bluuebunny/crossref_metadata_2025 huggingface dataset:
Highly Efficient and Environmentally Friendly Fabrication of Robust, Programmable, and Biocompatible Anisotropic, All‐Cellulose, Wrinkle‐Patterned Hydrogels for Cell Alignment
Authors: Zou Jie , Wu Shuangquan , Chen Jie , Lei Xiaojuan , Li Qihua , Yu Hui , Tang Shan , Ye Dongdong
Published: October 2019

Wrinkled hydrogels from biomass sources are potential structural biomaterials. However, for biorelated applications, engineering scalable, structure‐customized, robust, and biocompatible wrinkled hydrogels with highly oriented nanostructures and controllable intervals is still a challenge. A scalable biomass material, namely cellulose, is reported for customizing anisotropic, all‐cellulose, wrinkle‐patterned hydrogels (AWHs) through an ultrafast, auxiliary force, acid‐induced gradient dual‐crosslinking strategy. Direct immersion of a prestretched cellulose alkaline gel in acid and relaxation within seconds allow quick buildup of a consecutive through‐thickness modulus gradient with acid‐penetration‐directed dual‐crosslinking, confirmed by visual 3D Raman microscopy imaging, which drives the formation of self‐wrinkling structures. Moreover, guided by quantitative mechanics simulations, the structure of AWHs is found to exhibit programmable intervals and aligned nanostructures that differ between ridge and valley regions and can be controlled by tuning the prestretching strain and acid treatment time, and these AWHs successfully induce cell alignment. Thus, a new avenue is opened to fabricate polysaccharide‐derived, programmable, anisotropic, wrinkled hydrogels for use as biomedical materials via a bottom‐up method.
2D Electrocatalysts for Converting Earth‐Abundant Simple Molecules into Value‐Added Commodity Chemicals: Recent Progress and Perspectives
Authors: Yin Huajie , Dou Yuhai , Chen Shan , Zhu Zhengju , Liu Porun , Zhao Huijun
Published: October 2019

The electrocatalytic conversion of earth‐abundant simple molecules into value‐added commodity chemicals can transform current chemical production regimes with enormous socioeconomic and environmental benefits. For these applications, 2D electrocatalysts have emerged as a new class of high‐performance electrocatalyst with massive forward‐looking potential. Recent advances in 2D electrocatalysts are reviewed for emerging applications that utilize naturally existing H2O, N2, O2, Cl− (seawater) and CH4 (natural gas) as reactants for nitrogen reduction (N2 → NH3), two‐electron oxygen reduction (O2 → H2O2), chlorine evolution (Cl− → Cl2), and methane partial oxidation (CH4 → CH3OH) reactions to generate NH3, H2O2, Cl2, and CH3OH. The unique 2D features and effective approaches that take advantage of such features to create high‐performance 2D electrocatalysts are articulated with emphasis. To benefit the readers and expedite future progress, the challenges facing the future development of 2D electrocatalysts for each of the above reactions and the related perspectives are provided.
Impact of the Ink Formulation and Coating Speed on the Polymorphism and Morphology of a Solution‐Sheared Thin Film of a Blended Organic Semiconductor
Authors: Tamayo Adrián , Riera‐Galindo Sergi , Jones Andrew O. F. , Resel Roland , Mas‐Torrent Marta
Published: October 2019

Despite the recent encouraging advances in achieving high‐performance organic field effect transistors employing meniscus‐guided processing techniques compatible with roll‐to‐roll manufacturing, there is still a very limited knowledge about how all the coating parameters influence the thin film electrical characteristics. Here, the polymorphism and morphology of thin films of the organic semiconductor dibenzo‐tetrathiafulvalene blended with polystyrene deposited by bar‐assisted meniscus shearing (BAMS) are investigated in‐depth by modifying the coating speed and ink formulation. It is found that all these parameters significantly affect the crystallization process and the resulting thin film characteristics. Remarkably, pure polymorphs with optimized field‐effect mobilities can be achieved only within a narrow range of conditions. The precise control of the film morphology and crystal structure is of paramount importance in order to move toward real applications achieving high device‐to‐device reproducibility.
Understanding the Independent and Interdependent Role of Water and Oxidation on the Tribology of Ultrathin Molybdenum Disulfide (MoS2)
Authors: Arif Taib , Yadav Shwetank , Colas Guillaume , Singh Chandra Veer , Filleter Tobin
Published: October 2019

In this work, the tribological behavior of ultrathin MoS2 is investigated to understand the independent roles of water and oxidation. Water adsorption is identified as the primary interfacial mechanism for both SiO2/pristine‐MoS2 and SiO2/graphene interfaces, however, tribological behavior of pristine‐MoS2 is observed to be more sensitive to presence of water due to stronger MoS2–water interaction. Comparison of pristine‐MoS2 and oxidized‐MoS2 reveals that the oxidation of MoS2 significantly increases its friction and sensitivity to water by playing a more detrimental role. The specific effect of oxygen on friction via chemical interactions is studied in isolation through density functional theory simulations of a tip sliding on MoS2 basal planes and over edges before and after oxidation. The maximum change in energy, or energy barrier correlating with friction, as the tip moves across the surface, increases after oxidation by up to 66% for the basal plane and by 25% at the edge. Charge density analysis suggests that the more localized and nonuniform interfacial charge distribution on oxygen‐rich surfaces, as compared to pristine surfaces, leads to higher resistance to sliding. This confirms that oxygen presence alone increases friction and when coupled with the presence of water, both effects are additive in increasing friction.
Transcription‐Related Dynamics from Immune Disability into Endogenous Innovation
Authors: Zhang Yanna , Li Qian , Hou Panyan , Lu Yanan , Yang Huanhuan , Lin Xiaojuan , Su Chao , Wei Yuquan , Yang Xiulin , Yang Hanshuo , Zhao Xia , Chen Xiancheng
Published: October 2019

So far, thymus involution in adults is believed to be irreversible, and endogenous innovation for thymus‐related immunodeficiency remains to be an intractable puzzle. With the expectation of addressing this dilemma, human ovarian surface epithelium (OSE) has been reengineered as epithelial‐mesenchymal transition (EMT)‐tridimensional‐spheroid biologics (ETSB) using a dynamic EMT‐3D‐floating system along with 160 Gy X‐ray‐amelioration, which inoculates subcutaneously into aging rhesus and athymic Balb/cnu/nu mice. Herein, it is bioinformatically validated that ETSB can reset Clock/Arntl‐Per3/Tim molecule rhythm dynamics to re‐prime thymus residual (parathyroid or fatty‐like invalid vesicles yet no thymic architecture) to evolutionary transcription with overall cortex‐medulla endogenized by TECs undergoing MET/EMT reversion. Rhythm dynamics immediately resettles the bHLH‐LTβR‐NFκB‐RelA/B loop as a cascade to provoke the core immune microenvironment for multifunctional innovation of dynamic TCR orchestration, with harmonious naïve T‐subsets and TRECs renewals (P < 0.005). Subsequently, peripheral biological burden and tumor metastasis dynamics are addressed by innovative TCR‐defense/attack dynamics quickly (P < 0.005 vs Control), yet without autoimmune indication to hosts. Moreover, a functional blockade of core‐rhythm dynamics deeply impedes the endogenous innovation of invalid thymus residual. Thus this study may help pioneer a prospective strategy to innovate panoramic central‐peripheral immune microenvironments and defense dynamics for immune‐deficient/aging victims.
Recent Progress of Rare‐Earth Doped Upconversion Nanoparticles: Synthesis, Optimization, and Applications
Authors: Zhu Xiaohui , Zhang Jing , Liu Jinliang , Zhang Yong
Published: October 2019

Upconversion is a nonlinear optical phenomenon that involves the emission of high‐energy photons by sequential absorption of two or more low‐energy excitation photons. Due to their excellent physiochemical properties such as deep penetration depth, little damage to samples, and high chemical stability, upconversion nanoparticles (UCNPs) are extensively applied in bioimaging, biosensing, theranostic, and photochemical reactions. Here, recent achievements in the synthesis, optimization, and applications of UCNP‐based nanomaterials are reviewed. The state‐of‐the‐art approaches to synthesize UCNPs in the past few years are introduced first, followed by a summary of several strategies to optimize upconversion emissive properties and various applications of UCNPs. Lastly, the challenges and future perspectives of UCNPs are provided as a conclusion.
DNA‐Encoded Libraries: Aryl Fluorosulfonates as Versatile Electrophiles Enabling Facile On‐DNA Suzuki, Sonogashira, and Buchwald Reactions
Authors: Xu Hongtao , Ma Fei , Wang Nan , Hou Wei , Xiong Huan , Lu Fengping , Li Jie , Wang Shuyue , Ma Peixiang , Yang Guang , Lerner Richard A.
Published: October 2019

Using (hetero)aryl fluorosulfonates as versatile electrophiles, facile on‐DNA cross‐coupling reactions of Suzuki, Sonogashira, and Buchwald are reported here. Notably, all of these reactions show excellent functional group tolerance, mild reaction conditions (relative low temperature and open to air), rich heterocyclic coupling partners, and more importantly, DNA‐compatibility. Thus, these new reactions based on efficient formation of C(sp2)‐C(sp2), C(sp2)‐C(sp), and C(sp2)‐N bonds are highly amenable to synthesis of DNA‐encoded libraries with great molecular diversity.
Design and Construction of Sodium Polysulfides Defense System for Room‐Temperature Na–S Battery
Authors: Yang Tingting , Guo Bingshu , Du Wenyan , Aslam Muhammad Kashif , Tao Mengli , Zhong Wei , Chen Yuming , Bao Shu‐Juan , Zhang Xuan , Xu Maowen
Published: October 2019

Room‐temperature Na–S batteries are facing one of the most serious challenges of charge/discharge with long cycling stability due to the severe shuttle effect and volume expansion. Herein, a sodium polysulfides defense system is presented by designing and constructing the cathode‐separator double barriers. In this strategy, the hollow carbon spheres are decorated with MoS2 (HCS/MoS2) as the S carrier (S@HCS/MoS2). Meanwhile, the HCS/MoS2 composite is uniformly coated on the surface of the glass fiber as the separator. During the discharge process, the MoS2 can adsorb soluble polysulfides (NaPSs) intermediates and the hollow carbon spheres can improve the conductivity of S as well as act as the reservoir for electrolyte and NaPSs, inhibiting them from entering the anode to make Na deteriorate. As a result, the cathode‐separator group applied to room‐temperature Na–S battery can enable a capacity of ≈1309 mAh g−1 at 0.1 C and long cycling life up to 1000 cycles at 1 C. This study provides a novel and effective way to develop durable room‐temperature Na–S batteries.
Dynamic Profiling of Antitumor Activity of CAR T Cells Using Micropatterned Tumor Arrays
Authors: Wang Xiao , Scarfò Irene , Schmidts Andrea , Toner Mehmet , Maus Marcela V. , Irimia Daniel
Published: October 2019

Cancer immunotherapy based on the engineering of chimeric antigen receptors (CAR) on T cells has emerged as one of the most promising new therapies for patients with B‐cell malignancies. Preclinical assessments of essential CAR T cell functions such as trafficking and cytotoxicity are critical for accelerating the development of highly effective therapeutic candidates. However, current tools for evaluating CAR‐T functions lack sufficient precision. Here, a micropatterned tumor array (MiTA) is described that enables detailed and dynamic characterization of CAR T cell trafficking toward tumor‐cell islands and subsequent killing of tumor cells. It is shown that CAR T cells often merge into large clusters that envelop and kill the tumor cells with high efficiency. Significant differences are also measured between CAR T cells from different donors and between various CAR T cell constructs. Overall, the assay allows for multifaceted, dynamic, high‐content evaluation of CAR T trafficking, clustering, and killing and could eventually become a useful tool for immune‐oncology research and preclinical assessments of cell‐based immunotherapies.
Robust Amphiphobic Few‐Layer Black Phosphorus Nanosheet with Improved Stability
Authors: Liu Xiao , Bai Yunfei , Xu Jun , Xu Qingchi , Xiao Liangping , Sun Liping , Weng Jian , Zhao Yanli
Published: October 2019

Few‐layer black phosphorus (FL‐BP) has been intensively studied due to its attractive properties and great potential in electronic and optoelectronic applications. However, the intrinsic instability of FL‐BP greatly limits its practical application. In this study, the amphiphobic FL‐BP is achieved by functionalization of 1H,1H,2H,2H‐perfluorooctyltrichlorosilane (PFDTS) on the surface of FL‐BP. The obtained PFDTS coated FL‐BP (FL‐BP/PFDTS) demonstrates enhanced stability, which is not observed during significant degradation for 2 months in high moisture content environment (95% humidity). Particularly, attributing to the surface amphiphobicity, FL‐BP/PFDTS exhibits strong surface water repellency in the presence of oleic acid (as the contaminant), while other passivation coating layers (such as hydrophilic or hydrophobic coating) become hydrophilicity under such conditions. Owing to this advantage, the obtained FL‐BP/PFDTS demonstrates enhanced stability in high moisture content environment for 2 months, even though the surface is contaminated by oil liquid or other organic solvents (such as oleic acid, CH2Cl2, and N‐methyl‐2‐pyrrolidone). The passivation of FL‐BP by amphiphobic coating provides an effective approach for FL‐BP stabilization toward future applications.
Enhanced Stability of Li Metal Anodes by Synergetic Control of Nucleation and the Solid Electrolyte Interphase
Authors: Peng Zhe , Song Junhua , Huai Liyuan , Jia Haiping , Xiao Biwei , Zou Lianfeng , Zhu Guomin , Martinez Abraham , Roy Swadipta , Murugesan Vijayakumar , Lee Hongkyung , Ren Xiaodi , Li Qiuyan , Liu Bin , Li Xiaolin , Wang Deyu , Xu Wu , Zhang Ji‐Guang
Published: October 2019

Use of a protective coating on a lithium metal anode (LMA) is an effective approach to enhance its coulombic efficiency and cycling stability. Here, a facile approach to produce uniform silver nanoparticle‐decorated LMA for high‐performance Li metal batteries (LMBs) is reported. This effective treatment can lead to well‐controlled nucleation and the formation of a stable solid electrolyte interphase (SEI). Ag nanoparticles embedded in the surface of Li anodes induce uniform Li plating/stripping morphologies with reduced overpotential. More importantly, cross‐linked lithium fluoride‐rich interphase formed during Ag+ reduction enables a highly stable SEI layer. Based on the Ag‐LiF decorated anodes, LMBs with LiNi1/3Mn1/3Co1/3O2 cathode (≈1.8 mAh cm−2) can retain >80% capacity over 500 cycles. The similar approach can also be used to treat sodium metal anodes. Excellent stability (80% capacity retention in 10 000 cycles) is obtained for a Na||Na3V2(PO4)3 full cell using a Na‐Ag‐NaF/Na anode cycled in carbonate electrolyte. These results clearly indicate that synergetic control of the nucleation and SEI is an efficient approach to stabilize rechargeable metal batteries.
Correlated Migration Invokes Higher Na+‐Ion Conductivity in NaSICON‐Type Solid Electrolytes
Authors: Zhang Zhizhen , Zou Zheyi , Kaup Kavish , Xiao Ruijuan , Shi Siqi , Avdeev Maxim , Hu Yong‐Sheng , Wang Da , He Bing , Li Hong , Huang Xuejie , Nazar Linda F. , Chen Liquan
Published: October 2019

Na super ion conductor (NaSICON), Na1+nZr2SinP3–nO12 is considered one of the most promising solid electrolytes; however, the underlying mechanism governing ion transport is still not fully understood. Here, the existence of a previously unreported Na5 site in monoclinic Na3Zr2Si2PO12 is unveiled. It is revealed that Na+‐ions tend to migrate in a correlated mechanism, as suggested by a much lower energy barrier compared to the single‐ion migration barrier. Furthermore, computational work uncovers the origin of the improved conductivity in the NaSICON structure, that is, the enhanced correlated migration induced by increasing the Na+‐ion concentration. Systematic impedance studies on doped NaSICON materials bolster this finding. Significant improvements in both the bulk and total ion conductivity (e.g., σbulk = 4.0 mS cm−1, σtotal = 2.4 mS cm−1 at 25 °C) are achieved by increasing the Na content from 3.0 to 3.30–3.55 mol formula unit−1. These improvements stem from the enhanced correlated migration invoked by the increased Coulombic repulsions when more Na+‐ions populate the structure rather than solely from the increased mobile ion carrier concentration. The studies also verify a strategy to enhance ion conductivity, namely, pushing the cations into high energy sites to therefore lower the energy barrier for cation migration.
Tin Halide Perovskite (ASnX3) Solar Cells: A Comprehensive Guide toward the Highest Power Conversion Efficiency
Authors: Nasti Giuseppe , Abate Antonio
Published: October 2019

ASnX3 perovskite solar cells (Sn‐PSC) have the potential to deliver the most efficient solar cell technology with safe materials. In this review, a comprehensive introduction of the field is given, that is suitable for nonexperts, gradually leading the reader to a narrower and detailed analysis of the most recent and significant advances. A brief description is given of the leading alternatives for lead‐free PSC and the reasons for ASnX3 compounds' status as one of the most promising candidates are presented. The last part of the review focuses on the stabilization of ASnX3, which is the most compelling challenge to achieve the highest efficiency PSCs. The most promising approaches toward stable and efficient ASnX3 PSCs are identified and discussed.
Exploiting the Condensation Reactions of Acetophenone to Engineer Carbon‐Encapsulated Nb2O5 Nanocrystals for High‐Performance Li and Na Energy Storage Systems
Authors: Han Xianying , Russo Patrícia A. , Goubard‐Bretesché Nicolas , Patanè Salvatore , Santangelo Saveria , Zhang Rui , Pinna Nicola
Published: October 2019

Efficient synthetic methods to produce high‐performance electrode‐active materials are crucial for developing energy storage devices for large‐scale applications, such as hybrid supercapacitors (HSCs). Here, an effective approach to obtain controllable carbon‐encapsulated T‐Nb2O5 nanocrystals (NCs) is presented, based on the solvothermal treatment of NbCl5 in acetophenone. Two separate condensation reactions of acetophenone generate an intimate and homogeneous mixture of Nb2O5 particles and 1,3,5‐triphenylbenzene (TPB), which acts as a unique carbon precursor. The electrochemical performance of the resulting composites as anode electrode materials can be tuned by varying the Nb2O5/TPB ratio. Remarkable performances are achieved for Li‐ion and Na‐ion energy storage systems at high charge–discharge rates (specific capacities of ≈90 mAh g−1 at 100 C rate for lithium and ≈125 mAh g−1 at 20 C for sodium). High energy and power densities are also achieved with Li‐ and Na‐ion HSC devices constructed by using the Nb2O5/C composites as anode and activated carbon (YPF‐50) as cathode, demonstrating the excellent electrochemical properties of the materials synthesized with this approach.
Do young rhesus macaques know what others see?: A comparative developmental perspective
Authors: Arre Alyssa M. , Clark Chelsey S. , Santos Laurie R.
Published: October 2019

Humans undergo robust ontogenetic shifts in the theory of mind capabilities. Are these developmental changes unique to human development or are they shared with other closely related non‐human species? To explore this issue, we tested the development of the theory of mind capacities in a population of 236 infant and juvenile rhesus macaques (Macaca mulatta). Using a looking‐time method, we examined what developing monkeys know about others’ perceptions. Specifically, we tested whether younger monkeys predict that a person will reach for an object where she last saw it. Overall, we found a significant interaction between a monkey's age and performance on this task (p = .014). Juvenile monkeys (between two and 5 years of age) show a nonsignificant trend towards human infant‐like patterns of performance, looking longer during the unexpected condition as compared to the expected condition, though this difference is nonsignificant (p = .09). However, contrary to findings in human infants, infant rhesus macaques show a different trend. Infant monkeys on average look slightly longer on average during the expected condition than the unexpected condition, though this pattern was not significant (p = .06). Our developmental results in monkeys provide some hints about the development of the theory of mind capacities in non‐humans. First, young rhesus macaques appear to show some interest in the perception of other agents. Second, young rhesus seems able to make predictions based on the visual perspective of another agent, though the developmental pattern of this ability is not as clear nor as robust as in humans. As such, though an understanding of others’ perceptions is early‐emerging in human infants, it may require more experience interacting with other social agents in our non‐human relatives.
Tuning the Reactivity of Cyclopropenes from Living Ring‐Opening Metathesis Polymerization (ROMP) to Single‐Addition and Alternating ROMP
Authors: Su Jessica K. , Jin Zexin , Zhang Rui , Lu Gang , Liu Peng , Xia Yan
Published: October 2019

Ring‐opening metathesis polymerization (ROMP) has become one of the most important living polymerizations. Cyclopropenes (CPEs) remain underexplored for ROMP. Described here is that the simple swap of 1‐methyl to 1‐phenyl on 1‐(benzoyloxymethyl)CPEs elicited strikingly different modes of reactivity, switching from living polymerization to either selective single‐addition or living alternating ROMP. The distinct reactivity stems from differences in steric repulsions at the Ru alkylidene after CPE ring opening. Possible olefin or oxygen chelation from ring‐opened CPE substituents was also observed to significantly affect the rate of propagation. These results demonstrate the versatility of CPEs as a new class of monomers for ROMP, provide mechanistic insights for designing new monomers with rare single‐addition reactivity, and generate a new functionalizable alternating copolymer scaffold with controlled molecular weight and low dispersity.
A 3D Analogue of Phenyllithium: Solution‐Phase, Solid‐State, and Computational Study of the Lithiacarborane [Li−CB11H11]−
Authors: Dontha Rakesh , Zhu Tian‐Cheng , Shen Yunjun , Wörle Michael , Hong Xin , Duttwyler Simon
Published: October 2019

The lithiacarborane [Li−CB11H11]− plays a central role in carborane chemistry, as it is a key intermediate to achieve the selective functionalization of the monocarba‐closo‐dodecaborate [CB11H12]− for applications in various fields. Also, it is an organometallic species of fundamental interest because it represents a 3D analogue of phenyllithium featuring an exo C−Li bond in addition to the delocalized negative endo charge of the spherical cluster. For the first time, the elusive and highly reactive endo/exo formal dianion [CB11H11]2− has been isolated as its lithiate as well as zincate in pure form and fully characterized. DFT calculations corroborate the experimental findings and underscore the remarkably high reactivity of the lithiacarborane. Subsequent derivatizations demonstrate the relevance of its initial clean formation.
Free‐Standing CoO‐POM Janus‐like Ultrathin Nanosheets
Authors: Akram Bilal , Shi Wenxiong , Zhang Hao , Ullah Shaheed , Khurram Muhammad , Wang Xun
Published: October 2019

A single‐step solution‐based strategy is used to obtain 2D Janus‐like free‐standing ultrathin nanosheets build from two structurally unrelated species, that is, polyoxomolybdate (POM) and CoO. A controlled 2D‐to‐1D morphological transition was achieved by judiciously adjusting the solvent choice. These POM‐CoO heterostructures can behave as an ideal catalyst for the epoxidation of styrene. Benefiting from their amphiphilic nature, these 2D POM‐CoO nanosheets have also been used as surfactant to emulsify immiscible solvents. It is anticipated that structurally diverse polyoxometalates will offer promise as design elements for variety of structurally and compositionally tunable van der Waals integrated heteromaterials having a broad range applications.
Tuning the Electrochemical Performance of Titanium Carbide MXene by Controllable In Situ Anodic Oxidation
Authors: Tang Jun , Mathis Tyler S. , Kurra Narendra , Sarycheva Asia , Xiao Xu , Hedhili Mohamed N. , Jiang Qiu , Alshareef Husam N. , Xu Baomin , Pan Feng , Gogotsi Yury
Published: October 2019

MXenes are a class of two‐dimensional (2D) transition metal carbides, nitrides and carbonitrides that have shown promise for high‐rate pseudocapacitive energy storage. However, the effects that irreversible oxidation have on the surface chemistry and electrochemical properties of MXenes are still not understood. Here we report on a controlled anodic oxidation method which improves the rate performance of titanium carbide MXene (Ti3C2Tx, Tx refers to ‐F, =O, ‐Cl and ‐OH) electrodes in acidic electrolytes. The capacitance retention at 2000 mV s−1 (with respect to the lowest scan rate of 5 mV s−1) increases gradually from 38 % to 66 % by tuning the degree of anodic oxidation. At the same time, a loss in the redox behavior of Ti3C2Tx is evident at high anodic potentials after oxidation. Several analysis methods are employed to reveal changes in the structure and surface chemistry while simultaneously introducing defects, without compromising electrochemically active sites, are key factors for improving the rate performance of Ti3C2Tx. This study demonstrates improvement of the electrochemical performance of MXene electrodes by performing a controlled anodic oxidation.
Produktion von Wasserstoffperoxid durch photokatalytische Prozesse
Authors: Hou Huilin , Zeng Xiangkang , Zhang Xiwang
Published: October 2019

Wasserstoffperoxid (H2O2) steht verstärkt im Fokus der Forschung, da es nicht nur ein mildes und umweltschonendes Oxidationsmittel für die organische Synthese und Umweltsanierung ist, sondern auch ein aussichtsreicher flüssiger Brennstoff. Die Herstellung von H2O2 mittels Photokatalyse ist ein nachhaltiger Prozess, da dabei Wasser und Sauerstoff als Ausgangsmaterialien und Sonnenlicht als Energiequelle genutzt werden. In den letzten zehn Jahren wurden ermutigende Fortschritte in der Entwicklung von Prozessen zur photokatalytischen H2O2‐Produktion erzielt. In diesem Aufsatz bieten wir eine umfassende Zusammenfassung der Fortschritte auf dem Gebiet der photokatalytischen Produktion von H2O2. Nach einer kurzen Einleitung, in der die Vorteile der photokatalytischen H2O2‐Synthese herausgestellt werden, diskutieren wir die grundlegenden Prinzipien der Entwicklung effizienter photokatalytischer Systeme zur Produktion von H2O2 und stellen moderne Photokatalysatoren vor. Wir schließen den Aufsatz mit einer kurzen Zusammenfassung und einem Ausblick über die Fortschritte in diesem wachsenden Forschungsgebiet ab.
[3+2] Fragmentation of a Pentaphosphido Ligand by Cyanide
Authors: Hoidn Christian M. , Maier Thomas M. , Trabitsch Karolina , Weigand Jan J. , Wolf Robert
Published: October 2019

The activation of white phosphorus (P4) by transition‐metal complexes has been studied for several decades, but the functionalization and release of the resulting (organo)phosphorus ligands has rarely been achieved. Herein we describe the formation of rare diphosphan‐1‐ide anions from a P5ligand by treatment with cyanide. Cobalt diorganopentaphosphido complexes have been synthesized by a stepwise reaction sequence involving a low‐valent diimine cobalt complex, white phosphorus, and diorganochlorophosphanes. The reactions of the complexes with tetraalkylammonium or potassium cyanide afford a cyclotriphosphido cobaltate anion5and 1‐cyanodiphosphan‐1‐ide anions [R2PPCN]−(6‐R). The molecular structure of a related product7suggests a novel reaction mechanism, where coordination of the cyanide anion to the cobalt center induces a ligand rearrangement. This is followed by nucleophilic attack of a second cyanide anion at a phosphorus atom and release of the P2fragment.
A Photolabile Semiconducting Polymer Nanotransducer for Near‐Infrared Regulation of CRISPR/Cas9 Gene Editing
Authors: Lyu Yan , He Shasha , Li Jingchao , Jiang Yuyan , Sun He , Miao Yansong , Pu Kanyi
Published: October 2019

Noninvasive regulation of CRISPR/Cas9 gene editing is conducive to understanding of gene function and development of gene therapy; however, it remains challenging. Herein, a photolabile semiconducting polymer nanotransducer (pSPN) is synthesized to act as the gene vector to deliver CRISPR/Cas9 plasmids into cells and also as the photoregulator to remotely activate gene editing. pSPN comprises a 1O2‐generating backbone grafted with polyethylenimine brushes through 1O2‐cleavable linkers. NIR photoirradiation spontaneously triggers the cleavage of gene vectors from pSPN, resulting in the release of CRISPR/Cas9 plasmids and subsequently initiating gene editing. This system affords 15‐ and 1.8‐fold enhancement in repaired gene expression relative to the nonirradiated controls in living cells and mice, respectively. As this approach does not require any specific modifications on biomolecular components, pSPN represents the first generic nanotransducer for in vivo regulation of CRISPR/Cas9 gene editing.
Efficient Organocatalytic Dehydrogenation of Ammonia Borane
Authors: Hasenbeck Max , Becker Jonathan , Gellrich Urs
Published: October 2019

Dehydrogenation of ammonia borane by sterically encumbered pyridones as organocatalysts is reported. With 6‐tert‐butyl‐2‐thiopyridone as the catalyst, a turnover frequency (TOF) of 88 h−1 was achieved. Experimental mechanistic investigations, substantiated by DLPNO‐CCSD(T) computations, indicate a mechanistic scenario that commences with the protonation of a B−H bond by the mercaptopyridine form of the catalyst. The reactive intermediate formed by this initial protonation was observed by NMR spectroscopy and the molecular structure of a surrogate determined by SCXRD. An intramolecular proton transfer in this intermediate from the NH3 group to the pyridine ring with concomitant breaking of the S−B bond regenerates the thiopyridone and closes the catalytic cycle. This step can be described as an inorganic retro‐ene reaction.
Production of Hydrogen Peroxide by Photocatalytic Processes
Authors: Hou Huilin , Zeng Xiangkang , Zhang Xiwang
Published: October 2019

Hydrogen peroxide (H2O2) has received increasing attention because it is not only a mild and environmentally friendly oxidant for organic synthesis and environmental remediation but also a promising new liquid fuel. The production of H2O2 by photocatalysis is a sustainable process, since it uses water and oxygen as the source materials and solar light as the energy. Encouraging processes have been developed in the last decade for the photocatalytic production of H2O2. In this Review we summarize research progress in the development of processes for the photocatalytic production of H2O2. After a brief introduction emphasizing the superiorities of the photocatalytic generation of H2O2, the basic principles of establishing an efficient photocatalytic system for generating H2O2 are discussed, highlighting the advanced photocatalysts used. This Review is concluded by a brief summary and outlook for future advances in this emerging research field.
Synthesis and characterization of pH‐sensitive poly(acrylamide‐co‐methylenebisacrylamide‐co‐acrylic acid) hydrogel microspheres containing silica nanoparticles: Application in enhanced oil recovery processes
Authors: Jamali A. , Moghbeli M. R. , Ameli F. , Roayaie E. , Karambeigi M. S.
Published: October 2019

In this study, pH‐sensitive hydrogel microspheres consisted of acrylamide (AAm) and acrylic acid (AA) monomers, and silica nanoparticles (SNPs) were synthesized via inverse suspension polymerization. To find a proper formulation for synthesis of these microspheres, design of experiment was performed using the input parameters, such as stirring rate, AA/AAm ratio, and the amount of SNP content. Scanning electron microscopy micrographs indicated that mean size of the microspheres decreased by increasing the stirring rate and SNP content and by lowering the AA/AAm ratio. Moreover, morphological survey of the microparticles exhibited a spherical shape with smooth surface. Swelling behavior of the produced hydrogels was investigated in four different environments. The results showed that a decrease in temperature and an increase in salinity led to reduction of the equilibrium swelling ratio (SR) to some extent. Moreover, increasing the pH caused a drastic increment of the equilibrium SR. Response surface methodology approach was utilized to establish a functional relationship between the effective parameters for synthesis of hydrogels and their favorable SR. Finally, performance of the resultant hydrogels was visually examined in enhanced oil (EOR) recovery processes in two steps. The flooding test of the hydrogel spheres indicated 23% increase in oil recovery factor in comparison to water flooding. This observation revealed the potential efficiency of the synthesized hydrogels for EOR applications. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48491.

HIGHLIGHTS

Using inverse suspension method to synthesize spherical hydrogels containing nanosilica.

Investigation on the effects of temperature, water salinity, and pH on equilibrium swelling ratio of hydrogels.

Investigation on rheological characterization of the synthesized hydrogels by adding nanosilica.

Studying on the effect of synthesized hydrogels in macroscopic sweep efficiency using micromodels.

Application of the synthesized hydrogels for core‐flood tests and studying the oil recovery factor.
Influence of matrix viscosity on the dynamic mechanical performance of magnetorheological elastomers
Authors: Abdul Hadi Nur Haslina Nasirah , Ismail Hanafi , Abdullah Muhammad Khalil , Shuib Raa Khimi
Published: October 2019

Anisotropic magnetorheological elastomers (MREs) with different natural rubber matrix viscosities and industrial waste nickel zinc ferrite were prepared in order to assess the dynamic and mechanical performance of the materials. The curing characteristics of the anisotropic MREs were determined using a moving disk rheometer (MDR 2000). The loss tangent (tan δ) was measured through a parallel‐plate rheometer over a frequency range of 1─100 Hz (Hz) and a strain amplitude range of 0.1─6%. It was found that tan δ increased with increasing matrix viscosity over the range of frequency and strain amplitude explored. Furthermore, as the matrix viscosity increased, the height of the tan δ peak also increased and the glass transition temperature (Tg) valued shifted to a higher temperature. It was also found that tensile strength and elongation at break increased with increasing matrix viscosity. The SEM micrographs revealed that the columnar structures became longer and thicker with a decrease in matrix viscosity. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48492.
Influence of cornstarch on thermomechanical behavior of poly(vinyl) chloride bioplastics
Authors: Akram Nadia , Zia Khalid Mahmood , Saeed Muhammad , Usman Muhammad , Iqbal Shahzad Zafar , Shafi Amina , Khan Waheed Gul
Published: October 2019

The diverse and ubiquitous consumption of polymers urges the necessity to make these materials easily available. However, the excessively used petrochemical‐based polymers such as poly(vinyl) chloride (PVC) are nonbiodegradable, which is a motivation to modify it with “green” alternatives. In the present study, PVC (Mw = 48 000 g mol−1) has been incorporated with cornstarch (CS) to synthesize a series of 25 samples of bioplastics in addition to blank polymer samples. The films of five various thicknesses (0.1, 0.2, 0.3, 0.5, and 1.0 mm) have been synthesized using in situ polymerization. Each sample of pure PVC film and bioplastic has been induced with different concentrations of CS in the range of 1–5 wt %. The synthesized samples were subjected to the structural characterization by using Fourier transform infrared. Thermogravimetric analysis has demonstrated the three‐step degradation with the improved stability of 250 °C. The 3% concentration of CS has shown the optimum storage modulus (E′) of 1 660 MPa from dynamic mechanical analysis and Tan δ as 0.50. The swelling test performed using water has shown an induction of hydrophilicity in PVC up to 4%. CS‐induced bioplastics can be a potential ecofriendly alternative of conventional polymers. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48493.
Structure–mechanical property relationships in acrylate networks
Authors: Anastasio Rosaria , Cardinaels Ruth , Peters Gerrit W. M. , van Breemen Lambèrt C. A.
Published: October 2019

The objective of this work is to investigate the effect of the molecular mobility and resin formulation of UV‐curable acrylate systems on conversion and ultimate mechanical properties. Thin single‐layer films are produced from a series of nine mixtures of bisphenol A ethoxylate diacrylate, having different molecular weights (BisDAn = 2, BisDAn = 4, and a 50/50 mixture), with different amounts of tetraethylene glycol diacrylate (TEGDA) (0, 10, and 30 wt %). Fourier transform infrared analysis, tensile, and dynamic mechanical tests are carried out on UV post‐cured resins, and the results are correlated with the amount of TEGDA. A higher content of TEGDA gives rise to an increase in conversion and glass‐transition temperature. Tests on pure BisDAn = 2 and mixtures of BisDAn = 2 and BisDAn = 4 (BisDAn = 2 + 4) show that with increasing TEGDA content, the crosslink density increases. An increase in molecular weight of the acrylate monomer changes the final mechanical properties of UV‐cured products. A material having a rubber behavior is the result of this change. Next to UV post‐curing, the effect of thermal post‐curing is studied. The results show that thermal treatments affect the mechanical properties mainly if the polymer has a low crosslink density. Formulations highly loaded with TEGDA lead to polymers with high crosslink density, low network mobility, and consequently low mechanical properties if thermally treated. Correlations between, on the one hand, resin formulation and process conditions and, on the other hand, the final mechanical properties of UV‐cured systems are established allowing to optimize the structure–mechanical properties relationship in acrylate networks. © 2019 The Authors. Journal of Applied Polymer Science published by Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48498.
High gas permselectivity in ZIF‐302/polyimide self‐consistent mixed‐matrix membrane
Authors: Ghanem Akram S. , Ba‐Shammakh Mohamed , Usman Muhammad , Khan M. Faizan , Dafallah Hatim , Habib Mohamed A. M. , Al‐Maythalony Bassem A.
Published: October 2019

Zeolitic imidazolate framework‐302 (ZIF‐302) was incorporated within a polyimide (PI) matrix in order to develop a highly selective and permeable mixed‐matrix membrane (MMM) for gas separation processes. On the basis of varying fabrication procedures, two different MMMs were formed: a dense MMM (ZIF‐302/d‐PI) and a spongy, self‐consistent MMM (ZIF‐302/s‐PI). The spongy membrane was shown to have self‐consistent and disconnected pores with a reduction in overall membrane density. For ZIF‐302/d‐PI, a 1.2–1.5‐fold increase in the permeability of H2, O2, N2, CO2, and CH4 was observed when compared with the pure d‐PI membrane. For ZIF‐302/s‐PI, even better improvements (up to 19‐fold higher) in permeance were achieved with negligible effects on selectivity. The gas transport mechanism was then analyzed and showed a considerable enhancement of diffusion coefficients for ZIF‐302/s‐PI, while ideal gas pair selectivities for CO2/N2, H2/CH4, and H2/N2 were found to be 24.8, 42.3, and 62.6, respectively. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48513.
Swelling and rheological study of calcium phosphate filled bacterial cellulose‐based hydrogel scaffold
Authors: Basu Probal , Saha Nabanita , Saha Petr
Published: October 2019

This work focuses mainly about swelling and rheological properties of calcium phosphate filled bacterial cellulose (BC)‐based hydrogel scaffolds. Calcium phosphate is incorporated in the form of hydroxyapatite (HA) and β‐tricalcium phosphate (β‐TCP) in different ratios, that is, 00:00, 10:90, 20:80, 40:60, 50:50, and 60:40. These scaffolds are also comprised with polyvinylpyrrolidone (PVP), poly(ethylene glycol), agar, and glycerin; designated as “BC‐PVP” and “BC‐PVP‐β‐TCP/HA.” All the hydrogel scaffolds are showing the notable viscoelastic property at 28 and 37 °C temperatures. The degree of swelling is found significant in BC‐PVP‐β‐TCP/HA_50:50 scaffold and it is notably elastic at 37 °C after 5 min of swelling. However, after 60 min of swelling and at equilibrium swelling state, the elastic property of BC‐PVP‐β‐TCP/HA_20:80 is revealed the highest. Considering the degree of swelling and rheological properties, the BC‐PVP‐β‐TCP/HA_50:50 and BC‐PVP‐β‐TCP/HA_20:80 hydrogel scaffolds found suitable for their application in bone tissue engineering or bone tissue regeneration. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48522.
Starch‐based biodegradable hydrogel as seed coating for corn to improve early growth under water shortage
Authors: Pathak Vaibhav , Ambrose R. P. Kingsly
Published: October 2019

In this work, the effect of a biodegradable hydrogel as a seed coating on the early growth of corn seed was studied. The hydrogel was a succinate‐modified potato starch, and it had an equilibrium water absorption capacity of 260 g distilled water (DW)/g hydrogel. To coat corn seeds, the seeds were slightly wetted with an aqueous adhesive solution and then, in a closed container, mixed with a dry mixture of the modified starch (MS), bentonite, and talc. The damp coated seeds were air‐dried at 40 °C for 24 h. The seed emergence and postemergence growth of coated and uncoated seeds were assessed with respect to: (1) the amount of MS on coated seeds, and (2) the available water supply. At a water supply of 77% field capacity (FC), the coated seeds showed a significantly higher rate of emergence than uncoated seeds—however, only a minor improvement was observed at higher and lower water supply levels (92, 82, and 65% FC, respectively). This indicates that, while poor water absorption by hydrogel at low water supply (65% FC) has limited benefit to seed water availability, the effect of good water retention by the hydrogel at high water supply (92, 82% FC) appears redundant in the presence high soil water availability. After 14 and 21 days of growth, the dry weights of the corn plants' roots and shoots did not significantly differ between coated and uncoated seeds, which indicate that, after seed emergence and root development, the contribution of the hydrogel coating to the plant's water requirements becomes negligible. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48523.
Polypyrrole‐coated fiber‐scaffolds: Concurrent linear actuation and sensing
Authors: Harjo Madis , Zondaka Zane , Leemets Kaur , Järvekülg Martin , Tamm Tarmo , Kiefer Rudolf
Published: October 2019

Conducting polymers such as polypyrrole (PPy) can be deposited on various substrates to obtain conductive electroactive coatings. While electrochemical coatings are generally considered to be more effective, chemical coatings are more industrially suitable, especially on complex substrates. In this work, we aimed to explore the electro‐chemo‐mechanical response of conductive fiber scaffolds (CFS) prepared by coating PPy (chemically) on glucose‐gelatin nanofibre scaffolds. Electroactivity was readily observed in both aqueous and propylene carbonate solutions of lithium bis(trifluoromethanesulfonyl)imide, with mainly anion activity in both cases. A higher actuation response was achieved in the aqueous solutions with strain in the range of 1.2% and stress in the range of 3 kPa. Under both cyclic voltammetry and square wave potential steps driving, stable actuation for over 100 cycles was maintained. In addition to actuation, the CFS samples exhibited concurrent sensory properties, in sensing current densities and mechanical load. The PPy‐coated CFS material functioning as both an actuator and a sensor is envisaged to have potential applications in smart materials, soft robotics or e‐skin. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2020,137, 48533.
The Arylabialis Muscle of the Túngara Frog (Engystomops pustulosus)
Authors: Lagorio Amy D. , Grewal Kiran , Djuhari Shanise , Le Kevin , Mulhim Ramson , Gridi‐Papp Marcos
Published: October 2019

The current functional model of the anuran larynx includes four pairs of laryngeal muscles. Their contractions do not account, however, for the behavioral control of call complexity observed in male túngara frogs (Engystomops pustulosus), which optionally add a secondary note with distinct harmonic structure to their advertisement call. Examination of the túngara frog's laryngeal morphology through dissection and resin histology has revealed that the m. dilatator laryngis is divided into two separate bundles (superficial and deep). The superficial bundle closely matches the typical description of the m. dilatator laryngis and is well positioned to open the glottis. The deep bundle is exclusively innervated by the short laryngeal nerve and has an attachment to the fibrous mass, an internal laryngeal structure necessary for complex call production. This attachment indicates a separate role for the deep bundle in controlling the complexity of the call. Based on physical separation, exclusive attachments, distinct fiber orientation, exclusive innervation, and potential action, we recognize the deep bundle of the m. dilatator laryngis as a separate muscle. We also revalidate the name m. arylabialis which had been previously used to describe it. The split of the m. dilatator laryngis into two muscles results in a laryngeal innervation pattern that closely matches that of mammals. This study identified a novel laryngeal muscle in túngara frogs, a potential mechanism for the control of call complexity, and revealed new evidence of homologies between the laryngeal structures of amphibians and mammals. Anat Rec, 2019. © 2019 American Association for Anatomy Anat Rec, 303:1966–1976, 2020. © 2019 American Association for Anatomy