bluuebunny/crossref_metadata_2025 huggingface dataset:
The Mechanics of Art Materials and Its Future in Heritage Science
Authors: Rogala Dawn V. , DePriest Paula T. , Charola A. Elena , Koestler Robert J.
Published: December 2019

In late 2016, “The Mechanics of Art Materials and Its Future in Heritage Science: A Seminar and Symposium” was held at the Smithsonian Institution’s historic Arts and Industries Building. Organized by the Smithsonian’s Museum Conservation Institute (MCI) and the Royal Danish Academy of Fine Arts, Schools of Architecture, Design and Conservation, the two-day event brought experts in mechanics research from across the globe to discuss current and future trends in the study and preservation of cultural heritage. Speakers represented a continuum of innovative mechanics research in the cultural heritage sector, from its origins at the Smithsonian to current professionals working to shape the field and train future generations of scholars. The event began with the popular paint mechanics workshop created and taught by MCI senior research scientist emeritus Marion Mecklenburg, condensed into a single-day seminar of lectures and discussion. The second day featured an international group of speakers and case studies on the state of mechanics research around the globe, with an afternoon program focused on emerging U.S.-based speakers and their thoughts on the future of the field. This volume reflects a collaborative view of cultural heritage research in mechanics; beginning with a review of mechanics research at the Smithsonian Institution and followed by the nine papers presented by the symposium speakers, this publication incorporates the work of 15 national and international research centers. The Appendix includes a bibliography of Dr. Mecklenburg’s publications and his previously unpublished 1982 report on the mechanical behavior of painting materials.
Comprensión auditiva y percepción multimodal: una nueva mirada a la comprensión de la oralidad desde la coherencia al paradigma comunicativo de enseñanza de idiomas
Authors: Pérez Bernabeu Aarón
Published: December 2019

La actividad comunicativa de la comprensión auditiva suele ser la más problemática para los aprendientes de lenguas extranjeras, debido a que es la destreza más necesitada de una revisión de los contextos en que se presenta en el aula desde la perspectiva de la percepción humana: desentrañar cómo escuchamos nos ayuda a determinar cómo aprender a escuchar otra lengua. En el marco de la percepción multimodal, revisamos los fundamentos de la didáctica de la comprensión auditiva centrados en el español como lengua extranjera para justificar el cambio requerido hacia una didáctica más cercana a los preceptos del paradigma comunicativo, y volcaremos estas conclusiones en sugerencias de creación y transformación de actividades.
La traducción audiovisual como recurso didáctico para mejorar la comprensión audiovisual en lengua extranjera
Authors: Talaván Zanón Noa
Published: December 2019

Las distintas modalidades de traducción audiovisual (TAV), como la subtitulación o el doblaje, pueden utilizarse en el entorno educativo para mejorar diversos tipos de destrezas comunicativas en lengua extranjera (L2). Una de las habilidades lingüísticas más beneficiadas en este contexto es la comprensión oral (o audiovisual), dada la exposición continua del alumno al input en L2, y gracias al trabajo de reformulación para realizar la correspondiente traducción audiovisual del fragmento de vídeo preseleccionado, sea cual sea la modalidad de TAV utilizada. El presente artículo presentará los fundamentos teóricos y metodológicos para la utilización didáctica de la TAV en este contexto.
Didáctica del español con fines médicos y estrategias para el desarrollo de la competencia léxica
Authors: Moreno Navarro Aránzazu , Zagalaz Sánchez María Luisa , González de Mesa Camen González
Published: December 2019

Para planificar una propuesta didáctica de Español para Fines Específicos (EFE) es importante establecer los contenidos léxicos y desarrollar la competencia léxica mediante estrategias que permitan integrar las diferentes destrezas. Por consiguiente, el primer objetivo planteado se enfoca en una reflexión del papel del léxico y el análisis de los mecanismos de almacenamiento y acceso para la adquisición de dicha competencia. Asimismo, se analizan las técnicas de desarrollo de los contenidos léxicos en el ámbito especializado de la Medicina, elaborándose una propuesta didáctica centrada en la enseñanza y aprendizaje de la terminología médica con el enfoque por tareas. Las tareas elaboradas muestran que el aprendizaje del léxico debe producirse mediante estrategias que fomenten la reflexión, fijación y uso de las unidades terminológicas en dicho ámbito especializado.
Na czym polega różnica między bratnią pomocą a agresją? Sowiecki dowcip polityczny o agresji przeciwko Czechosłowacji w 1968 r.
Authors: Kramar Rostysław
Published: December 2019

The article concerns Soviet political jokes that arose as a reaction to the
aggression of the USSR in 1968 in Czechoslovakia. It is emphasized that
political folklore is an important source material that gives a fuller picture of
the contemporary moods of the Soviet society as well as its evaluation of the
Kremlin’s policy towards Czechoslovakia. In this article proposed a thematic
classification of Soviet political jokes on the events of 1968 in Czechoslovakia
and the so-called normalization.
Соціально-психологічні студії в доробку С. Балея
Authors: Mojsijenko Yaroslav
Published: December 2019

The present article deals with historic-psychological research on socialpsychological
heritage of two representatives of Ukrainian Diaspora – Stefan-
Maksym Balej. Topics of scientific interest of S. Balej and O. Kulchytzkyj were
defined. Problems of group psychology, psychology of crowd, propaganda and
ideology, status and subject of social psychology, characteristic features of
Ukrainian national character and group unconcsious has been analyzed and
specified. Cheracteristic features of S. Balej scientific thinking of were shown.
Między oportunizmem a rewolucją. Przeobrażenia instytucji i środowisk artystycznych Bydgoszczy w latach 1980–1981 (studium historyczno-socjologiczne)
Authors: Pastuszewski Stefan
Published: December 2019

The outbreak of “Solidarity” surprised the deep province, especially its artistic community. The seeds of the rebellion struck only in the young creators, especially in those who were not connected with the institutions. Most of them watched the events with concern, waiting for the development of the situation. The less conformist part of the creators however associated with the “Solidarity” movement, for which they organized a concerts and even a special theatrical performance. Young writers wrote occasional poems, and even associated themselves organizationally with “Solidarity” movement.
Spontaneous Cholecystocutaneous Fistula: A rare clinical Entity
Authors: Gupta Amit , Joshua Manoj , Kumar Navin , Chauhan Udit , Gupta Sweety
Published: December 2019

Introduction: Spontaneous Cholecystocutaneous Fistula occurs as a result of complication from untreated gall bladder stone disease infrequently seen in surgical practice due to early diagnosis of gall stone disease with imaging and appropriate and prompt antibiotic and surgical treatment. Case report: We report our experience with a 40-year-old woman who presented with a yellowish discharge from the umbilicus. Abdominal examination revealed a sinus opening at the umbilicus with the yellowish discharge and a vague mass in the right hypochondrium. CT fistulogram showed tract extending form the umbilicus to the gall bladder. Open cholecystectomy with excision of the fistulous tract was carried out. Histopathological examination showed chronic inflammation of the gall bladder with the fistulous tract lined by inflammatory granulation tissue. Post-operative recovery was normal and uneventful. The patient was normal in follow-up. Cholecystocutaneous fistula is a rare clinical entity. The diagnosis is established with CT and MRCP. Surgery remains the mainstay of treatment.
Bax Inhibitor 1 (BI-1) as a conservative regulator of Programmed Cell Death
Authors: Godlewski Mirosław , Kobylińska Agnieszka
Published: December 2019

Programmed cell death (PCD) is a physiological process in which infected or unnecessary cells due to their suicidal death capability can be selectively eliminated. Pro- and antiapoptotic proteins play an important role in the induction or inhibition of this process. Presented article shows property of Bax-1 (BI-1) inhibitor which is one of the conservative protein associated with the endoplasmic reticulum (ER) as well as its cytoprotective role in the regulation of cellular processes. It was shown that: 1) BI-1 is a small protein consisting of 237 amino acids (human protein - 36 kDa) and has 6 (in animals) and 7 (in plants) α-helical transmembrane domains, 2) BI-1 is expressed in all organisms and in most tissues, moreover its level depends on the functional condition of cells and it is involved in the development or reaction to biotic and abiotic stresses, 3) BI-1 forms a pH-dependent Ca2+ channel enabling release of these ions from the ER, 4) cytoprotective effects of BI-1 requires a whole, unchanged C-terminus, 5) BI-1 can interact directly with numerous other proteins, BI-1 protein affects numerous cellular processes, including: counteracting ER stress, oxidative stress, loss of cellular Ca2+ homeostasis as well as this protein influences on sphingolipid metabolism, autophagy, actin polymerization, lysosomal activity and cell proliferation. Studies of BI-1 functions will allow understanding the mechanisms of anticancer therapy or increases the knowledge of crop tolerance to environmental stresses.
Visualização dos Acessos a Fóruns em um Ambiente de Ensino à Distância
Authors: Tereso Cláudio Filipe da Silva , Carvalho Elizabeth Simão
Published: December 2019

Dos vários ambientes de aprendizagem virtual de ensino à distância existentes, o Moodle é a plataforma mais utilizada. No entanto, apesar de ser uma plataforma muito completa e flexível para o ensino à distância (EAD), ela não dispõe de ferramentas de fácil utilização para que os docentes possam aferir a interação dos alunos, dispondo unicamente de um módulo de visualização dos registros de utilização. A VAFAE - Visualização dos Acessos a Fóruns num Ambiente EAD é uma ferramenta web que mapeia visualmente esses dados e a sua respectiva análise numérica. De uma forma mais específica, a VAFAE visa auxiliar os docentes a perceber melhor o nível e qualidade de interação dos alunos com os módulos das unidades curriculares de EAD. Este artigo faz um resumo das ferramentas semelhantes existentes, aborda alguns conceitos subjacentes à teoria de visualização de informação e finalmente explica como foi construído o VAFAE e que tecnologias foram usadas.
Social Cohesion in Times of Forced Displacement. The Perspective of Youth in Jordan
Authors: Kuhnt Jana , Rischke Ramona , David Anda , Lechtenfeld Tobias
Published: December 2019

Dieser Artikel untersucht die Wahrnehmung des sozialen Zusammenhalts von in Jordanien lebenden jungen Erwachsenen (18-35 Jahre), sowie Veränderungen dieser Wahrnehmungen in Zeiten, in denen hohe und wachsende Zahlen syrischer Geflüchteter im Libanon leben. Ergebnisse einer Online-Umfrage weisen auf einen leichten Rückgang des sozialen Zusammenhalts in Jordanien hin. Junge Menschen wollen Akteur*innen des Wandels sein und haben ein klares Verlangen nach mehr sozialer Teilhabe. Unsere Ergebnisse weisen auf Möglichkeiten zur Stärkung des sozialen Zusammenhalts zwischen jungen Angehörigen der Mehrheitsgesellschaft und Geflüchteten sowie auf Hindernisse für die aktivere Teilnahme von jungen Menschen an der Gesellschaft hin.
‘What can be described can happen too…’: describing text semantics as a model structure of transworld relationships
Authors: Zolyan S. T.
Published: December 2019

In this article, I explore the content-related and formal aspects of describing the multidi­mensional semantic organization of a text, particularly, I focus on the possibility of using the apparatus of modal semantics to identify the relationship between sentential complexes. To those ends, I employ the concepts of model, model structure, and centred world. The latter is a system of functions that correlate language expressions, the language expressions of a text, states of affairs (possible worlds) described by language expressions, and the contexts in which a text occurs. Existence in the worlds of the text correlates with the possibility of description. Presumably, the text is a twofold notion: it refers to a linear sequence of segments and a mul­tidimensional semantic structure. In this work, I demonstrate the possibilities of integrating both approaches. I consider the correlation between the mechanisms of text coherence, on the one hand, and the relationships of transworld accessibility and of the identification of de­scribed individuals across possible worlds, on the other. Probably, the variety of cohesion mechanisms does not make it possible to use a single identification mechanism and requires taking into account various competing approaches. I illustrate the above conclusions, using Pushkin’s draft ‘If I were Tsar…’
Text reinterpretation and the motif of transformation in a short form of Internet poetry
Authors: Krongauz M. A.
Published: December 2019

In this article, I analyse the vehicles of humour in two short forms of Internet poetry that developed in the 2000s: the pirozhok (literary, a ‘stuffed bun’) and the poroshok (‘powder’). Poems of these genres are quatrains written in iambic tetrameter. Pirozhoks have no rhyme scheme, whereas, in poroshoks, the fourth line truncated to two syllables rhymes with the second line. The poroshok as a genre is a descendant of the pirozhok. Just as in jokes and several other genres, a punchline plays an important role in pirozhoks and poroshoks. In Russian, the punchline is termed puant, which is a borrowing from French (la pointe). The truncation of the final line in a poroshok puts it in a special position. The truncated line, independently or together with the third line, comprises the punchline of a poroshok. The punchline is practically mandatory and may be presented in greater detail inasmuch as it does not simply violate the reader’s expectations but enters into conflict with the beginning of the verse and forces the reader to reinterpret it. Reinterpretation manes that readers change their perception of the situation or carry out a ‘transformation’, that is, substitute the character or the entire situation. I identify common transformations, namely: thing → person, person → thing, person → animal, etc. Most frequent is the reciprocal transformation of men and cats. The transformation motif binds objects in the manner of a metaphor.
Development of a welfare assessment protocol for dairy calves from birth through to weaning
Authors: Barry J , Kennedy E , Sayers R , de Boer IJM , Bokkers EAM
Published: December 2019

The aim of this study was to develop a welfare assessment protocol using different indicators, for pre-weaned dairy calves, that is feasible and time efficient. To this end, the protocol had to combine animal-based indicators (measurements on physiology, general appearance and behaviour) providing the basis for welfare assessment, with resource-based indicators (measurements on management and the environment) providing the basis for identifying risk factors. Indicators, both animal-and resource-based, were selected by a review of existing literature and a process of expert consultation. Following the formulation phase, the protocol was then applied on five Irish dairy farms to develop further for completeness and on-farm feasibility. After each on-farm application, the protocol was critically evaluated, and modifications were made accordingly. Upon completion of the on-farm application phase, a feasible, reliable and time-efficient protocol was produced.
Amyloid and tau accumulate across distinct spatial networks and are differentially associated with brain connectivity
Authors: Pereira Joana B , Ossenkoppele Rik , Palmqvist Sebastian , Strandberg Tor Olof , Smith Ruben , Westman Eric , Hansson Oskar
Published: December 2019

The abnormal accumulation of amyloid-β and tau targets specific spatial networks in Alzheimer’s disease. However, the relationship between these networks across different disease stages and their association with brain connectivity has not been explored. In this study, we applied a joint independent component analysis to 18F- Flutemetamol (amyloid-β) and 18F-Flortaucipir (tau) PET images to identify amyloid-β and tau networks across different stages of Alzheimer’s disease. We then assessed whether these patterns were associated with resting-state functional networks and white matter tracts. Our analyses revealed nine patterns that were linked across tau and amyloid-β data. The amyloid-β and tau patterns showed a fair to moderate overlap with distinct functional networks but only tau was associated with white matter integrity loss and multiple cognitive functions. These findings show that amyloid-β and tau have different spatial affinities, which can be used to understand how they accumulate in the brain and potentially damage the brain’s connections.
Sequential phosphorylation of NDEL1 by the DYRK2-GSK3β complex is critical for neuronal morphogenesis
Authors: Woo Youngsik , Kim Soo Jeong , Suh Bo Kyoung , Kwak Yongdo , Jung Hyun-Jin , Nhung Truong Thi My , Mun Dong Jin , Hong Ji-Ho , Noh Su-Jin , Kim Seunghyun , Lee Ahryoung , Baek Seung Tae , Nguyen Minh Dang , Choe Youngshik , Park Sang Ki
Published: December 2019

Neuronal morphogenesis requires multiple regulatory pathways to appropriately determine axonal and dendritic structures, thereby to enable the functional neural connectivity. Yet, however, the precise mechanisms and components that regulate neuronal morphogenesis are still largely unknown. Here, we newly identified the sequential phosphorylation of NDEL1 critical for neuronal morphogenesis through the human kinome screening and phospho-proteomics analysis of NDEL1 from mouse brain lysate. DYRK2 phosphorylates NDEL1 S336 to prime the phosphorylation of NDEL1 S332 by GSK3β. TARA, an interaction partner of NDEL1, scaffolds DYRK2 and GSK3β to form a tripartite complex and enhances NDEL1 S336/S332 phosphorylation. This dual phosphorylation increases the filamentous actin dynamics. Ultimately, the phosphorylation enhances both axonal and dendritic outgrowth and promotes their arborization. Together, our findings suggest the NDEL1 phosphorylation at S336/S332 by the TARA-DYRK2-GSK3β complex as a novel regulatory mechanism underlying neuronal morphogenesis.
Evaluation of complexity and deliverability of prostate cancer treatment plans designed with a knowledge‐based VMAT planning technique
Authors: Wall Phillip D. H. , Fontenot Jonas D.
Published: December 2019

Purpose

Knowledge‐based planning (KBP) techniques have been reported to improve plan quality, efficiency, and consistency in radiation therapy. However, plan complexity and deliverability have not been addressed previously for treatment plans guided by an established in‐house KBP system. The purpose of this work was to assess dosimetric, mechanical, and delivery properties of plans designed with a common KBP method for prostate cases treated via volumetric modulated arc therapy (VMAT).

Methods

Thirty‐one prostate patients previously treated with VMAT were replanned with an in‐house KBP method based on the overlap volume histogram. VMAT plan complexities of the KBP plans and the reference clinical plans were quantified via monitor units, modulation complexity scores, the edge metric, and average leaf motion per degree of gantry rotation. Each set of plans was delivered to the same diode array and agreement between computed and measured dose distributions was evaluated using the gamma index. Varying percent dose‐difference (1–3%) and distance‐to‐agreement (1 mm to 3 mm) thresholds were assessed for gamma analyses.

Results

Knowledge‐based planning (KBP) plans achieved average reductions of 6.4 Gy (P < 0.001) and 8.2 Gy (P < 0.001) in mean bladder and rectum dose compared to reference plans, while maintaining clinically acceptable target dose. However, KBP plans were significantly more complex than reference plans in each evaluated metric (P < 0.001). KBP plans also showed significant reductions (P < 0.05) in gamma passing rates at each evaluated criterion compared to reference plans.

Conclusions

While KBP plans had significantly reduced bladder and rectum dose, they were significantly more complex and had significantly worse quality assurance outcomes than reference plans. These results suggest caution should be taken when implementing an in‐house KBP technique.
Unraveling Framework Nucleic Acid–Skin Cell Interactions with a Co‐Culture System
Authors: Wiraja Christian , Siantoputri Maria Esterlita , Liu Sihan , Shum Ho Cheung , Xu Chenjie
Published: December 2019

Framework nucleic acid (FNA) is an emerging drug carrier platform, with its biodegradability and uniform, tunable structures. Recently, its applicability in transdermal drug delivery has been demonstrated, extending the range of applications that are predominantly based on intravenous injection. However, FNA's interaction and impact toward the skin cells are yet to be elucidated. This study employs an optically clear keratinocyte/fibroblast co‐culture system to visualize the FNA–skin cell interactions. FNA's influence on these cells is evaluated through polymerase chain reaction analyses and metabolism assays. A size‐dependent interaction and cellular internalization on both keratinocytes and fibroblasts is observed, with no adverse effects on cell viability and functions.
Engineering Lipid Membranes with Programmable DNA Nanostructures
Authors: Shen Qi , Grome Michael W. , Yang Yang , Lin Chenxiang
Published: December 2019

Lipid and DNA are abundant biomolecules with critical functions in cells. The water‐insoluble, amphipathic lipid molecules are best known for their roles in energy storage (e.g., as triglyceride), signaling (e.g., as sphingolipid), and compartmentalization (e.g., by forming membrane‐enclosed bodies). The soluble, highly negatively charged DNA, which stores the cells' genetic information, has proven to be an excellent material for constructing programmable nanostructures in vitro thanks to its self‐assembling capabilities. These two seemingly distant molecules make contact within cell nuclei, often via lipidated proteins, with proposed functions of modulating chromatin structures. Carefully formulated lipid/DNA complexes are promising reagents for gene therapy. The past few years have seen an emerging research field of interfacing DNA nanostructures with lipid membranes, with an overarching goal of generating DNA/lipid hybrid materials that possess novel and controllable structure, dynamics, and function. An arsenal of DNA‐based tools has been created to coat, mold, deform, and penetrate lipid bilayers, affording the ability to manipulate membranes with nanoscopic precision. These membrane engineering methods not only enable quantitative biophysical studies, but also open new opportunities in synthetic biology (e.g., artificial cells) and therapeutics (e.g., drug delivery).
Complex‐Shaped Cellulose Composites Made by Wet Densification of 3D Printed Scaffolds
Authors: Hausmann Michael K. , Siqueira Gilberto , Libanori Rafael , Kokkinis Dimitri , Neels Antonia , Zimmermann Tanja , Studart André R.
Published: December 2019

Cellulose is an attractive material resource for the fabrication of sustainable functional products, but its processing into structures with complex architecture and high cellulose content remains challenging. Such limitation has prevented cellulose‐based synthetic materials from reaching the level of structural control and mechanical properties observed in their biological counterparts, such as wood and plant tissues. To address this issue, a simple approach is reported to manufacture complex‐shaped cellulose‐based composites, in which the shaping capabilities of 3D printing technologies are combined with a wet densification process that increases the concentration of cellulose in the final printed material. Densification is achieved by exchanging the liquid of the wet printed material with a poor solvent mixture that induces attractive interactions between cellulose particles. The effect of the solvent mixture on the final cellulose concentration is rationalized using solubility parameters that quantify the attractive interparticle interactions. Using X‐ray diffraction analysis and mechanical tests, 3D printed composites obtained through this process are shown to exhibit highly aligned microstructures and mechanical properties significantly higher than those obtained by earlier additively manufactured cellulose‐based materials. These features enable the fabrication of cellulose‐rich synthetic structures that more closely resemble the exquisite designs found in biological materials grown by plants in nature.
Reversible Crumpling of 2D Titanium Carbide (MXene) Nanocoatings for Stretchable Electromagnetic Shielding and Wearable Wireless Communication
Authors: Li Yang , Tian Xi , Gao Si‐Ping , Jing Lin , Li Kerui , Yang Haitao , Fu Fanfan , Lee Jim Yang , Guo Yong‐Xin , Ho John S. , Chen Po‐Yen
Published: December 2019

In the emerging Internet of Things, stretchable antennas can facilitate wireless communication between wearable and mobile electronic devices around the body. The proliferation of wireless devices transmitting near the human body also raises interference and safety concerns that demand stretchable materials capable of shielding electromagnetic interference (EMI). Here, an ultrastretchable conductor is fabricated by depositing a crumple‐textured coating composed of 2D Ti3C2Tx nanosheets (MXene) and single‐walled carbon nanotubes (SWNTs) onto latex, which can be fashioned into high‐performance wearable antennas and EMI shields. The resulting MXene‐SWNT (S‐MXene)/latex devices are able to sustain up to an 800% areal strain and exhibit strain‐insensitive resistance profiles during a 500‐cycle fatigue test. A single layer of stretchable S‐MXene conductors demonstrate a strain‐invariant EMI shielding performance of ≈30 dB up to 800% areal strain, and the shielding performance is further improved to ≈47 and ≈52 dB by stacking 5 and 10 layers of S‐MXene conductors, respectively. Additionally, a stretchable S‐MXene dipole antenna is fabricated, which can be uniaxially stretched to 150% with unaffected reflected power <0.1%. By integrating S‐MXene EMI shields with stretchable S‐MXene antennas, a wearable wireless system is finally demonstrated that provides mechanically stable wireless transmission while attenuating EM absorption by the human body.
Nanohybrid Materials with Tunable Birefringence via Cation Exchange in Polymer Films
Authors: Oosterlaken Bernette M. , Xu Yifei , van Rijt Mark M. J. , Pilz da Cunha Marina , Timmermans Gilles H. , Debije Michael G. , Friedrich Heiner , Schenning Albertus P. H. J. , Sommerdijk Nico A. J. M.
Published: December 2019

In this work, a nanohybrid material based on a freestanding polymeric liquid crystal network capable of postmodification via cation exchange to tune birefringence is proposed. The smectic liquid crystal films can be infiltrated with a variety of cations, thereby changing the refractive indices (ne and no) and the effective birefringence (Δn) of the nanohybrid material, with reversible cation infiltration occurring within minutes. Birefringence could be tuned between values of 0.06 and 0.19, depending on the cation infiltrated into the network. Upon infiltration, a decrease in the smectic layer spacing is found with layer contraction independent of the induced change in birefringence. Potential applications are in the field of specialty optical devices, such as flexible, retunable reflective filters.
Revealing the Dynamics of Hybrid Metal Halide Perovskite Formation via Multimodal In Situ Probes
Authors: Song Tze‐Bin , Yuan Zhenghao , Mori Megumi , Motiwala Faizan , Segev Gideon , Masquelier Eloïse , Stan Camelia V. , Slack Jonathan L. , Tamura Nobumichi , Sutter‐Fella Carolin M.
Published: December 2019

The exploration of the synthetic space of halide perovskites hinges on an enormous number of parameters requiring time‐consuming experimentation to decouple and optimize. Here, the formation of the prototype material CH3NH3PbI3 (MAPbI3) is investigated at different time and length scales using multimodal in situ measurements to monitor the evolution of crystalline phases, morphology, and photoluminescence as a function of the lead precursors. Kinetically fast formation of crystalline precursor phases already during the spin‐coat deposition is observed using lead iodide (PbI2) or lead chloride (PbCl2) routes. These precursor phases most likely template final MAPbI3 film morphology. In particular, the emergence of the “needle‐like” structure is shown to appear before film annealing. In situ photoluminescence measurements suggest nanoscale nucleation followed by rapid nuclei densification and growth. Using this multimodal in situ approach, different formation pathways can be identified either via precursor phases in the PbI2 and PbCl2 routes or direct perovskite formation from molecular building blocks as observed in the lead acetate (PbAc2) route. Correlation of in situ results with photovoltaic device performance demonstrates the power of in situ multimodal techniques, paves the way to a fast screening of synthetic parameters, and ultimately leads to controlled synthetic procedures that yield high‐efficiency devices.
Swim Bladder as a Novel Biomaterial for Cardiovascular Materials with Anti‐Calcification Properties
Authors: Liu Jing , Li Binhan , Jing Huimin , Wu Yongjian , Kong Deling , Leng Xigang , Wang Zhihong
Published: December 2019

Calcification is a major cause of cardiovascular materials failure and deterioration, which leads to the restriction of their wide application. To develop new materials with anti‐calcification capability is an urgent clinical requirement. Herein, a natural material derived from swim bladders as one promising candidate is introduced, which is prepared by decellularization and glutaraldehyde (GA) crosslinking. Data show that the swim bladder is mainly composed of collagen I, glycosaminoglycan (GAG), and elastin, especially rich in elastin, in accordance with higher elastic modulus in comparison to bovine pericardium. Moreover, the calcification of this material is proved dramatically lower than that of bovine pericardium by in vitro calcification assessments and in vivo assay using a rat subcutaneous implantation model. Meanwhile, good cytocompatibility, hemocompatibility, and enzymatic stability are demonstrated by in vitro assays. Further, a small diameter vascular graft using this material is successfully developed by rolling method and in situ implantation assay using a rat abdominal artery replacement model shows great performances in the aspect of higher patency and lower calcification. Taken together, these superior properties of swim bladder‐derived material in anti‐calcification, proper mechanical strength and stability, and excellent hemocompatibility and cytocompatibility endow it a great candidate as cardiovascular biomaterials.
Stimuli‐Responsive Hydrogels with Antibacterial Activity Assembled from Guanosine, Aminoglycoside, and a Bifunctional Anchor
Authors: Hu Jingjing , Hu Qianyu , He Xu , Liu Cenxi , Kong Yanlong , Cheng Yiyun , Zhang Yadong
Published: December 2019

Multistimuli‐responsive hydrogels with specific functions have attracted great interest for biomedical applications; however, these smart hydrogels usually require the presynthesis of macromolecular building blocks with multiple ligands and the integration of bioactive cargoes into the gels. Here, a multistimuli‐responsive hydrogel with potent antibacterial activity by a combination of supramolecular assembly and iminoboronate chemistry is reported. The hydrogel consists of all‐small‐molecule building blocks including aminoglycoside, guanosine, potassium ion, and a bifunctional anchor bearing both boronic acid and aldehyde groups. Guanosines form quadruplexes in the presence of potassium ions via supramolecular assembly, and the bifunctional anchor connects aminoglycosides, a class of potent antibiotics to cis‐diol groups on quadruplexes via dynamic iminoboronate chemistry, yielding a smart hydrogel containing abundant antibiotics. The hydrogel is sensitive to multistimuli such as heat, acids, oxidants, glucose and crown ether, which promote the release of antibiotics from the gels. Moreover, the prepared hydrogels show potent antibacterial activities both in vitro and in vivo. The results provide a new option to prepare antibacterial hydrogels with multistimuli responsiveness via facile chemistry using all‐small‐molecule building blocks.
Photocatalytic and Photoelectrochemical Systems: Similarities and Differences
Authors: Wu Hao , Tan Hui Ling , Toe Cui Ying , Scott Jason , Wang Lianzhou , Amal Rose , Ng Yun Hau
Published: December 2019

Photocatalytic and photoelectrochemical processes are two key systems in harvesting sunlight for energy and environmental applications. As both systems are employing photoactive semiconductors as the major active component, strategies have been formulated to improve the properties of the semiconductors for better performances. However, requirements to yield excellent performances are different in these two distinctive systems. Although there are universal strategies applicable to improve the performance of photoactive semiconductors, similarities and differences exist when the semiconductors are to be used differently. Here, considerations on selected typical factors governing the performances in photocatalytic and photoelectrochemical systems, even though the same type of semiconductor is used, are provided. Understanding of the underlying mechanisms in relation to their photoactivities is of fundamental importance for rational design of high‐performing photoactive materials, which may serve as a general guideline for the fabrication of good photocatalysts or photoelectrodes toward sustainable solar fuel generation.
Construction of Chiral, Helical Nanoparticle Superstructures: Progress and Prospects
Authors: Mokashi‐Punekar Soumitra , Zhou Yicheng , Brooks Sydney C. , Rosi Nathaniel L.
Published: December 2019

Chiral nanoparticle (NP) superstructures, in which discrete NPs are assembled into chiral architectures, represent an exciting and growing class of nanomaterials. Their enantiospecific properties make them promising candidates for a variety of potential applications. Helical NP superstructures are a rapidly expanding subclass of chiral nanomaterials in which NPs are arranged in three dimensions about a screw axis. Their intrinsic asymmetry gives rise to a variety of interesting properties, including plasmonic chiroptical activity in the visible spectrum, and they hold immense promise as chiroptical sensors and as components of optical metamaterials. Herein, a concise history of the foundational conceptual advances that helped define the field of chiral nanomaterials is provided, and some of the major achievements in the development of helical nanomaterials are highlighted. Next, the key methodologies employed to construct these materials are discussed, and specific merits that are offered by each assembly methodology are identified, as well as their potential disadvantages. Finally, some specific examples of the emerging applications of these materials are discussed and some areas of future development and research focus are proposed.
Magnetic Shape Memory Polymers with Integrated Multifunctional Shape Manipulation
Authors: Ze Qiji , Kuang Xiao , Wu Shuai , Wong Janet , Montgomery S. Macrae , Zhang Rundong , Kovitz Joshua M. , Yang Fengyuan , Qi H. Jerry , Zhao Ruike
Published: December 2019

Shape‐programmable soft materials that exhibit integrated multifunctional shape manipulations, including reprogrammable, untethered, fast, and reversible shape transformation and locking, are highly desirable for a plethora of applications, including soft robotics, morphing structures, and biomedical devices. Despite recent progress, it remains challenging to achieve multiple shape manipulations in one material system. Here, a novel magnetic shape memory polymer composite is reported to achieve this. The composite consists of two types of magnetic particles in an amorphous shape memory polymer matrix. The matrix softens via magnetic inductive heating of low‐coercivity particles, and high‐remanence particles with reprogrammable magnetization profiles drive the rapid and reversible shape change under actuation magnetic fields. Once cooled, the actuated shape can be locked. Additionally, varying the particle loadings for heating enables sequential actuation. The integrated multifunctional shape manipulations are further exploited for applications including soft magnetic grippers with large grabbing force, reconfigurable antennas, and sequential logic for computing.
Ferroelectric Domain Wall Motion in Freestanding Single‐Crystal Complex Oxide Thin Film
Authors: Bakaul Saidur R. , Kim Jaegyu , Hong Seungbum , Cherukara Mathew J. , Zhou Tao , Stan Liliana , Serrao Claudy R. , Salahuddin Sayeef , Petford‐Long Amanda K. , Fong Dillon D. , Holt Martin V.
Published: December 2019

Ferroelectric domain walls in single‐crystal complex oxide thin films are found to be orders of magnitude slower when the interfacial bonds with the heteroepitaxial substrate are broken to create a freestanding film. This drastic change in domain wall kinetics does not originate from the alteration of epitaxial strain; rather, it is correlated with the structural ripples at mesoscopic length scale and associated flexoelectric effects induced in the freestanding films. In contrast, the effects of the bond‐breaking on the local static ferroelectric properties of both top and bottom layers of the freestanding films, such as domain wall width and spontaneous polarization, are modest and governed by the change in epitaxy‐induced compressive strain.
Reactive Precursor Particles as Synthetic Platform for the Generation of Functional Nanoparticles, Nanogels, and Microgels
Authors: Gruber Alexandra , Navarro Lucila , Klinger Daniel
Published: December 2019

Precise control of the chemical functionality of polymer nanoparticles is a key requirement in tailoring their (dynamic) colloidal properties toward advanced applications. However, current synthetic techniques are still limited in the versatility of chemical design and preparation of such functional colloidal nanomaterials. Two major challenges remain: First, various particle preparation methods are restricted in their functional group tolerance, thus hindering certain combinations of polymer backbones with specific functional groups. Second, the preparation of particles with different functionalities requires the synthesis of different particle batches. But this often results in a simultaneous variation of colloidal features. As a result, the accurate determination of important structure–property relations is still hindered. To address these restrictions, postmodification of preformed reactive particles is gaining more attention. This technique has evolved from polymer synthesis, where postpolymerization functionalization enables the introduction of a plethora of functional groups without changing the degree of polymerization and the molecular weight distribution. Similarly, modifying precursor particles enables the introduction of functional groups into particles while reducing variations in colloidal features, e.g., particle size and size distribution. This powerful synthetic method complements established procedures for functionalization of particle surfaces, thereby enabling the facile preparation of (multi‐)functional particle libraries, which will allow precise investigations of structure–property relations.
Hierarchical N‐Doped HMCN/CNT Hybrid Carbon Frameworks Assembling Cobalt Selenide Nanoparticles for Advanced Properties of Lithium/Sodium Storage
Authors: Zhou Kehan , Han Yue , Tang Dongmei , Wu Huayu , Wu Xiaoyu , Diao Guowang , Li Haibo , Chen Ming
Published: December 2019

A hybrid nanostructure with Co0.85Se nanoparticles anchored in nitrogen‐doped hollow mesoporous carbon nanospheres/carbon nanotubes (Co0.85Se/N‐HMCNs/CNTs) is elaborately fabricated by a pyrolysis–reduction–selenization strategy derived from yolk–shell zeolitic imidazolate framework‐67 (ZIF‐67)@HMCNs, which are synthesized by the confined growth of ZIF‐67 inside HMCNs regarded as nanoreactors. Benefitting from the robust hollow carbon frameworks made of nitrogen‐doped hollow mesoporous carbon nanospheres, carbon nanotubes, and highly active Co0.85Se ultrafine nanoparticles, the as‐prepared nanocomposites show greatly enhanced lithium/sodium storage properties. When the Co0.85Se/N‐HMCNs/CNTs are applied to lithium‐ion batteries as anode materials, the advanced nanocomposite delivers excellent cycling stability (286 and 153 mA h g−1at 10 A g−1after 5000 and 10 000 cycles) and high rate performance (501 mA h g−1at 5 A g−1). When the Co0.85Se/N‐HMCNs/CNTs are applied to sodium‐ion batteries as anode materials, the material realizes better cycling performance (102 mA h g−1at 1 A g−1after 1000 cycles) and excellent rate performance (132 mA h g−1at 5 A g−1).
C–H Functionalization of Aromatic Amides
Authors: Zheng Quan , Liu Chen‐Fu , Chen Jie , Rao Guo‐Wu
Published: December 2019

Since the beginning of the 21stcentury, significant progress has been made in transition metal‐catalyzed C–H functionalization of aromatic amides. The achievements in this field have mainly focused onortho(proximal) functionalization, there have been far fewer reports on remote C–H functionalization, andpara‐andmeta‐selective functionalizations remain a major challenge. Interestingly, there are few related comments in this field. In a few published cases, the scope of the report is relatively narrow, either to comment on the functionalization of a specific directing group or to summarize the functionalization of a specific reaction site. Herein, for the first time, we have comprehensively summarized the C–H functionalization of aromatic amides. This review is divided into three parts:ortho‐,para‐andmeta‐C–H functionalization of aromatic amides, and is subdivided according to the type of catalyst. The directing groups, reaction types, conditions, mechanism and applications of the corresponding reactions are discussed in detail.

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Thermodynamic Reaction Control of Nucleoside Phosphorolysis
Authors: Kaspar Felix , Giessmann Robert T. , Neubauer Peter , Wagner Anke , Gimpel Matthias
Published: December 2019

Nucleoside analogs represent a class of important drugs for cancer and antiviral treatments. Nucleoside phosphorylases (NPases) catalyze the phosphorolysis of nucleosides and are widely employed for the synthesis of pentose‐1‐phosphates and nucleoside analogs, which are difficult to access via conventional synthetic methods. However, for the vast majority of nucleosides, it has been observed that either no or incomplete conversion of the starting materials is achieved in NPase‐catalyzed reactions. For some substrates, it has been shown that these reactions are reversible equilibrium reactions that adhere to the law of mass action. In this contribution, we broadly demonstrate that nucleoside phosphorolysis is a thermodynamically controlled endothermic reaction that proceeds to a reaction equilibrium dictated by the substrate‐specific equilibrium constant of phosphorolysis, irrespective of the type or amount of NPase used, as shown by several examples. Furthermore, we explored the temperature‐dependency of nucleoside phosphorolysis equilibrium states and provide the apparent transformed reaction enthalpy and apparent transformed reaction entropy for 24 nucleosides, confirming that these conversions are thermodynamically controlled endothermic reactions. This data allows calculation of the Gibbs free energy and, consequently, the equilibrium constant of phosphorolysis at any given reaction temperature. Overall, our investigations revealed that pyrimidine nucleosides are generally more susceptible to phosphorolysis than purine nucleosides. The data disclosed in this work allow the accurate prediction of phosphorolysis or transglycosylation yields for a range of pyrimidine and purine nucleosides and thus serve to empower further research in the field of nucleoside biocatalysis.

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Nanoscopic Insights of Amphiphilic Peptide against the Oligomer Assembly Process to Treat Huntington's Disease
Authors: He Ruei‐Yu , Lai Xiang‐Me , Sun Chia‐Sui , Kung Te‐Shien , Hong Jhu‐Ying , Jheng Yu‐Song , Liao Wei‐Neng , Chen Jen‐Kun , Liao Yung‐Feng , Tu Pang‐Hsien , Huang Joseph Jen‐Tse
Published: December 2019

Finding an effective therapeutic regimen is an urgent demand for various neurodegenerative disorders including Huntington's disease (HD). For the difficulties in observing the dynamic aggregation and oligomerization process of mutant Huntingtin (mHtt) in vivo, the evaluation of potential drugs at the molecular protein level is usually restricted. By combing lifetime‐based fluorescence microscopies and biophysical tools, it is showcased that a designed amphiphilic peptide, which targets the mHtt at an early stage, can perturb the oligomer assembly process nanoscopically, suppress the amyloid property of mHtt, conformationally transform the oligomers and/or aggregates of mHtt, and ameliorate mHtt‐induced neurological damage and aggregation in cell and HD mouse models. It is also found that this amphiphilic peptide is able to transport to the brain and rescue the memory deficit through intranasal administration, indicating its targeting specificity in vivo. In summary, a biophotonic platform is provided to investigate the oligomerization/aggregation process in detail that offers insight into the design and effect of a targeted therapeutic agent for Huntington's disease.
Universal Scaling Law for the Size Effect on Superelasticity at the Nanoscale Promotes the Use of Shape‐Memory Alloys in Stretchable Devices
Authors: Fuster Valeria , Gómez‐Cortés José F. , Nó María L. , San Juan Jose M.
Published: December 2019

Shape‐memory alloys (SMAs) are the most stretchable metallic materials thanks to their superelastic behavior associated with the stress‐induced martensitic transformation. This property makes SMAs of potential interest for flexible and wearable electronic technologies, provided that their properties will be retained at small scale. Nanocompression experiments on Cu‐Al‐Be SMA single crystals demonstrate that micro‐ and nanopillars, between 2 µm and 260 nm in diameter, exhibit a reproducible superelastic behavior fully recoverable up to 8% strain, even at the nanoscale. Additionally, these micro‐/nanopillars exhibit a size effect on the critical stress for superelasticity, which dramatically increases for pillars smaller than ≈1 µm in diameter, scaling with a power law of exponent n = −2. The observed size effect agrees with a theoretical model of homogeneous nucleation of martensite at small scale and the universality of this scaling power law for Cu‐based SMAs is proposed. These results open new directions for using SMAs as stretchable conductors and actuating devices in flexible and wearable technologies.
Dissociating Water at n‐Si Photoanodes Partially Covered with Fe Catalysts
Authors: Oh Kiseok , Dorcet Vincent , Fabre Bruno , Loget Gabriel
Published: December 2019

Stable, efficient, and low‐cost photoanodes are urgently required for manufacturing water‐splitting photoelectrochemical cells. Although silicon is a promising photoelectrode substrate, photocorrosion prevents its use in such devices, especially when employed as photoanodes for the oxygen evolution reaction (OER). Here, it is shown that Fe nanoparticles (NPs), deposited by cathodic electrodeposition onto n‐Si, can promote hole transfer for the OER. The influence of the surface coverage, the Si structure, as well as the electrolyte are studied here in detail. It is reported that the NP density and the Si structuration drastically affect the photoelectrochemical performance and that the electrolyte influences the stability, allowing operation times as long as 130 h for these inhomogeneously coated photoelectrodes.