bluuebunny/crossref_metadata_2025 huggingface dataset:
Engagement for Freedom
Authors: Rendtorff Jacob Dahl ,   Philosophy Documentation Center
Published: June 2020

This article presents Jean-Paul Sartre’s concept of the tension between existence and politics and the role of political commitment in existentialist philosophy. Based on Sartre’s concept of engagement, the article analyzes the transition from the personal to the political perceived as a movement from personal moral consciousness to the awareness of the importance of the individual as a social actor and citizen in society. Sartre’s concept of political engagement can be characterized as critical intellectual commitment and “Socratic Citizenship.” Accordingly, this article is also an acknowledgment of the two important philosophers of ecoethica, Tomonbu Imamichi and Peter Kemp, both committed public intellectuals who said that the role of the philosopher is to contribute to the public affair of cosmopolitan society. Thus, the article presents the political engagement in four major parts: (1) From the existential to political engagement, (2) Political commitment as a struggle for human freedom, (3) The Socratic Citizenship, and (4). Conditions of authentic political action. Political engagement represents an effort to realize the respect owed to each individual as a universal singular, as well as that owed to freedom and democracy in the Kingdom of Ends.
Croton calcareus: a new species of dragon’s blood (Euphorbiaceae) from dry forest in the state of Chiapas, Mexico
Authors: Mateo-Ramírez Leticia , Riina Ricarda
Published: June 2020

We describe Croton calcareus Riina & Mateo-Ram. sp. nov., a new species in Croton section Cyclostigma (dragon’s blood trees) from the state of Chiapas (Mexico). This species is a small tree growing in dry forest on calcareous substrates. Both morphological and molecular data support C. calcareus sp. nov. as a new species closely related to C. redolens, another dry forest taxon from northern Venezuela. We provide illustrations, a distribution map and suggestions for species conservation status. The new species along with Croton draco are the only known representatives of C. section Cyclostigma occurring in Mexico.
Price Differences between Voting and Non-Voting Shares in Crisis and Boom*
Authors: Niehoff Karin , Laskowski Piotr
Published: June 2020

When a company issues both voting and non-voting shares, the prices are usually different, due to the value of the voting right versus the preferred dividend of the non-voting share. This price difference may well be influenced by the business cycle. We analyze the price differences between voting and non-voting shares in Germany and Italy in different business cycles during the period 2003–2013, but find little influence attributable to the business cycle. However, the impact of the ownership structure and the market performance on the prices of voting and non-voting shares do differ in crisis and boom periods.
Legitimizing a Diversity Policy in a Challenging Environment: A Case Study of a French Business School
Authors: Marais Magalie , Joly Cédrine , Meyer Maryline , Jaeck Mélanie , Kessari Myriam , Andiappan Meena , Dufour Lucas
Published: June 2020

This paper explores how a diversity policy is legitimized along moral, pragmatic and cognitive dimensions in a challenging environment (conflicting demands with regard to diversity). In this case study-based paper, we use evidence gathered from 92 interviews with members of key stakeholder groups, observation, and secondary data sources in a French business school. We find that perceptions about the legitimacy of a diversity policy may be ambivalent when legitimacy is evaluated along several dimensions. We conclude that legitimizing a diversity policy requires step-by-step management, with the organization selecting and combining various legitimization strategies over time.
Le gendarme et les festivals
Authors: Picaud Myrtille
Published: June 2020

Cet article examine l’indemnisation des forces de l’ordre par les organisateurs d’événements musicaux, en particulier de festivals, en France. La gestion de l’ordre public y est marquée par la prééminence de l’État, ainsi que de la police nationale et la gendarmerie. L’indemnisation des services de ces dernières témoigne du pouvoir discrétionnaire du préfet, représentant de l’État, dans l’établissement (ou non) de la facturation, laquelle fait l’objet de fortes résistances de la part des organisateurs de festivals. En variant les dispositifs de sécurité ainsi que les montants de l’indemnisation, les préfets influent sur les relations entre forces de l’ordre et administrés. Dans le cas de l’indemnisation des forces de l’ordre par les organisateurs d’événements musicaux, sur qui s’exerce ce pouvoir discrétionnaire, et avec quels effets ? Et que révèle la mise en oeuvre de « droits », mais aussi de « passe-droits » par l’autorité préfectorale au sujet des relations entre État, police et société ? Une enquête qualitative, combinant entretiens, observations et sources documentaires variées, permet de répondre à ces questions. L’examen du recours différencié à l’indemnisation des forces de l’ordre par les préfets témoigne de la centralité des caractéristiques des territoires concernés, ainsi que des représentations préfectorales des événements musicaux et de leurs publics, prises en compte dans la définition du dispositif de sûreté. De surcroît, la définition des territoires professionnels et du monopole de l’État dans l’exercice de la violence légitime freine la concertation entre organisateurs et préfets sur la mise en oeuvre des dispositifs de sûreté.
Pas de révolution pour la police ?
Authors: Pluta Audrey
Published: June 2020

Cet article interroge les projets menés au nom de la réforme et de la démocratisation de la police en Tunisie post-révolution. La période suivant le départ de Ben Ali a effectivement connu une série de réajustements au sein des forces de sécurité, notamment à la suite d’une ouverture sur de nouvelles sources d’influence, émanant de professionnels de la sécurité organisés sous forme de syndicats ou d’associations, ou bien d’acteurs internationaux. Partant d’une analyse du projet de police de proximité porté par le PNUD et le ministère de l’Intérieur, cet article tâchera de montrer que, si les structures et les normes régissant les forces de l’ordre ne connaissent pas de modification profonde, le rapprochement entre policier et citoyen mené au nom de la réforme a pour effet de sélectionner la participation citoyenne en excluant les dominés. L’action menée par les syndicats policiers nouvellement formés contribue encore à réduire le spectre du changement politique en réduisant le contrôle sur les policiers en même temps que leur redevabilité vis-à-vis de la population. Ces syndicats parviennent, en reprenant à leur propre compte les discours de la « Réforme du secteur de la sécurité » (RSS), à légitimer et à consolider leur position de représentants des corps policiers. Il s’agira donc de revenir sur un processus de changement à l’oeuvre sans présumer de son issue, en le réinscrivant dans sa temporalité politique et entre les lignes de tension entourant la définition de ses termes au sein des forces de l’ordre.
Les violences policières en procès
Authors: Pregnolato Anthony
Published: June 2020

Plusieurs travaux sur la relation entre police et démocratie montrent comment, à la fois, le droit encadre et contraint l’usage de la violence par la police, et que le fonctionnement même des institutions policières, judiciaires et politiques offre à la police des normes d’usage de la violence en marge du droit. Même s’il arrive que des policiers et des policières soient jugées et condamnées, des victimes et des collectifs militants dénoncent une « impunité » policière et un manquement de l’État de droit — perçu comme garant de la démocratie — en matière de traitement des violences policières par la justice. À partir de l’observation du procès en appel du policier Damien Saboundjian à la cour d’assises de Paris en 2017, nous nous interrogeons sur la décision improbable qui a été prise au sein du tribunal : remettre en question la version du policier accusé et la légitimité de son usage de la violence. L’article émet l’hypothèse suivante : la condamnation, même exceptionnelle, repose sur la rupture d’un équilibre des rapports de force entre la justice et la police au sein d’une configuration spécifique qu’est le procès d’un membre de la police.
Les tensions entre police et citoyens sont-elles solubles dans la démocratie délibérative ?
Authors: Purenne* Anaïk , Balazard Hélène
Published: June 2020

À la fin de l’année 2018 s’est tenue, à Vaulx-en-Velin, une « conférence citoyenne de consensus » consacrée à la question du rapprochement police-population dans les quartiers populaires. L’enjeu de cet événement était d’outiller des citoyens « profanes » et, notamment, des jeunes de cette banlieue populaire de Lyon, ainsi que des gendarmes et policiers, pour qu’ils puissent réfléchir à des recommandations conjointes permettant de dépasser la conflictualité à l’oeuvre. Cet article propose de revenir sur les conditions de création et les effets de cet espace de dialogue, dans lequel les auteures de cet article ont joué le rôle de « tiers garant ». Cette implication a permis de mobiliser différentes sources. La participation observante a été complétée par l’analyse de sources écrites, ainsi que par la réalisation de focus-groupes et d’entretiens auprès d’une partie des participants et des animateurs afin d’appréhender les effets produits. L’intégration de ce dispositif dans une démarche de recherche-action participative inscrite sur le temps long, ainsi que l’établissement d’artefacts d’égalité entre les participants ont contribué à développer la confiance nécessaire au dialogue. Les effets de ce dispositif sont avant tout culturels, conduisant forces de l’ordre et (jeunes) citoyens à entamer un travail de déconstruction de leurs représentations réciproques. Des effets plus structurels sont également perceptibles : sur le territoire, les jeunes qui étaient les cibles des politiques de sécurité sont devenus des acteurs à inclure dans les processus de décision, même si cette reconnaissance n’est pas dénuée d’ambiguïtés.
La police « démocratique » comme productrice de (dés)ordres sociaux : les cas du Brésil et du Mexique
Authors: Dias Felix Annabelle
Published: June 2020

En utilisant une approche microsociologique et en s’appuyant sur deux études de cas, celles de Rio de Janeiro au Brésil et de Nezahualcóyotl au Mexique, le présent papier soutient que l’expérience vécue dans les programmes de police dits démocratiques peut être différente de — voire contraire à — l’image générale dépeinte par les autorités publiques et par les médias. Dans les cas « à succès » recensés au Brésil et au Mexique, des pratiques policières non démocratiques subsistent, mais sont invisibilisées par divers mécanismes. La première partie de cette contribution offre une définition de ce que serait un programme de police démocratique « à succès » selon la littérature en mettant l’accent sur les pratiques attendues d’un tel programme ainsi que sur les indicateurs de sa réussite. La seconde partie présente quant à elle les limites de cette définition du succès, démontrant qu’un changement de focale dévoile les dessous non démocratiques des pratiques policières.
Emocionalna inteligencija u školi
Authors: Pavlović Nebojša
Published: June 2020

EI predstavlja sklop više sposobnosti za razvoj učenika: poznavanje vlastitih emocija i vlastitih postupaka, upravljanje osećanjima, prevladavanje stresa, empatiju, komunikaciju, razumevanje potrebe za otvorenošću i poverenjem, prepoznavanje obrasca ponašanja drugih ljudi, prihvatanje svojih mana i procena svojih vrlina, preuzimanje odgovornosti i prepoznavanje posledica svojih odluka, samopouzdanje kroz izlaganje svojih briga i osećanja bez ljutnje i pasivnosti, osećaj za liderstvo, rešavanje sukoba. Osnovni cilj istraživanja je utvrditi da li se na osnovu školskog uspeha, ocene iz vladanja, stepena prihvatanja/neprihvatanja od strane drugih učenika u razredu i od pola učenika može predvideti nivo emocionalne inteligencije. Inetesovalo nas je da li su emocionalno inteligentniji ujedno i omiljeni, i učenici sa najboljim školskim postignućima.
Мотивација и инструкција у настави
Authors: Ђурђевић Сњежана
Published: June 2020

Мотивација и инструкција у настави су комплекни, суптилни и разнолики феномени које смо испитивали сложеним инструментаријем који је конструисао Ненад Сузић. Инструментима је обухваћен читав низ аспеката наставног часа који у цјелости дају слику о ефикасности наставе. Кључно питање у овом истраживању боло је да ли је могуће примјеном другачијег начина рада придобити ученике да се ангажују читавих четрдесет пет минута и да се баве градивом у сарадничкој и топлој радној атмосфери. У овој студији примијењено је низ педагошких едукативних радионица у екперименталној групи, а добијени налази у поређени су са контролномг групом у којој су ученици радили на уобичајен начин. Добијени налази отворили су многа питања, али су несумњиво потврдили да је учење учења могуће само уколико се створи одређена комуникација, разумијевање и сарадња међу ученицима у васпитно-образовном процесу.
Учење, емоције, настава
Authors: Кевић-Зрнић Сњежана
Published: June 2020

У научним круговима стидљиво се провлачи синтагма друштво учења и/или знања. Ово друштво које учи и својим знањем осигурава егзистенцију и напредак у свим сферама живота, не може постојати без појединаца који уче, користе и дограђују своје знање.
Lysosome activity is modulated by multiple longevity pathways and is important for lifespan extension in C. elegans
Authors: Sun Yanan , Li Meijiao , Zhao Dongfeng , Li Xin , Yang Chonglin , Wang Xiaochen
Published: June 2020

Lysosomes play important roles in cellular degradation to maintain cell homeostasis. In order to understand whether and how lysosomes alter with age and contribute to lifespan regulation, we characterized multiple properties of lysosomes during the aging process in C. elegans. We uncovered age-dependent alterations in lysosomal morphology, motility, acidity and degradation activity, all of which indicate a decline in lysosome function with age. The age-associated lysosomal changes are suppressed in the long-lived mutants daf-2, eat-2 and isp-1, which extend lifespan by inhibiting insulin/IGF-1 signaling, reducing food intake and impairing mitochondrial function, respectively. We found that 43 lysosome genes exhibit reduced expression with age, including genes encoding subunits of the proton pump V-ATPase and cathepsin proteases. The expression of lysosome genes is upregulated in the long-lived mutants, and this upregulation requires the functions of DAF-16/FOXO and SKN-1/NRF2 transcription factors. Impairing lysosome function affects clearance of aggregate-prone proteins and disrupts lifespan extension in daf-2, eat-2 and isp-1 worms. Our data indicate that lysosome function is modulated by multiple longevity pathways and is important for lifespan extension.
Experimental Study of Cold Atmospheric Pressure Plasma Jet and Its Application in the Surface Modification of Polypropylene
Authors: Baniya Hom Bahadur , Guragain Rajesh Prakash , Baniya Binod , Subedi Deepak Prasad
Published: June 2020

The cold plasma technology is gaining popularity as one of the most effective tools for a wide range of applications. Cold atmospheric pressure plasma jet (CAPPJ) has attracted considerable attention in recent times for materials processing such as surface modification and biomedical
applications. The cold atmospheric pressure plasma jet sustained in pure argon has been used here to modify the surface properties of polypropylene. CAPPJ has been generated by a high voltage power supply 5 kV at an operating frequency of 20 kHz. This paper reports the diagnostics of CAPPJ
in argon environment by electrical and optical methods and its application in the surface modification of polypropylene (PP). The surface properties of the untreated and plasma-treated PP samples were characterized by contact angle measurements, surface free energy determination, scanning
electron microscopy and Fourier transform infrared spectroscopy analysis. Most of the previous work has used RF power supply which is more expensive compared to the power supply used in the present study. The plasma jet is designed with locally available materials and can be used for continuous
treatment for long time. We have successfully developed a plasma device that is able to generate a non-equilibrium atmospheric pressure argon plasma jet of low temperature. Therefore, a cost-effective system of generating a plasma jet at atmospheric pressure with potential applications in
materials processing and biomedical research has been developed.
Effect of Gongronema latifolium and Ocimum basilicum Extracts on Antioxidant and Physicochemical Characteristics of Smoked Beef Stored under Room Temperature
Authors: Bassey Anthony Pius , Olusola Olubunmi Olufemi , Adeshola Ayobami , Ajibade Jumoke Folasade
Published: June 2020

Introduction: Incessant health risks associated with chemical preservatives have resorted to the need of exploring natural alternatives with antioxidant potentials in meat processing. In this study, the effect of Ocimum basilicum (OBE) and Gongronema latifolium (GLE) extracts were evaluated in smoked beef during 9 days of room storage (25±1°C).

Methodology: Beef samples were prepared from freshly cut rounds (2 kg each) allotted to four groups containing Nitrite, OBE, GLE and OBE+GLE respectively. Prepared beef samples were subjected to physicochemical (cooking loss, yield and colour), sensory characteristics, pH and lipid oxidative analyses. Data were analysed using descriptive statistics and ANOVA at α0.05.

Results: No significant change was observed in cooking yield and colour although higher values occurred in control samples. OBE and GLE inclusions exhibited a marked potential in sensory characteristics such as flavour, texture, tenderness, juiciness with the panelists rating the latter as the samples with overall acceptability. Results in storage period showed a significant progression in TBARS and pH values in all treatments with the highest and lowest values observed in control and OBE treatments.

Conclusion: GLE treated beef showed a marked efficacy throughout the storage period than the other extract-treated samples. With the need to provide natural alternatives against chemical preservatives, exploring its synergistic effects with other cheap, accessible and rich bioactive sources will be imperative in shelf life extension of meat.
A mutation in Asparagine‐Linked Glycosylation 12 (ALG12) leads to receptor misglycosylation and attenuated responses to multiple microbial elicitors
Authors: Trempel Fabian , Eschen‐Lippold Lennart , Bauer Nicole , Ranf Stefanie , Westphal Lore , Scheel Dierk , Lee Justin
Published: June 2020

Changes in cellular calcium levels are one of the earliest signalling events in plants exposed to pathogens or other exogenous factors. In a genetic screen, we identified an Arabidopsis thaliana ‘changed calcium elevation 1’ (cce1) mutant with attenuated calcium response to the bacterial flagellin flg22 peptide and several other elicitors. Whole‐genome resequencing revealed a mutation in asparagine‐linked glycosylation 12 that encodes the mannosyltransferase responsible for adding the eighth mannose residue in an α‐1,6 linkage to the dolichol‐PP‐oligosaccharide N‐glycosylation glycan tree precursors. While properly targeted to the plasma membrane, misglycosylation of several receptors in the cce1 background suggests that N‐glycosylation is required for proper functioning of client proteins.
Transcriptional profiling reveals a subset of human breast tumors that retain wt TP53 but display mutant p53‐associated features
Authors: Benor Gal , Fuks Garold , Chin Suet‐Feung , Rueda Oscar M. , Mukherjee Saptaparna , Arandkar Sharathchandra , Aylon Yael , Caldas Carlos , Domany Eytan , Oren Moshe
Published: June 2020

TP53 gene mutations are very common in human cancer. While such mutations abrogate the tumor suppressive activities of the wild‐type (wt) p53 protein, some of them also endow the mutant (mut) protein with oncogenic gain of function (GOF), facilitating cancer progression. Yet, p53 may acquire altered functionality even without being mutated; in particular, experiments with cultured cells revealed that wtp53 can be rewired to adopt mut‐like features in response to growth factors or cancer‐mimicking genetic manipulations. To assess whether such rewiring also occurs in human tumors, we interrogated gene expression profiles and pathway deregulation patterns in the METABRIC breast cancer (BC) dataset as a function of TP53 gene mutation status. Harnessing the power of machine learning, we optimized a gene expression classifier for ER+Her2‐ patients that distinguishes tumors carrying TP53 mutations from those retaining wt TP53. Interestingly, a small subset of wt TP53 tumors displayed gene expression and pathway deregulation patterns markedly similar to those of TP53‐mutated tumors. Moreover, similar to TP53‐mutated tumors, these ‘pseudomutant’ cases displayed a signature for enhanced proliferation and had worse prognosis than typical wtp53 tumors. Notably, these tumors revealed upregulation of genes which, in BC cell lines, were reported to be positively regulated by p53 GOF mutants. Thus, such tumors may benefit from mut p53‐associated activities without having to accrue TP53 mutations.
An Organic Laser Dye having a Small Singlet‐Triplet Energy Gap Makes the Selection of a Host Material Easier
Authors: Karunathilaka Buddhika S. B. , Balijapalli Umamahesh , Senevirathne Chathuranganie A. M. , Esaki Yu , Goushi Kenichi , Matsushima Toshinori , Sandanayaka Atula S. D. , Adachi Chihaya
Published: June 2020

Quenching of singlets by long‐lived triplets is a serious issue for lasing from organic laser dyes, especially under long pulse excitation. As a strategy to scavenge or manage unnecessary triplets, an organic laser dye is dispersed into a host material having high singlet and low triplet energy levels [a large singlet‐triplet energy gap (ΔEST)]. However, finding such a host material having a triplet scavenging capability is limited. In this study, an organic laser dye, 2,6‐dicyano‐1,1‐diphenyl‐λ5σ4‐phosphinine (DCNP), having a small ΔEST of ≈0.44 eV is synthesized, and thus 4‐4′‐bis[(N‐carbazole)styryl] biphenyl (BSBCz) can be employed as a triplet scavenging host, i.e., the triplets formed on DCNP are easily transferred to BSBCz. A 1 wt%‐DCNP‐doped BSBCz film is formed on a mixed‐order distributed feedback grating, showing lasing with a low threshold value of ≈0.86 µJ cm−2 and a full‐width‐at‐half‐maximum value of ≈0.5 nm. Because of the suppressed singlet‐triplet annihilation, DCNP‐based laser devices operating under a continuous‐wave regime, with a low threshold of 72 W cm−2 and a long laser half‐lifetime of ≈3 min, are demonstrated. These results indicate a possibility of the wider selection of host materials, easing a material design strategy of fabricating high‐performance laser devices in future.
Bend, Twist, and Turn: First Bendable and Malleable Toughened PLA Green Composites
Authors: Yeo Jayven Chee Chuan , Muiruri Joseph Kinyanjui , Koh Justin Junqiang , Thitsartarn Warintorn , Zhang Xikui , Kong Junhua , Lin Ting Ting , Li Zibiao , He Chaobin
Published: June 2020

The future of green electronics possessing great strength and toughness proves to be a promising area of research in this technologically advanced society. This work develops the first fully bendable and malleable toughened polylactic acid (PLA) green composite by incorporating a multifunctional polyhydroxybutyrate rubber copolymer filler that acts as an effective nucleating agent to accelerate PLA crystallization and performs as a dynamic plasticizer to generate massive polymer chain movement. The resultant biocomposite exhibits a 24‐fold and 15‐fold increment in both elongation and toughness, respectively, while retaining its elastic modulus at >3 GPa. Mechanism studies show the toughening effect is due to an amalgamation of massive shear yielding, crazing, and nanocavitation in the highly dense PLA matrix. Uniquely distinguished from the typical flexible polymer that stretches and recovers, this biocomposite is the first report of PLA that can be “bend, twist, turn, and fold” at room temperature and exhibit excellent mechanical robustness even after a 180° bend, attributes to the highly interconnected polymer network of innumerable nanocavitation complemented with an extensively unified fibrillar bridge. This unique trait certainly opens up a new horizon to future sustainable green electronics development.
Synthesis and Magnon Thermal Transport Properties of Spin Ladder Sr14Cu24O41 Microstructures
Authors: Chen Xi , Kim Jaehyun , Jia Qianru , Sullivan Sean E. , Xu Youming , Jarvis Karalee , Zhou Jianshi , Shi Li
Published: June 2020

The spin ladder compound (Sr,Ca,La)14Cu24O41 exhibits an incommensurate layered structure with strong antiferromagnetic coupling. Besides intriguing superconducting behavior, recent experiments on bulk Sr14Cu24O41 single crystals have revealed a remarkable magnon thermal conductivity, which is the largest above 100 K among all known quantum magnets. Although bulk (Sr,Ca,La)14Cu24O41 crystals have been synthesized and studied extensively, there have been few reports on the synthesis and magnon thermal transport investigation of their microstructures. Here, the synthesis and thermal transport properties of Sr14Cu24O41 microrods are reported. Electron microscopy studies indicate that these microrods synthesized by a coprecipitation method are single crystals grown preferentially along the ladder axis. Based on a four‐probe thermal transport measurement, the thermal conductivity of the microrods reveals appreciable magnon transport in the microstructures. According to a kinetic model analysis, magnon transport in the microrods is suppressed mainly by increased point defect scattering compared to the bulk crystals, whereas surface scattering is negligible for anisotropic 1D magnon transport along the ladder. Moreover, the thermal conductivity is enhanced after annealing as a result of reduced oxygen vacancies. These results help to build the foundation for future heterogeneous integration of magnetic microstructures in microscale devices for the transport of energy and quantum information.
Mediated Electrochemistry to Mimic Biology's Oxidative Assembly of Functional Matrices
Authors: Li Jinyang , Kim Eunkyoung , Gray Kelsey M. , Conrad Christina , Tsao Chen‐Yu , Wang Sally P. , Zong Guanghui , Scarcelli Giuliano , Stroka Kimberly M. , Wang Lai‐Xi , Bentley William E. , Payne Gregory F.
Published: June 2020

Biology uses diffusible oxidants to perform functions that range from signaling to matrix assembly, and these oxidation chemistries offer surprising selectivities. Here, it is reported that mediated electrochemistry can access the richness of such oxidation chemistries. Specifically, electrode‐imposed voltage inputs are used to locally generate oxidized mediators that can diffuse into polymer solutions and induce the formation of covalent bonds for the deposition and functionalization of hydrogels at the electrode surface. Depending on the mediator's redox potential (E0), it is possible to “gate” the voltage inputs to target specific residues (e.g., thiols or amines) and oxidation chemistries. Further, mediators of varying E0 offer different reactivities and thus allow control of reaction‐diffusion rates to modulate the hydrogel's crosslink density and mechanical properties. Importantly, this mediated oxidation can be performed under physiologically relevant conditions to preserve labile biological functionalities (e.g., cell viability and protein function). Finally, it is demonstrated that protein fusion tags can be engineered to have “targetable” amino acid residues that enable protein function to be oxidatively conjugated to electrodeposited hydrogels. In summary, mediated electrochemistry can engage orthogonal oxidation chemistries to create functionalized matrices and thus mediated electrochemistry should add important capabilities to the electrofabrication toolbox.
Orientation‐Controlled Selective‐Area Epitaxy of III–V Nanowires on (001) Silicon for Silicon Photonics
Authors: Chang Ting‐Yuan , Kim Hyunseok , Zutter Brian T. , Lee Wook‐Jae , Regan Brian C. , Huffaker Diana L.
Published: June 2020

Monolithic integration of III–V nanowires on silicon platforms has been regarded as a promising building block for many on‐chip optoelectronic, nanophotonic, and electronic applications. Although great advances have been made from fundamental material engineering to realizing functional devices, one of the remaining challenges for on‐chip applications is that the growth direction of nanowires on Si(001) substrates is difficult to control. Here, catalyst‐free selective‐area epitaxy of nanowires on (001)‐oriented silicon‐on‐insulator (SOI) substrates with the nanowires aligned to desired directions is proposed and demonstrated. This is enabled by exposing {111} planes on (001) substrates using wet chemical etching, followed by growing nanowires on the exposed planes. The formation of nanowire array‐based bottom‐up photonic crystal cavities on SOI(001) and their coupling to silicon waveguides and grating couplers, which support the feasibility for on‐chip photonic applications are demonstrated. The proposed method of integrating position‐ and orientation‐controllable nanowires on Si(001) provides a new degree of freedom in combining functional and ultracompact III–V devices with mature silicon platforms.
Photoprogrammable Mesogenic Soft Helical Architectures: A Promising Avenue toward Future Chiro‐Optics
Authors: Zheng Zhi‐Gang , Lu Yan‐Qing , Li Quan
Published: June 2020

Mesogenic soft materials, having single or multiple mesogen moieties per molecule, commonly exhibit typical self‐organization characteristics, which promotes the formation of elegant helical superstructures or supramolecular assemblies in chiral environments. Such helical superstructures play key roles in the propagation of circularly polarized light and display optical properties with prominent handedness, that is, chiro‐optical properties. The leveraging of light to program the chiro‐optical properties of such mesogenic helical soft materials by homogeneously dispersing photosensitive chiral material into an achiral soft system or covalently connecting photochromic moieties to the molecules has attracted considerable attention in terms of materials, properties, and potential applications and has been a thriving topic in both fundamental science and application engineering. State‐of‐the‐art technologies are described in terms of the material design, synthesis, properties, and modulation of photoprogrammable chiro‐optical mesogenic soft helical architectures. Additionally, the scientific issues and technical problems that hinder further development of these materials for use in various fields are outlined and discussed. Such photoprogrammable mesogenic soft helical materials are competitive candidates for use in stimulus‐controllable chiro‐optical devices with high optical efficiency, stable optical properties, and easy miniaturization, facilitating the future integration and systemization of chiro‐optical chips in photonics, photochemistry, biomedical engineering, chemical engineering, and beyond.
Recent Advances in Conjugated Polymers for Visible‐Light‐Driven Water Splitting
Authors: Zhao Chengxiao , Chen Zupeng , Shi Run , Yang Xiaofei , Zhang Tierui
Published: June 2020

With the ambition of solving the challenges of the shortage of fossil fuels and their associated environmental pollution, visible‐light‐driven splitting of water into hydrogen and oxygen using semiconductor photocatalysts has emerged as a promising technology to provide environmentally friendly energy vectors. Among the current library of developed photocatalysts, organic conjugated polymers present unique advantages of sufficient light‐absorption efficiency, excellent stability, tunable electronic properties, and economic applicability. As a class of rising photocatalysts, organic conjugated polymers offer high flexibility in tuning the framework of the backbone and porosity to fulfill the requirements for photocatalytic applications. In the past decade, significant progress has been made in visible‐light‐driven water splitting employing organic conjugated polymers. The recent development of the structural design principles of organic conjugated polymers (including linear, crosslinked, and supramolecular self‐assembled polymers) toward efficient photocatalytic hydrogen evolution, oxygen evolution, and overall water splitting is described, thus providing a comprehensive reference for the field. Finally, current challenges and perspectives are also discussed.
Pumping of Ionic Liquids by Liquid Metal‐Enabled Electrocapillary Flow under DC‐Biased AC Forcing
Authors: Xue Rui , Liu Weiyu , Jiang Tianyi , Song Chunlei , Jiang Hongyuan , Ren Yukun
Published: June 2020

A novel method is proposed to pump room‐temperature ionic liquids (ILs) by making use of liquid‐metal‐enabled electrocapillary flow driven by a DC‐biased AC forcing. The effectiveness of this pump strategy is demonstrated by both numerical simulation and experimental observation considering multiple frequency electrochemical polarization. The device can work practically in a wide range of different parameters, such as DC bias, AC voltage amplitude, the shape of the waveform, as well as the electrode separation. Though liquid metal (LM) has already been reported to help deliver the traditional sample of high‐conductivity aqueous electrolytes, its adaptability to drive ILs has apparent advantages, such as quicker pump flow rate due to greater initial interfacial ion adsorption, and much longer operating life due to its nonvolatile feature. The results prove invaluable for the elaborate construction of flexible electrokinetic platforms taking high‐speed ILs as the working fluid.
Unexpected Dual Action of Cetyltrimethylammonium Bromide (CTAB) in the Self‐Assembly of Colloidal Nanoparticles at Liquid–Liquid Interfaces
Authors: Li Chunchun , Xu Yikai , Li Xinyuan , Ye Ziwei , Yao Chaoyi , Chen Qinglu , Zhang Yuanfeng , Bell Steven E. J.
Published: June 2020

Self‐assembly of colloidal nanoparticles at water–oil interfaces offers an efficient way to construct multi‐dimensional arrays. Self‐assembly is generally induced by using adsorbing molecular “modifiers” or co‐solvents to remove the nanoparticles' surface charge. Here, it is shown that cetyltrimethylammonium bromide (CTAB), which is commonly used in bulk quantities in colloidal synthesis, can induce self‐assembly of negatively charged colloidal nanoparticles at water–oil interfaces, even at sub‐micromolar levels but it does this by providing charge screening rather than removing the surface charge. Since this is a physical effect, CTAB can promote assembly of nanoparticles regardless of their morphology or material composition. In the specific case of nanoparticles which allow CTAB to adsorb, such as Au, the self‐assembly mechanism switches from charge screening to chemical adsorption as the concentration is increased. These both explain previous observations of spontaneous interfacial assembly and open up further possibilities for deliberately constructing functional nanoparticle arrays without the need for additional modifiers or co‐solvents.
Biocompatible Direct Deposition of Functionalized Nanoparticles Using Shrinking Surface Plasmonic Bubble
Authors: Moon Seunghyun , Zhang Qiushi , Huang Dezhao , Senapati Satyajyoti , Chang Hsueh‐Chia , Lee Eungkyu , Luo Tengfei
Published: June 2020

Functionalized nanoparticles (NPs) are the foundation of diverse applications. Especially, in many biosensing applications, concentrating suspended NPs onto a surface without deteriorating their biofunction is usually an inevitable step to improve detection limit, which remains to be a great challenge. In this work, biocompatible deposition of functionalized NPs to optically transparent surfaces is demonstrated using shrinking bubbles. Leveraging the shrinking phase of bubble mitigates the biomolecule degradation problems encountered in traditional photothermal deposition techniques. The deposited NPs are closely packed, and the functional molecules are able to survive the process as verified by their strong fluorescence signals. Using high‐speed videography, it is revealed that the contracting contact line of the shrinking bubble forces the NPs captured by the contact line to a highly concentrated island. Such shrinking surface bubble deposition (SSBD) is low temperature in nature as no heat is added during the process. Using a hairpin DNA‐functionalized gold NP suspension as a model system, SSBD is shown to enable much stronger fluorescence signal compared to the optical‐pressure deposition and the conventional thermal bubble contact line deposition. The demonstrated SSBD technique capable of directly depositing functionalized NPs may significantly simplify biosensor fabrication and thus benefit a wide range of relevant applications.
Hugely Enhanced Output Power of Direct‐Current Triboelectric Nanogenerators by Using Electrostatic Breakdown Effect
Authors: Liu Di , Zhou Linglin , Li Shaoxin , Zhao Zhihao , Yin Xing , Yi Zhiying , Zhang Chunlei , Li Xinyuan , Wang Jie , Wang Zhong Lin
Published: June 2020

Electrostatic breakdown is a common but generally negative physical phenomenon. Here, efficient conversion of mechanical energy to electric power is achieved by enhanced direct‐current triboelectric nanogenerator (DC‐TENG) based on contact electrification and electrostatic breakdown. By verifying the high temperature can not only improve the triboelectric charge density but also enhance electrostatic breakdown of air dielectric due to thermionic emission of electrons and avalanche breakdown effect. Meanwhile an appropriate low atmosphere pressure is another favorable factor to air breakdown in DC‐TENG. As a result, its output power density is improved by three orders of magnitude at 473 K and 300 Pa compared to that at 298 K and standard atmosphere pressure. These findings not only provide a new paradigm to design high‐performance TENG, but realize efficiently harvesting mechanical energy and thermal energy in one device by coupling the two kinds of physical effects.
Nanoscale Structural and Emission Properties within “Russian Doll”‐Type InGaN/AlGaN Quantum Wells
Authors: Cheng Shaobo , Wu Zewen , Langelier Brian , Kong Xianghua , Coenen Toon , Hari Sangeetha , Ra Yong‐Ho , Rashid Roksana Tonny , Pofelski Alexandre , Yuan Hui , Li Xing , Mi Zetian , Guo Hong , Botton Gianluigi A.
Published: June 2020

Due to the increasing desire for nanoscale optoelectronic devices with green light emission capability and high efficiency, ternary III‐N‐based nanorods are extensively studied. Many efforts have been taken on the planar device configuration, which lead to unavoided defects and strains. With selective‐area molecular‐beam epitaxy, new “Russian Doll”‐type InGaN/AlGaN quantum wells (QWs) have been developed, which could largely alleviate this issue. This work combines multiple nanoscale characterization methods and k∙p theory calculations so that the crystalline structure, chemical compositions, strain effects, and light emission properties can be quantitatively correlated and understood. The 3D structure and atomic composition of these QWs are retrieved with transmission electron microscopy and atom probe tomography while their green light emission has been demonstrated with room‐temperature cathodoluminescence experiments. k∙p theory calculations, with the consideration of strain effects, are used to derive the light emission characteristics that are compared with the local measurements. Thus, the structural properties of the newly designed nanorods are quantitatively characterized and the relationship with their outstanding optical properties is described. This combined approach provides an innovative way for analyzing nano‐optical‐devices and new strategies for the structure design of light‐emitting diodes.
Polymer Materials for High‐Performance Triboelectric Nanogenerators
Authors: Chen Aihua , Zhang Chen , Zhu Guang , Wang Zhong Lin
Published: June 2020

As an emerging branch of energy conversion technologies, the triboelectric nanogenerator (TENG) pioneers a brand‐new path to effectively harness varieties of mechanical energies for the purpose of powering and/or sensing. Since its invention in 2012, the TENG has experienced a booming and revolutionary development in every respect, ranging from materials synthesis and modification, architecture design to performance optimization, power management, and application exploration. In comparison to the organic solar cell and organic light‐emitting diodes, TENG is a unique technique that opens the venue of using polymer materials (PMs) for harvesting mechanical energy. So far, by virtue of superior charge transfer and capturing capabilities during friction, various kinds of PMs have been developed and used as triboelectric materials in order to achieve high‐performance TENGs. Here, this work focuses on the utilization and development of PMs for the TENGs technology and first gives a summary of main PMs that are frequently adopted in currently reported energy‐harvesting TENGs. Second, several kinds of PMs used lately in a few novel TENGs for special or specific energy‐harvesting circumstances are introduced and highlighted. Finally, the perspectives on and challenges in developing high‐performance PMs toward TENGs technology are conceived and expected to be instructive to future research.
Anomalous vasculature in the neck diagnosed by ultrasound
Authors: Constantine Sarah , Roach Denise
Published: June 2020

Anomalous vascular anatomy was detected in the neck of a 52‐year‐old female with a Klippel–Feil anomaly. Ultrasound identified three separate arteries in the left carotid sheath without any branching or bifurcations. The vascular waveforms were used to identify the vessels as the internal carotid artery, external carotid artery and vertebral artery. This rare vascular anomaly was confirmed with CT angiography.
In Memoriam, Francis McGovern: Remembering His ADR Life
Authors: Green Eric D.
Published: June 2020

With Francis McGovern's passing on Feb. 14, the mediation and dispute resolution world lost one of its greatest pioneers, scholars, and practitioners.
C7‐Indole Amidations and Alkenylations by Ruthenium(II) Catalysis
Authors: Choi Isaac , Messinis Antonis M. , Ackermann Lutz
Published: June 2020

C7−H‐functionalized indoles are ubiquitous structural units of biological and pharmaceutical compounds for numerous antiviral agents against SARS‐CoV or HIV‐1. Thus, achieving site‐selective functionalizations of the C7−H position of indoles, while discriminating among other bonds, is in high demand. Herein, we disclose site‐selective C7−H activations of indoles by ruthenium(II) biscarboxylate catalysis under mild conditions. Base‐assisted internal electrophilic‐type substitution C−H ruthenation by weak O‐coordination enabled the C7−H functionalization of indoles and offered a broad scope, including C−N and C−C bond formation. The versatile ruthenium‐catalyzed C7−H activations were characterized by gram‐scale syntheses and the traceless removal of the directing group, thus providing easy access to pharmaceutically relevant scaffolds. Detailed mechanistic studies through spectroscopic and spectrometric analyses shed light on the unique nature of the robust ruthenium catalysis for the functionalization of the C7−H position of indoles.
Metal‐Free Photocatalytic Hydrogenation Using Covalent Triazine Polymers
Authors: Hu Yongpan , Huang Wei , Wang Hongshuai , He Qing , Zhou Yuan , Yang Ping , Li Youyong , Li Yanguang
Published: June 2020

Photocatalytic hydrogenation of biomass‐derived organic molecules transforms solar energy into high‐energy‐density chemical bonds. Reported herein is the preparation of a thiophene‐containing covalent triazine polymer as a photocatalyst, with unique donor‐acceptor units, for the metal‐free photocatalytic hydrogenation of unsaturated organic molecules. Under visible‐light illumination, the polymeric photocatalyst enables the transformation of maleic acid into succinic acid with a production rate of about 2 mmol g−1 h−1, and furfural into furfuryl alcohol with a production rate of about 0.5 mmol g−1 h−1. Great catalyst stability and recyclability are also measured. Given the structural diversity of polymeric photocatalysts and their readily tunable optical and electronic properties, metal‐free photocatalytic hydrogenation represents a highly promising approach for solar energy conversion.
Green synthesis of Fe3O4/ZnO magnetic core‐shell nanoparticles by Petasites hybridus rhizome water extract and their application for the synthesis of pyran derivatives: Investigation of antioxidant and antimicrobial activity
Authors: Ghasemian Dazmiri Mahboubeh , Alinezhad Heshmatollah , Hossaini Zinatossadat , Bekhradnia Ahmad R.
Published: June 2020

In this research, Fe3O4/ZnO magnetic core‐shell nanoparticles (Fe3O4/ZnO MCNPs) were synthesized through a green method using Petasites hybridus rhizome water extract as a reducing and stabilizing agent. The morphology and size of the Fe3O4/ZnO MCNPs was identified by X‐ray diffraction, scanning electron microscopy, and Energy‐dispersive X‐ray spectroscopy (EDX) analysis. The catalytic activity of the Fe3O4/ZnO MCNPs was evaluated in the efficient and green preparation of pyran derivatives in excellent yield using three‐component reactions of dimedone, aldehydes, and malononitrile in ethanol at room temperature. The ability of some synthesized compounds to scavenge the 2,2‐diphenyl‐1‐picrylhydrazyl radical was measured and the results proved this observation. Moreover, the antimicrobial activity of some synthesized compounds was proved by employing the disk diffusion test on Gram‐positive and Gram‐negative bacteria. The results for the disk diffusion test showed that compounds (4c, 4d, 4f and 4g) prevented bacterial growth.
Design, synthesis, and in vitro biological evaluation of novel thiazolopyrimidine derivatives as antileishmanial compounds
Authors: Istanbullu Huseyin , Bayraktar Gulsah , Akbaba Hasan , Cavus Ibrahim , Coban Gunes , Debelec Butuner Bilge , Kilimcioglu Ali Ahmet , Ozbilgin Ahmet , Alptuzun Vildan , Erciyas Ercin
Published: June 2020

A series of thiazolopyrimidine derivatives was designed and synthesized as a Leishmania major pteridine reductase 1 (LmPTR1) enzyme inhibitor. Their LmPTR1 inhibitor activities were evaluated using the enzyme produced by Escherichia coli in a recombinant way. The antileishmanial activity of the selected compounds was tested in vitro against Leishmania sp. Additionally, the compounds were evaluated for cytotoxic activity against the murine macrophage cell line RAW 264.7. According to the results, four compounds displayed not only a potent in vitro antileishmanial activity against promastigote forms but also low cytotoxicity. Among them, compound L16 exhibited an antileishmanial activity for both the promastigote and amastigote forms of L. tropica, with IC50 values of 7.5 and 2.69 µM, respectively. In addition, molecular docking studies and molecular dynamics simulations were also carried out in this study. In light of these findings, the compounds provide a new potential scaffold for antileishmanial drug discovery.