bluuebunny/crossref_metadata_2025 huggingface dataset:
Resumption of donor-origin spermatogenesis in senescent goldfish Carassius auratus (Linnaeus, 1758) following spermatogonial cell therapy
Authors: Majhi Sullip K. , Chowdhury Mog , Kumar Santosh , Singh Rajeev K. , Mohindra Vindhya , Lal Kuldeep K.
Published: August 2020

Stem cell research has come into prominence because of its applications in assisted reproductive technology and the treatment of deadly diseases. In teleost fishes, spermatogonial stem cells have been effectively used to produce surrogate gametes and progeny through germ cell transplantation technique. The present study is the first report of an innovative application of stem cell therapy in fish species for revitalising the reproductive competence of senescent individuals. Senescent male goldfish, Carassius auratus, approximately 10 years of age were procured from a fish-breeding farm and were reared locally in the lab for an additional two years. The senescence of the individuals was then evaluated and confirmed using histological analysis, gonadal index assessment, and germ-cell specific vasa gene expression. Analyses revealed absence of spermatogonial cells and other germ cells in the testes of the senescent fish (n = 5). Spermatogonial cells from sexually immature C. auratus male donor were isolated using discontinuous percoll gradients, labelled with the fluorescent dye PKH-26, and transplanted into the gonads of senescent C. auratus males through urogenital papilla. Six months after the transplant, spermatozoa were collected through applying gentle manual pressure on the abdomen and were observed under a microscope. All C. auratus males with the transplant had produced spermatozoa from the transplanted cells. This was confirmed by the retention of PKH-26 in the spermatozoa and diagnostic SSR locus. Gravid C. auratus females were artificially inseminated with the spermatozoa of those senescent males and natural spawning was allowed. As a result viable progeny were produced. These observation suggests that the reproductive competence of senescent male fishes can be revitalised through spermatogonial stem cell therapy to produce functional gametes.
Steroid hormones and chondrichthyan reproduction: physiological functions, scientific research, and implications for conservation
Authors: Becerril-García Edgar Eduardo , Arellano-Martínez Marcial , Bernot-Simon Daniela , Hoyos-Padilla Edgar Mauricio , Galván-Magaña Felipe , Godard-Codding Céline
Published: August 2020

The study of the reproductive aspects of chondrichthyans through the analysis of steroid hormones has been carried out for more than five decades in several species around the world. This scientific knowledge constitutes the basis of the reproductive endocrinology of chondrichthyans, which has provided information regarding their sexual maturation, gametogenesis, mating seasons, gestation periods, and parturition. The present review summarises the existing literature on steroid hormones in chondrichthyan reproduction and identifies future research directions addressing critical knowledge gaps in the reproductive physiology of this taxon. A total of 59 peer reviewed scientific papers from 1963 to 2020 were reviewed and the following parameters analysed: species, steroid hormones, biological matrix, field sampling (year, location), and methodology (assays, sample size, precision, and recoveries). We provided a summary of the methods, biological matrices, and the functions of up to 19 hormones on the biology of 34 species of chondrichthyans that have been analysed to date. The majority of the studies used radioimmunoassay as the main methodology (76.3%; n = 45/49); while the most frequent biological matrix used was plasma (69.5%; n = 41/49). A Kernel’s heat map was generated to present the scientific effort according to geographic location and evidenced a lack of research in high biodiversity areas for chondrichthyans worldwide. The implications of the study of steroid hormones for the conservation of chondrichthyans are discussed, as only 2.9% of the species of this group have been analysed and most of the scientific effort (93.2%; n = 55/59 papers) has focused on the analysis of less than six hormones.
The evolution of feeding within Euchelicerata: data from the fossil groups Eurypterida and Trigonotarbida illustrate possible evolutionary pathways
Authors: Haug Carolin
Published: August 2020

When the evolution of Euarthropoda is discussed, often the lineage of Chelicerata s. str. is assumed to be the more ‘primitive’ or ‘basal’ part of the tree, especially when compared to the other major lineage, Mandibulata. This claimed primitiveness is (at least partly) based on the assumption that different morphological structures are still in an ancestral state and did not evolve any further. One of these sets of structures is the feeding apparatus, which has been stated to be highly advanced in Mandibulata, but not ‘properly’ developed, or at least not to such a high degree, within Chelicerata s. str. In this study, I reinvestigate the feeding apparatus of different ingroups of Euchelicerata, with a focus on assumed ‘primitive’ groups such as Eurypterida and Trigonotarbida. The basis of this study is a large amount of material from different museum collections, with fossils with the entire feeding apparatuses being exceptionally well preserved. Based on high-resolution micro-photography and three-dimensional imaging, it is possible to resolve fine details of the feeding apparatuses. The results make clear that the feeding apparatuses of different ingroups of Euchelicerata are highly specialised and often possess morphological structures comparable to those of the feeding apparatuses of representatives of Mandibulata, apparently convergently evolved. Though the reconstruction of the evolution of the feeding apparatus within Euchelicerata is to a certain degree hampered by unclear phylogenetic relationships, there was clearly a shortening of the feeding apparatus from posterior (i.e. only the anterior appendages being involved in the feeding apparatus), probably linked to the colonisation of land in Arachnida.
CONFLITOS CONTEMPORÂNEOS: A CATEGORIA DE REFUGIADO NO TELEJORNALISMO BRASILEIRO
Authors: Mizga Liege Scremin , Trovão Susana
Published: August 2020

Entender a complexidade da mobilidade humana, em pleno século XXI, faz-se necessário não apenas na agenda dos direitos humanos, mas nos meios de comunicação social. Por meio de uma Análise de Conteúdo Qualitativa referente a cinco meses dos telejornais Jornal Nacional e Jornal da Record e, posteriormente, a uma Análise de Discurso de quatro peças, foi possível verificar que esses meios não tem o cuidado de diferenciar as variações existentes dentro das migrações, como os refugiados, por exemplo, atualmente protagonistas de grandes conflitos. Para embasar teoricamente o estudo foram utilizadas as Teorias da Comunicação e a hipótese de Agenda-Setting, assim como a influência de agências internacionais na pauta da mídia nacional e as Representações Sociais de Serge Moscovici.
EDITORIAL
Authors: Santana Joao Rodrigo Araujo , Bispo Bruno Vilas Boas , Silva Filho Cláudio Almeida
Published: August 2020

Editorial v. 8, n. 8 Demanda Livre
S‐allyl‐L‐cysteine protects hepatocytes from indomethacin‐induced apoptosis by attenuating endoplasmic reticulum stress
Authors: Chen Peng , Chen Chen , Hu Mingdao , Cui Rui , Liu Feng , Yu Henghai , Ren Yuling
Published: August 2020

Drug‐induced liver injury (DILI) can lead to acute liver failure, a lethal condition which may require liver transplantation. Hepatotoxicity associated with nonsteroidal anti‐inflammatory drugs (NSAIDs) accounts for ~ 10% of all DILI. In the current study, we determined whether indomethacin, one of the most commonly used NSAIDS, induced apoptosis in hepatocytes and investigated the underlying mechanism. Meanwhile, we investigated the protective effect of S‐allyl‐L‐cysteine (SAC), an active garlic derivative, on indomethacin‐induced hepatocyte apoptosis, and its implication on endoplasmic reticulum (ER) stress. We found that indomethacin triggered ER stress, as indicated by the elevated expression of phosphorylated eukaryotic translation initiation factor 2α (eIF2α), C/EBP homologous protein (CHOP) and spliced XBP1 in a rat liver BRL‐3A cell line. Following indomethacin treatment, caspase 3 activation and hepatocyte apoptosis were also observed. Inhibition of ER stress by chemical chaperone 4‐phenyl butyric acid alleviated cell apoptosis caused by indomethacin, indicating that ER stress is involved in indomethacin‐induced hepatocyte apoptosis. Moreover, SAC abated indomethacin‐induced eIF2α phosphorylation, inhibited CHOP upregulation and its nuclear translocation, abrogated the activation of caspase 3 and finally, protected hepatocytes from apoptosis. In conclusion, SAC protects indomethacin‐induced hepatocyte apoptosis through mitigating ER stress and may be suitable for development into a potential new therapeutic agent for the treatment of DILI.
Trial inspection of exterior‐tile wall specimens with a prototyped tile‐debonding diagnostic device
Authors: Soeta Tomomi , Ito Shutaro , Fujinuma Tomohiro , Mikami Takamasa
Published: August 2020

This paper details the ability of a tile‐debonding diagnostic device to detect artificially debonded areas on 12 exterior‐tile wall specimens, using a detection parameter proposed in a previous paper. The device has an impact force sensor and four microphones and outputs detection parameter RAF for each microphone. The maximum value of RAF at the four microphones was defined as RAF‐max. A threshold value of RAF‐max was set, and the results of detection of debonding were displayed on the figures of the specimens. Consequently, the effectiveness of the device and detection parameter was verified.
Dual Friction Mode Textile‐Based Tire Cord Triboelectric Nanogenerator
Authors: Seung Wanchul , Yoon Hong‐Joon , Kim Tae Yun , Kang Minki , Kim Jihye , Kim Han , Kim Seong Min , Kim Sang‐Woo
Published: August 2020

As vehicles become smarter, an alternative power solution will become increasingly important for future vehicle development. With this context, a triboelectric nanogenerator (TENG) is proposed which fully sits on tires and consists of textile‐based tire materials. Both polydimethylsiloxane‐coated silver textile, serving as an external tire tread material, and nylon woven textile, serving as an internal tire cord material, performing as opposing triboelectric materials, are well adaptable for rolling tires. It is demonstrated that tire material‐based TENG performs at its maximum as it makes mutual contact with the road. The power generation property is characterized under different driving situations such as different tire rotation speeds and varying numbers of devices on the tires. The TENG demonstrates a maximum output voltage and a current of about 225 V and 42 µA, respectively, along with an output power of 0.5 mW at optimum load. The work offers the possibility to not only directly operate minute power‐consuming electronics but also collect power and store it while driving a vehicle.
Advanced Materials to Enhance Central Nervous System Tissue Modeling and Cell Therapy
Authors: Muckom Riya J. , Sampayo Rocío G. , Johnson Hunter J. , Schaffer David V.
Published: August 2020

The progressively deeper understanding of mechanisms underlying stem cell fate decisions has enabled parallel advances in basic biology—such as the generation of organoid models that can further one's basic understanding of human development and disease—and in clinical translation—including stem cell based therapies to treat human disease. Both of these applications rely on tight control of the stem cell microenvironment to properly modulate cell fate, and materials that can be engineered to interface with cells in a controlled and tunable manner have therefore emerged as valuable tools for guiding stem cell growth and differentiation. With a focus on the central nervous system (CNS), a broad range of material solutions that have been engineered to overcome various hurdles in constructing advanced organoid models and developing effective stem cell therapeutics is reviewed. Finally, regulatory aspects of combined material‐cell approaches for CNS therapies are considered.
Deciphering, Designing, and Realizing Self‐Folding Biomimetic Microstructures Using a Mass‐Spring Model and Inkjet‐Printed, Self‐Folding Hydrogels
Authors: Cui Chunxiao , Yin Jie , Han Li‐Hsin
Published: August 2020

Flat, organic microstructures that can self‐fold into 3D microstructures are promising for tissue regeneration, for being capable of distributing living cells in 3D while forming highly complex, biomimetic architectures to assist cells in performing regeneration. However, the design of self‐folding microstructures is difficult due to a lack of understanding of the underlying formation mechanisms. This study helps bridge this gap by deciphering the dynamics of the self‐folding using a mass‐spring model. This numerical study reveals that self‐folding procedure is multi‐modal, which can become random and unpredictable by involving the interplays between internal stresses, external stimulation, imperfection, and self‐hindrance of the folding body. To verify the numerical results, bilayered, hydrogel‐based micropatterns capable of self‐folding are fabricated using inkjet‐printing and tested. The experimental and numerical results are consistent with each other. The above knowledge is applied to designing and fabricating self‐folding microstructures for tissue‐engineering, which successfully creates 3D, cell‐scaled, and biomimetic microstructures, such as microtubes, branched microtubes, and hollow spheres. Embedded in self‐folded microtubes, human mesenchymal stem cells proliferate and form linear cell‐organization mimicking the cell morphology in muscles and tendons. The above knowledge and study platforms can greatly contribute to the research on self‐folding microstructures and applications to tissue regeneration.
All‐Inorganic Ionic Polymer‐Based Memristor for High‐Performance and Flexible Artificial Synapse
Authors: Zhao Yong‐Yan , Sun Wu‐Ji , Wang Jia , He Jing‐Hui , Li Hua , Xu Qing‐Feng , Li Na‐Jun , Chen Dong‐Yun , Lu Jian‐Mei
Published: August 2020

The implementation of memristors that are wearable and transparent has attracted significant attention. However, the development of high‐performance memristors that simultaneously possess high flexibility and environmental stability has remained a tremendous challenge suffering from limited choice of materials with both good ion‐electron mobility and structural flexibility. Inspired by the unique poly‐ionic nature of ammonium polyphosphate (APP), a novel Au/APP/ITO memristor with favorable flexibility and stability is prepared. Synaptic behaviors can be stimulated by voltage pulses that are 20 ns in width, 0.1 V in amplitude, and repeatable under 104 pulse cycles, thereby outperforming several other benchmark memristors. Further, the device, prepared on conductive silicone, can sustain its synaptic performance even under 360° bending. Furthermore, the device can sustain its synaptic behaviors even after exposure to fire for 60 s and 5.6 kGy of ionic irradiation. Additionally, APP is determined to be nontoxic, biodegradable, and transparent when compared with all the organics and inorganics used in previous memristors. The results of this study will inspire the development of more inorganic polymers for their utilization in future environmentally stable and flexible electronics.
Redistributing Li‐Ion Flux by Parallelly Aligned Holey Nanosheets for Dendrite‐Free Li Metal Anodes
Authors: Zhou Yangen , Zhang Xiao , Ding Yu , Bae Jiwoong , Guo Xuelin , Zhao Yu , Yu Guihua
Published: August 2020

Li metal is the most ideal anode material to assemble rechargeable batteries with high energy density. However, nonuniform Li‐ion flux during repeated Li plating and stripping leads to continuous Li dendrite growth and dead Li formation, which causes safety risks and short lifetime and thus impedes the commercialization of Li metal batteries. Here, parallelly aligned holey nanosheets on a Li metal anode are reported to simultaneously redistribute the Li‐ion flux in the electrolyte and in the solid‐electrolyte interphase, which allows uniform Li‐ion distribution as well as fast Li‐ion diffusion for reversible Li plating and stripping. With holey MgO nanosheets as an example, the protected Li anodes achieve Coulombic efficiency of ≈99% and ultralong‐term reversible Li plating/stripping over 2500 h at a high current density of 10 mA cm−2. A full‐cell battery, using the protected anode, a 4 V Li‐ion cathode, and a commercial carbonate electrolyte, shows capacity retention of 90.9% after 500 cycles.
Multifunctional Self‐Powered E‐Skin with Tactile Sensing and Visual Warning for Detecting Robot Safety
Authors: Wang Feng‐Xia , Wang Ming‐Jiong , Liu Hui‐Cong , Zhang Yun‐Lin , Lin Qi‐Hang , Chen Tao , Sun Li‐Ning
Published: August 2020

Flexible electronic skins (e‐skins) are widely applied in human activities monitoring, medical health, and robotic perception. However, most of the reported e‐skins only focus on the physical force sensing. Herein, a novel multifunctional e‐skin possessing physical force sensing and real‐time visualization is proposed. The vertical‐separation triboelectric sensor is used as the tactile sensing units, showing excellent performance with the open‐circuit voltage (V0) of 376.8 V, the short‐circuit (Is) of 1.02 µA, and the maximum output power density of 7.225 W m−2, which also can carry out pressure detection with a wide detection range from 55.5 pa to 14 Kpa, a high sensitivity of 57.76 mV pa−1, and a fast response time of 5.6 ms. The electrochromic devices as the visualization window shows the excellent stability and the low driving voltage. This e‐skin can detect the instantaneous external force applied on the human arm and robotic arm and simultaneously shows the colors varying from light green to dark blue when experiencing the applied force. The proposed e‐skin shows a promising solution of realizing both the digitized physical force sensing and the direct visualization, which can greatly enhance the safety precaution in various fields, such as robotic production line.
PROteolysis TArgetting Chimeras (PROTACs) Strategy Applied to Kinases: Recent Advances
Authors: Feral Anthony , Laconde Guillaume , Amblard Muriel , Masurier Nicolas
Published: August 2020

Since the development of the first protein kinase inhibitor in the early 1980s, followed by the FDA approval of imatinib in 2001, kinases are one of the most intensively pursued targets in current medicinal chemistry research. These proteins are overrepresented in various diseases such as cancer, inflammation or autoimmune pathologies and play important roles in their physiopathogenic processes. Despite the development and approval of numerous potent kinase inhibitors, drug resistance and off‐target side effects are commonly encountered with kinase inhibitors. Thus, development of novel strategies to overcome these problems is necessary. Since 2013, many research groups have proposed the conversion of potent kinase inhibitors into PROteolysis TArgeting Chimera (PROTAC) compounds and shared relevant and encouraging results using this new technology, which degrades proteins by employing the cellular machinery. Generally, this strategy brings enhancements in biological effects compared to the use of only the parent inhibitor. In this review article, recent findings related to the PROTAC technology applied to kinases are discussed, with a special focus on publications since 2018.
Silent Synapse Activation by Plasma‐Induced Oxygen Vacancies in TiO2 Nanowire‐Based Memristor
Authors: Shan Xuanyu , Wang Zhongqiang , Lin Ya , Zeng Tao , Zhao Xiaoning , Xu Haiyang , Liu Yichun
Published: August 2020

Emulation of biological synapses by electronic devices will form a foundation for realizing brain‐inspired computational systems. In addition to mimicking functional synapses, it is also important to demonstrate activation functionality of silent synapses in memristors, to emulate the evolutionary processes of human brain development. Here, a silent synapse without synaptic plasticity is achieved in a single‐crystalline TiO2 nanowire‐based memristor. Importantly, the short‐term plasticity transforms to long‐term plasticity in plasma (O2, Ar, and Ar‐H2) treated devices, representing activation of a silent synapse to a functional synapse. The memristive mechanism is attributed to the accumulation and diffusion of oxygen vacancies at the Pt/TiO2 interface, which adjusts the Schottky barrier and conductance. The use of various plasma treatments also enables synaptic function modulation by changing the density of oxygen vacancies. The results provide a feasible method for activating silent synapses and modulating synaptic learning functions in a memristor‐based artificial synapse.
Recent Advances in MOF‐Derived Single Atom Catalysts for Electrochemical Applications
Authors: Song Zhongxin , Zhang Lei , Doyle‐Davis Kieran , Fu Xianzhu , Luo Jing‐Li , Sun Xueliang
Published: August 2020

Electrocatalysis plays a critical role in clean energy conversion, enabling great improvement for future sustainable technologies. Single atom catalysts (SACs) derived from metal–organic framework (MOF) are emerging extraordinary materials in electrochemical catalytic applications. Covering the merits of unique electronic structure, low‐coordination environment, quantum size effect, and metal–support interaction, SACs promise enhanced electrocatalytic activity, stability, and selectivity in the field of clean energy conversion. In this article, MOF synthesis routes to afford well‐dispersed SACs along with the respective synthesis mechanism are systematically reviewed first, and typical examples of each strategy are carefully discussed. Then the characterization techniques in understanding the isolated and spatial distribution, local electronic structure, coordination environment for SACs, and insights into stable mechanisms provided by density functional theory (DFT) calculations are summarized. In addition, several important electrocatalytic applications and electrocatalytic mechanisms of the MOF‐derived SACs, including for the oxygen reduction reaction, CO2 reduction reaction, nitrogen reduction reaction, hydrogen evolution reaction, oxygen evolution reaction, etc., are highlighted. To facilitate the future development of high‐performing SACs, several technical challenges and corresponding research directions are proposed.
Mesoporous Materials for Electrochemical Energy Storage and Conversion
Authors: Zu Lianhai , Zhang Wei , Qu Longbing , Liu Liangliang , Li Wei , Yu Aibing , Zhao Dongyuan
Published: August 2020

Developing high‐performance electrode materials is an urgent requirement for next‐generation energy conversion and storage systems. Due to the exceptional features, mesoporous materials have shown great potential to achieve high‐performance electrodes with high energy/power density, long lifetime, increased interfacial reaction activity, and enhanced kinetics. In this Essay, applications of mesoporous materials are reviewed in electrochemical energy conversion and storage devices. The synthesis, structure, and properties of mesoporous materials and their performance in rechargeable batteries, supercapacitors, fuel cells, and electrolyzers are discussed, providing practical details and enlightening comments on the construction of high‐performance mesoporous electrodes. Lastly, the research challenges and perspectives on mesoporous materials for the future development of energy conversion and storage devices are assessed.
Direct Observation Tools in Emergency Medicine: A Systematic Review of the Literature
Authors: Gottlieb Michael , Jordan Jaime , Siegelman Jeffrey N. , Cooney Robert , Stehman Christine , Chan Teresa M.
Published: August 2020

Objectives

Direct observation is important for assessing the competency of medical learners. Multiple tools have been described in other fields, although the degree of emergency medicine–specific literature is unclear. This review sought to summarize the current literature on direct observation tools in the emergency department (ED) setting.

Methods

We searched PubMed, Scopus, CINAHL, the Cochrane Central Register of Clinical Trials, the Cochrane Database of Systematic Reviews, ERIC, PsycINFO, and Google Scholar from 2012 to 2020 for publications on direct observation tools in the ED setting. Data were dual extracted into a predefined worksheet, and quality analysis was performed using the Medical Education Research Study Quality Instrument.

Results

We identified 38 publications, comprising 2,977 learners. Fifteen different tools were described. The most commonly assessed tools included the Milestones (nine studies), Observed Structured Clinical Exercises (seven studies), the McMaster Modular Assessment Program (six studies), Queen’s Simulation Assessment Test (five studies), and the mini‐Clinical Evaluation Exercise (four studies). Most of the studies were performed in a single institution, and there were limited validity or reliability assessments reported.

Conclusions

The number of publications on direct observation tools for the ED setting has markedly increased. However, there remains a need for stronger internal and external validity data.
Selenium biofortification of green spinach with optimum phosphorus fertilization and selenium application timing
Authors: Nayan Dayang Safinah , Zainol Rozlaily , Abdul Sukor Arina Shairah , Mohammad Yusoff Martini , Ishak Che Fauziah
Published: August 2020

A selenium (Se) biofortification program for vegetables has never been attempted in Malaysia. This study was performed to determine the optimum Se fertilization rates for high yield and Se uptake by green spinach (Amaranthus spp.) through a glasshouse experiment and to evaluate the effect of Se application timing on dry matter, growth, and Se accumulation in green spinach through field experiments. Glasshouse experiment conducted with factorial randomized complete block design showed that applying P fertilizer as recommended for green spinach increased yield and Se uptake by the leaves and stems of green spinach. Selenium application in the form of Se(IV) solution at 120 g ha–1 to sandy clay soil was determined to be the optimum application rate, as higher rates reduced plant yield and decreased Se uptake by green spinach. Three cycles of field experiments showed that a single application of 120 g ha–1 Se at 14 d after planting (DAP) produced the optimum results in terms of green spinach growth and dry matter. Although the highest Se accumulation in leaves was observed when Se was applied at 7 DAP (26.04–29.20 μg 10 plants–1), its detrimental effect on yield caused it to be considered an inappropriate time of application. Therefore, with optimum Se accumulation in leaves (21.16–22.38 μg 10 plants–1) and stems (5.89–5.98 μg 10 plants–1), application of Se as Se(IV) solution at 14 DAP at a rate of 120 g ha–1 has been identified as an effective Se fertilization management strategy for producing Se‐biofortified green spinach.
Das Konformationsgleichgewicht des Neuropeptid‐Y2‐Rezeptors in Lipidmembranen
Authors: Krug Ulrike , Gloge Anika , Schmidt Peter , Becker‐Baldus Johanna , Bernhard Frank , Kaiser Anette , Montag Cindy , Gauglitz Marcel , Vishnivetskiy Sergey A. , Gurevich Vsevolod V. , Beck‐Sickinger Annette G. , Glaubitz Clemens , Huster Daniel
Published: August 2020

Dynamische Strukturübergänge innerhalb des Sieben‐Transmembran‐Bündels stellen den Mechanismus dar, durch den G‐Protein‐gekoppelte Rezeptoren ein extrazelluläres chemisches Signal in eine intrazelluläre biologische Antwort umwandeln. In dieser Arbeit wurde die Konformationsdynamik des Neuropeptid‐Y‐Rezeptors Typ 2 (Y2R) während des Aktivierungsprozesses untersucht. Es wurden der apo‐Zustand, der Zustand des gebundenen vollen Agonisten und der Arrestin‐gebundene Zustand durch zellfreie Expression, funktionelle Faltung und Rekonstitution in Lipidmembranen präpariert. Um die konformationellen Übergänge zwischen den Zuständen zu untersuchen, wurden alle sechs Tryptophane des Y2R 13C‐markiert. Die NMR‐Signale wurden zugeordnet und die funktionalen Zustände des Rezeptors charakterisiert. Die Y2R‐Aktivierung wird durch molekulare Schalter wie das hoch konservierte Trp2816.48 und Trp3277.55 vermittelt. Trp11623.50 bildet mit einer Disulfidbrücke ein konformationell konserviertes cysteine‐lock‐Motiv.
Experimentally Observed Reverse Intersystem Crossing‐Boosted Lasing
Authors: Zhou Zhonghao , Qiao Chan , Wang Kang , Wang Lu , Liang Jie , Peng Qian , Wei Zhiyou , Dong Haiyun , Zhang Chuang , Shuai Zhigang , Yan Yongli , Zhao Yong Sheng
Published: August 2020

Thermally activated delayed‐fluorescent (TADF) materials are anticipated to overcome triplet‐related losses towards electrically driven organic lasers. Thus far, contributions from triplets to lasing have not yet been experimentally demonstrated owing to the limited knowledge about the excited‐state processes. Herein, we experimentally achieve reverse intersystem crossing (RISC)‐boosted lasing in organic microspheres with uniformly dispersed TADF emitters. In these materials, triplets are continuously converted to radiative singlets through RISC, giving rise to reduced losses in stimulated emission. The involvement of regenerated singlets in population inversion results in a thermally activated lasing; that is, the lasing intensity increases with increasing temperature, accompanied by accelerated depletion of the excited‐state population. Benefiting from the suppression of triplet accumulations by RISC processes, a high‐repetition‐rate microlaser was achieved.
Photoorganocatalyzed Divergent Reversible‐Deactivation Radical Polymerization towards Linear and Branched Fluoropolymers
Authors: Zhao Yucheng , Ma Mingyu , Lin Xinrong , Chen Mao
Published: August 2020

Topology influences the properties and applications of polymers. Consequently, considerable efforts have been made to control topological structures. In this work, we have developed a photoorganocatalyzed divergent synthetic approach based on reversible‐deactivation radical polymerization (RDRP) that enables the preparation of both linear and branched fluoropolymers of low dispersity (Ð), a tunable degree of branching and high chain‐end fidelity by exposure to LED light irradiation under metal‐free conditions. This method promotes the generation of complicated structures (e.g., necklace‐like and mop‐like fluoropolymers) via chain‐extension photo‐RDRP, and provides a novel and versatile platform to access fluoropolymer electrolytes with high Li‐ion transference number and good ionic conductivity, which should create improved opportunities for advanced material engineering.
Versatile Nickel(II) Scaffolds as Coordination‐Induced Spin‐State Switches for 19F Magnetic Resonance‐Based Detection
Authors: Xie Da , Yu Meng , Xie Zhu‐Lin , Kadakia Rahul T. , Chung Chris , Ohman Lauren E. , Javanmardi Kamyab , Que Emily L.
Published: August 2020

19F magnetic resonance (MR) based detection coupled with well‐designed inorganic systems shows promise in biological investigations. Two proof‐of‐concept inorganic probes that exploit a novel mechanism for 19F MR sensing based on converting from low‐spin (S=0) to high‐spin (S=1) Ni2+ are reported. Activation of diamagnetic NiL1 and NiL2 by light or β‐galactosidase, respectively, converts them into paramagnetic NiL0, which displays a single 19F NMR peak shifted by >35 ppm with accelerated relaxation rates. This spin‐state switch is effective for sensing light or enzyme expression in live cells using 19F MR spectroscopy and imaging that differentiate signals based on chemical shift and relaxation times. This general inorganic scaffold has potential for developing agents that can sense analytes ranging from ions to enzymes, opening up diverse possibilities for 19F MR based biosensing.
The Conformational Equilibrium of the Neuropeptide Y2 Receptor in Bilayer Membranes
Authors: Krug Ulrike , Gloge Anika , Schmidt Peter , Becker‐Baldus Johanna , Bernhard Frank , Kaiser Anette , Montag Cindy , Gauglitz Marcel , Vishnivetskiy Sergey A. , Gurevich Vsevolod V. , Beck‐Sickinger Annette G. , Glaubitz Clemens , Huster Daniel
Published: August 2020

Dynamic structural transitions within the seven‐transmembrane bundle represent the mechanism by which G‐protein‐coupled receptors convert an extracellular chemical signal into an intracellular biological function. Here, the conformational dynamics of the neuropeptide Y receptor type 2 (Y2R) during activation was investigated. The apo, full agonist‐, and arrestin‐bound states of Y2R were prepared by cell‐free expression, functional refolding, and reconstitution into lipid membranes. To study conformational transitions between these states, all six tryptophans of Y2R were 13C‐labeled. NMR‐signal assignment was achieved by dynamic‐nuclear‐polarization enhancement and the individual functional states of the receptor were characterized by monitoring 13C NMR chemical shifts. Activation of Y2R is mediated by molecular switches involving the toggle switch residue Trp2816.48 of the highly conserved SWLP motif and Trp3277.55 adjacent to the NPxxY motif. Furthermore, a conformationally preserved “cysteine lock”‐Trp11623.50 was identified.
Dynamic, 3D Schiff base networks for medical applications
Authors: Modak Piyush , Hammond Willis , Jaffe Michael , Nadig Malavika , Russo Richard
Published: August 2020

In this study, we utilized the reversible property of aqueous Schiff bases to design a dynamic three‐dimensional (3D) network. Two derivatized polysaccharides—acrylated chitosan (aCHN) and oxidized dextran (oDEX)—form a 3D network rapidly (<10 s) in situ without the use of external crosslinking agents. Reversible Schiff base (NC) pairs are formed between the amines of aCHN and aldehydes of oDEX. These bonds are mobile and reversible, allowing the network to form additional bonds, leading to lower energy state and densification. In the presence of a primary organic amine, the network dissolves completely, demonstrating network reversibility. The network has strong cohesion (85 ± 7 mmHg) and adhesion (0.017 ± 0.003 MPa) strengths. Rheological examination of the network demonstrates that both elastic storage (G') and viscous loss (G") moduli do not plateau but keep increasing over time. The network shrinks continuously over time, expelling fluid even when completely immersed in physiological solution, in contrast with conventional crosslinked networks that imbibe water and swell. Both rheology and shrinkage demonstrate the dynamic nature of the aCHN–oDEX networks. The dynamic nature of these networks is tunable and the properties of gelation, rheology, cohesion, adhesion, and densification can be modulated depending on the application of interest.
High pressure semibatch emulsion and miniemulsion copolymerization of vinyl acetate and ethylene
Authors: Narayanan Manu , Choi Kyu Yong
Published: August 2020

This study presents the experimental study of semibatch emulsion and miniemulsion copolymerization of vinyl acetate (VAc) and ethylene to vinyl acetate‐ethylene (VAE) copolymer at 60°C and 80–300 psig. In the miniemulsion copolymerization, a water‐soluble initiator (K2S2O8) is used and VAc miniemulsion is prepared in presence of surfactant and cosurfactant using a sonicator or a high‐shear homogenizer. Then, ethylene gas is supplied to the reactor at constant partial pressure. In a miniemulsion process, the mass transfer limitations of VAc from monomer droplets to the aqueous phase, and to micelles or polymer latex particles that are present in conventional macro‐emulsion polymerization can be eliminated and the transfer of ethylene dissolved in the aqueous phase to the miniemulsion droplets is the major ethylene transport process for the polymerization. The experimental data show that the amount of ethylene incorporation into the copolymer is higher in miniemulsion polymerization than in emulsion polymerization. The ethylene pressure has been found to have a strong impact on the ethylene incorporation into the copolymer phase in both emulsion and miniemulsion copolymerizations but the increase is more pronounced in miniemulsion case. The VAE copolymer latex particles prepared by miniemulsion polymerization exhibited higher storage stability than those prepared by macro‐emulsion polymerization.
Assessment of the physical characteristics and fishing performance of gillnets using biodegradable resin (PBS/PBAT and PBSAT) to reduce ghost fishing
Authors: Seonghun Kim , Pyungkwan Kim , Seongjae Jeong , Kyounghoon Lee
Published: August 2020

Ghost fishing is caused by derelict synthetic‐fibre nets that have been lost at sea. Thus, biodegradable nets have been developed with the aim of protecting marine ecosystems.

The performance of biodegradable nets and their ability to replace conventional gillnets was assessed. Two types of biodegradable nets were used in the experiment: one made from a blended resin containing 90 wt% polybutylene succinate (PBS) and 10 wt% polybutylene adipate‐co‐terephthalate (PBAT) (Bio‐1), and the other made from a polybutylene succinate co‐adipate‐co‐terephthalate (PBSAT) resin (Bio‐2) with improved flexibility and physical homogeneity.

For No. 3 monofilaments (standard diameter, Ø, 0.284 mm), Bio‐1 and Bio‐2 both showed a wet straight‐line breaking strength of around 99% that of polyamide (PA). For No. 2 monofilaments (Ø 0.200 mm), the wet straight‐line breaking strengths of Bio‐1 and Bio‐2 were 84.9 and 93.0% that of PA, respectively, indicating worse physical properties for Bio‐1 at No. 2 thickness.

The wet knotted breaking strengths of No. 3 thickness Bio‐1 and Bio‐2 were 92.9 and 82.7% that of PA, respectively. The straight‐line breaking strength of Bio‐2 was 1.1 times that of Bio‐1. The wet knotted breaking strengths of Bio‐1 and Bio‐2 were 80.2 and 93.4% that of PA, respectively, and the knotted breaking strength of Bio‐2 was around 1.2 times that of Bio‐1.

Regarding flexibility, for No. 3 thickness monofilaments, the mean wet stiffness values of PA, Bio‐1, and Bio‐2 were 9.50, 15.23, and 9.68 g, respectively, indicating that Bio‐2 was similar to PA and around 1.6 times softer than Bio‐1.

The fishing performance, by weight, was PA > Bio‐2 > Bio‐1; however, the difference between PA and Bio‐2 was not statistically significant. Biodegradable nets may not be a perfect solution, but we believe that they can contribute greatly to reducing ghost fishing and protecting marine ecosystems.
Dynamics of the use of magnetocardiography in the study of the cardiac conduction system of the chick embryo
Authors: Schellpfeffer Michael A. , Strasburger Janette F. , Baffa Oswaldo , Strand Sarah A , Lutter William , Phan Tan , Wakai Ronald T.
Published: August 2020

Introduction

Human fetal magnetocardiography (fMCG) has been done for several decades to evaluate fetal arrhythmias using a superconducting quantum interference device (SQUID) magnetometer, but there is little work in embryonic/fetal animal models. This study uses an optically‐pumped magnetometer (OPM) to obtain an fMCG in the chick embryo.

Methods

White Leghorn chick embryos were examined from incubation Day #10–19. Different examination chambers were tested to optimize embryonic thermal stability and magnetic signal acquisition. All examinations were done with magnetic shielding. The OPM sensors were placed next to the egg shell. The embryo's position was localized by transilluminating the intact egg or ultrasound imaging the egg with an open air cell to optimize sensor placement. The raw data for each embryo was postprocessed to obtain a fMCG composite waveform.

Results

fMCG's were obtained in embryos from Day #12 to 19. The best success with intact eggs was obtained using five sensors; one at the bottom and four around the lower perimeter of the egg at 90° intervals with the egg oriented vertically and the air cell up. Using ultrasound imaging with the air cell open only two sensors were necessary, one at the bottom and one laterally next to the embryo. fMCGs were analyzed for heart rate and rhythm, each portion of the PQRST waveform, and the PR interval, QRS complex, RR interval, and QT interval.

Conclusions

This study validates the chick embryo as an animal model to study in a longitudinal and noninvasive fashion the fetal cardiac conduction system by using OPM magnetocardiography.
Selective Covalent Targeting of Anti‐apoptotic BFL‐1 by a Sulfonium‐Tethered Peptide
Authors: Liu Na , Wang Dongyuan , Lian Chenshan , Zhao Rongtong , Tu Licheng , Zhang Yichi , Liu Jianbo , Zhu Huilin , Yu Mengying , Wan Chuan , Li Di , Li Shuiming , Yin Feng , Li Zigang
Published: August 2020

Anti‐apoptotic B cell lymphoma 2 (BCL‐2) family proteins are proven targets for human cancers. Targeting the BH3‐binding pockets of these anti‐apoptotic proteins could reactivate apoptosis in BCL‐2‐depedent cancers. BFL‐1 is a BCL‐2 family protein overexpressed in various chemoresistant cancers. A unique cysteine at the binding interface of the BH3 and BFL‐1 was previously proven to be an intriguing targeting site to irreversibly inhibit BFL‐1 functions with stabilized cyclic peptide bearing a covalent warhead. Recently, we developed a sulfonium‐tethered peptide cyclization strategy to construct peptide ligands that could selectively and efficiently react with the cysteine(s) of target proteins near the interacting interface. Using this method, we constructed a BFL‐1 peptide inhibitor, B4‐MC, that could selectively conjugate with BFL‐1 both in vitro and in cell. B4‐MC showed good cellular uptake, colocalized with BFL‐1 on mitochondria, and showed obvious growth inhibition of BFL‐1 over‐expressed cancer cell lines.
Exploring How Institutional Partners Vary in Outcomes for Transfer Students of Color
Authors: Meza Elizabeth Apple , Blume Grant
Published: August 2020

Institutional pairs of community college‐sending institutions and university‐receiving institutions are associated with significant variation in college completion outcomes, with such variation being especially pronounced for underserved transfer students of color. Higher performing institutional pairs tend to enroll a predominantly White student body, which highlights how inequities in transfer continue to manifest as a baccalaureate completion gap for transfer students of color.
Infusion of Equity‐Mindedness across Transfer Pathways in Washington State
Authors: Wellington‐Baker Kristi , Hammer Joyce
Published: August 2020

Too many Washingtonians, especially low‐income persons of color, are not completing postsecondary education credentials that lead to meaningful labor market returns. This chapter provides an evidence‐based, student‐centered transfer framework that reinforces transparency, equity‐mindedness, and the adaptive leadership necessary to transform higher education systems to support the success of all students.
Supporting an Evolving Transfer Partnership in Ohio: The UD Sinclair Academy
Authors: Collins Kimberly , Welch Christopher , Thompson Julia
Published: August 2020

This chapter describes how Sinclair Community College and University of Dayton (UD) developed a transfer partnership that encompasses all facets of campus life, financial benefits, and wrap‐around services.
Going Beyond Transfer Agreements: The Best Choices Program and a Web of Connections
Authors: DuVal Chris , Artis Wayne
Published: August 2020

This chapter describes a long‐term successful transfer partnership between Pikes Peak Community College (PPCC) and the University of Colorado‐Colorado Springs (UCCS). The Best Choices program provides clearly defined pathways for students planning on transferring from PPCC to UCCS, including overall transfer plans that extend from start to finish.
Catalysis in Confined Spaces of Metal Organic Frameworks
Authors: Dhakshinamoorthy Amarajothi , Asiri Abdullah M. , Garcia Hermenegildo
Published: August 2020

Compared to homogeneous catalysis, heterogeneous catalysis can achieve product selectivity due to spatial constraints and differences in molecular dimensions of substrates and products by performing the reaction in a confined space. Shape selectivity for substrates, products or transition states is a well‐established phenomenon observed in porous inorganic solids like zeolites with considerable impact in petrochemistry. More recently, metal organic frameworks (MOFs) have emerged as heterogeneous solid catalysts for a broad range of organic reactions due to their unique properties of large surface area, tuneable pore volume and high density of sites. The present mini‐review aims to describe the current evidences showing MOFs as shape‐selective catalysts. After a brief introduction on the concept, types and examples of shape‐selectivity, the available data on MOFs as shape‐selective catalysts have been organized according the nature of active sites promoting the reaction, starting from metal nodes as Lewis acid sites and commenting examples of encapsulated metal nanoparticles (NPs) and molecular guests as centers in various reactions such as addition to carbonyl compounds, hydrogenations, oxidations and oxidative dehydrogenations. The final section provides our view on the current achievements and prospective for future developments in the field.
Assessment of Five Electron‐Shuttling Molecules in the Extracellular Electron Transfer of Electromethanogenesis by using Methanosarcina barkeri
Authors: Liang Tian‐Tian , Zhou Lei , Irfan Muhammad , Bai Yang , Liu Xue‐Zhi , Zhang Ji‐Liang , Wu Zong‐Yang , Wang Wen‐Zhuo , Liu Jin‐Feng , Cheng Lei , Yang Shi‐Zhong , Ye Ru‐Qiang , Gu Ji‐Dong , Mu Bo‐Zhong
Published: August 2020

Electron‐shuttling molecules (ESMs), natural or synthetic, are utilized by microorganisms as electron acceptors or donors to facilitate electron transfer. In this study, five ESMs, namely anthraquinone‐2‐carboxylic acid (AQC), 9,10‐anthraquinone‐2‐sulfonicacid (AQS), 9,10‐anthraquinone‐2,6‐disulfonic acid (AQDS), Neutral red, and Thionin, were selected to assess their effects on electromethanogenesis under different electrochemical potentials and concentrations. Results showed that the rate of methanogenesis achieved in the presence of AQC was 7.4 times higher than that of the control (without ESMs) at −850 mV (vs. Ag/AgCl). The effectiveness on methanogenesis followed AQC, Neutral Red, AQS, AQDS, and Thionin in a decreasing order. Compared with the control, the addition of ESMs did not affect the biomass of methanogens significantly. Meanwhile, qPCR analysis of the ccdA gene indicated that the abundance of the Cytochrome c gene and the extent of CO2 reduction to methane correlated positively. The promoting effect of the selective ESMs on methanogenesis was mainly related to their electron transfer capabilities.
Nachhaltige Unterrichtsvorschläge zur Stickstoffproblematik
Authors: Lüsse Mientje , Brockhage Frauke , Pietzner Verena , Beeken Marco
Published: August 2020

Eine Vielzahl politischer Entschlüsse legen sowohl international als auch in Deutschland fest, Bildung für nachhaltige Entwicklung in den schulischen Kontext zu integrieren. Viele Initiativen wie Fridays For Future verdeutlichen darüber hinaus die Relevanz einer nachhaltigen Entwicklung in der heutigen Zeit. Um diesen Anforderungen gerecht zu werden, werden verschiedene Unterrichtsinhalte zum Thema Nachhaltigkeit in der Reihe „Fridays For Future und Schule?“ dargestellt und durch Experimente und entsprechendes Unterrichtsmaterial ergänzt. Dieser Beitrag behandelt Hintergründe und Auswirkungen der Stickstoffproblematik. Konkrete Unterrichtsvorschläge anhand ausgewählter Experimente und Diskussionsleitfäden sollen den Lernenden zu einem tieferen Verständnis vor dem Hintergrund einer nachhaltigen Lebensweise befähigen.