bluuebunny/crossref_metadata_2025 huggingface dataset:
Factors regulating growth pattern and condition factor of an amphibious fish Periophthalmus gracilis living in the Mekong Delta
Authors: Dinh Quang Minh , Nguyen Ton Huu Duc , Truong Ngon Trong , Nguyen-Ngoc Lam
Published: March 2022

Growth pattern and condition factor (CF) are essential to fish resource assessment but limited to Periophthalmus gracilis—an amphibious fish living in the mudflats along the Indo-Pacific regions, including the Mekong Delta (MD), Vietnam. This study lasted from April 2020 to March 2021 to verify if their growth pattern and CF change with sex, size, season, month and site. The total length and weight of 486 individuals (236 females and 250 males) were 2.9–5.9 cm and 0.13–1.66 g, respectively. The mudskipper displayed negative allometry as the slope value (b = 2.69 ± 0.06) obtained from length and weight (LWR) was significantly less than 3 (p < 0.01), indicating that most fish specimens were caught in the immature stage. The fish growth pattern did not change with sex as both males and females displayed negative allometry but varied by size since the mudskipper showed negative allometry in the immature group and isometry in the mature group. Likewise, growth type changed with season since fish showed negative allometry in the dry season but isometry in the wet season. As the slope value (b) varied by site and month, the mudskipper displayed spatiotemporal growth patterns, ranging from negative to positive allometry. The CF was impacted by sex as this value of females (1.09 ± 0.02) was higher than that of males (0.96 ± 0.01, p < 0.01). Besides, CF was regulated by fish length since this value was higher in the mature group (1.12 ± 0.03) than in the immature group (1.01 ± 0.01, p < 0.01). Likewise, CF was affected by season as this value was higher in the wet season (1.05 ± 0.02) than in the dry season (0.99 ± 0.01, p < 0.01). Although the CF varied with site and month variables (p < 0.01), this value (1.02 ± 0.01) was generally higher than 1, showing fish adapted well to their habitat. The fish length at first capture should be increased to exploit this species sustainably.
An overview of the nutritional value, health properties, and future challenges of Chinese bayberry
Authors: Zhang Shuwen , Yu Zheping , Sun Li , Ren Haiying , Zheng Xiliang , Liang Senmiao , Qi Xingjiang
Published: March 2022

Chinese bayberry (CB) is among the most popular and valuable fruits in China owing to its attractive color and unique sweet/sour taste. Recent studies have highlighted the nutritional value and health-related benefits of CB. CB has special biological characteristics of evergreen, special aroma, dioecious, nodulation, nitrogen fixation. Moreover, the fruits, leaves, and bark of CB plants harbor a number of bioactive compounds including proanthocyanidins, flavonoids, vitamin C, phenolic acids, and anthocyanins that have been linked to the anti-cancer, anti-oxidant, anti-inflammatory, anti-obesity, anti-diabetic, and neuroprotective properties and to the treatment of cardiovascular and cerebrovascular diseases. The CB fruits have been used to produce a range of products: beverages, foods, and washing supplies. Future CB-related product development is thus expected to further leverage the health-promoting potential of this valuable ecological resource. The present review provides an overview of the botanical characteristics, processing, nutritional value, health-related properties, and applications of CB in order to provide a foundation for further research and development.
Sonographic Placental Thickness Measurement: A Trustworthy Saviour for Foetal Age Estimation in Uncomplicated Pregnancy
Authors: Kumar Manish , Nigam Astha , Kumar Lalit , Mukherjee Shobha
Published: March 2022

Introduction: Placenta is a foeto-maternal organ playing a crucial role in endocrine, immunological, excretory, respiratory, and nutritional functions for the foetus. Gestational age estimation is usually based on the last menstrual period and ultrasonography. Many females having irregular menstruation present with unreliable last menstrual period and hence ultrasonography comes into play for correctly estimating the gestation. Various sonologically derived foetal parameters used for gestational age estimation are Crown Rump Length (CRL), Biparietal Diameter (BPD), Head Circumference (HC), and Abdominal Circumference (AC). The placental thickness measurement shows a direct correlation with the gestational age of the foetus till certain weeks of pregnancy, therefore could be utilised as a new and simple parameter in scenarios like term pregnancy where other parameters are unreliable. Aim: To study the relationship between sonographic placental thickness measurement and gestational age of the foetus and also correlating other biometric parameters i.e., BPD, AC, femur length with placental thickness. Materials and Methods: The present study was a cross- sectional study conducted in the Department of Radiodiagnosis, in collaboration with the Department of Obstetrics and Gynaecology, Rohilkhand Medical College and Hospital, Bareilly, Uttar Pradesh, India. Sample size constituted of 200 normal antenatal women in whom the placental thickness for various gestational age and correlation between placental thickness measurement with the gestational age of the foetus was done. Analysis of the relationship between placental thickness and other foetal parameters like BPD, femur length and AC was also assessed using Pearson correlation coefficient. Results: Placental thickness measurements for gestational age 11-39 weeks were calculated; it gradually increased from 11.29 mm (mean) at 11 weeks to 35 millimeters (mm) (mean) at 39 weeks of gestation. Correlation coefficient was 0.9685 and p-value <0.01. Also, there was a significant positive correlation of placental thickness with other foetal biometry parameters like BPD, femur length and AC (p<0.001). Conclusion: The measurement of placental thickness can become a key parameter for estimation of foetal age especially in cases where the exact duration of pregnancy is not known. It can also facilitate the detection of abnormal placental thickness associated with maternal and foetal complications in the early stages.
Synthesis of Copper Oxide Nanoparticles using Ocimum Gratissimum (Scent Leaf)
Authors: Abosede O. O. , Ikimi C. G.
Published: March 2022

Environmentally friendly synthesis of copper oxide nanoparticles (NPs) has been achieved using aqueous extracts of Ocimum gratissimum leaf (scent leaf). The reduction of Cu2+ was followed by the change of color from green to dark brown color and formation of precipitate. The reaction was monitored by visual observation and characterization of copper nanoparticles using UV-Visible spectrophotometer and Fourier Transform Infrared spectrophotometery. UV-Visible spectra of the aqueous solution containing copper nanoparticles showed a peak at 240 nm corresponding to the surface plasmon resonance of copper oxide nanoparticles. FTIR spectra also confirmed the formation of the copper oxide NPs by the appearance of bands corresponding to Cu-O stretching frequency, and the presence of phytochemicals present in Ocimum gratissimum adsorbed on the surface of the copper oxide nanoparticles presents these nanoparticles as promising biological agents. This green synthesis method replaces the use of toxic chemicals with Ocimum gratissimum extract which play the roles of reducing, stabilizing and capping agents during the synthesis.
Knowledge of Parents Regarding Polio Vaccination in Unvaccinated Children Less than 5 Years of Age: A Cross-sectional Study
Authors: Larik Sobia , Jamro Saifullah , Shaikh Abdul Rehman , Khokhar Iqra Rafique , Shaikh Raheel Ahmed , Chohan Muhammad Nadeem
Published: March 2022

Aim: The purpose of this study was to determine the knowledge of parents regarding polio vaccination in unvaccinated children less than 5 years of age.

Study Design: Cross-sectional study.

Place and Duration: Department of Pediatrics, Shaheed Mohtarma Benazir Bhutto Medical University, Larkana Pakistan from February 2018 till August 2018

Methodology:  All parents of unvaccinated children of either gender with ages from 2 months to less than 5 years of age visiting the hospital outpatient department for any reason were included in the study. Information about the OPV immunization status, demographics, education of the family earner, occupation and income, accessibility of vaccination center in terms of distance, the behavior of immunization staff, parents' views regarding vaccines were recorded. Questions were asked about the vaccination schedule.

Results: Mean age of the child and respondent’s age was 2.96 ±0.89 years and 31.40 ±3.96 years respectively. Male preponderance was found to be higher 146 (63.50%). Adequate knowledge about polio was found in 58 (25.20%) parents.

Conclusion: The Knowledge of parents regarding polio vaccination was found unsatisfactory in unvaccinated children less than 5 years of age.
Elaboration of instrument for assessing assistance to patients with tuberculosis in primary health care / Elaboração de instrumento de avaliação da assistência ao paciente com tuberculose na atenção primária em saúde
Authors: Wilhelm Daniela , Stein Airton Tetelbom , Schwambach Karin Hepp , Blatt Carine Raquel
Published: March 2022

Objetivo: elaborar e validar um instrumento de avaliação da assistência ao paciente com tuberculose na Atenção Primária em Saúde. Método: as etapas de construção do instrumento avaliativo foram: construção do modelo lógico, revisão bibliográfica, identificação das dimensões e subdimensões avaliativas e elaboração de indicadores. A Técnica Delfos com especialistas foi utilizada a fim de obter consenso sobre a relevância das dimensões e subdimensões e atribuir pesos aos indicadores. O teste piloto foi realizado em duas unidades de saúde. Resultados: o instrumento de avaliação resulta em uma nota máxima de dez pontos distribuída em recursos físicos, recursos humanos e capacidade técnica, subdividida em sete subdimensões e 44 indicadores. A avaliação possibilitou o conhecimento da realidade individual das unidades avaliadas. Conclusão: o instrumento proposto pode ser utilizado como instrumento de gestão, podendo ser útil na identificação de estratégias para qualificação da assistência do paciente com tuberculose na Atenção Primária em Saúde.
Cationic Macromolecular Engineering
Authors: De Priyadarsi , Faust Rudolf
Published: March 2022

Macromolecular engineering is defined as the total synthesis of tailor‐made macromolecules. The ultimate goal of this technology is to obtain a high degree of control over compositional and structural variables that affect the physical properties of macromolecules, including molecular weight, molecular weight distribution, end functionality, tacticity, stereochemistry, block sequence, and block topology, where the parameters of molecular characterization are well represented by the ensemble average. This review article summarizes the use of carbocationic polymerization for macromolecular engineering.
Time‐Programming, Clocking, and Self‐Oscillating Polymer Gels
Authors: Yoshida Ryo
Published: March 2022

In living systems, there are many autonomous and oscillatory phenomena to sustain life such as heart beating. “Self‐oscillating” polymer gels that undergo spontaneous cyclic swelling–deswelling changes without any on–off switching of external stimuli, as with heart muscle, were developed by the author's group. The self‐oscillating gels were designed by utilizing the Belousov–Zhabotinsky (BZ) reaction, an oscillating reaction, as a chemical model of the TCA cycle. They have systematically studied these self‐oscillating polymer gels since they were first reported in 1996. Potential applications of the self‐oscillating polymers and gels include several kinds of functional material systems such as biomimetic actuators, mass transport systems, and functional fluids. For example, it was demonstrated that an object was autonomously transported in the tubular self‐oscillating gel by the peristaltic pumping motion similar to an intestine. Further, self‐oscillating polymer brush surface like cilia, vesicles, or colloidosomes undergoing cell‐like autonomous shape oscillations with buckling, was prepared. Besides, autonomous sol‐gel oscillation and amoeba‐like motion were realized utilizing well‐designed block copolymer solution. In this article, recent progress on the self‐oscillating polymer gels is summarized.
Introduction to Synthesis and Materials Applications of Poly(Ionic Liquid)s
Authors: Yahia Mohamed , Zhou Xianjing , Yuan Jiayin
Published: March 2022

Poly(ionic liquid)s, sometimes termed polymerized ionic liquids or polymeric ionic liquids (PILs), have been recognized as a unique class of ionic polymers, which are normally the polymerization products of ionic liquid (IL) monomers. The rapid progress in the PIL research is demonstrated by many scientific publications from 2009 till now, and newly reported chemical structures with interesting properties and functions. In fact, synthesis of polymer structures from IL monomers has so far created a big library of functional polymers for a wide range of advanced applications, and it has harnessed a massive collaboration with scientific communities in different fields. In short, the combination of IL properties and functions with the polymer matrix makes it possible to manufacture new polymers and their devices with different talents. In this article, the chemical structures, the synthetic approaches, and the multipurpose applications of PILs will be discussed to deliver an overview of this innovative research topic.
Poly(2‐Oxazoline)s
Authors: Van Guyse Joachim F. R. , Hoogenboom Richard
Published: March 2022

The design and synthesis of macromolecules, i.e. macromolecular engineering, employ specific synthetic tools for the control over the functionality, topology, and composition of a macromolecule. In terms of macromolecular engineering, 2‐oxazolines present an attractive monomer class for the design of a structurally diverse set of macromolecules, as a wide array of monomer structures can be prepared via established synthetic pathways and macromolecules have been prepared from this monomer by cationic ring‐opening, zwitterionic, anionic, and radical polymerization techniques. Most prominently applied, however, is the cationic ring‐opening polymerization, since it is compatible with a wide range of 2‐oxazoline monomers and the living polymerization mechanism allows excellent control over the macromolecular architecture throughout the different steps of the polymerization. Furthermore, the obtained poly(2‐alkyl/aryl‐2‐oxazoline)s (PAOx) display excellent physical and chemical stability, as well as an overall biocompatible nature. These factors combined have led to a recent rise in popularity of PAOx as a highly modular polymer platform in biomedicine, where cutting‐edge macromolecular engineering is applied to face current challenges in biomedicine. In this article, the current state and opportunities in the macromolecular engineering of PAOx are discussed in great detail, thereby providing an overview of the developed synthetic methodologies to control their functionality, topology, and composition.
Polymerization Induced by Light
Authors: Lalevee J. , Fouassier J.P.
Published: March 2022

The present article presents an overview of photopolymerization reactions and is focused on photoinitiators, photosensitizers, radical and cationic monomers and oligomers, the film photopolymerization of acrylates, epoxides, vinyl ethers, thiol–enes, waterborne light‐curable systems, UV powder formulations, charge‐transfer monomers, dual cure and hybrid cure systems, the general functional properties of the cured materials, the applications, etc. The kinetics, the monitoring of the photopolymerization, the investigation of the excited state processes, the access to the rate constants of the chemical reactions, the solution and bulk reactivity, and the photochemical and chemical reactivity are also discussed.
Polymers from Renewable Resources: Macromolecular Materials for the Twenty‐First Century?
Authors: Gandini Alessandro , Lacerda Talita M.
Published: March 2022

Macromolecular materials based on renewable resources constitute a rapidly growing family of sustainable polymers which are synthesized following three distinct approaches, viz. (i) the use of renewable resources to prepare commodity polymers, such as poly(ethylene), traditionally based on fossil counterparts; (ii) the chemical modification of natural polymers; and (iii) the polymerization of monomers and macromonomers derived from renewable resources. Whereas the first approach simply provides alternative and sustainable routes to common current materials, the other strategies represent means to elaborate novel polymers with original, and often unique, properties. Here, after a brief treatment regarding the first topic, emphasis is placed on the latter two, with materials based on (ii) cellulose and nanocelluloses, hemicelluloses, starch, chitin and chitosan, lignin, suberin, proteins, natural rubber, and bacterial poly(hydroxyalkanoate)s on the one hand, and, on the other hand, on (iii) plant oils, glycerol, furans, terpenes, rosin, sugars, tannins, and lactic acid. Several instances are provided of materials involving the intervention of more than one of these precursors. The discussion of the chemical processes leading to these new polymers is complemented by their characterization and most relevant properties and applications. The additional implementation of green chemistry features to enhance sustainability is also highlighted whenever appropriate.
Polymer Synthesis by Enzymatic Catalysis
Authors: Loos Katja
Published: March 2022

Enzymatic polymerizations are defined as in vitro enzyme‐catalyzed syntheses of polymers that do not follow biosynthetic pathways. Polymer synthesis using biocatalytic pathways holds enormous promise in the fields of science. Use of enzymes for polymer synthesis can have tremendous environmental benefits as chemical approaches require large scale use of hazardous chemical solvents and substantial energy input. Enzymatic reactions can be carried out at ambient temperature, and reaction medium in many cases is water, which is a green solvent. Moreover, it also reduces the waste generated by chemical processes. Thus, enzymatic approaches to polymer synthesis are socially, environmentally, and economically superior to chemical approaches.
Vitrimer Chemistry and Applications
Authors: Van Zee Nathan J. , Nicolaÿ Renaud
Published: March 2022

Vitrimers are permanent yet dynamic polymer networks that ideally behave like conventional thermosets at service temperatures but flow like vitreous glasses at processing temperatures. They are characterized by constant, temperature‐independent network connectivity as well as the ability to completely relax stress as a result of dynamic exchange reactions between the cross‐links. Other important features include enhanced insolubility, healing properties, and facile shaping. Since the introduction of vitrimers in 2011, which were epoxy‐acid and epoxy‐anhydride resins loaded with a transesterification catalyst, many kinds of dynamic covalent chemistries have been employed in polymer networks to create new vitrimers. Born from these advancements, exciting new applications have been reported that cannot be realized with conventional thermosets. In this article, we introduce fundamental principles of vitrimer science and provide an overview of recent advances in vitrimer chemistry. Finally, we discuss the use of vitrimers in recycling, shape‐memory materials, composites, and a variety of other nascent applications.
Reactive and Responsive Polymers for Sensing Applications in Bodily Fluids
Authors: Zhang Qiang , Hu Liang , Guo Siyuan , Zhang Yingnan , Carvalho Wildemar S.P. , Serpe Michael J.
Published: March 2022

Detection of ions, small molecules, and biomolecules is of utmost importance for protecting human health and ensuring our well‐being. Therefore, a tremendous amount of research has been conducted to develop new sensor technology with increased sensitivity and selectivity to analytes, very short analysis times, ease of operation, and usability in complex media (i.e. bodily fluids). In this article, we cover many examples of stimuli‐responsive polymer (SPRs) and reactive polymer‐based sensors for detection and quantification of analytes in bodily fluids, e.g. saliva, cerebrospinal fluid, sweat, and urine. In each case, the details of the response of the polymer to the presence of analyte and the translation of that response to a signal are included.
Construction of Chemical Recycling Systems of Polymeric Materials Based on Equilibrium Polymerizations and Reversible Reactions
Authors: Endo Takeshi , Sudo Atsushi
Published: March 2022

Development of chemical recycling systems of polymer materials is one of the most important subjects in polymer chemistry, because such systems enable reduction of the consumption of fossil‐based chemicals used for production of polymer materials. This article describes our efforts to construct chemical recycling systems based on the equilibrium nature of ring‐opening polymerizations of properly designed multi‐cyclic monomers including spiroorthoesters (SOEs), bicycloorthoesters (BOEs), cyclic carbonates (CCs), and its analogs, and some reversible reactions of vicinal tricarbonyl compounds and benzoxazines. The recycling systems described herein include not only efficient depolymerizations of polymers into the corresponding monomers but also decrosslinking of networked polymers into the corresponding linear polymers.
Macromolecular Engineering by Atom Transfer Radical Polymerization
Authors: Matyjaszewski Krzysztof
Published: March 2022

Atom transfer radical polymerization (ATRP) is one of the most often used controlled radical polymerization techniques for the preparation of various well‐defined advanced materials. ATRP is a catalytic process based on Cu‐based complexes. New very active catalysts can be used at ppm levels, also in aqueous media, making ATRP more environmentally benign. Precise control over various elements of polymer architecture, such as functionality, composition, and topology affords well‐defined gradient or block copolymers, as well as stars, brushes, or networks. ATRP has been successfully used to covalently linked synthetic polymers with inorganics (nanoparticles and flat or curved surfaces) and natural products (proteins and nucleic acids). Advanced functional materials prepared by ATRP find applications as coatings, thermoplastic elastomers, surfactants, dispersants, nanostructured carbons, functionalized surfaces, and biorelated materials.
Ion Transport in Batteries with Polymer Electrolytes
Authors: Yu Xiaopeng , Lennartz Peter , Sahore Ritu , Dudney Nancy , Brunklaus Gunther , Balsara Nitash P.
Published: March 2022

We discuss polymer electrolytes for use in rechargeable lithium batteries. Polymer electrolytes have the potential to enable batteries with lithium metal anodes. These batteries have significantly higher theoretical energy densities than current lithium‐ion batteries. We consider binary mixtures of polymers and salts. We also cover more complex systems such as polymer electrolytes swollen with a solvent (gel polymer electrolytes) and microphase separated polymer electrolytes. By covalently attaching the anions to the chains in a polymer solid, one obtains a single‐ion conductor. We mainly focus on experiments wherein the polymer electrolyte is placed between two lithium metal electrodes. These experiments enable the determination of three transport parameters, ionic conductivity, salt diffusion coefficient, and transference number, and the thermodynamic factor. The properties of dry polymer electrolytes are contrasted with those of gel polymer electrolytes. The gel systems exhibit higher conductivity while the dry systems exhibit superior mechanical properties. We discuss interfacial impedance when lithium metal is contacted with polymer electrolytes and the importance of coulombic efficiency.
Neutron Scattering in Polymers
Authors: Richter Dieter , Schwahn Dietmar
Published: March 2022

We present a short overview about neutron applications in polymer science. After describing some neutron scattering basics such as neutron cross section and structure factors, we describe the major instrumentations that are used. Concerning structural research, we discuss neutron small‐angle scattering (SANS) and grazing incident SANS that because of space limitations stands also for reflectometry. In the realm of dynamics, we focus on quasielastic scattering (QENS) and address time of flight, backscattering, and neutron spin echo instruments. For both structural and dynamic studies, we present typical examples that demonstrate the breadth and width of neutron scattering in the field.
Polymer Mechanics: Processing‐Structure–Property
Authors: Wang Shi‐Qing
Published: March 2022

This chapter describes the phenomenological theoretical framework that unifies three subjects concerning polymers in liquid and solid states: (i) melt rheology, (ii) molecular mechanics of glassy polymers, (iii) plastic deformation of semicrystalline polymers. Based on the available phenomenology, it is proposed that chain networking is essential in all of the three cases for providing the structural integrity. Predictable control of this structure permits us to explore and establish the principle for Processing–Structure–Property (P–S–P). Specifically, in each of the three topics, examples are presented to show the latest successes that can be used to indicate the observed “chain” of P–S–P.
Macromolecular Engineering via Polyelectrolyte Complexation
Authors: Meng Siqi , Tirrell Matthew V.
Published: March 2022

Polyelectrolyte complexes (PECs) are materials formed when mixing aqueous solutions of polycations and polyanions, resulting in a polymer‐dense complex phase, separating out from a polymer‐poor supernatant phase. Ever since the first observation of this type of polymeric material almost a century ago, these ionic assemblies have attracted continued interest, not only because of the significant roles they play in diverse natural and biological systems but also due to their broad utility in a wide range of applications, particularly those that involve encapsulation and aqueous adhesion, such as drug delivery, underwater coating, water treatment, and food industry. In this article, we first introduce the key factors that govern the self‐assembly process of PECs and highlight several main industrial and biological applications. Next, we discuss the recent experimental, computational, and theoretical advancements in providing an in‐depth physical understanding of this important class of material from the perspectives of phase behavior, structural model, dynamics, water content, and solid–liquid transition.
Thickening of Isolated and Multilayered Crystals and Its Implications on Melting Kinetics; The Role of Inter‐ and intra‐crystalline Regions
Authors: Rastogi Sanjay , Romano Dario
Published: March 2022

Melting of crystalline region in a semicrystalline polymer is a complex phenomenon, which is strongly influenced by the topological constraints present in the noncrystalline region. In an isolated crystal, detachment of chain stems from its crystalline surface can occur in succession or in cluster. The difference in detachment of the chain stems strongly depends on the topological constraints of the chain segments on the fold surface. Successive detachment of the chain stems, observed on melting of crystals while annealing at the onset of the peak melting temperature, appears to occur when chain folding is facilitated by adjacent reentry. In the annealing process, no crystal thickening in isolated crystals, having molar mass sufficiently high to suppress the effect of chain ends, is observed, as the crystal thickening will require cooperative chain mobility of the chain stems within the crystal linked by the chain segments in the fold. Retrospectively, because of the possibility of successive chain detachment, melting temperature decreases with decreasing heating rate, contradicting the assumption of increase in melting temperature on annealing. In the isolated crystals, having complex reentrant chains on the fold surface, successive detachment of chains from a crystal surface is frustrated, and cluster melting is promoted. Such crystals, though isolated, do not show melting on annealing. However, in contrast to the isolated crystals, in multilayered crystals instead of melting on annealing at the onset melting temperature, crystal thickening will occur that would cause increase in the melting temperature. This thickening process is facilitated, as it requires the localized motion only rather than the cooperative motion of the chain stems within the crystals. Thickening in the isolated crystals, if observed during polymerization or due to the appearance of a transient mobile phase, is referred as the primary thickening, whereas the crystal thickening in the multilayered crystals is called the secondary thickening.
Nonequilibrium Properties of Thin Polymer Films
Authors: Chandran Sivasurender , Reiter Günter
Published: March 2022

Rapid industrial processes often freeze polymers in nonequilibrium conformations, which, in turn, cause material properties that are significantly different from the predictions of equilibrium theories. Such deviations in properties may introduce enhanced material performance. Thus, by choosing appropriate processing pathways, we potentially can control macroscopic properties and performance of polymers. However, due to our current lack of fundamental understanding of the behavior of nonequilibrated polymers, we have to rely on empirical knowledge, imposing trial‐and‐error approaches for achieving desired properties. Considering these aspects, we discuss recent studies on polymer films revealing that quantitative relations exist between properties and processing pathways, suggesting possible relations for processing‐induced deviations in chain conformations. These relations propose that long‐living and long‐ranged correlations between polymers have been induced by processing, as indicated by the observation of relaxation times much longer than known for equilibrated polymers. We present an example where control of processing conditions for thin films allowed to translate the molecular relaxations during equilibration into a predictable lifting of macroscopic loads. Motivated by the presented results, we conclude that a comprehensive understanding of polymers with nonequilibrium conformations may not only expand the available spectrum of polymer properties but will also widen the scope of polymer science.
Broadband Dielectric Spectroscopy and Its Application in Polymeric Materials
Authors: Popov Ivan , Cheng Shiwang , Sokolov Alexei P.
Published: March 2022

Relaxation processes in polymeric systems span over an extremely wide range of time scales. There are a few experimental techniques capable of covering such a range, and one of the most versatile of them is Broadband Dielectric Spectroscopy (BDS). Current BDS covers an enormous frequency range, from ∼10−5to ∼1012 Hz, enabling a practical study of the full spectrum of relaxation phenomena in a broad temperature and pressure range without involvement of time‐temperature superposition. In this article, we present capabilities of the BDS technique on examples of different polymeric systems and explain what kind of information can be extracted from the frequency spectra of the dielectric permittivity and conductivity. We present examples of dielectric studies of segmental and chain dynamics, secondary relaxations, explain additional phenomena in multicomponent systems (e.g. polymer nanocomposites and block copolymers), and discuss specifically examples of ion‐conducting polymers. We emphasize that BDS does not probe molecular motions directly and measures fluctuations of dipoles or diffusion of charges. So, combination of BDS with other experimental techniques is the best approach to study dynamics of various materials.
Pickering Emulsions as Designer Platforms for Polymer‐Based Hybrid Materials: Routes to Controlled Structures
Authors: Zhang Yunchong , Cheng Huan , Li Xiang , Wang Bijia , Feng Xueling , Mao Zhiping , Vancso G. Julius , Sui Xiaofeng
Published: March 2022

Polymer‐based hybrid materials have attracted great interest in academic research and industry because they can effectively combine the advantages of their different components. Pickering emulsions as designer platforms provide a very efficient and often unappreciated route to prepare polymer‐based hybrids. Their applications cover a broad range, including filter media, ion exchange modules, monolithic polymer supports for catalysis, covalent enzyme immobilization, and even scaffolds for tissue engineering. In this article, we first provide an introduction to the basics and formation of Pickering emulsions and then discuss how these systems can be used to obtain templates for the fabrication of materials with various morphologies, such as microspheres, fibers, films, and porous matrices. We then discuss the uniqueness of Pickering systems for morphology control and the resulting added value to obtain advanced complex and hybrid materials. We then review and summarize recent advances in the preparation approaches (polymerization and solvent evaporation) and physical morphologies (microspheres, fibers, films, and porous matrices). Finally, we offer an outlook for future developments.
Rheology of Unentangled Polymer Solutions Depends on Three Macromolecular Properties: Flexibility, Extensibility, and Segmental Dissymmetry
Authors: Dinic Jelena , Martínez Narváez Carina D. V. , Sharma Vivek
Published: March 2022

We elucidate the influence of chemical structure on macromolecular hydrodynamics and rheological response using poly(ethylene oxide) or PEO and 2‐hydroxyethyl cellulose (HEC). We contrast the shear rheology response measured using torsional rheometry and find the wellknown universalities like comparable shear viscosity for dilute solutions at comparable degree of chain overlap. We show that dripping‐onto‐substrate (DoS) rheometry protocols that we developed facilitate characterization of pinching dynamics and extensional rheology response even for weakly elastic, low viscosity fluids. Even for unentangled solutions with comparable shear viscosity and molecular weights, the PEO solutions exhibit distinctively higher values of extensional relaxation time, extent of strain hardening, transient extensional viscosity, and an overall delay in pinch‐off. We find that the extensional relaxation times exhibit concentration dependence distinct from shear rheology response, or anticipated by blob models, developed for relaxation of weakly perturbed chains. Most significantly, we show that the influence of polymer choice can be evaluateda priori, using three macromolecular parameters: flexibility, extensibility, and segmental dissymmetry, defined as the ratio of Kuhn length to packing length. We identify the minimum concentration above which elastocapillary response appears and define a stretched overlap concentration below which the extensional relaxation time is concentration independent.
Neurofilament light chain and retinal layers' determinants and association: A population‐based study
Authors: Garzone Davide , Finger Robert P. , Mauschitz Matthias M. , Santos Marina L. S. , Breteler Monique M. B. , Aziz N. Ahmad
Published: March 2022

Both retinal atrophy measured through optical coherence tomography and plasma neurofilament light chain (NfL) levels are markers of neurodegeneration, but their relationship is unknown. Therefore, we assessed their determinants and association in 4369 participants of a population‐based study. Both plasma NfL levels and inner retinal atrophy increased exponentially with age. In the presence of risk factors for neurodegeneration (including age, smoking, and a history of neurological disorders), plasma NfL levels were associated with inner retinal atrophy and outer retinal thickening. Our findings indicate that inner retinal atrophy can reflect neuroaxonal damage as mirrored by rising plasma NfL levels.
Personalized Risk Model and Leveraging of Magnetic Resonance Imaging–Based Structural Phenotypes and Clinical Factors to Predict Incidence of Radiographic Osteoarthritis
Authors: Lee Jinhee J. , Namiri Nikan K. , Astuto Bruno , Link Thomas M. , Majumdar Sharmila , Pedoia Valentina
Published: March 2022

Objective

Our study aimed to investigate the association between time to incidence of radiographic osteoarthritis (OA) and magnetic resonance imaging (MRI)–based structural phenotypes proposed by the Rapid Osteoarthritis MRI Eligibility Score (ROAMES).

Methods

A retrospective cohort of 2,328 participants without radiographic OA at baseline were selected from the Osteoarthritis Initiative study. Utilizing a deep‐learning model, we automatically assessed the presence of inflammatory, meniscus/cartilage, subchondral bone, and hypertrophic phenotypes from MRIs acquired at baseline and 12‐, 24‐, 36‐, 48‐, 72‐, and 96‐month follow‐up visits. In addition to 4 structural phenotypes, we examined severe knee injury history and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain scores as time dependent. We used Cox proportional hazards regression to analyze the association between 4 structural phenotypes and radiographic OA disease‐free survival, both univariate and adjusted for known risk factors including age, sex, race, body mass index, presence of Heberden's nodes, and knee malalignment.

Results

Inflammatory (hazard ratio [HR] 3.37 [95% confidence interval (95% CI) 2.45–4.63]), meniscus/cartilage (HR 1.55 [95% CI 1.21–1.98]), and subchondral bone (HR 1.84 [95% CI 1.63–2.09]) phenotypes were associated with time to radiographic OA at P < 0.05 when adjusted for the risk factors. Sex was a modifier of hypertrophic phenotype association with time to radiographic OA. Female participants with the hypertrophic phenotype were associated with 2.8 times higher risk of radiographic OA (95% CI 2.25–7.54) compared to male participants without the hypertrophic phenotype.

Conclusion

Four ROAMES phenotypes may contribute to time to radiographic OA incidence and if validated could be used as a promising tool for personalized OA management.
Overdose death data suggests Z‐drugs, gabapentinoids not without risks
Authors: Enos Gary
Published: March 2022

The percentage of overdose deaths involving non‐benzodiazepine sedative‐hypnotics (“Z‐drugs”) and gabapentinoids more than tripled between 2000 and 2018, according to a new analysis of U.S. health data published in The Lancet Regional Health — Americas. The study found that deaths in which these drugs were accompanied by the presence of benzodiazepines or opioids also increased at times during the same period, suggesting in some cases that patients engage in concurrent use of the drugs that Z‐drugs and gabapentinoids are often meant to replace.
Synergistic Solvation and Interface Regulations of Eco‐Friendly Silk Peptide Additive Enabling Stable Aqueous Zinc‐Ion Batteries
Authors: Wang Baojun , Zheng Rong , Yang Wei , Han Xin , Hou Chengyi , Zhang Qinghong , Li Yaogang , Li Kerui , Wang Hongzhi
Published: March 2022

Aqueous Zn‐ion batteries have aroused much attention recently, yet challenges still exist in the lack of low‐cost, highly stable electrolytes to tackle the serious side reactions at Zn anode–electrolyte interface. Herein, a ZnSO4‐based low‐cost aqueous electrolyte is demonstrated with a small amount of eco‐friendly silk peptide as an efficient additive. Compared with silk sericin and fibroin, silk peptide with abundant strong polar groups (COOH and NH2) suppresses the side reactions. Namely, silk peptide regulates the solvation structure of Zn2+ to decrease coordinated active H2O and SO42−, and tends to anchor on Zn anode surface for the isolation of contact H2O/SO42− as well as electrostatic shielding, demonstrating synergistic solvation and interface regulating effect. Consequently, the excellent cycle life (3000 h) and Coulombic efficiency (99.7%) of Zn anodes are revealed in 2 m ZnSO4 electrolyte with only 5 mg mL−1 of silk peptide (≈0.49 USD L−1), promising practical applications of reversible zinc‐ion batteries.
The Influence of Surface Chemistry on Critical Current Density for Garnet Electrolyte
Authors: Chen Shaojie , Nie Zhiwei , Tian Feifei , Nie Lu , Wei Ran , Yu Jiameng , Gao Tianyi , Sun Zhaoru , Yang Nan , Liu Wei
Published: March 2022

Garnet‐based solid state lithium batteries have attracted a lot of attention due to their potential advantages in safety and energy density. However, the high electrode–electrolyte interfacial resistance and low critical current density (CCD) related with lithium dendrite penetration have seriously hindered their further development and practical application. Here, for garnet‐type solid electrolyte, the surface Li2CO3, interlayer species, lithium wettability, interfacial impedance, and CCD are systematically investigated. It turns out that Li2CO3‐free garnet electrolyte is intrinsically lithiophilic, and the interfacial impedance is mainly affected by the amount of surface Li2CO3. In addition, the CCD values are manipulated by the interfacial impedance rather than the apparent Li wettability. This study provides a comprehensive understanding about the interrelationships among surface chemistry, lithium wettability, interfacial impedance, and critical current density for garnet‐type solid electrolytes.
Surfactant‐Inspired Coassembly Strategy to Integrate Aggregation‐Induced Emission Photosensitizer with Organosilica Nanoparticles for Efficient Theranostics
Authors: Yan Saisai , Sun Panpan , Niu Niu , Zhang Zhijun , Xu Weilin , Zhao Siyi , Wang Lei , Wang Dong , Tang Ben Zhong
Published: March 2022

Construction of versatile nanotemplate bearing inherent distinctive functions and prominent drug‐carrying capability is an appealing yet significantly challenging task. Here, inspired by the guiding role of surfactant in preparing nanoparticles, an amphiphilic aggregation‐induced emission (AIE) photosensitizer, namely MeOTTVP, is synthesized with attractive near‐infrared (NIR) emission and high‐performance reactive oxygen species production, and followed by dual‐templating‐assisted one‐pot method involving MeOTTVP as the skeleton to fabricate organosilica nanoparticles (AIE‐ONs). The presented AIE‐ONs perfectly inherit the functions of MeOTTVP, and are also capable of loading antibiotics and anticancer drugs. Doxorubicin can be assembled on AIE‐ONs and then capped with hyaluronic acid, endowing the resulting hybrid with NIR fluorescence imaging‐guided synergetic photodynamic/chemotherapy performance, thereby offering boosted anticancer efficacy and reduced side effects. Furthermore, by loading antibiotic rifampicin, the newly obtained AIE‐ONs integrating chemo‐photodynamic antibacterial functions provide broad‐spectrum antibacterial activity and fluorescence monitoring behavior. This study thus not only offers a promising strategy to fabricate NIR nanoparticles on a large scale, but also provides useful insights into designing an advanced theranostic protocol for treating both cancer and bacterial infections.
Electrochemical Thin‐Film Transistors using Covalent Organic Framework Channel
Authors: Hota Mrinal K. , Chandra Suman , Lei Yongjiu , Xu Xiangming , Hedhili Mohamed N. , Emwas Abdul‐Hamid , Shekhah Osama , Eddaoudi Mohamed , Alshareef Husam N.
Published: March 2022

Covalent organic framework (COF) thin films have been successfully prepared and utilized as a channel material in electrical double‐layer (EDL) electrochemical transistors. 4,4′‐azodianiline (Azo) and 1,3,5‐triformylphloroglucinol(Tp) precursors are introduced to prepare azo (NN) functionalized ß‐keto‐enamine COF (Tp‐Azo) thin films. The EDL transistor exhibits a switching ratio of 103 times, a low threshold voltage of 0.6 V, and a field‐effect mobility of 0.53 cm2 V−1 s−1. The dynamic behavior of the transistor under different input signals shows responses, which are very similar to the biological synaptic behavior, indicating that the COF devices can be used as artificial synapses. This report opens a new direction in covalent–organic framework development in iontronic applications.
Bioinspired Phototropic MXene‐Reinforced Soft Tubular Actuators for Omnidirectional Light‐Tracking and Adaptive Photovoltaics
Authors: Yang Mengyuan , Xu Yiyi , Zhang Xuan , Bisoyi Hari Krishna , Xue Pan , Yang Yanzhao , Yang Xiao , Valenzuela Cristian , Chen Yuanhao , Wang Ling , Feng Wei , Li Quan
Published: March 2022

Endowing artificial advanced materials and systems with biomimetic self‐regulatory intelligence is of paramount significance for the development of somatosensory soft robotics and adaptive optoelectronics. Herein, a bioinspired phototropic MXene‐reinforced soft tubular actuator is reported that exhibits omnidirectional self‐orienting ability and is capable of quickly sensing, continuously tracking, and adaptively interacting with incident light in all zenithal and azimuthal angles of 3D space. The novelty of the soft tubular actuator lies in three aspects: 1) the new polymerizable MXene nanomonomer shows high compatibility with liquid crystal elastomer (LCE) matrices and can be in situ photopolymerized into the polymer networks, thus enhancing the mechanical and photoactuation properties; 2) the distinct hollow and radially symmetrical structure facilitates the actuator with fast photoresponsiveness and phototropic performance through retarding the heat conduction along the radial direction; 3) the MXene‐LCE soft tubular actuator simultaneously integrates sensing, actuation, and built‐in feedback loop, thus leading to a high light‐tracking accuracy and adaptive phototropism like a hollow stem of plants in nature. As a proof‐of‐concept demonstration, an adaptive photovoltaic system with solar energy harvesting maximization is illustrated. This work can provide insights into the development of artificial intelligent materials toward adaptive optoelectronics, intelligent soft robotics, and beyond.
Ultrasensitive Airflow Sensors Based on Suspended Carbon Nanotube Networks
Authors: Jiang Qinyuan , Li Run , Wang Fei , Shi Xiaofei , Chen Fengxiang , Huang Ya , Wang Baoshun , Zhang Wenshuo , Wu Xueke , Wei Fei , Zhang Rufan
Published: March 2022

High‐performance airflow sensors are in great demand in numerous fields but still face many challenges, such as slow response speed, low sensitivity, large detection threshold, and narrow sensing range. Carbon nanotubes (CNTs) exhibit many advantages in fabricating airflow sensors due to their nanoscale diameters, excellent mechanical and electrical properties, and so on. However, the intrinsic extraordinary properties of CNTs are not fully exhibited in previously reported CNT‐based airflow sensors due to the mixed structures of macroscale CNT assemblies. Herein, this article presents suspended CNT networks (SCNTNs) as high‐performance airflow sensors, which are self‐assembled by ultralong CNTs and short CNTs in a one‐step floating catalyst chemical vapor deposition process. The SCNTN‐based airflow sensors achieved a record‐breaking short response time of 0.021 s, a high sensitivity of 0.0124 s m−1, a small detection threshold of 0.11 m s−1, and a wide detection range of ≈0.11–5.51 m s−1, superior to most of the state‐of‐the‐art airflow sensors. To reveal the sensing mechanism, an acoustic response testing system and a mathematical model are developed. It is found that the airflow‐caused intertube stress change resulted in the resistance variation of SCNTNs.