bluuebunny/crossref_metadata_2025 huggingface dataset:
Quand des enseignants de l’école primaire évaluent des résolutions de problèmes additifs : étude des incidents critiques en cours de jugement
Authors: Mottier Lopez Lucie , Morales Villabona Fernando
Published: February 2019

L’étude empirique présentée dans cet article examine le jugement évaluatif d’enseignants de l’école primaire genevoise lorsqu’ils attribuent des notes certificatives, plus particulièrement dans des contrôles écrits proposant des exercices de résolution de problèmes additifs. Les questions de recherche portent, d’une part, sur les caractéristiques des contrôles écrits élaborés par les enseignants. Elles portent, d’autre part, sur le jugement des enseignants quand ils verbalisent leur pensée en cours d’évaluation. À partir de l’analyse d’incidents critiques observés pendant la correction des travaux des élèves, les résultats de recherche donnent à voir la préoccupation des enseignants à comprendre le raisonnement mathématique des élèves, les amenant à devoir faire face à des réponses imprévues et singulières qui nécessitent une spécification de leurs référents. Les analyses entreprises débouchent sur la conceptualisation de différents cas de figure entre des jugements analytiques et holistiques, dont la mise en tension constructive peut être vue comme un enjeu majeur de développement pour l’évaluation d’apprentissages complexes, dont la résolution de problèmes de mathématiques.
Structuring Effect of the EU Framework Programmes in Estonia? The Case of Sociology
Authors: Tõnismann Teele
Published: February 2019

This article analyzes the extent that a European funding instrument, the Framework Programme (FP), has affected the structuring of sociologists’ project collaboration practices in a post-communist Estonia, which joined the EU in 2004. It is hypothesized that to better understand how the FP has structured the sociology discipline in Estonia, its usage should be studied in two distinct levels of academic context; the national and disciplinary levels. Science administrative elite have used the FP as a normative model for implementing national research funding policy reforms. In the case of sociologists, these reforms have engendered a partial auto-exclusion from competition for national grants perceived as highly competitive and resulted in an orientation towards commissioned contract funding both at a national and European level. This exposes the limited structuring effect of the FP in Estonia, a country otherwise considered an exemplary participant in EU programs.
When a Repository Is Not Enough: Redesigning a Digital Ecosystem to Serve Scholarly Communication
Authors: Sewell Robin R. , Potvin Sarah , Melgoza Pauline , Creel James Silas , Huff Jeremy T. , Bailey Gregory T. , Bondurant John , Buckner Sean , duPlessis Anton R. , Furubotten Lisa , Mosbo Ballestro Julie A. , Muise Ian W. , Wright Brian J.
Published: February 2019

INTRODUCTION Our library’s digital asset management system (DAMS) was no longer meeting digital asset management requirements or expanding scholarly communication needs. We formed a multiunit task force (TF) to (1) survey and identify existing and emerging institutional needs; (2) research available DAMS (open source and proprietary) and assess their potential fit; and (3) deploy software locally for in-depth testing and evaluation. DESCRIPTION OF PROGRAM We winnowed a field of 25 potential DAMS down to 5 for deployment and evaluation. The process included selection and identification of test collections and the creation of a multipart task based rubric based on library and campus needs assessments. Time constraints and DAMS deployment limitations prompted a move toward a new evaluation iteration: a shorter criteria-based rubric. LESSONS LEARNED We discovered that no single DAMS was “just right,” nor was any single DAMS a static product. Changing and expanding scholarly communication and digital needs could only be met by the more flexible approach offered by a multicomponent digital asset management ecosystem (DAME), described in this study. We encountered obstacles related to testing complex, rapidly evolving software available in a range of configurations and flavors (including tiers of vendor-hosted functionality) and time and capacity constraints curtailed in-depth testing. While we anticipate long-term benefits from “going further together” by including university-wide representation in the task force, there were trade-offs in distributing responsibilities and diffusing priorities. NEXT STEPS Shifts in scholarly communication at multiple levels—institutional, regional, consortial, national, and international—have already necessitated continual review and adjustment of our digital systems.
Assessment of Knowledge and Practice about Mosquito Born Disease among Rural Population of Kancheepuram District, Tamilnadu
Authors: Raja V. Pragadeesh , Ravivarman G. , Venmathi E. , Salomi M.
Published: February 2019

Background: Mosquito are one of the well known causing many diseases like Malaria, Dengue, Chikungunya, Lymphatic Filariasis, Japanese Encephalitis. They are more prevalent in rural area due to various social factors and lack of knowledge. The objective of this study was to assess knowledge of people and their practices regarding mosquito borne diseases in rural areas of Kancheepuram district, Tamilnadu.

Materials and Methods: A community based cross sectional study was conducted among the residents of Pooncheri, Kancheepuram district of Tamilnadu, between the period of August 2017 to September 2017 among 124 houses selected. After obtaining informed consent from the participants they were interviewed using a pretested semi structured questionnaire regarding their knowledge and practices on mosquito borne diseases.

Results: The study reported that in case of any symptoms suspected to be of mosquito born disease majority of the study population 82.2% reported consulting doctors.  The most preferred mode of prevention of mosquito bite was usage of spray (33.9%) in the breeding place followed by usage of electric repellents (31.4%).

Conclusion: The study indicated that majority of the study population were unaware bout the prevention practices despite knowing about these diseases. Thus, arises the need for effective propagation in the rural area about prevention strategies of mosquito born disease through mass education and social media.
Evaluation of Tolerable Upper Intake Levels for Vitamin D in Children and Adolescents
Authors: Haugen Margaretha , Holvik Kristin , Iversen Per Ole
Published: February 2019

In 2012, the European Food Safety Authority (EFSA) suggested a tolerable upper intake level (UL) for vitamin D at 100 µg/day for adults based on the risk of hypercalcaemia. EFSA concluded that consumption of up to 50 µg/day does not lead to hypercalcaemia in children and adolescents (10-17 years). Furthermore, EFSA stated that there is no reason to assume that children and adolescents in the phase of rapid bone formation and growth have a lower tolerance for vitamin D compared to adults, and a UL of 100 µg/day for adolescents aged 11-17 years and 50 µg/day in children 1-10 years, taking the smaller body size into account, was proposed.

The Norwegian Food Safety Authority (NFSA) is currently revising the national regulation of maximum limits in food supplements (not yet harmonised in the European Economic Area (EEA)), including maximum limits for vitamin D. NFSA has therefore requested the Norwegian Scientific Committee for Food Safety (VKM) to evaluate the assumption in the EFSA opinion that children and adolescents can tolerate the same amount of vitamin D as adults due to rapid bone formation and growth. In children and adolescents with lower weight than adults, this assumption actually implies that adolescents can tolerate more vitamin D per kg body weight than adults. VKM is therefore requested to evaluate if there is scientific evidence that a UL at 50 µg/day for children (1-10 years) and 100 µg/day for adolescents (11-17 years) is safe.

The present statement is prepared by members of the Panel on Nutrition, Dietetic Products and Novel Food and Allergy in VKM.

Three literature searches were performed to find new relevant studies investigating high intakes of vitamin D in children and adolescents and the role of vitamin D in bone formation and growth.

No studies supporting a higher tolerance to vitamin D in children and adolescents due to rapid bone formation and growth were retrieved in the literature search. Moreover, there is apparently no firm association between bone formation and vitamin D levels in children during their growth period into adolescence and adulthood. 

No studies investigating high intakes of vitamin D in children 1-10 years were found. Furthermore, no studies that have examined safety issues and/or adverse effects of vitamin D supplementation in doses above 50 µg/day in adolescents were identified. It can therefore not be concluded that the UL at 50 µg/day in children (1-10 years) and 100 µg/day in adolescents (11-17 years) is safe.

In the 2002 report from European Scientific Committee on Food (SCF), a UL was set at 25 µg/day for children aged 2-10 years, and 50 µg/day for adolescents aged 11-17 years (corresponding to the UL for adults at that time). To the best of knowledge no serious, harmful effects have been reported for these doses of vitamin D.
Risk Assessment of Specific Strains of Bifidobacterium spp. Used as "Other Substances"
Authors: Yazdankhah Siamak , Grahek-Ogden Danica , Eckner Karl , Kapperud Georg , Lassen Jørgen , Narvhus Judith , Nesbakken Truls , Robertson Lucy , Rosnes Jan Thomas , Skjerdal Olaug Taran , Skjerve Eystein , Vold Line , Wasteson Yngvild
Published: February 2019

The Norwegian Scientific Committee for Food Safety (Vitenskapskomiteen for mattrygghet, VKM) has, at the request of the Norwegian Food Safety Authority (Mattilsynet; NFSA), assessed the risk of "other substances" in food supplements sold in Norway. These risk assessments will provide NFSA with the scientific basis for regulation of the addition of “other substances” to food supplements and other foods.

"Other substances" are described in the food supplement directive 2002/46/EC as substances other than vitamins or minerals that have a nutritional and/or physiological effect. It is added mainly to food supplements, but also to other foods. VKM has not in this series of risk assessments of "other substances" evaluated any claimed beneficial effects from these substances, only possible adverse effects.

The present report is a risk assessment of Bifidobacterium lactis Bi-07, Bifidobacterium bifidum W23, Bifidobacterium longum Rosell-175, Bifidobacterium breve Rosell-70, and Bifidobacterium animalis sub. lactis Bb12 based on previous risk assessments and also publications retrieved from literature search.

The risk of the Bifidobacterium strains listed above was assessed for the general population. However, in previous assessments of probiotics published by VKM, concerns have been identified for specific groups. Therefore, the risk was assessed for the age group with immature gastro-intestinal microbiota (age group 0-36 months), population with mature gastro-intestinal microbiota (>3 years) and vulnerable groups with mature gastro-intestinal tract. VKM has also assessed the risk of Bifidobacterium spp. in food supplements and other foods independent of the dose and have assessed exposure in general terms.

VKM concludes that it is unlikely that B. lactis Bi-07, B. bifidum W23, B. longum Rosell-175, B. breve Rosell-70, and B. animalis sub. lactis Bb12 would cause adverse health effects in the general healthy population with mature gastro-intestinal tract.

However, no data on long-term adverse effects on infants and young children were identified. As evidence is accruing that the early microbial composition of the neonatal gut is important for the development of the gut microbiota and the immune system of the growing child, it is not possible to exclude that a daily supply of a single particular bacterial strain over a prolonged period of time to an immature gastro-intestinal tract may have long-term, although still unknown, adverse effects on that development.
Internet Addiction, Problematic Smartphone Use and Psychological Health of Nigerian University Undergraduates
Authors: Akpunne Bede C. , Akinnawo Olutope E.
Published: February 2019

Aim: This study examined Internet Addiction (IA) and Problematic Smartphone Use (PSU) as predictors of severities of anxiety, depression and psychological distress among university undergraduates in Nigeria.

Study Design: Exploratory /Descriptive survey design.

Place and Duration of Study: Redeemer’s University Nigeria, between April and August 2018.

Methodology: A total of 854 university undergraduates made up of 342 males and 512 females, mean age 20.5 years, were purposively selected from four universities in Osun state, southwestern Nigeria. Internet Addiction Test (IAT), Smartphone Addiction Scale – Short Version (SAS-SV), Beck Anxiety Inventory (BAI), Centre for Epidemiological Studies Depression Scale (CES-D) and General Health Questionnaire (GHQ-12) were used for data collection. 

Results: Observed prevalence of studied variables among respondents are: Internet Addiction (IA) 48.6%, Problematic Smartphone Use (PSU) (47.4%), anxiety disorder (50.6%), depression (49.8%) and psychological distress (47.6%). IA independently and significantly predicted severities of anxiety disorder (R² = .01, p = .025), depression (R² = .057, p = .000) and psychological distress (R² = .105, p = .000). PSU independently and significantly predicted severities of depression (R² = .073, p = .000) and psychological distress (R² = .094, p = .000). However PSU failed to significantly predict severity of anxiety disorder (R² = .00, p = .650) among the participants.

Conclusion: High prevalence of IA, PSU, anxiety disorder, depression and psychological distress exist among the participants. IA is a significant independent predictor of anxiety, depression and psychological distress. PSU is a significant independent predictor of depression and psychological distress but is not a significant predictor anxiety disorder among Nigerian undergraduates.
Polymyxins Nebulization over Intravenous Injection: Pharmacokinetics and Pharmacodynamics-Based Therapeutic Evaluation
Authors: Hasan Md. Jahidul
Published: February 2019

Polymyxins are the last line potential antibiotics against multi-drug resistant gram-negative bacteria and consist of two sister antibiotics: Polymyxin B and colistin (polymyxin E). Intravenous use of polymyxins was started from a long ago in the treatment of serious gram-negative infections and once their uses were restricted due to potential adverse drug reactions, such as nephrotoxicity and neurotoxicity. Lack of in vivo clinical studies on polymyxins mostly, in human body makes the pharmacokinetics and pharmacodynamics of polymyxin B and colistin unclear in many aspects, such as the distribution of polymyxins in different compartments of lung. The nebulization of polymyxins is practicing very limitedly and lack of clinical evidence has not justified this administration technique yet properly to date. The main objective of this review study was to evaluate the pharmacokinetic and pharmacodynamic properties of intravenous and nebulized polymyxins and the related therapeutic potentialities. Aerosolized polymyxins directly administered to the respiratory tract was found with higher drug concentration in different subcompartments of lungs than the intravenous administration and sustainably meets the minimum inhibitory concentration locally with superior bactericidal properties in respiratory tract infections. In contrast, intravenous administration of polymyxins shows similar anti-infective superiority in other organs, such as blood, urinary tract etc. So, during this alarming situation of rapidly emerging multidrug-resistant organisms in human communities, therapeutic administration techniques of last resort polymyxins should be clinically evidence-based for achieving optimum therapeutic outcomes with minimum chance of adverse drug reactions.
The Effect of Information Technology Application on Organizational Performance Through Cross Functional Team and Total Quality Management Implementation
Authors: Westonlie Tommy , Siagian Hotlan , Tarigan Zeplin Jiwa Husada
Published: February 2019

In this thesis discuss the effect of Information Technology Application on Organizational Performance through Cross Functional Team and Total Quality Management Implementation on the company. In this study using primary data with 102 population and 50 samples of manufacturing companies using data collection methods, namely 5 points Likert scale in the form of questionnaires distributed in companies that are open or closed that have large and medium industrial groups on firm manufacturing in East Java. This study uses Structural Equation Modeling analysis techniques, also called path modeling with SmartPLS tools. The questionnaire collected was 57 questionnaires. The result showed that the effect of Information Technology Application on Organizational Performance was significant. The results showed that the effect of Information Technology Application on Cross Functional Team was significant, the result showed that the effect of Information Technology Application on Total Quality Management Implementation was significant, the result showed that the effect of Cross-Functional Team on Organizational Performance was significant, the result showed that the effect of Cross-Functional Team on Total Quality Management Implementation was significant and the result showed that the effect of Total Quality Management Implementation on Organizational Performance was significant in firms manufacturing in East Java.
Neural Prostheses
Authors: Osborn Luke E. , Betthauser Joseph L. , Thakor Nitish V.
Published: February 2019

Millions of people worldwide are affected by some disability, including but not limited to limb loss, hearing loss, spinal cord injury, or visual impairment. Neural prostheses are designed to provide or replace lost functionality to these individuals. In the case of upper limb loss, simplified hook‐like body‐powered controlled prostheses can be used; however, recent technological developments have led to anthropomorphic dexterous manipulators that require more advanced control strategies. Further, direct control of these manipulators via neural motor signals is seen as a more natural and biomimetic solution. Recent work has utilized direct neural interfacing with the brain to measure motor commands for prosthesis control and to deliver sensory percepts to the user, either through the peripheral nervous system or through the cortex. Current upper limb prosthesis interfaces mainly rely on forward motor commands for control, but recent research has also focused on providing sensory feedback to the user, specifically the sense of touch. This article provides an introductory overview of neural prostheses, such as visual and auditory devices, and an in‐depth look at the state of the art in bidirectional neural prostheses, including control of a dexterous limbs with motor signals from the nervous system and the incorporation of sensory feedback.
HFSurface Wave Radar
Authors: Huang Weimin , Gill Eric W.
Published: February 2019

HF surface wave radar (HFSWR) has been recognized and accepted as an important tool for ocean remote sensing for more than four decades. In this article, a comprehensive tutorial of such an ocean sensor is presented. It begins with the concept of HFSWR. Next, the history of HFSWR is briefly reviewed. Then, the classification of HFSWR in terms of waveform, array signal processing technique, the number of operating frequencies, and configuration geometry is described in detail. Subsequently, the state‐of‐the‐art applications of this type of ocean radar for sea surface current, and wave parameter measurements, wind mapping, and hard targets detection and tracking are presented. The working principles and data processing associated with each application are also explained. The remaining challenges and future trends are also discussed.
Ground‐Penetrating Radar: Operation Principle and Data Processing
Authors: Catapano Ilaria , Gennarelli Gianluca , Ludeno Giovanni , Soldovieri Francesco , Persico Raffaele
Published: February 2019

Ground‐penetrating radar (GPR) is a technology exploiting radiofrequency and microwaves to image optically opaque media, with the main aim of gaining information about the geometry of buried or hidden targets. Differently from a conventional radar, which is used mostly for navigation and surveillance, GPR requires a more challenging design because it must be able to investigate loss media and mitigate multipath and clutter, which can obscure the targets of interest. This article presents a comprehensive overview of the main scientific and technical aspects for a reliable use of GPR technology and the production of easily interpretable images. Specifically, a survey of the hardware solutions and data processing procedures is provided by giving a brief review of the state of art solutions. In addition, the state of art microwave tomographic approach is presented and validated against experimental data collected in laboratory conditions.
Interplay of lncRNA H19/miR‐675 and lncRNA NEAT1/miR‐204 in breast cancer
Authors: Müller Volkmar , Oliveira‐Ferrer Leticia , Steinbach Bettina , Pantel Klaus , Schwarzenbach Heidi
Published: February 2019

Long noncoding RNAs (lncRNAs) are frequently precursor RNAs of microRNAs (miRNAs) or act as competing endogenous RNAs (ceRNAs) to interact with miRNAs. To better understand the shared impact of lncRNAs and miRNAs in the regulatory post‐transcriptional network, we focused here on the relationships between (a) lncRNA H19 and miR‐675, (b) NEAT1 and miR‐204, and (c) HOTAIR and miR‐331 in plasma of early breast cancer (BC) patients. We quantified each RNA in plasma samples of 63 BC patients and 10 healthy women by quantitative real‐time PCR. In cell culture experiments, the influence of these noncoding RNAs (ncRNAs) on proliferation and apoptosis of BC cell line MCF‐7 was examined. Plasma levels of H19 (P = 0.030), NEAT1 (P = 0.030), and miR‐331 (P = 0.012) were deregulated in BC patients compared with healthy women. In both cohorts, the concentrations of H19 correlated with those of miR‐675 (P = 0.0001). Higher H19 (P = 0.001) along with lower miR‐675 (P = 0.007) levels and higher miR‐204 (P = 0.017) along with lower NEAT1 (P = 0.030) levels were detected in plasma of HER2‐positive patients compared with the other BC subgroups. Whereas the expression of HOTAIR was below the detection level, miR‐331 levels correlated with nodal status (P = 0.002) and recurrence (P = 0.012). In cell culture experiments, a competitive impact on cell proliferation and apoptosis by these ncRNAs was also documented. Our findings describe a relationship of the plasma levels of H19/miR‐675 and NEAT1/miR‐204 in the different BC subtypes; in addition, they reveal an interplay between these lncRNAs and miRNAs in the regulatory network in MCF‐7 cells, which should also be considered in the search for new diagnostic and therapeutic markers.
Mitochondrial matrix pH acidifies during anoxia and is maintained by the F1Fo‐ATPase in anoxia‐tolerant painted turtle cortical neurons
Authors: Hawrysh Peter John , Buck Leslie Thomas
Published: February 2019

The western painted turtle (Chrysemys picta bellii) can survive extended periods of anoxia via a series of mechanisms that serve to reduce its energetic needs. Central to these mechanisms is the response of mitochondria, which depolarize in response to anoxia in turtle pyramidal neurons due to an influx of K+. It is currently unknown how mitochondrial matrix pH is affected by this response and we hypothesized that matrix pH acidifies during anoxia due to increased K+/H+ exchanger activity. Inhibition of K+/H+ exchange via quinine led to a collapse of mitochondrial membrane potential (Ψm) during oxygenated conditions in turtle cortical neurons, as indicated by rhodamine‐123 fluorescence, and this occurred twice as quickly during anoxia which indicates an elevation in K+ conductance. Mitochondrial matrix pH acidified during anoxia, as indicated by SNARF‐1 fluorescence imaged via confocal microscopy, and further acidification occurred during anoxia when the F1Fo‐ATPase was inhibited with oligomycin‐A, indicating that ΔpH collapse is prevented during anoxic conditions. Collectively, these results indicate that the mitochondrial proton electrochemical gradient is actively preserved during anoxia to prevent a collapse of Ψm and ΔpH.
Inhibition of miRNA‐27b enhances neurogenesis via AMPK activation in a mouse ischemic stroke model
Authors: Wang Zhengang , Yuan Yimei , Zhang Zhaoguang , Ding Kuiying
Published: February 2019

Stroke is a leading cause of death and disability, but treatment options remain limited. Recent studies have suggested that cerebral ischemia‐induced neurogenesis plays a vital role in post‐stroke repair. Overactivation of AMP‐activated protein kinase (AMPK), a master sensor of energy balance, has been reported to exacerbate neuron apoptosis, but the role of chronic AMPK stimulus in post‐stroke recovery remains unclear. MicroRNAs have emerged as regulators of neurogenesis and have been reported to be involved in neurological function. In this study, we verified that miR‐27b directly targets AMPK and inhibits AMPK expression. In cultured neural stem cells, miR‐27b inhibitor improved proliferation and differentiation via the AMPK signaling pathway, but did not have an obvious effect on cell viability under oxygen and glucose deprivation conditions. In a mouse middle cerebral artery occlusion model, administration of miR‐27b inhibitor significantly enhanced behavioral function recovery and spatial memory. Up‐regulation of neurogenesis was observed both in the subventricular zone and in the hippocampal dentate gyrus. Collectively, our data suggest that miR‐27b inhibition promotes recovery after ischemic stroke by regulating AMPK activity. These findings may facilitate the development of novel therapeutic strategies for stroke.
Palm Partners sues NAATP for defamation
Authors: Knopf Alison
Published: February 2019

Palm Partners LLC, a treatment program based in Delray Beach, Florida, has sued the National Association of Addiction Treatment Providers (NAATP) for defamation, trade libel and tortious interference. In the lawsuit filed Nov. 30, 2018, in the United States District Court for the Southern District of Florida, Palm Partners asks for $75,000 plus costs in damages. NAATP firmly denies the claims.
Appropriations update: DOJ and ONDCP now funded
Authors: Knopf Alison
Published: February 2019

President Trump has signed the Consolidated Appropriations Act of 2019, which funds the agencies that weren't funded in last fall's spending bill, which included the Department of Health and Human Services. In particular, for ADAW readers, the spending bill signed Feb. 15 includes the Department of Justice (DOJ), the Office of National Drug Control Policy (ONDCP), and the Food and Drug Administration, which weren't funded before due to the government shutdown.
HIPAA: On the way out? 42 CFR Part 2 is still here
Authors: Knopf Alison
Published: February 2019

The push to eliminate 42 CFR Part 2 (the confidentiality regulation requiring that substance use disorder [SUD] patients consent to release of their treatment records) and replace it with the Health Insurance Portability and Accountability Act (HIPAA) continues, even as the federal government seeks to weaken HIPAA (see ADAW, Jan. 21, Jan. 28). This month, with the deadline for comments on the Request for Information (RFI) to weaken HIPAA, there was no letup from the opponents of 42 CFR Part 2 on hopes for a new bill in Congress. Last year, the American Medical Association was widely credited for stopping such a bill from going forward (see ADAW, Oct. 1, 2018). The reason that the field has fought to keep the regulation is simple: Patients would not want to seek treatment if they couldn't protect their privacy.
Mimicking Adhesion in Minimal Synthetic Cells
Authors: Bartelt Solveig M. , Chervyachkova Elizaveta , Ricken Julia , Wegner Seraphine V.
Published: February 2019

Cell adhesions to the extracellular matrix and to neighboring cells are fundamental to cell behavior and have also been implemented into minimal synthetic cells, which are assembled from molecular building blocks from the bottom‐up. Investigating adhesion in cell mimetic models with reduced complexity provides a better understanding of biochemical and biophysical concepts underlying the cell adhesion machinery. In return, implementing cell–matrix and cell–cell adhesions into minimal synthetic cells allows reconstructing cell functions associated with cell adhesions including cell motility, multicellular prototissues, fusion of vesicles, and the self‐sorting of different cell types. Cell adhesions have been mimicked using both the native cell receptors and reductionist mimetics providing a variety of specific, reversible, dynamic, and spatiotemporally controlled interactions. This review gives an overview of different minimal adhesion modules integrated into different minimal synthetic cells drawing inspiration from cell and colloidal science.
Comparative Analysis of Wollastonite‐Diopside Glass‐Ceramic Structures Fabricated via Stereo‐Lithography
Authors: Elsayed Hamada , Schmidt Johanna , Bernardo Enrico , Colombo Paolo
Published: February 2019

One key feature of digital light processing consists of the high flexibility in the design of highly porous reticulated scaffolds. In the present paper, the authors report recent experiences concerning two glasses, both converted into wollastonite‐diopside (CaSiO3–CaMgSi2O6) glass‐ceramics by viscous flow sintering of fine powders (<45 μm) with concurrent crystallization. Glass particles are homogeneously dispersed in a photosensitive polymer, selectively hardened, layer‐by‐layer, by exposure to visible light, forming diamond cell lattices. The printing accuracy is slightly influenced by the glass chemistry, whereas the shape maintenance, after firing at 1100 °C, is observed for both compositions. The newly developed scaffolds are compared to other glass‐ceramic scaffolds, previously developed on the basis of the starting glass: the adoption of a new design does not determine any substantial degradation of mechanical properties.
Elastomeric Prepregs for Soft Robotics Applications
Authors: Wienzek Tristan , Seibel Arthur
Published: February 2019

Typically, soft robots that are driven with compressed air consist of two parts which are bonded together, a top and a strain‐limiting bottom part. This communication describes the possibility to simplify the manufacturing process by using textile semi‐finished products preimpregnated with liquid elastomer (prepregs) as the strain‐limiting part, which can be stored at low temperatures with significant slower cross‐linking reaction. For this, in long‐term tests, three typical elastomers (Elastosil M 4601, Ecoflex 00–30, and Sylgard 184) are stored at −25 °C, and in a weekly cycle over 12 weeks, the viscosity is measured to determine the curing characteristics. It turns out that Elastosil M 4601 and Sylgard 184 are suitable for this application. For comparison, short‐term viscosity measurements are conducted at room temperature in a 10 min cycle. The impregnability of several textiles (polyester/cotton blended fabric, nylon fabric, fleece, and flax fabric) is tested with the suitable elastomers. The applicability of prepregs for soft robotic applications is demonstrated by manufacturing soft bending actuators with various textile‐elastomer combinations.
Polyborosilazane‐Derived High Temperature Resistant SiBCNO
Authors: Luan Xingang , Zhang Qiqi , Yu Rong , Wang Lei , Cheng Laifei , Li Jianzhang , Fasel Claudia , Riedel Ralf
Published: February 2019

One of the main features of SiBCN‐based ceramics is their high temperature stability with respect to crystallization and decomposition in protective atmospheres. High temperature studies of a polyborosilazane in air up to 1500 °C show that the formation of coexisting nano‐quartz and amorphous B2O3 is suitable for the application as adhesive for bonding advanced ceramics. Spectroscopic and X‐ray studies combined with thermal analysis clearly demonstrate the strong influence of the presence of air on the cross‐linking and pyrolysis behavior and, thus, finally on the ceramization process of the applied SiBCN preceramic polymer. Accordingly, cross‐linking and subsequent pyrolysis of the SiBCN‐precursor up to 1600 °C in air result in the formation of a network structure comprised of SiO2 and B2O3 with minor amounts of residual amorphous SiBCN. In contrast to the polymer‐to‐ceramic transformation of the used polyborosilazane in protective atmospheres like Ar or N2, the ceramic yield at 1400 °C is high and amounts 85.6 wt%. Furthermore, the elemental composition of the resulting SiBCNO does not change significantly at T > 1200 °C even after heat‐treatment at 1600 °C indicating the high temperature stability of the resulting SiBCNO material.
Fundamental Theory of Biodegradable Metals—Definition, Criteria, and Design
Authors: Liu Yang , Zheng Yufeng , Chen Xie‐Hui , Yang Jian‐An , Pan Haobo , Chen Dafu , Wang Luning , Zhang Jialiang , Zhu Donghui , Wu Shuilin , Yeung Kelvin Wai Kwok , Zeng Rong‐Chang , Han Yong , Guan Shaokang
Published: February 2019

Until now there has been no fundamental theory applicable for biodegradable metals (BMs). First, this paper optimizes the definition of BMs given in 2014. Second, the dual criteria of biodegradability and biocompatibility are proposed for BMs, and all metallic elements in the periodic table with accessible data are screened on the basis of these criteria. Regarding biodegradability, electrode potential, reactivity series, galvanic series, Pilling–Bedworth ratio, and Pourbaix diagrams are all adopted as parameters to classify the degradable and nondegradable nature of a material, especially in a physiological environment. Considering the biocompatibility at different levels, cellular biocompatibility, tissue biocompatibility, and human/clinical related biocompatibility parameters are put forward to comprehensively evaluate the biosafety of BMs. Third, for the material design of BMs, mechanical properties, chemical properties, physical properties and biological properties should be considered and balanced to guarantee that the degradation behavior of BMs match well with a tissue regeneration/repair procedure as the function of time and spatial location. Besides the selected metallic elements, some nonmetallic elements are selected as suitable alloying elements for BMs. Finally, five classification/research directions for future BMs are proposed: biodegradable pure metals, crystalline alloys, bulk metallic glasses, high entropy alloys, and metal matrix composites.
Highly Efficient Mechanoelectrical Energy Conversion Based on the Near‐Tip Stress Field of an Antifracture Slit Observed in Scorpions
Authors: Wang Kejun , Zhang Junqiu , Song Honglie , Fang Yuqiang , Wang Xiaolong , Chen Daobing , Liu Linpeng , Niu Shichao , Yao Zhongwen , Han Zhiwu , Ren Luquan
Published: February 2019

In the field of engineering, a crack, inducing enormous mechanical energy concentration at a tip, is considered a typical kind of defect. However, it is found that, to maximize the sensitivity of slit‐based mechanoreceptors, the near‐tip stress field of “risky” crack‐shaped slits is ingeniously used by scorpions to precisely detect the cyclic loads acting on walking legs without the crack nucleation from the flaw‐like tip. As a sophisticated biological mechanoelectrical transducing microsystem, the mechanoreceptor can effectively collect mechanical energy contained in the mechanical signal through antifracture slit allays and then convert the mechanical energy into electrical energy through mechanosensory neuron. The highly efficient mechanoelectrical energy conversion mechanism is theoretically analyzed and experimentally verified in a bioinspired artificial mechanoreceptor. The results demonstrate the potential of basic “design” principles, underlying the slit‐dependent mechanoreceptor, for maximizing the electromechanical conversion efficiency of the industrial mechanoelectrical transducing microsystem such as nanogenerators, ultrasensitive mechanical sensors, self‐powered portable, and wearable electronics.
Self‐Healable Multifunctional Electronic Tattoos Based on Silk and Graphene
Authors: Wang Qi , Ling Shengjie , Liang Xiaoping , Wang Huimin , Lu Haojie , Zhang Yingying
Published: February 2019

Electronic tattoos (E‐tattoos), which can be intimately mounted on human skin for noninvasive and high‐fidelity sensing, have attracted the attention of researchers in the field of wearable electronics. However, fabricating E‐tattoos that are capable of self‐healing and sensing multistimuli, similar to the inherent attributes of human skin, is still challenging. Herein, a healable and multifunctional E‐tattoo based on a graphene/silk fibroin/Ca2+ (Gr/SF/Ca2+) combination is reported. The highly flexible E‐tattoos are prepared through printing or writing using Gr/SF/Ca2+ suspension. The graphene flakes distributed in the matrix form an electrically conductive path that is responsive to environmental changes, such as strain, humidity, and temperature variations, endowing the E‐tattoo with high sensitivity to multistimuli. The performance of the E‐tattoo is investigated as a strain, humidity, and temperature sensor that shows high sensitivity, a fast response, and long‐term stability. The E‐tattoo is remarkably healed after damage by water because of the reformation of hydrogen and coordination bonds at the fractured interface. The healing efficiency is 100% in only 0.3 s. Finally, as proof of concept, its applications for monitoring of electrocardiograms, breathing, and temperature are shown. Based on its unique properties and superior performance, the Gr/SF/Ca2+ E‐tattoo may be a promising candidate material for epidermal electronics.
All‐Day Operating Quaternary Blend Organic Photovoltaics
Authors: Nam Minwoo , Noh Hye Yeon , Cho Junhee , Park Yongkook , Shin Sang‐Chul , Kim Jung‐A , Kim Jehan , Lee Hyun Hwi , Shim Jae Won , Ko Doo‐Hyun
Published: February 2019

The unique properties of organic photovoltaics (OPVs) offer great promise in emerging applications such as wearable electronics or the Internet of Things. For their successful utilization, OPV operation should be designed for versatile irradiation circumstances in addition to solar light since they should be capable of providing electric power when there is no sunlight or when they operate indoors. Here, a quaternary OPV (Q‐OPV) as a semitransparent, colorful energy platform that operates efficiently under both solar and artificial light irradiation is demonstrated. The experimentally optimized Q‐OPV shows a broadened spectral response and improved charge transport process with suppressed recombination, thereby providing high output powers that are sufficient to autonomously operate low‐power electronic devices. In addition, the Q‐OPV benefits from improved morphological stability with a reduced driving force for grain growth by the increased entropy in the quaternary blend system. The important features of the Q‐OPV platform such as semitransparency, high tolerance to film thickness, and color codability, while pursuing the improved performance and thermal durability, further open new opportunities as an all‐day (24/7/365) power generator in broad practical applications.
Moving Frontiers in Transition Metal Catalysis: Synthesis, Characterization and Modeling
Authors: Sharapa Dmitry I. , Doronkin Dmitry E. , Studt Felix , Grunwaldt Jan‐Dierk , Behrens Silke
Published: February 2019

Nanosized transition metal particles are important materials in catalysis with a key role not only in academic research but also in many processes with industrial and societal relevance. Although small improvements in catalytic properties can lead to significant economic and environmental impacts, it is only now that knowledge‐based design of such materials is emerging, partly because the understanding of catalytic mechanisms on nanoparticle surfaces is increasingly improving. A knowledge‐based design requires bottom‐up synthesis of well‐defined model catalysts, an understanding of the catalytic nanomaterials “at work” (operando), and both a detailed understanding and a prediction by theoretical methods. This article reports on progress in colloidal synthesis of transition metal nanoparticles for preparation of model catalysts to close the materials gap between the discoveries of fundamental surface science and industrial application. The transition metal particles, however, often undergo extensive transformations when applied to the catalytic process and much progress has recently been achieved operando characterization techniques under relevant reaction conditions. They allow better understanding of size/structure–activity correlations in these systems. Moreover, the growth of computing power and the improvement of theoretical methods uncover mechanisms on nanoparticles and have recently predicted highly active particles for CO/CO2 hydrogenation or direct H2O2 synthesis.
Epitaxial Growth of CsPbX3 (X = Cl, Br, I) Perovskite Quantum Dots via Surface Chemical Conversion of Cs2GeF6 Double Perovskites: A Novel Strategy for the Formation of Leadless Hybrid Perovskite Phosphors with Enhanced Stability
Authors: Wei Yi , Li Kai , Cheng Ziyong , Liu Manman , Xiao Hui , Dang Peipei , Liang Sisi , Wu Zhijian , Lian Hongzhou , Lin Jun
Published: February 2019

Lead halide perovskites (LHPs) have received increased attention owing to their intriguing optoelectronic and photonic properties. However, the toxicity of lead and the lack of long‐term stability are potential obstacles for the application of LHPs. Herein, the epitaxial synthesis of CsPbX3 (X = Cl, Br, I) perovskite quantum dots (QDs) by surface chemical conversion of Cs2GeF6 double perovskites with PbX2 (X = Cl, Br, I) is reported. The experimental results show that the surface of the Cs2GeF6 double perovskites is partially converted into CsPbX3 perovskite QDs and forms a CsPbX3/Cs2GeF6 hybrid structure. The theoretical calculations reveal that the CsPbBr3 conversion proceeds at the Cs2GeF6 edge through sequential growth of multiple PbBr6
4− layers. Through the conversion strategy, luminescent and color‐tunable CsPbX3 QDs can be obtained, and these products present high stability against decomposition due to anchoring effects. Moreover, by partially converting red emissive Cs2GeF6:Mn4+ to green emissive CsPbBr3, the CsPbBr3/Cs2GeF6:Mn4+ hybrid can be employed as a low‐lead hybrid perovskite phosphor on blue LED chips to produce white light. The leadless CsPbX3/Cs2GeF6 hybrid structure with stable photoluminescence opens new paths for the rational design of efficient emission phosphors and may stimulate the design of other functional CsPbX3/Cs‐containing hybrid structures.
Atomically Transition Metals on Self‐Supported Porous Carbon Flake Arrays as Binder‐Free Air Cathode for Wearable Zinc−Air Batteries
Authors: Ji Dongxiao , Fan Li , Li Linlin , Peng Shengjie , Yu Deshuang , Song Junnan , Ramakrishna Seeram , Guo Shaojun
Published: February 2019

Metal single‐atom materials with their high atom utilization efficiency and unique electronic structures usually show remarkable catalytic performances in many crucial chemical reactions. Herein, a facile and easily scalable “impregnation‐carbonization‐acidification” strategy for fabricating a class of single‐atom‐anchored (including cobalt and nickel single atoms) monolith as superior binder‐free electrocatalysts for developing high‐performance wearable Zn–air batteries is reported. The as‐prepared single atoms, supported by N‐doped carbon flake arrays grown on carbon nanofibers assembly (M SA@NCF/CNF), demonstrate the dual characteristics of excellent catalytic activity (reversible oxygen overpotential of 0.75 V) and high stability, owing to the greatly improved active sites' accessibility and optimized single‐sites/pore‐structures correlations. Furthermore, wearable Zn–air battery based on Co SA@NCF/CNF air electrode displays superior stability under deformation, satisfactory energy storage capacity, and good practicality to be utilized as an integrated battery system. Theoretical calculations reveal a mechanism for the promotion of the catalytic performances on single atomic sites by lowering the overall oxygen reduction/evolution reaction barriers comparing to metal cluster co‐existing configuration. These findings provide a facile strategy for constructing free‐standing single‐atom materials as well as the engineering of high‐performance binder‐free catalytic electrodes.
Insight into the Interfacial Elastic Contact in Stacking Perovskite Solar Cells
Authors: Shao Yingying , Zhang Chunyang , Wang Shi , Yan Ying , Feng Yulin , Bian Jiming , Shi Yantao
Published: February 2019

Stacking perovskite solar cells (PSCs) are emerging cells with two detached electrodes during fabrication process, in which the crucial step is the intimate mechanical and electronic contact between the laminated parts. The interfacial elastic contact of stacking PSCs with four different p‐type organic semiconductors has been systematically studied. Studies confirm that poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is an elastic interface material with excellent performance. The convex–concave morphology of PEDOT:PSS surface and the interfacial elastic deformation make a contribution to a desirable conductive contact between two electrodes with sufficient contact area, thereby providing a highly reliable connection and efficient charge transport channel between the semi‐cells. Based on conducting polymer PEDOT:PSS, planar‐structured stacking PSCs are fabricated exhibiting power conversion efficiency of 13.49% with 1.0 cm2 area. Connecting electrodes with excellent conductivity and elasticity are also proved to be essential to the flexible assembly and readily detachment.
Iron‐Catalyzed Oxidative Coupling Reaction of Isocyanides and Simple Alkanes towards Amide Synthesis
Authors: Yuan Hongdong , Liu Zhiqiang , Shen Yushu , Zhao Hongbin , Li Chunju , Jia Xueshun , Li Jian
Published: February 2019

An iron‐catalyzed oxidative coupling reaction of isocyanide and readily available alkane has been disclosed. In the presence of a catalytic amount of FeCp2 (10 mol%), heating a mixture of alkane, isocyanide, and DTBP in DCE allows for the formation of an amide. This reaction tolerates many simple alkanes including cycloalkanes and chain alkanes. Furthermore, a series of aromatic isocyanides having different substituents on the aromatic ring are also proven to be effective reaction components. Unfortunately, the employment of aliphatic isocyanides fails to afford the desired products. The present strategy avoids tedious procedures and the employment of toxic starting materials, thus providing an environmentally benign and efficient protocol towards amide synthesis.

magnified image
Application of the Electrochemical Oxygen Reduction Reaction (ORR) in Organic Synthesis
Authors: Han Xiaoxin , Wang Kui , Zhang Guofeng , Gao Wei , Chen Jianbin
Published: February 2019

Compared with the well‐developed oxygen reduction reaction (ORR) in fuel cells, proton‐exchange membrane fuel cells and metal‐air batteries, the applications of ORR in electrochemical synthesis are less investigated. The electrogenerated superoxide ions O2−., products of ORR, can function as bases, nucleophiles, oxidants, reductants, electron transfer shuttles as well as free radicals. Herein, the advances in the electroorganic field involving oxygen reduction reactions are summarized in order to inspire innovations regarding the application of ORR for novel organic transformations.

magnified image