bluuebunny/crossref_metadata_2025 huggingface dataset:
English Teachers’ Attitude towards Professional Development in Kuwait
Authors: Alzankawi Maisoun
Published: April 2021

Teacher professional development is a life-long and continuous process in which teachers are expected to upgrade their knowledge, master new skills, and change their practices since advancement in their teaching career is finally for their students and education reform. Besides, teachers and their professional development must be seen as an investment. This study is designed to investigate the English teachers’ attitude towards professional development in Kuwait and the problems encountered by those teachers, and their need for professional development programs. It intends to devise innovative approaches for English teacher’s development in Kuwait based on teachers’ requirements to provide those teachers with all they need to overcome the obstacles they face in their professional lives. It will also assess teachers’ preferences of the pedagogical tools that enable them to convey the instructional material. The participants in this study were 20 experienced in-service English teachers who were chosen randomly from three different institutes at the Public Authority for Applied Education and Training (PAAET) in Kuwait. Data were gathered from two main sources: Interviews with in-service teachers of English, and questionnaires. Specifically, the study aimed to address questions related to the teachers’ future development and the possible problems facing them or expects that might face them in the future, and their feedback about the challenges and difficulties of teaching English in Kuwait. The findings revealed a lack of teachers’ development in some particular areas that need more skill development of English teachers. Intensive training courses should be applied for the in-service teachers, and professional development programs should promote and enhance teaching effectiveness and support professional growth. Teachers’ professional development should permit the transition to higher status and responsibility roles within the teaching profession. Therefore, teachers need access to new research and acknowledgment in teaching literacy, language development, and an integrated curriculum. Moreover, they need appropriate up-to-date qualifications in both the content area of the subject and teaching methodology. They also need opportunities to share expertise with other experienced teachers and educators, leading to reflection on practice. Furthermore, high-quality teaching should be focused on developing a strong, well informed, and well supported professional body to respond to community and educational concerns. Also, access to professional development is of paramount importance as it enables teachers to improve students’ learning outcomes. Finally, English teachers can actively participate in evaluating teaching practices and programs; and actively participate in the implementation of local state and national curriculum initiatives.
Towards Critique: The Place of Culture in English Language Teaching
Authors: Almutairi Mohammad
Published: April 2021

This study explores in a descriptive way the overlapping relation between culture and English-language teaching. It lays out the different points of view and interpretations of linguistic researchers about the hot debate of the importance of introducing culture into ESL/EFL classrooms. While some believe that the current age of globalization needs us to expose our ESL/EFL learners to foreign cultures in their ESL/EFL learning, others disagree and deny the importance of doing so. Some go more radical and consider it as linguistic imperialism that should be excluded. The current study also discusses the opinions and views of researchers on the integration of language teaching and culture with some empirical studies.
Ideology Manipulation of the Chinese-English Subtitled “Main Melody” Films: A Case Study of Wolf Warrior II and The Wandering Earth
Authors: Xie Ying
Published: April 2021

Films are the reflection of the mainstream ideology in a specific culture. More importantly, the process of film translation itself is equivalent to the rewriting process by the translator (Lefevere 1992), which embodies and even strengthens the manipulation of social ideology. As the “Main Melody” films that focus on propagandizing the official messages of the Communist Party of China (CPC), Wolf Warrior II (2017) and The Wandering Earth (2019)’s rewritten subtitles intensively embody the ideology manipulation under the regime of the CPC and the Chinese government. By discussing how audiences from different social, cultural, ethnic backgrounds might employ their experience and knowledge about the Chinese society and politics to decode the subtitles in ways that contradict the intended meaning, this paper seeks to investigate the effectiveness of the rewritten subtitles’ ideological manipulation towards the Chinese audience and the English-speaking audience.
Electronic Introspection in FL Learning
Authors: Al Khafaji Adil H. A.
Published: April 2021

This work tries to revive interest in introspection and accommodate it in foreign language e-learning. It sets up a theoretical construct to probe into learners’ mental processes during acts of learning. The aspiration is to involve learners in acts of self-directed verbalizations of thoughts to externalize their learning mechanism and make it manageable object of study. It is believed that opening such a window on learning trends can illuminate our understanding of important concerns that are usually in question.
Tensions of Adam and Iblis in the Quran: The Imagology Approach
Authors: Muzakki Akhmad , Irham -
Published: April 2021

This study investigates the tensions between Adam and Iblis in the Quran by using imagology as the main approach. The main focus of the imagology approach reveals the interrelationship between text, intertext, and context altogether, by focusing on contextualizing them in the story. This approach does not intend to judge the truth of representations but to analyze their values important to build community weltanschauung (view of life) that leads them to a social change, a changing of meaning, and a new understanding. The findings demonstrate that a triangular conversation between Allah (henceforth, God), the angels and the satan on the creation of Adam showed the big scenario about Adam’s image as a noble creature. Adam’s noble image was because God teaches him names (asma’ or the epistemology of science) on earth where Adam was then symbolized as God’s representative on earth due to his creativity in revealing names which resembled God’s manner as a creator in making innovation and change. God then governed angels and satan to kneel down before Adam as a form of honor. All did it except the Iblis who refused to obey due to his feeling of superiority over Adam. A psycological tension between Iblis’s superiority which is not supported by the capacity of knowledge is defeated by Adam’s inferiority which is strengthened by knowledge. The word ‘kneel’ was actually a theological word applied to the relation between human and God, but the word was used in this context as a symbol of appreciation for science.
Translation Trainees’ Uses of and Attitudes towards Different Types of Dictionaries: A Case Study
Authors: Altuwairesh Nasrin
Published: April 2021

The focus of most studies on dictionary users has been on foreign and second language learners, with seldom attention paid to translation trainees. Given that the dictionary is an indispensable tool used by translators and translators in the making alike, research in this regard is crucial to uncover the uses and attitudes of this group of dictionary users’ towards different forms of dictionaries. Revealing translation trainees’ practices facilitates the correction of wrong ones and helps in guiding students towards the efficient use of dictionaries. The ultimate goal is, thus, informing translation pedagogy. Hence, the present study aims at investigating translation trainees’ uses of dictionaries and their attitudes towards different types of dictionaries. The focus is on uncovering the uses and attitudes of Saudi undergraduate female translation trainees towards the different forms of dictionaries available for them today. The article in hand specifically reports on the quantitative phase of a two-phase, mixed-methods case study. A group of 95 undergraduate students answered a multi-item, online questionnaire, with the aim of revealing their dictionary uses and preferences. The results confirmed the participants’ preference for and heavy reliance on electronic dictionaries, due to their convenience, comprehensiveness, portability and being up-to-date. The results further indicated the participants’ preference for bilingual over monolingual dictionaries. Surprisingly, the results also showed that a high number of the respondents reported using Google Translate frequently. Despite these findings, the survey results revealed that the participants have good knowledge of and do in fact use a wide selection of bilingual and monolingual dictionaries, including paper and electronic ones.
H2O2‐Triggered Self Immolative Prodrug Nanoassemblies as Self‐Deliverable Nanomedicines for Targeted On‐Demand Therapy of Thrombotic Disorders
Authors: Jung Eunkyeong , Kim Taeeon , Bae Soochan , Kang Peter M. , Lee Dongwon
Published: April 2021

Formation of an occlusive thrombus is a critical pathophysiological feature of numerous cardiovascular diseases. Thrombosis is promoted by P‐selectin overexpressed on activated platelets and endothelium and tightly linked with the overproduction of hydrogen peroxide (H2O2). The overexpression of P‐selectin and overproduction of H2O2 become unique features of thrombosed vessels which provide a rationale for the development of targeted therapeutics for thrombosis. In this work, targeted self‐delivering and H2O2‐activatable antithrombotic nanomedicine (Fu–sBR) composed of a self‐immolative dimeric prodrug (sBR) and a P‐selectin targeting fucoidan, are reported. In the presence of fucoidan, sBR is formulated into stable nanoassemblies that can serve as carrier‐free nanodrugs and exert antioxidant, anti‐inflammatory, and antiplatelet activities in a H2O2‐triggered manner. In mouse models of carotid arterial thrombosis and deep vein thrombosis (DVT), Fu–sBR nanoassemblies specifically target thrombosed vessels to effectively suppress thrombus development by inhibiting the expression of tumor necrosis factor‐alpha (TNF‐α), interleukine‐1 beta (IL‐1β), and soluble CD40 ligand (sCD40L). Given their self‐delivering capability, thrombus targeting ability, and stimulus‐activatable therapeutic actions, Fu–sBR nanoassemblies have great translational potential as therapeutic agents for various thrombotic disorders.
Electrochemical Catalysts for Green Hydrogen Energy
Authors: Hyung Kweon Do , Jeon In-Yup , Baek Jong-Beom
Published: April 2021

Developing clean and renewable energy resources has become one of the world's most important challenges, given the double burden of energy scarcity and environmental pollution. For sustainable energy conversion and storage, efficient electrocatalysts play a pivotal role in important energy‐related reactions, including oxygen reduction, oxygen evolution, and hydrogen evolution. To satisfy practical requirements, the catalysts need to demonstrate high performance, durability, and acceptable cost. These are primary considerations when designing and preparing various new electrocatalysts. Among the research programs being actively conducted around the world, some promising recent results suggest strong potential alternatives to current expensive noble metal‐based catalysts. This review summarizes recent technical advances in the preparation of efficient electrocatalysts.
Alkyl Phosphine Free, Metal‐Ligand Cooperative Complex Catalyzed Alcohol Dehydrogenative Coupling Reactions
Authors: Roy Bivas Chandra , Ganguli Kasturi , Samim Sk. Abdus , Kundu Sabuj
Published: April 2021

In last two decades alcohol has drawn a special attention as a building blocks due to its abundance, low cost and less toxic nature which can be derived from various sustainable resources. By dehydrogenation of alcohol, aldehyde/ketone can be easily accessed which can be further coupled with several nucleophiles for the construction of complex molecules. Among the various strategies, metal‐ligand cooperation is a powerful and efficient tool for the utilization of alcohol to synthesize variety of value‐added products. Numerous alkyl phosphine based bifunctional complexes are well‐known in the literature for the alcohol dehydrogenative coupling reactions. However, the presence of alkyl phosphine moiety and air and moisture sensitive nature of the metal complexes hinder their broad application in catalysis. In this minireview, we highlighted air and moisture stable, metal‐ligand cooperative 5d, 4d and 3d metal‐based complexes which were effectively utilized to fabricate different value‐added compounds by alcohol dehydrogenative coupling reactions.
Direct α‐Tertiary Alkylations of Ketones in a Combined Copper–Organocatalyst System
Authors: Kurose Ayako , Ishida Yuto , Hirata Goki , Nishikata Takashi
Published: April 2021

Herein, we report an efficient method for the tertiary alkylation of a ketone by using an α‐bromocarbonyl compound as the tertiary alkyl source in a combined Cu‐organocatalyst system. This dual catalyst system enables the addition of a tertiary alkyl radical to an enamine. Mechanistic studies revealed that the catalytically generated enamine is a key intermediate in the catalytic cycle. The developed method can be used to synthesize substituted 1,4‐dicarbonyl compounds containing quaternary carbons bearing various alkyl chains.
XFEL Crystal Structures of Peroxidase Compound II
Authors: Kwon Hanna , Basran Jaswir , Pathak Chinar , Hussain Mahdi , Freeman Samuel L. , Fielding Alistair J. , Bailey Anna J. , Stefanou Natalia , Sparkes Hazel A. , Tosha Takehiko , Yamashita Keitaro , Hirata Kunio , Murakami Hironori , Ueno Go , Ago Hideo , Tono Kensuke , Yamamoto Masaki , Sawai Hitomi , Shiro Yoshitsugu , Sugimoto Hiroshi , Raven Emma L. , Moody Peter C. E.
Published: April 2021

Oxygen activation in all heme enzymes requires the formation of high oxidation states of iron, usually referred to as ferryl heme. There are two known intermediates: Compound I and Compound II. The nature of the ferryl heme—and whether it is an FeIV=O or FeIV‐OH species—is important for controlling reactivity across groups of heme enzymes. The most recent evidence for Compound I indicates that the ferryl heme is an unprotonated FeIV=O species. For Compound II, the nature of the ferryl heme is not unambiguously established. Here, we report 1.06 Å and 1.50 Å crystal structures for Compound II intermediates in cytochrome c peroxidase (CcP) and ascorbate peroxidase (APX), collected using the X‐ray free electron laser at SACLA. The structures reveal differences between the two peroxidases. The iron‐oxygen bond length in CcP (1.76 Å) is notably shorter than in APX (1.87 Å). The results indicate that the ferryl species is finely tuned across Compound I and Compound II species in closely related peroxidase enzymes. We propose that this fine‐tuning is linked to the functional need for proton delivery to the heme.
Siliciumtetrakis(trifluormethansulfonat): Ein einfaches, neutrales Silan als weiche und harte Lewis‐Supersäure
Authors: Hermannsdorfer André , Driess Matthias
Published: April 2021

Wir berichten über einen einfachen synthetischen Zugang zu donorfreiem Siliciumtetrakis(trifluormethansulfonat), Si(OTf)4, das als erstes neutrales Silan gegenüber weichen und harten Lewis‐Basen eine Lewis‐Supersäure ist. Die OTf‐Substituenten haben dabei zwei Funktionen: Sie sind exzellente Abgangsgruppen und modulieren das Maß an Reaktivität gegenüber weichen und harten Donoren. Mit weichen Lewis‐Basen bildet Si(OTf)4 Komplexe des Typs [L2Si(OTf)4] mit intakten Si‐OTf‐Bindungen (L=Isocyanid‐, Thioether‐ oder Carbonylverbindungen). Im Gegensatz dazu aktiviert das Silan die C‐X‐Bindungen (X=F, Cl) harter organischer Lewis‐Basen unter Halogenid‐Triflat‐Austausch mit einer hohen Neigung zur Bildung von SiX4 (X=F, Cl). Bemerkenswert ist die Oxydefluorierung von Mono‐ und Bis(trifluormethyl)benzolen mit Si(OTf)4 bei milden Bedingungen, wobei entstehende Benzoyliumkationen durch das schwach koordinierende [Si(OTf)6]‐Dianion stabilisiert werden.
Light‐Activation of DNA‐Methyltransferases
Authors: Wolffgramm Jan , Buchmuller Benjamin , Palei Shubhendu , Muñoz‐López Álvaro , Kanne Julian , Janning Petra , Schweiger Michal R. , Summerer Daniel
Published: April 2021

5‐Methylcytosine (5mC), the central epigenetic mark of mammalian DNA, plays fundamental roles in chromatin regulation. 5mC is written onto genomes by DNA methyltransferases (DNMT), and perturbation of this process is an early event in carcinogenesis. However, studying 5mC functions is limited by the inability to control individual DNMTs with spatiotemporal resolution in vivo. We report light‐control of DNMT catalysis by genetically encoding a photocaged cysteine as a catalytic residue. This enables translation of inactive DNMTs, their rapid activation by light‐decaging, and subsequent monitoring of de novo DNA methylation. We provide insights into how cancer‐related DNMT mutations alter de novo methylation in vivo, and demonstrate local and tuneable cytosine methylation by light‐controlled DNMTs fused to a programmable transcription activator‐like effector domain targeting pericentromeric satellite‐3 DNA. We further study early events of transcriptome alterations upon DNMT‐catalyzed cytosine methylation. Our study sets a basis to dissect the order and kinetics of diverse chromatin‐associated events triggered by normal and aberrant DNA methylation.
Ce=O Terminated CeO2
Authors: Grinter David C. , Allan Michael , Yang Hyun Jin , Salcedo Agustín , Murgida Gustavo E. , Shaw Bobbie‐Jean , Pang Chi L. , Idriss Hicham , Ganduglia‐Pirovano M. Verónica , Thornton Geoff
Published: April 2021

Multiply bonded lanthanide oxo groups are rare in coordination compounds and have not previously been reported for a surface termination of a lanthanide oxide. Here we report the observation of a Ce=O terminated ceria surface in a CeO2(111)‐(
×
)R30° reconstruction of ≈3 nm thick ceria islands prepared on Pt(111). This is evidenced by scanning tunnelling microscopy (STM), low energy electron diffraction (LEED) and high‐resolution electron energy loss spectroscopy (HREELS) measurements in conjunction with density functional theory (DFT) calculations. A Ce=O stretching frequency of 775 cm−1 is observed in HREELS, compared with 766 cm−1 calculated by DFT. The calculations also predict that the Ce=O bond is weak, with an oxygen vacancy formation energy of 0.85 eV. This could play an important role in the facile removal of lattice oxygen from CeO2, accompanied by the reduction of CeIV to CeIII, which is a key attribute of ceria‐based systems in connection with their unique catalytic properties.
Asymmetric Catalytic Vinylogous Addition Reactions Initiated by Meinwald Rearrangement of Vinyl Epoxides
Authors: Xu Jinxiu , Song Yanji , He Jun , Dong Shunxi , Lin Lili , Feng Xiaoming
Published: April 2021

The first catalytic asymmetric multiple vinylogous addition reactions initiated by Meinwald rearrangement of vinyl epoxides were realized by employing chiral N,N′‐dioxide/ScIII complex catalysts. The vinyl epoxides, as masked β,γ‐unsaturated aldehydes, via direct vinylogous additions with isatins, 2‐alkenoylpyridines or methyleneindolinones, provided a facile and efficient way for the synthesis of chiral 3‐hydroxy‐3‐substituted oxindoles, α,β‐unsaturated aldehydes and spiro‐cyclohexene indolinones, respectively with high efficiency and stereoselectivity. The control experiments and kinetic studies revealed that the Lewis acid acted as dual‐tasking catalyst, controlling the initial rearrangement to match subsequent enantioselective vinylogous addition reactions. A catalytic cycle with a possible transition model was proposed to illustrate the reaction mechanism.
Library Creation of Ultrasmall Multi‐metallic Nanoparticles Confined in Mesoporous MFI Zeolites
Authors: Jia Xiaoli , Jiang Jingang , Zou Shihui , Han Lu , Zhu Haiyin , Zhang Qing , Ma Yue , Luo Peng , Wu Peng , Mayoral Alvaro , Han Xinbao , Cheng Jun , Che Shunai
Published: April 2021

The development of materials integrated with ultrasmall multi‐metal nanoparticles (UMMNs) and mesoporous zeolite is a considerable challenge in chemistry and materials science. We designed a trifunctional surfactant, in which the pyridyl benzimidazole in the hydrophobic tail generates the mesopores through π–π stacking; the diquaternary ammonium in the hydrophilic headgroup direct the formation of MFI zeolite sheets and the nitrogen atoms in the heterocyclic rings coordinate with various metal ions to form UMMNs confined in the zeolite matrix after calcination and reduction. A library of 56 UMMNs confined within both micropores and mesopores of MFI zeolites (MMZs) with 4 mono‐, 14 bi‐ and 38 tri‐metallic nanoparticles (sizes of 1.3–4.7 nm) of combinations of Rh, Pd, Pt, Au, Fe, Co, Ni, Cu and Zn were made. An improved catalytic performance was exhibited in the sequence of Rh‐MMZ<Rh/Pt‐MMZ<Rh/Pt/Ni‐MMZ for the mild oxidation of methane to methanol or liquid acid.
Silicon Tetrakis(trifluoromethanesulfonate): A Simple Neutral Silane Acting as a Soft and Hard Lewis Superacid
Authors: Hermannsdorfer André , Driess Matthias
Published: April 2021

A facile synthesis and isolation of pristine silicon tetrakis(trifluoromethanesulfonate), Si(OTf)4, is reported, acting as the first neutral silicon‐based Lewis superacid suitable towards soft and hard Lewis bases. Its OTf groups have a dual function: they are excellent leaving groups and modulate the degree of reactivity towards soft and hard Lewis bases. Exposed to soft Lewis donors, Si(OTf)4 leads to [L2Si(OTf)4] complexes (L=isocyanide, thioether and carbonyl compounds) with retention of all Si−OTf bonds. In contrast, it can cleave C−X bonds (X=F, Cl) of hard organic Lewis bases with a high tendency to form SiX4 (X=F, Cl) after halide/triflate exchange. Most notable, Si(OTf)4 allows a gentle oxydefluorination of mono‐ and bis(trifluoromethyl)benzenes, resulting in the formation of the corresponding benzoylium species, which are stabilized by the weakly coordinating [Si(OTf)6] dianion.
Experimental and kinetic studies on ash fusion behavior: a high‐precision acquisition method for ash fusion temperatures
Authors: Lv Yuan , Niu Yanqing , Wang Guangyao , Xu Liang , Lei Yu , Hui Shi'en , Wang Denghui
Published: April 2021

Ash fusion characteristics including ash properties and morphological changes in high‐temperature fusion test were studied among four types of fuels comprising two woody biomass, three straw biomass, two bituminous coals, and three biomass/coal mixtures. On the basis of ash fusion behavior and kinetic analysis of the ash melting process, a high‐precision acquisition method for ash fusion temperatures (AFTs) was developed. First, a reading index of AFTs was proposed; that is, in high‐temperature fusion test, initial deformation temperature (IDT), softening temperature (ST), and fluid temperature (FT) could be identified by the height shrinkage of 38%, 86%, and 98%, or the area shrinkage of 50%, 77%, and 97%, respectively. Kinetic analysis conducted on height/area shrinkage indicated that activation energy was highly related to temperature difference among IDT, ST, and FT, and low activation energy facilitated the enlargement of the temperature differences of ST‐IDT and FT‐ST. XRD patterns illustrated low activation energy had a promotion effect on the generation of higher melting substances such as KAlSi3O8 and CaSiO3, causing the elevation of the ST and FT. At last, a calculation method for AFTs based on activation energy and average height/area shrinkage was performed, which had high repeatability within an average error of ~6°C.
Filter life comparison of different levels of nanofiber coated cleanable‐surface filter for gas turbine
Authors: Akduman Cigdem , Demirel Volkan , Tezcan Fatma
Published: April 2021

High‐efficiency air filtration is a basic requirement for the most cost‐effective operation of high‐efficiency gas turbines. The filtration system protects the gas turbine from damaging debris. In gas turbine/dust collector applications, higher efficiency filtration could be achieved with nanofibers, which provide higher equipment protection than traditional media. With a nanofiber performance filter layer, the dust accumulates on the surface of the filtration media rather than within the media and could be cleaned off easily with a back pulse resulting in long filter life and a low‐operating pressure drop. In this study five type of gas tribune nanofiber coated corrugated cellulose/synthetic filter media were developed. Nanofiber coating was adjusted for five filtration efficiency level, 50 ≤ E < 60, 60 ≤ E < 70, 70 ≤ E < 85, 85 ≤ E < 95 and 95 ≤ E, pore size and filter‐life of the developed media were evaluated. One of the developed nanofiber coated media was also compared with two other commercial nanofiber coated gas tribune filter media, a glass fiber type filter media and a commercial fine fiber gas tribune filter media. It was seen that, with decreasing penetration levels due to nanofiber coating level, initial 30 cycle durations of filter life evaluation could reach about 229.9 to 250.7 min. Highest final cycle duration of 188.7 min belonged to cellulose/synthetic blend corrugated filter media with penetration of 13.66%. Nanofiber based surface filter media was cleaned up better than fine fiber media and final 30 cycle sequences were significantly higher. Surface of the nanofiber coated media was smoother when compared to fine fiber media and during the initial and final cycle test dust could not penetrate inside and could not hang to this smooth surface. So, with back pulse cleaning cake releasing have performed easily. It was also seen that, for higher filter life nanofiber coating should be uniform and robust to back pulse cleaning.
Synthesis and biological evaluation of new 4‐oxo‐thiazolidin‐2‐ylidene derivatives as antimicrobial agents
Authors: Chaban Taras , Matiichuk Yulia , Chulovska Zoriana , Tymoshuk Oleksandr , Chaban Ihor , Matiychuk Vasyl
Published: April 2021

In this study, an efficient synthesis and the antimicrobial activity evaluation of some 4‐oxo‐thiazolidin‐2‐ylidene derivatives are presented. The structures of the target substances were confirmed by using 1H and 13C nuclear magnetic resonance spectroscopy, mass spectrometry, infrared spectroscopy, and elemental analysis. The synthesized compounds were evaluated for antimicrobial activity against five bacterial strains (Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Staphylococcus aureus) and two fungal strains (Candida albicans and Cryptococcus neoformans). It was shown that the compounds in this series possess antibacterial and antifungal activities.
Full coverage of a reader's interests in context‐based information filtering
Authors: Dumitrescu Alexandra , Santini Simone
Published: April 2021

We present a collection of algorithms to filter a stream of documents in such a way that the filtered documents will cover as well as possible the interest of a person, keeping in mind that, at any given time, the offered documents should not only be relevant, but should also be diversified, in the sense of covering all the interests of the person. We use a modification of the WEBSOM algorithm to create a user model based on a self‐organizing network trained using a collection of documents representative of the person's interests. We introduce the concepts offreshnessandcoverage. A document is fresh if it belongs to a semantic area of interest to a person for which no documents were seen in the recent past; a group of documents hascoverageto the extent to which it is a good representation of all the interests of a person. Our tests show that these algorithms can effectively increase the coverage of the documents that are shown to the user without overly affecting precision.
Kombinationsbewehrte Fundamentplatten im Geschosswohnungsbau
Authors: Haus Andreas
Published: April 2021

Im Zuge der Innenstadtverdichtung und der damit einhergehenden Parkplatzproblematik werden neue Geschossbauten immer häufiger auch mit Tiefgaragen in mehreren Ebenen ausgeführt. Derartige Fundamentplatten werden aufgrund hoher Lasten, aber vor allem auch aufgrund der erforderlichen Rissbreitenbeschränkung, oftmals hoch bewehrt. Neben der umfangreichen Baustellenlogistik, die ein solch hoher Bewehrungsgrad mit sich bringt, zeigt sich häufig, dass vor allem die Bereiche mit einer hohen Bewehrungskonzentration fehleranfällig sind. Durch den Einsatz von Stahlfaserbeton gemäß der DAfStb‐Richtlinie „Stahlfaserbeton” lässt sich die Wirkung der Stahlfasern sowohl im Grenzzustand der Tragfähigkeit als auch im Grenzzustand der Gebrauchstauglichkeit anwenden.
Leistungsfähige Spezialbetone für Industrieböden
Authors: Kuhfeldt Sven
Published: April 2021

Die Veränderlichkeit der Ausgangsstoffe verlangt, zusammen mit den zunehmend höheren Anforderungen an den Baustoff Beton selbst, eine ständige Weiterentwicklung der bestehenden Rezepturen. Das BV „Akasol” in Darmstadt spiegelt den Bedarf nach anspruchsvollen Betonen wider, die neben ihren normativen Eigenschaften auch noch ausführungsrelevante Anforderungen zu erfüllen haben. Durch den Einsatz von Dyckerhoff FERRODUR und VELODUR konnten nicht nur die Prozesse der Bauausführung wirtschaftlicher und ökonomischer gestaltet werden, sondern auch die Belastungen für Umwelt und Anwohner wirksam reduziert werden.
Multiple operant discrimination training to increase the precision of stimulus deltas following treatment of challenging behavior
Authors: Lambert Joseph M. , Lamers Mallory E. , Copeland Bailey A. , Banerjee Ipshita
Published: April 2021

Explicit instruction on how to maximize reinforcement in volatile reinforcement conditions could decrease the probability of persistent but ineffective requesting while also maintaining low rates of challenging behavior. We used a multiple probe design to demonstrate a functional relation between multiple‐operant discrimination training and manding for available reinforces from a child with autism spectrum disorder and complex communication needs who used a low‐tech augmentative and alternative communication system. Despite a history of severe challenging behavior, rates of challenging behavior remained low throughout this study.
Paving the road toward eco‐effectiveness: Exploring the link between greenhouse gas emissions and firm performance
Authors: Russo Angeloantonio , Pogutz Stefano , Misani Nicola
Published: April 2021

Climate change has increasingly attracted business attention over the last decade, focusing particularly on the eco‐efficiency debate. The goal of this paper is twofold. First, we contribute to the ongoing debate on the effects of environmental strategies on firm performance. We investigate this relationship by considering the relative greenhouse gas emissions (GHG) as a predictor of the eco‐efficiency of firms' environmental strategies. GHG emissions are a direct indicator of the environmental performance and effectively measure the firm's efforts in mitigating the impacts related to its processes and products. Second, we investigate the drivers that lead to an increase in the firm's environmental impact under the conditions of increasing market performance by the firm, therefore paving the road to the concept of eco‐effectiveness of corporate environmental strategies. To test our hypotheses, we use a sample of worldwide listed companies derived from the S&P 1200 list. A longitudinal analysis is run through generalized least squares regression models over the period 2004–2016. Results offer evidence of the direct relationship between the level of absolute emissions and market performance of the firm. Therefore, the findings have significant implications on the way we conceptualize corporate environmental sustainability and environmental strategies, shedding new light on the relation between environmental pressures and corporate growth.
Improving the learning of engineering students with interactive teaching applications
Authors: Corral Abad Eduardo , Gómez García María J. , Diez‐Jimenez Efren , Moreno‐Marcos Pedro M. , Castejón Sisamon Cristina
Published: April 2021

Over decades, Mechanical Engineering students often find some difficulties to grasp some contents and/or struggle with some parts of the course. With the increasing development of new technologies, promising innovations can be implemented enhancing learning and improving success rates. In this study, a new learning interactive method is proposed and evaluated using the experience of over 600 students of Mechanical Engineering. This study describes a 4‐year experiment based on new interactive applications for education. The experiment has been implemented using E‐learning techniques and new technologies (a combination of remote and virtual examples, videos, quizzes, and theory). Specifically, several applications have been programmed to be executed on different devices, such as mobile phones and PC/laptops (Android and Windows). The experiment is applied using small applications that help the students identify the most challenging contents and guide them throughout step‐by‐step. The main objective of this interactive method is to help students find their lack of knowledge and offer them contents to cover it. These didactic applications are portable and intuitive. Thanks to these interactive applications, it is possible to accomplish better practices of “E‐learning” and “Computer Simulation and Animation” together. Since they are portable applications, they allow the student to interact and check conceptual understandings at any place. Students really appreciate this aspect. The results of the course titled Mechanism and Machine Theory have been analyzed during these four last years in which these interactive applications have been offered to the students.
End‐stage renal disease patients undergoing angioplasty and bypass for critical limb ischemia have worse outcomes compared to non‐ESRD patients: Systematic review and meta‐analysis
Authors: Dawson Desireé B. , Telles‐Garcia Nelson A. , Atkins Jessica L. , Mina George S. , Abreo Adrian P. , Virk Chiranjiv S. , Dominic Paari S.
Published: April 2021

Background

End‐stage renal disease (ESRD) is associated with increased morbidity and mortality following lower extremity amputation for critical limb ischemia (CLI). Angioplasty and bypass are used in ESRD patients with CLI; however, the treatment of choice remains controversial. We compared the long‐term outcomes in patients with CLI undergoing angioplasty or bypass to evaluate the differences between patients with ESRD and those without ESRD.

Methods

Established databases were searched for observational studies comparing outcomes following bypass or angioplasty for CLI in patients with ESRD to those in non‐ESRD patients. End points included survival, limb salvage, amputation‐free survival (AFS), and primary and secondary patency at 1‐year post‐procedure. Pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated using a random effect model.

Results

We included 20 studies with a total of 24,851 patients. ESRD patients compared to non‐ESRD patients with CLI had significantly lower survival post‐angioplasty (OR 0.51, 95% CI 0.36–0.72, p < .001) and post‐bypass (OR 0.26, 95% CI 0.15–0.45, p < .001). ESRD patients had lower rates of limb salvage post‐bypass (OR 0.33, 95% CI 0.21–0.53, p < .001) and post‐angioplasty (OR 0.54, 95% CI 0.41–0.70, p < .001). AFS was significantly lower in ESRD patients compared to non‐ESRD patients following angioplasty (OR 0.48, 95% CI 0.32–0.71, p < .001) and bypass (OR 0.28, 95% CI 0.16–0.47, p < .001) despite no significant differences in primary patency. ESRD patients had overall worse secondary patency post‐angioplasty and/or bypass (OR 0.54, 95% CI 0.32–0.94, p = .03) compared to non‐ESRD patients. A meta‐analysis of four studies directly comparing survival in ESRD patients with CLI based on whether they underwent angioplasty or bypass showed no difference (OR 0.93, 95% CI 0.64–1.35, p = .69).

Conclusion

ESRD patients have worse survival, limb salvage, and AFS outcomes following angioplasty and bypass for CLI compared to non‐ESRD patients. Large randomized controlled trials comparing these two modalities of treatment in this patient population are needed for further clarity.
Incidence and outcomes of acute kidney injury stratified by cardiogenic shock severity
Authors: Padkins Mitchell , Breen Thomas , Van Diepen Sean , Barsness Gregory , Kashani Kianoush , Jentzer Jacob C.
Published: April 2021

Background

Acute kidney injury (AKI) is common among patients with cardiogenic shock (CS) and it is independently associated with mortality. We sought to assess the prevalence, severity, and prognosis of AKI as a function of cardiogenic shock severity in unselected Cardiac Intensive Care Unit (CICU) patients.

Methods

We retrospectively reviewed admissions to the Mayo Clinic between 2007 to 2015 and stratified patients by the AKI stage (based on modified Kidney Disease: Improving Global Outcomes criteria) and Society for cardiovascular angiography and interventions (SCAI) shock stage. The association with in‐hospital mortality was analyzed using multivariable logistic regression.

Results

We included 9,311 unique patients with a mean age of 67 years and 37% females. SCAI shock stages A, B, C, D, and E were present in 47%, 30%, 15%, 7%, and 1% of patients. The incidence of AKI of any severity was 39% in the CICU and 51% during the hospitalization. Hospital mortality occurred in 8% of all patients, and the risk increased as a function of the rising AKI and SCAI shock stage. Worsening AKI stage was associated with increased adjusted hospital mortality (adjusted OR per AKI stage 1.22, 95% CI 1.10–1.36, p < .001). Higher AKI stages were associated with increased adjusted hospital mortality in SCAI stage A/B (p < .001), but not in SCAI stage C, D, or E (all p > .05).

Conclusions

Higher AKI stages were independently associated with mortality in CICU patients after accounting for shock severity and may add incremental prognostic utility in patients with lower SCAI stages.
Probing the Influence of Counter Electrode Structure on Electrochromic‐Device Operating Potentials and Performance Using Electrochemical Impedance Spectroscopy
Authors: Ahmad Rana , Laschuk Nadia O. , Ebralidze Iraklii I. , Zenkina Olena V. , Easton E. Bradley
Published: April 2021

The paper reports a general methodology for the rational tuning and optimization of electrochromic devices (ECDs) that are based on a monolayer of Fe (II) (4’‐(4‐pyridyl)‐2,2’:6’,2”‐terpyridine)2 complex (Fe 4’T) covalently embedded onto a screen‐printed high‐surface area indium tin oxide working electrode. We demonstrate that the nature of the counter electrode and the resulting device configuration could drastically improve the long‐term stability of the ECD. We show that the replacement of the flat ITO glass electrode with a high surface area ITO electrode or the use of symmetrical working and counter electrode architecture leads to a much longer performance of the device. We propose a methodology to determine optimal operating conditions for ECDs by fine‐tuning the lower and upper operation potentials. In addition to using traditional cyclic voltammetry (CV), we utilize electrochemical impedance spectroscopy (EIS) to study the intrinsic properties of the devices and understand the factors that define the long‐term cycling stability, which is further described through the use of equivalent circuit models. The main reasoning behind decomposition processes in ECDs and ways to suppress them are discussed.
Zinc‐ and Cadmium meso‐Aryl‐Isoporphyrins: Non‐Aromatic NIR Dyes with Distinct Conformational Features
Authors: Baş Çağla , Krumsieck Jens , Möller William‐Dale , Körner Dominik , Bröring Martin
Published: April 2021

A series of pyrrolyl and dipyrrinyl isoporphyrins carrying different phenyl and thienyl groups is reported. The compounds are obtained by a one‐pot approach in the presence of a template reagent. Thienyl derivatives gave better yields, and were the only subclass to form with steric hindrance. The structural analyses carried out on compounds 1 and 14 revealed distinct conformational differences which are likely to result from an intramolecular NH…Cl hydrogen bridge of the pyrrolyl subclass. In addition, this hydrogen bridge strongly favors one of the two possible atropisomers. Hindered rotation of the meso‐aryl groups is observed only in the cases of methylbenzothienyl derivatives 10 and 15 and leads to the observation of several diastereomers. NIR absorptions up to 923 nm are found throughout. Electrochemical investigations into the 1e− and 2e− reduced species unravel axial ligand exchange dynamics for the zinc isoporphyrin radical, and the probable formation of a zinc phlorinate.
Pentafluorophenyl Esters as Exchangeable Stoppers for the Construction of Photoactive [2]Rotaxanes
Authors: Rémy Marine , Nierengarten Iwona , Park Boram , Holler Michel , Hahn Uwe , Nierengarten Jean‐François
Published: April 2021

Stable pillar[5]arene‐containing [2]rotaxane building blocks with pentafluorophenyl ester stoppers have been efficiently prepared on a multi‐gram scale. Reaction of these building blocks with various nucleophiles gave access to a wide range of [2]rotaxanes with amide, ester or thioester stoppers in good to excellent yields. The rotaxane structure is fully preserved during these chemical transformations. Actually, the addition‐elimination mechanism at work during these transformations totally prevents the unthreading of the axle moiety of the mechanically interlocked system. The stopper exchange reactions were optimized both in solution and under mechanochemical solvent‐free conditions. While amide formation is more efficient in solution, the solvent‐free conditions are more powerful for the transesterification reactions. Starting from a fullerene‐functionalized pillar[5]arene derivative, this new strategy gave easy access to a photoactive [2]rotaxane incorporating a C60 moiety and two Bodipy stoppers. Despite the absence of covalent connectivity between the Bodipy and the fullerene moieties in this photoactive molecular device, efficient through‐space excited state interactions have been evidenced in this rotaxane.
Investigations on the Droplet Entrainment in a Forced Circulation Flash Evaporator
Authors: Jasch Katharina , Scholl Stephan
Published: April 2021

This contribution presents results from entrainment measurements in a forced circulation flash evaporator which was designed to systematically investigate the droplet entrainment under real evaporating conditions. Operating pressures in a range of 100 to 800 mbar(a) and temperature differences between 5 and 55 K were conducted. Gas load factors up to fG = 4.0 Pa0.5 were achieved with glycerol‐water and water as evaporating liquids. A conductivity measurement was used to determine the absolute entrained liquid and entrainment ratios. The results show an exponential behavior between entrainment, gas load factor, and heat flux due to superimposing effects. Investigation on the pressure drop across the orifice plate showed no influence for operation at gas load factors of fG < 2.5 Pa0.5.
Ligand‐Mediated Synthesis of Mixed‐Phase Mn2+‐Doped Cesium Lead Chloride Nanocrystals
Authors: Xu Jie , Liu Lijia
Published: April 2021

Herein we report a study on the role of alkylamine ligand in tuning the crystal structure and the luminescence of Mn2+‐doped cesium lead chloride (Mn−CPC) nanocrystals. In a typical hot‐injection synthesis of Mn−CPC, oleic acid (OA) and oleylamine (OLA) are used as the capping ligands to mediate the size and surface structure of the nanocrystals. We found that by either increasing the concentration of OLA or substituting OLA with an amine with a shorter chain length (e. g. dodecylamine), the resulted Mn−CPC contains both CsPbCl3 and Cs4PbCl6 phases. The mixed‐phase Mn−CPC exhibit two major photoluminescence emission bands originated from the CsPbCl3 bandgap and the Mn d‐d transition, respectively. Besides, a near‐UV emission from Cs4PbCl6 near‐band‐gap exciton emission also appears and is highly sensitive to the excitation wavelength. The formation mechanism of mixed‐phase Mn−CPC nanocrystals is proposed.
When Can Nonrandomized Studies Support Valid Inference Regarding Effectiveness or Safety of New Medical Treatments?
Authors: Franklin Jessica M. , Platt Richard , Dreyer Nancy A. , London Alex John , Simon Gregory E. , Watanabe Jonathan H. , Horberg Michael , Hernandez Adrian , Califf Robert M.
Published: April 2021

The randomized controlled trial (RCT) is the gold standard for evaluating the causal effects of medications. Limitations of RCTs have led to increasing interest in using real‐world evidence (RWE) to augment RCT evidence and inform decision making on medications. Although RWE can be either randomized or nonrandomized, nonrandomized RWE can capitalize on the recent proliferation of large healthcare databases and can often answer questions that cannot be answered in randomized studies due to resource constraints. However, the results of nonrandomized studies are much more likely to be impacted by confounding bias, and the existence of unmeasured confounders can never be completely ruled out. Furthermore, nonrandomized studies require more complex design considerations which can sometimes result in design‐related biases. We discuss questions that can help investigators or evidence consumers evaluate the potential impact of confounding or other biases on their findings: Does the design emulate a hypothetical randomized trial design? Is the comparator or control condition appropriate? Does the primary analysis adjust for measured confounders? Do sensitivity analyses quantify the potential impact of residual confounding? Are methods open to inspection and (if possible) replication? Designing a high‐quality nonrandomized study of medications remains challenging and requires broad expertise across a range of disciplines, including relevant clinical areas, epidemiology, and biostatistics. The questions posed in this paper provide a guiding framework for assessing the credibility of nonrandomized RWE and could be applied across many clinical questions.
Photochemical Construction of Ni/CdS Double‐Walled Magnetic Hollow Microspheres with Simultaneously Enhanced Visible‐Light Photocatalytic Activity and Recyclability
Authors: Zhong Wenyu , Zhuang Zefeng , Zhu Zhimin , Zhou Guangying , Zhu Ximiao , Ma Lijun , Xu Bingjia , He Guping , Gu Fenglong , Sun Fengqiang
Published: April 2021

A new magnetic recyclable photocatalyst, consisting of a Ni/CdS double‐walled hollow microsphere based on a polymer microsphere template, was constructed entirely by use of a photochemical method. Under an ultraviolet lamp, the poly(styrene‐co‐acrylamide) microsphere template, the Ni magnetic wall and the CdS wall were fabricated in sequence in corresponding precursor solutions, and then the template was remove to obtain the structure. Both walls were mesoporous and molecularly passable, and their sequential assembly facilitated their respective roles in photocatalysis. The CdS wall was assembled on the outside of the structure to maximize exposure to its active sites, whereas the Ni wall was inside the structure and acted as a support, as a magnetic component, and also as an heterogeneous enhancer. When the structure was employed in photodegradation of methylene blue or in photocatalytic hydrogen evolution from water under visible light, it exhibited considerably enhanced activities, recyclability and stability compared to pure CdS hollow microspheres. Such a construction strategy using simply light energy is promising in the acquisition of high performance photocatalysts with recyclability or other functions.