bluuebunny/crossref_metadata_2025 huggingface dataset:
High follicle‐stimulating hormone levels accelerate cartilage damage of knee osteoarthritis in postmenopausal women through the PI3K/AKT/NF‐κB pathway
Authors: Liu Yaping , Zhang Mengqi , Kong Dehuan , Wang Yan , Li Jian , Liu Wenjuan , Fu Yilin , Xu Jin
Published: September 2020

Osteoarthritis is the main cause of pain and disability in the elderly, with the most commonly affected joint being the knee. The prevalence of knee osteoarthritis (KOA) is significantly increased in postmenopausal women, although the mechanisms underlying KOA remain unclear. The present study aimed to investigate the association between follicle‐stimulating hormone (FSH) and postmenopausal women with KOA aged between 50 and > 70 years, as well as explore its underlying molecular mechanisms. Here, we report that the 50–60 years age group had the highest level of serum FSH. Compared to the low FSH group (< 40 mIU·mL−1) in the same age group, the high FSH group (> 40 mIU·mL−1) showed more severe cartilage damage. Furthermore, phosphorylated (p)‐phosphoinositide 3‐kinase (PI3K)/PI3K, p‐AKT/AKT and p‐nuclear factor kappa B (NF‐κB)/NF‐κB levels were significantly higher in the high FSH group compared to the low FSH group. Immunofluorescence experiments showed that FSH stimulation promoted the translocation of NF‐κB p65 into the nucleus, and decreased type II collagen and aggrecan in ATDC5 cells. Moreover, we used western blotting in ATDC5 cells to demonstrate that FSH decreased type II collagen and increased p‐PI3K/PI3K, p‐AKT/AKT, p‐NF‐κB/NF‐κB and p‐IKB/IKB in a concentration‐dependent manner. Our results suggest that increased FSH levels are associated with KOA for postmenopausal women aged 50–60 years and that high FSH levels might damage the cartilage tissues through the PI3K/AKT/NF‐κB pathway.
A Detailed Analysis of the Association between Urate Deposition and Erosions and Osteophytes in Gout
Authors: Pecherstorfer Caroline , Simon David , Unbehend Sara , Ellmann Hanna , Englbrecht Matthias , Hartmann Fabian , Figueiredo Camille , Hueber Axel , Haschka Judith , Kocijan Roland , Kleyer Arnd , Schett Georg , Rech Jürgen , Bayat Sara
Published: September 2020

Objective

To characterize in detail the structural bone changes associated with the deposition of monosodium urate crystals in the first metatarsophalangeal (MTP1) joint in patients with tophaceous gout.

Methods

Twenty patients with tophaceous gout and involvement of the MTP1 joint received both dual‐energy computed tomography (DECT) of the feet for the detection of tophi and high‐resolution peripheral quantitative computed tomography (HR‐pQCT) of the feet for the detection of bone erosions and osteophytes. Demographic and clinical data were collected. Tophi in DECT and erosions and osteophytes in HR‐pQCT were overlayed to define their anatomical relation. In addition, the feet of 20 sex‐ and age‐matched healthy controls were scanned to define the normal architecture of the MTP1 joint.

Results

Patients with gout had an increased number and extent of bone erosions and osteophytes compared with their healthy counterparts (erosions: 5 [0‐17] vs 1 [1‐2], 45.32 mm3 [7.26‐550.32] vs 0.82 mm3 [0.15‐21.8]; osteophytes: 10.5 [0‐26] vs 1 [0‐10], 4.93 mm [0.77‐7.19 mm] vs 0.93 mm [0.05‐7.61 mm]; all P < 0.001). The median tophi volume detected by DECT (0.12 mm3 [0.01‐2.53]) was highly associated with the total volume of erosions (r = 0.597, P = 0.005).

Conclusion

Gout patients show increased changes in their bone microarchitecture. The extent of uric acid deposition is positively correlated with the extent of bone loss at the MTP1 joint, highlighting the strong cohesion of inflammation and erosive changes.
Strain‐Hardening Behavior in an AA6060‐T6 Alloy Processed by Equal Channel Angular Pressing
Authors: Khelfa Tarek , Muñoz-Bolaños Jairo-Alberto , Li Fuguo , Cabrera-Marrero José-María , Khitouni Mohamed
Published: September 2020

Strain hardening is a useful mechanism for improving mechanical properties in materials. This study investigates the strain‐hardening behavior of an AA6060 alloy processed by equal channel angular pressing (ECAP) up to 12 passes. Analysis by electron backscattered diffraction (EBSD) shows that the average geometrically necessary dislocations (GNDs) density increases continually up to the fourth pass and then saturates at a value of ≈1.85 × 1014 m−2. Hollomon and Kocks–Mecking–Estrin (KME) analysis are used to investigate the strain‐hardening behavior of the resulting ultrafine‐grained alloy. Results indicate that the strain‐hardening capacity (HC) and the strain‐hardening exponent (n) of all deformed specimens are lower in comparison with the as‐received condition. Moreover, the strain‐hardening rate fluctuates with the ECAP passes. First, it increases from the first ECAP pass up to the fourth pass, then diminishes up to the fifth pass, and finally, it increases again with further deformation. The difference in the strain‐hardening behavior of the ECAPed AA6060 is examined in terms of the grain size effect. It is shown that the strain‐hardening curves change notably with diminishing the grain size. In addition, the KME model is used to depict the storage and annihilation of dislocations in the ECAPed specimens.
DNA‐Based Assembly of Multi‐Compartment Polymersome Networks
Authors: Luo Rongcong , Göpfrich Kerstin , Platzman Ilia , Spatz Joachim P.
Published: September 2020

Polymersomes exhibit increased stability and reduced permeability compared to conventional lipid‐based compartments—making them an increasingly popular choice for the bottom‐up construction of synthetic cells. Here, the contraction and expansion of functionalized polymersome networks controlled by cholesterol‐tagged deoxyribonucleic acid (DNA) is demonstrated. Different types of block‐copolymer membranes are systematically screened to design a general framework for the self‐assembly of cholesterol‐tagged DNA into the polymersome membrane. Since the developed approach is DNA‐based, the individual symmetric and asymmetric functionalization of the inner and outer polymersome leaflets is possible, a feature which makes it unique in terms of anchoring flexibility and efficiency. In addition to the variety with regard to functionalization, the choice of DNA and temperature can also be used to manipulate the polymersome contact line and the polymersome bending energy. Overall, the strategy potentially allows for the unprecedented possibility to precisely control the contraction and expansion of polymersome network assembly.
Optoelectronic Ferroelectric Domain‐Wall Memories Made from a Single Van Der Waals Ferroelectric
Authors: Xue Fei , He Xin , Liu Wenhao , Periyanagounder Dharmaraj , Zhang Chenhui , Chen Mingguang , Lin Chun‐Ho , Luo Linqu , Yengel Emre , Tung Vincent , Anthopoulos Thomas D. , Li Lain‐Jong , He Jr‐Hau , Zhang Xixiang
Published: September 2020

Due to the potential applications in optoelectronic memories, optical control of ferroelectric domain walls has emerged as an intriguing and important topic in modern solid‐state physics. However, its device implementation in a single ferroelectric, such as conventional BaTiO3 or PZT ceramics, still presents huge challenges in terms of the poor material conductivity and the energy mismatch between incident photons and ferroelectric switching. Here, using the generation of photocurrent in conductive α‐In2Se3 (a van der Waals ferroelectric) with a two‐terminal planar architecture, the first demonstration of optical‐engineered ferroelectric domain wall in a non‐volatile manner for optoelectronic memory application is reported. The α‐In2Se3 device exhibits a large optical‐writing and electrical‐erasing (on/off) ratio of >104, as well as multilevel current switching upon optical excitation. The narrow direct bandgap of the multilayer α‐In2Se3 ferroelectric endows the device with broadband optical‐writing wavelengths greater than 900 nm. In addition, photonic synapses with approximate linear weight updates for neuromorphic computing are also achieved in the ferroelectric devices. This work represents a breakthrough toward technological applications of ferroelectric nanodomain engineering by light.
Recent Advances in Self‐Powered Tribo‐/Piezoelectric Energy Harvesters: All‐In‐One Package for Future Smart Technologies
Authors: Karan Sumanta Kumar , Maiti Sandip , Lee Ju Hyun , Mishra Yogendra Kumar , Khatua Bhanu Bhusan , Kim Jin Kon
Published: September 2020

Electric devices has become a necessity in modern smart societies. The energy research community is continually exploring new solutions that can be employed as potential and reliable alternatives to satisfy future energy requirements in this context. Triboelectric/piezoelectric nanogenerators (TNGs/PNGs) are considered promising renewable energy harvesting technologies. TNGs/PNGs are gaining considerable research attention because of their advantages such as ease of fabrication, cost effectiveness, flexibility, lightweightness, long‐term‐durability, and excellent output performance. The TNGs/PNGs have enormous potential in harvesting energy from water waves (blue energy), airflow (wind energy), sound frequency (acoustic energy), vibrations/mechanical motions (such as body motions activities/sleeping), and in vivo body motions. These technologies are thus an “all‐in‐one package,” which is a unique selling point. The advantage of this technology is that all sources are natural and abundant. This paper provides a review of the potential use of PNGs/TNGs and includes a description of the rise of nanogenerators, their underlying mechanisms, different materials used, various models, possible applications, and future prospects. Stored energy can be used to develop smart/informative technologies (as ultrasensitive sensors) and self‐powered biomedical science. Owing to their considerable effects, these harvesting technologies are expected to dominate the future smart world.
Recent Advances of Emerging 2D MXene for Stable and Dendrite‐Free Metal Anodes
Authors: Wei Chuanliang , Tao Yuan , An Yongling , Tian Yuan , Zhang Yuchan , Feng Jinkui , Qian Yitai
Published: September 2020

Metal anodes based on a plating/stripping electrochemistry such as metallic Li, Na, K, Zn, Mg, Ca, Al, and Fe have attracted widespread attention over the past several years because of their high theoretical specific capacity, low electrochemical potential, and superior electronic conductivity. Metal anodes can be paired with cathodes to construct high‐energy‐density rechargeable metal batteries. However, inherent issues including large volume changes, uncontrollable growth of dangerous dendrites, and an unstable solid electrolyte interphase (SEI) hinder their further development. MXene as an emerging 2D material has shown great potential to address the inherent issues of metal anodes due to its 2D structure, abundant surface functional groups, and the ability to construct macroscopic architectures. To date, under the assistance of MXene, various strategies have been proposed to achieve stable and dendrite‐free metal anodes, such as MXene‐based host design, designing metalphilic MXene‐based substrates, modifying the metal surface with MXene, constructing MXene arrays, and decorating separators or electrolytes with MXene. Herein the applications and advances of MXene in stable and dendrite‐free metal anodes are carefully summarized and analyzed. Some perspectives and outlooks for future research are also proposed.
Versatile Tunability of the Metal Insulator Transition in (TiO2)m/(VO2)m Superlattices
Authors: Eres Gyula , Lee Shinbuhm , Nichols John , Sohn Changhee , Ok Jong Mok , Mazza Alessandro R. , Liu Chenze , Duscher Gerd , Lee Ho Nyung , McNally Daniel E. , Lu Xingye , Radovic Milan , Schmitt Thorsten
Published: September 2020

In contrast to perovskites that share only common corners of cation‐occupied octahedra, binary‐oxides in addition share edges and faces increasing the versatility for tuning the properties and functionality of reduced dimensionality systems of strongly correlated oxides. This approach for tuning the electronic structure is based on the ability of X‐ray spectroscopy methods to monitor the creation and transformation of occupied and unoccupied electronic states produced by interface coupling and lattice distortions. X‐ray diffraction reveals a new range of structural metastability in (TiO2)m/(VO2)m/TiO2(001) superlattices with m = 1, 3, 5, 20, 40, and electrical transport measurements show metal insulator transition (MIT) behavior typically associated with presence of high oxygen vacancy concentrations. However, X‐ray absorption spectroscopy (XAS) at the Ti and V L3,2‐edge and resonant inelastic X‐ray scattering (RIXS) at the Ti and V L3‐edge show no excitations characteristic of oxygen vacancy induced valance change in V and negligible intensities in Ti RIXS. The unexpected absence of oxygen vacancy related states in the X‐ray spectroscopy data suggests that superlattice fabrication is capable of suppressing oxygen vacancy formation while still affording a wide tunability range of the MIT. Achieving a wide range of MIT tunability while reducing or eliminating oxygen vacancies that are detrimental to electrical properties is highly desirable for technological applications of strongly correlated oxides.
Mechanically Compatible UV Photodetectors Based on Electrospun Free‐Standing Y3+‐Doped TiO2 Nanofibrous Membranes with Enhanced Flexibility
Authors: Li Ziliang , Joshi Mahesh K. , Chen Jiaxin , Zhang Zhiming , Li Ziqing , Fang Xiaosheng
Published: September 2020

Free‐standing flexible TiO2 nanofibrous membranes (NFMs) are highly desired for the construction of high‐performance wearable electronic devices. Nevertheless, tremendous challenges still exist due to the fragile characteristics of the polycrystalline TiO2 nanofibers. Here, ultra‐flexible TiO2 NFMs with robust fatigue strength and photoelectric properties are achieved via a simple element doping approach and the electrospinning technique. The 2 mol% Y3+‐doped NFM‐based photodetector exhibits excellent UV detecting performance at 3 V under 350 nm illumination, that is, responsivity of 4.5 A W−1, detectivity of 1.6 × 1011 Jones, and photocurrent of ≈1.6 µA. By effectively tuning the distribution and bonding state of Y3+ ions, the NFM shows significantly enhanced flexibility, where its original photocurrent is successfully maintained in various bending states (angle, radius, spiral state). Importantly, the resultant Y3+‐doped TiO2 NFM maintains ≈60% of its original photocurrent after bending at ≈145° for more than 20 000 times. A plausible prototype accounts for the effective bending deformation mechanism is proposed on the basis of the systematic analyses of the microstructural characteristics and the stress distribution achieved by using the finite element method. Finally, a wearable UV monitoring system that outputs real‐time photocurrent signals with different motion combinations of the remote‐controlled robot is demonstrated.
Prelithiation/Presodiation Techniques for Advanced Electrochemical Energy Storage Systems: Concepts, Applications, and Perspectives
Authors: Zou Kangyu , Deng Wentao , Cai Peng , Deng Xinglan , Wang Baowei , Liu Cheng , Li Jiayang , Hou Hongshuai , Zou Guoqiang , Ji Xiaobo
Published: September 2020

Prelithiation/presodiation techniques are regarded as indispensable procedures in electrochemical energy storage (EES) systems, which can effectively compensate irreversible capacity loss, raise working voltage, and increase Li+/Na+ concentration in the electrolyte. Various prelithiation/presodiation methods have been successfully exploited and a revolutionary impact has been achieved through the utilization of prelithiation/presodiation techniques. It is well acknowledged that different prelithiation/presodiation strategies possess their own specific mechanisms, which play vital roles in the advancement of EES systems. However, there has rarely been systematical reviews about the concept and progress of prelithiation/presodiation techniques. Hence, in this review various prelithiation/presodiation approaches are comprehensively analyzed and summarized, and in‐depth prelithiation/presodiation behaviors and other innovative applications (including optimization of separators, amelioration of binders, regeneration of spent batteries) are discussed in detail. Finally, suggested future directions of prelithiation/presodiation techniques are proposed and it is expected that these prelithiation/presodiation techniques could provide guidance for construction of advanced EES systems and propel the commercialization process with a focus on safety considerations.
2D Side‐Chain Engineered Asymmetric Acceptors Enabling Over 14% Efficiency and 75% Fill Factor Stable Organic Solar Cells
Authors: Cao Jinru , Wang Hongtao , Qu Shenya , Yu Jiangsheng , Yang Linqiang , Zhang Zhuohan , Du Fuqiang , Tang Weihua
Published: September 2020

The charge transport and morphology of active layers are key considerations for device performance and stability in organic solar cells (OSCs). Such properties can be fine‐tuned via elaborate molecular design of fused‐ring electron acceptors (FREAs), especially conjugation extension and side chain engineering. In this work, N‐functionalized conjugation is explored in the design of high‐efficient asymmetric FREAs. The twisting of N‐conjugated side chains from backbone endows three FREAs with similar energy levels and light absorptions (≈850 nm edge). Their blends with PBDB‐T exhibit high charge carrier mobility and ordered phase separation. Excitingly, IPT2F‐TT based OSCs yield a champion power conversion efficiency (PCE) of 14.02% with a fill factor (FF) of 75.06%, outperforming PBDB‐T devices with IPT2F‐Th (12.52%, 71.20%), IPT2F‐Ph (13.13%, 72.11%), and octylated IPT‐2F (13.70%, 71.50%). The PCE over 14% and FF over 75% are among the highest values for 2D FREAs OSCs reported to date. More importantly, outstanding thermal stability and light soaking stability are observed with PCE over 12% maintained after thermal or light aging for 100 h. This work demonstrates N‐conjugated FREAs design as an effective strategy to simultaneously improve the photovoltaic performance and device stability for the OSCs.
Excellent Excitonic Photovoltaic Effect in 2D CsPbBr3/CdS Heterostructures
Authors: Jin Bao , Zuo Nian , Hu Zhi‐Yi , Cui Wenjun , Wang Renyan , Van Tendeloo Gustaaf , Zhou Xing , Zhai Tianyou
Published: September 2020

P–n photovoltaic junctions are essential building blocks for optoelectronic devices for energy conversion. However, this photovoltaic efficiency has almost reached its theoretical limit. Here, a brand‐new excitonic photovoltaic effect in 2D CsPbBr3/CdS heterostructures is revealed. These heterostructures, synthesized by epitaxial growth, display a clean interface and a strong interlayer coupling. The excitonic photovoltaic effect is a function of both the built‐in equilibrium electrical potential energy and the chemical potential energy, which is generated by the significant concentration gradient of electrons and holes at the heterojunction interface. Excitingly, this novel photovoltaic effect results in a large open‐circuit voltage of 0.76 V and a high power conversion efficiency of 17.5%. In addition, high photodetection performance, including a high photoswitch ratio (Ilight/Idark) of 105 and a fast response rate of 23 µs are obtained. These findings provide a new platform for photovoltaic applications.
Highly Stable Lithium–Sulfur Batteries Achieved by a SnS/Porous Carbon Nanosheet Architecture Modified Celgard Separator
Authors: Li Zhi , Zhang Fan , Cao Tong , Tang Linbin , Xu Qunjie , Liu Haimei , Wang Yonggang
Published: September 2020

Lithium‐sulfur batteries (LSB) are one of the potential candidates for the next generation of electrochemical energy storage technology, due to their advantages of high theoretical capacity and high energy density. However, sluggish redox kinetics and the shuttle effect of polysulfides in the cyclic process lead to low sulfur utilization, severe polarization and poor cyclic stability. Herein, an SnS modified porous carbon nanosheet (SnS/PCNS) hybrid material is synthesized by a simple hydrothermal method and used to modify the separator of the LSB for the first time. Specifically, SnS/PCNS can not only adsorb polysulfides, but also enhance the redox reaction of polysulfides. In addition, SnS/PCNS are shown to promote rapid nucleation and uniform deposition of Li2S, and to improve the discharge capacity and heighten cyclic stability. The initial capacity is 1270 mAh g−1 at 0.5 C, the slow decay rate of each cycle is 0.039% at 1 C. When the sulfur loading is improved to 6 mg cm−2, the high reversible capacity is 955.3 mAh g−1 at 0.5 C. As a new polysulfides adsorbent, SnS provides a potential route for the commercialization of LSBs.
Nanoparticle‐Based Electrodes with High Charge Transfer Efficiency through Ligand Exchange Layer‐by‐Layer Assembly
Authors: Ko Yongmin , Kwon Cheong Hoon , Lee Seung Woo , Cho Jinhan
Published: September 2020

Organic‐ligand‐based solution processes of metal and transition metal oxide (TMO) nanoparticles (NPs) have been widely studied for the preparation of electrode materials with desired electrical and electrochemical properties for various energy devices. However, the ligands adsorbed on NPs have a significant effect on the intrinsic properties of materials, thus influencing the performance of bulk electrodes assembled by NPs for energy devices. To resolve these critical drawbacks, numerous approaches have focused on developing unique surface chemistry that can exchange bulky ligands with small ligands or remove bulky ligands from NPs after NP deposition. In particular, recent studies have reported that the ligand‐exchange‐induced layer‐by‐layer (LE‐LbL) assembly of NPs enables controlled assembly of NPs with the desired interparticle distance, and interfaces, dramatically improving the electrical/electrochemical performance of electrodes. This emerging approach also demonstrates that efficient surface ligand engineering can exploit the unique electrochemical properties of individual NPs and maximize the electrochemical performance of the resultant NP‐assembled electrodes through improved charge transfer efficiency. This report focuses on how LE‐LbL assembly can be effectively applied to NP‐based energy storage/conversion electrodes. First, the basic principles of the LE‐LbL approach are introduced and then recent progress on NP‐based energy electrodes prepared via the LE‐LbL approach is reviewed.
Shape Changing Robots: Bioinspiration, Simulation, and Physical Realization
Authors: Shah Dylan , Yang Bilige , Kriegman Sam , Levin Michael , Bongard Josh , Kramer‐Bottiglio Rebecca
Published: September 2020

One of the key differentiators between biological and artificial systems is the dynamic plasticity of living tissues, enabling adaptation to different environmental conditions, tasks, or damage by reconfiguring physical structure and behavioral control policies. Lack of dynamic plasticity is a significant limitation for artificial systems that must robustly operate in the natural world. Recently, researchers have begun to leverage insights from regenerating and metamorphosing organisms, designing robots capable of editing their own structure to more efficiently perform tasks under changing demands and creating new algorithms to control these changing anatomies. Here, an overview of the literature related to robots that change shape to enhance and expand their functionality is presented. Related grand challenges, including shape sensing, finding, and changing, which rely on innovations in multifunctional materials, distributed actuation and sensing, and somatic control to enable next‐generation shape changing robots are also discussed.
Multifunctional Polymer‐Regulated SnO2 Nanocrystals Enhance Interface Contact for Efficient and Stable Planar Perovskite Solar Cells
Authors: You Shuai , Zeng Haipeng , Ku Zhiliang , Wang Xiaoze , Wang Zhen , Rong Yaoguang , Zhao Yang , Zheng Xin , Luo Long , Li Lin , Zhang Shujing , Li Min , Gao Xingyu , Li Xiong
Published: September 2020

Perovskite solar cells (PSCs) have rapidly developed and achieved power conversion efficiencies of over 20% with diverse technical routes. Particularly, planar‐structured PSCs can be fabricated with low‐temperature (≤150 °C) solution‐based processes, which is energy efficient and compatible with flexible substrates. Here, the efficiency and stability of planar PSCs are enhanced by improving the interface contact between the SnO2 electron‐transport layer (ETL) and the perovskite layer. A biological polymer (heparin potassium, HP) is introduced to regulate the arrangement of SnO2 nanocrystals, and induce vertically aligned crystal growth of perovskites on top. Correspondingly, SnO2–HP‐based devices can demonstrate an average efficiency of 23.03% on rigid substrates with enhanced open‐circuit voltage (VOC) of 1.162 V and high reproducibility. Attributed to the strengthened interface binding, the devices obtain high operational stability, retaining 97% of their initial performance (power conversion efficiency, PCE > 22%) after 1000 h operation at their maximum power point under 1 sun illumination. Besides, the HP‐modified SnO2 ETL exhibits promising potential for application in flexible and large‐area devices.
A Narrow‐Bandgap n‐Type Polymer with an Acceptor–Acceptor Backbone Enabling Efficient All‐Polymer Solar Cells
Authors: Sun Huiliang , Yu Han , Shi Yongqiang , Yu Jianwei , Peng Zhongxiang , Zhang Xianhe , Liu Bin , Wang Junwei , Singh Ranbir , Lee Jaewon , Li Yongchun , Wei Zixiang , Liao Qiaogan , Kan Zhipeng , Ye Long , Yan He , Gao Feng , Guo Xugang
Published: September 2020

Narrow‐bandgap polymer semiconductors are essential for advancing the development of organic solar cells. Here, a new narrow‐bandgap polymer acceptor L14, featuring an acceptor–acceptor (A–A) type backbone, is synthesized by copolymerizing a dibrominated fused‐ring electron acceptor (FREA) with distannylated bithiophene imide. Combining the advantages of both the FREA and the A–A polymer, L14 not only shows a narrow bandgap and high absorption coefficient, but also low‐lying frontier molecular orbital (FMO) levels. Such FMO levels yield improved electron transfer character, but unexpectedly, without sacrificing open‐circuit voltage (Voc), which is attributed to a small nonradiative recombination loss (Eloss,nr) of 0.22 eV. Benefiting from the improved photocurrent along with the high fill factor and Voc, an excellent efficiency of 14.3% is achieved, which is among the highest values for all‐polymer solar cells (all‐PSCs). The results demonstrate the superiority of narrow‐bandgap A–A type polymers for improving all‐PSC performance and pave a way toward developing high‐performance polymer acceptors for all‐PSCs.
Tunable Piezoelectricity of Multifunctional Boron Nitride Nanotube/Poly(dimethylsiloxane) Stretchable Composites
Authors: Snapp Peter , Cho Chullhee , Lee Dongwon , Haque Md Farhadul , Nam SungWoo , Park Cheol
Published: September 2020

Boron nitride nanotubes (BNNT) uniformly dispersed in stretchable materials, such as poly(dimethylsiloxane) (PDMS), could create the next generation of composites with augmented mechanical, thermal, and piezoelectric characteristics. This work reports tunable piezoelectricity of multifunctional BNNT/PDMS stretchable composites prepared via co‐solvent blending with tetrahydrofuran (THF) to disperse BNNTs in PDMS while avoiding sonication or functionalization. The resultant stretchable BNNT/PDMS composites demonstrate augmented Young's modulus (200% increase at 9 wt% BNNT) and thermal conductivity (120% increase at 9 wt% BNNT) without losing stretchability. Furthermore, BNNT/PDMS composites demonstrate piezoelectric responses that are linearly proportional to BNNT wt%, achieving a piezoelectric constant (|d33|) of 18 pmV−1 at 9 wt% BNNT without poling, which is competitive with commercial piezoelectric polymers. Uniquely, BNNT/PDMS accommodates tensile strains up to 60% without plastic deformation by aligning BNNTs, which enhances the composites’ piezoelectric response approximately five times. Finally, the combined stretchable and piezoelectric nature of the composite was exploited to produce a vibration sensor sensitive to low‐frequency (≈1 kHz) excitation. This is the first demonstration of multifunctional, stretchable BNNT/PDMS composites with enhanced mechanical strength and thermal conductivity and furthermore tunable piezoelectric response by varying BNNT wt% and applied strain, permitting applications in soft actuators and vibration sensors.
Photoinitiated Transformation of Nanocrystal Superlattice Polymorphs Assembled at a Fluid Interface
Authors: Gao Yingjie , Huang Jen‐Yu , Balazs Daniel M. , Xu Yuanze , Hanrath Tobias
Published: September 2020

Directing the assembly of nanoscale building blocks into programmable superstructures is of broad scientific and technological interest. Advances in nanocrystal self‐assembly at fluid interfaces are combined with digital light processing to demonstrate that how the extent and spatial region of superlattice structure transformation can be controlled. It is shown that the addition of a photoacid generator to the fluid subphase provides new experimental degrees of freedom to modulate the dynamic equilibrium of ligands bound to the colloidal nanocrystal surface. Within the photoexposed regions, the nanocrystal ligand coverage is reduced which impacts the interactions between proximate nanocrystals and drives the transformation from a sixfold to a fourfold symmetric superlattice. Structural analysis is presented from transmission electron microscopy and chemical analysis is presented from infrared spectroscopy to establish the relationship between superlattice structure and ligand coverage. Beyond new insights understanding of and control over deprotection of colloidal nanocrystals at fluid interfaces, the processing method described in this work presents new opportunities to create nanocrystal assemblies with spatially programmable structures.
Poly‐ε‐Lysine or Mel4 Antimicrobial Surface Modification on a Novel Peptide Hydrogel Bandage Contact Lens
Authors: Lace Rebecca , Doherty Kyle G. , Dutta Debarun , Willcox Mark D. P. , Williams Rachel L.
Published: September 2020

Microbial keratitis (MK) is a serious issue in many countries and is often caused by contact lens wear. Antimicrobial peptides (AMPs) are a potentially useful tool for creating antimicrobial surfaces in light of increasing antibiotic resistance. Poly‐ε‐lysine (pεK) is an AMP that has been used extensively as a food preservative and Mel4 has recently been synthesized and studied as an antimicrobial coating for contact lenses. A hydrogel synthesized of pεK cross‐linked with biscarboxylic acids provides a potential lens material which has many surface free amines, that can be subsequently used to attach additional AMPs, creating an antimicrobial lens. The aim of this study is to investigate pεK hydrogels against a clinical strain of Pseudomonas aeruginosa (P. aeruginosa) for preventing or treating MK. Covalent attachment of AMPs is investigated and confirmed by fluorescently tagged peptides. Bound pεK effectively reduces the number of adherent P. aeruginosa in vitro (>3 log). In ex vivo studies positive antimicrobial activity is observed on bare pεK hydrogels and those with additionally bound pεK or Mel4; lenses allow the maintenance of the corneal epithelium. A pεK hydrogel contact lens with additional AMPs can be a therapeutic tool to reduce the incidence of MK.
3D Printing of Core–Shell Capsule Composites for Post‐Reactive and Damage Sensing Applications
Authors: Rupp Harald , Binder Wolfgang H.
Published: September 2020

3D printing of multicomponent materials as an advantageous method over traditional mold casting methods is demonstrated, developing small core–shell capsule composites fabricated by a two‐step 3D printing process. Using a two‐print‐head system (fused deposition modeling extruder and a liquid inkjet print head), micro‐sized capsules are manufactured in sizes ranging from 100 to 800 µm. The thermoplastic polymer poly(ε‐caprolactone) (PCL) is chosen as matrix/shell material due to its optimal interaction with the embedded hydrophobic liquids. First, the core–shell capsules are printed with model liquids and pure PCL to optimize the printing parameters and to ensure fully enclosed capsules inside the polymer. As a proof of concept, novel “click” reaction systems, used in self‐healing and stress‐detection applications, are manufactured in which PCL composites with nano‐ and micro‐fillers are combined with reactive, encapsulated liquids. The so generated 3D printed core–shell capsule composite can be used for post‐printing reactions and damage sensing when combined with a fluorogenic dye.
Propargylic Alcohols as Coupling Partners in Transition‐Metal‐Catalyzed Arene C−H Activation
Authors: Kumar Gadi Ranjith , Rajesh Manda , Lin Shuimu , Liu Shouping
Published: September 2020

Transition‐metal‐catalyzed site selective arene C−H bond activation concomitant functionalization with various coupling partners gain magnificent attraction in synthetic organic chemistry as complementary to traditional transformations. Mechanistically, these C−H functionalization approaches involve directing group assisted concerted metalation‐deprotonation (CMD), migratory insertion, and reductive elimination sequences. In this realm, diverse categories of coupling partners were employed as C−H functionalization buddies. Particularly alkynes gain enormous attention as annulating agents. These units coordinates with metalcycle through π‐interaction produce annulation outcomes in a straightforward manner. Very recently, propargylic alcohols were appointed as valuable archetypes in arene C−H activation armoury, as they have shown regio‐ and chemoselective migratory insertion into primary metalcycle species via hydroxy chelation. The influential regioselectivity was drawn by dual coordination of metal complexes with the pendent directing group and a propargylic hydroxyl group. In this review, we focused on annulations and functionalization of arenes and propargylic alcohols, which afford intricate cycles as well as complex acyclic motifs in a trouble‐free manner. We categorized these transformations based on number of atoms of propargylic alcohols involved in annulation along with some addition reactions. We anticipate to pave a way towards enhanced endeavours for discovering novel reaction avenues.

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One‐Dimensional π–d Conjugated Coordination Polymer for Electrochromic Energy Storage Device with Exceptionally High Performance
Authors: Cai Guofa , Cui Peng , Shi Wenxiong , Morris Samuel , Lou Shi Nee , Chen Jingwei , Ciou Jing‐Hao , Paidi Vinod K , Lee Kug‐Seung , Li Shuzhou , Lee Pooi See
Published: September 2020

The rational design of previously unidentified materials that could realize excellent electrochemical‐controlled optical and charge storage properties simultaneously, are especially desirable and useful for fabricating smart multifunctional devices. Here, a facile synthesis of a 1D π–d conjugated coordination polymer (Ni‐BTA) is reported, consisting of metal (Ni)‐containing nodes and organic linkers (1,2,4,5‐benzenetetramine), which could be easily grown on various substrates via a scalable chemical bath deposition method. The resulting Ni‐BTA film exhibits superior performances for both electrochromic and energy storage functions, such as large optical modulation (61.3%), high coloration efficiency (223.6 cm2 C−1), and high gravimetric capacity (168.1 mAh g−1). In particular, the Ni‐BTA film can maintain its electrochemical recharge‐ability and electrochromic properties even after 10 000 electrochemical cycles demonstrating excellent durability. Moreover, a smart energy storage indicator is demonstrated in which the energy storage states can be visually recognized in real time. The excellent electrochromic and charge storage performances of Ni‐BTA films present a great promise for Ni‐BTA nanowires to be used as practical electrode materials in various applications such as electrochromic devices, energy storage cells, and multifunctional smart windows.
Teff [Eragrostis tef (Zucc.)] rainfed yield response to planting method, seeding density, and row spacing
Authors: Mihretie Fekremariam , Tsunekawa Atsushi , Bitew Yayeh , Chakelie Gobezie , Derebe Bitwoded , Getahun Wudu , Beshir Omer , Tadesse Zelalem , Asfaw Mitiku
Published: September 2020

Teff [Eragrostis tef (Zucc.)] grain yield is low due to lack of improved management practices. We evaluated grain yield and cost of planting methods (broadcast, row, and transplanting), row spacing (10, 15, 20, 25, and 30 cm), and seeding densities (2.5, 5.0, 7.5, 10, 15, 20, and 25 kg ha−1) for teff in the 2012 and 2013 cropping seasons at the Adet Agricultural Research Center farm in northwest Ethiopia. Transplanting (1,675 kg ha−1) resulted in 34 and 75% greater grain yield (P < .05) than row (1,247 kg ha−1) and broadcast planting (958 kg ha−1), respectively. Row planting gave greater (30%) grain yield than broadcasting. Seeding density did not significantly influence grain yield in broadcast or row planting. Row spacing significantly influenced grain yield under row planting but did not significantly influence grain yield under transplanting. Regression analysis indicated grain yield increased as seeding density increased from 2.5 to 10 kg ha−1, then declined at greater seeding densities for both broadcast and row planting. Grain yield declined sharply as row spacing increased from 15 to 30 cm for both transplanting and row planting. Partial‐budget analysis showed that although teff transplanting gave the greatest grain yield, it was not economical due to low straw (biomass) yield and high cost of labor. Row planting at a spacing from 10 to 15 cm at 15 kg seed ha−1 was the most economically effective teff production method, with a net benefit of $1,640 ha−1.
Postoperative pancreatic fistula after gastrectomy for gastric cancer
Authors: Washio Marie , Yamashita Keishi , Niihara Masahiro , Hosoda Kei , Hiki Naoki
Published: September 2020

Postoperative pancreatic fistula is one of the most severe complications after gastric cancer surgery, and can cause critical patient conditions leading to surgery‐related death. Fortunately, the incidence of postoperative pancreatic fistula after gastrectomy seems to be decreasing with changes in operative procedures. The rate was reported at about 30% after open gastrectomy with Appleby's method in 1997, but lately has improved below 1% for robotic gastrectomy in 2019. For the diagnosis of postoperative pancreatic fistula, drain amylase concentration has been demonstrated to be beneficial and some reports have proposed the optimal cut‐off values of drain amylase to predict major postoperative pancreatic fistula. There have been many reports identifying risk factors for postoperative pancreatic fistula, including overweight patients, pancreatic anatomy, blunt trauma from compression of the pancreas, and thermal injuries caused by the continuous use of energy devices. And importantly, laparoscopic gastrectomy has been shown to be more often associated with postoperative pancreatic fistula than open gastrectomy in the prospective national clinical database in Japan. Hence, further sophistication of surgical techniques to reduce pancreas compression would have great promise in reducing postoperative pancreatic fistula after laparoscopic gastrectomy.
Injuries during the first hour at work in the U.S. mining industry
Authors: De Sudeshna , Almberg Kirsten S. , Cohen Robert A. , Friedman Lee S.
Published: September 2020

Background

The first hour of a shift in a mine is characterized by a large movement of miners from incoming and outgoing shifts, in addition to safety and maintenance checks of mining equipment. These activities rely on communication to ensure a safe transition between shifts. This study aims to identify risk factors for injury among miners during the first hour of a work shift and to characterize injury outcomes.

Methods

Data from U.S. Mine Safety and Health Administration Part 50 reports, 1983–2015, were used to identify injuries occurring within the first hour of a shift. Multivariable logistic regression was used to evaluate predictors of injuries occurring during the first shift‐hour and to assess the outcome of these injuries.

Results

Out of the 545,537 cases included in the analysis, 16,446 injuries occurred during the first hour of a shift. Risk factors associated with these injuries included being female, being older, working on Sunday and Monday, having an irregular shift start, working night shifts, employed in surface mining operations, and mine operations with <200 employees, and mechanisms of injury related to falls, movement of equipment and personnel, and being struck by or caught between boxes and containers. Injurious incidents occurring during the first hour of work were associated with mass injury events involving five or more workers (aOR = 3.58; 95% CI: 2.77, 4.64).

Conclusions

Although injury rates were substantially lower during the first hour of work compared to all other work hours, this study identified risk factors and mechanisms of injury that are highly preventable during the first hour of work.
Etiological diagnosis in limb reduction defects and the number of affected limbs: A population‐based study in the Northern Netherlands
Authors: Bergman Jorieke E. H. , Löhner Katharina , van der Sluis Corry K. , Rump Patrick , de Walle Hermien E. K.
Published: September 2020

Limb reduction defects (LRDs) that affect multiple limbs are considered to be more often heritable, but only few studies have substantiated this. We aimed to investigate if an etiological diagnosis (genetic disorder or clinically recognizable disorder) is more likely to be made when multiple limbs are affected compared to when only one limb is affected. We used data from EUROCAT Northern Netherlands and included 391 fetuses and children with LRDs born in 1981–2017. Cases were classified as having a transverse, longitudinal (preaxial/postaxial/central/mixed), intercalary, or complex LRD of one or more limbs and as having an isolated LRD or multiple congenital anomalies (MCA). We calculated the probability of obtaining an etiological diagnosis in cases with multiple affected limbs versus one affected limb using relative risk (RR) scores and Fisher's exact test. We showed that an etiological diagnosis was made three times more often when an LRD occurred in multiple limbs compared to when it occurred in one limb (RR 2.9, 95% CI 2.2–3.8, p < 0.001). No genetic disorders were found in isolated cases with only one affected limb, whereas a genetic disorder was identified in 16% of MCA cases with one affected limb. A clinically recognizable disorder was found in 47% of MCA cases with one affected limb. Genetic counseling rates were similar. We conclude that reduction defects of multiple limbs are indeed more often heritable. Genetic testing seems less useful in isolated cases with one affected limb, but is warranted in MCA cases with one affected limb.
Mit der nächsten Generation von Zink‐Bisguanidin‐Polymerisationskatalysatoren zu hochkristallinen, biologisch abbaubaren Polyestern
Authors: Hermann Alina , Hill Stephen , Metz Angela , Heck Joshua , Hoffmann Alexander , Hartmann Laura , Herres‐Pawlis Sonja
Published: September 2020

Polylactid und Polycaprolacton sind biologisch abbaubare Polymere, die durch metallkatalysierte Ringöffnungspolymerisation hergestellt werden. Für einen nachhaltigen Lebenszyklus dieser Polymere ist es wichtig, den industriell verwendeten zytotoxischen Katalysator [Sn(Oct)2] durch ungiftige Alternativen zu ersetzen. Wir berichten hier über den schnellsten robusten Katalysator in der Polymerisation von Lactid und ϵ‐Caprolacton. Dieser Zink‐Guanidin‐Katalysator kann unaufgereinigtes technisches rac‐Lactid und ϵ‐Caprolacton in der Schmelze bei verschiedenen [M]/[I]‐Verhältnissen mit schnellen Geschwindigkeitskonstanten, hohen Molmassen und hohen Umsätzen in kurzer Zeit polymerisieren, was zu farblosem, transparentem Polymer führt. Darüber hinaus besitzt durch diesen Komplex hergestelltes Polylactid und Polycaprolacton vorteilhafte hohe Kristallinitäten. Tatsächlich weist das erhaltene Polylactid aufgrund eines höheren Kristallinitätsgrades ein robusteres Abbauprofil auf als sein Sn(Oct)2‐katalysiertes Äquivalent.
Hydroxylamin‐abgeleitetes Reagenz als duales Oxidationsmittel und Aminogruppendonor für die eisenkatalysierte Herstellung von ungeschützten Sulfinamiden aus Thiolen
Authors: Chatterjee Sayanti , Makai Szabolcs , Morandi Bill
Published: September 2020

Es wurde eine eisenkatalysierte Reaktion für die selektive Umwandlung von Thiolen (‐SH) in Sulfinamide (‐SONH2) durch direkte Übertragung von ‐O und freien ‐NH2‐Gruppen entwickelt. Die Reaktion läuft unter milden Bedingungen unter Verwendung eines luftstabilen, von Hydroxylamin abgeleiteten Reagenz ab, weist eine breite Toleranz gegenüber funktionellen Gruppen auf, ist skalierbar und verläuft ohne die Verwendung eines Edelmetallkatalysators oder eines zusätzlichen Oxidationsmittels. Diese neuartige, praktische Reaktion führt zur Bildung von zwei verschiedenen neuen Bindungen (S=O und S−N) in einem einzigen Schritt, um chemoselektiv wertvolle, ungeschützte Sulfinamidprodukte zu bilden. Vorläufige mechanistische Studien implizieren die Rolle des alkoholischen Lösungsmittels als Sauerstoffatomdonor.
Gold‐Catalyzed C−H Functionalization Polycondensation for the Synthesis of Aromatic Polymers
Authors: King Eric R. , Tropp Joshua , Eedugurala Naresh , Gonce Lauren E. , Stanciu Sonia , Azoulay Jason D.
Published: September 2020

Homogeneous gold (Au) complexes have demonstrated tremendous utility in modern organic chemistry; however, their application for the synthesis of polymers remains rare. Herein, we demonstrate the first catalytic application of Au complexes toward the polycondensation of alkyne‐containing comonomers and heteroarene nucleophiles. Polymerization occurs through successive intermolecular hydroarylation reactions to produce high molecular weight aromatic copolymers with 1,1‐disubstituted alkene backbone linkages. Clear correlations between the rate and degree of polymerization (DP) were established based on catalyst structure and counterion pairing, thus enabling polymerization reactions that proceeded with remarkable efficiency, high reactivity, and exceptional DPs. The reactivity is broad in scope, enabling the copolymerization of highly functionalized aromatic and aliphatic monomers. These results highlight the untapped utility of Au catalysis in providing access to new macromolecular constructs.
Three‐dimensionally cross‐linked styrene‐methyl methacrylate‐divinyl benzene terpolymer networks for organic solvents and crude oil absorption
Authors: Krishnan Mohan Raj , Aldawsari Yazeed Fahad , Alsharaeh Edreese H.
Published: September 2020

The present study reports, high‐performance polymer absorbents for crude oil and organic solvents based on 3D cross‐linked polystyrene‐polymethyl methacrylate/divinyl benzene (PS‐PMMA/DVB). The preparation of the 3D cross‐linked polymer absorbents has been carried out by bulk polymerization method using styrene (S) and methyl methacrylate (MMA) monomers in the presence of DVB with azobisisobutyronitrile as an initiator. The prepared cross‐linked polymer absorbents were characterized by Fourier transform infrared spectroscopy, thermogravimetric and differential scanning calorimetry, and dynamic mechanical analyses. The absorption kinetics, thermodynamics of the absorption process as well as the recyclability of the cross‐linked polymer absorbents were investigated in detail. The developed 3D cross‐linked PS‐PMMA/DVB absorbents have demonstrated excellent absorption capacities for both organic solvents and crude oil. For instance, the developed polymer absorbent (PS‐PMMA/DVB [1 wt%]) shows a maximum absorption capacity of 12 g/g for chloroform, 6 g/g for tetrahydrofuran, and 3 g/g for crude oil. The absorption capacities by the polymer absorbents show a direct relationship with the polarity of the solvents. Moreover, the change of absorption capacity after several repeated cycles of absorption/desorption was only marginal. The demonstrated absorption capacities and the excellent recyclability make polymer absorbents as potential candidates for the oilfield applications and produced water treatments.