CI: 1.38–1.83, I2=24%, p <0.001). In conclusion, higher TyG index may be independently associated with higher incidence of MACEs in patients with ACS.
Ineffective Feeding Practices and Their Effect on Malocclusion: A Narrative Review
Authors: Mokashi Pratima R. , Bhandary Srikala
Published: July 2021

Objective The aim of this narrative review is to highlight the association of ineffective feeding practices with the development of malocclusion in children and the role of a pediatric dentist in identifying the cues and signs of improper feeds, and encourage effective breastfeeding practices.

Introduction There has been an ongoing debate on the role of effective breastfeeding in the prevention of malocclusion. Although no specific claim supports the positive impact of the same, a detailed reviewing of the literature helps to identify the method of feeding to be chosen considering health benefits and personal preference.

Materials and Methods A broad search of all resources linked to the topic was performed in PubMed, Medline, World Health Organization web site, government web sites, and Google Scholar search engine. Keywords used in the search included breastfeeding, ineffective breastfeeding, bottle feeding, pacifier, and malocclusion. A total of 60 articles published in the period from 2000 to 2019 were segregated. Selected articles comprised original research, meta-analysis, and systematic reviews.

Results Parameters such as duration, posture, and non-nutritive sucking habits had an impact on effective breastfeeding.

Discussion Effective breastfeeding and maintaining appropriate posture and duration helps to positively impact the normal growth and development of the jaws, muscular functioning, and speech. Thereby, the risk of developing malocclusion in primary dentition can be prevented.

Conclusion An understanding of the role of breastfeeding and malocclusion will help in the early intervention and prevention of malocclusion and deviated muscular function. Highlighting the role of counseling and effective feeding practices is also an area that should be focused upon by budding clinicians.
Liver Imaging Reporting and Data System: Review of Pros and Cons
Authors: Terzi Eleonora , Ayuso Carmen , Piscaglia Fabio , Bruix Jordi
Published: July 2021

The American College of Radiology has released the Liver Imaging Reporting and Data System (LI-RADS) scheme which categorizes focal liver lesions (FLLs) in patients at risk for hepatocellular carcinoma (HCC) according to the degree of risk of nodules to be HCC. It subgroups FLL in LR-1 (definitely benign), LR-2 (probably benign), LR-3 (intermediate probability of malignancy), LR-4 (probably HCC), LR-5 (definitely HCC), and LR-M (probable malignancy not specific for HCC). Computed tomography/magnetic resonance imaging (CT/MRI) and contrast enhanced ultrasound (CEUS) LI-RADS diagnostic algorithm have the goal to standardize the acquisition, interpretation, reporting, and data collection for imaging examinations in patients at risk for HCC. Nevertheless, there remain controversial issues that should be dealt with. The aim of this review is to discuss the pros and cons of the interpretation and reporting part of CT/MRI and CEUS LI-RADS diagnostic algorithm to permit future refinements of the scheme and optimize patient and nodule management.
Hemoglobin estimation using ultra-low path length in microfluidic chips by quantifying Soret band
Authors: Arcot Lokanathan , Kandaswamy Srinivasan , Modali Anil , Rai Dastidar Tathagato
Published: July 2021

Blood is the most analyzed body fluid for diagnostic purposes, and complete blood count is a widely performed blood test, wherein hemoglobin estimation is performed colorimetrically, while other parameters including counts of platelets, Red Blood Cells (RBCs) and White Blood Cells (WBCs) are estimated using imaging or impedance or light scattering techniques. Artificial Intelligence (AI) powered automated imaging systems in conjunction with microfluidic chips are some of the most promising cost-effective medical diagnostic solutions poised to revolutionize the field of Point-of-Care (POC) healthcare. Performing imaging based colorimetry would enable minimizing the cost and also the footprint of POC blood analyzers. We report the development and verification of an imaging based on-chip colorimetric assay to estimate hemoglobin in blood using ultra-low path lengths by transitioning from a widely utilized Q band absorbance peak to a more intense Soret peak associated with Sodium Lauryl Sulfate (SLS) assay. Initial SLS reagent customization characterization of the SLS reagent was performed using a nanospectrophotometer with in-house prepared hemoglobin standards and also whole blood samples. Subsequently, the imaging based SLS assay was optimized on a microfluidic chip (chamber height: 190 µm) in conjunction with an automated microscope (AI-100) equipped with a violet LED whose emission peak coincided with the Soret peak of the SLS–hemoglobin complex. The thus optimized on-chip hemoglobin assay was verified for clinical performance using a sample set consisting of 30 blood samples. The verification study indicated an accuracy (R2) of 0.98, a sensitivity of 100%, and a specificity of 87.5%. Overall, we present an imaging based on-chip hemoglobin assay using a microfluidic chip with ultra-low path lengths by quantifying the Soret peak associated with the customized SLS assay.
One Potoroo
Authors: Jaye Penny , Rogerson Alicia
Published: July 2021

When a bushfire destroys Potoroo’s home, he becomes one of the last surviving Gilbert’s Potoroos at Two Peoples Bay in Western Australia. Frightened, hurt and alone, Potoroo needs a new home – somewhere safe from predators and with plenty of his favourite food. Luckily, a team of conservationists know where Potoroo can go to be safe.
One Potoroo: A Story of Survival is a beautifully illustrated book about the world’s most endangered marsupial, the Gilbert’s Potoroo, and the conservation work that has kept this unique Australian alive.
Reading level varies from child to child, but we recommend this book for ages 6–9.
Genetic analysis of boron tolerance in burr medic (
Authors: Peck David M. , Michelmore Simon , Sutton Tim
Published: July 2021

Soils with toxic levels of boron (B) are widespread in the cereal-livestock zone of southern Australia. The annual pasture legume burr medic (Medicago polymorpha L.) is widely grown in rotation with grain crops in this zone, but current cultivars are susceptible to high levels of B. We tested the boron tolerance of several putative B tolerant burr medic accessions and developed four F2 populations by crossing two tolerant accessions with two susceptible cultivars. We tested a B tolerance SSR marker developed for barrel medic (M. truncatula Gaernt) on tolerant burr medic accessions but found a new marker was required. We identified several B tolerant burr medic accessions. In our four F2 populations tolerance was inherited in a 3 : 1 (tolerant : susceptible) ratio and we identified a molecular marker that accounts for 0.84 of the variation. The B tolerant accessions, along with the B tolerance marker, will allow for the efficient introgression of B tolerance into widely adapted genetic backgrounds and will allow breeders to efficiently develop cultivar(s) that are tolerant of a widespread subsoil constraint.